756 research outputs found

    Seeded Native Shrub Establishment on Disturbed Sites in Southwestern Wyoming

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    Critical wildlife habitat supporting mule deer, antelope, and sage grouse in high elevation rangeland and sagebrush ecosystems of southwest Wyoming is threatened by an expanding population and energy exploration and development. Our objective was to evaluate native shrub species establishment for restoration after disturbance. In October 2005, on a well-pad disturbance, 16 accessions of 12 native shrub species were drill-seeded in single species plots in a randomized complete block design with four replications. Also, two seed mixtures (Bridger and Shell) of grass, forb, and shrub species were broadcast- or drill-seeded, and one seed mixture (Shell) was hydro-seeded to separate areas outside of the replicated plots. Densities were sampled in September 2007. By 2007, nine of the 16 shrub accessions established in the replicated plots. Atriplex aptera had the greatest establishment at six plants/m2 followed by Atriplex canescens at four plants/m2. Establishment of the other seven accessions was similar and ranged from two to 0.4 plants/m2. Where the Bridger mix was broadcast seeded, Artemisia tridentata ssp. wyomingensis, Atriplex aptera, and Krascheninnikovia lanata establishment was estimated at 10,000, 6,770, and 1,120 plants/ha, respectively. Where drill seeded, establishment of the three shrubs was 0, 4,480, and 2,240 plants/ha, respectively. Where the Shell mix was broadcast seeded, Artemisia tridentata ssp. wyomingensis, Krascheninnikovia lanata, and Atriplex canescens establishment was estimated at 21,300, 4,500, and 4,500 plants/ha, respectively. Where drill seeded, establishment for the three species was 7,800, 10,000, and 1,100 plants/ha, respectively. Where the Shell mix was hydro-seeded, only Krascheninnikovia lanata established at 1,100 plants/ha

    An Exploratory Study of Lecturers' Views of Out-of-class Academic Collaboration Among Students

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    This article reports an exploratory study of lecturers' perceptions of out-of-class academic collaboration (OCAC) among students at a large Singapore university. Two types of OCAC were investigated: collaboration initiated by students, e.g., groups decide on their own to meet to prepare for exams, and collaboration required by teachers, e.g., teachers assign students to do projects in groups. Data were collected via one-on-one interviews with 18 faculty members from four faculties at the university. Findings suggest that OCAC, especially of a teacher-required kind, is fairly common at the university. Faculty members' views on factors affecting the success of OCAC are discussed for the light they might shed on practices to enhance the effectiveness of OCAC

    Impact of Sex and Menopausal Status on Episodic Memory Circuitry in Early Midlife

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    Cognitive neuroscience of aging studies traditionally target participants age 65 and older. However, epidemiological surveys show that many women report increased forgetfulness earlier in the aging process, as they transition to menopause. In this population-based fMRI study, we stepped back by over a decade to characterize the changes in memory circuitry that occur in early midlife, as a function of sex and women's reproductive stage. Participants (N = 200; age range, 45ā€“55) performed a verbal encoding task during fMRI scanning. Reproductive histories and serologic evaluations were used to determine menopausal status. Results revealed a pronounced impact of reproductive stage on task-evoked hippocampal responses, despite minimal difference in chronological age. Next, we examined the impact of sex and reproductive stage on functional connectivity across task-related brain regions. Postmenopausal women showed enhanced bilateral hippocampal connectivity relative to premenopausal and perimenopausal women. Across women, lower 17Ī²-estradiol concentrations were related to more pronounced alterations in hippocampal connectivity and poorer performance on a subsequent memory retrieval task, strongly implicating sex steroids in the regulation of this circuitry. Finally, subgroup analyses revealed that high-performing postmenopausal women (relative to low and middle performers) exhibited a pattern of brain activity akin to premenopausal women. Together, these findings underscore the importance of considering reproductive stage, not simply chronological age, to identify neuronal and cognitive changes that unfold in the middle decades of life. In keeping with preclinical studies, these human findings suggest that the decline in ovarian estradiol production during menopause plays a significant role in shaping memory circuitry

    Dysfunctional attitudes scale perfectionism: a predictor and partial mediator of acute treatment outcome among clinically depressed adolescents.

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    The effect of perfectionism on acute treatment outcomes was explored in a randomized controlled trial of 439 clinically depressed adolescents (12-17 years of age) enrolled in the Treatment for Adolescents with Depression Study (TADS) who received cognitive behavior therapy (CBT), fluoxetine, a combination of CBT and FLX, or pill placebo. Measures included the Children\u27s Depression Rating Scale-Revised, the Suicidal Ideation Questionnaire-Grades 7-9, and the perfectionism subscale from the Dysfunctional Attitudes Scale (DAS). Predictor results indicate that adolescents with higher versus lower DAS perfectionism scores at baseline, regardless of treatment, continued to demonstrate elevated depression scores across the acute treatment period. In the case of suicidality, DAS perfectionism impeded improvement. Treatment outcomes were partially mediated by the change in DAS perfectionism across the 12-week period

    Brain-Derived Neurotrophic Factor Val66Met and Blood Glucose: A Synergistic Effect on Memory

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    Age-related declines in episodic memory performance are frequently reported, but their mechanisms remain poorly understood. Although several genetic variants and vascular risk factors have been linked to mnemonic performance in general and age differences therein, it is unknown whether and how they modify age-related memory declines. To address that question, we investigated the effect of Brain-Derived Neurotrophic Factor (BDNF) Val66Met polymorphism that affects secretion of BDNF, and fasting blood glucose level (a vascular risk factor) on episodic memory in a sample of healthy volunteers (age 19ā€“77). We found that advanced age and high-normal blood glucose levels were associated with reduced recognition memory for name-face associations and poorer prose recall. However, elevated blood glucose predicted lower memory scores only in carriers of the BDNF 66Met allele. The effect on associative memory was stronger than on free recall. These findings indicate that even low-level vascular risk can produce negative cognitive effects in genetically susceptible individuals. Alleviation of treatable vascular risks in such persons may have a positive effect on age-related cognitive declines

    Effects of a Tailored Follow-Up Intervention on Health Behaviors, Beliefs, and Attitudes

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    Background: The high rates of relapse that tend to occur after short-term behavioral interventions indicate the need for maintenance programs that promote long-term adherence to new behavior patterns. Computer-tailored health messages that are mailed to participants or given in brief telephone calls offer an innovative and time-efficient alternative to ongoing face-to-face contact with healthcare providers. Methods: Following a 1-year behavior change program, 22 North Carolina health departments were randomly assigned to a follow-up intervention or control condition. Data were collected from 1999 to 2001 by telephone-administered surveys at preintervention and postintervention for 511 low-income, midlife adult women enrolled in the Well-Integrated Screening and Evaluation for Women Across the Nation (WISEWOMAN) program at local North Carolina health departments. During the year after the behavior change program, intervention participants were mailed six sets of computer-tailored health messages and received two computer-tailored telephone counseling sessions. Main outcomes of dietary and physical activity behaviors, beliefs, and attitudes were measured. Results: Intervention participants were more likely to move forward into more advanced stages of physical activity change (p = 0.02); control participants were more likely to increase their level of dietary social support at follow-up (p = 0.05). Both groups maintained low levels of reported saturated fat and cholesterol intake at follow-up. No changes were seen in physical activity in either group. Conclusions: Mailed computer-tailored health messages and telephone counseling calls favorably modified forward physical activity stage movement but did not appreciably affect any other psychosocial or behavioral outcomes

    Integrated Multiparametric Radiomics and Informatics System for Characterizing Breast Tumor Characteristics with the OncotypeDX Gene Assay

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    Optimal use of multiparametric magnetic resonance imaging (mpMRI) can identify key MRI parameters and provide unique tissue signatures defining phenotypes of breast cancer. We have developed and implemented a new machine-learning informatic system, termed Informatics Radiomics Integration System (IRIS) that integrates clinical variables, derived from imaging and electronic medical health records (EHR) with multiparametric radiomics (mpRad) for identifying potential risk of local or systemic recurrence in breast cancer patients. We tested the model in patients (n = 80) who had Estrogen Receptor positive disease and underwent OncotypeDX gene testing, radiomic analysis, and breast mpMRI. The IRIS method was trained using the mpMRI, clinical, pathologic, and radiomic descriptors for prediction of the OncotypeDX risk score. The trained mpRad IRIS model had a 95% and specificity was 83% with an Area Under the Curve (AUC) of 0.89 for classifying low risk patients from the intermediate and high-risk groups. The lesion size was larger for the high-risk group (2.9 Ā± 1.7 mm) and lower for both low risk (1.9 Ā± 1.3 mm) and intermediate risk (1.7 Ā± 1.4 mm) groups. The lesion apparent diffusion coefficient (ADC) map values for high- and intermediate-risk groups were significantly (p \u3c 0.05) lower than the low-risk group (1.14 vs. 1.49 Ɨ 10āˆ’3 mm2/s). These initial studies provide deeper insight into the clinical, pathological, quantitative imaging, and radiomic features, and provide the foundation to relate these features to the assessment of treatment response for improved personalized medicine

    Yoga and pilates in the management of low back pain

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    Many interventions for the management of low back pain exist, however most have modest efficacy at best, and there are few with clearly demonstrated benefits once pain becomes chronic. Therapeutic exercise, on the other hand, does appear to have significant benefits for managing patients with chronic low back pain (CLBP) in terms of decreasing pain and improving function. In addition, because chronic pain is complex and does not fit a simple model, there have also been numerous trials investigating and demonstrating the efficacy of multidisciplinary pain programs for CLBP. It follows that interventions that treat more than one aspect of LBP would have significant benefits for this patient population. Yoga and Pilates which have, both been gaining in popularity over the last decade are two mindā€“body exercise interventions that address both the physical and mental aspects of pain with core strengthening, flexibility, and relaxation. There has been a slow evolution of these nontraditional exercise regimens into treatment paradigms for LBP, although few studies examining their effects have been published. The following article will focus on the scientific and theoretical basis of using yoga and Pilates in the management of CLBP
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