417 research outputs found

    Morphology, activity area, and movement patterns of the frugivorous monitor lizard Varanus Bitatawa

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    The newly described Varanus bitatawa is a large, frugivorous, monitor lizard endemic to the northern Sierra Madre mountain range in Luzon, Philippines. This study presents the first description of its ecology from tracking and camera trapping. We captured five adult lizards weighing 1.0-5.1 kg with snout-vent lengths (SVL) from 40-66 cm and total lengths from 100-164 cm. Activity areas were non-overlapping with a mean of 12,400 m(2); males (23,300 m(2)) had larger activity areas than females (5,200 m(2)). Capture and camera trap records indicate that lizards move most frequently between 1000 and 1500. Movements were characterized by straight line distances between trees with a mean distance travelled between trees of 79 m. Mean daily distance covered was 176 m with larger distances covered by males (228 m vs 142 m for females).Environmental BiologyConservation Biolog

    Photon recycling in CsPbBr3 All-Inorganic Perovskite Nanocrystals

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    Photon recycling, the iterative process of re-absorption and re-emission of photons in an absorbing medium, can play an important role in the power-conversion efficiency of photovoltaic cells. To date, several studies have proposed that this process may occur in bulk or thin films of inorganic lead-halide perovskites, but conclusive proof of the occurrence and magnitude of this effect is missing. Here, we provide clear evidence and quantitative estimation of photon recycling in CsPbBr nanocrystal suspensions by combining measurements of steady-state and time-resolved photoluminescence (PL) and PL quantum yield with simulations of photon diffusion through the suspension. The steady-state PL shows clear spectral modifications including red shifts and quantum yield decrease, while the time-resolved measurements show prolonged PL decay and rise times. These effects grow as the nanocrystal concentration and distance traveled through the suspension increase. Monte Carlo simulations of photons diffusing through the medium and exhibiting absorption and re-emission account quantitatively for the observed trends and show that up to five re-emission cycles are involved. We thus identify 4 quantifiable measures, PL red shift, PL QY, PL decay time, and PL rise time that together all point toward repeated, energy-directed radiative transfer between nanocrystals. These results highlight the importance of photon recycling for both optical properties and photovoltaic applications of inorganic perovskite nanocrystals

    The Coarse-Grained Plaque: A Divergent Aβ Plaque-Type in Early-Onset Alzheimer’s Disease

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    Alzheimer’s disease (AD) is characterized by amyloid-beta (Aβ) deposits, which come in myriad morphologies with varying clinical relevance. Previously, we observed an atypical Aβ deposit, referred to as the coarse-grained plaque. In this study, we evaluate the plaque’s association with clinical disease and perform in-depth immunohistochemical and morphological characterization. The coarse-grained plaque, a relatively large (Ø ≈ 80 µm) deposit, characterized as having multiple cores and Aβ-devoid pores, was prominent in the neocortex. The plaque was semi-quantitatively scored in the middle frontal gyrus of Aβ-positive cases (n = 74), including non-demented cases (n = 15), early-onset (EO)AD (n = 38), and late-onset (LO)AD cases (n = 21). The coarse-grained plaque was only observed in cases with clinical dementia and more frequently present in EOAD compared to LOAD. This plaque was associated with a homozygous APOE ε4 status and cerebral amyloid angiopathy (CAA). In-depth characterization was done by studying the coarse-grained plaque’s neuritic component (pTau, APP, PrPC), Aβ isoform composition (Aβ40, Aβ42, AβN3pE, pSer8Aβ), its neuroinflammatory component (C4b, CD68, MHC-II, GFAP), and its vascular attribution (laminin, collagen IV, norrin). The plaque was compared to the classic cored plaque, cotton wool plaque, and CAA. Similar to CAA but different from classic cored plaques, the coarse-grained plaque was predominantly composed of Aβ40. Furthermore, the coarse-grained plaque was distinctly associated with both intense neuroinflammation and vascular (capillary) pathology. Confocal laser scanning microscopy (CLSM) and 3D analysis revealed for most coarse-grained plaques a particular Aβ40 shell structure and a direct relation with vessels. Based on its morphological and biochemical characteristics, we conclude that the coarse-grained plaque is a divergent Aβ plaque-type associated with EOAD. Differences in Aβ processing and aggregation, neuroinflammatory response, and vascular clearance may presumably underlie the difference between coarse-grained plaques and other Aβ deposits. Disentangling specific Aβ deposits between AD subgroups may be important in the search for disease-mechanistic-based therapies

    ABO-incompatible kidney transplantation in perspective of deceased donor transplantation and induction strategies:a propensity-matched analysis

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    BACKGROUND: Kidney transplant candidates are blood group incompatible with roughly one out of three potential living donors. We compared outcomes after ABO-incompatible (ABOi) kidney transplantation with matched ABO-compatible (ABOc) living and deceased donor transplantation and analyzed different induction regimens. METHODS: We performed a retrospective study with propensity matching and compared patient and death-censored graft survival after ABOi versus ABOc living donor and deceased donor kidney transplantation in a nationwide registry from 2006 till 2019. RESULTS: 296 ABOi were compared to 1184 center and propensity matched ABOc living donor and 1184 deceased donor recipients (matching: recipient age, sex, blood group and PRA). Patient survival was better compared to deceased donor (hazard ratio (HR) for death of HR 0.69 [0.49-0.96], and not-significantly different from ABOc living donor recipients (HR 1.28 [0.90-1.81]). Rate of graft failure was higher compared to ABOc living donor transplantation (HR 2.63 [1.72-4.01]). Rejection occurred in 47% of 140 rituximab versus 22% of 50 rituximab/basiliximab, and 4% of 92 alemtuzumab treated recipients (p <0.001). CONCLUSIONS: ABOi kidney transplantation is superior to deceased donor transplantation. Rejection rate and graft failure are higher compared to matched ABOc living donor transplantation, underscoring the need for further studies into risk stratification and induction therapy

    A Situational Alignment Framework for PACS

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    This paper reports the outcomes of a study on an integrated situational alignment framework for picture archiving and communication systems (PACS) labeled as PISA. Following the design research cycle, complementary validation methods and pilot cases were used to assess the proposed framework and its operationalized survey. In this paper, the authors outline (a) the process of the framework’ development, (b) the validation process with its underlying iterative steps, (c) the outcomes of pilot cases, and (d) improvement opportunities to refine and further validate the PISA framework. Results of this study support empirical application of the framework to hospital enterprises in order to gain insights into their PACS maturity and alignment. We argue that the framework can be applied as a valuable tool for assessments, monitoring and benchmarking purposes and strategic PACS planning

    GP-initiated preconception counselling in a randomised controlled trial does not induce anxiety

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    BACKGROUND: Preconception counselling (PCC) can reduce adverse pregnancy outcome by addressing risk factors prior to pregnancy. This study explores whether anxiety is induced in women either by the offer of PCC or by participation with GP-initiated PCC. METHODS: Randomised trial of usual care versus GP-initiated PCC for women aged 18–40, in 54 GP practices in the Netherlands. Women completed the six-item Spielberger State Trait Anxiety Inventory (STAI) before PCC (STAI-1) and after (STAI-2). After pregnancy women completed a STAI focusing on the first trimester of pregnancy (STAI-3). RESULTS: The mean STAI-1-score (n = 466) was 36.4 (95% CI 35.4 – 37.3). Following PCC there was an average decrease of 3.6 points in anxiety-levels (95% CI, 2.4 – 4.8). Mean scores of the STAI-3 were 38.5 (95% CI 37.7 – 39.3) in the control group (n = 1090) and 38.7 (95% CI 37.9 – 39.5) in the intervention group (n = 1186). CONCLUSION: PCC from one's own GP reduced anxiety after participation, without leading to an increase in anxiety among the intervention group during pregnancy. We therefore conclude that GPs can offer PCC to the general population without fear of causing anxiety. Trial Registration: ISRCTN5394291
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