298 research outputs found
Geometric Mixing, Peristalsis, and the Geometric Phase of the Stomach
Mixing fluid in a container at low Reynolds number - in an inertialess
environment - is not a trivial task. Reciprocating motions merely lead to
cycles of mixing and unmixing, so continuous rotation, as used in many
technological applications, would appear to be necessary. However, there is
another solution: movement of the walls in a cyclical fashion to introduce a
geometric phase. We show using journal-bearing flow as a model that such
geometric mixing is a general tool for using deformable boundaries that return
to the same position to mix fluid at low Reynolds number. We then simulate a
biological example: we show that mixing in the stomach functions because of the
"belly phase": peristaltic movement of the walls in a cyclical fashion
introduces a geometric phase that avoids unmixing.Comment: Revised, published versio
Flexible attention allocation to visual and auditory working memory tasks: manipulating reward induces a trade-off
Prominent roles for general attention resources are posited in many models of working memory, but the manner in which these can be allocated differs between models or is not sufficiently specified. We varied the payoffs for correct responses in two temporally-overlapping recognition tasks, a visual array comparison task and a tone sequence comparison task. In the critical conditions, an increase in reward for one task corresponded to a decrease in reward for the concurrent task, but memory load remained constant. Our results show patterns of interference consistent with a trade-off between the tasks, suggesting that a shared resource can be flexibly divided, rather than only fully allotted to either of the tasks. Our findings support a role for a domain-general resource in models of working memory, and furthermore suggest that this resource is flexibly divisible
Rearrangement of Retinogeniculate Projection Patterns after Eye-Specific Segregation in Mice
It has been of interest whether and when the rearrangement of neuronal circuits can be induced after projection patterns are formed during development. Earlier studies using cats reported that the rearrangement of retinogeniculate projections could be induced even after eye-specific segregation has occurred, but detailed and quantitative characterization of this rearrangement has been lacking. Here we delineate the structural changes of retinogeniculate projections in the C57BL/6 mouse in response to monocular enucleation (ME) after eye-specific segregation. When ME was performed after eye-specific segregation, rearrangement of retinogeniculate axons in the dorsal lateral geniculate nucleus (dLGN) was observed within 5 days. Although this rearrangement was observed both along the dorsomedial-ventrolateral and outer-inner axes in the dLGN, it occurred more rapidly along the outer-inner axis. We also examined the critical period for this rearrangement and found that the rearrangement became almost absent by the beginning of the critical period for ocular dominance plasticity in the primary visual cortex. Taken together, our findings serve as a framework for the assessment of phenotypes of genetically altered mouse strains as well as provide insights into the mechanisms underlying the rearrangement of retinogeniculate projections
Ecological restoration in a cultural landscape:conservationist and Chagossian approaches to controlling the 'coconut chaos' on the Chagos Archipelago
The Difference in Pharmacists’ Interventions across the Diverse Settings in a Children’s Hospital
Aims: This study aimed to document and compare the nature of clinical pharmacists’ interventions made in different practice settings within a children’s hospital. Methods: The primary investigator observed and documented all clinical interventions performed by clinical pharmacists for between 35–37 days on each of the five study wards from the three practice settings, namely general medical, general surgical and hematology-oncology. The rates, types and significance of the pharmacists’ interventions in the different settings were compared.Results: A total of 982 interventions were documented, related to the 16,700 medication orders reviewed on the five wards in the three practice settings over the duration of the study. Taking medication histories and/or patient counselling were the most common pharmacists’ interventions in the general settings; constituting more than half of all interventions. On the Hematology-Oncology Ward the pattern was different with drug therapy changes being the most common interventions (n = 73/195, 37.4% of all interventions). Active interventions (pharmacists’ activities leading to a change in drug therapy) constituted less than a quarter of all interventions on the general medical and surgical wards compared to nearly half on thespecialty Hematology-Oncology Ward. The majority (n = 37/42, 88.1%) of a random sample of the active interventions reviewed were rated as clinically significant. Dose adjustment was the most frequent active interventions in the general settings, whilst drug addition constituted the most common active interventions on the Hematology-Oncology Ward. The degree of acceptance of pharmacists’ active interventions by prescribers was high (n = 223/244, 91.4%).Conclusions: The rate of pharmacists’ active interventions differed across different practice settings, being most frequent in the specialty hematology-oncology setting. The nature and type of the interventions documented in the hematologyoncology were also different compared to those in the general medical and surgical settings
Avoiding Treatment Interruptions: What Role Do Australian Community Pharmacists Play?
OBJECTIVE: To explore the reported practice of Australian community pharmacists when dealing with medication supply requests in absence of a valid prescription. METHODS: Self-administered questionnaire was posted to 1490 randomly selected community pharmacies across all Australian states and territories. This sample was estimated to be a 20% of all Australian community pharmacies. RESULTS: Three hundred eighty five pharmacists participated in the study (response rate achieved was 27.9% (there were 111 undelivered questionnaires). Respondents indicated that they were more likely to provide medications to regular customers without a valid prescription compared to non-regular customers (p<0.0001). However, supply was also influenced by the type of prescription and the medication requested. In the case of type of prescription (Standard, Authority or Private) this relates to the complexity/probability of obtaining a valid prescription from the prescriber at a later date (i.e. supply with an anticipated prescription). Decisions to supply and/or not supply related to medication type were more complex. For some cases, including medication with potential for abuse, the practice and/or the method of supply varied significantly according to age and gender of the pharmacist, and pharmacy location (p<0.05). CONCLUSIONS: Although being a regular customer does not guarantee a supply, results of this study reinforce the importance for patients having a regular pharmacy, where pharmacists were more likely to continue medication supply in cases of patients presenting without a valid prescription. We would suggest, more flexible legislation should be implemented to allow pharmacists to continue supplying of medication when obtaining a prescription is not practical
Synthesis of tenascin and laminin beta2 chain in human bronchial epithelial cells is enhanced by cysteinyl leukotrienes via CysLT1 receptor
<p>Abstract</p> <p>Background</p> <p>Cysteinyl leukotrienes (CysLTs) are key mediators of asthma, but their role in the genesis of airway remodeling is insufficiently understood. Recent evidence suggests that increased expression of tenascin (Tn) and laminin (Ln) β2 chain is indicative of the remodeling activity in asthma, but represents also an example of deposition of extracellular matrix, which affects the airway wall compliance. We tested the hypothesis that CysLTs affect production of Tn and Ln β2 chain by human bronchial epithelial cells and elucidated, which of the CysLT receptors, CysLT<sub>1 </sub>or CysLT<sub>2</sub>, mediate this effect.</p> <p>Methods</p> <p>Cultured BEAS-2B human bronchial epithelial cells were stimulated with leukotriene D<sub>4 </sub>(LTD<sub>4</sub>) and E<sub>4 </sub>(LTE<sub>4</sub>) and evaluated by immunocytochemistry, Western blotting, flow cytometry, and RT-PCR. CysLT receptors were differentially blocked with use of montelukast or BAY u9773.</p> <p>Results</p> <p>LTD<sub>4 </sub>and LTE<sub>4 </sub>significantly augmented the expression of Tn, whereas LTD<sub>4</sub>, distinctly from LTE<sub>4</sub>, was able to increase also the Ln β2 chain. Although the expression of CysLT<sub>2 </sub>prevailed over that of CysLT<sub>1</sub>, the up-regulation of Tn and Ln β2 chain by CysLTs was completely blocked by the CysLT<sub>1</sub>-selective antagonist montelukast with no difference between montelukast and the dual antagonist BAY u9773 for the inhibitory capacity.</p> <p>Conclusion</p> <p>These findings suggest that the CysLT-induced up-regulation of Tn and Ln β2 chain, an important epithelium-linked aspect of airway remodeling, is mediated predominantly by the CysLT<sub>1 </sub>receptor. The results provide a novel aspect to support the use of CysLT<sub>1 </sub>receptor antagonists in the anti-remodeling treatment of asthma.</p
TECNOB: study design of a randomized controlled trial of a multidisciplinary telecare intervention for obese patients with type-2 diabetes
Obesity is one of the most important medical and public health problems of our time: it increases the risk of many health complications such as hypertension, coronary heart disease and type 2 diabetes, needs long-lasting treatment for effective results and involves high public and private costs. Therefore, it is imperative that enduring and low-cost clinical programs for obesity and related co-morbidities are developed and evaluated.
METHODS/DESIGN:
TECNOB (TEChnology for OBesity) is a comprehensive two-phase stepped down program enhanced by telemedicine for the long-term treatment of obese people with type 2 diabetes seeking intervention for weight loss. Its core features are the hospital-based intensive treatment (1-month), that consists of diet therapy, physical training and psychological counseling, and the continuity of care at home using new information and communication technologies (ICT) such as internet and mobile phones. The effectiveness of the TECNOB program compared with usual care (hospital-based treatment only) will be evaluated in a randomized controlled trial (RCT) with a 12-month follow-up. The primary outcome is weight in kilograms. Secondary outcome measures are energy expenditure measured using an electronic armband, glycated hemoglobin, binge eating, self-efficacy in eating and weight control, body satisfaction, healthy habit formation, disordered eating-related behaviors and cognitions, psychopathological symptoms and weight-related quality of life. Furthermore, the study will explore what behavioral and psychological variables are predictive of treatment success among those we have considered.
DISCUSSION:
The TECNOB study aims to inform the evidence-based knowledge of how telemedicine may enhance the effectiveness of clinical interventions for weight loss and related type-2 diabetes, and which type of obese patients may benefit the most from such interventions. Broadly, the study aims also to have a effect on the theoretical model behind the traditional health care service, in favor of a change towards a new "health care everywhere" approach
Genetic diversity of the African malaria vector Anopheles gambiae
The sustainability of malaria control in Africa is threatened by the rise of insecticide resistance in Anopheles mosquitoes, which transmit the disease1. To gain a deeper understanding of how mosquito populations are evolving, here we sequenced the genomes of 765 specimens of Anopheles gambiae and Anopheles coluzzii sampled from 15 locations across Africa, and identified over 50 million single nucleotide polymorphisms within the accessible genome. These data revealed complex population structure and patterns of gene flow, with evidence of ancient expansions, recent bottlenecks, and local variation in effective population size. Strong signals of recent selection were observed in insecticide-resistance genes, with several sweeps spreading over large geographical distances and between species. The design of new tools for mosquito control using gene-drive systems will need to take account of high levels of genetic diversity in natural mosquito populations
Translating global recommendations on HIV and infant feeding to the local context: the development of culturally sensitive counselling tools in the Kilimanjaro Region, Tanzania
BACKGROUND: This paper describes the process used to develop an integrated set of culturally sensitive, evidence-based counselling tools (job aids) by using qualitative participatory research. The aim of the intervention was to contribute to improving infant feeding counselling services for HIV positive women in the Kilimanjaro Region of Tanzania. METHODS: Formative research using a combination of qualitative methods preceded the development of the intervention and mapped existing practices, perceptions and attitudes towards HIV and infant feeding (HIV/IF) among mothers, counsellors and community members. Intervention Mapping (IM) protocol guided the development of the overall intervention strategy. Theories of behaviour change, a review of the international HIV/IF guidelines and formative research findings contributed to the definition of performance and learning objectives. Key communication messages and colourful graphic illustrations related to infant feeding in the context of HIV were then developed and/or adapted from existing generic materials. Draft materials were field tested with intended audiences and subjected to stakeholder technical review. RESULTS: An integrated set of infant feeding counselling tools, referred to as 'job aids', was developed and included brochures on feeding methods that were found to be socially and culturally acceptable, a Question and Answer Guide for counsellors, a counselling card on the risk of transmission of HIV, and an infant feeding toolbox for demonstration. Each brochure describes the steps to ensure safer infant feeding using simple language and images based on local ideas and resources. The brochures are meant to serve as both a reference material during infant feeding counselling in the ongoing prevention of mother to child transmission (pMTCT) of HIV programme and as take home material for the mother. CONCLUSION: The study underscores the importance of formative research and a systematic theory based approach to developing an intervention aimed at improving counselling and changing customary feeding practices. The identification of perceived barriers and facilitators for change contributed to developing the key counselling messages and graphics, reflecting the socio-economic reality, cultural beliefs and norms of mothers and their significant others
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