The effect of phosphorus binding clay (Phoslock®) in mitigating cyanobacterial nuisance: a laboratory study on the effects on water quality variables and plankton

This laboratory study examined the lanthanum modified clay Phoslock® for its effectiveness to bind soluble reactive phosphorus (SRP), release of nutrients from this modified clay, its influence on water quality variables (pH, oxygen saturation %, conductivity and turbidity), effects on phytoplankton growth (green alga Scenedesmus obliquus, cyanobacteria Microcystis aeruginosa and Anabaena sp.), and, lastly, its effect on the population growth of the rotifer Brachionus calyciflorus. A clear dose–response for SRP binding by the modified clay was observed. A small amount of ammonium is released from Phoslock®. We found no effect of Phoslock® on pH or oxygen saturation. Conductivity increased with the increasing concentration of Phoslock®. An application of Phoslock® caused a transient increase of turbidity up to 211 NTU. However, due to rapid settlement, turbidity fell below 13 NTU (~1 m Secchi depth), after 6 h. Phoslock® addition caused a reduction in growth of all phytoplankton species tested that we attribute to the combined effects of light limitation, flocculation with the bentonite and binding of SRP to Phoslock®. We estimated the EC50 of Phoslock® on the population growth of rotifer B. calyciflorus to be 0.15 g Phoslock® l-1. Overall, the results of our study indicate Phoslock® seems to be suitable for field applications

Sex-Specific Differences in Shoaling Affect Parasite Transmission in Guppies

Background: Individuals have to trade-off the costs and benefits of group membership during shoaling behaviour. Shoaling can increase the risk of parasite transmission, but this cost has rarely been quantified experimentally. Guppies (Poecilia reticulata) are a model system for behavioural studies, and they are commonly infected by gyrodactylid parasites, notorious fish pathogens that are directly transmitted between guppy hosts. Methodology/Principal Findings:Parasite transmission in single sex shoals of male and female guppies were observed using an experimental infection of Gyrodactylus turnbulli. Parasite transmission was affected by sex-specific differences in host behaviour, and significantly more parasites were transmitted when fish had more frequent and more prolonged contact with each other. Females shoaled significantly more than males and had a four times higher risk to contract an infection. Conclusions/Significance: Intersexual differences in host behaviours such as shoaling are driven by differences in natural and sexual selection experienced by both sexes. Here we show that the potential benefits of an increased shoaling tendency are traded off against increased risks of contracting an infectious parasite in a group-living species

Supplementary feeding in the care of the wasted HIV infected patient

Wasting and food insecurity are commonly seen in patients receiving antiretroviral treatment (ART) programs in sub-Saharan Africa and south Asia, and supplementary feeding is often offered in conjunction with ART. Evidence for the effectiveness of such supplementary feeding is scant. A randomised, investigatorblinded, controlled clinical trial of two types of supplementary food, corn/ soy blended flour and a ready-to-use peanut butterbased lipid paste, in wasted adults in Blantyre, Malawi is describedand the results summarised. A historical control group who did not receive supplementary food is described as well. Provision of about half of the daily energy requirement as a supplementary food for 14 weeks resulted in more rapid restoration of a normal BMI; and the energy-dense, ready-to-use paste was associated with more rapid weight gain than the blended flour. Survival was similar among the 3 groups. The strong association between lower BMI and survival indirectly suggests that there may well beclinical benefit from supplementary feeding in this population. No differences were seen in ART adherence or quality of life with more rapid restoration of BMI. Further research is urgently needed concerning the widespread practice of supplementary feeding in HIV/ AIDS care to most effectively utilize this intervention

Pathological features of rheumatoid synovitis in the context of therapeutic interventions and clinical settings

This thesis discusses several aspects of therapeutic interventions for arthritis of the knee, especially arthroscopic lavage. Arthroscopic lavage is a technique in which the inflamed knee of the patient is rinced with saline. After the procedure corticosteroids can be administered to suppress inflammation. Arthroscopic lavage was superior in suppressing recurrence of arthritis compared to standard joint injections with corticosteroids. The occurence of fibrosis in the inflamed joint was predictive of an inferior response. During arthroscopic lavage synovial tissue samples can be obtained. These biopsies were studied before and after treatment with anti-TNF in longstanding and early (therapy-naieve) Rheumatoid Arthritis (RA)patients. The clinical and synovial effect were comparable between both groups. In the latter part differences in synovial inflamation between RA patients with and without antibodies against cyclic citrullinated peptides (CCP) are discussed in relation to the occurence of joint damage. In anti-CCP positive patients we found more infiltrating lymphocytes leading to progression of joint damage. Also, temporal changes in synovial inflammation differed between anti-CCP positive and anti_CCP negative RA, underlining the fenotypical differences betwen both disease entities.Dutch arthritis foundation Wyeth Inc. Abbott Inc. Schering-Plough Inc.UBL - phd migration 201

The effect of blockholders in corporate governance

Unlike the Anglo-Saxon model, whereby ownership of publicly traded companies is typically in the hands of dispersed shareholders, in continental Europe ownership often lies in the hands of what are known as ‘blockholders’. But how does this affect corporate governance, especially when employees, protected by strong labour institutions, are also powerful

Underreporting of side effects of standard first-line ART in the routine setting in Blantyre, Malawi

Introduction: In the Malawi ART programme, 92% of 250,000 patients are using the standard first-line regime of stavudine-lamivudine-nevaripine. National ART reports indicate <4% experience ART side effects, much less than expected from literature.Methods: We interviewed adult patients on standard first-line ART for at least one year, after routine visits to an urban clinic in Blantyre, Malawi. We determined the prevalence of symptoms that are common side-effects, described discrepancies between symptoms that patients reported to us and those that had been recorded by attending staff as side-effects in the point-of-care electronic monitoring system, and studied factors associated with such discrepancies.Results: Of 170 participants, 75 (44%) reported at least one symptom, most common were symptoms suggesting peripheral neuropathy (n=57) and lipodystrophy (n=16). Forty-six (66%) symptomatic patients said they reported symptoms to attending ART staff. Side-effects were recorded in the clinic database for just 4 patients. Toxicity recording was too low for meaningful analysis of factors associated with discrepancies between reporting and recording of side-effects. The prevalence of symptoms indicating characteristic side-effects of the standard first-line regimen was 39% based on interviews, and 2% in the electronic monitoring system. Conclusion: There was gross under-recording of side-effects in this setting, mainly due to not recording by ART staff. Pressure of work and insufficient perceived benefit of side-effect recording are suspected causes. Local and national ART reports do not reflect the true toxicity of the standard firstline regimen

Ward Round - Non-resolving pleural effusion in a patient with HIV infection

No Abstrac

Cryptic MHC Polymorphism Revealed but Not Explained by Selection on the Class IIB Peptide-Binding Region

The immune genes of the major histocompatibility complex (MHC) are characterized by extraordinarily high levels of nucleotide and haplotype diversity. This variation is maintained by pathogen-mediated balancing selection that is operating on the peptide-binding region (PBR). Several recent studies have found, however, that some populations possess large clusters of alleles that are translated into virtually identical proteins. Here, we address the question of how this nucleotide polymorphism is maintained with little or no functional variation for selection to operate on. We investigate circa 750–850 bp of MHC class II DAB genes in four wild populations of the guppy Poecilia reticulata. By sequencing an extended region, we uncovered 40.9% more sequences (alleles), which would have been missed if we had amplified the exon 2 alone. We found evidence of several gene conversion events that may have homogenized sequence variation. This reduces the visible copy number variation (CNV) and can result in a systematic underestimation of the CNV in studies of the MHC and perhaps other multigene families. We then focus on a single cluster, which comprises 27 (of a total of 66) sequences. These sequences are virtually identical and show no signal of selection. We use microsatellites to reconstruct the populations' demography and employ simulations to examine whether so many similar nucleotide sequences can be maintained in the populations. Simulations show that this variation does not behave neutrally. We propose that selection operates outside the PBR, for example, on linked immune genes or on the “sheltered load” that is thought to be associated to the MHC. Future studies on the MHC would benefit from extending the amplicon size to include polymorphisms outside the exon with the PBR. This may capture otherwise cryptic haplotype variation and CNV, and it may help detect other regions in the MHC that are under selection

Experimental harvesting of fish populations drives genetically based shifts in body size and maturation

Size-selective harvesting in commercial fisheries can induce rapid changes in biological traits. While experimental and wild harvested populations often exhibit clear shifts in body size and maturation associated with fishing pressure, the relative contributions of genetic and environmental factors to these shifts remain uncertain and have been much debated. To date, observations of so-called fisheries-induced evolution (FIE) have been based solely on phenotypic measures, such as size data. Genetic data are hitherto lacking. Here, we quantify genetic versus environmental change in response to size-selective harvesting for small and large body size in guppies (Poecilia reticulata) across three generations of selection. We document for the first time significant changes at individual genetic loci, some of which have previously been associated with body size. In contrast, variation at neutral microsatellite markers was unaffected by selection, providing direct genetic evidence for rapid evolution induced by size-selective harvesting. These findings demonstrate FIE in an experimental system, with major implications for the sustainability of harvested populations, as well as impacts on size-structured communities and ecosystem processes. These findings highlight the need for scientists and managers to reconsider the capacity of harvested stocks to adapt to, and recover from, harvesting and predation. © 2013 The Ecological Society of America