Differential influence of Pomphorhynchus laevis (Acanthocephala) on the behaviour of native and invader gammarid species.

Although various species of acanthocephalan parasites can increase the vulnerability of their amphipod intermediate hosts to predation, particularly by altering their photophobic behaviour, their influence on the structure of amphipod communities and the success of invader species has so far received little attention. We compared the prevalence and behavioural influence of a fish acanthocephalan parasite, Pomphorhynchus laevis, in two species of amphipods, Gammarus pulex and Gammarus roeseli in sympatry in the river Ouche (Burgundy, eastern France). There, G. pulex is a resident species, whereas G. roeseli is a recent coloniser. Both uninfected G. pulex and G. roeseli were strongly photophobic, although less so in the invading species. However, there was no significant difference in reaction to light between infected and uninfected G. roeseli, whereas infected G. pulex were strongly photophilic. We discuss our results in relation to the parasite's ability to manipulate invading host species, the possibility that resistant individuals have been selected during the invasion process, and the role that acanthocephalan parasites can play in shaping the structure of amphipod communities.     

兰科植物microRNA的研究进展

microRNA (miRNA)是一类广泛存在的非编码小分子RNA,在植物的生长发育和应激反应等过程中起到重要的调控作用.本文从miRNA在植物中的作用机制出发,对近10年来兰科植物各属miRNA的鉴定、几类miRNA的具体功能及miRNA的其他相关技术研究进行综述,以期为兰科植物小分子RNA的功能作用及调控网络解析提...     

新一代生物防治及其在天敌瓢虫中的研究进展

生物防治是一种利用自然天敌控制有害生物的手段.当前生物防治的发展面临着使用成本高和效果不稳定的两大难题.这要求我们更精准地选育和释放天敌.随着测序技术的进步,学界提出了新一代生物防治(Next Generation Biological Control),旨在利用遗传学和基因组学来认识天敌昆虫种下水平的多样性和变异规律...     

湖南、湖北、贵州土家族成人的体成分比较

体成分指的是身体脂肪、蛋白质、肌肉、水等含量在体质量中所占的百分比.各成分之间的合理比例,对于维持机体的正常运行,十分重要.因此身体成分的研究一直是国内外研究的热点.体成分存在着人种和民族差异,因此它也是人类学研究的重要课题.目前的研究主要集中在中国青少年、大学生的体成分及体成分与其他身体指标的关系,而对于土家族的研究...     

Chemical and biological pathways in the bacterial oxidation of arsenopyrite

Abstract: A moderately thermophilic mixed culture of bacteria catalysed the oxidative solubilization of arsenopyrite to give Fe(III), S(VI) and As(V). Toxic effects were observed in a few experiments due to teh build-up of As(III). The bacterial oxidation of arsenopyrite involved direct attack of the bacteria on the mineral to give AS(III). Subsequent oxidation of AS(III) to AS(V) occurred reaction with FE(III), but only in the presence of pyrite, which provide a catalytic surface. Arsenopyrite was unable to act as a catalyst. The pyrite- catalysed oxidation of As(III) to AS(V) by FE(III) usually only went to completion in the presence of bacteria, possibly due to their role in the provision of clean catalytic surfaces. Thus, toxic concentrations of As(III) may accumulate in reactors during the bacterial oxidation of arsenopyrite due to the absence of pyrite or a clean pyrite surface or to low concentrations of the effective oxidizing agent, Fe(III).     

Insight into the biological impact of COVID-19 and its vaccines on human health

COVID-19 (coronavirus disease-2019) is a contagious illness that has been declared a global epidemic by the World Health Organization (WHO). The coronavirus causes diseases ranging in severity from the common cold to severe respiratory diseases and death. Coronavirus primarily affects blood pressure by attaching to the angiotensin converting enzyme 2 (ACE 2) receptor. This virus has an impact on multiple organ systems, including the central nervous system, immune system, cardiovascular system, peripheral nervous system, gastrointestinal tract, endocrine system, urinary system, skin, and pregnancy. For the prevention of COVID-19, various vaccines such as viral-like particle vaccines, entire inactivated virus vaccines, viral vector vaccines, live attenuated virus vaccines, subunit vaccines, RNA vaccines, and DNA vaccines are now available. Some of the COVID-19 vaccines are reported to cause a variety of adverse effects that range from mild to severe in nature. SARS-CoV-2 replication is controlled by the RNA-Dependent RNA-Polymerase enzyme (RdRp). The availability of FDA-approved anti-RdRp drugs (Ribavirin, Remdesivir, Sofosbuvir, Galidesivir, and Tenofovir) as potent drugs against SARS-CoV-2 that tightly bind to its RdRp may aid in the treatment of patients and reduce the risk of the mysterious new form of COVID-19 viral infection. RdRp inhibitors, such as remdesivir (an anti-Ebola virus experimental drug) and favipiravir (an anti-influenza drug), inhibit RdRp and thus slow the progression of COVID-19 and associated clinical symptoms, as well as significantly shorten recovery time. Molnupiravir, an orally active RdRp inhibitor and noval broad spectrum antiviral agent, is an isopropyl pro-drug of EIDD-1931 for emergency use. Galidesivir's in vitro and in vivo activities are limited to RNA of human public health concern. Top seeds for antiviral treatments with high potential to combat the SARS-CoV-2 strain include guanosine derivatives (IDX-184), setrobuvir, and YAK. The goal of this review is to compile scattered information on available COVID-19 vaccines and other treatments for protecting the human body from their harmful effects and to provide options for making better choices in a timely manner.     

Additive multiple predator effects can reduce mosquito populations

1. Multiple predator interactions may profoundly alter ecological community dynamics and can complicate predictions of simpler pairwise predator–prey interaction strengths. In particular, multiple predator effects may lessen or enhance prey risk, with implications for community-level stability. Such emergent effects may modulate natural enemy efficacy towards target organisms. 2. In the present study, a functional response approach was used to quantify emergent multiple predator effects among natural enemies towards the disease vector mosquito complex, Culex pipiens. Conspecific multiple predator–predator interactions of the cyclopoid copepod Macrocyclops albidus (intermediate predator) were quantified by comparing multiple predator consumption simulations, based on individual consumption rates, with multiple predator consumption rates that were experimentally observed. Further, the study examined the influence of the presence of a predator at a higher trophic level, Chaoborus flavicans, on copepod group predation. 3. Both predators displayed type II functional responses, with C. flavicans consuming significantly more prey than M. albidus individually. Overall consumption levels of mosquitoes increased with greater predator density and richness. Antagonistic or synergistic emergent multiple predator effects between conspecifics of M. albidus were not detected, and the higher-level predator did not reduce effects of the intermediate predator. Accordingly, evidence for additive multiple predator interactions was found. 4. The lack of predator–predator interference between cyclopoid copepods and larval chaoborid midges provides strong support for their combined application in mosquito biocontrol. It is proposed that there should be increased examination of multiple predator effects in assessments of natural enemy efficacies to better understand overall predatory effects within communities and utilities in vector control.     

Lancea tibetica as the Tibetan herb: A review of its phytochemistry and pharmacology

This review, based on nearly 25 literary sources, discusses the chemical nature and biological effects of the whole plant of Lancea tibetica Hook. f. et Thoms (Scrophulariaceae). Several types of chemical constituents have been isolated from Lancea tibetica (LT) including 34 phenolpropanoids (16 lignans, 5 neolignans, 5 nonanones, 4 phenylpropanoid glycosides, and 4 propanediols), 9 flavones, 6 triterpenoids, and 11 amino acids. Various extracts and individual compounds derived from this species have been determined to possess a variety of pharmacological effects, such as anti-tumour and antioxidant functions. The results of data analysis on the chemical and pharmacological characteristics of LT support the view that this plant has many therapeutic properties, suggesting its potential as an effective herbal remedy. Finally, suggestions for further avenues of research on the chemical and pharmacological properties of LT and ways in which to further exploit LT are presented in this review.