6,407 research outputs found
Contextual barriers to mobile health technology in African countries: a perspective piece
On a global scale, healthcare practitioners are now beginning to move from traditional desktop-based computer technologies towards mobile computing environments[1]. Consequently, such environments have received immense attention from both academia and industry, in order to explore these promising opportunities, apparent limitations, and implications for both theory and practice[2]. The application of mobile IT within a medical context, referred to as mobile health or mHealth, has revolutionised the delivery of healthcare services as mobile technologies offer the potential of retrieving, modifying and entering patient-related data/information at the point-of-care. As a component of the larger health informatics domain mHealth may be referred as all portable computing devices (e.g. mobile phones, mobile clinical assistants and medical sensors) used in a healthcare context to support the delivery of healthcare services
GFIT2: an experimental algorithm for vertical profile retrieval from near-IR spectra
An algorithm for retrieval of vertical profiles from ground-based spectra in the near IR is described and tested. Known as GFIT2, the algorithm is primarily intended for CO₂, and is used exclusively for CO₂ in this paper. Retrieval of CO₂ vertical profiles from ground-based spectra is theoretically possible, would be very beneficial for carbon cycle studies and the validation of satellite measurements, and has been the focus of much research in recent years. GFIT2 is tested by application both to synthetic spectra and to measurements at two Total Carbon Column Observing Network (TCCON) sites. We demonstrate that there are approximately 3° of freedom for the CO2 profile, and the algorithm performs as expected on synthetic spectra. We show that the accuracy of retrievals of CO₂ from measurements in the 1.61μ (6220 cm⁻¹) spectral band is limited by small uncertainties in calculation of the atmospheric spectrum. We investigate several techniques to minimize the effect of these uncertainties in calculation of the spectrum. These techniques are somewhat effective but to date have not been demonstrated to produce CO₂ profile retrievals with sufficient precision for applications to carbon dynamics. We finish by discussing ongoing research which may allow CO₂ profile retrievals with sufficient accuracy to significantly improve the scientific value of the measurements from that achieved with column retrievals
The impact of neurological illness on marital relationships
The current study investigated the impact of neurological illness on marital relationship satisfaction. Participants numbered 423 patients and 335 carers from motor neurone disease (MND), Huntington\u27s disease (HD), Parkinson\u27s, and multiple sclerosis (MS). The results demonstrated that patients and carers with HD had a significantly lower level of relationship satisfaction and sex life satisfaction than the other three illness groups. Further, patients with HD indicated a significantly higher level of relationship satisfaction than their carers. For MS and MND patients, social support predicted marital relationship satisfaction, and for Parkinson\u27s patients, social support and sex life satisfaction predicted marital relationship satisfaction. <br /
Whole genome sequence analysis reveals the broad distribution of the RtxA type 1 secretion system and four novel putative type 1 secretion systems throughout the Legionella genus.
Type 1 secretion systems (T1SSs) are broadly distributed among bacteria and translocate effectors with diverse function across the bacterial cell membrane. Legionella pneumophila, the species most commonly associated with Legionellosis, encodes a T1SS at the lssXYZABD locus which is responsible for the secretion of the virulence factor RtxA. Many investigations have failed to detect lssD, the gene encoding the membrane fusion protein of the RtxA T1SS, in non-pneumophila Legionella, which has led to the assumption that this system is a virulence factor exclusively possessed by L. pneumophila. Here we discovered RtxA and its associated T1SS in a novel Legionella taurinensis strain, leading us to question whether this system may be more widespread than previously thought. Through a bioinformatic analysis of publicly available data, we classified and determined the distribution of four T1SSs including the RtxA T1SS and four novel T1SSs among diverse Legionella spp. The ABC transporter of the novel Legionella T1SS Legionella repeat protein secretion system shares structural similarity to those of diverse T1SS families, including the alkaline protease T1SS in Pseudomonas aeruginosa. The Legionella bacteriocin (1-3) secretion systems T1SSs are novel putative bacteriocin transporting T1SSs as their ABC transporters include C-39 peptidase domains in their N-terminal regions, with LB2SS and LB3SS likely constituting a nitrile hydratase leader peptide transport T1SSs. The LB1SS is more closely related to the colicin V T1SS in Escherichia coli. Of 45 Legionella spp. whole genomes examined, 19 (42%) were determined to possess lssB and lssD homologs. Of these 19, only 7 (37%) are known pathogens. There was no difference in the proportions of disease associated and non-disease associated species that possessed the RtxA T1SS (p = 0.4), contrary to the current consensus regarding the RtxA T1SS. These results draw into question the nature of RtxA and its T1SS as a singular virulence factor. Future studies should investigate mechanistic explanations for the association of RtxA with virulence
Do anti-epileptic drugs, regardless of the treatment indication, predict an increased risk in the incidence of falls and fractures?
Anti-epileptic medications (AEDs) are an important group of medications and their use is increasing for treatment of not alone epilepsy but for their indications for mental illness such as bipolar affective disorder and schizoaffective disorder. There has been concern since the 1960s that these medications impacted on bone health and this was initially studied in people with epilepsy. This study was carried out to examine the totality of evidence from primary studies about fracture risk and falls risk in people using AEDs, regardless of the indication for use. This study consists of a systematic review of prospective cohort studies examining fracture and falls in adults using AEDs, regardless of indication. Eleven studies were selected for inclusion, seven from the United States, two from the Netherlands and one each from Finland and the United Kingdom. The results of the included studies were analysed and assessed from the standpoint of methodological quality. The studies were compared across their main outcomes of interest; risk of fracture and risk of fall. It was found that there was an increased risk of fracture with AED use and three of the five studies looking at falls found the risk to be increased. Initial and repeat prescriptions for AED treatment (with its risks of side effects) require the same attention to the four principles of bioethics as all medical care should receive. This process should be structured, aided and, if necessary informed, by regulatory and legal percept which have been developed over years of interaction between the legal system and complex healthcare matters
The PELskin project—part I: fluid–structure interaction for a row of flexible flaps: a reference study in oscillating channel flow
Previous studies of flexible flaps attached to the aft part of a cylinder have demonstrated a favourable effect on the drag and lift force fluctuation. This observation is thought to be linked to the excitation of travelling waves along the flaps and as a consequence of that, periodic shedding of the von Kármán vortices is altered in phase. A more general case of such interaction is studied herein for a limited row of flaps in an oscillating flow; representative of the cylinder case since the transversal flow in the wake-region shows oscillating character. This reference case is chosen to qualify recently developed numerical methods for the simulation of fluid–structure interaction in the context of the EU funded ‘PELskin’ project. The simulation of the two-way coupled dynamics of the flexible elements is achieved via a structure model for the flap motion, which was implemented and coupled to two different fluid solvers via the immersed boundary method. The results show the waving behaviour observed at the tips of the flexible elements in interaction with the fluid flow and the formation of vortices in the gaps between the flaps. In addition, formation of vortices upstream of the leading and downstream of the trailing flap is seen, which interact with the formation of the shear-layer on top of the row. This leads to a phase shift in the wave-type motion along the row that resembles the observation in the cylinder case
Improving thermal and electrical efficiency in photovoltaic thermal systems for sustainable cooling system integration
Research into photovoltaic thermal systems is important in solar technologies as photovoltaic thermal systems are designed to produce both electrical and thermal energy, this can lead to improved performance of the overall system. The performance of photovoltaic thermal systems is based on several factors that include photovoltaic thermal materials, design, ambient temperature, inlet and outlet fluid temperature and photovoltaic cell temperature. The aim of this study is to investigate the effect of photovoltaic thermal outlet water temperatures and solar cell temperature on both electrical and thermal efficiency for different range of inlet water temperature. To achieve this, a mathematical model of a photovoltaic thermal system was developed to calculate the anticipated system performance. The factors that affect the efficiency of photovoltaic thermal collectors were discussed and the outlet fluid temperature from the photovoltaic thermal is investigated in order to reach the highest overall efficiency for the solar cooling system. An average thermal and electrical efficiency of 65% and 13.7%, respectively, was achieved and the photovoltaic thermal mathematical model was validated with experimental data from literature
The PELskin project: part II—investigating the physical coupling between flexible filaments in an oscillating flow
The fluid-structure interaction mechanisms of a coating composed of flexible flaps immersed in a periodically oscillating channel flow is here studied by means of numerical simulation, employing the Euler-Bernoulli equations to account for the flexibility of the structures. A set of passively actuated flaps have previously been demonstrated to deliver favourable aerodynamic impact when attached to a bluff body undergoing periodic vortex shedding. As such, the present configuration is identified to provide a useful test-bed to better understand this mechanism, thought to be linked to experimentally observed travelling waves. Having previously validated and elucidated the flow mechanism in Paper 1 of this series, we hereby undertake a more detailed analysis of spectra obtained for different natural frequency of structures and different configurations, in order to better characterize the mechanisms involved in the organized motion of the structures. Herein, this wave-like behaviour, observed at the tips of flexible structures via interaction with the fluid flow, is characterized by examining the time history of the filaments motion and the corresponding effects on the fluid flow, in terms of dynamics and frequency of the fluid velocity. Results indicate that the wave motion behaviour is associated with the formation of vortices in the gaps between the flaps, which itself are a function of the structural resistance to the cross flow. In addition, formation of vortices upstream of the leading and downstream of the trailing flap is seen, which interact with the formation of the shear-layer on top of the row. This leads to a phase shift in the wave-type motion along the row that resembles the observation in the cylinder case
The hiding-exposure effect revisited:A method to calculate the mobility of bimodal sediment mixtures
Predicting seabed mobility is hampered by the limited accuracy of sediment transport models when the bed is composed of mixed sediments. The hiding-exposure (HE) effect modifies the threshold of motion of individual grain classes in sediment mixtures and its strength is dependent on the grain size distribution. However, an appropriate method of predicting this effect for bimodal sediment mixtures remains to be developed. The prototypical example of a bimodal mixture is that consisting of a well-sorted sand and gravel for the fine and coarse fractions respectively. Through a comprehensive series of laboratory experiments, the HE effect has been quantified for a full range of sand-gravel mixtures from pure sand to pure gravel, the choice of which has been underpinned by an integrated study of offshore geophysical and sedimentological data found in coastal and shelf seas. In the sand–gravel mixtures used in the present study the critical shear stress needed to mobilise the sand and gravel fractions increased by up to 75% and decreased by up to 64%, respectively, compared to that needed to mobilise well-sorted sediment of similar size. The HE effect was found to be dependent on the percentage of gravel (coarse mode) present in the bimodal mixture, whereby the effect for the mixture is the weighted sum of the HE effect for the fine and coarse modes
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