Self-assembling behavior in decane solution of potential wax crystal nucleators based on poly(co-olefins)

The control of the precipitation and gelation of long chain paraffins from oil remains an enduring technological challenge regarding the processing and recovery of refined fuels and waxy crudes. Wax crystal modifiers based on polyethylene -poly(ethylene-propylene) (PE-PEP) diblock copolymers function as efficient nucleators for wax crystals in middle distillate fuels. These diblock polymers self-assemble in oil to form expansive platelike aggregates consisting of a PE core cloaked behind the amorphous PEP brush layer. The PE core thus promotes nucleation of solubilized long chain alkanes. Additional candidate structures for wax crystal nucleators include linear and star copolyolefins where the composition variation signals the alteration between crystalline and amorphous segments. This study focuses upon the self-assembling behavior in solution of these materials. The characteristics of the single chains and the aggregates formed at lower temperatures were determined via small-angle neutron scattering. Both plates and needlelike structures were found. The placement of the amorphous and crystalline blocks in the arms of the star shaped polymers was found to influence the architecture of the self-assembled micelles. As a point of comparison a commercial copolymer of ethylene-vinyl acetate (EVA) was also investigated. The EVA material was found to be relatively "undisciplined" in comparison to the structurally more uniform anionically prepared counterparts

Burden, causes, and outcomes of people with epilepsy admitted to a rural hospital in Kenya

Objective: People with epilepsy (PWE) develop complications and comorbidities often requiring admission to hospital, which adds to the burden on the health system, particularly in low-income countries. We determined the incidence, disability-adjusted life years (DALYs), risk factors, and causes of admissions in PWE. We also examined the predictors of prolonged hospital stay and death using data from linked clinical and demographic surveillance system. Methods: We studied children and adults admitted to a Kenyan rural hospital, between January 2003 and December 2011, with a diagnosis of epilepsy. Poisson regression was used to compute incidence and rate ratios, logistic regression to determine associated factors, and the DALY package of the R-statistical software to calculate years lived with disability (YLD) and years of life lost (YLL). Results: The overall incidence of admissions was 45.6/100,000 person-years of observation (PYO) (95% confidence interval [95% CI] 43.0–48.7) and decreased with age (p \u3c 0.001). The overall DALYs were 3.1/1,000 (95% CI, 1.8–4.7) PYO and comprised 55% of YLD. Factors associated with hospitalization were use of antiepileptic drugs (AEDs) (odds ratio [OR] 5.36, 95% CI 2.64–10.90), previous admission (OR 11.65, 95% CI 2.65–51.17), acute encephalopathy (OR 2.12, 95% CI 1.07–4.22), and adverse perinatal events (OR 2.87, 95% CI 1.06–7.74). Important causes of admission were epilepsy-related complications: convulsive status epilepticus (CSE) (38%), and postictal coma (12%). Age was independently associated with prolonged hospital stay (OR 1.02, 95% CI 1.00–1.04) and mortality (OR, 1.07, 95% CI 1.04–1.10). Significance: Epilepsy is associated with significant number of admissions to hospital, considerable duration of admission, and mortality. Improved supply of AEDs in the community, early initiation of treatment, and adherence would reduce hospitalization of PWE and thus the burden of epilepsy on the health system

Analysis of the UK Government's 2011 tourism policy

This review considers the UK Government's 2011 tourism policy document. The policy was produced during a period of public sector restructuring in the UK and also during the global economic crisis, which began in 2008. The policy sets out a number of reforms to the governance of tourism at the national and local levels, which aim to increase the level of private sector involvement in leading and developing the tourism sector and to reduce the sector's dependence on public funding. During a period of economic slowdown in the UK, the tourism industry can make a significant contribution to growth, but it is not yet clear whether these proposed reforms will support or impede the future development of the tourism industry in the UK

Resonance in Bose-Einstein condensate oscillation from a periodic variation in scattering length

Using the explicit numerical solution of the axially-symmetric Gross-Pitaevskii equation we study the oscillation of the Bose-Einstein condensate induced by a periodic variation in the atomic scattering length $a$. When the frequency of oscillation of $a$ is an even multiple of the radial or axial trap frequency, respectively, the radial or axial oscillation of the condensate exhibits resonance with novel feature. In this nonlinear problem without damping, at resonance in the steady state the amplitude of oscillation passes through maximum and minimum. Such growth and decay cycle of the amplitude may keep on repeating. Similar behavior is also observed in a rotating Bose-Einstein condensate.Comment: 14 REVTEX4 pages, 18 PS figures, final version Accepted in Journal of Physics

Is Lilongwe Technical College ready to manage an Electronic Library?

E-library is a relatively new concept in technical colleges in Malawi. Over the past three decades, Technical College libraries have been traditional in nature despite the world of information and communication is going through a period of supreme and accelerating transformations. To stay abreast with the latest changes in technologies, the Malawi’s technical educational institutes have now started adopting agile services such as e-libraries to utilize on the internet technology to provide a variety of information resources and services to the scholarly community. The e-library initiative at Lilongwe Technical College was championed by African Development Bank (AfDB) under Higher Education and Science Technology (HEST) Project with an overall goal of fusing Information Communication Technologies (ICTS) in information service delivery, as a basic ingredient for information availability, accessibility and dissemination. Being a new development at the college, a quantitative survey was instituted with the aim of exploring the readiness of Lilongwe Technical College (LTC) in managing such a digital archive as the e-library. Among other aspects, the study closely looked at what are the contents of an e-library, benefits of e-library initiatives in technical colleges, anticipated challenges and suggested solutions in managing the electronic library at LTC. A questionnaire with closed ended questions was used to elicit responses from purposively selected 9 participants (Library staff and ICT instructors/Technicians). The data collected were later analyzed using the Statistical Package for the Social Sciences (SPSS) version 20.0. The frequencies (f) and percentages (%) which were created using SPSS were then exported to MS Excel to produce charts and MS. Word to produce tables. Our findings revealed that library staff and ICT instructors/Technicians had little knowledge on the contents of an electronic library as they only indicated e-books as the major contents of an e-library. Saving storage space and 24/7 access to the library resources among others were the perceived benefits of an e-library initiative at the college. Finally, managing an electronic library at LTC will be associated with the following major challenges: inadequate government funding, poor state of ICT infrastructural development at the college, lack of laws, policies and strategies to guide the selection and acquisitions of e-resources, problems with long term preservation and access to e-resources; and copyright and licensing issues are of a great concern in a virtual environment. The study has set out strategies to counter deal with these challenges in order to answer the question: “is Lilongwe Technical College ready to manage an e-library?

The detection of Gravitational Waves

This chapter is concerned with the question: how do gravitational waves (GWs) interact with their detectors? It is intended to be a theory review of the fundamental concepts involved in interferometric and acoustic (Weber bar) GW antennas. In particular, the type of signal the GW deposits in the detector in each case will be assessed, as well as its intensity and deconvolution. Brief reference will also be made to detector sensitivity characterisation, including very summary data on current state of the art GW detectors.Comment: 33 pages, 12 figures, LaTeX2e, Springer style files --included. For Proceedings of the ERE-2001 Conference (Madrid, September 2001

Bridging Gender Disparities in Mathematics Achievement through Computer Based Learning

The purpose of this paper was to establish the influence of computer based learning (CBL) in Mathematics on learners’ achievement level in relation to gender. Specifically, the study sought to find out if there is any significant difference in achievement between boys and girls when exposed to CBL among secondary school students in Bungoma North District, Western Province, Kenya. This study was based on the theory of situated learning which states that learning as it normally occurs is a function of the activity, context and culture in which it occurs (Lave, 1988). The study adopted an experimental design where pre-test and post-test control group was used. The target population of the study was 1,173 form three secondary school students from Bungoma North District, Kenya. Purposive sampling was used to select schools with and without computers after which simple random sampling was used to select nine schools for the study. The study used a sample size of 240 respondents. Purposive sampling was used to select students who were computer literate then simple random sampling was applied to choose the respondents of the study. Mathematics achievement tests were used to collect data from the respondents. In data analysis both descriptive and inferential statistics were used. Descriptive statistics involved means, while inferential statistics utilized independent samples t-test. It was found out that there was no significant difference between boys and girls in Mathematics achievement when exposed to CBL. The paper therefore made the following recommendations: gender digital divide to be addressed, develop and use interactive Mathematics programmes, rural electrification to be continued, teachers to be equipped with the skills and knowledge they need to use the CBL technology, computer studies to be made compulsory in secondary schools. All this recommendations aim at bringing CBL into classroom to give every student, especially girls, a competitive edge in mathematics achievement. Keywords: Achievement, Bridging, Computer Based Learning, Gender Disparit

The Availability, Adequacy and Improvisation and the Use of Instructional Resources for Teaching Mathematics in Secondary Schools in West Pokot District, Kenya

This study examined the factors that influence the use of instructional resources/materials in the teaching of mathematics in secondary schools. Among the instructional materials that were investigated in their use are: Textbooks and mathematical tables. The study focused on their use in terms of their availability, adequacy and improvisation. The research design that was used in the study is descriptive survey. The research instruments included questionnaire, interview schedules and document analysis. The sampling techniques that were used in this research are stratified, simple random and purposive sampling. The respondents comprised 24 mathematics teachers and 372 form two students. Four teachers were interviewed. Data analysis was done by use of descriptive statistics. The study revealed that the selected instructional materials are not adequate. The main recommendations are that school administrators, teachers, students and parents should be sensitized on the importance of provision of instructional materials adequately. Keywords: Availability, Adequacy, Improvisation, Use and Instructional Resources (textbooks and mathematical tables)

Incidence and risk factors for neonatal tetanus in admissions to Kilifi County Hospital, Kenya.

BACKGROUND: Neonatal Tetanus (NT) is a preventable cause of mortality and neurological sequelae that occurs at higher incidence in resource-poor countries, presumably because of low maternal immunisation rates and unhygienic cord care practices. We aimed to determine changes in the incidence of NT, characterize and investigate the associated risk factors and mortality in a prospective cohort study including all admissions over a 15-year period at a County hospital on the Kenyan coast, a region with relatively high historical NT rates within Kenya. METHODS: We assessed all neonatal admissions to Kilifi County Hospital in Kenya (1999-2013) and identified cases of NT (standard clinical case definition) admitted during this time. Poisson regression was used to examine change in incidence of NT using accurate denominator data from an area of active demographic surveillance. Logistic regression was used to investigate the risk factors for NT and factors associated with mortality in NT amongst neonatal admissions. A subset of sera from mothers (n = 61) and neonates (n = 47) were tested for anti-tetanus antibodies. RESULTS: There were 191 NT admissions, of whom 187 (98%) were home deliveries. Incidence of NT declined significantly (Incidence Rate Ratio: 0.85 (95% Confidence interval 0.81-0.89), P<0.001) but the case fatality (62%) did not change over the study period (P = 0.536). Younger infant age at admission (P = 0.001) was the only independent predictor of mortality. Compared to neonatal hospital admittee controls, the proportion of home births was higher among the cases. Sera tested for antitetanus antibodies showed most mothers (50/61, 82%) had undetectable levels of antitetanus antibodies, and most (8/9, 89%) mothers with detectable antibodies had a neonate without protective levels. CONCLUSIONS: Incidence of NT in Kilifi County has significantly reduced, with reductions following immunisation campaigns. Our results suggest immunisation efforts are effective if sustained and efforts should continue to expand coverage