Dans le contexte des changements globaux, la biodiversité en Méditerranée est menacée, notamment par une sécheresse plus intense, avec des modifications probables du fonctionnement des écosystèmes. Cette thèse étudie l’effet de la sécheresse accrue sur la végétation et la modulation des effets par la diversité végétale, par une expérimentation d’exclusion de pluie dans une garrigue au nord de Marseille avec un gradient naturel de diversité. Les performances des 4 arbustes dominants, la diversité spécifique et fonctionnelle, les relations interspécifiques et la relation diversité-productivité de la garrigue ont été étudiés sous deux niveaux de pluieAprès 2,5 années, les effets de la sécheresse accrue sur la performance des 4 arbustes dépendent de l’espèce et du paramètre évalués et peuvent être modulés par la diversité des co-dominantes. Q.coccifera parait plus résistante et résiliente, suivie de R.officinalis et finalement de C.albidus et U.parviflorus. Ceci s’explique en partie par leurs différentes stratégies d’acquisition, utilisation et conservation du carbone et de l’eau. Les traits foliaires et la diversité fonctionnelle et spécifique ne sont pas affectés significativement par la réduction des pluies, mais dépendent du nombre, l’identité et le recouvrement des dominantes. Au vu de l’effet différentiel de la sécheresse accrue sur les espèces dominantes, on peut s’attendre à un effet négatif indirect de la sécheresse sur la biodiversité et donc sur le fonctionnement de la garrigue. On confirme l’importance d’intégrer les facteurs biotiques dans les modèles visant à prévoir le fonctionnement et les services des écosystèmes dans le cadre du changement climatique. / In the global change context, the biodiversity in the Mediterranean is under threat, mainly due to the more intense drought, which could lead to modification of ecosystem functioning. This thesis focuses on the effects of higher drought on the aboveground vegetation and the modulation of these effects by plant diversity thanks to a precipitation exclusion experiment in a shrubland in the south of France whith a natural diversity gradient. The 4 dominant shrub species performances, the specific and functional diversity, the interspecific interaction, and the biodiversity-productivity relationship were studied under 2 rain levelsAfter 2,5 years the effects of increased drought on the 4 dominant shrub performances was species- and parameter-dependant and can be modulated by the diversity of the co-dominant species. Q. coccifera seems the most resistant and resilient, followed by R. officinalis and finally by C. albidus and U. parviflorus. This is partly explained by the different strategies of acquisition, utilization and conservation of carbon and water of the four species. The leaf traits, the functional and specific diversity are not significantly affected by the precipitation decrease, but they depend on the number, the identity and the cover of the dominant shrubs. Given the differential effect of higher drought on the dominant species performances, we could expect an indirect negative effect of drought on the shrubland diversity and so on ecosystem functioning. We confirm the importance of taking into account the biotic factors in models aiming to predict the ecosystem functioning and environmental risks and services under future in the climate change context

The rates of non-medical prescription drug use in the United States (U.S.) have increased dramatically in the last two decades, leading to a more than 300% increase in deaths from overdose, surpassing motor vehicle accidents as the leading cause of injury deaths. In rural areas, deaths from unintentional overdose have increased by more than 250% since 1999 while urban deaths have increased at a fraction of this rate. The objective of this research was to test the hypothesis that cultural, economic, and environmental factors prevalent in rural America affect the rate of substance use disorder (SUD) in that population, and that diagnosis of these disorders across rural and urban populations may not be generalizable due to these same effects. This study applies measurement invariance analysis and factor analysis techniques: item response theory (IRT), multiple indicators, multiple causes (MIMIC), and latent class analysis (LCA), to the DSM-IV abuse and dependency diagnosis instrument. The sample used for the study was a population of adult past-year illicit drug users living in a rural or urban area drawn from the 2011-2012 National Survey on Drug Use and Health data files (N = 3,369| analyses 1 and 2; N = 12,140| analysis 3). Results of the IRT and MIMIC analyses indicated no significant variance in DSM item function across rural and urban sub-groups; however, several socio-demographic variables including age, race, income, and gender were associated with bias in the instrument. Latent class structures differed across the sub-groups in quality and number, with the rural sample fitting a 3-class structure and the urban fitting 6-class model. Overall the rural class structure exhibited less diversity and lower prevalence of SUD in multiple drug categories (e.g. cocaine, hallucinogens, and stimulants). This result suggests underlying elements affecting SUD patterns in the two populations. These findings inform the development of surveillance instruments, clinical services, and public health programming tailored to specific communities.

No description available.

abstract: With a growing number of adults with autism spectrum disorder (ASD), more and more research has been conducted on majority male cohorts with ASD from young, adolescence, and some older age. Currently, males make up the majority of individuals diagnosed with ASD, however, recent research states that the gender gap is closing due to more advanced screening and a better understanding of how females with ASD present their symptoms. Little research has been published on the neurocognitive differences that exist between older adults with ASD compared to neurotypical (NT) counterparts, and nothing has specifically addressed older women with ASD. This study utilized neuroimaging and neuropsychological tests to examine differences between diagnosis and sex of four distinct groups: older men with ASD, older women with ASD, older NT men, and older NT women. In each group, hippocampal size (via FreeSurfer) was analyzed for differences as well as correlations with neuropsychological tests. Participants (ASD Female, n = 12; NT Female, n = 14; ASD Male, n = 30; NT Male = 22), were similar according to age, IQ, and education. The results of the study indicated that the ASD Group as a whole performed worse on executive functioning tasks (Wisconsin Card Sorting Test, Trails Making Test) and memory-related tasks (Rey Auditory Verbal Learning Test, Weschler Memory Scale: Visual Reproduction) compared to the NT Group. Interactions of sex by diagnosis approached significance only within the WCST non-perseverative errors, with the women with ASD performing worse than NT women, but no group differences between men. Effect sizes between the female groups (ASD female vs. NT female) showed more than double that of the male groups (ASD male vs. NT male) for all WCST and AVLT measures. Participants with ASD had significantly smaller right hippocampal volumes than NT participants. In addition, all older women showed larger hippocampal volumes when corrected for total intracranial volume (TIV) compared to all older men. Overall, NT Females had significant correlations across all neuropsychological tests and their hippocampal volumes whereas no other group had significant correlations. These results suggest a tighter coupling between hippocampal size and cognition in NT Females than NT Males and both sexes with ASD. This study promotes further understanding of the neuropsychological differences between older men and women, both with and without ASD. Further research is needed on a larger sample of older women with and without ASD. / Dissertation/Thesis / Masters Thesis Speech and Hearing Science 2019

Episodic future thinking is defined as the ability to mentally project oneself into the future into a specific time and place. Episodic future thinking has been explored extensively in neuroscience. However, it has not been determined whether the measurement of episodic future thinking might be valuable in a clinical neuropsychological setting. The current study examined the relationship between episodic future thinking and instrumental activities of daily living (IADLs), which is a domain of adaptive functioning frequently assessed by neuropsychologists to examine independent living potential including the ability to handle finances, prepare food, complete household duties, and manage medications. A secondary aim was to examine whether episodic future thinking is related to IADLs over and above standard measures of cognition. 61 older adults with heterogeneous neurological conditions and 41 healthy older adults completed a future thinking task (the adapted Autobiographical Interview), two measures of IADLs (an informant report measure called the Everyday Cognition Scale and a performance-based measure called the Independent Living Scales), and standard measures of memory and executive functioning. Episodic future thinking was significantly associated with performance-based IADLs when accounting for age, education, gender, and depression (r=.26, p=.010). Episodic future thinking significantly predicted performance-based IADLs over and above executive functioning (R2=.025, p=.030). Episodic future thinking was not predictive of performance-based IADLs over and above memory (p=.157). Episodic future thinking was not significantly associated with informant reported IADLs when accounting for age, education, gender, and depression (p=.284). This study suggests that episodic future thinking is significantly associated with IADLs, beyond what can be accounted for by executive functioning. Episodic future thinking may provide information about IADLs to clinical neuropsychologists so they can improve their recommendations for independent living.

Depression and anxiety are common psychiatric disturbances in Parkinson's disease (PD). Past studies have demonstrated a relationship between depression and cognitive decline in PD; however, the unique influence of anxiety has not been well studied. The objective of the present study was to differentiate the unique influences of depression and anxiety on cognitive functioning in PD. Sixty-eight cognitively intact PD patients with mild to moderate motor disease severity completed self-report questionnaires and neuropsychological tests. Two hierarchical regression analyses were conducted with executive functioning performance as the criterion variable, and two additional hierarchical regression analyses were conducted with memory performance as the criterion variable. Depression and anxiety, as measured by the Depression Anxiety and Stress Scales (DASS), served as predictors for all analyses. Each set of analyses examined the amount of added, unique variance accounted for by anxiety when depression was entered as the first predictor, and also examined the amount of added, unique variance accounted for by depression when anxiety was entered as the first predictor. It was found that depression significantly predicted delayed recall memory performance when entered as the first and second predictor. In contrast, anxiety did not significantly predict performance on any of the cognitive measures. Two DASS subscales assess for the physical symptoms of anxiety, and these subscales were not significantly correlated with any cognitive variables. However, the DASS subscales tapping into non-physical aspects of anxiety were significantly associated with several cognitive variables. Patients may have endorsed physical symptoms of anxiety due to the symptoms associated with PD, and not as a result of the genuine presence of anxiety. This could have masked a potential relationship between anxiety and cognitive functioning in PD, and suggests that specific components of anxiety may be associated with cognition in PD. Future adaptation of the DASS may be necessary to differentiate the unique influences of depression and anxiety in PD patients.

Eating disorders and non-suicidal self-injury (NSSI) are pervasive behaviors that typically begin in early to mid-adolescence. They commonly co-occur, resulting in increasingly negative psychological and physical outcomes than either behavior alone. Emotion reactivity and family functioning have been studied in relation to both eating disorders and NSSI. Both constructs have demonstrated strong relationships to these behaviors, but emotion reactivity appears to be more strongly associated with NSSI, while family functioning appears to be more strongly related to eating disorders. The current study sought to determine whether emotion reactivity and family functioning could differentiate between adolescents with only an eating disorder, only NSSI, or both behaviors. Data were collected from 229 adolescents in both inpatient and outpatient treatment programs who reported either a diagnosed eating disorder, past week NSSI, or both. Results indicated that increased emotion reactivity increased the likelihood that an individual was categorized in the NSSI only group compared to the eating disorder group and the comorbid group. There was no main effect for family functioning across all analyses. Based on these results, emotion reactivity may be an important variable to consider in distinguishing between adolescents with eating disorders who may or may not engage in NSSI, and may provide further insight when examined longitudinally

Self-regulation (SR) and executive functioning (EF) are important factors for successful student outcomes. Research suggests that executive skills facilitate the process of behavioral self-regulation. Well-developed SR and EF skills make learning more likely. Proper SR has the ability to improve attention levels and EF includes the use of working memory, both of which are essential components of the information processing system that students use continuously. One type of SR, referred to as self-management, involves a cycle of observing and recording one’s own behavior, then evaluating one’s self-assessments against those of an external observer. Self-management interventions have previously been found to reduce students’ inappropriate and off-task behaviors as well as increase classroom preparedness, on-task behavior, and academic performance. This study investigated the impact of a self-management intervention on a middle school student’s classroom preparation behaviors and his EF skills. Results suggest the participant’s overall classroom preparation behaviors were enhanced through his participation in the intervention. A few significant changes were also found in the participant’s pre- and post-intervention EF scores.

Substantial evidence from previous research has supported the idea that greater self-regulation in the form of “cool” self-regulation or executive functioning and “hot” self-regulation or effortful control is associated with higher academic achievement within the preschool years and school readiness in the kindergarten years (Anaya, 2016; Carlson, 2005). However, there are only a few studies that assess the prediction of school readiness through validated cool and hot self-regulation tasks (Carlson, 2005; Krain, Wilson, Arbuckle, Kastellanos, & Wilham, 2006; Rothbart, Ellis, Rueda, & Posner, 2003; Thompson & Giedd, 2000). There also few studies examining to what extent cool and hot-self-regulation tasks predict socio-emotional (Blair, 2002) and academic achievement (Bull & Scherif, 2001), which are aspects of school readiness. The current study examined the validity of hot and cool tasks as measures of school readiness within a preschool sample (n = 86) enrolled in one of two programs: one blended Head Start and one full Head Start program. Adapted hot and cool self-regulation tasks, global observer ratings of hot and cool self-regulation tasks (Preschool Self-Regulation Assessment Assessor Report (PSRA-AR) and the Observation of Child Temperament Scale), Woodcock Johnson subtests (Letter Word, Applied Problems, and Picture Vocabulary), teacher ratings of social competence (Social Competence and Behavioral Evaluation) and emotional competence (Emotion Regulation Checklist) were collected in the fall of the school year. Results indicated that performance on cool tasks of measures cool self-regulation were highly correlated with academic performance and that the Snack Delay task and the PSRA-AR component scores (Attention/Impulse Control and Positive Emotion) of hot self-regulation were correlated with socio-emotional competence. Additionally, there were no age differences for hot self-regulation. Regression analyses suggested that hot self-regulation predicted socio-emotional competence and cool tasks predicted academic achievement. However, conclusions regarding hot self-regulation age differences and predictive validity are limited by the sole use of one hot task within this study and the results do not warrant a conclusion regarding whether hot self-regulation and cool self-regulation are separate self-regulation constructs, given the use of only one hot task.

Participation is generally considered the ultimate rehabilitation outcome and, for individuals with progressive illnesses, elucidating the factors that impact participation is critical. Parkinson’s disease (PD) is a chronic degenerative, neurological condition affecting nearly 1 million people in the United States, making PD the second most prevalent neurodegenerative disorder. PD has a profound negative effect on functioning and activity, but limited literature exists assessing the relationship between PD and community participation. The purpose of this study was to use the World Health Organization (WHO) International Classification of Functioning, Disability, and Health (ICF) as a framework for explaining how PD affects participation. Additionally, because the ICF explains the impact of chronic illness and disability as consisting of interactions between different contextual and disease-related factors, this investigation also addressed whether the personal factors, Positive Psychological Capital (PsyCap), mediated the relationship between functioning with PD and community participation. A total of 114 individuals were surveyed from peer-led PD support groups in a Midwestern state. The study examined the individual and collective contributions of demographic characteristics, activities/functioning, environmental factors, and personal factors on community participation. Results from the hierarchical regression analysis suggest that demographic characteristics account for only 15% of the variance in participation, but when functioning was added to the model, 65% of the variance was accounted for. The addition of environmental and personal covariates did not result in any significant change in overall variance in participation. These results, along with the strong, positive linear correlations between functioning and participation (r = .78), indicate that functioning largely predicts an individual’s participation. The study also sought to identify any mediating effect of personal factors (PsyCap) on the relationship between functioning and participation. The results indicated that the completely standardized indirect coefficient was not significant, b = .065, SE = .0617, 95% CI = -.213, .029, with 0 falling within the CI, which confirms no significant effect of the mediator PsyCap. The study contributes new knowledge to the association between the symptoms associated with PD and one’s community participation. Clearly, functioning is the primary predictor of participation. The lack of mediation of PsyCap, again, supports the strength of the relationship between functioning and participation. Although PsyCap did not mediate the relationship, implications for future research are discussed.