Internuclear gene silencing in Phytophthora infestans is established through chromatin remodelling

In the plant pathogen Phytophthora infestans, nuclear integration of inf1 transgenic DNA sequences results in internuclear gene silencing of inf1. Although silencing is regulated at the transcriptional level, it also affects transcription from other nuclei within heterokaryotic cells of the mycelium. Here we report experiments exploring the mechanism of internuclear gene silencing in P. infestans. The DNA methylation inhibitor 5-azacytidine induced reversion of the inf1-silenced state. Also, the histone deacetylase inhibitor trichostatin-A was able to reverse inf1 silencing. inf1-expression levels returned to the silenced state when the inhibitors were removed except in non-transgenic inf1-silenced strains that were generated via internuclear gene silencing, where inf1 expression was restored permanently. Therefore, inf1-transgenic sequences are required to maintain the silenced state. Prolonged culture of non-transgenic inf1-silenced strains resulted in gradual reactivation of inf1 gene expression. Nuclease digestion of inf1-silenced and non-silenced nuclei showed that inf1 sequences in silenced nuclei were less rapidly degraded than non-silenced inf1 sequences. Bisulfite sequencing of the endogenous inf1 locus did not result in detection of any cytosine methylation. Our findings suggest that the inf1-silenced state is based on chromatin remodelling

Pesticidal Effects of Extracts from Hyptis suaveolens and Hyptis spicigera on Cowpea Weevils

This experimental research was conducted with the view of determining the effectiveness of Hyptis suaveolens and Hyptis spicigera extracts on cowpea seeds in deterring the feeding habit and life span of cowpea weevils. Masses of 400 and 500 grammes of pulverized samples of the two plants, Hyptis suaveolens and Hyptis spicigera were separately extracted by percolation with 2200 millilitres of 95% ethanol respectively. The percolates were evaporated to dryness at room temperature to give crude extracts of both plants which were each subjected to a partition process. Soluble solvent extracts of the two plants were applied on cowpea seeds and subjected to cowpea weevils by two-choice feeding deterrent method. The chloroform soluble extracts were found to be most active extracts of both plants with the least percentage consumption indices and higher percentage mortalities. This was a clear indication that these chloroform soluble extracts contained most of the toxic component(s) of the plants which can be used to protect cowpea seeds to some period of time. The study tasks the Ministry of Food and Agriculture to consider providing funding and further research into the use of the pesticides from these plant extracts to maintain the buoyancy of biodiversity as well as the environment in Ghana

Covert contraceptive use among women attending a reproductive health clinic in a municipality in Ghana.

BACKGROUND: Covert contraceptive use (CCU) in sub-Saharan Africa is an indication of women's inability to exercise autonomy in their reproductive choices. The aim of this study was to assess the prevalence and determinants of CCU among a sample of FP clients in a municipality of Ghana. METHODS: We conducted a mixed method study among women attending a public reproductive health clinic in Sunyani, a city of over 250,000 inhabitants in Ghana. An initial survey inquired into sociodemographic characteristics, use of family planning (FP) methods and partner awareness of contraceptive use. The predictors of CCU were explored using logistic regressions. We used the findings to develop a guide which we applied in-depth interviews and focus group discussions with attendants at the same facility. Qualitative data analysis was conducted using a framework approach. RESULTS: We interviewed 300 women, 48 % of whom were aged between 26-33 years. The injectable was the most widely used method (56 %). The prevalence of CCU was 34 %. In multivariate analysis, single women were more likely to practice CCU than married or co-habiting women (Adjusted OR = 12.12, 95 % C.I. 4.73-31.1). Muslim and traditionalist women were similarly more likely to practice CCU than non-Muslim, non-traditionalist (Adjusted OR = 4.56, 2.29-9.06). Women who preferred to have their first or next child in 4 or more years from the time of the interview were more likely to be in CCU than women who intended to have children within 4 years of the interview (2.57; 1.37-4.83). Single women saw in covert use a statement of their social autonomy. To succeed in CCU, women wished that clinic attendance cards would not be given to them to keep at home. Though many participants saw in CCU a source of anxiety, they expected health workers to consider it and uphold confidentiality in the provision of services. CONCLUSIONS: Covert contraceptive use was high in this municipality and being single was the strongest predictor of the practice. Providers of FP services should reflect on how to adequately address the challenges faced by women who practice CCU

Is diversity good?

Prominent ethical and policy issues such as affirmative action and female enrollment in science and engineering revolve around the idea that diversity is good. However, even though diversity is an ambiguous concept, a precise definition is seldom provided. We show that diversity may be construed as a factual description, a craving for symmetry, an intrinsic good, an instrumental good, a symptom, or a side effect. These acceptions differ vastly in their nature and properties. The first one cannot lead to any action and the second one is mistaken. Diversity as intrinsic good is a mere opinion, which cannot be concretely applied; moreover, the most commonly invoked forms of diversity (sexual and racial) are not intrinsically good. On the other hand, diversity as instrumental good can be evaluated empirically and can give rise to policies, but these may be very weak. Finally, symptoms and side effects are not actually about diversity. We consider the example of female enrollment in science and engineering, interpreting the various arguments found in the literature in light of this polysemy. Keywords: ethics, policy, higher education, female students, minority students, affirmative actionComment: 7 page

Eureka and beyond: mining's impact on African urbanisation

This collection brings separate literatures on mining and urbanisation together at a time when both artisanal and large-scale mining are expanding in many African economies. While much has been written about contestation over land and mineral rights, the impact of mining on settlement, notably its catalytic and fluctuating effects on migration and urban growth, has been largely ignored. African nation-states’ urbanisation trends have shown considerable variation over the past half century. The current surge in ‘new’ mining countries and the slow-down in ‘old’ mining countries are generating some remarkable settlement patterns and welfare outcomes. Presently, the African continent is a laboratory of national mining experiences. This special issue on African mining and urbanisation encompasses a wide cross-section of country case studies: beginning with the historical experiences of mining in Southern Africa (South Africa, Zambia, Zimbabwe), followed by more recent mineralizing trends in comparatively new mineral-producing countries (Tanzania) and an established West African gold producer (Ghana), before turning to the influence of conflict minerals (Angola, the Democratic Republic of Congo and Sierra Leone)

Potential groundwater pollution from improper oil and metal waste disposal in Suame, Ghana

Suame is an industrialized hub in Kumasi, Ghana, that is noted for vehicle repairs and servicing, sale of automobile spare parts, and metal fabrication. Some of these activities generate huge volumes of waste oil and metals that are often disposed off indiscriminately into the environment. These could pose a threat to the quality of groundwater in the area, especially if they continuously accumulate in the environment. This study, therefore, investigated the potential impact of the waste disposal on groundwater quality in the area. The methods employed involved mapping all the potential waste oil spillage sources and sampling the soils in such areas (at 0 – 30 and 30 – 60 cm depths) and groundwater supply points for laboratory analyses to determine the presence of the waste. In all, 36 samples (comprising 12 soil and 24 groundwater) were analysedfor the presence of heavy metals including Cd, Ni, Cu, Pb, Zn and Cr, which were used as traceelements for the presence of the waste in the samples. Computedgeo-accumulation indices from the results show the soils are moderately to heavily polluted with Cd and Pb whilst the groundwater, when compared to the WHO drinking water guidelines, is polluted with Pb and Ni. Althoughthe source of the high Pb content observed could be attributed to its transport directly from the activities in the area, the presence of high Ni makes it inconclusive since the Ni in the soil was within the concentration expected of the parent rock geochemistry. This notwithstanding, the study has indicated that groundwater in the area is not safe for human consumption unless the lead and nickel concentrations are reduced to acceptable standard for drinking.Keywords: Groundwater quality, pollution, waste disposal, Suame, Ghan

Facing the stranger in the mirror: Staged complicities in recent South African performances

The staging of complicity has developed into one of the most prevalent trends in recent South Africa theatre. The audience may become aware of their own complicity in injustice, or complicity may feature as a subject to be explored in the play. I will argue that one can identify three broadly defined performance modalities which shape current engagements with complicity. These modalities are identified by the adjectives, 'thick' (as in densely layered, complex, deep), 'reflective' (as in reflecting upon as well as revealing), and 'hard' (in the sense of direct, uncompromising, difficult to penetrate). Rather than signifying distinct categories, these terms are attributed to a cluster of performance dynamics.DHE

The everyday experience of xenophobia: performing The Crossing from Zimbabwe to South Africa

Debates on the underlying causes of xenophobia in South Africa have proliferated since the attacks -between March and May 2008. Our article shows how exploring the everyday 'ordinariness' of xenophobia as performance can contribute additional insights not readily available in the public media or in works such as the recently published Go home or die here.- violence, xenophobia and the reinvention of difference (Hassim et al. 2009). The claim that as metaphor the meaning of performance is discovered in the dialectic established between the fictitious and actual context, provides a point of departure for a discussion of an autobiographical one-man play, The Crossing, in which Jonathan Nkala performs .his hazardous and 'illegal' rites of passage from Zimbabwe to South Africa. The play's aesthetic of 'witnessing', associated with the protest generation, intersects with and looks beyond a post-Truth and Reconciliation Commission (TRC) aesthetic. To contextualise our discussion of Nkala's work we track trends in responses to xenophobia, including the suggestion that the attacks were underpinned by prevailing discourses of exceptianaJism and indigeneity. However, the intimacy of targeting those living close to you needs fuller anatysis. We will argue that the liminality of the performance event provides scope for making connections not directly 'there' at the moment of performance. This has a bearing on the 'return' to Fanon and claims about 'negrophobia' characterising many reports in the public domain on the events of 2008. In turn, this invites speculation about the re-alignments indicated here.DHE