125 research outputs found
The role of coherence entropy of physical twin observables in entanglement
The concept of physical twin observables (PTO) for bipartite quantum
states,introduced and proved relevant for quantum information theory in recent
work, is substantially simplified. The relation of observable and state is
studied in detail from the point of view of coherence entropy. Properties of
this quantity are further explored. It is shown that, besides for pure states,
quantum discord (measure of entanglement) can be expressed through the
coherence entropy of a PTO complete in relation to the state.Comment: 19 pages, Latex+Revtex
Unique Aggregation of Sterigmatocystin in Water Yields Strong and Specific Circular Dichroism Response Allowing Highly Sensitive and Selective Monitoring of Bio-Relevant Interactions
We demonstrated the hitherto unknown property of the mycotoxin sterigmatocystin (STC) to provide homogeneous solutions in aqueous medium by forming a unique aggregate type (not formed by analogous aflatoxins), characterized by exceptionally strong circular dichroism (CD) bands in the 300-400 nm range. Results showed that these CD bands do not originate from intrinsic STC chirality but are a specific property of a peculiar aggregation process similar to psi-DNA CD response. Transmission electron microscopy (TEM) experiments revealed a fine fiber network resembling a supramolecular gel structure with helical fibers. Thermodynamic studies of aggregates by differential scanning calorimetry (DSC) revealed high reversibility of the dominant aggregation process. We demonstrated that the novel STC psi-CD band at 345 nm could be applied at biorelevant conditions (100 nanomolar concentration) and even in marine-salt content conditions for specific and quantitative monitoring of STC. Also, we showed that STC strongly non-covalently interacts with ds-DNA with likely toxic effects, thus contrary to the previous belief requiring prior enzyme epoxidation
Mixed-state twin observables
Twin observables, i.e. opposite subsystem observables A+ and A- that are
indistinguishable in measurement in a given mixed or pure state W, are
investigated in detail algebraicly and geometrically. It is shown that there is
a far-reaching correspondence between the detectable (in W) spectral entities
of the two operators. Twin observables are state-dependently quantum-logically
equivalent, and direct subsystem measurement of one of them ipso facto gives
rise to the indirect (i.e. distant) measurement of the other. Existence of
nontrivial twins requires singularity of W. Systems in thermodynamic
equilibrium do not admit subsystem twins. These observables may enable one to
simplify the matrix representing W.Comment: 13 page
The role of wages in the migration of health care professionals from developing countries
Several countries are increasingly relying on immigration as a means of coping with domestic shortages of health care professionals. This trend has led to concerns that in many of the source countries – especially within Africa – the outflow of health care professionals is adversely affecting the health care system. This paper examines the role of wages in the migration decision and discusses the likely effect of wage increases in source countries in slowing migration flows. This paper uses data on wage differentials in the health care sector between source country and receiving country (adjusted for purchasing power parity) to test the hypothesis that larger wage differentials lead to a larger supply of health care migrants. Differences in other important factors affecting migration are discussed and, where available, data are presented. There is little correlation between the supply of health care migrants and the size of the wage differential between source and destination country. In cases where data are available on other factors affecting migration, controlling for these factors does not affect the result. At current levels, wage differentials between source and destination country are so large that small increases in health care wages in source countries are unlikely to affect significantly the supply of health care migrants. The results suggest that non-wage instruments might be more effective in altering migration flows
Developing a Standard Set of Patient-centred Outcomes for Adult Oral Health - An International, Cross-disciplinary Consensus.
OBJECTIVE: To develop a minimum Adult Oral Health Standard Set (AOHSS) for use in clinical practice, research, advocacy and population health. MATERIALS AND METHODS: An international oral health working group (OHWG) was established, of patient advocates, researchers, clinicians and public health experts to develop an AOHSS. PubMed was searched for oral health clinical and patient-reported measures and case-mix variables related to caries and periodontal disease. The selected patient-reported outcome measures focused on general oral health, and oral health-related quality of life tools. A consensus was reached via Delphi with parallel consultation of subject matter content experts. Finally, comments and input were elicited from oral health stakeholders globally, including patients/consumers. RESULTS: The literature search yielded 1,453 results. After inclusion/exclusion criteria, 959 abstracts generated potential outcomes and case-mix variables. Delphi rounds resulted in a consensus-based selection of 80 individual items capturing 31 outcome and case-mix concepts. Global reviews generated 347 responses from 87 countries, and the patient/consumer validation survey elicited 129 responses. This AOHSS includes 25 items directed towards patients (including demographics, the impact of their oral health on oral function, a record of pain and oral hygiene practices, and financial implications of care) and items for clinicians to complete, including medical history, a record of caries and periodontal disease activity, and types of dental treatment delivered. CONCLUSION: In conclusion, utilising a robust methodology, a standardised core set of oral health outcome measures for adults, with a particular emphasis on caries and periodontal disease, was developed
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Mid-level providers in emergency obstetric and newborn health care: factors affecting their performance and retention within the Malawian health system
<p>Abstract</p> <p>Background</p> <p>Malawi has a chronic shortage of human resources for health. This has a significant impact on maternal health, with mortality rates amongst the highest in the world. Mid-level cadres of health workers provide the bulk of emergency obstetric and neonatal care. In this context these cadres are defined as those who undertake roles and tasks that are more usually the province of internationally recognised cadres, such as doctors and nurses. While there have been several studies addressing retention factors for doctors and registered nurses, data and studies addressing the perceptions of these mid-level cadres on the factors that influence their performance and retention within health care systems are scarce.</p> <p>Methods</p> <p>This exploratory qualitative study took place in four rural mission hospitals in Malawi. The study population was mid-level providers of emergency obstetric and neonatal care. Focus group discussions took place with nursing and medical cadres. Semi-structured interviews with key human resources, training and administrative personnel were used to provide context and background. Data were analysed using a framework analysis.</p> <p>Results</p> <p>Participants confirmed the difficulties of their working conditions and the clear commitment they have to serving the rural Malawian population. Although insufficient financial remuneration had a negative impact on retention and performance, the main factors identified were limited opportunities for career development and further education (particularly for clinical officers) and inadequate or non-existent human resources management systems. The lack of performance-related rewards and recognition were perceived to be particularly demotivating.</p> <p>Conclusion</p> <p>Mid-level cadres are being used to stem Africa's brain drain. It is in the interests of both the government and mission organizations to protect their investment in these workers. For optimal performance and quality of care they need to be supported and properly motivated. A structured system of continuing professional development and functioning human resources management would show commitment to these cadres and support them as professionals. Action needs to be taken to prevent staff members from leaving the health sector for less stressful, more financially rewarding alternatives.</p
Human resources for health and burden of disease: an econometric approach
<p>Abstract</p> <p>Background</p> <p>The effect of health workers on health has been proven to be important for various health outcomes (e.g. mortality, coverage of immunisation or skilled birth attendants). The study aim of this paper is to assess the relationship between health workers and disability-adjusted life years (DALYs), which represents a much broader concept of health outcome, including not only mortality but also morbidity.</p> <p>Methods</p> <p>Cross-country multiple regression analyses were undertaken, with DALYs and DALYs disaggregated according to the three different groups of diseases as the dependent variable. Aggregate health workers and disaggregate physicians, nurses, and midwives were included as independent variables, as well as a variable accounting for the skill mix of professionals. The analysis also considers controlling for the effects of income, income distribution, percentage of rural population with access to improved water source, and health expenditure.</p> <p>Results</p> <p>This study presents evidence of a statistically negative relationship between the density of health workers (especially physicians) and the DALYs. An increase of one unit in the density of health workers per 1000 will decrease, on average, the total burden of disease between 1% and 3%. However, in line with previous findings in the literature, the density of nurses and midwives could not be said to be statistically associated to DALYs.</p> <p>Conclusions</p> <p>If countries increase their health worker density, they will be able to reduce significantly their burden of disease, especially the burden associated to communicable diseases. This study represents supporting evidence of the importance of health workers for health.</p
Intent to migrate among nursing students in Uganda: Measures of the brain drain in the next generation of health professionals
Background: There is significant concern about the worldwide migration of nursing professionals from low-income countries to rich ones, as nurses are lured to fill the large number of vacancies in upper-income countries. This study explores the views of nursing students in Uganda to assess their views on practice options and their intentions to migrate.
Methods: Anonymous questionnaires were distributed to nursing students at the Makerere Nursing School and Aga Khan University Nursing School in Kampala, Uganda, during July 2006,
using convenience sampling methods, with 139 participants. Two focus groups were also conducted at one university.
Results: Most (70%) of the participants would like to work outside Uganda, and said it was likely that within five years they would be working in the U.S. (59%) or the U.K. (49%). About a fourth (27%) said they could be working in another African country. Only eight percent of all students
reported an unlikelihood to migrate within five years of training completion. Survey respondents were more dissatisfied with financial remuneration than with any other factor pushing them
towards emigration. Those wanting to work in the settings of urban, private, or U.K./U.S. practices were less likely to express a sense of professional obligation and/or loyalty to country. Those who
have lived in rural areas were less likely to report wanting to emigrate. Students with a desire to work in urban areas or private practice were more likely to report an intent to emigrate for financial reasons or in pursuit of country stability, while students wanting to work in rural areas or
public practice were less likely to want to emigrate overall.
Conclusion: Improving remuneration for nurses is the top priority policy change sought by nursing students in our study. Nursing schools may want to recruit students desiring work in rural areas or public practice to lead to a more stable workforce in Uganda.University of Washington Department of Global Healt
The use of discrete choice experiments to inform health workforce policy: a systematic review.
BACKGROUND: Discrete choice experiments have become a popular study design to study the labour market preferences of health workers. Discrete choice experiments in health, however, have been criticised for lagging behind best practice and there are specific methodological considerations for those focused on job choices. We performed a systematic review of the application of discrete choice experiments to inform health workforce policy. METHODS: We searched for discrete choice experiments that examined the labour market preferences of health workers, including doctors, nurses, allied health professionals, mid-level and community health workers. We searched Medline, Embase, Global Health, other databases and grey literature repositories with no limits on date or language and contacted 44 experts. Features of choice task and experimental design, conduct and analysis of included studies were assessed against best practice. An assessment of validity was undertaken for all studies, with a comparison of results from those with low risk of bias and a similar objective and context. RESULTS: Twenty-seven studies were included, with over half set in low- and middle-income countries. There were more studies published in the last four years than the previous ten years. Doctors or medical students were the most studied cadre. Studies frequently pooled results from heterogeneous subgroups or extrapolated these results to the general population. Only one third of studies included an opt-out option, despite all health workers having the option to exit the labour market. Just five studies combined results with cost data to assess the cost effectiveness of various policy options. Comparison of results from similar studies broadly showed the importance of bonus payments and postgraduate training opportunities and the unpopularity of time commitments for the uptake of rural posts. CONCLUSIONS: This is the first systematic review of discrete choice experiments in human resources for health. We identified specific issues relating to this application of which practitioners should be aware to ensure robust results. In particular, there is a need for more defined target populations and increased synthesis with cost data. Research on a wider range of health workers and the generalisability of results would be welcome to better inform policy
Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV
The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration
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