Diversity in parasitic nematode genomes: the microRNAs of Brugia pahangi and Haemonchus contortus are largely novel

<b>BACKGROUND:</b> MicroRNAs (miRNAs) play key roles in regulating post-transcriptional gene expression and are essential for development in the free-living nematode Caenorhabditis elegans and in higher organisms. Whether microRNAs are involved in regulating developmental programs of parasitic nematodes is currently unknown. Here we describe the the miRNA repertoire of two important parasitic nematodes as an essential first step in addressing this question. <b>RESULTS:</b> The small RNAs from larval and adult stages of two parasitic species, Brugia pahangi and Haemonchus contortus, were identified using deep-sequencing and bioinformatic approaches. Comparative analysis to known miRNA sequences reveals that the majority of these miRNAs are novel. Some novel miRNAs are abundantly expressed and display developmental regulation, suggesting important functional roles. Despite the lack of conservation in the miRNA repertoire, genomic positioning of certain miRNAs within or close to specific coding genes is remarkably conserved across diverse species, indicating selection for these associations. Endogenous small-interfering RNAs and Piwi-interacting (pi)RNAs, which regulate gene and transposon expression, were also identified. piRNAs are expressed in adult stage H. contortus, supporting a conserved role in germline maintenance in some parasitic nematodes. <b>CONCLUSIONS:</b> This in-depth comparative analysis of nematode miRNAs reveals the high level of divergence across species and identifies novel sequences potentially involved in development. Expression of novel miRNAs may reflect adaptations to different environments and lifestyles. Our findings provide a detailed foundation for further study of the evolution and function of miRNAs within nematodes and for identifying potential targets for intervention

Does autonomic function link social position to coronary risk? The Whitehall II study.

BACKGROUND: Laboratory and clinical studies suggest that the autonomic nervous system responds to chronic behavioral and psychosocial stressors with adverse metabolic consequences and that this may explain the relation between low social position and high coronary risk. We sought to test this hypothesis in a healthy occupational cohort. METHODS AND RESULTS: This study comprised 2197 male civil servants 45 to 68 years of age in the Whitehall II study who were undergoing standardized assessments of social position (employment grade) and the psychosocial, behavioral, and metabolic risk factors for coronary disease previously found to be associated with low social position. Five-minute recordings of heart rate variability (HRV) were used to assess cardiac parasympathetic function (SD of N-N intervals and high-frequency power [0.15 to 0.40 Hz]) and the influence of sympathetic and parasympathetic function (low-frequency power [0.04 to 0.15 Hz]). Low employment grade was associated with low HRV (age-adjusted trend for each modality, P< or =0.02). Adverse behavioral factors (smoking, exercise, alcohol, and diet) and psychosocial factors (job control) showed age-adjusted associations with low HRV (P<0.03). The age-adjusted mean low-frequency power was 319 ms2 among those participants in the bottom tertile of job control compared with 379 ms2 in the other participants (P=0.004). HRV showed strong (P<0.001) linear associations with components of the metabolic syndrome (waist circumference, systolic blood pressure, HDL cholesterol, triglycerides, and fasting and 2-hour postload glucose). The social gradient in prevalence of metabolic syndrome was explained statistically by adjustment for low-frequency power, behavioral factors, and job control. CONCLUSIONS: Chronically impaired autonomic function may link social position to different components of coronary risk in the general population

Spatial synchronization and extinction of species under external forcing

We study the interplay between synchronization and extinction of a species. Using a general model we show that under a common external forcing, the species with a quadratic saturation term in the population dynamics first undergoes spatial synchronization and then extinction, thereby avoiding the rescue effect. This is because the saturation term reduces the synchronization time scale but not the extinction time scale. The effect can be observed even when the external forcing acts only on some locations provided there is a synchronizing term in the dynamics. Absence of the quadratic saturation term can help the species to avoid extinction.Comment: 4 pages, 2 figure

Morphologic Parameters for Successful Lunar Landing Sites

The Moon, with its abundant resources, intriguing science questions, and vast unexplored surface area, is the most attainable and useful near-term target for future human exploration. In recognition of this fact, Presidential Space Policy Directive 1 (PSPD-1) has directed the United States to return to the Moon for long-term exploration and utilization, beginning with the 7th American human lunar landing by 2024 and building to sustainable surface presence by 2028

CAMERA: a compact, automated, laser adaptive optics system for small aperture telescopes

CAMERA is an autonomous laser guide star adaptive optics system designed for small aperture telescopes. This system is intended to be mounted permanently on such a telescope to provide large amounts of flexibly scheduled observing time, delivering high angular resolution imagery in the visible and near infrared. The design employs a Shack Hartmann wavefront sensor, a 12x12 actuator MEMS device for high order wavefront compensation, and a solid state 355nm ND:YAG laser to generate a guide star. Commercial CCD and InGaAs detectors provide coverage in the visible and near infrared. CAMERA operates by selecting targets from a queue populated by users and executing these observations autonomously. This robotic system is targeted towards applications that are diffcult to address using classical observing strategies: surveys of very large target lists, recurrently scheduled observations, and rapid response followup of transient objects. This system has been designed and costed, and a lab testbed has been developed to evaluate key components and validate autonomous operations

Risk of tuberculous infection in adolescents and adults in a rural community in Ethiopia

BACKGROUND: The incidence of tuberculosis (TB) in sub-Saharan Africa is one of the highest in the world. OBJECTIVE: To evaluate the prevalence of TB, the annual risk of tuberculous infection (ARTI) and associated risk factors in rural Ethiopia. METHODS: A tuberculin skin test was performed among 2743 individuals in a rural community of Ethiopia around Ginci town, west of Addis Ababa, to estimate the prevalence of tuberculin reactivity and to assess factors associated with tuberculous infection. RE SULTS: Among 2743 volunteer participants, test results were available for 2640, 691 (26.2%) of whom had an identifiable bacille Calmette-Guérin (BCG) scar; 221 (8.3%) reported household contact with a known TB case. The overall prevalence of TST reactions of ≥10 mm was 29.7%. The ARTI was estimated at 1.7%. Tuberculin reactivity varied with age, sex, income and history of household contact with a TB case. Presence of BCG scar was not related to tuberculin reactivity. CONCLUSIONS: Our findings indicate that despite an effective TB control programme, TB transmission rates are still high in rural Ethiopia. Provision of isoniazid prophylaxis in close contacts of active TB cases among the poorest population groups may reduce TB incidence.</p