关键词： agile wallaby   feral bovines   fire   macropods   wallaroo  

摘要： Australian savannas lack native megaherbivores (>500 kg body mass), but since the commencement of European colonisation in the 19th century bovine livestock, such as cattle (Bos sp.) and water buffalo (Bubalus bubalis), have established large feral populations that continue to geographically expand. The largest extant native herbivores are marsupials in the family Macropodidae (henceforth 'macropods': common wallaroo, Osphranter robustus [c. 40 kg];antilopine wallaroo, O. antilopinus [c. 35 kg] and agile wallaby, Notamacropus agilis [c. 20 kg]). These species occur at low densities, with evidence that some species are in decline, the cause of which remains uncertain. We tested the hypothesis that bovines and macropods compete for nutritious forage in the North Kimberley, Western Australia by using carbon isotope analysis of feral cattle and native macropod dung (as a proxy for the relative contribution of C-4 grass to their diet) and nutrient analysis of standing herbaceous biomass. Grass consumption varied between macropod species and was highest in larger wallaroo species and lowest in the smaller agile wallaby reflecting its broader diet. Grass consumption by wallaroos was maximal on fertile sites. The relative abundance of grass in the diet of cattle was lowest in the middle of the dry season with an interaction between fire and substrate fertility where grass consumption was highest on fertile sites, particularly those recently burnt. Grass consumption by cattle and wallaroos was negatively correlated with fibre content of live biomass, which was lowest on fertile and burnt sites. Introduced bovines shift their diets to non-grasses as quality of herbaceous biomass declines with increasing fibre content, and by contrast, the largest macropod herbivores do not have this dietary flexibility. We conclude a plausible mechanism for the success of bovines and the decline of large macropods in Australian savannas is competition for nutritious grass that is abundant imm

关键词： 感染性疾病   动物模型   应用研究  

摘要： 树鼩是一种非人类灵长类动物,树鼩全基因组测定显示出与人类高度同源性。从感染性疾病的角度来看,树鼩易受非人类宿主病原体的感染,表现出类似于人类感染的临床症状,使它们成为研究感染性疾病的理想的实验动物模型。在这里,我们对树鼩(Tupaia)在感染性疾病动物模型中的应用进行综述。

关键词： Neotropical savannas   Exotic grass   Diversity loss   Invertebrates   Stable isotopes   Mixing model  

摘要： Much of the Brazilian savanna (known locally as the Cerrado) has been converted to pasture of African C4 grasses (exotic pastures) for livestock production. The resulting habitat simplification and decreased resource availability may be significant factors underlying the impact on some soil arthropod groups, although it is still unclear how the different soil groups respond to this impact in the Brazilian savanna. We sampled epigeic arthropods in exotic pastures, adjacent woodland savanna fragments (cerrado sensu stricto), and savanna-pasture boundaries to investigate the impact of pasture on their diversity and activity, identifying the arthropods that contribute most to the between-habitat dissimilarities and those most vulnerable to pasture implementation. We also estimated the contribution of native and exotic plants to the diets of frequently observed arthropods in each habitat using carbon and nitrogen stable isotope analysis. We found lower richness and diversity of epigeic arthropods in pastures, where we also observed decreased activity of predator groups, whereas the activity of Symphypleona and Poduromorpha springtails increased. Springtail orders and Myrmicinae morphospecies were the main contributors to the between-habitat dissimilarities. Staphylinidae, Ptiliidae, and Zodariidae morphospecies seem to be vulnerable to exotic pastures. Our isotopic models show that woodland savanna arthropods feed preferentially on native C3-plant sources, while also showing signs of exotic C4 sources in their diet. These outcomes indicate that foraging or dispersal events may occur between habitats since arthropods captured in pastures also show signs of native sources in their diet.

关键词： Arterial stiffness   Blood pressure   Carica papaya L.   Hypertension   Pulse wave velocity  

摘要： Objectives: Hypertension is defined as an increase in systolic and/or diastolic blood pressure of more than 140/90 mmHg. Epidemiological studies showed that there is a relationship between hypertension and the incidence of arterial stiffness, especially in the elderly. Blood pressure management aims to prevent damage to various target organs such as the heart, brain, kidneys, eyes and peripheral arteries. Papaya leaves (Carica papaya L.) have been known empirically to treat hypertension. This study aimed to determine the effect of papaya leaves processed into Nori preparation on blood pressure and arterial stiffness. Methods: This study was carried out on animal models of male Wistar rats induced hypertension. A total of 30 male-Wistar rats were randomly divided into 6 groups consisting of control negative group and control positive group (received drug carriers), the group received captopril 2.5 mg/kg and groups received Nori of papaya leaves 5, 10 and 20% in their diet. All groups except the control negative group received 66% fructose in their food for 21 days. Parameters measured were systolic and diastolic blood pressure, pulse wave velocity (PWV) on days 0, 7, 14 and 21 after treatment. Results: The group received Nori 10% showed normalize both systolic and diastolic blood pressure and a decreased in arterial stiffness compared to the group received captopril (p>0.05). Conclusion: It can be concluded that papaya leaves in Non preparation is effective as an antihypertensive and reduced arterial stiffness.

关键词： 流感病毒   跨种属感染   致病特性   免疫机制  

摘要： 目的:　　甲型流感病毒(influenzaAvirus，IAV)具有宿主范围广、型别多、易变异、传播迅速等特点，常导致流感反复季节性局部流行甚至世界大流行，且部分型别可跨种属传播至人，给人类健康造成极大威胁。动物模型对于研究疾病的感染传播过程、发病机制、宿主抗病免疫机制以及评价新型药物和疫苗的效果及安全性等极为重要。目前已尝试建立了多种流感病毒动物模型，但各有利弊，迄今尚未有十分理想的流感病毒动物模型。树鼩(Tupaiabelangeri，treeshrew)在亲缘关系和种系发育上与人类非常接近，是灵长类动物的旁亲，基因组测序结果也证实树鼩与灵长类具有很高的亲缘性。因其体型小，生长繁殖快，驯养条件及成本较黑猩猩、猴类低，且其生理特征、解剖特点、神经发育、免疫、生化代谢和心理压力等方面与人类高度相似，利用树鼩作为多种疾病的动物模型研究日渐受到极大关注。迄今国内外已有用树鼩成功建立人H1N1亚型流感病毒以及H9N2、H5N1、H7N9亚型禽流感病毒感染模型的案例，但尚未利用树鼩模型对具有感染人潜能的低致病性猪和陆禽流感病毒的致病、感染和免疫特征等进行详细研究。　　为了阐明具备感染人潜能的低致病性猪和陆禽流感病毒的致病机制、免疫特点，以及跨种属感染的潜力，为流感大流行的防控和治疗提供更充分的策略依据，本研究选用前期证实可体外感染猪和人肺组织、体内可未经适应感染小鼠引起病变的具有感染人潜力的两株不同种属来源的IAV:基因组整合了2009新甲型H1N1大流行流感病毒(pdm/09)基因片段的新现H3N2亚型猪流感病毒（简称SW2783）和我国家禽中呈主要流行的陆禽鸡H6N6亚型禽流感病毒（简称ZZ346），以树鼩作为实验动物模型，观察两株流感病毒的致病性、免疫特征及跨种属感染的潜力;利用高通量深度测序和生物信息学分析方法，获得SW2783感染树鼩呼吸道组织的mRNA表达谱，从分子水平较全面分析动物IAV感染与宿主免疫相关mRNA表达情况，为进一步探讨具有感染人潜能的低致病性动物流感病毒与宿主相互作用机制打下坚实基础，同时也为进一步开发树鼩在抗病毒药物、疫苗效果及安全性评价等方面提供理论依据;另外，为深入研究流感病毒等病原体感染树鼩后的免疫应答及免疫病理机制奠定分子检测基础，本研究还探讨了人、小鼠和大鼠三种不同物种抗体芯片检测树鼩抗感染免疫相关分子的可行性，为解决目前缺乏树鼩相关分子检测试剂难题提供参考。　　方法:　　1.建立SW2783和ZZ346树鼩呼吸道组织体外感染模型，同时以pdm/09疫苗株CA09（简称CA09）和水禽鸭流感病毒H9N2亚型（简称ST3208）为参考病毒株，采用病毒血凝试验(HA)、半数组织细胞感染试验(TCID50)、免疫组化等方法观察4种病毒株对树鼩体外呼吸道组织的感染和复制能力及致病性特征。　　2.建立SW2783和ZZ346树鼩体内感染模型，通过HA、TCID50、HE染色、免疫组化、实时定量PCR等实验方法观察两种不同种属来源低致病流感病毒体内感染树鼩的能力、致病特征及抗病毒免疫分子的变化情况。　　3.利用转录组高通量测序技术(RNA-seq)检测SW2783体内感染树鼩后第3d、5d、7d鼻甲组织中差异表达mRNA，并结合生物信息学方法对其进行GO和KEGG富集及蛋白质互作网络(PPI)分析，观察mRNA差异表达谱特征以及其变化趋势。　　4.采用人、小鼠和大鼠三个物种抗体芯片检测树鼩脾细胞中抗感染相关免疫分子，探讨采用非树鼩种属特异性抗体检测树鼩相应分子的可行性。　　结果:　　1.4株流感病毒未经适应性培养均能体外感染树鼩呼吸道组织，但感染能力存在差异。新现H3N2亚型猪流感病毒SW2783株和陆禽H6N6亚型鸡流感病毒ZZ346株对树鼩体外上呼吸道鼻甲、气管组织具有较好的感染能力(TCID50)，SW2783复制能力(HA)较ZZ346强;人pdm/09疫苗株CA09也可在树鼩呼吸道组织中复制，但其复制能力相对较弱;而鸭流感病毒株ST3208虽然也能感染树鼩呼吸道组织，但显现出有限的感染能力。　　***2783和ZZ346未经适应性培养均可体内感染树鼩，显现出一定的致病性，但感染能力(TCID50)、病理变化及临床症状相对较轻，类似于人类普通流感感染，其中SW2783感染能力强于ZZ346，提示其可能进化成具有较好结合人型SAα2，6-Gal受体的能力而具有跨种属感染人的潜能。　　***2783和ZZ346感染树鼩后第3d、5d、7d抗病毒及炎症效应分子Mx1、MDA5、TNF-α、IL-6、MCP-1、IP-10、IFN-γ、IL-10等表达上调，提示感染早期启动有效抗病毒固有免疫应答;感染后第7d，部分动物产生流感病毒特异抗体，第14d所有动物均产生流感病毒特异抗体，提示流感病毒感染树鼩后

摘要： 路县故城遗址既是北京最重要的大遗址之一,也是北京城市副中心迄今所知年代最早的遗址。专家评价,城市建设中,完整地保护一座新发现汉代县城遗址并建设遗址公园,在全国范围内绝无仅有。"路县故城的全面保护,留下了北京的‘根’与‘魂’,不仅对北京城市副中心建设,也对大遗址保护、文化建设、京津冀协同发展、中华民族优秀传统文化继承和弘扬,都有着示范、深远、积极的影响",参与路县考古的北京市文物研究所相关负责人曾这样评价路县故城遗址公园的建设。

关键词： Climate change mitigation   CO2 offsetting   Forest carbon pools   Nambor Wildlife Sanctuary  

摘要： A study was carried out to assess tree diversity, forest carbon stock and carbon dioxide (CO₂) sequestration in Nambor tropical semi-evergreen forest. A total of 53 tree species from 47 genera and 32 families were recorded in the forest. Vatica lanceifolia was the dominant tree species with maximum 33.78 importance value index (IVI), 0.30 Shannon diversity index (H′) and 0.03 Simpson’s index (D) followed by Lagerstroemia reginae (20.75 IVI, 0.18 H′ and 0.004 D), Dysoxylum excelsum (17.70 IVI, 0.20 H′ and 0.006 D), Sterculia villosa (14.15 IVI, 0.09 H′ and 0.0007 D) and Toona ciliata (11.60 IVI, 0.07 H′ and 0.0004 D) as codominant species. Among the forest carbon pools, maximum 50.32% carbon was stored in soil followed by 39.42% in above ground biomass and 10.21, 0.03 and 0.02% in below ground, leaf litter and dead debris pools, respectively. Total ecosystem carbon stock in Nambor forest was estimated to be 244.78 Mg ha⁻¹. The estimated carbon stock was extrapolated over 3700 hectare area and found to be 905186.50 Mg. The total forest carbon stock was also converted into CO₂ equivalents and estimated as 3,322,034.46 Mg. The study observed that forest ecosystem offsets significant amount of atmospheric CO₂;therefore, conservation and management of forest resources are imperative to combat global climate change. © 2019, The National Academy of Sciences, India.

关键词： gallery forests   hominins   last common ancestor   paleoecology   strontium isotopes  

摘要： Objectives Riparian or gallery forests are critical habitats for numerous plants and animals today. Paleoanthropologically, reliance on such habitats informs behavioral and ecological reconstructions;for example, gallery forest habitats likely played a critical role in the transition from ape to hominin in the early Pliocene and may represent a preferred habitat for the last common ancestor of chimpanzees and humans. Direct indicators for gallery forest habitats preference are lacking. The objective of this article is to assess whether strontium isotope ratios are a reliable indicator of habitat preference for fauna living in and around gallery forests. Materials and methods We report bioavailable strontium isotope ratios from the Mugiri River, its tributaries, and its gallery forest (Toro-Semliki Wildlife Reserve, southwestern Uganda), and compare them to surrounding savanna-grassland values. We compare these environmental values to strontium isotopes ratios in faunal tooth enamel to determine if habitat preferences are accurately reflected. Results Gallery forest and savanna-grassland vegetations have significantly different strontium isotope ratio profiles. We trace these isotopic differences to the influence of the Mugiri tributaries, which originate on Paleoproterozoic gneiss deposits on top of the surrounding escarpments. These isotopic differences in vegetation are mirrored in the tissues of fauna with habitat preferences for either the gallery forest or the surrounding grasslands. Discussion This research demonstrates the potential of strontium isotope ratios to identify habitat preferences in modern or fossil fauna under proper geologic variability. It provides a methodological model for future studies seeking to reconstruct habitat preferences in early hominins.

关键词： Species trees   Gene trees   Divergence times   Phylogenomics   Substitution models   Exons  

摘要： BackgroundThe flood of genomic data to help build and date the tree of life requires automation at several critical junctures, most importantly during sequence assembly and alignment. It is widely appreciated that automated alignment protocols can yield inaccuracies, but the relative impact of various sources error on phylogenomic analysis is not yet known. This study employs an updated mammal data set of 5162 coding loci sampled from 90 species to evaluate the effects of alignment uncertainty, substitution models, and fossil priors on gene tree, species tree, and divergence time estimation. Additionally, a novel coalescent likelihood ratio test is introduced for comparing competing species trees against a given set of gene *** aligned DNA sequences of 5162 loci from 90 species were trimmed and filtered using trimAL and two filtering protocols. The final dataset contains 4 sets of alignments - before trimming, after trimming, filtered by a recently proposed pipeline, and further filtered by comparing ML gene trees for each locus with the concatenation tree. Our analyses suggest that the average discordance among the coalescent trees is significantly smaller than that among the concatenation trees estimated from the 4 sets of alignments or with different substitution models. There is no significant difference among the divergence times estimated with different substitution models. However, the divergence dates estimated from the alignments after trimming are more recent than those estimated from the alignments before *** results highlight that alignment uncertainty of the updated mammal data set and the choice of substitution models have little impact on tree topologies yielded by coalescent methods for species tree estimation, whereas they are more influential on the trees made by concatenation. Given the choice of calibration scheme and clock models, divergence time estimates are robust to the choice of substitution models, but remo