Feeding habits of invasive American mink (Neovison vison) in northern Germany—potential implications for fishery and waterfowl

In order to collect ecological data of invasive American mink (Neovison vison) at a fishpond area in northeastern Germany, we conducted a telemetry study in which 14 mink were radio-tracked. During this project, 2,502 scats from radio-tracked individuals were collected in the period from October 2003 to October 2005. Investigated mink principally prey on fish, small mammals and birds (eggs inclusive), whereas amphibians, reptiles and invertebrates were caught infrequently. Analysing mink scats of different seasons, we found significant seasonal variations of diet composition. In spring, fish, mammals and birds were hunted in similar amounts. During summer, birds made up the main part of the diet followed by mammals. In autumn, the proportion of birds in the mink diet decreased, whereas fish gained in importance. This trend continued during the winter period, when mink preyed almost exclusively on fish. Amphibians, crustaceans, insects, molluscs and reptiles were found only occasionally in scat samples. Among birds, the mink preyed mainly on the Eurasian Coot (Fulica atra) followed by the Mallard (Anas platyrhynchos). Mammalian prey was clearly dominated by the water vole (Arvicola terrestris) and among fish, mink hunted especially perch (Perca fluviatilis), roach (Rutilus rutilus) and carp (Cyprinus carpio). Results clearly demonstrate that mink is an opportunistic predator, which hunts its prey according to availability and vulnerability, respectively. Despite the high portions of fish in their autumn and winter diet, the economic damage caused by mink seems to be negligible. However, high predation rates on birds during the breeding season indicate a potential negative impact of mink on waterfowl.     

Effects of Grazing Intensity and Environmental Factors on Species Composition and Diversity in Typical Steppe of Inner Mongolia,China

In the present study, we aim to analyze the effect of grazing, precipitation and temperature on plant species dynamics in the typical steppe of Inner Mongolia, P.R. China. By uncoupling biotic and abiotic factors, we provide essential information on the main drivers determining species composition and species diversity. Effects of grazing by sheep were studied in a controlled experiment along a gradient of seven grazing intensities (from ungrazed to very heavily grazed) during six consecutive years (2005–2010). The results show that plant species composition and diversity varied among years but were little affected by grazing intensity, since the experimental years were much dryer than the long term average, the abiotic constraints may have overridden any grazing effect. Among-year differences were predominantly determined by the abiotic factors of precipitation and temperature. Most of the variation in species dynamics and coexistence between C3 and C4 species was explained by seasonal weather conditions, i.e. precipitation and temperature regime during the early-season (March-June) were most important in determining vegetation dynamics. The dominant C3 species Stipa grandis was highly competitive in March-June, when the temperature levels were low and rainfall level was high. In contrast, the most common C4 species Cleistogenes squarrosa benefited from high early-season temperature levels and low early-season rainfall. However, biomass of Stipa grandis was positively correlated with temperature in March, when effective mean temperature ranges from 0 to 5°C and thus promotes vernalization and vegetative sprouting. Our results suggest that, over a six-year term, it is temporal variability in precipitation and temperature rather than grazing that determines vegetation dynamics and species co-existence of grazed steppe ecosystems. Furthermore, our data support that the variability in the biomass of dominant species, rather than diversity, determine ecosystem functioning. The present study provides fundamental knowledge on the complex interaction of grazing – vegetation – climate.     

Young Seedling Stripe1 encodes a chloroplast nucleoid-associated protein required for chloroplast development in rice seedlings

Planta - Young Seedling Stripe1 (YSS1) was characterized as an important regulator of plastid-encoded plastid RNA polymerase (PEP) activity essential for chloroplast development at rice seedling...     

Cytotoxic and Anti‐inflammatory Sesquiterpenes from Ainsliaea henryi

Three new sesquiterpenoids, 4α‐hydroxyeudesm‐11(13)‐en‐12‐yl 3‐methylbutanoate ( 1 ), diaspanolide E ( 2 ), and (13α)‐germacra‐1(10),4‐dien‐12,8α‐olid‐15‐oic acid ( 3 ), along with eight known sesquiterpenoids ( 4 – 11 ), were isolated from the aerial parts of Ainsliaea henryi. The chemical structures of compounds 1 – 3 were elucidated by spectroscopic analysis (1D‐, 2D‐NMR, MS and HR/MS). All isolates were evaluated for their inhibitory activities against nitric oxide (NO) production in lipopolysaccharide‐induced RAW264.7 macrophage cells. Compound 10 exhibited significantly inhibition against NO release with an IC₅₀ value of 6.54 ± 0.16 μm . Also, all isolated compounds were tested for cytotoxicity against three human tumor cell lines A549, MGC803, and HCT116, among which compound 5 significantly inhibited the proliferation of MGC803 cell lines with an IC₅₀ value of 2.2 ± 0.2 μm .     

Segmental Kinematic Coupling of the Human Spinal Column during Locomotion

As one of the most important daily motor activities, human locomotion has been investigated intensively in recent decades. The locomotor functions and mechanics of human lower limbs have become relatively well understood. However, so far our understanding of the motions and functional contributions of the human spine during locomotion is still very poor and simultaneous in-vivo limb and spinal column motion data are scarce. The objective of this study is to investigate the delicate in-vivo kinematic coupling between different functional regions of the human spinal column during locomotion as a stepping stone to explore the locomotor function of the human spine complex. A novel infrared reflective marker cluster system was constrncted using stereophotogrammetry techniques to record the 3D in-vivo geometric shape of the spinal column and the segmental position and orientation of each functional spinal region simultaneously. Gait measurements of normal walking were conducted. The preliminary results show that the spinal column shape changes periodically in the frontal plane during locomotion. The segmental motions of different spinal functional regions appear to be strongly coupled, indicating some synergistic strategy may be employed by the human spinal column to facilitate locomotion. In contrast to traditional medical imaging-based methods, the proposed technique can be used to investigate the dynamic characteristics of the spinal column, hence providing more insight into the functional biomechanics of the human spine.     

TRPV5 and TRPV6 are expressed in placenta and bone tissues during pregnancy in mice

We investigated the dynamic expression of calcium transporters, TRPV5 and TRPV6, in placenta and bone to determine their role in maternal and fetal calcium balance during gestation. In placenta, TRPV5 was expressed predominantly in syncytiotrophoblasts of the labyrinthine zone, whereas TRPV6 was expressed in spongiotrophoblasts of the junction zone. In bone, the two transporters were found in osteoblasts, osteoclasts, cartilage and bone matrices. During the first half of gestation, TRPV5 and TRPV6 levels in bone were increased on pregnancy day (P) 0.5, then decreased on P3.5 followed by a slight increase on P6.5. During the second half of pregnancy, both the proteins and their mRNAs gradually increased from P9.5 to P15.5?P17.5 in both bone and placenta, followed at parturition by relatively high amounts in placenta, but markedly decreased amounts in bone. The expression pattern is likely related to the fetal and maternal calcium requirement during gestation, which may be regulated by estrogen and other hormones, because the fetal demand for calcium is greatest during the last few days of gestation for rats; maternal calcium metabolism is designed to meet the calcium needs of the fetus during this period. We found that TRPV5 and TRPV6 are involved in calcium transport in the placenta and bone, and therefore play a role in calcium homeostasis during embryonic and fetal development.     

STAT6 ASODN对哮喘小鼠脾淋巴细胞影响的实验研究

目的研究STAT6反义寡核苷酸对哮喘小鼠脾淋巴细胞的影响作用。方法实验细胞分组:正常鼠空白组(A组)、正常鼠OVA组(B组)、哮喘空白组(C组)、哮喘OVA组(D组)、哮喘治疗组(E组)。正常设计并人工合成一段互补于小鼠STAT6 mRNA翻译起始区271-290的反义寡核苷酸片段,全链硫代修饰。用卵白蛋白和氢氧化铝复制哮喘模型,用淋巴细胞分离液分离脾淋巴细胞,进行体外培养并导入由阳离子脂质体转染剂Geneshuttle携带的反义寡核苷酸,观察反义寡核苷酸的转染对脾淋巴细胞STAT6蛋白表达水平及细胞培养上清中IL-4分泌水平的影响。免疫细胞化学观察脾淋巴细胞中STAT6蛋白的表达水平,同时采用酶联免疫吸附(ELISA)法测定脾细胞培养上清液中IL-4的浓度。结果D组细胞STAT6蛋白表达明显高于其余各组,均具有显著性差异(P均<0.01),STAT6 ASODN转染后,E组细胞该蛋白的表达量明显下降(P<0.01);D组脾淋巴细胞培养上清中IL-4分泌水平明显高于其余各组,均具有显著性差异(P均<0.01);STAT6 ASODN转染后,E组培养上清中IL-4分泌水平显著低于D组(P<0.01)。结论STAT6 ASODN可特异性抑制哮喘鼠脾淋巴细胞中STAT6蛋白的表达,并可特异性抑制脾淋巴细胞中IL-4的分泌,为反义基因技术治疗哮喘提供了依据。     

玉米秸秆分批补料获得高还原糖浓度酶解液的条件优化

木质纤维素高浓度还原糖水解液的获得是纤维乙醇产业化发展的方向。在发酵工业领域,分批补料法是实现这一目标的重要研究途径。本研究采用分批补料法对获得高浓度玉米秸秆酶解还原糖的条件进行了优化。以稀硫酸预处理的玉米秸秆为原料,考察了液固比、补加量与补加时间对分批补料糖化的影响。结果表明,秸秆高浓度酶解液条件的初始物料为20％ (重量/体积),木聚糖酶220 U/g (底物),纤维素酶6 FPU/g (底物),果胶酶50 U/g (底物),在24 h、48 h后分批补加8％预处理后的物料,同时添加与补料量相应的木聚糖酶20 U/g (底物),纤维素酶2 FPU/g (底物),72 h后,最终糖化结果与非补料法相比,还原糖浓度从48.5 g/L提高到138.5 g/L,原料的酶解率最终达到理论值的62.5％。试验结果表明补料法可以显著提高秸秆水解液还原糖浓度。     

冬小麦生长季不同灌溉模式对冬小麦-夏玉米产量与水分利用的影响

在华北平原黑龙港流域对冬小麦实行3种灌溉模式,研究了不同灌溉模式对冬小麦-夏玉米产量、耗水特性和水分利用效率的影响.结果表明:浇底墒水+拔节水处理(W2,75 mm+90 mm)和浇底墒水+拔节水+灌浆水处理(W3,75 mm+90 mm+60 mm)周年总产量均显著高于只浇底墒水处理(W1,75 mm),增幅分别为8.7%和12.5%.冬小麦全生育期对土壤水的消耗随灌溉量的增加而减少,夏玉米季总耗水量随冬小麦季灌溉量的增加而增加.W2处理冬小麦水分利用效率(WUE)比W3处理高11.1%,而其夏玉米水分利用效率(WUE)与W3处理差异不显著.W2和W1处理的周年水分利用效率(WUET)分别为21.28和21.60 kg.mm-1.hm-2,比W3处理分别高7.8%和9.4%.综合周年产量、耗水量和水分利用效率,W2是较好的节水丰产灌溉模式.