Automatic Determination of Stellar Atmospheric Parameters and Construction of Stellar Spectral Templates of the Guoshoujing Telescope (LAMOST)

A number of spectroscopic surveys have been carried out or are planned to study the origin of the Milky Way. Their exploitation requires reliable automated methods and softwares to measure the fundamental parameters of the stars. Adopting the ULySS package, we have tested the effect of different resolutions and signal-to-noise ratios (SNR) on the measurement of the stellar atmospheric parameters (effective temperature Teff, surface gravity log g, and metallicity [Fe/H]). We show that ULySS is reliable to determine these parameters with medium-resolution spectra (R~2000). Then, we applied the method to measure the parameters of 771 stars selected in the commissioning database of the Guoshoujing Telescope (GSJT). The results were compared with the SDSS/SEGUE Stellar Parameter Pipeline (SSPP), and we derived precisions of 167 K, 0.34 dex, and 0.16 dex for Teff, log g and [Fe/H] respectively. Furthermore, 120 of these stars are selected to construct the primary stellar spectra template library (Version 1.0) of GSJT, and will be deployed as basic ingredients for the GSJT automated parametrization pipeline.Comment: 23 pages, 15 figures, accepted by RA

Accelerated in vivo proliferation of memory phenotype CD4+ T-cells in human HIV-1 infection irrespective of viral chemokine co-receptor tropism.

CD4(+) T-cell loss is the hallmark of HIV-1 infection. CD4 counts fall more rapidly in advanced disease when CCR5-tropic viral strains tend to be replaced by X4-tropic viruses. We hypothesized: (i) that the early dominance of CCR5-tropic viruses results from faster turnover rates of CCR5(+) cells, and (ii) that X4-tropic strains exert greater pathogenicity by preferentially increasing turnover rates within the CXCR4(+) compartment. To test these hypotheses we measured in vivo turnover rates of CD4(+) T-cell subpopulations sorted by chemokine receptor expression, using in vivo deuterium-glucose labeling. Deuterium enrichment was modeled to derive in vivo proliferation (p) and disappearance (d*) rates which were related to viral tropism data. 13 healthy controls and 13 treatment-naive HIV-1-infected subjects (CD4 143-569 cells/ul) participated. CCR5-expression defined a CD4(+) subpopulation of predominantly CD45R0(+) memory cells with accelerated in vivo proliferation (p = 2.50 vs 1.60%/d, CCR5(+) vs CCR5(-); healthy controls; P<0.01). Conversely, CXCR4 expression defined CD4(+) T-cells (predominantly CD45RA(+) naive cells) with low turnover rates. The dominant effect of HIV infection was accelerated turnover of CCR5(+)CD45R0(+)CD4(+) memory T-cells (p = 5.16 vs 2.50%/d, HIV vs controls; P<0.05), naïve cells being relatively unaffected. Similar patterns were observed whether the dominant circulating HIV-1 strain was R5-tropic (n = 9) or X4-tropic (n = 4). Although numbers were small, X4-tropic viruses did not appear to specifically drive turnover of CXCR4-expressing cells (p = 0.54 vs 0.72 vs 0.44%/d in control, R5-tropic, and X4-tropic groups respectively). Our data are most consistent with models in which CD4(+) T-cell loss is primarily driven by non-specific immune activation

An Opportunistic Relaying Selection Scheme Based on Relay Fairness

Opportunistic relaying scheme is a single cooperative relay selection method based on Channel State Information. However, the failure probability of the best relay selection may become unacceptable when the number of relays increases. Although most of the existing solutions can reduce the failure probability of relay selection, they ignore the fairness of the relay selection. In order to improve the fairness of the relay selection without affecting the failure probability of the best relay selection, we propose a modified practical best relay selection scheme in this paper,  and by introducing proportional fair algorithm, the relay timer will be given a smaller correlation coefficient. The proposed method makes the probability of selection be improved. In the light of defined fairness factor, the relay fairness is represented. Simulation results show that the new algorithm can improve the fairness of the relay selection on the basis of maintaining the original failure probability of relay selection. DOI : http://dx.doi.org/10.11591/telkomnika.v12i1.391

Evasion of HSR in the charmless decays of excited PP-wave charmonia

We investigate the charmless decays of excited $P$-wave charmonia $\chi_{c1}^\prime \to VV$ and $\chi_{c2}^\prime \to VP$ via intermediate charmed meson loops, where $V$ and $P$ denote the light vector and pseudoscalar mesons, respectively. Within the model parameters, the charmed meson loop contributions are evaluated by using the effective Lagrangian approach. For $\chi_{c1}^\prime \to VV$, the partial widths of the $\rho\rho$, $\omega\omega$, and $K^*{\bar K}^*$ channels can reach to the order of MeV, while the partial width of the $\phi\phi$ channel is very small and in the order of keV. For $\chi_{c2}^\prime \to V P$, the partial widths of $\chi_{c2}^{\prime} \to K^\ast \bar{K}+c.c$ turns out to be sizeable, while the partial widths of $\chi_{c2}^{\prime} \to \rho^+\pi^- +c.c$ is found to be much smaller than the $K^\ast \bar{K}+c.c$ channel. Our calculations may be examined by the future BESIII experiments.Comment: 7 pages, 7 figures, to appear in Eur. Phys. J.

ASXL1 interacts with the cohesin complex to maintain chromatid separation and gene expression for normal hematopoiesis

ASXL1 is frequently mutated in a spectrum of myeloid malignancies with poor prognosis. Loss of Asxl1 leads to myelodysplastic syndrome-like disease in mice; however, the underlying molecular mechanisms remain unclear. We report that ASXL1 interacts with the cohesin complex, which has been shown to guide sister chromatid segregation and regulate gene expression. Loss of Asxl1 impairs the cohesin function, as reflected by an impaired telophase chromatid disjunction in hematopoietic cells. Chromatin immunoprecipitation followed by DNA sequencing data revealed that ASXL1, RAD21, and SMC1A share 93% of genomic binding sites at promoter regions in Lin-cKit+ (LK) cells. We have shown that loss of Asxl1 reduces the genome binding of RAD21 and SMC1A and alters the expression of ASXL1/cohesin target genes in LK cells. Our study underscores the ASXL1-cohesin interaction as a novel means to maintain normal sister chromatid separation and regulate gene expression in hematopoietic cells

MicroRNA-19b downregulates insulin 1 through targeting transcription factor NeuroD1

AbstractMiR-17-92 cluster miRNAs are disclosed to contribute to the development of multiple organs and tumorigenesis, but their roles in pancreas development remains unclear. In this study, we found that miR-19b, a member of miR-17-92, was highly expressed in the pancreatic progenitor cells, and miR-19b could target the 3′ UTR of NeuroD1 mRNA to decrease its protein and mRNA levels. Functional analysis showed that miR-19b exerted little effect on the proliferation of pancreatic progenitors, whereas it inhibited the expression of insulin 1, but not insulin 2 in MIN6 cells. These results suggest that miR-19b can downregulate insulin 1 expression through targeting transcription factor NeuroD1, and thus regulate the differentiation and function of β-cells

MedEval: A Multi-Level, Multi-Task, and Multi-Domain Medical Benchmark for Language Model Evaluation

Curated datasets for healthcare are often limited due to the need of human annotations from experts. In this paper, we present MedEval, a multi-level, multi-task, and multi-domain medical benchmark to facilitate the development of language models for healthcare. MedEval is comprehensive and consists of data from several healthcare systems and spans 35 human body regions from 8 examination modalities. With 22,779 collected sentences and 21,228 reports, we provide expert annotations at multiple levels, offering a granular potential usage of the data and supporting a wide range of tasks. Moreover, we systematically evaluated 10 generic and domain-specific language models under zero-shot and finetuning settings, from domain-adapted baselines in healthcare to general-purposed state-of-the-art large language models (e.g., ChatGPT). Our evaluations reveal varying effectiveness of the two categories of language models across different tasks, from which we notice the importance of instruction tuning for few-shot usage of large language models. Our investigation paves the way toward benchmarking language models for healthcare and provides valuable insights into the strengths and limitations of adopting large language models in medical domains, informing their practical applications and future advancements.Comment: Accepted to EMNLP 2023. Camera-ready version: updated IRB, added more evaluation results on LLMs such as GPT4, LLaMa2, and LLaMa2-cha

Stacking-Dependent Interlayer Phonons in 3R and 2H MoS2_{2}

We have investigated the interlayer shear and breathing phonon modes in MoS$_{2}$ with pure 3R and 2H stacking order by using polarization-dependent ultralow-frequency Raman spectroscopy. We observe up to three shear branches and four breathing branches in MoS$_{2}$ with thickness from 2 to 13 layers. The breathing modes show the same Raman activity behavior for both polytypes, but the 2H breathing frequencies are consistently several wavenumbers higher than the 3R breathing frequencies, signifying that 2H MoS$_{2}$ has slightly stronger interlayer lattice coupling than 3R MoS$_{2}$. In contrast, the shear-mode Raman spectra are strikingly different for 2H and 3R MoS$_{2}$. While the strongest shear mode corresponds to the highest-frequency branch in the 2H structure, it corresponds to the lowest-frequency branch in the 3R structure. Such distinct and complementary Raman spectra of the 3R and 2H polytypes allow us to survey a broad range of shear modes in MoS$_{2}$, from the highest to lowest branch. By combining the linear chain model, group theory, effective bond polarizability model and first-principles calculations, we can account for all the major observations in our experiment.Comment: 18 pages, 8 figures (supplemental material: 23 pages, 13 figures). 2D Materials, Accepted Manuscript online 24 January 201

Abnormal diastolic function underlies the different beneficial effects of cardiac resynchronization therapy on ischemic and non-ischemic cardiomyopathy

OBJECTIVES: To investigate the association between diastolic function and the different beneficial effects of cardiac resynchronization therapy in patients with heart failure due to different causes. METHODS: The 104 enrolled patients were divided into an ischemic cardiomyopathy group (n=27) and a non-ischemic cardiomyopathy group (n=77) according to the cause of heart failure. Before implantation, left ventricular diastolic function was evaluated in all patients using echocardiography. After six months of follow-up, the beneficial effects of cardiac resynchronization therapy were evaluated using a combination of clinical symptoms and echocardiography parameters. RESULTS: The ischemic cardiomyopathy group included significantly more patients with restrictive filling than the non-ischemic cardiomyopathy group. The response rate after the implantation procedure was significantly higher in the non-ischemic cardiomyopathy group than in the ischemic cardiomyopathy group. Degrees of improvement in echocardiography parameters were significantly greater in the non-ischemic cardiomyopathy group than in the ischemic cardiomyopathy group. Multivariate regression analysis showed that a restrictive filling pattern was an independent factor that influenced responses to cardiac resynchronization therapy. CONCLUSIONS: This study again confirmed that the etiology of heart failure affects the beneficial effects of cardiac resynchronization therapy and a lower degree of improvement in ventricular systolic function and remodelling was observed in ischemic cardiomyopathy patients than in non-ischemic cardiomyopathy patients. In addition, systolic heart failure patients with severe diastolic dysfunction had poor responses to cardiac resynchronization therapy. Ischemic cardiomyopathy patients exhibited more severe diastolic dysfunction than non-ischemic cardiomyopathy patients, which may be a reason for the reduced beneficial effect of cardiac resynchronization therapy