Ultrasonic wave propagation in cylindrical vessels and implications for ultrasonic reactor design

Reactors in which processes are enhanced by ultrasound are hampered by the lack of a theoretical framework on their design. Simulation results of ultrasonic wave propagation in a cylindrical geometry are presented in this work, which are then used to develop guidelines for the design of ultrasonic reactors. These guidelines are used to design a new type of reactor with a novel geometry, operating at a frequency of 27kHz, 39kHz and 82kHz. This reactor is characterized using Weissler's reaction dosimetr

Protocol: Precision engineering of plant gene loci by homologous recombination cloning in Escherichia coli.

© 2005 Roden et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Plant genome sequence data now provide opportunities to conduct molecular genetic studies at the level of the whole gene locus and above. Such studies will be greatly facilitated by adopting and developing further the new generation of genetic engineering tools, based on homologous recombination cloning in Escherichia coli, which are free from the constraints imposed by the availability of suitably positioned restriction sites. Here we describe the basis for homologous recombination cloning in E. coli, the available tools and resources, together with a protocol for long range cloning and manipulation of an Arabidopsis thaliana gene locus, to create constructs coordinately driven by locus-specific regulatory elements.Peer reviewe

A new RNASeq-based reference transcriptome for sugar beet and its application in transcriptome-scale analysis of vernalization and gibberellin responses.

BACKGROUND: Sugar beet (Beta vulgaris sp. vulgaris) crops account for about 30% of world sugar. Sugar yield is compromised by reproductive growth hence crops must remain vegetative until harvest. Prolonged exposure to cold temperature (vernalization) in the range 6 °C to 12 °C induces reproductive growth, leading to bolting (rapid elongation of the main stem) and flowering. Spring cultivation of crops in cool temperate climates makes them vulnerable to vernalization and hence bolting, which is initiated in the apical shoot meristem in processes involving interaction between gibberellin (GA) hormones and vernalization. The underlying mechanisms are unknown and genome scale next generation sequencing approaches now offer comprehensive strategies to investigate them; enabling the identification of novel targets for bolting control in sugar beet crops. In this study, we demonstrate the application of an mRNA-Seq based strategy for this purpose. RESULTS: There is no sugar beet reference genome, or public expression array platforms. We therefore used RNA-Seq to generate the first reference transcriptome. We next performed digital gene expression profiling using shoot apex mRNA from two sugar beet cultivars with and without applied GA, and also a vernalized cultivar with and without applied GA. Subsequent bioinformatics analyses identified transcriptional changes associated with genotypic difference and experimental treatments. Analysis of expression profiles in response to vernalization and GA treatment suggested previously unsuspected roles for a RAV1-like AP2/B3 domain protein in vernalization and efflux transporters in the GA response. CONCLUSIONS: Next generation RNA-Seq enabled the generation of the first reference transcriptome for sugar beet and the study of global transcriptional responses in the shoot apex to vernalization and GA treatment, without the need for a reference genome or established array platforms. Comprehensive bioinformatic analysis identified transcriptional programmes associated with different sugar beet genotypes as well as biological treatments; thus providing important new opportunities for basic scientists and sugar beet breeders. Transcriptome-scale identification of agronomically important traits as used in this study should be widely applicable to all crop plants where genomic resources are limiting.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Tuberculosis treatment delays and associated factors within the Zimbabwe national tuberculosis programme.

BACKGROUND: Delayed presentation of pulmonary TB (PTB) patients for treatment from onset of symptoms remains a threat to controlling individual disease progression and TB transmission in the community. Currently, there is insufficient information about treatment delays in Zimbabwe, and we therefore determined the extent of patient and health systems delays and their associated factors in patients with microbiologically confirmed PTB. METHODS: A structured questionnaire was administered at 47 randomly selected health facilities in Zimbabwe by trained health workers to all patients aged ≥18 years with microbiologically confirmed PTB who were started on TB treatment and entered in the health facility TB registers between 01 January and 31 March 2013. Multivariate logistic regression was used to calculate adjusted odds ratios (aOR) and 95% confidence intervals (CIs) for associations between patient/health system characteristics and patient delay >30 days or health system delay >4 days. RESULTS: Of the 383 recruited patients, 211(55%) were male with an overall median age of 34 years (IQR, 28-43). There was a median of 28 days (IQR, 21-63) for patient delays and 2 days (IQR, 1-5) for health system delays with 184 (48%) and 118 (31%) TB patients experiencing health system delays >30 days and health system delays >4 days respectively. Starting TB treatment at rural primary healthcare vs district/mission facilities [aOR 2.70, 95% CI 1.27-5.75, p = 0.01] and taking self-medication [aOR 2.33, 95% CI 1.23-4.43, p = 0.01] were associated with encountering patient delays. Associated with health system delays were accessing treatment from lower level facilities [aOR 2.67, 95% CI 1.18-6.07, p = 0.019], having a Gene Xpert TB diagnosis [aOR 0.21, 95% CI 0.07-0.66, p = 0.008] and >4 health facility visits prior to TB diagnosis [(aOR) 3.34, 95% CI 1.11-10.03, p = 0.045]. CONCLUSION: Patient delays were longer and more prevalent, suggesting the need for strategies aimed at promoting timely seeking of appropriate medical consultation among presumptive TB patients. Health system delays were uncommon, suggesting a fairly efficient response to microbiologically confirmed PTB cases. Identified risk factors should be explored further and specific strategies aimed at addressing these factors should be identified in order to lessen patient and health system delays

Zimbabwe's Drought Conundrum: vulnerability and coping in Buhera and Chikomba districts

Faced with an increasing frequency of droughts, the local communities of Buhera and Chikomba are constantly at risk of food insecurity and water stress due to their dependence upon rain-fed agriculture. This study employed semi-structured questionnaires, interviews with key informants, observations and media monitoring in a mixed research methods approach. It was conducted in order to assess the people’s degrees of vulnerability to drought impacts, and to review their survival mechanisms and adaptive strategies. The introductory chapter briefly reviews the country’s agricultural sector and the internationally politicised land question so as to contextualise the study, and introduces the vulnerability concepts and theoretical approaches used in the research. Some state policies were found to have actually contributed to the vulnerability of the people in the communities. The country has not maintained a national strategic grain reserve since the late 1990s and its focus on cash crops created a near-monoculture of maize, a crop variety that is vulnerable to moisture fluctuations. The economic challenges and the violent political environment of 2008 contributed to food shortages and the closure of a majority of rural shops. Some humanitarian organisations inadvertently worsened households’ vulnerability to drought impacts through ill-informed screening methods and flawed relief aid targeting. Increased morbidity and school dropouts, the lowering of the water table and an upsurge in livestock and grain thefts were among the effects of droughts experienced in Buhera and Chikomba. Wild fruits and relief aid became alternative food sources. The study revealed that the people in these communities were not passive victims in the face of a disaster; instead, they were enterprising and innovative, and employed their indigenous knowledge systems to predict weather patterns in the absence of conventional modern weather predictions. The local communities developed mitigation strategies to protect themselves against the climatic exigencies, despite their difficult conditions. The study concludes with some recommendations largely developed from suggestions by informants in the communities and representatives of the NGOs and government departments, as well as ideas based upon the broader literature on droughts

Surface structure and solidification morphology of aluminum nanoclusters

Classical molecular dynamics simulation with embedded atom method potential had been performed to investigate the surface structure and solidification morphology of aluminum nanoclusters Aln (n = 256, 604, 1220 and 2048). It is found that Al cluster surfaces are comprised of (111) and (001) crystal planes. (110) crystal plane is not found on Al cluster surfaces in our simulation. On the surfaces of smaller Al clusters (n = 256 and 604), (111) crystal planes are dominant. On larger Al clusters (n = 1220 and 2048), (111) planes are still dominant but (001) planes can not be neglected. Atomic density on cluster (111)/(001) surface is smaller/larger than the corresponding value on bulk surface. Computational analysis on total surface area and surface energies indicates that the total surface energy of an ideal Al nanocluster has the minimum value when (001) planes occupy 25% of the total surface area. We predict that a melted Al cluster will be a truncated octahedron after equilibrium solidification.Comment: 22 pages, 6 figures, 34 reference

Disability Grant and Individual Labour Force Participation: The Case of South Africa

Despite the explosive growth in the number of people receiving disability benefits in South Africa, very little is known about the labour supply effects of the disability grant (DG). This study investigates the impact of disability grant receipt on labour force participation. Consideration is given to potential bias that may arise from unobserved confounding factors

Factors Associated with Ever Being HIV-Tested in Zimbabwe: An Extended Analysis of the Zimbabwe Demographic and Health Survey (2010-2011).

INTRODUCTION: Zimbabwe has a high human immunodeficiency virus (HIV) burden. It is therefore important to scale up HIV-testing and counseling (HTC) as a gateway to HIV prevention, treatment and care. OBJECTIVE: To determine factors associated with being HIV-tested among adult men and women in Zimbabwe. METHODS: Secondary analysis was done using data from 7,313 women and 6,584 men who completed interviewer-administered questionnaires and provided blood specimens for HIV testing during the Zimbabwe Demographic and Health Survey (ZDHS) 2010-11. Factors associated with ever being HIV-tested were determined using multivariate logistic regression. RESULTS: HIV-testing was higher among women compared to men (61% versus 39%). HIV-infected respondents were more likely to be tested compared to those who were HIV-negative for both men [adjusted odds ratio (AOR) = 1.53; 95% confidence interval (CI) (1.27-1.84)] and women [AOR = 1.42; 95% CI (1.20-1.69)]. However, only 55% and 74% of these HIV-infected men and women respectively had ever been tested. Among women, visiting antenatal care (ANC) [AOR = 5.48, 95% CI (4.08-7.36)] was the most significant predictor of being tested whilst a novel finding for men was higher odds of testing among those reporting a sexually transmitted infection (STI) in the past 12 months [AOR = 1.86, 95%CI (1.26-2.74)]. Among men, the odds of ever being tested increased with age ≥ 20 years, particularly those 45-49 years [AOR = 4.21; 95% CI (2.74-6.48)] whilst for women testing was highest among those aged 25-29 years [AOR = 2.01; 95% CI (1.63-2.48)]. Other significant factors for both sexes were increasing education level, higher wealth status and currently/formerly being in union. CONCLUSIONS: There remains a high proportion of undiagnosed HIV-infected persons and hence there is a need for innovative strategies aimed at increasing HIV-testing, particularly for men and in lower-income and lower-educated populations. Promotion of STI services can be an important gateway for testing more men whilst ANC still remains an important option for HIV-testing among pregnant women

The Effectiveness of Joint Community-Police Partnership in Crystal, Minnesota: A Case Study of Stakeholders Experiences

This qualitative research study primarily explored the lived experiences of police officers and community members at Crystal, Minnesota. The primary purpose was to evaluate and assess the role of the Joint Community-Police Partnership (JCPP) program in the effective building of communication, understanding of cultures, and mutual trust between law enforcement officers and multi-cultural communities. The researcher conducted the study on a wide range of participants from different cultural backgrounds who work, live, worship, or study in Crystal. The research question focused on how police officers and citizens perceive the impact of JCPP strategies in enhancing communication, understanding cultures, and mutual trust. The data collected used a combination of convenience and a purposive sample of eight police officers and ten residents/community members who participated in a qualitative survey and virtual (zoom) interviews. Data were inductively coded and subjected to thematic analysis. Key findings revealed police officers and community members believe JCPP strategies have increased police visibility, improved the level of engagement in a meaningful dialogue, and created awareness of cultures between police and residents. In addition, it has improved community trust and public support with crime, safety, transparency, and accountability. Also, findings revealed that participants believe JCPP has achieved removing barriers to community collaboration with law enforcement. Finally, the participants proposed developing a strategy or goal in the JCPP program to focus on community representation. Meaning participants would like to see more community members are getting represented, which they believe can increase the level of trust between police officers and community members. The results of this study contribute to a positive social change by offering practical strategies for stakeholders in Crystal, Minnesota, to foster collaborative relationships between police officers and community members

African Women and Education: Vision, Myth, and Reality

Zimbabwe, which seemed on the verge of a breakthrough on rights of women just fifteen years ago, was set back by an April unanimous decision of its Supreme Court that adult females are inherently inferior to males and have a status akin to that of a teenager. The court cited ‘the nature of African society’ as its basis