Shorter Length Of Time Research Articles

Planning and Verification of Intensity-modulated Arc Therapy (IMAT): A Prostate Case Study

Introduction: IMAT has the potential to treat the patient with intensity-modulated radiotherapy (IMRT) from all coplanar beam angles in a short length of time, thereby offering maximum plan quality and minimum intrafraction motion. A patient previously treated in the trial of Conventional versus Hypofractionated High-dose IMRT for Prostate cancer (CHHIP) was used as a model.

Rf Method of Reciprocity Performance Testing, Part II: Long Term Performance Verification

Modern image stability testing typically involves the isolation of each environmental variable that is believed to impact image permanence and the measurement and quantification of the effects produced by exposure to such variables over time. The high stability of modern photographic products makes testing under ambient conditions too lengthy for new product development cycles, which results in the use of accelerated aging whereby the impacting variables are held at levels considerably greater than ambient, forcing the image to a failure point in a far shorter length of time than normal. In Part I, we discussed the calculation of reciprocity factors and explored a new method of testing for reciprocity performance by demonstrating a 2−4X reduction in the time required for test completion while potentially improving the accuracy of the results and predictions. This paper extends that discussion with the use of actual test data specifically designed to show the benefits of higher replication and optimal sampling protocols. These techniques can further reduce the time that is needed to run reciprocity tests while improving the accuracy of the conclusions.

Characteristics of childhood cancer survivors predicted their successful tracing

Objective The Childhood Cancer Survivor Study is a retrospective cohort study that was initiated to explore late effects of childhood cancer and its therapies. We evaluated the characteristics of those requiring tracing and factors that influenced tracing success. Study design and setting Medical record review identified 20,051 eligible individuals from 25 institutions in the United States and Canada. Of these, 13,021 had a current address in the medical record at the treating institution, and 7,030 had an incorrect address and required tracing by a commercial firm. Results Tracing was successful for 4,188 persons (60%). Younger age at contact, shorter length of time since last contact, having a middle initial available, an uncommon last name, and socioeconomic factors were found to predict successful tracing. Compared to those with a current address available in medical records, subjects successfully traced were less likely to have accessed health care during the previous 2 years; and more likely to be current smokers, obese, and to report moderate to severe impairments (pain, functional status, and activity). Conclusion These findings provide an empirical basis concerning determinants and predictors of tracing success. If tracing had not been performed in this cohort, spurious associations may have been obtained for some health outcomes of interest.

Kinetic proofreading by the cavity system of myoglobin: protection from poisoning.

Throughout its matrix of atoms, myoglobin has a network of cavities that are inhabited for short lengths of time by ligands released by photolysis from the myoglobin heme. The purpose or effect of this cavity network is not clear. A recently published kinetic scheme that fits data from many native and mutant myoglobin oxygen photolysis experiments can be modified easily into a kinetic scheme that includes kinetic proofreading. Proofreading would provide protection against contaminants and, specifically, might help protect the cell from carbon monoxide poisoning. Here we present a two-part model: (1) myoglobin represented by a kinetic description, which includes proofreading reactions associated with the cavities, and (2) a reaction-diffusion description of a myocyte model in which the part 1 myoglobin acts as a mobile buffer in simultaneous carbon monoxide and oxygen gradients. The non-equilibrium nature of part 2 should promote the proofreading function of part 1. A simulation using the model demonstrates that the cavity system can in principle proofread, reducing mitochondrial enzyme contamination.

Dexamethasone therapy in neonates treated with extracorporeal membrane oxygenation

Objective To test the hypothesis that infants who received dexamethasone would have a shorter length of time on extracorporeal membrane oxygenation (ECMO). Study design Infants placed on ECMO for respiratory failure were randomly assigned to receive either dexamethasone for 3 days or placebo. Chest radiographs were scored through the use of a validated standard scoring system to assess lung injury. Results Thirty infants received dexamethasone and 29 received placebo. The median (25th%, 75th%) duration of time on ECMO was 143.5 (100, 313) hours in the dexamethasone group and 160 (111, 303) hours in the placebo group (not significant). Survival was 80% in the dexamethasone group and 83% in the placebo group. Radiographic lung injury scores (mean±SEM) were significantly improved in the dexamethasone group (10.5±0.6) versus placebo (12.3±0.5) on day 3 of ECMO ( P = .013). Hypertension developed in 27 of the 30 infants receiving dexamethasone and 13 of the 29 infants in the placebo group during ECMO ( P<.01). Conclusions Dexamethasone given during the first 3 days of ECMO results in significant improvement in lung injury scores by day 3 of ECMO but does not significantly decrease the duration of ECMO or improve survival. The preponderance of evidence would not support the use of dexamethasone in this setting.

Overview: Hidden Hunger and the Role of Public-Private Partnership

Mineral and vitamin deficiencies adversely affect the health intellect and physical ability of some one and a half billion people worldwide. The World Bank has estimated that for less than 0.3% of their GDP most developing countries could rid themselves of these preventable conditions and diseases which now cost them 5% of their GDP in lost lives disability and low productivity. The world needs to give much more attention to problems of protein-energy malnutrition and poor growth in children; to parasitic viral and bacterial infections that cause extensive preventable morbidity and mortality; and to reductions in poverty and intolerable inequity. Nevertheless the control of vitamin and mineral deficiencies using existing scientific knowledge and technologies offers an extraordinarily large opportunity to improve human well-being and to accelerate development at relatively low cost. Furthermore it is something that is within our grasp to achieve in a relatively short length of time. The World Bank considers micronutrient control programs to be among the most cost-effective of all health interventions. (excerpt)

Overview: Hidden Hunger and the Role of Public-Private Partnership

Mineral and vitamin deficiencies adversely affect the health intellect and physical ability of some one and a half billion people worldwide. The World Bank has estimated that for less than 0.3% of their GDP most developing countries could rid themselves of these preventable conditions and diseases which now cost them 5% of their GDP in lost lives disability and low productivity. The world needs to give much more attention to problems of protein-energy malnutrition and poor growth in children; to parasitic viral and bacterial infections that cause extensive preventable morbidity and mortality; and to reductions in poverty and intolerable inequity. Nevertheless the control of vitamin and mineral deficiencies using existing scientific knowledge and technologies offers an extraordinarily large opportunity to improve human well-being and to accelerate development at relatively low cost. Furthermore it is something that is within our grasp to achieve in a relatively short length of time. The World Bank considers micronutrient control programs to be among the most cost-effective of all health interventions. (excerpt)

DRIS FOLIAR NORMS FOR COFFEE

Foliar diagnosis norms for coffee (Coffea Arabica L.) were developed through a DRIS approach by searching for, selecting and sampling, the most productive individuals of four coffee varieties (Mundo Nuevo, Caturra, Catuai Rojo, Catuai Amarillo) of different ages. Nutrient data of plants with yield over 7 kg per plant of cherry coffee, corresponding to the top 36% of the trees sampled, were computer stored to develop a data bank. Processing such data through conventional statistical methods, the norms were developed. According to DRIS system reports, mean values of each of the studied nutrients were developed as the norms. Finally, DRIS norms corresponding to the nutrient content in g per kg of dry matter of N (32.3); P (1.5); K (13.5); Ca (19.4); Mg (4.7) and on mg per kg of Zn (21); Fe (101); Cu (16) and Mn (196), plus the 36 binary relationships of quotients and products among those 9 nutrients were developed. Standard deviations and variation coefficients for each norm are also reported. Developed norms were compared with previously published values showing close values with previously reported coffee nutritional data. The close general agreement among the published values and the norms developed here plus the short length of time (2 years) used in this work for norms development, suggests the approach used could become an economic, relatively fast and reliable method for developing foliar diagnostic norms on perennial fruit plants, even without previous data.

Calidad de la relación médico paciente y resultados de los encuentros clínicos en atención primaria de Alicante: un estudio con grupos focales

The relationship between the quality of the physician-patient relationship and the outcomes of the clinical encounters in primary care are examined. Focus groups of physicians and patients. A total of 24 professionals and 22 patients took part. The physicians perceived a relationship to exist between the scarcity of healthcare resources (short length of time with each patient, care-providing overload, lack of specific resources, lack of training), conflicts with "difficult" patients and the influence of the psychosocial factors in the clinical encounter and error, burnout, defensive medicine and the low quality of the services. Communication/examination-related problems during the clinical interview and by negative feelings acted as intermediary factors in this relationship. The patients perceived a relationship to exist between an operating pattern characterized by short office visits scheduled at an overloaded pace and physician, patient communications problems and error and conflict in the clinical encounter. There is also a relationship between the physician's humanist attitude and a better outcome of the health problems. The objectives and priorities of the health care system, out of touch with the needs of the community, are seen as being key determining factors as regards the lacks considered to exist. The physician-patient relationship processes play a mediating role between the health care resources and the outcomes of the clinical encounters. Improving the care provided and the physician-patient relationship in primary care requires a multi-dimensional approach and view which goes beyond the measures taken regarding individual physician and patient-related factors.

La perspectiva de las cuidadoras informales sobre la atención domiciliaria: un estudio cualitativo con ayuda de un programa informático

A hot debate exists in our country as to the models of home care which must be developed. This study is aimed at ascertaining how the family caregivers of terminal cancer patients, of the elderly suffering from dementia and of individuals having undergone major operations in outpatient surgery programs rate the quality of the home care provided. A phenomenological type qualitative study based on discussion groups (9), triangular groups (5) and in-depth interviews (22). This study was conducted in Andalusia throughout the 1999-2000 period. The subjects of the study were the main caregivers of patients provided with home care through the healthcare centers. The information must be analyzed by means of a Nudist-4 software-aided content analysis. The analysis variables were those of the Servqual model. For the caregivers of cancer patients, the most important aspects of the quality of the home care provided were the Response Capacity and Accessibility. This analysis revealed that the patients suffered pain but the pain was not controlled. Negative aspects hindering accessibility were the lack of home care coverage outside of regular working hours, the difficulty of getting in touch by phone, the length of time it takes for someone to come and the visits solely on request. The caregivers of patients having undergone major outpatient surgery want Security and Reliability. They complain of the short length of time within which the patients are released from the hospital and of the home care provided by the health care center. The caregivers of the elderly with dementia place top priority on being provided with the materials they need to take care of these patients. Caregivers' and patients' expectations differ, depending on health problems, therefore, the type of home care provided should vary, according to the health problems involved. It is necessary to develop a flexible model, capable of adapting to different patient needs and the diverse circumstances that affect family caregivers.

Nonlinear FEM-BEM formulation and model-free inversion procedure for reconstruction of cracks using pulse eddy currents

Pulse eddy currents are proposed as a nondestructive testing (NDT) technique to detect flaws in conductive structures with large thickness. The harmonic component of a pulse is rich, so that the pick-up signal containing the amount of information corresponds to a multifrequency analysis. Due to the short time length of the pulse, the amplitude of the excitation increases up to 100 times of the amplitude for an AC signal. Both direct simulation of pulse eddy-currents phenomena using an A-/spl phi/ FEM-BEM code and neural network-based inversion techniques are performed. Numerical results for the inversion of signals due to outer defects are shown.

Achieving competency in reading stained smears for sperm morphology in an IVF laboratory.

Objective: To determine the length of time necessary to achieve competency in accurately evaluating sperm morphology and identifying specific aspects of morphology that are most difficult to assess and therefore require most attention during training. Design: Morphologic assessment of sperm by the technology staff undergoing training in an IVF laboratory and comparing the readings to those of an expert andrologist. Materials/Methods: Smears for sperm morphology were prepared, stained and read by the same technologist in a large IVF laboratory during a 28 day training period where 1–2 slides were read/day. Smears were prepared using fresh semen, air dried and stained. Smears were evaluated microscopically (1000×) for sperm morphology based on a 200 cell count based on strict criteria in the following categories: Head (normal oval and abnormal forms [irregular (amorphous), tapered, large, small and duplicate]), Midpiece (bent or broken neck, misalignment of head and neck and thickness), Tail (coil, blunt, duplicate) and Cytoplasmic Droplet. During early training 10 slides were read over 10 days (Group 1). At midpoint, 10 slides were read over 9 days (Group II). In late training 9 slides were read over 9 days (Group III). These slides were then reread by the same technologist and by an expert. Paired group t-test was used for test of significance. Results: In the category of head defects, readings by the same technologist across the three groups revealed the following: oval, taper and large heads showed significant differences Group I and II (p < 0.05) and no significant difference in Group 3. Small and duplicate head categories showed a significant in Group II only (p < 0.02). The irregular head category showed significant differences across all three groups (p < 0.02). However, the mean differences decrease from Group I to Group III. With respect to tail abnormalities no significant difference was noted across the three groups except for coiled defects in group II (p < 0.05) and duplicate tails in group III (p < 0.02). The difference in the detection of mid-piece defects was significant only in group I (p < 0.01). No significant difference was noted in the morphologic assessment of nine randomly selected smears (3 from each group) by an expert andrologist and those of the technologist upon completion of training. Conclusions: 1) The length of training in this study was adequate to achieve competency in morphologic assessment of sperm based on strict criteria with regards to oval, taper, small, large, and duplicate head shapes. 2) The irregular (amorphous) head shape proved most difficult to evaluate accurately and therefore requires the greatest degree of attention during training. 3) Tail and mid-piece defects were easiest to detect accurately evidenced by the short length of time required to achieve proficiency.

Twenty-nine years after carbon monoxide intoxication

Carbon monoxide (CO) is a worldwide environmental toxin and a leading cause of deliberate or accidental poisoning. There is an extensive literature devoted to the clinical features and treatment of those victims who have survived acute CO poisoning for a short length of time. The long-term sequelae of non-fatal poisoning have received scanty references, and the prospects for the long-lasting survivors of acute CO intoxication are less clear. Literature review uncovered reports of only three patients who were followed for a considerable period of time. We present a case of CO poisoning with progressive neurological and psychological deterioration that began 17 years after recovery from a severe, accidental CO asphyxia. The patient was examined in the neurology out patient clinic 29 years after the initial CO intoxication. We believe the unique status of this patient, her similarity to one other case in the literature and the circumstances allowing correlation of the clinical picture to the CO poisoning warrants emphasis.

Thermoelectric properties of (Bi0.25Sb0.75)2Te3 alloys fabricated by hot-pressing method

Thermoelectric properties of the hot-pressed p-type (Bi0.25Sb0.75)2Te3 alloy were characterized with variation of the hot-pressing temperature and the starting powder size. The roles of the factors which affect the Seebeck coefficient of the hot-pressed (Bi0.25Sb0.75)2Te3 alloy has been elucidated in this study. The donor-like behavior of oxygen could be one of the possible explanations for the higher Seebeck coefficient of the hot-pressed (Bi0.25Sb0.75)2Te3 alloy. Te vacancies formed by mechanical deformation during the powdering process significantly promote the diffusion of second phase Te atoms into their lattice sites so that the matrix Te solubility approaches its equilibrium value at a given temperature in a relatively short length of time. Using the Seebeck coefficient at various hot-pressing temperatures, the micro-phase diagram near the stoichiometric composition of (Bi0.25Sb0.75)2Te3 was evaluated.

Survey into health problems of elderly people: a comparison of self-report with proxy information.

This study was conducted as part of the Medical Research Council Cognitive Function and Ageing Study. To compare information given by elderly people on their past and current health and family history of illness with similar information obtained from a relative, friend or carer. Screening and assessment stages of a prevalence study. Three urban and two rural areas of England and Wales. A subsample weighted by age and cognitive status of random population samples of people >/=65 years, living in their own home or in a residential or nursing home, interviewed between 1991 and 1994. A relative, friend or carer identified by each elderly person to provide proxy information. INTERVIEW: Computerized schedules including items on demographic details, cognitive function, lifetime illnesses, current health problems and family history of illness. The rate of proxy 'don't know' responses and the agreement between the elderly person and their proxy were calculated for each item, both for the overall sample and for subgroups based on characteristics of the respondent and of the proxy and on the relationship between them. Higher 'don't know' rates were found to be particularly associated with more distant relationships, questions on family history, a shorter length of time known and a lack of co-residence. Agreement was strongly related to the nature of the question and less to co-residence, with other factors such as relationship having much smaller effects. Proxy information on past and current health problems can be almost complete and in good agreement with self-report, particularly where the proxy lives with the respondent. On family history of illness, history of head injury or boxing and current sleep problems, proxy information is likely to be less complete and show poor agreement. A proxy who is not a close relative is likely to give less complete information but agreement will not be substantially lower.

Fuzzy Nets Based on-line Cutting Power Recognition in Milling Operations

A self-organising fuzzy-nets optimisation system was developed to generate a knowledge bank able to demonstrate the required cutting power on-line for a short length of time in an NC verifier. This fuzzy-nets system (FNS) uses a five-step self-learning procedure, and was examined for end-milling operations on a Fadal VMC40 vertical machining centre. Data collected from the operations were used to train and test the FNS. Three approaches were employed to predict the cutting power. 1. Metal cutting theory model. 2. Fuzzy-nets model using theoretical data for training. 3. Fuzzy-nets model using experimental data for training. To compare the quality of the data obtained from these approaches, three hypotheses were formulated for this study. The results showed that the FNS possessed a satisfactory range of accuracy with the intended applications of the model.

High voltage subnanosecond breakdown

Present-day ultra-wideband radiation sources produce Megavolt pulses at hundreds of picosecond (ps) risetimes. Empirical data on the breakdown characteristics for dielectric media at these short time lengths and high voltages are either extremely limited or nonexistent. In support of the design of these ultra-wideband sources, we are investigating the breakdown characteristics, at these voltages and time lengths, of several liquids and high-pressure gases. These include air, N/sub 2/, H/sub 2/, SF/sub 6/, and transformer oil. Gap voltages attained were over 700 kV and gas pressures were over 150 atm (15 MPa). Breakdown times achieved were on the order of 600 ps. Electric field strengths observed for given breakdown times were higher than predicted by other investigators. An empirical fit is presented for the data obtained.

Synthesis of wax ester through triolein alcoholysis: Choice of the lipase and study of the mechanism

Eight microbial lipases and one animal tissue lipase were tested for their ability to support alcoholysis between triolein and stearyl alcohol to produce wax ester. The lipases from Alcaligenes sp. and Chromobacterium viscosum were shown to produce the best ester yield (about 53%); however, the reaction was catalyzed in a shorter length of time using the lipase from Alcaligenes sp. (5 h) as compared to the lipase from C. viscosum (200 h). The lipases from Mucor javanicus, Mucor miehei, and Pseudomonas fluorescens showed 35% ester yield within 150 h. The other lipases, i.e., the lipases extracted from porcine pancreas, Candida rugosa, Rhizopus javanicus, and Rhizopus niveus showed only low catalytic activity (less than 20%). The lipase from Alcaligenes sp. was used for further investigations on the mechanism of the reaction. A regioselectivity toward the sn-1,3-positions of the acylglycerols was shown during the first hours of reaction. After 5 h when ester synthesis and triolein consumption stopped, the continuous evolution of the concentration of monoolein and diolein isomer forms was ascribed to isomerization reactions.

Bistable switching in nonlinear Bragg gratings

We present a new approach to all-optical switching in nonlinear Bragg gratings. In contrast to previous schemes in which the system remains in the switched state for a short length of time we permanent switch a CW probe from a state of high reflectivity to a low reflectivity state using a short optical pump. Finally we discuss the practicality of the device.

Analysis of cohort effects in mixed longitudinal data sets.

Mixed longitudinal designs are among the most efficient for the study of growth and developmental processes. In this approach, one studies several (birth) cohorts, each for a relatively short length of time, and then links the growth curves for the individual cohorts together to obtain the growth curve for the entire length of time spanned by the ages of the subjects in all cohorts. Thus, e.g., in the Nijmegen Growth Study, three cohorts were each studied for 5 years, the intent being to join the three curves together to form a single curve covering the entire period from 4 to 14 years of age. In order for this approach to be valid, there either should be no cohort effects (secular trends) or the fitted curve must be adjusted in some way to correct for such effects if they exist. The question thus arises as to how one should test for the presence of cohort effects and what one should do about them if found. The problems which may arise using height and weight data from the Nijmegen Growth Study are illustrated. In particular for girls, height and weight both show cohort effects (at 9.25 years of age) when the raw data are used. If, however, the observed data are used to estimate the values at the target age, and these values are used in the comparison, differences between the cohorts are no longer significant. The problems are further illustrated using data from a mixed longitudinal data set of cleft lip and palate patients and data from the National Dutch Growth Study 1980.