171 research outputs found

    Evaluation of factors influencing the performance of Kenyan Secondary School Students in English Grammar: A Case of Nyamaiya Division, Nyamira County, Kenya.

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    This study assessed the factors influencing the performance of secondary school students in English Grammar in Nyamaiya Division, Nyamira County. The study employed 31 public Secondary schools of which seventeen are day and fourteen are boarding schools. Sex was not a factor in the study. There were 150 respondents (31 head teachers, 31 deputies, 30 students and 58 teachers of English). Purposive and simple random sampling techniques were used in selecting the sample for the study. Five point likert type scale questionnaires were used to obtain data for the study. 150 questionnaires were administered to 150 respondents which covered the following areas: influence of mother tongue, problem areas in English grammar, academic and professional qualifications and experience of these teachers. The objectives were: to investigate the attitude secondary school students have towards English grammar, to find out how mother tongue impacts on learning English grammar in secondary schools, to establish the areas in English grammar that are problematic to students in secondary schools and to find out the academic and professional qualifications of teachers teaching English grammar to students in secondary schools. Teacher’s responses on attitude indicated that most of the students did not like English grammar. Regarding influence of mother tongue on performance in English grammar, the study showed that most of the students were influenced by mother tongue while others were not. On problem areas in English majority of the students experienced problems in the use of phrasal verbs and the use of auxiliaries. Other problems experienced are the use of punctuation marks, poor handwriting of the students and lack of practice in English. Majority of these teachers had degrees and some had KCSE certificates and very few had a master’s degree. Most of the sampled schools had not taught the subject for more than five years and some had taught the subject for more than 20 years. The data collected was analyzed by use of descriptive statistics and the chi – square test using the SPSS package. Recommendations based on the findings were made to guide policy makers to find appropriate ways to improve on performance in English grammar. Key words: evaluation, English Grammar, Nyamaiya Division, Nyamira Count

    Electrospray Deposition of Polyvinylidene Fluoride (PVDF) Microparticles: Impact of Solvents and Flow Rate

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    Polymeric microparticles have been shown to have great impacts in the area of drug delivery, biosensing, and tissue engineering. Electrospray technology, which provides a simple yet effective technique in the creation of microparticles, was utilized in this work. In addition, altering the electrospray experimental parameters such as applied voltage, flow rate, collector distance, solvents, and the polymer-solvent mixtures can result in differences in the size and morphology of the produced microparticles. The effects of the flow rate at (0.15, 0.3, 0.45, 0.6, 0.8, and 1 mL/h) and N, N-Dimethylformamide (DMF)/acetone solvent ratios (20:80, 40:60, 60:40, 80:20, 100:0 v/v) in the production of polyvinylidene fluoride (PVDF) microparticles were studied. Scanning electron microscopy (SEM) was used to observe changes in the morphology of the microparticles, and this revealed that a higher acetone to DMF ratio produces deformed particles, while flow rates at (0.3 and 0.45 mL/h) and a more optimized DMF to acetone solvent ratio (60:40 v/v) produced uniform spherical particles. We discovered from the Raman spectroscopy results that the electrosprayed PVDF microparticles had an increase in piezoelectric β phase compared to the PVDF pellet used in making the microparticles, which in its original form is α phase dominant and non-piezoelectric

    Biomechanics of Pharyngeal Deglutitive Function Following Total Laryngectomy

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    Copyright © 2016 American Academy of Otolaryngology—Head and Neck Surgery Foundation. Reprinted by permission of SAGE PublicationsObjective: Post-laryngectomy surgery, pharyngeal weakness and pharyngoesophageal junction (PEJ) restriction are the underlying candidate mechanisms of dysphagia. We aimed to determine, in laryngectomees whether: 1) hypopharyngeal propulsion is reduced and/or PEJ resistance is increased; 2) endoscopic dilatation improves dysphagia; and 3) if so, whether symptomatic improvement correlate with reduction in resistance to flow across the PEJ. Methods: Swallow biomechanics were assessed in 30 total laryngectomees. Average peak contractile pressure (hPP) and hypopharyngeal intrabolus pressure (hIBP) were measured from combined high resolution manometry and video-fluoroscopic recordings of barium swallows (2, 5&10ml). Patients were stratified into severe dysphagia (Sydney Swallow Questionnaire (SSQ)>500) and mild/nil dysphagia (SSQ≤500). In 5 patients, all measurements were repeated after endoscopic dilatation. Results: Dysphagia was reported by 87%, and 57% had severe and 43% had minor/nil dysphagia. Laryngectomees had lower hPP than controls (110±14mmHg vs 170±15mmHg; p<0.05), while hIBP was higher (29±5mmHg vs 6±5mmHg; p<0.05). There were no differences in hPP between patient groups. However, hIBP was higher in severe than in mild/nil dysphagia (41±10mmHg vs 13±3mmHg; p<0.05). Pre-dilation hIBP (R2=0.97) and its decrement following dilatation (R2=0.98) were good predictors of symptomatic improvement. Conclusion: Increased PEJ resistance is the predominant determinant of dysphagia as it correlates better with dysphagia severity than peak pharyngal contractile pressure. While both baseline PEJ resistance and its decrement following dilatation are strong predictors of outcome following dilatation, the peak pharyngeal pressure is not. PEJ resistance is vital to detect as it is the only potentially reversible component of dysphagia in this context

    Light intensity-induced phase transitions in graphene oxide doped polyvinylidene fluoride

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    The coupling of light with low-frequency functionalities of dielectrics and liquid crystals and an ability to turn “on” and “off” the pyro-, piezo-, or ferro- electric properties of materials on demand by optical means leads to fascinating science and device applications. Moreover, to achieve all-optical control in nano-circuits, the coupling of the light with mechanical degrees of freedom is highly desirable and has been elusive until recently. In this work, we report on the light intensity-induced structural phase transitions in graphene oxide doped piezoelectric polyvinylidene fluoride (PVDF) film observed by micro-Raman spectroscopy. Increasing the laser power results in a steady transformation of the Raman spectrum featured piezoelectric phase to one of non-piezoelectric structure. This effect is accompanied by volumetric change of a PVDF unit cell by a factor of two, useful for a photostriction materials application. Furthermore, we observed the reversible switching of α and phases as a function of the light intensity (laser power between 5.7–31.3 mW). This opens up a new route for multi-functionality control where strain, piezoelectric constants and polarization can be modified by light

    Follow-up study to assess the use and performance of household filters in Zambia.

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    Effective household water treatment can improve drinking water quality and prevent disease if used correctly and consistently over time. One year after completion of a randomized controlled study of water filters among households in Zambia with children < 2 years old and mothers who were human immunodeficiency virus (HIV)-positive, we conducted a follow-up study to assess use and performance of new filters distributed at the conclusion of the study; 90% of participating households met the criteria for current users, and 75% of participating households had stored water with lower levels of fecal contamination than source water. Microbiologically, the filters continued to perform well, removing an average of 99.0% of fecal indicator bacteria. Although this study provides some encouraging evidence about the potential to maintain high uptake and filter performance, even in the absence of regular household visits, additional research is necessary to assess whether these results can be achieved over longer periods and with larger populations

    Treatment delays in children and young adults with lymphoma: report from an East Africa Lymphoma Cohort Study

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    Background: Affordable treatments for lymphoma from the WHO's essential medicine list are available in low-income settings. However, precise diagnosis is often lacking and prolonged time to diagnosis and treatment results in poor treatment outcomes. So far, a detailed analysis of the root causes of the treatment delay is lacking. Methods: This prospective cohort study was conducted at three tertiary cancer hospitals in Tanzania and one cancer centre, St. Mary's Hospital-Lacor Hospital, in Northern Uganda. The study included patients with a confirmed diagnosis of lymphoma. The primary outcome was the median total treatment delay and its components. Total treatment delay was defined as the time taken from the onset of symptoms to receiving definitive cancer treatment. Results: The median age of patients was 12 years (IQR 9-18), and 100 (68%) were males. The median Total Treatment Delay for the entire cohort was 124 days (95% CI 107 - 136). Not started treatment probability for the entire cohort was 64% (95% CI 56-72) at 90 days and 30% (24 - 39) at 180 days. The median Total Treatment Delay for Burkitt lymphoma was 91 days (95% CI 80 - 115), while for DLBCL and Hodgkin lymphoma, it was 114 days (95% CI 84 - 148) and 232 days (95% CI 179 - 305), respectively. Conclusion: Significant treatment delay for lymphoma patients emanates from healthcare system-related factors. Due to delays in referrals from primary care and lack of capacity of pathology in secondary care, initial treatment decisions are still often based on clinical suspicion and urgency

    Taphonomic and zooarchaeological investigations at the middle Pleistocene site of Ti's al Ghadah, western Nefud Desert, Saudi Arabia

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    In recent years, the Arabian Peninsula has emerged as a key region for elucidating hominin and faunal evolution and dispersals between Africa and Eurasia. Central to this research is the middle Pleistocene site of Ti's al Ghadah (TAG) which has yielded a diverse and abundant fossil faunal assemblage and the earliest chronometrically dated evidence for hominins in this part of the world. Here, we present the first detailed taphonomic study of the large Unit 5 fossil assemblage from the site. We aim to assess which actor/s were responsible for the accumulation of the assemblage and evaluate evidence that might be consistent with the accumulation of fauna by hominins. We also describe, for the first time, fossils and lithic artefacts from stratigraphic horizons not previously considered, providing taphonomic insights into their accumulation. The taphonomic work shows that the Unit 5 faunal assemblage was accumulated by ambush predators, likely large felids and hominins, in a lake side environment, and that carcasses were subsequently scavenged by more durophagus carnivores such as hyenas and canids. Less can be reliably said regarding the newly described fossil assemblages given their poor preservation and significant wind abrasion, but large carnivores again appear to have played a role, and hominins probably played a role in the accumulation of at least one of these. This study provides the first detail insights into the interplay between hominins, carnivores, and herbivores in Arabia, and suggests that watering holes have been a focus on the Arabian landscape for resources since the middle Pleistocene

    Trends in malaria morbidity following the introduction of artesunate plus amodiaquine combination in M'lomp village dispensary, south-western Senegal

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    BACKGROUND: In Thailand, South Africa and Zanzibar, a decrease in malaria morbidity was observed following the introduction of artemisinin-based combination therapy (ACT). In Senegal, therapeutic trials supervised the in vivo efficacy of artesunate plus amodiaquine from 1999 to 2005 at the M'lomp village dispensary. The trends in malaria morbidity in this village were evaluated from 2000 to 2002. METHODS: Each year, between July and December inclusive, fevers treated with antimalarials and slide-proven, uncomplicated malaria cases were collected from dispensary health records. Data were also collected in 1998, just prior to ACT introduction. Pearson's chi square tests and Student tests were used to compare two percentages or two means respectively (alpha = 0.05). RESULTS: Between 1998 and 2002, the total number of fevers treated with antimalarials and their repetitiveness progressively decreased: From 2824 to 945 fevers and from 17.6% to 9.7% (RR1998-2002 = 0.55; [0.44-0.69]; p < 0.0001) respectively. Considering uncomplicated malaria cases only, a decrease was observed in their total number between 2001 and 2002, from 953 to 570 cases. The incidence rate and repetitiveness also decreased. The incidence rate fell from 46.1% in 2001 to 37.5% in 2002 (p < 0.0001) and the repetitiveness decreased from 13.0% in 2000 to 6.6% in 2002 (RR2000-2002 = 0.51; [0.35-0.72]; p = 0.0001). CONCLUSION: The percentage of uncomplicated malaria cases treated with ACT increased, from 18.9% in 2000 to 64.0% in 2002, making it tempting to conclude an impact on malaria morbidity. Nonetheless, the decline in incidence rate of uncomplicated malaria was slight and a lower recorded rainfall was reported in 2002 which could also explain this decline. The context in which ACT is introduced affects the impact on malaria morbidity. In M'lomp, in contrast to studies in Thailand, South Africa and Zanzibar, ACT coverage of malaria cases was low and no vector control measure was deployed. Moreover, the malaria transmission level is higher. In sub-Saharan countries, in order to optimize the impact on malaria morbidity, ACT deployment must be supported, on the one hand, by a strengthening of public health system to ensure a high ACT coverage and, on the other hand, by others measures, such vector control measures

    The Ď•6 Cystovirus Protein P7 Becomes Accessible to Antibodies in the Transcribing Nucleocapsid: A Probe for Viral Structural Elements

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    Protein P7 is a component of the cystovirus viral polymerase complex. In the unpackaged procapsid, the protein is situated in close proximity to the viral directed RNA polymerase, P2. Cryo-electron microscopy difference maps from the species ϕ6 procapsid have demonstrated that P7 and P2 likely interact prior to viral RNA packaging. The location of P7 in the post-packaged nucleocapsid (NC) remains unknown. P7 may translocate closer to the five-fold axis of a filled procapsid but this has not been directly visualized. We propose that monoclonal antibodies (Mabs) can be selected that serve as probe- reagents for viral assembly and structure. A set of Mabs have been isolated that recognize and bind to the ϕ6 P7. The antibody set contains five unique Mabs, four of which recognize a linear epitope and one which recognizes a conformational epitope. The four unique Mabs that recognize a linear epitope display restricted utilization of Vκ and VH genes. The restricted genetic range among 4 of the 5 antibodies implies that the antibody repertoire is limited. The limitation could be the consequence of a paucity of exposed antigenic sites on the ϕ6 P7 surface. It is further demonstrated that within ϕ6 nucleocapsids that are primed for early-phase transcription, P7 is partially accessible to the Mabs, indicating that the nucleocapsid shell (protein P8) has undergone partial disassembly exposing the protein’s antigenic sites
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