433 research outputs found
The Social Orienting Continuum and Response Scale (SOC-RS): A Dimensional Measure for Preschool-aged Children
Children with autism show deficits in social orienting, joint attention, orienting to their names, and social smiling as early as the first year of life. The present study describes the development of the Social Orienting Continuum and Response Scale (SOC-RS), a quantitative scale that is designed to be used in the context of video-recorded Autism Diagnostic Observation Schedule (ADOS) sessions. The SOC-RS was shown to be reliable and valid, and when applied to a longitudinal sample of children with autism studied at 2 and 4 years of age, was shown to be sensitive to decreased levels of social referencing, joint attention, orientating to name, and social smiling in autism. The implications of these findings and potential applications of the SOC-RS are discussed
Development of Thalamocortical Connectivity during Infancy and Its Cognitive Correlations
Although commonly viewed as a sensory information relay center, the thalamus has been increasingly recognized as an essential node in various higher-order cognitive circuits, and the underlying thalamocortical interaction mechanism has attracted increasing scientific interest. However, the development of thalamocortical connections and how such development relates to cognitive processes during the earliest stages of life remain largely unknown. Leveraging a large human pediatric sample (N = 143) with longitudinal resting-state fMRI scans and cognitive data collected during the first 2 years of life, we aimed to characterize the age-dependent development of thalamocortical connectivity patterns by examining the functional relationship between the thalamus and nine cortical functional networks and determine the correlation between thalamocortical connectivity and cognitive performance at ages 1 and 2 years. Our results revealed that the thalamus–sensorimotor and thalamus–salience connectivity networks were already present in neonates, whereas the thalamus–medial visual and thalamus–default mode network connectivity emerged later, at 1 year of age. More importantly, brain–behavior analyses based on the Mullen Early Learning Composite Score and visual–spatial working memory performance measured at 1 and 2 years of age highlighted significant correlations with the thalamus–salience network connectivity. These results provide new insights into the understudied early functional brain development process and shed light on the behavioral importance of the emerging thalamocortical connectivity during infancy
The Use of Stereoscopy in a Neurosurgery Training Virtual Environment
Published in Presence: Teleoperators and Virtual EnvironmentsWe have previously investigated the effectiveness of a custom built virtual environment in assisting training of a ventriculostomy procedure, which is a commonly performed procedure by a neurosurgeon and a core task for trainee surgeons. The training tool (called VCath) was initially developed as a low fidelity app for a tablet platform to provide easy access and availability to trainees. Subsequently we have developed a high fidelity version of VCath that uses a stereoscopic display to immerse the trainee in the virtual environment. This paper reports on two studies that have been carried out to compare the low and high fidelity versions of VCath, particularly to assess the value of stereoscopy. Study 1 was conducted at the second annual boot camp organized for all year one trainees in neurosurgery in the UK. Study 2 was performed on lay people, with no surgical experience. Our hypothesis was that using stereoscopy in the training task would be beneficial. Results from Study 1 demonstrated that performance improved for both the control group and the group trained with the tablet version of VCath. The group trained on the high fidelity version of VCath with a stereoscopic display showed no performance improvement. The indication is that our hypothesis is false. In Study 2, six different conditions were investigated that covered the use of training with VCath on a tablet, a mono display at two different sizes, a stereo display at two different sizes, and a control group who received no training. Results from this study with lay people show that stereoscopy can make a significant improvement to the accuracy of needle placement. The possible reasons for these results and the apparent contradiction between the two studies are discussed
Medicos, poultice wallahs and comrades in service: masculinity and military medicine in Britain during the First World War
The subject of British military medicine during the First World War has long been a fruitful one for historians of gender. From the bodily inspection of recruits and conscripts through the expanding roles of women as medical care providers to the physical and emotional aftermath of conflict experienced by men suffering from war-related wounds and illness, the medical history of the war has shed important light on how the war shaped British masculinities and femininities as cultural, subjective and embodied identities. Much of this literature has, however, focused on the gendered identities of female nurses and sick and wounded servicemen. Increasingly, however, more complex understandings of the ways in which medical caregiving in wartime shaped the gender identities of male caregivers are starting to emerge. This article explores some of these emerging understandings of the masculinity of male medical caregivers, and their relationship to the wider literature around the complex and sometimes contradictory relationship between warfare and medicine. It examines the ways in which the masculine identity of male medical caregivers from the ranks of the Royal Army Medical Corps, namely stretcher bearers and medical orderlies, was perceived and represented both by the men themselves and those they cared for. In doing so it argues that total war played a crucial role in shaping social and cultural perceptions of caregiving as a gendered practice. It also identifies particular tensions between continuity and change in social understandings of medical care as a gendered practice which would continue to shape twentieth-century British society in the war’s aftermath
Environmental and Organismal Predictors of Intraspecific Variation in the Stoichiometry of a Neotropical Freshwater Fish
The elemental composition of animals, or their organismal stoichiometry, is thought to constrain their contribution to nutrient recycling, their interactions with other animals, and their demographic rates. Factors that affect organismal stoichiometry are generally poorly understood, but likely reflect elemental investments in morphological features and life history traits, acting in concert with the environmental availability of elements. We assessed the relative contribution of organismal traits and environmental variability to the stoichiometry of an insectivorous Neotropical stream fish, Rivulus hartii. We characterized the influence of body size, life history phenotype, stage of maturity, and environmental variability on organismal stoichiometry in 6 streams that differ in a broad suite of environmental variables. The elemental composition of R. hartii was variable, and overlapped with the wide range of elemental composition documented across freshwater fish taxa. Average %P composition was ∼3.2%(±0.6), average %N∼10.7%(±0.9), and average %C∼41.7%(±3.1). Streams were the strongest predictor of organismal stoichiometry, and explained up to 18% of the overall variance. This effect appeared to be largely explained by variability in quality of basal resources such as epilithon N∶P and benthic organic matter C∶N, along with variability in invertebrate standing stocks, an important food source for R. hartii. Organismal traits were weak predictors of organismal stoichiometry in this species, explaining when combined up to 7% of the overall variance in stoichiometry. Body size was significantly and positively correlated with %P, and negatively with N∶P, and C∶P, and life history phenotype was significantly correlated with %C, %P, C∶P and C∶N. Our study suggests that spatial variability in elemental availability is more strongly correlated with organismal stoichiometry than organismal traits, and suggests that the stoichiometry of carnivores may not be completely buffered from environmental variability. We discuss the relevance of these findings to ecological stoichiometry theory
Adaptive Evolution in Ecological Communities
Multi-species interactions can influence evolution in ways that are unpredictable from studies that focus on simpler communities because direct and indirect species interactions alter the strength and direction of selection
Alterations in Skeletal Muscle Fatty Acid Handling Predisposes Middle-Aged Mice to Diet-Induced Insulin Resistance
OBJECTIVE-Although advanced age is a risk factor for type 2 diabetes, a clear understanding of the changes that occur during middle age that contribute to the development of skeletal muscle insulin resistance is currently lacking. Therefore, we sought to investigate how middle age impacts skeletal muscle fatty acid handling and to determine how this contributes to the development of diet-induced insulin resistance. RESEARCH DESIGN AND METHODS-Whole-body and skeletal muscle insulin resistance were studied in young and middle-aged wild-type and CD36 knockout (KO) mice fed either a standard or a high-fat diet for 12 weeks. Molecular signaling pathways, intramuscular triglycerides accumulation, and targeted metabolomics of in vivo mitochondrial substrate flux were also analyzed in the skeletal muscle of mice of all ages. RESULTS-Middle-aged mice fed a standard diet demonstrated an increase in intramuscular triglycerides without a concomitant increase in insulin resistance. However, middle-aged mice fed a high-fat diet were more susceptible to the development of insulin resistance a condition that could be prevented by limiting skeletal muscle fatty acid transport and excessive lipid accumulation in middle-aged CD36 KO mice. CONCLUSION-Our data provide insight into the mechanisms by which aging becomes a risk factor for the development of insulin resistance. Our data also demonstrate that limiting skeletal muscle fatty acid transport is an effective approach for delaying the development of age-associated insulin resistance and metabolic disease during exposure to a high-fat diet. Diabetes 59:1366-1375, 201
The genome of the Trinidadian guppy, Poecilia reticulata, and variation in the Guanapo population
For over a century, the live bearing guppy, Poecilia reticulata, has been used to study sexual selection as well as local adaptation. Natural guppy populations differ in many traits that are of intuitively adaptive significance such as ornamentation, age at maturity, brood size and body shape. Water depth, light supply, food resources and predation regime shape these traits, and barrier waterfalls often separate contrasting environments in the same river. We have assembled and annotated the genome of an inbred single female from a high-preda- tion site in the Guanapo drainage. The final assembly comprises 731.6 Mb with a scaffold N50 of 5.3 MB. Scaffolds were mapped to linkage groups, placing 95% of the genome assembly on the 22 autosomes and the X-chromosome. To investigate genetic variation in the population used for the genome assembly, we sequenced 10 wild caught male individu- als. The identified 5 million SNPs correspond to an average nucleotide diversity (π) of 0.0025. The genome assembly and SNP map provide a rich resource for investigating adap- tation to different predation regimes. In addition, comparisons with the genomes of other Poeciliid species, which differ greatly in mechanisms of sex determination and maternal resource allocation, as well as comparisons to other teleost genera can begin to reveal how live bearing evolved in teleost fish
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