286 research outputs found

    Socio-Economic Impacts of Computer Viruses in Tanzania

    Get PDF
    This paper reports on a research project conducted with an objective of identifying and assessing various approaches used by different computer users (Management, System Administrators and end users) in Tanzania to combat computer viruses (CVs), and to assess users' awareness level on CVs. Specifically, the study aimed at assessing the awareness level on CVs to the Tanzanian business community; analyze the socio -economic impact caused by CVs in Tanzania and; assess existing methods, capacity and limitations on controlling CVs in Tanzania. Data was collected using both questionnaires and interview from financial institutions such as NBC and BOT, and telecommunications sector such as TTCL and VODACOM. Other institutions where data was collected included the higher learning institutions such as UDSM, DIT & IFM, Government institutions such as the Government Chemist, and COSTECH and Non-governmental institutions such as REPOA and ESRF. After data analysis, it was found out that majority of the surveyed organisations were aware of CVs and about half of them employ client-server technique to successfully deal with the threat. These organisations spend between US$ 12,000 to 40,000 per year to deal with CVs. This cost is mainly for paying licence fees for anti-viruses and for data back-ups. Some organisations rely on pirated anti-virus which are unreliable and in most cases lead to disasters and losses of data and production time. It was concluded that CVs control should be given the highest priority to all JCT users. Also a policy on CVs should be well written and be instituted. Knowledge exchange on Anti-viruses' configuration should be enhanced among System Administrators within Tanzania. CVs control training should be done frequently to all workers. The use of an inert operating system such as Linux to control the spread of CVs should be promoted for use in workstations and for newly established organizations. Budget for CVs control should be considered at early stages

    Some combinatorial identities related to commuting varieties and Hilbert schemes

    Get PDF
    In this article we explore some of the combinatorial consequences of recent results relating the isospectral commuting variety and the Hilbert scheme of points in the plane

    Anomalous Scaling of Structure Functions and Dynamic Constraints on Turbulence Simulations

    Get PDF
    The connection between anomalous scaling of structure functions (intermittency) and numerical methods for turbulence simulations is discussed. It is argued that the computational work for direct numerical simulations (DNS) of fully developed turbulence increases as Re4Re^{4}, and not as Re3Re^{3} expected from Kolmogorov's theory, where ReRe is a large-scale Reynolds number. Various relations for the moments of acceleration and velocity derivatives are derived. An infinite set of exact constraints on dynamically consistent subgrid models for Large Eddy Simulations (LES) is derived from the Navier-Stokes equations, and some problems of principle associated with existing LES models are highlighted.Comment: 18 page

    Comparison of least absolute shrinkage and selection operator and maximum likelihood estimators to establish determinants of immunization in Trans - Nzoia County

    Get PDF
    The client factors that influence under-five child guardian compliance to the immunization schedule are interlinked based on household characteristics, socioeconomic status, and maternal health practices. An incentive to motivate the mothers to prioritize their child’s health practices especially on vaccination, works perfectly towards the achievement of full immunization coverage. A randomly sampled study carried out within Weonia Location–Trans Nzoia County in March 2014 with target population of under-five children showed the vital role an incentive innovation plays towards immunization coverage. Multinomial logistic regression model was used to analyze the determinant of partial or none-immunized and the parameters estimated using the maximum likelihood estimator (MLE) and the shrinkage estimator-Least Absolute Shrinkage and Selection Operator (LASSO). The shrinkage estimator method gave a sparse model that was easy to interpret and increased the estimated predictability accuracy. Maternal health practices and access to a motivating intervention are significant factors that ensure a guardian’s compliance to their child immunization

    Strong Universality in Forced and Decaying Turbulence

    Full text link
    The weak version of universality in turbulence refers to the independence of the scaling exponents of the nnth order strcuture functions from the statistics of the forcing. The strong version includes universality of the coefficients of the structure functions in the isotropic sector, once normalized by the mean energy flux. We demonstrate that shell models of turbulence exhibit strong universality for both forced and decaying turbulence. The exponents {\em and} the normalized coefficients are time independent in decaying turbulence, forcing independent in forced turbulence, and equal for decaying and forced turbulence. We conjecture that this is also the case for Navier-Stokes turbulence.Comment: RevTex 4, 10 pages, 5 Figures (included), 1 Table; PRE, submitte

    Enhancing meat quality of weaned piglets with the dietary incorporation of Ulva lactuca and carbohydrases supplementation

    Get PDF
    Pubmed Free articleThe impact of the dietary incorporation of 7% Ulva lactuca, a green seaweed, on the quality and nutritional value of piglet’s meat was assessed. U. lactuca is rich in nutrients and bioactive compounds but its cell wall is composed of complex polysaccharides that reduce their bioavailability. Therefore, the effect of supplementing piglet diets with exogenous carbohydrases was also assessed here. A total of 40 male weaned piglets were divided into four dietary groups, each with 10 piglets: control (wheat, maize and soybean meal-based diet), UL (7% U. lactuca replacing the control diet), UL +R (UL and 0.005% Rovabio®), and UL +E (UL and 0.01% ulvan lyase). The piglets were fed the diets for 2 weeks. The results showed that incorporating U. lactuca in piglet diets did not influence most of the meat quality traits (P >0.05). However, the incorporation of U. lactuca with the commercial carbohydrase (UL +R) increased the amount of the docosahexaenoic acid (DHA; 22:6n-3) in their meat (P =0.011) compared with the control, by 54%. In addition, meat from piglets fed seaweed diets showed a nearly two-fold increase in iodine contents (P <0.001). Meat tenderness, juiciness and overall acceptability of piglets fed the control diet and the UL diet were lower than those fed the diets containing seaweed and carbohydrases (P <0.001). Overall, the findings indicate that 7% U. lactuca in the diets of weaned piglets had no major detrimental effects on meat quality and their carbohydrase supplementation has the potential to improve meat sensory traits.Funding: This research was funded by Fundação para a Ciência e a Tecnologia (FCT), Portugal, through PTDC/CAL-ZOO/30238/2017 grant, associated with a post-doc contract to M.C., and PhD fellowships to J.M. P. (SFRH/BPD/116816/2016) and D.M.R. (SFRH/BD/143992/2019). CIISA (UIDB/00276/2020), AL4AnimalS (LA/P/0059/2020) and LEAF (UIDB/04129/2020) grants, also from FCT, are also acknowledged. The authors acknowledge Teresa Costa from Indukern, Lda. (Sintra, Portugal), for the Rovabio® Excel AP kind donation. The graphical abstract was created using BioRender.com (https://biorender.com/).info:eu-repo/semantics/publishedVersio

    Multilevel analysis of factors associated with unmet need for family planning among Malawian women

    Get PDF
    Background: Malawi has a high fertility rate which is also characterized by a relatively high prevalence of unmet need for contraception. However, little is known about the influence of individual- and community- level characteristics on unmet need in Malawi. This study examined the individual- and community- level factors associated with unmet need for family planning (FP) among Malawian women. Methods: Data from the 2015–16 Malawi demographic and health survey were used to analyze 15, 931 women. The association between individual- and community- level factors and unmet need was assessed using multilevel binary logistic regression models. Results: The prevalence of total unmet need was 21.0%. Women aged ≥35 years were more likely to have total unmet need [adjusted odds ratio (aOR) = 1.19, 95% confidence interval (CI) = 1.04–1.35] compared with those aged 15–24 years. Women who were married [aOR = 0.41, 95% CI = 0.35–0.48], and those employed [aOR = 0.78, 95% CI = 0.71–0.85] were associated with less likelihood of having total unmet need compared with unmarried, and unemployed women, respectively. At community-level, women from communities with a high percentage of women from rich households [aOR = 0.81, 95% CI = 0.67–0.96], and those from communities with a middle and high percentage of educated women [aOR = 0.86, 95% CI = 0.76–0.96 and aOR = 0.81, 95% CI = 0.70–0.93, respectively] were less likely to have total unmet need for FP compared with those from communities with low percentages of rich and educated women, respectively. The proportional change in variance showed that about 36.0% of total variations in the odds of unmet need across the communities were explained by both individual- and community-level factors. Moreover, the intraclass correlation showed that about 3.0% of the total variation remained unexplained even after controlling for both individual- and community-level factors. Conclusion: Both individual- and community- level factors influenced unmet need for FP in Malawi. Public health practitioners should conduct community profiling and consider individual and community factors when designing FP programs

    Sequential design of computer experiments for the estimation of a probability of failure

    Full text link
    This paper deals with the problem of estimating the volume of the excursion set of a function f:RdRf:\mathbb{R}^d \to \mathbb{R} above a given threshold, under a probability measure on Rd\mathbb{R}^d that is assumed to be known. In the industrial world, this corresponds to the problem of estimating a probability of failure of a system. When only an expensive-to-simulate model of the system is available, the budget for simulations is usually severely limited and therefore classical Monte Carlo methods ought to be avoided. One of the main contributions of this article is to derive SUR (stepwise uncertainty reduction) strategies from a Bayesian-theoretic formulation of the problem of estimating a probability of failure. These sequential strategies use a Gaussian process model of ff and aim at performing evaluations of ff as efficiently as possible to infer the value of the probability of failure. We compare these strategies to other strategies also based on a Gaussian process model for estimating a probability of failure.Comment: This is an author-generated postprint version. The published version is available at http://www.springerlink.co

    Early surgery versus conservative treatment in patients with traumatic intracerebral hematoma:a CENTER-TBI study

    Get PDF
    Purpose: Evidence regarding the effect of surgery in traumatic intracerebral hematoma (t-ICH) is limited and relies on the STITCH(Trauma) trial. This study is aimed at comparing the effectiveness of early surgery to conservative treatment in patients with a t-ICH. Methods: In a prospective cohort, we included patients with a large t-ICH (&lt; 48 h of injury). Primary outcome was the Glasgow Outcome Scale Extended (GOSE) at 6 months, analyzed with multivariable proportional odds logistic regression. Subgroups included injury severity and isolated vs. non-isolated t-ICH. Results: A total of 367 patients with a large t-ICH were included, of whom 160 received early surgery and 207 received conservative treatment. Patients receiving early surgery were younger (median age 54 vs. 58 years) and more severely injured (median Glasgow Coma Scale 7 vs. 10) compared to those treated conservatively. In the overall cohort, early surgery was not associated with better functional outcome (adjusted odds ratio (AOR) 1.1, (95% CI, 0.6–1.7)) compared to conservative treatment. Early surgery was associated with better outcome for patients with moderate TBI and isolated t-ICH (AOR 1.5 (95% CI, 1.1–2.0); P value for interaction 0.71, and AOR 1.8 (95% CI, 1.3–2.5); P value for interaction 0.004). Conversely, in mild TBI and those with a smaller t-ICH (&lt; 33 cc), conservative treatment was associated with better outcome (AOR 0.6 (95% CI, 0.4–0.9); P value for interaction 0.71, and AOR 0.8 (95% CI, 0.5–1.0); P value for interaction 0.32). Conclusions: Early surgery in t-ICH might benefit those with moderate TBI and isolated t-ICH, comparable with results of the STITCH(Trauma) trial.</p
    corecore