807 research outputs found

    Wild Horses, Livestock, and Wildlife Use of Springs and Riparian Areas on the Devil\u27s Garden

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    In Modoc County, located in northeastern California there is a unique rangeland area heavily populated by wild horses and managed primarily by United States Forest Service known as the Devil\u27s Garden. Wild horses have significantly exceeded (4000 horses) appropriate management levels (206-402 horses) in recent years and expanded their range outside of the wild horse territory (258,000 acres) and on to private and tribal lands (over 450,000 acres). This increase has prompted concern about resource degradation particularly associated with riparian areas. In otherwise arid sage steppe rangelands, springs provide critical watering sources as well as wildlife habitat for sage grouse, deer, elk, pronghorn, and other wildlife. Our objective is to quantify the relative frequency, duration, and timing of use by horses, permitted livestock, and wildlife at spring locations. We correlate how varying levels of horse and/or livestock use affects spring site vegetation and riparian health standards. Ten representative study locations were selected on the Devil’s Garden and motion sensitive cameras were deployed at each location for 14-day sampling periods during the spring, summer and fall of 2015-2017. All photos were visually assessed to record species present, number of each species, and the time, date, and location of the observation. We present preliminary occupancy data, as well as results of corresponding vegetative cover, plant community, and bank alteration sampling. Implications for management and on-going research are discussed

    Two Photon Absorption in Chromophore Doped Solid Matrices

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    Over the past decades organic materials have shown an important potential for applications in the field of nonlinear optics. Two-photon absorbing materials can be optically addressed in three dimensions of space, which make them unique for many new applications, including 3D displays, optical memories, bio-sensors, etc. Fluorescent organic chromophores can be synthesized with structures especially optimized for this nonlinear optical property. Yet, for some applications, they have to be incorporated in solid state matrices. We especially investigate hybrid organic/inorganic doped matrices synthesized by solgel process. However , the linear transmission for such molecules is often significantly less than unity. Two-photon absorption (TPA) offers the advantage of very high transmission at low incident intensity, while being sensitive to high intensity laser pulses. Our aim is to record a 3D layered pattern of optical memory inside the sample by the use of the picosecond pulsed ND3+:YAG laser at 532nm, or 1064nm

    A mouse model of autism implicates endosome pH in the regulation of presynaptic calcium entry.

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    Psychoactive compounds such as chloroquine and amphetamine act by dissipating the pH gradient across intracellular membranes, but the physiological mechanisms that normally regulate organelle pH remain poorly understood. Interestingly, recent human genetic studies have implicated the endosomal Na+/H+ exchanger NHE9 in both autism spectrum disorders (ASD) and attention deficit hyperactivity disorder (ADHD). Plasma membrane NHEs regulate cytosolic pH, but the role of intracellular isoforms has remained unclear. We now find that inactivation of NHE9 in mice reproduces behavioral features of ASD including impaired social interaction, repetitive behaviors, and altered sensory processing. Physiological characterization reveals hyperacidic endosomes, a cell-autonomous defect in glutamate receptor expression and impaired neurotransmitter release due to a defect in presynaptic Ca2+ entry. Acute inhibition of synaptic vesicle acidification rescues release but without affecting the primary defect due to loss of NHE9

    Physics, Stability and Dynamics of Supply Networks

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    We show how to treat supply networks as physical transport problems governed by balance equations and equations for the adaptation of production speeds. Although the non-linear behaviour is different, the linearized set of coupled differential equations is formally related to those of mechanical or electrical oscillator networks. Supply networks possess interesting new features due to their complex topology and directed links. We derive analytical conditions for absolute and convective instabilities. The empirically observed "bull-whip effect" in supply chains is explained as a form of convective instability based on resonance effects. Moreover, it is generalized to arbitrary supply networks. Their related eigenvalues are usually complex, depending on the network structure (even without loops). Therefore, their generic behavior is characterized by oscillations. We also show that regular distribution networks possess two negative eigenvalues only, but perturbations generate a spectrum of complex eigenvalues.Comment: For related work see http://www.helbing.or

    Learning together through international collaboration in teacher education in Malaysia. Report of a project to develop a Bachelor of Education (Honours) in Primary Mathematics

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    Copyright University of Hertfordshire, School of Education 2011Learning together through international collaboration in teacher education in Malaysia is the report of an enterprising partnership between the University of Hertfordshire, UK, the Ministry of Education Malaysia and two Institutes of Teacher Education in Malaysia. Working collaboratively with colleagues in Malaysia, the University of Hertfordshire School of Education designed, validated, supported and quality assured a Bachelor of Education (Honours) degree programme for initial teacher training for a single cohort of 120 students over four years. All the students graduated in 2010. Learning together through international collaboration in teacher education in Malaysia provides a record of the project itself. It also documents in-depth insights from contributors to the project in two main areas: the collaborative approach to working together and issues relating to learning and teaching, including the Action – Reflection – Modelling (ARM) pedagogical approach, which underpinned the degree programme. Senior managers, teacher educators and lecturers share some of their learning from working together to develop and implement the new degree programme. Student teachers voice some experiences from their school placements. They describe how they used ARM; highlight some of the benefits of the approach and identify some of the challenges associated with introducing a different pedagogy in schools as they were 'learning to teach'. There are glimpses of 'lively and attractive' classes in which 'pupils enjoy and feel comfortable to learn' and 'are eager to answer my questions'. School mentors provide additional insights into the student teachers' learning and teaching practice. The richness of the contributions is reflected in the many quotations included in the report. The successful completion of this project was due to the dedication and expertise of many contributors. The findings documented in this report are relevant for all those engaged in international collaboration and teacher education.Final Published versio

    A Randomized Controlled Trial: Attachment-Based Family and Nondirective Supportive Treatments for Youth Who Are Suicidal

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    Objective: To evaluate the efficacy of attachment-based family therapy (ABFT) compared with a family-enhanced nondirective supportive therapy (FE-NST) for decreasing adolescents’ suicide ideation and depressive symptoms. Method: A randomized controlled trial of 129 adolescents who are suicidal ages 12- to 18-years-old (49% were African American) were randomized to ABFT (n ¼ 66) or FE-NST (n ¼ 63) for 16 weeks of treatment. Assessments occurred at baseline and 4, 8, 12, and 16 weeks. Trajectory of change and clinical recovery were calculated for suicidal ideation and depressive symptoms. Results: There was no significant between-group difference in the rate of change in self-reported ideation (Suicidal Ideation Questionnaire-Jr; F1,127 ¼ 181, p ¼ .18). Similar results were found for depressive symptoms. However, adolescents receiving ABFT showed a significant decrease in suicide ideation (t127 ¼ 12.61, p \u3c .0001; effect size, d ¼ 2.24). Adolescents receiving FE-NST showed a similar significant decrease (t127 ¼ 10.88, p \u3c .0001; effect size, d ¼ 1.93). Response rates (ie, 50% decrease in suicide ideation symptoms from baseline) at post-treatment were 69.1% for ABFT versus 62.3% for FE-NST. Conclusion: Contrary to expectations, ABFT did not perform better than FE-NST. The 2 treatments produced substantial decreases in suicidal ideation and depressive symptoms that were comparable to or better than those reported in other more intensive, multicomponent treatments. The equivalent outcomes could be attributed to common treatment elements, different active mechanisms, or regression to the mean. Future studies will explore long-term follow up, secondary outcomes, and potential moderators and mediators

    Improvements in health-related quality of life with belimumab, a B-lymphocyte stimulator-specific inhibitor, in patients with autoantibody-positive systemic lupus erythematosus from the randomised controlled BLISS trials

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    OBJECTIVE: Assess the effects of belimumab treatment plus standard systemic lupus erythematosus (SLE) therapy on health-related quality of life (HRQOL) in patients with active, autoantibody-positive SLE. METHODS: Patients received standard therapy plus placebo or belimumab 1 or 10 mg/kg in two multicentre, randomised controlled trials of 52 (BLISS-52; N=865) and 76 (BLISS-76; N=819) weeks' duration. Responders were evaluated by SLE Responder Index at week 52. Patient-reported outcome assessments included SF-36, Functional Assessment of Chronic Illness Therapy (FACIT)-Fatigue, and EQ-5D. RESULTS: Mean SF-36 Physical Component Summary (PCS) scores at week 24 was a major secondary endpoint. Baseline SF-36 scores were 1.5 SDs below age-/sex-matched US norms with similar improvement at week 24 across treatment groups. Mean changes from baseline in PCS scores were significantly (p<0.05) greater with belimumab 1 mg/kg (4.20) and 10 mg/kg (4.18) versus placebo (2.96) in BLISS-52, week 52. In BLISS-76, significantly (p<0.05) greater improvements were seen with belimumab 1 mg/kg in PCS (belimumab 1 mg/kg=4.37, 10 mg/kg=3.41 vs placebo=2.85) and Mental Component Summary (MCS) scores (belimumab 1 mg/kg=3.14, 10 mg/kg=2.70 vs placebo=1.40) at week 52, and in MCS score at week 76 (belimumab 1 mg/kg=3.05, 10 mg/kg=2.28 vs placebo=1.36). In pooled analysis, significantly greater improvements in PCS, SF-36 vitality domain, and FACIT-Fatigue scores at week 52 were evident with both belimumab doses. CONCLUSIONS: The clinically meaningful improvements in HRQOL in autoantibody-positive patients with active SLE treated with belimumab and standard therapy are consistent with the reductions in disease activity observed in these trials

    Detection of a dna methylation signature for the intellectual developmental disorder, x-linked, syndromic, armfield type

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    A growing number of genetic neurodevelopmental disorders are known to be associated with unique genomic DNA methylation patterns, called episignatures, which are detectable in peripheral blood. The intellectual developmental disorder, X-linked, syndromic, Armfield type (MRXSA) is caused by missense variants in FAM50A. Functional studies revealed the pathogenesis to be a spliceosomopathy that is characterized by atypical mRNA processing during development. In this study, we assessed the peripheral blood specimens in a cohort of individuals with MRXSA and detected a unique and highly specific DNA methylation episignature associated with this disorder. We used this episignature to construct a support vector machine model capable of sensitive and specific identification of individuals with pathogenic variants in FAM50A. This study contributes to the expanding number of genetic neurodevelopmental disorders with defined DNA methylation episignatures, provides an additional understanding of the associated molecular mechanisms, and further enhances our ability to diagnose patients with rare disorders
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