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Around 1000 years ago, Madagascar experienced the collapse of populations of large vertebrates that ultimately resulted in many species going extinct. The factors that led to this collapse appear to have differed regionally, but in some ways, key processes were similar across the island. This review evaluates four hypotheses that have been proposed to explain the loss of large vertebrates on Madagascar: Overkill, aridification, synergy, and subsistence shift. We explore regional differences in the paths to extinction and the significance of a prolonged extinction window across the island. The data suggest that people who arrived early and depended on hunting, fishing, and foraging had little effect on Madagascar’s large endemic vertebrates. Megafaunal decline was triggered initially by aridification in the driest bioclimatic zone, and by the arrival of farmers and herders in the wetter bioclimatic zones. Ultimately, it was the expansion of agropastoralism across both wet and dry regions that drove large endemic vertebrates to extinction everywhere.
Objectives/Goals: The aim of the study is to identify resistance factors for substance use (i.e., factors that explicitly help to avoid or reduce drug use). Identification of resistance factors could inform strategies that seek to reduce the prevalence of substance use and related disorders. Methods/Study Population: Adult twins aged 30–70 years were recruited from the Mid-Atlantic Twin Registry. A mixed-method approach, group concept mapping, was used to identify factors influencing participants to resist using substances. Approximately 155 participants produced 97 statements reflecting substance use resistance factors. Hierarchical cluster analysis and multidimensional scaling assessed how participants sorted and rated statements for their lifetime and current importance. Factor analysis was used to reduce data dimensionality. Reliability analyses were conducted to identify a subset of statements anticipated to consistently represent each cluster. Results were shared with participants to assess accuracy with their experiences. Results/Anticipated Results: Participants sorted 97 statements into 9 thematic clusters: (1) Controlling Personal, Negative Consequences; (2) Concern About Health and Well-being; (3) Lack of Desire; (4) Outside Influences; (5) Social Norms and My Reputation; (6) Career and Legal Impacts, (7) Avoiding Harm to Family and Relationships; (8) Preserving Family Relationships; and (9) Family and Friends Impact on Me. Participants consistently identified health concerns as an important substance use resistance factor. The statements will be further reduced to represent a smaller subset for future use as a scale to measure exposure to resistance factors. Discussion/Significance of Impact: Health concerns related to substance use were identified as an important resistance factor. This has been supported by research on smoking cessation and implemented in smoking prevention campaigns. Therefore, prioritizing health-related outcomes in prevention may be important to reduce substance use prevalence.
Cognitive impairment, anxiety, depression, fatigue, and dependence in instrumental activities of daily living (ADL) are common after stroke; however, little is known about how these outcomes may differ following treatment with endovascular clot retrieval (ECR), intravenous tissue plasminogen activator (t-PA), or conservative management.
Methods:
Patients were recruited after acute treatment and invited to participate in an outcome assessment 90–120 days post-stroke. The assessment included a cognitive test battery and several questionnaires. The COVID-19 pandemic led to significant disruptions in recruitment and data collection, and the t-PA and conservative management groups were combined into a standard medical care (SMC) group.
Results:
Sixty-two participants were included in the study (ECR = 31, SMC = 31). Mean age was 66.5 (20–86) years, and 35 (56.5%) participants were male. Participants treated with ECR had significantly higher National Institutes of Health Stroke Scale scores at presentation and significantly lower education. After adjusting for stroke severity, premorbid intellectual ability, and age, treatment with ECR was associated with significantly better performances on measures of cognitive screening, visual working memory, and verbal learning and memory. Participants treated with ECR also experienced less fatigue and were more likely to achieve independence in basic and instrumental ADLs. Despite this, cognitive impairment and fatigue were still common among participants treated with ECR and anxiety and depression symptoms were experienced similarly by both groups.
Conclusions:
Cognitive impairment and fatigue were less common but still prevalent following treatment with ECR. This has important practical implications for stroke rehabilitation, and routine assessment of cognition, emotion, and fatigue is recommended for all stroke survivors regardless of stroke treatment and functional outcome.
Acute Appendicitis (AA) is an inflammatory condition of the vermiform appendix in the caecum of the colon. Genetic polymorphisms have been suggested as risk factors predisposing to AA susceptibility but have remained relatively unknown, due to insufficient sample size in previous analyses. Therefore, the primary research aim was to identify genetic variants associated with AA. It was hypothesised that gene polymorphisms associated with AA will provide a connection to other diet-related inflammatory diseases. Genetic variants associated with AA were studied via a Genome-Wide Association Scan (GWAS) using the Global Biobank Meta-Analysis Initiative (GBMI). The GBMI is a collaborative consortium of 23 biobanks with a publicly released repository of de-identified genetic data linked with digital health records spanning 4 continents with a study population size of over 2.2 million consented individuals of multiple ancestral backgrounds1. A linear regression model was used to estimate the association between single nucleotide polymorphisms (SNPs), across the human genome, and AA by each contributing biobank. The results were then meta-analysed with a total of 32,706 cases and 1,075,763 controls. In the present study, the free open-source Complex Traits Genetic Virtual Lab (CTG-VL) platform was used to access, analyse, and visualise the GWAS summary statistics of AA2. Genome-wide significantly associated SNPs (p-value < 5 x 10-8) were further searched for their associations with health-related traits in publicly available GWAS summary statistics. Upon analysis, significantly associated SNPs for AA were identified within or nearby nine genes. HLX, NKX2-3, LTBR, and DLEU1 are genes involved in immune responses; IRF8 associated with maturation of myeloid cells; OSR-1 responsible for transmembrane ion transporter activity; NCALD a regulator of G protein-coupled signal transduction. In addition, based on the hypothesis, the SNP of key clinical importance was the HLA-C rs2524046 (p-value = 2.38 x 10-8), with the AA risk-increasing allele C being also strongly associated with a higher risk of coeliac disease (CD). The CD is an autoimmune condition where gluten, a protein present in grains such as barley, rye, and wheat, elicits an inflammatory response that results in damage to the small intestine lining. Considering how both AA and CD share the same SNP, it is possible to speculate whether gluten initiates a similar pathophysiological mechanism that exacerbates inflammation in the vermiform appendix in AA. In conclusion, the top AA associated SNPs suggests its development could be due to immunological responses influenced by dietary nutrient intake. The HLA-C SNP is common to AA and CD, suggesting that the gluten protein found in certain cereal grains possibly contributes to the pathophysiology of AA like CD. This warrants further investigations into whether dietary gluten could play a key role in AA development.
Individuals tend to overestimate their abilities in areas where they are less competent. This cognitive bias is known as the Dunning-Krueger effect. Research shows that Dunning-Krueger effect occurs in persons with traumatic brain injury and healthy comparison participants. It was suggested by Walker and colleagues (2017) that the deficits in cognitive awareness may be due to brain injury. Confrontational naming tasks (e.g., Boston Naming Test) are used to evaluate language abilities. The Cordoba Naming Test (CNT) is a 30-item confrontational naming task developed to be administered in multiple languages. Hardy and Wright (2018) conditionally validated a measure of perceived mental workload called the NASA Task Load Index (NASA-TLX). They found that workload ratings on the NASA-TLX increased with increased task demands on a cognitive task. The purpose of the present study was to determine whether the Dunning-Kruger effect occurs in a Latinx population and possible factors driving individuals to overestimate their abilities on the CNT. We predicted the low-performance group would report better CNT performance, but underperform on the CNT compared to the high-performance group.
Participants and Methods:
The sample consisted of 129 Latinx participants with a mean age of 21.07 (SD = 4.57). Participants were neurologically and psychologically healthy. Our sample was divided into two groups: the low-performance group and the high-performance group. Participants completed the CNT and the NASA-TLX in English. The NASA-TLX examines perceived workload (e.g., performance) and it was used in the present study to evaluate possible factors driving individuals to overestimate their abilities on the CNT. Participants completed the NASA-TLX after completing the CNT. Moreover, the CNT raw scores were averaged to create the following two groups: low-performance (CNT raw score <17) and high-performance (CNT raw score 18+). A series of ANCOVA's, controlling for gender and years of education completed were used to evaluate CNT performance and CNT perceived workloads.
Results:
We found the low-performance group reported better performance on the CNT compared to the high-performance, p = .021, np2 = .04. However, the high-performance group outperformed the low-performance group on the CNT, p = .000, np2 = .53. Additionally, results revealed the low-performance group reported higher temporal demand and effort levels on the CNT compared to the high-performance group, p's < .05, nps2 = .05.
Conclusions:
As we predicted, the low-performance group overestimated their CNT performance compared to the high-performance group. The current data suggest that the Dunning-Kruger effect occurs in healthy Latinx participants. We also found that temporal demand and effort may be influencing awareness in the low-performance group CNT performance compared to the high-performance group. The present study suggests subjective features on what may be influencing confrontational naming task performance in low-performance individuals more than highperformance individuals on the CNT. Current literature shows that bilingual speakers underperformed on confrontational naming tasks compared to monolingual speakers. Future studies should investigate if the Dunning-Kruger effects Latinx English monolingual speakers compared to Spanish-English bilingual speakers on the CNT.
Performance validity tests (PVTs) are included in neuropsychological testing to ensure examinees are performing to the best of their abilities. There are two types of PVTs: embedded and free standing. Embedded PVTs are tests that are derived from standard neuropsychological tests of various cognitive domains. Freestanding PVTs are tests that are designed with the intention of being a PVT. Research studies show that undergraduate samples do not always performed to the best of their abilities. The purpose of this study was to cross-validate previous research on the topic of performance validity in a college sample. It was predicted that the non-credible group would demonstrate higher failure rates on embedded PVTs compared to the credible group.
Participants and Methods:
The sample consisted of 198 neurologically and psychologically healthy undergraduate students with a mean age of 19.69 (SD = 2.11). Participants were broken into two groups: non-credible (i.e., participants that failed two or more PVTs) and credible (i.e., participants that did not failed two or more PVTs). The Rey-Osterrith copy test, Comalli Stroop part A (CSA), B (CSB), and C (CSC), Trail Making Test part A and B, Symbol Digit Modalities Test written (SDMT-W) and oral (SDMT-O) parts, Controlled Oral Word Association Test (COWAT) letter fluency, and Finger Tapping Test were used to evaluate failure rates in our sample. PVT cutoff scores were use from previously validated in the literature. Chi-square analysis was used to evaluate failure rates between the groups.
Results:
Chi-square analysis revealed significant failure rate differences between groups on several PVTs. Results revealed that 15% of the non-credible group failed the CSA compared to 1% of the credible group, X2=14.77, p=.000. Meanwhile, 26% of the non-credible group failed the CSB compared to 2% of the credible group, X2=24.72, p=.000. Furthermore, results showed that 11% of the non-credible group failed the CSC compared to 1% of the credible group, X2=13.05, p=.000.Next, 48% of the non-credible group failed the Trail Making Test part A compared to 8% of the credible group, X2=31.61, p=.000. We also found that 15% of the non-credible group failed the SDMT-W part compared to 1% of the credible group,X2=19.18, p=.000. Meanwhile, on the SDMT-O part 19% of the non-credible group failed compared to 1% of the credible group, X2=25.52, p =.000. On the COWAT letter fluency task 74% of the non-credible group failed compared to 19% of the credible group, X2=36.90, p=.000. Finally, results revealed on the Finger Tapping Test 19% of the non-credible group failed compared to 3% of the credible group, X2=10.01, p=.002.
Conclusions:
As expected, the non-credible participants demonstrated significantly higher PVT failure rates compared to credible participants. A possible explanation driving higher failure rates in our sample can be due to cultural variables (e.g., bilingualism). It was suggested by researchers that linguistic factors may be impacting higher PVT failure rates and developing a false-positive error. Future research using undergraduate samples need to identify which PVT’s are being impacted by linguist factors.
In our article, we share the lessons we have learned after creating and running a successful legal laboratory over the past seven years at Yale Law School. Our legal laboratory, which focuses on the intersection of law and severe brain injury, represents a unique pedagogical model for legal academia, and is closely influenced by the biomedical laboratory.
The U.S. Department of Agriculture–Agricultural Research Service (USDA-ARS) has been a leader in weed science research covering topics ranging from the development and use of integrated weed management (IWM) tactics to basic mechanistic studies, including biotic resistance of desirable plant communities and herbicide resistance. ARS weed scientists have worked in agricultural and natural ecosystems, including agronomic and horticultural crops, pastures, forests, wild lands, aquatic habitats, wetlands, and riparian areas. Through strong partnerships with academia, state agencies, private industry, and numerous federal programs, ARS weed scientists have made contributions to discoveries in the newest fields of robotics and genetics, as well as the traditional and fundamental subjects of weed–crop competition and physiology and integration of weed control tactics and practices. Weed science at ARS is often overshadowed by other research topics; thus, few are aware of the long history of ARS weed science and its important contributions. This review is the result of a symposium held at the Weed Science Society of America’s 62nd Annual Meeting in 2022 that included 10 separate presentations in a virtual Weed Science Webinar Series. The overarching themes of management tactics (IWM, biological control, and automation), basic mechanisms (competition, invasive plant genetics, and herbicide resistance), and ecosystem impacts (invasive plant spread, climate change, conservation, and restoration) represent core ARS weed science research that is dynamic and efficacious and has been a significant component of the agency’s national and international efforts. This review highlights current studies and future directions that exemplify the science and collaborative relationships both within and outside ARS. Given the constraints of weeds and invasive plants on all aspects of food, feed, and fiber systems, there is an acknowledged need to face new challenges, including agriculture and natural resources sustainability, economic resilience and reliability, and societal health and well-being.
Mental health problems are elevated in autistic individuals but there is limited evidence on the developmental course of problems across childhood. We compare the level and growth of anxious-depressed, behavioral and attention problems in an autistic and typically developing (TD) cohort.
Methods
Latent growth curve models were applied to repeated parent-report Child Behavior Checklist data from age 2–10 years in an inception cohort of autistic children (Pathways, N = 397; 84% boys) and a general population TD cohort (Wirral Child Health and Development Study; WCHADS; N = 884, 49% boys). Percentile plots were generated to quantify the differences between autistic and TD children.
Results
Autistic children showed elevated levels of mental health problems, but this was substantially reduced by accounting for IQ and sex differences between the autistic and TD samples. There was small differences in growth patterns; anxious-depressed problems were particularly elevated at preschool and attention problems at late childhood. Higher family income predicted lower base-level on all three dimensions, but steeper increase of anxious-depressed problems. Higher IQ predicted lower level of attention problems and faster decline over childhood. Female sex predicted higher level of anxious-depressed and faster decline in behavioral problems. Social-affect autism symptom severity predicted elevated level of attention problems. Autistic girls' problems were particularly elevated relative to their same-sex non-autistic peers.
Conclusions
Autistic children, and especially girls, show elevated mental health problems compared to TD children and there are some differences in predictors. Assessment of mental health should be integrated into clinical practice for autistic children.
Background: Recently, we showed cathodal high-definition transcranial direct current stimulation (HD-tDCS) inhibits spikes in refractory status epilepticus (RSE) patients. We sought to characterize relative power changes within regional frequency bands to explore connectivity throughout stimulation. Methods: 28 ICU-EEGs from 10 patients were filtered with 1Hz-lower/127Hz-upper/60Hz-notch. Power spectral density was computed for each individual bipolar-longitudinal (excluding midline) electrode chain in delta/theta/alpha/beta/gamma frequency bands. Relative power was extracted throughout recordings by Welch’s method with 2.5-second Hanning window size with 50% overlap every 10 seconds. The average of relative powers from ≤20-minute pre/during/post stimulation windows were calculated per session/chain/band. Absolute maximal relative power change between pre-during and during-post were computed. ANOVA statistically tested for differences. Results: Change in pre-during for delta/theta/alpha/beta/gamma were respectively -0.7%/-3.1%/-2.8%/-2.1%/8.2%, and during-post were 1.3%/2.8%/2.3%/1.7%/-7%. Positive average changes are increases in average relative power where negative changes show decreases. Changes in absolute maximal average relative power between pre-during and during-post stimulation between frequency bands were significant respectively (p=0.0011, p=0.0139). Conclusions: Relative power in all bands drop pre-during and increase during-post except gamma which correlates with desynchronization being a mechanism for HD-tDCS efficacy in RSE. These frequency band power changes may imply brain connectivity changes that need to be further explored.
The coronavirus disease 2019 (COVID-19) pandemic highlighted the lack of agreement regarding the definition of aerosol-generating procedures and potential risk to healthcare personnel. We convened a group of Massachusetts healthcare epidemiologists to develop consensus through expert opinion in an area where broader guidance was lacking at the time.
While unobscured and radio-quiet active galactic nuclei are regularly being found at redshifts
$z > 6$
, their obscured and radio-loud counterparts remain elusive. We build upon our successful pilot study, presenting a new sample of low-frequency-selected candidate high-redshift radio galaxies (HzRGs) over a sky area 20 times larger. We have refined our selection technique, in which we select sources with curved radio spectra between 72–231 MHz from the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. In combination with the requirements that our GLEAM-selected HzRG candidates have compact radio morphologies and be undetected in near-infrared
$K_{\rm s}$
-band imaging from the Visible and Infrared Survey Telescope for Astronomy Kilo-degree Infrared Galaxy (VIKING) survey, we find 51 new candidate HzRGs over a sky area of approximately
$1200\ \mathrm{deg}^2$
. Our sample also includes two sources from the pilot study: the second-most distant radio galaxy currently known, at
$z=5.55$
, with another source potentially at
$z \sim 8$
. We present our refined selection technique and analyse the properties of the sample. We model the broadband radio spectra between 74 MHz and 9 GHz by supplementing the GLEAM data with both publicly available data and new observations from the Australia Telescope Compact Array at 5.5 and 9 GHz. In addition, deep
$K_{\rm s}$
-band imaging from the High-Acuity Widefield K-band Imager (HAWK-I) on the Very Large Telescope and from the Southern Herschel Astrophysical Terahertz Large Area Survey Regions
$K_{\rm s}$
-band Survey (SHARKS) is presented for five sources. We discuss the prospects of finding very distant radio galaxies in our sample, potentially within the epoch of reionisation at
$z \gtrsim 6.5$
.
Adolescent major depressive disorder (MDD) is associated with disrupted processing of emotional stimuli and difficulties in cognitive reappraisal. Little is known however about how current pharmacotherapies act to modulate the neural mechanisms underlying these key processes. The current study therefore investigated the neural effects of fluoxetine on emotional reactivity and cognitive reappraisal in adolescent depression.
Methods
Thirty-one adolescents with MDD were randomised to acute fluoxetine (10 mg) or placebo. Seventeen healthy adolescents were also recruited but did not receive any treatment for ethical reasons. During functional magnetic resonance imaging (fMRI), participants viewed aversive images and were asked to either experience naturally the emotional state elicited (‘Maintain’) or to reinterpret the content of the pictures to reduce negative affect (‘Reappraise’). Significant activations were identified using whole-brain analysis.
Results
No significant group differences were seen when comparing Reappraise and Maintain conditions. However, when compared to healthy controls, depressed adolescents on placebo showed reduced visual activation to aversive pictures irrespective of the condition. The depressed adolescent group on fluoxetine showed the opposite pattern, i.e. increased visuo-cerebellar activity in response to aversive pictures, when compared to depressed adolescents on placebo.
Conclusions
These data suggest that depression in adolescence may be associated with reduced visual processing of aversive imagery and that fluoxetine may act to reduce avoidance of such cues. This could reflect a key mechanism whereby depressed adolescents engage with negative cues previously avoided. Future research combining fMRI with eye-tracking is nonetheless needed to further clarify these effects.
The Hierarchical Taxonomy of Psychopathology (HiTOP) has emerged out of the quantitative approach to psychiatric nosology. This approach identifies psychopathology constructs based on patterns of co-variation among signs and symptoms. The initial HiTOP model, which was published in 2017, is based on a large literature that spans decades of research. HiTOP is a living model that undergoes revision as new data become available. Here we discuss advantages and practical considerations of using this system in psychiatric practice and research. We especially highlight limitations of HiTOP and ongoing efforts to address them. We describe differences and similarities between HiTOP and existing diagnostic systems. Next, we review the types of evidence that informed development of HiTOP, including populations in which it has been studied and data on its validity. The paper also describes how HiTOP can facilitate research on genetic and environmental causes of psychopathology as well as the search for neurobiologic mechanisms and novel treatments. Furthermore, we consider implications for public health programs and prevention of mental disorders. We also review data on clinical utility and illustrate clinical application of HiTOP. Importantly, the model is based on measures and practices that are already used widely in clinical settings. HiTOP offers a way to organize and formalize these techniques. This model already can contribute to progress in psychiatry and complement traditional nosologies. Moreover, HiTOP seeks to facilitate research on linkages between phenotypes and biological processes, which may enable construction of a system that encompasses both biomarkers and precise clinical description.
Depression is characterised by negative views of the self. Antidepressant treatment may remediate negative self-schema through increasing processing of positive information about the self. Changes in affective processing during social interactions may increase expression of prosocial behaviours, improving interpersonal communications.
Aims
To examine whether acute administration of citalopram is associated with an increase in positive affective learning biases about the self and prosocial behaviour.
Method
Healthy volunteers (n = 41) were randomised to either an acute 20 mg dose of citalopram or matched placebo in a between-subjects double-blind design. Participants completed computer-based cognitive tasks designed to measure referential affective processing, social cognition and expression of prosocial behaviours.
Results
Participants administered citalopram made more cooperative choices than those administered placebo in a prisoner's dilemma task (β = 20%, 95% CI: 2%, 37%). Exploratory analyses indicated that participants administered citalopram showed a positive bias when learning social evaluations about a friend (β = 4.06, 95% CI: 0.88, 7.24), but not about the self or a stranger. Similarly, exploratory analyses found evidence of increased recall of positive words and reduced recall of negative words about others (β = 2.41, 95% CI: 0.89, 3.93), but not the self, in the citalopram group.
Conclusions
Participants administered citalopram showed greater prosocial behaviours, increased positive recall and increased positive learning of social evaluations towards others. The increase in positive affective bias and prosocial behaviours towards others may, at least partially, be a mechanism of antidepressant effect. However, we found no evidence that citalopram influenced self-referential processing.
Potential loss of energetic ions including alphas and radio-frequency tail ions due to classical orbit effects and magnetohydrodynamic instabilities (MHD) are central physics issues in the design and experimental physics programme of the SPARC tokamak. The expected loss of fusion alpha power due to ripple-induced transport is computed for the SPARC tokamak design by the ASCOT and SPIRAL orbit-simulation codes, to assess the expected surface heating of plasma-facing components. We find good agreement between the ASCOT and SPIRAL simulation results not only in integrated quantities (fraction of alpha power loss) but also in the spatial, temporal and pitch-angle dependence of the losses. If the toroidal field (TF) coils are well-aligned, the SPARC edge ripple is small (0.15–0.30 %), the computed ripple-induced alpha power loss is small (${\sim } 0.25\,\%$) and the corresponding peak surface power density is acceptable ($244\ \textrm{kW}\ \textrm {m}^{-2}$). However, the ripple and ripple-induced losses increase strongly if the TF coils are assumed to suffer increasing magnitudes of misalignment. Surface heat loads may become problematic if the TF coil misalignment approaches the centimetre level. Ripple-induced losses of the energetic ion tail driven by ion cyclotron range of frequency (ICRF) heating are not expected to generate significant wall or limiter heating in the nominal SPARC plasma scenario. Because the expected classical fast-ion losses are small, SPARC will be able to observe and study fast-ion redistribution due to MHD including sawteeth and Alfvén eigenmodes (AEs). SPARC's parameter space for AE physics even at moderate $Q$ is shown to reasonably overlap that of the demonstration power plant ARC (Sorbom et al., Fusion Engng Des., vol. 100, 2015, p. 378), and thus measurements of AE mode amplitude, spectrum and associated fast-ion transport in SPARC would provide relevant guidance about AE behaviour expected in ARC.