基于Hough变换的交通流状态辨别方法

交通流状态辨别在智能交通系统中起着十分重要的作用。本文根据对交通流状态辨别研究的分析,提出基于Hough变换方法和模糊C均值聚类方法的交通状态辨别方法。其中,基于Hough变换的图像识别方法用于交通畅通流的辨别,模糊C均值聚类方法用于其它交通状态分类。而且利用快速路固定型交通检测器实时数据进行了实证分析,且与模糊C均值聚类方法进行了对比分析。分析结果表明本文方法与FCM方法相比,更符合于三相交通流理论,且满足城市快速路交通流的特征。该方法可用于交通流状态分析。     

ON INVENTORY STRATEGIES OF ONLINE RETAILERS

1.Introduction This research focuses on online retailers(etailers,hereafter)who engage in the sale of physical goods.In general,the order fulfillment process of such an etailer can be depicted by Figure1.As presented in Figure1,a customer will place an order at the etailer’s website.Upon receipt of each order,the etailer will confirm whether or not stock is available to fulfill the order.Assuming that inventory is indeed available,the order will be packaged,after which it will be delivered …     

Characterisation of burrow architecture under natural conditions in the sand-dwelling wolf spider Allocosa brasiliensis

Allocosa brasiliensis (Petrunkevitch, 1910) is a wolf spider that constructs silk-lined burrows along the coastal sand dunes of Argentina, Brazil and Uruguay. This species shows a reversal in typical sex roles and sexual size dimorphism expected for spiders. Females are the smaller and mobile sex, which initiates courtship at the male burrow entrance. Mating occurs in the male burrow, and when it ends, the male leaves and the female stays inside. Females prefer to mate with those males showing longest burrows, so burrow dimensions would be under strong sexual selection pressures. Previous studies in the laboratory indicated that male burrows are longer than those of virgin females, which were described as simple silk capsules. Preliminary observations suggested that juvenile burrows presented differences from those of adults; however, detailed observations of A. brasilienisis burrow characteristics at the field were lacking. The aim of this study was to characterise the burrows of adults and juveniles of A. brasiliensis under natural conditions. We recorded the dimensions of burrows inhabited by males, females and juveniles (n = 30 for each category) and created beeswax moulds that reflected burrow shape. Juveniles inhabited tubular burrows with two branches and two openings; on the contrary, adults were found in tubular burrows with a single entry. Males and females inhabited burrows of similar length and width, but those of juveniles were shorter and narrower. We discuss the results and their possible functional explanations according to the selective pressures expected for each developmental stage and sex.     

The structure of byssochlamic acid

Zusammenfassung Die Struktur desp-Bromphenylhydrazids der Byssochlamsäure, des charakteristischen Stoffwechselproduktes vonByssochlamys fulva, wurde durch dreidimensionale Röntgenanalyse bestimmt. Die Resultate stellen eine Bestimmung der Konstitution und Stereochemie (abgesehen von der absoluten Konfiguration) desp-Bromphenylhydrazids als (I) und demnach der Byssochlamsäure als (II) dar.     

Genome-wide association study in individuals of South Asian ancestry identifies six new type 2 diabetes susceptibility loci

We carried out a genome-wide association study of type-2 diabetes (T2D) in individuals of South Asian ancestry. Our discovery set included 5,561 individuals with T2D (cases) and 14,458 controls drawn from studies in London, Pakistan and Singapore. We identified 20 independent SNPs associated with T2D at P < 10(-4) for testing in a replication sample of 13,170 cases and 25,398 controls, also all of South Asian ancestry. In the combined analysis, we identified common genetic variants at six loci (GRB14, ST6GAL1, VPS26A, HMG20A, AP3S2 and HNF4A) newly associated with T2D (P = 4.1 × 10(-8) to P = 1.9 × 10(-11)). SNPs at GRB14 were also associated with insulin sensitivity (P = 5.0 × 10(-4)), and SNPs at ST6GAL1 and HNF4A were also associated with pancreatic beta-cell function (P = 0.02 and P = 0.001, respectively). Our findings provide additional insight into mechanisms underlying T2D and show the potential for new discovery from genetic association studies in South Asians, a population with increased susceptibility to T2D.     

Meta-analysis of genome-wide association studies identifies eight new loci for type 2 diabetes in east Asians

We conducted a three-stage genetic study to identify susceptibility loci for type 2 diabetes (T2D) in east Asian populations. We followed our stage 1 meta-analysis of eight T2D genome-wide association studies (6,952 cases with T2D and 11,865 controls) with a stage 2 in silico replication analysis (5,843 cases and 4,574 controls) and a stage 3 de novo replication analysis (12,284 cases and 13,172 controls). The combined analysis identified eight new T2D loci reaching genome-wide significance, which mapped in or near GLIS3, PEPD, FITM2-R3HDML-HNF4A, KCNK16, MAEA, GCC1-PAX4, PSMD6 and ZFAND3. GLIS3, which is involved in pancreatic beta cell development and insulin gene expression, is known for its association with fasting glucose levels. The evidence of an association with T2D for PEPD and HNF4A has been shown in previous studies. KCNK16 may regulate glucose-dependent insulin secretion in the pancreas. These findings, derived from an east Asian population, provide new perspectives on the etiology of T2D.     

Regulation of Plasmodium falciparum Pfnek3 relies on phosphorylation at its activation loop and at threonine 82

A mitogen-activated protein kinase (MAPK), Pfmap2, has been identified in Plasmodium falciparum. However, its bona fide activator remains elusive as no MAPK kinase (MAPKK) homologues have been found so far. Instead, Pfnek3, a NIMA (never in mitosis, Aspergillus)-related kinase, was earlier reported to display a MAPKK-like activity due to its activating effect on Pfmap2. In this study, the regulatory mechanism of Pfnek3 was investigated. Pfnek3 was found to possess a SSEQSS motif within its activation loop that fulfills the consensus SXXXS/T phospho-activating sequence of MAPKKs. Functional analyses of the SSEQSS motif by site-directed mutagenesis revealed that phosphorylation of residues S221 and S226 is essential for mediating Pfnek3 activity. Moreover, via tandem mass-spectrometry, residue T82 was uncovered as an additional phosphorylation site involved in Pfnek3 activation. Collectively, these results provide valuable insights into the potential in vivo regulation of Pfnek3, with residues T82, S221 and S226 functioning as phospho-activating sites.     

The hematopoietic stem-cell niche in health and leukemia

Research in the last decade has shown that hematopoietic stem cells (HSCs) interact with and are modulated by a complex multicellular microenvironment in the bone marrow, which includes both the HSC progeny and multiple non-hematopoietic cell types. Intense work is gradually throwing light on the composition of the HSC niche and the molecular cues exchanged between its components, which has implications for HSC production, maintenance and expansion. In addition, it has become apparent that bidirectional interactions between leukemic cells and their niche play a previously unrecognized role in the initiation and development of hematological malignancies. Consequently, targeting of the malignant niche holds considerable promise for more specific antileukemic therapies. Here we summarize the latest insights into HSC niche biology and recent work showing multiple connections between hematological malignancy and alterations in the bone marrow microenvironment.     

Resident pulmonary lymphocytes expressing the gamma/delta T-cell receptor

The biological role of cells bearing the gamma delta T-cell antigen receptor (TCR) is as yet unclear. Although there are indications that some gamma delta+ cells can mediate cytotoxicity, their antigen-related functions have not yet been defined. In the mouse, gamma delta+ cells constitute 1-3% of T cells in lymphoid organs. Intestinal intraepithelial lymphocytes (IELs) and dendritic epidermal cells (DECs) also appear to carry the gamma delta TCR. The strategic locations of DECs and IELs have led to the suggestion that gamma delta+ cells could constitute a first line of defence in the vicinity of large surfaces of contact with the environment. We report here that an estimated 8-20% of resident pulmonary lymphocytes (RPLs) are CD3+ alpha beta TCR-, and presumably gamma delta TCR+. Furthermore, mice exposed to aerosols containing a Mycobacterium tuberculosis extract have an increased number of activated CD3+ alpha beta-TCR- pulmonary T cells which can be propagated in vitro.