Epidemiology of antibiotic resistance in culture-positive hospitalized patients in selected hospitals in Khartoum, Sudan

Objective: To study the prevelence of antibiotic resistance and the prevalent bacterial isolates in hospitalized patients in Khartoum hospitals. Materials & Methods: A cross-sectional prevalence study was carried out during the period of April–November 2015 in Khartoum; 226 bacterial cultures were included. Identification of isolates using standard biochemical tests and antibiotic susceptibilities were determined using disc diffusion method. Results were interpreted according to the standards of the British society of antimicrobial chemotherapy. Results: Eight bacterial species were isolated: Staphylococcus aureus, Enterococcus faecalis, Streptococcus spp., Klebsiella pneumoniae, Pseudomonas spp., Escherichia coli, Proteus spp., and Acinetobacter spp. S. aureus was the most prevalent, the majority of which were resistant to methicillin/oxacillin (MRSA). Cultures in our study were mainly from urine (36.7%), blood samples (37.2%), and wound cultures (19%). More than 90% of the tested isolates were resistant to cefuroxime; 54% and 73.8% of Gram-positive and Gram-negative isolates, respectively, were resistant to ceftazidime. Furthermore, there was a high meropenem resistance among Gram-negative isolates tested. Multi-resistant Acinetobacter spp. as well as vancomycin-resistant S. aureus was isolated. Gram-negative isolates showed good susceptibilities to aminoglycosides as well as ciprofloxacin. However, the high resistance rate to these antibiotics was observed in Gram-positive isolates in these hospitals. Conclusion: Methicillin-resistant S. aureus was the most prevalent organism. Gramnegative isolates showed good susceptibilities to aminoglycosides and ciprofloxacin. There were high resistance rates to cefuroxime, ceftazidime, and meropenem. Five vancomycin-resistant S. aureus were identified

Approaches to Learning to Control Dynamic Uncertainty

In dynamic environments, when faced with a choice of which learning strategy to adopt, do people choose to mostly explore (maximizing their long term gains) or exploit (maximizing their short term gains)? More to the point, how does this choice of learning strategy influence one’s later ability to control the environment? In the present study, we explore whether people’s self-reported learning strategies and levels of arousal (i.e., surprise, stress) correspond to performance measures of controlling a Highly Uncertain or Moderately Uncertain dynamic environment. Generally, self-reports suggest a preference for exploring the environment to begin with. After which, those in the Highly Uncertain environment generally indicated they exploited more than those in the Moderately Uncertain environment; this difference did not impact on performance on later tests of people’s ability to control the dynamic environment. Levels of arousal were also differentially associated with the uncertainty of the environment. Going beyond behavioral data, our model of dynamic decision-making revealed that, in actual fact, there was no difference in exploitation levels between those in the highly uncertain or moderately uncertain environments, but there were differences based on sensitivity to negative reinforcement. We consider the implications of our findings with respect to learning and strategic approaches to controlling dynamic uncertainty.This study was supported by the Engineering and Physical Sciences Research Council

Decision making in uncertain times: what can cognitive and decision sciences say about or learn from economic crises?

B.M. was supported by a Visiting Scholar Award from the British Academy and Grant ME 3717/2 from the Deutsche Forschungsgemeinschaft (DFG) as part of the priority program ‘New Frameworks of Rationality’ (SPP 1516)

Analysis of complex contagions in random multiplex networks

We study the diffusion of influence in random multiplex networks where links can be of $r$ different types, and for a given content (e.g., rumor, product, political view), each link type is associated with a content dependent parameter $c_i$ in $[0,\infty]$ that measures the relative bias type-$i$ links have in spreading this content. In this setting, we propose a linear threshold model of contagion where nodes switch state if their "perceived" proportion of active neighbors exceeds a threshold \tau. Namely, a node connected to $m_i$ active neighbors and $k_i-m_i$ inactive neighbors via type-$i$ links will turn active if $\sum{c_i m_i}/\sum{c_i k_i}$ exceeds its threshold \tau. Under this model, we obtain the condition, probability and expected size of global spreading events. Our results extend the existing work on complex contagions in several directions by i) providing solutions for coupled random networks whose vertices are neither identical nor disjoint, (ii) highlighting the effect of content on the dynamics of complex contagions, and (iii) showing that content-dependent propagation over a multiplex network leads to a subtle relation between the giant vulnerable component of the graph and the global cascade condition that is not seen in the existing models in the literature.Comment: Revised 06/08/12. 11 Pages, 3 figure

Effects of Ethrel Application and Packaging on Mango Fruit Quality

    Experiments were conducted at the National Institute for the Promotion  of Horticultural Exports, University of Gezira, Wad  Medani, Sudan, during May 1997 and 1998 to investigate the effects of Ethrel and polyethylene packaging on mango fruit quality. Mango fruit quality, Mango fruits were  harvested at the mature-green stage and treated with Ethrel or  left as control. Fruits were packed in either intact or perforated polyetlhylene packages or left unpacked. The experiments were set up in a completely randomized design with three replications. Ethrel treatment accelerated  the rate of fruit ripening as shown by an increase in total soluble solids, yellowing and a decrease in fruit firmness and starch content Fruits packed in intact polyethylene packages resulted in the  lowest weight loss, followed by those packed in perforated films, whereas unpacked fruits showed the highest weight loss and lowest quality manifested in shriveling and deterioratio

Enhanced Removal of Lead by Chemically and Biologically Treated Carbonaceous Materials

Hybrid sorbents and biosorbents were synthesized via chemical and biological treatment of active carbon by simple and direct redox reaction followed by surface loading of baker's yeast. Surface functionality and morphology of chemically and biologically modified sorbents and biosorbents were studied by Fourier Transform Infrared analysis and scanning electron microscope imaging. Hybrid carbonaceous sorbents and biosorbents were characterized by excellent efficiency and superiority toward lead(II) sorption compared to blank active carbon providing a maximum sorption capacity of lead(II) ion as 500 μmol g−1. Sorption processes of lead(II) by these hybrid materials were investigated under the influence of several controlling parameters such as pH, contact time, mass of sorbent and biosorbent, lead(II) concentration, and foreign ions. Lead(II) sorption mechanisms were found to obey the Langmuir and BET isotherm models. The potential applications of chemically and biologically modified-active carbonaceous materials for removal and extraction of lead from real water matrices were also studied via a double-stage microcolumn technique. The results of this study were found to denote to superior recovery values of lead (95.0–99.0 ± 3.0–5.0%) by various carbonaceous-modified-bakers yeast biosorbents

Real-time analysis of insoluble particles in glacial ice using single-particle mass spectrometry

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Atmospheric Measurement Techniques 10 (2017): 4459-4477, doi:10.5194/amt-10-4459-2017.Insoluble aerosol particles trapped in glacial ice provide insight into past climates, but analysis requires information on climatically relevant particle properties, such as size, abundance, and internal mixing. We present a new analytical method using a time-of-flight single-particle mass spectrometer (SPMS) to determine the composition and size of insoluble particles in glacial ice over an aerodynamic size range of  ∼  0.2–3.0 µm diameter. Using samples from two Greenland ice cores, we developed a procedure to nebulize insoluble particles suspended in melted ice, evaporate condensed liquid from those particles, and transport them to the SPMS for analysis. We further determined size-dependent extraction and instrument transmission efficiencies to investigate the feasibility of determining particle-class-specific mass concentrations. We find SPMS can be used to provide constraints on the aerodynamic size, composition, and relative abundance of most insoluble particulate classes in ice core samples. We describe the importance of post-aqueous processing to particles, a process which occurs due to nebulization of aerosols from an aqueous suspension of originally soluble and insoluble aerosol components. This study represents an initial attempt to use SPMS as an emerging technique for the study of insoluble particulates in ice cores.This work was supported by an internal Reed Grant from MIT and National Science Foundation award PLR-1205196 to Sarah B. Das. Matthew Osman acknowledges government support awarded by DoD, Air Force Office of Scientific Research, National Defense Science and Engineering Graduate (NDSEG) Fellowship, 32 CFR 168a. Maria A. Zawadowicz acknowledges the support of NASA Earth and Space Science Fellowship. Daniel J. Cziczo acknowledges the support of the Victor P. Starr Career Development Chair at MIT

DETECTION OF CHRONIC TYPHOID CARRIERS AMONG FOOD HANDLERS IN WAD MEDANI , GEZIRA STATE , SUDAN

Typhoid fever remains a disease of major public health importance in the tropics. This cross sectional prospective descriptive study was carried out between July 2005 to July 2008 in Wad Medani Town. The objective of the study was to identify chronic typhoid carriers among food handlers in Wad Medani. To achieve this objective, Vi agglutination test was used to determine suggested typhoid carriers among food handlers then stool culture was performed on those with a positive Vi agglutination test. A questionnaire was designed to collect data from suggested typhoid carriers about hygienic practices during food handling and processing .  The collected data were reviewed and coded. Data were analyzed using SPSS versions 10.0 software for tabulation and statistical analysis. The results showed that, ten percent of the examined food handlers were found positive typhoid carriers by Vi agglutination test, 48.5% of the suspected of typhoid carriers were found positive by stool culture, street vendors were more common among suspected typhoid carriers, all of whom had not received any health education about typhoid disease. The study suggested the following recommendations: Regular health authority inspection visitor food handling personnel specially street vendors to exclude typhoid carriers among them, education and training course in good hygienic practices should be provided to all food handlers specially typhoid carriers by Food Control Department, Ministry of Health, Gezira State

Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disease in which symptoms of aging are manifested at an early age. In the present report, we describe a 9 months old female child presented with a history of progressive coarsening of skin, failure to thrive and irregular bumps over thighs, buttocks and lower limbs for the last 7½ months. In the course of time, she developed alopecia, hyperpigmented spots over the abdomen with thickening and a typical facial profile of HGPS including micrognathia, absent ear lobules, prominent eyes, loss of eyelashes, eyebrows and a bluish hue over the nose