Is HIV-1 RNA dimerization a prerequisite for packaging? Yes, no, probably?

During virus assembly, all retroviruses specifically encapsidate two copies of full-length viral genomic RNA in the form of a non-covalently linked RNA dimer. The absolute conservation of this unique genome structure within the Retroviridae family is strong evidence that a dimerized genome is of critical importance to the viral life cycle. An obvious hypothesis is that retroviruses have evolved to preferentially package two copies of genomic RNA, and that dimerization ensures the proper packaging specificity for such a genome. However, this implies that dimerization must be a prerequisite for genome encapsidation, a notion that has been debated for many years. In this article, we review retroviral RNA dimerization and packaging, highlighting the research that has attempted to dissect the intricate relationship between these two processes in the context of HIV-1, and discuss the therapeutic potential of these putative antiretroviral targets

Archaeological Survey Investigations of Private Land within the boundaries of the proposed Lower Bois d’Arc Creek Reservoir Project, Fannin County, Texas

At the request of a private landowner that has property within the boundaries of the proposed Lower Bois d’Arc Creek Reservoir in Fannin County, we completed volunteer archaeological survey investigations on a portion of this tract of private land on July 18, 2015. The proposed Lower Bois d’Arc Creek Reservoir is to be more than 16,500 acres in size; the project sponsor is the North Texas Municipal Water District, and the Tulsa District of the U.S. Army Corps of Engineers is currently reviewing the project sponsor’s application for a Department of the Army permit under Section 404 of the Clean Water Act to construct the reservoir and associated facilities. Although the project area associated with the proposed reservoir is more than 17,000 acres, only 5,000 acres of the proposed project have received an archaeological survey. Based on consultation between the project sponsor, the Texas Historical Commission, and the Tulsa District, the remainder of the project area will apparently not receive archaeological survey investigations. The private lands we have investigated along Bois d’Arc Creek in the proposed reservoir area have not been examined previously by a professional archaeological survey team; these lands will be inundated by the flood pool of the reservoir as currently proposed. The landowner had contacted the Tulsa District in 2008 to inform them that there were archaeological sites on the property, but the Tulsa District has yet to follow up on that information

IDENTIFYING ECONOMIC RISK IN CATTLE FEEDING

Closeout data from two western Kansas commercial feedlots are examined to determine how cattle prices, feed costs, and animal performance impact the variability of cattle feeding profits. The relative impacts of these factors are studied across sex, placement weight, and placement month using standardized beta coefficients. Feeder cattle prices have a greater impact on profit variability for spring and fall placements. The effect of animal performance on variability of cattle feeding profits is greater for fall placements. Results suggest that fed cattle and feeder cattle prices should be emphasized in managing the overall risk in cattle feeding because they are the largest contributors to profit variability.cattle finishing profitability, cattle performance, feedlot closeouts, standardized beta coefficients, Livestock Production/Industries,

A Search for Variable Stars and Planetary Occultations in NGC2301 I: Techniques

We observed the young open cluster NGC 2301 for 14 nights in Feb. 2004 using the orthogonal transfer CCD camera (OPTIC). We used PSF shaping techniques ("square stars") during the observations allowing a larger dynamic range (4.5 magnitudes) of high photometric precision results ($\le$2 mmag) to be obtained. These results are better than similar observing campaigns using standard CCD imagers. This paper discusses our observational techniques and presents initial results for the variability statistics found in NGC 2301. Details of the variability statistics as functions of color, variability type, stellar type, and cluster location will appear in paper II

Policy brief: investing in health information systems

Health information systems need to be recognised as an essential component of health service delivery in the Asia and Pacific regions, and valued for their ability to provide evidence for decision-making. Globally, there is increasing understanding of the importance of efficient and effective health information systems that underpin health services. There are increasing requirements for governments to be accountable, and thus a strong need for measuring health outputs and outcomes

XVII International AIDS Conference: From Evidence to Action - Clinical and biomedical prevention science

The question of whether to initiate ART at higher CD4+ cell counts than currently recommended by World Health Organization (WHO) treatment guidelines received much attention at the XVII International AIDS Conference (AIDS 2008). If studies presented at the conference ultimately lead to a revision of WHO treatment guidance, the estimated number of people who will need ART globally will increase substantially. Task-shifting is emerging as an important strategy for dealing with the acute shortage of health care workers in many high-burden countries, and several studies presented at AIDS 2008 demonstrated the impressive health system efficiencies garnered by using nurses or other health care providers to deliver HIV care and treatment. Other key presentations and discussion at the conference focused on the optimal time to start TB treatment in HIV-infected patients, the growing risk of resistance in high-burden countries, including its impact on future treatment options, and several large cohort trials testing optimal drug regimens in resource-limited settings

Photosynthetic performance of Xanthoria mawsonii C. W. Dodge in coastal habitats, Ross Sea region, continental Antarctica

Xanthoria mawsonii C. W. Dodge was found to perform well physiologically in a variety of habitats at high latitudes in continental Antarctica. The net photosynthetic rate of 7•5 μ mol CO2 kg−1 s−1 is exceptionally high for Antarctic lichens. Field and laboratory measurements proved the photosynthetic apparatus to be highly adapted to strong irradiance. The cold resistance of the photosystem II reaction centres is higher than the photosynthetic CO2 fixation process. Optimum temperature for net photosynthesis was c. 10°C. The lichen grows along water channels where it is frequently inundated and hydrated to maximum water content, although net photosynthesis is strongly depressed by super saturation. In these habitats the lichen is photosynthetically active for long periods of time. Xanthoria mawsonii also grows at sites where it depends entirely on the early spring snow melt and occasional snow fall for moisture. It has an exceptionally short reactivation phase and is able to utilize snow immediately. Recovery of activity by absorbing water vapour from air, though practically possible, seems to be of ecological importance only under snow at subzero temperatures

Comparison of Anesthesia for Dental/Oral Surgery by Office-based Dentist Anesthesiologists versus Operating Room-based Physician Anesthesiologists

Few studies have examined the practice characteristics of dentist anesthesiologists and compared them to other anesthesia providers. Using outcomes from the National Anesthesia Clinical Outcomes Registry and the Society for Ambulatory Anesthesia Clinical Outcomes Registry for dental/oral surgery procedures, we compared 7133 predominantly office-based anesthetics by dentist anesthesiologists to 106,420 predominantly operating room anesthetics performed by physician anesthesia providers. These encounters were contrasted with 34,191 previously published encounters from the practices of oral and maxillofacial surgeons. Children younger than 6 years received the greatest proportion of general anesthetic services rendered by both dentist anesthesiologists and hospital-based anesthesia providers. These general anesthesia services were primarily provided for complete dental rehabilitation for early childhood caries. Overall treatment time for complete dental rehabilitation in the office-based setting by dentist anesthesiologists was significantly shorter than comparable care provided in the hospital operating room and surgery centers. The anesthesia care provided by dentist anesthesiologists was found to be separate and distinct from anesthesia care provided by oral and maxillofacial surgeons, which was primarily administered to adults for very brief surgical procedures. Cases performed by dentist anesthesiologists and hospital-based anesthesia providers were for much younger patients and of significantly longer duration when compared with anesthesia administered by oral and maxillofacial surgeons. Despite the limited descriptive power of the current registries, office-based anesthesia rendered by dentist anesthesiologists is clearly a unique and efficient mode of anesthesia care for dentistry

Mate Choice in Temperate and Tropical Spiny Lobsters With Contrasting Reproductive Systems

Sperm limitation ofreproductive success is commonin decapod crustaceans, favouringmating systems in which females compete for large males of high reproductive value. We investigated these phenomena in two species of spiny lobsters—one temperate, one tropical—with contrasting reproductive systems: the Southern Rock Lobster (Jasus edwardsii) and the Caribbean Spiny Lobster (Panulirus argus). We hypothesized that female mateselection shouldbemorepronounced in thetemperate J. edwardsii than in the tropical P. argus because J. edwardsii matures later, has a shorter mating season, and produces just one clutch of eggs per year that benefit from significant maternal investment of resources. As hypothesized, experiments conducted in large mesocosms revealed that female J. edwardsii cohabited with large males more often than expected by chance during their receptive period, but not at other times. Large male J. edwardsii cohabited in dens with the largest unmated females, whereas small males exhibited no mate size preference. In contrast, the proportion of female and male P. argus that co-occupied dens with the opposite sex was no more than expected by chance. Cohabitation patterns in the wild supported these laboratory findings for both species. Our results demonstrate the tight connection between contrasting reproductive strategies and the specificity of mate choice in spiny lobsters that are consistent with predictions based on environmental seasonality in temperate vs. tropical ecosystems