For the random design nonparametric regression, cross-validation is a popular bandwidth selector. It is constructed by using the criterion of "weighted" integrated square error. In practice, however, ...the weighting scheme by the design density in the criterion causes that its associated cross-validation function puts more emphasis in regions with more data, gives little attention to regions with few data, but has no consideration for regions without data. In such a case, the value of the cross-validated bandwidth depends on the distribution of the design points, but is independent of the location of the interval on which the regression function value is estimated. Hence, if there are sparse regions in the realization of the design, then the resulting cross-validated bandwidth is usually not large enough in magnitude such that its corresponding kernel regression function estimate has rough appearance in these sparse regions. To avoid this drawback to cross-validation, we suggest using the criterion of "unweighted" integrated square error to construct the bandwidth selector. Under the criterion, a bandwidth selector called integrated cross-validation is proposed, and the resulting bandwidth is shown to be asymptotically optimal. Empirical studies demonstrate that the kernel regression function estimate obtained by using our proposed bandwidth is better than that employing the ordinary cross-validated bandwidth, in both senses of having smoother appearance and yielding smaller sample unweighted integrated square error.
Cannabis is the most widely used illicit drug in the world. Delta-9-tetrahydrocannabinol (Δ9-THC) is the main psychoactive component of cannabis and its effects have been well-studied. However, ...cannabis contains many other cannabinoids that affect brain function. Therefore, these studies investigated the effect of cannabis smoke exposure on locomotor activity, rearing, anxiety-like behavior, and the development of dependence in rats. It was also investigated if cannabis smoke exposure leads to tolerance to the locomotor-suppressant effects of the endogenous cannabinoid anandamide. Cannabis smoke was generated by burning 5.7% Δ9-THC cannabis cigarettes in a smoking machine. The effect of cannabis smoke on the behavior of rats in a small and large open field and an elevated plus maze was evaluated. Cannabis smoke exposure induced a brief increase in locomotor activity followed by a prolonged decrease in locomotor activity and rearing in the 30-min small open field test. The cannabinoid receptor type 1 (CB1) receptor antagonist rimonabant increased locomotor activity and prevented the smoke-induced decrease in rearing. Smoke exposure also increased locomotor activity in the 5-min large open field test and the elevated plus maze test. The smoke exposed rats spent more time in the center zone of the large open field, which is indicative of a decrease in anxiety-like behavior. A high dose of anandamide decreased locomotor activity and rearing in the small open field and this was not prevented by rimonabant or pre-exposure to cannabis smoke. Serum Δ9-THC levels were 225 ng/ml after smoke exposure, which is similar to levels in humans after smoking cannabis. Exposure to cannabis smoke led to dependence as indicated by more rimonabant-precipitated somatic withdrawal signs in the cannabis smoke exposed rats than in the air-control rats. In conclusion, chronic cannabis smoke exposure in rats leads to clinically relevant Δ9-THC levels, dependence, and has a biphasic effect on locomotor activity.
Understanding urban environments and their spatio-temporal changes is essential for regional and local planning and environmental management. To facilitate monitoring and analyzing urban ...environments, remotely sensed data have been applied extensively because of its synoptic view and repeat coverage over large geographic areas. Compared with traditional per-pixel and sub-pixel image analyses, spectral indices have apparent advantages due to their easy implementation. However, most spectral indices are designed to highlight only one land cover, and confusion between other land cover types, in particular impervious surfaces and bare soil, has not been successfully addressed. This study proposes a biophysical composition index (BCI) for simple and convenient derivation of urban biophysical compositions for practical applications following Ridd's conceptual vegetation – impervious surface – soil triangle model by a reexamination of the Tasseled Cap (TC) transformation. Further, this research explores the applicability of BCI in various remotely sensed images at different spatial resolutions. Results indicate that, BCI has a closer relationship with impervious surface abundance than those of normalized difference vegetation index (NDVI), normalized difference built-up index (NDBI) and normalized difference impervious surface index (NDISI), with correlation coefficients of approximately 0.8 at various resolutions. Also, the performances of BCI in quantifying vegetation abundance are comparable with NDVI at all three spatial scales. Additionally, with much higher values of separability metrics than any other index, the study confirms that BCI was shown to be the most effective index of the four evaluated for separating impervious surfaces and bare soil.
► We develop a biophysical composition index (BCI) to characterize urban environments. ► We compare the performances of BCI with NDVI, NDBI, and NDISI at three resolutions. ► BCI is among the best in representing impervious surfaces abundance at each scale. ► BCI is also effective in quantifying vegetation abundance when compared to NDVI. ► With BCI, impervious surfaces and bare soil can be moderately separated.
We report on the observation of the accreting pulsar GRO J1008-57 performed by Insight-HXMT at the peak of the source's 2017 outburst. Pulsations are detected with a spin period of 93.283(1) s. The ...pulse profile shows double peaks at soft X-rays, and only one peak above 20 keV. The spectrum is well described by the phenomenological models of X-ray pulsars. A cyclotron resonant scattering feature is detected with very high statistical significance at a centroid energy of \(E_{\rm cyc}=90.32_{-0.28}^{+0.32}\) keV, for the reference continuum and line models, HIGHECUT and GABS respectively. Detection is very robust with respect to different continuum models. The line energy is significantly higher than what suggested from previous observations, which provided very marginal evidence for the line. This establishes a new record for the centroid energy of a fundamental cyclotron resonant scattering feature observed in accreting pulsars. We also discuss the accretion regime of the source during the Insight-HXMT observation.
Bark protects the tree against environmental insults. Here, we analyzed whether this defensive strategy could be utilized to broadly enhance protection against colitis. As a proof of concept, we show ...that exosome‐like nanoparticles (MBELNs) derived from edible mulberry bark confer protection against colitis in a mouse model by promoting heat shock protein family A (Hsp70) member 8 (HSPA8)‐mediated activation of the AhR signaling pathway. Activation of this pathway in intestinal epithelial cells leads to the induction of COP9 Constitutive Photomorphogenic Homolog Subunit 8 (COPS8). Utilizing a gut epithelium‐specific knockout of COPS8, we demonstrate that COPS8 acts downstream of the AhR pathway and is required for the protective effect of MBELNs by inducing an array of anti‐microbial peptides. Our results indicate that MBELNs represent an undescribed mode of inter‐kingdom communication in the mammalian intestine through an AhR‐COPS8‐mediated anti‐inflammatory pathway. These data suggest that inflammatory pathways in a microbiota‐enriched intestinal environment are regulated by COPS8 and that edible plant‐derived ELNs may hold the potential as new agents for the prevention and treatment of gut‐related inflammatory disease.
Synopsis
Mulberry bark derived exosome‐like nanoparticles (MBELNs) prevent gut inflammation via plant heat shock protein HSPA8‐mediated activation of AhR/COPS8 pathways. Treatment with MBELNs promotes the restoration of gut microbiome homeostasis, ameliorating intestinal inflammatory pathologies.
Mulberry bark derived exosome‐like nanoparticles (MBELNs) prevent mouse colitis via the AhR/COPS8 pathway.
Binding of MBELN‐derived heat shock protein HSPA8 to AhR leads to the activation of AhR signaling.
Activation of AhR leads to the induction of an array of anti‐microbial peptides (AMPs) via COP9/COPS8.
AhR/COPS8‐dependent induction of AMPs inhibits intestinal inflammation and alters fecal gut microbiota composition.
Mulberry bark derived exosome‐like nanoparticles (MBELNs) prevent gut inflammation via plant heat shock protein HSPA8‐mediated activation of AhR/COPS8 pathways. Treatment with MBELNs promotes the restoration of gut microbiome homeostasis, ameliorating intestinal inflammatory pathologies.
The pre-implantation protein 3 (prei3), which might play a role in pre-implantation embryogenesis, is one of the promising candidate genes for litter size traits in pigs. In this study, a single ...nucleotide polymorphism (SNP: T802G) in intron 6 of the pig prei3 gene was detected and a genotyping assay for this SNP was developed. An association study for this SNP with litter size was performed in two independent populations. One population consisted of crossbred sows derived from Landrace, Large White, Chinese Tongcheng and / or Chinese Meishan (Line DIV). The other population constituted of crossbred animals derived from Chinese Qingping and Duroc (QD). Statistical analysis demonstrated that, in first parity, 2.65 more piglets were born and 3.82 more piglets were born alive in sows in Line DIV with genotype TT than with genotype GG. For second and subsequent litters, in both the DIV and QD lines there were significant differences in the number of piglets born alive between TG and GG sows, with the TG sows producing more piglets born alive than the GG sows. These results suggest that the prei3 SNP is significantly associated with litter size in the two populations studied, and could be useful in selection for increasing litter size in pigs. Further investigations on more pig populations with large sample sizes are needed to confirm this.
Summary Osteoporotic fracture (OF) is a serious outcome of osteoporosis. Important risk factors for OF include reduced bone mineral density and unstable bone structure. This genome-wide copy number ...variation association study suggested VPS13B gene for osteoporosis in Caucasians. Introduction Bone mineral density (BMD) and femoral neck cross-sectional geometric parameters (FNCSGPs) are under strong genetic control. DNA copy number variation (CNV) is an important source of genetic diversity for human diseases. This study aims to identify CNVs associated with BMD and FNCSGPs. Methods Genome-wide CNV association analyses were conducted in 1,000 unrelated Caucasian subjects for BMD at the spine, hip, femoral neck, and for three FNCSGPs —cortical thickness (CT), cross-section area (CSA), and buckling ratio (BR). BMD was measured by dual energy X-ray absorptiometry (DEXA). CT, CSA, and BR were estimated using DEXA measurements. Affymetrix 500K arrays and copy number analysis tool was used to identify CNVs. Results A CNV in VPS13B gene was significantly associated with spine, hip and FN BMDs, and CT, CSA, and BR (p < 0.05). Compared to subjects with two copies of the CNV, carriers of one copy had an average of 14.6%, 12.4%, and 13.6% higher spine, hip, and FN BMD, 20.0% thicker CT, 10.6% larger CSA, and 12.4% lower BR. Thus, a decrease of the CNV consistently produced stronger bone, thereby reducing osteoporotic fracture risk. Conclusions VPS13B gene, via affecting BMD and FNCSGPs, is a novel osteoporosis risk gene.
A two-dimensional transient model with considering vanadium ion crossover was presented to examine the influence of asymmetric electrolyte concentrations and operation pressures strategies on the ...characteristics of capacity decay, vanadium ions crossover and charge-discharge performance of a vanadium redox flow battery during battery cycling. It was indicated that for asymmetric electrolyte operating concentrations, with increasing the initial concentration of positive electrolyte while keeping initial concentration of negative electrolyte unchanged, the discharge capacity decay behavior during battery cycling can be effectively mitigated due to the reason that the imbalance of vanadium ions crossover is alleviated by the increased diffusion flux of VO2+/VO2+ couple from positive to negative side. Also, the overall charge-discharge performance of the battery is greatly improved due to the reduced potential losses of both electrode reactions. Moreover, it was shown that the discharge capacity decay can also be suppressed by increasing the outlet pressure of positive electrode, which is attributed to the reason that the imbalance of vanadium ions crossover can be eliminated with the increased vanadium osmotic convection driven by pressure gradient. However, asymmetric operation pressures showed little impact on batter charge-discharge voltages.
•A VRFB model with considering vanadium ions crossover was presented.•Capacity decay and charge-discharge behaviors of a VRFB were analyzed.•Effects of asymmetric electrolyte concentrations were examined.•Effects of asymmetric operation pressures were examined.•Overall performance was improved with asymmetric operating conditions.
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