The algal spring bloom in the Baltic Sea represents an anomaly from the winter-spring bloom patterns worldwide in terms of frequent and recurring dominance of dinoflagellates over diatoms. Analysis of approximately 3500 spring bloom samples from the Baltic Sea monitoring programs revealed (i) that within the major basins the proportion of dinoflagellates varied from 0.1 (Kattegat) to >0.8 , and (ii) substantial shifts (e.g. from 0.2 to 0.6 in the Gulf of Finland) in the dinoflagellate proportion over four decades. During a recent decade (1995–2004) the proportion of dinoflagellates increased relative to diatoms mostly in the northernmost basins  and in the Gulf of Finland, (0.4 to 0.6) which are typically ice-covered areas. We hypothesize that in coastal areas a specific sequence of seasonal events, involving wintertime mixing and resuspension of benthic cysts, followed by proliferation in stratified thin layers under melting ice, favors successful seeding and accumulation of dense dinoflagellate populations over diatoms. This head-start of dinoflagellates by the onset of the spring bloom is decisive for successful competition with the faster growing diatoms. Massive cyst formation and spreading of cyst beds fuel the expanding and ever larger dinoflagellate blooms in the relatively shallow coastal waters. Shifts in the dominant spring bloom algal groups can have significant effects on major elemental fluxes and functioning of the Baltic Sea ecosystem, but also in the vast shelves and estuaries at high latitudes, where ice-associated cold-water dinoflagellates successfully compete with diatoms. On a geological time scale, the development of ocean and atmosphere chemistry has been highly integrated with the evolution of photosynthesis in the ocean, and still today, approximately half the global C-fixation takes place in the sea These two phylogenetic groups exhibit unique and distinct, often contrasting adaptive ecologies, explaining their global niche partitioning on the turbulence-nutrient matrix of habitats and onshore-offshore gradient The Baltic Sea is an exceptional coastal, brackish water body, which functionally is much like a large estuary with both horizontal and vertical salinity gradients. Due to the partly enclosed geography and high anthropogenic influence, environmental problems such as eutrophication are amplified in the Baltic Sea. Environmental pressures related to eutrophication are getting more common in coastal areas worldwide e.g. , resultiThe Baltic Sea is an exception to the general trend of diatom dominance during spring with a unique and anomalous niche overlap of diatoms and dinoflagellates during the spring bloom. Large (20–30 µm) cold-water dinoflagellates match or even clearly exceed the biomass of diatoms during spring bloom Despite their growth and nutrient uptake capabilities describing r- and K-strategies , the two phylogenetic groups appear to be functional surrogates, as both are separately capable of exhausting the wintertime inorganic nutrient pools in spring, and of producing bloom-level biomasses Several authors have suggested that the role of dinoflagellates in the Baltic Sea spring bloom has increased over the last decades, both in the northern Baltic Sea We hypothesized that in relation to ongoing eutrophication in the Baltic Sea, we should see the increase in both, the bloom magnitude and share of the faster growing diatoms in the spring bloom biomass. In contrast, dinoflagellates should be favored by climatic and weather conditions enhancing the water column stratification at the onset of the bloom, with distinct north-south gradient , as well as by topographical properties of sub-basins (proximity to the seed banks). If proved correct, these general hypotheses would predict different trajectories for the diatoms and dinoflagellates in different Baltic Sea sub-basins, especially under climate change.In the present study we analyze decadal-scale trends in the Baltic Sea spring bloom dinoflagellates and diatoms. We specifically asked the following questions: (a) have the proportions of spring bloom diatoms and dinoflagellates changed on a decadal time scale; (b) are there spatial differences in the biomass, relative proportion, or rate of temporal change of either group over the Baltic Sea; (c) is the intensity of spring bloom associated with the dominance of either group; and (d) is there an association between the proportion of dinoflagellates and winter-spring climate variability, reflected by the North Atlantic Oscillation (NAO) index?The biomass of diatoms and dinoflagellates in the major basins  and not so much the main effect of basins. Therefore basin-specific intercepts were not calculated; basins were treated as a random component in the mixed effect statistical model, reducing the number of estimated parameters and preserving the degrees of freedom.−1).The spatial pattern of the average total spring bloom biomass  reflects−1), particularly in the Bay of Kiel (ca. 6 mg L−1). Similarly, dinoflagellates dominate the spring blooms both in the highly eutrophied Gulf of Finland as well as in the offshore waters of the northern Baltic Proper (>0.8), which shows moderate to low average spring bloom biomass values (ca. 1.5 mg L−1).There was apparently no association between the spring bloom biomass and dominance patterns of dinoflagellates or diatoms , as diatThe proportion of diatoms and dinoflagellates in the Baltic Sea spring bloom has been highly variable in time and space during the past 4 decades. No common all-Baltic trend or pattern can be shown for the different areas of the Sea, indicating that mechanisms driving the change have a strong regional and fine-scaled component, characteristic for coastal ecosystems in general The most pronounced decadal-scale increase in the dinoflagellate proportion from 0.1 to 0.7 has taken place in the eutrophied Gulf of Finland. Dinoflagellates have also increased in the Bothnian Bay and the Bothnian Sea, but spring blooms in these northern basins are still largely diatom-dominated. In the central, offshore Baltic Sea, where the spring bloom biomass is relatively low, dinoflagellates hold a strong, dominating position (>0.7). The main basins where diatoms dominate the spring bloom are the northern Bothnian Bay, the southwestern Baltic Sea and also the eutrophied Gulf of Riga, but in all these basins, long-term, temporal changes have been distinct .No consistent association between the relative dominance of diatoms or dinoflagellates, and the intensity of the spring bloom, was found across the sub-basins. This supports the functionally surrogate role of these phylogenetic groups in system-wide biogeochemical cycles and undermines the hypothesis that anthropogenic nutrient enrichment favors the fast-growing diatoms.Decreasing dissolved silica (DSi) availability and lowering DSi:N ratios, associated with eutrophication However, some spring bloom diatoms in the Baltic Sea rely entirely on benthic resting stages to survive the warm summer, and require large amounts of DSi when heavily silicified spores are formed In specific cases, low DSi may set the upper limit of diatom spring bloom magnitude. Long-term data analysis showed that the semi-enclosed Gulf of Riga went through a DSi depletion event culminating in 1993 Globally, diatoms are ubiquitous generalists thriving in most aquatic habitats, while habitat specialization of dinoflagellates is considered to make them particularly responsive to niche changes. Altered niche structure and community ecology leads to geographic range expansion, newly achieved competitive dominance, and bloom expansion of dinoflagellates The spring bloom dinoflagellates of the Baltic Sea are inferior growth competitors compared to diatoms when nutrients are plentiful. They also tend to have a lower light saturation level, and appear to be better competitors when nutrients are low Competition between cold-water diatoms and dinoflagellates can therefore be interpreted in a planktonic r vs. K-selection framework. Small fast-growing diatoms thrive in unstable, turbulent conditions , while slow-growing, large and motile dinoflagellates seem to require a specific habitat setting for bloom formation, allowing them to acquire competitive advantage through building a superior head-start biomass (K-strategy).Stratification of the water column is generally a prerequisite for most dinoflagellate blooms to develop in temperate areas e.g. . As the In the Baltic Sea, dinoflagellates are more sensitive to hydrographic conditions and climate fluctuations than to the nutrient conditions at the bloom onset. It has been shown that initial stratification, necessary for spring bloom commencement, is due to spreading of freshwater from the coastal zone in the Baltic Sea, instead of the temperature-driven stratification characteristic of lakes and full-saline marine regions Early salinity stratification is found in biotopes with large freshwater inflow, such as estuaries, and in the literature, there are a few examples of dinoflagellate-dominated estuarine spring blooms, e.g. in the uppermost Chesapeake Bay Biecheleria baltica involves massive cyst formation at the end of the bloom. Extensive cyst beds formed in the Gulf of Finland B. baltica has negligible bloom intensity in the nearby Gulf of Riga, where cysts of this species are virtually absent from the sediment The life-cycle strategy of the dominant dinoflagellate species in the Gulf of Finland and the northern Baltic Sea, B. baltica to produce such large quantities of survival stages is relatively uncommon among the better known dinoflagellate species. Cyst yields of most dinoflagellates studied in this respect, are significantly lower than of B. baltica, with cyst fluxes and cyst concentrations in the sediment differing by orders of magnitudes B. baltica more competitive with diatoms than other dinoflagellates.The strategy of Gymnodinium corollarium, produces also conspicuous quantities of resting cysts Large inocula of seeds at the beginning of the growth season may compensate for the slow growth of the dinoflagellates and enable them to persist against diatoms, which, due to their high growth rates, are generally very effectively seeded even from minor inocula of resting propagules Specific hydrological settings and a seasonal sequence of events are required for the dominance of cold-water dinoflagellates during the spring bloom in coastal waters. Wintertime mixing incidents promote introduction of benthic seed populations to the upper water column −1The conspicuous dominance of dinoflagellates in the ice-free central Baltic Proper calls for further research. We believe the permanent halocline at 60–80 m depth in the Gotland Basin is a strong barrier for local cyst re-suspension from the sediment surface to the euphotic layer. Anoxic sediments and bottom waters in the deep parts of the Gotland Basin are not favorable for cyst germination The observed differences in bloom dominance between Baltic Sea sub-basins can thus be assumed to reflect physical habitat properties: topographical differences (proximity to sediment seed banks), distance to major freshwater discharges promoting initial stratification, and the N-S gradient governing the probability and extent of ice cover, and the permanent salinity stratification in deeper off-shore areas.Biecheleria baltica success in the Gulf of Finland, why does the species not thrive in the Gulf of Bothnia, where these habitat properties play even a stronger role? Instead, the recent increase in dinoflagellate proportion in both the latter Gulf and the deep, usually ice-free Baltic proper is due to another effective cyst former, Gymnodinium corollarium while the Gulf of Riga, which witnessed strongly increasing dinoflagellate proportions in 1990's, appears to be a domain of Peridiniella catenata.It remains open, however, exactly how these physical differences relate to the different dominance patterns and trends in different sub-basins. If ice cover, freshwater-induced stratification, and relatively shallow seed banks are instrumental for the observed A combination of a founder effect, low connectivity between basins, and a threshold in cyst accumulation in sediments, before a hang-around species is able to build the necessary head-start under supportive physical conditions, and thus to secure future success in the habitat, seems a plausible hypothesis for the demonstrated dinoflagellate expansion, but it cannot be verified by the current data. Coupling of data on species-specific life cycles and succession to physical circulation and mixing models, as well as to ice cover dynamics, appears necessary to explain the different outcomes in different neighboring habitats. The overall picture anyhow emphasizes the habitat specialist character of cold-water dinoflagellates, as previously addressed to their warm-water relatives.Inter-annual variability in weather conditions, e.g. mild or harsh winters, the ice cover and its extent, and the sea surface temperature have frequently been suggested to shape the vernal phytoplankton assemblage in the different sub-regions of the Baltic Sea In the predominantly ice-free northwestern Baltic Proper, the significant effect of NAO could be explained by the strong seasonal sequence of the spring blooms, starting with diatoms and proceeding with dinoflagellates. Our preliminary analysis (data not shown) suggests that the successional shift from diatoms to dinoflagellates takes place earlier in the season in years of positive NAO phase, leading to significantly higher overall dominance of dinoflagellates. Increasing dinoflagellate proportion towards the end of the spring bloom appears to be characteristic for all ice-free central and southern areas of the Baltic Sea. Yet higher dinoflagellate proportions do not appear to link specifically with positive NAO phase anywhere else than in the Gulf of Finland and northwestern Baltic Proper.In areas with regular ice-cover (the Gulfs of Bothnia and Finland), development of stratification is less predictable and therefore less connected to a climate proxy as coarse as the winter NAO index. The local extent and the type of the ice-cover seem to pose the highest uncertainty on the seeding success of the spring blooms, and require in-depth analysis.Shifts in the spring bloom composition have consequences on the biogeochemical cycling and fate of the new production. In the northern temperate and boreal seas, including the Baltic Sea, the spring bloom typically dominates the annual phytoplankton productivity cycle. The spring bloom lasts approximately 1 month, but contributes 40 to 60% of the annual carbon fixation, and due to the mismatch between the timing of spring bloom and development of main grazers in the Baltic Sea, up to 80% of this fixed carbon sinks out of the euphotic layer, feeding the benthic system The relative abundance of diatoms or dinoflagellates, or the dominance of either group determines the proportion and quality of the new production that settles to the sea floor, and how much is disintegrated in the upper water column 11 cysts m−2, equivalent to 16 g C m−2, during a strong bloom −2). Spilling & Lindström Spring bloom dinoflagellates can deposit up to 3×102-fixing cyanobacterial blooms, promoted by the benthic P release Benthic decomposition rates directly affect basin-wide eutrophication processes through associated oxygen decomposition and phosphorus release. The northern Baltic Sea spring blooms are nitrogen-limited, while summertime planktonic communities display spatially extensive NPeridiniella catenataMuch of the discussion on dinoflagellates as habitat specialists and global expansion focuses on warm-water 'red tide' species, which are temporally and often spatially distinct from the spring bloom, or upwelling-induced diatom blooms This ignorance is unfortunate, since climatic forcing is most accentuated in the polar regions, projected to cause future changes in habitats over large oceanic and shelf areas. In all these regions, early stratification is induced by salinity, either due to ice melt or river plumes, rather than by temperature. This feature, together with the relatively shallow depths enabling the formation of extensive benthic cyst beds, seem to be the key features associated with success of dinoflagellates over diatoms, in the Baltic Sea as well as worldwide.In the era of rapid environmental changes in the polar regions, either due to climate change or direct anthropogenic pressure, we can expect cold-water bloom-forming dinoflagellates to successfully exploit the newly opened niches, leading to their increased role in the coastal carbon cycles, as has taken place in the Baltic Sea during the past decades. The interplay between local hydrography, climatic and weather forcing, and the adaptive strategies of species are an obvious source of this variability The spatial and temporal distribution of phytoplankton was obtained from monitoring datasets provided by national monitoring agencies around the Baltic Sea (see Acknowledgements). The original data tables from national agencies or international organizations (HELCOM) were structurally unified and the taxonomy was carefully harmonized. With a few exceptions, the phytoplankton data were counted from Lugol fixed, surface mixed layer integrated samples (0–5 or 0–10 m) with an inverted microscope after settling for 24 h as suggested by Edler The onset and duration of the spring bloom varies with latitude in the Baltic Sea. Based on seasonal development of the total phytoplankton biomass we used the following basin-specific time windows: day of the year 100–200 in the Bothnian Bay, 100–180 in the Bothnian Sea and Quark, 80–160 in the Northern Baltic Proper and Archipelago Sea, 100–170 in the Gulf of Finland, 80–160 in the Eastern Gotland Basin and the Gulf of Riga, 60–120 in the Southern Baltic Proper (incl. Bornholm basin) and 50–100 in the Sound, Belt Sea and Kattegat. Altogether 3500 quantitative spring blooms samples were used in the study.All statistics were done in the R computing environment The long-term trends in dinoflagellate and diatom biomass, and the proportion of dinoflagellates (the biomass of dinoflagellates divided by the combined biomass of diatoms and dinoflagellates), were analyzed for the entire temporal time span according to the basin specific availability of data. In order to show the most general trends, we pooled the data into six datasets after the major basins: Gulf of Bothnia (Bothnian Sea and Bothnian Bay), Gulf of Finland and the Archipelago Sea, northwestern Baltic Proper, Gulf of Riga, Southern Baltic Sea, and Kattegat with the straits of Denmark (the Sound and the Belt Sea) . To accogam’ function from ‘mgcv’ package in R With no reason to assume any parametric relationship between the phytoplankton biomass variables and the time, the long-term trends (sampling year as explanatory variable) and seasonal succession patterns (day of the year as explanatory variable) were analyzed with generalized additive models (GAM). GAM is a non-parametric method that fits a smoothing curve through the data. ‘Phytoplankton samples from the period 1995–2004 (1500 samples) were used to estimate the spatial distribution of the spring bloom peak biomass in the Baltic Sea. For each unique sampling location  present in the dataset, the mean of the upper quartile of log-transformed biomass values was calculated based on the samples within 50 km radius.‘geoR’ software library The point estimates were then spatially interpolated using a geostatistical kriging method (Ordinary kriging (as in previous section) was also used to estimate the average proportion of dinoflagellates in 1995 to 2004 over the Baltic Sea grid. The proportion of dinoflagellates in all the 1500 samples was used with equal weight in the kriging algorithm.‘spgwr’ in R). GWR is a statistical tool for analyzing spatially varying linear relationships In addition, the direction and rate of change of dinoflagellate proportion was analyzed with geographically weighted regression (GWR) (library ‘nlme’ package in R) with NAO index–basin interaction term as a fixed effect , and intercept per basin as a random effect. The dinoflagellate proportion was arcsine - square root transformed to normalize the error distribution. Phytoplankton field populations have high spatial and temporal variability (patchiness). Sampling these populations inevitably incorporates both, spatial and temporal autocorrelation, which are not trivial to separate with the existing statistical methods. We used basin-wide averages of dinoflagellate proportions to reduce the effect of spatial variation and autocorrelation. To account for temporal autocorrelation we used weekly averages of dinoflagellate proportions and a correlation structure based on exponential variogram model. Values of NAO index are freely available from the Climate Analysis Section, NCAR, Boulder, USA (http://www.cgd.ucar.edu/cas/jhurrell/indices.html).NAO index, describing the major variability of the climatic conditions over the northern hemisphere, is frequently used as a proxy to characterize the climate-related physical forcing  on the biological components of the Baltic Sea ecosystem


KIC, of a cortical bone has been experimentally determined by several researchers. The variation of KIC values occurs from the variation of specimen orientation, shape, and size during the experiment. The fracture toughness of a cortical bone is governed by the severest flaw and, hence, may be analyzed using Weibull statistics. To the best of the authors' knowledge, however, no studies of this aspect have been published. The motivation of the study is the evaluation of Weibull parameters at the circumferential-longitudinal (CL) and longitudinal-circumferential (LC) directions. We hypothesized that Weibull parameters vary depending on the bone microstructure. In the present work, a two-parameter Weibull statistical model was applied to calculate the plane-strain fracture toughness of bovine femoral cortical bone obtained using specimens extracted from CL and LC directions of the bone. It was found that the Weibull modulus of fracture toughness was larger for CL specimens compared to LC specimens, but the opposite trend was seen for the characteristic fracture toughness. The reason for these trends is the microstructural and extrinsic toughening mechanism differences between CL and LC directions bone. The Weibull parameters found in this study can be applied to develop a damage-mechanics model for bone.The fracture toughness,  Bone is anisotropic material. The fracture toughness of bone varies depending on sampling site and the initial crack orientation of fracture test samples with respect to the applied load. Researchers prepared specimen in different orientations to measure fracture toughness –4. The oKIC, in different bone materials  obtained under both quasistatic and dynamic loading conditions . Univariate regression analyses of the F(KIC) against the KIC data was conducted to calculate m and Ko using Microsoft Excel Weibull analysis add-on . The regression model coefficients for the least square fit of Weibull graphs for both specimens are given in F(KIC)) ((KIC) )  againstm, and characteristic fracture toughness, K0, were calculated for each group (P < 0.001) between the specimen groups, as expected because the slopes are related to the specimens' material failure properties. The Weibull modulus of the CL specimens is higher than that of the LC specimen. This means that the scatterness of the fracture toughness value was lower for the CL specimen compared to the LC specimen. Since the scale parameter of the LC specimens is higher than that of the CL specimens, one expects to find that the fracture toughness is higher for the LC specimens than that for the CL specimens for a particular failure probability (ch group . The Weibability .KIC between the two groups. This explanation is in agreement with Lipson and Katz [Different distribution of structural types in front of the propagation crack in CL and LC directions specimens can be the reason for the difference of Weibull parameters of and Katz . The autand Katz , extrinsThere are no publications on Weibull parameters of fracture toughness data for bovine cortical bone in CL and LC to compare the results of this investigation. However, Pithioux et al.  applied The results of this study can be utilized to quantify the role of bone toughening mechanism on the failure probability of extremely diverse range of biomedical and nonbiomedical applications and has potential use for orthopedic bone cement. Also, a failure model that considers the physiological process like remodeling, adaptation can be investigated. This study will enable biomedical researchers to predict more effectively the microdamage associated with bone damage and design bone-implant systems.The individual fracture toughness data for each direction of specimen tested follow the two-parameter Weibull distribution. Each distribution was characterized by a different Weibull modulus.LC direction cortical bone possesses greater fracture toughness than LC direction specimen for a particular failure probability level.There is a statistically significant difference of Weibull modulus and characteristic fracture toughness for specimens of different orientation. The observed variability in the fracture of bovine cortical bone in CL and LC directions was explained by microstructural variables depending on the direction.The aim of this paper was to compare the bovine cortical bone fracture toughness in two different directions: CL and LC. Weibull statistical law was used to analyze the fracture failure variation and characteristic fracture toughness values of CL and LC specimens. The results of this study are as follows.


Baccharopelma dracunculifoliae (Psyllidae) on leaves of Baccharis dracunculifolia DC. (Asteraceae) on developmental basis. The homogalacturonans (HGAs) (labeled by JIM5) and the arabinans (labeled by LM6) were detected either in non-galled leaves or in young galls, and indicated stiffening of epidermal cell walls, which is an important step for cell redifferentiation. The labeling of HGAs by JIM7 changed from young to senescent stage, with an increase in the rigidity of cell walls, which is important for the acquaintance of the final gall shape and for the mechanical opening of the gall. The variation on the degree of HGAs during gall development indicated differential PMEs activity during gall development. The epitopes recognized by LM2 (AGP glycan) and LM5  had poor alterations from non-galled leaves towards gall maturation and senescence. Moreover, the dynamics of pectin and AGPs on two comparable mature kidney-shaped galls on B. dracunculifolia and on B. reticularia revealed specific peculiarities. Our results indicate that similar gall morphotypes in cogeneric host species may present distinct cell responses in the subcelular level, and also corroborate the functions proposed in literature for HGAs.Insect galls may be study models to test the distribution of pectins and arabinogalactan-proteins (AGPs) and their related functions during plant cell cycles. These molecules are herein histochemically and immunocitochemically investigated in the kidney-shaped gall induced by  The biotic stress induced by the galling herbivores on plant tissues Cell wall compounds, the microfibrils of cellulose The immunocitochemical labeling of HGAs and RGs with monoclonal antibodies (MAbs) in the cells of insect-induced plant galls may constitute an elegant tool to demonstrate the relationship between pectin distribution and its biological functions at the level of cells and tissues as proposed by Verhertbruggen et al. Together with the HGAs and RGs, structural and highly soluble glycosylated proteins, the arabinogalactan proteins (AGPs), are associated with the cell wall or the plasmalemma Baccharis dracunculifolia, as a model of study of subcellular responses to external stimuli, is evaluated by the comparison of the current results with those presented for B. reticulariaB. reticularia, the pectin distribution was studied in three distinct gall morphotypes only in mature phase, while herein we analyse a single and similar morphotype on developmental basis. Current study is based on the premise that pectins are important in the determination of the new shape and functionality of plant galls, which develop through highly specific and repetitive cell cycles Baccharis species should present similar immunolabeling for pectins and associated proteins. Our objective is to evaluate histochemically and immunocitochemically the presence and distribution of pectins and AGPs during gall development, checking their association with the functional aspects of gall tissue layers.The galls on Baccharis dracunculifolia (Asteraceae), and galls induced by Baccharopelma dracunculifoliae (Psyllidae) on three developmental stages: young (completely folded leaf), mature  and senescent   . CollectTwo sets of samples were used for the histochemical detection of pectins. The first set was freehand sectioned and stained with a saturated solution of ruthenium red The samples were fixed in 2.5% glutaraldehyde and 2% formaldehyde in 0.1 M phosphate buffer (PBS), pH 7.2 Baccharis dracunculifolia are simple, lanceolate with straight margins  and temporal  distribution . In non-The AGPs epitope was continuously bound by the LM2 antibody in the cell walls of the parenchyma either in mesophyll or vascular bundles . In younB. dracunculifolia has homogenous and parenchymatic mesophyll, small secretory ducts, and unlignified periciclic fibers associated to the vascular bundles The mature kidney-shaped gall of B. dracunculifolia strongly prove the potential of ruthenium red and coriphosphine for the histochemical detection of overall pectins, but did not corroborate their efficiency for evaluating the degree of pectin esterification.One of the cell wall components, the pectins, was histochemically detected in all tissue layers of non-galled and galled samples by the positive reaction to ruthenium red and coriphosphine . This seB. dracunculifolia  herein analyzed changed from the non-galled tissues towards the senescent galls, which should require the action of pectin methyl esterases (PME) Arabidopsis thalianaB. dracunculifoliae governs the reduction in cell wall extensibility and the cessation of growth, from the outer towards the inner portions of the kidney-shaped gall of B. dracunculifolia.In general, it can be assumed that the decrease in the degree of methyl-esterification of the HGAs in the parenchymatic cell walls during gall maturation is necessary given that the cells increase their volumes, as previously observed in the somatic embryos of B. dracunculifolia, which contradicts the expected relationship between this proteins and cell metabolism. The AGPs are known to be involved in cell proliferation, cell wall formation B. dracunculifoliae seems not only to activate PME but to block the synthesis and deposition of AGPs in cell walls, whose consequence is the disruption of normal morphogenesis, as postulated by Cassab B. dracunculifolia seems to be independent of AGPs regulationn, which culminate with their total absence in senescence, the stage when cell cycles end. This proposal is reinforced by the apoptotic cytological features of senescent galls Nicotiana tabacumZea maysThe AGPs epitopes presented decreasing signals from non-galled to galled condition in Solanum tuberosum L.) Lycopersicon esculentum) The association of (1→4)β-D-galactans with the HGAs should maintain the mechanical estability of cell wall B. dracunculifolia. The co-occurrence of galactans with the arabinans may influence the alignment of the HGAs Both the (1→5)α-L-arabinans and (1→4)β-D-galactans are absent during maturation of galls, but reappear during senescence, which illustrate the dynamics of cell wall components by the end of gall development on the leaves of B. dracunculifolia is related to the elasticity and porosity in young and mature galls, and to the rigidity acquired from maturity towards senescence. The dynamics of the pectin composition of the cell walls in the galls of B. dracunculifolia has revealed to be distinct from that of B. reticulariaB. dracunculifolia have proved to the elegant models for the study of the dynamics of cell walls during the cell cycles.The cyclic and repetitive transformations of the cells on galls, and in their distinct tissue layers have confirmed the proposed functions of the HGAs.Current results definitely proved the histochemical reagents, ruthenium red and coriphosphine, are not usefull to indicate the degree of pectin methylesterification. The data obtained by immunocitochemical labeling demonstrated that there was an increase in the degree of methylesterification from young to senescent galls. The differences in the distribution of pectins and AGPs along the development of the kidney-shaped gall of


Acquired memory is initially dependent on the hippocampus (HPC) for permanent memory formation. This hippocampal dependency of memory recall progressively decays with time, a process that is associated with a gradual increase in dependency upon cortical structures. This process is commonly referred to as systems consolidation theory. In this paper, we first review how memory becomes hippocampal dependent to cortical dependent with an emphasis on the interactions that occur between the HPC and cortex during systems consolidation. We also review the mechanisms underlying the gradual decay of HPC dependency during systems consolidation from the perspective of memory erasures by adult hippocampal neurogenesis. Finally, we discuss the relationship between systems consolidation and memory precision. The hippocampus (HPC) is crucial for the formation of episodic memories during the mnemonic process -5. In meThe systems consolidation process involves a time-limited interaction between the HPC and neocortical areas that eventually store long-term memory traces ,25. StudThere is a central question regarding the complementary learning systems framework, as originally articulated by McClelland, McNaughton, and O'Reilly . These aThere is an agreement among various memory systems consolidation models that interaction between the HPC and cortex  after the recent memory formation is crucial for the systems consolidation process ,12-15,28An initial experiment to investigate these connections was conducted by Remondes and Schuman . These aNakashiba et al.  examinedRecently, Lesburgueres et al.  sought tBased on these studies, it appears that information from networks of various neocortical regions is rapidly and temporarily linked through the HPC . The HPCDuring the systems consolidation process, a memory becomes progressively independent from the HPC. This decay of hippocampal dependency is thought to be an active process and plays a role in clearing old memories out of the HPC once the memory has been stored in the cortical networks, thereby allowing the HPC to continuously store new information . Thus, nThe HPC is thought to be critical in the formation of the contextual component of episodic memories ,46. ContIn the DG, new neurons are continuously generated in the subgranular zone throughout adulthood in many mammals, including mice, rats, monkeys, and humans, even during old age -62. The Kitamura et al.  examinedDecreased neurogenesis by irradiation also enhances the long-term retention of long-term potentiation  of the Electron microscopic examinations have also suggested that synaptic competition between old and new neurons occurs when newborn neurons form synaptic connections with pre-existing boutons in the DG ,66. SpecConsistent with our idea, Frankland et al.  also devKitamura et al.  showed tHow does adult neurogenesis contribute to the acceleration of shift of memory dependency from HPC to cortical structures? One possibility is that adult hippocampal neurogenesis in the DG helps to generate the SPWs in CA3 -40. The It has been suggested that the quality of original memories transforms from a precise  form to a less precise  form with a time course similar to that of the systems consolidation process -104. SpaTo directly evaluate context memory without using fear association protocols, Kitamura et al.  examinedConsidering the mechanisms of systems consolidation of contextual fear memory from the perspective of the levels of memory engram ,112,113,Although pharmacological and lesion approaches continue to be very useful for testing memory dependency on the HPC and cortical regions, an optogenetic approach using transgenic mice combined with viral technologies, in which the manipulation of cellular activity is more restricted to a specific population of memory-related cells, allows improved anatomy- and memory engram-based analyses and is better suited to understanding the mechanisms of the systems consolidation process.The authors declare that they have no competing interests.TK and KI prepared the manuscript. Both authors read and approved the final manuscript.


Recent studies about the generation and propagation of coordinated activity in cultured neuronal networks reported the existence of privileged neurons that consistently fire earlier than others at the onset of synchronized bursting events , which have been termed major burst leaders (MBL) . At the We electrically stimulated rat cortical networks cultured on micro-electrode arrays from different locations, either MBL or non-MBL. We evaluated the intensity and the delay of responses from either MBL or non-MBL and we also compared the spontaneous and the evoked activation patterns.By comparing the responses obtained by stimulating either MBL or non-MBL, we found that the stimulation from MBL induces on average earlier responses. By comparing the responses of MBL and non-MBL, we found that MBL respond better and more rapidly to the stimulation coming from any other site in the network. Some networks showed different spontaneous propagation patterns within synchronized bursts depending on the identity of the corresponding MBL Figure . In thesTo summarize, we demonstrated that MBLs do not only drive the propagation of coordinated spontaneous activations, but also play a special role in coordinating and driving the evoked bursts of activity.


The dual concepts of pan and core genomes have been widely adopted as means to assess the distribution of gene families within microbial species and genera. The core genome is the set of genes shared by a group of organisms; the pan genome is the set of all genes seen in any of these organisms. A variety of methods have provided drastically different estimates of the sizes of pan and core genomes from sequenced representatives of the same groups of bacteria.We use a combination of mathematical, statistical and computational methods to show that current predictions of pan and core genome sizes may have no correspondence to true values. Pan and core genome size estimates are problematic because they depend on the estimation of the occurrence of rare genes and genomes, respectively, which are difficult to estimate precisely because they are rare. Instead, we introduce and evaluate a robust metric - genomic fluidity - to categorize the gene-level similarity among groups of sequenced isolates. Genomic fluidity is a measure of the dissimilarity of genomes evaluated at the gene level.The genomic fluidity of a population can be estimated accurately given a small number of sequenced genomes. Further, the genomic fluidity of groups of organisms can be compared robustly despite variation in algorithms used to identify genes and their homologs. As such, we recommend that genomic fluidity be used in place of pan and core genome size estimates when assessing gene diversity within genomes of a species or a group of closely related organisms. The advent of technologies to rapidly sequence entire genomes provides a resource of sequenced genomes spanning the entire tree of life -4. Indee12 genomes). Results of such extrapolations have been widely divergent. In the most well-studied case, the pathogen Streptococcus agalactiae, estimates of the pan genome size vary from tens of thousands [Thus far, attempts to quantify the size of the core and pan genomes have been based on extrapolations from a limited number of sequenced strains  to the entire group , 107 (B), and 105 (C) and their core genome sizes were 103 (A), 10 (B), and 103 (C)  contributes as much to the pan genome as does a core gene  and coverage (c) from 0.5 to 0.8 in increments of 0.02 (see Methods). In 225 trials, we found 4 distinct orderings of genomic fluidity, three of which accounted for 224/225 orderings . We find there is a statistically significant and unambiguous rank order of genomic fluidity for 11 = 21 comparisons of relative rank order among the 7 species examined in all 3 alignment parameter conditions corresponding to the dominant rank orderings  to nearly 1 (at the phylum level) . In addition, genomic fluidity restricts itself to one component of genomic difference. There are a variety of forms of genomic differences beyond gene compositional differences or the more classic finding of single-nucleotide polymorphisms. Genomes may differ in terms of gene synteny , copy nuE. coli based phages despite sharing many common genes and genome architecture [Genomic fluidity is an integrated measure of gene diversity within a group of organisms. Genomic fluidity is both estimable given a small number of sequenced genomes and robust to variation in alignment parameters. As such, we recommend that genomic fluidity be used in place of pan and core genome size estimates when assessing gene diversity within a species or a group of closely related organisms. However, the precise relationship between variation in gene composition and genomic fluidity with underlying mechanisms of gene family diversification are yet to be resolved . Recent itecture . Genomicc fraction of each gene's length and identity in the alignment exceeded i. To improve performance, alignments were parallelized between nodes on a compute cluster using the Torque PBS job scheduler.Complete annotated genomes and draft annotated genomes were retrieved from NCBI GenBank in the GenBank format. Genomes were automatically re-annotated without hand-curation using a recently developed infrastructure resulting in new GenBank-formatted files . AutomatNext, genes were clustered into gene families using a strict clique requirement, i.e. each new gene considered for inclusion into a family must have an alignment with every member of the family satisfying the minimum criteria described above. In this implementation, we compare all members of a gene family to each other on an equal basis and do not distinguish between orthologs, homologs, or paralogs. This homology-based approach is appropriate, since the fine resolution and gene family structure afforded by true ortholog reconstruction does not affect the inclusion or exclusion of genes with marginal evidence of homology.N genomes, the variance isAlignments were processed in order of increasing E-value, to prevent lower quality alignments from disrupting formation of families using higher quality alignments. Each gene was allowed to participate in only one family; if the gene could not be joined into any gene family, it formed its own singleton family. Gene family assignments were used to calculate fluidity using Eq. (1). We used the jackknife estimator  to estimi ,where Mean and variance of fluidity for the species and conditions examined here are presented in Additional file n1 genomes, the second set consisting of n2 genomes. For each pair of genomes, we determine the fraction of the total number of unique genes and the total number of genes. Averaging over all pairs in the first set gives the fluidity Consider two sets of genomes, the first set consisting of U-statistics it is known that the estimated fluidity has approximately a normal distribution [z-test with one degree of freedom (the effective number of degrees of freedom are taken into account by the jackknife estimation).From the theory of ribution . The meaAOK, BH, NHB, and JSW designed the study. AOK implemented the bioinformatics pipeline. BH and JSW developed and implemented the fluidity metric. AOK, BH and JSW analyzed results. JSW wrote the paper with the help of AOK, BH and NHB. All authors read and approved the final manuscript.Supplementary figures and tables. A combined set of supplementary figures and tables referenced in the manuscript, including Figures S1-S5 and Tables S1-S7.Click here for fileSpreadsheet of fluidity values. Mean and variance of fluidity for all species and all bioinformatic pipeline values utilized in the manuscript.Click here for file


For decades, the dynamics of tropical deforestation in sub-Saharan Africa (SSA) have defied easy explanation. The rates of deforestation have been lower than elsewhere in the tropics, and the driving forces evident in other places, government new land settlement schemes and industrialized agriculture, have largely been absent in SSA. The context and causes for African deforestation become clearer through an analysis of new, national-level data on forest cover change for SSA countries for the 2000–2005 period. The recent dynamic in SSA varies from dry to wet biomes. Deforestation occurred at faster rates in nations with predominantly dry forests. The wetter Congo basin countries had lower rates of deforestation, in part because tax receipts from oil and mineral industries in this region spurred rural to urban migration, declines in agriculture and increased imports of cereals from abroad. In this respect, the Congo basin countries may be experiencing an oil and mineral fuelled forest transition. Small farmers play a more important role in African deforestation than they do in southeast Asia and Latin America, in part because small-scale agriculture remains one of the few livelihoods open to rural peoples. For decades, observers have identified rural population growth as the chief driver of deforestation in SSA [Over the past 10 years, a measure of consensus has developed among analysts about the rates and drivers of tropical deforestation. The rates of deforestation appear to have continued at relatively high rates until 2005 when declines began .1 The drn in SSA –6. Some n in SSA . At the The divergence between SSA and other regions in their patterns of deforestation should not be surprising given the exceptional human ecology of SSA. Three salient regional features are immediately apparent. First, the human population of SSA has long been much poorer and more rural in its distribution than the populations of Latin America and Asia. Second, relative to tropical Asia and Latin America, tropical Africa has a more arid climate  with seaThe following pages present this argument in a detailed way, beginning with arguments about the dynamics of national political economies that might explain long established patterns of African deforestation as well as recent shifts in those patterns. The article then describes the data that make it possible to assess, at least in part, the accuracy of this explanation. The following section presents the results of the quantitative analyses. The next section discusses how the quantitative analyses, when viewed within the human ecological context of SSA, account for recent patterns among the country-level drivers of deforestation. The paper concludes with a description of important unanswered questions about deforestation's drivers in SSA.2.When natural scientists first became aware of the rapid rates of forest destruction in the tropics, many of them concluded that expanding populations of shifting cultivators had driven the rapid rates of forest decline . By this2 The rapid increase in the sale of the newly discovered commodity (oil) creates demands for labour in the booming sector which raises the price of labour throughout the country and creates problems for labour intensive enterprises such as agriculture. The high wages in the booming sector attract workers from these enterprises, creating labour scarcities or raising wages to the point where farmers can no longer profit from their work. In this context, farmers may choose to abandon agriculture. At the same time, the national currency may appreciate in value because, for example, overseas purchasers want the currency in order to purchase the extracted oil. If the agricultural sector is producing a crop for sale overseas, such as cacao, the appreciating currency  makes their product more expensive relative to the same crop grown in a country with a depreciating currency, so agricultural producers from the oil producing countries would lose market share. The strong currency also makes it easier to import grains from overseas and substitute these foodstuffs for locally produced foods. For all of these reasons, a booming extractive sector would discourage agricultural expansion into forests [Significant changes in political economies during the past four decades may have begun to disrupt this rural population growth-driven pattern of deforestation in the SSA states, replacing it with a more urban focused pattern of forest losses. The political and economic changes stem in large part from the increased extraction of oil and minerals from African deposits. The discovery of the deposits triggered economic booms in the extractive sectors of economies. The sectoral booms set off cascades of economic side effects that may have retarded agricultural expansion, accelerated urban expansion and probably slowed the destruction of tropical forests in remote rural places. This theoretical line of reasoning, referred to as ‘Dutch disease’, goes as follows ,12.2 The forests ,13.Of course what appears to work in theory may not work in practice. In the case of the offshore oil deposits found in four of the six Congo Basin Forest Initiative countries, the booms generated relatively little demand for local labour, but they did lead to large increases in government receipts from royalty agreements. The increase in government revenues touched off booms in construction spending and government staffing in urban centres. The increase in urban jobs accelerated urban population growth and, by pulling rural people off of the land, it should have discouraged agricultural expansion, so, in theory, the booms would have had an overall forest preserving effect.Consistent with this pattern, societies in SSA had the highest rates of urban population growth, 3.71%, in the world between 2000 and 2005 . With thThese theoretical expectations would of course play out in a larger regional agro-ecology marked by extensive areas that are not suitable for agriculture because they receive so little rain . This ciIn theory then, the recent growth in extractive industries would contribute indirectly to urban population growth and retard agricultural expansion, especially in the humid forest zones where the extractive industries have been especially dominant. The resulting patterns of forest loss should have an urban focus and be more prevalent in countries with dry forests. Recently published, remote-sensing-derived estimates for national changes in sub-Saharan forest cover provide an opportunity to put these expectations to an empirical test.3.Over the past 25 years, scientists have conducted hundreds of studies, similar to this one, of variations across nations in rates of deforestation. The units of analyses in these studies follow the political boundaries of states rather than the ecological boundaries of watersheds or forests. The use of political units of analysis acknowledges that, because human behaviours drive deforestation, human variability from nation to nation may provide crucial evidence about the configuration of driving forces that generates forest clearing. The use of the nation state as a unit of analysis for studying deforestation may seem too coarse grained to portray and analyse the household decision-making that drives deforestation. Certainly, micro-focused studies of deforestation have value, but so do larger scale studies, largely because they incorporate national-level variables such as large-scale tax receipts from petroleum production into our understanding of the drivers of landscape changes. Coarse-grained studies similar to this one also make it possible to incorporate regional differences in landscapes, between humid and dry tropical forests for example, into analyses.3All of the deforestation studies prior to 2000 used unreliable measures of forest losses gathered using different procedures from country to country . The avaWhile the MODIS data represent a distinct improvement over previous national-level deforestation data, the coarse-grained resolution of the MODIS data could produce erroneous national estimates, especially in the smaller- to medium-sized countries with fewer pixels. Acknowledging this potential source of error, the conceivable salience of macro-scale determinants of deforestation in SSA argue for doing an analysis of the cross-national variations in the MODIS deforestation data. The measures for the variables in these multivariate analyses and the sources for these data are listed in 4 The dataset for these analyses is available in the electronic supplementary material.The analysis presented in 4.r2 = −0.900, p = 0.014), as Dutch disease theory would predict.The analyses reported in The findings from the spatial regression analyses reported in 5.The results from the multivariate analyses reported in Although all of these associations are at a large-scale, they fit the patterns evident in more micro-scale analyses of forest cover change in the SSA. In ‘State and the evolution of African rainforests between 1990 and 2010’ in this issue , the autDeforestation in the DRC departs from the regional pattern in its trend lines but resembles the regional pattern in its drivers. Unlike other countries in the Congo Basin Partnership, deforestation in the DRC appears to have increased significantly from 1990–2000 to 2000–2005 . PoliticMore generally, the DRC case exposes the hazards of continental-scale generalizations. The dynamics of deforestation in the DRC appear to differ significantly from the dynamics in the other Congo Basin countries where humid forests predominate. These differences in humid forest zone deforestation dynamics need to be viewed in the context of large differences in deforestation dynamics between countries with predominantly humid forests, such as Gabon and Congo, on the one hand and countries with predominantly dry forests, such as Tanzania and Zambia, on the other hand. While there are common elements that, together, compose a continental pattern of deforestation, urbanization being one important factor, no one country fully exemplifies the larger pattern apparent in this analysis.6.Do the patterns described above attest to a continuation into the twenty-first century of African exceptionalism in forest destruction? The analysis carried out here suggests that crucial differences in the context rather than in the dynamics of deforestation explain the differences in deforestation processes between SSA and other regions. The people are poorer, the extractive sectors of economies are larger, and the climate is more arid.Acknowledging these differences, some deforestation pressures seem common to all regions. Growth in urban populations encouraged tropical deforestation in southeast Asia and Latin America early in the twenty-first century , and thePoverty explains one important difference between African deforestation and Asian–Latin American deforestation. While large plantations, farms and ranches have become the primary agents for tropical deforestation in southeast Asia and South America, smallholders continue to play an important role in driving African agricultural expansion and forest losses. The continuing salience of smallholders in African agricultural expansion reflects the poverty of the people in the region and in particular the urbanization of societies without industrialization. The absence of well-remunerated non-farm jobs in cities and elsewhere makes the continued exploitation of the forests through shifting cultivation and charcoal production a more attractive prospect for rural people .The rapid growth of SSA cities reflects in part the economic booms brought by increased receipts from extractive enterprises. Food imports increased, especially in oil-based economies with strong currencies, and, as evident in Some subregional differences raise important questions for further research. Among the most pressing questions raised by this analysis involves the higher rates of deforestation occurring outside of the humid Central African forests. Recent reports show a concentration of fires in the dry forest regions , perhaps


The management of atherosclerotic carotid occlusive disease for stroke prevention has entered a time of dramatic change. Improvements in medical management have begun to challenge traditional interventional approaches to asymptomatic carotid stenosis. Simultaneously, carotid artery stenting (CAS) has emerged as an alternative to carotid endarterectomy (CE). Finally, multiple factors beyond degree of stenosis and symptom status now mitigate clinical decision making. These factors include brain perfusion, plaque morphology, and patency of intracranial collaterals (circle of Willis). With all of these changes, it seems prudent to review the role of carotid duplex ultrasonography in the management of atherosclerotic carotid occlusive disease for stroke prevention. Carotid duplex ultrasonography (CDU) for initial and serial imaging of the carotid bifurcation remains an essential component in the management of carotid bifurcation disease. However, correlative axial imaging modalities (computer tomographic angiography (CTA) and contrast-enhanced magnetic resonance angiography (CE-MRA)) increasingly aid in the assessment of individual stroke risk and are important in treatment decisions. The purpose of this paper is twofold: (1) to discuss foundations and advances in CDU and (2) to evaluate the current role of CDU, in light of other imaging modalities, in the clinical management of carotid atherosclerosis. Carotid atherosclerosis is one of several etiological factors for stroke, an important health problem with a high burden of disease in the western world and in developing countries. Of all strokes, an estimated 88% are ischemic in nature –5. Less The mortality rate for stroke in the United States has declined by nearly 70% since 1950 . The ideDiagnostic imaging has also played a central role in the clinical management of patients with carotid atherosclerosis. With the advent of vascular ultrasound in the 1980s, it became possible to identify atheroma in the carotid bifurcation noninvasively. Compared to conventional catheter-based angiography, CDU is a low-cost, low-risk, and highly portable alternative. As such, it is an attractive imaging modality for asymptomatic as well as symptomatic patients.The technique for CDU has evolved over the years as has our understanding of the disease process. Traditionally, patients were selected for intervention based on their clinical presentation and the degree of luminal narrowing in the internal carotid artery. Modern management includes an individualized assessment of risk and takes into account brain perfusion, plaque morphology, and the presence of intracranial collateralization. These factors are essential in risk stratification and illustrate the importance of adding correlative axial imaging studies to the diagnostic work-up.CDU is useful and accurate in the assessment of the entire spectrum of carotid atherosclerosis, from preclinical intimal-medial thickening to total internal carotid occlusion. The modality easily detects minimal disease that is not hemodynamically significant. Overestimation of mild to moderate degrees of stenoses, in fact, has been a consistent problem . NeverthHemodynamically significant stenosis is diagnosed primarily through the measurement of markedly elevated flow velocities using spectral Doppler, one component of CDU, in the narrowed portion of the internal carotid lumen. The increase in velocity is proportional to the severity of the obstruction. To diagnose stenosis, measurements of peak systolic velocity (PSV) are compared to velocity thresholds derived from correlations with conventional angiography. Secondary parameters for quantifying stenosis include end-diastolic velocity, internal carotid artery (ICA) to common carotid artery (CCA) ratio, degree of spectral broadening, and presence of plaque on B-mode imaging. Other factors to consider when interpreting studies include the presence of calcific plaque , contralateral high-grade stenosis, and kinking or bends in the vessel .The initial work into establishing clinically relevant thresholds was done by investigators at the University of Washington. They developed broad categories of stenosis  as folloThe Asymptomatic Carotid Atherosclerosis Study (ACAS) was a landmark prospective, randomized clinical trial which examined the role of carotid endarterectomy in patients without symptoms . ACAS randomized 1662 asymptomatic patients with a 60% or greater ICA stenosis to either medical therapy alone or to medical therapy plus CE. In 1995, this study reported CE drastically reduced the estimated risk of ipsilateral stroke or death from 11% to 5.1%  and the AbuRahma et al.  used theThe technique of CDU continues to evolve as a result of experience and advances in technology. Experience has been gained through research, continuing education, and establishment of quality standards through vascular lab accreditation and credentialing of sonographers and interpreting physicians. Advances in technology include continued improvements in gray-scale resolution, Power Doppler, and computer-assisted normalization of images to aid in the evaluation of plaque surface and structure characteristics . No longFor nearly half a century, the management of carotid atherosclerosis has been dictated by the severity of disease (percent stenosis) and classification of clinical presentation between “symptomatic” and “asymptomatic”. The design and results of previous clinical trials on surgical versus medical treatment of carotid atherosclerosis for stroke prevention as well as current studies comparing CE and CAS have led to this distinction. Currently, an individual's risk of stroke can be assessed by taking into account supplementary diagnostic information such as plaque morphology and the integrity of intracranial collateralization. This information identifies plaque vulnerable to disruption and atheroembolization leading to a better calculation of an individual's risk for stroke. The recognition of vulnerable plaque is also paramount in the surgical management of carotid atherosclerosis, particularly when CAS is planned. Carotid plaques with a large lipid core and thin fibrous cap are more likely to rupture . When thLarge pressure gradients across a stenosis can influence plaque by increasing the wall shear stress (WSS) and causing cap disruption , 35. Li The identification of additional parameters contributing to an individual's risk of stroke may warrant modifications to the diagnostic work-up for carotid atherosclerosis. The current role of CDU and correlative axial imaging (CE-MRA and CTA) is outlined in The sensitivity and accuracy of CDU in the detection of hemodynamically significant stenosis has led to its widespread use in the initial evaluation of patients with neck bruits  and in symptomatic patients for the detection of ≥70% carotid artery stenosis. But, the relative low specificity of CDU, especially in the 50–69% category , justifiWhile conventional angiography is still considered the “gold standard” for defining carotid disease, there has been a growing interest in performing CE based on clinical evaluation and CDU alone. One reason for this strategy is to improve patient outcomes. There is a higher risk of stroke (10–20%) within the first 14 days following a cerebrovascular event. After this time, the stroke risk declines to that of the “asymptomatic” stenosis (1-2%/year) . To maxiThis trend has also been stimulated by improvements in the accuracy and utility of CDU, along with increasing demands to minimize both the risks and cost of medical care. In many centers, carotid angiography is no longer done routinely, even when planning intervention, to eliminate the procedural risk of neurologic events, which is around 1% , 39. A sWith the emergence of CAS as an alternative to CE, there has been an increased focus on CDU's ability to distinguish plaque morphology. Plaque morphology includes surface (smooth versus irregular) and structure  characteristics . CertainIndividual risk assessment of patients being considered for surgical intervention is limited with CDU. For example, the assessment of plaque morphology is not routinely available in every vascular lab and requires specific protocols to assure standardization of results. The use of image normalization and software calculation of gray-scale median values can minimize inter- and intraobserver variability, but is not the current standard of practice. CDU also fails to provide diagnostic information with regard to brain perfusion, arch pathology, intracranial collateralization, and vascular anomalies such as aneurysms. The CoW can be interrogated with transcranial Doppler, although few labs employ this technique.Recurrent stenosis is one of the most prevalent complications of CAS. The current risk of hemodynamically significant (≥80%) in-stent restenosis (ISR) is 6.4% at 5 years . BecauseISR is primarily caused by neointimal hyperplasia. The course of neointimal hyperplasia is difficult to predict; it may progress to a high-grade stenosis requiring reintervention or follow a more benign course. Lal et al.  have stuA full discussion of ISR is beyond the scope of this paper. What is important is that CDU is a reproducible technique that can be applied to the identification and classification of types and severity of ISR. CDU surveillance should include a thorough investigation of the stented segment noting the length of any narrowing and its relationship to the stent. Standard practice is to obtain baseline CDU prior to discharge following CAS. Follow-up CDUs are obtained at 3 months and then at 6-month intervals for the next 18 months. If there is no evidence of significant ISR at two years, surveillance CDUs are then performed annually . Since lCDU surveillance following CE, on the other hand, is a topic of controversy. Stroke prevention is the goal of any surveillance program. Strokes can be prevented by detection of significant restenosis prior to the onset of neurologic events and through follow-up of contralateral carotid bifurcation disease. Opponents to routine surveillance argue that there is no real stroke prevention benefit. While recurrent stenosis is somewhat common after CE with a reported incidence of 1% to 37%, fewer than 8% of patients become symptomatic –48. RestRoutine screening of the general asymptomatic population is controversial. The United States Preventive Services Task Force (USPSTF) recommended against routine screening for asymptomatic carotid artery stenosis in 2007. It concluded it was not possible to identify people from a high-risk group  who might benefit from screening and treatment with CE or CAS . Similarly, new guidelines on the management of patients with carotid artery disease were released in January 2011 by the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Specific to screening, the task force recommended against screening in asymptomatic patients without significant risk factors for atherosclerosis or physical signs of carotid disease. However, screening for carotid stenosis “may be considered among individuals with at least two major risk factors for atherosclerosis or with a diagnosis of other cardiovascular disease such as coronary artery disease or peripheral artery disease” . Screening in high-risk groups has also been reported in Hong Kong. Cheng et al.  used CDUAtherosclerosis is a systemic disease with potentially devastating consequences such as stroke, ischemic heart disease, and peripheral arterial disease. Emerging advances in carotid ultrasound allow for the detection of atherosclerosis at its earliest stages. These advances include the use of carotid intima-media thickness (CIMT) calculations and administration of contrast ultrasound agents during CDU. The application of CIMT has become an accepted, reliable surrogate marker for determination of atherosclerosis and is endorsed by the U.S. Food and Drug Administration (FDA) and the European Agency for the Evaluation of Medicinal Products , 54. CIMContrast-enhanced ultrasound (CEUS) is another emerging advancement in technology. While not routinely used, contrast agents are an exciting adjunct to CDU and have two potential benefits. First, they can be used to identify neovascularization within the adventitial layer of the CCA which precedes the development of increased IMT , 55. CliDespite the abundance of the literature on the benefit of advanced noninvasive technologies in the assessment of cardiovascular risk, their role is still emerging. In the United States, CIMT and CEUS are not generally reimbursable. Additionally, contrast ultrasound agents are currently FDA approved only for use in the imaging of cardiac structures. Their off-label use in vascular imaging may require institutional approval. In developing countries, emerging advances in CDU may be of greater immediate benefit. This is especially true of CIMT which can be measured relatively simply and is well-suited for large-scale population studies.The role of CDU in the management of carotid atherosclerosis has evolved. The technique was developed as a diagnostic tool to identify asymptomatic and symptomatic patients with significant (≥60–99%) carotid stenosis. These were the patients likely to benefit from carotid revascularization either by CE or CAS. Today, correlative axial imaging (CE-MRA and CTA) studies supplement CDU and provide diagnostic information on brain perfusion, plaque morphology, and intracranial collateralization. These factors are important in the individual assessment of stroke risk and may improve the clinical management of patients with carotid atherosclerosis.


We report on a case of autoimmune thyroiditis in a 6-month-old patient with cortico-resistant nephrotic syndrome. Normal serum levels of thyroid hormons and thyroid-stimulating hormone were detected with high titers of circulant antithyroid antibodies and a dysomogeneous ultrasound appearance of the gland, typical of autoimmune thyroiditis. The research of maternal thyroid antibodies was negative. This is the first case of autoimmune thyroiditis found in such a young patient with pre-existing nephrotic syndrome ever described in literature. This association is random because nephrotic syndrome does not have an autoimmune pathogenesis and the genes involved in autoimmune thyroiditis are not related to those of nephrotic syndrome. Autoimmune diseases are very rare conditions in infancy, especially in the first year of life-4. We reD.S. was admitted to our hospital at 6 months of age because of the appearance, two weeks before, of bilateral periorbital oedema associated with hypoalbuminemia , hypoprotidemia (seric proteins 3.7 g/dl), proteinuria  and dyslipidemia . The diagnosis of nephrotic syndrome was established and a substitutive therapy including human albumin was immediately started, as well as calcium and potassium supplementation, diuretics and intravenous immunoglobulines. After a few days albumin levels further decreased, general conditions became more serious and subcutaneous succulence spread especially in abdominal, scrotal and palpebral regions. For this reason, it became necessary to intensify albumin infusion as well as diuretic supply and to introduce prednisone  in association with an ACE-inhibitor  for its antiproteinuric effect, in order to potentiate steroid action. This therapy was given for overall eight weeks without any response: therefore this form of nephrotic syndrome can be defined “cortico-resistant”. After a few days, for the aggravation of clinical conditions, also cyclophosphamide (dose 1 mg/Kg/die) and spironolactone (potassium-sparing) were introduced unsuccessfully. Blood pressure was always normal. Because of the massive proteinuria, due to the renal failure, an evaluation of thyroid function was made: thyroid hormones were normal but high titers of circulating antithyroglobulin and anti-microsomal thyroid antigen antibodies were detected[After a month a blood assay revealed the persistence of high titers of antithyroid antibodies associated to a slight decrease of thyroid hormones  and normal levels of thyroid-stimulating hormone, without any clinical sign of hypothyroidism. Because of the aggravation of the renal disease, the patient was transferred to another hospital where he continued human albumin replacement therapy and cyclophosphamide and than he began haemodiafiltration. During this period he was subjected to renal biopsy which demonstrated the presence of a focal and segmental glomerulonephritis with mesangial matrix proliferation and an increase of Immunoglobulines M. Currently the patient is undergoing peritoneal dialysis waiting for kidney transplantation.The significance of this study is due to the early onset of autoimmune thyroiditis in association with nephrotic syndrome in a child under one year of age. The association found in our patient seems to be random because nephrotic syndrome does not have an autoimmune pathogenesis and there is no genetic or antigenic relation between autoimmune thyroiditis and nephrotic syndrome-10. FinaWritten informed consent was obtained from the patient’s parents for publication of this case report and any accompanying images.The authors have indicated they have no relationships relevant to this article to disclose.FU carried out the endocrinological and nephrological studies, drafted the manuscript and got the image. AA carried out the molecular genetic and pathogenetic studies. GA participated in the sequence alignment. RP provided the literature. LC coordinated the work. All authors read and approved the final manuscript.


In this review, we discuss the possibility that the glycosylation of West Nile (WN) virus E-protein may be associated with enhanced pathogenicity and higher replication of WN virus. The results indicate that E-protein glycosylation allows the virus to multiply in a heat-stable manner and therefore, has a critical role in enhanced viremic levels and virulence of WN virus in young-chick infection model. The effect of the glycosylation of the E protein on the pathogenicity of WN virus in young chicks was further investigated. The results indicate that glycosylation of the WN virus E protein is important for viral multiplication in peripheral organs and that it is associated with the strong pathogenicity of WN virus in birds. The micro-focus reduction neutralization test (FRNT) in which a large number of serum samples can be handled at once with a small volume (15 μL) of serum was useful for differential diagnosis between Japanese encephalitis and WN virus infections in infected chicks. Serological investigation was performed among wild birds in the Far Eastern region of Russia using the FRNT. Antibodies specific to WN virus were detected in 21 samples of resident and migratory birds out of 145 wild bird samples in the region. The West Nile (WN) virus is a mosquito-borne flavivirus of the Japanese encephalitis (JE) serocomplex group that causes lethal encephalitis in humans and horses. WN virus was first isolated in 1937 from the blood of a febrile patient in the WN district of Uganda ,3,4. OutCulex mosquito vectors. Viremic levels of the avian host directly affect the infection rates of vector mosquitoes; birds with higher viremia generate more infected mosquitoes after blood feeding . Th. ThCulex variant . MoreoveWe previously examined the role of the N-linked glycans of E protein in tick-borne encephalitis (TBE) virus particle secretion using subviral particles . SecretiMutations of NS3 or NS4B of the NY strain of WN virus were reported to be responsible for the increased pathogenicity and viremic level in avian or mammalian hosts ,40. Impo5 PFU/mL) in 2-day-old chicks, and high levels of virus were detected in the hearts, spleens, and kidneys  virus ,60,61, iAlthough it is difficult to distinguish the specific flavivirus neutralizing antibodies in multiple infections with heterologous viruses, micro FRNT is able to differentiate antibodies against WN virus and JE virus in single infection. Therefore, micro FRNT is a quite useful method to conduct serological survey in the area where WN and JE viruses are both prevalent.Anseriformes, Charadriiformes, Columbiformes, and Pelecaniformes. Birds in these orders are known to support WN virus propagation with high levels of viremia, and to serve as efficient amplifying hosts for the transmission of WN virus to mosquitoes [Field surveys were conducted in Far East Russia in 2005 and 2006 to know the seroprevalence of WN virus in wild birds using micro FRNT. Neutralizing antibody to WN virus was identified in 21 serum samples taken from 145 wild birds (14.5%)  62]. Bi. Bi62]. squitoes . The JE squitoes ,31. TherColumba livia ) tested and some eastern turtle doves , which are resident birds, had WN virus antibodies and were probably infected with the virus near Khanka Lake. Because Khanka Lake lies far to the east of where WN was first isolated in Russia, the WN virus appears to have been transmitted among wild birds in Far Eastern Russia. The other WN virus-positive birds identified in this study were spotbills (Anas poecilorhyncha), harlequin ducks (Histrionicus histrionicus), red-breasted mergansers (Mergus serrator), black-headed gulls (Larus ridibundus), and common terns (Sterna hirundo), which are all migratory birds, therefore it is possible that these birds were infected with the WN virus in Far Eastern Russia and carried the virus into other regions of East Asia. In the Asia-Pacific region, migratory water birds typically display north-south flying patterns [Sterna hirundo) is a long-distance migratory species that may migrate between Far East Russia and Australasia. The possibility that the WN virus-positive antibodies in common tern might be the result of the Kunjin virus infection could not be excluded because of the limitation of the neutralization test. Recent studies of migration routes of mallard (Anas platryhynchos) determined by satellite telemetry have shown that besides the northward flyway from Japan to Russia, a northwestward flyway also exists in Far East Russia [All of the rock doves ( patterns . Long-dit Russia . In Japat Russia . In Hokkt Russia .The results of this study suggest that WN virus is distributed throughout Far Eastern Russia and that it may spread to East Asian countries with the migration of wild birds. To prepare for the introduction of WN virus to East Asia, the development of a diagnostic test that can accurately differentiate between WN and JE virus infection is needed. In addition, continued epizootiological evaluation of WN virus infection among birds and humans in Far Eastern Russia and East Asia will be important for monitoring the spread of the disease.WN virus causes serious problems in public health since a large numbers of patients with severe encephalitis are reported in various regions of the World. The distribution of the virus is still expanding  and the The highly pathogenic WN virus appeared to emerge in the late 1990s and the glycosylation in E protein may be one of the factors of increased pathogenicity of WN virus. The virus replication in birds is enhanced by the glycosylation of E protein and it may result in the increased transmissibility among bird population and higher pathogenicity in birds. It is quite important to know that only one amino acid substitution of the virus may influence the distribution and pathogenicity of WN virus.Apparently, there is a strong need for vaccine and specific treatments to WN virus infection. To develop these specific measures to WN virus infection, basic research for understanding the replication and pathogenicity of West Nile virus should be further encouraged.


This correction is issued to acknowledge the previous work by Dr Ulrike Koch and her colleagues which had stimulated our research and influenced our experimental approach but was unfortunately omitted from the list of cited references.Daphnia sp. (Koch 2009). In a part of her thesis, she addressed the potential role of single amino acids for the reproductive mode of Daphnia. This work has stimulated our subsequent research presented in our paper . In her studies, Dr. Koch could demonstrate that the addition of specific dissolved amino acids (namely arginine and histidine) to a diet of the green alga Scenedesmus sp.  triggered a change in Daphnia’s reproductive strategy from the production of resting eggs to the production of subitaneously developing eggs; this change also increased the population growth rate of daphnids . In our study using a similar experimental setup, we corroborated several of Dr. Koch’s findings, but also have extended her findings as well as reported some striking differences.In her PhD thesis, Dr. Koch investigated food quality effects on and clonal differences in resting egg production of Chlamydomonas), we could confirm that addition of the amino acids arginine and histidine to a green algal diet induces a switch from resting egg production to the development of subitaneous eggs under crowding conditions. Interestingly, Koch (2009) has reported quite different effects of the two green algae Scenedesmus and Chlamydomonas on the reproduction of daphnids in her thesis: While she found daphnids to produce mostly subitaneous eggs on a diet of Chlamydomonas, but mostly resting eggs on a diet of Scenedesmus (under crowding conditions), our results suggest that also Chlamydomonas as a food organism leads to an increased resting egg production of daphnids compared to a high quality cryptophyte diet. Because of the effects of amino acid addition on the reproduction mode of Daphnia, Koch et al. (2011) investigated the effect of amino acid additions on the daphnids’ population growth rate. In our study, we followed another, independent hypothesis that the amino acid addition could also affect somatic growth of Daphnia. In an extension to the investigations of Koch et al. (2011), we further have demonstrated that the addition of arginine and histidine also influenced either the the timing of the release of eggs from the ovary into the brood chamber or the actual embryonic development of cladoceran eggs.Using a different green algal genus . This corroborates earlier work by Ahlgren et al. (1992) who found no taxon-specific amino acid profiles in numerous phytoplankton taxa. Hence, our data suggests that the algal amino acid composition cannot explain the observed effects of algal diet on the reproductive strategy of Daphnia . These partially contradicting results on the content of essential amino acids of freshwater phytoplankton species and their potential consequences for herbivorous zooplankton remain to be resolved by future studies.The most striking differences in the results of Dr. Koch and our study lie in the reported relative difference of the amino acid contents in the hydrolysates of the food algae. Koch (2009) and Koch et al. (2011) related the effects of algal diets on Daphnia. Unfortunately, the citation of the work of Dr. Koch was accidentally deleted from a previous version of our manuscript during the assembly of our paper and was therefore unintentionally not included in the paper.Taken together, the results of Koch and colleagues  and our findings  indicate a high, but previously overlooked importance of specific essential amino acids for the reproductive strategy of the aquatic keystone herbivore These references, for the omitted acknowledgements, were not listed in the published References list:Daphnia: food quality effects and clonal differences. PhD thesis. Limnological Institute, University of Konstanz, Germany52.Koch U (2009) Resting egg production in 53.Koch U, Martin-Creuzburg D, Grossart HP, Straile D. (2011) Single dietary amino acids control resting egg production and affect population growth of a key freshwater herbivore. Oecologia 167 (4): 981-989. DOI: 10.1007/s00442-011-2047-4


Tracheal reconstructions are aimed at rearranging or replacing parts of the tracheal tissue by different techniques. Here we introduce a new technique for tracheal reconstruction.In 10 adult dogs, after intubation with an endotracheal tube, a segment of trachea including seven tracheal rings was resected circumferentially. A submuscular tunnel was induced between mucosal and muscular layers of the adjacent esophagus lying right next to the trachea. The esophageal submuscular tunnel starts and ends exactly at the level of distal and proximal ends of tracheal resection, respectively. Inforced Gore-Tex passed through the esophageal submuscular tunnel the distal segment of trachea and end-to-end anastomosis were made between distal ends of Gore-Tex and trachea, then endotracheal tube removed and the same procedure was made for proximal ends of Gore-Tex and trachea. Afterward, the proximal and distal ends of the esophageal tunnel were approximated to proximal and distal tracheal parts over the anastomosis.All dogs, except one due to anesthetic problem, survived and tolerated the operation; the first two dogs experienced postoperative fever, aspiration pneumonia, and died due to tracheoesophageal fistula. All survived animals were eating and barking well. We started to scarify dogs at least 6 and 12 weeks after operation for microscopy and pathologic examination. The Gore-Texes were patent and supported externally with fibrous connective tissue in esophageal tunneling, with in growth of respiratory epithelium on inner surfaces.Air tightness, good re-epithelialization, and relatively no limitation of esophageal length and no risk of luminal collapse are advantages of tracheal reconstruction by submuscular esophageal tunneling. This new method is worthy of further investigation, as it is technically feasible and easy to implement. A few examples of limited tracheal resection and primary anastomosis were cited in the first half of the 20thcentury.[Experimental and clinical tracheal repair or anastomosis began in the late 19Further experimental investigation on potential extent of tracheal resection and primary anastomosis without prosthesis greatly widened these possibilities. Approximately half of the adult trachea could be removed and primary reanastomosis performed–5 so, moThe general limits of safe resection are about half of the tracheal length in adults and probably one third in small children. These patients are now treated with palliative techniques namely irradiation and stents or T tubes.The reconstruction of the trachea after extensive resection remains a tremendous challenge and one of the most technically demanding of all thoracic procedures.Numerous techniques have been described to date to confront the challenge of tracheal reconstruction.The various tracheal substitutes and techniques of reconstruction were recently analyzed by Grillo, who clasIn a previous work, we investigated living autologous aortic conduit to avoid immunologic reactions. We foundIn another study we introduced a new method of reconstruction of circumferential tracheal with submuscular esophageal tunneling. In this This experiment was done on a total of 10 adult cross-breed dogs weighing 16.5 to 24 kg in animal research laboratory of Shiraz University of Medical Sciences. The procedures and the handling of the animals were reviewed and approved by the research and ethics committees of the Shiraz University of Medical Sciences  in accordance with the Principles of Laboratory Animal Care that have been formulated by the US National Society for Medical Research and with the Guide for the Care and Use of Laboratory Animals that has been published by the US National Institutes of Health .All procedures were carried out under aseptic conditions. The animals were kept in pathogen-free laboratory conditions . The protocols for anesthesia, operation, and sacrifice were identical for all animals. Anesthesia was induced by intravenous thiopental (15 mg/kg). Antibiotic therapy was done preoperatively using intravenous cefazolin sodium (100 mg/kg) on induction of anesthesia. In addition, intramuscular cefazolin sodium (100 mg/kg/d) was administered to dogs for a total of 7 days after the operation. After endotracheal intubation  no.8), the animals were maintained on controlled ventilation with halothane and 100% oxygen. The animal was prepared with povidone-iodine solution and draped; the skin and subcutaneous tissues were incised in the midline from 3 cm below the larynx to a length of 15 cm. The cervical trachea and esophagus were exposed by a midline separation of the paired strap muscles; the peritracheal sheath of the 10 tracheal rings was freed, and the trachea was mobilized circumferentially for 6 cm according to the planned resection.The adjacent esophagus lying right next to the trachea was mobilized gently to prevent vascular injury. Then about half the circumference of the anterior muscular part in both esophageal ends was incised and, by gentle and careful insertion of a tissue dissector between the mucosal and muscular layers of esophagus, a submuscular tunnel was made and about 8 cm reinforced gore-tex  passed cautiously through the esophageal submuscular tunnel. A segment of trachea including seven tracheal rings (rings 5 through 11) was dissected and resected circumferentially. The animals were extubated and again re-intubated, using another cuffed ETT no. 7 via Gore-tex lumen and the distal segment of trachea and end to end anastomoses were made between distal ends of Gore-Tex and trachea over the ETT with a couple of running nonabsorbable 4-0 prolyn continuous sutures then ETT removed and the same procedure was made for proximal ends of Gore-tex and trachea. the esophageal submuscular tunnel starts and ends exactly at the level of distal and proximal ends of tracheal resection, respectively Afterward, the proximal and distal ends of the esophageal tunnel were approximated to proximal and distal tracheal parts over the anastomosis sites with running absorbable 3-0 Vicryl continuous sutures .The strap muscles were re-approximated; the skin was closed in two layers with a couple of running absorbable 3-0 Vicryl sutures for subcutaneous tissue and interrupted 3-0 nylon sutures for skin, and then oxytetracycline antibiotic spray was applied.The dogs were returned to their individual cages on the day of the operation. No oral feeding was given on the first and second postoperative days; fluid was resumed on the third day, and then the dogs were advanced to liquid and soft diet (without any hard bony component). The dogs were observed daily for coughing and dyspnea. The cervical incisions were evaluated daily for swelling, inflammation, seroma formation, and subcutaneous emphysema. Other cares were routine for the research facility.In a preprogrammed manner, the surviving animals were put to death for macroscopic and microscopic observations by a rapid intravenous overdose of potassium chloride. Three dogs killed after 6 weeks and the 3 dogs were killed after 12 weeks postoperatively and were autopsied. One dog kept alive for long term result and sacrificed after 4 months at the end of study. The entire reconstructed trachea including the larynx and intra-esophageal parts was removed for histological evaluation. The anastomosis was evaluated for integrity, degree of luminal stenosis, granuloma formation, and histological response. After formalin fixation, specimens for histology were taken through the anastomosis, luminar surface of Gore-Tex and intra-esophageal parts, embedded in paraffin, stained with hematoxylin and eosin, and examined by means of light microscopy. All of the animals received humane care throughout the study.All dogs, except one due to anesthetic problem, survived and tolerated the operation. The operation time was one hour on average. The first two dogs experienced postoperative fever, dyspnea with respiratory distress and died during the first and second post-operative week.Postmortem examination revealed a small perforation of esophageal mucosa and formation of a 3-4 mm tracheoesophageal fistula. Otherwise all of the dogs were alive, eating and barking well and had uneventful post-operative courses until they were put to death.On post-mortem examination in neck exploration, there was no abscess or sign of infection in the site of graft. There was evidence of adhesion of adjacent muscles to the trachea. Both proximal and distal anastomosis had healed well, no significant anastomotic stenosis, sign of infection, any crust or deformity was found at the site of anastomosis. The Gore-Texes were supported externally with fibrous connective tissue in esophageal tunneling. Inner surfaces of Gore-Texes showed a well-defined area of gray with healed tissues .Microscopic examination of hematoxylin and eosin stained of mucosa spanning the junction between the Gore-Tex and trachea demonstrated well-healed anastomosis in all dogs.In the section from Gore-Texes graft 6 weeks after operation showed that necrotic epithelium covered the entire surface, mild chronic inflammation, fibrosis, granulation and foci in growth of squamous metaplasia .In the section from Gore-Texes graft 12 weeks after operation showed chronic inflammation, fibrosis, and epithelialization with mixed squamous/mucociliary metaplasia .Although most organs are successfully transplanted to date, the trachea remains an exception. Tracheal replacement with prosthetic or biological substitutes such as allografts or autologous grafts  did not provide results satisfactory enough to lead to clinical application.–13Another line of experimental reconstruction with host tissue has been the use of adjacent esophagus to replace a long segment of trachea. Mural splinting is required to maintain patency, although, amazingly enough, in some experiments the splinting seems to have been unneeded. In one study, placement of a series of discontinuous polypropylene rings failed when the adjacent supported segments caused obstruction by sliding laterally. A suggestion that an esophageal segment be substituted for trachea just to provide a channel for a T tube seems toClinically, multi-staged cutaneous tubes have been widely used for construction of cervical trachea. Multiple trough techniques have been devised and used.17 Edgertin situ has also been used to patch the membranous tracheal wall and to serve as a long linear patch for congenital stenosis.[Esophagus stenosis.20 Fonkalstenosis.22 tried In a previous work, we reported that sub muscular esophageal tunneling could be a valuable substitute to the trachea for a period of 6 months. But the In the present study, we replaced the cervical trachea with submuscular esophageal tunneling. Esophagus was not resected and there was no need for mucosal anastomosis. Therefore, there was low possibility of leakage and infection. We used this technique in reconstructing rather short tracheal defects. Due to formation of fibrous tissue between skeletal muscular structures of the neck and the external layer of the channelized esophagus, the new airway remained patent. We suppose that tracheal reconstruction by the esophageal tunneling technique has the potential to be considered reliable for the circumferential reconstruction of extensive laryngotracheal defects not amenable to being cured by conventional techniques.In this method we do not need to keep ETT as a temporary stent and the Gore-Tex inhibits the collapse or stenosis of the tracheal lumen.Yet, additional studies should be done on use of esophageal submuscular tunneling for reconstruction of larger tracheal defects, in other animals, or for the possibility of clinical application of this method. In addition, longer term studies should be done to evaluate the potential of granulation tissue formation and conduit stenosis in the new trachea.In conclusion, air tightness, good re-epithelialization, and relatively no limitation of esophageal length and no risk of luminal collapse are advantages of tracheal reconstruction by submuscular esophageal tunneling. This new method is worthy of further investigation, as it is technically feasible and easy to implement.