175 research outputs found
“Kulak” and Food Crisis during the Civil War in Soviet Russia
Food crisis was a very serious issue during the Civil War in Soviet Russia, which was mainly due to the revolt or resistance of the kulak in the countryside of Soviet Russia. To some extent, “Kulak” allowed the hunger situation in some regions of the Soviet Russia to go unchecked, which was believed to be a very severe threat for the new Soviet regime. Therefore, to eradicate the menace, the Bolsheviks led by Lenin adopted the policy of the resolute repression and deprivation of the kulak. As a matter of fact, in a word, according to the logic of the Bolsheviks, kulak was the culprit that engendered the famine, so kulak must be responsible for it, and kulak must pay the bill
Observation and simulation study on the rapid intensification mechanism of Typhoon “Mekkhala” (2006)
Based on Doppler Weather radar observations and numerical simulations applying the Weather Research and Forecasting (WRF) system, this study focused on the rapid intensification (RI) of Typhoon “Mekkhala” (2006) in the inshore area in 2020. The simulated track of the typhoon relatively matched with the observation, with a slight eastward bias compared to the observed track. During the phase of RI, there was a slight weakening of vertical wind shear between 200–500 hPa. The temporary decrease in vertical wind shear became a favorable factor for the intensification of the typhoon. In general, vertical wind shear of the lower atmosphere is the key to supporting the RI of Typhoon Mekkhala. In the middle troposphere, the southward component of the vertical wind shear suddenly increases, indicates that the inflow of southern wind to the core of the typhoon had strengthened. Thus, the strengthening of the moisture transport by enhanced southern wind, contributed to the intensification of the typhoon. During the intensification of the typhoon, the low-level vorticity was significantly enhanced, and the high vorticity values expanded from the lower to higher troposphere. The vertical distribution of vorticity transformed from symmetry to asymmetry. The development of secondary circulation on both sides of the typhoon is a dynamic factor for intensification
Case report: Advanced primary squamous cell carcinoma in the periampullary area with upregulation of programmed cell death-ligand 1 expression and response to sintilimab immunotherapy
Primary squamous cell carcinoma (SCC) of the periampullary area is exceedingly rare. We report a case of a 45-year-old woman who presented with progressive upper abdominal pain and melena. Laboratory testing revealed an elevated level of carcinoembryonic antigen. Esophagogastroduodenoscopy revealed a very large irregular ulcerated tumor in the periampullary area. Contrast-enhanced computed tomography (CT) of the chest, abdomen, and pelvis, 18 F-fluorodeoxyglucose positron emission tomography/CT, and thin-prep cytologic test excluded metastasis of the primary tumor to the periampullary area from other sites. Immunohistochemistry revealed positive p40 and cytokeratin (CK)5/6, indicating SCC. The expression of programmed cell death-ligand 1 (PD-L1) in tumor cells was upregulated, and the patient responded well to chemotherapy combined with immunotherapy. To the best of our knowledge, this is the first reported case of advanced primary SCC in the periampullary area with high expression of PD-L1
Target splitting non-coplanar RapidArc radiation therapy for a diffuse sebaceous carcinoma of the scalp: a novel delivery technique
Molecular basis of ligand recognition and activation of human V2 vasopressin receptor.
Vasopressin type 2 receptor (V2R) belongs to the vasopressin (VP)/oxytocin (OT) receptor subfamily of G protein-coupled receptors (GPCRs), which comprises at least four closely related receptor subtypes: V1aR, V1bR, V2R, and OTR. These receptors are activated by arginine vasopressin (AVP) and OT, two endogenous nine-amino acid neurohypophysial hormones, which are thought to mediate a biologically conserved role in social behavior and sexual reproduction. V2R is mainly expressed in the renal collecting duct principal cells and mediates the antidiuretic action of AVP by accelerating water reabsorption, thereby playing a vital role in controlling water homeostasis. Moreover, numerous gain-of-function and loss-of-function mutations of V2R have been identified and are closely associated with human diseases, including nephrogenic syndrome of inappropriate diuresis (NSIAD) and X-linked congenital nephrogenic diabetes insipidus (NDI). Thus, V2R has attracted intense interest as a drug target. However, due to a lack of structural information, how AVP recognizes and activates V2R remains elusive, which hampers the V2R-targeted drug design. Here, we determined a 2.6 Å resolution cryo-EM structure of the full-length, G s -coupled human V2R bound to AVP (Fig. 1a; Supplementary information, Table S1). The G s protein was engineered based on mini-G s that was used in the crystal structure determination of the G s -coupled adenosine A 2A receptor (A 2A R) to stabilize the V2R–G s protein complex (Supplementary information, Data S1). The final structure of the AVP–V2R–G s complex contains all residues of AVP (residues 1–9), the Gα s Ras-like domain, Gβγ subunits, Nb35, scFv16, and the V2R residues from T31 to L339 8.57 (superscripts refer to Ballesteros–Weinstein numbering). The majority of amino acid side chains, including AVP, transmembrane domain (TMD), all flexible intracellular loops (ICLs) and extracellular loops (ECLs) except for ICL3 and G185–G188 in ECL2, were well resolved in the model, refined against the EM density map (Fig. 1a; Supplementary information, Figs. S1–3). The complex structure can provide detailed information on the binding interface between AVP and helix bundle of the receptor, as well as the receptor–G s interface
Rankitect: Ranking Architecture Search Battling World-class Engineers at Meta Scale
Neural Architecture Search (NAS) has demonstrated its efficacy in computer
vision and potential for ranking systems. However, prior work focused on
academic problems, which are evaluated at small scale under well-controlled
fixed baselines. In industry system, such as ranking system in Meta, it is
unclear whether NAS algorithms from the literature can outperform production
baselines because of: (1) scale - Meta ranking systems serve billions of users,
(2) strong baselines - the baselines are production models optimized by
hundreds to thousands of world-class engineers for years since the rise of deep
learning, (3) dynamic baselines - engineers may have established new and
stronger baselines during NAS search, and (4) efficiency - the search pipeline
must yield results quickly in alignment with the productionization life cycle.
In this paper, we present Rankitect, a NAS software framework for ranking
systems at Meta. Rankitect seeks to build brand new architectures by composing
low level building blocks from scratch. Rankitect implements and improves
state-of-the-art (SOTA) NAS methods for comprehensive and fair comparison under
the same search space, including sampling-based NAS, one-shot NAS, and
Differentiable NAS (DNAS). We evaluate Rankitect by comparing to multiple
production ranking models at Meta. We find that Rankitect can discover new
models from scratch achieving competitive tradeoff between Normalized Entropy
loss and FLOPs. When utilizing search space designed by engineers, Rankitect
can generate better models than engineers, achieving positive offline
evaluation and online A/B test at Meta scale.Comment: Wei Wen and Kuang-Hung Liu contribute equall
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