Enrolment in Medieval English Government: Sickness or Cure?

In the Middle Ages, rolls were ubiquitous as a writing support. While scholars have long examined the texts and images on rolls, they have rarely taken the manuscripts themselves into account. This volume readdresses this imbalance by focusing on the materiality and various usages of rolls in late medieval England and France. Researchers from England, France, Germany and Singapore demonstrate in 11 contributions how this approach can increase our understanding of the rolls and their contents, as well as the contexts in which they were produced and used

Life at low Reynolds number Re-visited: The efficiency of microbial propulsion

It has for over 40 years been taken as a truth universally acknowledged that microbial swimming efficiency by flagellar propulsion is fixed by fluid mechanical limitations at 1–2%. And that the missing 98% dissipated as heat is inefficient or wasted. Estimates of such low swimming efficiency make no sense. Microbes have had billions of years to evolve highly efficient swimming; images of microbes in motion show movement with alacrity and maximum speeds of up to 10 body lengths per second, equivalent to the running and swimming speeds of far larger animals. This paradox can be resolved by taking into account the hydrogen-bonded nature of water and how efficient viscous flow over the surface of the animal is established. The minimal requirement for viscous flow is that the activation energy barrier be overcome. The activation energy for viscous flow in water and sea water is the amount of energy required to break 2 hydrogen bonds—breaking apart the dominant water pentamer into the single H2O species, thus greatly reducing the size of the molecular hole required for flow. Microbial swimming efficiency is made highly efficient by devoting some 95% of the energy expended (some must be lost to entropy) into the breaking of hydrogen bonds

Life at low Reynolds Number Re-visited: The apparent activation energy of viscous flow in sea water

In a 1976 lecture entitled “Life at low Reynolds Number,” Edward Purcell examined constraints on mobility of small aquatic animals defining the energetic challenge as “to move far enough to beat diffusion.” We show that the essential requirement is the need to do sufficient work to overcome the activation energy of viscous flow. Raman spectroscopy shows that sea water is dominated (78–85%) by the hydrogen bonded forms, primarily as the large (H2O)5 tetrahedral pentamer form. Two hydrogen bonds must be broken to disrupt this structure. The strength of the hydrogen bond in water is ~8.4 kJ/mol and the experimentally determined activation energy of viscous flow (~16.7 kJ/mol) is approximately equal to that required to break two hydrogen bonds in water. For viscous flow to occur a molecular vacancy must form for a flowing molecule to move into; the smaller the vacancy needed the less energy required. The heat created by a small animal swimming breaks hydrogen bonds thus forming a layer of small non-hydrogen bonded H2O molecules around the animal. These “lubricate” the surface yielding far more efficient viscous flow. The activation energy of the viscous flow of water decreases with pressure most likely due to the weaker strength of the hydrogen bond under pressure – lab and field data support this observation. The dissipation of tidal energy as heat, often attributed to “intermolecular forces,” is directly related to the breaking of hydrogen bonds

Systematic InSAR tropospheric phase delay corrections from global meteorological reanalysis data

6p.International audienceDespite remarkable successes achieved by Differential InSAR, estimations of low tectonic strain rates remain challenging in areas where deformation and topography are correlated, mainly because of the topography‐related atmospheric phase screen (APS). In areas of high relief, empirical removal of the stratified component of the APS may lead to biased estimations of tectonic deformation rates. Here we describe a method to correct interferograms from the effects of the spatial and temporal variations in tropospheric stratification by computing tropospheric delay maps coincident with SAR acquisitions using the ERA‐ Interim global meteorological model. The modeled phase delay is integrated along vertical profiles at the ERA‐I grid nodes and interpolated at the spatial sampling of the interferograms above the elevation of each image pixel. This approach is validated on unwrapped interferograms. We show that the removal of the atmospheric signal before phase unwrapping reduces the risk of unwrapping errors in areas of rough topography

New approaches, new activities and new outcomes in international conferences on HIV/AIDS in Africa – Report of the 3rd African Conference on the social aspects of HIV/AIDS, Dakar, 10 - 14 October 2005

Africa's HIV/AIDS situation remains cause for concern. The impact of HIV is considerable and threatens the survival and development of African societies. Although much has been attempted, the results still leave much to be desired. AIDS is an epidemic that needs to be addressed with much creativity and spirit of initiative. It is against this background that the 3rd African conference on the social aspects of HIV/AIDS brought innovations in the way international conferences are designed, activities implemented and results obtained. The innovations concerned the approach to international conferences and take into account reconceptualising HIV/AIDS so as to encourage holistic approaches and better visibility of vulnerable groups.The activities of the conference were organised in such a way as to get people living with HIV/AIDS (PLWHA), grassroots communities and marginalised groups to play a focal role.The conference offered an opportunity for developing cultural activities that would translate the African cultural concepts that had been identified as important in the HIV situation and response analysis. Interaction at the conference created an opportunity to analyse the various dimensions of the political, cultural and economic determinants. The conference offered food for thought around response construction while singling out the themes of urgency and acceleration of response, synergy construction, and coordination and conception of political responses. Keywords: conference, policies, HIV/AIDS, cultural aspects, responses, determinants Journal of Social Aspects of HIV/AIDS Vol. 3 (2) August 2006: 424-44

Gas hydrate measurements at Hydrate Ridge using Raman spectroscopy

Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 71: 2947-2959, doi:10.1016/j.gca.2007.03.032.Oceanic gas hydrates have been measured near the seafloor for the first time using a seagoing Raman spectrometer at Hydrate Ridge, Oregon, where extensive layers of hydrates have been found to occur near the seafloor. All of the hydrates analyzed were liberated from the upper meter of the sediment column near active gas venting sites in water depths of 770-780 m. Hydrate properties, such as structure and composition, were measured with significantly less disturbance to the sample than would be realized with core recovery. The natural hydrates measured were sI, with methane as the predominant guest component, and minor/trace amounts of hydrogen sulfide present in three of the twelve samples measured. Methane large-to-small cage occupancy ratios of the hydrates varied from 1.01 to 1.30, in good agreement with measurements of laboratory synthesized and recovered natural hydrates. Although the samples visually appeared to be solid, varying quantities of free methane gas were detected, indicating the presence of occluded gas a hydrate bubble fabric and/or partial hydrate dissociation in the under-saturated seawater.This work was supported through National Undersea Research Program grant UAF03-0098. DORISS and PUP development was funded by a grant to MBARI from the David and Lucile Packard Foundation

Screening and brief interventions for hazardous and harmful alcohol use among patients with active tuberculosis attending primary care clinics in South Africa: a cluster randomized controlled trial protocol

<p>Abstract</p> <p>Background</p> <p>In 2008 the World Health Organization (WHO) reported that South Africa had the highest tuberculosis (TB) incidence in the world. This high incidence rate is linked to a number of factors, including HIV co-infection and alcohol use disorders. The diagnosis and treatment package for TB and HIV co-infection is relatively well established in South Africa. However, because alcohol use disorders may present more insidiously, making it difficult to diagnose, those patients with active TB and misusing alcohol are not easily cured from TB. With this in mind, the primary purpose of this cluster randomized controlled trial is to provide screening for alcohol misuse and to test the efficacy of brief interventions in reducing alcohol intake in those patients with active TB found to be misusing alcohol in primary health care clinics in three provinces in South Africa.</p> <p>Methods/Design</p> <p>Within each of the three selected health districts with the highest TB burden in South Africa, 14 primary health care clinics with the highest TB caseloads will be selected. Those agreeing to participate will be stratified according to TB treatment caseload and the type of facility (clinic or community health centre). Within strata from 14 primary care facilities, 7 will be randomly selected into intervention and 7 to control study clinics (42 clinics, 21 intervention clinics and 21 control clinics). At the clinic level systematic sampling will be used to recruit newly diagnosed TB patients. Those consenting will be screened for alcohol misuse using the AUDIT. Patients who screen positive for alcohol misuse over a 6-month period will be given either a brief intervention based on the Information-Motivation-Behavioural Skills (IMB) Model or an alcohol use health education leaflet.</p> <p>A total sample size of 520 is expected.</p> <p>Discussion</p> <p>The trial will evaluate the impact of alcohol screening and brief interventions for patients with active TB in primary care settings in South Africa. The findings will impact public health and will enable the health ministry to formulate policy related to comprehensive treatment for TB and alcohol misuse, which will result in reduction in alcohol use and ultimately improve the TB cure rates.</p> <p>Trial registration number</p> <p>PACTR: <a href="http://apps.who.int/trialsearch/trial.aspx?trialid=PACTR201105000297151">PACTR201105000297151</a></p

Report and policy brief from the 4th Africa Conference on Social Aspects of HIV/AIDS Research: Innovations in access to prevention, treatment and care in HIV/AIDS, Kisumu, Kenya, 29 April - 3 May 2007

About 520 delegates from all over Africa and 21 countries attended the conference. This report and policy brief summarises the key findings and suggested policy options that emerged from rapporteur reports of conference proceedings including the following themes: (1) Orphans and vulnerable children, (2) Treatment, (3) Prevention, (4) Gender and male involvement, (5) Male circumcision, (6) People living with HIV/AIDS, (7) Food and nutrition, (8) Socioeconomics, and (9) Politics/policy. Two (11.8%) of the 17 OVC projects from the three countries were classified as best practice interventions. Of the 83 abstracts that were accepted at the conference, only 7 (8.4%) were dealing with antiretroviral therapy (ART).There has been tremendous effort by various organisations to provide information about prevention of HIV/AIDS. Information received by adolescents has been effective in increasing their knowledge, but without positive sexual behaviour change.The conference noted the contribution of gender discrimination and violence to the HIV epidemic and the different risks that men and women face in relation to the epidemic. Social scientists need to study the deep cultural meanings attached to male circumcision among different ethnic groups to be able to guide the debate on the latest biomedical findings on the protective effect of circumcision against HIV. Palliative care and support is crucial for coping among people living with HIV/AIDS (PLWHA) in order to deal with medical and psychological issues. Results from several countries have helped researchers to explore alternative ways of examining poverty in the context of HIV and AIDS. Policy frameworks which are likely to succeed in combating HIV/AIDS need to be updated to cover issues of access, testing, disclosure and stigma. In general, the conference was successful in identifying innovations in access to prevention, treatment and care in HIV/AIDS. SAHARA J Vol. 4 (2) 2007: pp. 640-65