ABSTRACT
Bioindication has become an indispensable part of water quality monitoring in most countries of the world, with the presence and abundance of bioindicator taxa, mostly multicellular eukaryotes, used for biotic indices. In contrast, microbes (bacteria, archaea and protists) are seldom used as bioindicators in routine assessments, although they have been recognized for their importance in environmental processes. Recently, the use of molecular methods has revealed unexpected diversity within known functional groups and novel metabolic pathways that are particularly important in energy and nutrient cycling. In various habitats, microbial communities respond to eutrophication, metals, and natural or anthropogenic organic pollutants through changes in diversity and function. In this review, we evaluated the common trends in these changes, documenting that they have value as bioindicators and can be used not only for monitoring but also for improving our understanding of the major processes in lotic and lentic environments. Current knowledge provides a solid foundation for exploiting microbial taxa, community structures and diversity, as well as functional genes, in novel monitoring programs. These microbial community measures can also be combined into biotic indices, improving the resolution of individual bioindicators. Here, we assess particular molecular approaches complemented by advanced bioinformatic analysis, as these are the most promising with respect to detailed bioindication value. We conclude that microbial community dynamics are a missing link important for our understanding of rapid changes in the structure and function of aquatic ecosystems, and should be addressed in the future environmental monitoring of freshwater ecosystems.
Subject(s)
Biological Monitoring , Ecosystem , Archaea/genetics , Environmental Biomarkers , Environmental Monitoring , Fresh WaterABSTRACT
Monitoring the quality of well-established multisite clerkships can be aided by the use of trend analysis and graphic-oriented presentations. Five years of data on student performance, experience, and perceptions are reported for an obstetrics and gynecology clerkship offered at eight geographically dispersed sites. Of the five measures of student performance, two (final written and oral examinations) showed major changes. Trends also appeared in student participation in deliveries and student ratings of teaching over time. The results of these analyses were communicated to faculty at each site and used to make improvements in the clerkship. The implications and use of these longitudinal evaluation procedures are discussed.
Subject(s)
Clinical Clerkship/standards , Education, Medical, Undergraduate/standards , Gynecology/education , Obstetrics/education , Educational Measurement , Time Factors , WashingtonABSTRACT
Aphanomyces astaci sporulation is crucial for the spreading potential of this disease agent. For the first time, we are reporting timing and quantity of A. astaci spores released from noble crayfish (Astacus astacus) suffering from crayfish plague under practical aquatic conditions. We infected nine noble crayfish with A. astaci PsI-genotype and maintained them in individual 8L tanks. Spores (zoospores and cysts) were quantified from water samples (3 × 1 mL) taken every 12h over 10 d using A. astaci specific qPCR. A clear sporulation trend was found, together with a high individual spore estimate variation. The median spore counts from two days before death to 12h post mortem were from ~500 to ~2000 spores L(-1). A significant sporulation increase occurred after 24h post mortem (~12,000 spores L(-1)) and reached a peak after two days (~65,000 spores L(-1)) before declining to or below pre mortem levels from the fourth day. The single most sporulating crayfish released from ~75,000 to ~400,000 spores L(-1) during the mass sporulating period, yielding a maximum estimate of ~3,200,000 spores released from a single crayfish if we assume homogeneous spore distribution. The results confirm a mass A. astaci spore release from moribund and recently dead infected noble crayfish, with a sporulation peak one to three days post mortem. The acute crayfish mortality only three days after zoospore exposure confirm the lethal potential of the PsI-genotype. The powerful sporulation potential observed here may be one of the key virulence factors of this genotype.
Subject(s)
Aphanomyces/physiology , Astacoidea , Infections/veterinary , Animals , Aphanomyces/genetics , Aphanomyces/isolation & purification , Genotype , Real-Time Polymerase Chain Reaction , Stress, PsychologicalABSTRACT
Studies of medical student performance have focused on various factors, including premedical academics, maturity, familial background and support, and personal experiences with illness. Most studies have been conducted in countries with highly developed educational systems and similar cultural and social systems. It is not clear that these findings can be applied to developing countries, where the educational and cultural experiences may be very different, and where medical instruction is carried out in a non-native language. Information was obtained from a survey of 153 fifth- and sixth-year medical students at King Abdulaziz University in Saudi Arabia. The survey measured premedical educational, social and cultural experiences that might affect medical school performance. Men performed as well as women in the medical school despite heavy familial and social commitments. Women's performance seems to be more influenced by changes in living environment. Achievement in premedical years was correlated positively with grade performance in medical school. Competence in the high-school English courses was related to medical school performance. Interest in the study of medicine prior to medical school was not related to performance. Other motivations, such as social gains, financial benefits or family wish, were related to lower performance. Current interest in clinical medicine correlated negatively with performance. Students motivated by the presence of chronic ill health in their families performed significantly lower. Factors influencing medical school performance in developed countries had similar impact on medical students in a developing country. Social factors, unique to the country, also play a role in medical student performance.
Subject(s)
Achievement , Culture , Educational Measurement , Social Environment , Students, Medical , Education, Medical, Undergraduate , Family , Female , Humans , Male , Saudi ArabiaABSTRACT
Graduate doctors are the primary output of medical education programmes. It is important for institutions to identify systematically the types of medical activities in which their former students are involved in order to determine the effectiveness of the curriculum, assessing academic standards and reviewing admissions policies. Information was obtained from a survey of men and women graduates from three of the early graduation classes of King Abdulaziz University College of Medicine in Saudi Arabia about postgraduate medical training, certification, practice patterns, and other curriculum issues. Information collected from 151 graduates (90%) indicated that 96% were practising medicine in a variety of medical specialties and subspecialties. Six were not practising at the time of the study. Significant differences were found in the specialties being practised when men and women were compared. Men tended to practise in medicine, surgery, dermatology, urology, ENT, ophthalmology and orthopaedics, while women concentrated in obstetrics and gynaecology and paediatrics. Certification beyond medical school was earned by 49% with no significant difference being found comparing men to women. Men earned the majority of their postgraduate certifications outside Saudi Arabia while most women earned theirs in Saudi Arabia. Graduates indicated that departments in the basic sciences were least helpful in preparing them as doctors, while selected clinical departments were most helpful. It was concluded from the study that the curriculum goals of the College of Medicine, namely a curriculum of international standards producing graduates to take leadership roles in both teaching and medical practice, were realized in part by the graduates surveyed.