684 research outputs found
The tobacco industry’s past role in weight control related to smoking
Background: Smoking is thought to produce an appetite-suppressing effect by many smokers. Thus, the fear of body weight gain often outweighs the perception of health benefits associated with smoking cessation, particularly in adolescents. We examined whether the tobacco industry played a role in appetite and body weight control related to smoking and smoking cessation. Methods: We performed a systematic search within the archives of six major US and UK tobacco companies (American Tobacco, Philip Morris, RJ Reynolds, Lorillard, Brown & Williamson and British American Tobacco) that were Defendants in tobacco litigation settled in 1998. Findings are dated from 1949 to 1999. Results: The documents revealed the strategies planned and used by the industry to enhance effects of smoking on weight and appetite, mostly by chemical modifications of cigarettes contents. Appetite-suppressant molecules, such as tartaric acid and 2-acetylpyridine were added to some cigarettes. Conclusion: These tobacco companies played an active and not disclaimed role in the anti-appetite effects of smoking, at least in the past, by adding appetite-suppressant molecules into their cigarettes
A stochastic SIS epidemic model with heterogeneous contacts.
A stochastic model for the spread of an SIS epidemic among a population consisting of N individuals, each having heterogeneous infectiousness and/or susceptibility, is considered and its behavior is analyzed under the practically relevant situation when N is small. The model is formulated as a finite time-homogeneous continuous-time Markov chain X. Based on an appropriate labeling of states, we first construct its infinitesimal rate matrix by using an iterative argument, and we then present an algorithmic procedure for computing steady-state measures, such as the number of infected individuals, the length of an outbreak, the maximum number of infectives, and the number of infections suffered by a marked individual during an outbreak. The time till the epidemic extinction is characterized as a phase-type random variable when there is no external source of infection, and its Laplace-Stieltjes transform and moments are derived in terms of a forward elimination backward substitution solution. The inverse iteration method is applied to the quasi-stationary distribution of X, which provides a good approximation of the process X at a certain time, conditional on non-extinction, after a suitable waiting time. The basic reproduction number R0 is defined here as a random variable, rather than an expected value
FLPe functions in zebrafish embryos
To assay the efficiency of the FLP/FRT site-specific recombination system in Danio rerio, a construct consisting of a muscle-specific promoter driving EGFP flanked by FRT sites was developed. FLPe capped RNA was microinjected into transgenic single cell stage zebrafish embryos obtained by crossing hemizygous transgenic males with wild-type females. By 48 h post fertilization (hpf), the proportion of embryos displaying green fluorescence following FLPe RNA microinjection was significantly lower (7.7%; P < 0.001) than would be expected from a cross in the absence of the recombinase (50%). Embryos that retained fluorescence displayed marked mosaicism. Inheritance of the excised transgene in non-fluorescent, transgenic embryos was verified by PCR analysis and FLPe-mediated recombination was confirmed by DNA sequencing. Sperm derived from confirmed transgenic males in these experiments was used to fertilize wild-type eggs to determine whether germline excision of the transgene had occurred. Clutches sired by FLPe-microinjected males contained 0–4% fluorescent embryos. Transgenic males that were phenotypically wild-type produced no fluorescent progeny, demonstrating complete excision of the transgene from their germline. FLPe microinjected males that retained some fluorescent muscle expression produced a small proportion of fluorescent offspring, suggesting that in mosaic males not all germline cells had undergone FLPe-mediated transgene excision. Our results show that FLPe, which is derived from Saccharomyces cerevisiae, is an efficient recombinase in zebrafish maintained at 28.5°C
Recommended from our members
Family planning in conflict: results of cross-sectional baseline surveys in three African countries
Background: Despite the serious consequences of conflict for reproductive health, populations affected by conflict and its aftermath face tremendous barriers to accessing reproductive health services, due to insecurity, inadequate numbers of trained personnel and lack of supplies. Family planning is often particularly neglected. Methods: In six conflict-affected areas in Sudan, northern Uganda and the Democratic Republic of Congo, household surveys of married or in-union women of reproductive age were conducted to determine baseline measures of family planning knowledge, attitudes and behaviors regarding contraception. Health facility assessments were carried out to assess baseline measures of family planning services availability. Data were double-entered into CSPro 3.2 and exported to SAS 9.2, which was used to calculate descriptive statistics. The studies' purposes were to guide program activities and to serve as a baseline against which program accomplishments could be measured. Results: Knowledge of modern contraceptive methods was low relative to other sub-Saharan African countries, and use of modern methods was under 4% in four sites; in two sites with prior family planning services it was 12% and 16.2%. From 30% to 40% of women reported they did not want a child within two years, however, and an additional 12% to 35% wanted no additional children, suggesting a clear need for family planning services. The health facilities assessment showed that at most only one-third of the facilities mandated to provide family planning had the necessary staff, equipment and supplies to do so adequately; in some areas, none of the facilities were prepared to offer such services. Conclusions: Family planning services are desired by women living in crisis situations when offered in a manner appropriate to their needs, yet services are rarely adequate to meet these needs. Refugee and internally displaced women must be included in national and donors' plans to improve family planning in Africa
Implementation Evaluation of a Complex Intervention to Improve Timeliness of Care for Veterans with Transient Ischemic Attack
Background: The Protocol-guided Rapid Evaluation of Veterans Experiencing New Transient Neurologic Symptoms (PREVENT) program was designed to address systemic barriers to providing timely guideline-concordant care for patients with transient ischemic attack (TIA).
Objective: We evaluated an implementation bundle used to promote local adaptation and adoption of a multi-component, complex quality improvement (QI) intervention to improve the quality of TIA care Bravata et al. (BMC Neurology 19:294, 2019).
Design: A stepped-wedge implementation trial with six geographically diverse sites.
Participants: The six facility QI teams were multi-disciplinary, clinical staff.
Interventions: PREVENT employed a bundle of key implementation strategies: team activation; external facilitation; and a community of practice. This strategy bundle had direct ties to four constructs from the Consolidated Framework for Implementation Research (CFIR): Champions, Reflecting & Evaluating, Planning, and Goals & Feedback.
Main measures: Using a mixed-methods approach guided by the CFIR and data matrix analyses, we evaluated the degree to which implementation success and clinical improvement were associated with implementation strategies. The primary outcomes were the number of completed implementation activities, the level of team organization and > 15 points improvement in the Without Fail Rate (WFR) over 1 year.
Key results: Facility QI teams actively engaged in the implementation strategies with high utilization. Facilities with the greatest implementation success were those with central champions whose teams engaged in planning and goal setting, and regularly reflected upon their quality data and evaluated their progress against their QI plan. The strong presence of effective champions acted as a pre-condition for the strong presence of Reflecting & Evaluating, Goals & Feedback, and Planning (rather than the other way around), helping to explain how champions at the +2 level influenced ongoing implementation.
Conclusions: The CFIR-guided bundle of implementation strategies facilitated the local implementation of the PREVENT QI program and was associated with clinical improvement in the national VA healthcare system
First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data
Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of
continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a
fully coherent search, based on matched filtering, which uses the position and rotational parameters
obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto-
noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch
between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have
been developed, allowing a fully coherent search for gravitational waves from known pulsars over a
fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of
11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial
outliers, further studies show no significant evidence for the presence of a gravitational wave signal.
Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of
the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for
the first time. For an additional 3 targets, the median upper limit across the search bands is below the
spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried
out so far
Effective board governance of safe care: a (theoretically underpinned) cross-sectioned examination of the breadth and depth of relationships through national quantitative surveys and in-depth qualitative case studies
Background: Recent high-profile reports into serious failings in the quality of hospital care in the NHS raise concerns over the ability of trust boards to discharge their duties effectively.
Objectives: Our study aimed to generate theoretically grounded empirical evidence on the associations between board governance, patient safety processes and patient-centred outcomes. The specific aims were as follows: (1) to identify the types of governance activities undertaken by hospital trust boards in the English NHS with regard to ensuring safe care in their organisation; (2) in foundation trusts, to explore the
role of boards and boards of governors with regards to the oversight of patient safety in their organisation;
(3) to assess the association between particular hospital trust board oversight activities and patient safety processes and clinical outcomes; (4) to identify the facilitators and barriers to developing effective hospital trust board governance of safe care; and (5) to assess the impact of external commissioning arrangements and incentives on hospital trust board oversight of patient safety.
Methods: The study comprised three distinct but interlocking strands: (1) a narrative systematic review in order to describe, interpret and synthesise key findings and debates concerning board oversight of patient safety; (2) in-depth mixed-methods case studies in four organisations to assess the impact of hospital board governance and external incentives on patient safety processes and outcomes; and (3) two national surveys exploring board management in NHS acute and specialist hospital trusts in England, and relating board characteristics to whole-organisation outcomes.
Results: A very high proportion of trust boards reported the kinds of desirable characteristics and board-related processes that research says may be associated with higher performance. Our analysis of the symbolic aspects of board activities highlights the role and differences in local processes of organising the governance of patient safety. Most boards do allocate considerable amount of time to discussing patient safety and quality-related issues and were using a wide range of hard performance metrics and soft intelligence to monitor its organisation with regard to patient safety. Although the board of governors is generally perceived to be well-meaning, they were also considered to be being largely ineffective in helping to promote and deliver safer care for their organisations. We did not find any statistically significant relationship between board attributes (self-reported) and processes and any patient safety outcome measures. However, we did find a significant relationship between two dimensions of the Board Self-Assessment Questionnaire and two specific-and-related national staff survey organisational ‘process’ measures: (1) staff feeling safe to raise concerns about errors, near-misses and incidents and (2) staff feeling confident that their organisation would address their concerns, if raised. We also found that contracting and external financial incentives appeared to play only a relatively minor role in incentivising quality and safety improvement.
Conclusions: Our research is the first large-scale mixed-methods study of hospital board activity and behaviour related to the oversight of patient safety in the English NHS and the key findings should be used to influence the design of future governance arrangements as well as the training and support of board.
Funding: The National Institute for Health Research Health Services and Delivery Research programme
Detailed Analysis of a Contiguous 22-Mb Region of the Maize Genome
Most of our understanding of plant genome structure and evolution has come from the careful annotation of small (e.g., 100 kb) sequenced genomic regions or from automated annotation of complete genome sequences. Here, we sequenced and carefully annotated a contiguous 22 Mb region of maize chromosome 4 using an improved pseudomolecule for annotation. The sequence segment was comprehensively ordered, oriented, and confirmed using the maize optical map. Nearly 84% of the sequence is composed of transposable elements (TEs) that are mostly nested within each other, of which most families are low-copy. We identified 544 gene models using multiple levels of evidence, as well as five miRNA genes. Gene fragments, many captured by TEs, are prevalent within this region. Elimination of gene redundancy from a tetraploid maize ancestor that originated a few million years ago is responsible in this region for most disruptions of synteny with sorghum and rice. Consistent with other sub-genomic analyses in maize, small RNA mapping showed that many small RNAs match TEs and that most TEs match small RNAs. These results, performed on ∼1% of the maize genome, demonstrate the feasibility of refining the B73 RefGen_v1 genome assembly by incorporating optical map, high-resolution genetic map, and comparative genomic data sets. Such improvements, along with those of gene and repeat annotation, will serve to promote future functional genomic and phylogenomic research in maize and other grasses
- …