What we Know about the Composition and Structure of Igapó Forests in the Amazon Basin

The Amazon contains some of the most critical ecosystems on earth and Igapó forests are one of those ecosystems. They are flooded by “black-water”, leached runoff of forest litter. To help in our understanding of igapó forests, and to act as a resource for their future research, I review what we know about their composition and structure. I used my own sampling data to construct floristics tables of the tree species, and tables of physical structural parameters such as tree density, species richness basal area and above-ground biomass (AGB). In addition I used data gotten from literature searches on google scholar, biosys, WorldCat discovery services and other databases for all papers that sampled trees in plots within igapó forests. I found there was a total of 59 families sampled in all the plots. The families with the most genera were Fabaceae and Caesalpiniaceae, with the most species were Fabaceae and Euphorbiaceae, and with the most tree stems were Fabaceae and Euphorbiaceae. The most common genera were Mouriri and Lincania and the most common species were Virola elongate and Swartzia polyphylla. For structure, total stems had a wide range between 167 and 683 per ha, stem sizes generally conformed to a “reverse J” distribution pattern, mean stem sizes were ~20 cm diameter at breast height, there was a species richness range between 90 and 119 per ha, and igapó forests were more open than other forest-types in the Amazon basin. While these plots were in primary igapó forest, my samplings of secondary igapó forests showed they had a reduced structure compared to primary igapó forests but were similar within the different kinds of secondary igapó forests.     

What Is the Good of It—Ethical Controls of Human Subject Health Research?

The term “ethics” covers a multitude of virtues and possibly some sins where ethical perspectives differ. Given the diversity of ethical philosophies there is a question about what common ground can, or should, inform health research ethics. At a minimum it must be consistent with the law. Beyond that, ethics embraces a variety of possible approaches. This raises the question—what criteria are applied in determining the appropriate approach and what standards by way of quality control are applied to its decisional application by ethics committees or other authorities exercising responsibility in this difficult area. The particular issue of ethical perspectives on the use of “big data” in medical research also raises complex issues for consideration.     

Storage of vaccines in the community: weak link in the cold chain?

OBJECTIVE--To assess quality of storage of vaccines in the community. DESIGN--Questionnaire survey of general practices and child health clinics, and monitoring of storage temperatures of selected refrigerators. SETTING--Central Manchester and Bradford health districts. SUBJECTS--45 general practices and five child health clinics, of which 40 (80%) responded. Eight practices were selected for refrigeration monitoring. MAIN OUTCOME MEASURES--Adherence to Department of Health guidelines for vaccine storage, temperature range to which vaccines were exposed over two weeks. RESULTS--Of the 40 respondents, only 16 were aware of the appropriate storage conditions for the vaccines; eight had minimum and maximum thermometers but only one of these was monitored daily. In six of the eight practices selected for monitoring of refrigeration temperatures the vaccines were exposed to either subzero temperatures (three fridges) or temperatures up to 16 degrees C (three). Two of these were specialised drug storage refrigerators with an incorporated thermostat and external temperature gauges. CONCLUSION--Vaccines were exposed to temperatures that may reduce their potency. Safe storage of vaccines in the clinics cannot be ensured without adhering to the recommended guidelines. Provision of adequate equipment and training for staff in maintaining the \"cold chain\" and the use and care of equipment are important components of a successful immunisation programme.     

What determines the impact of alien birds and mammals in Europe?

An often-cited reason for studying the process of invasion by alien species is that the understanding sought can be used to mitigate the impacts of the invaders. Here, we present an analysis of the correlates of local impacts of established alien bird and mammal species in Europe, using a recently described metric to quantify impact. Large-bodied, habitat generalist bird and mammal species that are widespread in their native range, have the greatest impacts in their alien European ranges, supporting our hypothesis that surrogates for the breadth and the amount of resources a species uses are good indicators of its impact. However, not all surrogates are equally suitable. Impacts are generally greater for mammal species giving birth to larger litters, but in contrast are greater for bird species laying smaller clutches. There is no effect of diet breadth on impacts in birds or mammals. On average, mammals have higher impacts than birds. However, the relationships between impact and several traits show common slopes for birds and mammals, and relationships between impact and body mass and latitude do not differ between birds and mammals. These results may help to anticipate which species would have large impacts if introduced, and so direct efforts to prevent such introductions.     

What Are the Roles and Responsibilities of the Media in Disseminating Health Information?

BACKGROUND TO THE DEBATE: In December 2004 three news stories in the popular press suggested that the side effects of single-dose nevirapine, which has been proven to prevent mother-to-child transmission of HIV, had been covered up. Many HIV experts believed that the stories were unwarranted and that they would undermine use of the drug, leading to a rise in neonatal HIV infection. The controversy surrounding these stories prompted the PLoS Medicine editors to ask health journalists, and others with an interest in media reporting of health, to share their views on the roles and responsibilities of the media in disseminating health information.     

What counts? Volunteers and their organisations in the recording and monitoring of biodiversity

There is a pressing need for volunteer amateur naturalists to participate in data collection for biodiversity monitoring programmes in Europe. It is being addressed in some countries, but less so in others. This paper discusses the results from qualitative research using semi-structured interviews, focus groups and participant observation within nine Participatory Monitoring Network (PMN) organisations in six European countries. The paper examines the features that facilitate recruitment, retention and motivations of volunteers to participate in biodiversity monitoring, including the social and cultural milieus in which they operate. The paper concludes that volunteers place a high degree of significance on their social experience within PMNs. Successful creation and management of PMNs thus requires that similar levels of attention be paid to social aspects of the organisation as are paid to the generation and management of data.     

What are Backshoots Good For? Seasonal Changes in Mineral, Carbohydrate and Water Content of Different Organs of the Epiphytic Orchid, Dimerandra emarginata

The epiphytic orchid, Dimerandra emarginata (G. Meyer) Hoehne,keeps older stems (‘ backshoots’) after the attachedfoliage dies. I investigated seasonal changes in the water,carbohydrate and nutrient content of these leafless stems alongwith associated, connected organs for 1 year. Older stems significantlyincrease the water storage capacity of a plant, allowing itto tolerate long periods of drought. Reduction in total non-structuralcarbohydrates (TNC) at the beginning of the growing season indicatedan important role of carbon stored in older stems for the re-initiationof vegetative growth after the dry season, while the lack ofan increase in TNC before fruiting suggests no such role forreproduction. While seasonal fluctuations in water contentsand TNC were pronounced, concentrations of nutrients (N, P,K) showed only small seasonal variation in all vegetative organs.Allocation of carbon and nutrients to developing fruits wasrather high, exceeding, e.g. 20% of the total plant pool ofpotassium. This large investment in fruits was derived fromall vegetative organs. I conclude that persistent stems servea crucial function in the water, carbon and nutrient relationsof epiphytes such as D. emarginata, which live in habitats whereaccess to water and key nutrients is often severely limited.Copyright 1999 Annals of Botany Company Barro Colorado Island, Dimerandra emarginata, epiphytes, mineral nutrients, orchids, reproduction, resource allocation, total non-structural carbohydrates.     

What Controls the Acute Viral Infection Following Yellow Fever Vaccination?

Does target cell depletion, innate immunity, or adaptive immunity play the dominant role in controlling primary acute viral infections? Why do some individuals have higher peak virus titers than others? Answering these questions is a basic problem in immunology and can be particularly difficult in humans due to limited data, heterogeneity in responses in different individuals, and limited ability for experimental manipulation. We address these questions for infections following vaccination with the live attenuated yellow fever virus (YFV-17D) by analyzing viral load data from 80 volunteers. Using a mixed effects modeling approach, we find that target cell depletion models do not fit the data as well as innate or adaptive immunity models. Examination of the fits of the innate and adaptive immunity models to the data allows us to select a minimal model that gives improved fits by widely used model selection criteria (AICc and BIC) and explains why it is hard to distinguish between the innate and adaptive immunity models. We then ask why some individuals have over 1000-fold higher virus titers than others and find that most of the variation arises from differences in the initial/maximum growth rate of the virus in different individuals.     

What sets the odds of winning and losing?

Social experience influences the outcome of conflicts such that winners are more likely to win again and losers will more likely lose again, even against different opponents. Although winner and loser effects prevail throughout the animal kingdom and crucially influence social structures, the ultimate and proximate causes for their existence remain unknown. We propose here that two hypotheses are particularly important among the potential adaptive explanations: the 'social-cue hypothesis', which assumes that victory and defeat leave traces that affect the decisions of subsequent opponents; and the 'self-assessment hypothesis', which assumes that winners and losers gain information about their own relative fighting ability in the population. We discuss potential methodologies for experimental tests of the adaptive nature of winner and loser effects.     

What is the role of carohydrates in interferons?

Carbohydrates present in β- and γ-interferons seem to play a role in the synthesis, secretion, distribution and catabolism of these glycoproteins.     

What lies in the future of high-pressure bioscience?

Without being comprehensive in this mini-review, I will address perspectives, some speculative, for the development and use of high pressure to explore biochemical phenomena. This will be illustrated with several examples.     

What is new in the treatment of hypospadias?

Hypospadias is a congenital anomaly characterized by a ventrally placed urethral meatus in a more proximal position on the midline than its normal position in the glanular part of the penis. In 1961, C. E. Horton and C. J. Devine, Jr., developed single-stage modern surgical techniques, namely, local skin flaps and free skin grafts, for urethra reconstruction in hypospadias repair, which may be applied to almost any case with different localizations of the meatus. Later, two new methods, advancement of the urethra and preputial island flap techniques, were added to the surgical algorithm. Because acceptable results were observed, the authors have insisted on using these four techniques for all hypospadias cases since 1972. Complication rates (mainly fistula formation) were quite high (50 percent) in their early series of adults as a result of erection and hematoma formation. The complication rate of their patient population, which is now mainly composed of preschool children, has decreased to 7 to 8 percent, primarily as a result of careful selection of appropriate techniques for each individual case, the development of better surgical materials and equipment, and taking necessary precautions for postoperative care. A brief summary of modern hypospadias repair techniques is presented in four major classes. The results of the authors' 30-year experience and the precautions necessary to avoid postoperative complications are evaluated. The authors conclude that the four modern techniques and their modifications should be performed meticulously for successful hypospadias repair.