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.     

Gene expression and the evolution of phenotypic diversity in social wasps

Background  

Organisms are capable of developing different phenotypes by altering the genes they express. This phenotypic plasticity provides a means for species to respond effectively to environmental conditions. One of the most dramatic examples of phenotypic plasticity occurs in the highly social hymenopteran insects (ants, social bees, and social wasps), where distinct castes and sexes all arise from the same genes. To elucidate how variation in patterns of gene expression affects phenotypic variation, we conducted a study to simultaneously address the influence of developmental stage, sex, and caste on patterns of gene expression in Vespula wasps. Furthermore, we compared the patterns found in this species to those found in other taxa in order to investigate how variation in gene expression leads to phenotypic evolution.     

Boll weevil (Coleoptera: Curculionidae) survival through cotton gin trash fans

There is concern that cotton gins may serve as loci for reintroduction of boll weevils, Anthonomus grandis grandis Boheman, to eradicated or suppressed zones when processing weevil-infested cotton from neighboring zones. Previous work has shown that virtually all weevils entering the gin in the seed cotton will be removed before they reach the gin stand. Those not killed by the seed cotton cleaning machinery will be shunted alive into the trash fraction, which passes through a centrifugal trash fan before exiting the gin. The objective of this study was to determine survival potential of boll weevils passed through a trash fan. Marked adult weevils were distributed in gin trash and fed through a 82.6-cm (32.5-in.) diameter centrifugal fan operated across a range of fan-tip speeds. A small number of boll weevils were recovered alive immediately after passage through the fan, but all were severely injured and did not survive 24 h. In another experiment, green bolls infested with both adult- and larval-stage weevils were fed through the fan. Several teneral adults survived 24 h, and there was no evidence that fan-tip speed affected either initial survival of weevils, or the number of unbroken boll locks that could harbor an infesting weevil. Thus, designating a minimum fan-tip speed for ensuring complete kill is not possible for the boll weevil. Experiments suggest that a device installed in a gin that partially crushes or cracks bolls open before entering a trash fan will increase mortality, possibly enough that further precautions would be unnecessary.     

Comparison of Phenotypic and Genotypic Methods Used for the Species Identification of Lactobacillus NP51 and Development of a Strain-Specific PCR Assay

The species level identity of Lactobacillus NP51, a commercial direct-fed microbial previously identified as Lactobacillus acidophilus NP51, was re-evaluated to determine whether new technologies resulted in changes in the original identification. The phenotypic methods for species identification included API 50 CHL kit and two automated systems, Vitek 2 and MIDI (FAME analysis; a total of three independent FAME analyses). Discrepancies among the identification results with all methods of phenotypic analysis were reported. MicroSeqID 500 16S rRNA system (SeqWright Inc., Houston, TX), a genotypic method, identified the organism as Lactobacillus animalis. Cloning, sequencing and subsequent sequence comparison of NP51 16S–23S intergenic spacer region (ISRs) to nucleotide sequence databases using the BLAST search tool indicated that NP51 can now be named L. animalis. When NP51 was originally identified as L. acidophilus, the designation of L. animalis did not exist taxonomically. The NP51 sequence comparisons using BLAST also revealed that NP51 and a strain previously identified as L. animalis LA51 HOFG1 by Flint and Angert are identical strains under different names. A strain-specific primer pair was also identified for HOFG1 by the same research group. A primer pair (using HOFG1 forward pair) also produced an amplicon unique to NP51. These methods demonstrate the significance of genetic-based detection methods both for scientific identification of organisms from biological samples and to prevent misidentification in food and health industry related microorganisms in which proprietary considerations are an important concern.     

A randomised, blinded, placebo-controlled trial in dementia patients continuing or stopping neuroleptics (the DART-AD trial)

Background

There have been increasing concerns regarding the safety and efficacy of neuroleptics in people with dementia, but there are very few long-term trials to inform clinical practice. The aim of this study was to determine the impact of long-term treatment with neuroleptic agents upon global cognitive decline and neuropsychiatric symptoms in patients with Alzheimer disease.

Methods and Findings

Design: Randomised, blinded, placebo-controlled parallel two-group treatment discontinuation trial.Setting: Oxfordshire, Newcastle and Gateshead, London and Edinburgh, United Kingdom.Participants: Patients currently prescribed the neuroleptics thioridazine, chlorpromazine, haloperidol trifluoperazine or risperidone for behavioural or psychiatric disturbance in dementia for at least 3 mo.Interventions: Continue neuroleptic treatment for 12 mo or switch to an identical placebo.Outcome measures: Primary outcome was total Severe Impairment Battery (SIB) score. Neuropsychiatric symptoms were evaluated with the Neuropsychiatric Inventory (NPI).Results: 165 patients were randomised (83 to continue treatment and 82 to placebo, i.e., discontinue treatment), of whom 128 (78%) commenced treatment (64 continue/64 placebo). Of those, 26 were lost to follow-up (13 per arm), resulting in 51 patients per arm analysed for the primary outcome. There was no significant difference between the continue treatment and placebo groups in the estimated mean change in SIB scores between baseline and 6 mo; estimated mean difference in deterioration (favouring placebo) −0.4 (95% confidence interval [CI] −6.4 to 5.5), adjusted for baseline value (p = 0.9). For neuropsychiatric symptoms, there was no significant difference between the continue treatment and placebo groups (n = 56 and 53, respectively) in the estimated mean change in NPI scores between baseline and 6 mo; estimated mean difference in deterioration (favouring continue treatment) −2.4 (95% CI −8.2 to 3.5), adjusted for baseline value (p = 0.4). Both results became more pronounced at 12 mo. There was some evidence to suggest that those patients with initial NPI ≥ 15 benefited on neuropsychiatric symptoms from continuing treatment.

Conclusions

For most patients with AD, withdrawal of neuroleptics had no overall detrimental effect on functional and cognitive status. Neuroleptics may have some value in the maintenance treatment of more severe neuropsychiatric symptoms, but this benefit must be weighed against the side effects of therapy.Trial registration: Cochrane Central Registry of Controlled Trials/National Research Register (#ISRCTN33368770).     

Applications and safety considerations of Lactobacillus salivarius as a probiotic in animal and human health

The goals of this review are to summarize the current knowledge on the application of Lactobacillus salivarius as a probiotic in animals and humans, and to address safety concerns with its use on live hosts. Overall, several strains of L. salivarius are well established probiotics with multiple applications in animal health, particularly to reduce colonization by gastrointestinal pathogens, and to a lesser extent, as a production and quality aid. In humans, L. salivarius has been used to prevent and treat a variety of chronic diseases, including asthma, cancer, atopic dermatitis and halitosis, and to a much limited extent, to prevent or treat infections. Based on the results from primary research evidence, it seems that L. salivarius does not pose a health risk to animals or humans in the doses currently used for a variety of applications; however, there is a systematic lack of studies assuring the safety of many of the strains intended for clinical use. This review provides researchers in the field with up‐to‐date information regarding applications and safety of L. salivarius. Furthermore, it helps researchers identify knowledge gaps and potential opportunities for microbiological and clinical research.     

Do Brooding Pythons Recognize their Clutches? Investigating External Cues for Offspring Recognition in the Children's Python,Antaresia childreni

Parental care provides substantial benefits to offspring but exacts a high cost to parents, necessitating the evolution of offspring recognition systems when the risk of misdirected care is high. In species that nest, parents can use cues associated with the offspring (direct offspring recognition) or the nest (indirect offspring recognition) to reduce the risk of misdirected care. Pythons have complex parental care, but a low risk of misdirected care. Thus, we hypothesized that female Children's pythons (Antaresia childreni) use indirect cues to induce and maintain brooding behavior. To test this, we used a series of five clutch manipulations to test the importance of various external brooding cues. Contrary to our hypothesis, we found that female A. childreni are heavily internally motivated to brood, needing only minimal external cues to induce and maintain egg‐brooding behavior. Females were no more likely to brood their own clutch in the original nest as they were to brood a clutch from a conspecific, a pseudoclutch made from only the shells of a conspecific, or their clutch in a novel nest. The only scenario where brooding was reduced, but even then not eliminated, was when the natural clutch was replaced with similarly sized stones. These results suggest that egg recognition in pythons is similar to that of solitary‐nesting birds, which have similar nesting dynamics.     

Ice premelting during differential scanning calorimetry

Premelting at the surface of ice crystals is caused by factors such as temperature, radius of curvature, and solute composition. When polycrystalline ice samples are warmed from well below the equilibrium melting point, surface melting may begin at temperatures as low as -15 degrees C. However, it has been reported (. Biophys. J. 65:1853-1865) that when polycrystalline ice was warmed in a differential scanning calorimetry (DSC) pan, melting began at about -50 degrees C, this extreme behavior being attributed to short-range forces. We show that there is no driving force for such premelting, and that for pure water samples in DSC pans curvature effects will cause premelting typically at just a few degrees below the equilibrium melting point. We also show that the rate of warming affects the slope of the DSC baseline and that this might be incorrectly interpreted as an endotherm. The work has consequences for DSC operators who use water as a standard in systems where subfreezing runs are important.