bluuebunny/crossref_metadata_2025 huggingface dataset:
Semi-presidentialism, Cohabitation and the Collapse of Electoral Democracies, 1990–2008
Authors: Elgie Robert
Published: December 2009

Semi-presidentialism is the situation where a constitution makes provision for both a directly elected fixed-term president and a prime minister and cabinet who are responsible to the legislature. A common argument against the adoption of a semi-presidential constitution by a new democracy is the problem of cohabitation – where a president from one party holds power at the same time as a prime minister from an opposing party and where the president's party is not represented in the cabinet. The concern is that cohabitation creates competing power centres within the executive that are dangerous for young democracies. This article shows that cohabitation has been directly associated with the collapse of a young democracy in only one case. Moreover, by specifying the conditions under which cohabitation can occur, we also show that the threat of cohabitation has been associated with collapse in only one further case. We suggest that this is so because cohabitation refers to a very specific situation that can only occur under a certain combination of circumstances that can often be avoided. Overall, we show that there is little evidence to support one of the most well-known and long-standing arguments against semi-presidentialism. Thus, while semi-presidentialism may indeed be perilous for new democracies, we conclude that it is perilous for reasons other than the problem of cohabitation.
Co-optation and Resistance in Thailand's Muslim South: The Changing Role of Islamic Council Elections
Authors: McCargo Duncan
Published: December 2009

During times of violent conflict, states may closely scrutinize the loyalty of those who lead minority religious communities. November 2005 saw elections for Islamic councils in Thailand's three southern border provinces. The Muslim-majority subregion had experienced escalating political violence since January 2004. Allegations of electoral manipulation were rife; the elections were proxy struggles between the Thai state and potential opponents. This article positions these elections within wider debates about the nature of the relationship between Islam and the state, in Thailand and beyond. It argues that politicizing Islamic organizations may be a dangerous game for states and elite actors to play.
Focused Vascular Access Education to Reduce the Use of Chronic Tunneled Hemodialysis Catheters: Results of a Network Quality Improvement Initiative
Authors: Kulawik Deuzimar , Sands Jeffrey J. , Mayo Kelly , Fenderson Mary , Hutchinson Janet , Woodward Cindy , Gore Sally , Asif Arif
Published: December 2009

Tunneled hemodialysis catheters (TDCs) carry the highest mortality risk for chronic hemodialysis patients of any access modality. Recent data have emphasized that mortality risk decreases when these devices are discontinued. Herein, we present the results of a gap‐reduction assisted catheter elimination strategy that Network 7 employed as its quality improvement initiative to reduce the use of TDCs. Hemodialysis facilities with high catheter rates (>90 days) were identified. Interventions included focused vascular access education, monthly follow‐up and site visits to assist the facility catheter reduction program. The “goal” of interventions was defined as the gap‐reduction of 50% from the baseline catheter rate to the Network mean plus sustainability of catheter reduction for at least 3 consecutive months. Fifteen facilities (n = 891) were identified with high catheter rates (31.5 ± 5.3%) in May 2006. Interventions resulted in a catheter reduction to 12.2 ± 8.5% in May 2007 (p = 0.0001). Five of the 15 facilities (n = 280) achieved the goal (preintervention = 31.7 ± 5.3%, postintervention = 8.7 ± 2.8%, p = 0.001). In May 2007, eight additional facilities (n = 438) with high catheter rates (31.7 ± 7.8%) were added to the 10 that failed to achieve the goal previously. Interventions employed in these 18 facilities (n = 1,049) resulted in catheter reduction in all (preintervention = 31.5 ± 5.5%, postintervention = 16.2 ± 5%, p = 0.01). Five of these 18 met the goal (preintervention = 32 ± 8%, postintervention = 5.9 ± 4.3%). Overall, all 23 facilities (n = 1,329) demonstrated catheter reduction postintervention (preintervention = 31.6 ± 6%, postintervention = 13.9 ± 6%, p = 0.001), and 10/23 (43%) met the project goal (preintervention = 31.9 ± 6%, postintervention = 7.3 ± 4%, p = 0.002). Medical director’s involvement had a positive impact in achieving the goal (p = 0.003). The presence or absence of a vascular access coordinator did not affect catheter reduction. The results of this analysis reveals that an organized approach implemented by an ESRD Network can have a significant impact in reducing catheter use.
Innovation in the Treatment of Uremia: Proceedings from the Cleveland Clinic Workshop: Cellular Therapy of Kidney Diseases
Authors: Imai Naohiko , Kaur Tarundeep , Rosenberg Mark E. , Gupta Sandeep
Published: December 2009

The understanding of cellular sources of kidney regeneration has rapidly evolved in the last decade. It is now believed that regeneration occurs predominantly from cells that reside within the injured kidney, with minimal contribution from extra‐renal cells. We now know that improved kidney regeneration seen following exogenous administration of stem cells occur predominantly by noncellular paracrine mechanisms. Of all extra‐renal stem cells, mesenchymal stem cells (MSC) are the most promising stem cell type for treating kidney diseases. There is an ongoing clinical trial evaluating safety and efficacy of MSC in treating acute kidney injury (AKI). Results of this trial are expected to bring use of MSC closer to the clinical realm. An improved understanding of the small molecules that facilitate kidney regeneration and are secreted by MSC will likely result in the development of new therapies for treating AKI. Identification of adult stem cell markers will result in improved understanding of pathophysiology of kidney diseases and could lead to the development of new cellular therapies. Directed differentiation of stem cells into desired cell types such as erythropoietin producing cells will allow selective replacement of lost kidney function. Cell‐based therapies for patients with chronic kidney disease are presently in proof‐of‐principle stage and are expected to evolve in the coming years with improved understanding of stem cell biology. Technological advancement in cellular therapy is expected to provide improved therapeutic options for patients with kidney diseases in the near future.
Innovation in the Treatment of Uremia: Proceedings from the Cleveland Clinic Workshop: Sorbents in Treatment of Uremia: A Short History and a Great Future
Authors: Ash Stephen R.
Published: December 2009

To regenerate dialysate in hemodialysis for kidney failure, it is necessary to remove all uremic toxins, avoid excessive removal of various electrolytes, and supply beneficial components such as bicarbonate. Surprisingly, a simple collection of components can accomplish this task very well: charcoal, urease, cation exchanger, and anion exchanger. From the early days of use of the Redy system and the Sorb cartridge, improvements have been made both in machine design and column chemical function. This article describes the chemical function of the Sorb cartridge, recent improvements, and the methods to predict the chemical function of the column. It also describes a number of improvements made in dialysis machines using sorbent regeneration of the dialysate. Some ongoing improvements in sorbent chemistry are also described.
Innovation in the Treatment of Uremia: Proceedings from the Cleveland Clinic Workshop: Uremic Toxicity, Oxidative Stress, and Hemodialysis as Renal Replacement Therapy
Authors: Himmelfarb Jonathan
Published: December 2009

Patients with uremia are subject to greatly increased cardiovascular risk that cannot be completely explained by traditional cardiovascular risk factors. An increase in oxidative stress and inflammation has been proposed as contributory nontraditional uremic cardiovascular risk factors. Oxidative stress reflects the balance between oxidant generation and antioxidant defense mechanisms. Reduction/oxidation (redox) reactions may result in a stochastic process leading to oxidation of neighboring macromolecules. However, in many instances the reactive oxygen species target particular amino acid residues or lipid moieties. This provides a mechanism by which increased oxidative stress and/or alteration of antioxidant mechanisms can alter cell signaling. In individuals with advanced chronic kidney disease, the redox balance is not in equilibrium and is tipped toward oxidation resulting in the dysregulation of cellular process with subsequent vascular and tissue injury. In this review, the major oxidant and antioxidant pathways and the biomarkers to assess redox status in uremia are discussed, as well as the data linking the pathogenesis of oxidative stress, inflammation, cardiovascular events, and the progressive loss of kidney function in chronic kidney disease.
Innovation in the Treatment of Uremia: Proceedings from the Cleveland Clinic Workshop: Causes of Dysregulation of Lipid Metabolism in Chronic Renal Failure
Authors: Vaziri Nosratola D.
Published: December 2009

End‐stage renal disease (ESRD) is associated with accelerated atherosclerosis and premature death from cardiovascular disease. These events are driven by oxidative stress inflammation and lipid disorders. ESRD‐induced lipid abnormalities primarily stem from dysregulation of high‐density lipoprotein (HDL), triglyceride‐rich lipoprotein metabolism, and oxidative modification of lipoproteins. In this context, production and plasma concentration of Apo‐I and Apo‐II are reduced, HDL maturation is impaired, HDL composition is altered, HDL antioxidant and anti‐inflammatory functions are depressed, clearance of triglyceride‐rich lipoproteins and their atherogenic remnants is impaired, their composition is altered, and their plasma concentration is elevated in ESRD. The associated defect in HDL maturation is largely caused by acquired lecithin‐cholesterol acyltransferase deficiency while its triglyceride enrichment is due to hepatic lipase deficiency. Hypertriglyceridemia, abnormal composition, and impaired clearance of triglyceride‐rich lipoproteins and their remnants are mediated by down‐regulation of lipoprotein lipase, hepatic lipase, very low‐density lipoprotein (VLDL) receptor, and LDL receptor‐related protein, relative reduction in ApoC‐II/ApoC‐III ratio, up‐regulation of acyl‐CoA cholesterol acyltransferase, and elevated plasma level of cholesterol ester‐poor prebeta HDL. Impaired clearance and accumulation of oxidation‐prone VLDL and chylomicron remnants and abnormal LDL composition in the face of oxidative stress and inflammation favors their uptake by macrophages and resident cells in the artery wall. The effect of heightened influx of lipids is compounded by impaired HDL‐mediated reverse cholesterol transport leading to foam cell formation which is the central event in atherosclerosis plaque formation and subsequent plaque rupture, thrombosis, and tissue damage.
Innovation in the Treatment of Uremia: Proceedings from the Cleveland Clinic Workshop: Bottom‐Up Nanotechnology: The Human Nephron Filter
Authors: Nissenson Allen R.
Published: December 2009

Over one million patients worldwide have end‐stage renal disease and require dialysis or kidney transplantation. Despite the availability of these forms of renal replacement therapy for nearly four decades, mortality and morbidity are high and patients often have a poor quality of life. We have developed a human nephron filter (HNF) utilizing bottom‐up nanotechnology that would eventually make feasible a continuously functioning, wearable or implantable artificial kidney. The device consists of two membranes operating in series within one device cartridge. The first membrane mimics the function of the glomerulus, using convective transport to generate a plasma ultra filtrate, which contains all solutes approaching the molecular weight of albumin. The second membrane mimics the function of the renal tubules, selectively reclaiming designated solutes to maintain body homeostasis. No dialysis solution is used in this device. The HNF has been computer modeled, and operating 12 hour per day, 7 days per week the HNF provides the equivalent of 30 ml/min glomerular filtration rate (compared to half that amount for conventional thrice‐weekly hemodialysis). The HNF system, by eliminating dialysate and utilizing a novel membrane system created through applied nanotechnology, represents a breakthrough in renal replacement therapy based on the functioning of native kidneys. The enhanced solute removal and wearable design should substantially improve patient outcomes and quality of life.
Technologies in Use for Second Language Learning
Authors: LEVY MIKE
Published: December 2009

This article describes the technologies in use for second language learning, in relation to the major language areas and skills. In order, these are grammar, vocabulary, reading, writing, pronunciation, listening, speaking, and culture. With each language area or skill, the relevant technologies are discussed with examples that illustrate how practitioners have employed the technological tool to help assist the language learner. In each case, the examples are chosen to highlight current points of focus and priorities, to give an indication of successful applications, and, in some cases, to draw attention to areas in which further work is required before a viable application is achieved.
Computer‐Assisted Language Learning Authoring Issues
Authors: OTTO SUE E. K. , PUSACK JAMES P.
Published: December 2009

Computer‐assisted language learning (CALL) authoring refers to a wide variety of creative development activities using software tools that run the gamut from simple templates (easy‐to‐use predefined forms into which content is typed) to complex authoring environments (flexible but harder‐to‐use systems, requiring advanced skills and a great deal of time and resources). Authoring choices range from generic tools (productivity software, course management systems, general‐purpose authoring systems) to authoring templates and courseware authoring/management systems specifically for foreign languages. Good CALL authoring tools enable teachers to produce software specific to the needs of language teaching and learning, meeting high standards of suitability, interactivity, use of media, record keeping, ease of use, and accessibility. Teachers face significant barriers to CALL development: brief life span of software and lack of time, resources, training, and professional recognition. A shift in CALL authoring away from traditional tutorial CALL programs has taken place with the evolution of the Web, which has given rise to many services and applications that facilitate online communication, collaboration, information sharing, social networking, and virtual simulations. In a future when most instructional activities involve some form of computer/digital technology, we may well abandon the terms CALL and authoring for other more nuanced designations.
Developments and Challenges in the Use of Computer‐Based Testing for Assessing Second Language Ability
Authors: OCKEY GARY J.
Published: December 2009

Computer‐based testing (CBT) to assess second language ability has undergone remarkable development since Garret (1991) described its purpose as “the computerized administration of conventional tests” in The Modern Language Journal. For instance, CBT has made possible the delivery of more authentic tests than traditional paper‐and‐pencil tests. CBT has also made it possible to more reliably, practically, and almost instantaneously score essays, oral speech samples, and other types of test responses. Unfortunately, however, due to a number of unresolved problems, CBT has failed to realize its anticipated potential. CBT has limited usability because systems that ensure test and score security have yet to be developed. Computer‐adaptive testing, one of the most promising areas of CBT has not met expectations because of failure to solve problems with the statistical techniques on which it is based and the lack of resources necessary to implement it in most assessment contexts. In spite of these and other limitations, given the growing capability of CBT to deliver more authentic tests than paper‐and‐pencil, its use for assessing second language ability will undoubtedly continue to expand.
Using Electronic Portfolios for Second Language Assessment
Authors: CUMMINS PATRICIA W. , DAVESNE CÉLINE
Published: December 2009

Portfolio assessment as developed in Europe presents a learner‐empowering alternative to computer‐based testing. The authors present the European Language Portfolio (ELP) and its American adaptations, LinguaFolio and the Global Language Portfolio, as tools to be used with the Common European Framework of Reference for languages and the American national standards, which reference the American Council on the Teaching of Foreign Languages proficiency scale. The ELP's characteristic three‐part format, consisting of a language passport, a language biography, and a dossier, builds on earlier research on portfolios and second language assessment. The portfolios' qualitative assessment complements other types of quantitative assessment measures. The authors also explore the unique affordances offered by electronic portfolios to connect teaching and learning to assessment, discuss the effectiveness of portfolios as an assessment tool, and point to future directions for e‐portfolio research and development for language learning.
A Novel 3‐D Reconstruction System for the Assessment of Bifurcation Lesions Treated by the Mini‐Crush Technique
Authors: GALASSI ALFREDO R. , TOMASELLO SALVATORE D. , CAPODANNO DAVIDE , SEMINARA DARIO , CANONICO LUCIANA , OCCHIPINTI MICHELE , TAMBURINO CORRADO
Published: December 2009

Background:

Conventional two‐dimensional angiography lacks the ability to properly image the true bifurcation geometry, and its percutaneous coronary intervention‐induced changes in the clinical setting.

Methods and Results:

A novel three‐dimensional reconstruction system was investigated by retrospectively analyzing 39 lesions in 35 consecutive patients with coronary bifurcation disease treated with the mini‐crush technique. At baseline, significant correlations were proved between two‐ and three‐dimensional systems in terms of either reference vessel diameter (R2= 0.68 and 0.29 for main and side branches, respectively), minimum lumen diameter (R2= 0.73 and 0.36), stenosis diameter (R2= 0.69 and 0.29), and lesion length (R2= 0.48 and 0.58). These results were consistent with those observed after the procedure and at 8‐month follow‐up. Lesion length was significantly longer with the three‐dimensional compared to the two‐dimensional system for both main and side branches (P < 0.001, and P = 0.007, respectively).

Conclusions:

The three‐dimensional quantitative reconstruction system may provide accurate evaluation of the complex curvilinear structure of bifurcation lesions when using a double stent technique. (J Interven Cardiol 2010;23:46–53)
Lesser double‐collared sunbirdsNectarinia chalybeado not compensate for hatching asynchrony by adjusting egg mass or yolk androgens
Authors: Eising Corine M. , Robles Raquel , Lasthuizen Maarten , Groothuis Ton G. G.
Published: December 2009

Substantial amounts of maternal androgens are found in birds’ eggs and have been shown to benefit offspring development. Within‐clutch patterns of increasing androgen concentrations over the laying sequence are often hypothesized to compensate for the negative effects of hatching asynchrony. However, detrimental effects to offspring fitness of exposure to high yolk androgen levels have also been demonstrated. This suggests that mothers should forego these costs to their offspring when the need for compensation for hatching asynchrony is low or when alternative compensatory strategies, e.g. in terms of increasing egg mass, are available. Here we show that in the south‐temperate lesser double‐collared sunbirdNectarinia chalybea, a species with hatching asynchrony but also with high survival of last‐hatched chicks, mothers do not deposit resources differentially in terms of either yolk androgen concentration or egg mass across the laying sequence. We discuss to what extend this challenges the original explanation of within‐clutch variation in these egg parameters and offer some explanation for their between‐clutch variation which was related to female body mass.
Do adult and juvenile dunlins Calidris alpina form randomly mixed flocks during fall migration?
Authors: Henningsson Sara S. , Karlsson Håkan
Published: December 2009

Many northerly breeding shorebird species show a separation in timing of adult and juvenile migration. If, in addition to genetic control of migration, learning from experienced conspecifics is advantageous, juveniles should join adult birds during their first fall migration when possible. We here present a method to test if juveniles mix with adults during the period of overlap during southward migration, using dunlin Calidris alpina migrating over southern Sweden as an example. While taking timing differences between age classes into account, we compare flock compositions observed in the field against randomized flock‐compositions based on the pool of available individuals derived from the field data. During both the early, the adult‐dominated, and later, the juvenile‐dominated, part of the season, age classes segregate. Applied to other shorebird species, our method could be used in a comparative sense to evaluate the potential for social learning of migration routes.
Diurnal patterns of body mass change during stopover in a migrating songbird, the northern wheatear Oenanthe oenanthe
Authors: Delingat Julia , Dierschke Volker , Schmaljohann Heiko , Bairlein Franz
Published: December 2009

In migrating birds body mass change during stopover is often used to evaluate the quality of a stopover site. Because such body mass changes are difficult to survey in migrating birds various methods were developed to allow the analysis of larger sample sizes. In this article we present patterns of repeated body mass measurements of individual birds and the commonly used method of plotting body mass over time of day of birds being trapped only once. We repeatedly measured body mass of 89 northern wheatears Oenanthe oenanthe, when stopping over at a small island in the North Sea. A balance beneath bowls offering mealworms ad libitum was used to weigh their body mass several times per day. From these repeated body mass measurements we have generated a general model of daily mass gain patterns and nocturnal mass loss. Daily body mass changes followed in general an asymptotic curve progression with highest gain rates in the morning hours. During night birds lost about 5% of the evening body mass irrespectively of local wind force, temperature, night length or precipitation. By plotting first traps by time of day no such pattern in body mass increase was evident. Even in a simulated situation with repeatedly measured birds increasing their body mass, no such body mass increase could be shown when plotting one randomly chosen measurement of each bird per day. This “first‐traps‐by‐time‐of‐day‐method” depends highly on sample size, overall mass increase and the mass variation between individuals and will produce a traceable body mass increase only under certain circumstances.
Analysis of multilocus DNA reveals hybridization in a contact zone betweenEmpidonaxflycatchers
Authors: Rush Andrew C. , Cannings Richard J. , Irwin Darren E.
Published: December 2009

Contact zones between recently diverged taxa offer unique opportunities to test whether the forms are reproductively isolated and therefore distinct species. The Pacific‐slope flycatcherEmpidonax difficilisand Cordilleran flycatcherEmpidonax occidentalisare closely related taxa that were officially separated into two species in 1989, a treatment that has been controversial due to reports of phenotypically intermediate birds across the southern interior of British Columbia and Alberta. We present the first analysis of molecular variation across this region, in order to determine whether there is genetic introgression between the taxa. Allopatric populations of Pacific‐slope and Cordilleran flycatchers belong to distinct mitochondrial clades, and all of the individuals sampled in interior southwestern Canada have the Pacific‐slope haplotype. In contrast, variation in nuclear DNA (AFLPs) indicates hybridization between Pacific‐slope and Cordilleran flycatchers in this region. We suggest that the discordance between the mitochondrial and nuclear markers most likely results from stochastic loss of Cordilleran mitochondrial haplotype lineages facilitated by asymmetries in mating due to earlier arrival and greater abundance of Pacific‐slope flycatchers in the contact zone. The discovery of hybridization between Pacific‐slope and Cordilleran flycatchers in southwestern Canada may call into question the decision to split them into two species. On the other hand, allopatric populations are genetically distinct in both mitochondrial and nuclear DNA, and the hybridization might not affect populations outside of the contact zone. This study highlights the importance of employing multiple genetic markers in studies of contact zones between closely related species.
Relationships of the New Guinean songbird genera Amalocichla and Pachycare based on mitochondrial and nuclear DNA sequences
Authors: Norman Janette A. , Boles Walter E. , Christidis Les
Published: December 2009

The New Guinean songbird fauna contains numerous enigmatic species and genera whose phylogenetic affinities have been difficult to resolve. Two such genera are ditypic Amalocichla and monotypic Pachycare. Here we obtained DNA sequences of two nuclear gene regions and a mitochondrial gene to ascertain the phylogenetic positions of these genera. Amalocichla was identified as the sister of the Australasian robins (Petroicidae) contrary to most recent classifications, which align it with the New Guinean mouse‐warblers Crateroscelis in the family Acanthizidae. The morphological characters used to place Amalocichla in the Acanthizidae appear to be convergent and linked to ground‐living adaptations. Pachycare was found to be most closely related to the Acanthizidae and not to the Pachycephalidae, corvine assemblage, or Petroicidae, as most commonly assumed. Morphological and behavioural characters support the molecular data in this conclusion. Previous taxonomic placements appear to have been based on superficial similarities in plumage coloration and vocal characterizations.
Does weather affect biting fly abundance in avian nests?
Authors: Martínez‐de la Puente Josué , Merino Santiago , Lobato Elisa , Rivero‐de Aguilar Juan , Del Cerro Sara , Ruiz‐de‐Castañeda Rafael , Moreno Juan
Published: December 2009

Environmental factors may strongly affect avian‐biting fly interactions in different ways because insects are heterothermic organisms that depend greatly on environmental variables to activate their metabolism and behaviour. We studied the effects of weather on both blackfly (Simuliidae) and biting midgeCulicoides(Ceratopogonidae) abundance in nests of three passerine species: blue titsCyanistes caeruleus, great titsParus majorand pied flycatchersFicedula hypoleuca,breeding in the same area. We controlled for different host‐related factors (hatching date, brood size and host species). Blackfly abundance was negatively related to minimum temperature. In addition, blackfly and biting midge abundances were negatively affected by wind speed measured at 07.00 h, but blackfly abundance was positively associated to wind speed at 18.00 h. We found higher blackfly and biting midge abundances in nests with larger broods breeding later in the season, and significantly higher biting midge abundance in pied flycatcher nests as compared to tit nests. These results represent, to our knowledge, the first report of both environmental and host‐related effects on haematophagous fly abundance in the nests of wild hole‐nesting birds.
Human bone marrow stroma stem cell distribution in calcium carbonate scaffolds using two different seeding methods
Authors: Zhu Huiyong , Schulz Jutta , Schliephake Henning
Published: December 2009

Objective: The aim of this study was to develop a method for the determination of the three‐dimensional (3D) distribution of cells in mineralized scaffolds and to compare the effect of two different methods of cell seeding of human bone marrow stroma cells (hBMSCs) in long‐term cultures.

Materials and methods: hBMSCs were seeded into CaCO3 scaffolds by droplet seeding using culture medium with and without the addition of fibrin. After 2, 7, 14, and 21 days of culture, the constructs were embedded into methylmethacrylate and serially sectioned using undecalcified thick section technology. Sections were serially scanned from the surface to the bottom of the scaffolds and DAPI‐stained cells were automatically counted in each section using structured illumination fluorescence microscopy (FM) with serial optical sectioning and image analysis software.

Results: The data showed that the seeding efficiency was significantly higher in the scaffolds seeded with the addition of fibrin. Moreover, the number of cells increased to higher levels and remained higher for longer periods with the use of the fibrin matrix, whereas cells seeded in the medium suspension exhibited a sharp decrease after the first week of cultivation. There were distinct differences in the 3D cell distribution between the center and the periphery of the scaffolds. The use of a fibrin matrix was associated with a more uniform cell distribution 1 and 2 weeks after seeding in different levels (center vs. periphery: P>0.05), whereas cells in the medium solution group accumulated at the periphery of the scaffolds.

Conclusions: In conclusion, automated serial optical sectioning using structured illumination FM can assess cell numbers and the 3D distribution of hBMSCs in mineralized scaffolds. This allows for a detailed analysis of the effect of different in vitro procedures used for cell seeding. The use of fibrin during seeding increases seeding efficiency and enhances both proliferation and cell survival in the central parts of the scaffolds.

To cite this article:
 Zhu H, Schulz J, Schliephake H. Human bone marrow stroma stem cell distribution in calcium carbonate scaffolds using two different seeding methods. Clin. Oral Impl. Res. 21, 2010; 182–188. doi: 10.1111/j.1600‐0501.2009.01816.x
Novel ceramic bone replacement material CeraBall® seeded with human mesenchymal stem cells
Authors: Douglas Timothy , Liu Qin , Humpe Andreas , Wiltfang Jörg , Sivananthan Sureshan , Warnke Patrick H.
Published: December 2009

Objectives: Hydroxyapatite (HA) and tricalcium phosphate (TCP) are two very common ceramic materials for bone replacement. A recently developed material for bone replacement is CeraBall®, which is a mixed HA–TCP scaffold available as porous spherical scaffolds of diameter 4 and 6 mm. Before their use as bone replacement materials in vivo, in vitro testing of these scaffolds is necessary. The goal of this study was to characterise 4 and 6 mm CeraBall® scaffolds in vitro with a view to their future use as bone replacement materials.

Materials and methods: The proliferation of human mesenchymal stromal cells (hMSCs) seeded on CeraBall® scaffolds was evaluated quantitatively using the WST [Water soluble tetrazolium ((4‐[3‐(4‐ Iodophenyl)‐2‐(4‐nitrophenyl)‐2H‐5‐tetrazolio]‐1, 3‐benzene disulfonate)] test and qualitatively by scanning electron microscopy (SEM). In addition, the standard MTT [(3‐(4, 5‐Dimenthylthiazol‐2‐Y1)‐2, 5‐Diphenyltetrazolium bromide)] biocompatibility test and cell vitality staining were performed using hMSCs. CeraBall® scaffolds were also tested for their mechanical properties.

Results: SEM and WST test results showed that hMSCs proliferated on CeraBall® scaffolds over the course of 9 days. Proliferation was similar to that seen on tissue culture polystyrene (control). Cells showed a well‐spread morphology and formed ‘sheets’ on the surface of scaffolds. Invasion of pores was observed. Good biocompatibility was demonstrated by MTT test results and cell vitality staining. Scaffolds of both 4 and 6 mm were able to withstand compressive loads of 5 N.

Conclusions: CeraBall® scaffolds show good biocompatibility in vitro for hMSCs. This opens the way for in vivo applications.

To cite this article:
 Douglas T, Liu Q, Humpe A, Wiltfang J, Sivananthan S, Warnke PH. Novel ceramic bone replacement material CeraBall® seeded with human mesenchymal stem cells. Clin. Oral Impl. Res. 21, 2010; 262–267. doi: 10.1111/j.1600‐0501.2009.01818.x
Diagnosis of implant stability and its impact on implant survival: a prospective case series study
Authors: Rodrigo Daniel , Aracil Luis , Martin Conchita , Sanz Mariano
Published: December 2009

Objectives: To assess the predictability of implant stability assessment either clinically or by resonance frequency analysis (RFA).

Material and methods: This prospective case series study evaluated 4114 consecutive SLA Straumann® implants in two private clinics. Primary stability was classified in four categories, depending on the degree of implant rotation when tightening the healing cap: A (no rotation at all), B (light rotation with a feeling of resistance), C (rotation without resistance) and D (rotation and lateral oscillation). In one clinic (n=542 implants), RFA method was also used the day of the surgery (Osstell 1) and at restoration placement (Osstell 2). Survival rates were stratified according to the clinical classification categories using life table analysis. The association between Osstell 1 and 2 and the clinical classification was tested with ANOVA.

Results: 3899 implants were classified as stable (A) and 213 as unstable (B–D). Their survival rates were 99.1% and 97.2%, respectively. The unstable implants were further classified in B (158), C (51) and D (4), with survivals of 98.1%, 94.1% and 100%, respectively, being these differences statistically significant (P<0.009). Using Osstell®, implants were stratified in two groups according to a predefined threshold of implant stability quotient (≥60). At the Osstell 1 measurement there was no significant association between primary stability and implant survival (P<0.753). In Osstell 2, however, the association was significant (P<0.001).

Conclusions: Only secondary stability RFA values were able to significantly predict implant outcomes, but not primary stability values. There was a good correlation between RFA and the proposed clinical classification of primary stability.

To cite this article:
 Rodrigo D, Aracil L, Martin C, Sanz M. Diagnosis of implant stability and its impact on implant survival: a prospective case series study. Clin. Oral Impl. Res. 21, 2010; 255–261. doi: 10.1111/j.1600‐0501.2009.01820.x
Melatonin improves sleep and reduces nitrite in the exhaled breath condensate in cystic fibrosis – a randomized, double‐blind placebo‐controlled study
Authors: De Castro‐Silva Claudia , De Bruin Veralice Meireles Sales , Cunha Geanne Matos Andrade , Nunes Deuzilane Muniz , Medeiros Camila Andrade Mendes , De Bruin Pedro Felipe Carvalhedo
Published: December 2009

Abstract:  Cystic fibrosis (CF) is a chronic progressive disorder characterized by repeated episodes of respiratory infection. Impaired sleep is common in CF leading to reduced quality of life. Melatonin, a secretory product of the pineal gland, has an important function in the synchronization of circadian rhythms, including the sleep–wake cycle, and has been shown to possess significant anti‐oxidant properties. To evaluate the effects of exogenous melatonin on sleep and inflammation and oxidative stress markers in CF, a randomized double‐blind, placebo‐controlled study initially involving 20 patients with CF was conducted. One individual failed to conclude the study. All subjects were clinically stable when studied and without recent infectious exacerbation or hospitalization in the last 30 days. Groups were randomized for placebo (n = 10; mean age 12.1 ± 6.0) or 3 mg melatonin (n = 9; mean age 16.6 ± 8.26) for 21 days. Actigraphy was performed for 6 days before the start of medication and in the third week (days 14–20) of treatment. Isoprostane and nitrite levels were determined in exhaled breath condensate (EBC) at baseline (day 0) and after treatment (day 21). Melatonin improved sleep efficiency (P = 0.01) and tended to improve sleep latency (P = 0.08). Melatonin reduced EBC nitrite (P = 0.01) but not isoprostane. In summary, melatonin administration reduces nitrite levels in EBC and improves sleep measures in clinically stable CF patients. The failure of melatonin to reduce isoprostane levels may have been a result of the low dose of melatonin used as a treatment.
Synergistic antitumor effect of melatonin with several chemotherapeutic drugs on human Ewing sarcoma cancer cells: potentiation of the extrinsic apoptotic pathway
Authors: Casado‐Zapico Sara , Rodriguez‐Blanco Jezabel , García‐Santos Guillermo , Martín Vanesa , Sánchez‐Sánchez Ana M. , Antolín Isaac , Rodriguez Carmen
Published: December 2009

Abstract:  Ewing sarcoma, the second most frequent bone cancer type, affects mainly adolescents, who have a survival of 50% 5 yr after diagnosis. Current treatments include a combination of surgery, radiotherapy and chemotherapy, which present potential serious side effects. Melatonin, a natural molecule without relevant side effects, has been previously shown to induce cytotoxicity in SK‐N‐MC cells, a Ewing sarcoma cell line. Here, we found that there is a synergy in the antitumor effect when melatonin (50 μm–1 mm) is combined with vincristine at the concentration of 5–10 nm or with ifosfamide at the range of 100 μm–1 mm. This synergism is due to the potentiation of cell death, particularly to the potentiation of apoptosis, i.e., mainly the extrinsic apoptotic pathway. There is a significant increase in the activation of caspase‐3, ‐8, ‐9 and Bid when melatonin is combined with vincristine or ifosfamide compared to the individual treatments. Finally, there is also a potentiation of the early free radical production, likely dependent on the extrinsic apoptosis pathway activation, when the drugs are combined with melatonin. Other proteins which are related to this pathway including mitogen‐activated protein kinase or protein kinase B/Akt are not involved in apoptosis induced by these agents separately or when combined. The results shown here together with the facts that: (i) no relevant side effects have been reported for melatonin and (ii) melatonin has a cytoprotective effect on noncancer cells, opens the door for a new approach in the treatment of the Ewing sarcoma family of tumors.
Malaria: therapeutic implications of melatonin
Authors: Srinivasan Venkataramanujan , Spence D. Warren , Moscovitch Adam , Pandi‐Perumal Seithikurippu R. , Trakht Ilya , Brown Gregory M. , Cardinali Daniel P.
Published: December 2009

Abstract: Malaria, which infects more than 300 million people annually, is a serious disease. Epidemiological surveys indicate that of those who are affected, malaria will claim the lives of more than one million individuals, mostly children. There is evidence that the synchronous maturation ofPlasmodium falciparum, the parasite that causes a severe form of malaria in humans andPlasmodium chabaudi, responsible for rodent malaria, could be linked to circadian changes in melatonin concentration. In vitro melatonin stimulates the growth and development ofP. falciparumthrough the activation of specific melatonin receptors coupled to phospholipase‐C activation and the concomitant increase of intracellular Ca2+. The Ca2+signaling pathway is important to stimulate parasite transition from the trophozoite to the schizont stage, the final stage of intraerythrocytic cycle, thus promoting the rise of parasitemia. Either pinealectomy or the administration of the melatonin receptor blocking agent luzindole desynchronizes the parasitic cell cycle. Therefore, the use of melatonin antagonists could be a novel therapeutic approach for controlling the disease. On the other hand, the complexity of melatonin’s action in malaria is underscored by the demonstration that treatment with high doses of melatonin is actually beneficial for inhibiting apoptosis and liver damage resulting from the oxidative stress in malaria. The possibility that the coordinated administration of melatonin antagonists (to impair the melatonin signal that synchronizesP. falciparum) and of melatonin in doses high enough to decrease oxidative damage could be a novel approach in malaria treatment is discussed.
Sirtuins, melatonin and circadian rhythms: building a bridge between aging and cancer
Authors: Jung‐Hynes Brittney , Reiter Russel J. , Ahmad Nihal
Published: December 2009

Abstract:  Histone deacetylases (HDAC) have been under intense scientific investigation for a number of years. However, only recently the unique class III HDAC, sirtuins, have gained increasing investigational momentum. Originally linked to longevity in yeast, sirtuins and more specifically, SIRT1 have been implicated in numerous biological processes having both protective and/or detrimental effects. SIRT1 appears to play a critical role in the process of carcinogenesis, especially in age‐related neoplasms. Similarly, alterations in circadian rhythms as well as production of the pineal hormone melatonin have been linked to aging and cancer risk. Melatonin has been found act as a differentiating agent in some cancer cells and to lower their invasive and metastatic status. In addition, melatonin synthesis and release occurs in a circadian rhythm fashion and it has been linked to the core circadian machinery genes (Clock, Bmal1, Periods, and Cryptochromes). Melatonin has also been associated with chronotherapy, the timely administration of chemotherapy agents to optimize trends in biological cycles. Interestingly, a recent set of studies have linked SIRT1 to the circadian rhythm machinery through direct deacetylation activity as well as through the nicotinamide adenine dinucleotide (NAD+) salvage pathway. In this review, we provide evidence for a possible connection between sirtuins, melatonin, and the circadian rhythm circuitry and their implications in aging, chronomodulation, and cancer.
A Seasonal Inverse Almost Ideal Demand System for North American Fresh Tomatoes
Authors: Grant Jason H. , Lambert Dayton M. , Foster Kenneth A.
Published: December 2009

Increased fresh tomato trade has prompted a number of trade disputes between the United States, Canada, and Mexico. One precondition of an antidumping dispute is meeting the “likeness of product” criterion. However, fresh tomato shipments and imports are highly seasonal, suggesting that the degree of substitutability (or product likeness) may depend fundamentally on whether fresh tomato varieties are in‐ or out‐of‐season. We develop a seasonally adjusted inverse demand system using Canadian and Mexican monthly import data along with U.S. state shipping data to address both seasonality and product substitutability in the fresh tomato market. We find that market equilibrium and the degree of product substitution are affected by seasonality and product availability in the consumer choice set.

Le commerce accru de la tomate fraîche suscite des différends commerciaux entre les États‐Unis, le Canada et le Mexique. L'une des préconditions d'un différend en matière d'antidumping est liée au respect du critère de la « similarité du produit ». Toutefois, les expéditions et les importations de tomate fraîche sont très saisonnières, ce qui laisse supposer que le degré de substituabilité (ou de similarité du produit) puisse reposer fondamentalement sur le fait qu'il s'agisse ou non de variétés de tomate fraîche pleine saison ou hors‐saison. Nous avons mis au point un système désaisonnalisé de la demande inverse utilisant des données mensuelles sur les importations canadiennes et mexicaines et des données sur les expéditions des États‐Unis pour étudier la saisonnalité et la substituabilité dans le marché de la tomate fraîche. Nous sommes arrivés à la conclusion que la saisonnalité et la disponibilité des produits offerts au consommateur influent sur l'équilibre du marché et le degré de substitution du produit.
Alberta Consumers’ Valuation of Extrinsic and Intrinsic Red Meat Attributes: A Choice Experimental Approach
Authors: Steiner Bodo , Gao Fei , Unterschultz Jim
Published: December 2009

This paper analyzes Alberta consumers’ perceptions toward extrinsic and intrinsic attributes of bison and beef steaks. In contrast to published Canadian consumer studies on bison meat that were undertaken prior to May 2003, before the first BSE case of Canadian origin was identified in beef cattle, this study provides a “post‐BSE” assessment of consumer perceptions toward selected bison meat attributes. The results from an attribute‐based choice experiment provide little support that simple traceability assurance schemes have value to consumers of bison and beef steaks, thus confirming similar findings of earlier beef studies that have employed different methodological approaches. The results also suggest that consumers are willing to pay significant premiums for bison steaks that are certified as being produced without genetically modified organisms, an attribute that has so far been unexplored in previous published bison studies.

Le présent article analyse les perceptions des consommateurs de l’Alberta envers des attributs intrinsèques et extrinsèques du bifteck de bœuf et de bison. Contrairement aux études canadiennes sur la consommation de viande de bison publiées avant mai 2003, soit avant l’apparition du premier cas d’ESB dans un troupeau de bovins canadien, la présente étude livre une évaluation « post‐ESB » des perceptions des consommateurs envers des attributs sélectionnés de la viande de bison. Les résultats obtenus à partir de la méthode des choix multi‐attributs apportent peu d’appui à l’idée voulant que les mécanismes simples d’assurance de la traçabilité aient de la valeur pour les consommateurs de bifteck de bison et de bœuf, ce qui confirme les résultats similaires d’études antérieures sur le bœuf effectuées à l’aide de diverses approches méthodologiques. De plus, les résultats ont montré que les consommateurs sont prêts à payer un supplément appréciable pour du bifteck de bison certifié sans organisme génétiquement modifié (OGM), un attribut qui n’a pas été examiné dans les études sur le bison publiées antérieurement.
Origin of rotational kinematics in the globular cluster system of M31: a new clue to the bulge formation
Authors: Bekki Kenji
Published: December 2009

We propose that the rotational kinematics of the globular cluster system (GCS) in M31 can result from a past major merger event that could have formed its bulge component. We numerically investigate kinematical properties of globular clusters (GCs) in remnants of galaxy mergers between two discs with GCs in both their disc and halo components. We find that the GCS formed during major merging can show strongly rotational kinematics with the maximum rotational velocities of ∼140–170 km s−1 for a certain range of orbital parameters of merging. We also find that a rotating stellar bar, which can be morphologically identified as a boxy bulge if seen edge-on, can be formed in models for which the GCSs show strongly rotational kinematics. We thus suggest that the observed rotational kinematics of GCs with different metallicities in M31 can be closely associated with the ancient major merger event. We discuss whether the formation of the rotating bulge/bar in M31 can be due to the ancient merger.