Seroprevalence of arboviruses in Ecuador: Implications for improved surveillance

Introduction:Arthropod-borne viruses (arboviruses) cause morbidity and mortality in humans and domestic animals worldwide. The percentage of population immunity or susceptibility to these viruses in Ecuador is unknown.Objectives:To investigate the proportion of Ecuadorian populations with IgG antibodies (Abs) (past exposure/immunity) and IgM Abs (current exposure) against flaviviruses and alphaviruses and to study the activity of these viruses in Ecuador.Materials and methods:During 2009-2011, we conducted a serosurvey for selected arboviruses in humans (n=1,842), equines (n=149), and sentinel hamsters (n=84) at two coastal locations and one in the Amazon basin (Eastern Ecuador) using enzyme-linked immunosorbent assay and hemagglutination inhibition test.Results:From 20.63% to 63.61% of humans showed IgG-antibodies for the flaviviruses: Dengue virus (DENV), yellow fever virus (YFV) Saint Louis encephalitis virus, and West Nile virus (WNV); from 4.67% to 8.63% showed IgG-Abs for the alphaviruses: Venezuelanequine encephalitis virus, eastern equine encephalitis virus, and western equine encephalitis virus. IgM-Abs were found for DENV and WNV. Equines and hamsters showed antibodies to alphaviruses in all locations; two hamsters seroconverted to YFV in the Amazonia.Conclusions:The results show a YFV vaccination history and suggest the activity of arboviruses not included in the current surveillance scheme. Enhanced arbovirus and mosquito surveillance, as well as continued YFV vaccination and evaluation of its coverage/ effectiveness, are recommended.     

Localization of the bacterial agent of juvenile oyster disease (Roseovarius crassostreae) within affected eastern oysters (Crassostrea virginica)

The bacterium Roseovarius crassostreae causes seasonal mortalities among commercially produced eastern oysters (Crassostrea virginica) grown in the Northeastern United States. Phylogenetically, the species belongs to a major lineage of marine bacteria (the Roseobacter clade), within which Roseovarius crassostreae is the only known pathogen to be isolated in laboratory culture. The objective of the current study was to determine the location and nature of R. crassostreae interactions with oysters affected by juvenile oyster disease (JOD). Scanning electron microscopy of diseased individuals revealed abundant colonization of the inner shell surfaces by bacteria which were morphologically similar to R. crassostreae. The same types of cells were also observed on and within layers of host-derived conchiolin on the inner valves. Most bacterial cells were alive as determined by the use of a fluorescent viability stain. Further, most were clearly attached at the cell poles, which is consistent with the ability of R. crassostreae to express polar fimbriae. When material from the pallial fluid, soft tissue and inner valve surfaces was cultured, the highest numbers of R. crassostreae were recovered from the inner valves. These samples also contained the greatest abundance of R. crassostreae as a percentage of total colonies. Cloning and sequencing of 16S rRNA genes provided culture-independent evidence of the numerical dominance of R. crassostreae among the bacterial consortia associated with the inner shell surfaces of JOD-affected animals. The ability of R. crassostreae to colonize shell and conchiolin is consistent with the described JOD-pathology and may aid the bacteria in avoiding hemocyte-mediated killing.     

From the Bay of Naples to the River Don: the Campanian Ignimbrite eruption and the Middle to Upper Paleolithic transition in Eastern Europe

The Campanian Ignimbrite (CI) eruption, dated by ⁴⁰Ar/³⁹Ar and various stratigraphic methods to ca. 39,000 cal BP, generated a massive ash plume from its source in southern Italy across Southeastern and Eastern Europe. At the Kostenki-Borshchevo open-air sites on the Middle Don River in Russia, Upper Paleolithic artifact assemblages are buried below, within, and above the CI tephra (which is redeposited by slope action at most sites) on the second terrace. Luminescence and radiocarbon dating, paleomagnetism, and soil and pollen stratigraphy provide further basis for correlation with the Greenland and North Atlantic climate stratigraphy. The oldest Upper Paleolithic occupation layers at Kostenki-Borshchevo may be broadly correlated with warm intervals that preceded the CI event and Heinrich Event 4 (HE4; Greenland Interstadial: GI 12-GI 9) dating to ca. 45,000-41,000 cal BP. These layers contain an industry not currently recognized in other parts of Europe. Early Upper Paleolithic layers above the CI tephra are correlated with HE4 and warm intervals that occurred during 38,000-30,000 cal BP (GI 8-GI 5), and include an assemblage that is assigned to the Aurigancian industry, associated with skeletal remains of modern humans.     

武陵山东段不同样地小型兽类群落结构及多样性分布(英文）

2000—2004年对长江三峡南岸的武陵山东段7个不同样地、3个不同海拔梯度和6种生境类型的啮齿等小兽进行了5年调查。共布放鼠铗29297铗次,获得啮齿等小兽2271只;其他方法获26只,分隶于8科19属24种。其中啮齿目占70.83%,食虫目占29.17%。对所获数据分析结果表明:1)虽物种丰富度具有从南向北随海拔升高而增加的趋势,但在垂直分布上有相当一部分物种呈现较宽的分布;2)无论在7个不同样地,还是在6种生境,1200m以下均以黑线姬鼠(Apodemus agrarius)和褐家鼠(Rattus norvegicus)为优势种;1300m以上则以短尾鼩(Anourosorex squamipes)、社鼠(Niviventer confucianus)和中华姬鼠(Apodemus draco)为优势,但在数量上缺乏规律性;3)冬季密度明显大于春季,沿海拔高度呈梯度增高,但不同样地的密度缺乏一致规律性;4)7个不同样地多样性和均匀度均呈现较大变化。这可能与该地区人为干预较多有关。     

Development and application of boundary-line release criteria

Identifying releases from suppression represents one of the most fundamental dendroecological procedures for quantifying forest disturbance histories. In this study we evaluate boundary-line release criteria, which incorporates the effects of growth history on release response. In eastern hemlock (Tsuga canadensis L.) the maximum possible value of a pulse in percent-growth change is dependent on growth decline immediately prior to the pulse. Maximum values of percent-growth-change decline exponentially as prior growth rate increases. This negative exponential rate is quantified as a boundary line, which is used to scale each percent-growth change pulse by the maximum possible value predicted by prior growth rate. The consistency of the relationship between radial growth prior to a release and the magnitude of the release is evaluated in multiple eastern hemlock data sets. Trees from diverse sites show large releases that approach the maximum value predicted by the prior-growth rates. These sites tend to have a history of disturbance, suggesting that disturbance is the most influential variable determining the magnitude of release response. Possible exceptions are sites on the northern and western borders of eastern hemlock's range, which consistently fall short of the boundary line and may be exhibiting unique relationships between prior growth and percent-growth change. Yet overall the relationship between prior growth and percent-growth change appears to be consistent across much of eastern hemlock's range. Furthermore, we demonstrate that similar boundary lines occur in Pinus ponderosa (Laws.), Pinus echinata (Mill.), Quercus alba (L.), and Quercus macrocarpa (Michx.). This suggests that prior growth could form the basis of a more unified set of release criteria better able to standardize release responses within and among species. Standardized release criteria would allow more accurate comparisons of disturbance histories among sites, species, and even across landscapes.     

新疆黄鹀冬季的生物学资料

调查资料表明,黄鹀(Emberiza citronella erythrogenys)在中国境内新疆北部越冬,并非是偶见冬候鸟或迷鸟。     

兰科紫纹兜兰的保育生物学研究

深圳市梧桐山是濒危物种紫纹兜兰(Paphiopedilum purpuratum)仅存的几个自然分布地之一。自1998年10月1日至2002年2月28日,我们在梧桐山选取了9个调查点,对407个基株进行了观察,研究了该地的气候、植被、土壤和其他环境因素与紫纹兜兰之间的关系。观察结果表明,梧桐山地区的紫纹兜兰在次生阔叶林下生长良好;短刺刺腿食蚜蝇(Ischiodon scutellaris)为其有效传粉者;大多数开花的紫纹兜兰均能结果。我们认为,紫纹兜兰生存所面临的主要威胁应该是其生境亦即森林的破坏,而不是其自身存在的生物学缺陷。     

秦岭种子植物区系分区研究

在吴征镒1983年中国植物区系分区的基础上,依据秦岭山地的自然环境特点,并结合植被优势种及区系特有种和特征种的分布情况,按照发生学原则,将秦岭种子植物区系划分为两大植物地区,五个植物亚地区,七个植物省,并对每个植物省区系的特点进行了分析,结果进一步证明秦岭是我国植物区系南北分异的一条主要界限。