Effects of three food enrichment items on the behavior of black lemurs (Eulemur macaco macaco) and Ringtail Lemurs (Lemur catta) at the Henson Robinson Zoo, Springfield, Illinois

This study tested 3 food enrichment items mentioned in a laboratory primate newsletter with 6 adult Eulemur macaco and 3 adult Lemur catta to examine whether the items would affect the behavior of the lemurs. The results suggest that Food Enrichment Item 3 (a wire box filled with whole grapes, apples, or both hidden in straw hung from a branch within the enclosure) caused a significant decrease in the incidence of resting and a significant increase in the incidences of playing and grooming, with no significant effect on the incidence of feeding or foraging. The lemurs' behavior appeared to be most affected by the food enrichment item that required the most manipulation, closely followed by an enrichment that required a moderate amount of manipulation. The order of the exposure to the food enrichment items and the day of the week appear to have an attenuation effect on these behaviors and did affect the incidence of 3 stereotypic behaviors exhibited by a male L. catta such that 3 behaviors declined in occurrence as the study progressed.     

Sleep characteristics of persons with chronic fatigue syndrome and non-fatigued controls: results from a population-based study

Background  

The etiology and pathophysiology of chronic fatigue syndrome (CFS) remain inchoate. Attempts to elucidate the pathophysiology must consider sleep physiology, as unrefreshing sleep is the most commonly reported of the 8 case-defining symptoms of CFS. Although published studies have consistently reported inefficient sleep and documented a variable occurrence of previously undiagnosed primary sleep disorders, they have not identified characteristic disturbances in sleep architecture or a distinctive pattern of polysomnographic abnormalities associated with CFS.     

Mitotic Recombination in Yeast: Isolation and Characterization of Mutants with Enhanced Spontaneous Mitotic Gene Conversion Rates

Semi-dominant mutants displaying greatly elevated (up to 200-fold above control) levels of spontaneous mitotic recombination have been isolated in a disomic haploid strain of yeast heteroallelic at the arg4 locus. They are designated by the symbol MIC. The mutants variously exhibit associated sensitivity to UV and ionizing radiation and to methyl methanesulfonate, enhanced UV-induced mitotic recombination, and enhanced spontaneous forward mutation rates. Possible enzyme defects and involvement in repair and editing of DNA are discussed. The mutants are expected to simplify the analysis of recombination pathways in yeast.     

Optimization of a histopathological biomarker for sphingomyelin accumulation in acid sphingomyelinase deficiency

Niemann-Pick disease (types A and B), or acid sphingomyelinase deficiency, is an inherited deficiency of acid sphingomyelinase, resulting in intralysosomal accumulation of sphingomyelin in cells throughout the body, particularly within those of the reticuloendothelial system. These cellular changes result in hepatosplenomegaly and pulmonary infiltrates in humans. A knockout mouse model mimics many elements of human ASMD and is useful for studying disease histopathology. However, traditional formalin-fixation and paraffin embedding of ASMD tissues dissolves sphingomyelin, resulting in tissues with a foamy cell appearance, making quantitative analysis of the substrate difficult. To optimize substrate fixation and staining, a modified osmium tetroxide and potassium dichromate postfixation method was developed to preserve sphingomyelin in epon-araldite embedded tissue and pulmonary cytology specimens. After processing, semi-thin sections were incubated with tannic acid solution followed by staining with toluidine blue/borax. This modified method provides excellent preservation and staining contrast of sphingomyelin with other cell structures. The resulting high-resolution light microscopy sections permit digital quantification of sphingomyelin in light microscopic fields. A lysenin affinity stain for sphingomyelin was also developed for use on these semi-thin epon sections. Finally, ultrathin serial sections can be cut from these same tissue blocks and stained for ultrastructural examination by electron microscopy.     

Generation time of zebrafish (Danio rerio) and medakas (Oryzias latipes) housed in the same aquaculture facility

The zebrafish and the medaka are both important model organisms in biomedical research. Both species are frequently characterized as having a generation time of approximately 2-4 months, but the precise onset of sexual maturity and the variability of reproductive success with age have not been previously examined. The authors studied reproduction in replicate groups of wild-type zebrafish (strain AB) and medakas (strain Cab) that were maintained together in the same aquaculture system. Length, weight and survival of the fish were measured and recorded once per week. Reproductive success and viability of offspring were also evaluated. Both zebrafish and medakas began producing viable embryos within 60 d post-fertilization. These findings show that it is possible to successfully maintain populations of both species within the same research infrastructure without compromising reproductive success or embryo viability.     

Visual extrapolation under risk: human observers estimate and compensate for exogenous uncertainty

Humans commonly face choices between multiple options with uncertain outcomes. Such situations occur in many contexts, from purely financial decisions (which shares should I buy?) to perceptuo-motor decisions between different actions (where should I aim my shot at goal?). Regardless of context, successful decision-making requires that the uncertainty at the heart of the decision-making problem is taken into account. Here, we ask whether humans can recover an estimate of exogenous uncertainty and then use it to make good decisions. Observers viewed a small dot that moved erratically until it disappeared behind an occluder. We varied the size of the occluder and the unpredictability of the dot''s path. The observer attempted to capture the dot as it emerged from behind the occluded region by setting the location and extent of a ‘catcher’ along the edge of the occluder. The reward for successfully catching the dot was reduced as the size of the catcher increased. We compared human performance with that of an agent maximizing expected gain and found that observers consistently selected catcher size close to this theoretical solution. These results suggest that humans are finely tuned to exogenous uncertainty information and can exploit it to guide action.     

Estimating the impact of newly arrived foreign-born persons on tuberculosis in the United States

Background

Among approximately 163.5 million foreign-born persons admitted to the United States annually, only 500,000 immigrants and refugees are required to undergo overseas tuberculosis (TB) screening. It is unclear what extent of the unscreened nonimmigrant visitors contributes to the burden of foreign-born TB in the United States.

Methodology/Principal Findings

We defined foreign-born persons within 1 year after arrival in the United States as “newly arrived”, and utilized data from U.S. Department of Homeland Security, U.S. Centers for Disease Control and Prevention, and World Health Organization to estimate the incidence of TB among newly arrived foreign-born persons in the United States. During 2001 through 2008, 11,500 TB incident cases, including 291 multidrug-resistant TB incident cases, were estimated to occur among 20,989,738 person-years for the 1,479,542,654 newly arrived foreign-born persons in the United States. Of the 11,500 estimated TB incident cases, 41.6% (4,783) occurred among immigrants and refugees, 36.6% (4,211) among students/exchange visitors and temporary workers, 13.8% (1,589) among tourists and business travelers, and 7.3% (834) among Canadian and Mexican nonimmigrant visitors without an I-94 form (e.g., arrival-departure record). The top 3 newly arrived foreign-born populations with the largest estimated TB incident cases per 100,000 admissions were immigrants and refugees from high-incidence countries (e.g., 2008 WHO-estimated TB incidence rate of ≥100 cases/100,000 population/year; 235.8 cases/100,000 admissions, 95% confidence interval [CI], 228.3 to 243.3), students/exchange visitors and temporary workers from high-incidence countries (60.9 cases/100,000 admissions, 95% CI, 58.5 to 63.3), and immigrants and refugees from medium-incidence countries (e.g., 2008 WHO-estimated TB incidence rate of 15–99 cases/100,000 population/year; 55.2 cases/100,000 admissions, 95% CI, 51.6 to 58.8).

Conclusions/Significance

Newly arrived nonimmigrant visitors contribute substantially to the burden of foreign-born TB in the United States. To achieve the goals of TB elimination, direct investment in global TB control and strategies to target nonimmigrant visitors should be considered.     

The impact of 1080 bait removal by Lace Monitors (Varanus varius) on a Red Fox (Vulpes vulpes) control programme

The use of toxic bait over large areas is a cost‐effective and widely used technique for the management of wild canids in Australia. Lace Monitors are known to also take baits, and though unlikely to be lethal to these reptiles the effect on the efficacy of control operations is largely unknown. During a five year Red Fox control programme in eastern Victoria, Lace Monitors removed significantly higher numbers of toxic baits than canids during the warmer months, reducing the likelihood of foxes encountering bait and reducing the efficacy of the control programme. Suggestions are made to mitigate bait take by Lace Monitors.     

Speeded Reaching Movements around Invisible Obstacles

We analyze the problem of obstacle avoidance from a Bayesian decision-theoretic perspective using an experimental task in which reaches around a virtual obstacle were made toward targets on an upright monitor. Subjects received monetary rewards for touching the target and incurred losses for accidentally touching the intervening obstacle. The locations of target-obstacle pairs within the workspace were varied from trial to trial. We compared human performance to that of a Bayesian ideal movement planner (who chooses motor strategies maximizing expected gain) using the Dominance Test employed in Hudson et al. (2007). The ideal movement planner suffers from the same sources of noise as the human, but selects movement plans that maximize expected gain in the presence of that noise. We find good agreement between the predictions of the model and actual performance in most but not all experimental conditions.