Ultraviolet Radiation Influences Perch Selection by a Neotropical Poison-Dart Frog

Ambient ultraviolet-B radiation can harm amphibian eggs, larvae and adults. However, some amphibians avoid UV-B radiation when given the opportunity. The strawberry poison dart frog, Oophaga pumilio, is diurnal and males vocalize throughout the day in light gaps under forest canopies that expose them to solar radiation. Previous studies have demonstrated that males calling from high perches are more successful at mating than those at lower perches. We investigated whether frogs at higher perches receive more ultraviolet-B than those calling from lower perches. We also investigated whether frogs on perches receiving relatively low ultraviolet-B levels maintained their positions for longer compared to individuals calling from perches receiving higher levels of ultraviolet-B. Finally, since it has been hypothesized that some animals utilize levels of UV-A as a visual cue to avoid UV-B damage, we artificially elevated ultraviolet-A levels to examine whether males exposed to artificially elevated ultraviolet-A abandoned their perches sooner compared to males exposed to visible light. We found that frogs called from perches receiving low ultraviolet-B regardless of perch height, and that frogs maintain their positions longer on perches receiving low ultraviolet-B compared to perches receiving even slightly higher ultraviolet-B levels. Exposing the frogs to artificially elevated levels of ultraviolet-A radiation caused males to move off of their perches faster than when they were exposed to a control light source. These experiments suggest that ultraviolet radiation plays an important role in frog behavior related to perch selection, even in rainforests where much of the solar radiation is shielded by the forest canopy

The rainbow trout is affecting the occupancy of native amphibians in Patagonia

In this work, we assessed the occupancy of two native amphibian species of the Valcheta stream in the Somuncura Plateau, northern Patagonia: the Valcheta frog, Pleurodema somuncurense and the Argentine common toad, Rhinella arenarum. We hypothesized that the occupancy of both amphibian species will be shaped by the presence of trout; we also expected a decline in occupancy assuming that the new predator in the system will affect native amphibian populations. Between December 2014 and March 2015, we conducted surveys in 148 sites along the headwaters of Valcheta stream. We modelled the occupancy by including the presence of trout, the temperature of water and the coverage of rocks and vegetation as site-habitat covariates. Models including trout were among the best ranked for both amphibian species. The presence of trout reduced the occupancy of both species and the magnitude of this reduction was much higher in the Valcheta frog than in the Argentine common toad. Overall, our results are of great relevance for land managers considering that the Valcheta frog is among the only three IUCN Critically Endangered amphibians in Argentina.Facultad de Ciencias Naturales y Muse

Hitting sbottom in natural SUSY

We compare the experimental prospects of direct stop and sbottom pair production searches at the LHC. Such searches for stops are of great interest as they directly probe for states that are motivated by the SUSY solution to the hierarchy problem of the Higgs mass parameter - leading to a "Natural" SUSY spectrum. Noting that sbottom searches are less experimentally challenging and scale up in reach directly with the improvement on b-tagging algorithms, we discuss the interplay of small TeV scale custodial symmetry violation with sbottom direct pair production searches as a path to obtaining strong sub-TeV constraints on stops in a natural SUSY scenario. We argue that if a weak scale natural SUSY spectrum does not exist within the reach of LHC, then hopes for such a spectrum for large regions of parameter space should sbottom out. Conversely, the same arguments make clear that a discovery of such a spectrum is likely to proceed in a sbottom up manner.Comment: 18 pages, 8 figures,v2 refs added, JHEP versio

New Particles Working Group Report of the Snowmass 2013 Community Summer Study

This report summarizes the work of the Energy Frontier New Physics working group of the 2013 Community Summer Study (Snowmass)

Strongly Correlated Quantum Fluids: Ultracold Quantum Gases, Quantum Chromodynamic Plasmas, and Holographic Duality

Strongly correlated quantum fluids are phases of matter that are intrinsically quantum mechanical, and that do not have a simple description in terms of weakly interacting quasi-particles. Two systems that have recently attracted a great deal of interest are the quark-gluon plasma, a plasma of strongly interacting quarks and gluons produced in relativistic heavy ion collisions, and ultracold atomic Fermi gases, very dilute clouds of atomic gases confined in optical or magnetic traps. These systems differ by more than 20 orders of magnitude in temperature, but they were shown to exhibit very similar hydrodynamic flow. In particular, both fluids exhibit a robustly low shear viscosity to entropy density ratio which is characteristic of quantum fluids described by holographic duality, a mapping from strongly correlated quantum field theories to weakly curved higher dimensional classical gravity. This review explores the connection between these fields, and it also serves as an introduction to the Focus Issue of New Journal of Physics on Strongly Correlated Quantum Fluids: from Ultracold Quantum Gases to QCD Plasmas. The presentation is made accessible to the general physics reader and includes discussions of the latest research developments in all three areas.Comment: 138 pages, 25 figures, review associated with New Journal of Physics special issue "Focus on Strongly Correlated Quantum Fluids: from Ultracold Quantum Gases to QCD Plasmas" (http://iopscience.iop.org/1367-2630/focus/Focus%20on%20Strongly%20Correlated%20Quantum%20Fluids%20-%20from%20Ultracold%20Quantum%20Gases%20to%20QCD%20Plasmas

Excess Higgs Production in Neutralino Decays

The ATLAS and CMS experiments have recently claimed discovery of a Higgs boson-like particle at ~5 sigma confidence and are beginning to test the Standard Model predictions for its production and decay. In a variety of supersymmetric models, a neutralino NLSP can decay dominantly to the Higgs and the LSP. In natural SUSY models, a light third generation squark decaying through this chain can lead to large excess Higgs production while evading existing BSM searches. Such models can be observed at the 8 TeV LHC in channels exploiting the rare diphoton decays of the Higgs produced in the cascade decay. Identifying a diphoton resonance in association with missing energy, a lepton, or b-tagged jets is a promising search strategy for discovery of these models, and would immediately signal new physics involving production of a Higgs boson. We also discuss the possibility that excess Higgs production in these SUSY decays can be responsible for enhancements of up to 50% over the SM prediction for the observed rate in the existing inclusive diphoton searches, a scenario which would likely by the end of the 8 TeV run be accompanied by excesses in the diphoton + lepton/MET and SUSY multi-lepton/b searches and a potential discovery in a diphoton + 2b search.Comment: 42 pages, 19 figure

Cost-effectiveness of a structured progressive task-oriented circuit class training programme to enhance walking competency after stroke: The protocol of the FIT-Stroke trial

<p>Abstract</p> <p>Background</p> <p>Most patients who suffer a stroke experience reduced walking competency and health-related quality of life (HRQoL). A key factor in effective stroke rehabilitation is intensive, task-specific training. Recent studies suggest that intensive, patient-tailored training can be organized as a circuit with a series of task-oriented workstations.</p> <p>Primary aim of the FIT-Stroke trial is to evaluate the effects and cost-effectiveness of a structured, progressive task-oriented circuit class training (CCT) programme, compared to usual physiotherapeutic care during outpatient rehabilitation in a rehabilitation centre. The task-oriented CCT will be applied in groups of 4 to 6 patients. Outcome will be defined in terms of gait and gait-related ADLs after stroke. The trial will also investigate the generalizability of treatment effects of task-oriented CCT in terms of perceived fatigue, anxiety, depression and perceived HRQoL.</p> <p>Methods/design</p> <p>The multicentre single-blinded randomized trial will include 220 stroke patients discharged to the community from inpatient rehabilitation, who are able to communicate and walk at least 10 m without physical, hands-on assistance. After discharge from inpatient rehabilitation, patients in the experimental group will receive task-oriented CCT two times a week for 12 weeks at the physiotherapy department of the rehabilitation centre. Control group patients will receive usual individual, face-to-face, physiotherapy. Costs will be evaluated by having each patient keep a cost diary for the first 24 weeks after randomisation. Primary outcomes are the mobility part of the Stroke Impact Scale (SIS-3.0) and the EuroQol. Secondary outcomes are the other domains of SIS-3.0, lower limb muscle strength, walking endurance, gait speed, balance, confidence not to fall, instrumental ADL, fatigue, anxiety, depression and HRQoL.</p> <p>Discussion</p> <p>Based on assumptions about the effect of intensity of practice and specificity of treatment effects, FIT-Stroke will address two key aims. The first aim is to investigate the effects of task-oriented CCT on walking competency and HRQoL compared to usual face-to-face physiotherapy. The second aim is to reveal the cost-effectiveness of task-oriented CCT in the first 6 months post stroke. Both aims were recently recommended as priorities by the American Hearth Association and Stroke Council.</p> <p>Trial registration</p> <p>This study is registered in the Dutch Trial Register as NTR1534.</p

New Physics from the Top at the LHC

The top quark may hold the key to new physics associated with the electroweak symmetry-breaking sector, given its large mass and enhanced coupling to the Higgs sector. We systematically categorize generic interactions of a new particle that couples to the top quark and a neutral particle, which is assumed to be heavy and stable, thus serving as a candidate for cold dark matter. The experimental signatures for new physics involving top quarks and its partners at the Large Hadron Collider (LHC) may be distinctive, yet challenging to disentangle. We optimize the search strategy at the LHC for the decay of the new particle to a top quark plus missing energy and propose the study of its properties, such as its spin and couplings. We find that, at 14 TeV with an integrated luminosity of 100 fb^-1, a spin-zero top partner can be observed at the 5-sigma level for a mass of 675 GeV. A spin-zero particle can be differentiated from spin-1/2 and spin-1 particles at the 5-sigma level with a luminosity of 10 fb^-1.Comment: 19 pages, 7 figures; v2: journal versio

Selective Molecular Alterations in the Autophagy Pathway in Patients with Lewy Body Disease and in Models of α-Synucleinopathy

Lewy body disease is a heterogeneous group of neurodegenerative disorders characterized by α-synuclein accumulation that includes dementia with Lewy bodies (DLB) and Parkinson's Disease (PD). Recent evidence suggests that impairment of lysosomal pathways (i.e. autophagy) involved in α-synuclein clearance might play an important role. For this reason, we sought to examine the expression levels of members of the autophagy pathway in brains of patients with DLB and Alzheimer's Disease (AD) and in α-synuclein transgenic mice.By immunoblot analysis, compared to controls and AD, in DLB cases levels of mTor were elevated and Atg7 were reduced. Levels of other components of the autophagy pathway such as Atg5, Atg10, Atg12 and Beclin-1 were not different in DLB compared to controls. In DLB brains, mTor was more abundant in neurons displaying α-synuclein accumulation. These neurons also showed abnormal expression of lysosomal markers such as LC3, and ultrastructural analysis revealed the presence of abundant and abnormal autophagosomes. Similar alterations were observed in the brains of α-synuclein transgenic mice. Intra-cerebral infusion of rapamycin, an inhibitor of mTor, or injection of a lentiviral vector expressing Atg7 resulted in reduced accumulation of α-synuclein in transgenic mice and amelioration of associated neurodegenerative alterations.This study supports the notion that defects in the autophagy pathway and more specifically in mTor and Atg7 are associated with neurodegeneration in DLB cases and α-synuclein transgenic models and supports the possibility that modulators of the autophagy pathway might have potential therapeutic effects