549 research outputs found

    Panel Discussion - Management of Eurasian watermilfoil in the United States using native insects: State regulatory and management issues

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    While researchers have evaluated the potential of native insect herbivores to manage nonindigenous aquatic plant species such as Eurasian watermilfoil ( Myriophyllum spicatum L.), the practical matters of regulatory compliance and implementation have been neglected. A panel of aquatic nuisance species program managers from three state natural resource management agencies (Minnesota, Vermont and Washington) discussed their regulatory and policy concerns. In addition, one ecological consultant attempting to market one of the native insects to manage Eurasian watermilfoil added his perspective on the special challenges of distributing a native biological control agent for management of Eurasian watermilfoil

    Chimeric protein repair of laminin polymerization ameliorates muscular dystrophy phenotype

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    Mutations in laminin α2-subunit (Lmα2, encoded by LAMA2) are linked to approximately 30% of congenital muscular dystrophy cases. Mice with a homozygous mutation in Lama2 (dy2J mice) express a nonpolymerizing form of laminin-211 (Lm211) and are a model for ambulatory-type Lmα2-deficient muscular dystrophy. Here, we developed transgenic dy2J mice with muscle-specific expression of αLNNd, a laminin/nidogen chimeric protein that provides a missing polymerization domain. Muscle-specific expression of αLNNd in dy2J mice resulted in strong amelioration of the dystrophic phenotype, manifested by the prevention of fibrosis and restoration of forelimb grip strength. αLNNd also restored myofiber shape, size, and numbers to control levels in dy2J mice. Laminin immunostaining and quantitation of tissue extractions revealed increased Lm211 expression in αLNNd-transgenic dy2J mice. In cultured myotubes, we determined that αLNNd expression increased myotube surface accumulation of polymerization-deficient recombinant laminins, with retention of collagen IV, reiterating the basement membrane (BM) changes observed in vivo. Laminin LN domain mutations linked to several of the Lmα2-deficient muscular dystrophies are predicted to compromise polymerization. The data herein support the hypothesis that engineered expression of αLNNd can overcome polymerization deficits to increase laminin, stabilize BM structure, and substantially ameliorate muscular dystrophy

    Making Classical Ground State Spin Computing Fault-Tolerant

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    We examine a model of classical deterministic computing in which the ground state of the classical system is a spatial history of the computation. This model is relevant to quantum dot cellular automata as well as to recent universal adiabatic quantum computing constructions. In its most primitive form, systems constructed in this model cannot compute in an error free manner when working at non-zero temperature. However, by exploiting a mapping between the partition function for this model and probabilistic classical circuits we are able to show that it is possible to make this model effectively error free. We achieve this by using techniques in fault-tolerant classical computing and the result is that the system can compute effectively error free if the temperature is below a critical temperature. We further link this model to computational complexity and show that a certain problem concerning finite temperature classical spin systems is complete for the complexity class Merlin-Arthur. This provides an interesting connection between the physical behavior of certain many-body spin systems and computational complexity.Comment: 24 pages, 1 figur

    Structural correlates of semantic and phonemic fluency ability in first and second languages

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    Category and letter fluency tasks are commonly used clinically to investigate the semantic and phonological processes central to speech production, but the neural correlates of these processes are difficult to establish with functional neuroimaging because of the relatively unconstrained nature of the tasks. This study investigated whether differential performance on semantic (category) and phonemic (letter) fluency in neurologically normal participants was reflected in regional gray matter density. The participants were 59 highly proficient speakers of 2 languages. Our findings corroborate the importance of the left inferior temporal cortex in semantic relative to phonemic fluency and show this effect to be the same in a first language (L1) and second language (L2). Additionally, we show that the pre-supplementary motor area (pre-SMA) and head of caudate bilaterally are associated with phonemic more than semantic fluency, and this effect is stronger for L2 than L1 in the caudate nuclei. To further validate these structural results, we reanalyzed previously reported functional data and found that pre-SMA and left caudate activation was higher for phonemic than semantic fluency. On the basis of our findings, we also predict that lesions to the pre-SMA and caudate nuclei may have a greater impact on phonemic than semantic fluency, particularly in L2 speakers

    MAPIR: An Airborne Polarmetric Imaging Radiometer in Support of Hydrologic Satellite Observations

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    In this age of dwindling water resources and increasing demands, accurate estimation of water balance components at every scale is more critical to end users than ever before. Several near-term Earth science satellite missions are aimed at global hydrologic observations. The Marshall Airborne Polarimetric Imaging Radiometer (MAPIR) is a dual beam, dual angle polarimetric, scanning L band passive microwave radiometer system developed by the Observing Microwave Emissions for Geophysical Applications (OMEGA) team at MSFC to support algorithm development and validation efforts in support of these missions. MAPIR observes naturally-emitted radiation from the ground primarily for remote sensing of land surface brightness temperature from which we can retrieve soil moisture and possibly surface or water temperature and ocean salinity. MAPIR has achieved Technical Readiness Level 6 with flight heritage on two very different aircraft, the NASA P-3B, and a Piper Navajo

    Barriers to Insulin Initiation: The Translating Research Into Action for Diabetes Insulin Starts Project

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    OBJECTIVE Reasons for failing to initiate prescribed insulin (primary nonadherence) are poorly understood. We investigated barriers to insulin initiation following a new prescription. RESEARCH DESIGN AND METHODS We surveyed insulin-naïve patients with poorly controlled type 2 diabetes, already treated with two or more oral agents who were recently prescribed insulin. We compared responses for respondents prescribed, but never initiating, insulin (n = 69) with those dispensed insulin (n = 100). RESULTS Subjects failing to initiate prescribed insulin commonly reported misconceptions regarding insulin risk (35% believed that insulin causes blindness, renal failure, amputations, heart attacks, strokes, or early death), plans to instead work harder on behavioral goals, sense of personal failure, low self-efficacy, injection phobia, hypoglycemia concerns, negative impact on social life and job, inadequate health literacy, health care provider inadequately explaining risks/benefits, and limited insulin self-management training. CONCLUSIONS Primary adherence for insulin may be improved through better provider communication regarding risks, shared decision making, and insulin self-management training

    Diversity among Equals: Educational Opportunity and the State of Affirmative Admissions in New England

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    This report reviews the practice of Affirmative Admissions as a strategy for achieving diversity within New England colleges and universities. It shows how educational leaders perceive Affirmative Admissions, the nature of regional Affirmative Admissions policies, and the numbers of student affected by current enrollment strategies. This report is part of a larger series on educational access and opportunity in New England. Research was organized into five components: (1) analysis of pertinent legal issues related to postsecondary access and equity; (2) interviews with postsecondary campus and state leaders (n=104); (3) interviews with K-12 leaders and educators at state, district, and school levels (n=45); (4) a survey of 221 postsecondary education institutions in New England; and (5) econometric analyses of student data. The focus was on groups of institutions, 18 groups clustered by admissions policies and restrictions. The most compelling conclusion is that there is no significant evidence that colleges have reduced standards to admit greater numbers of minority students. By increasing educational access to a broader segment of the population, the regions higher education institutions have taken crucial steps toward assuring the vitality and vibrancy of New Englands future economy and civic life. The study also indicates that the pool of qualified minority students is much too small, highlighting the need to improve the preparation of minority students. Three appendixes contain details about survey methodology, participating institutions, and regression coefficients. Prepared by the Center for Education Policy (CEP) and Massachusetts Institute for Social and Economic Research (MISER), University of Massachusetts at Amherst. Sponsored by the Nellie Mae Education Foundation

    ASL MRI informs blood flow to chronic stroke lesions in patients with aphasia

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    Introduction: Response to post-stroke aphasia language rehabilitation is difficult to anticipate, mainly because few predictors can help identify optimal, individualized treatment options. Imaging techniques, such as Voxel-based Lesion Symptom Mapping have been useful in linking specific brain areas to language behavior; however, further development is required to optimize the use of structural and physiological information in guiding individualized treatment for persons with aphasia (PWA). In this study, we will determine if cerebral blood flow (CBF) mapped in patients with chronic strokes can be further used to understand stroke-related factors and behavior.Methods: We collected perfusion MRI data using pseudo-Continuous Arterial Spin Labeling (pCASL) using a single post-labeling delay of 2,200 ms in 14 chronic PWA, along with high-resolution structural MRI to compute maps of tissue damage using Tissue Integrity Gradation via T2w T1w Ratio (TIGR). To quantify the CBF in chronic stroke lesions, we tested at what point spatial smoothing should be applied in the ASL analysis pipeline. We then related CBF to tissue damage, time since stroke, age, sex, and their respective cross-terms to further understand the variability in lesion CBF. Finally, we assessed the feasibility of computing multivariate brain-behavior maps using CBF and compared them to brain-behavior maps extracted with TIGR MRI.Results: We found that the CBF in chronic stroke lesions is significantly reduced compared to its homologue grey and white matter regions. However, a reliable CBF signal (although smaller than expected) was detected to reveal a negative relationship between CBF and increasing tissue damage. Further, the relationship between the lesion CBF and age, sex, time since stroke, and tissue damage and cross-terms suggested an aging-by-disease interaction. This relationship was strongest when smoothing was applied in the template space. Finally, we show that whole-brain CBF relates to domain-general visuospatial functioning in PWA. The CBF-based brain-behavior maps provide unique and complementary information to structural (lesion-based) brain-behavior maps.Discussion: Therefore, CBF can be detected in chronic stroke lesions using a standard pCASL MRI acquisition and is informative at the whole-brain level in identifying stroke rehabilitation targets in PWAs due to its relationship with demographic factors, stroke-related factors, and behavior
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