Common Problem (common + problem)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Student Finance and Widening Participation in the British Isles: Common Problems, Different Solutions

HIGHER EDUCATION QUARTERLY, Issue 4 2006
Nick Adnett
Across the British Isles there are common forces encouraging an expansion of higher education (HE) while constraining the ability and willingness of governments to finance it. We examine the nature of these forces and conclude that together they are likely to lead over time to the general taxpayer funding a declining share of HE costs. While there are some potential efficiency and social equity benefits from reforms of student finance motivated by switching more of the costs towards students and their parents, the likely impact of these reforms on widening participation is unclear. We examine the current student finance systems in the British Isles and assess whether or not a system based upon income-contingent student loans, means-tested grants and targeted bursaries can deliver both the desired expansion and widening access. [source]


Scientific Structuralism: Structuralism(s) About Science: Some Common Problems

ARISTOTELIAN SOCIETY SUPPLEMENTARY VOLUME, Issue 1 2007
Bas C. Van Fraassen
Structuralist views of science can be realist or empiricist but face some of the same problems. The identity of indiscernibles: if not honoured in mathematics, nevertheless required to relate mathematics to the phenomena?Metaphysics: does Ladyman's ,radically naturalized metaphysics' still violate empiricist scruples?'Structure is all there is': can we accept the ,disappearance' of objects (things that bear structure but aren't themselves structure)? What could it mean to do without those sorts of entities in thinking about the world(-picture) of the physical sciences? [source]


Timeliness and effectiveness in the surgical management of persistent post-treatment periapical pathosis

ENDODONTIC TOPICS, Issue 1 2005
MIN-KAI WU
Common problems that cause persistent post-treatment periapical pathosis include infection remaining in the apical inaccessible areas, extraradicular infection including apically extruded dentine debris with bacteria present in dentinal tubules, radicular true cysts, foreign body reactions, inadequate non-surgical root canal treatment with or without iatrogenically altered root canal morphology, and vertical root fractures. Inadequate root canal treatment may be corrected non-surgically, while more complex problems may require surgical intervention. The important factors that warrant a successful surgery include good quality of the orthograde root canal treatment, deep retrograde preparation of the apical canal, and carefully cleaning and filling of the exposed isthmuses and accessory canals. Ideally, apical surgery and orthograde retreatment are performed simultaneously. In a recent study, 97% of the lesions including large ones of >10 mm in diameter healed completely within 1 year after surgical intervention. Of the teeth that showed ,complete healing' at 4 years more than 85% already ,completely healed' at 2 years; thus, the endodontic post-treatment disease might be treated surgically or non-surgically within 2 years after the previous treatment. [source]


Translating questionnaire items for a multi-lingual worker population: The iterative process of translation and cognitive interviews with English-, Spanish-, and Chinese-speaking workers,,

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 2 2010
Kaori Fujishiro PhD
Abstract Background The increasing ethnic diversity of the US workforce has created a need for research tools that can be used with multi-lingual worker populations. Developing multi-language questionnaire items is a complex process; however, very little has been documented in the literature. Methods Commonly used English items from the Job Content Questionnaire and Quality of Work Life Questionnaire were translated by two interdisciplinary bilingual teams and cognitively tested in interviews with English-, Spanish-, and Chinese-speaking workers. Results Common problems across languages mainly concerned response format. Language-specific problems required more conceptual than literal translations. Some items were better understood by non-English speakers than by English speakers. De-centering (i.e., modifying the English original to correspond with translation) produced better understanding for one item. Conclusions Translating questionnaire items and achieving equivalence across languages require various kinds of expertise. Backward translation itself is not sufficient. More research efforts should be concentrated on qualitative approaches to developing useful research tools. Am. J. Ind. Med. 53:194,203 2010. Published 2009 Wiley-Liss, Inc. [source]


Occupational health crossing borders part 2: Comparison of 18 occupational health systems across the globe

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 1 2010
Katja Radon MSc
Abstract Background Occupational health and safety (OHS) is considered one of the most important factors for a sustainable development; however, it is often considered a luxury by decision-makers. This article compares OHS systems of 18 countries at different stages of development. Methods In an international summer school, structure of the national OHS system, definition of occupational accidents and diseases, procedures for compensation claims, outcome (expressed as incidence of occupational accidents) and training opportunities were presented. Results National OHS systems ranged from non-existent to systems implemented almost 200 years ago. Priorities, incidence of occupational accidents and training opportunities varied. Common problems included the lack of OHS service for small enterprises and in rural areas. Conclusions International training programs like this summer school might enhance the exchange about OHS opportunities around the globe and contribute to improved workers health. Am. J. Ind. Med. 53:55,63, 2010. © 2009 Wiley-Liss, Inc. [source]


The Implementation of Innovation by a Multinational Operating in Two Different Environments: A Comparative Study

CREATIVITY AND INNOVATION MANAGEMENT, Issue 2 2002
Mohamed Zain
The aim of the paper is to examine the innovation initiatives and processes followed by two subsidiaries of a German multinational company operating in Europe and Asia and to compare the innovativeness of their operations in these two locations. The study examined the innovation processes followed by the two subsidiary firms operating in Germany and Malaysia, the actual problems faced by them, the critical success factors involved in the implementation, and the work climates of the firms. Interestingly, it was found that both firms followed similar innovation processes. Nevertheless, different types of problems and critical success factors were applicable to both firms. The results showed that the Malaysian subsidiary faced more behavioural problems while the German subsidiary encountered more technical problems. Further, the study showed that a lack of knowledge was the common problem faced equally by both firms. The study demonstrated that the German subsidiary had better working climate compared to its counterpart in Malaysia. Finally, the German subsidiary was found to be more innovation,active than the Malaysian subsidiary as it introduced more types of innovation, interacted with more types of entity in the external environment and introduced more types of training. [source]


Knowledge-based system for structured examination, diagnosis and therapy in treatment of traumatised teeth

DENTAL TRAUMATOLOGY, Issue 1 2001
A. Robertson
Abstract , Dental trauma in children and adolescents is a common problem, and the prevalence of these injuries has increased in the last 10,20 years. A dental injury should always be considered an emergency and, thus, be treated immediately to relieve pain, facilitate reduction of displaced teeth, reconstruct lost hard tissue, and improve prognosis. Rational therapy depends upon a correct diagnosis, which can be achieved with the aid of various examination techniques. It must be understood that an incomplete examination can lead to inaccurate diagnosis and less successful treatment. Good knowledge of traumatology and models of treatments can also reduce stress and anxiety for both the patient and the dental team. Knowledge-based Systems (KBS) are a practical implementation of Artificial Intelligence. In complex domains which humans find difficult to understand, KBS can assist in making decisions and can also add knowledge. The aim of this paper is to describe the structure of a knowledge-based system for structured examination, diagnosis and therapy for traumatised primary and permanent teeth. A commercially available program was used as developmental tool for the programming (XpertRule, Attar, London, UK). The paper presents a model for a computerised decision support system for traumatology. [source]


Botulinum Toxin for the Treatment of Facial Flushing

DERMATOLOGIC SURGERY, Issue 1 2004
Melanie Yuraitis MS
Background. Facial flushing is a common problem that is encountered by fair-skinned patients of Celtic and Northern European descent. Although usually transient in nature, some patients display a persistent reddened skin tone, with periods of increased erythema. Treatment of this condition is limited. Objective. To describe a novel method for the treatment of persistent facial flushing. Method. We report a case of persistent facial flushing that was resistant to multiple pulsed dye laser treatments and was successfully treated with botulinum toxin A. Results. The posttreatment appearance was dramatic, and the patient was highly satisfied with the cosmetic outcome. Conclusion. Botulinum toxin A can be used in small quantities to decrease persistent facial flushing temporarily. [source]


Laser Hair Removal: Long-Term Results with a 755 nm Alexandrite Laser

DERMATOLOGIC SURGERY, Issue 11 2001
Sorin Eremia MD
Background. Hypertrichosis is a common problem for which laser hair removal is becoming the treatment of choice. Optimal wavelength, pulse duration, spot size, fluence, and skin cooling parameters for various skin types have not yet been firmly established. Objective. To evaluate the long-term efficacy and safety of a 3-msec 755 nm alexandrite laser equipped with a cryogen cooling device for patients with Fitzpatrick skin types I,V. Methods. Eighty-nine untanned patients with skin types I,V underwent a total of 492 treatments of laser hair removal over a 15-month period. Each patient in the study underwent a minimum of three treatment sessions spaced 4,6 weeks apart (mean treatments 5.6). Retrospective chart review and patient interviews were used to establish hair reduction results. Treatment sites included the axillae, bikini, extremities, face, and trunk. A 3-msec pulse width, 755 nm alexandrite laser equipped with a cryogen spray cooling device was used in this study. Spot sizes of 10,15 mm were used. A spot size of 10 mm was used for fluences greater than 40 J/cm2, a spot size of 12 mm was used for fluences of 35,40 J/cm2, and spot sizes of 12 and 15 mm were used for fluences less than 30 J/cm2. Fluences ranging from 20 to 50 J/cm2 (mean fluence 36 J/cm2) were used. Results. The patients had a mean 74% hair reduction. Skin type I patients had an average of 78.5% hair reduction using a mean fluence of 40 J/cm2 (35,50 J/cm2) and a 10,12 mm spot size (12 mm in more than 95% of treatments). Skin type II patients had a mean 74.3% hair reduction using a mean fluence of 38 J/cm2 (30,40 J/cm2) and a 12,15 mm spot size. Skin type III patients had a mean 73.4% hair reduction using a mean fluence of 37 J/cm2 (25,40 J/cm2) and a 12,15 mm spot size. Skin type IV patients had a mean 71.0% hair reduction using a mean fluence of 31 J/cm2 (25,35 J/cm2) and a 12,15 mm spot size. A patient with skin type V had a 60% hair reduction using a mean fluence of 23 J/cm2 (20,25 J/cm2) and a 12,15 mm spot size. The efficiency of hair removal directly correlates significantly with the fluence used. Rare side effects included transient postinflammatory hyperpigmentation (n = 9; 10%), burn with blisters (n = 1; 1%), and postinflammatory hypopigmentation (n = 2; 2%). All complications resolved without permanent scarring. Conclusion. The 3-msec cryogen cooling-equipped alexandrite laser can safely and effectively achieve long-term hair removal in patients with skin types I,V. The best results are achieved in untanned patients with skin types I,IV. [source]


Comparison of Long-Pulsed Diode and Long-Pulsed Alexandrite Lasers for Hair Removal: A Long-Term Clinical and Histologic Study

DERMATOLOGIC SURGERY, Issue 7 2001
Christiane Handrick MD
Background. Unwanted facial and body hair is a common problem, generating a high level of interest for treatment innovations. Advances in laser technology over the past several years has led to the development and distribution of numerous red and infrared lasers and light sources to address this issue. Despite the impressive clinical results that have been reported with the use of individual laser hair removal systems, long-term comparative studies have been scarce. Objective. To compare the clinical and histologic efficacy, side effect profile, and long-term hair reduction of long-pulsed diode and long-pulsed alexandrite laser systems. Methods. Twenty women with Fitzpatrick skin types I,IV and dark terminal hair underwent three monthly laser-assisted hair removal sessions with a long-pulsed alexandrite laser (755 nm, 2-msec pulse, 10 mm spot) and a long-pulsed diode laser (800 nm, 12.5 msec or 25 msec, 9 mm spot). Axillary areas were randomly assigned to receive treatment using each laser system at either 25 J/cm2 or 40 J/cm2. Follow-up manual hair counts and photographs of each area were obtained at each of the three treatment visits and at 1, 3, and 6 months after the final laser session. Histologic specimens were obtained at baseline, immediately after the initial laser treatment, and 1 and 6 months after the third treatment session. Results. After each laser treatment, hair counts were successively reduced and few patients found it necessary to shave the sparsely regrown hair. Optimal clinical response was achieved 1 month after the second laser treatment, regardless of the laser system or fluence used. Six months after the third and final treatment, prolonged clinical hair reduction was observed with no significant differences between the laser systems and fluences used. Histologic tissue changes supported the clinical responses observed with evidence of initial follicular injury followed by slow follicular regeneration. Side effects, including treatment pain and vesiculation, were rare after treatment with either laser system, but were observed more frequently with the long-pulsed diode system at the higher fluence of 40 J/cm2. Conclusion. Equivalent clinical and histologic responses were observed using a long-pulsed alexandrite and a long-pulsed diode laser for hair removal with minimal adverse sequelae. While long-term hair reduction can be obtained in most patients after a series of laser treatments, partial hair regrowth is typical within 6 months, suggesting the need for additional treatments to improve the rate of permanent hair removal. [source]


Medical and surgical therapies for alopecias in black women

DERMATOLOGIC THERAPY, Issue 2 2004
Valerie D. Callender
ABSTRACT:, Hair loss is a common problem that challenges the patient and clinician with a host of cosmetic, psychological and medical issues. Alopecia occurs in both men and women, and in all racial and ethnic populations, but the etiology varies considerably from group to group. In black women, many forms of alopecia are associated with hair-care practices (e.g., traction alopecia, trichorrhexis nodosa, and central centrifugal cicatricial alopecia). The use of thermal or chemical hair straightening, and hair braiding or weaving are examples of styling techniques that place African American women at high risk for various "traumatic" alopecias. Although the exact cause of these alopecias is unknown, a multifactorial etiology including both genetic and environmental factors is suspected. A careful history and physical examination, together with an acute sensitivity to the patient's perceptions (e.g., self-esteem and social problems), are critical in determining the best therapy course. Therapeutic options for these patients range from alteration of current hair grooming practices or products, to use of specific medical treatments, to hair replacement surgery. Since early intervention is often a key to preventing irreversible alopecia, the purpose of the present article is to educate the dermatologist on all aspects of therapy for hair loss in black women,including not only a discussion of the main medical and surgical therapies but also an overview of ethnic hair cosmetics, specific suggestions for alterations of hair-care practices, and recommendations for patient education and compliance. [source]


Ophthalmological problems of the premature infant

DEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 4 2002
Michael X. Repka
Abstract Preterm infants are more likely than term infants to have significant abnormalities of all parts of the visual system leading to reduced vision. The most common problem is retinopathy of prematurity (ROP). The frequency and severity of this disorder is inversely related to gestational age. Damage ranges from minor to catastrophic. Preterm infants also have higher rates of amblyopia, strabismus, refractive error, and cortical visual impairment. The later problem is largely associated with neonatal brain injury. Years later, these children may develop glaucoma and retinal detachments. MRDD Research Reviews 2002;8:249,257. © 2002 Wiley-Liss, Inc. [source]


A review of basal insulins

DIABETIC MEDICINE, Issue 11 2003
Anthony H. Barnett
Abstract Tight glycaemic control (ideally, HbA1c < 7%) is central to reducing the risk of long-term complications of diabetes. This approach, for both Type 1 and Type 2 diabetes, commonly involves the use of basal insulin, and must be achieved with minimal risk of hypoglycaemia (particularly nocturnal episodes). Indeed, concern around hypoglycaemia is a major barrier to achieving tight glycaemic control, and is a common problem with those protracted-acting insulins most frequently used in clinical practice for basal insulin supply. Other drawbacks include inter- and intra-patient variability that compromises dosing reproducibility and unsuitability for single daily dosing. New long-acting human insulin analogues with action profiles designed to overcome these problems are now available in clinical practice or are under evaluation in clinical trials. Clinical evidence suggests efficacy and safety advantages for these analogues over NPH insulin (the most commonly used basal insulin), and may bring closer the goal of tight glycaemic control in patients with diabetes. [source]


Diabetes in the elderly: problems of care and service provision

DIABETIC MEDICINE, Issue 2002
S. Croxson
Abstract Diabetes is common in the elderly and old UK citizens, affecting between 10% and 25%. There is considerable associated morbidity and mortality, with dementia being a common problem. The diabetic elder is also at risk of drug side-effects. Most of the evidence base for treatment is based on trials performed in younger diabetic subjects or older nondiabetic subjects; however, we can practice evidence-biased medicine whilst awaiting the results of ongoing trials. The older persons national service framework (NSF) may share some similarities with the diabetes NSF; it was 1 year late, and had no clear funding, amongst several other worries. Residential care, which is more likely to be required by diabetic elders, is also under-funded with major concerns about the quality of care for the diabetic resident. The little evidence that we have regarding care of the older diabetic person also suggests inadequacies. Given the likelihood that we will have to manage with present resources, managed clinical networks may be one way to cope. [source]


Evaluation of systemic oxidative status and mononuclear leukocytes DNA damage in children with caustic esophageal stricture

DISEASES OF THE ESOPHAGUS, Issue 4 2006
M. Kaya
SUMMARY., Esophageal stricture (ES) due to accidentally caustic digestions is a common problem in children. Mucosal damage and repeated dilatations lead to chronic inflammation and finally ES. We investigated the oxidative status and DNA damage of children with ES. Five children with ES were compared with the same age- and sex-matched healthy subjects. Oxidative status of plasma was evaluated by measuring myeloperoxidase (MPO) activity, and total peroxide (TP) level. Anti-oxidative status of the plasma was evaluated by measuring catalase (CAT) activity, and total antioxidant response (TAR). We used the Single Cell Gel Electrophoresis (also called Comet Assay) to measure DNA strand break in peripheral blood mononuclear leukocytes. Mean MPO activity and TP levels in the ES group were significantly higher than the control group (0.83 ± 0.35, 0.09 ± 0.03 and 0.98 ± 0.38, 0.34 ± 0.20, P = 0.009 and P = 0.047 respectively). There was no significant difference in CAT activity and TAR levels between the two groups (P = 0.347). DNA damage in patients with ES was increased compared to control subjects (108.8 ± 51.2 and 57.6 ± 31.2 arbitrary units, respectively), but this difference was not significant statistically (P= 0.09). This study shows that systemic oxidative stress and alteration at the nuclear level occur in patients with ES, as a result of multiple dilatations and tissue injury. On the other hand, these results support that patients with ES may benefit from antioxidant treatment. [source]


Testing for trends in the violation frequency of an environmental threshold in rivers

ENVIRONMETRICS, Issue 1 2009
Lieven Clement
Abstract Nutrient pollution in rivers is a common problem. It can provoke algae blooms which are related to increased fish mortality. To restore the water status, the regulator recently has promulgated more restrictive regulations. In Flanders for instance, the government has introduced several manure decrees (MDs) to restrict nutrient pollution. Environmental regulations are commonly expressed in terms of threshold levels. This provides a binary response to the decision maker. To handle such data, we propose the use of marginalised generalised linear mixed models. They provide valid inference on trends in the exceedance frequency. The spatio-temporal dependence of the river monitoring network is incorporated by the use of a latent variable. The temporal dependence is assumed to be AR(1) and the spatial dependence is derived from the river topology. The mean model contains a term for the trend and corrects for seasonal variation. The model formulation allows an assessment on the level of individual sampling locations and on a more regional scale. The methodology is applied to a case study on the river Yzer (Flanders). It assesses the impact of the MDs on the violation probability of the nitrate standard. A trend change is detected after the introduction of the second MD. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Bench to Bedside: Electrophysiologic and Clinical Principles of Noninvasive Hemodynamic Monitoring Using Impedance Cardiography

ACADEMIC EMERGENCY MEDICINE, Issue 6 2003
Richard L. Summers MD
Abstract The evaluation of the hemodynamic state of the severely ill patient is a common problem in emergency medicine. While conventional vital signs offer some insight into delineating the circulatory pathophysiology, it is often impossible to determine the true clinical state from an analysis of blood pressure and heart rate alone. Cardiac output measurements by thermodilution have been the criterion standard for the evaluation of hemodynamics. However, this technology is invasive, expensive, time-consuming, and impractical for most emergency department environments. Impedance cardiography (ICG) is a noninvasive method of obtaining continuous measurements of hemodynamic data such as cardiac output that requires little technical expertise. ICG technology was first developed by NASA in the 1960s and is based on the idea that the human thorax is electrically a nonhomogeneous, bulk conductor. Variation in the impedance to flow of a high-frequency, low-magnitude alternating current across the thorax results in the generation of a measured waveform from which stroke volume can be calculated by a modification of the pulse contour method. To adequately judge the possible role of this technology in the practice of emergency medicine, it is important to have a sufficient understanding of the basic scientific principles involved as well as the clinical validity and limitations of the technique. [source]


Smoking Cessation a Byproduct of EEG Telemetry Monitoring

EPILEPSIA, Issue 4 2005
Syed Nizamuddin Ahmed
Summary:, Smoking is a common problem in epilepsy patients. The inpatient video-EEG monitoring (VEEG) unit provides a unique and conducive environment for epilepsy patients to participate actively in a smoking-cessation program. The restrictions and confinement to the telemetry bed impose a forced abstinence from smoking. It has been suggested that patients who are hospitalized may be more receptive to smoking-cessation advice. We report two patients who were successfully able to quit smoking after admission for VEEG. [source]


Vascular hyporesponsiveness in cirrhosis , many facets of a common problem!

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2 2001
D. Kapoor
[source]


Upper limb movement interruptions are correlated to freezing of gait in Parkinson's disease

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2009
Alice Nieuwboer
Abstract Freezing of gait (FOG) in patients with Parkinson's disease (PD) is a common problem of unknown origin, which possibly reflects a general motor control deficit. We investigated the relationship between the frequency of freezing episodes during gait and during a bimanual task in control and subjects with PD with and without FOG. Group differences in spatiotemporal characteristics were also examined as well as the effects of visual cueing. Twenty patients with PD in the off-phase of the medication cycle and five age-matched controls performed a repetitive drawing task in an anti-phase pattern on a digitizer tablet. The task was offered at two different speeds (comfortable and maximal) and two different amplitudes (small and large) with and without visual cueing. The results showed that freezing episodes in the upper limbs occurred in only 10.4% of patient trials and that their occurrence was correlated with FOG scores (Spearman's rho = 0.64). Overall, few spatiotemporal differences were found between freezers, non-freezers and controls, except for an overshooting of the target amplitude in controls. Effects of visual cueing were largely similar in all groups, except for the variability of relative phase, which decreased in non-freezers and controls, and was unaffected in freezers. Despite the fact that general motor differences between subgroups were small, freezing episodes were manifest during a bimanual repetitive upper limb task and were correlated to FOG. Further study into upper limb movement breakdown is warranted to understand the parallel deficits that lead up to FOG. [source]


Pharmacogenomics in dermatology: from susceptibility genes to personalized therapy

EXPERIMENTAL DERMATOLOGY, Issue 4 2009
Carlo Pincelli
Abstract:, A significant proportion of patients with skin disease do not respond to treatment and adverse drug reactions are a common problem. Genetic factors are important determinants for both drug efficacy and toxicity. The fields of pharmacogenetics and pharmacogenomics examine inter-individual variations in the DNA sequence that are related to drug efficacy and toxicity. Here, we present pharmacogenomic data relevant to dermatology and explore the role of dermatologists in identifying patients who may respond to treatment or experience adverse drug reactions. [source]


Simple relative space,time scaling of electrical and electromagnetic depth sounding arrays: implications for electrical static shift removal and joint DC-TEM data inversion with the most-squares criterion

GEOPHYSICAL PROSPECTING, Issue 4 2005
Max A. Meju
ABSTRACT A simple scaling relationship is shown to facilitate comparison, correlation and integration of data recorded using the common experimental configurations in electrical and electromagnetic depth sounding. Applications of the scheme to field data from typical geological and landfill environments show that it is robust and, where transient electromagnetic (TEM) data are available, enables easy identification and quantification of electrical static shift (galvanic distortion) in magnetotelluric and direct current (DC) sounding curves. TEM-based procedures are suggested for both the direct removal of static shift in DC sounding curves and effective joint data inversion with the most-squares criterion in the presence of static shift. A case study of aquifer characterization using sounding data from borehole sites in the Vale of York in England shows that static shift is a common problem in this glacial-covered terrain and demonstrates the effectiveness of the proposed joint DC-TEM inversion strategy in handling distorted soundings. [source]


Climatic signals in growth and its relation to ENSO events of two Prosopis species following a latitudinal gradient in South America

GLOBAL CHANGE BIOLOGY, Issue 5 2006
BERNAT C. LÓPEZ
Abstract Semiarid environments throughout the world have lost a major part of their woody vegetation and biodiversity due to the effects of wood cutting, cattle grazing and subsistence agriculture. The resulting state is typically used for cattle production, but the productivity of these systems is often very low, and erosion of the unprotected soil is a common problem. Such dry-land degradation is of great international concern, not only because the resulting state is hardly productive but also because it paves the way to desertification. The natural distribution of the genus Prosopis includes arid and semiarid zones of the Americas, Africa and Asia, but the majority of the Prosopis species are, however, native to the Americas. In order to assess a likely gradient in the response of tree species to precipitation, temperature and their connection to El Niño southern oscillation (ENSO) events, two Prosopis species were chosen along a latitudinal gradient in Latin America, from northern Peru to central Chile: Prosopis pallida from a semi-arid land in northern and southern Peru and P. chilensis from a semiarid land in central Chile. Growth rings of each species were crossdated at each sampling site using classical dendrochronological techniques. Chronologies were related with instrumental climatic records in each site, as well as with SOI and N34 series. Cross-correlation, spectral and wavelet analysis techniques were used to assess the relation of growth with precipitation and temperature. Despite the long distance among sites, the two Prosopis species presented similar responses. Thus, the two species' growth is positively correlated to precipitation, while with temperature it is not. In northern Peru, precipitation and growth of P. pallida present a similar cyclic pattern, with a period of around 3 years. On the other hand, P. pallida in southern Peru, and P. chilensis also present this cyclic pattern, but also another one with lower frequency, coinciding with the pattern of precipitation. Both cycles are within the range of the ENSO band. [source]


The North American Immune Tolerance Registry: contributions to the thirty-year experience with immune tolerance therapy

HAEMOPHILIA, Issue 1 2009
D. DIMICHELE
Summary., The North American Immune Tolerance Registry (NAITR) began in 1992 as a project of the ISTH Factor VIII/IX Subcommittee with the goal of further determining immune tolerance induction (ITI) practices in Canada and the United States. This retrospective registry study, published in 2002, was limited in its capacity to provide definitive answers to many unresolved ITI practice issues. Nonetheless, it played a role in developing guidelines for current ITI practice and in generating hypotheses that must now be examined through rigorous prospective data collection efforts. For haemophilia A, the logical next step has been the initiation of international prospective randomized studies of ITI outcome relative to factor VIII (FVIII) dose and purity for subjects with high titre inhibitors. Both trials will additionally provide platforms for translational study of the immunology of tolerance, a prelude to the next generation of safe and effective tolerizing strategies. For the less common problem of FIX inhibitor eradication, prospective randomized studies will not be a feasible way to confirm the NAITR observations. Coordinated international efforts will still be required to prospectively collect data on ITI outcome to document new potentially effective therapeutic strategies for inhibitor eradication. These registries will hopefully also serve to identify potential subjects for scientific studies of immunology of haemophilia B-related allergic phenomena, a devastating complication of FIX antibody development. [source]


Total joint arthroplasty in haemophilia

HAEMOPHILIA, Issue 5 2000
Beeton
In severely affected haemophilic patients arthropathy is a common problem which can lead to considerable pain and functional deficit. Surgical management, including total joint arthroplasty, can be undertaken if conservative management fails. A search of the literature showed that a number of studies describing the use of total knee arthroplasty (TKA) and total hip arthroplasty (THA) in haemophilia have been published, whereas shoulder, elbow and ankle arthroplasties are confined to case reports. This paper reviews the functional outcome of arthroplasty in the different joints, the postoperative and long-term complications, and the impact of HIV. Although complications are commonly described and the surgery is technically demanding, the results suggest that arthroplasty, particularly of the hip and knee, can be a valuable option in the management of severe haemophilic arthropathy. [source]


The analysis of efficiency among a small number of organisations: How inferences can be improved by exploiting patient-level data

HEALTH ECONOMICS, Issue 6 2008
Kim Rose Olsen
Abstract Those responsible for monitoring and managing the performance of health-care organisations face the common problem that the relationship between observed performance and effort is difficult to establish. A solution is to compare the performance of multiple organisations, but this requires a sufficient number of comparators. Faced with a small sample, it may be possible to exploit other information sources. Multilevel regression models are applied to analyse the performance of six Danish vascular departments in 2004 using a patient-level data set. We find that treatment costs are higher for smokers, older patients, patients with cerebrovascular and pulmonal diseases and for those subject to acute hospitalisation and with longer lengths of stay. Costs are lower for patients who are having follow-up surgery and for patients who receive some form of home care, suggesting that there may be some substitution of care input between vascular departments and other care providers. We estimate the relative efficiency of each department. The construction of confidence intervals allows the six departments to be sorted into two groups containing the least and most efficient departments. Conclusions about relative efficiency are robust to model specification, choice of estimator and hold at the 95% confidence level. Copyright © 2007 John Wiley & Sons, Ltd. [source]


A study of the extracorporeal rate of blood flow and blood pressure during hemodialysis

HEMODIALYSIS INTERNATIONAL, Issue 4 2007
Hariprasad S. TRIVEDI
Abstract Hemodynamic instability is a common problem during hemodialysis (HD). The effect of blood flow rate (BFR) on blood pressure (BP) during HD has not been previously evaluated. Subjects receiving HD for the treatment of renal failure were enrolled (n=34). For each patient, during the last hour of 2 consecutive HD sessions the BFR was set at 200 mL/min for 30 min and at 400 mL/min for 30 min, during which period the fluid removal rate was kept constant. The order of the BFR alterations was randomized. The study procedure was repeated during the next HD session but with reversal of the order of the altered BFR. During each 30-min period, BP was recorded at baseline and subsequently every 10 min. During the BFR of 400 mL/min, subjects had a higher systolic BP by an average of 4.1 mmHg compared with the BFR of 200 mL/min (95% confidence interval [CI] 0.22,7.98; p=0.038). Similarly, during the BFR of 400 mL/min, subjects had a higher diastolic BP by an average of 3.04 mmHg compared with the BFR of 200 mL/min (95% CI 0.55,5.53; p=0.017). Likewise, during the BFR of 400 mL/min, subjects had a higher mean arterial pressure by an average of 3.44 mmHg (95% CI 0.77,6.11; p=0.012). The findings suggest that during HD, BPs are maintained higher at higher BFRs as compared with lower BFRs. [source]


Changes in hydrology and erosion over a transition from grassland to shrubland

HYDROLOGICAL PROCESSES, Issue 4 2010
Laura Turnbull
Abstract The degradation of grasslands is a common problem across semi-arid areas worldwide. Over the last 150 years, much of the south-western United States has experienced significant land degradation, with desert grasslands becoming dominated by shrubs and concurrent changes in runoff and erosion which are thought to propagate further the process of degradation. Plot-based experiments to determine how spatio-temporal characteristics of soil moisture, runoff and erosion change over a transition from grassland to shrubland were carried out at four sites over a transition from black grama (Bouteloua eriopoda) grassland to creosotebush (Larrea tridentata) shrubland at the Sevilleta NWR LTER site in New Mexico. Each site consisted of a 10 × 30 m bounded runoff plot and adjacent characterization plots with nested sampling points where soil moisture content was measured. Results show distinct spatio-temporal variations in soil moisture content, which are due to the net effect of processes operating at multiple spatial and temporal scales, such as plant uptake of water at local scales versus the redistribution of water during runoff events at the hillslope scale. There is an overall increase in runoff and erosion over the transition from grassland to shrubland, which is likely to be associated with an increase in connectivity of bare, runoff-generating areas, although these increases do not appear to follow a linear trajectory. Erosion rates increased over the transition from grassland to shrubland, likely related in part to changes in runoff characteristics and the increased capacity of the runoff to detach, entrain and transport sediment. Over all plots, fine material was preferentially eroded which has potential implications for nutrient cycling since nutrients tend to be associated with fine sediment. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Impaired intestinal iron absorption in Crohn's disease correlates with disease activity and markers of inflammation

INFLAMMATORY BOWEL DISEASES, Issue 12 2006
Gaith Semrin MD
Abstract Background: Anemia in patients with Crohn's disease (CD) is a common problem of multifactorial origin, including blood loss, malabsorption of iron, and anemia of inflammation. Anemia of inflammation is caused by the effects of inflammatory cytokines [predominantly interleukin-6 (IL-6)] on iron transport in enterocytes and macrophages. We sought to elucidate alterations in iron absorption in pediatric patients with active and inactive CD. Methods: Nineteen subjects with CD (8 female, 11 male patients) were recruited between April 2003 and June 2004. After an overnight fast, serum iron and hemoglobin levels, serum markers of inflammation [IL-6, C-reactive protein (CRP), and erythrocyte sedimentation rate], and a urine sample for hepcidin assay were obtained at 8 am. Ferrous sulfate (1 mg/kg) was administered orally, followed by determination of serum iron concentrations hourly for 4 hours after the ingestion of iron. An area under the curve for iron absorption was calculated for each patient data set. Results: There was a strong inverse correlation between the area under the curve and IL-6 (P = 0.002) and area under the curve and CRP levels (P = 0.04). Similarly, the difference between baseline and 2-hour serum iron level (,[Fe]2hr) correlated with IL-6 (P = 0.008) and CRP (P = 0.045). When cutoff values for IL-6 (>5 pg/mL) and CRP (>1.0 mg/dL) were used, urine hepcidin levels also positively correlated with IL-6 and CRP levels (P = 0.003 and 0.007, respectively). Conclusions: Subjects with active CD have impaired oral iron absorption and elevated IL-6 levels compared with subjects with inactive disease. These findings suggest that oral iron may be of limited benefit to these patients. Future study is needed to define the molecular basis for impaired iron absorption. [source]


Numerical characteristics of a simple finite element formulation for consolidation analysis

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 10 2004
Guofu Zhu
Abstract The spatial oscillation of values in the consolidation analysis when using small time increments has been a common problem for most existing methods. In this paper, the numerical characteristics of a simple finite element formulation for 1-D consolidation analysis recently proposed by the authors have been examined in detail. This paper proves that the commonly encountered phenomenon of spatial oscillation due to small time increments does not occur in the simple finite element formulation. The criterion of minimum time step used in most existing methods can be eliminated at least for linear situations by using the simple formulation proposed by the authors. Thus, the consolidation analysis can be carried easily for many situations, such as the one involving a relatively impermeable clay layer sandwiched between sandy layers. Copyright © 2004 John Wiley & Sons, Ltd. [source]