bluuebunny/crossref_metadata_2025 huggingface dataset:
A hard day’s night: a longitudinal study on the relationships among job demands and job control, sleep quality and fatigue
Authors: DE LANGE ANNET H. , KOMPIER MICHIEL A. J. , TARIS TOON W. , GEURTS SABINE A. E. , BECKERS DEBBY G. J. , HOUTMAN IRENE L. D. , BONGERS PAULIEN M.
Published: May 2009

This prospective four‐wave study examined (i) the causal direction of the longitudinal relations among job demands, job control, sleep quality and fatigue; and (ii) the effects of stability and change in demand–control history on the development of sleep quality and fatigue. Based on results of a four‐wave complete panel study among 1163 Dutch employees, we found significant effects of job demands and job control on sleep quality and fatigue across a 1‐year time lag, supporting the strain hypothesis (Demand–Control model; Karasek and Theorell, Basic Books, New York, 1990). No reversed or reciprocal causal patterns were detected. Furthermore, our results revealed that cumulative exposure to a high‐strain work environment (characterized by high job demands and low job control) was associated with elevated levels of sleep‐related complaints. Cumulative exposure to a low‐strain work environment (i.e. low job demands and high job control) was associated with the highest sleep quality and lowest level of fatigue. Our results revealed further that changes in exposure history were related to changes in reported sleep quality and fatigue across time. As expected, a transition from a non‐high‐strain towards a high‐strain job was associated with a significant increase in sleep‐related complaints; conversely, a transition towards a non‐high‐strain job was not related to an improvement in sleep‐related problems.
Fitness, daily activity and body composition in children with newly diagnosed, untreated asthma
Authors: Vahlkvist S. , Pedersen S.
Published: May 2009

Background:  Information about how the asthma disease affects the life style and health in children is sparse.

Aim:  To measure fitness, daily physical activity and body composition in children with newly diagnosed, untreated asthma and healthy controls, and to assess the association between the level of asthma control and these parameters.

Methods:  Daily physical activity measured using accelerometry, cardiovascular fitness and body composition (per cent fat, per cent lean tissue and bone mineral density) were measured in 57 children with newly diagnosed, untreated asthma and in 157 healthy age‐ and sex‐matched controls. The level of asthma control was assessed by measurements of a variety of asthma outcomes.

Results:  Children with asthma were less fit (35.1 vs 39.3 ml O2/min/kg) (P < 0.001), had a higher body per cent fat (22.8 vs 19.5%) (P < 0.01) and a higher frequency of overweight (24.6 vs 14.2%) (P < 0.05) than healthy controls. Per cent body fat correlated negativly to overall daily activity (P < 0.001) and to time spent in high or vigorous activity (P < 0.001). Fitness corrrelated positively to time spent in high and vigorous activity (P < 0.001). Within the asthma group, the level of asthma control, fitness and the time spent in vigorous activity correlated positively (P < 0.02).

Conclusion:  Children with untreated asthma are less fit and have a higher body per cent fat and frequency of obesity than their healthy peers. Uncontrolled asthma is associated with a reduced fitness and daytime spent in intensive activity. Overweight children are physically less active than normal weight children.
Grading quality of evidence and strength of recommendations in clinical practice guidelines: Part 2 of 3. The GRADE approach to grading quality of evidence about diagnostic tests and strategies
Authors: Brożek J. L. , Akl E. A. , Jaeschke R. , Lang D. M. , Bossuyt P. , Glasziou P. , Helfand M. , Ueffing E. , Alonso‐Coello P. , Meerpohl J. , Phillips B. , Horvath A. R. , Bousquet J. , Guyatt G. H. , Schünemann H. J. ,   for the GRADE Working Group
Published: May 2009

The GRADE approach to grading the quality of evidence and strength of recommendations provides a comprehensive and transparent approach for developing clinical recommendations about using diagnostic tests or diagnostic strategies. Although grading the quality of evidence and strength of recommendations about using tests shares the logic of grading recommendations for treatment, it presents unique challenges. Guideline panels and clinicians should be alert to these special challenges when using the evidence about the accuracy of tests as the basis for clinical decisions. In the GRADE system, valid diagnostic accuracy studies can provide high quality evidence of test accuracy. However, such studies often provide only low quality evidence for the development of recommendations about diagnostic testing, as test accuracy is a surrogate for patient‐important outcomes at best. Inferring from data on accuracy that using a test improves outcomes that are important to patients requires availability of an effective treatment, improved patients’ wellbeing through prognostic information, or – by excluding an ominous diagnosis – reduction of anxiety and the opportunity for earlier search for an alternative diagnosis for which beneficial treatment can be available. Assessing the directness of evidence supporting the use of a diagnostic test requires judgments about the relationship between test results and patient‐important consequences. Well‐designed and conducted studies of allergy tests in parallel with efforts to evaluate allergy treatments critically will encourage improved guideline development for allergic diseases.
High‐frequency stimulation of the nucleus accumbens core and shell reduces quinpirole‐induced compulsive checking in rats
Authors: Mundt Adrian , Klein Julia , Joel Daphna , Heinz Andreas , Djodari‐Irani Anais , Harnack Daniel , Kupsch Andreas , Orawa Helmut , Juckel Georg , Morgenstern Rudolf , Winter Christine
Published: May 2009

Electrical deep brain stimulation (DBS) is currently studied in the treatment of therapy‐refractory obsessive compulsive disorders (OCDs). The variety of targeted brain areas and the inconsistency in demonstrating anti‐compulsive effects, however, highlight the need for better mapping of brain regions in which stimulation may produce beneficial effects in OCD. Such a goal may be advanced by the assessment of DBS in appropriate animal models of OCD. Currently available data on DBS of the nucleus accumbens (NAc) on OCD‐like behavior in rat models of OCD are contradictory and partly in contrast to clinical data and theoretical hypotheses about how the NAc might be pathophysiologically involved in the manifestation of OCD. Consequently, the present study investigates the effects of DBS of the NAc core and shell in a quinpirole rat model of OCD. The study demonstrates that electrical modulation of NAc core and shell activity via DBS reduces quinpirole‐induced compulsive checking behavior in rats. We therefore conclude that both, the NAc core and shell constitute potential target structures in the treatment of OCD.
Metabotropic glutamate receptor 1 activity generates persistent, N‐methyl‐d‐aspartate receptor‐dependent depression of hippocampal pyramidal cell excitability
Authors: Clement J. P. , Randall A. D. , Brown J. T.
Published: May 2009

Metabotropic glutamate receptors (mGluRs) are involved in many forms of neuronal plasticity. In the hippocampus, they have well‐defined roles in long‐lasting forms of both synaptic and intrinsic plasticity. Here, we describe a novel form of long‐lasting intrinsic plasticity that we call (S)‐3,5‐dihydroxyphenylglycine (DHPG)‐mediated long‐term depression of excitability (DHPG‐LDE), and which is generated following transient pharmacological activation of group I mGluRs. In extracellular recordings from hippocampal slices, DHPG‐LDE was expressed as a long‐lasting depression of antidromic compound action potentials (cAPs) in CA1 or CA3 cells following a 4‐min exposure to the group I mGluR agonist (S)‐DHPG. A similar phenomenon was also seen for orthodromic fibre volleys evoked in CA3 axons. In single‐cell recordings from CA1 pyramids, DHPG‐LDE was manifest as persistent failures in antidromic action potential generation. DHPG‐LDE was blocked by (S)‐(+)‐a‐amino‐4‐carboxy‐2‐methylbenzeneacetic acid (LY367385), an antagonist of mGluR1, but not 2‐methyl‐6‐(phenylethynyl)pyridine hydrochloride (MPEP), an mGluR5 inhibitor. Although insensitive to antagonists of α‐amino‐3‐hydroxyl‐5‐methyl‐4‐isoxazole‐propionate/kainate and γ‐aminobutyric acidA receptors, DHPG‐LDE was blocked by antagonists of N‐methyl‐d‐aspartate (NMDA) receptors. Similarly, in single‐cell recordings, DHPG‐mediated antidromic spike failures were eliminated by NMDA receptor antagonism. Long after (S)‐DHPG washout, DHPG‐LDE was reversed by mGluR1 antagonism. A 4‐min application of (S)‐DHPG also produced an NMDA receptor‐dependent persistent depolarization of CA1 pyramidal cells. This depolarization was not solely responsible for DHPG‐LDE, because a similar level of depolarization elicited by raising extracellular K+ increased the amplitude of the cAP. DHPG‐LDE did not involve HCN channels or protein synthesis, but was eliminated by blockers of protein kinase C or tyrosine phosphatases.
Which do students prefer to evaluate their essays: Peers or computer program
Authors: Lai Yi‐hsiu
Published: May 2009

The purpose of this study was to investigate problems and potentials of new technologies in English writing education. The effectiveness of automated writing evaluation (AWE) (MY Access) and of peer evaluation (PE) was compared. Twenty‐two English as a foreign language (EFL) learners in Taiwan participated in this study. They submitted their draft toMY Access, received feedback from this automated grading system and then made some revision. In addition to the AWE, they also had peer revision in writing class. Three issues, including how writers used the feedback from these two kinds of evaluation, what progress they made in writing and how they perceived these two kinds of evaluation, are discussed. Results showed that EFL learners in Taiwan generally opted for PE over AWE. These findings raise several relevant issues, including social learning, feedback strategies, computer anxiety and cultural impact.
Working with primary care practices to improve service delivery for people with learning disabilities – a pilot study
Authors: Webb Jenny , Stanton Melanie
Published: May 2009

Accessible summary

 People with learning disability have worse health than other people

 General practitioners and other people working with them were offered training on different topics such as communication and the work of the community team.

 Afterwards all the GP practices introduced changes which made it easier for people with learning disability to use their local surgery.

The relatively poor health of people with learning disability reflects the failure of primary care practitioners to improve the accessibility of the service they offer. This North Essex study involved evaluation of a project to work with three primary care practices to raise staff awareness, improve their training, and adapt their working practice. While GPs and other practice staff recognised their training needs, only one practice released all staff for a one day training course. Nevertheless, all practices worked to produce Practice Development Plans which resulted in improved accessibility for People with Learning Disability. The project also opened up a channel of communication between the practices and the Community Team for People with Learning Disabilities (CTPLD). This study forms one strand of a three‐part project to improve access to primary care.
Notch receptor and Notch ligand expression in developing avian cartilage
Authors: Williams Rebecca , Nelson Larissa , Dowthwaite Gary P. , Evans Darrell J. R , Archer Charles W.
Published: May 2009

The development of limb cartilage involves complex signalling pathways allowing the formation of distinct segments of cartilage that are maintained in the fully developed joint. In this study, we investigated the Notch signalling pathway and its role in cartilage development. The differential distribution of the Notch signalling family of receptors and their corresponding ligands in developing avian (gallus gallus) cartilage revealed expression of Notch 1, Delta 1, Jagged 1 and Jagged 2 in all limb mesenchyme cells at the early stages of cartilage anlagen development, which were subsequently restricted to the developing cartilage element. Expression of both Notch 1 and Jagged 1 became increasingly restricted to the surface cartilage once joint cavity formation had occurred. Delta 1 and Jagged 1 were restricted to a layer of cells underneath the surface cartilage and were also observed in the hypertrophic chondrocytes, where Notch 1 expression was evident in stage 40–44 limbs. Notch 2, Notch 3 and Notch 4 were not evident in early stage limbs but were present after cavitation, although expression was lost in late stage limbs (stage 40–44). We also demonstrated that inhibition of the Notch pathway leads to altered Notch receptor expression, disrupting cartilage differentiation. From these data it is clear that Notch signalling is a necessary and critical factor in regulating cell fate decisions allowing controlled chondrogenesis, elongation and subsequent maintenance of limb cartilage.
Art and brain: insights from neuropsychology, biology and evolution
Authors: Zaidel Dahlia W.
Published: May 2009

Art is a uniquely human activity associated fundamentally with symbolic and abstract cognition. Its practice in human societies throughout the world, coupled with seeming non‐functionality, has led to three major brain theories of art. (1) The localized brain regions and pathways theory links art to multiple neural regions. (2) The display of art and its aesthetics theory is tied to the biological motivation of courtship signals and mate selection strategies in animals. (3) The evolutionary theory links the symbolic nature of art to critical pivotal brain changes in Homo sapiens supporting increased development of language and hierarchical social grouping. Collectively, these theories point to art as a multi‐process cognition dependent on diverse brain regions and on redundancy in art‐related functional representation.
Antibiotic lock: In vitro stability of vancomycin and four percent sodium citrate stored in dialysis catheters at 37°C
Authors: BATTISTELLA Marisa , WALKER Scott , LAW Shirley , LOK Charmaine
Published: May 2009

Catheter‐related bacteremia (CRB) is a major cause of morbidity and mortality especially among patients receiving hemodialysis (HD). Antibiotic lock therapy represents a promising technique in the treatment of CRB. Several studies have evaluated antibiotics in combination with heparin as an interdialytic locking solution as adjunctive therapy for CRB. The objective of this study was to evaluate the chemical stability of the vancomycin in 4% sodium citrate in HD catheters as an interdialytic lock. Vancomycin was prepared and diluted with sodium citrate 4% and stored in polyvinyl chloride syringes, 2 carbothane dialysis catheters (Hemostar®) and 2 dual floating HD catheters (CardioMed®). Syringes were stored at 4 °C or 23 °C and the catheters were stored in an incubator at 37 °C for 72 hours. Samples underwent daily chromatographic analysis and the luminal concentration of vancomycn was determined on study days 0, 1, and 3. When vancomycin is reconstituted with normal saline to achieve a concentration of 50 mg/mL, and then further diluted in 4% sodium citrate, to achieve concentrations of either 1 or 3 mg/mL, and then stored at 4 °C, room temperature, or 37 °C, solutions were observed to retain >92% of the initial concentration for the study period of 3 days. Based on the fastest degradation rate determined with 95% confidence interval, >90% is retained for 6.53 days. We conclude that vancomycin—4% citrate solutions stored in polyvinyl chloride syringes or HD catheters are not significantly affected by temperature or concentration within the 72 hours storage period. Therefore, these solutions can be anticipated to be suitable as a HD interdialytic antibiotic lock in standard HD catheters.
Hypoparathyroidism associated with severe mineral bone disease postrenal transplantation, treated successfully with recombinant PTH
Authors: MAHAJAN Ashutosh , NARAYANAN Mohanram , JAFFERS Gregory , CONCEPCION Luis
Published: May 2009

Chronic kidney disease (CKD) is commonly, if not universally, associated with derangements in bone and mineral metabolism, characterized by hyperphosphatemia, low calcitriol levels, and secondary hyperparathyroidism. The spectrum of these disorders is termed renal osteodystrophy or chronic kidney disease‐mineral bone disease complex. Aggressive phosphorus control is the cornerstone of management to prevent debilitating complications. Dietary control, phosphate binders, and administration of active vitamin D analogues is the most common initial therapy. Frequently parathyroidectomy is required to reverse or slow the pathological changes when medical management fails. The most common adverse effect of parathyroidectomy is hypocalcemia. We describe a case report of severe hypocalcemia (secondary to surgical hypoparathyroidism) and “hungry bone syndrome,” treated successfully with teriparatide (Forteo®) in a patient who underwent renal transplantation following subtotal parathyroidectomy.
Ocular myopathy and mitochondrial DNA deletion
Authors: Magalhães Paulo J. , Sjö Ole , Nørby Søren
Published: May 2009

ABSTRACT This paper summarizes the data on Danish patients with ocular myopathy and mitochondrial DNA deletion (ΔmtDNA). To date, a single Danish patient harbouring ΔmtDNA has been reported. In the present study we have identified seven additional ones and characterized the nature of their deletion, both qualitatively and quantitatively. All patients are sporadic cases each with a single deletion in the range of 2.3–7.8 kb, the ΔmtDNA accounting for 10–75% of the total mtDNA in the biopsy analyzed. The clinical severity correlates with the percentage of deletion molecules, and not with the size of the deletion.
Prenatal diagnosis of choroideremia
Authors: Schwartz Marianne , Rosenberg Thomas
Published: May 2009

ABSTRACT With the mapping of the locus CHM for choroideremia and the subsequent cloning of the gene, reliable carrier and prenatal diagnosis has become a possibility. We discuss our experience with prenatal diagnosis of choroideremia, an X‐linked choroidoretinal dystrophy leading to blindness in otherwise healthy males. In the period 1987–1995, five prenatal diagnoses have been performed by either indirect linkage analysis or by direct detection of the disease‐causing mutation, reflecting the impact of molecular biology in clinical genetic practice.
A syndrome with retinitis pigmentosa, progressive hearing impairment, vestibular dysfunction, and congenital cataract
Authors: Rosenberg Thomas , Parving Agnete
Published: May 2009

ABSTRACT A family with an unusual association of retinitis pigmentosa, progressive and severe hearing impairment, vestibular dysfunction, and congenital zonular cataract is described. The disease had a rather uniform appearance in five affected individuals. Parental consanguinity was documented in all cases and a common ancestor born in 1702 was identified. Consequently, autosomal recessive inheritance seems to be the most likely mode of transmission. This disorder possibly represents a new clinical entity among combined retinal dystrophy and hearing impairment syndromes.
Blue‐yellow perimetry in patients with ocular hypertone
Authors: Serra A. , Zucca I. , Tanda A. , Piras V. , Fossarello M.
Published: May 2009

The authors report the data of the blue‐yellow (B‐Y) perimetry compared with the Standard perimetry in normal subjects with endocular hypertension or with initial glaucoma. With the aim of evaluating the relationship with chromatic sense deficits, precociously found in glaucoma, the F‐M 100 Hue test and Lanthony D 15 Desaturé test were done. Checks were made of refraction, visual acuity, pupil diameter and assumption of medications. Sensitivity reduction in eyes with initial glaucoma is highly significant with the B‐Y perimetry. Pupil diameter reduction is quite uninfluential while the chromatic sense shows some quantitative and qualitative deficits.
Theory of mind impairment: a distinct trait‐marker for schizophrenia spectrum disorders and bipolar disorder?
Authors: Bora E. , Yücel M. , Pantelis C.
Published: May 2009

Objective:  The aim of this study was to critically review the literature in order to determine if Theory of Mind (ToM) impairment can be considered a trait‐marker for schizophrenia spectrum disorders and bipolar disorder (BD).

Method:  After a thorough literature search, we reviewed the empirical studies investigating ToM impairments in remitted schizophrenia patients, first episode patients, subjects at high‐risk (HR) for psychosis and first‐degree relatives of schizophrenia patients. Studies investigating ToM impairment in other schizophrenia spectrum conditions, affective psychosis and BD were also reviewed.

Results:  ToM abnormalities exist at onset and continue throughout the course of schizophrenia, persist into remission, and while less severe, are apparent in HR populations. Mentalizing impairments are also observed in other forms of psychotic illness and BD.

Conclusion:  Mentalizing impairment in schizophrenia spectrum disorders and BD might reflect underlying general cognitive deficits and residual symptom expression, rather than representing a specific trait‐marker.
White matter lesions in euthymic patients with bipolar disorder
Authors: Lloyd A. J. , Moore P. B. , Cousins D. A. , Thompson J. M. , McAllister V. L. , Hughes J. H. , Ferrier I. N. , Young A. H.
Published: May 2009

Objective:  We aimed to quantify both load and regional distributions of hyperintensities on magnetic resonance imaging (MRI) in prospectively verified euthymic bipolar patients and matched controls.

Method:  Cerebral hyperintensities on T2, proton density and fluid‐attenuated inversion recovery (FLAIR) MRI were compared between 48 bipolar and 47 control subjects using semi‐quantitative rating scales.

Results:  Bipolar subjects had more severe frontal deep white matter lesions (DWML). Hyperintensity load was independent of age in bipolar patients but increased with age in controls. Global prevalence and severity of hyperintensities did not differ between groups. Exploratory analysis showed DWML in excess in the left hemisphere in bipolar subjects but not in controls.

Conclusion:  Findings are consistent with clinical, particularly some neurocognitive, features of bipolar disorder and implicate fronto‐subcortical circuits in its neurobiology. They more probably reflect a trait abnormality or illness scar rather than a mood state‐dependent finding. Processes other than ageing and vascular factors may underlie their development.
Differences in sensitivity to the convulsant pilocarpine in substrains and sublines of C57BL/6 mice
Authors: Müller C. J. , Gröticke I. , Hoffmann K. , Schughart K. , Löscher W.
Published: May 2009

In rodents, the cholinomimetic convulsant pilocarpine is widely used to induce status epilepticus (SE), followed by hippocampal damage and spontaneous recurrent seizures, resembling temporal lobe epilepsy. This model has initially been described in rats, but is increasingly used in mice, including the C57BL/6 (B6) inbred strain. In the present study, we compared the effects of pilocarpine in three B6 substrains (B6JOla, B6NHsd and B6NCrl) that were previously reported to differ in several behavioral and genetic aspects. In B6JOla and B6NHsd, only a small percentage of mice developed SE independently of whether pilocarpine was administered at high bolus doses or with a ramping up dosing protocol, but mortality was high. The reverse was true in B6NCrl, in which a high percentage of mice developed SE, but mortality was much lower compared to the other substrains. However, in subsequent experiments with B6NCrl mice, striking differences in SE induction and mortality were found in sublines of this substrain coming from different barrier rooms of the same vendor. In B6NCrl from Barrier #8, administration of pilocarpine resulted in a high percentage of mice developing SE, but mortality was low, whereas the opposite was found in B6NCrl mice from four other barriers of the same vendor. The analysis of F1 mice from a cross of female Barrier 8 pilocarpine‐susceptible mice with resistant male mice from another barrier (#9) revealed that F1 male mice were significantly more sensitive to pilocarpine than the resistant parental male mice whereas female F1 mice were not significantly different from resistant Barrier 9 females. These observations strongly indicate X‐chromosome linked genetic variation as the cause of the observed phenotypic alterations. To our knowledge, this is the first report which demonstrates that not only the specific B6 substrain but also sublines derived from the same substrain may markedly differ in their response to convulsants such as pilocarpine. As the described differences have a genetic basis, they offer a unique opportunity to identify the genes and pathways involved and contribute to a better understanding of the underlying molecular mechanisms of seizure susceptibility.
Using occupancy models to determine mammalian responses to landscape changes
Authors: NICHOLSON Jeremy M. , VAN MANEN Frank T.
Published: May 2009

Determining impacts of anthropogenic landscape changes on wildlife populations is difficult. Besides the challenges of designing field studies to document conditions before and after landscape changes occur, assessment of population responses (e.g. changes in population density) often provide poor inference because of sampling limitations. Estimation of occupancy, however, only requires data on detection or non‐detection of a species and might provide better inference. To demonstrate the utility of occupancy models, we used data from an American black bear (Ursus americanusPallas) population in North Carolina, USA to test our research hypothesis that documented declines in site occupancy of black bears would be greater near a new four‐lane highway. We used multi‐season occupancy models to estimate site occupancy based on bear visitation to survey sites before and after completion of the new highway and as a function of distance to the highway. Site occupancy declined from 0.81 to 0.35 between the two study phases, but was not a function of distance to the highway. Therefore, the impact of the new highway on occupancy extended to the entire study area. Our case study demonstrates that occupancy models can provide powerful inference regarding the potential impacts of landscape changes on species occupancy. As urban areas and transportation infrastructure are rapidly expanding in developing regions of the world, the need to determine how these changes affect mammal populations and how they might be mitigated increases accordingly. Because field sampling for occupancy models only requires detection data, surveys can be conducted for extensive geographic areas, thus making these surveys particularly applicable to studies of large mammals.
Executive Selection — Response to Commentaries
Authors: Hollenbeck George P.
Published: May 2009

My goal was to generate both heat and light in executive selection. Each of the commentaries adds some light to the context of executive selection as well as new issues, but none were very heated concerning my “rights and wrongs.” I was surprised that no one addressed the central issues of character (although Smith & Howard strike a glancing blow) or the many paths to success in executive jobs; but either of those could be articles in themselves. We have begun a discussion–let the games begin!
Phase report of medical treatment in Sichuan Province, China after the Wenchuan earthquake
Authors: Dai Xiaozhou , Shen Ji , Zhao Wanhua , Jiao Yunzhi , Jiang Hong
Published: May 2009

Objective To retrospectively analyze medical treatment during the Wenchuan earthquake and evaluate the emergency medical response.

Method On the basis of the data reported to the provincial disaster relief headquarters by cities and counties in Sichuan Province, we established a database for data processing by using SPSS v11.0. Descriptive statistical analysis was performed.

Results The emergency response of Sichuan health system was quick, effective, and powerful.

Conclusion In the face of extraordinary disaster, Sichuan Province effectively completed emergency medical treatment despite the enormous workload and associated difficulties achieving initial success in earthquake relief.
Can paying for results help to achieve the Millennium Development Goals? Overview of the effectiveness of results‐based financing
Authors: Oxman Andrew D , Fretheim Atle
Published: May 2009

Objective Results‐based financing and pay‐for‐performance refer to the transfer of money or material goods conditional on taking a measurable action or achieving a predetermined performance target. Results‐based financing is widely advocated for achieving health goals, including the Millennium Development Goals.

Methods We undertook an overview of systematic reviews of the effectiveness of RBF. We searched the Cochrane Library, EMBASE, and MEDLINE (up to August 2007). We also searched for related articles in PubMed, checked the reference lists of retrieved articles, and contacted key informants. We included reviews with a methods section that addressed the effects of any results‐based financing in the health sector targeted at patients, providers, organizations, or governments. We summarized the characteristics and findings of each review using a structured format.

Results We found 12 systematic reviews that met our inclusion criteria. Based on the findings of these reviews, financial incentives targeting recipients of health care and individual healthcare professionals are effective in the short run for simple and distinct, well‐defined behavioral goals. There is less evidence that financial incentives can sustain long‐term changes. Conditional cash transfers to poor and disadvantaged groups in Latin America are effective at increasing the uptake of some preventive services. There is otherwise very limited evidence of the effects of results‐based financing in low‐ or middle‐income countries. Results‐based financing can have undesirable effects, including motivating unintended behaviors, distortions (ignoring important tasks that are not rewarded with incentives), gaming (improving or cheating on reporting rather than improving performance), widening the resource gap between rich and poor, and dependency on financial incentives.

Conclusion There is limited evidence of the effectiveness of results‐based financing and almost no evidence of the cost‐effectiveness of results‐based financing. Based on the available evidence and likely mechanisms through which financial incentives work, they are more likely to influence discrete individual behaviors in the short run and less likely to create sustained changes.
Two Unusual Bovine Spongiform Encephalopathy Cases Detected in Great Britain
Authors: Stack M. , Focosi‐Snyman R. , Cawthraw S. , Davis L. , Jenkins R. , Thorne L. , Chaplin M. , Everitt S. , Saunders G. , Terry L.
Published: May 2009

Bovine spongiform encephalopathy (BSE) was first identified in Great Britain (GB) in 1986 and was subsequently detected in many other countries, world‐wide. A decade after the start of the bovine epidemic, the first cases of new variant Creutzfeldt‐Jakob disease (vCJD) in humans were linked to probable ingestion of BSE infected tissue, highlighting a new zoonotic disease. An abnormal protease‐resistant protein (PrPres) in a diseased subject, derived from a post‐translational change of a normal host cellular membrane protein (PrPc), is a reliable disease marker for the whole group of neurodegenerative transmissible spongiform encepalopathies (TSEs). Immunology‐based techniques, such as Western immunoblotting, have previously indicated that BSE cases all give a uniform molecular profile for PrPres. Periodic lesion profiling of the spongiform change throughout different brain regions of infected mice and cattle has also indicated a single agent for BSE. However, in 2001 rapid testing for PrPres was introduced for the active surveillance of ruminants within Europe, and approximately 40 BSE cases have now been recognized that differ in their molecular profiles from those typically found. These unusual BSE cases have been detected in several European countries, and in Japan and the USA. At present, the cases appear as two distinct types based on the molecular mass (Mm) of the unglycosylated PrPres protein band relative to that of classical BSE. One type is of a higher Mm (H‐type) and the other shows a lower Mm (L‐type). Transmission studies in mice have shown that both H‐type and L‐type BSE have biological characteristics that are different from those of the classical BSE agent. This study describes the prion protein (PRNP) genotype and molecular profiles of the first two cases of H‐type BSE detected in GB in comparison with those obtained for classical BSE, scrapie in sheep from GB and a control H‐type BSE case from France.
Prediction of Slug Liquid Holdup in Horizontal Pipes
Authors: Al-Safran Eissa
Published: May 2009

Slug liquid holdup is a critical parameter of slug flow, which influences the average liquid holdup and pressure drop along pipelines. The objective of this study is to develop a new correlation to predict slug liquid holdup in horizontal pipes. A large data set with wide ranges of operational, geometrical, and physical property parameters was used to develop the new correlation. The new correlation is a function of one independent mechanistic dimensionless variable, namely, the momentum transfer rate between the slug body and the liquid film. Physical modeling and statistical analyses suggested the appropriateness of the dimensionless momentum transfer rate as an independent parameter, which accounts for a large part of the variation in slug liquid holdup. A correlation validation and comparison study showed the accuracy of the new correlation. The statistical evaluation of the correlation resulted in an average percent relative error and percent standard deviation of 4.1% and 2.4%, respectively. Furthermore, the developed correlation was compared with other correlations and showed superior performance among all correlations, with the lowest relative performance factor of 0.01.
Cement Seal Failure at Casing Shoe in Shallow Marine Sediments
Authors: Zhou Desheng , Wojtanowicz Andrew K.
Published: May 2009

This paper describes the hypothetical mechanisms of cement seal failure during casing shoe leak-off testing (LOT) of surface holes in the shallow-marine sediments (SMSs)—parting of cement sheath from formation by LOT wellbore pressure. Presented is a theoretical proof—supported by LOT field data—explaining why, in SMSs, casing shoe failure occurs at pressures smaller than the rock fracturing pressures. Hence, for upper well sections in SMSs the prediction of casing shoe strength should be based on critical conditions for cement seal failure rather than rock fracturing. It is also shown that pressure required for cement seal failure can be determined from contact stress between cement and wellbore. Contact stress develops during the process of cement setting as a result of volumetric changes in the annulus. Proposed is a mathematical model of contact stress based on cement volume reduction compensated by compressibility of the casing string, cement, and wellbore. An example demonstrates potential application of the model. The study identifies two factors resulting from drilling process, which may control the critical pressure of cement seal failure in SMSs: contact stress at casing shoe, from cementing operations, and liquid penetration, an invasion of drilling fluid into the cement-rock interface around the casing shoe. It is shown that changes in cementing and drilling practices may increase casing shoe integrity and reduce the need for cement squeeze treatments.
The Quest for More Efficient Industrial Engines: A Review of Current Industrial Engine Development and Applications
Authors: Cullen Barry , McGovern Jim
Published: May 2009

This paper addresses the need for efficiency gains in the modern industrial engine as utilized in combined heat and power (CHP) generation and other distributed generation situations. Power generation is discussed in terms of reciprocating-engine-based plant operating on Otto type thermodynamic cycles. The current state of the technology and the research being conducted is examined. Internal combustion engine performance improvement in the industrial engine sector focuses on improvements in the combustion characteristics of the plant, with emphasis on areas such as piston design, valve timing, and supercharging. Maximum brake-thermal efficiencies, in percentage terms, are currently in the 40s. In CHP generation, most of the energy not utilized for mechanical power is recovered as heat from various engine systems, such as jacket water and exhaust, and utilized for space or process heating. In other distributed generation situations, this energy is not utilized in this manner and is lost to the surroundings. While second law analysis would provide a more meaningful interpretation of the efficiency defect, this approach is still not the norm. Distributed generation benefits directly from efficiency improvements; the more efficient use of primary energy leads to reduced fuel costs. Combined heat and power generation is, however, more sensitive to the matching between the plant and its energy sinks, as its successful implementation is dictated by the ability of a site to fully utilize the heat and electrical power produced by the plant. At present, the energy balance of such engines typically dictates that heat is produced in greater quantity than electrical power, the ratio being of the order of 1.1–1.5:1. Due to this production imbalance, it is accepted that in order to be economically feasible, thermal and electrical demand should be coincident and also all heat and power should be utilized. This has traditionally led to certain sectors being deemed unsuitable for CHP use. Some current research is aimed at tipping the production balance of these engines in favor of electrical power production; however, performance gains in this regard are slow. This paper concludes with some brief commentary on current industrial engine developments and applications.
Investigation of Particle Electrophoretic Motion in Converging-Diverging Microchannels
Authors: Xuan Xiangchun , Xu Bo , Li Dongqing
Published: May 2009

We studied experimentally the particle electrophoretic motion in converging-diverging microchannels on a poly(dimethylsiloxane) (PDMS) chip. The whole process of particle acceleration and deceleration was visualized through traditional optical microscopy, with which the accelerated particle electrophoretic separation is demonstrated. The effects of electric field, particle size, particle moving passage, and channel configuration on particle electrophoretic motion are examined individually. We find that the ratio of particle velocity in the throat to that in the straight channel is insensitive to both the particle moving passage and the length of converging/diverging channel, but increased for smaller particles moving through symmetric converging-diverging channels under lower electric fields. Moreover, we find that the particle velocity ratio in electrically driven flows is significantly lower than the cross-sectional area ratio of the straight channel to the throat. We have attributed this discrepancy to the particle-induced distortion in the electric potential distribution. The computed contour of electric field in a converging-diverging microchannel has revealed that the electric field is locally higher around the two poles of a particle than all other regions inside the channel.
Experimental Study of Flow Boiling Heat Transfer in Mini-Tube
Authors: Wang Lihong , Chen Min , Groll Manfred
Published: May 2009

Flow boiling heat transfer characteristics of R134a were experimentally investigated in a horizontal stainless steel mini-tube. The inner diameter of the test tube is 1.3 mm and the tube wall thickness is 0.1 mm. Local heat transfer coefficients are obtained over a range of vapor qualities up to 0.8, mass fluxes from 310 to 860 kg/m2s, heat fluxes from 21 to 50 kW/m2, and saturation pressures from 6.5 to 7.5 bar. The mass flux, heat flux, saturation pressure, and vapor quality dependences of heat transfer coefficients are demonstrated. Based on an available model in recent literature potential heat transfer mechanisms are also analyzed.
Thermocapillary Convection in Thin Liquid Films on Walls With Microgrooves
Authors: Alexeev Alexander , Gambaryan-Roisman Tatiana , Stephan Peter
Published: May 2009

Thermocapillary induced convection in thin liquid films on a horizontal wall with microgrooves is studied experimentally and numerically. To this end, we carry out experiments with silicon oil on a heated copper wall with parallel groves. The flow is visualized by tracking glass spheres seeded within the liquid film. The results of velocity measurements are reported. A numerical model for a liquid film on a structured wall is proposed. The full incompressible Navier-Stokes equations and the energy equation are integrated by a finite difference algorithm, whereas the mobile gas-liquid interface is tracked by the volume-of-fluid method. The numerical model is verified by comparison with the experimental data showing good agreement. The model is used to study flow patterns and film rupture caused by thermocapillary forces. We demonstrate that at any Marangoni number, either positive or negative, thermocapillary convection characterized by rolls develops within the film. In the experiments, two rolls in each groove are observed. The numerical solutions predict that at certain conditions the rolls are doubled under the influence of the wall structure guiding the flow. It is also found that an abrupt increase in wall temperature may rupture the liquid film near the structure crest. The results of this study may be applied to the design of microfluidic mixers and heat exchangers.
The Effect of Type of Working Fluid on the Heat Transport Capacity of a Micro Heat Pipe
Authors: Dharmalingam Sugumar , Tio Kek Kiong
Published: May 2009

In order to elucidate the effects of working fluid’s properties on the heat transport capacity of a micro heat pipe, 3 commonly used fluids are selected for this study: water, ammonia and methanol. From the results obtained, it shows that for operating temperatures lower than 50°C, ammonia is preferred, but if the operating temperature exceeds 50°C, water is more suitable in transferring heat. Over the temperature range of 20°C∼100°C, the behavior of the heat transport capacity is found to be dominated by a property which is the ratio of the working fluid’s surface tension and liquid viscosity. This property which has the dimension of velocity has a controlling effect on the working fluid’s rate of circulation and therefore, the heat transport capacity.
Micro Air Bubble Manipulation by Electrowetting Principle: Transporting, Merging and Eliminating
Authors: Zhao Yuejun , Cho Sung Kown
Published: May 2009

For the first time we report a series of micro air bubble manipulations (transporting, merging and eliminating of air bubbles) in two-dimensional microchannels filled with a water solution. Air bubbles (∼1.2 mm3 in volume) are driven by electrowetting-on-dielectric (EWOD) principle. By sequentially energizing an array of electrodes covered with dielectric layers, micro air bubbles can be transported along a programmed path, merged into a single larger one, and eliminated out of a bulk water solution. These three fundamental micro bubble operations demonstrated will facilitate efficient micro bubble handling essentially required in micro gas analysis systems.
On the Slip Mechanism of Microfluidics by Means of a Mean-Field Free-Energy Lattice Boltzmann Method
Authors: Zhang Junfeng , Kwok Daniel Y.
Published: May 2009

In this paper, we studied liquid-solid slip by employing a mean-field free-energy lattice Boltzmann approach recently proposed [Zhang et al., Phy. Rev. E. 69, 032602, 2004]. With a general bounce-back no-slip boundary condition applied to the interface, liquid slip was observed because of the specific fluid-solid interaction. The slip length is clearly related to the interaction strength: the stronger the interaction, the less hydrophobic the surface and hence results in less slipping. Unlike other lattice Boltzmann models, a contact angle value between 0–180° can be generated here without using a less realistic repulsive fluid-solid interaction. We found that system size does not affect the absolute slip magnitude; however, the ratio of the slip length to system size increases quickly as the system becomes smaller, illustrating that slip becomes important in smaller-scale systems. A small negative slip length can also be produced with a strong fluid-solid attraction. These results are in qualitative agreement with those from experimental and molecular dynamics studies.
On the Presence of Carbon Nanotubes During Streaming Potential Measurements in Microfluidics
Authors: Bhalla Shallu , Lu Fuzhi , Mansouri Ali , Chai Jinan , Kwok Daniel Y.
Published: May 2009

Alignment of carbon nanotubes (CNTs) has been studied in details for the past decades. In this paper, we examine the presence of single wall carbon nanotubes on experimental microfluidic systems during streaming potential measurements. The PMMA surface modified by CNTs has been characterized by high resolution scanning electron microscope (SEM), contact angles and streaming potential measurements. Preliminary results demonstrate clearly the effect of CNTs on microfluidic experiments in terms of streaming potentials.
Effect of Liquid-Solid Interaction on Liquid Transport Properties in a Nanometer Capillary Tube
Authors: Huang Cunkui , Nandakumar K. , Kwok Daniel Y.
Published: May 2009

In the present paper, molecular dynamics is applied to study the effect of interaction between liquid-solid on liquid transport properties, especially a stagnant layer to a slip layer, in a circular nano tube under a constant injection flow rate boundary condition. In simulations, a full 12-6 Lennard-Jones potential, truncated at 2.2σ, is used to govern the interaction between liquid-liquid and liquid-solid molecules. Six cases with different interactions (or energy scales) between liquid-solid are carried out. The non-equilibrium molecular dynamics (NEMD) simulation results show that the interaction between liquid-solid causes a wavelike density distribution in normal wall direction and the amplitude of wave is proportional to the interaction between liquid-solid; the interaction between liquid-solid dominates the motion of first liquid layer close to the solid substrate, i.e., the strong interaction between liquid-solid can result in the a stagnant layer; the weak interaction between liquid-solid produces a slip layer and the intermediate interaction between liquid-solid made a slip and sub-slip layers.