Lolium perenne cv. Aberdart tillers were studied in both spring and autumn in increasing and decreasing day length conditions, respectively, and dissected to define the development status of roots of known age on successive phytomers basipetally on the tiller axis. Over a 90-day observation period spring and autumn tillers produced 10.4 and 18.1 root bearing phytomers (Pr), respectively. Four stages of root development were identified: (0) main axis elongation (~0–10 days), (1) primary branching (~10–18 days), (2) secondary branching (~18–25 days), and (3) tertiary and quaternary branching without further increase in root dry weight. The individual spring roots achieved significantly greater dry weight (35%) than autumn roots, and a mechanism for seasonal shift in substrate supply to roots is proposed. Our data define a root turnover pattern likely also occurring in field swards and provide insight for modelling the turnover of grass root systems for developing nutrient efficient or stress tolerant ryegrass swards.Grasses have a segmental morphology. Compared to leaf development, data on root development at the phytomer level are scarce. Leaf appearance interval was recorded over time to allow inference about the age of segmental sites that later form roots. Hydroponically grown  Grass tillers are composed of recurring segmental units known as phytomers. Over their life cycle, phytomers undergo a series of developmental changes following their differentiation at the apical meristem ,2,3, incIn comparison to leaf development, little has been reported on root developmental succession along the tiller axis. Early field studies typically reported an annual pattern of root replacement under grass swards without clarifying root formation and developmental activity at the tiller axis e.g., ,9,10). S,10. S9,1Little previous research has examined the developmental morphology of individual roots on the tiller axis. It is axiomatic that so long as there is a lack of data on root developmental activity and function over the life-span of root-bearing phytomers on the tiller axis, it will be difficult to formulate breeding criteria for enhancement of root contribution to forage grass performance, or even understand which root system traits might be beneficial. A range of methodologies, such as minirhizotrons ,16,17 anIn this paper, we report data for the United Kingdom-bred perennial ryegrass cultivar Aberdart. There were two research objectives: (i) To present descriptive data on root development over time, including root dry weight (RDW), root axis length (RAL), number of roots per phytomer (Rp), and a WinRhizo analysis of an age-series of roots to document the morphological development and branching process from root appearance to around 80 days of age and formulate a synthesis of the root development process. (ii) To compare data collected in spring and autumn for any evidence of seasonal differences in numbers of new roots formed per new leaf, and differences in mature root dry weight that might be attributable to seasonal difference in the rhizochron:phyllochron ratio.An inventory of the data collected, the numbers of plants or roots involved in each measurement and the analytical procedures employed, appears in p < 0.001) of similar age. The leaf elongation rate (LER) rose with temperature in spring from 1.4 to 2.5 mm °C.d−1 over the course of the experiment. In autumn LER rose with falling temperatures over the first 30 days of the experiment from 2.0 to 2.7 mm °C.d−1, then as temperatures fell further LER decreased to 1.7 mm °C.d−1 at the end of the experiment. Tillers developed to a larger size in the autumn experiment than in the spring experiment. Leaf dry weight per tiller was more than 3× higher and number of live leaves per tiller 1.5-fold higher in autumn tillers than in spring tillers  to 16.6 °C in the closing 10 days. The average phyllochron length was 9.22 and 4.44 d in spring and autumn, respectively. As a result, spring tillers had on average 10.4 ± 0.17 live root bearing phytomers compared with 18.1 ± 0.53 in autumn plants (p = 0.006 in repeat measures ANOVA), but this should be interpreted in conjunction with the more than three-fold greater leaf dry weight per tiller in autumn (p = 0.748 in repeat measures ANOVA). The highest observed RDWi values were reached in both seasons after approximately 50 days of growth. The mean RDWi for roots of age ≥ 48 days  in spring was 20.1 ± 1.19 mg, with these roots located at phytomer (Pr) 7–10 considering the youngest leaf (EL in p = 0.033 for the phytomer position × season interaction in repeat measures ANOVA). An analysis with fine roots of diameter classes < 0.1 mm and 0.11–2.0 mm indicated that, compared to autumn roots, old spring roots produced much greater root length and surface area, and had a greater volume of fine roots  of spring tillers was less than half of that in autumn tillers (n autumn . Howeveraf EL in A as the ne roots . Root mane roots .p = 0.005). Root dry matter deposition rate declined as roots aged, reaching zero approximately 50 days after root initiation , and ratios of length:volume  and surface area:volume   . Generalm2 mm−3)  continuiVisual scoring identified tertiary order branching of older roots in spring and some quaternary order branching of older roots in autumn. Based on development of successive orders of root branches, four phases of root development were identified, as illustrated by representative scans : Phase 0Poa pratensis [Carex bigelowii [Examples of shoot axis observation to recover historic information on plant development include studies of ratensis , and Carigelowii . Matthewigelowii  adapted −1 with little or no branching in the first 10 days (Phase 0); (ii) over days 10–25, active main root axis elongation continued with the appearance of primary and secondary branches (Phases 1 and 2); and (iii) between days 30–40, main axis elongation ceased and tertiary root branching began to occur (Phase 3). In phase 3, there was typically continued increase in specific root length and the ratio of RSA:root mass (or volume), and sometimes appearance of quaternary branches, but no trend of increase in root mass, volume, or numbers of tips, suggesting simultaneous senescence and ongoing ramification in different branches of the same roots.The main features of the root development process indicated by the data from these experiments were, (i) in both seasons, the main axis elongated after initiation at an average rate of approximately 1.3 cm d−1 d−1 allowed the construction of approximately 50 mm2 RSA, not considering the impact of root hairs on RSA. The rate of dry matter deposition decreased by approximately 50% at Pr3–4 when first order of branching commenced and further decreased to one-quarter its initial rate at Pr6–7 when secondary and tertiary order root branching occurred. The decline in dry matter deposition with root age was shown [In younger phytomers, the addition of <1.0 mg dry matter Pras shown  to be maas shown . At the The maximum mean root axis length (RAL) measured in these experiments was 42 cm ; however, in some other studies perennial ryegrass roots can grow to more than 1.0 m in length . PreviouFor individual phytomers on the tiller axis, this ontogenetic root development sequence captured in these data can be conceptualized as continuous with and paralleling the leaf development and senescence sequence  which isThe basis of the postulated architectural signal resulting in enhanced C-supply to spring roots compared to autumn roots effectively stems from seasonally driven changes in the ratio between the rate of new leaf formation and the rate of new root formation. These shifts are a result of leaf appearance happening earlier in the life of a phytomer, with root appearance occurring on the same phytomer several weeks later. Thus, changes in the rate of phytomer development will first manifest in the leaf area, with a lag period before being mirrored by changes in root initiation. Although not in itself definitive, we observed on average 11 phytomers with roots initiated over 83 days in spring and 18 phytomers with roots initiated over 80 days in autumn, a 70% higher potential root appearance rate in autumn.In addition, values for number of roots per phytomer were higher in warmer temperatures of autumn, averaging 1.89 and 2.63 in spring and autumn, respectively , indicatThe root branching process is continuous and the commencement of one branching order does not require the termination of another. Root branching produces sequentially finer roots, which greatly reduces construction costs . A linea3 of volume per day . Harvesting took place over eight consecutive days. During the growing period only the parent tiller and the two first-formed daughter tillers were allowed to develop and all other daughter tillers were removed on appearance . The ti® was not feasible due to time constraints. Consequently, root dry weights were recorded for all harvested roots, and scanned images were made of subsets of roots. Two randomly selected plants of two different genotypes for each cultivar in each season were scanned as described below.A total of 571 individual roots were isolated from 301 phytomers from 30 tillers in spring and 766 individual roots from 288 phytomers from 16 tillers in autumn. Scanning all roots for detailed morphological data using WinRHIZO® analysis were preserved in 70% ethanol. Remaining roots were dried in a forced air draft oven at 60 °C for two days, and the root dry weights from individual phytomers (RDWp) were determined. Roots from the spring experiment were preserved in 70% ethanol and stored until the samples could be processed.In the autumn experiment, roots selected for scanning and WinRHIZO® software . Individual roots were placed in a clear acrylic tray and spread out using a needle so there were no overlapping roots. The roots were scanned on a flatbed scanner  at 210 dpi resolution. Values for root length  which included main axis and branches, surface area , volume , and mean diameter  were obtained. A set of old roots from both spring and autumn grown plants were also scanned to investigate the behaviour of fine root statistics. The total number of tips for individual roots (RTi) was counted using Videopro 32® software .In spring, roots from all phytomers and in autumn, the roots from even-numbered phytomers of the two selected plants were scanned . A totalThe roots kept in ethanol for scanning were rinsed in water and oven dried at 60 °C for 48 h. Dry weights were corrected by for an assumed 22.4% weight loss of alcohol soluble sugars during storage .Root dry weights were recorded for the individual phytomers (RDWp). From those data the mean dry weight of the individual roots (RDWi) was obtained as RDWp divided by number of roots per phytomer (Rp).−1 d−1) was estimated from the difference in root dry weight between that Pr and successively older Pr, assuming the age difference of roots at the successive phytomers was equal to the phyllochron at that Pr.DMDp (mg Pr−1), specific root surface area  and specific root volume  of the scanned roots were calculated as the ratio between the respective individual root data for each trait and dry weights for those particular individual roots (RDWi) at the different phytomer positions.The specific root length  at the different phytomers in succession moving down the tiller axis was scored by visual assessment of the root images. To obtain a branching score-sheet for all scanned roots, phytomer positions were numbered from Pr1 to Pr ‘n’ (where n is the oldest phytomer) on the As a measure of the extent to which branching and associated mean diameter reduction in older roots enabled greater soil exploration and absorptive area per unit of RDW, the ratios RL:RV and RSA:RV were derived. Dimension corrections of these ratios often used in plant allometry to separate effects of size and shape were not adopted in this study because grass roots at each successive branching order were considered to be cylindrical in form and of uniform diameter along their length.Data were analysed using the ‘repeat measures’ procedure in SAS version 9.4  Proc GLM ,49 to teTo test the effect of season, genotypes within season and phytomer positions within season a user-defined ANOVA model was applied see . To testA Pearson correlation analysis was conducted between roots per node and mean temperature for the period when root initiation occurred at that phytomer. A linear regression coefficient between root volume and root age up to 37 days was obtained.In conclusion, the data presented here have characterized perennial ryegrass root development over time in spring (with increasing day-length and temperature) and autumn (with decreasing day-length and temperature) using a phyllochron time scale. Surprisingly, while such data for leaf development at successive phytomer positions on the tiller axis have been available for over 40 years  the cor


Tropical forests cover 7% of the earth's surface and hold 50% of known terrestrial arthropod species. Alarming insect declines resulting from human activities have recently been documented in temperate and tropical ecosystems worldwide, but reliable data from tropical forests remain sparse. The sap-sucking tribe Athysanini is one herbivore group sensitive to anthropogenic perturbation and the largest within the diverse insect family Cicadellidae distributed in America's tropical forests. To measure the possible effects of deforestation and related activities on leafhopper biodiversity, a survey of 143 historic collecting localities was conducted to determine whether species documented in the Mexican dry tropical forests during the 1920s to 1940s were still present. Biostatistical diversity analysis was performed to compare historical to recent data on species occurrences. A data matrix of 577 geographical records was analysed. In total, 374 Athysanini data records were included representing 115 species of 41 genera. Historically, species richness and diversity were higher than found in the recent survey, despite greater collecting effort in the latter. A strong trend in species decline was observed (−53%) over 75 years in this endangered seasonally dry ecosystem. Species completeness was dissimilar between historic and present data. Endemic taxa were significantly less important and represented in the 1920s–1940s species records. All localities surveyed in the dry tropical forest are disturbed and reduced by modern anthropogenic processes. Mexico harbours highly endemic leafhopper taxa with a large proportion of these inhabiting the dry forest. These findings provide important data for conservation decision making and modelling of distribution patterns of this threatened seasonally dry tropical ecosystem. Theseet al. [Arthropods are the most diverse inhabitants of tropical forests but remain among the least studied, although growing evidence suggests that they have suffered dramatic declines worldwide . Unfortuet al. ). No attArthropod species diversity in the SDTF remains inadequately studied with available data mostly scattered among disparate taxonomic papers and in museum collections. Within this seasonal ecosystem, insects are diverse and highly endemic ,15. AmonThe SDTF occupies 11.26% of the land area of Mexico, equivalent to 33 million hectares . It is aTo provide an initial assessment of biodiversity loss in arthropod fauna of Mexican SDTF, this study had the following objectives: (i) compare the numbers of athysanine leafhopper species and genera associated with the SDTF during the 1920s–1940s to those present today; (ii) assess changes in species composition between DeLong's original collections and taxa presently occurring in the same areas; and (iii) document current athysanine leafhopper biodiversity and provide an overview of vegetation fidelity in the threatened SDTF ecosystem. This study represents the first attempt to compare recent and historical levels of leafhopper biodiversity in a tropical forest ecosystem.. 2. 2.1This study was conducted mainly over the historic distributional area of the SDTF in Mexico in the states of Sonora, Jalisco, Sinaloa, Michoacán, Guerrero, Tamaulipas, San Luis Potosi, Morelos, Estado de Mexico, Oaxaca, Chiapas, Puebla and Yucatan. This ecosystem is characterized by the presence of deciduous trees 4–10 m in height distributed in humid and sub-humid tropical climate zones with mean temperatures ranging from 20 to 29°C and annual precipitation of 300 to 1200 mm, from sea level to 1800 m.a.s.l., with a dry seasonal period of four to eight months . This research focused on herbivorous insects of the leafhopper tribe Athysanini   because . 2.2Leafhopper surveys during the 1920s in Mexico were primarily conducted by running a prototype light trap by Alfonso Dampf and all material collected were eventually dispersed into international collections . Later, During this study, new sampling expeditions in Mexico were undertaken using the same collecting methods used in the 1940s, but sampling was more intensive, with multiple 15-day trips covering all seasons made between 2010 and 2020 (inclusive). Sweep sampling was conducted for 10 h during the day followed by 6 h of light trapping during each 24 h period. Our recent sampling covered a larger number of individual sites than in the historic sampling, with most historic and recent sites revisited multiple times. Special efforts were made to intensively sample DeLong's and Dampf's type localities with more than 10 h in 10 continuous days devoted to each of these localities and surrounding areas with similar vegetation also sampled.. 2.3Databasing was conducted in two phases. First, all historical locality records (1920s–1940s) were georeferenced and compiled based on published records and specimens deposited in the following collections: Colección Nacional de Insectos del Instituto de Biología, Mexico (CNIN), Colección de Auchenorrhyncha de Jorge Adilson Pinedo-Escatel, Zapopan, Jalisco, Mexico (CAJAPE), Triplehorn Collection, USA (OSUC), Illinois Natural History Survey, USA (INHS), and National Museum of Natural History, USA (NMNH). Second, recent records were added, including collections made during 1995, 2001 and 2005 by C. H. Dietrich and colleagues, and new collections by the first author made continuously from 2010–2020 . A totalBursera spp., Lysiloma spp., Ipomoea spp., Ceiba aesculifolia, Acrocomia aculeata, Neobuxbaumia spp., Pachycereus spp. and Vachelia spp. (full habitat characterization in Rzedowski [Adult leafhoppers were collected using two methods: (i) direct catch using an entomological sweep net 37 cm in diameter and 72 cm in depth by 800 continuous sweeps on average per collection event and (ii) a light trap equipped with a 400 W metal additive bulb and 100 W black light running 6 h at night starting from twilight. Both methods used, sweep net and light trap, were conducted in areas with key-indicator SDTF vegetation, e.g. zedowski ). Materizedowski , Rakitovzedowski  and Dmitzedowski .. 2.4Is = 2c/(a + b), was used to evaluate variables in a and b are species (or genera) present in samples A  and B (present), respectively, and c are the species shared by both historical and present samples. Similarity values range from 0 when there are no shared species and a value of 1 represents identical species composition [Exploratory analyses were performed on the two data matrices resulting from the two phases of databasing described above. Analyses used the following variables: endemic species, species number, genera number, abundance obtained per species and total leafhopper abundance. A normality test by Shapiro–Wilk and a Wilcoxon test to determine significant differences among variables as shown in position . Analyseposition .Table 1. 2.5qgis software. The resulting occurrence points were coupled and fitted with the current and historical known distributional area of the SDTF in Mexico according to the Comisión Nacional para el Conocimiento y Uso de la Biodiversidad [Geospatial sampling points of the historic and recent leafhopper surveys were mapped using versidad .. 3In total, 577 geographical occurrence records were obtained, of which 374 Athysanini leafhopper records were included, comprising 115 species and 41 genera .Figure p = 2.20 × 10−16) and genera (p = 1.13 × 10−10) between the 1940s and the present . By contrast, Sorensen's index shows similar proportions of endemic species between the historic and present surveys but a substantially higher proportion of endemic genera in the recent survey . Most species were documented in both surveys (Cocrassana sexvarus (DeLong) and Crassana marginella DeLong & Hershberger, were more abundant in the recent samples than in the historic collections, possibly due to the greater sampling effort of the recent surveys. However, despite the greater sampling effort and coverage of collecting localities throughout the SDTF in the recent survey, several species recorded in the 1940s were not documented by our extensive recent surveys. For example, Ollarianus insignis DeLong was frequently collected during DeLong's surveys but was not encountered in our recent sampling. Less surprisingly, several other species that were rare in the historic collections, e.g. Tenuisanus costatus DeLong and Sanuca badia DeLong, were not encountered in our recent surveys, despite higher sampling effort and coverage, and may be extinct . Nevertheless, some new (undescribed) species not documented in the historical surveys were found in the recent survey and our study of DeLong's collection also indicates that he sometimes lumped multiple morphologically distinct species together under a single name [Tropical forests are peculiar ecosystems that often comprise species-rich and highly endemic communities within small geographic areas . We repo surveys , and a fgle name . Our docDeclines in leafhopper species and genus richness documented here are similar to those documented in the temperate zone of Britain for carabid beetles  and largThe SDTF has a limited distribution in the Neotropics as a result of various historic events and climatic changes during the Pleistocene . The MexDespite our increased sampling effort compared with the historical surveys, we recovered fewer leafhopper species. Only 47% of the total species recorded from Mexico were observed in this study between 1995 and 2020. Both the historical and recent surveys identified several sites with high species occurrence, such as the Iguala locality containing 72 records (21.12%) of 49 species and 21 genera. Most other leafhoppers recorded (approx. 50%) occurred near these local ‘hotspots’.b,e). A large percentage of the original forest has been replaced by secondary vegetation, pastureland for livestock, or has been completely deforested during the past 20 years (figure 8b) [Forest and insect diversity losses are an unfortunate reality of our modern age. Improved understanding of species declines and how they relate to forest fragmentation and loss will be key to understanding responses of a threatened ecosystem to increased anthropogenic pressure . Declinefigure 8gure 8b) ,54. As sAcunasus spp., Cozadanus spp., Retusanus spp., etc.) (a) over the past century. Several species have not been reported since they were originally described by DeLong, and recent sampling in the areas where they were first reported  as well as in other areas of the Mexican SDTF, failed to provide evidence that they still exist. In some cases, the original localities no longer support native SDTF vegetation and have been converted to agricultural monocultures or urban neighbourhoods (d). Clearly, a significant species decline has occurred over 75 years and this may be attributable to habitat loss.Changes in occurrence patterns of athysanine leafhoppers in the SDTF show significant reductions and losses of species and even genera  a over thourhoods d. Clearlb). The information generated provides the first conservation assessment of this possibly endangered component of the biota. Our results may be indicative of similar declines in other insects and reflect an overall ongoing threat to the SDTF biota.The 354 georeferenced collecting events in the Mexican SDTF strongly indicate that this ecosystem historically supported a rich and highly endemic fauna of athysanine leafhoppers . The present study provides, for the first time, precise geographical coordinates  documenting the presence of populations of this insect fauna and indicates areas where species reported in the 1920s–1940s are still extant b. The inClick here for additional data file.


A shape memory polymer was prepared by melt mixing a semicrystalline maleated polyolefin elastomer (mPOE) with a small amount of polyaniline (PANI) (up to 15 wt.%) in an internal mixer. Transmission electron microscopy (TEM), FTIR analysis, DMA, DSC, melt rheological analysis, and a tensile test were performed to characterize the structure and properties of the mPOE/PANI blends. The results revealed that the blends form a physically crosslinked network via the grafting of PANI onto the mPOE chains, and the PANI dispersed at the nanometer scale in the POE matrix served as a photo-thermal agent and provided increased crosslinking points. These structural features enabled the blends to exhibit a shape memory effect upon near-infrared (NIR) light irradiation. With increasing PANI content, the shape recovery rate of the blend under NIR stimulation was improved and reached 96% at 15 wt.% of PANI. A shape memory polymer (SMP) is a smart material that can memorize its original shape and recover to its original shape from temporarily fixed shapes, and responds to various types of external stimuli, such as heat, light, water, and electric or magnetic fields. Compared to metallic shape memory alloys, SMPs have several advantages, including low density, good processability, high deformability, biocompatibility, as well as easy control of transition temperature, which make these materials have various applications ,2,3,4,5.Among the various types of SMPs, light-responsive SMPs have gained interest due to several advantages they possess over conventional, thermally activated SMPs, such as remote activation ability and spatial controllability . The mosConjugated polymers, such as polyaniline, polypyrrole, and polythiophene, show strong absorption of near-infrared energy, and transform it into thermal energy with high efficiency, which enables them to be used in photothermal therapy ,21,22,23PANI, which has a sulfonic acid group on its aromatic ring, is of particular interest, since it has a self-doped structure without the addition of any external dopants and exhibits strong absorption in the near-infrared (NIR) region ,28,29, wSemicrystalline maleated polyolefin elastomer  was procured from DuPont . Aniline-3- sulfonic acid  and ammonium persulfate  were purchased from Sigma-Aldrich . Pyridine and acetone were procured from Junsei Chemical Co., Ltd. .Polyaniline (PANI) was synthesized by oxidative chemical polymerization using ANISA as a monomer and APS as an oxidant as reported in the literature . BrieflymPOE/PANI blends with 3, 5, 10 and 15 wt.% PANI were prepared by melt blending in a Haake mixer  for 10 min at 180 °C with a rotor speed of 60 rpm. The resulting mixtures were then molded as sheets by using an electrically heated hydraulic press at 180 °C for 10 min.Phase morphology of the blends was examined using transmission electron microscopy (TEM), with a JEOL 200CX TEM with an acceleration voltage of 200 kV. Ultra-thin sections were cut from the compression-molded specimens with a thickness of 100 nm using a Reichert ultracut cryo-microtome.−1 under nitrogen atmosphere. The empty sample chamber and ATR stage were used to obtain the background spectra.FTIR analysis was carried out using Bucker ALPHA spectrometer , equipped with an attenuated total reflectance (ATR) accessory, to characterize the PANI, and evaluate the possible interactions between the mPOE and PANI as well. The sample was placed on the ATR sample holder. The number of scans for each spectra was 16. The FTIR spectra were obtained in the range of 2000–700 cmDynamic mechanical tests were carried out using a dynamic mechanical analyzer . Samples were subjected to a cyclic tensile strain with an amplitude of 0.2% at a frequency of 1 Hz. The temperature was increased at a heating rate of 10 °C/min over the range from −100 to 150 °C.Thermal properties of the samples were examined by using a differential scanning calorimeter . Samples were first heated from 30 to 200 °C at a rate of 10 °C/min under a nitrogen atmosphere and were kept for 5 min at this temperature to remove prior thermal history. The samples were then cooled down to −50 °C at a cooling rate of 10 °C/min (cooling scan), and were reheated to 200 °C at the same heating rate (second heating scan).Tensile properties of the samples were measured by using a universal testing machine  with a crosshead speed of 50 mm/min. The test was repeated at least five times at room temperature for each sample. Melt rheological measurements were conducted on an MCR 102 rheometer . Dynamic oscillatory shear measurements were performed at 180 °C using parallel plate geometry with a plate diameter of 25 mm and 1–2-mm-thick samples. The dynamic frequency sweep test was carried out between 0.1 and 100 rad/s. 2 positioned at 30 cm from the sample. An infrared (IR) lamp with a red filter  was used as a light source. Photothermal effects of the blend were examined by measuring the surface temperature of the NIR-exposed sample using a digital thermometer during the NIR irradiation of the sample with 805 nm NIR at power density of 1.0 W/cmTm of the sample) followed by cooling the deformed shape to 0 °C. Then, the temporarily deformed samples were exposed to NIR irradiation to analyze the shape recovery. The shape fixing ratio (Rf) and shape recovery ratio (Rr) of samples were determined by the following equations:Li denotes the initial gauge length of the sample, Lu denotes the stretched length under load (1.5 × Li in this experiment), Ls denotes the stretched length without load, and Lr denotes the recovered length upon NIR exposure, respectively. Shape memory behavior of the samples was evaluated using dog-bone-shaped specimens with a thickness of about 1 mm. Temporarily fixed sample was obtained by uniaxial deformation of the specimen to 50% at 70 °C , whereas the modulus of mPOE/PANI blends keeps quite stable up to 200 °C. Such a persistent modulus indicates that the blends form a crosslinked structure, which was obtained via the chemical reaction between the mPOE and PANI in the blends, as was confirmed by FTIR analysis. Tm) and heat of fusion (ΔHm) with the composition of the blends, and those values and the associated degree of crystallinity (χc) of the samples are listed in Hm per gram of mPOE obtained from DSC measurements and the ΔHm corresponding to 100% crystalline low-density polyethylene (LDPE) (293 J/g) [Tm and χc of the mPOE phase of the blends were continuously decreased upon increasing the PANI content in the blends. This suggests that the ordered crystalline structure of the semicrystalline mPOE was disturbed in the mPOE/PANI blends due to the formation of a crosslinked structure, which caused a decrease in the molecular mobility of the POE chains, and, thus, the crystallization is restricted, as manifested by the decrease in Tm and χc [DSC analysis was performed to observe the variation in melting temperature (293 J/g) . As illum and χc ,37.The stress–strain curves of neat mPOE and the mPOE/PANI blends are shown in It was observed that the blends are melt processable, even though they form a crosslinked structure, which suggests that the blends formed a physically crosslinked structure. In order to observe the effect of blend composition on melt rheological properties, melt viscosity was measured as a function of frequency by an oscillatory rheometer, and the results are presented in 2). A photothermal effect occurs when the exposed light is absorbed by a substance and is converted into thermal energy, thereby increasing the substance temperature. The photothermal effect of the samples was observed by measuring the surface temperature under irradiation of NIR light (1.0 W/cmRf) and shape recovery (Rr), calculated according to Equations (1) and (2), respectively, are shown in Rr increased with increasing PANI content in the blends, and reached 96% for the blend with a PANI content of 15 wt.%. The improved shape recovery of the blends with a higher PANI content is ascribed to the increased crosslinked points, as well as the higher photothermal effects, as shown in the sections above. When the blend sample was deformed under a tensile load above its Tm, elastic energy was stored during this deformation. Photothermal heating led to the melting of the crystalline domains of the temporarily fixed sample, and the polymer chains recovered to its original shape by releasing the stored energy. As discussed above, the mPOE/PANI blends formed a crosslinked structure via the chemical reaction between PANI and semicrystalline maleated POE, and the modulus in the plateau region, which is related with crosslink density, increased with increasing PANI content. Further, the mPOE/PANI blends exhibited higher photothermal behavior with increasing PANI content. These results indicate that PANI acted as a crosslinking agent for the semicrystalline elastomer, as well as a photothermal nanoheater. These structural features of the blends enable them to exhibit shape memory behavior, i.e., crosslinked points stabilize the permanent shape, and a reversible phase, which has a crystalline melting transition, serves as a switch. A tensile recovery test was used to evaluate the light-induced shape memory effects of the samples. Shape recovery was observed to occur when the temporarily fixed specimen was exposed to NIR light, and the results are demonstrated in This study demonstrated that an NIR light-responsive shape memory elastomer can be fabricated by simple melt blending of a maleated semicrystalline polyolefin elastomer, with a small amount of polyaniline. Studies on phase morphology, thermo-mechanical analysis, and melt rheological analysis revealed that the blends formed a physically crosslinked semicrystalline polymer network, and the polyaniline nanodomains dispersed in the semicrystalline POE matrix acted as photothermal agents, as well as crosslinked points. Due to photothermal heating by the PANI nanoparticles, the crosslinked blends exhibited shape memory effects under NIR light irradiation. This novel shape memory elastomer may have potential applications, such as in remotely and spatially controllable soft actuators and grippers.


Bos taurus taurus × Bos taurus indicus hybrids using Brahman as the B. t. indicus source. By 1954, U.S. Breed Associations had been formed for Brangus (5/8 Angus × 3/8 Brahman), Beefmaster (½ Brahman × ¼ Shorthorn × ¼ Hereford), and Santa Gertrudis (5/8 Shorthorn × 3/8 Brahman). While these breeds were developed using mating designs expected to create base generation animals with the required genome contributions from progenitor breeds, each association has now registered advanced generation animals in which selection or drift may have caused the realized genome compositions to differ from initial expected proportions. The availability of high-density SNP genotypes for 9,161 Brangus, 3,762 Beefmaster, and 1,942 Santa Gertrudis animals allowed us to compare the realized genomic architectures of breed members to the base generation expectations. We used RFMix to estimate local ancestry and identify genomic regions in which the proportion of Brahman ancestry differed significantly from a priori expectations. For all three breeds, lower than expected levels of Brahman composition were found genome-wide, particularly in early-generation animals where we demonstrate that selection on beef production traits was likely responsible for the taurine enrichment. Using a proxy for generation number, we also contrasted the genomes of early- and advanced-generation animals and found that the indicine composition of the genome has increased with generation number likely due to selection on adaptive traits. Many of the most-highly differentiated genomic regions were breed specific, suggesting that differences in breeding objectives and selection intensities exist between the breeds. Global ancestry estimation is commonly performed in admixed animals to control for stratification in association studies. However, local ancestry estimation provides the opportunity to investigate the evolution of specific chromosomal segments and estimate haplotype effects on trait variation in admixed individuals. Investigating the genomic architecture of the American Breeds not only allows the estimation of indicine and taurine genome proportions genome-wide, but also the locations within the genome where either taurine or indicine alleles confer a selective advantage.Development of the American Breeds of beef cattle began in the 1920s as breeders and U. S. Experiment Station researchers began to create  Bos taurus indicus Brahman . Breed Associations for the American Breeds began to be formed in the 1940’s and advanced generation composite animals now exist for the older Brangus, Beefmaster, and Santa Gertrudis breeds.Indicine cattle were first imported into the United States from India in 1906 and then from Brazil in the 1920’s and were used via crossbreeding with taurine cattle and backcrossing to develop the  Brahman  which has genome . The Ame country . Indicin country  and the B. t. taurus) and Brahman cattle in Oklahoma, Mississippi, Texas, and Louisiana in the 1930’s and have been stabilized at an expected genome content of ⅜ Brahman and ⅝ Angus (http://afs.okstate.edu/breeds/cattle/brangus/index.html/). The American Brangus Breeders Association was formed in 1949 but was later renamed the International Brangus Breeders Association (https://gobrangus.com/jan-17-bj-con-lilley/). Santa Gertrudis cattle were initially developed on the King Ranch in Kingsville, Texas, where experimental crossbreeding between Shorthorn (B. t. taurus), and Brahman cattle between 1910 and 1920 led to the birth of the bull “Monkey” from which all registered Santa Gertrudis cattle descend (http://afs.okstate.edu/breeds/cattle/santagertrudis/index.html). However, the utilized Brahman bulls ranged in composition from ¾ to ⅞ B. t. indicus and, consequently, the Santa Gertrudis breed is considered to have a composition of ⅜ Brahman and ⅝ Shorthorn (B. t. taurus) on the Lasater Ranch in Falfurrias, Texas and are now maintained at an expected pedigree proportion of ½ Brahman, ¼ Hereford, and ¼ Shorthorn  in admixed individuals, however, these applications have primarily been focused on recently admixed populations. Individuals from admixed populations have chromosomes that comprise mosaics of chromosomal segments originating from each of the ancestral populations . On the Genotype data were obtained for deidentified individuals from the International Brangus Breeders Association, Beefmaster Breeders United, and Santa Gertrudis Breeders International Breed Associations (American Breed Associations) . These iLocal ancestry estimation requires a reference panel of genotypes for representatives of each ancestral population. We developed two reference panels for each American Breed. The first panel was identical for all three breeds and comprised animals registered by the American Angus Association, American Hereford Association, American Shorthorn Association, and American Brahman Breeders Association for which CRUMBLER  breed co1, and back-cross animals used to create first generation registered animals to enable a complete pedigree based on consistent registration numbers within their herdbook. To determine if some of these animals may have been genotyped and provided by the Breed Associations, we removed samples assigned by CRUMBLER to be ≥ 50% Brahman or ≥ 90% Angus or Shorthorn ancestry from the Brangus and Santa Gertrudis data, respectively . For the Beefmaster, we removed samples with ≥ 90% assignment to Shorthorn, Hereford, or Brahman to remove potential purebred founders and any samples with ≤ 5% assignment to any one of these breeds to remove potential F1 individuals (n = 10).Many of the American Breed Associations allow the registration of the purebred, FN = 58) of each animal and the average length of all haplotypes within the diploid genome. Under the assumption of selective neutrality, the number of haplotypes within the genome should increase each generation due to recombination and correspondingly, the average length of the haplotypes should decrease each generation. Purebred and F1 animals have 58 haplotypes represented as full length chromosomes and assuming an average of one crossover per chromosome pair each meiosis, back-cross (Purebred × F1) animals have, on average, 87 haplotypes which average ¾ of the chromosome length and F2 (F1 × F1) animals have, on average, 116 haplotypes which average ½ of the chromosome length.Genotypes used in this study were provided by the American Breed Associations with each animal’s identity anonymized and without pedigree or generation information. Since selection operates each generation, the cumulative effects of selection on a composite genome should increase with generation number. To enable the stratification of the animals within each American Breed based on generation number, we utilized the RFMix output to compute the total number of taurine and indicine haplotypes present within the diploid autosomal genome (2ith window within the genome we tested the null hypothesis that Ho: ith window. The parameter 1 × Purebred crosses (¾ taurine × ¼ indicine) which were then randomly mated to independently sampled F1 individuals. The first-generation animals were then randomly mated to produce 1,000 s generation individuals and so on for 8 generations of random mating. Ten replicate simulations were performed and within each replicate, 1 genomes (½ taurine × ½ indicine). Estimates of p-values proposed by https://www.animalgenome.org/cgi-bin/QTLdb/BT/search; Within each of the American Breeds, for the Within each of the American Breeds, we sampled ∼10% of individuals with the smallest and largest number of haplotypes with their genomes to characterize early- and advanced-generation individuals, respectively. Sampling was such that all animals within a haplotype number class were included resulting in slightly unequal sample sizes. There were 918, 207, and 400 animals in the early- and 955, 213, and 423 Brangus, Santa Gertrudis, and Beefmaster animals in the advanced-generation groups, respectively.ith window within the genome, we tested the null hypothesis that Ho: ith window Brahman proportions within the early- and advanced-generation individuals within the breed, which are estimated by the sample proportions p-values at a FDR For the RFMix generates three output files for each analysis: 1) the most likely reference population assignments for each haplotype found in a window, 2) the marginal probabilities of each reference population being the ancestral population of origin for the haplotypes found in the window, and 3) global diploid ancestry estimates . We utilFollowing the strategy employed by Since RFMix concatenates contiguous windows with the same ancestry to form extended haplotypes within individuals and considering the large number of SNPs used in this study, we were interested in whether a window size of 25 SNPs would impact the analysis in terms of resolution near recombination breakpoints or the ability to discriminate between haplotype breed of origin. Using the RFMix output for all samples provided by the American Breed Associations , we estiThe correlation between the number of Angus and Brahman haplotypes in each Brangus individual was 0.80, while the correlation between the number of Shorthorn and Brahman haplotypes in each Santa Gertrudis individual was 0.73. This follows our expectation that the total number of haplotypes from each of the foundation breeds increases in advanced generation animals due to recombination. However, the correlation between the number of Brahman and taurine (Shorthorn and Hereford) haplotypes in each Beefmaster individual was only 0.40. The correlation between the number of Brahman and Hereford haplotypes was 0.50 while the correlation between the number of Brahman and Shorthorn haplotypes was −0.11 suggesting that other forces such as selection may be influencing the evolution of the Beefmaster genome.The average Brahman genome content was 25.81 ± 8.01%  for Brangus and 27.60 ± 7.05% for Santa Gertrudis , far lesX-axes and see 10p = 3.0527 for Brangus, 3.0506 for Santa Gertrudis, and 3.0193 for Beefmaster. Using these values, 88.6% of tests performed for Brangus, 85.2% for Santa Gertrudis, and 95.2% for Beefmaster were significant. Values of the −log10Pi values for each American breed are plotted according to their chromosomal coordinates in Nominal significance thresholds to achieve a FDR <0.001 using the The 5 most differentiated windows for Brahman genome content within each of the American breeds are in p < 3.13E-23), Santa Gertrudis (p < 0.0002), and Beefmaster (p < 0.0012) individuals, respectively.The average number of haplotypes was 112.10 ± 9.03, 125.21 ± 11.16, and 103.60 ± 4.25 within the early-generation and 177.06 ± 5.12, 172.28 ± 5.13, and 140.71 10p = 3.0317 for Brangus, 3.2030 for Santa Gertrudis, and 3.2399 for Beefmaster. Using these values, 91.23% of tests performed for Brangus, 62.61% for Santa Gertrudis, and 57.46% for Beefmaster were significant. The Brahman proportion was greater in the advanced-generation animals for all significant regions in Brangus and Santa Gertrudis and for 93.84% of the significant regions in Beefmaster. Values of the −log10Pi values for each American breed are plotted according to their chromosomal coordinates in Nominal significance thresholds to achieve a FDR <0.001 using the The 5 most differentiated windows for Brahman genome content between early and advanced-generation animals within each of the American Breeds are in Reference panel sample sizes have been shown to have significant effects on the accuracy of RFMix estimates . ReferenTo examine genome evolution in these breeds, we utilized the total number of haplotypes present within the genomes of the animals as proxy for the generation number of the animal. Under selective neutrality we would expect the number of taurine and indicine haplotypes present within individuals to increase with generation number due to recombination among homologous chromosomes at each meiosis. Indeed, we found quite strong correlations (70–80%) between the numbers of indicine and taurine haplotypes within Brangus and Santa Gertrudis, but less so (50%) in Beefmaster. Strong selection for alleles found predominantly in one of the breeds will reduce the strength of this correlation and reduce the accuracy of the proxy for the prediction of generation number. However, we did not have any animals with known generation numbers with which to directly validate the utility of the proxy. Moreover, the results for Beefmaster may have been affected by our use of the most likely breed of haplotype origin, an absolute assignment, rather than the marginal probabilities of breed assignment. If the marginal probabilities of haplotype assignment to Shorthorn and Hereford are similar, but tend to favor one breed throughout the genome, we could see large differences in predicted Hereford and Shorthorn proportions genome-wide when, in fact, this is an artifact, and the true differences genome-wide are small. This would also artificially impact the correlations between taurine and indicine haplotype numbers in Beefmaster.https://gobrangus.com/tperkins-breeding-up/). Despite this, the two interesting features of these plots are that the proportions of Brahman within all three of these breeds are far less than would be expected based upon the mating schemes used to produce the animals, and the proportion of Brahman within the genomes of advanced generation animals is consistently increasing supporting our results from the direct comparison of early- and advanced-generation animals. Our interpretation of these results are that breeders of American Breed cattle select very strongly for performance and type  characteristics, particularly in early generation animals, resulting in a selective advantage for taurine alleles which creates widespread linkage drag throughout the genome dramatically reducing the Brahman content. However, in advanced-generation cattle, selection emphases change towards adaptive alleles  favoring indicine alleles. In the Beefmaster, the increase in Brahman genome content in advanced-generation animals appears to be primarily at the expense of the Shorthorn content  and to have solid black or red coat colors. Santa Gertrudis cattle may be horned or polled, with a light or dark solid red coat color preferred; roan (red coat with white patches) or white outside the underline or other spotting in other parts of the body disqualifies an animal from registration. Beefmaster cattle may be horned or polled and while brownish-red is the most common color, the breed has no color standards. Brahman cattle are primarily horned and have complex coat colors that can range from solid gray to brindled. Angus are polled due to the autosomal dominant mosome 1  and haveat KITLG  located mosome 6 . QTL asse 6  and Shorthorn alleles , respectively. These windows were among the 5 most differentiated windows for Brahman genome content in both breeds , Brahman alleles in Santa Gertrudis , and Brahman alleles in Beefmaster . This suggests that selection has occurred for solid coat color patterns in all three breeds for both aesthetic and economic reasons due to losses caused by ocular squamous cell carcinoma, which is most common in Hereford animals that lack pigment around their eyes  in Beefmaster. The window detected in Santa Gertrudis was almost 6 Mb from those found in Brangus and Beefmaster, but Longissimus Dorsi Muscle Area  and MSRB3 . In human, HMGA2 has been associated with 62 traits , including body height, birth weight, systolic blood pressure, brain cortical volume, intelligence, and insomnia. Brahman females are known to suppress the birth weight of their calves  including brain cortical volume, snoring, lung function, height, and temperament. The window with the greatest Brahman ancestry in Santa Gertrudis overlaps CPNE8, associated with 14 human traits  including chronotype and circadian rhythm, IgG glycosylation, heart rate, and bipolar disorder. Consequently, this broad genomic region includes genes which may explain several of the physiological differences between B. t. taurus and B. t. indicus cattle, including birth weight, height, blood vessel morphology, hair morphology, disease resistance, and temperament.The genes closest to the windows with the greatest Brahman ancestry in Brangus and Beefmaster are r calves  to increB. t. taurus × B. t. indicus hybrid populations. We also collapsed database entries from the same author with separate QTL identities into a single QTL when they co-localized within the genome. For example, the query for chromosome 14 region retrieved 5 database entries for Birth Weight from https://www.animalgenome.org/cgi-bin/QTLdb/index; Accessed August 11, 2021). The bovine autosomal genome length is 2,489.39 Mb in the ARS-UCD1.2 bovine reference genome assembly and so if QTL are randomly located through the genome, we would expect to find an average of 64.98 QTL within each 1 Mb window. We retrieved an average of 61.25 ± 45.49 QTL or Association entries for 27.83 ± 12.07 traits within the 12 genomic windows in We queried CattleQTLdb for the remaining 12 loci in Two features of Ten of the regions in These results suggest that artificial selection on production traits practiced by breeders of American Breed cattle is responsible for the surfeit of taurine alleles at the 12 loci in Although statistical power was limited when comparing the Brahman content of the genomes of early- and advanced-generation animals due to the use of only ∼10% of the animals from each breed in each tail of the haplotype number distribution, these analyses clearly revealed that the Brahman proportion of the genome of these American breeds has increased with generation number and that this increase has occurred almost genome-wide.p = 3.88E-55), indicating that the selected loci in these regions impact traits that have not been well studied in cattle, suggesting that they may have roles in environmental adaptation. Second, the locus on chromosome 6 at 71.5 Mb in Beefmaster supports our conjecture that Beefmaster breeders have selected for solid coat colors in advanced-generation animals, despite the fact that the breed does not have coat color standards. Finally, if we remove the locus on chromosome 6 at 71.5 Mb in Beefmaster, 11 of the 12 genomic regions with identified QTL harbor QTL that influence heat tolerance or animal health, immune response, parasite burden or disease susceptibility. The probability of 11 or all 12 regions harboring disease or parasite CattleQTLdb entries reduces to 0.18. These results suggest that these genomic regions have been selected to increase the proportion of Brahman alleles because they confer an adaptive advantage in American Breed cattle.There are several interesting features of B. t. taurus × B. t. indicus hybrid cattle that were developed to capitalize on breed complementarity and heterosis to produce cattle that were suited to harsh, subtropical climates as well as disease and parasite threats, while still maintaining acceptable levels of growth and productivity. The breeds employed mating systems designed to produce cattle that were either ⅝ taurine and ⅜ indicine (Brangus and Santa Gertrudis) or ½ taurine and ½ indicine (Beefmaster). However, we found strong evidence that selection for polledness, coat color phenotypes, growth, calving ease, and intra-muscular fat content produced early-generation cattle with much smaller than expected indicine composition within the genomes of all three breeds. At least 85% of the genomes within each of the breeds possess less Brahman ancestry than expected in the absence of selection and drift. We utilized the total number of haplotypes predicted by RFMix in the diploid genome of each animal as a proxy for the generation number for each animal and when we ranked animals based on this proxy, we detected an increase in the Brahman genome content in advanced-generation cattle of all three breeds. By comparing the genomes of early- and advanced-generation animals within each breed, we found evidence for strong selection for indicine alleles which likely confer an adaptive advantage for heat tolerance and healthfulness in advance-generation animals.The American breeds are advanced generation


Bemisia tabaci that transmits two diseases that in combination with the direct feeding damage cause significant yield losses. Land-use changes due to crop rotations can impact pest dynamics but not much is known about these processes in dynamic smallholder production landscapes. This study investigated how seasonal land-use changes impacted B. tabaci and its parasitoids in an agricultural landscape in Uganda using a semi-manipulative field-experiment on smallholder farmers land. The dominant species of B. tabaci on cassava was Sub-Saharan Africa 1 (SSA1), which was also found on some other surrounding crops and weeds. The highest abundance of B. tabaci SSA1 nymphs in cassava fields occurred at times when landscapes had large areas of weeds, low to moderate areas of maize, and low areas of banana. These results are important to guide the development of land-use strategies that smallholder farmers can employ to manage whitefly pests.Cassava is one of the most important subsistence crops for smallholder farmers in East and central Africa. Cassava is increasingly infested by the whitefly Manihot esculenta Crantz), an important commercial and food security crop in East and Central Africa, continues to be adversely affected by the whitefly Bemisia tabaci. In Uganda, changes in smallholder farming landscapes due to crop rotations can impact pest populations but how these changes affect pest outbreak risk is unknown. We investigated how seasonal changes in land-use have affected B. tabaci population dynamics and its parasitoids. We used a large-scale field experiment to standardize the focal field in terms of cassava age and cultivar, then measured how Bemisia populations responded to surrounding land-use change. Bemisia tabaci Sub-Saharan Africa 1 (SSA1) was identified using molecular diagnostics as the most prevalent species and the same species was also found on surrounding soybean, groundnut, and sesame crops. We found that an increase in the area of cassava in the 3–7-month age range in the landscape resulted in an increase in the abundance of the B. tabaci SSA1 on cassava. There was a negative relationship between the extent of non-crop vegetation in the landscape and parasitism of nymphs suggesting that these parasitoids do not rely on resources in the non-crop patches. The highest abundance of B. tabaci SSA1 nymphs in cassava fields occurred at times when landscapes had large areas of weeds, low to moderate areas of maize, and low areas of banana. Our results can guide the development of land-use strategies that smallholder farmers can employ to manage these pests.Cassava ( Invertebrate populations are influenced by a number of factors associated with both cultivated and uncultivated habitats in the landscape surrounding a target field . In largManihot esculenta Crantz) is an important commercial and food security crop in many African countries where it is also ranked as a number one staple crop [Cassava  have been increasing in abundance on cassava over the past 20 years [Bemisia species densities in Sub-Saharan Africa are limited, but cassava varieties that are resistant or tolerant to the diseases have been developed [Bemisia tabaci cryptic species alone have been reported to reduce cassava yields by 40% [Bemisia density. However, the density of Bemisia nymphs and the parasitism of nymphs were heavily influenced by landscape factors, including the size of the cassava field, and total area of cassava in the landscape. This therefore suggests that by understanding these relationship(s), we may be able to identify landscape factors that could be altered by farmers to reduce the risk of whitefly outbreaks and cassava diseases.The two major diseases of cassava, cassava mosaic disease (CMD) and cassava brown streak disease (CBSD), remain key factors limiting cassava production in Africa . These d20 years . Managemeveloped ,12. Regas by 40% . Biologis by 40% ,14,15,16s by 40%  that incBemisia species and their parastioids in cassava fields in Uganda. Whilst Macfadyen et al. [Bemisia species on cassava and other plants in the landscape. We address the following research questions: (i) does the area of cassava and cassava plant age in the landscape correlate positively, at any point in time, with Bemisia abundance in the focal field; (ii) what combination(s) of the dominant crop types in the landscape correlate positively with Bemisia species abundance in the focal field; (iii) does an increase in the area of semi-natural habitats lead to increased parasitism of Bemisia nymphs in the focal field and therefore a decrease in Bemisia abundance? The term “focal field” is used here to refer to the cassava that was experimentally planted in the landscapes and therefore standardized for age, cultivar, and source parameters as different from farmer-planted cassava fields found in the surrounding landscapes.In this study, we investigated how temporal changes in land-use across a season affect the abundance of n et al.  examinedB. tabaci species, and there are often no environmental extremes within a season to limit population growth [Landscape studies were undertaken in Kamuli district n growth .With permission from the landholders, cassava was planted in one-acre trial plots in 10 different landscapes in Kamuli district, namely, Bugaga-Bulogo (1A), Buganza-Kasozi (1B), Butamwa-Buluya (1C), Mukokotokwa (1D), Tibwamulala-Butansi (1E), Bukafuga-Namwendwa (2A), Buganza-Namusagali (2B), Butamwa-Buluya (2C), Kasana-Mbulamuti (2D), and Tibwamulala-Butansi (2E) Field boundaries and landscape features were digitized and entered on Android tablets using offline maps and satellite image base layers, authored in ArcGIS Collector  and the Bemisia and their parasitoids occurred fortnightly from one to four MAP, then monthly until 12 MAP. Data were collected using the open data kit  mobile data collection software  on predesigned electronic forms. Each plant was assigned a unique barcode that enabled easy cross-referencing of landscape, focal field, plant, and associated nymph and parasitoid data.The sampling of Bemisia adults, nymphs, and parasitoids on cassava were sampled on 30 randomly selected plants in each field at each time point (15 plants per variety). Adults were counted on the top-five fully expanded leaves per plant. For nymphs, an individual leaf (between the 8th and 10th positions) from lower down the stem with observable developed instars-at least 3rd instars, was collected, barcoded, packaged in a paper bag, placed in a cool box, and preserved for counting later in the laboratory. Nymphs were counted per leaf and categorized by instars  under a microscope. Parasitized and apparently healthy unparasitized nymphs were differentiated based on the position of mycetomes and the color changes in the nymphs. A parasitized nymph has displaced mycetomes while a healthy one has mycetomes directly opposite each other. Nymphs parasitized by Eretmocerus spp. have displaced mycetomes with shiny orange pupal skin (with pupae having red eyes), while those parasitized by Encarsia spp. have black pupal cases with brown meconia symmetrically located posteriorly on both sides. After counting individual nymphs under a microscope, the leaf was placed in an emergence container and incubated at room temperature for up to two weeks until the parasitoids or adult Bemisia emerged. The insects were placed in ethanol in a Petri dish and counted and identified under a microscope. Parasitoids were identified to genus level; namely Eretmocerus spp. and Encarsia spp. based on morphological characters [Bemisia adults or nymphs on these crops was recorded. A decision was made on the area to conduct the search based on the availability of potential host plants as well as other refugia  in the 100 m radius from the centroid of the focal field.aracters . OutsideBemisia individuals were collected at 2, 4, 6, 8, 10 and 12 MAP for molecular identification. Nymph samples were also from several other crop types at 2, 6, 10 and 12 MAP, all preserved in 95–100% ethanol and stored for DNA extraction later. In the laboratory, nymphs were removed from leaves and separated into parasitized or unparasitized groups with the aid of a dissecting microscope. Unparasitized nymphs were counted into groups of 20 or 40 individuals representing individual populations and placed in individual sterile 1.5 mL Eppendorf tubes with 1 mL of >95% ethanol and stored at –18 °C until the DNA extraction stage. We used nymphs rather than adults for genomic (gDNA) extraction in order to link recovered nymphs to their plant hosts. Nymphs determined under microscope to be unparasitized may in actual fact have included some that were in early stages of parasitism . These individuals will have both whitefly and parasitoid DNA to enable Bemisia and parasitoid species identification by mitochondrial DNA cytochrome oxidase subunit I (mtCOI) sequence characterization.In the focal cassava fields, nymphs (on leaves) and adult Nymphs were dried briefly (5–10 min) at 56 °C to remove all traces of ethanol and gDNA was extracted from nymph populations using a Qiagen Blood and Tissue DNA extraction  kit and followed the protocol as provided, and 4 µL RNase A  was added to remove RNA. Extracted gDNA was eluted twice in 100 µL  of Elution Buffer (EB) (Qiagen). For downstream high throughput sequencing (HTS) of amplicon, we followed the protocol of Tay et al. .Bemisia species was amplified using specific HTS primer pairs [Bemisia species using reference sequences for Sub-Saharan Africa (SSA)1, SSA2, MED, IO and for pseudogene detection [Eretmocerus and Encarsia parasitoids were identified using the reference sequences , prior to species identification against curated sequences in GenBank.The concentration of individual gDNA samples was quantified and standardized to 5 ng/µL using EB buffer and kept at –18 °C until it was needed for PCR amplicon DNA library preparation for Illumina MiSeq NGS. The desired 3′ partial mitochondrial DNA cytochrome oxidase subunit I (mtCOI) gene widely used in molecular diagnostics of er pairs . Amplicoer pairs  and analer pairs  using thetection . Detecti2) of each land-use type was calculated as well as the percentage cover of each land-use in the 100 m radius circle. To establish the effect of cassava age, we further classified cassava patches into 3–7 MAP, ideal for Bemisia growth and development or most suitable cassava; 0–3 MAP, young/less suitable cassava; greater than 7 MAP, old/least suitable cassava based on Sseruwagi et al. [The identity of land-use types present in each landscape (composition) was established while the amount (proportion) of each was calculated in Fragstats version 4.2 by taking the absolute area of each land-use type relative to the total area of the landscape . We devei et al. .Bemisia nymphs per field at each time point; for the research question (iii), we used the percentage parasitism of Bemisia nymphs per field at each time point. Percentage parasitism at the field-level was calculated as the sum of parasitized Bemisia nymphs divided by the total sum of Bemisia nymphs counted from that field, expressed as a percentage. The explanatory variables were age of cassava (MAP) and a site identifier, and the landscape factors relating to each of the crop and non-crop components of the landscape  using MAP as a covariate and using the “lm” function in the R “stats” package. For research question 1 (where the focus was cassava) and 3 , we used individual crop types in the models. For research question 2, we used two approaches; the ANCOVA that focused on individual crop types and the cluster analysis that focused on combinations of crop types . We also established (by Spearman’s rank correlation) the relationship between the different crop types and Bemisia nymph abundance in cassava. All the analyses were conducted in R 3.5.0 [We calculated response variables from our sampling data. For the research question (i) and (ii), we used the sum of andscape . We chec R 3.5.0 .We used cluster analysis  based on the similarity of responses to different landscape variables) as implemented in the “Class Discovery” data package in R. The clustering was done hierarchically (hclust function) using Ward’s method  that joiBemisia and percent parasitism. A finer definition of cassava age was used in the cluster analysis. Four groups were identified: 1–2.5 MAP (“1early”), 3–5 MAP (“2peak”), 6–8 MAP (“3mid”), and 9–12 MAP (“4late”). We used the counts of Bemisia nymphs rather than adults (which move between plants) in analysis which were log (x + 1) transformed while counts of parasitized nymphs were log (x + 0.1) transformed prior to analysis.Based on the minimum distance of the initial cluster, the 30 field time points in the landscape were grouped into seven clusters  clean Bemisia sequences from the 93 cassava populations sequenced representing 2842 nymphs, with <3% unidentified sequences in the majority of populations. The dominant Bemisia species found on cassava in the different landscapes was the B. tabaci Sub-Saharan 1 species . The soybean Bemisia populations produced 148,810 and 164,843 clean reads with 97.7% and 98.2% assembled mtCO1 gene sequences matching to the SSA1 species, respectively.We analyzed 93 Bemisia species within the landscapes  of sequences showed identity to the Encarsia genus. Whilst B. tabaci SSA1 was dominant on cassava, it was also present on non-cassava host crops . Other B. tabaci species (excluding SSA1) were found on sweet potato, pumpkin, sesame, beans, and Euphorbia weeds  while old cassava was marginally negatively correlated . Only cassava in the ideal-age range (3–7 MAP) was positively correlated with the abundance of B. tabaci SSA1   of cassava crops did not significantly correlate positively with the abundance of f nymphs . Young c<0.0002) . Site 2Bpositive  but we cBemisia host plants such as sweet potato, groundnuts, soybean, beans, and sesame. Besides coffee and banana which are perennial crops, the next most commonly planted crops in the landscapes were maize , sweet potato . The other planted crops after sweet potato were groundnuts, beans, soybean, and sesame, respectively. Other non-cassava crops planted in smaller areas included Bambara nuts, pumpkin, tomato, coffee, rice, millet, sorghum, cocoyam, and eggplant. Weeds (including a Euphorbia species) were present in the landscape. Percentage weed cover varied between landscapes from 0 to 41% in season 1, and from 0.8 to 56% in season 2. Across time, crop diversity varied between landscapes and between seasons. For example, diversity ranged between 4 and 14 crop types in season one landscapes, and between 2 and 10 crop types in season two landscapes. There was a higher diversity of crop types observed between 1 and 3 MAP, and 7 MAP in season 1, respectively, while this was true between 8 and 9 MAP in season 2  in terms of B. tabaci SSA1 abundance was 7, 6, 2, 3, 1, 4, 5, respectively.A cluster analysis was conducted to group the landscapes according to the area of different crop types found. We identified seven clusters that broadly differed in the amount of maize and weeds surrounding the focal cassava field . The cluB. tabaci SSA1 in the landscape. Cluster 5 with the most nymphs (highest population) had a relatively higher proportion of weed cover at 54% with 22% under maize, 19% under banana, 14% under beans, 3% under soybean, and <1% under cocoyam. Cluster 4 with the second highest nymph population had 78% covered by weeds with 18% under maize, 3% under banana and 1% under beans. Comparatively, cluster 7 with the lowest nymphs comprised of 85% maize, the highest in all clusters, 7% soybean, 6% weeds and 2% beans  and significantly by cassava age (MAP) (p = 0.007) with highest abundance in the 3–5 MAP group, followed by the 6–8 MAP . An increased area of non-crop, therefore, resulted in decreased parasitism of nymphs in the cassava field. Conversely, percent parasitism increased with an increase in the area of weeds, a relationship that was positively significant   varied between landscapes and ranged between 0 and 60% in season 1 and between 3 and 52% in season 2 . The per = 0.04) .B. tabaci SSA1 nymph abundance to specific changes that take place within these landscapes. Our study has shown, firstly, that an increase in area of cassava fields in the ideal-age range results in an increase in the abundance of the B. tabaci SSA1 on cassava. Secondly, we found that the highest abundance B. tabaci SSA1 nymphs in cassava fields occurred at times when landscapes had the largest areas of weeds, low to moderate areas of maize, and low areas of banana. The mechanisms underlying these relationships are not clear and most likely involve processes such as colonization and oviposition behaviors of adults flying around these diverse landscapes [This is the first study quantifying the diversity of land-use changes that take place across a season in dynamic smallholder farming landscapes in Africa. By using an experimentally planted field, we could standardize the focal field for age and cultivar whilst allowing the surrounding landscape to change as it normally would under traditional smallholder production practices. We then linked the patterns in ndscapes , biotic Bemisia species. From a comprehensive collection of nymph samples (93 cassava populations ~2842 nymphs), across fields and across time, and using a molecular method for identification, we can conclude that B. tabaci SSA1 is the predominant species in these landscapes. This result contrasts with cassava fields in Malawi that can have higher proportions of other species such as Bemisia afer and more diversity in terms of number of Bemisia species in cassava fields [B. tabaci SSA1 was also recorded on other crops in the landscape, namely, sesame, soybean, and groundnut, which could be used as alternative host plants. Importantly, the molecular identification process we used was based on nymph samples rather than adults which can easily move between plants but not use them as a resource.In smallholder production landscapes across Uganda, there was a year-round presence of cassava and other hosts plants that are potentially suitable for a fields . In our B. tabaci SSA1 nymphs in the focal fields. However, when separated into three age-classes , there was a positive relationship between nymph abundance in the cassava field and the area of ideal-age cassava in the landscape.Our analysis shows that if the patches of cassava in a landscape were not differentiated by their age, then there was no significant relationship to the abundance of B. tabaci SSA1. The increased amount of suitable-age cassava in the landscape leads to increased nymph numbers. The age of cassava plants plays an important role with respect to whitefly. Sseruwagi et al. [Bemisia species peaked between 5 and 7 MAP and then dropped drastically as the plant became taller, woodier and less succulent. Several other changes in disease and virus characteristics in cassava have also been attributed to changes in the age of the crop  for Bemisia abundance. Those landscapes with the most B. tabaci SSA1 in cassava (cluster 4) had the highest proportion of weeds (78%), low–moderate maize area (18%) and low banana area (3%). In comparison, landscapes with the lowest B. tabaci SSA1 population in cassava (cluster 7) comprised of large maize areas (85%) and smaller weeds areas (6%). Cluster 7, however, consisted of only one field indicating low variation in its composition and highlighting the importance of spatial differences.When focusing on the composition and diversity of non-cassava crops, it is clear that there are types of landscapes that result in high B. tabaci complex are polyphagous . FurtheB. tabaci SSA1 in cassava. Although some of these may be suitable host plants for B. tabaci SSA1, such crops may be relatively less suitable and less favored than cassava [Aleurotrachelus socialis Bondar and Trialeurodes variabilis (Quaintance) [B. tabaci SSA1 is thought to be well-adapted to cassava [Many potential host plants in the landscape see  showed a cassava . Field sintance)  while anintance) . The act cassava . For thi cassava .B. tabaci SSA1 nymphs in cassava as has been observed in other farming landscapes [B. tabaci SSA1 parasitism showed temporal and spatial variation across landscapes and seasons. Overall, parasitism rate was relatively high for an agricultural production landscape, reflecting the low use of pesticides on these farms. The relationship between parasitism and non-crop components of the landscape has been found to be inconsistent in other studies [An increased area of non-crop vegetation in the landscape did not lead to increased parasitism of ndscapes ,41. Inst studies , althoug studies , which wBemisia resources in the cassava fields.The negative correlation observed between parasitism and area of non-crop in the landscape is an indication that parasitoid species may not be reliant on resources in the non-crop areas. This pattern does not preclude the use of resources outside the cassava field, but perhaps the cassava and other crops may be more of an assured source of food for the parasitoids than the semi-natural patches. In Asian cassava fields, within-field variables such as soil parameters and the plant phytopathogen status were found to be important for interactions between a cassava mealybug and its parasitoid . LandscaEretmocerus mundus, Encarsia Sophia, E. mineoi, and Encarsia sp-blackhead) that attack Bemisia species on cassava in Uganda [Eretmocerus and Encarisa species diversity in African cassava landscapes . There Bemisia species and their parasitoids in a focal field. This knowledge can be used to guide the development of cultural/landscape manipulation techniques that farmers can use to more effectively manage these pests. With infrequent insecticide use in these landscapes, habitat management techniques to promote or conserve parasitoids could provide options to better manage Bemisia populations. As established, whitefly population dynamics are governed not only by host plant availability and suitability but also by crop cultivation regime [Bemisia species could be achieved by having greater cropping synchronicity across landscapes and establishing a fallow period [Bemisia species are focused on the field scale, our study has highlighted the need to provide evidence for developing a landscape approach to manage this pest and the diseases it vectors.Our results demonstrated that spatial and temporal changes in the surrounding landscape can impact both n regime . There iw period . Parry ew period  using a


Delayed intracerebral hemorrhage (DICH) secondary to ventriculoperitoneal (VP) shunt is considered to be a potentially severe event. This study aimed to investigate the association between a ratio of postoperative neutrophil-to-lymphocyte ratio to preoperative neutrophil-to-lymphocyte ratio (NLRR) and DICH secondary to VP shunt. We performed a retrospective review of patients who underwent VP shunt between January 2016 and June 2020. Multivariable logistic regression analysis was used to assess the association of DICH and NLRR. Then patients were divided into two groups according to the optimal cut-off point of NLRR, propensity score matching (PSM) method was performed to reconfirm the result. A total of 130 patients were enrolled and DICH occurred in 29 patients. Elevated NLRR and history of craniotomy were independent risk factors for DICH secondary to VP shunt. The optimal cut off point of NLRR was 2.05, and the sensitivity was 89.7%, the specificity was 63.4%. Patients with NLRR > 2.05 had much higher incidence of DICH (40.6% vs 4.5%). Our finding suggested that DICH following VP shunt was not a rare complication and elevated NLRR could independently predict DICH. Inflammatory responses might play an important role in the development of DICH following VP shunt. The common complications secondary to VP shunt are shunt obstruction, infection, seizure, subdural hemorrhage and shunt malfunction4. Mild hemorrhage is frequently observed in the ventricle or in the parenchyma soon after operation5, and the rate could be up to 43.1%6. However, the delayed intracerebral hemorrhage (DICH) is considered to be a rare but potentially severe event7, the mortality is as high as 50%4. The risk factors and underlying mechanisms of DICH are still not fully elucidated. There are several risk factors proposed by previously published articles11: (1) advanced age, age ≥ 60 years; (2) history of craniotomy; (3) delayed partial thromboplastin time (PTT); (4) brain edema around catheter; (5) postoperative manipulation of valve system; (6) postoperative anticoagulation.Ventriculoperitoneal (VP) shunt is the most common treatment for hydrocephalus12. We hereby hypothesize that inflammatory response is one of the mechanisms associated with DICH following VP shunt. The neutrophil-to-lymphocyte ratio (NLR), as a rapid and economic biomarker of systemic inflammation13, has been a dependable predictor of clinical outcome in patients with spontaneous intracerebral hemorrhage14 and traumatic brain injury15. Considering that the value of NLR is greatly influenced by the basic systemic inflammatory statuses such as pneumonia or urinary infection, we proposed a new parameter named NLRR, what is a ratio of postoperative NLR to preoperative NLR. In this study, we sought to test the hypothesis that elevated NLRR is associated with the DICH secondary to VP shunt.A recent study pointed out that the systemic inflammatory responses might be involved in the pathologic process of active cerebral hemorrhageWe performed a retrospective review of patients who underwent VP shunt between January 2016 and June 2020 from the Neurosurgery Department of Ningbo Medical Center Lihuili Hospital. Inclusion criteria were as follows: (1) age ≥ 18 years; (2) the diagnosis of hydrocephalus was confirmed by clinical symptoms and imaging examination, and VP shunt was performed in our hospital; (3) laboratory tests (blood routine and coagulation function) within 5 days before VP shunt, and blood routine on the first morning after VP shunt; (4) postoperative brain computed tomography (CT) scan was performed on the first day after operation (later than the postoperative test of blood routine), and at least one CT scan was performed within 5–10 days after operation. The exclusion criteria were as follows: (1) patients on a regimen of anticoagulant or antiplatelet therapy; (2) patients with Ommaya reservoir implantation, the Ommaya tube was directly connected to the shunt pump without ventricular puncture, or the Ommaya tube was removed during the surgery; (3) cranioplasty and VP shunt were performed simultaneously; (4) a revision of the VP shunt; (5) early intracerebral hemorrhage after VP shunt, which was defined as bleeding on the first day after operation.DICH was defined as subsequent hemorrhage in the ventricle or the parenchyma along the catheter path which was not found in the CT scan on the first day after operation. The patients enrolled in the study were divided into two groups according to whether or not DICH. The patient flowchart was summarized in Fig. 2O), normal pressure hydrocephalus , high pressure hydrocephalus . For the patients with DICH secondary to VP Shunt, the onset day of hemorrhage, types of hemorrhage, with or without symptom after hemorrhage and the Glasgow outcome scale (GOS) were also collected. Laboratory variables were retrieved from our hospital’s database. International normalized ration (INR), prothrombin time (PT), activated partial thromboplastin time (APTT), serum thrombocytes, neutrophils and lymphocytes were collected within 5 days before operation. Postoperative serum neutrophils and lymphocytes were collected on the first morning after operation. All of the preoperative and postoperative brain CT scans were obtained, and respectively reviewed by one neurosurgeon and one radiologist who blinded to the detail information  of patients. The different opinions between them were resolved by consultation. The volume of hematoma was calculated by 3D slicer (version 4.10.2). Besides, postoperative cerebral edema around catheter on the first postoperative CT scan was also collected.Demographic characteristics and clinical variables were collected such as: sex and age; history of hypertension and diabetes; history of craniotomy and skull defect; preoperative pneumonia and Glasgow Coma Scale (GCS); primary intracranial lesions including normal hydrocephalus, trauma, spontaneous intracerebral hemorrhage(ICH), tumor and inflammation; hydrocephalus types including low pressure hydrocephalus  and R Software (version 4.0.2) were used for data analysis with statistical significance was defined as P < 0.05. The Kolmogorov–Smirnov test was used to determine the distributions of continuous variables. The continuous variables with non-normally distributions were analyzed by Mann–Whitney test, presented as the median (50th) with interquartile range (IQR). Categorical variables were presented as number (proportion). Mann–Whitney test was used for ordered categorical variables, and unordered categorical variables were analyzed by Pearsons chi-square test, Continuous correction chi-square test or Fishers exact test. The variables with P < 0.1 and variables proposed by previously published articles, were selected by Least Absolute Shrinkage and Selection Operator (LASSO) regression, and then included into multivariable logistic regression analysis to assess the association of DICH and NLRR. The predictive value of NLRR for DICH following VP shunt in patients was evaluated by receiver operating characteristic (ROC) curve analysis. According to the optimal cut-off point of NLRR , patients were divided into two groups (NLRR ≤ cut-off point group and NLRR > cut-off point group). Propensity score matching (PSM) method was performed to adjust for imbalances of patients’ characteristics between two groups. Covariates such as sex, age, history of hypertension and diabetes, history of craniotomy and skull defect, preoperative pneumonia and GCS grade, primary intracranial lesion, hydrocephalus type, preoperative PT and APTT, preoperative INR and PLT, puncture site, initial pressure of vale system, brain edema around catheter and postoperative manipulation of valve system were matched at a ratio of 1:1 using a caliper width of 0.2. The estimation algorithm of propensity score was logistic regression and matching algorithm was nearest neighbor matching. After PSM, 82 patients  were selected to analysis.This study was performed in accordance with the Declaration of Helsinki of the World Medical Association, and all procedures were carried out in accordance with the approved guidelines and regulations. This study was approved by our institutional ethics committee . Participant data were retrospectively reviewed and deidentified. Because of anonymization, consent was waived by the ethics committee of Ningbo Medical Center Lihuili Hospital.A total of 130 patients underwent VP shunt were included in this study. Because there were 36 patients with early intracerebral hemorrhage after VP shunt who were excluded, the overall incidence of DICH secondary to VP shunt was 17.5% (29/166). The median age of the 130 patients was 60 years, and 78 (60.0%) patients were male  and age, brain edema around catheter, postoperative manipulation of valve system (proposed by previously published articles), were included. The linear relationships between the continuous independent variables and the logit conversation of dependent variable were confirmed by Box–Tidwell test. The indicators of multicollinearity  were statistically tested, and the results of eigenvalue and condition index showed that there was multicollinearity among above variables. In order to solve the multicollinearity problem, Least Absolute Shrinkage and Selection Operator (LASSO) analysis in R software (package glmnet) was used to select variables   Fig. A, and thup) Fig. B. The coup) Fig. .Figure 3The mean onset day of DICH after operation was 6.10 ± 0.53 day, ranged from 2 to 13 day. Intraventricular hemorrhage was the most common type, which was presented in 13 patients 44.8%). 16 patients (55.2%) with hematoma volume less than 1 ml, only three patients (10.3%) had hematoma volume more than 15 ml, and the maximum hematoma volume was 74.5 ml. 6 patients (20.7%) were found to be symptomatic, such as vomiting, epilepsy and decreased consciousness. 15 patients (51.7%) had a GOS = 3 at the time of discharge, while only one patient (3.4%) had a GOS = 1, whose hematoma volume was 74.1 ml. The scatter plot of NLRR and hematoma volume was shown in Fig. 4.8%. 16 17. It was considered to be a rare complication with incidence varies from 0.4 to 4%18. However, the incidence might be underestimated. Patient with small hematoma might be missed if CT scan was not performed frequently4. An article published in 2017 reported that the incidence of postoperative DICH was 7.8% (17/218)10. In our study, the incidence was 17.5%, which was much higher than previous studies. Another article published in 2018 reported that the incidence was 23.7% (34/143) without excluding patients with anticoagulant and antiplatelet therapy11. Just as our study, they included the patients with hematoma volume less than 1 ml which would be ignored easily and maybe it is the reason. The incidence of symptomatic DICH was 3.6% (6/166) in our study.DICH is one of complications of VP shunt surgery and was first reported in 198519. Savitz and Bobroff5 pointed out that the mechanism of DICH was more likely erosion of surface or deeper small vessel by catheter. This opinion was supported by most reports because most hematomas located along the catheters4. The hypercapnia, hypoxia and venous congestion might encourage developing of hematoma at the sites of injury just as the mechanism of traumatic delayed ICH20. A study published in 2017 found that postoperative cerebral edema around the catheter observed on the first CT scan was an independent risk factor for DICH9, which might be a sign of vascular erosion. Nevertheless, this difference was not found in our study. Advanced age, history of craniotomy were considered to be the risk factors for DICH secondary to VP shunt in several articles11, and these factors might increase the fragility of cerebral tissue. However, one article published in 2017 reported that there was no difference between two groups with respect to age10. In our study, we also found that history of craniotomy was an independent risk factor for DICH, while advanced age was not. DIC induced by catheter insertion was considered to be another potential mechanism of DICH. Two cases of DIC associated with VP shunt were reported22. A Korean study found that prolonged partial thromboplastin time was major risk factor of DICH11. Some studies showed that dual antiplatelet therapy and postoperative anticoagulation therapy would increase the risk of DICH23. As for our study, we excluded the patients with anticoagulant or antiplatelet therapy in order to control the confounding factors, and we found that preoperative PT, APTT, INR and PLT were not risk factors for DICH. Two articles presented that postoperative manipulation of valve system might be a risk factor for DICH secondary to VP shunt8, which was not supported in our study either.The mechanisms underlying the DICH secondary to VP shunt are still controversial. Several hypotheses have been proposed: (1) erosion of cerebral vasculature by the insertion of catheter; (2) fragility of cerebral tissue caused by advanced age, craniotomy, trauma or stroke; (3) disseminated intravascular coagulation (DIC) induced by VP shunt; (4) coagulopathy, anticoagulant or antiplatelet therapy; (5) sudden change of intracranial pressure after manipulation of the valve system24. A study pointed out that immune response might be elicited by VP shunt in some patients and could lead to shunt malfunctions25. Neutrophils and giant cells were found on the surface of catheters by scanning electron microscopy26. In view of the above, we hypothesize that the inflammatory responses may arise from the stimulation of catheter as a foreign body. The acute inflammation phase of foreign body reaction against biomaterials is characterized by migration, adhesion, activation of neutrophils and mast cells, and lasts for hours to few days27. Just as the process of brain injury28, neutrophils’ number increase greatly in the peripheral blood and they can enter central nervous system through the damaged blood brain barrier early15. Recruitment and infiltration of neutrophils around catheter could induce neurotoxicity by following pathways: production of cytotoxic mediators and proinflammatory cytokines, activation of matrix metalloproteinases and increase of oxidate stress31. The ensuing further destruction of blood brain barrier, cellular swelling and increased permeability of capillary might trigger cerebral edema and active bleeding36. Lymphocytes play an important part in the cellular and humoral immune. It was found that autoreactive T cells could promote vascular reconstruction and healing after cerebral trauma37. Studies showed that depletion of blood neutrophils would reduce Blood–Brain Barrier breakdown39, while increase of blood regulatory T lymphocytes could alleviate the degradation of Blood–Brain Barrier40. Therefore, Elevated NLRR (an increase of blood neutrophils or decrease of lymphocytes) might aggravate the degradation of Blood–Brain Barrier and induce DICH secondary to VP shunt. We suggest that the patients with NLRR > 2.05 should be more carefully observed after VP shunt. However, there was no correlation between the NLRR and hematoma volume. The volume of hematoma might be affected by many factors, such as blood pressure, coagulation function and so on. Since limited understanding of the mechanisms of DICH, our finding would also contribute to identify potential preventive and curative strategies.As the main purpose of the study, we concluded that elevated NLRR could independently predict DICH secondary to VP shunt, which suggested that inflammatory responses might play an important role in the development of DICH. Catheters of VP shunt are made of silicones and may not be immunologically inertNLRR, as a new inflammatory parameter, has smaller variation range than NLR, and can roughly represent the change of inflammatory status due to surgery (including anesthesia) and perioperative treatment. Maybe it could be used as predictors of other diseases requiring surgery, such as postoperative rebleeding of ICH following minimally invasive surgery.There are several limitations in our study. The first, it is a retrospective study with small sample size, and a quarter of patients were excluded due to incomplete laboratory or radiological data, which may induce potential selection of bias. The second, there were five variables included in the multivariate logistic regression analysis, the model might be unstable, even though the result was reconfirmed by PSM analysis. The third, the time of ventricular puncture attempt and postoperative treatments such as hemostatic therapy were not included in our study, which might be confounding factors. Finally, preoperative neutrophils and lymphocytes were collected within 5 days before surgery. In general, patient’s condition was stable before operation, fever or other unusual situation would lead to cancellation of operation, and the laboratory indexes would not change greatly in these days. However, there were still small deviations in these data and they could not represent the preoperative inflammatory status accurately. NLRR’s predictive value should be verified by further larger prospective studies.In this study, we proposed a new parameter named NLRR, and suggested that DICH following VP shunt was not a rare complication. History of craniotomy and elevated NLRR were independent risk factors for DICH secondary to VP shunt. According to the results, we proposed that inflammatory responses might play an important role in the developing of DICH. More attention should be paid to the patients with NLRR > 2.05 after VP shunt.Supplementary Figure S1.Supplementary Table S1.