3,405 research outputs found

    Assessing the Abundance of Caucasian Salamander, Mertensiella caucasica (Caudata, Salamandridae), with N-mixture Model in Northeastern Anatolia

    Get PDF
    The endangered Caucasian salamander, Mertensiella caucasica (Waga, 1876), is endemic to the western Lesser Caucasus. Here, we used N-mixed models to analyse repeated count data of Caucasian salamanders from the eastern Black Sea region of Turkey. We estimated a mean detection probability of 0.29, a population size of 21 individuals, and a range of 9 to 36 individuals per 20 × 10 m plot. Our results provide preliminary data on the population status of the Caucasian salamander in northeastern Anatolia. These results would contribute to the effective management and conservation of the species

    Neurophysiological effects of human-derived pathological tau conformers in the APPKM670/671NL.PS1/L166P amyloid mouse model of Alzheimer's disease

    Get PDF
    Alzheimer's Disease (AD) is a neurodegenerative disease characterized by two main pathological hallmarks: amyloid plaques and intracellular tau neurofibrillary tangles. However, a majority of studies focus on the individual pathologies and seldom on the interaction between the two pathologies. Herein, we present the longitudinal neuropathological and neurophysiological effects of a combined amyloid-tau model by hippocampal seeding of human-derived tau pathology in the APP.PS1/L166P amyloid animal model. We statistically assessed both neurophysiological and pathological changes using linear mixed modelling to determine if factors such as the age at which animals were seeded, genotype, seeding or buffer, brain region where pathology was quantified, and time-post injection differentially affect these outcomes. We report that AT8-positive tau pathology progressively develops and is facilitated by the amount of amyloid pathology present at the time of injection. The amount of AT8-positive tau pathology was influenced by the interaction of age at which the animal was injected, genotype, and time after injection. Baseline pathology-related power spectra and Higuchi Fractal Dimension (HFD) score alterations were noted in APP.PS1/L166P before any manipulations were performed, indicating a baseline difference associated with genotype. We also report immediate localized hippocampal dysfunction in the electroencephalography (EEG) power spectra associated with tau seeding which returned to comparable levels at 1 month-post-injection. Longitudinal effects of seeding indicated that tau-seeded wild-type mice showed an increase in gamma power earlier than buffer control comparisons which was influenced by the age at which the animal was injected. A reduction of hippocampal broadband power spectra was noted in tau-seeded wild-type mice, but absent in APP.PS1 animals. HFD scores appeared to detect subtle effects associated with tau seeding in APP.PS1 animals, which was differentially influenced by genotype. Notably, while tau histopathological changes were present, a lack of overt longitudinal electrophysiological alterations was noted, particularly in APP.PS1 animals that feature both pathologies after seeding, reiterating and underscoring the difficulty and complexity associated with elucidating physiologically relevant and translatable biomarkers of Alzheimer's Disease at the early stages of the disease

    Quark zero modes in intersecting center vortex gauge fields

    Get PDF
    The zero modes of the Dirac operator in the background of center vortex gauge field configurations in R2\R^2 and R4\R^4 are examined. If the net flux in D=2 is larger than 1 we obtain normalizable zero modes which are mainly localized at the vortices. In D=4 quasi-normalizable zero modes exist for intersecting flat vortex sheets with the Pontryagin index equal to 2. These zero modes are mainly localized at the vortex intersection points, which carry a topological charge of ±1/2\pm 1/2. To circumvent the problem of normalizability the space-time manifold is chosen to be the (compact) torus \T^2 and \T^4, respectively. According to the index theorem there are normalizable zero modes on \T^2 if the net flux is non-zero. These zero modes are localized at the vortices. On \T^4 zero modes exist for a non-vanishing Pontryagin index. As in R4\R^4 these zero modes are localized at the vortex intersection points.Comment: 20 pages, 4 figures, LaTeX2e, references added, treatment of ideal vortices on the torus shortene

    Investigation of opening position on natural cross ventilation for an isolated building

    Get PDF
    The opening position is one of the factors that affect the ventilation performance of a building. In this study, the effect of opening position on natural cross ventilation of isolated building was investigated. The airflow pattern and ventilation rate under different opening configurations were analyzed. Eight different opening configurations were considered, including aligned and unaligned openings, as well as vertical-opening design. Computational fluid dynamics (CFD) simulation with 3D steady-state RANS equation Shear Stress Transport (SST) k-ω turbulence model was used. The parameters of streamwise dimensionless wind speed ratio (U/Uref), pressure coefficient (Cp) and dimensionless flow rate (DFR) were analyzed in this study. The results show that the aligned opening configuration Top-Top has the highest DFR at 0.60. This result is similar to that obtained from the literature. In addition, the design of vertical openings can improve the DFR of the building. The DFR of the building is mainly affected by the position of the opening on the windward side. This concludes that the opening positions exert an imperative role in affecting the internal airflow pattern, air recirculation and DFR of a naturally cross ventilated building

    Measurement of the CKM angle γ from a combination of B±→Dh± analyses

    Get PDF
    A combination of three LHCb measurements of the CKM angle γ is presented. The decays B±→D K± and B±→Dπ± are used, where D denotes an admixture of D0 and D0 mesons, decaying into K+K−, π+π−, K±π∓, K±π∓π±π∓, K0Sπ+π−, or K0S K+K− final states. All measurements use a dataset corresponding to 1.0 fb−1 of integrated luminosity. Combining results from B±→D K± decays alone a best-fit value of γ =72.0◦ is found, and confidence intervals are set γ ∈ [56.4,86.7]◦ at 68% CL, γ ∈ [42.6,99.6]◦ at 95% CL. The best-fit value of γ found from a combination of results from B±→Dπ± decays alone, is γ =18.9◦, and the confidence intervals γ ∈ [7.4,99.2]◦ ∪ [167.9,176.4]◦ at 68% CL are set, without constraint at 95% CL. The combination of results from B± → D K± and B± → Dπ± decays gives a best-fit value of γ =72.6◦ and the confidence intervals γ ∈ [55.4,82.3]◦ at 68% CL, γ ∈ [40.2,92.7]◦ at 95% CL are set. All values are expressed modulo 180◦, and are obtained taking into account the effect of D0–D0 mixing

    Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics

    Get PDF
    A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN
    corecore