Detailing the phonetic environment: a sociophonetic study of the London-Bengali community

The present study investigated variability in the production of English by London Bengali adults who speak the Sylheti dialect of Bengali. Speakers had been resident in London for differing lengths of time. They were recorded producing /l/, /r/ and the eleven monophthongal vowels in English. Phonetically trained listeners rated speakers' productions of /l/ and /r/ in terms of manner and place. F1 and F2 formant frequency values, and duration were measured for all monophthongal vowels. The results demonstrated that older speakers (first-generation immigrants) tended to use Sylhetilike variants when speaking English, whilst second-generation speakers tended to use native English-like variants. These findings will be used to inform studies of the role of phonetic input in child language acquisition from the London Bengali community

Growing up in an immigrant community: the phonemic development of sequential bilingual children

The majority of bilingual speech research has focused on simultaneous bilinguals. Yet, in immigrant communities, children are often initially exposed to their heritage language (L1) before becoming gradually immersed in the host country’s language (L2) when they start full-time education. This is typically referred to as sequential bilingualism. These children are often exposed to differing amounts of the L1 and L2, as well as accented variants. To date, little is known about the developmental trajectories of such children. This thesis investigates the influence of this highly variable language environment on the acquisition of L2 phonemes. Specifically this thesis focuses on Sylheti-English speaking children from the London-Bengali community. To provide a baseline of the children’s speech environment, Study 1 investigated the speech production of Sylheti (L1) and English (L2) by adult speakers from the London-Bengali community. The results show differences in production of both the L1 and L2 depending on the speaker’s language background. Studies 2 and 3 tracked the acquisition of English vowel and plosive contrasts, both perception and production, by Sylheti-English bilingual children and their monolingual peers. Using a longitudinal design, children were tested at two time points: after seven months of English language experience in nursery (Time 1) and approximately one year later, when the children were in the first year of Primary school (Time 2). At Time 1 the bilingual children displayed difficulties with phonemic contrasts that do not exist in Sylheti. However, by Time 2, the bilingual children had rapidly changed to match that of their monolingual peers. Studies 4 and 5 explored the influence of language exposure and caregiver speech on the bilingual children’s English phoneme acquisition. The results suggest that sequential bilingual children are particularly sensitive to the amount of language exposure to each language as well as fine-grained phonetic differences in caregiver speech

Caesarean Section among Referred and Self-Referred Birthing Women: A Cohort Study from a Tertiary Hospital, Northeastern Tanzania.

The inequity in emergency obstetric care access in Tanzania is unsatisfactory. Despite an existing national obstetric referral system, many birthing women bypass referring facilities and go directly to higher-level care centres. We wanted to compare Caesarean section (CS) rates among women formally referred to a tertiary care centre versus self-referred women, and to assess the effect of referral status on adverse outcomes after CS. We used data from 21,011 deliveries, drawn from the birth registry of a tertiary hospital in northeastern Tanzania, during 2000-07. Referral status was categorized as self-referred if the woman had bypassed or not accessed referral, or formally-referred if referred by a health worker. Because CS indications were insufficiently registered, we applied the Ten-Group Classification System to determine the CS rate by obstetric group and referral status. Associations between referral status and adverse outcomes after CS delivery were analysed using multiple regression models. Outcome measures were CS, maternal death, obstetric haemorrhage ≥ 750 mL, postpartum stay > 9 days, neonatal death, Apgar score < 7 at 5 min and neonatal ward transfer. Referral status contributed substantially to the CS rate, which was 55.0% in formally-referred and 26.9% in self-referred birthing women. In both groups, term nulliparous singleton cephalic pregnancies and women with previous scar(s) constituted two thirds of CS deliveries. Low Apgar score (adjusted OR 1.42, 95% CI 1.09-1.86) and neonatal ward transfer (adjusted OR 1.18, 95% CI 1.04-1.35) were significantly associated with formal referral. Early neonatal death rates after CS were 1.6% in babies of formally-referred versus 1.2% in babies of self-referred birthing women, a non-significant difference after adjusting for confounding factors (adjusted OR 1.37, 95% CI 0.87-2.16). Absolute neonatal death rates were > 2% after CS in breech, multiple gestation and preterm deliveries in both referral groups. Women referred for delivery had higher CS rates and poorer neonatal outcomes, suggesting that the formal referral system successfully identifies high-risk birth, although low volume suggests underutilization. High absolute rates of post-CS adverse outcomes among breech, multiple gestation and preterm deliveries suggest the need to target self-referred birthing women for earlier professional intrapartum care

The inevitable youthfulness of known high-redshift radio galaxies

Radio galaxies can be seen out to very high redshifts, where in principle they can serve as probes of the early evolution of the Universe. Here we show that for any model of radio-galaxy evolution in which the luminosity decreases with time after an initial rapid increase (that is, essentially all reasonable models), all observable high-redshift radio-galaxies must be seen when the lobes are less than 10^7 years old. This means that high-redshift radio galaxies can be used as a high-time-resolution probe of evolution in the early Universe. Moreover, this result helps to explain many observed trends of radio-galaxy properties with redshift [(i) the `alignment effect' of optical emission along radio-jet axes, (ii) the increased distortion in radio structure, (iii) the decrease in physical sizes, (iv) the increase in radio depolarisation, and (v) the increase in dust emission] without needing to invoke explanations based on cosmology or strong evolution of the surrounding intergalactic medium with cosmic time, thereby avoiding conflict with current theories of structure formation.Comment: To appear in Nature. 4 pages, 2 colour figures available on request. Also available at http://www-astro.physics.ox.ac.uk/~km

Transport of Explosive Residue Surrogates in Saturated Porous Media

Department of Defense operational ranges may become contaminated by particles of explosives residues (ER) as a result of low-order detonations of munitions. The goal of this study was to determine the extent to which particles of ER could migrate through columns of sandy sediment, representing model aquifer materials. Transport experiments were conducted in saturated columns (2 × 20 cm) packed with different grain sizes of clean sand or glass beads. Fine particles (approximately 2 to 50 μm) of 2,6-dinitrotoluene (DNT) were used as a surrogate for ER. DNT particles were applied to the top 1 cm of sand or beads in the columns, and the columns were subsequently leached with artificial groundwater solutions. DNT migration occurred as both dissolved and particulate phases. Concentration differences between unfiltered and filtered samples indicate that particulate DNT accounted for up to 41% of the mass recovered in effluent samples. Proportionally, more particulate than dissolved DNT was recovered in effluent solutions from columns with larger grain sizes, while total concentrations of DNT in effluent were inversely related to grain size. Of the total DNT mass applied to the uppermost layer of the column, <3% was recovered in the effluent with the bulk remaining in the top 2 cm of the column. Our results suggest there is some potential for subsurface migration of ER particles and that most of the particles will be retained over relatively short transport distances

Body mass index, physical activity, and dietary behaviors among members of an urban community fitness center: a questionnaire survey

<p>Abstract</p> <p>Background</p> <p>Development of effective behavioral interventions to promote weight control and physical activity among diverse, underserved populations is a public health priority. Community focused wellness organizations, such as YMCAs, could provide a unique channel with which to reach such populations. This study assessed health behaviors and related characteristics of members of an urban YMCA facility.</p> <p>Methods</p> <p>We surveyed 135 randomly selected members of an urban YMCA facility in Massachusetts to examine self-reported (1) physical activity, (2) dietary behaviors, (3) body mass index, and (4) correlates of behavior change among short-term (i.e., one year or less) and long-term (i.e., more than one year) members. Chi-square tests were used to assess bivariate associations between variables, and multivariate linear regression models were fit to examine correlates of health behaviors and weight status.</p> <p>Results</p> <p>Eighty-nine percent of short-term and 94% of long-term members reported meeting current physical activity recommendations. Only 24% of short-term and 19% of long-term members met fruit and vegetable consumption recommendations, however, and more than half were overweight or obese. Length of membership was not significantly related to weight status, dietary behaviors, or physical activity. Most respondents were interested in changing health behaviors, in the preparation stage of change, and had high levels of self-efficacy to change behaviors. Short-term members had less education (p = 0.02), lower household incomes (p = 0.02), and were less likely to identify as white (p = 0.005) than long-term members. In multivariate models, females had lower BMI than males (p = 0.003) and reported less physical activity (p = 0.008). Physical activity was also inversely associated with age (p = 0.0004) and education (p = 0.02).</p> <p>Conclusion</p> <p>Rates of overweight/obesity and fruit and vegetable consumption suggested that there is a need for a weight control intervention among members of an urban community YMCA. Membership in such a community wellness facility alone might not be sufficient to help members maintain a healthy weight. The data indicate that YMCA members are interested in making changes in their dietary and physical activity behaviors. Targeting newer YMCA members might be an effective way of reaching underserved populations. These data will help inform the development of a weight control intervention tailored to this setting.</p

Prevalence of fetal alcohol spectrum disorder in Greater Manchester, UK: An active case ascertainment study

Background: Despite high levels of prenatal alcohol exposure in the UK, evidence on the prevalence of fetal alcohol spectrum disorders (FASD) is lacking. This paper reports on FASD prevalence in a small sample of children in primary school. Methods: A 2-phase active case ascertainment study was conducted in 3 mainstream primary schools in Greater Manchester, UK. Schools were located in areas that ranged from relatively deprived to relatively affluent. Initial screening of children aged 8–9 years used prespecified criteria for elevated FASD risk (small for age; special educational needs; currently/previously in care; significant social/emotional/mental health symptoms). Screen-positive children were invited for detailed ascertainment of FASD using gold standard measures that included medical history, facial dysmorphology, neurological impairment, executive function, and behavioral difficulties. Results: Of 220 eligible children, 50 (23%) screened positive and 12% (26/220) proceeded to Phase 2 assessment. Twenty had a developmental disorder, of whom 4 had FASD and 4 were assessed as possible FASD. The crude prevalence rate of FASD in these schools was 1.8% (95% CI: 1.0%, 3.4%) and when including possible cases was 3.6% (2.1%, 6.3%). None of these children had previously been identified with a developmental diagnosis. Conclusions: FASD was found to be common in these schools and most of these children's needs had not previously been identified. A larger, more definitive study that uses a random sampling technique stratified by deprivation level to select schools is needed to make inferences regarding the population prevalence of FASD

Explaining the Atypical Reaction Profiles of Heme Enzymes with a Novel Mechanistic Hypothesis and Kinetic Treatment

Many heme enzymes show remarkable versatility and atypical kinetics. The fungal extracellular enzyme chloroperoxidase (CPO) characterizes a variety of one and two electron redox reactions in the presence of hydroperoxides. A structural counterpart, found in mammalian microsomal cytochrome P450 (CYP), uses molecular oxygen plus NADPH for the oxidative metabolism (predominantly hydroxylation) of substrate in conjunction with a redox partner enzyme, cytochrome P450 reductase. In this study, we employ the two above-mentioned heme-thiolate proteins to probe the reaction kinetics and mechanism of heme enzymes. Hitherto, a substrate inhibition model based upon non-productive binding of substrate (two-site model) was used to account for the inhibition of reaction at higher substrate concentrations for the CYP reaction systems. Herein, the observation of substrate inhibition is shown for both peroxide and final substrate in CPO catalyzed peroxidations. Further, analogy is drawn in the “steady state kinetics” of CPO and CYP reaction systems. New experimental observations and analyses indicate that a scheme of competing reactions (involving primary product with enzyme or other reaction components/intermediates) is relevant in such complex reaction mixtures. The presence of non-selective reactive intermediate(s) affords alternate reaction routes at various substrate/product concentrations, thereby leading to a lowered detectable concentration of “the product of interest” in the reaction milieu. Occam's razor favors the new hypothesis. With the new hypothesis as foundation, a new biphasic treatment to analyze the kinetics is put forth. We also introduce a key concept of “substrate concentration at maximum observed rate”. The new treatment affords a more acceptable fit for observable experimental kinetic data of heme redox enzymes