Biodegradation of sulfamethoxazole: current knowledge and perspectives

Antibiotic compounds, like sulfamethoxazole (SMX), have become a concern in the aquatic environment due to the potential development of antibacterial resistances. Due to extensive consumption, excretion and disposal, SMX has been frequently detected in wastewaters and surface waters. This has led to numerous studies investigating the nature of SMX, with many researchers focusing on the biodegradation and persistence of SMX during wastewater treatment and in the environment. This review provides a summary of recent developments, outlines the discrepancies in observations and results, and demonstrates the need for further research to determine optimal biological removal strategies for SMX and other antibiotics.     

Sweet-taste-suppressing compounds: current knowledge and perspectives of application

Sweet-tasting compounds are recognized by a heterodimeric receptor composed of the taste receptor, type 1, members 2 (T1R2) and 3 (T1R3) located in the mouth. This receptor is also expressed in the gut where it is involved in intestinal absorption, metabolic regulation, and glucose homeostasis. These metabolic functions make the sweet taste receptor a potential novel therapeutic target for the treatment of obesity and related metabolic dysfunctions such as diabetes. Existing sweet taste inhibitors or blockers that are still in development would constitute promising therapeutic agents. In this review, we will summarize the current knowledge of sweet taste inhibitors, including a sweet-taste-suppressing protein named gurmarin, which is only active on rodent sweet taste receptors but not on that of humans. In addition, their potential applications as therapeutic tools are discussed.     

Lactic acid bacteria and proteomics: current knowledge and perspectives

Lactic acid bacteria (LAB) are widely used in the agro-food industry. Some of the LAB also participate in the natural flora in humans and animals. We review here proteomic studies concerning LAB. Two methods of research can be distinguished. In the first one, a systematic mapping of proteins is attempted, which will be useful for taxonomy and to function assignment of proteins. The second one focuses particularly on proteins whose synthesis is induced by various environmental situations or stresses. However, both approaches are complementary and will give new insights for the use of bacteria in industry, in human health and in the struggle against bacterial pathogens. Interest in LAB is growing, showing thus an increasing concern of their rational use and one can foresee in the near future an increasing use of proteomics as well as genomics.     

植物功能性状、功能多样性与生态系统功能: 进展与展望

植物功能性状与生态系统功能是生态学研究的一个重要领域和热点问题。开展植物功能性状与生态系统功能的研究不仅有助于人类更好地应对全球变化情景下生物多样性丧失的生态学后果,而且能为生态恢复实践提供理论基础。近二十年来,该领域的研究迅速发展,并取得了一系列的重要研究成果,增强了人们对植物功能性状-生态系统功能关系的认识和理解。本文首先明确了植物功能性状的概念, 评述了近年来植物功能性状-生态系统功能关系领域的重要研究结果, 尤其是植物功能性状多样性-生态系统功能关系研究现状; 提出了未来植物功能性状与生态系统功能关系研究中应加强植物地上和地下性状之间关系及其与生态系统功能、植物功能性状与生态系统多功能性、不同时空尺度上植物功能性状与生态系统功能, 以及全球变化和消费者的影响等方面。     

Understanding the equine cecum-colon ecosystem: current knowledge and future perspectives

Having evolved as a grazing animal, a horse's digestive physiology is characterized by rapid gastric transit, a rapid but intense enzymatic digestion along the small intestine, and a long and intense microbial fermentation in the large intestine. The process of understanding and describing feed degradation mechanisms in the equine digestive system in general, and in the hindgut ecosystem in particular, is essential. Regardless of its importance for the nutritional status of the host, the significance of the cecum-colon ecosystem has not yet been fully understood, and few reports have focused deeply on the contribution of the hindgut microbial population to the nitrogen and energy requirements of the horse. Compared to ruminal activity, very little is known about hindgut ecosystem activity in the horse. Information concerning the metabolism of this microbial population and its requirements is lacking. The use of internal bacterial markers for quantifying microbial outflow in ruminants is widely reported. These techniques can be applied to cecum-colon microbial quantification, contributing to a better characterization of this ecosystem. It is likely wrong to believe that the optimization strategy in the hindgut is similar to what happens in the rumen - that is, to maximize microbial growth and, therefore, fermentation. If we consider the type of substrate that, in normal conditions, arrives in the hindgut, we can expect it to be nitrogen limiting, providing limited nitrogen-based substrates for microbial fermentation. In this review paper, we intend to gather existing information on the equine ecosystem and to provide future perspectives of research.     

Biodegradation of phenol and its derivatives by engineered bacteria: current knowledge and perspectives

Biodegradation of phenolic compounds is a promising alternative to physical and chemical methods used to remove these toxic pollutants from the environment. The ability of various microorganisms to metabolize phenol and its derivatives (alkylphenols, nitrophenols and halogenated derivatives) has therefore been intensively studied. Knowledge of the enzymes catalyzing the individual reactions, the genes encoding these enzymes and the regulatory mechanisms involved in the expression of the respective genes in bacteria serves as a basis for the development of more efficient degraders of phenols via genetic engineering methods. Engineered bacteria which efficiently degrade phenolic compounds were constructed in laboratories using various approaches such as cloning the catabolic genes in multicopy plasmids, the introduction of heterologous genes or broadening the substrate range of key enzymes by mutagenesis. Efforts to apply the engineered strains in in situ bioremediation are problematic, since engineered strains often do not compete successfully with indigenous microorganisms. New efficient degraders of phenolic compounds may be obtained by complex approaches at the organism level, such as genome shuffling or adaptive evolution. The application of these engineered bacteria for bioremediation will require even more complex analysis of both the biological characteristics of the degraders and the physico-chemical conditions at the polluted sites.     

Intraguild predation involving Harmonia axyridis: a review of current knowledge and future perspectives

As an effective generalist predator of aphids and other hemipteran pests H. axyridis has been a successful biological control agent. However, the very functional traits that have contributed to its success in this regard also implicate it as an intraguild predator that poses a significant risk not only to the diversity of other natural enemies of Hemiptera (and their associated ecosystem services), but to biodiversity more widely. In this paper we will specifically review the existing data on intraguild predation involving H. axyridis, and consider the strength and symmetry of such interactions both within its native guild and within exotic guilds where it has established as an invasive alien. We will use these studies to interpret the observed population declines in predator diversity in the field, predict species at risk in regions not yet invaded and consider implications for resulting ecosystem services. We will also indicate gaps in our knowledge that require further study in order to identify opportunities for mitigation.     

Tick-borne haemoparasitic diseases in small ruminants in Pakistan: Current knowledge and future perspectives

Livestock industry is an essential part of Pakistan’s economy, and a variety of ruminants (including sheep and goats) are reared for the increasing demand of milk, meat and hide products. Haemoparasitic illnesses such as theileriosis, anaplasmosis, and babesiosis are a significant health risk for small ruminants in our country. Information regarding distribution patterns, the tick species involved and effective strategies to control tick-borne diseases (TBD) in goats and sheep of Pakistan is limited. To this end, it is required to assess the present rank of TBDs in small ruminants of Pakistan with a note on their vector ticks in order to control and identify the gaps in the knowledge of TBDs. This will recommend areas for future research and will add to the understanding of these diseases and will draw attention to the need for better-quality tools for the diagnosis and control of TBDs in small ruminants of Pakistan.     

SaudiVeg ecoinformatics: Aims,current status and perspectives

During the last decade many electronic databases of vegetation plots were established in many countries around the world. These databases contain valuable phytosociological information assisting both governmental and NGO (Non-governmental organizations) agencies to formulate strategies and on-ground plans to manage and protect nature resources. This paper provides an account on aims, current status and perspectives of building of a vegetation database for the Central Region (Najd) of Saudi Arabia – the founding element of the Saudi Vegetation Database (SVD). The data stored by the database are sample plots (vegetation relevés) collected according to the field techniques of the Braun-Blanquet approach (lists of taxa accompanied by semi-quantitative cover assessment), and are accompanied by general vegetation characteristics such as vegetation layering and cover, information on life-form of the recorded species, geographical coordinates, altitude, soil typology, topography and many more. More than 2900 vegetation-plot records (relevés) have so far been collected in the Najd region; of these more than 2000 have already been stored using the Turboveg database platform. These field records cover many habitats such as depressions, wadis (dry river beds), agricultural lands, sand dunes, sabkhas, and ruderal habitats. The ecological information collected in the database is currently the largest set of vegetation data collated into a database in the Middle East. These data are of great importance for biodiversity studies in Saudi Arabia, since the region is recording a loss of biodiversity at a fast rate due to environmental problems such as global warming and land-use changes. We envisage that this database would catalyze further data collection on vegetation of the entire Arabian Peninsula, and shall serve as one of the most important datasets for classification and mapping of the vegetation of the Kingdom of Saudi Arabia.     

Camptothecin: current perspectives

This review provides a detailed discussion of recent advances in the medicinal chemistry of camptothecin, a potent antitumor antibiotic. Two camptothecin analogues are presently approved for use in the clinic as antitumor agents and several others are in clinical trials. Camptothecin possesses a novel mechanism of action involving the inhibition of DNA relaxation by DNA topoisomerase I, and more specifically the stabilization of a covalent binary complex formed between topoisomerase I and DNA. This review summarizes the current status of studies of the mechanism of action of camptothecin, including topoisomerase I inhibition and additional cellular responses. Modern synthetic approaches to camptothecin and several of the semi-synthetic methods are also discussed. Finally, a systematic evaluation of novel and important analogues of camptothecin and their contribution to the current structure-activity profile are considered.     

消费者多样性对食物网结构和生态系统功能的影响

前所未有的生物多样性丧失使人们越来越关注生物多样性的生态系统功能.现有的绝大多数研究都是局限在单一营养级别上,主要是植物上,但是今天越来越多的证明表明消费者的多样性对生态系统结构和功能具有深刻影响.综述了消费者多样性对相邻或非相邻营养级的种群密度、物种多样性和生产力等方面影响的最新进展,同时也提出了若干研究展望.总体上.消费者多样性,无论是草食动物还是肉食动物,都倾向于增加该消费者所在营养级的养分和能量利用效率,以及生产力.这可能源于取样效应,或者物种之间的互补作用,类似于植物物种多样性影响初级生产力的机制.草食动物可能降低或者提高植物物种多样性,或者没有显著影响,其具体效应取决于生态系统生产力水平和草食动物的大小.捕食者哌能通过直接抑制草食动物而间接提高植物的多样性和生产力,但这种效应的大小差异很大,甚至效应的方向,都可能随团体内捕食者所占的比例而改变.未来的研究,应该考虑应用较大尺度的实验来检测食物网复杂营养关系对生态系统特性的影响,继续探讨消费者对生态系统功能的影响机制.认为异速生长法则和生态化学计量学在食物网组分关系研究中的应用将有利于增强人们对消费者.生态系统功能关系的理解.另外,全球变暖和转基因植物对食物网中消费者结构和生态系统的功能的影响也将是未来的一个重要研究方向.     

Testosterone and sport: current perspectives

Testosterone and other anabolic-androgenic steroids enhance athletic performance in men and women. As a result, exogenous androgen is banned from most competitive sports. However, due to variability in endogenous secretion, and similarities with exogenous testosterone, it has been challenging to establish allowable limits for testosterone in competition. Endogenous androgen production is dynamically regulated by both exercise and winning in competition. Furthermore, testosterone may promote athletic performance, not only through its long-term anabolic actions, but also through rapid effects on behavior. In women, excess production of endogenous testosterone due to inborn disorders of sexual development (DSD) may convey a competitive advantage. For many years, female competitors have been subject to tests of sexual genotype and phenotype known as gender verification. Although gender verification has not identified any normal man competing as a woman, this process has identified women athletes with DSD. As understanding of DSD has expanded in recent years, women with DSD are increasingly able to continue athletic competition.     

Antioxidants: current situation and perspectives

In the overview one can find analysis medico-biological aspects of free radical theory, clinical experience of antioxidants using, perspectives of new active agents and possible directions of theirs practical use.