bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct imaging of the structural change generated by dielectric breakdown in MgO based magnetic tunnel junctions
Authors: Thomas A. , Drewello V. , Schäfers M. , Weddemann A. , Reiss G. , Eilers G. , Münzenberg M. , Thiel K. , Seibt M.
Published: October 2008

MgO based magnetic tunnel junctions are prepared to investigate the dielectric breakdown of the barrier. The breakdown is visualized by transmission electron microscopy measurements. The broken tunnel junctions are prepared for the microscopy measurements by focused ion beam out of the junctions characterized by transport investigations. A direct comparison of transport behavior and structure of the intact and broken junctions is obtained. The MgO barrier shows many microscopic pinholes after breakdown. This can be explained within a model assuming a relationship between the current density at the breakdown and the rate of pinhole formation.
Enhancement of dielectric energy density in the poly(vinylidene fluoride)-based terpolymer/copolymer blends
Authors: Chu Baojin , Neese Bret , Lin Minren , Lu Sheng-guo , Zhang Q. M.
Published: October 2008

This paper investigates dielectric properties of the blends of poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) terpolymer and poly(vinylidene fluoride-chlorotrifluoroethylene) copolymer. The high field (>50 MV/m) polarization response of the blends with a small amount of copolymer (5 and 10 wt % copolymer) is higher than that of the neat terpolymer due to the interface contribution. At the same time the breakdown field was also greatly improved by mixing a small amount of the copolymer with the terpolymer. Consequently, a higher energy density of about 11.5 J/cm3 is obtained in these blends in contrast to about 9 J/cm3 in the terpolymer.
Agricultural drought analyses for temperate Australia using a biophysical pasture model. 1. Identifying and characterising drought periods
Authors: Lodge G. M. , Johnson I. R.
Published: October 2008

The SGS Pasture Model was used to estimate daily total soil water content (mm) for the period 1998–2001 (using experimental data) and from July 1905 to June 2005 (using a 100-year daily climate file). For both model simulations, the correlation coefficient for actual and predicted data was >0.86. Four sites were examined, three in the winter-rainfall zone (Albany, Western Australia; Hamilton, Victoria; and Wagga Wagga, New South Wales) and one in the predominantly summer-rainfall zone (Barraba, New South Wales) of temperate Australia. Trends were detected in long-term rainfall data for lower mean annual rainfall at the Albany site since the mid 1950s and at the Hamilton site since the mid 1970s.
Analyses of days in which herbage accumulation was likely to be limited only by water allowed a minimum soil water content to be defined; below this value, soil water was in deficit. A drought period was defined as occurring after >50 consecutive days of predicted soil water deficit. For the four sites, six categories of drought duration were described, ranging from >50–120 days (seasonal drought) to >364 days (exceptional drought).
Numbers of predicted droughts were 90, 90, 65, and 60, respectively, at Albany, Hamilton, Wagga Wagga, and Barraba sites. At the three winter-rainfall sites, most predicted droughts occurred in a regular pattern and were an extension of a seasonal drought, but at the Barraba site they were of a longer duration and irregular in occurrence.
Effect of hormonal growth promotants on palatability and carcass traits of various muscles from steer and heifer carcasses from a Bos indicus - Bos taurus composite cross
Authors: Watson R. , Polkinghorne R. , Gee A. , Porter M. , Thompson J. M. , Ferguson D. , Pethick D. , McIntyre B.
Published: October 2008

The effect of several different hormonal growth promotant (HGP) implant strategies on the palatability and carcass traits of different muscles in beef carcasses was investigated using samples from heifer and steer carcasses from a Bos indicus composite breed. In experiment 1, there were seven different implant strategies evaluated in heifers that were given different combinations of up to three implants (implanted at weaning, during backgrounding and at feedlot entry). A total of 112 heifers were slaughtered and 11 muscles or portions were collected from both sides [Mm. adductor femoris, gracilus, semimembranosus, longissimus dorsi lumborum, triceps brachii caput longum, semispinalis capitis, serratus ventralis cervicis, spinalis dorsi, biceps femoris (syn. gluteobiceps), tensor fasciae latae, gluteus medius (both the ‘D’ and the ‘eye’ portions) rectus femoris, vastus intermedius, vastus lateralis and vastus medialis]. These muscles were used to prepare a total of 1030 sensory samples which were aged for either 7 or 21 days and frozen. Thawed samples were cooked using different cooking methods (grill, roast and stir frying) before being evaluated by a consumer taste panel that scored samples for tenderness, juiciness, like flavour and overall liking. Experiment 2 used the steer portion from the same calving, which were treated to a similar array of HGP strategies, except that they were given up to four implants between weaning and slaughter at ~3 years of age. In experiment 2, there was a total of 12 different HGP implant strategies tested. At boning, three muscles (Mm. psoas major, longisimuss dorsi thoracis and lumborum portions) were collected from each of 79 carcasses with a total of 237 steak samples that consumers tested as grilled steaks.
For both experiments, the mean of the HGP implant strategies resulted in increased ossification scores (P < 0.05) and decreased marbling scores (P < 0.05) compared with the controls, with the effect on ossification being much larger in the older steer groups. In both experiments, the different HGP strategies decreased (P < 0.05) all sensory scores compared with the controls, for all cooking method and muscle combinations. In experiment 1, there was no interaction between the mean HGP effect and muscle (P > 0.05), and aging rates differed among the muscles (P < 0.05). In experiment 2, there was a significant (P < 0.05) muscle × HGP treatment interaction, with a decrease in tenderness score due to HGP implant strategies in the M. longisimuss thoracis and lumborum portions, compared with no significant effect in the M. psoas major. For both experiments, there were no significant differences among the different implantation strategies on sensory scores (P > 0.05).
Development of a commercial system to apply the Meat Standards Australia grading model to optimise the return on eating quality in a beef supply chain
Authors: Polkinghorne R. , Philpott J. , Gee A. , Doljanin A. , Innes J.
Published: October 2008

A major trial was conducted to develop, test and demonstrate the application of Meat Standards Australia (MSA) research findings in a beef retailing environment. A new concept retail store was established whereby a mix of raw beef products and pre-cooked meals were merchandised under an eating quality grade defined by MSA palatability scores. Products were presented fully prepared within cooking method with pricing based on the predicted cooked results. Large price differentials were established between the three grades offered, with 5-star product priced at more than double the 3-star product.
The principle of pricing being directly related to eating quality was extended from the retail store sales to fabrication and the purchase of source cattle from producers. This encouraged considerable innovation to optimise eating quality and returns, demonstrating the potential for truly transparent value-based pricing systems to achieve change.
Novel systems were developed to break down and fabricate the carcass into ‘retail-ready’ product with extensive software development to trace the eating quality, value and location of individual cuts and products. Detailed feedback provided the producer with an accurate measure of value and sufficient data to evaluate possible alternative production strategies.
Results at each level of the supply chain were encouraging with compound annual growth in sales exceeding 12% at retail level and continued innovation through fabrication and on-farm areas combining to improve eating quality and financial outcomes. It was demonstrated that the consumer focus delivered by MSA grades could be applied at a commercial level providing an opportunity to reposition beef as a contemporary consumer product and to implement a value-based system across all sectors.
Length of exposure to high post-rigor temperatures affects the tenderisation of the beef M. longissmus dorsi
Authors: Thomson K. L. , Gardner G. E. , Simmons N. , Thompson J. M.
Published: October 2008

This experiment examined the effect of length of exposure of bovine M. longissmus dorsi to high temperatures (37°C) on proteolytic activity during post-mortem aging and subsequent meat tenderness. To avoid confounding between pH decline and incubation treatments, the experiment was conducted on post-rigor meat (pH < 5.6), which had entered rigor at 15°C. This meat was first incubated at 15°C until rigor (pH < 5.6), whereupon samples were then reheated and maintained at 37°C for 0, 1 or 3 h. Following incubation, samples were aged at 1°C for 1–21 days. Control groups were incubated at either 15 or 37°C until pH < 5.6, followed by aging at 1°C. High rigor temperatures accelerated post-mortem proteolysis early in the post-mortem period, as indicated by a rapid decline in shear force (P < 0.01), but post-mortem aging ceased at about day 3 post-mortem and the high rigor temperature treatment was ultimately 30% tougher at day 21 post-mortem (P < 0.01). The process of reheating samples from 15 to 37°C had minimal effect on tenderness levels, but was associated with a slight increase in proteolysis, identified by myofibril length, and was associated with an increase in cook loss percentage (P < 0.05). Shear force in the length of exposure experiment was affected by an incubation time × post-mortem aging interaction (P < 0.01). This indicated an initial acceleration of post-mortem aging with increased length of exposure, but also a reduction in the ultimate tenderness of product after extended post-mortem aging. This was presumably due to the loss of proteolytic enzyme activity caused by the instability of proteolytic enzymes at high ionic strength conditions such as those present in post-mortem muscle.
Habitat complexity explains species-specific occupancy but not species richness in a Western Australian woodland
Authors: Cousin Jarrad A. , Phillips Ryan D.
Published: October 2008

Habitat complexity is an important factor governing species richness and habitat selection in birds. The present study examined this relationship in a large wandoo woodland in Western Australia. Habitat complexity (comprising canopy, shrub, ground vegetation, log and leaf litter cover) and bird species richness was recorded in 48 sites, each ~3 ha in size. We found no significant correlation of habitat complexity with species richness. We propose that the absence of such a relationship results from the resource-poor environment of the woodlands of south-western Australia. The relative scarcity of food resources results in a species richness threshold beyond which there are insufficient niches and resources to support additional species with increasing habitat complexity. Only two species exhibited significant associations with habitat complexity, with the western yellow robin (Eopsaltria griseogularis) occupying sites with higher habitat complexity, and the restless flycatcher (Myiagra inquieta) occupying sites with lower habitat complexity. Although some species may respond specifically to habitat complexity, management of avian biodiversity within Australian woodlands should take into account the potentially greater role that productivity and resource availability play in influencing species richness, rather than habitat complexity per se. Furthermore, the individual components comprising habitat complexity may be of equal importance in assessing relationship of species richness to overall habitat complexity.
Relationships between nestling condition and variability in coccidian prevalence among three species of wild-nesting birds in New Zealand
Authors: Cassey Phillip , Ewen John G.
Published: October 2008

Coccidian protozoa are widespread intestinal parasites of vertebrate species. Currently, our understanding of the dynamics of host–coccidia relationships among birds remains poor beyond domestic poultry and species held in captivity. The various threats that parasites can impose have resulted in demands to monitor and quantify different parasites and incorporate their impacts on hosts into ecological models of risk assessment. Here, we estimate prevalence of coccidian infections from nestlings of three species of exotic, free-living European passerines in New Zealand (Turdus merula, T. philomelos, Sturnus vulgaris). We find that despite high prevalence of infection among clutches (~40%) these infections appear asymptomatic and are not related to indices of nestling condition or fledging success. We encourage additional studies to provide results on variation in parasite prevalence and pathogenicity in order to build our understanding of host dynamics.
Helminth assemblages of Uromys spp. (Muridae : Hydromyinae) from Australia, Papua New Guinea and Papua Indonesia and comparison with assemblages in Melomys spp.
Authors: Smales L. R. , Spratt D. M.
Published: October 2008

This study documents the helminth assemblages of Uromys caudimaculatus (Krefft, 1867) from Papua New Guinea and Australia as well as listing helminths found in U. anak Thomas, 1907 from Papua Indonesia and Papua New Guinea, and U. hadrourus (Winter, 1984) from Queensland Australia. In total, 36 species of helminth, comprising one acanthocephalan, three cestodes (excluding unidentifiable fragments) and 32 nematodes (including two not identified to genus) from 65 hosts were found. The Trichostrongylina nematodes were the dominant group of helminths, the most prevalent species being Odilia uromyos (Mawson, 1961), found in each of the species of Uromys across all regions, and O. melomyos (Mawson, 1961), occurring in U. caudimaculatus from Papua New Guinea and Australia. The helminth species assemblage from U. caudimaculatus, 14 species of helminth from 11 hosts from Papua New Guinea and 23 species of helminth from 51 hosts from Australia, had high species richness but was relatively equitable overall (1/SI = 0.92). The differences found between the helminth assemblages of U. caudimaculatus from Papua New Guinea and Australia suggest that U. caudimaculatus may have travelled to Australia from New Guinea with a small pool of helminth species that was subsequently added to by host switching from sympatric rodent hosts. Alternatively, U. caudimaculatus may have lost many of the helminths that travelled with it following arrival in Australia.
Basking and diurnal foraging in the dasyurid marsupial Pseudantechinus macdonnellensis
Authors: Pavey Chris R. , Geiser Fritz
Published: October 2008

Several mammal species bask to passively rewarm during arousal from torpor, a strategy that can decrease energetic costs. Nothing is known about basking behaviour in these species or the trade-offs between energetic benefits of basking and potential costs associated with changes in activity patterns and increased predation risk. We assessed basking during winter in Pseudantechinus macdonnellensis, an Australian arid-zone marsupial that belongs to a family (Dasyuridae) that is typically nocturnal. Animals were implanted with temperature-sensitive transmitters to assess body temperatures and to assist in visually locating animals active during the day. Tagged animals regularly exhibited diurnal foraging. Foraging bouts occurred throughout the day; however, most bouts were observed within 3 h of sunset. By comparison, basking occurred much more frequently in the morning. Basking and a shift towards diurnal foraging in winter is associated with a decrease in richness and abundance of predators. P. macdonnellensis appears to compensate for the occurrence of torpor during the active phase (i.e. night) in winter by changing activity patterns such that foraging commences during what is usually the rest phase. These activity patterns are not expected to occur during the remainder of the year.
Low levels of extra-pair paternity in southern emu-wrens (Aves : Maluridae)
Authors: Maguire Grainne S. , Mulder Raoul A.
Published: October 2008

The frequency of extra-pair paternity (EPP) among birds varies considerably, with the highest rates (56–76%) reported in several species of fairy-wren (Maluridae). According to the ‘constrained female’ hypothesis, such high frequencies arise when females are emancipated from constraints on mate choice because they have access to alternative sources of parental care (cooperative breeding). We investigated the genetic mating system of a close relative of the fairy-wrens within the Maluridae, the southern emu-wren (Stipiturus malachurus). Southern emu-wrens share several life-history attributes with the fairy-wrens, but show relatively low levels of cooperation, providing an opportunity to assess how the frequency of cooperative breeding correlates with the frequency of EPP. We assessed paternity for 50 offspring within 27 emu-wren broods using species-specific microsatellite markers. Overall, only 12% of genotyped offspring resulted from extra-pair paternity, and 15% of broods contained at least one extra-pair offspring. We argue that opportunities for mate choice by female emu-wrens are restricted by their dependence on paternal care for offspring survival, as suggested by the constrained female hypothesis. The low occurrence of cooperative breeding in the southern emu-wren may thus help explain the extreme variation in the frequency of extra-pair paternity within this family.
Efficient coding in heterogeneous neuronal populations
Authors: Chelaru Mircea I. , Dragoi Valentin
Published: October 2008

A ubiquitous feature of neuronal responses within a cortical area is their high degree of inhomogeneity. Even cells within the same functional column are known to have highly heterogeneous response properties when the same stimulus is presented. Whether the wide diversity of neuronal responses is an epiphenomenon or plays a role for cortical function is unknown. Here, we examined the relationship between the heterogeneity of neuronal responses and population coding. Contrary to our expectation, we found that the high variability of intrinsic response properties of individual cells changes the structure of neuronal correlations to improve the information encoded in the population activity. Thus, the heterogeneity of neuronal responses is in fact beneficial for sensory coding when stimuli are decoded from the population response.
It all hinges on the vowels
Authors: Swank Heidi
Published: October 2008

I argue that formal and ethnographic studies of written language could benefit from greater reciprocal engagement. Recent work on formal aspects of written language has made plain that orthographic typology can help us to understand readers’ phonological awareness as well as inform and shape pedagogical strategies. However, much work on orthographic typologies has not examined actual use of writing systems. Peter Daniels stated that writing can be “adapted … at will” (1996a:2). This notion of adaptability of writing poses problems for studies of writing systems that do not look at its actual usage. Through a cross-orthographic study of writing adaptability, I suggest that an ethnographic examination of writing systems challenges the definition of the term alphasyllabary proposed in Bright (1999). I offer that a focus on the relative independence of vowels and consonants provides a solid typological classification system that accounts for changes and current variability in writing system usage.
Improving Cleaning of the Environment Surrounding Patients in 36 Acute Care Hospitals
Authors: Carling Philip C. , Parry Michael M. , Rupp Mark E. , Po John L. , Dick Brian , Von Beheren Sandra ,   Healthcare Environmental Hygiene Study Group
Published: October 2008

Objective.

The prevalence of serious infections caused by multidrug-resistant pathogens transmitted in the hospital setting has reached alarming levels, despite intensified interventions. In the context of mandates that hospitals ensure compliance with disinfection procedures of surfaces in the environment surrounding the patient, we implemented a multihospital project to both evaluate and improve current cleaning practices.

Design.

Prospective quasi-experimental, before-after, study.

Setting.

Thirty-six acute care hospitals in the United States ranging in size from 25 to 721 beds.

Methods.

We used a fluorescent targeting method to objectively evaluate the thoroughness of terminal room disinfection cleaning before and after structured educational and procedural interventions.

Results.

Of 20,646 standardized environmental surfaces (14 types of objects), only 9,910 (48%) were cleaned at baseline (95% confidence interval, 43.4-51.8). Thoroughness of cleaning at baseline correlated only with hospital expenditures for environmental services personnel (P = .02). After implementation of interventions and provision of objective performance feedback to the environmental services staff, it was determined that 7,287 (77%) of 9,464 standardized environmental surfaces were cleaned (P < .001). Improvement was unrelated to any demographic, fiscal, or staffing parameter but was related to the degree to which cleaning was suboptimal at baseline (P < .001).

Conclusions.

Significant improvements in disinfection cleaning can be achieved in most hospitals, without a substantial added fiscal commitment, by the use of a structured approach that incorporates a simple, highly objective surface targeting method, repeated performance feedback to environmental services personnel, and administrative interventions. However, administrative leadership and institutional flexibility are necessary to achieve success, and sustainability requires an ongoing programmatic commitment from each institution.
Grunting for worms: seismic vibrations cause
Diplocardia
earthworms to emerge from the soil
Authors: Mitra O , Callaham M.A , Smith M.L , Yack J.E
Published: October 2008

Harvesting earthworms by a practice called ‘worm grunting’ is a widespread and profitable business in the southeastern USA. Although a variety of techniques are used, most involve rhythmically scraping a wooden stake driven into the ground, with a flat metal object. A common assumption is that vibrations cause the worms to surface, but this phenomenon has not been studied experimentally. We demonstrate that
Diplocardia
earthworms emerge from the soil within minutes following the onset of grunting. Broadband low frequency (below 500 Hz) pulsed vibrations were present in the soil throughout the area where worms were harvested, and the number of worms emerging decreased as the seismic signal decayed over distance. The findings are discussed in relation to two hypotheses: that worms are escaping vibrations caused by digging foragers and that worms are surfacing in response to vibrations caused by falling rain.
On the direct determination of the eigenmodes of finite flow–structure systems
Authors: Pitman Mark W , Lucey Anthony D
Published: October 2008

A new method for directly determining the eigenmodes of finite flow–structure systems is presented using the classical problem of the interaction of a uniform incompressible flow with a flexible panel, held at both ends, as an exemplar. The method is a hybrid of theoretical analysis and computational modelling. This method is contrasted with Galerkin and travelling-wave methods, which are most often used to study the hydroelasticity of such systems. The new method does not require ana prioriapproximation of perturbations via a finite sum of modes. Instead, the coupled equations for the wall–flow system are used to derive a single matrix equation for the system that is a second-order differential equation for the panel-displacement variable. This is achieved in this exemplar by applying a combination of boundary-element and finite-element methods to the discretized system. Standard state-space methods are then used to extract the eigenmodes of the system directly. We present the results for the stability of the case of an unsupported flexible plate, elucidating its divergence and flutter characteristics, and the effect of energy dissipation in the structure. We then present the results for the case of a spring-backed flexible plate, showing that its motion is dominated by travelling waves. Finally, we illustrate the versatility of the approach by extracting the stability diagrams and modes for a panel with spatially varying properties and a panel with non-standard boundary conditions. In doing so, we show how spatial inhomogeneity can modify the energy exchanges between flow and structure, thereby introducing a single-mode flutter instability at pre-divergence flow speeds.
Origin, adaptive radiation and diversification of the Hawaiian lobeliads (Asterales: Campanulaceae)
Authors: Givnish Thomas J , Millam Kendra C , Mast Austin R , Paterson Thomas B , Theim Terra J , Hipp Andrew L , Henss Jillian M , Smith James F , Wood Kenneth R , Sytsma Kenneth J
Published: October 2008

The endemic Hawaiian lobeliads are exceptionally species rich and exhibit striking diversity in habitat, growth form, pollination biology and seed dispersal, but their origins and pattern of diversification remain shrouded in mystery. Up to five independent colonizations have been proposed based on morphological differences among extant taxa. We present a molecular phylogeny showing that the Hawaiian lobeliads are the product of one immigration event; that they are the largest plant clade on any single oceanic island or archipelago; that their ancestor arrived roughly 13 Myr ago; and that this ancestor was most likely woody, wind-dispersed, bird-pollinated, and adapted to open habitats at mid-elevations. Invasion of closed tropical forests is associated with evolution of fleshy fruits. Limited dispersal of such fruits in wet-forest understoreys appears to have accelerated speciation and led to a series of parallel adaptive radiations inCyanea, with most species restricted to single islands. Consistency ofCyaneadiversity across all tall islands except Hawai i suggests that diversification ofCyaneasaturates in less than 1.5 Myr. Lobeliad diversity appears to reflect a hierarchical adaptive radiation in habitat, then elevation and flower-tube length, and provides important insights into the pattern and tempo of diversification in a species-rich clade of tropical plants.
Male-derived cuticular hydrocarbons signal sperm competition intensity and affect ejaculate expenditure in crickets
Authors: Thomas Melissa L , Simmons Leigh W
Published: October 2008

Female sexual promiscuity can have significant effects on male mating decisions because it increases the intensity of competition between ejaculates for fertilization. Because sperm production is costly, males that can detect multiple matings by females and allocate sperm strategically will have an obvious fitness advantage. The presence of rival males is widely recognized as a cue used by males to assess sperm competition. However, for species in which males neither congregate around nor guard females, other more cryptic cues might be involved. Here, we demonstrate unprecedented levels of sperm competition assessment by males, which is mediated via the use of chemical cues. Using the cricket
Teleogryllus oceanicus
, we manipulated male perception of sperm competition by experimentally coating live unmated females with cuticular compounds extracted from males. We found that males adjusted their ejaculate allocation in response to these compounds: the viability of sperm contained within a male's ejaculate decreased as the number of male extracts applied to his virgin female partner was increased. We further show that males do not respond to the relative concentration of male compounds present on females, but rather to the number of distinct signature odours of individual males. Our results conform to sperm competition theory, and show for the first time, to our knowledge, that males can detect different intensities of sperm competition by using distinct chemical cues of individual males present on females.
Congenital Gastric Outlet Obstruction and Nonimmune Hydrops Fetalis: A Prenatal Sonographic Diagnosis of a Case with Hydrothorax and Ascites
Authors: Abdulkadir A. Yisau , Adesiyun O. A. M. , Fawole A. Adisa , Aboyeji A. Peter
Published: October 2008

A case of a male fetus with sonographic diagnosis of hydrops fetalis at 19-week gestation is reported. The fetus had anasarca, bilateral massive pleural effusion, and ascites, in addition to cardiac arrhythmia and congenital gastric outlet obstruction. Mother's clinical history and laboratory workup excluded immune hydrops. The etiological dilemma and fetal outcome are discussed. We concluded, based on this case, that when fetal hydrops occurs early and is associated with multiple congenital anomalies, prolonging the pregnancy may be futile.
A Case Study on the Implementation of a Positive Youth Development Program (Project P.A.T.H.S.) in Hong Kong: Learning from the Experimental Implementation Phase
Authors: Lee Tak Yan
Published: October 2008

This investigation of the implementation of a positive youth development program (Project P.A.T.H.S.) was part of a large study undertaken comprehensively to explore how effective the Tier 1 Program was in practice and how the results can shed light on future developments. Utilizing a case study approach, individual and focus group interviews were conducted in 2007 to examine the factors that influence the process and quality of implementation of the Tier 1 Program of the Project P.A.T.H.S. The focus of this study was on how the implementers of a school made use of the experience gained in the Experimental Implementation Phase (EIP) in 2005/06 to improve the program implementation quality in the Full Implementation Phase (FIP) in 2006/07. Results showed that the program implementation in the FIP was generally high and the program was well received by the implementers. Factors that facilitated the implementation of the program were identified, including the adoption of an incremental change strategy, the incorporation of the program into both formal and informal curricula, positive perceptions of the program among staff and agency social workers, sufficient school administrative support, excellent cooperation between the school and the social work agency, presence of a dedicated school contact person and instructors who engaged themselves in continuous quality improvement of the implementation, and an emphasis on application of what had been learned. Difficulties encountered by the school in the process of implementation were also observed. Based on the present findings, key process variables that facilitate or impede the implementation of positive youth development programs are discussed. Implications for future program implementation are also discussed.
Caudal, a key developmental regulator, is a DPE-specific transcriptional factor
Authors: Juven-Gershon Tamar , Hsu Jer-Yuan , Kadonaga James T.
Published: October 2008

The regulation of gene transcription is critical for the proper development and growth of an organism. The transcription of protein-coding genes initiates at the RNA polymerase II core promoter, which is a diverse module that can be controlled by many different elements such as the TATA box and downstream core promoter element (DPE). To understand the basis for core promoter diversity, we explored potential biological functions of the DPE. We found that nearly all of the Drosophila homeotic (Hox) gene promoters, which lack TATA-box elements, contain functionally important DPE motifs that are conserved from Drosophila melanogaster to Drosophila virilis. We then discovered that Caudal, a sequence-specific transcription factor and key regulator of the Hox gene network, activates transcription with a distinct preference for the DPE relative to the TATA box. The specificity of Caudal activation for the DPE is particularly striking when a BREu core promoter motif is associated with the TATA box. These findings show that Caudal is a DPE-specific activator and exemplify how core promoter diversity can be used to establish complex regulatory networks.
Clinical trial: sodium phosphate tablets are preferred and better tolerated by patients compared to polyethylene glycol solution plus bisacodyl tablets for bowel preparation
Authors: LICHTENSTEIN G. R. , GRANDHI N. , SCHMALZ M. , LOTTES S. R. , FORBES W. P. , WALKER K. , ZHANG B.
Published: October 2008

Background  Patient acceptance of bowel preparation can affect colon cancer screening compliance.

Aim  To compare patient acceptance, preference and tolerability of 32‐sodium phosphate tablets vs. 2L polyethylene glycol solution plus 4 bisacodyl tablets for bowel preparation.

Methods  A prospective, randomized, investigator‐blinded, multicentre trial was performed. Results were based on responses to a patient questionnaire.

Results  411 patients (205 sodium phosphate; 206 polyethylene glycol plus bisacodyl) completed the study preparation and patient questionnaire prior to colonoscopy. More patients receiving sodium phosphate vs. polyethylene glycol plus bisacodyl found it easy to take (77% vs. 42%), reported it to be without taste (47% vs. 6%), found it easy to take with respect to volume of liquid prescribed (72% vs. 27%) and indicated they would take the same preparation again in the future (96% vs. 74%, P < 0.0001 for all). Fewer patients receiving sodium phosphate vs. polyethylene glycol plus bisacodyl had to take time off work or change ordinary activities to take the study preparation (18% vs. 52%, P < 0.0001). Nausea, vomiting, bloating and abdominal pain were reported less frequently with sodium phosphate (P < 0.0013).

Conclusion  The 32‐tablet sodium phosphate dosing regimen was easier to take and better tolerated, when compared to 2L polyethylene glycol plus bisacodyl tablets for bowel preparation.
Colonic stent versus surgery for the management of acute malignant colonic obstruction: a decision analysis
Authors: SIDDIQUI A. , KHANDELWAL N. , ANTHONY T. , HUERTA S.
Published: October 2008

Background  Acute colonic obstruction because of advanced colonic malignancy is a surgical emergency.

Aim  To compare the clinical outcomes and cost‐effectiveness of endoscopic self‐expanding metal stent (SEMS) vs. surgery for emergent management of acute malignant colonic obstruction in patients with metastatic colorectal cancer over a 6‐month period.

Methods  Decision analysis was used to calculate the cost‐effectiveness and success of two competing strategies in a hypothetical patient with metastatic colon cancer presenting with acute, malignant colonic obstruction: (i) emergent colonic stent (SEMS cohort); (ii) emergent surgical resection followed by diversion (surgery cohort).

Results  Self‐expanding metal stent resulted in a success and a lower mortality rate when compared to surgery over a 6‐month period. Colonic SEMS was also associated with a lower mean cost per patient ($27 225 vs. $57 398). Mortality in the surgery group was 25 times that of the SEMS cohort. One‐ and two‐way sensitivity analyses identified SEMS as the dominant strategy.

Conclusion  Colonic stent insertion is more effective and less costly than surgery for the management of colonic obstruction in patients with metastatic colon cancer.
Individualized population pharmacokinetic model with limited sampling for cyclosporine monitoring after liver transplantation in clinical practice
Authors: LANGERS P. , CREMERS S. C. L. M. , DEN HARTIGH J. , RIJNBEEK E. M. T. , RINGERS J. , LAMERS C. B. H. W. , HOMMES D. W. , VAN HOEK B.
Published: October 2008

Background  We recently developed and validated limited sampling models (LSMs) for cyclosporine monitoring after orthotopic liver transplantation based on individualized population pharmacokinetic models with Bayesian modelling.

Aim  To evaluate LSM in practice, and to seek optimal balance between benefit and discomfort.

Methods  In 30 stable patients, more than 6 months after orthotopic liver transplantation, previously switched from trough‐ to 2 h post‐dose (C2)‐monitoring, we switched to 3‐monthly LSM 0,1,2,3 h‐monitoring. During 18 months we evaluated dose, creatinine clearance, calculated area under the curve, intra‐patient pharmacokinetic variability and ability to assess systemic exposure by several previously validated LSMs.

Results  Within patients, there was variability of cyclosporine‐area under the curve with the same dose (CV of 15%). Compared to C2‐monitoring, there was no significant difference in dose (P = 0.237), creatinine clearance (P = 0.071) and number of rejections. Some models showed excellent correlation and precision with LSM 0,1,2,3 h comparing area under the curves (0,2 h: r2 = 0.88; 0,1,3 h: r2 = 0.91; 0,2,3 h: r2 = 0.92, all P < 0.001) with no difference in advised dose.

Conclusions  The limited sampling model, with only trough‐ and 2‐h sampling, yields excellent accuracy and assesses systemic exposure much better than C2 with less bias and greater precision. Considering the calculated intra‐patient variability, more precision is redundant, so LSM 0,2 h seems the optimal way of cyclosporine‐monitoring.
Review article: vaccination and viral hepatitis – current status and future prospects
Authors: KOFF R. S.
Published: October 2008

Background  Viral hepatitis is the most common cause of liver disease in the world. In the past 25 years, vaccines have become available for two of the five hepatitis viruses, and, where implemented, vaccination has become a key component of hepatitis prevention.

Aims  To provide an update on recent advances in the use of current hepatitis vaccines and to examine progress in the development of vaccines for the remaining hepatitis viruses.

Methods

A Medline search was undertaken to identify the recent relevant literature. Search terms included hepatitis vaccines, hepatitis vaccination and hepatitis A–E vaccines.

Results  Dramatic vaccine‐induced declines in the incidence of both hepatitis A and B have occurred in the USA. Strategies to integrate hepatitis A vaccine into universal childhood immunization are being adopted. Similarly, strategies with the goal of eliminating transmission of hepatitis B have been promulgated. A vaccine for hepatitis E has been reported to be effective and safe, but progress in the development of vaccines for hepatitis C and D has been limited.

Conclusion  During the next few decades, the goals of eliminating hepatitis A and B virus transmission may be reached in the USA and elsewhere.
Review article: the assessment of liver function using breath tests
Authors: ILAN Y.
Published: October 2008

Background  Hepatologists have long sought to develop a test for assessing liver function, but this aim has been stalled by the complexity of the liver and its diverse functions. Results of metabolic tests, including breath tests, correlate with clinical and histological parameters of patients with liver disorders; however, these tests tend to be cumbersome and impractical for everyday use. The recent development of a real‐time, point‐of‐care liver function breath test has made it straightforward to assess the metabolic function of the liver.

Aim  To review the available data on the use of breath tests for assessing liver reserve in various conditions and their application in various clinical hepatology settings.

Results  The 13C‐methacetin breath test enables accurate follow‐up of patients with acute or chronic liver damage, where overall hepatic function is significantly suppressed by known causes of liver disorders, including acute, sub‐acute or chronic conditions. The metabolic breath test can detect both gradual and spontaneous improvements in liver function and the effects of treatment.

Conclusions  Breath testing that provides continuous quantification of methacetin metabolism may be a sensitive tool for the diagnosis and follow‐up of patients with liver disorders.
Clinical trial: acupuncture vs. doubling the proton pump inhibitor dose in refractory heartburn
Authors: DICKMAN R. , SCHIFF E. , HOLLAND A. , WRIGHT C. , SARELA S. R. , HAN B. , FASS R.
Published: October 2008

Background  The current standard of care in proton pump inhibitor failure is to double the proton pump inhibitor dose, despite limited therapeutic gain.

Aims  To determine the efficacy of adding acupuncture vs. doubling the proton pump inhibitor dose in gastro‐oesophageal reflux disease patients who failed symptomatically on proton pump inhibitors once daily.

Methods  Thirty patients with classic heartburn symptoms who continued to be symptomatic on standard‐dose proton pump inhibitors were enrolled into the study. All participants underwent upper endoscopy while on proton pump inhibitors once daily. Subsequently, patients were randomized to either adding acupuncture to their proton pump inhibitor or doubling the proton pump inhibitor dose over a period of 4 weeks. Acupuncture was delivered twice a week by an expert.

Results  The two groups did not differ in demographic parameters. The acupuncture + proton pump inhibitor group demonstrated a significant decrease in the mean daytime heartburn, night‐time heartburn and acid regurgitation scores at the end of treatment when compared with baseline, while the double‐dose proton pump inhibitor group did not demonstrate a significant change in their clinical endpoints. Mean general health score was only significantly improved in the acupuncture + proton pump inhibitor group.

Conclusion  Adding acupuncture is more effective than doubling the proton pump inhibitor dose in controlling gastro‐oesophageal reflux disease‐related symptoms in patients who failed standard‐dose proton pump inhibitors.
Hospitalization for gastrointestinal adverse events attributable to the use of low‐dose aspirin among patients 50 years or older also using non‐steroidal anti‐inflammatory drugs: a retrospective cohort study
Authors: RAHME E. , NEDJAR H. , BIZZI A. , MORIN S.
Published: October 2008

Background  Use of aspirin with non‐steroidal anti‐inflammatory drugs increases the risk of gastrointestinal ulcers; however, it is not clear if this risk varies with the non‐steroidal anti‐inflammatory drug used.

Aim  To assess the risk of gastrointestinal hospitalizations attributable to aspirin in patients 50 years or older also using non‐steroidal anti‐inflammatory drugs.

Methods  Administrative data of patients 50 years or older who received a non‐steroidal anti‐inflammatory drug or acetaminophen prescription between 1998 and 2004 were used.

Results  Study patients received 7 412 992 non‐steroidal anti‐inflammatory drug prescriptions and 5 614 044 acetaminophen prescriptions among which 23% and 32%, respectively, were dispensed to aspirin users. Time‐dependent Cox regression models revealed that, compared to patients using acetaminophen (without aspirin), the adjusted hazard ratio (95% CI) among non‐users of aspirin were: rofecoxib 1.3 (1.2, 1.5), celecoxib 0.7 (0.6, 0.8), diclofenac 1.5 (1.2, 1.7), ibuprofen 0.9 (0.6, 1.4), naproxen 2.5 (2.1, 3.0) and piroxicam 1.5 (0.8, 2.8); among users of aspirin: rofecoxib 3.2 (2.8, 3.7), celecoxib 1.8 (1.5, 2.1), diclofenac 2.8 (2.2, 3.5), ibuprofen 1.4 (0.8, 2.7), naproxen 2.2 (1.6, 3.0) and piroxicam 2.0 (0.8, 5.4). The risk attributable to aspirin varied from none with naproxen to 61% (53%, 68%) with celecoxib.

Conclusion  The increase in gastrointestinal hospitalization attributable to aspirin differed with the non‐steroidal anti‐inflammatory drug used, and seemed higher with cyclo‐oxygenase‐2 inhibitors than with non‐selective non‐steroidal anti‐inflammatory drugs.
Evidence of allelic heterogeneity for associations between the NOD2/CARD15 gene and ulcerative colitis among North Indians
Authors: JUYAL G. , AMRE D. , MIDHA V. , SOOD A. , SEIDMAN E. , THELMA B. K.
Published: October 2008

Background  Three common disease susceptibility variants in the NOD2 gene are associated with inflammatory bowel disease in Caucasians, but not in Asians.

Aim  To screen for NOD2 variants and examine susceptibility for inflammatory bowel disease in North Indians.

Methods  A case–control study was carried out in Punjab, India. Confirmed cases of ulcerative colitis and Crohn’s disease and healthy controls matched for age (±10 years) and ethnicity were studied. Besides genotyping the three disease susceptibility variants (SNP8, SNP12 and SNP13), all 12 exons were resequenced to determine other potential single nucleotide polymorphisms.

Results  Two hundred and ninety‐eight ulcerative colitis, 25 Crohn’s disease and 262 controls were investigated. Median age (range) at diagnosis was 39 (7–78) years for ulcerative colitis and 40 (32–58) years for Crohn’s disease. All three disease susceptibility variants were either monomorphic or rare in the population. Sequencing (n = 30) revealed two single nucleotide polymorphisms: SNP5 (268 Pro/Ser) and rs2067085 (178 Ser/Ser). The frequency of SNP5 was higher among ulcerative colitis (17% vs. 12% in controls, P = 0.016) and Crohn’s disease cases (20% vs. 12%, P = 0.28). SNP5 carriers had elevated risks for ulcerative colitis (OR = 1.72, 95% CI = 1.17–2.52, P = 0.005).

Conclusions  The absence of known inflammatory bowel disease susceptibility variants and potential associations between SNP5 and ulcerative colitis in North Indians suggests the presence of allelic heterogeneity for ulcerative colitis susceptibility.
Relevance of mild ineffective oesophageal motility (IOM) and potential pharmacological reversibility of severe IOM in patients with gastro‐oesophageal reflux disease
Authors: FORNARI F. , BLONDEAU K. , DURAND L. , REY E. , DIAZ‐RUBIO M. , DE MEYER A. , TACK J. , SIFRIM D.
Published: October 2008

Background  Several studies showed high prevalence of ineffective oesophageal motility (IOM) in gastro‐oesophageal reflux disease (GERD) and suggested an important role for ineffective oesophageal motility in increased acid exposure. However, impedance‐manometric studies proposed that only severe ineffective oesophageal motility might affect oesophageal clearance.

Objectives  (i) To re‐assess the relevance of mild IOM in GERD and (ii) to test the reversibility of IOM.

Methods  Oesophageal motility, clearance and acid exposure were assessed in 191 GERD patients: 99 without IOM; 58 with mild IOM (30–80% ineffective contractions) and 34 with severe IOM (>80% ineffective contractions). In 30 patients with oesophagitis, the potential reversibility of IOM was evaluated with edrophonium intravenously.

Results  Patients with mild IOM had identical oesophageal clearance and acid exposure in comparison with those without IOM. Patients with severe IOM had a higher probability of prolonged supine clearance and acid exposure [odds ratio: 2.88 (1.16–7.17); 2.48 (0.99–6.17)]. This effect was independent of the presence of hiatal hernia and male sex. Severe IOM could be transiently reverted in 55% of patients.

Conclusions  Mild IOM does not affect oesophageal clearance. Only severe IOM is associated with prolonged clearance and acid exposure, particularly in supine periods. The edrophonium test might be useful to predict severe IOM response to prokinetic medications.