Studies on the economic life of Mesopotamia in the 10th century.

In the economic development of medieval Mesopotamia, the 10th century was a decisive period, in addition to the process of evolution, the foreign domination of the Buwaihids opened the door to manifold changes and innovations. For the first time, the fief system was militarized; uncanonical taxes multiplied; currency depreciation was resorted to as a financial expedient; banking reached full development; an influential capitalist class came into prominence; and the Labour Movement was organized. This branch of Arabic history has been least studied; and this work is an attempt to throw some light on a complex life in an obscure, yet important period

Time Resolved Correlation measurements of temporally heterogeneous dynamics

Time Resolved Correlation (TRC) is a recently introduced light scattering technique that allows to detect and quantify dynamic heterogeneities. The technique is based on the analysis of the temporal evolution of the speckle pattern generated by the light scattered by a sample, which is quantified by $c\_I(t,\tau)$, the degree of correlation between speckle images recorded at time $t$ and $t+\tau$. Heterogeneous dynamics results in significant fluctuations of $c\_I(t,\tau)$ with time $t$. We describe how to optimize TRC measurements and how to detect and avoid possible artifacts. The statistical properties of the fluctuations of $c\_I$ are analyzed by studying their variance, probability distribution function, and time autocorrelation function. We show that these quantities are affected by a noise contribution due to the finite number $N$ of detected speckles. We propose and demonstrate a method to correct for the noise contribution, based on a $N\to \infty$ extrapolation scheme. Examples from both homogeneous and heterogeneous dynamics are provided. Connections with recent numerical and analytical works on heterogeneous glassy dynamics are briefly discussed.Comment: 19 pages, 15 figures. Submitted to PR

Evaluating the contribution of APOBEC3G haplotypes, on influencing HIV infection in a Zimbabwean paediatric population

Background. Apolipoprotein B mRNA-editing catalytic polypeptide like-3G (APOBEC3G) is an antiviral enzyme that reduces viral fitness by introducing uracil to thymidine hypermutations in viral genomes. Thus, polymorphisms in the APOBEC3G gene have been implicated in differential outcomes of HIV infection and disease progression. However, there is insufficient evidence on the role of APOBEC3G gene variants on HIV infection, especially in African populations. This study therefore describes polymorphisms in the APOBEC3G gene in a Zimbabwean paediatric population and evaluates their effects on susceptibility to HIV infection among children born to HIV-infected mothers. Methods. A total of 104 children aged between 7 and 9 years, comprising 68 perinatally exposed to HIV (32 born infected (EI) and 36 born uninfected (EU)) and 36 unexposed and uninfected (UEUI) controls were recruited. Allelic variants (n=5) in the APOBEC3G gene were characterised. Results. Frequencies for minor APOBEC3G alleles in the HIV-uninfected groups (EU and UEUI) were c.557G (40%), g.-90C (32%), g.-571C (12%), c.467-85C (42%), and c.582-162G (6%). APOBEC3G c.467-85C frequency was statistically significantly different when compared to the Masai of Kinyawa, Kenya population (42% v. 18%). None of the single nucleotide polymorphisms individually or as part of haplotypes were significantly associated with HIV infection when comparing the EI and EU groups. Conclusions. Our findings suggest that APOBEC3G polymorphisms alone may not have significant predictive power for inferring genetic susceptibility to vertical transmission of HIV in children perinatally exposed to HIV

Supercritical water gasification of microalgae: The impact of the algal growth water

This is the final version. Available on open access from Elsevier via the DOI in this recordData availability: Data will be made available on request.Investigation into the supercritical water gasification (SCWG) of microalgae has largely used deionized water as the reaction medium. However, real systems would use the algal growth water directly, containing ions that have been known to catalyse SCWG (K+, Na+, OH-, Fe3+, Cl-). Investigation into the effect of the growth water on SCWG was carried out for a range of temperatures (450–550), biomass concentrations (1–3wt%) and catalysts (KOH, Ru/C), using glucose or Chlorella vulgaris as the feedstock was performed. A significant increase in CO2 and reduction in CO content in the gas was observed without a catalyst and with a Ru/C catalyst. An increase in char/tar was also observed without a catalyst. As a result, the impact of the growth water should be considered for the SCWG of microalgae, in laboratory experiments and the selection of algal growth media in industrial applications.Engineering and Physical Sciences Research Council (EPSRC

Human Immunodeficiency Virus (HIV) types Western blot (WB) band profiles as potential surrogate markers of HIV disease progression and predictors of vertical transmission in a cohort of infected but antiretroviral therapy naïve pregnant women in Harare, Zimbabwe

<p>Abstract</p> <p>Background</p> <p>Expensive CD4 count and viral load tests have failed the intended objective of enabling access to HIV therapy in poor resource settings. It is imperative to develop simple, affordable and non-subjective disease monitoring tools to complement clinical staging efforts of inexperienced health personnel currently manning most healthcare centres because of brain drain. Besides accurately predicting HIV infection, sequential appearance of specific bands of WB test offers a window of opportunity to develop a less subjective tool for monitoring disease progression.</p> <p>Methods</p> <p>HIV type characterization was done in a cohort of infected pregnant women at 36 gestational weeks using WB test. Student-t test was used to determine maternal differences in mean full blood counts and viral load of mothers with and those without HIV <it>gag </it>antigen bands. Pearson Chi-square test was used to assess differences in lack of bands appearance with vertical transmission and lymphadenopathy.</p> <p>Results</p> <p>Among the 64 HIV infected pregnant women, 98.4% had pure HIV-1 infection and one woman (1.7%) had dual HIV-1/HIV-2 infections. Absence of HIV pol antigen bands was associated with acute infection, p = 0.002. All women with chronic HIV-1 infection had antibody reactivity to both the HIV-1 envelope and polymerase antigens. However, antibody reactivity to gag antigens varied among the women, being 100%, 90%, 70% and 63% for p24, p17, p39 and p55, respectively. Lack of antibody reactivity to gag p39 antigen was associated with disease progression as confirmed by the presence of lymphadenopathy, anemia, higher viral load, p = 0.010, 0.025 and 0.016, respectively. Although not statistically significant, women with p39 band missing were 1.4 times more likely to transmit HIV-1 to their infants.</p> <p>Conclusion</p> <p>Absence of antibody reactivity to pol and gag p39 antigens was associated with acute infection and disease progression, respectively. Apart from its use in HIV disease diagnosis, WB test could also be used in conjunction with simpler tests like full blood counts and patient clinical assessment as a relatively cheaper disease monitoring tool required prior to accessing antiretroviral therapy for poor resource settings. However, there is also need to factor in the role of host-parasite genetics and interactions in disease progression.</p

Fluctuations in glassy systems

We summarize a theoretical framework based on global time-reparametrization invariance that explains the origin of dynamic fluctuations in glassy systems. We introduce the main ideas without getting into much technical details. We describe a number of consequences arising from this scenario that can be tested numerically and experimentally distinguishing those that can also be explained by other mechanisms from the ones that we believe, are special to our proposal. We support our claims by presenting some numerical checks performed on the 3d Edwards-Anderson spin-glass. Finally, we discuss up to which extent these ideas apply to super-cooled liquids that have been studied in much more detail up to present.Comment: 33 pages, 7 figs, contribution to JSTAT special issue `Principles of Dynamical Systems' work-shop at Newton Institute, Univ. of Cambridge, U

Feasibility and yield of screening for diabetes mellitus among tuberculosis patients in Harare, Zimbabwe.

SETTING: A resource-limited urban setting in Zimbabwe with a high burden of tuberculosis (TB) and human immunodeficiency virus (HIV). OBJECTIVES: To determine the feasibility and yield of diabetes mellitus (DM) screening among TB patients in primary health care facilities. DESIGN: A descriptive study. RESULTS: Of the 1617 TB patients registered at 10 pilot facilities, close to two thirds (60%) were male and 798 (49%) were bacteriologically confirmed. The median age was 37 years; two thirds (67%) were co-infected with HIV. A total of 1305 (89%) were screened for DM, and 111 (8.5%, 95% CI 7.0-10.2) were newly diagnosed with DM. Low TB notifying sites were more likely than high TB notifying sites to screen patients using random blood glucose (RBG) (83% vs. 79%; P < 0.04). Screening increased gradually per quarter over the study period. There were, however, notable losses along the screening cascade, the reasons for which will need to be explored in future studies. CONCLUSION: The study findings indicate the feasibility of DM screening among TB patients, with considerable yield of persons newly diagnosed with DM. Scaling up of this intervention will need to address the observed losses along the screening cascade

Growing dynamical length, scaling and heterogeneities in the 3d Edwards-Anderson model

We study numerically spatio-temporal fluctuations during the out-of-equilibrium relaxation of the three-dimensional Edwards-Anderson model. We focus on two issues. (1) The evolution of a growing dynamical length scale in the glassy phase of the model, and the consequent collapse of the distribution of local coarse-grained correlations measured at different pairs of times on a single function using {\it two} scaling parameters, the value of the global correlation at the measuring times and the ratio of the coarse graining length to the dynamical length scale (in the thermodynamic limit). (2) The `triangular' relation between coarse-grained local correlations at three pairs of times taken from the ordered instants $t_3 \leq t_2 \leq t_1$. Property (1) is consistent with the conjecture that the development of time-reparametrization invariance asymptotically is responsible for the main dynamic fluctuations in aging glassy systems as well as with other mechanisms proposed in the literature. Property (2), we stress, is a much stronger test of the relevance of the time-reparametrization invariance scenario.Comment: 24 pages, 12 fig

Survival of HIV Infected Children Born to Mothers Enrolled in a PMTCT Program in a Resource Poor Setting *

ABSTRACT Background: Pediatric HIV is a leading cause of morbidity and mortality worldwide. The substantial expansion in PMTCT has generated information on rates of transmission and associated factors, but there are limited studies on disease progression and mortality in vertically infected children, especially from resource poor settings. Methods: A birth cohort study was initiated in 2002 to focus on the role of a single dose of nevirapine in HIV transmission before Highly Active Antiretroviral Therapy (HAART) was readily available. The enrolment of women and subsequent follow up of the children occurred at 3 peri urban clinics around Harare. Findings: 479 women were HIV infected. From these, 93 (19%) children became HIV infected, 182 (38.0%) uninfected and 204 (43%) lost to follow up before HIV diagnosis. Of the HIV infected children, 40 (43%) died before the fifth birthday, 26 (28%) were lost to follow up and 27 (29%) were alive five years after maternal enrolment prior to availability of cART. Conclusion: In this setting, there was unacceptable high mortality from HIV infected children and loss to follow up prior to availability of HAART. A small proportion of HIV vertically infected children is surviving in resource poor settings without antiretroviral therapy

Fluctuations in the coarsening dynamics of the O(N) model: are they similar to those in glassy systems?

We study spatio-temporal fluctuations in the non-equilibrium dynamics of the d dimensional O(N) in the large N limit. We analyse the invariance of the dynamic equations for the global correlation and response in the slow ageing regime under transformations of time. We find that these equations are invariant under scale transformations. We extend this study to the action in the dynamic generating functional finding similar results. This model therefore falls into a different category from glassy problems in which full time-reparametrisation invariance, a larger symmetry that emcompasses time scale invariance, is expected to be realised asymptotically. Consequently, the spatio-temporal fluctuations of the large N O(N) model should follow a different pattern from that of glassy systems. We compute the fluctuations of local, as well as spatially separated, two-field composite operators and responses, and we confront our results with the ones found numerically for the 3d Edwards-Anderson model and kinetically constrained lattice gases. We analyse the dependence of the fluctuations of the composite operators on the growing domain length and we compare to what has been found in super-cooled liquids and glasses. Finally, we show that the development of time-reparametrisation invariance in glassy systems is intimately related to a well-defined and finite effective temperature, specified from the modification of the fluctuation-dissipation theorem out of equilibrium. We then conjecture that the global asymptotic time-reparametrisation invariance is broken down to time scale invariance in all coarsening systems.Comment: 57 pages, 5 figure