Road hazard: a systematic review of traffic injuries following recreational cannabis legalization.

PURPOSE: Acute cannabis use is associated with impaired driving performance and increased risk of motor vehicle crashes. Following the Canadian Cannabis Act's implementation, it is essential to understand how recreational cannabis legalization impacts traffic injuries, with a particular emphasis on Canadian emergency departments. This study aims to assess the impact of recreational cannabis legalization on traffic-related emergency department visits and hospitalizations in the broader context of North America. METHODS: A systematic review was conducted according to best practices and reported using PRISMA 2020 guidelines. The protocol was registered on July 5, 2022 (PROSPERO CRD42022342126). MEDLINE(R) ALL (OvidSP), Embase (OvidSP), CINAHL (EBSCOHost), and Scopus were searched without language or date restrictions up to October 12, 2023. Studies were included if they examined cannabis-related traffic-injury emergency department visits and hospitalizations before and after recreational cannabis legalization. The risk of bias was assessed. Meta-analysis was not possible due to heterogeneity. RESULTS: Seven studies were eligible for the analysis. All studies were conducted between 2019 and 2023 in Canada and the United States. We found mixed results regarding the impact of recreational cannabis legalization on emergency department visits for traffic injuries. Four of the studies included reported increases in traffic injuries after legalization, while the remaining three studies found no significant change. There was a moderate overall risk of bias among the studies included. CONCLUSIONS: This systematic review highlights the complexity of assessing the impact of recreational cannabis legalization on traffic injuries. Our findings show a varied impact on emergency department visits and hospitalizations across North America. This underlines the importance of Canadian emergency physicians staying informed about regional cannabis policies. Training on identifying and treating cannabis-related impairments should be incorporated into standard protocols to enhance response effectiveness and patient safety in light of evolving cannabis legislation.

RéSUMé: OBJECTIF: La consommation aiguë de cannabis est associée à une conduite avec facultés affaiblies et à un risque accru d'accidents de la route. À la suite de la mise en œuvre de la Loi canadienne sur le cannabis, il est essentiel de comprendre l'incidence de la légalisation du cannabis à des fins récréatives sur les blessures de la route, en mettant l'accent sur les services d'urgence canadiens. Cette étude vise à évaluer l'impact de la légalisation du cannabis à des fins récréatives sur les visites et les hospitalisations aux urgences liées à la circulation dans le contexte plus large de l'Amérique du Nord. MéTHODES: Une revue systématique a été menée selon les meilleures pratiques et a été rapportée en utilisant les directives PRISMA 2020. Le protocole a été enregistré le 5 juillet 2022 (PROSPERO CRD42022342126). MEDLINE(R) ALL (OvidSP), Embase (OvidSP), CINAHL (EBSCOHost) et Scopus ont été fouillés sans restriction de langue ou de date jusqu'au 12 octobre 2023. Des études ont été incluses si elles examinaient les visites aux urgences et les hospitalisations avant et après la légalisation du cannabis à des fins récréatives. Le risque de biais a été évalué. La méta-analyse n'était pas possible en raison de l'hétérogénéité. RéSULTATS: Sept études étaient admissibles à l'analyse. Toutes les études ont été menées entre 2019 et 2023 au Canada et aux États-Unis. Nous avons trouvé des résultats mitigés concernant l'impact de la légalisation du cannabis récréatif sur les visites aux urgences pour les blessures de la route. Quatre des études incluaient une augmentation des accidents de la route après la légalisation, tandis que les trois autres études n'ont révélé aucun changement significatif. Le risque global de biais était modéré parmi les études incluses. CONCLUSIONS: Cet examen systématique met en évidence la complexité de l'évaluation de l'impact de la légalisation du cannabis récréatif sur les blessures de la route. Nos résultats montrent un impact varié sur les visites aux urgences et les hospitalisations en Amérique du Nord. Cela souligne l'importance pour les médecins d'urgence canadiens de se tenir informés des politiques régionales sur le cannabis. La formation sur l'identification et le traitement des déficiences liées au cannabis devrait être intégrée aux protocoles normalisés afin d'améliorer l'efficacité de l'intervention et la sécurité des patients à la lumière de l'évolution de la législation sur le cannabis.

Learning Plan Use in Undergraduate Medical Education: A Scoping Review.

PURPOSE: How to best support self-regulated learning (SRL) skills development and track trainees' progress along their competency-based medical education learning trajectory is unclear. Learning plans (LPs) may be the answer; however, information on their use in undergraduate medical education (UME) is limited. This study summarizes the literature regarding LP use in UME, explores the student's role in LP development and implementation, and identifies additional research areas. METHOD: MEDLINE, Embase, PsycInfo, Education Source, and Web of Science databases were searched for articles published from database inception to March 6, 2024, and relevant reference lists were manually searched. The review included studies of undergraduate medical students, studies of LP use, and studies of the UME stage in any geographic setting. Data were analyzed using quantitative and qualitative content analyses. RESULTS: The database search found 7,871 titles and abstracts with an additional 25 found from the manual search for a total of 7,896 articles, of which 39 met inclusion criteria. Many LPs lacked a guiding framework. LPs were associated with self-reported improved SRL skill development, learning structure, and learning outcomes. Barriers to their use for students and faculty were time to create and implement LPs, lack of training on LP development and implementation, and lack of engagement. Facilitators included SRL skill development, LP cocreation, and guidance by a trained mentor. Identified research gaps include objective outcome measures, longitudinal impact beyond UME, standardized framework for LP development and quality assessment, and training on SRL skills and LPs. CONCLUSIONS: This review demonstrates variability of LP use in UME. LPs appear to have potential to support medical student education and facilitate translation of SRL skills into residency training. Successful use requires training and an experienced mentor. However, more research is required to determine whether benefits of LPs outweigh the resources required for their use.

Decisional needs and interventions for young women considering contraceptive options: an umbrella review.

BACKGROUND: Although women face a wide range of contraceptive options, globally, young women are at risk of unintended pregnancies. Our umbrella review aimed to determine the decisional needs of nulligravida women aged 11 to 30 considering contraceptive options and identify effective interventions to support their involvement in making decisions about contraceptive use. METHODS: We followed Joanna Briggs Institute methods for umbrella reviews, theoretically guided by the Ottawa Decision Support Framework. We searched six electronic databases. Two reviewers independently screened citations, extracted data, and appraised quality using AMSTAR2. We analysed findings descriptively. RESULTS: Of 124 citations, we identified 11 reviews of variable quality (critically low to moderate quality): Six reported decisional needs and 5 reported on interventions. Decisional needs of young women were: (a) information needs about contraceptive options (e.g., mechanism of actions, eligibility, administration, side effects); (b) unclear values (concerns about hormone use) and features of different options (based on their religious values); and (c) need for support and resources (support from society and need for privacy). Compared to controls, decision support interventions including patient decision aids and patient education material increased knowledge and improved discussion of options with their clinicians. CONCLUSION: Young women making contraceptive decisions experience unmet decisional needs. Effective interventions such as patient decision aids and general patient education materials may address their decisional needs and enhance their level of participation in making contraception decisions. Implications and contribution to the field: Young women's decisional needs when considering contraceptive use are informational needs, unclear values (including religious influences), need for support and resources when facing this decision. Interventions, such as patient decision aid and patient education material can, address decisional needs by improving young women's knowledge about contraceptive options.

Weighted Blanket: An Anxiety Reduction Tool in the Outpatient Oncology Infusion Setting.

BACKGROUND: Adults with cancer experience a significantly higher level of anxiety compared with the general population. Anxiety is reported at diagnosis and throughout the cancer trajectory, and it is particularly heightened at the initiation of infusion treatments. In 2020, the COVID-19 pandemic exacerbated anxiety levels in patients receiving cancer treatments. OBJECTIVES: This evidence-based practice project evaluated the feasibility and effectiveness of using medical-grade weighted blankets to reduce anxiety in patients with cancer receiving the first two infusion treatments in the ambulatory setting. METHODS: Patients completed a modified version of the Visual Analog Scale for Anxiety to self-report anxiety pre- and postimplementation. Patients and nurses completed feasibility surveys. FINDINGS: Patients reported reduced anxiety after using a weighted blanket and described weighted blankets as comforting and soothing. More than 90% of surveyed patients agreed or strongly agreed that the blanket was comfortable, not too heavy, and easy to put on, and did not interfere with nursing care or their own activities. Nurses valued the ease of use and adherence to infection control standards.

Protocol for a scoping review study on learning plan use in undergraduate medical education.

BACKGROUND: The current paradigm of competency-based medical education and learner-centredness requires learners to take an active role in their training. However, deliberate and planned continual assessment and performance improvement is hindered by the fragmented nature of many medical training programs. Attempts to bridge this continuity gap between supervision and feedback through learner handover have been controversial. Learning plans are an alternate educational tool that helps trainees identify their learning needs and facilitate longitudinal assessment by providing supervisors with a roadmap of their goals. Informed by self-regulated learning theory, learning plans may be the answer to track trainees' progress along their learning trajectory. The purpose of this study is to summarise the literature regarding learning plan use specifically in undergraduate medical education and explore the student's role in all stages of learning plan development and implementation. METHODS: Following Arksey and O'Malley's framework, a scoping review will be conducted to explore the use of learning plans in undergraduate medical education. Literature searches will be conducted using multiple databases by a librarian with expertise in scoping reviews. Through an iterative process, inclusion and exclusion criteria will be developed and a data extraction form refined. Data will be analysed using quantitative and qualitative content analyses. DISCUSSION: By summarising the literature on learning plan use in undergraduate medical education, this study aims to better understand how to support self-regulated learning in undergraduate medical education. The results from this project will inform future scholarly work in competency-based medical education at the undergraduate level and have implications for improving feedback and supporting learners at all levels of competence. SCOPING REVIEW REGISTRATION: Open Science Framework osf.io/wvzbx.

Understanding Low Vaccine Uptake in the Context of Public Health in High-Income Countries: A Scoping Review.

Although the COVID-19 pandemic has caused the need for the largest mass vaccination campaign ever undertaken to date, African, Caribbean, and Black (ACB) populations have shown both a disproportionately high degree of negative impacts from the pandemic and the lowest willingness to become vaccinated. This scoping review aims to investigate low vaccine uptake in ACB populations relative to public health in high-income countries. A search was conducted in MEDLINE(R) ALL (OvidSP), Embase (OvidSP), CINAHL (EBSCOHost), APA PsycInfo (OvidSP), the Cochrane Central Register of Controlled Trials (OvidSP), the Cochrane Database of Systematic Reviews (OvidSP), the Allied and Complimentary Medicine Database (Ovid SP), and the Web of Science following the Joanna Briggs Institute (JBI) framework for scoping reviews, supplemented by PRISMA-ScR. Theoretical underpinnings of the intersectionality approach were also used to help interpret the complexities of health inequities in the ACB population. The eligibility criteria were based on the population, concept, context (PCC) framework, and publications from 2020-19 July 2022 which discussed vaccine uptake amongst ACB people in high-income countries were included. Analysis was carried out through thematic mapping and produced four main themes: (1) racism and inequities, (2) sentiments and behaviors, (3) knowledge and communication, and (4) engagement and influence. This study has contributed to the identification and definition of the issue of low vaccine uptake in ACB populations and has illustrated the complexity of the problems, as vaccine access is hampered by knowledge, psychological, socioeconomic, and organizational barriers at the individual, organizational, and systemic levels, leading to structural inequities that have manifested as low vaccine uptake.

Bioaccumulation of estuarine pollutants in leaf oysters (Isognomon ephippium) on the mid-north coast, New South Wales, Australia.

Filter feeding bivalves are useful bioindicators for the detection of biologically available pollutants. We investigated trace metals, metalloids, and pesticides in leaf oyster (Isognomon ephippium) soft tissue and shells and compared them to sediment in five estuaries in northern New South Wales, Australia. Concentrations of Pb, Cr, Mn, Ni, Fe and Al were higher in sediments, whereas Zn, Cd, Ag, Hg, Se and As bioaccumulated in the soft tissue. The amount of Cu, Hg and Ni in the sediment from Tweed and Richmond River estuaries exceeded the Australian national sediment quality guideline values. Only one pesticide, atrazine, was detected in leaf oyster soft tissue. Combinations of six elements in the soft tissue were the best predictors of oyster condition index and shell size, whereas sediment contaminants showed weak relationships. Overall, the bioaccumulation of metals and metalloids increases with leaf oyster size and reduces leaf oyster condition, suggesting these large bivalves are useful bioindicators for pollution in estuarine environments.

Water quality and the health of remnant leaf oyster (Isognomon ephippium) populations in four Australian estuaries.

Leaf oysters (Isognomon ephippium) are large intertidal bivalves that form shellfish reefs. They have a patchy and restricted distribution in estuaries in northern New South Wales, Australia, where the water quality is impacted by a range of anthropogenic stressors from coastal agriculture, urbanisation, industry and recreational activities, along with natural stochastic events such as flooding. Little, however, is currently known about the tolerance of leaf oysters to poor water quality. This study investigated the condition of leaf oyster populations in four estuaries, by assessing the density, size-frequency and condition index. These biological parameters were modelled against habitat water quality parameters including nutrient loads, organic and inorganic carbon, algal biomass, sedimentation and total alkalinity. The water quality assessments were replicated during dry conditions and after rain in two estuaries. Leaf oyster density, size, and body condition significantly differed among the four estuaries. Density ranged from as few as 0.04 oysters per m2 in the heavily impacted Richmond River, up to 267 oysters per m2 in the Tweed River. Overall water quality was also significantly different among the four estuaries, and significant declines in water quality were observed after rain. Distance based linear models revealed significant correlations between biological indicators of leaf oyster reef health and a range of water quality parameters. Leaf oysters with higher condition occur in locations with high dissolved oxygen and salinity levels, whereas low pH and high nutrient run-off were associated with low density and poorer oyster condition. Nevertheless, dense populations were found to persist in areas with pH below 7.9, in high turbidity (over 27 NTU) and areas dominated by fine silt. Their ability to form dense reefs on estuarine soft muddy bottom habitats with low water flow, suggests that leaf oysters could be used to complement rock oysters in future intertidal shellfish reef restoration programs.

Climate change alters shellfish reef communities: A temperate mesocosm experiment.

Climate change is expected to cause significant changes to rocky shore diversity. This study used outdoor mesocosms to test the predictions that warming and ocean acidification will alter the responses of native Trichomya hirsuta and introduced Mytilus galloprovincialis mussels, and their associated communities of infauna. Experiments consisted of orthogonal combinations of temperature (ambient 22 °C or elevated 25 °C), pCO2 (ambient 400 µatm or elevated 1000 µatm), mussel species (T. hirsuta or M. galloprovincialis), and mussel configuration (native, introduced, or both), with n = 3 replicates. Elevated pCO2 reduced the growth of T. hirsuta but not that of M. galloprovincialis, and warming and pCO2 influenced the infauna that colonised both species of mussels. There was a reduction in infaunal molluscs and an increase in polychaetes; there was, however, no effect on crustaceans. Results from this study suggest that climate-driven changes from one mussel species to another can significantly influence infaunal communities.

The structural basis of fatty acid elongation by the ELOVL elongases.

Very long chain fatty acids (VLCFAs) are essential building blocks for the synthesis of ceramides and sphingolipids. The first step in the fatty acid elongation cycle is catalyzed by the 3-keto acyl-coenzyme A (CoA) synthases (in mammals, ELOVL elongases). Although ELOVLs are implicated in common diseases, including insulin resistance, hepatic steatosis and Parkinson's, their underlying molecular mechanisms are unknown. Here we report the structure of the human ELOVL7 elongase, which comprises an inverted transmembrane barrel surrounding a 35-Å long tunnel containing a covalently attached product analogue. The structure reveals the substrate-binding sites in the narrow tunnel and an active site deep in the membrane. We demonstrate that chain elongation proceeds via an acyl-enzyme intermediate involving the second histidine in the canonical HxxHH motif. The unusual substrate-binding arrangement and chemistry suggest mechanisms for selective ELOVL inhibition, relevant for diseases where VLCFAs accumulate, such as X-linked adrenoleukodystrophy.

Disentangling autism spectrum and attention-deficit/hyperactivity symptoms over development in fragile X syndrome.

Even genetic disorders associated with monogenic aetiologies are characterized by complex and variable risk for poor outcomes, highlighting the need to follow trajectories longitudinally. Here, we investigated the longitudinal relationships between attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) symptoms in a population at high risk for both: boys with fragile X syndrome. 59 boys with fragile X syndrome aged 3-10 years old at entry participated in this study, and were followed up one and two years after their first visit. As expected, we found strong relationships over three timepoints for ADHD symptoms (as measured by the parent-rated Conners scale) and ASD symptoms (as measured by the Social Communication Questionnaire [SCQ]). In addition, using structural equation modeling (SEM) we found that ADHD symptoms at time 2 predicted ASD symptoms at time 3, suggestive of a causal relationship. Importantly, these relationships hold when including chronological age at entry to the study, as well as when including severity of impairment as measured by IQ, and their effects on both ASD and ADHD symptoms do not reach significance. This result highlights the need to study outcomes longitudinally and it informs the comorbidity of the two symptom domains in FXS as well as their potential directionality, both of which have been little researched. In addition, our findings may suggest a future need to study how ADHD symptoms and their treatment impact individuals with ASD.

OAS1, OAS2 and OAS3 restrict intracellular M. tb replication and enhance cytokine secretion.

The 2',5' (OASs) are known as mediators of the antiviral response system through activation of the RNA cleavage pathway. Interestingly, we observe OAS1, OAS2 and OAS3 upregulation in a number of gene expression signatures which discriminate active TB from latent TB infection, however their biological role during bacterial infection has not yet been elucidated. We observed that the expression of these genes was associated with pathogenicity and virulence of mycobacteria as infection with Mycobacterium bovis BCG failed to significantly induce OAS expression. Further, we observed that after silencing of these genes, M. tb CFU counts increased significantly 96h post-infection in comparison to the respective controls. Luminex revealed that OAS silencing significantly decreased IL-1ß, TNF-α and MCP-1 and had no effect of IL-10 secretion. We show for the first time that OAS1, 2 and 3 restrict intracellular pathogenic mycobacterial replication and enhance pro-inflammatory cytokine secretion.

Do conventional cooking methods alter concentrations of per- and polyfluoroalkyl substances (PFASs) in seafood?

Per-and poly-fluoroalkyl substances (PFASs) are bioaccumulative chemicals of emerging concern. Some PFASs accumulate in seafood, and can contribute to dietary exposure. Previous work has suggested cooking seafood decreases concentrations of neutral organic contaminants, however, previous studies dealing with PFASs have shown conflicting results. In this study, the potential changes of PFAS concentrations as a result of boiling, frying and baking are systematically examined. Blue Swimmer Crab (Portunus armatus), Dusky Flathead (Platycephalus fuscus) and School Prawn (Metapenaeus macleayi) were obtained from near a known PFAS point source and a reference location (affected by diffuse sources). Raw and cooked samples were analysed for commonly found PFASs. Of 23 target analytes, PFOS was the most frequently detected compound. PFOS, PFHxS and PFOA concentrations in School Prawn effectively doubled after boiling, and PFOS increased when Dusky Flathead was baked. There was no significant difference in PFOS concentration when Dusky Flathead was fried, or when the Blue Swimmer Crab was boiled. PFHxS and PFOA concentrations in Blue Swimmer Crab effectively halved after boiling. Increase in PFAS concentrations possibly arise from mass loss during the cooking process. Our data show that cooking does not consistently reduce PFAS concentrations, and cannot mitigate dietary exposure.

Enhanced coronary arteriolar contraction to vasopressin in patients with diabetes after cardiac surgery.

OBJECTIVE: Cardioplegic arrest (CP) and cardiopulmonary bypass (CPB) are associated with vasomotor dysfunction of coronary arterioles in patients with diabetes (DM) undergoing cardiac surgery. We hypothesized that DM may up-regulate vasopressin receptor expression and alter the contractile response of coronary arterioles to vasopressin in the setting of CP/CPB. METHODS: Right atrial tissue samples of patients with DM and without (ND) (n = 8 in each group) undergoing cardiac surgery were harvested before and after CP/CPB. The isolated coronary arterioles (80-150 µm) dissected from the harvested right atrial tissue samples were cannulated and pressurized (40 mm Hg) in a no-flow state. The changes in diameter were measured with video microscopy. The protein expression/localization of vasopressin 1A receptors (V1A) and vasopressin 1B receptors (V1B) in the atrial tissue were measured by immune-blotting and immunohistochemistry. RESULTS: The pre-CP/CPB contractile responses of the coronary arterioles to vasopressin were significantly increased post-CP/CPB in both the ND and DM groups. This effect was more pronounced in the vessels from patients in the DM group than that of vessels from patients in the ND group (P < .05). Vasopressin-induced contractile response of the coronary arterioles was inhibited in the presence of the specific V1A antagonist SR 49059 (10-7 M) in both ND and DM vessels (P < .05). The post-CP/CPB protein levels of V1A were significantly increased compared with pre-CP/CPB values in both the ND and DM groups (P < .05), whereas this increase was greater in DM than that of ND (P < .05). Immunohistochemistry staining further indicates that V1B were mainly expressed in the myocardium but not in vascular smooth muscle. CONCLUSIONS: CP/CPB and DM are both associated with up-regulation in V1 receptor expression/localization in human myocardium. Vasopressin may induce coronary arteriolar constriction via V1A. This alteration may lead to increased coronary arteriolar spasm in patients with DM undergoing CP/CPB and cardiac surgery.

Decreased coronary arteriolar response to KCa channel opener after cardioplegic arrest in diabetic patients.

We have recently found that diabetes is associated with the inactivation of the calcium-activated potassium channels (KCa) in endothelial cells, which may contribute to endothelial dysfunction in diabetic patients at baseline. In the current study, we further investigated the effects of diabetes on coronary arteriolar responses to the small (SK) and intermediate (IK) KCa opener NS309 in diabetic and non-diabetic patients and correlated that data with the changes in the SK/IK protein expression/distribution in the setting of cardioplegic ischemia and reperfusion (CP) and cardiopulmonary bypass (CPB). Coronary arterioles from the harvested right atrial tissue samples from diabetic and non-diabetic patients (n = 8/group) undergoing cardiac surgery were dissected pre- and post-CP/CPB. The in vitro relaxation response of pre-contracted arterioles was examined in the presence of the selective SK/IK opener NS309 (10-9-10-5 M). The protein expression/localization of KCa channels in the harvested atrial tissue samples, coronary microvessels, and primary cultured human coronary endothelial cells were assayed by Western blotting and immunohistochemistry. The relaxation response to NS309 post-CP/CPB was significantly decreased in diabetic and non-diabetic groups compared to their pre-CP/CPB responses, respectively (P < 0.05). Furthermore, this decrease was greater in the diabetic group than that of the non-diabetic group (P < 0.05). There were no significant differences in the total protein expression/distribution of SK/IK in the human myocardium, coronary microvessels or coronary endothelial cells between diabetic and non-diabetic groups or between pre- and post-CP/CPB (P > 0.05). Our results suggest that diabetes further inactivates SK/IK channels of coronary microvasculature early after CP/CPB and cardiac surgery. The lack of diabetic changes in SK/IK protein abundances in the setting of CP/CPB suggests that the effect is post-translational. This alteration may contribute to post-operative endothelial dysfunction in the diabetic patients early after CP/CPB and cardiac surgery.

Latitudinal gradients in ecosystem engineering by oysters vary across habitats.

Ecological theory predicts that positive interactions among organisms will increase across gradients of increasing abiotic stress or consumer pressure. This theory has been supported by empirical studies examining the magnitude of ecosystem engineering across environmental gradients and between habitat settings at local scale. Predictions that habitat setting, by modifying both biotic and abiotic factors, will determine large-scale gradients in ecosystem engineering have not been tested, however. A combination of manipulative experiments and field surveys assessed whether along the east Australian coastline: (1) facilitation of invertebrates by the oyster Saccostrea glomerata increased across a latitudinal gradient in temperature; and (2) the magnitude of this effect varied between intertidal rocky shores and mangrove forests. It was expected that on rocky shores, where oysters are the primary ecosystem engineer, they would play a greater role in ameliorating latitudinal gradients in temperature than in mangroves, where they are a secondary ecosystem engineer living under the mangrove canopy. On rocky shores, the enhancement of invertebrate abundance in oysters as compared to bare microhabitat decreased with latitude, as the maximum temperatures experienced by intertidal organisms diminished. By contrast, in mangrove forests, where the mangrove canopy resulted in maximum temperatures that were cooler and of greater humidity than on rocky shores, we found no evidence of latitudinal gradients of oyster effects on invertebrate abundance. Contrary to predictions, the magnitude by which oysters enhanced biodiversity was in many instances similar between mangroves and rocky shores. Whether habitat-context modifies patterns of spatial variation in the effects of ecosystem engineers on community structure will depend, in part, on the extent to which the environmental amelioration provided by an ecosystem engineer replicates that of other co-occurring ecosystem engineers.

Face processing in Williams syndrome is already atypical in infancy.

Face processing is a crucial socio-cognitive ability. Is it acquired progressively or does it constitute an innately-specified, face-processing module? The latter would be supported if some individuals with seriously impaired intelligence nonetheless showed intact face-processing abilities. Some theorists claim that Williams syndrome (WS) provides such evidence since, despite IQs in the 50s, adolescents/adults with WS score in the normal range on standardized face-processing tests. Others argue that atypical neural and cognitive processes underlie WS face-processing proficiencies. But what about infants with WS? Do they start with typical face-processing abilities, with atypicality developing later, or are atypicalities already evident in infancy? We used an infant familiarization/novelty design and compared infants with WS to typically developing controls as well as to a group of infants with Down syndrome matched on both mental and chronological age. Participants were familiarized with a schematic face, after which they saw a novel face in which either the features (eye shape) were changed or just the configuration of the original features. Configural changes were processed successfully by controls, but not by infants with WS who were only sensitive to featural changes and who showed syndrome-specific profiles different from infants with the other neurodevelopmental disorder. Our findings indicate that theorists can no longer use the case of WS to support claims that evolution has endowed the human brain with an independent face-processing module.

Mapping developmental trajectories of attention and working memory in fragile X syndrome: developmental freeze or developmental change?

Fragile X syndrome (FXS) has a characteristic cognitive "signature" that by late childhood includes core weaknesses in attention and working memory (WM), but their earlier developmental trajectories remain uncharted. Using a combined cross-sectional and prospective longitudinal design, we tested whether early profiles of attention and WM impairment in FXS indicate developmental freeze or developmental change. In Study 1, 26 young boys with FXS and 55 typically developing (TD) boys completed two experimental paradigms designed to assess cognitive aspects of attention and WM, in addition to behavioral indices of inattention and hyperactivity. Study 2 mapped longitudinal changes in 21 children with FXS and 21 TD children. In Study 1, significant weaknesses emerged for boys with FXS, with no substantial improvement over chronological age. Mapping performance against mental age level revealed delay, but it also yielded a similar attention and WM profile to TD boys. In Study 2, longitudinal improvements for boys with FXS paralleled those in TD children. In conclusion, cognitive attention and WM, although delayed in FXS, reveal developmental change, rather than "arrest." Our findings underscore the need for going beyond cross-sectional group comparisons and gross behavioral indices to map cognitive changes longitudinally in developmental disorders.

Does attention constrain developmental trajectories in fragile x syndrome? A 3-year prospective longitudinal study.

Basic attentional processes and their impact on developmental trajectories in fragile X syndrome were assessed in a 3-year prospective study. Although fragile X syndrome is a monogenic X-linked disorder, there is striking variability in outcomes even in young boys with the condition. Attention is a key factor constraining interactions with the environment, so it is a perfect candidate to predict trajectories in cognitive and behavioral outcomes. In this study, 48 boys with fragile X syndrome were assessed 3 times over 24 months. Although nonverbal IQ declined, there were significant improvements in nonverbal growth scores and in cognitive attention. In contrast, behavioral difficulties (i.e., autistic symptomatology, hyperactivity-inattention) remained stable over this time frame. Attentional markers in the visual and auditory modalities predicted intellectual abilities and classroom behavior, whereas auditory markers alone predicted autistic symptomatology.