Optimizing Guided Traversal for Fast Learned Sparse Retrieval

Recent studies show that BM25-driven dynamic index skipping can greatly accelerate MaxScore-based document retrieval based on the learned sparse representation derived by DeepImpact. This paper investigates the effectiveness of such a traversal guidance strategy during top k retrieval when using other models such as SPLADE and uniCOIL, and finds that unconstrained BM25-driven skipping could have a visible relevance degradation when the BM25 model is not well aligned with a learned weight model or when retrieval depth k is small. This paper generalizes the previous work and optimizes the BM25 guided index traversal with a two-level pruning control scheme and model alignment for fast retrieval using a sparse representation. Although there can be a cost of increased latency, the proposed scheme is much faster than the original MaxScore method without BM25 guidance while retaining the relevance effectiveness. This paper analyzes the competitiveness of this two-level pruning scheme, and evaluates its tradeoff in ranking relevance and time efficiency when searching several test datasets.Comment: This paper is published in WWW'2

Uptake, sequestration and tolerance of cadmium at cellular levels in the hyperaccumulator plant species Sedum alfredii.

Sedum alfredii is one of a few plant species known to hyperaccumulate cadmium (Cd). Uptake, localization, and tolerance of Cd at cellular levels in shoots were compared in hyperaccumulating (HE) and non-hyperaccumulating (NHE) ecotypes of Sedum alfredii. X-ray fluorescence images of Cd in stems and leaves showed only a slight Cd signal restricted within vascular bundles in the NHEs, while enhanced localization of Cd, with significant tissue- and age-dependent variations, was detected in HEs. In contrast to the vascular-enriched Cd in young stems, parenchyma cells in leaf mesophyll, stem pith and cortex tissues served as terminal storage sites for Cd sequestration in HEs. Kinetics of Cd transport into individual leaf protoplasts of the two ecotypes showed little difference in Cd accumulation. However, far more efficient storage of Cd in vacuoles was apparent in HEs. Subsequent analysis of cell viability and hydrogen peroxide levels suggested that HE protoplasts exhibited higher resistance to Cd than those of NHE protoplasts. These results suggest that efficient sequestration into vacuoles, as opposed to rapid transport into parenchyma cells, is a pivotal process in Cd accumulation and homeostasis in shoots of HE S. alfredii. This is in addition to its efficient root-to-shoot translocation of Cd

Prognostic factors and treatment of neuroendocrine tumors of the uterine cervix based on the FIGO 2018 staging system: a single-institution study of 172 patients

Objective This study aimed to explore the prognostic factors and outcomes of patients with neuroendocrine tumors (NETs) of the cervix and to determine appropriate treatment. Methods A single-institution retrospective analysis of 172 patients with NETs was performed based on the new International Federation of Gynecology and Obstetrics (FIGO 2018) staging system. Results Among the 172 eligible patients, 161 were diagnosed with small cell neuroendocrine carcinoma (SCNEC), six with large cell neuroendocrine carcinoma, four with typical carcinoid tumors and one with SCNEC combined with an atypical carcinoid tumor. According to the FIGO 2018 staging guidelines, 31 were stage I, 66 were stage II, 57 were stage III, and 18 were stage IV. The 5-year survival rates of patients with stage I–IV disease were 74.8%, 56.2%, 41.4% and 0%, respectively. The 5-year progression-free survival rates of patients with stage I–IV disease were 63.8%, 54.5%, 30.8% and 0%, respectively. In the multivariate analysis, advanced FIGO stage, large tumor and older age were identified as independent variables for 5-year survival in patients with stage I–IV disease. FIGO stage, tumor size and para-aortic lymph node metastasis were independent prognostic factors for 5-year progression-free survival in patients with stage I–IV disease. For the patients receiving surgery (n = 108), tumor size and pelvic lymph node metastasis were independent prognostic factors for 5-year survival, and pelvic lymph node metastasis for 5-year progression-free survival. In stage IVB, at least six cycles of chemotherapy (n = 7) was associated with significantly better 2-year OS (83.3% vs. 9.1%, p < 0.001) and 2-year PFS (57.1% vs. 0%, p = 0.01) than fewer than six cycles of chemotherapy(n = 11). Conclusion Advanced FIGO stage, large tumor, older age and lymph node metastasis are independent prognostic factors for NETs of the cervix. The TP/TC and EP regimens were the most commonly used regimens, with similar efficacies and toxicities. Standardized and complete multimodality treatment may improve the survival of patients with NETs

Polyploidy underlies co-option and diversification of biosynthetic triterpene pathways in the apple tribe

Whole-genome duplication (WGD) plays important roles in plant evolution and function, yet little is known about how WGD underlies metabolic diversification of natural products that bear significant medicinal properties, especially in nonmodel trees. Here, we reveal how WGD laid the foundation for co-option and differentiation of medicinally important ursane triterpene pathway duplicates, generating distinct chemotypes between species and between developmental stages in the apple tribe. After generating chromosome-level assemblies of a widely cultivated loquat variety and Gillenia trifoliata, we define differentially evolved, duplicated gene pathways and date the WGD in the apple tribe at 13.5 to 27.1 Mya, much more recent than previously thought. We then functionally characterize contrasting metabolic pathways responsible for major triterpene biosynthesis in G. trifoliata and loquat, which pre- and postdate the Maleae WGD, respectively. Our work mechanistically details the metabolic diversity that arose post-WGD and provides insights into the genomic basis of medicinal properties of loquat, which has been used in both traditional and modern medicines

Large room-temperature magnetoresistance in van der Waals ferromagnet/semiconductor junctions

The magnetic tunnel junction (MTJ) is the core component in memory technologies, such as the magnetic random-access memory, magnetic sensors and programmable logic devices. In particular, MTJs based on two-dimensional (2D) van der Waals (vdW) heterostructures offer unprecedented opportunities for low power consumption and miniaturization of spintronic devices. However, their operation at room temperature remains a challenge. Here, we report a large tunnel magnetoresistance (TMR) of up to 85% at room temperature (T = 300 K) in vdW MTJs based on a thin (< 10 nm) semiconductor spacer WSe2 layer embedded between two Fe3GaTe2 electrodes with intrinsic above-room-temperature ferromagnetism. The TMR in the MTJ increases with decreasing temperature up to 164% at T = 10 K. The demonstration of TMR in ultra-thin MTJs at room-temperature opens a realistic and promising route for next-generation spintronic applications beyond the current state of the art

Principles of early human development and germ cell program from conserved model systems

Human primordial germ cells (hPGCs), the precursors of sperm and eggs, originate during week 2-3 of early postimplantation development(1). Using in vitro models of hPGC induction(2-4), recent studies suggest striking mechanistic differences in specification of human and mouse PGCs(5). This may partly be due to the divergence in their pluripotency networks, and early postimplantation development(6-8). Since early human embryos are inaccessible for direct studies, we considered alternatives, including porcine embryos that, as in humans, develop as bilaminar embryonic discs. Here we show that porcine PGCs (pPGCs) originate from the posterior pre-primitive streak competent epiblast by sequential upregulation of SOX17 and BLIMP1 in response to WNT and BMP signalling. Together with human and monkey in vitro models simulating peri-gastrulation development, we show conserved principles for epiblast development for competency for PGC fate, followed by initiation of the epigenetic program(9-11), regulated by a balanced SOX17–BLIMP1 gene dosage. Our combinatorial approach using human, porcine and monkey in vivo and in vitro models, provides synthetic insights on early human development

Вихретоковый анизотропный термоэлектрический первичный преобразователь лучистого потока

Представлена оригинальная конструкция первичного преобразователя лучистого потока, который может служить основой для создания приемника неселективного излучения с повышенной чувствительностью

New 11-Methoxymethylgermacranolides from the Whole Plant of <i>Carpesium divaricatum</i>

Eight new 11-methoxymethylgermacranolides (1–8) were isolated from the ethanol extract of the whole plant of Carpesium divaricatum. The planar structures and relative configurations of the new compounds were determined by detailed spectroscopic analysis. The absolute configuration of 1 was established by electronic circular dichroism (ECD) spectrum and X-ray crystallographic analysis, and the stereochemistry of the new compounds 2–8 were determined by similar ECD data with 1. The absolute configurations of 5 and 7 were further confirmed by using quantum chemical electronic circular dichroism (ECD) calculations. Compound 4 exhibited weak cytotoxicity against MCF-7 cells. Compound 8 could potently decrease PGE2 productions in LPS-induced RAW 264.7 cells