306 research outputs found
Infant feeding practices in a high HIV prevalence rural district of KwaZulu-Natal, South Africa
Aim: To describe infant feeding practices at birth and at 14 weeks post-partum in the Ugu-North Health District, KwaZulu-Natal, South Africa.Methods: A prospective, cohort study design was used. Mothers who delivered over a one-month period were interviewed at birth and14 weeks later. Results: Initially, 168 mothers were interviewed within 24 hours of delivery, of whom 117 (70%) were contactable at 14 weeks post-partum. The vast majority (96%) initiated breast-feeding at birth. At birth, less than one-third (55/168 [32.7%]) of mothers declared an intention to both breast and formula (mix) feed in the next 14 weeks, but by the 14th week post-partum over three-quarters (89/117 [76.1%]) actually practised mixed feeding. At 14 weeks, the prevalence of exclusive breast-feeding was 18%: 52% of infants were offered water and 73% solids. The majority (20/23 [87%]) of HIV infected mothers chose to breastfeed their infants at birth. Nevertheless, they were significantly more likely to formula feed their infants compared to HIV negative mothers (3/23 [13.0%] vs 2/145 [1.4%], OR 10.73, 95% CI 1.34 – 99.16, p = 0.02). By 14 weeks, only 11% of HIV positive mothers were still exclusively breast-feeding, while almost two-thirds (12/19 [63%]) practised mixed feeding. This change was mainly ascribed to their need to return to school (40%) or to work (20%). Conclusions: Most infants were fed inappropriately by 14 weeks of age. The failure to maintain exclusive breast-feeding, despite high initiation rates, is of greatest concern. Routine prevention of mother-to-child transmission of HIV services was ineffective in influencing mothers to follow any feeding regimen exclusively
Parallel-Processing Equalizers for Multi-Gbps Communications
Architectures have been proposed for the design of frequency-domain least-mean-square complex equalizers that would be integral parts of parallel- processing digital receivers of multi-gigahertz radio signals and other quadrature-phase-shift-keying (QPSK) or 16-quadrature-amplitude-modulation (16-QAM) of data signals at rates of multiple gigabits per second. Equalizers as used here denotes receiver subsystems that compensate for distortions in the phase and frequency responses of the broad-band radio-frequency channels typically used to convey such signals. The proposed architectures are suitable for realization in very-large-scale integrated (VLSI) circuitry and, in particular, complementary metal oxide semiconductor (CMOS) application- specific integrated circuits (ASICs) operating at frequencies lower than modulation symbol rates. A digital receiver of the type to which the proposed architecture applies (see Figure 1) would include an analog-to-digital converter (A/D) operating at a rate, fs, of 4 samples per symbol period. To obtain the high speed necessary for sampling, the A/D and a 1:16 demultiplexer immediately following it would be constructed as GaAs integrated circuits. The parallel-processing circuitry downstream of the demultiplexer, including a demodulator followed by an equalizer, would operate at a rate of only fs/16 (in other words, at 1/4 of the symbol rate). The output from the equalizer would be four parallel streams of in-phase (I) and quadrature (Q) samples
'You were quiet - I did all the marching': Research processes involved in hearing the voices of South Asian girls
This article is available open access through the publisher’s website at the link below. Copyright @ 2011
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Academic
Publishers.This article provides insights into the outcomes of reflection following two interview approaches used to explore narratives of the lived, individual experiences of South-Asian girls living in West London. In attempting to illuminate and re-present the cultural experiences as told by these girls, the choice of interview approach became critical in allowing the voices to be effectively heard (Rogers, 2005). This article therefore considers how a semi-structured interview approach offered valuable insights into the girls' experiences but became constraining for both researcher and participant in unveiling the complexity and depth of their lives. These constraints emerged through reflection by both participants and researcher. As a result of reflexivity during the research process, the researcher moved towards the use of research conversations during the second phase of the study. Ultimately the study revealed how the girls felt empowered by the opportunity to narrate their individual experiences and tell of their lives. In narrating their reflections on being part of the research, there was a clear recognition that the process facilitated the articulation of new voices and ‘multi-voicedness’ (Moen, 2006
Exploratory investigation of drivers of attainment in ethnic minority adult learners
There is evidence that ethnic minority learners in further education in England either under-achieve or are under-represented because they face various inhibitors connected to their ethnicity. Motivators may be in place, however, which increase attainment specifically for some ethnic groups. This exploratory study intends to examine what works and what does not among South Asian (Pakistani and Bangladeshi heritage) females and black male adult learners in FE. A mixed-method study was carried out using questionnaires and focus groups with 68 ethnic minority students in three further education colleges in England. The combination of the results showed that being a member of a minority culture and/or religion may increase feelings of isolation in academic settings; teaching staff who are knowledgeable about the student’s culture increase feelings of inclusion; and role models are crucially important. Results are discussed in light of British data of school experiences of ethnic minority learners
The (co-)occurrence of problematic video gaming, substance use, and psychosocial problems in adolescents
Aims. The current study explored the nature of problematic (addictive) video gaming and the association with game type, psychosocial health, and substance use. Methods. Data were collected using a paper and pencil survey in the classroom setting. Three samples were aggregated to achieve a total sample of 8478 unique adolescents. Scales included measures of game use, game type, the Video game Addiction Test (VAT), depressive mood, negative self-esteem, loneliness, social anxiety, education performance, and use of cannabis, alcohol and nicotine (smoking). Results. Findings confirmed problematic gaming is most common amongst adolescent gamers who play multiplayer online games. Boys (60%) were more likely to play online games than girls (14%) and problematic gamers were more likely to be boys (5%) than girls (1%). High problematic gamers showed higher scores on depressive mood, loneliness, social anxiety, negative self-esteem, and self-reported lower school performance. Nicotine, alcohol, and cannabis using boys were almost twice more likely to report high PVG than non-users. Conclusions. It appears that online gaming in general is not necessarily associated with problems. However, problematic gamers do seem to play online games more often, and a small subgroup of gamers – specifically boys – showed lower psychosocial functioning and lower grades. Moreover, associations with alcohol, nicotine, and cannabis use are found. It would appear that problematic gaming is an undesirable problem for a small subgroup of gamers. The findings encourage further exploration of the role of psychoactive substance use in problematic gaming
The construction of ethnic identity: insights from identity process theory
Ethnicity has received much empirical and theoretical attention in the social sciences. Yet, it has scarcely been explored in terms of its relationship with the motivational principles of identity. Here it is argued that there is much heuristic and predictive value in applying identity process theory (IPT), a socio-psychological model of identity threat, to the substantive literature on ethnicity. The paper explores the potential psychological benefits of ethnic identification. Key theoretical strands from anthropology and sociology, such as the ‘relational self’ in ethnic identification, are discussed in relation to IPT. The intergroup dimension of ethnic identification is explored through the discussion of ethnic 'boundaries'. Finally, the paper discusses the construct of 'hybridization' in relation to social psychology. This paper attempts to reconcile psychological and sociological perspectives on ethnic identification, advocating a multi-methodological approach. Key theoretical points are outlined in the form of testable hypotheses which are open to empirical exploration
A meta-analysis of long-term effects of conservation agriculture on maize grain yield under rain-fed conditions
Conservation agriculture involves reduced tillage, permanent soil cover and crop rotations to enhance soil fertility and to supply food from a dwindling land resource. Recently, conservation agriculture has been promoted in Southern Africa, mainly for maize-based farming systems. However, maize yields under rain-fed conditions are often variable. There is therefore a need to identify factors that influence crop yield under conservation agriculture and rain-fed conditions. Here, we studied maize grain yield data from experiments lasting 5 years and more under rain-fed conditions. We assessed the effect of long-term tillage and residue retention on maize grain yield under contrasting soil textures, nitrogen input and climate. Yield variability was measured by stability analysis. Our results show an increase in maize yield over time with conservation agriculture practices that include rotation and high input use in low rainfall areas. But we observed no difference in system stability under those conditions. We observed a strong relationship between maize grain yield and annual rainfall. Our meta-analysis gave the following findings: (1) 92% of the data show that mulch cover in high rainfall areas leads to lower yields due to waterlogging; (2) 85% of data show that soil texture is important in the temporal development of conservation agriculture effects, improved yields are likely on well-drained soils; (3) 73% of the data show that conservation agriculture practices require high inputs especially N for improved yield; (4) 63% of data show that increased yields are obtained with rotation but calculations often do not include the variations in rainfall within and between seasons; (5) 56% of the data show that reduced tillage with no mulch cover leads to lower yields in semi-arid areas; and (6) when adequate fertiliser is available, rainfall is the most important determinant of yield in southern Africa. It is clear from our results that conservation agriculture needs to be targeted and adapted to specific biophysical conditions for improved impact
'My language, my people': language and ethnic identity among British‐born South Asians
This study explores how a group of second generation Asians (SGA) understood and defined language, focusing upon the role they perceived language to have played in their identity. Twelve SGA were interviewed and the data were subjected to qualitative thematic analysis. Four superordinate themes are reported, entitled 'Mother tongue and self', #A sense of ownership and affiliation', 'Negotiating linguistic identities in social space' and 'The quest for a positive linguistic identity'. Participants generally expressed a desire to maintain continuity of self‐definition as Asian, primarily through the maintenance of the heritage language (HL). An imperfect knowledge of the HL was said to have a negative impact upon psychological well‐being. There were ambivalent responses to the perception of language norms, and various strategies were reported for dealing with dilemmatic situations and identity threat arising from bilingualism. Recommendations are offered for interventions that might aid the ‘management’ of bilingualism among SGA
Circular dichroism spectroscopic detection of ligand binding induced subdomain IB specific structural adjustment of human serum albumin
This work demonstrates for the first time that binding of various compounds within subdomain IB of human serum albumin (HSA) provokes characteristic changes in the near-UV circular dichroism (CD) spectrum of the protein. It can be inferred from the spectroscopic features of difference ellipticity signals and from CD displacement experiments that tyrosine residues located in subdomain IB are the source of the observed spectral alterations. It is proposed that inclusion of some ligand molecules (bile acids, dehydroepiandrosterone sulfate, steroidal terpenes, fatty acids, ibuprofen, and gemfibrozil) into the pocket of subdomain IB disrupts the Tyr138?Tyr161 interhelical π?π stacking interaction, which is reflected in the CD spectrum. This phenomenon can be utilized for the CD detection of subdomain IB specific binding of endo- as well as exogenous agents and to study the drug binding associated local conformational adaptation of the HSA molecule
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