Evaluating the role of total organic carbon in predicting the treatment efficacy of biosand filters for the removal of Vibrio cholerae in drinking water during startup.

AIMS: In biosand filters (BSF), treatment is largely driven by the development of a biolayer (schmutzdecke) which establishes itself during the startup phase. In this study, the effect of changing influent total organic carbon (TOC) loading on the removal efficiency of Vibrio cholerae in laboratory-operated BSFs was quantified. METHODS AND RESULTS: BSFs were charged with high, medium or low TOC influents and removal efficacy and schmutzdecke composition was monitored over 2 months. The highest V. cholerae removal efficiencies were observed in the BSF receiving the lowest TOC. Schmutzdecke composition was found to be influenced by influent TOC, in terms of microbial community structure and amount of extracellular polymeric substance (EPS). CONCLUSIONS: Physical/chemical attachment was shown to be important during startup. The BSF receiving influent water with lower TOC had a higher attachment coefficient than the BSF receiving high TOC water, suggesting more physical/chemical treatment in the lower TOC BSF. The high TOC BSF had more EPS than did the biofilm from the low-TOC BSF, suggesting that schmutzdecke effects may be more significant at high TOC. SIGNIFICANCE AND IMPACT OF THE STUDY: Overall, this study confirms that influent water characteristics will affect BSF treatment efficacy of V. cholerae especially during the startup phase.

Barriers to maternal health service use in Chikhwawa, Southern Malawi.

INTRODUCTION: Research was conducted to get a community's perspective on the factors contributing to continued maternal and neonatal deaths. The aim of the study was to identify and understand experiences, perceptions and needs of the community on maternal health service utilization. METHODS: Qualitative data was obtained through focus group discussions with community leaders, women, men and youth in the catchment areas of three remote health centres. A total of fourteen focus groups were held: three each with community leaders, men, women, boys and two with girls. Data was transcribed and analyzed manually through the use of thematic analysis. RESULTS: The discussions revealed the following as barriers to maternal health service utilization: walking long distances to access health facilities, lack of midwives, lack of or insufficient items to be used during delivery, long stay and rude health personnel. Seeking help from Traditional Birth Attendants (TBAs) during delivery was a common option because TBAs are within reach, do not demand many items for delivery, and treat the women with respect. CONCLUSION: This study suggests some factors that are contributing to the high burden of maternal deaths in Malawi. Interventions should be developed and implemented to improve the barriers reported.

Household and community variations and nested risk factors for diarrhoea prevalence in southern Malawi: a binary logistic multi-level analysis.

This paper examines household and community-level influences on diarrhoeal prevalence in southern Malawi. A Bayesian multi-level modelling technique is used in the estimation of hierarchically built data from a survey of individuals nested within households nested within communities. Households have strong unobserved influence on diarrhoeal illness (sigma(2)(u) = 4.476; 95% CI: 2.081, 6.871). A joint Wald test of significance shows that an individual's age [chi(2)(4) = 55.921, p = 0.000] and school [chi(2)(2) = 18.203, p = 0.000] have strong influence on an individual's diarrhoeal prevalence. An individual's history of malarial-like illness also has a strong positive relationship with diarrhoeal prevalence [beta = 0.606, p = 0.000]. Household factors that influence diarrhoea include employment status of head of household [beta = -0.619, p < 0.021], maternal age [beta = -0.013, p < 0.003], and size of household [beta = -0.669, p = 0.000]. The positive relationship between diarrhoea and malaria-like episodes highlights common risk factors hence the need for common approaches to combat the diseases. Significant household effects underline the importance of household considerations in policy issues.

Care-Seeking Behaviour and Implications for Malaria Control in Southern Malawi

Although malaria is a controllable and preventable disease; it remains among the leading causes of mortality and morbidity in southern Malawi. The importance of early diagnosis and prompt treatment with hospital prescribed drugs and effective home management to control malaria is well established; however; these in part depend on how households make their decisions when family members have suffered from malaria. This study examines the behaviour of households with regard to decisions they make in managing malaria illness. Using hierarchically built data from a survey of 1;400 mothers nested within 33 communities; a series of two-level logistic regression models with Bayesian estimation was used to determine predictors of care-seeking behaviour towards malaria when a family member or a child was perceived to have malaria. The results show that most families normally visit or use medication prescribed at health facilities for both adult (80) and child (86) members when they are perceived to have malaria. The main obstacle to accessing the nearest health facility was distance and transport costs (73) and the main problems encountered at health facilities were long waiting time or absence of health workers (73) and shortage of drugs (35). Among the main predictor variables for choices of treatment for childhood malaria was the absence of a health surveillance assistant for those that visited hospitals [Beta=0.56; 95CI:-0.86;-0.26]; bought medication from open markets [Beta=0.51; 95CI:0.20;0.82]; and those that used other traditional methods or did nothing [Beta=0.70; 95CI:-0.04;1.44; p=0.06].. The results have an important role to play in the control and prevention of malaria in Malawi. The results reveal the need for increased awareness about the dangers of purchasing drugs from non-medical and/or uncertified private institutions and sources such as those found in open markets. They also show the important role of community health workers in the delivery of health systems. The study recommends empowerment of community health workers through rigorous and relevant health promotion programmes to update both their knowledge and their skills in communication and counselling

Care-Seeking Behaviour and Implications for Malaria Control in Southern Malawi

Abstract:Although malaria is a controllable and preventable disease; it remains among the leading causes of mortality and morbidity in southern Malawi. The importance of early diagnosis and prompt treatment with hospital prescribed drugs and effective home management to control malaria is well established; however; these in part depend on how households make their decisions when family members have suffered from malaria. This study examines the behaviour of households with regard to decisions they make in managing malaria illness. Using hierarchically built data from a survey of 1;400 mothers nested within 33 communities; a series of two-level logistic regression models with Bayesian estimation was used to determine predictors of care-seeking behaviour towards malaria when a family member or a child was perceived to have malaria. The results show that most families normally visit or use medication prescribed at health facilities for both adult (80) and child (86) members when they are perceived to have malaria. The main obstacle to accessing the nearest health facility was distance and transport costs (73) and the main problems encountered at health facilities were long waiting time or absence of health workers (73) and shortage of drugs (35). Among the main predictor variables for choices of treatment for childhood malaria was the absence of a health surveillance assistant for those that visited hospitals [?=0.56; 95 CI:-0.86;-0.26]; bought medication from open markets [?=0.51; 95 CI:0.20;0.82]; and those that used other traditional methods or did nothing [?=0.70; 95

High quantum efficiency of near-infrared emission in bismuth doped AlGeP-silica fiber.

A self-calibrating method is described for measuring the radiative quantum efficiency (QE) in doped optical fibers. The method uses an integrating sphere to collect the fluorescence from the fiber, with pump light transmitted through the fiber end serving as a reference. QE measurements for a 780 or 808 nm pump were made on bismuth-doped AlGeP-silica fibers prepared by aerosol deposition. For both wavelengths, a value of QE=1.0+/-0.05 was obtained. Fluorescence was observed in two bands centered around 800 and 1300 nm, and the relative strength of these bands was found to vary with the pump wavelength.

Incidence of cryptosporidiosis species in paediatric patients in Malawi.

We determined the incidence of cryptosporidiosis in children aged <5 years presenting with diarrhoea in an urban and rural hospital-based setting in Malawi. Stools were collected over a 22-month period during both rainy and dry seasons. A range of microscopic methods were used to determine the presence of Cryptosporidium spp. oocysts. Species determination was by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of oocyst-extracted DNA using 18S rRNA and COWP gene loci. Cryptosporidium spp. oocysts were seen in 5.9% (50/848) of samples, of which 43 amplified by PCR-RFLP indicated the following species: C. hominis, C. parvum, C. hominis/C. parvum, C. meleagridis and C. andersoni. Seven samples could not be amplified by PCR. Wider species diversity was found in the rural setting, and may be a result of increased malnutrition and zoonotic exposure in this area. Improvements in water, sanitation, household hygiene and animal control are required to reduce the incidence of infection in this population.

Nerve conduction and sensorineural function in dental hygienists using high frequency ultrasound handpieces.

BACKGROUND: Oscillatory vibration from industrial power tools poses a well-recognized risk of peripheral nerve injury. There have been reports of elevated vibrotactile perception thresholds (VPT) among dentists, dental technicians, and dental hygienists, using rotary devices and ultrasonics. Elevated VPTs are an indicator of small fiber nerve or mechanoreceptor injury, but the high frequencies associated with dental instruments are presumed by the ISO to exceed physiological response upper thresholds. This study examines nerve conduction and sensorineural deficits in dental hygienists. METHODS: A cross-sectional study of 94 experienced dental hygienists was conducted to assess peripheral nerve function and clinical signs and symptoms. Specialized testing included measurement of VPTs for three different categories of mechanoreceptors, sensory nerve conduction tests with fractionated digit and palmar segments, and measurement of calibrated pinch force with force sensitive resistors (FSRs) during a simulated procedure. RESULTS: Chronic hand paresthesias were described by 44.7% of experienced dental hygienists. Sensory nerve conduction velocity (SNCV) across the wrist-palm segment of the median nerve. VPTs were particularly elevated at the FAII mechanoreceptor among experienced dental hygienists. Compared to participants without carpal tunnel syndrome (CTS), as defined by study criteria, 14 experienced hygienists with diagnosed CTS had almost twice the average weekly use of vibratory instruments -8.3 hr versus 4.5 hr, and had SNCV deficits along the digit -47.11 m/sec (+8.70) versus 42.57 m/sec (+8.25), and across the wrist -44.04 m/sec (+7.15) versus 41.36 m/sec (+9.27). There was a distinct subset of dental hygienists (27%) with a combination of low calibrated pinch force in simulations, subjective loss of strength and elevated VPTs, especially in the FAII mechanoreceptor population -110.82 db (+8.57) versus 104.84 db (+6.80) in the rest of the cohort. This subset also had a higher prevalence of paresthesias (67% vs. 39%) and greater cumulative vibration exposure (OR = 1.206 [CI 1.005-1.448]), than other hygienists. CONCLUSIONS: The high levels of paresthesias observed among dental hygienists appear to be attributable to several pathophysiological mechanisms, including, sensory nerve demyelination at the carpal tunnel and intrinsic to the digits, and dysfunction of fingertip mechanoreceptors. A distinct sub-population appears to exhibit a high level of accumulated abnormality.

Intra-cavity fiber laser technique for high accuracy birefringence measurement.

When a device under test (DUT) with birefringence is placed within a laser cavity two distinct sets of orthogonally polarized longitudinal modes will result. If the output of the laser is sent through a 45(o) linear polarizer, polarization mode beating (PMB) between these two sets of longitudinal modes can be detected. We demonstrate the relation between PMB and the birefringence of the DUT and show that by tracking the PMB it provides a sensitive measurement of the birefringence of the device. We first examined the birefringence of a Newport PM fiber and then measured the birefringence of a 3M (Austin, TX) Chirped grating 1.0 m in length. For comparison, birefringence measurements were performed using a Hewlett-Packard Polarization Analyzer (HP 8509B).

Segmental nerve conduction velocity in vibration-exposed shipyard workers.

OBJECTIVES: Segmental sensory nerve conduction velocity (SNCV) was measured from the wrists to the hands and digits of a population of vibration-exposed shipyard workers. This study was designed to investigate whether SNCV was selectively slowed in the fingers and whether a laboratory approach could be adapted for robust field use. METHODS: Wrist-palm, palm-proximal digit, and digital segments were determined from stimulation at the wrist with recording electrodes placed distally and adjusted to individual anatomy. The cohort was selected on the basis of current use of vibratory tools. RESULTS: Wrist-palm and digital segments were slower than palm-proximal digit segments for dominant and non-dominant hands and for both ulnar and median nerves. In the dominant-hand median nerve of participants with current exposure, the SNCV was 41.4 m/s (SD 8.0) for the wrist-palm segment, 50.8 (SD 9.5) for the palm segment, and 42.1 m/s (SD 9.3) for the digital segment. Temperature had an important effect on nerve conduction velocity but not equally across segments. Other explanatory variables had modest effect on SNCV. CONCLUSIONS: Reduced SNCV in the digits may be a consequence of industrial exposure to vibration. Each sensory nerve segment appeared to have a different characteristic velocity and different pattern of association with skin temperature. There are differences between median and ulnar nerve segments, with potentially important consequences when standard distances are used to assess wrist-digit velocity.

Skin temperature recovery from cold provocation in workers exposed to vibration: a longitudinal study.

BACKGROUND: Vibration white finger (VWF) is characterised by arterial hyperresponsiveness and vasoconstriction following cold provocation. Several years after of removal from exposure, most subjects show improved finger systolic blood pressure (FSBP) under conditions of cold challenge, but continue to report cold hands and finger blanching. AIMS: To assess the underlying reasons for the persistence of cold symptoms. METHODS: A total of 204 former users of pneumatic tools with cold related hand symptoms were evaluated and then re-evaluated a year later. Symptoms were evaluated using the Stockholm Workshop Scale. Finger systolic blood pressure per cent (FSBP%) was assessed by comparing digital blood pressure in a cold provoked and normalised state. Fingertip skin temperature was measured during cooling and occlusion and during rewarming and recovery. RESULTS: There were dramatic improvements in FSBP% (14.3 mm Hg %), modest improvement in recovered skin temperature (0.86 degrees C), and no change in symptom stage. When the most symptomatic subjects (n = 75) were compared with the less symptomatic subjects (n = 129), there were similar inter-test improvements in FSBP%. Skin temperature recovery improved in the less symptomatic (+1.49 degrees C), but did not change in the most symptomatic group (-0.12 degrees C). However, the more symptomatic group had higher temperatures at the initial test, thus qualifying the result. CONCLUSIONS: Skin temperature recovery after cold challenge in subjects with VWF remains reduced in the symptomatic subjects several years after exposure removal. This is evident even when blood pressure has increased in the setting of cold provocation. Results suggest that in VWF, the dermal circulation remains impaired, even after the restoration of arterial blood pressure in the digits.

Broadband amplified spontaneous emission from an Er(3+)-Tm(3+)-codoped silica fiber.

A new type of amplified spontaneous emission (ASE) based on an Er-Tm-codoped silica fiber is reported. When the fiber was pumped at 980 nm, the emission yielded a 3-dB bandwidth over 90 nm (1460-1550 nm) without any external filters, which is twice larger than that produced by conventional Er-doped fiber ASE sources. We believe that the superposition of two ASE bands, one from Er ions near 1530 nm and the other from Tm ions near 1450 nm, results in the broad bandwidth. Temperature-dependent ASE powers and fiber-length-dependent spectra strongly suggest that photon-assisted energy transfer between the sensitizing ion, Er, and the acceptor ion, Tm, plays an important role in changes in the bandwidth's size.

The creation of ergonomic data sheets for hazard communication of work-related musculoskeletal disorders.

Information on human health hazards caused by chemical exposure has traditionally been supplied through Material Safety Data Sheets (MSDS). This report describes development of an analogous Ergonomic Data Sheet (EDS) to address hazards of work-related musculo-skeletal disorders (WRMSD) from use of hand tools. The EDS includes sections on risk factors for WRMSD, design aspects of the tool that decrease risks, precautionary measures, and objective testing of the tool compared to other comparable tools. The EDS can be used within an Ergonomic Communication Program similar to a Hazard Communication Program.

MMPI-2 fake-bad scales: an attempted cross-validation of proposed cutting scores for outpatients.

Minnesota Multiphasic Personality Inventory-2 (MMPI-2) results were compared in 118 psychiatric outpatients given standard instructions, instructions to exaggerate their problems, instructions to feign a disorder they did not have, or instructions to feign global psychological disturbance. The groups were comparable on demographic, occupational and diagnostic characteristics as well as intake MMPI-2 results. Experimental MMPI-2 results showed that clinical scales were generally elevated in the feigning groups, with only modest differences across dissimulating instruction sets. The feigning groups had reliably higher scores than controls on all overreporting indexes examined, although no significant differences between feigning groups were present for overreporting indexes. Classification rates using previously proposed cutting scores for outpatients on individual feigning indexes showed near perfect specificity, but low to at best moderate sensitivity. Multiple regression analyses indicated that Gough's (1954) Dissimulation Scale (Ds2) was most strongly related to feigning status, and no other feigning scale contributed a significant increment in predictive power once Ds2 was entered.

Capture-recapture estimation of unreported work-related musculoskeletal disorders in Connecticut.

BACKGROUND: Estimates of the extent of musculoskeletal disorders (MSD) are usually based upon workers' compensation reports, although recent reports indicate that there may be widespread under-reporting of MSD. METHODS: An estimate of the incidence of arm and hand work-related MSD was made using capture-recapture analysis of the overlap between state workers' compensation reports and physician reports in Connecticut for 1995. The resulting estimate was compared to a population-based survey of MSD. RESULTS: There was very small overlap between the two state injury reporting systems: 6.7% of 793 reported workers' compensation cases, or 8% of 661 physician's reports. The estimate for MSD not captured by either system was 13,285, resulting in 14,686 (95% CI: 9,733-18,453) total reported and non-reported cases. This compares to an estimate of 13,775 cases (95% CI: 8,800-18,800) based on a phone survey. CONCLUSIONS: This analysis points to substantial under-reporting of MSD in Connecticut: estimates of unreported cases exceed those officially reported by a factor of 11:1. The findings have an important bearing on injury prevention programs and policy making.

Pharmacokinetics and safety of oral eletriptan during different phases of the menstrual cycle in healthy volunteers.

The purpose of this study was to determine the pharmacokinetics and safety of eletriptan in different phases of the menstrual cycle. Female volunteers (n = 16) with a regular menstrual cycle (28 +/- 4 days) received a single oral dose of 80 mg eletriptan during each of the four cycle phases: phase 1 (menses), days 1 to 4; phase 2 (follicular), days 6 to 10; phase 3 (ovulatory), days 11 to 13; and phase 4 (luteal), days 21 to 24. Eletriptan plasma concentrations were determined from serial plasma samples taken during a 24-hourperiod after dosing. Blood pressure, pulse rate, and ECG measurements were performed at baseline, 1 and 24 hours after dosing. No significant differences between phases were observed for maximum plasma concentration (cmax, range of means = 188-234 ng/ml), time to maximum concentration (tmax, range of means = 1.8-2.5 h), or systemic exposure (area under the curve [AUC], range of means = 1194-1514 ng x h/ml). Although there was a statistically significant difference in the terminal phase elimination rate constant (kel) between phases 1 and2 (0.175/h vs. 0.158/h, p = 0.044), the corresponding difference in terminal phase half-life (t 1/2) (4.0 h vs. 4.4 h) was not considered to be clinicallyrelevant. No clinically relevant differences in blood pressure, pulse rate, or ECG were observed, and the incidence, nature, and severity of adverse events were similar in all phases. The different phases of the menstrual cycle had no clinically significant effect on the pharmacokinetics, safety, or tolerability of oral 80 mg eletriptan in healthy females.

A unitary patient record improves admission documentation in a medical assessment unit in a major teaching hospital.

OBJECTIVE: To ascertain the impact of the introduction of a unitary patient record (UPR) on clerking documentation of emergency medical admissions. DESIGN: Retrospective casenote audit. SUBJECTS AND SETTING: Random sample of 100 unselected admissions to the medical assessment unit of a major teaching hospital, comprising two groups pre- and post-introduction of the UPR. RESULTS: Statistically significant improvements in the documentation of several items were achieved; function before episode, ethnic origin, chest pain, breathlessness, ankle oedema, cough, bowel habit and locomotor symptoms and recording of blood pressure and peripheral pulses. There were trends towards improvement in other areas and there were no areas in which the UPR performed less well than standard documentation. CONCLUSIONS: Introduction of the UPR represents the successful application of multidisciplinary principles to over 10,000 acute general medical admissions. It has improved some, but not all, aspects of documentation. Revision of the design of the UPR should lead to further progress, as part of an ongoing process of development and re-audit.

The effects of ketoconazole on ziprasidone pharmacokinetics--a placebo-controlled crossover study in healthy volunteers.

AIMS: To assess the effects of multiple oral doses of ketoconazole on the single-dose pharmacokinetics of oral ziprasidone HCl. METHODS: This was a 14-day, open-label, randomized, crossover study in 14 healthy subjects aged 18-31 years. Group 1 received oral ketoconazole 400 mg once daily for 6 days, followed by a 2 day wash-out period and 6 days of placebo administration. Group 2 received placebo followed by ketoconazole. Single oral doses of ziprasidone HCl 40 mg were administered on days 5 and 13 in both groups. Ziprasidone pharmacokinetic parameters were compared between placebo and ketoconazole administration periods. RESULTS: Co-administration of ziprasidone with ketoconazole was associated with a modest increase in ziprasidone exposure; mean ziprasidone AUC(0,infinity) increased by 33%, from 899 ng ml(-1) h with placebo to 1199 ng ml(-1) h with ketoconazole. Mean Cmax increased by 34%, from 89 ng ml(-1) to 119 ng ml(-1), respectively. The treatment effect on both of these parameters was statistically significant (P<0.02). Most adverse events were of mild intensity. There were no serious adverse events, laboratory abnormalities, abnormal ECGs, or clinically significant alterations in vital signs throughout the study. CONCLUSIONS: The concurrent administration of ketoconazole and ziprasidone led to modest, statistically significant increases in ziprasidone exposure, although the changes seen were not considered clinically relevant. This suggests that other inhibitors of CYP3A4 are unlikely to significantly affect the pharmacokinetics of ziprasidone.

Biomechanical, psychosocial, and organizational risk factors for WRMSD: population-based estimates from the Connecticut upper-extremity surveillance project (CUSP).

In a case-control study of a population-based telephone survey of 3,798 working adults, symptoms of work-related musculoskeletal disorder (WRMSD) were associated with biomechanical, psychosocial, and organizational factors. In several models, biomechanical exposures with strong associations were static postures (odds ratios [ORs] = 2.00-5.45); repeated pushing, pulling, lifting (ORs = 1.86-12.75); and repeated neck bending (ORs = 1.07-12.8). Psychosocial and organizational factors consistently retained in these models were demands (ORs = 1.26-1.59) and organizational support (ORs = 0.53-0.79). Decision latitude entered less frequently (ORs = 0.30-0.49). This research may have implications for intervention strategies. First, reducing both biomechanical and psychosocial risk may be more effective than focusing solely on engineering controls. Second, organizational culture and policy may have strong implications for WRMSD prevalence and control.

Occupational disease in Connecticut, 2000.

This study was designed to establish the magnitude and distribution of reported occupational diseases in Connecticut based on 1998 data. Occupational disease is a reportable disease in Connecticut, yet is under-reported particularly for chronic conditions. The number of reported occupational diseases was 3,556 from workers' compensation reports, 1,444 from physician reports, and 5,510 from the Connecticut OSHA-Labor Department survey. Musculoskeletal disorders dominate the reports in all three databases, ranging from 46% to 62% of all illness reports. Skin conditions range from 8% to 18%; lung conditions from 9% to 16%; and infections from 1% to 18%. There are approximately 1.52 million workers in Connecticut, which results in a rate of 36.2 cases of occupational disease per 10,000 workers based on the Bureau of Labor Statistics figures. These conditions are broken down by type, industry, and cause. Improved identification of work linkages can lead to better treatment and job placement, as well as improved prevention.