气调包装生鲜冷却牛肉贮藏中微生物多样性分析

【目的】分析普通包装和气调包装(65%O2和35%CO2)生鲜冷却牛肉在贮藏(4°C)过程中的微生物多样性。【方法】通过16S rDNA V3区PCR-DGGE(变性梯度凝胶电泳)方法和16S rDNA克隆分析法研究生鲜冷却牛肉中微生物菌落结构及菌相变化规律。【结果】初始菌相主要有嗜冷杆菌属(Psychrobacter)和假单胞菌属(Pseudomonas)。贮藏过程中,普通包装和气调包装生鲜冷却牛肉中优势菌均为Brochothrix和Pseudomonas。气调包装冷却牛肉中细菌种类较少,两种包装生鲜牛肉在贮藏前期菌相变化明显。【结论】不同包装冷却牛肉中微生物菌落结构有较大差异,气调包装中CO2对Pseudomonas等细菌起到了一定的抑制作用。     

浙江拟漆姑草属一新变种

对浙江省石竹科Caryophyllaceae一新变种闭花拟漆姑草（Spergulariamarinavat．cleistogama）进行了描述和绘图。与原变种的主要区别在于本变种托叶三角状卵形,萼片宽度不等,花瓣0～4枚,有的花瓣变为雄蕊,闭锁,雌蕊具0．2～0．3nlm的柄,雄蕊5～7枚,蒴果为宿存的花萼所包被,种子扁平,卵形。     

裸盖菇和斑褶菇属真菌菌种的有效分离方法

【目的】探讨获取裸盖菇属及斑褶菇属真菌纯培养的有效分离方法。【方法】采用菌褶接种法和孢子弹射法进行分离,以形态鉴定为基础,通过ITS区测序并与DNA序列库中已知序列进行比对的分子鉴定方法鉴别分离培养物的真伪,以确定分离方法的可靠性。【结果】对采自云南的28个裸盖菇属和斑褶菇属菌株进行了分离,菌褶接种法有24个菌株分离纯化成功,成功率达86%,而孢子弹射法仅有7个菌株分离成功,成功率为25%。【结论】菌褶接种法对于裸盖菇属和斑褶菇属真菌是一种有效而简便易行的分离方法,该法利用菌褶为产孢组织的优势,无需对菌褶进行表面消毒,易于纯化成功,值得在其他类似的腐生小型薄盖伞菌类群的分离中尝试应用。     

Spatial and temporal nature of reactive oxygen species production and programmed cell death in elm (Ulmus pumila L.) seeds during controlled deterioration

Seed deterioration is poorly understood and remains an active area for research. Seeds of elm (Ulmus pumila L.) were aged at 37 °C above water [controlled deterioration treatment (CDT)] for various lengths of time to assess programmed cell death (PCD) and reactive oxygen species (ROS) product in embryonic tissues during a 5 d period. The hallmarks of PCD were identified in the elm seeds during CDT including TUNEL experiments, DNA laddering, cytochrome c (cyt c) leakage and enzymatic activities. These analyses indicated that PCD occurred systematically and progressively in deteriorated elm seeds. Cyt c release and increase in caspase‐3‐like/DEVDase activity occurred during CDT, which could be suppressed by ascorbic acid (AsA) and caspase‐3 inhibitor Ac‐DEVD‐CHO, respectively. In situ localization of ROS production indicated that the distinct spatial‐temporal signature of ROS during CDT coincided with the changes in PCD hallmark features. Multiple antioxidant elements were activated during the first few days of CDT, but were subsequently depleted as PCD progressed. Taken together, our findings identify PCD as a key mechanism that occurs asymmetrically during elm seeds CDT and suggest an important role for PCD in seeds deterioration.     

Single chamber microbial fuel cell with spiral anode for dairy wastewater treatment

The circulating population of peripheral T lymphocytes obtained from a blood sample can provide a large amount of information about an individual's medical status and history. Recent evidence indicates that the detection and functional characterization of antigen-specific T cell subsets within the circulating population may provide a diagnostic indicator of disease and has the potential to predict an individual's response to therapy. In this report, a microarray detection platform that combines grating-coupled surface plasmon resonance imaging (GCSPRI) and grating-coupled surface plasmon coupled emission (SPCE) fluorescence detection modalities were used to detect and characterize CD4(+) T cells. The microspot regions of interest (ROIs) printed on the array consisted of immobilized antibodies or peptide loaded MHC monomers (p/MHC) as T cell capture ligands mixed with additional antibodies as cytokine capture ligands covalently bound to the surface of a corrugated gold sensor chip. Using optimized parameters, an unlabeled influenza peptide reactive T cell clone could be detected at a frequency of 0.1% in a mixed T cell sample using GCSPRI. Additionally, after cell binding was quantified, differential TH1 cytokine secretion patterns from a T cell clone cultured under TH1 or TH2 inducing conditions was detected using an SPCE fluorescence based assay. Differences in the secretion patterns of 3 cytokines, characteristic of the inducing conditions, indicated that differences were a consequence of the functional status of the captured cells. A dual mode GCSPRI/SPCE assay can provide a rapid, high content T cell screening/characterization tool that is useful for diagnosing disease, evaluating vaccination efficacy, or assessing responses to immunotherapeutics.     

Variability and adaptability of Miscanthus species evaluated for energy crop domestication

A growing body of evidence indicates that second‐generation energy crops can play an important role in the development of renewable energy and the mitigation of climate change. However, dedicated energy crops have yet to be domesticated in order to fully realize their productive potential under unfavorable soil and climatic conditions. To explore the possibility of domesticating Miscanthus crops in northern China where marginal and degraded land is abundant, we conducted common garden experiments at multiple locations to evaluate variation and adaptation of three Miscanthus species that are likely to serve as the wild progenitors of the energy crops. A total of 93 populations of Miscanthus sinensis, Miscanthus sacchariflorus, and Miscanthus lutarioriparius were collected across their natural distributional ranges in China and grown in three locations that represent temperate grassland with cold winter, the semiarid Loess Plateau, and relatively warm and wet central China. Evaluated with growth traits such as plant height, tiller number, tiller diameter, and flowering time, the Miscanthus species showed high levels of genetic variation within and between species. There were significant site × population interactions for almost all traits of M. sacchariflorus and M. sinensis, but not M. lutarioriparius. The northern populations of M. sacchariflorus had the highest establishment rates at the most northern site owing to their strong cold tolerance. An endemic species in central China, M. lutarioriparius, produced not only the highest biomass of the three species but also higher biomass at the Loess Plateau than the southern site near its native habitats. These results demonstrated that the wild species harbored a high level of genetic variation underlying traits important for crop establishment and production at sites that are colder and drier than their native habitats. The natural variation and adaptive plasticity found in the Miscanthus species indicated that they could provide valuable resources for the development of second‐generation energy crops.     

An Outbreak of Tularemia in a Colony of Outdoor-Housed Rhesus Macaques (Macaca mulatta)

Since an epizootic and detection of clinical cases of tularemia (Francisella tularensis) in 1996 at the Oregon National Primate Research Center, only 8 cases were identified in the succeeding 13 y. However, within a period of 7 mo, primarily during Winter 2010, 6 rhesus macaques were confirmed positive for Francisella tularensis type B by the Centers for Disease Control and Prevention by culture and fluorescent antibody testing. All cases had similar gross pathologic findings, which included necrotizing splenitis and lymphadenitis. Recent colony management efforts have focused on minimizing nonhuman primate exposure to commonly observed reservoir species and controlling rodent access to corral-style housing. Strategies continue to evolve with regard to managing a large breeding colony of nonhuman primates in the presence of this threat.Abbreviation: ONPRC, Oregon National Primate Research CenterFrancisella tularensis, the causative agent of tularemia, is a small pleomorphic gram-negative coccobacillus.¹¹ Severe disease and potentially death in humans can result from exposure to as few as 10 cfu of this highly infectious organism.^7,10 The disease is also known as rabbit fever and deer-fly fever, reflecting 2 common sources of infection for humans.³ F. tularensis is classified by the United States Department of Health and Human Services as a Category A Select Agent.⁶ It is considered a potential agent of biologic warfare, and in fact, has been weaponized and stockpiled in the past.¹⁰ The 2 biovars that are referenced most frequently in published human and nonhuman primate literature are tularensis (type A) and holarctica (formerly paleartica; type B).^4,12,13,23 An additional biovar, novicida (type C), has been described, but its virulence in humans is decreased due to its lack of a capsule.¹⁰Tularemia is endemic to many parts of the northern hemisphere, which includes the region surrounding the Oregon National Primate Research Center (ONPRC), an AAALAC-accredited facility.²⁰ Tularemia has one of the broadest host ranges of all bacteria, encompassing well over 200 mammalian species primarily, in addition to birds, amphibians, fish, and various arthropods such as fleas, ticks, mosquitoes, and flies.^10,15,19,20 The ONPRC is located in a mixed forest and field environment which is bordered by wetlands and residential neighborhoods outside of Portland. More than 4500 nonhuman primates are housed here, and most live outdoors in breeding groups. Therefore, exposure to this potentially life-threatening and zoonotic pathogen is inevitable, due to its persistence in the environment and the close proximity of several reservoir species. Presumed reservoir species commonly observed at ONPRC include meadow voles (Microtus pennsylvanicus), brown rats (Rattus norvegicus), deer mice (genus Peromyscus), house mice (Mus musculus), and California ground squirrels (Spermophilus beecheyi). Potential arthropod vectors that are monitored regularly at ONPRC include biting flies and mosquitoes. At this time, testing of prospective rodent carriers for tularemia is ongoing; therefore, in the interest of caution, all of the rodent and arthropod species listed are considered potential carriers of the disease.Tularemia was first recognized at the ONPRC in 1996 during an epizootic that resulted in 24 deaths among corral-housed rhesus macaques. Serology results from banked sera and sera collected during and after the outbreak demonstrated a seroconversion rate of approximately 25% in 723 animals. During the succeeding 13 y, only 8 sporadic cases were diagnosed. However, within a period of 3 mo during the winter of 2010, 5 rhesus macaques were diagnosed with Francisella tularensis type B by the Centers for Disease Control and Prevention (Atlanta, GA). Four months later, an additional case was confirmed. All 6 macaques were younger than 1 y and were assigned to a breeding colony protocol approved by the ONPRC Animal Care and Use Committee. The current report describes the clinical signs and gross and histologic findings associated with these cases, as well as methods for prevention and control of future cases of disease.     

烟草种间杂交亲和性

以野生烟草Nicotiana alata、N.rustica、N.repanda、N.stocktonnii与栽培烟草K326、红花大金元、Yun87、Yun97为材料,进行种间正反杂交,研究种间杂交亲和性。田间观察杂交后的坐果情况并统计坐果率,采用显微荧光染色观察授粉后花粉管在雌蕊上的生长情况,并结合杂交后代萌发检测的方法。结果表明：N.rustica、N.repanda、N.stocktonnii与栽培烟草杂交不亲和。N.rustica花粉能够穿过K326花柱,N.repanda和N.stocktonnii花粉在K326柱头上很少萌发生长。N.alata花粉可以穿过K326的花柱,并得到果实,但是萌发实验显示其种子无活力。N.alata作为母本与栽培烟草杂交不亲和。     

中国外来入侵植物研究现状及存在的问题

生物入侵是当今各国发展的一大挑战,特别是像中国这样的发展中国家。然而,我们对外来入侵种的本底资料还很不清楚,更缺乏相关的深入调查;对生物入侵所造成的生态和经济影响还没有引起足够的重视,同时也忽视了盲目引种可能带来的各种危害。本文在文献调研的基础上,从外来植物的入侵历史和文化、中国外来入侵植物的调查现状、外来植物入侵对生态安全及经济的影响等方面进行了全面系统的总结,并提出了中国外来入侵植物研究领域存在的问题及应对措施。     

Composition and diversity of weed communities in Al-Jouf province,northern Saudi Arabia

The aim of this study was to identify the main weed communities in Al-Jouf province in northern Saudi Arabia. Moreover, the composition and diversity of these communities were studied in relation to soil variables and crop type. Some 54 stands representing olive orchards, date palm orchards, wheat crop and watermelon crop were studied, using ten quadrats (1 × 1 m) per stand. A total of 71 species belonging to 22 families and 61 genera were observed. The classification of vegetation using the Two Way Indicator Species Analysis (TWINSPAN) resulted in the recognition of four vegetation groups representing wheat crop, orchards in winter season, orchards in summer season and watermelon crop. These results suggested the importance of both crop and season for the formation of weed community. Detrended Correspondence Analysis (DCA) showed that these groups are clearly distinguished by the first two DCA axes. The species richness was higher in both olive and date palm orchards than in wheat and watermelon crops. This pattern of species richness could be related to farm management practices and habitat micro-heterogeneity. Soil electrical conductivity, organic carbon and soil texture showed significant correlations with species richness and the cover values of some dominant species, suggesting the significant role of soil characteristics in weed community structure and diversity.