Clinical effectiveness and cost-effectiveness of a brief accessible cognitive behavioural therapy programme for stress in school-aged adolescents (BESST): a cluster randomised controlled trial in the UK.

BACKGROUND: Depression and anxiety are increasingly prevalent in adolescents. The Brief Educational Workshops in Secondary Schools Trial investigated the effectiveness of a brief accessible stress workshop programme for 16-18-year-olds. We aimed to investigate the clinical effectiveness and cost-effectiveness of the DISCOVER cognitive behavioural therapy (CBT) workshop on symptoms of depression in 16-18-year-olds at 6 months compared with treatment-as-usual. METHODS: We conducted a multicentre, cluster randomised controlled trial in UK schools or colleges with sixth forms to evaluate clinical effectiveness and cost-effectiveness of a brief CBT workshop (DISCOVER) compared with treatment-as-usual. We planned to enrol 60 schools and 900 adolescents, using a self-referral system to recruit participants. Schools were randomised in a 1:1 ratio for participants to receive either the DISCOVER workshop or treatment-as-usual, stratified by site and balanced on school size and index of multiple deprivation. Participants were included if they were 16-18 years old, attending for the full school year, seeking help for stress, and fluent in English and able to provide written informed consent. The outcome assessors, senior health economist, senior statistician, and chief investigator were masked. People with lived experience were involved in the study. The primary outcome was depression symptoms measured with the Mood and Feelings Questionnaire (MFQ) at 6-month follow-up, in the intention-to-treat population of all participants with full covariate data. The trial was registered with the ISRCTN registry (ISRCTN90912799). FINDINGS: 111 schools were invited to participate in the study, seven were deemed ineligible, and 47 did not provide consent. Between Oct 4, 2021, and Nov 10, 2022, 933 students at 57 schools were screened for eligibility, seven were not eligible for inclusion, and 26 did not attend the baseline meeting and assessment, resulting in 900 adolescents participating in the study. The DISCOVER group included 443 participants (295 [67%] female and 136 [31%] male) and the treatment-as-usual group included 457 participants (346 [76%] female and 92 [20%] male). 468 (52%) of the 900 participants were White, and the overall age of the participants was 17·2 years (SD 0·6). 873 (97%) adolescents were followed up in the intention-to-treat population. The primary intention-to-treat analysis (n=854) found an adjusted mean difference in MFQ of -2·06 (95% CI -3·35 to -0·76; Cohen's d=-0·17; p=0·0019) at the 6-month follow-up, indicating a clinical improvement in the DISCOVER group. The probability that DISCOVER is cost- effective compared with treatment-as-usual ranged from 61% to 78% at a £20 000 to £30 000 per quality-adjusted life-year threshold. Nine adverse events (two of which were classified as serious) were reported in the DISCOVER group and 14 (two of which were classified as serious) were reported in the treatment-as-usual group. INTERPRETATION: Our findings indicate that the DISCOVER intervention is modestly clinically effective and economically viable and could be a promising early intervention in schools. Given the importance of addressing mental health needs early in this adolescent population, additional research is warranted to explore this intervention. FUNDING: National Institute for Health and Care Research Health Technology Assessment Programme.

Brief Educational Workshops in Secondary Schools Trial (BESST trial), a school-based cluster randomised controlled trial of the DISCOVER workshop for 16-18-year-olds: recruitment and baseline characteristics.

BACKGROUND: The Brief Educational Workshops in Secondary Schools Trial (BESST) is an England-wide school-based cluster randomised controlled trial assessing the clinical and cost-effectiveness of an open-access psychological workshop programme (DISCOVER) for 16-18-year-olds. This baseline paper describes the self-referral and other recruitment processes used in this study and the baseline characteristics of the enrolled schools and participants. METHOD: We enrolled 900 participants from 57 Secondary schools across England from 4th October 2021 to 10th November 2022. Schools were randomised to receive either the DISCOVER day-long Stress workshop or treatment as usual which included signposting information. Participants will be followed up for 6 months with outcome data collection at baseline, 3-month, and 6-month post randomisation. RESULTS: Schools were recruited from a geographically and ethnically diverse sample across England. To reduce stigma, students were invited to self-refer into the study if they wanted help for stress. Their mean age was 17.2 (SD = 0.6), 641 (71%) were female and 411 (45.6%) were from ethnic minority groups. The general wellbeing of our sample measured using the Mood and Feelings Questionnaire (MFQ) found 314 (35%) of students exhibited symptoms of depression at baseline. Eighty percent of students reported low wellbeing on the Warwick Edinburgh Mental Wellbeing Scale (WEMWBS) suggesting that although the overall sample mean is below the cut-off for depression, the self-referral approach used in this study supports distressed students in coming forward. CONCLUSION: The BESST study will continue to follow up participants to collect outcome data and results will be analysed once all the data have been collected. TRIAL REGISTRATION: ISRCTN registry ISRCTN90912799. Registered on 28 May 2020.

A weakly structured stem for human origins in Africa.

Despite broad agreement that Homo sapiens originated in Africa, considerable uncertainty surrounds specific models of divergence and migration across the continent1. Progress is hampered by a shortage of fossil and genomic data, as well as variability in previous estimates of divergence times1. Here we seek to discriminate among such models by considering linkage disequilibrium and diversity-based statistics, optimized for rapid, complex demographic inference2. We infer detailed demographic models for populations across Africa, including eastern and western representatives, and newly sequenced whole genomes from 44 Nama (Khoe-San) individuals from southern Africa. We infer a reticulated African population history in which present-day population structure dates back to Marine Isotope Stage 5. The earliest population divergence among contemporary populations occurred 120,000 to 135,000 years ago and was preceded by links between two or more weakly differentiated ancestral Homo populations connected by gene flow over hundreds of thousands of years. Such weakly structured stem models explain patterns of polymorphism that had previously been attributed to contributions from archaic hominins in Africa2-7. In contrast to models with archaic introgression, we predict that fossil remains from coexisting ancestral populations should be genetically and morphologically similar, and that only an inferred 1-4% of genetic differentiation among contemporary human populations can be attributed to genetic drift between stem populations. We show that model misspecification explains the variation in previous estimates of divergence times, and argue that studying a range of models is key to making robust inferences about deep history.

Predicting the shape, size, and placement of adult human pubic symphyses.

OBJECTIVES: When reconstructing fossil pelves, the articulation of the pelvic bones largely relies on subjective decisions by researchers. Different positionings at the pubic symphysis can affect the overall morphology of the pelvis and the subsequent biological interpretation associated with that individual or species. This study aims to reduce this subjectivity using quantitative models to predict pubic symphysis morphology. METHODS: We collected 3D landmarks and semilandmarks on the pubic symphysis and adjacent aspects on the CT scans of 103 adults. Using geometric morphometrics we, (1) quantified pubic symphysis morphology, (2) trained simple and two-stage least-squares linear regression models to predict pubic symphysis shape, and (3) assessed the shape variation in the sample. The model with the lowest prediction error was identified as the best model. Principal components analysis was used to explore the effects of each variable on shape and hypothetical shapes were generated from the model to illustrate these effects. RESULTS: The best model is a two-stage least-squares model that predicts pubic symphysis size at the first stage using additive effects of sex and age, then subsequently interacts pubic symphysis size with sex and age at the second stage to predict pubic symphysis shape. Other models with low prediction errors included variables reflecting pelvic size and breadth. CONCLUSION: Linear regression modeling can be used to systematically predict pubic symphysis morphology. This method can be used in addition to other techniques to improve fossil reconstructions by more accurately estimating the morphology of this region of the pelvis.

Developing an automated skeletal phenotyping pipeline to leverage biobank-level medical imaging databases.

OBJECTIVES: Collecting skeletal measurements from medical imaging databases remains a tedious task, limiting the research utility of biobank-level data. Here we present an automated phenotyping pipeline for obtaining skeletal measurements from DXA scans and compare its performance to manually collected measurements. MATERIALS AND METHODS: A pipeline that extends the Advanced Normalization Tools (ANTs) framework was developed on 341 whole-body DXA scans of UK Biobank South Asian participants. A set of 10 measurements throughout the skeleton was automatically obtained via this process, and the performance of the method was tested on 20 additional DXA images by calculating percent error and concordance correlation coefficients (CCC) for manual and automated measurements. Stature was then regressed on the automated femoral and tibia lengths and compared to published stature regressions to further assess the reliability of the automated measurements. RESULTS: Based on percent error and CCC, the performance of the automated measurements falls into three categories: poor (sacral and acetabular breadths), variable (trunk length, upper thoracic breadth, and innominate height), and high (maximum pelvic aperture breadth, bi-iliac breadth, femoral maximum length, and tibia length). Stature regression plots indicate that the automated measurements reflect realistic body proportions and appear consistent with published data reflecting these relationships in South Asian populations. DISCUSSION: Based on the performance of this pipeline, a subset of measurements can be reliably extracted from DXA scans, greatly expanding the utility of biobank-level data for biological anthropologists and medical researchers.

Brief Educational Workshops in Secondary Schools Trial (BESST): protocol for a school-based cluster randomised controlled trial of open-access psychological workshop programme for 16-18-year-olds.

Anxiety and depression are increasingly prevalent in adolescents, often causing daily distress and negative long-term outcomes. Despite the significant and growing burden, less than 25% of those with probable diagnosis of anxiety and depression are receiving help in England. Significant barriers to help-seeking exist in this population, with a scarcity of easily accessible, effective, and cost-effective interventions tailored specially for this age group. One intervention that has been shown to be feasible to deliver and with the promise of reducing stress in this age group is a school-based stress workshop programme for 16-18-year-olds (herein called DISCOVER). The next step is to rigorously assess the effectiveness, and cost-effectiveness, of the DISCOVER intervention in a fully powered cluster randomised controlled trial (cRCT). If found to be clinically and cost-effective, DISCOVER could be scaled up as a service model UK-wide and have a meaningful impact on the mental health of adolescents across the country.Trial registration: ISRCTN registry ISRCTN90912799. Registered with ISRCTN 28 May 2020.

Open Dialogue compared to treatment as usual for adults experiencing a mental health crisis: Protocol for the ODDESSI multi-site cluster randomised controlled trial.

Background 'Open Dialogue' is a social network model of crisis and continuing mental healthcare which involves elements of service delivery such as immediate response and a style of therapeutic meeting called network meetings. Although there are indications from non-randomised studies that it may help people in their recovery from severe mental health crises and improve long-term outcomes, this has yet to be tested in a randomised controlled trial. Methods This paper outlines the protocol for a multi-site cluster-randomised control trial assessing the clinical and cost-effectiveness of Open Dialogue compared to treatment as usual (TAU) for individuals presenting in crisis to six mental health services in England. The primary outcome is time to relapse, with secondary outcomes including measures of recovery and service use. Participants will be followed-up for two years, with data collected from electronic medical records and researcher-led interviews. The analysis will compare outcomes between treatment groups as well as investigating potential mediators of effect: shared decision-making and social network quality and size. Carers of a subsample of participants will be asked about their experiences of shared decision-making, carer burden, and satisfaction. Discussion This trial will provide evidence of whether Open Dialogue services implemented in the English mental health system is an effective alternative to current care and may have important implications for the organization of community mental health services. Trial registration: retrospectively registered (108 participants recruited of 570 target) on 20/12/2019, ISRCTN52653325.

Synergistic Action of Antimicrobial Lung Proteins against Klebsiella pneumoniae.

As key components of innate immunity, lung antimicrobial proteins play a critical role in warding off invading respiratory pathogens. Lung surfactant protein A (SP-A) exerts synergistic antimicrobial activity with the N-terminal segment of the SP-B proprotein (SP-BN) against Klebsiella pneumoniae K2 in vivo. However, the factors that govern SP-A/SP-BN antimicrobial activity are still unclear. The aim of this study was to identify the mechanisms by which SP-A and SP-BN act synergistically against K. pneumoniae, which is resistant to either protein alone. The effect of these proteins on K. pneumoniae was studied by membrane permeabilization and depolarization assays and transmission electron microscopy. Their effects on model membranes of the outer and inner bacterial membranes were analyzed by differential scanning calorimetry and membrane leakage assays. Our results indicate that the SP-A/SP-BN complex alters the ultrastructure of K. pneumoniae by binding to lipopolysaccharide molecules present in the outer membrane, forming packing defects in the membrane that may favor the translocation of both proteins to the periplasmic space. The SP-A/SP-BN complex depolarized and permeabilized the inner membrane, perhaps through the induction of toroidal pores. We conclude that the synergistic antimicrobial activity of SP-A/SP-BN is based on the capability of this complex, but not either protein alone, to alter the integrity of bacterial membranes.

Preclinical MRI to Quantify Pulmonary Disease Severity and Trajectories in Poorly Characterized Mouse Models: A Pedagogical Example Using Data from Novel Transgenic Models of Lung Fibrosis.

Structural remodeling in lung disease is progressive and heterogeneous, making temporally and spatially explicit information necessary to understand disease initiation and progression. While mouse models are essential to elucidate mechanistic pathways underlying disease, the experimental tools commonly available to quantify lung disease burden are typically invasive (e.g., histology). This necessitates large cross-sectional studies with terminal endpoints, which increases experimental complexity and expense. Alternatively, magnetic resonance imaging (MRI) provides information noninvasively, thus permitting robust, repeated-measures statistics. Although lung MRI is challenging due to low tissue density and rapid apparent transverse relaxation (T2* <1 ms), various imaging methods have been proposed to quantify disease burden. However, there are no widely accepted strategies for preclinical lung MRI. As such, it can be difficult for researchers who lack lung imaging expertise to design experimental protocols-particularly for novel mouse models. Here, we build upon prior work from several research groups to describe a widely applicable acquisition and analysis pipeline that can be implemented without prior preclinical pulmonary MRI experience. Our approach utilizes 3D radial ultrashort echo time (UTE) MRI with retrospective gating and lung segmentation is facilitated with a deep-learning algorithm. This pipeline was deployed to assess disease dynamics over 255 days in novel, transgenic mouse models of lung fibrosis based on disease-associated, loss-of-function mutations in Surfactant Protein-C. Previously identified imaging biomarkers (tidal volume, signal coefficient of variation, etc.) were calculated semi-automatically from these data, with an objectively-defined high signal volume identified as the most robust metric. Beyond quantifying disease dynamics, we discuss common pitfalls encountered in preclinical lung MRI and present systematic approaches to identify and mitigate these challenges. While the experimental results and specific pedagogical examples are confined to lung fibrosis, the tools and approaches presented should be broadly useful to quantify structural lung disease in a wide range of mouse models.

Effects of hybridization on pelvic morphology: A macaque model.

Ancient DNA analyses have shown that interbreeding between hominin taxa occurred multiple times. Although admixture is often reflected in skeletal phenotype, the relationship between the two remains poorly understood, hampering interpretation of the hominin fossil record. Direct study of this relationship is often impossible due to the paucity of hominin fossils and difficulties retrieving ancient genetic material. Here, we use a sample of known ancestry hybrids between two closely related nonhuman primate taxa (Indian and Chinese Macaca mulatta) to investigate the effect of admixture on skeletal morphology. We focus on pelvic shape, which has potential fitness implications in hybrids, as mismatches between maternal pelvic and fetal cranial morphology are often fatal to mother and offspring. As the pelvis is also one of the skeletal regions that differs most between Homo sapiens and Neanderthals, investigating the pelvic consequences of interbreeding could be informative regarding the viability of their hybrids. We find that the effect of admixture in M. mulatta is small and proportional to the relatively small morphological difference between the parent taxa. Sexual dimorphism appears to be the main determinant of pelvic shape in M. mulatta. The lack of difference in pelvic shape between Chinese and Indian M. mulatta is in contrast to that between Neanderthals and H. sapiens, despite a similar split time (in generations) between the hybridizing pairs. Greater phenotypic divergence between hominins may relate to adaptations to disparate environments but may also highlight how the unique degree of cultural buffering in hominins allowed for greater neutral divergence. In contrast to some previous work identifying extreme morphologies in first- and second-generation hybrids, here the relationship between pelvic shape and admixture is linear. This linearity may be because most sampled animals have a multigenerational admixture history or because of relatively high constraints on the pelvis compared with other skeletal regions.

Surfactant protein C mutation links postnatal type 2 cell dysfunction to adult disease.

Mutations in the gene SFTPC, encoding surfactant protein C (SP-C), are associated with interstitial lung disease in children and adults. To assess the natural history of disease, we knocked in a familial, disease-associated SFTPC mutation, L188Q (L184Q [LQ] in mice), into the mouse Sftpc locus. Translation of the mutant proprotein, proSP-CLQ, exceeded that of proSP-CWT in neonatal alveolar type 2 epithelial cells (AT2 cells) and was associated with transient activation of oxidative stress and apoptosis, leading to impaired expansion of AT2 cells during postnatal alveolarization. Differentiation of AT2 to AT1 cells was also inhibited in ex vivo organoid culture of AT2 cells isolated from LQ mice; importantly, treatment with antioxidant promoted alveolar differentiation. Upon completion of alveolarization, SftpcLQ expression was downregulated, leading to resolution of chronic stress responses; however, the failure to restore AT2 cell numbers resulted in a permanent loss of AT2 cells that was linked to decreased regenerative capacity in the adult lung. Collectively, these data support the hypothesis that susceptibility to disease in adult LQ mice is established during postnatal lung development, and they provide a potential explanation for the delayed onset of disease in patients with familial pulmonary fibrosis.

Inferring archaic introgression from hominin genetic data.

Questions surrounding the timing, extent, and evolutionary consequences of archaic admixture into human populations have a long history in evolutionary anthropology. More recently, advances in human genetics, particularly in the field of ancient DNA, have shed new light on the question of whether or not Homo sapiens interbred with other hominin groups. By the late 1990s, published genetic work had largely concluded that archaic groups made no lasting genetic contribution to modern humans; less than a decade later, this conclusion was reversed following the successful DNA sequencing of an ancient Neanderthal. This reversal of consensus is noteworthy, but the reasoning behind it is not widely understood across all academic communities. There remains a communication gap between population geneticists and paleoanthropologists. In this review, we endeavor to bridge this gap by outlining how technological advancements, new statistical methods, and notable controversies ultimately led to the current consensus.

Rapid and cost-effective nutrient content analysis of cotton leaves using near-infrared spectroscopy (NIRS).

The development of portable near-infrared spectroscopy (NIRS) combined with smartphone cloud-based chemometrics has increased the power of these devices to provide real-time in-situ crop nutrient analysis. This capability provides the opportunity to address nutrient deficiencies early to optimise yield. The agriculture sector currently relies on results delivered via laboratory analysis. This involves the collection and preparation of leaf or soil samples during the growing season that are time-consuming and costly. This delays farmers from addressing deficiencies by several weeks which impacts yield potential; hence, requires a faster solution. This study evaluated the feasibility of using NIRS in estimating different macro- and micronutrients in cotton leaf tissues, assessing the accuracy of a portable handheld NIR spectrometer (wavelength range of 1,350-2,500 nm). This study first evaluated the ability of NIRS to predict leaf nutrient levels using dried and ground cotton leaf samples. The results showed the high accuracy of NIRS in predicting essential macronutrients (0.76 ≤ R 2 ≤ 0.98 for N, P, K, Ca, Mg and S) and most micronutrients (0.64 ≤ R 2 ≤ 0.81 for Fe, Mn, Cu, Mo, B, Cl and Na). The results showed that the handheld NIR spectrometer is a practical option to accurately measure leaf nutrient concentrations. This research then assessed the possibility of applying NIRS on fresh leaves for potential in-field applications. NIRS was more accurate in estimating cotton leaf nutrients when applied on dried and ground leaf samples. However, the application of NIRS on fresh leaves was still quite accurate. Using fresh leaves, the prediction accuracy was reduced by 19% for macronutrients and 11% for micronutrients, compared to dried and ground samples. This study provides further evidence on the efficacy of using NIRS for field estimations of cotton nutrients in combination with a nutrient decision support tool, with an accuracy of 87.3% for macronutrients and 86.6% for micronutrients. This application would allow farmers to manage nutrients proactively to avoid yield penalties or environmental impacts.

Virtual reconstruction of the Kebara 2 Neanderthal pelvis.

The paucity of well-preserved pelvises in the hominin fossil record has hindered robust analyses of shifts in critical biological processes throughout human evolution. The Kebara 2 pelvis remains one of the best preserved hominin pelvises, providing a rare opportunity to assess Neanderthal pelvic morphology and function. Here, we present two new reconstructions of the Kebara 2 pelvis created from CT scans of the right hip bone and sacrum. For both reconstructions, we proceeded as follows. First, we virtually reconstructed the right hip bone and the sacrum by repositioning the fragments of the hip bone and sacrum. Then, we created a mirrored copy of the right hip bone to act as the left hip bone. Next, we 3D printed the three bones and physically articulated them. Finally, we used fiducial points collected from the physically articulated models to articulate the hip bones and sacrum in virtual space. Our objectives were to (1) reposition misaligned fragments, particularly the ischiopubic ramus; (2) create a 3D model of a complete pelvis; and (3) assess interobserver reconstruction variation. These new reconstructions show that, in comparison with previous measurements, Kebara 2 possessed a higher shape index (maximum anteroposterior length/maximum mediolateral width) for the pelvic inlet and perhaps the outlet and a more anteriorly positioned sacral promontory and pubic symphysis relative to the acetabula. The latter differences result in a lower ratio between the distances anterior and posterior to the anterior margins of the acetabula. Generally, the new reconstructions tend to accentuate features of the Kebara 2 pelvis--the long superior pubic ramus and anteriorly positioned pelvic inlet--that have already been discussed for Kebara 2 and other Neanderthals.

In Vivo Generation of Lung and Thyroid Tissues from Embryonic Stem Cells Using Blastocyst Complementation.

Rationale: The regeneration and replacement of lung cells or tissues from induced pluripotent stem cell- or embryonic stem cell-derived cells represent future therapies for life-threatening pulmonary disorders but are limited by technical challenges to produce highly differentiated cells able to maintain lung function. Functional lung tissue-containing airways, alveoli, vasculature, and stroma have never been produced via directed differentiation of embryonic stem cells (ESCs) or induced pluripotent stem cells. We sought to produce all tissue components of the lung from bronchi to alveoli by embryo complementation.Objectives: To determine whether ESCs are capable of generating lung tissue in Nkx2-1-/- mouse embryos with lung agenesis.Methods: Blastocyst complementation was used to produce chimeras from normal mouse ESCs and Nkx2-1-/- embryos, which lack pulmonary tissues. Nkx2-1-/- chimeras were examined using immunostaining, transmission electronic microscopy, fluorescence-activated cell sorter analysis, and single-cell RNA sequencing.Measurements and Main Results: Although peripheral pulmonary and thyroid tissues are entirely lacking in Nkx2-1 gene-deleted embryos, pulmonary and thyroid structures in Nkx2-1-/- chimeras were restored after ESC complementation. Respiratory epithelial cell lineages in restored lungs of Nkx2-1-/- chimeras were derived almost entirely from ESCs, whereas endothelial, immune, and stromal cells were mosaic. ESC-derived cells from multiple respiratory cell lineages were highly differentiated and indistinguishable from endogenous cells based on morphology, ultrastructure, gene expression signatures, and cell surface proteins used to identify cell types by fluorescence-activated cell sorter.Conclusions: Lung and thyroid tissues were generated in vivo from ESCs by blastocyst complementation. Nkx2-1-/- chimeras can be used as "bioreactors" for in vivo differentiation and functional studies of ESC-derived progenitor cells.

Structured Psychological Support for people with personality disorder: feasibility randomised controlled trial of a low-intensity intervention.

BACKGROUND: National guidance cautions against low-intensity interventions for people with personality disorder, but evidence from trials is lacking. AIMS: To test the feasibility of conducting a randomised trial of a low-intensity intervention for people with personality disorder. METHOD: Single-blind, feasibility trial (trial registration: ISRCTN14994755). We recruited people aged 18 or over with a clinical diagnosis of personality disorder from mental health services, excluding those with a coexisting organic or psychotic mental disorder. We randomly allocated participants via a remote system on a 1:1 ratio to six to ten sessions of Structured Psychological Support (SPS) or to treatment as usual. We assessed social functioning, mental health, health-related quality of life, satisfaction with care and resource use and costs at baseline and 24 weeks after randomisation. RESULTS: A total of 63 participants were randomly assigned to either SPS (n = 33) or treatment as usual (n = 30). Twenty-nine (88%) of those in the active arm of the trial received one or more session (median 7). Among 46 (73%) who were followed up at 24 weeks, social dysfunction was lower (-6.3, 95% CI -12.0 to -0.6, P = 0.03) and satisfaction with care was higher (6.5, 95% CI 2.5 to 10.4; P = 0.002) in those allocated to SPS. Statistically significant differences were not found in other outcomes. The cost of the intervention was low and total costs over 24 weeks were similar in both groups. CONCLUSIONS: SPS may provide an effective low-intensity intervention for people with personality disorder and should be tested in fully powered clinical trials.

Ontogeny of the distal femoral metaphyseal surface and its relationship to locomotor behavior in hominoids.

OBJECTIVE: Distal femoral metaphyseal surface morphology is highly variable in extant mammals. This variation has previously been linked to differences in locomotor behavior. We perform the first systematic survey and description of the development of this morphology in extant hominoids. MATERIALS AND METHODS: We collected 3D surface laser scans of the femora of 179 human and great ape individuals throughout all subadult stages of development. We qualitatively and quantitatively describe metaphyseal surface morphology. RESULTS: We find that the metaphysis is topographically simple in all hominoids during the fetal and infant periods relative to later developmental periods, and in apes it develops significant complexity throughout development. Humans, by contrast, retain relatively flat metaphyseal surfaces throughout ontogeny. DISCUSSION: Major shifts in morphology appear to coincide with major shifts in locomotor behavior, suggesting that metaphyseal morphology is developmentally plastic and highly dependent on the biomechanical loadings at the knee joint. This is consistent with a large body of biomedical research, which demonstrates the primacy of mechanical forces in determining growth plate ossification patterns. Additionally, specific metaphyseal morphology appears highly correlated with specific locomotor modes, suggesting that metaphyseal surface morphology will be useful for reconstructing the locomotor behavior of fossil primate taxa.