1,258 research outputs found
Identification and Doubly Robust Estimation of Data Missing Not at Random with an Ancillary Variable
Search for Gamma-ray Emission from Dark Matter Annihilation in the Large Magellanic Cloud with the Fermi Large Area Telescope
At a distance of 50 kpc and with a dark matter mass of
M, the Large Magellanic Cloud (LMC) is a natural target for indirect
dark matter searches. We use five years of data from the Fermi Large Area
Telescope (LAT) and updated models of the gamma-ray emission from standard
astrophysical components to search for a dark matter annihilation signal from
the LMC. We perform a rotation curve analysis to determine the dark matter
distribution, setting a robust minimum on the amount of dark matter in the LMC,
which we use to set conservative bounds on the annihilation cross section. The
LMC emission is generally very well described by the standard astrophysical
sources, with at most a excess identified near the kinematic center
of the LMC once systematic uncertainties are taken into account. We place
competitive bounds on the dark matter annihilation cross section as a function
of dark matter particle mass and annihilation channel.Comment: 33 pages, 22 figures Version 2: minor corrections and clarifications
after journal peer review proces
Absorption, Excretion, and Biotransformation of Dimethyl Sulfoxide in Man and Miniature Pigs After Topical Application as an 80% Gel
The absorption, excretion, and biotransformation of dimethyl sulfoxide (DMSO) 80% gel, DEMASORB®, was studied in man and in miniature pigs. DMSO 80% gel (15 cc, t.i.d.) was applied topically to the elbows of human subjects and allowed to remain there for 30 minutes after each application. Under these conditions, daily absorption of DMSO 80% gel ranged from 25 to 40% of the total dose. DMSO 80% gel (15 g, t.i.d.) was completely absorbed within 4 hours after application to the shaved backs of miniature pigs. Both man and miniature pig transformed DMSO to dimethylsulfone (DMSO2) and dimethylsulfide (DMS). DMSO and DMSO2 were excreted in the urine, whereas DMS was eliminated in the expired air. In man, the relative amounts of DMSO and DMSO2 in the plasma were similar to those found in the urine. The biological half-life of DMSO2 in both the plasma and urine of man was 2.5 to 3 days. Urinary excretion of DMSO plus DMSO2 ranged from 9 to 35% of the dose in both man and miniature pigs; only 1.6% of the dose was present in the feces of miniature pigs. Whereas DMSO2 was the main excretory product in the urine of man, DMSO was the major component in the urine of miniature pigs
Sex- and Stress-Dependent Effects on Dendritic Morphology and Spine Densities in Putative Orexin Neurons
We recently found that non-stressed female rats have higher basal prepro-orexin expression and activation of orexinergic neurons compared to non-stressed males, which lead to impaired habituation to repeated restraint stress at the behavioral, neural, and endocrine level. Here, we extended our study of sex differences in the orexin system by examining spine densities and dendritic morphology in putative orexin neurons in adult male and female rats that were exposed to 5 consecutive days of 30-min restraint. Analysis of spine distribution and density indicated that putative orexinergic neurons in control non-stressed females had significantly more dendritic spines than those in control males, and the majority of these were mushroom spines. This morphological finding may suggest more excitatory input onto orexin neurons in female rats. As orexin neurons are known to promote the hypothalamic–pituitary–adrenal response, this morphological change in orexin neurons could underlie the impaired habituation to repeated stress in female rats. Dendritic complexity did not differ between non-stressed males and females, however repeated restraint stress decreased total dendritic length, nodes, and branching primarily in males. Thus, reduced dendritic complexity of putative orexinergic neurons is observed in males but not in females after 5 days of repeated restraint stress. This morphological change might be reflective of decreased orexin system function, which may allow males to habituate more fully to repeated restraint than females. These results extend our understanding of the role of orexin neurons in regulating habituation and demonstrate changes in putative orexin cell morphology and spines that may underlie sex differences in habituation
Sex- and Stress-Dependent Effects on Dendritic Morphology and Spine Densities in Putative Orexin Neurons
We recently found that non-stressed female rats have higher basal prepro-orexin expression and activation of orexinergic neurons compared to non-stressed males, which lead to impaired habituation to repeated restraint stress at the behavioral, neural, and endocrine level. Here, we extended our study of sex differences in the orexin system by examining spine densities and dendritic morphology in putative orexin neurons in adult male and female rats that were exposed to 5 consecutive days of 30-min restraint. Analysis of spine distribution and density indicated that putative orexinergic neurons in control non-stressed females had significantly more dendritic spines than those in control males, and the majority of these were mushroom spines. This morphological finding may suggest more excitatory input onto orexin neurons in female rats. As orexin neurons are known to promote the hypothalamic–pituitary–adrenal response, this morphological change in orexin neurons could underlie the impaired habituation to repeated stress in female rats. Dendritic complexity did not differ between non-stressed males and females, however repeated restraint stress decreased total dendritic length, nodes, and branching primarily in males. Thus, reduced dendritic complexity of putative orexinergic neurons is observed in males but not in females after 5 days of repeated restraint stress. This morphological change might be reflective of decreased orexin system function, which may allow males to habituate more fully to repeated restraint than females. These results extend our understanding of the role of orexin neurons in regulating habituation and demonstrate changes in putative orexin cell morphology and spines that may underlie sex differences in habituation
EfficientFormer: Vision Transformers at MobileNet Speed
Vision Transformers (ViT) have shown rapid progress in computer vision tasks,
achieving promising results on various benchmarks. However, due to the massive
number of parameters and model design, e.g., attention mechanism, ViT-based
models are generally times slower than lightweight convolutional networks.
Therefore, the deployment of ViT for real-time applications is particularly
challenging, especially on resource-constrained hardware such as mobile
devices. Recent efforts try to reduce the computation complexity of ViT through
network architecture search or hybrid design with MobileNet block, yet the
inference speed is still unsatisfactory. This leads to an important question:
can transformers run as fast as MobileNet while obtaining high performance? To
answer this, we first revisit the network architecture and operators used in
ViT-based models and identify inefficient designs. Then we introduce a
dimension-consistent pure transformer (without MobileNet blocks) as a design
paradigm. Finally, we perform latency-driven slimming to get a series of final
models dubbed EfficientFormer. Extensive experiments show the superiority of
EfficientFormer in performance and speed on mobile devices. Our fastest model,
EfficientFormer-L1, achieves top-1 accuracy on ImageNet-1K with only
ms inference latency on iPhone 12 (compiled with CoreML), which { runs as
fast as MobileNetV2 ( ms, top-1),} and our largest
model, EfficientFormer-L7, obtains accuracy with only ms
latency. Our work proves that properly designed transformers can reach
extremely low latency on mobile devices while maintaining high performance
Improved Animal Model for Vibration Injury Study
Hand-Arm Vibration Syndrome is a debilitating condition that affects millions of power-tool users in the U.S. Research into its etiology has been hampered by deficiencies in animal models used for vibration studies. Our objective was to design an animal vibration injury model that: 1) vibrates only the studied limb, not the body; and 2) avoids anaesthesia, thus allowing purer focus on physiological effects of vibration while reducing pain and distress for the animals, thereby enhancing their well-being. We compared advantages and disadvantages of several models, studying body temperature, body weight, tissue perfusion, vascular pathohistology, and general animal condition. Our model uses an apparatus that limits vibration to one body part and a specially designed cage that minimizes animal stress and suffering, eliminating the need for anaesthesia. It is ideal for the study of vibration injury, providing tissue damaged purely by vibration that can be used for pathohistology and biochemical study.
Lengthscale effects on exchange coupling in Co-Pt L10 + L12 nanochessboards
The Co-Pt nanochessboard is a quasi-periodic, nanocomposite tiling of L10 and L12 magnetic phases that offers a novel structure for the investigation of exchange coupling, relevant to permanent magnet applications. Periodicity of the tiling is controlled by the rate of cooling through the eutectoid isotherm, resulting in control over the L10-L12 exchange coupling. First order reversal curve analysis reveals a transition from partial coupling to nearly complete exchange-coupling in a Co40.2Pt59.8 nanochessboard structured alloy as the periodicity is reduced below the critical correlation length. Micromagnetic simulations give insights into how exchange coupling manifests in the tiling, and its impact on microscopic magnetization reversal mechanisms
Toward automated irrigation management with integrated crop water stress index and spatial soil water balance
Decision support systems intended for precision irrigation aim at reducing irrigation applications while optimizing crop yield to achieve maximum crop water productivity (CWP). These systems incorporate on-site sensor data, remote sensing inputs, and advanced algorithms with spatial and temporal characteristics to compute precise crop water needs. The availability of variable rate irrigation (VRI) systems enables irrigation applications at a sub-field scale. The combination of an appropriate VRI system along with a precise decision support system would be ideal for improved CWP. The objective of this study was to compare and evaluate two decision support systems in terms of seasonal applied irrigation, crop yield, and CWP. This study implemented the Spatial EvapoTranspiration Modeling Interface (SETMI) model and the Irrigation Scheduling Supervisory Control and Data Acquisition (ISSCADA) system for management of a center pivot irrigation system in a 58-ha maize-soybean field during the 2020 and 2021 growing seasons. The irrigation scheduling methods included: ISSCADA plant feedback, ISSCADA hybrid, common practice, and SETMI. These methods were applied at irrigation levels of 0, 50, 100, and 150% of the full irrigation prescribed by the respective irrigation scheduling method. Data from infrared thermometers (IRTs), soil water sensors, weather stations, and satellites were used in the irrigation methods. Mean seasonal irrigation prescribed was different among the irrigation levels and methods for the 2 years. The ISSCADA plant feedback prescribed the least irrigation among the methods for majority of the cases. The common practice prescribed the largest seasonal irrigation depth among the methods for three crop-year cases. The maize yield in rainfed was found to be significantly lower than the irrigated levels in 2020 since 2020 was a dry year. No significant differences were observed in crop yield among the different irrigation methods for both years. The CWP among the different irrigation methods ranged between 2.72 and 3.15 kg m−3 for 2020 maize, 1.03 and 1.13 kg m−3 for 2020 soybean, 3.57 and 4.24 kg m−3 for 2021 maize, and 1.19 and 1.48 kg m−3 for 2021 soybean. Deficit level (50%) had the largest irrigation water productivity in all crop-year cases in this study. The ISSCADA and SETMI systems were found to reduce irrigation applications as compared to the common practice while maintaining crop yield. This study was the first to implement the newly developed integrated crop water stress index (iCWSI) thresholds and the ISSCADA system for site-specific irrigation of maize and soybean in Nebraska
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