bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distinguishing importation from diversification of quinolone-resistant Neisseria gonorrhoeae by molecular evolutionary analysis
Authors: Pérez-Losada Marcos , Crandall Keith A , Bash Margaret C , Dan Michael , Zenilman Jonathan , Viscidi Raphael P 
Published: June 2007

Abstract

Background
Distinguishing the recent introduction of quinolone resistant gonococci into a population from diversification of resistant strains already in the population is important for planning effective infection control strategies. We applied molecular evolutionary analyses to DNA sequences from 9 housekeeping genes and gyrA, parC and porB of 24 quinolone resistant N. gonorrhoeae (QRNG) and 24 quinolone sensitive isolates collected in Israel during 2000–2001.

Results
Phylogenetic and eBURST analyses and estimates of divergence time indicated QRNG were introduced on 3 separate occasions and underwent limited diversification by mutation, deletion and horizontal gene transfer. Reconstruction of N. gonorrhoeae demography showed a slowly declining effective strain population size from 1976 to 1993, rapid decline between 1994 and 1999, and an increase from 1999 to 2001. This is partially attributable to declining gonorrhea case rates from 1973 to 1994. Additional contributing factors are selective sweeps of antibiotic resistant gonococci and increased transmission from sex workers. The abrupt decline in the mid-1990s heralded an increased incidence of gonorrhea from 1997 to the present. The subsequent increase in effective strain population size since 1999 reflects the increased gonococcal census population and introduction of quinolone resistance strains.

Conclusion
Our study demonstrates the effective use of population genetic approaches to assess recent and historical population dynamics of N. gonorrhoeae.
A review of methodology and analysis of nutrition and mortality surveys conducted in humanitarian emergencies from October 1993 to April 2004
Authors: Prudhon Claudine , Spiegel Paul B 
Published: June 2007

Abstract
Background
Malnutrition prevalence and mortality rates are increasingly used as essential indicators to assess the severity of a crisis, to follow trends, and to guide decision-making, including allocation of funds. Although consensus has slowly developed on the methodology to accurately measure these indicators, errors in the application of the survey methodology and analysis have persisted. The aim of this study was to identify common methodological weaknesses in nutrition and mortality surveys and to provide practical recommendations for improvement.

Methods
Nutrition (N = 368) and crude mortality rate (CMR; N = 158) surveys conducted by 33 non-governmental organisations and United Nations agencies in 17 countries from October 1993 to April 2004 were analysed for sampling validity, precision, quality of measurement and calculation according to several criteria.

Results
One hundred and thirty (35.3%) nutrition surveys and 5 (3.2%) CMR surveys met the criteria for quality. Quality of surveys varied significantly depending on the agency. The proportion of nutrition surveys that met criteria for quality rose significantly from 1993 to 2004; there was no improvement for mortality surveys during this period.

Conclusion
Significant errors and imprecision in the methodology and reporting of nutrition and mortality surveys were identified. While there was an improvement in the quality of nutrition surveys over the years, the quality of mortality surveys remained poor. Recent initiatives aimed at standardising nutrition and mortality survey quality should be strengthened. There are still a number of methodological issues in nutrition and mortality surveys in humanitarian emergencies that need further study.
Who should be undertaking population-based surveys in humanitarian emergencies?
Authors: Spiegel Paul B 
Published: June 2007

Abstract
Background
Timely and accurate data are necessary to prioritise and effectively respond to humanitarian emergencies. 30-by-30 cluster surveys are commonly used in humanitarian emergencies because of their purported simplicity and reasonable validity and precision. Agencies have increasingly used 30-by-30 cluster surveys to undertake measurements beyond immunisation coverage and nutritional status. Methodological errors in cluster surveys have likely occurred for decades in humanitarian emergencies, often with unknown or unevaluated consequences.

Discussion
Most surveys in humanitarian emergencies are done by non-governmental organisations (NGOs). Some undertake good quality surveys while others have an already overburdened staff with limited epidemiological skills. Manuals explaining cluster survey methodology are available and in use. However, it is debatable as to whether using standardised, 'cookbook' survey methodologies are appropriate. Coordination of surveys is often lacking. If a coordinating body is established, as recommended, it is questionable whether it should have sole authority to release surveys due to insufficient independence. Donors should provide sufficient funding for personnel, training, and survey implementation, and not solely for direct programme implementation.

Summary
A dedicated corps of trained epidemiologists needs to be identified and made available to undertake surveys in humanitarian emergencies. NGOs in the field may need to form an alliance with certain specialised agencies or pool technically capable personnel. If NGOs continue to do surveys by themselves, a simple training manual with sample survey questionnaires, methodology, standardised files for data entry and analysis, and manual for interpretation should be developed and modified locally for each situation. At the beginning of an emergency, a central coordinating body should be established that has sufficient authority to set survey standards, coordinate when and where surveys should be undertaken and act as a survey repository. Technical expertise is expensive and donors must pay for it. As donors increasingly demand evidence-based programming, they have an obligation to ensure that sufficient funds are provided so organisations have adequate technical staff.
The use of personal digital assistants for data entry at the point of collection in a large household survey in southern Tanzania
Authors: Shirima Kizito , Mukasa Oscar , Schellenberg Joanna Armstrong , Manzi Fatuma , John Davis , Mushi Adiel , Mrisho Mwifadhi , Tanner Marcel , Mshinda Hassan , Schellenberg David 
Published: June 2007

Abstract
Background
Survey data are traditionally collected using pen-and-paper, with double data entry, comparison of entries and reconciliation of discrepancies before data cleaning can commence. We used Personal Digital Assistants (PDAs) for data entry at the point of collection, to save time and enhance the quality of data in a survey of over 21,000 scattered rural households in southern Tanzania.

Methods
Pendragon Forms 4.0 software was used to develop a modular questionnaire designed to record information on household residents, birth histories, child health and health-seeking behaviour. The questionnaire was loaded onto Palm m130 PDAs with 8 Mb RAM. One hundred and twenty interviewers, the vast majority with no more than four years of secondary education and very few with any prior computer experience, were trained to interview using the PDAs. The 13 survey teams, each with a supervisor, laptop and a four-wheel drive vehicle, were supported by two back-up vehicles during the two months of field activities. PDAs and laptop computers were charged using solar and in-car chargers.
Logical checks were performed and skip patterns taken care of at the time of data entry. Data records could not be edited after leaving each household, to ensure the integrity of the data from each interview. Data were downloaded to the laptop computers and daily summary reports produced to evaluate the completeness of data collection. Data were backed up at three levels: (i) at the end of every module, data were backed up onto storage cards in the PDA; (ii) at the end of every day, data were downloaded to laptop computers; and (iii) a compact disc (CD) was made of each team's data each day.
A small group of interviewees from the community, as well as supervisors and interviewers, were asked about their attitudes to the use of PDAs.

Results
Following two weeks of training and piloting, data were collected from 21,600 households (83,346 individuals) over a seven-week period in July-August 2004. No PDA-related problems or data loss were encountered.
Fieldwork ended on 26 August 2004, the full dataset was available on a CD within 24 hours and the results of initial analyses were presented to district authorities on 28 August. Data completeness was over 99%.
The PDAs were well accepted by both interviewees and interviewers.

Conclusion
The use of PDAs eliminated the usual time-consuming and error-prone process of data entry and validation. PDAs are a promising tool for field research in Africa.
Sampling in health geography: reconciling geographical objectives and probabilistic methods. An example of a health survey in Vientiane (Lao PDR)
Authors: Vallée Julie , Souris Marc , Fournet Florence , Bochaton Audrey , Mobillion Virginie , Peyronnie Karine , Salem Gérard 
Published: June 2007

Abstract
Background
Geographical objectives and probabilistic methods are difficult to reconcile in a unique health survey. Probabilistic methods focus on individuals to provide estimates of a variable's prevalence with a certain precision, while geographical approaches emphasise the selection of specific areas to study interactions between spatial characteristics and health outcomes. A sample selected from a small number of specific areas creates statistical challenges: the observations are not independent at the local level, and this results in poor statistical validity at the global level. Therefore, it is difficult to construct a sample that is appropriate for both geographical and probability methods.

Methods
We used a two-stage selection procedure with a first non-random stage of selection of clusters. Instead of randomly selecting clusters, we deliberately chose a group of clusters, which as a whole would contain all the variation in health measures in the population. As there was no health information available before the survey, we selected a priori determinants that can influence the spatial homogeneity of the health characteristics. This method yields a distribution of variables in the sample that closely resembles that in the overall population, something that cannot be guaranteed with randomly-selected clusters, especially if the number of selected clusters is small. In this way, we were able to survey specific areas while minimising design effects and maximising statistical precision.

Application
We applied this strategy in a health survey carried out in Vientiane, Lao People's Democratic Republic. We selected well-known health determinants with unequal spatial distribution within the city: nationality and literacy. We deliberately selected a combination of clusters whose distribution of nationality and literacy is similar to the distribution in the general population.

Conclusion
This paper describes the conceptual reasoning behind the construction of the survey sample and shows that it can be advantageous to choose clusters using reasoned hypotheses, based on both probability and geographical approaches, in contrast to a conventional, random cluster selection strategy.
Don't spin the pen: two alternative methods for second-stage sampling in urban cluster surveys
Authors: Grais Rebecca F , Rose Angela MC , Guthmann Jean-Paul 
Published: June 2007

AbstractIn two-stage cluster surveys, the traditional method used in second-stage sampling (in which the first household in a cluster is selected) is time-consuming and may result in biased estimates of the indicator of interest. Firstly, a random direction from the center of the cluster is selected, usually by spinning a pen. The houses along that direction are then counted out to the boundary of the cluster, and one is then selected at random to be the first household surveyed. This process favors households towards the center of the cluster, but it could easily be improved. During a recent meningitis vaccination coverage survey in Maradi, Niger, we compared this method of first household selection to two alternatives in urban zones: 1) using a superimposed grid on the map of the cluster area and randomly selecting an intersection; and 2) drawing the perimeter of the cluster area using a Global Positioning System (GPS) and randomly selecting one point within the perimeter. Although we only compared a limited number of clusters using each method, we found the sampling grid method to be the fastest and easiest for field survey teams, although it does require a map of the area. Selecting a random GPS point was also found to be a good method, once adequate training can be provided. Spinning the pen and counting households to the boundary was the most complicated and time-consuming. The two methods tested here represent simpler, quicker and potentially more robust alternatives to spinning the pen for cluster surveys in urban areas. However, in rural areas, these alternatives would favor initial household selection from lower density (or even potentially empty) areas. Bearing in mind these limitations, as well as available resources and feasibility, investigators should choose the most appropriate method for their particular survey context.
Reliability of voluntary step execution behavior under single and dual task conditions
Authors: Melzer Itshak , Shtilman Irena , Rosenblatt Noah , Oddsson Lars IE 
Published: May 2007

Abstract

Background
The current study investigated the repeatability (test-retest reliability) of ground reaction force parameters recorded during a voluntary step execution under single (motor task) and dual task (motor and cognitive task) conditions for healthy adults and elderly individuals as well as the number of trials required to produce repeatable results.

Methods
Twenty-four healthy adults (21–63 years old) and 16 elderly adults (66–87 years) performed a voluntary rapid step execution following a tap on their heel while standing on a force platform under single and dual task conditions on three separate occasions. The first two tests were performed 30–60 minutes apart and the third test was performed a week later. Variables analyzed from the ground reaction force data included onset latency of step initiation (initiation phase), preparation and swing phases, foot-off and foot-contact times.

Results
Intraclass correlation coefficients (ICC(2,1)) were good to excellent across all parameters and test conditions for the pooled population and for elderly (0.74–0.92 and 0.62–0.88, respectively) except for the swing phase duration where lower values were seen (0.54–0.60 and 0.32–0.64 respectively). Values were similar under single and dual task conditions.

Conclusion
A voluntary step execution test, performed under single and dual task conditions especially foot-off and foot-contact times, is a reliable outcome measure that may be a useful tool to asses dynamic balance function for diagnostic purposes as well as clinical intervention trials.
Creating sustainable small to medium enterprises through technological innovation
Authors: Thomas A J 
Published: May 2007

In order for UK manufacturing companies to meet the current pressures of a modern manufacturing environment they need to develop leaner, flexible, and more responsive manufacturing systems. At the heart of these requirements is the need to introduce advanced manufacturing technologies (AMT) into companies in order to improve their efficiency and responsiveness to customer demands. While technology continues to be developed at unprecedented rates, the number of companies implementing such technologies is low. This in turn threatens their long-term economic sustainability. This paper initially identifies the reasons why small to medium enterprises (SMEs) fail to adopt new and advanced technologies. It then goes on to propose a coherent strategy for the effective introduction and application of AMT in SMEs before proposing a model for the introduction of new and advanced technologies into these companies. The model is subsequently evaluated through its application in a number of SMEs and compares its performance through assessing the companies who adopted the model against those who decided not to use such a formal approach to technology implementation (TI). The creation of a generic TI model provides a framework for a wider number of SMEs to introduce AMT into their respective organizations since it provides for a systematic approach for SMEs to introduce AMT in an efficient and effective manner, thus reducing implementation costs and improving project management efficiency.
Perspective: Quantifying Osteoblast and Osteocyte Apoptosis: Challenges and Rewards
Authors: Jilka Robert L , Weinstein Robert S , Parfitt A Michael , Manolagas Stavros C 
Published: June 2007

Abstract
Since the initial demonstration of the phenomenon in murine and human bone sections ∼10 yr ago, appreciation of the biologic significance of osteoblast apoptosis has contributed greatly not only to understanding the regulation of osteoblast number during physiologic bone remodeling, but also the pathogenesis of metabolic bone diseases and the pharmacology of some of the drugs used for their treatment. It is now appreciated that all major regulators of bone metabolism including bone morphogenetic proteins (BMPs), Wnts, other growth factors and cytokines, integrins, estrogens, androgens, glucocorticoids, PTH and PTH-related protein (PTHrP), immobilization, and the oxidative stress associated with aging contribute to the regulation of osteoblast and osteocyte life span by modulating apoptosis. Moreover, osteocyte apoptosis has emerged as an important regulator of remodeling on the bone surface and a critical determinant of bone strength, independently of bone mass. The detection of apoptotic osteoblasts in bone sections remains challenging because apoptosis represents only a tiny fraction of the life span of osteoblasts, not unlike a 6-mo -long terminal illness in the life of a 75-yr -old human. Importantly, the phenomenon is 50 times less common in human bone biopsies because human osteoblasts live longer and are fewer in number. Be that as it may, well-controlled assays of apoptosis can yield accurate and reproducible estimates of the prevalence of the event, particularly in rodents where there is an abundance of osteoblasts for inspection. In this perspective, we focus on the biological significance of the phenomenon for understanding basic bone biology and the pathogenesis and treatment of metabolic bone diseases and discuss limitations of existing techniques for quantifying osteoblast apoptosis in human biopsies and their methodologic pitfalls.
Pregnancy and STD Prevention Counseling Using an Adaptation of Motivational Interviewing: A Randomized Controlled Trial
Authors: Petersen Ruth , Albright Jennifer , Garrett Joanne M. , Curtis Kathryn M. 
Published: June 2007

CONTEXT:  Given levels of unintended pregnancy and STDs, an effective counseling intervention is needed to improve women’s consistent use of effective prevention methods. METHODS:  A sample of 764 women aged 16–44 who were at risk of unintended pregnancy were enrolled in a randomized controlled trial in North Carolina in 2003–2004. Intervention participants received pregnancy and STD prevention counseling, adapted from motivational interviewing, both at enrollment and two months later; controls received only a session of general health counseling. Levels of contraceptive use (categorized as high, low or none on the basis of the effectiveness of the method and the consistency of use) and barriers to use were measured at two, eight and 12 months; chi‐square tests were used to compare selected outcomes between the groups. Rates of unintended pregnancy and chlamydia infection were assessed over the study period. RESULTS:  At baseline, 59% of all participants reported a high level of contraceptive use, 19% a low level and 22% nonuse. At two months, the proportions of intervention and control participants who had improved their level of use or maintained a high level (72% and 66%, respectively) were significantly larger than the proportions who had reported a high level of use at baseline (59% and 58%, respectively). No significant differences were found between the groups at 12 months, or between baseline and 12 months for either group. During the study, 10–11% of intervention and control participants became pregnant, 1–2% received a chlamydia diagnosis and 7–9% had another STD diagnosed. CONCLUSIONS:  Repeated counseling sessions may be needed to improve contraceptive decision‐making and to reduce the risk of unintended pregnancy and STDs.
Social Ecological Predictors of Repeat Adolescent Pregnancy
Authors: Raneri Leslie G. , Wiemann Constance M. 
Published: June 2007

CONTEXT: Women with multiple pregnancies in adolescence may experience medical, psychological and social complications. Improved understanding of the individual‐, dyad‐, family‐, peer/community‐ and social system‐level risk factors for repeat pregnancy may lead to the development of more effective prevention strategies for adolescent mothers in a variety of settings.METHODS: Between 1993 and 1996, white, black and Mexican American adolescent mothers at a labor and delivery unit in Texas were interviewed after delivery and completed written surveys prospectively for up to 48 months. Logistic regression analyses were used to determine predictors of repeat pregnancy within 24 months, using social ecological theory as a guide.RESULTS: Forty‐two percent of adolescent mothers experienced a repeat pregnancy within 24 months; 73% of these delivered a second child. Individual‐level predictors were planning to have another baby within five years (odds ratio, 1.6) and not using long‐acting contraceptives within three months of delivery (2.4). Dyad‐level predictors were not being in a relationship with the father of the first child three months after delivery (2.0), being more than three years younger than the first child’s father (1.6) and experiencing intimate partner violence within three months after delivery (1.9). Peer/community‐level predictors were not being in school three months postpartum (1.8) and having many friends who were adolescent parents (1.5).CONCLUSION: Adolescent mothers are at high risk for a rapid subsequent pregnancy. Interventions that address the complex and multifaceted aspects of the lives of adolescent mothers are needed to prevent repeat pregnancy.