Transient reflectance of photoexcited Cd\u3csub\u3e3\u3c/sub\u3eAs\u3csub\u3e2\u3c/sub\u3e

We report ultrafast transient-grating measurements of crystals of the three-dimensional Dirac semimetal cadmium arsenide, Cd3As2, at both room temperature and 80 K. After photoexcitation with 1.5-eV photons, charge-carriers relax by two processes, one of duration 500 fs and the other of duration 3.1 ps. By measuring the complex phase of the change in reflectance, we determine that the faster signal corresponds to a decrease in absorption, and the slower signal to a decrease in the light\u27s phase velocity, at the probe energy. We attribute these signals to electrons\u27 filling of phase space, first near the photon energy and later at lower energy. We attribute their decay to cooling by rapid emission of optical phonons, then slower emission of acoustic phonons. We also present evidence that both the electrons and the lattice are strongly heated

Antigenic characterisation of lyssaviruses in South Africa

There are at least six Lyssavirus species that have been isolated in Africa, which include classical rabies virus, Lagos bat virus, Mokola virus, Duvenhage virus, Shimoni bat virus and Ikoma lyssavirus. In this retrospective study, an analysis of the antigenic reactivity patterns of lyssaviruses in South Africa against a panel of 15 anti-nucleoprotein monoclonal antibodies was undertaken. A total of 624 brain specimens, collected between 2005 and 2009, confirmed as containing lyssavirus antigen by direct fluorescent antibody test, were subjected to antigenic differentiation. The lyssaviruses were differentiated into two species, namely rabies virus (99.5%) and Mokola virus (0.5%). Furthermore, rabies virus was further delineated into two common rabies biotypes in South Africa: canid and mongoose. Initially, it was found that the canid rabies biotype had two reactivity patterns; differential staining was observed with just one monoclonal antibody. This difference was likely to have been an artefact related to sample quality, as passage in cell culture restored staining. Mongoose rabies viruses were more heterogeneous, with seven antigenic reactivity patterns detected. Although Mokola viruses were identified in this study, prevalence and reservoir host species are yet to be established. These data demonstrate the usefulness of monoclonal antibody typing panels in lyssavirus surveillance with reference to emergence of new species or spread of rabies biotypes to new geographic zones

Prevalence of primary Caesarean Section deliveries among primiparous and multiparous women at Iringa Regional Referral Hospital, Tanzania

Introduction: Primary Caesarean Section (CS) is an operation that is performed for the first time on a pregnant woman. Primary CS is of particular interest because it has an influence on future modes of delivery. There is also an issue about the original indication for the procedure both in a woman who has never tried her pelvis for vaginal delivery and a woman who has delivered vaginally in the past.Objectives: To determine the prevalence, indications, and outcomes of primary CS deliveries among primiparous and multiparous women, and associations with some demographic characteristics among pregnant women who deliver at Iringa Regional Referral Hospital, Tanzania.Methods: An analytical cross section hospital based study was used with a quantitative research approach. A sample size of 247 of primary CS deliveries was obtained. A structured questionnaire was used to collect the data and the Statistical Package for Service Solutions (v. 23) software programme was used for data entry and analysis.Results: The prevalence rate of primary CS delivery was 247 (21.6%) out of 1144 deliveries between January 2017 and June 2018. The highest indication for CS was foetal distress which was foetal heart rate below 120b/m and above 160 b/m 79 (32.0%) followed by prolonged labour 65 (25.1%). Maternal outcomes revealed that 65 (26.3%) women experienced significant blood loss which was above 1000mls, with blood transfusion of at least more than one unit of blood (PPH) followed by 29 (11.7%) who experienced a high body temperature above 37.5 degree of centigrade. The new born outcomes found that 128 (51.8%) were unable to breast feed and 95 (38.5%) had low Apgar scores below 7 in the 1st and 5th minute.Conclusion: There was a high prevalence of primary CS among primiparous and multiparous women which is above the recommended WHO threshold of 15%. Also, the highest indication for primary CS was foetal distress. The most common complication for the mother was significant blood loss and the commonest newborn complication was that the baby was unable to breastfeed.Keywords: Caesarean Section (CS), primiparous and multiparous, Iringa, TanzaniaSouth Sudan Medical Journal Vol 12. No 3 August 201

Knowledge on prevention and management of preeclampsia and eclampsia among nurses in primary health settings: baseline findings from an interventional study in Dodoma Region, Tanzania

Background: Preeclampsia and eclampsia are conditions which increase maternal and foetal morbidity and mortality worldwide.These conditions are ranked as the second leading cause of maternal deaths. Nurses have a critical role in preventing and managing preeclampsia. However, their knowledge has not been evaluated particularly among those working in primary health facilities, where opportunities for continue education is limited.Objective: To assess knowledge on prevention and management of preeclampsia and eclampsia among nurses working in the primary health care settings.Methods: Analysis of baseline data from an intervention study which test the effectiveness of simulation-based training on obstetric and neonatal emergencies among nurses in managing maternal and newborn emergencies in primary health care settings. A total of 39 primary health centres within 7 districts in Dodoma Region were selected to take part in the interventional study. Individual participants were nurses working in maternity units were involved. 172 nurses were selected using a simple random method. Nurses’ knowledge on prevention and management of PEE and its predictors were assessed using a self-administered questionnaire. Descriptive statistics analysis was done to determine the distribution of the background characteristics of nurses and logistic regression analysis was performed to explore predictors of nurses’ knowledgeResults: Overall knowledge on preeclampsia and eclampsia was 88 (51.2%). Professional qualification was a predictor associated with a nurse’s knowledge about preeclampsia and eclampsia. Registered nurses were more knowledgeable compared to enrolled nurses (AOR3.311; CI, 1.62 to 6.768; P value =.001), years of working experience showed no association with knowledge on preeclampsia and eclampsia (AOR 0.98; CI: 0.39-2.47; P values = 0.970)Conclusion: This study showed there is a critical knowledge deficiency in the prevention and management of preeclampsia and eclampsia among nurses working in maternal units of primary health care setting. Effective regular training on prevention and management of preeclampsia and eclampsia for frontline nurses is required in order to improve maternal and neonatal survival

Exact firing rate model reveals the differential effects of chemical versus electrical synapses in spiking networks

Chemical and electrical synapses shape the dynamics of neuronal networks. Numerous theoretical studies have investigated how each of these types of synapses contributes to the generation of neuronal oscillations, but their combined effect is less understood. This limitation is further magnified by the impossibility of traditional neuronal mean-field models—also known as firing rate models or firing rate equations—to account for electrical synapses. Here, we introduce a firing rate model that exactly describes the mean-field dynamics of heterogeneous populations of quadratic integrate-and-fire (QIF) neurons with both chemical and electrical synapses. The mathematical analysis of the firing rate model reveals a well-established bifurcation scenario for networks with chemical synapses, characterized by a codimension-2 cusp point and persistent states for strong recurrent excitatory coupling. The inclusion of electrical coupling generally implies neuronal synchrony by virtue of a supercritical Hopf bifurcation. This transforms the cusp scenario into a bifurcation scenario characterized by three codimension-2 points (cusp, Takens-Bogdanov, and saddle-node separatrix loop), which greatly reduces the possibility for persistent states. This is generic for heterogeneous QIF networks with both chemical and electrical couplings. Our results agree with several numerical studies on the dynamics of large networks of heterogeneous spiking neurons with electrical and chemical couplings

Maternal vaginorectal colonization by Group B Streptococcus and Listeria monocytogenes and its risk factors among pregnant women attending tertiary hospital in Mwanza, Tanzania

Background: Group B streptococcus (GBS) and Listeria monocytogenes are members of the normal microbes of the female genital tract. During labour GBS and Listeria monocytogenes may infect the new-borns, leading to neonatal sepsis and meningitis. So far, there is no report on prevalence of GBS and Listeria monocytogenes among pregnant women in Mwanza. The objective of the study was to determine the magnitude of Group B Streptococcus and Listeria monocytogenes and its associated factors at Bugando Medical Centre, Mwanza, Tanzania.Methods: The study was a cross section conducted from 1st November 2011 to 31st May 2012 at Bugando Medical Centre in Mwanza, Tanzania.  Vaginal and rectal swabs were obtained and cultured on 5% sheep blood agar and susceptibility testing done using disk diffusion technique.Results: A total of 295 pregnant women participated in the study. GBS strains were isolated from 28 (9.49%) and only two (0.68%) had isolates of Listeria spp. All GBS and Listeria spp. isolates were sensitive to penicillin and ampicillin. Eight GBS isolates were resistant to erythromycin (28.6%), seven GBS isolates were resistant to clindamycin (25%) and 15 of GBS isolates were resistant to tetracycline (53.6%). One Listeria spp isolate was resistant to cotrimoxazole. Pregnant women with no formal education and those dwelling in rural areas were more frequently colonized by GBS.Conclusion: There is a significant prevalence rate of GBS culture positive at Bugando Medical Centre with demonstrable resistant to some common antibiotics (tetracycline, erythromycin and Clindamycin). Screening for GBS should be instituted in Tanzania between 35 and 37 weeks of gestation coupled with regular check up for antimicrobial susceptibility pattern due to emerging resistance toward existing antibiotics

The role of fixed delays in neuronal rate models

Fixed delays in neuronal interactions arise through synaptic and dendritic processing. Previous work has shown that such delays, which play an important role in shaping the dynamics of networks of large numbers of spiking neurons with continuous synaptic kinetics, can be taken into account with a rate model through the addition of an explicit, fixed delay. Here we extend this work to account for arbitrary symmetric patterns of synaptic connectivity and generic nonlinear transfer functions. Specifically, we conduct a weakly nonlinear analysis of the dynamical states arising via primary instabilities of the stationary uniform state. In this way we determine analytically how the nature and stability of these states depend on the choice of transfer function and connectivity. While this dependence is, in general, nontrivial, we make use of the smallness of the ratio in the delay in neuronal interactions to the effective time constant of integration to arrive at two general observations of physiological relevance. These are: 1 - fast oscillations are always supercritical for realistic transfer functions. 2 - Traveling waves are preferred over standing waves given plausible patterns of local connectivity

Immune recovery among HIV-infected patients in northwestern Tanzania after 2 years of anti-retroviral therapy use: a retrospective cohort study

 Background: The use of antiretroviral therapy (ART) for the treatment of human immunodeficiency virus (HIV) is associated with significant and sustained decrease in the viral RNA levels that allows the immune system to recover. The extent of this immune recovery depends on the baseline CD4 count. Evidence on the extent of immune recovery in patients with advanced HIV from resource limited settings is scarce. The objective of this study was to determine immune recovery in a cohort of HIV infected outpatients after using ART for a period of 2 years. Methods: This retrospective cohort study was conducted in an outpatient HIV clinic at Bugando Medical Centre in northwestern Tanzania. CD4+ T-cell counts for HIV-positive adults at the time of enrolment were measured and retrospectively followed up during ART eligibility screening process prior to initiation of antiretroviral (ARV) drugs. We then compared the CD4+ T-cell counts at baseline and that during the enrolment. Results: A total of 238 patients files were screened for enrolment. Of the 238 patients, 171 (71.8%) fulfilled the criteria and were enrolled for the study. The lack of participation was due to death 17 (7.1%), lost to follow-up 32 (13.4%) and refusal 18 (9.5%). Of the 171 patients, the median CD4 count at the time of ART initiation was 153 cells/µl [Interquartile range (IQR): 78 – 199], 164 (95.9%) had increased their CD4 cells count, with 74.3% having an increase of more than 150 cells/µl. Only 8 (4.7%) patients had a decline of CD4 cell count. The median CD4 cells count after a 2-year follow up was significantly higher (396 [IQR: 295 – 567]) than at baseline (153 [IQR: 78 – 199]) cells/ul; p-value <0.0001). Conclusion: The CD4 cells count increased significantly after a follow up period of 2 years after ART use in this cohort. Early diagnosis and ART initiation could therefore improve outcomes in HIV-infected patients in resource limited settings.

Haplotype and isoform specific expression estimation using multi-mapping RNA-seq reads

We present a novel pipeline and methodology for simultaneously estimating isoform expression and allelic imbalance in diploid organisms using RNA-seq data. We achieve this by modeling the expression of haplotype-specific isoforms. If unknown, the two parental isoform sequences can be individually reconstructed. A new statistical method, MMSEQ, deconvolves the mapping of reads to multiple transcripts (isoforms or haplotype-specific isoforms). Our software can take into account non-uniform read generation and works with paired-end reads