A 1‐year‐old girl from an underserved community presented with irritability, pain, and delayed motor skills. Our genetics outreach program facilitated the diagnosis of Ehlers‐Danlos syndrome masquerading as developmental delay after noting hyperextensible skin. Diagnosis for this family allows for state‐of‐the‐art cardiac monitoring and appropriate symptomatic treatment for this rare disease. Due to the limited medical resources on the small Caribbean island where this child and her family reside, it is necessary to travel to a larger nearby island to access pediatric care. The parents were concerned about the child's extreme irritability and delayed developmental milestones. Physical examination revealed low muscle tone and diminished reflexes accompanied with failure to sustain eye contact, suggesting a neurological disorder. By fortuitous chance, a visiting clinical geneticist was able to examine the patient and noted velvety, doughy, slightly hyperextensible skin, and joint laxity. Exome sequencing of the family triad revealed that the child carried a novel de novo mutation in the Collagen, Type V, Alpha 1 (COL5A1) gene suggesting Ehlers‐Danlos syndrome (EDS). This diagnosis caused management to focus away from a neurological disorder and instead address issues related to defective collagen production. Now appropriate medical care has been implemented to monitor for possible cardiac manifestations as well as to address the musculoskeletal pain and poor muscle tone associated with this child's EDS.Exome sequencing has identified As permanent and visiting geneticists teaching at a medical school in the Caribbean, we realize that our expertise can be of great benefit to our community. We are assisting local and near by physicians who, because of geographical isolation and disparities in socioeconomic status, are unable to access medical genetic services. Our evolving role gives the physicians of this community the power to initiate appropriate therapies and suggest lifestyle modifications for some of their patients. One successful example of this practice lay with that of a 1‐year‐old baby girl with developmental delay who was suspected to have a form of autism, after exome sequencing received a correct diagnosis and treatment for Ehlers‐Danlos syndrome.Ehlers‐Danlos syndrome (EDS) is a group of heritable connective tissue disorders caused by a defect in collagen fibrils or collagen‐modifying enzymes.COL5A1 and COL5A2.COL5A1, COL5A2, and COL5A3 encode proteins which can form either two heterotrimers ([α1(V)]2α2(V) or α1(V)α2(V)α3(V)) or a homotrimer ([α3(V)]3). More than half of the patients with classic EDS carry a mutation on either COL5A1 or COL5A2 genes. The most common type of mutation introduces a premature stop codon in the mRNA transcript which then leads to halpoinsufficiency of the peptide.In the late 1970s, electron microscopy studies of skin biopsies from persons with classical EDS showed a disturbance in heterotypic collagen fibrils made of collagen types I and V. Notably, these fibrils were 13%‐40% larger in diameter with an irregular shape compared to controls.There is no known cure for EDS and therapy is often multi‐layered, based on presenting features. Typically, children with classical EDS receive regular cardiac monitoring by electrocardiogram to monitor for aortic dilation and/or mitral valve prolapse, physiotherapy to assist with hypotonia and motor development, non‐weight‐bearing exercise to promote coordination and muscle strength, advice for treatment of wounds, and help to manage pain.2Consent was obtained from the parents of the patient. We used a local consenting form that was constructed under the auspices of our local institutional review board (IRB) to best relate to the local customs of our patients and families. This is a Caribbean community IRB that is registered with the Office of Human Research Protections (OHRP) in the US Department of Health and Human Services, (IRB Registration Number: IRB00010095). All authors received USA National Institutes of Health approved training for human subject research. Additionally, consent was obtained to allow genetic analysis in a Canadian research facility .Whole blood was sent in an insulated container by FedEx to the McGill Group for Suicide Studies at the Douglas Mental Health University Institute. DNA was extracted with the PureGene kit . Sequencing was done using the Agilent SureSelect for ExomeSeq platform on an Illumina HiSeq 2500 to a read depth of 100. Sequence was analyzed using FastQC for quality control. Adapter clipping and read trimming was done with the FASTX‐Toolkit and Trimmomatic. Alignment was accomplished with Bowtie2 software. We used Genome Analysis Toolkit for variant calling.3An Afro‐Caribbean couple sought pediatric medical advice because their 10‐month‐old female infant displayed extreme irritability since birth. The mother remarked that the infant cried excessively especially when being lifted up and her limbs were hypermobile. Despite great effort, mother was often unable to provide comfort to her child. The parents were also concerned that the child was not reaching key developmental milestones. Upon physical examination, the infant was alert, had relatively good neck control but was unable to crawl or sit without support. Head circumference was at the 98th percentile and her ears were low set. It was noted that the girl was not sustaining eye contact and was not cooperative. In addition, vocalization was not developing appropriately for her age. A non‐contrast CT scan was performed which revealed a normal variant of cavum septum pellucidum et vergae which has occasionally been associated with fetal neural maldevelopment. Based on the above features a possible neurological cause for her condition was being discussed.By fortuitous chance, we organized a meeting between a visiting clinical geneticist, the local pediatrician, and the family when the child was 15 months old. Physical examination of the child showed global low muscle tone and diminished reflexes, low set ears, deformational plagiocephaly, and joint hypermobility. Her right leg had a tendency to cross over the left leg. Bilateral hyperextension of the lower limbs was noted with a more severe hyperextension of the left leg. While trying to grasp an object, the child first flexed her fingers and then flexed the thumb. The thumb did not exhibit a coordinated movement. A slight reduction in Babinski reflexes was noted.The child's skin was soft, velvety, and slightly hyper extensible Figure 4The exon region of genes comprises approximately 1% of the entire genome yet the majority of disease‐causing genetic variants are found within this region. Recent innovations to next‐generation sequencing technology have decreased the cost of sequencing while increasing both the speed and accuracy of acquired sequence data. Whole exome sequencing specifically targets the generation of sequence information from only the exon region. Thus, we chose the cost‐effective whole exome sequencing as our first‐tier test.COL5A1 gene. This deletion is predicted to create a frameshift mutation at amino acid number 315 of the pro‐α1(V) chain. The frameshift would then introduce a premature stop codon resulting in an altered 556 amino acids long pro‐peptide—p.Thr315Argfs*242 Figure Whole exome sequencing revealed a heterozygous deletion of a single cytosine base, NM_000093.4:c.944delC, which is in the seventh exon of the With this information, our team immediately contacted the family to discuss caring for a child with EDS. We then organized for a charitable organization to perform a baseline echocardiogram and schedule annual cardiac monitoring. The local pediatrician implemented a protocol for the treatment of pain. Our team visited the family 1 year after diagnosis. The characteristic skin hyperextensibility of EDS became more prominent. The parents were happy to report that their daughter appeared to be less irritable, and her development was progressing well. Both the baseline echocardiogram and a follow up 1 year later were unremarkable. At this consultation, the parents expressed appreciation for knowing that their daughter had a condition affecting her connective tissue, and that they need not worry as much about her neurological development.5EDS is a rare disorder and to our knowledge, only one case has been published about this condition in the Caribbean region.Initially, the family was most concerned about the child's history of an irritable disposition and delayed developmental milestones. At 10 months of age, physical examination showed that the child was alert but did not sustain eye contact. Neurological examination showed low muscle tone and diminished reflexes with a weak Babinski reflex. The medical community and the family began to suspect that the child could have a developmental, behavioral, or neurological disorder. Following the diagnosis of EDS, the family was informed that the constant crying was likely due the baby's discomfort. Numerous reports document chronic pain in patients with EDS.The parents of our patient were relieved to have an explanation for their daughter's behavior and that her symptoms can now be addressed. The diagnosis has helped this family plan and prepare for a healthier life that includes managing the disorder in their child.,Importantly, genetic diagnosis allowed us to immediately schedule the baby for a baseline echocardiogram, and ensure yearly monitoring. The parents were advised to monitor their child's physical activities to avoid skin tears. Educational pamphlets were provided to the parents for best practices for suturing of cuts, and treatment of minor wounds. This educational material was then placed into the child's medical file. We were also able to include advice for combined management of pain including analgesics, heat, and physical therapy.This case illustrates the power of a definitive diagnosis and the importance of genetic services in a resource‐limited community. Here, we describe a pro bono team of clinical geneticists, research geneticists, and the people of a molecular genetics laboratory who had the privilege of assisting a family who hitherto had restricted access to genetic testing.There are no conflict of interests to disclose by any of the authors.: wrote the original manuscript; BN and WAH: assessed the patient and wrote the clinical synopsis; CE and JFT: generated and analyzed the in‐depth exome sequencing; AS: coordinated clinical visits, institutional IRB approval and reviewed the manuscript; MM: edited the manuscript, generated the figures, and supervised the project.AW & TJ


Examining the impact of maintenance on processing speed allows us to test whether storage and processing resources are shared. Comparing these relationships in children of different ages allows further insight into whether one or multiple resources for these operations must be assumed and whether remembering is proactive throughout childhood. We tested 185 4‐ to 6‐ and 8‐ to 10‐year‐old children using adaptive complex span tasks, in which simple judgments were interleaved between to‐be‐remembered items. The adaptiveness of our tasks ensured that all participants frequently correctly recalled the items. If storage and processing require a single resource, and if participants serially reactivate the memoranda between processing episodes, processing response times should increase with serial position of the processing judgment within lists. We observed different within‐list dynamics for each age group. Older children's processing judgments slowed gradually when more than two memory items were maintained. By contrast, younger children showed no evidence of slower processing with increasing memory load. Our results support models of working memory that assume that some common resource is responsible for verbal and spatial storage and processing. They also support the notion that remembering becomes more proactive as children mature. Examining the impact of maintenance on processing speed allows us to test whether storage and processing resources are shared. Comparing these relationships in children of different ages allows further insight into whether one or multiple resources for these operations must be assumed and whether remembering is proactive throughout childhood. Our ability to remember novel information even when we are interrupted is a seminal, benchmark finding that must be explained by models of working memory (WM). Evidence that storing memories and forming judgments may not interfere much with each otherMultiple‐component WM modelsAlternatively, many other models of WM assume that processes requiring attention rely on a common resource that may be used for maintenance of information.Much of the evidence informing debate about how and when storage and processing operations interfere comes from complex span tasks (CSTs). CSTs measure how much one can remember when maintenance is interrupted by interleaved processing operations. As in a simple memory span task, participants are given a sequence of memoranda to be recalled in serial order. Between the presentations of each to‐be‐remembered item, participants must make some decision about an intervening stimulus, for instance, solving an arithmetic problem,Though investigations of CSTs usually focus on variations in memory performance while controlling processing task performance,et al.et al. found that effects of accumulating memory load on processing responses depended on which aspect of the processing task participants were performing. Their participants viewed each component of the processing tasks for as long as they chose. For instance, in operation span, participants looked serially at each element of the equation. When they were ready for the next element, they pressed a key to receive it. Participants could thus spend as long as they needed contemplating each element of the processing task and the to‐be‐remembered item. Engle et al. analyzed viewing times separately for the first element in the operation, the subsequent elements combined, and the memory item. They found that viewing times to the processing task elements increased with accumulating memory load, but only for participants with high WM span. When it came to viewing the memory item, voluntary viewing times generally increased for the first few items and then decreased, producing an inverted U‐shaped curve. Similarly, Friedman and MiyakeTwo additional studies confirm that execution of the processing task depends on a variety of related factors that may obscure diagnostic patterns and limit interpretations of processing response times during CSTs. Engle Establishing whether (and under what conditions) accumulating memory loads impede processing during CSTs in children would benefit theories of WM development and of WM and executive functioning more broadly. Developmental trends can help distinguish among theories. If there are separate resources for storage and processing, these resources may show different developmental trajectories. By measuring CST performance in different age ranges, we can see whether observed differences among patterns of interference between storage and processing may be explained by supposing that components mature at different rates. If at least one component has not yet matured, then presumably conflicts between storage and processing would be greater for younger than older children. Some previous research suggests that the multiple components of the WM system are not set before age 7 or so,et al.et al. did not observe this. Barrouillet et al.Processing task data from CSTs in children indeed present a somewhat different picture than in adults. Towse We present an analysis of the effects of accumulating memory load on processing task response times taken from two novel, adaptive CSTs. This large data set was collected as part of a preliminary study conducted to establish procedures for a study examining executive function training in school‐aged children. Here, we opportunistically extract the processing times from a 30‐min session of personally adaptive CST training, in which list length was determined per trial depending on the memory accuracy of the previous trial. The adaptiveness of our CST task ensures that every participant was performing our CSTs at challenging levels, where each would report the entire memory list correctly on ∼50% of trials. This affords a large sample of participants with ample number of trials to examine processing response times in which we can be sure that participants accurately retained the memoranda. We tested two groups of children aged between 48 and 72 or 96 and 119 months, and roughly half from each age group undertook a CST pairing visual processing with spatial memory, while half completed a task pairing visual processing with verbal memory. In both tasks, the processing judgment was to be performed on the memory stimulus itself, as in many previous studies.This sample therefore offers us the chance to fully describe effects of memory on processing, so that we may detect and model fine‐grained effects of accumulating memory loads across the full spectrum of serial positions and possibly observe nonlinear trends, such as those reported previously in adults,Study participants included 185 children in two age groups: 84 4‐ to 6‐year‐olds  and 101 8‐ to 10‐year‐olds . An additional 20 children were removed due to inability to operate the mouse independently, and an additional three were removed from the younger group because they never responded correctly on a trial with two or more memory items. Participants were recruited through university databases, schools, and advertisements on social media. Before participation, informed consent was obtained from the children's caregivers.Participants were tested individually by trained experimenters either in the laboratory or in a quiet room in their kindergarten or daycare in a single 90‐min session. Sessions began with a 22‐item language proficiency measure (the Peabody Picture Vocabulary Test (PPVT‐4)Participants performed the main CST experiment on Dell Precision 5510 laptops using the mouse to respond. The experiment was programmed in E‐Prime 2.0.The CST tasks are depicted in Figure In the verbal memory condition, children remembered lists of animals. Drawings of animals were presented in the center of a field scene, with the names of the animals simultaneously presented aurally. Animals were chosen randomly from a set of eight  with single‐syllable names in both English and German, with none repeated within a trial. The animal images could be presented in color or grayscale. The child was to remember the animal name and judge whether the animal was in color by clicking either a colored or grayscale beach ball presented at the lower left and right corners of the screen. Progression to the next item occurred after the child's judgment about the animal's color. Immediately after the final judgment, an array including the set of eight animals was presented in the cells of a 3 × 3 grid, and the child was prompted to click the animals that were presented on that trial in serial order. The animals always appeared in the same cells within the grid, with the central cell left blank.We used an adaptive procedure to ensure the task remained challenging. If the child got both the memory and processing responses correct, the trial length increased by one item. If they got the memory response correct but the processing task incorrect, they stayed at the same trial length, and if they got the memory response incorrect their trial length decreased by one item. Children were not given accuracy feedback and were not explicitly told how long each list would be, but they would have gradually learned that if the trial length changed; it differed by one item at most. Each new block began with the trial length of their prior trial.We considered four factors of interest in addressing our theoretical questions: age group (4‐ to 6‐year‐olds and 8‐ to 10‐year‐olds), domain of the memory items , the trial length (ranging from 1 to 6 adaptively and thus differing per child), and the serial position  within a trial. Trial length and serial position are both manipulations of mnemonic load on processing, but, because of the personalized adaptivity we employed, exact trial length is unbalanced across participants. We therefore focus on the effects of accumulating memory load on processing, which is reflected in the serial position factor. Analyzing processing responses as a function of serial position within a trial allows us to further test specific hypotheses about how storage and processing trade off. If participants engage in cumulative serial reactivation, then effects of memory load on processing should increase as the trial progresses, leading to ever‐slower processing response times. We estimated Bayesian repeated‐measures analysis of variance (ANOVA) modelset al.,We took care to ensure that the data we included in our analyses were likely to reflect legitimate processing decision activity. As described above, we excluded data from participants who were unable to personally operate the mouse. We then excluded responses in which we detected that the child erroneously clicked an invalid location before clicking the intended spot. Our programs did not mark when a mis‐click occurred, but we could detect most instances of invalid clicks by comparing recorded response times against deduced response times calculated from known onset times of trial events. We lost ∼7% of trials due to detection of an invalid click. As recommended by Vergauwe Our Bayes factor modeling was performed on per‐participant averages of processing accuracies and per‐trial log‐transformed processing response times. Accuracy averages were used for the convenience of obtaining continuous values. For response times, analyzing trial‐level responses was important to avoid distorting effects of serial position, which should not be conflated across different trial lengths. We report the Bayes factors for the models that emerge from each analysis with the strongest support and then evaluate the presence or absence of terms of interest by comparing the model including or excluding the term of interest with the best model. We invert Bayes factors less than 1 so that we consistently express support for or against including the term in integers.t‐test comparing the maximum trials lengths reached by participants in the verbal and spatial memory groups did not reveal any evidence of a difference (inverted BF = 5.56).Table x‐axis), and overall trial length (separated by color). We ran a four‐way Bayes factor ANOVA on processing task proportions correctly (subjected to arcsine square root transformation), including each factor in our design. This analysis allowed us to rule out effects of trial length or serial position, as well as any interaction involving these factors, on processing task accuracy. Excluding these terms from the complete model was preferred by factors of at least 8 (and as much as 889). We looked at potential effects of age group and memory domain more closely in a two‐way ANOVA, because the omnibus analysis suggested that these factors might have an impact. The model with the highest BF included a main effect of age group only (BF = 41.94 ± 1.30%). The models that also include memory domain and the interaction between age group and memory domain could not be definitively ruled out (the BFs for excluding these terms were 1.28–1.58). If anything, 4‐ to 6‐year‐old children performed less well overall with verbal  than with spatial memoranda , while 8‐ to 10‐year‐old children performed equally well in both memory conditions . Clearly, performance was at ceiling in each case. These few errors were excluded from the analysis of response times.In both age groups and regardless of memoranda domain, participants had no trouble making accurate decisions on the processing tasks. Figure trimrWe trimmed response times for further analysis using the R package 455 ± 2.35%) included each main effect, a three‐way interaction between age group, memory domain, and serial position, and two‐way interactions between age group and memory domain and each factor with serial position. This model was favored decisively over the next best model (which included more terms) by a factor of 135. Including the three‐way interaction was even more decisively favored , which justifies analyzing data from each age group separately in two more interpretable three‐way ANOVAs. We turned immediately to those.Figure 124 ± 1.70%). Inclusion of both terms was decisively favored (BFs > 121), and exclusion of their interaction was favored by a factor of 5.84. Both trial length and serial position represent memory load, which suggests that memory load affected processing speed in 4‐ to 6‐year‐olds. However, any effects of trial length or serial position in this group go against expectations. Response times obviously decreased with each serial position . Because of our adaptive procedure, trial length differences may largely reflect speed differences among children; individuals would not all have contributed equally to means for each trial length. However, both findings are inconsistent with the idea that memory load impairs processing task performance in children younger than 6.The best model included only main effects of trial length and serial position . Inclusion of each term in this model was decisively favored by factors of more than 1 million.The winning model included main effects of trial length, memory domain, and serial position, plus interactions between trial length and serial position and memory domain and serial position (BF = 1.47 ×1074 ± 1.66%). This model was decisively favored over the next‐best simpler serial position model by a factor of more than 18,000. This means that, with verbal memoranda, from serial position 2 onward, processing times increased incrementally, as one would expect if participants cumulatively refreshed the verbal memoranda, and if these maintenance operations impinge on the same resource needed for processing , but this model was only slightly favored (by a factor of 3.39) over a model including the simpler serial position coding in which positions 3, 4, and 5 do not differ from each other. From Figure Because trial length varied among participants and is thus difficult to interpret, we focus on the interaction between memory domain and serial position. To diagnose the meaning of this interaction, we carried out separate series of ANOVAs for verbal and spatial memoranda conditions. Within each, we compared alternative codings of serial position to allow for four possibilities: (1) that only the first serial position differed from the others; (2) that the first and fifth serial position differed from the second, third, and fourth; 3) that serial positions 1 and 2 were unique, and other positions were the same; and (4) that all serial positions differed. We always included trial length in the modeling to ensure that serial positions from different trial lengths remained distinct. With verbal memoranda, the best model required the most complex serial position coding in which each serial position differed (BF = 6.49  that serOur adaptive procedure ensured that participants of all ages were performing the CSTs at a level of performance well off both floor and ceiling. Achieving this naturally means that younger children receive shorter lists than older children. To check that the apparent differences between 4‐ to 6‐ and 8‐ to 10‐year‐old children are not only due to the older children being able to recall more and reach longer trial lengths, we repeated our analysis on the data from both groups from trial length 3, the longest common length across groups for which we obtained sufficient data. The best model included effects of age group, memory domain, and serial position, plus interactions between age group and serial position and memory domain and serial position. The interaction between age group and serial position was favored by a factor of more than 400, which confirms the idea that interlist dynamics differ by age. However, this should be interpreted cautiously: response times were much slower overall in the 4‐ to 6‐year‐olds, and three items was the minimum span achieved by the older children and thus was not challenging for most 8‐ to 10‐year‐olds.We analyzed response times for the processing components of CSTs recorded while participants correctly maintained verbal and spatial memoranda. In 4‐ to 6‐year old children, memory load did not slow processing task response times. In 8‐ to 10‐year old children, we observed a complex pattern of results: while responses on the first processing judgment in a trial were consistently the slowest, processing judgments slowed from the second item onward when the memoranda were verbal. With spatial memoranda, processing judgments also tended to slow from the second onward, but the pattern was somewhat less compelling. Our data confirm that effects of memory load on processing emerge between 6 and 8 years of age, which is consistent with other theoretical accounts of WM development.Our findings contradict the notion that domain‐specific short‐term storage systems are developing in this period. According to the classic multicomponent WM account, storage and processing should be distinct, and memory load should not affect processing. Even if we relax this assumption by allowing that processing might involve briefly representing to‐be‐processed stimuli in a short‐term store and thereby provoking interference, one might expect to observe within‐domain interference between spatial storage and visual processing, where spatial memory load increases visual processing task response times, but verbal memory load does not. In younger children, we observed decisive evidence against any difference between verbal and spatial mnemonic load on visual processing, not the dissociation that would be expected if visual–spatial information were maintained in a dedicated short‐term store. If one sort of store was undergoing development and not yet functional, we should have seen more evidence of interference in younger children with underdeveloped WM components, not less evidence of interference, as we clearly did. In older children, we observed evidence that memory loads impaired processing and interactions showing that verbal and spatial mnemonic loads differentially affected processing. However, the evidence that increasing verbal load resulted in slower processing was stronger than the evidence for the analogous effect with spatial load. These effects are incompatible with the domain‐specific short‐term store assumptions, because, if anything, within‐domain interference should have been greater than between‐domain interference. Our results are more compatible with accounts that clearly acknowledge that general processes are used in the service of verbal and spatial WM storage.et al.One interpretation of the development of multicomponent WM across childhood is that the verbal rehearsal component is only fluently applied after age 7.Aspects of our findings are also consistent with the predictions of the TBRS model. TBRSn might entail not merely representing a single item, but also establishing the representational object that the remainder of the list will eventually populate. Though we can only speculate as to why we may have observed these slow processing responses to the first memory item, it may be that the temporal context of the first item in a list is unique from the others. Models of memory frequently attempt to account for this (see summaries of models described by Hurlstone et al.The slowest processing responses consistently occurred for the first processing item, a pattern not predicted by either WM model we consider in depth here or any other model of which we are aware. It may be tempting to disregard this observation, but we are not the only ones to report it,Finally, we acknowledge that the accounts we compared were not the only viable accounts of CST performance. Many other models of WM may be called upon to explain CST performance. The multicomponent and TBRS models make differing predictions about phenomena we could address given the variables we manipulated for a different purpose. With these tasks, we were unable to fully differentiate maintenance processes acting to strengthen memoranda from processes that may act to inhibit or remove distractors, which leaves us unable to comment much on that contemporary discussion.Despite these caveats, these data uniquely portray how accumulating verbal and spatial memory lists affect an interleaved processing task throughout to‐be‐remembered lists in 4‐ to 10‐year‐old children. Previous investigations of CSTs in this age rangeThe authors declare no competing interests.


GATA factors play central roles in the programming of blood and cardiac cells during embryonic development. Using the experimentally accessible Xenopus and zebrafish models, we report observations regarding the roles of GATA‐2 in the development of blood stem cells and GATA‐4, ‐5, and ‐6 in cardiac development. We show that blood stem cells develop from the dorsal lateral plate mesoderm and GATA‐2 is required at multiple stages. Firstly, GATA‐2 is required to make the cells responsive to VEGF‐A signalling by driving the synthesis of its receptor, FLK‐1/KDR. This leads to differentiation into the endothelial cells that form the dorsal aorta. GATA‐2 is again required for the endothelial‐to‐haematopoietic transition that takes place later in the floor of the dorsal aorta. GATA‐2 expression is dependent on BMP signalling for each of these inputs into blood stem cell programming. GATA‐4, ‐5, and ‐6 work together to ensure the specification of cardiac cells during development. We have demonstrated redundancy within the family and also some evolution of the functions of the different family members. Interestingly, one of the features that varies in evolution is the timing of expression relative to other key regulators such as Nkx2.5 and BMP. We show that the GATA factors, Nkx2.5 and BMP regulate each other and it would appear that what is critical is the mutually supportive network of expression rather than the order of expression of each of the component genes. In Xenopus and zebrafish, the cardiac mesoderm is adjacent to an anterior population of cells giving rise to blood and endothelium. This population is not present in mammals and we have shown that, like the cardiac population, the blood and endothelial precursors require GATA‐4, ‐5, and ‐6 for their development. Later, blood‐specific or cardiac‐specific regulators determine the ultimate fate of the cells, and we show that these regulators act cross‐antagonistically. Fibroblast growth factor (FGF) signalling drives the cardiac fate, and we propose that the anterior extension of the FGF signalling field during evolution led to the recruitment of the blood and endothelial precursors into the heart field ultimately resulting in a larger four chambered heart. Zebrafish are able to successfully regenerate their hearts after injury. To understand the pathways involved, with a view to determining why humans cannot do this, we profiled gene expression in the cardiomyocytes before and after injury, and compared those proximal to the injury with those more distal. We were able to identify an enhancement of the expression of regulators of the canonical Wnt pathway proximal to the injury, suggesting that changes in Wnt signalling are responsible for the repair response to injury. ALPManterior lateral plate mesodermATAC‐seqassay for transposase‐accessible chromatin‐sequencingBMPbone morphogenetic proteinCHTcaudal haematopoietic tissueCMcardiomyocyteDAdorsal aortaDHdefinitive haemangioblastDLPdorsal lateral plateDpidays post injuryDPPdecapentaplegicEGFPenhanced green fluorescent proteinEHTendothelial to haematopoietic transitionFACSfluorescence activated cell sortingGFPgreen fluorescent proteinGOgene ontologyhpfhours post fertilisationhpihours post injuryHSChaematopoietic stem cellMImyocardial infarctionMOmorpholinoMYmillion yearsRNA‐seqRNA‐sequencingTGF‐βtransforming growth factor‐βVEGF‐Avascular endothelial growth factor‐A1GATA factors were first discovered in the erythroid cells of the blood, specifically the first three members of the family.Blood or haematopoietic stem cells (HSCs) are found in the bone marrow of mammals, including humans. However, they are made during embryonic development outside the bone marrow and subsequently migrate to it. Therefore to understand how to make HSCs, it is necessary to study their generation in the embryo. This is quite difficult to do for obvious reasons in human embryos. We therefore use the experimentally accessible amphibian (Xenopus) and zebrafish embryos, and the mechanisms discovered there have been shown to be applicable to mammals including humans where tested.Our lineage analysis showed that the HSCs are derived from the most dorsal lateral plate (DLP) mesoderm, which is located immediately adjacent to the forming somites. Programming of these cells involves signals from the somites. The cells then migrate under the somites towards the midline of the embryo where they form a cord of cells that lumenises and forms the dorsal aorta (DA).2VEGF‐A is the inducing signal affecting the DLP/DH and its expression in the somites is positively regulated by the ETS factor, ETV‐6.In the case of GATA‐2, we speculated that BMP signalling would be involved because both blood development and GATA factor expression have many connections with BMP signalling in the literature. However, BMP is required for the whole of lateral plate mesoderm formation and general patterning of the early embryo. Therefore, to test the specific role around the time when GATA‐2 expression was turned on in the DLP/DHs, we had to make use of conditional inhibition of BMP signalling.3Evidence published by othersDespite the significant reduction in RUNX‐1 expressing cells in the DA in the GATA‐2a enhancer mutants at 26 hours post fertilisation (hpf), we found that the number of derivatives of the HSC found at 48 hpf in the caudal haematopoietic tissue (CHT) and the thymus was unaffected.44.1GATA‐4, ‐5, and ‐6 are all expressed in the developing myocardium but knockout of individual GATA factors in the mouse has in general failed to abolish myocardial specification,As mentioned above, knock down of GATA‐5 in Xenopus had little effect on its own.Cardiac tissue derives from the anterior lateral plate mesoderm (ALPM) where GATA‐4, ‐5, and ‐6 are co‐expressed.4.2A common cause of heart failure in humans is the inability of cardiomyocytes (CMs) to proliferate and regenerate the lost myocardium after myocardial infarction (MI). We therefore carried out RNA sequencing (RNA‐seq) analysis of injury‐reactivated CMs in the zebrafish, where regeneration of the heart occurs, to identify spatially distinct gene expression profiles within injured ventricles. Importantly, we found that canonical Wnt antagonists were enriched in proliferating CMs proximal to the injury zone, suggesting a potential role in governing CM proliferation during heart regeneration.gata4:EGFP) zebrafish model was employed.gata4:EGFP+ CMs following injury using FACS analysis at 5 hours postinjury (hpi) and 4 days postinjury (dpi). A dramatic increase in the number of gata4:EGFP+ cells in the injury‐proximal region was observed, whereas the number was unchanged in the distal region. This observation strongly suggests that injury‐proximal gata4:EGFP+ CM cells expand by proliferation and indicates spatio‐temporal heterogeneity within CMs after injury. To identify molecular changes underlying reactivation of CM proliferation following injury, we performed an RNA‐seq experiment on injury‐activated gata4:EGFP+ CMs at 4dpi. To understand the selective induction of proliferation in proximal gata4:EGFP+ CMs, we carried out two‐way comparisons of RNA‐seq transcriptome data. Firstly, the transcriptome of FACS sorted gata4:EGFP+ CMs from whole ventricles at 4 dpi was compared to that of myl7:EGFP+ CMs from whole ventricles of sham‐operated animals. This identified 967 genes that are upregulated in the gata4:EGFP+ CMs. Secondly, ventricles of 4dpi Tg(gata4:EGFP) fish were cut into two, to separate the injury‐proximal and ‐distal regions before FACS isolation of gata4:EGFP+ CMs for spatial comparison within the injured heart. This analysis identified 956 genes upregulated in the injury‐proximal region. By intersecting these data sets, we identified 808 genes specifically upregulated in the injury‐proximal signature of gata4:EGFP+ CMs, 820 genes in the distal signature and 149 injury‐activated genes that are shared between both regions.To study this, the Tg‐term analysis indicated that CMs in the injured zone were enriched for cell division, angiogenesis, wound healing, and amino acid metabolism, consistent with their active role in proliferation and regenerating myocardium. In contrast, CMs in the distal myocardium were enriched for genes associated with heart and skeletal development, cell differentiation, and organ morphogenesis. The GO‐terms enriched within the proximal data set were also characterised by regulators of growth such as Wnt signalling. Interestingly, we found that positive and negative regulators of canonical Wnt signalling were enriched in the proximal signature,


Geschlechtstrieb] asked: ‘What approximately are the highest and lowest limits in age of the people to whom you feel drawn, or is age of no importance to you?’In 1902, founder of the Berlin Institute for Sexual Science, Magnus Hirschfeld, developed a ‘psychobiological questionnaire’ to investigate human sexuality.the erastes) and passive roles (the eromenos). Moreover, attraction to younger same‐sex partners was not seen to exclude opposite‐sex relationships: men who desired male youths could also be married to women. The influence of this material on individual identities can be found, for example, in sexological case studies or letters received by prominent Hellenic writers.As is well known, the erotic charge provided by age difference was central to many culturally prominent eighteenth‐ and nineteenth‐century understandings of same‐sex desire.At the same time, this idealisation of age‐differentiated erotics reinforced existing associations between same‐sex activity and the sexual misuse of younger people by older men.Throughout the nineteenth century, male same‐sex acts were frequently associated with the sexual coercion of young people in news media and forensic, legal and literary writings. The assumption that same‐sex relations were violations of youth fundamentally shaped sexual scientific investigations of same‐sex desire and informed intersecting explorations of childhood and adolescent sexual development.From the mid‐nineteenth century, sexual science, alongside other scientific, legal and literary discussions of childhood, constructed children as at risk of physical and moral molestation.Étude médico‐légale sur les attentats aux moeurs (1857), which included sections on sexual acts committed by adult men against boys under the age of twelve, and on male youth prostitution. Tardieu's analysis was not isolated.Ausführliches Handbuch der gerichtlichen Medizin (1826), for instance, explicitly characterised unchaste acts between males as corrupting attacks on youth. In favouring the terms ‘Knabenschande’/ ‘Knabenschändung’ [boy defilement] and ‘Päderastie’, he typified same‐sex acts as age‐differentiated, involving an ‘old man weak in body and mind’ who ‘follows boys and young men with lustful eyes’.Such depictions of the violation of young males brought into focus the image of the male sexual predator. Forensic debates reinforced an association between male same‐sex desire and the abuse of youth. Of particular importance is Ambroise Tardieu's broad study of sex crimes Die Welt als Wille und Vorstellung, Arthur Schopenhauer described pederasty as a ‘vice [Laster] of old men’ who targeted ‘male adolescents’ [Jünglinge].Terminal Essay, the ‘vice against nature’ [le vice contre nature] was predominantly perpetrated across the so‐called ‘sodatic zone’ on young male victims.Untrodden Fields of Anthropology (1896), published under the pseudonym Jacobus X, includes similar accounts of the alleged global prevalence of ‘depraved’ ‘Arabs’, ‘Chinamen’ and ‘Europeans’ demanding ‘unnatural acts’ from ‘precocious debauchees’ whose ages (when stated) ranged from seven to twenty.Similarly, in philosophical and anthropological writings, same‐sex sex acts were frequently depicted as exploitations of boys and young males, often in the form of prostitution. Reading these texts as depicting proto‐homosexual bonds between adults obscures how male same‐sex desire was framed as a form of youth corruption. For instance, in the 1859 edition of Such nineteenth‐century accounts of age‐differentiated sexual exploitation resonated with sexual scientific questions about childhood and adolescent sexual development. The understanding that early sexual experiences might be physically injurious and psychologically damaging with long‐term impacts on later life was central to sexual scientific debates which constructed childhood and adolescence as crucial periods that required careful management.The intense scrutiny of childhood and adolescent sexual development intensified towards the end of the nineteenth century. Following the work of Max Dessoir, sexual scientists like Albert Moll, Havelock Ellis and Sigmund Freud began to argue that even very young children experienced sexual desires.Nineteenth‐century investigations of childhood and adolescent sexuality and the association of male same‐sex acts with the corruption of youth had a profound impact on constructions of male homosexuality in sexual science. As the following section shows, the distinctive sexual scientific model of male homosexuality as an inborn and unchanging identity emerged in direct response to concerns about age‐differentiated bonds.To assuage fears about the violation of youth, homophile sexual scientists keen to present a socially acceptable model of male same‐sex relationships rejected affirmative framings of age‐differentiated relationships. They constructed an influential alternative model of homosexuality that was increasingly at odds with existing Hellenising accounts of same‐sex erotics that celebrated bonds between older and younger men.This sexual scientific model had four interrelated elements. First, male homosexuality was framed as involving adults rather than boys and children. Second, the concept of consent was marshalled to distinguish between legitimate and illegitimate same‐sex acts. Third, the homosexual was constructed as a person who was driven by gendered desires, rather than the desire for youth: the key characteristics of the homosexual became his attraction to other men and his lack of desire for women. Fourth, homosexuality was constructed as an inborn and unchanging lifelong orientation that was not caused by seduction or experiences in youth. This new model excluded men whose desire was directed towards younger partners. The category of the paedophile came into existence to describe such individuals and to establish clear distinctions between homosexuality and age‐differentiated desires.From the mid‐nineteenth century onwards, it was increasingly difficult for homophile authors to affirm the eroticisation of age‐differentiated male‐male relations without raising the spectre of the predatory violation of vulnerable youth. By the 1890s, Oscar Wilde's court‐room defence of the ‘love that dare not speak its name’ as an admirable form of pederastic eros was doomed in the face of a prosecution that accused him of trying to seduce the nation's youth.Sexual Inversion (1896), a book that argued for the decriminalisation of same‐sex relations between adult men only.unisexualité’, which excluded people like Wilde who, he argued, were justly convicted for their criminal influence on ‘youthful dandies’ [jeunes vanités].In response, many sexual scientists and reformers distanced themselves from the acceptance of age‐differentiated relationships. John Addington Symonds tried to reconcile his attraction to Hellenic models of age‐differentiated desires with his awareness that ‘Greek Love’ was often associated with youth corruption.Urning’ in 1864 to move away from the language of ‘boy love [Knabenliebe] – [which] gives rise to the misunderstanding that the urning really loves boys, when he loves young men (puberes)’.Some sexual scientists adopted new linguistic frameworks when writing about attachments between males to replace a language of pederasty that might imply the violation of younger people.Practisches Handbuch der gerichtlichen Medizin (1860), called for a recognition that cases of ‘Knaben‐ oder Jünglingsliebe’ [the love of boys or young men] involved adult men and mature youths.Knabenliebe’ when translating Classicist Erich Bethe's Die dorische Knabenliebe (1907), since it suggested ‘an inferiority of age too great’.Other sexual scientists, despite being equally concerned to distinguish homosexuality from child abuse, continued to acknowledge youth as an erotic stimulus of homosexual desire. These voices stressed that the erotic appeal of young males was analogous to the admiration that adult men frequently felt for younger women and, crucially, was not directed to the very young (a category that remained undefined). Such authors argued that men in ancient Greece entered into relationships with younger men who were sufficiently mature. German forensic scientist Johann Ludwig Casper, in his Building on this argument, the concept of consent assumed a key role in attempts to legitimize same‐sex behaviours and distance homosexuality from associations with youth corruption. Hirschfeld promoted raising the age of consent laws and called for the legalisation of same‐sex sex acts provided that they were consensual and involved over‐16s.Schutzaltersfrage], Hirschfeld remarked that consent could be variously defined on the basis of the biological age of maturity, the age of criminal responsibility, the age of citizenship or the age of military service.Entscheidungsfähigkeit], a stance that was cited approvingly by Bloch.Yet, determining the precise age at which the young person was able to consent was difficult, especially in the context of ongoing contestations around childhood and adolescent sexual development. Commenting on recent discussions of the ‘age of protection’  sexual horror towards women’.In constructing homosexuality as involving consenting adults, sexual scientists recast same‐sex desire as driven by the gender of the partner and not their youth. Ulrichs, for example, in the passage immediately preceding his definition of Genuine homosexuality exhibits, like heterosexuality, the character of an impulse [Triebes] arising from the very nature of the personality which, from the cradle to the grave, expresses the continuity of the individual in respect also of this specific sexual tendency; there does not exist a homosexuality limited to a particular period of life, such as childhood or youth … As such, Schopenhauer's pederasty of old men [Greisenpäderastie] … and the love of Greek boys for older men do not count as [genuine] homosexuality ….The disassociation of male‐male same‐sex desire from the seduction of youth was reinforced by the construction of male homosexuality as inborn. According to Bloch, who came to embrace the inborn model around 1906:Such presentations of homosexuality as inborn and unchanging allowed sexual scientists to reject the idea that it was caused by improper seduction in youth. Hirschfeld insisted that bonds between older and younger males were not damaging, since only young people who were congenitally predisposed towards homosexuality would enter into such relationships in the first place.pädophilia erotica’ in an 1896 article, developing an idea originally articulated in the first edition of Psychopathia Sexualis (1886).Pädophile’ in Das Sexualleben des Kindes (1908).The establishment of male homosexuality as separate from the pederastic seduction of youth presented sexual scientists with a further problem: how to account for what Symonds termed ‘the depraved debauchee who abuses boys’?Urning who was accused of abusing and murdering two boys (aged five and fifteen) in 1869, Ulrichs insisted that the man was not an Urning, but suffered from the distinct pathological desire for ‘boys too young for sex’ [unmannbaren Knaben], a pathology that also afflicted heterosexual men.unglücklichste Veranlagung] that was also exceedingly rare, affecting only 5 per cent of male homosexuals.To maintain this distinction, sexual scientists employed different strategies when confronted with cases of men who appeared to be homosexual and who also desired children.Tracing the intertwined emergence of the sexological categories of the homosexual and the paedophile in the late nineteenth and early twentieth centuries sheds new light on both the history of homosexuality and the history of paedophilia. With regard to the latter, scholars have generally maintained that a distinct construction of paedophilia did not take hold until the 1970s.The model of male homosexuality as an inborn and unchanging gender‐based orientation did not neutralise concerns about age‐differentiated relationships and the corruption of youth. Sexual scientific writings featured abundant examples apparently indicating the inculcation of young people into homosexuality. Sexual scientists did not ignore this evidence, but drew on it in considering the causes of homosexuality and debating whether it was inborn or acquired. In so doing, they engaged with and contributed to theorisations of childhood sexuality, which further destabilised the inborn model and undermined aetiological certainty.The Origin and Development of Moral Ideas (1906), he concluded that same‐sex experiences in youth, a time when the ‘sexual instinct’ was ‘somewhat indefinite’, were capable of shaping a young person's desires in ‘a homosexual direction’.Züchtung], giving the example of boys in male same‐sex brothels in China.Sexual Inversion ‘vicious cases’ involving age‐differentiated same‐sex bonds that were injurious to the younger person.Even sexual scientists seeking to present homosexuality as inborn acknowledged that formative experiences in youth could cause a younger person to develop same‐sex desires. Historical and anthropological materials  drew attention to cultures that appeared to encourage same‐sex desires in the young.echter] inborn homosexuality and acquired pseudo‐homosexuality, a distinction and terminology that Hirschfeld adopted.In response, sexual scientists began to label different kinds of homosexuality. Ellis and Symonds employed the category of ‘pseudo‐homosexuality’ to understand cases in which male homosexuality was acquired.Modern Ethics, Symonds discusses the case of the homosexual awakening experienced by a man who was touched by ‘a comrade rather older’ than himself at the age of eight.Sexual Inversion describe fantasies or actual sexual encounters with older boys and men.Attempts to differentiate between inborn and acquired homosexuality also drew attention to childhood as a decisive period in the individual's development. On the one hand, explorations of childhood sexuality supported the inborn model: demonstrating that homosexual tendencies were evident from the earliest stages of development eliminated seduction as a causative factor. Ellis and Symonds suggested that discerning whether an individual was a ‘true’ inborn homosexual required ‘a sufficiently minute knowledge of the subject in early life’.The inborn model was destabilised further by theorisations of childhood sexuality as naturally diffuse. Acknowledging that a child's desires might be undifferentiated drew attention to the developmental processes and external  forces shaping sexual orientation. Freud's accounts of sexual development, for instance, focused on the impact of young people's relationships with older persons, especially parents.scharf heterosexuell] later on in life, experienced same‐sex desires in youth.Explorations of the role of youthful seduction in causing homosexuality were not limited to psychoanalysis, but cut across different branches of sexual science.Other sexologists, especially those less invested in the project of homosexual reform, concluded that it was impossible to draw a clear distinction between inborn and acquired forms of homosexuality. In response to sexologists like Chevalier or Benjamin Tarnowsky, who stressed that homosexuality could be caused by ‘moral contagion and seduction’ in youth, Moll agreed that, alongside cases of inborn homosexuality, there were instances in which young people were corrupted into permanent homosexuality due to the diffuse nature of childhood sexuality.Even if many sexual scientists continued to foreground congenital factors in the causation of homosexuality, the inborn model was continuously challenged by arguments about childhood sexuality that drew attention to the power of external influence, including instances of youthful seduction. Despite their different investments, sexual scientists shared a fascination with the question of how and why the child developed from a state of undifferentiated sexuality into adult homo‐ or heterosexuality, which not only created divisions, but also led to ongoing dialogue between different branches of sexual science. Through these contestations, early twentieth‐century sexual science produced a range of explanatory models regarding the causes of homosexuality in which age‐differentiated relationships continued to play a significant role.Conflicts around the construction of male homosexuality as an age‐neutral, inborn gender orientation were amplified by those who wanted to validate age‐differentiated same‐sex relationships. Some deemed the championing of relationships between older and younger partners that had been a mainstay of homoerotic subcultures in late nineteenth‐century Germany and Britain incompatible with sexual scientific constructions of homosexuality. Others, including authors who were close to or part of sexual scientific circles, continued to champion age‐differentiated attachments, while simultaneously engaging with and participating in sexual scientific debate. Drawing on the claim that childhood sexuality was naturally undifferentiated, writers argued that same‐sex attachments in youth were not always opposed to the child's own desires or interests. They also rejected the idea that age‐structured relationships between males were necessarily corruptive. Indeed, they maintained that such relationships could be beneficial to both young people and society as a whole. These arguments resonated with early twentieth‐century sexual scientific debates. Instead of a clean break between proponents of age‐structured erotics and sexual scientists, concerns about sexual development in youth became a point of ongoing debate between these intersecting networks.Scientific‐Humanitarian Committee [Wissenschaftlich‐Humanitäres Kommittee (WHK)] and homophile group Die Gemeinschaft der Eigenen [Society of the Unique/One's Own/Self‐Owners], which was led by Adolf Brand and Benedict Friedländer.Die Gemeinschaft saw Hirschfeld's model of homosexuality as antithetical to their own erotic ideals, which often comprised marriage to women as well as the celebration of age‐unequal relationships between males, as expressed in their journal Der Eigene. The German‐British novelist and Der Eigene contributor John Henry Mackay, for instance, rejected sexual science altogether, criticising ‘so‐called scientific research … whose horrible confusion causes us to suffer more today than we did previously’ and castigating scientists for sacrificing the ‘love of the older man for the younger of his sex’ in pursuit of the ‘legalization of love between adults’.For some, the move to create an age‐neutral, inborn model of male homosexuality unnecessarily fractured a joint homophile project. British criminologist and law reformer George Ives was frustrated with a model of homosexuality that left little room for the erotics of age.Die Gemeinschaft, Friedländer did not see sexual science as incompatible with an affirmative understanding of age‐differentiated erotics. Friedländer, who studied zoology and claimed a position of scientific expertise, continued to collaborate with Hirschfeld and saw scientific methodologies, including biological and statistical approaches, as central to studies of human sexuality.Jahrbuch as well as his book Renaissance des Eros‐Uranios (1904), Friedländer concluded that ‘the human male is capable of experiencing the erotic drive [Liebestrieb] in both directions’.Yet, championing age‐structured attachments did not necessitate a rejection of sexual science, as much previous scholarship has suggested.frühreife] children might welcome them.Arguments about the undifferentiated nature of sexuality in childhood and youth made it possible to suggest that, far from being seduced, a young person might actively initiate a sexual relationship. In ‘Affection in Education’ 1899), Carpenter suggested: ‘[O]ften, indeed, I think they [age‐differentiated relationships] are begun by the younger [person] … [who] naively allows his admiration of the elder one to become visible’., Carpentbisexuelle Veranlagung] of all humans, falsely suggesting that same‐sex tendencies were specific to the Urning and presenting a damaging image of homosexual men as pathological and effeminate.arête’.Der Eigene, as well as Gustav Wyneken and Stefan George as part of the Free School Community [Freie Schulgemeinde] Free School Community movement.Advocates for age‐structured relationships also appropriated the sexual scientific argument that young minds were susceptible to external influences, recasting such attachments as valuable. Challenging the image of older men as damaging corruptors of youth, they suggested that there was a developmental benefit provided by intimate bonds with mature partners. This argument was further supported by the theory of universal bisexuality, which suggested that same‐sex relationships were not constitutionally alien and could be enjoyed by all members of society.Der Eigene supported such claims through an engagement with literary and historical sources, whereas writers such as Friedländer drew on biological and zoological evidence.Jahrbuch commended von Kupffer's and Carpenter's work for illustrating the ‘ethical and social significance of homosexuality’.These writers stressed that age‐differentiated bonds benefited society as a whole and not just the individual. Whereas heterosexuality served the purpose of biological reproduction, male same‐sex relationships, it was claimed, furthered social, cultural and national progress.Proponents of age‐differentiated bonds vigorously rejected an inborn model of homosexuality that involved the life‐long and singular attraction to adult males. While for some this stance entailed a break with sexual science, others expressed their interest in the erotics of age by engaging with and contributing to sexual science, drawing especially on the scientific frameworks of child development and universal bisexuality. These voices troubled the attempted erasure of the erotics of age from constructions of male homosexuality, and compelled even those sexual scientists most invested in the inborn model to continue to confront issues around age.Concerns about the erotics of age played a fundamental role in shaping modern understandings of male homosexuality. In particular, anxieties about age‐differentiated relationships drove the very emergence of the inborn model that presented homosexuality as impervious to external influence and corruption, and constructed gender (rather than age) as the central motivator of sexual desire. Yet, as demonstrated by questions about the individual's age preferences in Hirschfeld's questionnaire, which formed the starting point of this article, attempts to assert an age‐irrelevant gender‐based framework for theorising sexuality did not succeed in sidelining age‐differentiated forms of desire. The continued theorising of age also reflects the centrality of broader explorations of childhood and adolescent sexual development within British and German sexual science. Ongoing debates about the undifferentiated nature of childhood and adolescent sexuality and the role of external stimuli in shaping desire resulted in uncertainty regarding the causes of homosexuality. The idea that relationships between older and younger men and boys might shape sexual orientation remained live and contested. By demonstrating how age as a category of analysis modifies understandings of the history of male homosexuality, this article also makes a broader methodological intervention. It reveals the many different ways in which age, and figurations of sexual desire across the life course intersected with gender in shaping constructions of modern sexualities. As such, it calls upon historians of sexuality to incorporate age and gender alongside other crucial categories like race and class, which have not received full treatment in this article, in their future research.


In a presentation at the annual meeting of the Heart Failure Association of the European Society of Cardiology, investigators from Brigham and Women’s Hospital recently presented evidence that a next–generation cardiac pump device not only improves long–term outcomes but may also decrease cost of care over time for heart failure patients.The research team analysed results from the MOMENTUM 3 trial, which compared two devices: the HeartMate II (current generation) and HeartMate 3 , both manufactured by Abbott Inc, which sponsored the study.‘The HeartMate 3 left–ventricular assist device (LVAD) is a more forgiving pump in terms of clinical adverse events, and now we can confirm that its increased effectiveness is associated with decreased costs,’ said Dr Mandeep Mehra, executive director of the Centre for Advanced Heart Disease and medical director of the Heart & Vascular Centre at Brigham and Women’s Hospital. ‘In medicine, most often, a therapy that demonstrates increased effectiveness usually comes at a higher price, and we are able to show that this new technology actually decreases costs to payers and patients over time.’Mehra and colleagues found that the newer device reduced costs due to re–hospitalisation by 51%, largely driven by a decrease in stroke and pump malfunction requiring re–operation due to pump thrombosis. Patients who received the HeartMate 3 experienced fewer hospitalisations and, on average, spent 8.3 fewer days in the hospital per year than those who received the HeartMate II. The authors note that it may be possible to further reduce costs by decreasing outlier complications and reducing hospital length of stay and decrease early complications by improving patient selection criteria and considering this therapy before patients get too sick.In April, Abbott Inc issued a field safety notice regarding HeartMate 3 outflow graft twist complications with an incidence rate of 0.72%. The US Food and Drug Administration (FDA) issued a Class I recall but did not recommend the return of LVADs or avoidance of use in new patients. The current study re–reviewed 20 hospitalisations (five in the HeartMate 3 and 15 in the HeartMate II populations) and in a conservative analysis, classified them as being device–related for the purposes of this analysis. Nonetheless, the data still demonstrated a reduction in re–hospitalisation–related hospital days and significant cost savings for the HeartMate 3 compared to the HeartMate II.


Miguel A. ArandaKristiina MäkinenJeanmarie VerchotWe are very pleased to present in this Special Issue of Molecular Plant Pathology a series of short reviews on the topic “Extracellular and intracellular perception of plant viruses”. The issue summarizes important breakthroughs in plant defence against viruses. Significant advances made in recent years provide new insights into the mechanisms of antiviral immunity after virus recognition by host cells. Plant viruses constitute an important cause of major crop losses worldwide and threaten food security. The advances in the field of plant–virus interactions will expand the potential strategies for breeding and engineering resistance in crops. The articles in this issue discuss the co‐evolving virulence and plant resistance strategies exemplifying the evolutionary arms race between viruses and their hosts.nucleotide‐binding leucine‐rich repeat (NLR) receptors leading to effector‐triggered immunity (ETI), have been seen as the most critical contributions to antiviral defence in plants. As discussed in the review entitled “Perspectives on intracellular perception of plant viruses” by Meier et al. in this issue, a considerable body of knowledge on how viruses are perceived by NLRs, and how NLRs are activated and use downstream signalling pathways to initiate defence responses, has developed during these years. In spite of that, our understanding of the underlying phenomena is still far from complete. After their concise but comprehensive review, the authors draw future lines for research, and point out structural analyses of NLRs complexed with their partners as one source of critical information to understand intracellular perception of plant virus and defences activation.For the past twenty years, the endogenous RNA silencing pathway acting to degrade viral RNAs, and intracellular perception of viral proteins by et al. also discuss these aspects in their review entitled “Virus perception at the cell surface: revisiting the roles of receptor‐like kinases as viral pattern recognition receptors”. Importantly, they make a case of the NUCLEAR SHUTTLE PROTEIN (NSP)‐INTERACTING KINASE 1 (NIK1), an RLK identified in an interaction screening with NSP, which is a begomoviral protein. Activation of NIK1 leads to repression of ribosomal protein genes, suppression of global translation, including begomoviral mRNAs, and confers resistance to begomoviruses. Their data nicely fits in a model in which begomovirus‐derived nucleic acids could act as PAMPs to activate NIK1, and NSP acts as a viral effector that suppresses NIK1. Whether or not this model could be extended outside of begomoviruses is a matter of future studies.In a first layer of the plant immune system, extracellular perception of pathogen‐associated molecular patterns (PAMPs) leads to pathogen‐triggered immunity (PTI). Recent findings strongly suggest the existence of PTI‐like responses against viral infection. The newly uncovered layer of antiviral defence initiates at the plasma membrane and leads to a broad range of early responses to plant viruses. As discussed in “Molecular dialogues between viruses and receptor‐like kinases in plants” by Macho and Lozano‐Duran, activation of receptor‐like kinases (RLKs) on the cell surface during virus infection leads to activation of PTI‐related genes and multiple outcomes of plant's antiviral defence. Effects on the level of developmental rearrangements and cell‐to‐cell movement of RNAi are also possible. It is under debate whether plant viral proteins can directly act as PAMPs or whether the infection induces production of danger‐associated molecular patterns (DAMPs) for RLK activation. An increasing body of evidence is revealing that RKLs are targets of viral proteins. Teixeira Both RNA silencing and, as recently found, antiviral PTI, recognize double‐stranded (ds) RNAs as defence signals. During virus infection, replication and expression of viral genomes leads to accumulation of virus‐derived transcripts and dsRNAs. Since viruses are intracellular pathogens, we have well accepted that the cellular RNA silencing machinery recognizes viral RNAs. Antimicrobial PTI, however, involves plasma membrane‐localized pattern‐recognition receptors (PRRs). In the insightful review entitled “Perception of double‐stranded RNA in plant antiviral immunity”, Annette Niehl and Manfred Heinlein discuss several different scenarios on how perception of dsRNA by PRRs could happen during dsRNA‐mediated antiviral PTI.The series of papers closes with a review on autophagy and plant viruses. During the recent years, autophagy has turned out to have an important role in plant virus infection and antiviral immunity as highlighted by Kushwaha, Hafren and Hoffius in their review entitled “Autophagy‐virus interplay in plants: from antiviral recognition to pro‐viral manipulation”. The authors discuss a wide variety of examples of autophagy in antiviral recognition and degradation, pro‐viral counterdefence and manipulation, disease‐related cell death, immunity‐related hypersensitive reaction and other viral functions.The coming years will inevitably deepen our still limited knowledge on the mechanisms and functions of extracellular and intracellular recognition of viruses, and the contribution of autophagy in plant virus infection. We are sincerely convinced that this series of reviews can contribute to identify new important research avenues, particularly for young researchers joining the exciting field of plant virology.


Satellite scatterometers provide the only regular observations of surface wind vectors over vast swaths of the world oceans, including coastal regions, which are of great scientific and societal interest but still present challenges for remote sensing. Here we demonstrate systematic scatterometer wind errors near Hawaii's Big Island: Two counter‐rotating lee vortices, which are clear in the International Comprehensive Ocean‐Atmosphere Data Set ship‐based wind climatology and in aircraft observations, are absent in the Jet Propulsion Laboratory and Remote Sensing Systems scatterometer wind climatologies. We demonstrate similar errors in the representation of transient Catalina Eddy events in the Southern California Bight. These errors likely arise from the nonuniqueness of scatterometer wind observations, that is, an “ambiguity removal” is required during processing to select from multiple wind solutions to the geophysical model function. We discuss strategies to improve the ambiguity selection near coastal mountains, where small‐scale wind reversals are common. Orographic wind features near Hawaii's Big Island and southern California are absent in satellite scatterometer wind observationsThese systematic scatterometer wind errors near coastal mountains are due at least partially to ambiguity removal errorsPrior studies based on scatterometer winds therefore likely underestimate the influence of coastal mountains on coastal ocean circulation These are the only regular vector wind observations over vast swaths of the global oceans and are therefore vital for climate study  version 4 QuikSCAT winds  Release 3  climatology Figure , the revLg=U/f≈200 km  standard deviation, which we refer to as the wind direction error, at the five buoy locations.  QuikSCAT winds at offshore buoys 69 and 47 have direction errors <20°, within the typical range for scatterometer wind observations  is used to select an initial wind field from the ambiguous estimates. Nudging is done to ensure general wind trends are present. However, due to the coarse resolution of the nudging field, small‐scale features  may not be adequately represented, because the nudging field is too coarse to resolve them.After nudging, the wind field is processed using a median filter‐based ambiguity selection scheme to ensure consistency while preserving wind fronts Schultz, . At eachJPL uses relatively coarse (∼1°) National Centers for Environmental Prediction operational analysis winds as the nudge field for QuikSCAT processing . The JJA climatology of the JPL nudge winds is shown for the Big Island region in Figure For comparison, the ICOADS ship‐based JJA wind climatology is plotted again in Figure The Big Island lee vortices and reverse flow do not appear in JPL's nudge winds or processed QuikSCAT winds. Unfortunately RSS does not provide nudge winds in their QuikSCAT or ASCAT files, so we examine KNMI ASCAT winds instead. KNMI uses a different processing methodology than the JPL/RSS procedure described above, that is, KNMI makes its ambiguity selection according to a variational procedure that incorporates information from a background wind field and from the scatterometer ambiguities . The JJA background wind climatology shows light westerly flow in the lee of Big Island, with 40–70% westerly wind occurrence  NWP winds as the nudge field for QuikSCAT processing  are fit to the GMF, which is inverted to produce a wind field at each time. For relatively steady mesoscale wind features like in the lee of Hawaii's Big Island, it may be possible to utilize σ0 observations over a longer period to produce, say, 7‐day or 14‐day averaged winds, where the additional σ0 observations could be incorporated into the GMF inversion to improve the wind field at lower frequencies. This may require the development of a new GMF inversion technique.The systematic scatterometer wind direction errors we have identified near Hawaii and southern California are due at least partially to ambiguity selection section , which cOne implication of the wind errors highlighted in this study is that the orographic influence on surface winds is likely substantially larger than in previous scatterometer‐based estimates  winds do not capture the southeasterly winds associated with transient Catalina Eddy events. The wind errors can be traced to the ambiguity selection that is required due to the nonuniqueness of scatterometer wind observations. Similar scatterometer wind errors are likely near coastal mountains around the world, underscoring the challenge of remote sensing in the coastal zone.Supporting Information S1Click here for additional data file.


Increased treatment package time is an independent poor prognostic factor for outcomes in head and neck squamous cell carcinoma (HNSCC). Similarly the timeliness of treatment initiation is a risk factor for disease recurrence. Despite these well-known issues, the timeliness of treatment initiation is actually worsening in the United States and the expeditious completion of radiation treatments continues to be difficult secondary to a number of patients and treatment related issues. This analysis evaluates the current data on treatment intervals in the management of head and neck cancer. Rapid staging/diagnosis of head and neck cancer, appropriate referrals to providers qualified to treat said cancer, and expeditious treatment completion remains the most cost-effective, widely applicable method to improve outcomes in head and neck cancer. Time abides long enough for those who make use of it – Leonardo Da VinciIncreased treatment package time (defined as duration between the initiation and completion of curative therapy), increased time to treatment initiation (TTI – defined as the duration between the histologic diagnosis and initiation of treatment) and increased radiation treatment time  have all been demonstrated to be detrimental in the management of head and neck squamous cell carcinoma (HNSCC). In addition, prolonged TTI affects patient satisfaction and quality of life  and exacMany different types of evidence suggest that it is prudent to avoid the prolongation of initiating potentially curative radiation therapy  and cancHistorically, increased TTI was a consequence of an imbalance of supply and demand. Largely due to an increase in the use of radiation resources for breast and prostate cancers , radioth18Ffluorodeoxyglucose/positron emission tomography (FDG/PET) when used for the diagnosis, staging, and restaging of head and neck cancers [Reported TTI evaluations of patients treated with curative radiotherapy demonstrate a remarkably similar trend Table  – patien cancers . Clinici cancers . The inc cancers  to near  cancers . In addi cancers . Data fr cancers .Table 1Tp < 0.001) [p < 0.001) [Quantifying TTI is straightforward. Patients have a date of biopsy and a date of treatment start – the difference is the TTI. Evaluating the impact of TTI is much more complex. Most increases in TTI are caused in large part by the pursuit of improved care. Imaging studies to better identify areas of tumor spread pre-treatment, transitions in care to allow treatment by a more experienced provider, additional scheduling to allow concurrent chemotherapy – all of these increase TTI but also improve patient outcomes. For this reason critical appraisal of the TTI literature is somewhat difficult. Some analyses do not report a significant survival detriment to TTI , 25 whil< 0.001) . Evaluat< 0.001) .TTI is increasing in the United States and a prime reason for this increase is the pursuit of better care. This is not to say that treatment should begin in haste – patients need advanced imaging, pre-treatment dental attention, and increasingly complex treatment planning that takes time. However these necessary aspects of patient care can be completed without dangerously extended TTI. This need to coordinate multiple aspects of care in a limited amount of time is likely best accomplished by centers with high head and neck treatment volumes and likely in part responsible for said centers improved survival .While it is evident that cancer progresses over time, granular detail about growth rate is difficult to obtain. Thus, clinicians rarely directly observe this feature of tumor biology that is intricately linked to TTI. However, in an era of competition among different tumor types for limited resources (radiation treatment machine time or operating room time) the practice of definitive treatment of head and neck cancer with primary radiotherapy offers a simple mechanism to observe growth rate; most patients undergo an initial cross sectional imaging scan at the time of diagnosis and then have a similar scan performed for radiation treatment planning. Given the current state of TTI, these two scans are generally separated by a sufficiently long enough interval to allow for a measurement of tumor growth Table .Table 2GWhile predictors of a fast growth rate are not clear among different analyses, one oropharynx cancer dataset demonstrated that human papillomavirus (HPV)-negative disease grew at a faster rate than HPV-positive disease, with a suggestion that HPV-positive disease with a smoking history may also increase growth rate . Other aTreatment package time refers to patients managed with primary surgery and adjuvant (chemo)radiation. The treatment package is the interval from the extirpative operation and the eventual completion of adjuvant therapy. Initial interrogation of this phenomenon suggested that patients whose radiation was initiated more than 6 weeks after surgery had poorer control rates than those whose radiation was begun earlier –36. Othep = 0.03) and OS (p = 0.01) for the patients treated over 7 weeks, while not significant for those treated according to the accelerated schedule. As a consequence, the package time was significant for both LRC and OS [Given the suspicion that time factors most significantly influence the prognosis of high risk patients, a prospective study was conducted that evaluated accelerated adjuvant radiation alone in the setting of high risk resected head and neck cancer – both arms of the randomization received an equivalent adjuvant dose of 63 Gy, however it was administered in either 5 weeks via a concomitant boost technique or 7 weeks via daily fractionation. High risk patients treated in 5 weeks demonstrated a non-significant trend towards improved locoregional control (LRC) and overall survival (OS). Furthermore, the 5 week course was more forgiving with respect to the time interval between surgery and radiation. A prolonged interval in the time between surgery and radiation was significantly associated with worse LRC  continued to demonstrate the significant influence of treatment package time. In this analysis a significant improvement in overall survival was appreciated for those patients whose treatment was initiated within 42 days (6 weeks) of surgery when compared to those whose treatment did not begin for ≥50 days  , this anMost treatment prolongation is unplanned and likely due to acute toxicity – thus the results of prolonged RTT are difficult to study. By contrast the effects of treatment acceleration have been frequently investigated. The Radiation Therapy Oncology Group (RTOG) ran multiple trials investigating accelerated fractionation schedules for the definitive management of stage III/IV head and neck cancer with radiation alone, culminating in a large 4-arm trial of radiation alone (RTOG 9003) demonstrating, in part, that delivering 72 Gy in 6 weeks rather than 70 Gy in 7 weeks improved 2 year local-regional control by 8% . AlthougThe role of RTT in the setting of chemoradiation is less clear. Randomized trials suggest that the addition of concurrent chemotherapy improves the results of hyperfractionated definitive radiotherapy but acceleration of radiation does not enhance definitive concurrent chemoradiation , 48. Givp = 0.0013) and chemoradiation settings (HR 1.22 95% CI 1.01–1.46 p = 0.0368). Prolonged RTT has many causes, but this series was limited to patients who completed therapy. Thus, patients who expired during treatment or did not finish their radiation course as prescribed are not included. In view of this study’s generous definition of prolongation (treatment needed to be extended at least a week prior to be classified as ‘prolonged’) it would require unsustainable acceleration to mitigate the effect of a prolonged RTT  resulted in worsening survival in both the radiation alone  contribute to make the timely completion of a treatment package difficult.P = 0.002) than those treated at historically high accruing centers  despite having somewhat more favorable stage and performance status [P < 0.001) although timing was not specifically evaluated [Logic would suggest that the aforementioned difficulty in the expeditious initiation and completion of therapy could be ameliorated by familiarity; institutions that treat a high volume of head and neck cancer are likely better at the delivery of swift, high quality care. This would be expected to improve outcomes. Recent large data analyses support this premise. Patients treated on RTOG 0129 at historically low-accruing head and neck centers  had significantly worse 5-year survival  who will actually deliver care. Providers must not only perform the correct tasks in the correct order – they also must be done in parallel (i.e. visit to the dentist and staging imaging scan on the same day). Expediting treatment start and completion represents a simple, cost-effective mechanism to improve patient outcomes.


Plant peroxisomes are unique subcellular organelles which play an indispensable role in several key metabolic pathways, including fatty acid β‐oxidation, photorespiration, and degradation of reactive oxygen species. The compartmentalization of metabolic pathways into peroxisomes is a strategy for organizing the metabolic network and improving pathway efficiency. An important prerequisite, however, is the exchange of metabolites between peroxisomes and other cell compartments. Since the first studies in the 1970s scientists contributed to understanding how solutes enter or leave this organelle. This review gives an overview about our current knowledge of the solute permeability of peroxisomal membranes described in plants, yeast, mammals and other eukaryotes. In general, peroxisomes contain in their bilayer membrane specific transporters for hydrophobic fatty acids (ABC transporter) and large cofactor molecules . Smaller solutes with molecular masses below 300–400 Da, like the organic acids malate, oxaloacetate, and 2‐oxoglutarate, are shuttled via non‐selective channels across the peroxisomal membrane. In comparison to yeast, human, mammals and other eukaryotes, the function of these known peroxisomal transporters and channels in plants are discussed in this review. Nicole LinkaEdited by: Jianping Hu, Michigan State University, USAPeroxisomes are surrounded by a single membrane which functions as a permeability barrier to solutes by forming a confined compartment for peroxisomal metabolism. To connect peroxisomes to the metabolic network of the cell, the peroxisomal bilayer membrane embeds different transport proteins allowing the passage of a variety of solutes  and the ATP‐binding cassette (ABC) transporter family have been found in the peroxisomal membranes of mammals, plants and yeast Figure  Linka a. These tThe peroxisomal ABC transporters belong to the D subfamily of the ATP‐binding cassette (ABC) transporter family   precursor 12‐oxo‐phytodienoic acid (OPDA)  inside yeast peroxisomes  represents the largest group of eukaryotic transport proteins with 35 members in S. cerevisiae, called ScAnt1p (Adenine nucleotide transporter 1)   and hyperaccumulation of OPC8:0 in wound‐induced leaves .Beyond fatty acid β‐oxidation peroxisomal ATP is required for other enzymatic reactions inside peroxisomal lumen. In plants, for example, β‐oxidation is involved in phytohormone biosynthesis , short auxin . Since ATP as the energy currency plays such an important role in the cellular metabolism, it is likely that other peroxisomal pathways in addition to β‐oxidation need ATP. This includes the mevalonate pathway (MVA) in plants that is involved in the formation of isopentenyl diphosphate (IPP) and dimethylallyl pyrophosphate (DMAPP), the building blocks of isoprenoids  are located to peroxisomes: phosphomevalonate kinase (PMK) and mevalonate diphosphate decarboxylase (MVD)  has been localized to peroxisomes and oil bodies and has been reported to be involved in salt and drought stress response as well as pathogen resistance  metabolism through their contribution to the redox status of compounds, such as glutathione, thioredoxins and ascorbate  kinase family ATNADK1, AtNADK2 and AtNADK3. While AtNADK1 and AtNADK2 localize to the cytosol and plastids, respectively, AtNADK3 was shown to reside in peroxisomes  have become well established as key energy transducers , indicating that other peroxisomal NAD‐dependent reactions are not restricted in plants. A photometric screen discovered a possible contribution of AtPXN to photorespiration under fluctuating and high light conditions , fatty acid biosynthesis (plastids) and degradation (peroxisomes) , and the adenine nucleotides by counter‐exchange  is still unknown Figure . The perArabidopsis CTS it was demonstrated that during the transport process of acyl‐CoA esters the CoA moiety is cleaved off. If the CoA molecule is released into the peroxisomal matrix, the need for a peroxisomal CoA importer would obliviate. In this scenario, the role of a peroxisomal CoA carrier in plants could be to regulate the peroxisomal CoA homeostasis by exporting CoA from the peroxisomes. For instance, in plants each glyoxylate cycle releases free CoA into the peroxisomal lumen. Still, due to the presence of the human peroxisomal CoA carrier it is most likely that in plants the CoA carrier is also a member of the MCF.As a reminder, for the peroxisomal ABC transporter in Trypanosoma brucei, indicating that the existence of these channel proteins is highly conserved within the eukaryote lineage  and the outer envelope proteins of plastids (OEPs)  and are predicted to form homotrimers. Several reports demonstrated that both the mitochondrial and peroxisomal members of this family are non‐selective channels with similar basic properties   is one of the most abundant integral peroxisomal membrane proteins found in eukaryotes. It belongs to a small family of putative uncharacterized transport proteins, called MPV17/PMP22 family , and three members in yeast  (Abe and Fujiki Peroxin 11 (PEX11) is an integral membrane protein of the peroxisomal bilayer membrane with at least two predicted α‐helical transmembrane domains and both termini exposed to the cytosol  shares 40% sequence similarity to the transient receptor potential cation‐selective channel  and group 2 . In Arabidopsis mutant plants in which single PEX11 genes were silenced the peroxisome number and size were reduced  and lauric acid (C12:0), as sole carbon and energy source Table . While tpex11Δ yeast mutant to grow on oleic acid and rescue the peroxisome morphology phenotype, it remains to be solved how PEX11 proteins can fulfill two distinct functions in the eukaryotic cell − as a solute channel and as a factor required for peroxisome proliferation  (Schrader et al. de novo from vesicles from the ER and mitochondria and replicate by growth and division (Sugiura et al. An alternative mechanism for peroxisomes to exchange solutes is the transfer of vesicles from the ER or mitochondria, which both play an important role in peroxisome biogenesis. Peroxisomes derive