The behaviors and sources of dissolved arsenic and antimony in Bohai Bay

In this paper, we determined the concentrations of antimony species (antimonite (Sb(III)), antimonate (Sb(V)) and dissolved inorganic antimony (DISb)) and arsenic, in Bohai Bay seawaters, as well as the relationships of the analytes with environmental factors such as seawater characteristics (e.g., suspended particulate material (SPM), salinity and total organic carbon (TOC)), heavy metals, nutrients and phytoplankton species, and evaluated the sources of arsenic and antimony. Dissolved arsenic and antimony concentrations in the surface waters were ranging spatially from 1.03 to 1.26 ng/ml and 0.386 to 1.075 ng/ml, with mean values of 1.18 and 0.562 ng/ml, respectively. Sb(V) as the prominent chemical species constituted about 89%. Regarding arsenic concentrations in the surface waters, there was a tendency for a small variation. However, antimony species concentrations were much variable than arsenic. The highest arsenic and antimony concentrations were found near the Haihe Estuary. These distribution patterns were controlled mainly by environmental factors, biological activities and sources. In this region, DISb and Sb(V) negatively correlated with salinity. Besides, arsenic and antimony correlated well with the nutrients, chlorophyll a and phytoplankton, implying that arsenic and antimony had been involved in biological cycling. In addition, according to our estimate, about 333.5 x 10(8) mg/year of arsenic and 454.2 x 10(8) mg/year of antimony reached Bohai Bay via rivers. (C) 2010 Elsevier Ltd. All rights reserved.

印度与欧亚板块强烈相互作用区深部结构特征研究

The central-south Tibet is a part of the products of the continental plate collision between Eurasia and India. To study the deep structure of the study area is significant for understanding the dynamics of the continental-continental collision. A 3-D density model matched well with the observations in the central-south Tibet was proposed in this study. In addition, this study has also used numerical simulation method to prove that Quasi-Love (QL) wave is deduced by anisotropy variation but not by lateral heterogeneity. Meanwhile, anisotropy variation in the upper mantle of the Qiangtang terrane and Lhasa terrane is detected by the QL waves observed in recorded seismograms. Based on the gravity modeling, some results are summarized as follows: 1) Under the constrain of geometrical structure detected by seismic data, a 3-D density model and Moho interface are proposed by gravity inversion of the central-south Tibet. 2) The fact that the lower crustal densities are smaller than 3.2 g/cm3, suggests absence of eclogite or partial eclogitization due to delamination under the central-south Tibet. 3) Seismicity will be strong or weak in the most negative Bouguer gravity anomaly. So there is no a certain relationship between seismicity and Bouguer gravity anomaly. 4) Crustal composition are determined after temperature-pressure calibration of seismic P wave velocity. The composition of lower crust might be one or a mixture of: 1. amphibolite and greenschist facies basalt beneath the Qiangtang terrane; 2. gabbro-norite-troctolite and mafic granulite beneath the Lhasa terrane. Because the composition of the middle crust cannot be well constrained by the above data set, the data set published by Rudnick & Fountain (1995) is used for comparison. It indicated the composition of the middle crust is granulite facies and might be pelitic gneisses.Granulite facies used to be interpreted as residues of partial melting, which coincidences with the previous study on partial melting middle crust. Amphibolite facies are thought to be produced after delamination, when underplating works in the rebound of the lower crust and lithospheric mantle. From the seismology study, I have made several followed conclusions: 1) Through the numerical simulation experiment of surface wave propagating in heterogeneity media, we can find that amplitude and polarization of surface wave only change a little when considering heterogeneity. Furthermore, it is proved that QL waves, generated by surface wave scattering, are caused by lateral variation of anisotropy but not by heterogeneity. 2) QL waves are utilized to determine the variation of uppermost mantle anisotropy of the Tibetan plateau. QL waves are identified from the seismograms of the selected paths recorded by the CAD station. The location of azimuth anisotropy gradient is estimated from the group velocities of Rayleigh wave, Love wave and QL wave. It suggests that south-north lateral variation of azimuthal anisotropy locates in Tanggula mountain, and east-west lateral variation in the north of Gandese mountain with 85°E longitude and near the Jinsha river fault with 85°E longitude.

Aeroacoustics on Non-Dedicated Workstations

The simulation of subsonic aeroacoustic problems such as the flow-generated sound of wind instruments is well suited for parallel computing on a cluster of non-dedicated workstations. Simulations are demonstrated which employ 20 non-dedicated Hewlett-Packard workstations (HP9000/715), and achieve comparable performance on this problem as a 64-node CM-5 dedicated supercomputer with vector units. The success of the present approach depends on the low communication requirements of the problem (low communication to computation ratio) which arise from the coarse-grain decomposition of the problem and the use of local-interaction methods. Many important problems may be suitable for this type of parallel computing including computer vision, circuit simulation, and other subsonic flow problems.

Exploring human resource development: a level of analysis approach.

Levels of analysis perform an important function in framing research and practice in human resource development (HRD). The purpose of this paper is to examine the concept of HRD from the individual, organizational and community/societal levels of analysis. The paper highlights both the distinctiveness and usefulness of each level of analysis, identifies tensions within and between them, and outlines differences in underpinning assumptions, characteristics of HRD provision and delivery of HRD interventions. By adopting this approach, the paper draws attention to variations in meaning, intent, content and practice with implications for developing both the theory and practice of HRD.

Regulation of yeast oscillatory dynamics

Douglas B. Murray, Manfred Beckmann, and Hiroaki Kitano. (2007). Regulation of yeast oscillatory dynamics. Proceedings of the National Academy of Sciences of the USA, 104 (7), 2241-2246 Sponsorship: Solution-Oriented Research for Science and Technology Agency to the Systems Biology Institute /21st Century Center of Excellence Program and Special Coordination Program of the Ministry of Education, Sports, Culture, Science, and Technology to Keio University RAE2008

Association of candidate genes with flowering time and water-soluble carbohydrate content in Lolium perenne (L.)

Sk?t, L., Humphreys, J., Humphreys, M. O., Thorogood, D., Gallagher, J. A., Sanderson, R., Armstead, I. P., Thomas, I. D. (2007). Association of candidate genes with flowering time and water-soluble carbohydrate content in Lolium perenne (L.). Genetics, 177 (1), 535-547. Sponsorship: BBSRC RAE2008

Alignment of the genomes of brachypodium distachyon and temperate cereals and grasses using bacterial artificial chromosome landing with fluorescence in situ hybridization

Robert Hasterok, Agnieszka Marasek, Iain S. Donnison, Ian Armstead, Ann Thomas, Ian P. King, Elzbieta Wolny, Dominika Idziak, John Draper and Glyn Jenkins (2006). Alignment of the genomes of brachypodium distachyon and temperate cereals and grasses using bacterial artificial chromosome landing with fluorescence in situ hybridization.Genetics, 73 (1), 349-362. Sponsorship: Royal Society / BBSRC;BBSRC RAE2008

Boosting Nearest Neighbor Classifiers for Multiclass Recognition

This paper introduces an algorithm that uses boosting to learn a distance measure for multiclass k-nearest neighbor classification. Given a family of distance measures as input, AdaBoost is used to learn a weighted distance measure, that is a linear combination of the input measures. The proposed method can be seen both as a novel way to learn a distance measure from data, and as a novel way to apply boosting to multiclass recognition problems, that does not require output codes. In our approach, multiclass recognition of objects is reduced into a single binary recognition task, defined on triples of objects. Preliminary experiments with eight UCI datasets yield no clear winner among our method, boosting using output codes, and k-nn classification using an unoptimized distance measure. Our algorithm did achieve lower error rates in some of the datasets, which indicates that, in some domains, it may lead to better results than existing methods.

Genome-scale analyses of health-promoting bacteria: probiogenomics

The human body is colonized by an enormous population of bacteria (microbiota) that provides the host with coding capacity and metabolic activities. Among the human gut microbiota are health-promoting indigenous species (probiotic bacteria) that are commonly consumed as live dietary supplements. Recent genomics-based studies (probiogenomics) are starting to provide insights into how probiotic bacteria sense and adapt to the gastrointestinal tract environment. In this Review, we discuss the application of probiogenomics in the elucidation of the molecular basis of probiosis using the well-recognized model probiotic bacteria genera Bifidobacterium and Lactobacillus as examples.

Interleukin-15 receptor blockade in non-human primate kidney transplantation.

BACKGROUND: Interleukin (IL)-15 is a chemotactic factor to T cells. It induces proliferation and promotes survival of activated T cells. IL-15 receptor blockade in mouse cardiac and islet allotransplant models has led to long-term engraftment and a regulatory T-cell environment. This study investigated the efficacy of IL-15 receptor blockade using Mut-IL-15/Fc in an outbred non-human primate model of renal allotransplantation. METHODS: Male cynomolgus macaque donor-recipient pairs were selected based on ABO typing, major histocompatibility complex class I typing, and carboxy-fluorescein diacetate succinimidyl ester-based mixed lymphocyte responses. Once animals were assigned to one of six treatment groups, they underwent renal transplantation and bilateral native nephrectomy. Serum creatinine level was monitored twice weekly and as indicated, and protocol biopsies were performed. Rejection was defined as a increase in serum creatinine to 1.5 mg/dL or higher and was confirmed histologically. Complete blood counts and flow cytometric analyses were performed periodically posttransplant; pharmacokinetic parameters of Mut-IL-15/Fc were assessed. RESULTS: Compared with control animals, Mut-IL-15/Fc-treated animals did not demonstrate increased graft survival despite adequate serum levels of Mut-IL-15/Fc. Flow cytometric analysis of white blood cell subgroups demonstrated a decrease in CD8 T-cell and natural killer cell numbers, although this did not reach statistical significance. Interestingly, two animals receiving Mut-IL-15/Fc developed infectious complications, but no infection was seen in control animals. Renal pathology varied widely. CONCLUSIONS: Peritransplant IL-15 receptor blockade does not prolong allograft survival in non-human primate renal transplantation; however, it reduces the number of CD8 T cells and natural killer cells in the peripheral blood.

Impact of Leukocyte Function-Associated Antigen-1 Blockade on Endogenous Allospecific T Cells to Multiple Minor Histocompatibility Antigen Mismatched Cardiac Allograft.

BACKGROUND: Blocking leukocyte function-associated antigen (LFA)-1 in organ transplant recipients prolongs allograft survival. However, the precise mechanisms underlying the therapeutic potential of LFA-1 blockade in preventing chronic rejection are not fully elucidated. Cardiac allograft vasculopathy (CAV) is the preeminent cause of late cardiac allograft failure characterized histologically by concentric intimal hyperplasia. METHODS: Anti-LFA-1 monoclonal antibody was used in a multiple minor antigen-mismatched, BALB.B (H-2B) to C57BL/6 (H-2B), cardiac allograft model. Endogenous donor-specific CD8 T cells were tracked down using major histocompatibility complex multimers against the immunodominant H4, H7, H13, H28, and H60 minor Ags. RESULTS: The LFA-1 blockade prevented acute rejection and preserved palpable beating quality with reduced CD8 T-cell graft infiltration. Interestingly, less CD8 T cell infiltration was secondary to reduction of T-cell expansion rather than less trafficking. The LFA-1 blockade significantly suppressed the clonal expansion of minor histocompatibility antigen-specific CD8 T cells during the expansion and contraction phase. The CAV development was evaluated with morphometric analysis at postoperation day 100. The LFA-1 blockade profoundly attenuated neointimal hyperplasia (61.6 vs 23.8%; P < 0.05), CAV-affected vessel number (55.3 vs 15.9%; P < 0.05), and myocardial fibrosis (grade 3.29 vs 1.8; P < 0.05). Finally, short-term LFA-1 blockade promoted long-term donor-specific regulation, which resulted in attenuated transplant arteriosclerosis. CONCLUSIONS: Taken together, LFA-1 blockade inhibits initial endogenous alloreactive T-cell expansion and induces more regulation. Such a mechanism supports a pulse tolerance induction strategy with anti-LFA-1 rather than long-term treatment.

Transgenerational Effects of Early Life Starvation on Growth, Reproduction, and Stress Resistance in Caenorhabditis elegans.

Starvation during early development can have lasting effects that influence organismal fitness and disease risk. We characterized the long-term phenotypic consequences of starvation during early larval development in Caenorhabditis elegans to determine potential fitness effects and develop it as a model for mechanistic studies. We varied the amount of time that larvae were developmentally arrested by starvation after hatching ("L1 arrest"). Worms recovering from extended starvation grew slowly, taking longer to become reproductive, and were smaller as adults. Fecundity was also reduced, with the smallest individuals most severely affected. Feeding behavior was impaired, possibly contributing to deficits in growth and reproduction. Previously starved larvae were more sensitive to subsequent starvation, suggesting decreased fitness even in poor conditions. We discovered that smaller larvae are more resistant to heat, but this correlation does not require passage through L1 arrest. The progeny of starved animals were also adversely affected: Embryo quality was diminished, incidence of males was increased, progeny were smaller, and their brood size was reduced. However, the progeny and grandprogeny of starved larvae were more resistant to starvation. In addition, the progeny, grandprogeny, and great-grandprogeny were more resistant to heat, suggesting epigenetic inheritance of acquired resistance to starvation and heat. Notably, such resistance was inherited exclusively from individuals most severely affected by starvation in the first generation, suggesting an evolutionary bet-hedging strategy. In summary, our results demonstrate that starvation affects a variety of life-history traits in the exposed animals and their descendants, some presumably reflecting fitness costs but others potentially adaptive.

To grow or not to grow: nutritional control of development during Caenorhabditis elegans L1 arrest.

It is widely appreciated that larvae of the nematode Caenorhabditis elegans arrest development by forming dauer larvae in response to multiple unfavorable environmental conditions. C. elegans larvae can also reversibly arrest development earlier, during the first larval stage (L1), in response to starvation. "L1 arrest" (also known as "L1 diapause") occurs without morphological modification but is accompanied by increased stress resistance. Caloric restriction and periodic fasting can extend adult lifespan, and developmental models are critical to understanding how the animal is buffered from fluctuations in nutrient availability, impacting lifespan. L1 arrest provides an opportunity to study nutritional control of development. Given its relevance to aging, diabetes, obesity and cancer, interest in L1 arrest is increasing, and signaling pathways and gene regulatory mechanisms controlling arrest and recovery have been characterized. Insulin-like signaling is a critical regulator, and it is modified by and acts through microRNAs. DAF-18/PTEN, AMP-activated kinase and fatty acid biosynthesis are also involved. The nervous system, epidermis, and intestine contribute systemically to regulation of arrest, but cell-autonomous signaling likely contributes to regulation in the germline. A relatively small number of genes affecting starvation survival during L1 arrest are known, and many of them also affect adult lifespan, reflecting a common genetic basis ripe for exploration. mRNA expression is well characterized during arrest, recovery, and normal L1 development, providing a metazoan model for nutritional control of gene expression. In particular, post-recruitment regulation of RNA polymerase II is under nutritional control, potentially contributing to a rapid and coordinated response to feeding. The phenomenology of L1 arrest will be reviewed, as well as regulation of developmental arrest and starvation survival by various signaling pathways and gene regulatory mechanisms.

The steady-state visual evoked potential in vision research: A review.

Periodic visual stimulation and analysis of the resulting steady-state visual evoked potentials were first introduced over 80 years ago as a means to study visual sensation and perception. From the first single-channel recording of responses to modulated light to the present use of sophisticated digital displays composed of complex visual stimuli and high-density recording arrays, steady-state methods have been applied in a broad range of scientific and applied settings.The purpose of this article is to describe the fundamental stimulation paradigms for steady-state visual evoked potentials and to illustrate these principles through research findings across a range of applications in vision science.