Age and sex-specific disability-free life expectancy in urban and rural settings of Bangladesh

BACKGROUND

Disability-free life expectancy (DFLE) has been used to gain a better understanding of the population's quality of life.

OBJECTIVES

The authors aimed to estimate age and sex-specific disability-free life expectancy (DFLE) for urban and rural areas of Bangladesh, as well as to investigate the differences in DFLE between males and females of urban and rural areas.

METHODS

Data from the Bangladesh Sample Vital Statistics-2016 and the Bangladesh Household Income and Expenditure Survey (HIES)-2016 were used to calculate the disability-free life expectancy (DFLE) of urban and rural males and females in Bangladesh in 2016. The DFLE was calculated using the Sullivan method.

RESULTS

With only a few exceptions, rural areas have higher mortality and disability rates than urban areas. For both males and females, statistically significant differences in DFLE were reported between urban and rural areas between the ages of birth and 39 years. In comparison to rural males and females, urban males and females had a longer life expectancy (LE), a longer disability-free life expectancy, and a higher share of life without disability.

CONCLUSION

This study illuminates stark urban-rural disparities in LE and DFLE, especially among individuals aged < 1-39 years. Gender dynamics reveal longer life expectancy but shorter disability-free life expectancy for Bangladeshi women compared to men, emphasizing the need for targeted interventions to address these pronounced health inequalities.

Association of dietary diversity of 6-23 months aged children with prenatal and postnatal obstetric care: evidence from a nationwide cross-sectional study

BACKGROUND

Dietary diversity is a key determinant of infant and young child eating patterns for a variety of food groups taken by children between the ages of 6-23 months. The study aimed to examine the association between prenatal and postnatal obstetric care factors of mother and child's dietary diversity, and specific food practices in Bangladesh.

METHODS

This study analyzed the data of 2497 children between the age of 6-23 extracted from the latest countrywide Bangladesh Demographic Health Survey 2017-2018 and explored relationships between prenatal and postnatal obstetric care received by mother and dietary diversity score (DDS), minimum dietary diversity (MDD), and introduction of solid, semi-solid, and soft foods (ISSSF) of their children.

RESULTS

Findings revealed that ≥ 4 antenatal care (ANC) visits care visits increased the DDS (adjusted [Formula: see text]: 0.32, 95% CI [0.21, 0.43]), increased the likelihood of MDD (AOR 1.54, 95% CI [1.23, 1.93]), and ISSSF (AOR 1.24, 95% CI [1.08, 1.48]), consuming eggs (AOR 1.47, 95% CI [1.23, 1.76]), and vitamin A vegetables and fruits (AOR 1.38, 95% CI [1.15, 1.66]). Moreover, DDS (adjusted β: 0.05, 95% CI [0.00, 0.11]) and MDD (AOR 1.66, 95% CI [1.31, 2.11]) are linked to childbirth in a medical facility. The C-section delivery influences the DDS (adjusted [Formula: see text]: 0.05, 95% CI [0.00, 0.10]), MDD (AOR 1.39, 95% CI [1.10, 1.75]), and ISSSF (AOR 1.22, 95% CI [1.02, 1.48]). Besides, postnatal visits within 48 h of delivery linked to MDD (AOR 0.66, 95% CI [0.49, 0.89]) and ISSSF (AOR 0.76, 95% CI [0.59, 0.97]), and physicians or professionals providing postnatal checkups were significantly associated with DDS (adjusted [Formula: see text]: 0.09, 95% CI [0.02, 0.16]), MDD (AOR 1.69, 95% CI [1.26, 2.26]), and ISSSF (AOR 1.30, 95% CI [1.04, 1.62]).

CONCLUSION

Knowledge of child nutritional feeding should emphasize during prenatal and postnatal obstetric care of mother, particularly during antenatal and postnatal visits, C-section delivery, and birth in a healthcare facility to eradicate malnutrition and establish healthy child feeding practices.

Positive impacts of COVID-19 Lock down in Bangladesh: An online investigation

Background

This research focuses on the positive impacts of the COVID-19 lockdown on society and the environment, despite acknowledging the widespread negative effects of the pandemic and lockdown measures. The research was aimed at pinpointing and evaluating the beneficial results stemming from these measures.

Method

Data for the study was collected through an online survey distributed via Google forms to adults over the age of 18 across the country. A total of 1230 participants completed the survey, mostly from rural areas (61.7%), providing valuable insights for analysis. The questionnaire encompassed personal, family, and cohesive social data, along with information on the environment and biodiversity. The study utilized structural equation modeling (SEM) and confirmatory factor analysis (CFA) to analyze the data and examine correlations between variables.

Results

The findings indicated that the COVID-19 lockdown had positive implications for individuals and society, leading to increased health consciousness, improved family relationships, and constructive social attitudes. Moreover, restrictions on access to natural tourist destinations and parks during the lockdown contributed to positive changes in biodiversity. These results highlight the importance of adopting appropriate measures during pandemics to foster personal and social well-being, as well as the preservation of natural environments and biodiversity.

Conclusion

This study emphasizes the need for further research to promote sustainable living in similar situations. By understanding the data appropriately, individuals can play a constructive role in future pandemics, leading to positive outcomes for both society and the environment.

Influencing factors associated with maternal delivery at home in urban areas: a cross-sectional analysis of the Bangladesh Demographic and Health Survey 2017-2018 data

BACKGROUND

The associated factors and patterns of giving birth in home settings of rural areas have been extensively studied in Bangladeshi literature. However, urban areas still need to be explored, particularly with recent data. Therefore, the authors aimed to investigate the influential determinants of delivery at home in urban areas of Bangladesh.

MATERIALS AND METHODS

In this study, 1699 urban-dwelling women who had given birth within the previous 60 months of the survey and lived in urban areas were used. The secondary data were extracted from the latest Bangladesh Demographic and Health Survey 2017-2018. Descriptive statistics and logistic regression were applied along with the association among selected variables were examined by the Chi-square test.

RESULTS

Findings depict that 36.49% of women who lived in urban areas of Bangladesh delivered at home, whereas, 63.51% delivered at different govt. and private health care facilities. Women who lived in Chittagong [adjusted odds ratio (AOR) = 2.11, 95% CI 1.24-3.60], Barisal [AOR = 2.05, 95% CI 1.16-3.64] and Sylhet [AOR = 1.92, 95% CI 1.08-3.43] divisions have more likelihood to deliver at home (36.85%). Urban women following Christian religion [AOR = 10.71, 95% CI 1.32-86.68] have higher odds of delivering child at home (0.47%). Urban women having three or more children before her latest delivery (22.37%) and who are employed (29.37%) have more likelihood to deliver at home. However, women aged between 25 and 34 years (43.50%), who have higher education (25.90%), play the role of household head (9.06%), have parity of more than two births (2.24%), and read daily newspapers (68.69%) had a lower chance of delivery at home. Furthermore, women from wealthier families (89.12%) and more antenatal care (ANC) visits (94.93%) were less likely to have a delivery at home.

CONCLUSION

Despite significant progress in women and reproductive health in Bangladesh, the proportion of delivery in the home in urban areas is alarming and should be emphasized more. The authors believe the identified factors will help design interventions and policy development on this issue.

An extendable optical fibre probe survey meter for naturally occurring radioactive material (NORM) and other weak emitters

We have developed a radioluminescence-based survey meter for use in industries in which there is involvement in naturally occurring radioactive material (NORM), also in support of those needing to detect other weak emitters of radiation. The functionality of the system confronts particular shortcomings of the handheld survey meters that are currently being made use of. The device couples a LYSO:Ce scintillator with a photodetector via a polymer optical fibre waveguide, allowing for "intrinsically safe" inspection within pipework, separators, valves and other such component pieces. The small-diameter optical fibre probe is electrically passive, immune to electromagnetic interference, and chemically inert. The readout circuit is entirely incorporated within a handheld casing housing a silicon photomultiplier (SiPM) detection circuit and a microprocessor circuit connected to an LCD display. A 15 m long flexible PMMA optical fibre waveguide is butt coupled to an ABS plastic probe that retains the LYSO:Ce scintillator. Initial tests have included the use of lab-based mixed gamma-ray sources, measurements being made in concert with a reference conventional GM survey-meter. Characterization, via NORM sources at a decontamination facility, has shown useful sensitivity, covering the dose-rate range 0.10- to 28 µSv h^-1 (R-squared 0.966), extending to 80 µSv/h as demonstrated in use of a Cs-137 source. The system is shown to provide an effective tool for detection of radioactivity within hard to access locations, in particular for sources emitting at low radiation levels, down to values that approach background.

Point of care ultrasound: Current and future directions for Acute Medicine

Point of care ultrasound (POCUS) represents an exciting tool for current and future acute care practitioners. POCUS has come a long way in a short space of time and its widespread implementation may well be one of the biggest changes seen in acute medicine across the next decade. This narrative review explores the increasing evidence base for the accuracy of POCUS use in various acute scenarios, whilst also addressing current gaps in the evidence and areas for potential future POCUS development.

Review of stentless, tubeless, apposed renal (STAR) transplant wound management programme

INTRODUCTION We aimed to review the necessity of conventional interventions in renal transplant for preventing complications arising out of the use of wound drains, ureteral stents and stapled skin closures. METHODS We reviewed a series of 33 patients who received stentless, tubeless/drainless and suture-apposed living donor renal transplants (STAR group) and compared the results to a control non-STAR group of 36 patients in whom all three interventions of drains, stents and skin staples were used. RESULTS No significant differences in demographics and clinical characteristics were observed between the two groups. With regard to the overall surgical complications, no significant differences in terms of wound infection, seroma, perinephric collections, urinoma, bacteriuria or vascular complications were observed between the groups. When analysed according to the interventions specific for preventing complications, although slightly more asymptomatic perinephric collections were observed and two lymphoceles required treatment in the STAR group, these differences were not statistically significant. Similarly, no significant differences in ureteric or skin-related complications were observed between the groups. Both groups had comparable good outcomes for renal function, graft survival and patient survival. CONCLUSION The routine use of ureteric stents, drains or skin staples may not be necessary for uncomplicated renal transplants. Potential complications associated with the placement of these interventions can be avoided without compromising on the safety of patients and/or the outcome of transplants.

THU0604 UNDIAGNOSED RHEUMATIC DISEASE IN NEWLY PRESENTING MGUS PATIENT

Background:

Monoclonal gammopathy of undetermined significance (MGUS) is considered to be a premalignant condition with on average of 1% annual risk of progression to multiple myeloma or other lymphoproliferative disorders [1]. Numerous studies have highlighted a common feature of autoimmune inflammatory diseases is non-specific hypergammaglobulinaemia which can be associated with monoclonal gammopathy [2, 3]. We looked at a population of 3.6 million where patients with MGUS was referred to haematology network for evaluation.

Objectives:

Our hypothesis was that undiagnosed rheumatic diseases were being referred to haematology rather than rheumatology erroneously.

Methods:

The Haematological Malignancy Research Network (HMRN) ethics approval (REC 04/01/1205/69) from Leeds West Research Ethics Committee. The HMRN that comprises a population-based cohort of patients newly diagnosed by a single integrated haemato-pathology laboratory in two adjacent UK Cancer Networks (population 3.6 million). The database includes prognostic factors, sequential treatment/response history and socio-demographic details which are recorded to clinical trial standards. 255 patients were screened in this study. We looked at a range of autoimmune/innate immune conditions diagnosed after MGUS.

Results:

In the 255 patients cohort group, the average age at the diagnosis of MGUS was 70.23 ± 11.95 years (median 70.2 years), with more subjects being male (n=145, 56.9%). Mean duration of follow up was 2570 days. 10 out of the 255 patients progressed onto multiple myeloma.

Diagnosed rheumatic disease was found in 48 patients (18.8%). None of the patient in this group has disease progression to multiple myeloma. In this group, 37 patients (14.5%) presented the rheumatic disease before their MGUS diagnosis and 11 (4.3%) were diagnosed after their MGUS referral. Interestingly, among the 11, more males(n=8, 72.7%) have their rheumatic disease diagnosed after MGUS.

Those 11 cases included crohn’s disease (1), polymyalgia rheumatica (2), immune thrombocytopenia (2), autoimmune hepatitis (2), Schnitzler’s syndrome (1), giant cell arteritis (1), rheumatoid arthritis (2).

Conclusion:

Approaching 1 in 20 cases of MGUS have an underlying inflammatory disease that may often be non-specifically driving antibody production including monoclonal band formation. When diagnosing MGUS, clinicians should be aware of the potential underlying autoimmune rheumatic conditions.

References:

[1]Kyle, R.A., et al.,A long-term study of prognosis in monoclonal gammopathy of undetermined significance.N Engl J Med, 2002.346(8): p. 564-9.

[2]Renier, G., et al.,Ankylosing spondylitis and monoclonal gammopathies.Ann Rheum Dis, 1992.51(8): p. 951-4.

[3]Sugai, S., et al.,Non-IgM monoclonal gammopathy in patients with Sjogren's syndrome.Am J Med, 1980.68(6): p. 861-6.

Disclosure of Interests:

Qiao Zhou: None declared, Kaiwen Wang: None declared, Laiba Rahman: None declared, Abdulla Watad: None declared, Sinisa Savic: None declared, Eve Roman: None declared, Dennis McGonagle Grant/research support from: Janssen Research & Development, LLC

Why has the caesarean rate increased dramatically in Bangladesh?

OBJECTIVE

The objective is to assess the reasoning by families in deciding between a home vs. facility delivery and vaginal vs. caesarean.

STUDY DESIGN

The authors selected a convenience sample of 16 villages in Sathkira district in southwest Bangladesh. Evidence was drawn from detailed in-home post-delivery interviews with all mothers in these villages who delivered in 2015 or 2016.

METHODS

Local family health workers and paramedics used a structured questionnaire that enabled gathering of relevant quantitative and qualitative evidence. Mothers' reasons for selection of delivery location and type were categorized, and regression analysis was conducted to assess significance of variables that proxy supply and demand factors.

RESULTS

Among 492 completed interviews, 48% were home deliveries, 52% facility deliveries; two-thirds of facility deliveries in private clinics. Overall, sample caesarean rate is 39%, public hospital rate 53%, private clinic rate 86%. Over half of reasons for home delivery refer to pregnancy without complication or access to trusted birth attendant. Over half of reasons for facility delivery refer to medical complications allegedly precluding home delivery, or requiring home-to-facility transfer during labour for reasons not clear to the mother. The decision depends on both 'demand' factors originating with the family (proxied by family income, birth order and education levels) and 'supply' factors originating with obstetric care providers (proxied by number of antenatal visits and variation of caesarean rate by village). In a regression controlling for both demand and supply variables, the above proxy variables are all significant.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

Bangladesh has inadequate nursing support for vaginal delivery in either home or facility. Hence, physicians frequently recommend that women deliver in a facility (usually a physician's clinic). Physicians are reluctant to hire adequate nurses to attend vaginal deliveries. Hence, families with some discretionary income are increasingly opting for a caesarean over vaginal delivery. Facility deliveries reduce incidence of obstructed labour fistula, but probably contribute to rising incidence of iatrogenic fistula. Reducing caesarean rates requires a large increase in numbers of nurses and midwives, and acceptance by physicians of a broad scope of practice for nurses/midwives in vaginal deliveries.

Extreme chromosomal instability forecasts improved outcome in ER-negative breast cancer: a prospective validation cohort study from the TACT trial

BACKGROUND

Chromosomal instability (CIN) has been shown to be associated with drug resistance and poor clinical outcome in several cancer types. However, in oestrogen receptor (ER)-negative breast cancer we have previously demonstrated that extreme CIN is associated with improved clinical outcome, consistent with a negative impact of CIN on tumour fitness and growth. The aim of this current study was to validate this finding using previously defined CIN thresholds in a much larger prospective cohort from a randomised, controlled, clinical trial.

PATIENTS AND METHODS

As a surrogate measurement of CIN, dual centromeric fluorescence in situ hybridisation was performed for both chromosomes 2 and 15 on 1173 tumours from the breast cancer TACT trial (CRUK01/001). Each tumour was scored manually and the mean percentage of cells deviating from the modal centromere number was used to define four CIN groups (MCD1-4), where tumours in the MCD4 group were defined as having extreme CIN.

RESULTS

In a multivariate analysis of disease-free survival, with a median follow-up of 91 months, increasing CIN was associated with improved outcome in patients with ER-negative cancer (P trend = 0.03). A similar pattern was seen in ER-negative/HER2-negative cancers (Ptrend = 0.007).

CONCLUSIONS

This prospective validation cohort study further substantiated the association between extreme CIN and improved outcome in ER-negative breast cancers. Identifying such patients with extreme CIN may help distinguish good from poor prognostic groups, and therefore support treatment and risk stratification in this aggressive breast cancer subtype.

Amelogenesis imperfecta: a diagnostic and pathological review with case illustration

Amelogenesis mperfecta is an inherited disorder of enamel development, which results n morphological defects of both the primary and secondary dentition, usually in the absence of systemic involvement. Mutational defects involving the genes that encode for enamel matrix proteins and proteinases are mplicated in this disorder. The phenotypic expression is variable, spanning a spectrum from barely discernible changes to severe aesthetic and functional enamel defects. The specific type and location of the genetic mutation, as well as the mode of inheritance, determine the clinical presentation Clinical recognition and early therapeutic intervention are required for the most successful outcome. An essentia component of the treatment process includes patient counselling and education. Patient management requires a dedicated multi-disciplinary approach. The disorder is reviewed here with emphasis on the clinical significance for the oral healthcare worker. In addition, a case is presented in order to provide an example of treatment panning and dental management.

Factors associated with the development of impulse compulsive disorders in Parkinson patients

OBJECTIVE

The aim of this study is to identify the prevalence of impulse compulsive disorder (ICD) in Parkinson's disease (PD) patients and to study potential associative factors that may be related to the onset of ICD while on parkinsonian medications.

METHOD

The study was conducted in two parts. In Part A, the prevalence of ICD in 140 PD patients was first assessed, followed by identifying any common variables that may be associated with the development of ICD. Finally, using a detailed chart review, Part B of the study examined the prevalence of ICD in all patients who presented with identical risk factors gathered in Part A.

RESULTS

Of the 140 patients, 8 patients developed symptoms of ICD. Seven of these patients were found to have five common variables that included gender (males), stages 1-2 of PD, young onset of PD, maximum dosage of the drug and the use of dopamine agonists (DAs). Of the 140 patients, 22 patients fit the above-mentioned five criteria and of those 22 patients, 33% developed symptoms of ICD.

CONCLUSION

The use of DA therapy in the treatment of PD patients should be carefully monitored, especially in younger male patients who exhibit early signs of parkinsonian symptoms. As such, it is crucial for physicians to adjust DA dosages while also seeking alternative treatments to avoid the risk of ICD while on DAs.

GENOTYPIC AND PHENOTYPIC CORRELATION AND PATH ANALYSIS FOR LODGING RESISTANCE TRAITS IN BREAD WHEAT (Triticum aestivum L.)

Relationships between the traits associated with lodging resistance in wheat were studied within the period of 1999-2002 at Wheat Research Center, Dinajpur in both F1 and F2 generations of a 9 × 9 diallel cross without reciprocal. The genotypic and phenotypic correlation coefficients studied in F1 and F2 generations were similar with some exceptions. In both F1 and F2 generation, the second internode breaking strength was positively correlated with diameter, wall thickness and unit-stem weight of second internode, and main shoot weight but negatively with plant height and second internode length at both genotypic and phenotypic levels. It was observed from path coefficient analysis in both F1 and F2 generations that the second internode unit-stem weight had high positive direct effect on it’s breaking strength. Main shoot weight, second internode diameter and wall thickness positively influenced breaking strength through its unit-stem weight. Simultaneous selection for the traits contributing to lodging resistant in semi-dwarf wheat might be effective in the improvement of lodging resistance in bread wheat.DOI: http://dx.doi.org/10.3329/bjpbg.v20i2.17036

Transgenic expression of human thymidylate synthase accelerates the development of hyperplasia and tumors in the endocrine pancreas

Thymidylate synthase (TS) is an essential enzyme for DNA synthesis and repair and elevated levels of TS have been identified as an important prognostic biomarker for colorectal cancer and several other common human malignancies. In addition, TS gene expression has been linked with cell-cycle regulation and cell proliferation through the ability of retinoblastoma protein to repress the transcriptional activation of E2F target genes such as TS. Therefore, overproduction of TS could participate in the progression to a neoplastic phenotype. Consistent with this model, a recent study has suggested that ectopic TS expression can induce a transformed phenotype in mammalian cells. To investigate the role of deregulated TS activity in tumor development, we generated transgenic mice that express high levels of catalytically active human TS (hTS) exclusively in the pancreas and low levels of hTS in multiple other tissues. Analyses of pancreatic tissue in TS transgenic mice revealed abnormalities within the endocrine pancreas, ranging from pancreatic islet hyperplasia to the detection of islet cell tumors. Overexpression of hTS in murine islets provides a new model to study genetic alterations associated with the progression from normal cells to hyperplasia to islet cell tumors, and suggests that this mouse model may be useful for regulating TS activity in vivo for development of cancer prevention and new therapies.

EGFRvIII undergoes activation-dependent downregulation mediated by the Cbl proteins

The overexpression or mutation of tyrosine kinases (TKs), such as the epidermal growth factor receptor (EGFR), can lead to the development of cancer. The most common mutation of the EGFR in glioblastomas is the deletion of exons 2-7 known as the EGFRvIII. This mutant receptor cannot bind EGF but, instead, is constitutively active. The Cbl family of ubiquitin ligases (Cbl, Cbl-b, and Cbl-c) targets the activated EGFR for degradation. As the EGFRvIII is transforming, we investigated whether it could be downregulated by the Cbl proteins. The overexpression of all three Cbl proteins resulted in the ubiquitination and degradation of the EGFRvIII. As with the wild-type EGFR, the TK-binding domain and the RING finger of Cbl-b are sufficient for the downregulation of the EGFRvIII. Also, we found that Cbl-b is recruited to the EGFRvIII and inhibits the transformation of NIH 3T3 cells by the EGFRvIII. Mutation of the Cbl-binding site (Y1045F) in the EGFRvIII inhibits its ubiquitination and downregulation by Cbl-b and enhances its ability to transform. Furthermore, the EGFR TK inhibitor, AG 1478, prevents the downregulation of the EGFRvIII by the Cbl proteins and antagonizes the ability of an immunotoxin directed against the EGFRvIII to kill cells expressing this receptor. In conclusion, the EGFRvIII does not transform by escaping regulation by Cbl proteins and this activation-induced downregulation of the EGFRvIII has an important role in mediating the toxicity of anti-EGFRvIII immunotoxins.

An efficient in vitro procedure for micropropagation and generation of somaclones of rose scented Pelargonium

Efficient protocols have been established for both direct and indirect regeneration of plants in Pelargonium graveolens Indian cultivar Hemanti (Algerian type). Murashige and Skoog's (MS) medium [T. Murashige, F. Skoog, A revised medium for rapid growth and bioassays with tobacco tissue cultures. Physiol. Plant. 15 (1962) 473-497] supplemented with 5.0 mg/l kinetin and 1.0 mg/l NAA was optimal for direct regeneration of plants from leaf explants while 8.0 mg/l kinetin and 1.0 mg/l NAA proved optimum for nodal explants for maximum number of shoots per explant. Callus induction was observed from nodal explants on MS medium supplemented with 10 mg/l kinetin and 1.0 mg/l NAA. Callus on further transfer to MS medium with 0.5 mg/l BAP and 0.1 mg/l NAA exhibited regeneration of maximum number of shoots. In vitro grown shoots of both direct and indirect origin rooted within 7-10 days following transfer to half strength MS medium with 1.0 mg/l IBA. Plantlets were acclimatized under glass house conditions with 90% survival. Randomly selected 85 individual Calliclones were subjected to field trial with 85-95% survival for two successive years along with control in randomized block design with three replicates. Screening of these calliclones revealed two distinct morphotypes, one with parental type highly dentated leaves (HDL) and the other with less dentated, round leaves (LDL). Only HDL calliclones flowered under field conditions. The LDL clones differed in several herb related agronomic characteristics such as plant height, herb yield, canopy size and number of branches per plant from the parental type as well as from the parent, which seems advantageous for commercial exploitation of such clones. The HDL clones closely resemble the parent in having higher content of citronellol than geraniol while the LDL clones contain almost equal contents of citronellol and geraniol in their essential oils as revealed by gas chromatography analysis. It is noticeable that the variability both in terms of agronomic characters and essential oil profiles among the clones were stable over 2 years of field trials.

The distribution of Ascaris lumbricoides in human hosts: a study of 1765 people in Bangladesh

The Ascaris lumbricoides expelled by 1765 people in a poor urban community in Bangladesh were recovered and counted after the subjects had been treated with pyrantel pamoate. The subjects were divided into 22 classes by age and sex (mean n = 80) to examine how prevalence, mean worm burdens and measures of aggregation of worms varied with age and between the sexes, and to see how a measure of aggregation, k, calculated in 3 ways (by maximum likelihood, from moments, or from the percentage uninfected) compared with an empirical aggregation index (the percentage of subjects who expelled an arbitrary 80% of all worms) and with the proportion who were moderately to heavily infected (defined as > or = 15 worms). The prevalence of infection ranged from 64% to 95%, mean worm burdens ranged from 7 to 23 worms, and k ranged from 0.3 to 1.2. There were significant differences between adult males and females in the prevalence of infection, mean worm burdens and measures of aggregation, differences which are probably driven more by behaviour than immunity. The parameter k was better described in terms of the proportion who were moderately to heavily infected (linear; range 0.15-0.58) than by the empirical aggregation index (non-linear; range 0.30-0.49).

Synchronization of two passively mode-locked erbium-doped fiber lasers by an acousto-optic modulator and grating scheme

We synchronize two passively mode-locked erbium-doped fiber lasers by adjusting only the cavity length to correct both the repetition rate and the phase. The interlaser jitter is less than 6 ps (1.3 times the pulse width) and is extracted from the cross correlation of the two lasers. The lock can be maintained for extended periods of time. These results are obtained by use of a novel acousto-optic-modulator-grating scheme, which provides an equivalent of 300 microm in cavity length tuning with a bandwidth of 10 kHz. These parameters are 30 times the length and 10 times the bandwidth of a typical piezoelectric transducer.

High-power erbium-doped fiber laser mode locked by a semiconductor saturable absorber

Using an erbium-doped fiber laser (EDFL) passively mode locked by a semiconductor saturable absorber, we generate 5.5-ps pulses of a 2.3-nJ/pulse, which are more than three times higher in energy than for other reported EDFL's. We show that, by introduction of a linear loss element within the cavity, multiple pulsing behavior at high pump powers can be suppressed. We also determine the saturable-absorber characteristics-absorbance versus wavelength near band gap-that are necessary to produce short mode-locked pulses.

Validity of the coupled-oscillator model for laser-array dynamics

We show that the coupled-oscillator model accurately describes the dynamics of laser arrays. Excellent qualitative and quantitative agreement is obtained between this model and the results of experiments on Nd:YAG laser arrays. Recent claims of instantaneous phase locking are shown to be in error.

Improved coupled-mode theory for the dynamics of semiconductor laser arrays

We present an improved coupled-mode model to describe the dynamics of weakly index-guided semiconductor laser arrays. The model is derived from a partial differential equation model that includes the effects of carrier diffusion and gain guiding. Results from the two models are compared, and good qualitative and quantitative agreement is obtained.

[Influence of the speed of spheronization on the physical properties and dissolution availability of theophylline minigranules prepared by extrusion-spheronization]

From the minigranules of the theophylline-based that prepared by extrusion-spheronization, the authors have envisaged the study of one of the parameters of operation (spheronizer speed) on the physical properties and lyoavailability of the active ingredient. It emerges that there is a clear influence of that parameters on the particle size distribution, the hardness, the friability, the density and the lyoavailability.