Formation and decay of ethylenethiourea (ETU) in soil and water under tropical conditions

Mancozeb is a fungicide frequently used in tropical countries. It rapidly decomposes into ethylenethiourea (ETU), a more stable and toxic metabolite than mancozeb that is, therefore, regarded as a pollutant of concern. The objective was to study ETU formation and decay kinetics in soil and water under tropical conditions in order to assess its potential for accumulation. Batch experiments, spiked with either mancozeb or ETU, were carried out under natural (= active) as well as tyndallized conditions. In active soils, dissipation of ETU occurred significantly faster (half‐life 1.5 h) than in tyndallized soils (half‐life time 28 h). In water under natural and sterile conditions, decay was slower than in soils with an ETU half‐life time of 115 and 99 h, respectively. Microbial activity was seen to play an important role in ETU dissipation in soil. However, in water nonbiological processes seem to be more important in the breakdown of the molecule, with hydrolysis being the most probable decay mechanism. Decay of both mancozeb and ETU was found to occur more rapidly than previously reported. The high humidity and temperatures under the simulated humid tropical conditions, and higher microbial activity, lead to more rapid decay of these molecules than under other conditions. Nevertheless, a concentration of 1.29 mg ETU L^–1 was still observed 8 d after adding mancozeb (20.83 mg L^–1) to water under humid tropical conditions. These results suggest that, in comparable regions in the humid tropics, it is unlikely that ETU would accumulate in soil but it represents a potential risk for accumulation in water bodies.     

Babesia canis vogeli,Ehrlichia canis,and Anaplasma platys infection in a dog

A 12‐month‐old male neutered mixed breed dog was presented with a history of diarrhea, lethargy, emaciation, polydypsia, and sniffling. Physical examination findings included pale mucous membranes, increased heart and respiratory rates, and normal rectal temperature (38°C). Hematologic abnormalities included anemia and thrombocytopenia. Biochemical abnormalities included hypoalbuminemia, hyperbilirubinemia, and elevated ALP and ALT activities. A SNAP 4Dx test result was positive for Ehrlichia canis. Babesia canis vogeli organisms were found in the peripheral blood films, while morulae of E canis were not seen. Real‐time polymerase chain reaction testing confirmed the presence of both B c vogeli and E canis organisms, and also was positive for Anaplasma platys infection. The dog recovered following treatment with doxycycline and imidocarb dipropionate, with normal hematology and biochemical profiles.     

The conserved surface M-protein SiMA of Streptococcus iniae is not effective as a cross-protective vaccine against differing capsular serotypes in farmed fish

Streptococcus iniae causes invasive infections in fresh and saltwater fish and occasional zoonoses. Vaccination against S. iniae is complicated by serotypic variation determined by capsular polysaccharide. A potential target for serologically cross-protective vaccines is the M-like protein SiMA, an essential virulence factor in S. iniae that is highly conserved amongst virulent strains. The present study determined how SiMA is regulated and investigated potential as a cross-protective vaccine for fish. Electrophoretic mobility shift suggested that SiMA is regulated by the multigene regulator Mgx via a binding site in the −35 region of the simA promoter. Moreover, expression of simA and mgx was highly correlated, with the highest level of simA and mgx expression during exponential growth under iron limitation (20-fold increase in relative expression compared to growth in Todd-Hewitt broth). Based on these results, a vaccination and challenge experiment was conducted in barramundi (Lates calcarifer) to determine whether SiMA is protective against S. iniae infection and cross-protective against a different capsular serotype. The challenge resulted in 60% mortality in control fish. Formalin-killed bacterins prepared from the challenge strain resulted in 100% protection, whereas bacterins prepared from a serotypically heterologous strain resulted in significantly reduced protection, even when culture conditions were manipulated to optimise SiMA expression. Moreover, recombinant SiMA protein was not protective against the challenge strain in spite of eliciting specific antibody response in vaccinated fish. Specific antibody did not increase oxidative activity or phagocytosis by barramundi macrophages. Indeed incubating S. iniae with antisera significantly reduced phagocytosis. Lack of specific-antibody mediated opsonisation in spite of 100% protection against challenge with the homologous vaccine suggests that other immune parameters result in protection of challenged fish.     

加强高校图书馆环境和制度文化建设的对策研究

根据高校图书馆现状及相关文件,明确高校图书馆的中心工作,提出在学校中心工作的引领下,创造性地开展图书馆工作。改善图书馆环境。构建现代图书馆制度体系,加强高校图书馆的文化建设,恰当把握其建设要领和发展方向,从而优质、高效地推动图书馆工作向前发展。     

Mitigating surface urban heat island by a tree protection policy: A case study of The Woodland,Texas, USA

The Woodlands Township, TX, has a tree protection policy that consists of tree removal permits and minimum tree and shrub cover regulations. This paper examined the effect of The Woodlands’ tree protection policy on surface urban heat island (SUHI) at the neighborhood scale by comparing the mean land surface temperatures (LSTs) derived from 37 thermal infrared bands of Landsat TM images between The Woodlands’ neighborhoods and nearby control neighborhoods without such a policy. To rule out the effect of confounding factors that may influence LSTs, the control neighborhoods were selected to be similar in physical and socioeconomic status to The Woodlands’ neighborhoods. LSTs of The Woodlands’ neighborhoods were, on average, 1.5–3.9 °C lower than those of the control neighborhoods. The cooling effect of The Woodlands’ tree protection policy was more prominent in summer when SUHI mitigation was mostly needed. Based on these findings, it can be concluded that a local tree protection policy is effective in mitigating SUHI at the neighborhood scale.     

汉江上游与黄河晋陕峡谷历史大洪水对比研究

对汉江上游与黄河中游晋陕峡谷公元1800a以来发生的大洪水事件进行统计与对比分析。结果表明:1)历史时期汉江上游大洪水发生频率高于晋陕峡谷。1920a以后,随着全球气候变暖,汉江上游和黄河中游大洪水都有发生频率增大、间隔年份缩短的趋势。2)受副高边缘到达时间差异的影响,汉江上游大洪水时间过程呈"M"型;晋陕峡谷大洪水时间过程呈"A"型。3)影响两地降水的环流形式相似,但水汽的主要来源有所不同。在汉江上游,水汽来源既有东南季风也有西南季风带来的暖湿气流;在黄河中游,东南季风带来的水汽是降水的主要来源。两地降水多少及大洪水的发生时间、强度与频次,受到东南季风、西南季风强弱及其组合情况的共同影响与控制。     

Structural analysis of a new cytotoxic demethylated analogue of neo-N-methylsansalvamide with a different peptide sequence produced by Fusarium solani isolated from potato

A novel cytotoxic cyclic pentadepsipeptide, neosansalvamide, was produced by Fusarium solani KCCM90040 isolated from Fusarium -contaminated potato in Korea. The molecular formula of neosansalvamide was analyzed as C??H??N?O? by electrospray ionization tandem mass spectrometry and combined structural analysis. The one- and two-dimensional nuclear magnetic resonance and absolute configuration of amino acid spectral data allowed for the resolution of cyclic five subunits linked in the following order: (S)-leucic acid, two L-leucine, L-valine, and L-phenylalanine, and this sequence shows a molecular structure as a new demethylated analogue of neo-N-methylsansalvamide but having a different peptide sequence. The cytotoxic effects of neosansalvamide were investigated by sulforhodamine B bioassay on four human cancer cell lines. The IC?? value of neosansalvamide required to inhibit cell growth in vitro by 50% for A549 (lung cancer), SK-OV-3 (ovarian cancer), SK-MEL-2 (skin melanoma), and MES-SA (uterine sarcoma) cell lines were 11.70 ± 0.55, 10.38 ± 0.64, 13.99 ± 1.32, and 11.75 ± 0.13 μM, respectively (mean ± standard error).     

Free Radical Scavenging Activity of 4-(3,4-Dihydroxybenzoyloxymethyl)phenyl-O-β-d-glucopyranoside from Origanum vulgare and Its Protection against Oxidative Damage

4-(3,4-Dihydroxybenzoyloxymethyl)phenyl-O-β-d-glucopyranoside (DBPG), a polyphenolic glycoside, isolated from Origanum vulgare has shown 1,1-diphenyl-2-picrylhydrazyl (DPPH(?))-scavenging capacity in previous work. This study demonstrated that DBPG exhibits antioxidant activity by a series of DPPH(?), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS(?+)), and superoxide anion radical (O(2)(?-)) radical-scavenging assays. The inhibition of lipid peroxidation (LP) by DBPG exceeded that by l-ascorbic acid (AA) in a liposome model system. Adding DBPG to mouse liver and brain tissue inhibited the formation of thiobarbituric acid reactive substances (TBARS) to a greater extent than did trolox. In the oxygen stress test, BNLCL2 and HaCaT cells pretreated with DBPG showed increased activities of glutathione peroxidase (GPx), perhaps as a result of reduction of the production of reactive oxygen species (ROS). These findings proved that DBPG had antioxidant activities and a cytoprotective effect in hepatocytes and keratinocytes, suggesting that DBPG may be a useful food and cosmetic additive.