Achievable efficiencies for probabilistically cloning the states

We present an example of quantum computational tasks whose performance is enhanced if we distribute quantum information using quantum cloning. Furthermore we give achievable efficiencies for probabilistic cloning the quantum states used in implemented tasks for which cloning provides some enhancement in performance.Comment: 9 pages, 8 figure

Balancing socio-Economic and Academic Needs: A case of Higher Education Graduate Students.

The need to pursue higher degrees to meet job demands, while at the same time working for social obligations, can be quite challenging. This is especially so when such students have to pay their tuition privately. This paper is based on the findings of a study done among students on masters programs in higher education at Makerere University in 2008. It reports some of the challenges graduate students face as they struggle to attain higher degree qualifications needed in order to secure better jobs, gain promotion, or toretain their jobs at their current places of work. Specifically, it reports some of the risks students take while looking for additional funds to pay university fees; while at the same time sustaining families and other social economic obligations. A lot of study time is lost in various activities students engage in to realize the needed funds, a fact that could have adverse effects on the quality of their study performance

Prevalence of Hypertension and Associated Factors in Bedele Town, Southwest Ethiopia

Background: Hypertension is the leading cause of death in the world and is the commonest cause for outpatient visits to physicians. The objective of this study was to assess the prevalence of hypertension and its risk factors among adults in Bedele Town, South-west Ethiopia.Method: A community-based cross-sectional survey was conducted by interviewing participants regarding their socio-demographic characteristics, history of hypertension, its risk factors and knowledge of its complications and treatment. Measurements of their blood pressure, body weight, height, and waist circumferences were also done on the same day. The data were analyzed using SPSS Version 16 statistical software. Chi-square test and odds ratio with 95% CI were used to assess the association between dependent and independent variables. Logistic regression model was used to determine the independent risk factors for hypertension. P-values of < 0.05 were considered statistically significant.Results: A total of 396 adults of whom 67.4% were males participated in the study. Prevalence of hypertension, defined as systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥ 90 mmHg or reported use of anti-hypertensive medication, was 16.9%. However, only 44.8% of those with hypertension were aware of their status, and the overall control rate of hypertension was only 22.4%. Only age and waist circumference were found to be independent predictors of hypertension in the community.Conclusion: Hypertension was found to be prevalent in the community. However, the respondents’ awareness about the problem and the overall control rates were very low. Activities targeted at increasing awareness of hypertension in the community and its risk reduction are very important for intervention. There should also be a national strategy for early detection and treatment of hypertension and related cardiovascular diseases.Keywords: Hypertension, Cardiovascular disease, Ethiopi

Quantum field theoretic approach to neutrino oscillations in matter

We consider neutrino oscillations in non-uniform matter in a quantum field theoretic (QFT) approach, in which neutrino production, propagation and detection are considered as a single process. We find the conditions under which the oscillation probability can be sensibly defined and demonstrate how the properly normalized oscillation probability can be obtained in the QFT framework. We derive the evolution equation for the oscillation amplitude and discuss the conditions under which it reduces to the standard Schr\"odinger-like evolution equation. It is shown that, contrary to the common usage, the Schr\"odinger-like evolution equation is not applicable in certain cases, such as oscillations of neutrinos produced in decays of free pions provided that sterile neutrinos with $\Delta m^2\gtrsim 1$ eV$^2$ exist.Comment: LaTeX, 24 pages + 16 pages of appendices, 1 figure. V2: typos correcte

Long-Distance Wind-Dispersal of Spores in a Fungal Plant Pathogen: Estimation of Anisotropic Dispersal Kernels from an Extensive Field Experiment

Given its biological significance, determining the dispersal kernel (i.e., the distribution of dispersal distances) of spore-producing pathogens is essential. Here, we report two field experiments designed to measure disease gradients caused by sexually- and asexually-produced spores of the wind-dispersed banana plant fungus Mycosphaerella fijiensis. Gradients were measured during a single generation and over 272 traps installed up to 1000 m along eight directions radiating from a traceable source of inoculum composed of fungicide-resistant strains. We adjusted several kernels differing in the shape of their tail and tested for two types of anisotropy. Contrasting dispersal kernels were observed between the two types of spores. For sexual spores (ascospores), we characterized both a steep gradient in the first few metres in all directions and rare long-distance dispersal (LDD) events up to 1000 m from the source in two directions. A heavy-tailed kernel best fitted the disease gradient. Although ascospores distributed evenly in all directions, average dispersal distance was greater in two different directions without obvious correlation with wind patterns. For asexual spores (conidia), few dispersal events occurred outside of the source plot. A gradient up to 12.5 m from the source was observed in one direction only. Accordingly, a thin-tailed kernel best fitted the disease gradient, and anisotropy in both density and distance was correlated with averaged daily wind gust. We discuss the validity of our results as well as their implications in terms of disease diffusion and management strategy

Towards designing robust coupled networks

Natural and technological interdependent systems have been shown to be highly vulnerable due to cascading failures and an abrupt collapse of global connectivity under initial failure. Mitigating the risk by partial disconnection endangers their functionality. Here we propose a systematic strategy of selecting a minimum number of autonomous nodes that guarantee a smooth transition in robustness. Our method which is based on betweenness is tested on various examples including the famous 2003 electrical blackout of Italy. We show that, with this strategy, the necessary number of autonomous nodes can be reduced by a factor of five compared to a random choice. We also find that the transition to abrupt collapse follows tricritical scaling characterized by a set of exponents which is independent on the protection strategy

Awareness and experience in needle stick injuries among dental students at the University of Nairobi, Dental Hospital

Background: Needle stick injuries (NSI) are the commonest route by which blood borne viruses and/or infections such as HIV, Hepatitis B and C are transmitted from patients to health care workers (HCW). Dental students are also at risk of such infections and injuries due to accidental contamination during their practical occupational exposure. There is hardly any information regarding the knowledge and experiences of NSI among dental students in Kenya.Objective: To determine the knowledge and experiences of NSI among dental students at the University of Nairobi Dental Hospital (UONDH).Design: Descriptive cross-sectional study.Setting: University of Nairobi Dental Hospital premises. The population included undergraduate and postgraduate dental students pursuing their degrees at the university.Results: Seventy two questionnaires were issued and a response rate of 62(81%) was achieved. The age of the respondents ranged from 21-35 years with a mean age of 24 years (SD± 4.7) years. There were 33(53%) males and 29(47%) females. Most of the students were undergraduates (87%) while the rest were postgraduate students (13%). The majority (97%) of the respondents reported that NSI was a means of cross-infection. Only 29% of the respondents had suffered NSI. Of those who had suffered NSI, 36% of the incidents occurred when administering local anaesthesia, while 23% were during scaling, 18% when recapping needles, 18% while clearing up and 5% when suturing. Only seven of those who had suffered NSI (39%) had reported of NSI. The reasons for not reporting were: fear of stigmatisation (25%) or the fear of consequences of crossinfection (38%). All the respondents who had experienced NSI were undergraduates with no statistical significant difference between the undergraduate and postgraduate students (X2=3.758, p=0.052). Among the respondents who had experienced NSI, nine were males and nine were females with no statistical significance between the two genders (X2=0.106, p=0.48l). All the respondents recorded inadequate knowledge on the modes of prevention of NSI. Less than half (27%) of the respondents had accurate knowledge on the procedure followed in case of NSI. Only 27% of the respondents had taken post-exposure prophylaxis (PEP) after suffering NSI with no statistically significant difference between males and females (X2=44, p=0.108).Conclusion: Although the level of knowledge on the risk of cross-infection from NSI was high, there was decreased awareness on the means of prevention and protocol