Discontinuous genetic variation among mesophilic Naegleria isolates: further evidence that N. gruberi is not a single species.

Naegleria isolates which are currently placed in the type species N. gruberi display great genetic, physiological and morphological heterogeneity. There are two possible interpretations of the nature of this species--that N. gruberi is a species complex or that it is a single continuously variable species. To distinguish between these alternatives, allelic states were determined for 33 loci in 74 new isolates selected to represent wide geographic sources and diverse temperature limits for growth. The results were compared with data for culture collection strains of N. gruberi and other species in the genus. The isolates formed a discontinuous series of clusters, separated by genetic distances similar to those separating the better-characterised taxa N. fowleri, N. lovaniensis, N. jadini, N. australiensis australiensis and N. australiensis italica. Culture collection strains assigned to N. gruberi fell into six distinct clusters, while other clusters were not represented by reference strains. The data are most consistent with the interpretation that N. gruberi is a group of several distinct species, each equivalent to the recently described species in the genus. Naegleria andersoni andersoni and N. andersoni jamiesoni also formed two distinct clusters, equivalent to species. Characteristics temperature limits for growth show that the mesophilic species are ecological as well as genetic entities.     

Grooming and Anxiety in Barbary Macaques

Grooming is a fundamental component of sociality in many gregarious animal species, and elucidating the costs and benefits of this behaviour is crucial for understanding its function. There is evidence that animals giving grooming pay a cost in terms of the time and energy they invest, while recipients benefit not just from the removal of dirt and parasites, but also from the relaxing effects of being groomed. Recently, however, studies of primates have indicated that giving grooming may also provide such hedonic benefits, reducing levels of stress or anxiety in the groomer. In this study of free‐ranging adult female Barbary macaques at Trentham Monkey Forest (Stoke‐on‐Trent, UK), we tested the hypothesis that grooming reduces anxiety in the donor and/or the recipient. During focal follows, we quantified females' rates of self‐scratching as a behavioural index of their anxiety levels. Self‐scratching rates in the 2‐min periods after bouts of grooming (given, received and reciprocated) were compared to overall mean self‐scratching rates; we predicted that if grooming reduces anxiety, self‐scratching rates would be significantly lower after grooming bouts than mean levels. We first analysed all grooming bouts and then analysed separately grooming bouts with adult males, with all adult females, with subordinate adult females and with dominant adult females. Contrary to our prediction, self‐scratching rates were never seen to be lower after grooming than mean levels. In fact, for the majority of grooming partner–direction combinations, we found significantly higher rates of self‐scratching after grooming compared to mean levels. The hypothesis that grooming reduces anxiety was therefore not supported. Grooming seems in some cases to increase, not alleviate, anxiety. We explore possible explanations for these unexpected results.     

Stromal-cell-derived factor (SDF) 1-alpha in combination with BMP-2 and TGF-β1 induces site-directed cell homing and osteogenic and chondrogenic differentiation for tissue engineering without the requirement for cell seeding

The clinical translation of tissue engineering approaches is limited by the requirement of a cell source. Cell guidance is a new concept that provides an alternative approach, obviating a requirement for an external cell source. This relies on site-specific homing and differentiation of the patient??s own cells to an implanted scaffold through controlled delivery of cytokines. In this study, we used stromal-cell-derived factor 1-alpha (SDF-1??) in combination with bone morphogenic protein (BMP)-2 or transforming growth factor (TGF)-??1 to induce cell migration and osteogenic or chondrogenic differentiation, respectively, in implanted scaffolds in a rat model. A customized cytokine microdelivery apparatus was used to ensure the constant rate and concentration of cytokine delivery around the scaffold. The formation of osteoid or early cartilage was observed after 4?weeks in specimens treated with SDF-1?? and either BMP-2 or TGF-??1. The density of cellular infiltrate and formation of differentiated tissue were lower in scaffolds treated only with BMP-2 or TGF-??1. Thus, controlled SDF-1?? delivery induces cell migration into scaffolds and can result in enhanced osteogenesis and chondrogenesis when used in combination with differentiation cytokines for purposes of tissue engineering.     

Effect of Metalaxyl on the incidence and severity of Pearl millet downy mildew disease in Northern Nigeria

Pearl millet downy mildew (DM) incidence, severity and yield losses of two pearl millet varieties (local and improved) due to the disease were determined in the field. Significant differences in the disease incidence and severity were recorded in the plots sown with metalaxyl-treated seeds and those sown with non-treated seeds, indicating the efficacy of the fungicide on the fungus. Yield losses due to non-treatment of seeds with metalaxyl was 40.88 and 45.39% in a local variety and 43.00 and 18.60% in an improved variety in the 2000 and 2001 cropping seasons respectively. Significant differences between plots sown with metalaxyl-treated and those sown with non-treated seeds were obtained for other yield components such as 1000-grains weight, panicle length and weight.     

Stable isotopes as indicators of wastewater effects on the macroinvertebrates of urban rivers

Rivers in urban locations frequently receive contaminated wastewater and particulate waste either directly from storm overflows or from sewage treatment facilities. Although many urban streams are now recovering from wide-scale historic pollution, lower-level effects on water chemistry, nutrients and biotic composition are still widespread. We aimed to determine whether such effects could be detected using stable isotope ratios (??¹⁵N, ??¹³C and ??³⁴S) in macroinvertebrates alone or in conjunction with traditional biomonitoring. Macroinvertebrates were collected upstream and downstream of 11 different secondary wastewater treatment works (WwTW) in South Wales and the Welsh borders (United Kingdom). Overall, mean invertebrate ??¹⁵N signatures downstream of the WwTW were significantly enriched despite variation amongst sites. Moreover, changes between upstream and downstream macroinvertebrate ??¹⁵N values were highly correlated with patterns in macroinvertebrate community composition, increased total macroinvertebrate abundance, and reduced Shannon Diversity and other biomonitoring indices (% EPT, % shredders and ASPT scores). Changes in invertebrate ??¹⁵N values also paralleled the consented discharge volumes and population equivalents from each WwTW. In contrast, isotopic ratios of ??¹³C and ??³⁴S were unable to distinguish or quantify wastewater input into the rivers but differences were apparent amongst study streams. Overall, these results suggest that macroinvertebrate ??¹⁵N signatures can detect and quantify the effects of secondary sewage treatment inputs to riverine ecosystems. Moreover, the method potentially provides a sensitive means for tracing sewage-derived nutrients into food webs while inferring effects on aquatic communities where sewage-loads are subtle or confounded by other stressors.     

Skin and Soft Tissue Infections and Associated Complications among Commercially Insured Patients Aged 0–64 Years with and without Diabetes in the U.S.

Introduction

Skin and soft tissue infections (SSTIs) are common infections occurring in ambulatory and inpatient settings. The extent of complications associated with these infections by diabetes status is not well established.

Methods

Using a very large repository database, we examined medical and pharmacy claims of individuals aged 0–64 between 2005 and 2010 enrolled in U.S. health plans. Diabetes, SSTIs, and SSTI-associated complications were identified by ICD-9 codes. SSTIs were stratified by clinical category and setting of initial diagnosis.

Results

We identified 2,227,401 SSTI episodes, 10% of which occurred in diabetic individuals. Most SSTIs were initially diagnosed in ambulatory settings independent from diabetes status. Abscess/cellulitis was the more common SSTI group in diabetic and non-diabetic individuals (66% and 59%, respectively). There were differences in the frequencies of SSTI categories between diabetic and non-diabetic individuals (p<0.01). Among SSTIs diagnosed in ambulatory settings, the SSTI-associated complication rate was over five times higher in people with diabetes than in people without diabetes (4.9% vs. 0.8%, p<0.01) and SSTI-associated hospitalizations were 4.9% and 1.1% in patients with and without diabetes, respectively. Among SSTIs diagnosed in the inpatient setting, bacteremia/endocarditis/septicemia/sepsis was the most common associated complication occurring in 25% and 16% of SSTIs in patients with and without diabetes, respectively (p<0.01).

Conclusions

Among persons with SSTIs, we found SSTI-associated complications were five times higher and SSTI-associated hospitalizations were four times higher, in patients with diabetes compared to those without diabetes. SSTI prevention efforts in individuals with diabetes may have significant impact on morbidity and healthcare resource utilization.