Contribution of a bonded scholarship scheme to staffing rural health facilities

BACKGROUND

Local and international research has identified rural origin as an important reason why healthcare professionals (HCPs) work in rural areas, and in South Africa (SA) considerable effort has gone into recruiting and training rural-origin students. However, there is little information in the SA literature on where graduates supported by these initiatives work, and whether they contribute to the rural workforce long term.

OBJECTIVE

To determine the number of years that rural-origin Umthombo Youth Development Foundation (UYDF)-supported graduates of different disciplines worked at rural public healthcare facilities (PHCFs).

METHODS

A retrospective descriptive study reviewed work record data of 405 UYDF graduates, to calculate the number of years they worked at a rural PHCF. Data were analysed descriptively and presented in tables with totals and percentages.

RESULTS

Ninety percent (363/405) of UYDF-supported graduates returned to work at a rural PHCF. High percentages of social workers (85%), optometrists (80%), speech therapists, nurses (72%) and dental therapists (70%) worked for ≥5 years at a rural PHCF, while only 13% of audiologists, 14% of doctors, 29% of pharmacists, and 28% of dentists and occupational therapists worked at a rural PHCF for ≥5 years. Ten percent (42/405) of graduates did not work at a rural PHCF at all. A total of 110/124 (89%) of doctors supported by UYDF had worked at a rural PHCF, with 32% (40/124) working at a rural PHCF for ≥3 years. Overall, 54% of UYDF-supported graduates (219/405) worked for ≥3 years at a rural PHCF, and 38.5% (157/405) worked for ≥5 years at rural PHCFs. The majority of UYDF graduates had contributed towards long-term staffing of rural PHCFs. Lack of professional development opportunities at rural PHCFs as well as the reduced number of funded posts at rural PHCFs reduced the effectiveness of the UYDF initiative.

CONCLUSION

The UYDF Scholarship Scheme has shown that investment in rural students through a bonded scholarship can contribute to staffing rural PHCFs, as >90% of graduates worked at rural PHCFs, and for some disciplines >70% of graduates worked for ≥5 years at a rural PHCF. Allied HCPs worked on average for longer periods at rural PHCFs than doctors.

All-Optical GeV Electron Bunch Generation in a Laser-Plasma Accelerator via Truncated-Channel Injection

We describe a simple scheme, truncated-channel injection, to inject electrons directly into the wakefield driven by a high-intensity laser pulse guided in an all-optical plasma channel. We use this approach to generate dark-current-free 1.2 GeV, 4.5% relative energy spread electron bunches with 120 TW laser pulses guided in a 110 mm-long hydrodynamic optical-field-ionized plasma channel. Our experiments and particle-in-cell simulations show that high-quality electron bunches were only obtained when the drive pulse was closely aligned with the channel axis, and was focused close to the density down ramp formed at the channel entrance. Start-to-end simulations of the channel formation, and electron injection and acceleration show that increasing the channel length to 410 mm would yield 3.65 GeV bunches, with a slice energy spread ∼5×10^{-4}.

NTRK expression is common in xanthogranuloma and is associated with the solitary variant

BACKGROUND

Previously identified mutually-exclusive driver genes in juvenile xanthogranuloma (JXG) and adult xanthogranuloma (AXG) include mutations in MAP kinase pathway genes such as MAP2K1, BRAF, ARAF, KRAS, NRAS, PIK3CD as well as fusions in BRAF and ALK, with a subset of cases with no identified driver yet. NTRK fusion has been identified in rare cases.

METHODS

We identified two consecutive index cases of localized JXG or AXG with NTRK1 fusion by next-generation sequencing (NGS) and confirmed by pan-NTRK immunostain. We expanded the study to a total of 50 cases of JXG and AXG using screening by pan-NTRK immunostain. We confirmed the specificity of our approach with negative results in 5 cases of histiocytic neoplasia lacking an NTRK fusion by NGS and 14 cases of non-neoplastic histiocytic disease.

RESULTS

We found 23 cases of JXG or AXG with overexpression of NTRK by immunostain, and these cases were restricted to localized disease (23 of 43 cases, 53.5%) rather than disseminated disease (zero of seven cases).

CONCLUSIONS

NTRK expression is common in JXG or AXG and associated with localized rather than disseminated disease. We speculate that the potential importance of this in JXG and AXG has not been previously appreciated due to the tendency to focus sequencing studies on disseminated disease. We confirm the presence of an NTRK1 fusion in two positive cases by NGS, however, additional genetic studies are necessary to further explore this.

Measurement of the decay of laser-driven linear plasma wakefields

We present measurements of the temporal decay rate of one-dimensional (1D), linear Langmuir waves excited by an ultrashort laser pulse. Langmuir waves with relative amplitudes of approximately 6% were driven by 1.7J, 50fs laser pulses in hydrogen and deuterium plasmas of density n_{e0}=8.4×10^{17}cm^{-3}. The wakefield lifetimes were measured to be τ_{wf}^{H_{2}}=(9±2) ps and τ_{wf}^{D_{2}}=(16±8) ps, respectively, for hydrogen and deuterium. The experimental results were found to be in good agreement with 2D particle-in-cell simulations. In addition to being of fundamental interest, these results are particularly relevant to the development of laser wakefield accelerators and wakefield acceleration schemes using multiple pulses, such as multipulse laser wakefield accelerators.

Dark Energy Survey Year 1 Results: Cosmological Constraints from Cluster Abundances, Weak Lensing, and Galaxy Correlations

We present the first joint analysis of cluster abundances and auto or cross-correlations of three cosmic tracer fields: galaxy density, weak gravitational lensing shear, and cluster density split by optical richness. From a joint analysis (4×2pt+N) of cluster abundances, three cluster cross-correlations, and the auto correlations of the galaxy density measured from the first year data of the Dark Energy Survey, we obtain Ω_{m}=0.305_{-0.038}^{+0.055} and σ_{8}=0.783_{-0.054}^{+0.064}. This result is consistent with constraints from the DES-Y1 galaxy clustering and weak lensing two-point correlation functions for the flat νΛCDM model. Consequently, we combine cluster abundances and all two-point correlations from across all three cosmic tracer fields (6×2pt+N) and find improved constraints on cosmological parameters as well as on the cluster observable-mass scaling relation. This analysis is an important advance in both optical cluster cosmology and multiprobe analyses of upcoming wide imaging surveys.

Defining adaptive capacity in healthcare: A new framework for researching resilient performance

Resilience principles show promise for improving the quality of healthcare, but there is a need for further theoretical development to include all levels and scales of activity across the whole healthcare system. Many existing models based on engineering concepts do not adequately address the prominence of social, cultural and organisational factors in healthcare work. Promising theoretical developments include the four resilience potentials, the CARE model and the Moments of Resilience Model, but they are all under specified and in need of further elaboration. This paper presents the Integrated Resilience Attributes Framework in which these three theoretical perspectives are integrated to provide examples of anticipating, responding, monitoring and learning at different scales of time and space. The framework is intended to guide researchers in researching resilience, especially the linkages between resilience at different scales of time and space across the whole healthcare system.

Beyond ‘find and fix’: improving quality and safety through resilient healthcare systems

Objective

The aim was to develop a method based on resilient healthcare principles to proactively identify system vulnerabilities and quality improvement interventions.

Design

Ethnographic methods to understand work as it is done in practice using concepts from resilient healthcare, the Concepts for Applying Resilience Engineering model and the four key activities that are proposed to underpin resilient performance—anticipating, monitoring, responding and learning.

Setting

Accident and Emergency Department (ED) and the Older People’s Unit (OPU) of a large teaching hospital in central London.

Participants

ED—observations 104 h, and 14 staff interviews. OPU—observations 60 h, and 15 staff interviews.

Results

Data were analysed to identify targets for quality improvement. In the OPU, discharge was a complex and variable process that was difficult to monitor. A system to integrate information and clearly show progress towards discharge was needed. In the ED, patient flow was identified as a complex high-intensity activity that was not supported by the existing data systems. The need for a system to integrate and display information about both patient and organizational factors was identified. In both settings, adaptive capacity was limited by the absence of systems to monitor the work environment.

Conclusions

The study showed that using resilient healthcare principles to inform quality improvement was feasible and focused attention on challenges that had not been addressed by traditional quality improvement practices. Monitoring patient and workflow in both the ED and the OPU was identified as a priority for supporting staff to manage the complexity of the work.

Nursing teamwork in the care of older people: A mixed methods study

Healthcare is increasingly complex and requires the ability to adapt to changing demands. Teamwork is essential to delivering high quality care and is central to nursing. The aims of this study were to identify the processes that underpin nursing teamwork and how these affect the care of older people, identify the relationship between perceived teamwork and perceived quality of care, and explore in depth the experience of working in nursing teams. The study was carried out in three older people's wards in a London teaching hospital. Nurses and healthcare assistants completed questionnaires (n = 65) on known dynamics of teamwork (using the Nursing Teamwork Survey) together with ratings of organisational quality (using an adapted AHRQ HSPS scale). A sample (n = 22; 34%) was then interviewed about their perceptions of care, teamwork and how good outcomes are delivered in everyday work. Results showed that many care difficulties were routinely encountered, and confirmed the importance of teamwork (e.g. shared mental models of tasks and team roles and responsibilities, supported by leadership) in adapting to challenges. Perceived quality of teamwork was positively related to perceived quality of care. Work system variability and the external environment influenced teamwork, and confirmed the importance of team adaptive capacity. The CARE model shows the centrality of teamwork in adapting to variable demand and capacity to deliver care processes, and the influence of broader system factors on teamworking.

Cosmological Constraints from Multiple Probes in the Dark Energy Survey

The combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured 207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy clustering. Here we present combined results from these probes, deriving constraints on the equation of state, w, of dark energy and its energy density in the Universe. Independently of other experiments, such as those that measure the cosmic microwave background, the probes from this single photometric survey rule out a Universe with no dark energy, finding w=-0.80_{-0.11}^{+0.09}. The geometry is shown to be consistent with a spatially flat Universe, and we obtain a constraint on the baryon density of Ω_{b}=0.069_{-0.012}^{+0.009} that is independent of early Universe measurements. These results demonstrate the potential power of large multiprobe photometric surveys and pave the way for order of magnitude advances in our constraints on properties of dark energy and cosmology over the next decade.

Knowledge of final-year medical students at the University of KwaZulu-Natal about family medicine, and long-term career choices

Background: While international experience suggests that well-trained primary care physicians improve the quality and cost effectiveness of health care, family medicine (FM) as the discipline of the specialist primary care physician appears to not be an attractive career for medical graduates in South Africa (SA). The aim of this study was to establish final-year medical students’ knowledge about FM and its relevance to the healthcare system, explore their perceptions of the discipline’s relevance, and identify their specialty preference.Methods: This was a descriptive study conducted amongst final-year medical students at the University of KwaZulu-Natal (UKZN) in 2017 at the conclusion of their seven-week FM module. Data were collected using a self-administered questionnaire and results were analysed descriptively.Results: The response rate of completed questionnaires was 80.2% (157/196). Students reported limited exposure to FM in their early undergraduate years and low levels of awareness about essential public health programmes. Students showed good awareness of the six roles of family physicians (FPs), but FM was only the sixth most popular choice for specialisation.Conclusions: In general, students had favourable views concerning FM and its role in the future of healthcare delivery in SA, although their knowledge of essential health programmes was poor. The majority of students had limited interest in pursuing a career in FM. A key recommendation to address these issues is to introduce FM into the curriculum earlier, to cover the key roles of the FP, and provide teaching that highlights the relevance of FM to health system programmes.

Rotationally inelastic collisions of excited NaK and NaCs molecules with noble gas and alkali atom perturbers

We report measurements of rate coefficients at T ≈ 600 K for rotationally inelastic collisions of NaK molecules in the 2(A)¹Σ⁺ electronic state with helium, argon, and potassium atom perturbers. Several initial rotational levels J between 14 and 44 were investigated. Collisions involving molecules in low-lying vibrational levels (v = 0, 1, and 2) of the 2(A)¹Σ⁺ state were studied using Fourier-transform spectroscopy. Collisions involving molecules in a higher vibrational level, v = 16, were studied using pump/probe, optical-optical double resonance spectroscopy. In addition, polarization spectroscopy measurements were carried out to study the transfer of orientation in these collisions. Many, but not all, of the measurements were carried out in the "single-collision regime" where more than one collision is unlikely to occur within the lifetime of the excited molecule. The analysis of the experimental data, which is described in detail, includes an estimate of effects of multiple collisions on the reported rate coefficients. The most significant result of these experiments is the observation of a strong propensity for ΔJ = even transitions in collisions involving either helium or argon atoms; the propensity is much stronger for helium than for argon. For the initial rotational levels studied experimentally, almost all initial orientation is preserved in collisions of NaK 2(A)¹Σ⁺ molecules with helium. Roughly between 1/3 and 2/3 of the orientation is preserved in collisions with argon, and almost all orientation is destroyed in collisions with potassium atoms. Complementary measurements on rotationally inelastic collisions of NaCs 2(A)¹Σ⁺ with argon do not show a ΔJ = even propensity. The experimental results are compared with new theoretical calculations of collisions of NaK 2(A)¹Σ⁺ with helium and argon. The calculations are in good agreement with the absolute magnitudes of the experimentally determined rate coefficients and accurately reproduce the very strong propensity for ΔJ = even transitions in helium collisions and the less strong propensity for ΔJ = even transitions in argon collisions. The calculations also show that collisions with helium are less likely to destroy orientation than collisions with argon, in agreement with the experimental results.

Implementing resilience engineering for healthcare quality improvement using the CARE model: a feasibility study protocol

BACKGROUND

Resilience engineering (RE) is an emerging perspective on safety in complex adaptive systems that emphasises how outcomes emerge from the complexity of the clinical environment. Complexity creates the need for flexible adaptation to achieve outcomes. RE focuses on understanding the nature of adaptations, learning from success and increasing adaptive capacity. Although the philosophy is clear, progress in applying the ideas to quality improvement has been slow. The aim of this study is to test the feasibility of translating RE concepts into practical methods to improve quality by designing, implementing and evaluating interventions based on RE theory. The CARE model operationalises the key concepts and their relationships to guide the empirical investigation.

METHODS

The settings are the Emergency Department and the Older Person's Unit in a large London teaching hospital. Phases 1 and 2 of our work, leading to the development of interventions to improve the quality of care, are described in this paper. Ethical approval has been granted for these phases. Phase 1 will use ethnographic methods, including observation of work practices and interviews with staff, to understand adaptations and outcomes. The findings will be used to collaboratively design, with clinical staff in interactive design workshops, interventions to improve the quality of care. The evaluation phase will be designed and submitted for ethical approval when the outcomes of phases 1 and 2 are known.

DISCUSSION

Study outcomes will be knowledge about the feasibility of applying RE to improve quality, the development of RE theory and a validated model of resilience in clinical work which can be used to guide other applications. Tools, methods and practical guidance for practitioners will also be produced, as well as specific knowledge of the potential effectiveness of the implemented interventions in emergency and older people's care. Further studies to test the application of RE at a larger scale will be required, including studies of other healthcare settings, organisational contexts and different interventions.

Self-reported knowledge and use of emergency contraception among women presenting for termination of pregnancy

Background: Emergency contraception (EC) is widely accepted as a safe method of preventing conception following unprotected coitus. Use of EC has been promoted in South Africa, yet uptake among women appears to remain low.Aim: The aim of this study was to access knowledge and use of EC among women presenting for termination of pregnancy at a district hospital in KwaZulu-Natal.Methods: This was a hospital-based cross-sectional study. Data were collected from women attending a termination of pregnancy (ToP) service at a district hospital using a questionnaire and analysed descriptively.Results: A total of 218 women participated, of whom 25% were under 20 years of age and 87% were single. Reported knowledge of EC was good with 70% of participants indicating that they knew about EC. However, knowledge around EC was not complete, with less than 50% knowing the time interval between intercourse and EC action and some believing that EC acted by inducing an abortion. Reported usage of EC was only 40%.Conclusion: This study revealed that there is much more to be done to enhance knowledge and use of EC in this context. Reasons for the discrepancy between knowledge and usage need further exploration.

Large-Scale Distribution of Total Mass versus Luminous Matter from Baryon Acoustic Oscillations: First Search in the Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey Data Release 10

Baryon acoustic oscillations in the early Universe are predicted to leave an as yet undetected signature on the relative clustering of total mass versus luminous matter. A detection of this effect would provide an important confirmation of the standard cosmological paradigm and constrain alternatives to dark matter as well as nonstandard fluctuations such as compensated isocurvature perturbations (CIPs). We conduct the first observational search for this effect, by comparing the number-weighted and luminosity-weighted correlation functions, using the SDSS-III BOSS Data Release 10 CMASS sample. When including CIPs in our model, we formally obtain evidence at 3.2σ of the relative clustering signature and a limit that matches the existing upper limits on the amplitude of CIPs. However, various tests suggest that these results are not yet robust, perhaps due to systematic biases in the data. The method developed in this Letter used with more accurate future data such as that from DESI, is likely to confirm or disprove our preliminary evidence.

Evaluating multisite multiprofessional simulation training for a hyperacute stroke service using the Behaviour Change Wheel

BACKGROUND

Stroke is a clinical priority requiring early specialist assessment and treatment. A London (UK) stroke strategy was introduced in 2010, with Hyper Acute Stroke Units (HASUs) providing specialist and high dependency care. To support increased numbers of specialist staff, innovative multisite multiprofessional simulation training under a standard protocol-based curriculum took place across London. This paper reports on an independent evaluation of the HASU training programme. The main aim was to evaluate mechanisms for behaviour change within the training design and delivery, and impact upon learners including potential transferability to the clinical environment.

METHODS

The evaluation utilised the Behaviour Change Wheel framework. Procedures included: mapping training via the framework; examination of course material; direct and video-recorded observations of courses; pre-post course survey sheet; and follow up in-depth interviews with candidates and faculty.

RESULTS

Patient management skills and trainee confidence were reportedly increased post-course (post-course median 6 [IQ range 5-6.33]; pre-course median 5 [IQ range 4.67-5.83]; z = 6.42, P < .001). Thematic analysis showed that facilitated 'debrief' was the key agent in supporting both clinical and non-clinical skills. Follow up interviews in practice showed some sustained effects such as enthusiasm for role, and a focus on situational awareness, prioritization and verbalising thoughts. Challenges in standardising a multi-centre course included provision for local context/identity.

CONCLUSIONS

Pan-London simulation training under the London Stroke Model had positive outcomes in terms of self-reported skills and motivation. These effects persisted to an extent in practice, where staff could recount applications of learning. The evaluation demonstrated that a multiple centre simulation programme congruent with clinical practice can provide valuable standard training opportunities that support patient care.

Problems with medicines use: The Bolton project

The overall results are reported from a project designed to identify the type and frequency of problems associated with the use of medicine by the general public, and to establish any differences between the inner urban area and the rest of the borough of Bolton, England. Two separate groups in the community have been identified who need assistance with medicines. One group, referred by health care professionals, need extensive support and supervision of their medicines. The other group, identified by postal questionnaire, exhibit specific problems, such as difficulties with medicine packaging, general use and storage problems. All could be resolved, to varying degrees, by the intervention of pharmacists.

Difficulties in the use of medicine packaging

A postal questionnaire sent to a large group of the general public asked about difficulties encountered in the use of liquid medicine bottles, eye-drop containers, ointment/cream tubes and inhalers. Liquid medicine bottles and ointment/cream tubes were the most widely used, with eye-drop bottles having been used by approximately half of the respondents. Only 16 per cent had used inhalers. The use of eye-drop bottles and ointment/cream tubes caused the greatest number of difficulties for the majority of users. Other than with inhalers, those aged under 40 years reported the greatest number of difficulties with medicine containers. It is suggested that new medicine containers be designed to overcome the large number of difficulties reported by the general public.

The EEL-1 ubiquitin ligase promotes DNA damage-induced germ cell apoptosis in C. elegans

E3 ubiquitin ligases target a growing number of pro- and anti-apoptotic proteins, including tumour suppressor p53, caspases, and the Bcl-2 family. The core apoptosis pathway is well conserved between mammals and Caenorhabditis elegans, but the extent to which ubiquitin ligases regulate apoptotic cell death is not known. To investigate the role of E3 ligases in apoptosis, we inhibited 108 of the 165 predicted E3 ubiquitin ligase genes by RNA interference and quantified apoptosis in the C. elegans germline after genotoxic stress. From this screen, we identified the homologous to E6-associated protein C terminus-domain E3 ligase EEL-1 as a positive regulator of apoptosis. Intriguingly, the human homologue of EEL-1, Huwe1/ARF-BP1/Mule/HectH9, has been reported to possess both pro- and anti-apoptotic functions through its ability to stimulate Mcl-1 and p53 degradation, respectively. Here, we demonstrate that eel-1 is required to promote DNA damage-induced germ cell apoptosis, but does not have a role in physiological germ cell apoptosis or developmental apoptosis in somatic tissue. Furthermore, eel-1 acts in parallel to the p53-like gene cep-1 and intersects the core apoptosis pathway upstream of the Bcl-2/Mcl-1 orthologue ced-9. Although ee1-1 mutants exhibit hypersensitivity to genotoxic stress they do not appear to be defective in DNA repair, suggesting a distinct role for EEL-1 in promoting damage-induced apoptosis in the germline.

Citicoline enhances frontal lobe bioenergetics as measured by phosphorus magnetic resonance spectroscopy

Citicoline supplementation has been used to ameliorate memory disturbances in older people and those with Alzheimer's disease. This study used MRS to characterize the effects of citicoline on high-energy phosphate metabolites and constituents of membrane synthesis in the frontal lobe. Phosphorus ((31)P) metabolite data were acquired using a three-dimensional chemical-shift imaging protocol at 4 T from 16 healthy men and women (mean +/- SD age 47.3 +/- 5.4 years) who orally self-administered 500 mg or 2000 mg Cognizin Citicoline (Kyowa Hakko Kogyo Co., Ltd, Ibaraki, Japan) for 6 weeks. Individual (31)P metabolites were quantified in the frontal lobe (anterior cingulate cortex) and a comparison region (parieto-occipital cortex). Significant increases in phosphocreatine (+7%), beta-nucleoside triphosphates (largely ATP in brain, +14%) and the ratio of phosphocreatine to inorganic phosphate (+32%), as well as significant changes in membrane phospholipids, were observed in the anterior cingulate cortex after 6 weeks of citicoline treatment. These treatment-related alterations in phosphorus metabolites were not only regionally specific, but tended to be of greater magnitude in subjects who received the lower dose. These data show that citicoline improves frontal lobe bioenergetics and alters phospholipid membrane turnover. Citicoline supplementation may therefore help to mitigate cognitive declines associated with aging by increasing energy reserves and utilization, as well as increasing the amount of essential phospholipid membrane components needed to synthesize and maintain cell membranes.

New spectroscopic data, spin-orbit functions, and global analysis of data on the AΣu+1 and bΠu3 states of Na2

The lowest electronically excited states of Na2 are of interest as intermediaries in the excitation of higher states and in the development of methods for producing cold molecules. We have compiled previously obtained spectroscopic data on the A 1Sigmau+ and b 3Piu states of Na2 from about 20 sources, both published and unpublished, together with new sub-Doppler linewidth measurements of about 15,000 A<--X transitions using polarization spectroscopy. We also present new ab initio results for the diagonal and off-diagonal spin-orbit functions. The discrete variable representation is used in conjunction with Hund's case a potentials plus spin-orbit effects to model data extending from v=0 to very close to the 3 2S+3 2P12 limit. Empirical estimates of the spin-orbit functions agree well with the ab initio functions for the accessible values of R. The potential function for the A state includes an exchange potential for S+P atoms, with a fitted coefficient somewhat larger than the predicted value. Observed and calculated term values are presented in an auxiliary (EPAPS) file as a database for future studies on Na2.

A full analytic potential energy curve for the a 3 Sigma+ state of KLi from a limited vibrational data set

Fourier transform spectra of near-infrared laser-induced fluorescence in (39)K(6)Li show transitions to high vibrational levels of both the X (1)Sigma(+) and a (3)Sigma(+) electronic states. These include 147 transitions into six vibrational levels of the a (3)Sigma(+) state, which lie between 7 and 88 cm(-1) below the dissociation asymptote. Unfortunately, their energies span less than 30% of the well depth. However, fitting those data to eigenvalues of analytical model potential functions whose outer limbs incorporate the theoretically predicted long-range form, V(R) approximately D-C(6)R(6)-C(8)R(8), yields complete, plausible potential curves for this state. The best fits converge to remarkably similar solutions which indicate that D(e)=287(+/-4) cm(-1) and R(e)=4.99(+/-0.09) A for the a (3)Sigma(+) state of KLi, with omega(e)=47.3(+/-1.4) and 44.2(+/-1.5) cm(-1) for (39)K(6)Li and (39)K(7)Li, respectively. Properties of the resulting potential are similar to those of a published ab initio potential and are consistent with those of the analogous states of Li(2), K(2), Na(2), and NaK.

1H MRS in stroke patients with and without cognitive impairment

The pathophysiological basis of cognitive impairment in patients with cerebrovascular disease (CVD) is not well understood, particularly in relation to the role of non-infarction ischemic change and associated Alzheimer-type pathology. We used single voxel 1H MRS to determine the differences in brain neurometabolites in non-infarcted frontal white matter and occipito-parietal gray matter of 48 stroke patients with or without cognitive impairment and 60 elderly controls. The results showed that there were no significant neurometabolite differences between the stroke cohort and healthy elderly controls, but there was a difference in NAA/H2O between the stroke patients that had cognitive impairment (vascular dementia (VaD) and vascular cognitive impairment (VCI)) compared with those patients with no impairment. This was significant in the occipito-parietal gray matter, but not in the frontal white matter, although the results were in the same direction for the latter. This suggests that cognitive impairment in stroke patients may be related to cortical neuronal dysfunction rather than purely subcortical change. Moreover, cortical regions not obviously infarcted may have dysfunctional neurons, the pathophysiological basis for which needs further study.

Isotope effects and Born-Oppenheimer breakdown in excited singlet states of the lithium dimer

Observation of infrared electronic transitions involving the 1 (1)Deltag state of 7Li2 has instigated an investigation of Born-Oppenheimer breakdown in four singlet electronic states correlating with (2s+2s), (2s+2p), and (2p+2p) lithium atoms. The 1 (1)Deltag state, which correlates at long range with (2p+2p) atoms, has been observed in emission from the (5p) (1)Piu Rydberg state and in 1 (1)Deltag-B (1)Piu bands, in both instances following optical-optical double-resonance excitation. The latter transition was observed previously for the lighter isotopomer, 6Li2 [C. Linton, F. Martin, P. Crozet, A. J. Ross, and R. Bacis, J. Mol. Spectrosc. 158, 445 (1993)]. By analyzing multiple-isotopomer data for several electronic systems simultaneously, we have determined the electronic isotope shifts and the leading vibrational and/or rotational Born-Oppenheimer breakdown terms for the X (1)Sigmag+, A (1)Sigmau+, B (1)Piu, and 1 (1)Deltag states of the lithium dimer. This paper also reports Fourier transform measurements of the B-X absorption spectra of 6Li2 and 7Li2, which were required to better define the bottom portion of the B (1)Piu state potential.

Speech and language sequelae of severe malaria in Kenyan children

PRIMARY OBJECTIVE

To conduct a preliminary investigation into the occurrence of speech and language impairments following severe malaria in Kenyan children.

RESEARCH DESIGN

Cohort study comparing the prevalence of impairments in children exposed or unexposed to severe malaria.

METHODS AND PROCEDURES

The study recruited 25 children who had previously been admitted to hospital with severe falciparum malaria and 27 unexposed to the disease. Assessments of comprehension, syntax, lexical semantics, higher level language abilities, pragmatics and phonology were administered to each child at 8-9 years of age, at least 2 years after admission to hospital in children exposed to severe malaria.

MAIN OUTCOMES AND RESULTS

Exposed children were found to have lower scores on each assessment and significantly lower scores on four aspects of language ability: comprehension (p = 0.02); syntax (p = 0.02); content words (p = 0.02) and function words (p = 0.004) components of lexical semantics.

CONCLUSIONS

These data suggest that speech and language deficits may be an important and under-recognized sequela of severe falciparum malaria.

An efficient and stereoselective synthesis of beta-D-Arap-(1-->2)-beta-D-Galp-(1-->3)-beta-D-Galp-(1-->4)-alpha-D-Manp, a tetrasaccharide fragment of Leishmania major lipophosphoglycan

A tetrasaccharide fragment of Leishmania major lipophosphoglycan (which seems to be involved in a biological mechanism for the parasite transmission) has been synthesised using the thioglycoside, trichloroacetimidate and halide-exchange glycosylation procedures and step-wise chain elongation strategy.

BCLW mediates survival of postmitotic Sertoli cells by regulating BAX activity

Male mice deficient in BCLW, a death-protecting member of the BCL2 family, are sterile due to an arrest in spermatogenesis that is associated with a gradual loss of germ cells and Sertoli cells from the testis. As Bclw is expressed in both Sertoli cells and diploid male germ cells, it has been unclear which of these cell types requires BCLW in a cell-autonomous manner for survival. To determine whether death of Sertoli cells in Bclw mutants is influenced by the protracted loss of germ cells, we examined testes from Bclw/c-kit double mutant mice, which lack germ cells from birth. Loss of BCLW-deficient Sertoli cells occurs in the absence of germ cells, indicating that germ cell death is not required to mediate loss of Sertoli cells in BCLW-deficient mice. This suggests that Sertoli cells require BCLW in a cell-intrinsic manner for long-term survival. The loss of Sertoli cells in Bclw mutants commences shortly after Sertoli cells have become postmitotic. In situ hybridization analysis indicates that Bclw is expressed in Sertoli cells both before and after exit from mitosis. Therefore, Bclw-independent pathways promote the survival of undifferentiated, mitotic Sertoli cells. We show that BAX and BAK, two closely related death-promoting members of the BCL2 family, are expressed in Sertoli cells. To determine whether either BAX or BAK activity is required for Sertoli cell death in Bclw mutant animals, we analyzed survival of Sertoli cells in Bclw/Bax and Bclw/Bak double homozygous mutant mice. While mutation of Bak had no effect, ablation of Bax suppressed the loss of Sertoli cells in Bclw mutants. Thus, BCLW mediates survival of postmitotic Sertoli cells in the mouse by suppressing death-promoting activity of BAX.

BH3-only proteins that bind pro-survival Bcl-2 family members fail to induce apoptosis in the absence of Bax and Bak

The BH3-only proteins Bim and Bad bind to the antiapoptotic Bcl-2 proteins and induce apoptosis in wild-type cells and cells from either bax(-/-) or bak(-/-) animals. In contrast, constitutively active forms of Bim and Bad failed to induce apoptosis in bax(-/-)bak(-/-) cells. Expression of Bax restored susceptibility of the cells to Bim and Bad. In addition, Bax but not Bim or Bad sensitized the bax(-/-)bak(-/-) cells to a wide variety of cell death stimuli including UV irradiation, chemotherapeutic agents, and ER stress. These results suggest that neither activation of BH3-only proteins nor suppression of pro-survival Bcl-2 proteins is sufficient to kill cells in the absence of both Bax and Bak. Furthermore, whereas mouse embryo fibroblasts (MEF) expressing only Bax or Bak displayed resistance to transformation, bax(-/-)bak(-/-) MEF were nearly as prone to oncogenic transformation as p53(-/-) MEF. Thus, the function of either Bax or Bak appears required to initiate most forms of apoptosis and to suppress oncogenic transformation.