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Heavy Load (heavy + load)
Selected AbstractsCorrelation of echocardiography parameters with cardiac magnetic resonance imaging in transfusion-dependent thalassaemia majorEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 1 2007Athanassios Aessopos Abstract Background and objective:,Heart iron load (cardiac Fe) can be indirectly quantified by cardiac magnetic resonance (CMR) T2*. CMR accessibility is limited, whereas echocardiography (Echo) is relatively inexpensive and readily available. The objective was to find Echo parameters that may be useful for predicting cardiac Fe. Design and methods:,We compared a number of parameters derived from Echo to cardiac Fe in 142 thalassaemia major patients who had undergone a CMR study. Results:,All patients with decreased left ventricular (LV) function had cardiac Fe. After removing those patients from the analysis, the total diameter index (Tdi) >5.57 cms/m2, left atrial diameter index >2.41 cm/m2, and the diastolic parameter E/A > 1.96 were highly specific (91.4%, 97.1% and 96.9% respectively) but had low sensitivity (31.8%, 20.45% and 21.8%) in predicting iron load. A right ventricular index >1.47 cm/m2, LV systolic index >2.26 cm/m2 or Tdi >6.26 cm/m2 discriminated between patients with no, or mild to moderate cardiac Fe from those with heavy load, with specificity of 91%, 98.5%, and 98.5%, respectively, but with low sensitivity. Interpretation and conclusions:,Echo parameters for cardiac Fe prediction have restricted value, whereas CMR is essential to assess cardiac Fe. However, patients with decreased LV systolic function should be considered a priori as having cardiac Fe, and chelation therapy should be intensified. This also applies to patients who have the above-described Echo criterion values, even if CMR is not available. Once a patient is found by CMR to have cardiac Fe, then the above Echo criterion values may be useful for ongoing monitoring. [source] Performance evaluation of LIBTA/hybrid time-slot selection algorithm for cellular systems,INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 6 2001Jyh-Horng Wen Abstract This paper studies the performance of radio assignment algorithms for portable access in cellular systems. Several channel access procedures are proposed and simulated using block oriented network simulator (BONeS) simulation of a model 36-port system. Simulation results exhibit that load-sharing system with LIBTA algorithm is better than directed retry system with the same algorithm by around 0.9 erlangs while better than quasi-fixed channel assignment (QFCA) system by around 2 erlangs if the grade of service (GOS) is constrained to less than 10 per cent. Plus, a hybrid time-slot selection procedure is proposed to enhance the system performance. It is observed that systems with hybrid time-slot selection perform better than those with LIBTA algorithm in GOS under heavy load. It is also observed that load sharing system with hybrid time-slot selection algorithm is better than directed retry system with the same algorithm by around 0.7 erlangs and better than QFCA system by around 2 erlangs. Copyright © 2001 John Wiley & Sons, Ltd. [source] Mental health nursing students' experience of stress: burdened by a heavy loadJOURNAL OF PSYCHIATRIC & MENTAL HEALTH NURSING, Issue 4 2009M. FREEBURN msc pgrad dip bsc(hons) rpn rnt This paper reports research outcomes of a study into personal stress experienced by mental health student nurses undertaking a diploma programme in Ireland. It uses a phenomenological research approach. The sample was purposive and involved in-depth interviews with six students. The purpose of the study was to contribute to the knowledge of the impact of personal life stressors. Findings from this study focus on the following themes: event, meaning, effects, ability to move beyond the stress, influence on life and constraints and demands. Key points arising are that the stress experience does impact students' internal and external worlds, potentially lessening functioning and inhibiting growth and development. This paper presents student narratives that offer insights into their inner worlds, providing true accounts of the essence of stress for them. This knowledge has implications for lecturers, personal tutors, nurse educationalists and nursing curricula, highlighting need for more proactive approaches to the provision of guidance on professional support for students and staff. Insights derived from this study are relevant not only to mental health nurse education but also to academic staff delivering professional education programmes to healthcare practitioners in a variety of settings. [source] Asymptotic and spectral analysis of non-selfadjoint operators generated by a filament model with a critical value of a boundary parameterMATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 3 2003Marianna A. Shubov Abstract We consider a class of non-selfadjoint operators generated by the equation and the boundary conditions, which govern small vibrations of an ideal filament with non-conservative boundary conditions at one end and a heavy load at the other end. The filament has a non-constant density and is subject to a viscous damping with a non-constant damping coefficient. The boundary conditions contain two arbitrary complex parameters. In our previous paper (Mathematical Methods in the Applied Sciences 2001; 24(15) : 1139,1169), we have derived the asymptotic approximations for the eigenvalues and eigenfunctions of the aforementioned non-selfadjoint operators when the boundary parameters were arbitrary complex numbers except for one specific value of one of the parameters. We call this value the critical value of the boundary parameter. It has been shown (in Mathematical Methods in the Applied Sciences 2001; 24(15) : 1139,1169) that the entire set of the eigenvalues is located in a strip parallel to the real axis. The latter property is crucial for the proof of the fact that the set of the root vectors of the operator forms a Riesz basis in the state space of the system. In the present paper, we derive the asymptotics of the spectrum exactly in the case of the critical value of the boundary parameter. We show that in this case, the asymptotics of the eigenvalues is totally different, i.e. both the imaginary and real parts of eigenvalues tend to ,as the number of an eigenvalue increases. We will show in our next paper, that as an indirect consequence of such a behaviour of the eigenvalues, the set of the root vectors of the corresponding operator is not uniformly minimal (let alone the Riesz basis property). Copyright © 2003 John Wiley & Sons, Ltd. [source] Asymptotics of eigenfrequencies and eigenmodes of non-homogeneous inextensible filament with an end loadMATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 15 2001Marianna A. Shubov Abstract We consider a class of non-selfadjoint operators generated by the equation and the boundary conditions, which govern small vibrations of an ideal filament with non-conservative boundary conditions at one end and a heavy load at the other end. The filament has a non-constant density and is subject to a viscous damping with a non-constant damping coefficient. The boundary conditions contain two arbitrary complex parameters. We derive the spectral asymptotics for the aforementioned two-parameter family of non-selfadjoint operators. In the forthcoming papers, based on the asymptotical results of the present paper, we will prove the Riesz basis property of the eigenfunctions. The spectral results obtained in the aforementioned papers will allow us to solve boundary and/or distributed controllability problems for the filament using the spectral decomposition method. Copyright © 2001 John Wiley & Sons, Ltd. [source] Lifestyle, occupation, and whole bone morphology of the pre-Hispanic Maya coastal population from Xcambó, Yucatan, MexicoINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 3 2007Isabel S. Wanner Abstract The present bioarchaeological study examines the external diaphyseal geometric properties of humeri, radii, femora and tibiae of the Classic period skeletal population of Xcambó, Yucatan, Mexico. The diaphysial proportions are evaluated using a biomechanical approach together with data from the material context and other osteological information. Our intent is to provide new answers to questions concerning lifestyle, domestic labour division and subsistence strategies of this coastal Maya settlement that was inhabited from the Late and Terminal Preclassic (300 BC,350 AD) to the Postclassic Period (900,1500 AD). Our results provide evidence for a marked sexual division of labour when compared with values from contemporaneous inland populations. The overall male and female loading patterns differ remarkably in terms of form and in bilateral comparison. A high directional asymmetry in the upper limbs is evident among males, a condition related to maritime transportation and trading activities. On the other hand, female upper limbs are characterized by very low side differences. Forces on the arms of women were probably dominated by food processing, in particular the grinding of grains or seeds. In the lower limbs, males show significantly higher anteroposterior bending strengths, which can be explained by greater engagement in transportation tasks and carrying heavy loads. In the course of the Classic period (350,900 AD), diachronic changes affect the male sample only, which suggests a shift of occupational pattern and physical demands. This shift, in turn, reflects Xcambó's changing role as the centre of a densifying settlement area and its place in the trading activities of northern Yucatan. Other topics of discussion relate to general regional trends and local prehispanic subsistence strategies. Our conclusions emphasize the value of geometric long bone analysis in the reconstruction of activity patterns and lifestyles in ancient coastal settlements. Copyright © 2007 John Wiley & Sons, Ltd. [source] Musculoskeletal pain in women working in small-scale agriculture in South AfricaAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 3 2009S. Naidoo MBChB Abstract Background Musculoskeletal pain is associated with demographic, occupational and physical factors. Methods Our study investigated the prevalence and factors associated with musculoskeletal pain in 911 women working in small-scale agriculture in rural northern KwaZulu-Natal, South Africa in 2006 using a questionnaire survey. Results In total, 67% (n,=,574) of women reported any chronic musculoskeletal pain. The 12-month prevalence of pain ranged from 63.9% to 73.3% and the prevalence of specific chronic pain lasting more than 3 months ranged from 42.8% to 48.3%. Older age, carrying heavy loads, working with hands above shoulder height, and frequently squatting and kneeling were associated with chronic musculoskeletal pain. Conclusion The prevalence of pain reported in our study, was similar to other developing countries, but considerably higher than in developed countries. Ergonomic interventions including improved and adapted work techniques and tools should be considered to reduce the prevalence of pain in our study population. Am. J. Ind. Med. 52:202,209, 2009. © 2008 Wiley-Liss, Inc. [source] | ||||||||||