bluuebunny/crossref_metadata_2025 huggingface dataset:
Task‐Based Language Learning: A Review of Issues
Authors: Robinson Peter
Published: May 2011

Theoretically motivated, empirical research into task‐based language learning has been prompted by proposals for task‐based language teaching. In this review I describe early and more recent proposals for how task‐based learning can stimulate acquisition processes and the theoretical rationales that have guided research into them. I also describe taxonomies of task characteristics that have been proposed and claims made about the effects of task characteristics on interaction, attention to input, and speech production. I then relate the issues raised to findings described in the five empirical studies in this issue concerning the effects of pedagogic task design on the accuracy, fluency, and complexity of learner language; the influence of individual differences in cognitive and motivational variables on task performance; the extent to which tasks, and teacher interventions, promote the quantity and quality of interaction that facilitate L2 learning; and the generalizability of task‐based learning research in laboratory contexts to instructed classroom settings.
Task‐Based Interactions in Classroom and Laboratory Settings
Authors: Gass Susan , Mackey Alison , Ross‐Feldman Lauren
Published: May 2011

This study was originally motivated by claims by a few classroom researchers (e.g., Foster, 1998, see Foster & Ohta, 2005) that the findings of laboratory‐based studies of second‐language interaction cannot automatically be applied to classroom language learning settings. Instead of simply accepting this assumption, we treated it as an empirical question. Our study was designed to examine the impact of setting—classroom and laboratory—on task‐based interactions. We worked with learners of Spanish as a foreign language. Seventy‐four university‐level learners in dyads completed three interactive tasks. The tasks were designed in partnership with their instructors to be consistent with activities that these learners would do as part of their regular instruction. They were also consistent with activities that second language researchers typically use to elicit data in experimental work. Half of the learners worked in the classroom with their regular teacher and the other half met in a laboratory and were supervised by a researcher. Our findings indicated that there were significant differences in the incidence of interactional modifications among tasks. Interestingly, however, these differences were found in both the classroom and laboratory settings. No significant differences in interactional patterns were found between the two settings. Our finding that there were no significant differences between classroom and laboratory settings has been widely cited in publications on task‐based language learning (e.g., Bygate & Samuda, 2009; Eckerth, 2009; Ellis, 2010; Fujii, Obata, Takahashi, & Tanabe, 2008; Jenks, 2009; Johnstone, 2006; Nassaji, 2007; Philp, Oliver, & Mackey, 2006; Révész, 2009). Subsequent work in the field has continued to find similar task effects on interaction in other learner populations and instructional settings (e.g., Eckerth, 2009; Fujii & Mackey, 2009; Gilabert, Baron, & Llanes, 2009). In summary then, a major contribution of our study was to raise awareness that the effects of setting on interactional processes cannot simply be assumed and claimed but should be empirically demonstrated. The onus is on both classroom and laboratory researchers to determine whether setting has influenced their findings, and if so, how and to what degree.
Multidimensional Re‐creation of Vulnerabilities and Potential for Resilience in International Migration
Authors: Julca Alex
Published: May 2011

International labour migration is a multidimensional process and primarily a family mechanism intended to reduce vulnerabilities associated with underlying inequalities. However, for immigrants, the break‐up of physical contact with family members is an enduring feature of vulnerability in their communication with origins (often in developing countries). On the whole, family relationships are transformed: the absence of physical contact is traded‐off with remittances sent home to family members. Remittances create potential for resilience by increasing human development of children, while reducing extreme poverty at the local level. Remittance flows are also an important source of foreign exchange for countries of origin. However, labour markets’ polarization, backlash, and economic downturns at destinations (often in developed countries), and governments’ moral hazard, currency revaluation, and production inertia at origins recreate vulnerabilities and disrupt the potential build‐up of resilience. In fact, the re‐creation of vulnerabilities largely outweighs the generation of resilience threads. The paper develops a typology that highlights the dynamic interaction between vulnerabilities and resilience, revealing the multiple aspects of people and remittances flows, the potential for mainstreaming migration policies into economic development, and the scale of the policy task to reduce vulnerabilities associated to international labour migration.
Economic or Environmental Migration? The Push Factors in Niger
Authors: Afifi Tamer
Published: May 2011

This paper identifies the main environmental problems in Niger and detects their impact on migration at the national and international level. It mainly focuses on droughts, soil degradation, the shrinking of Lake Chad, the Niger River problems, deforestation, and sand intrusion, as important push factors that might influence the migration decision of the people of Niger. The paper addresses the question of whether their decision to migrate is influenced by purely economic or environmental problems and concludes that the economic factor represents the mechanism through which the environmental damage influences migration, introducing hereby the term “environmentally induced economic migration”.
Drought Triggered Temporary Migration in an East Indian Village
Authors: Jülich Sebastian
Published: May 2011

This case study in the village of Khaliakani examines the impact of drought disasters on the rural population in the Indian state Orissa and analyses the importance of temporary migration as a coping and adaptation strategy. Social, economic, and spatial patterns of the forced migration caused by the last drought disaster in 2003 are being investigated at the household level in order to explore the links between vulnerability and temporary migration for labour. The drivers leading to environmental forced migration, the requirements necessary to migrate, and the resulting outcomes for the migrants are explored and comprised in a conceptual model of environmental forced migration for labour.
A Decision Framework for Environmentally Induced Migration
Authors: Renaud Fabrice G. , Dun Olivia , Warner Koko , Bogardi Janos
Published: May 2011

Global environmental change, including climate change, is increasingly affecting ecosystems and the communities who rely on them. Reflecting on the manner in which the environment changes can help provide insights into the different mechanisms by which humans respond and adapt to deal with the environmental stress they face. When it comes to migrating as a response strategy to environmental stress, the pace of change in the environment will have a significant influence on the mode of displacement and migration‐related decisions. Determining the exact extent that environmental stresses play in forcing people to move is complex for at least two reasons. First, deciphering which of several push and pull factors influence a decision to move is difficult as multiple factors (e.g., social, political and economic factors) often act simultaneously. Second, environmental degradation processes are often a consequence of the degradation of social, economic and political conditions and vice versa. Reflecting on the concept of social‐ecological systems and the notion of ecosystem services is useful for understanding this complexity and can help in determining the extent to which ecosystem degradation plays a role in forcing people to migrate. An attempt is made to address the gap in conceptualising environmental change and migration by sketching a decision framework for categorising people moving due to environmental stressors. The approach examines the circumstances leading to a decision to move, including the state of the environment and coping capacities / adaptive abilities of those individuals or communities affected. This conceptualisation is not a final scheme but rather, a point of departure for debate and discussion. It is hoped that, following in‐depth discussions and improvements of such a framework, it will become a useful tool for operational agencies that have to provide support to people who are displaced or migrate because of environmental stresses.
Autophagy deregulation in neurodegenerative diseases – recent advances and future perspectives
Authors: Cheung Zelda H. , Ip Nancy Y.
Published: May 2011

J. Neurochem. (2011) 118, 315–316.

Autophagy is an evolutionarily conserved homeostatic process for the turnover of cellular contents, organelles and misfolded proteins through the lysosomal machinery. Recently, the involvement of autophagy in the pathophysiology of neurodegenerative diseases has attracted considerable interest because autophagy deregulation has been linked to some of these neurodegenerative disorders. This interest is further heightened by the demonstration that various autophagic pathways, including macroautophagy and chaperone‐mediated autophagy, are implicated in the turnover of proteins that are prone to aggregation in cellular or animal disease models. These observations have stimulated new awareness in the pivotal role of the autophagic pathways in neurodegenerative disease pathophysiology, and have sparked extensive research aimed at deciphering the mechanisms by which autophagy is altered in these disorders. Here, we summarize the latest advances in our understanding of the role of autophagy deregulation in Parkinson’s, Alzheimer’s and Huntington’s disease.
Proterozoic phytoplankton and timing of Chlorophyte algae origins
Authors: MOCZYDŁOWSKA MAŁGORZATA , LANDING ED , ZANG WENLONG , PALACIOS TEODORO
Published: May 2011

Abstract: Morphological and reproductive features and cell wall ultrastructure and biochemistry of Proterozoic acritarchs are used to determine their affinity to modern algae. The first appearance datum of these microbiota is traced to infer a minimum age of the divergence of the algal classes to which they may belong. The chronological appearance of microfossils that represent phycoma‐like and zygotic cysts and vegetative cells and/or aplanospores, respectively, interpreted as prasinophyceaen and chlorophyceaen microalgae is related to the Viridiplantae phylogeny. An inferred minimum age of the Chlorophyte origin is beforec. 1800 Ma, the Prasinophyceae atc. 1650 Ma and the Chlorophyceae atc. 1450 Ma. These divergence times differ from molecular clock estimates, and the palaeontological evidence suggests that they are older.
Cytotoxicity and Endothelial Cell Adhesion of Lyophilized and Irradiated Bovine Pericardium Modified With Silk Fibroin and Chitosan
Authors: Rodas Andrea C.D. , Polak Roberta , Hara Priscila H. , Lee Emily I. , Pitombo Ronaldo N.M. , Higa Olga Z.
Published: May 2011

Grafts of biological tissues have been used since the 1960s as an alternative to the mechanical heart prostheses. Nowadays, the most consolidated treatment to bovine pericardial (BP) bioprostheses is the crosslinking with glutaraldehyde (GA), although GA may induce calcification in vivo. In previous work, our group demonstrated that electron beam irradiation applied to lyophilized BP in the absence of oxygen promoted crosslinks among collagen fibers of BP tissue. In this work, the incorporation of silk fibroin (SF) and chitosan (CHIT) in the BP not treated with GA was studied. The samples were irradiated and then analyzed for their cytotoxicity and the ability of adhesion and growth of endothelial cells. Initially, all samples showed cytotoxicity. However, after a few washing cycles, the cytotoxicity due to acetic acid and ethanol residues was removed from the biomaterial making it suitable for the biofunctional test. The samples modified with SF/CHIT and electron beam irradiated favored the adhesion and growth of endothelial cells throughout the tissue.
Influence of Heat Treatment and Oxygen Doping on the Mechanical Properties and Biocompatibility of Titanium‐Niobium Binary Alloys
Authors: da Silva Luciano Monteiro , Claro Ana Paula Rosifini Alves , Donato Tatiani Ayako Goto , Arana‐Chavez Victor E. , Moraes João Carlos Silos , Buzalaf Marília Afonso Rabelo , Grandini Carlos Roberto
Published: May 2011

The most commonly used titanium (Ti)‐based alloy for biological applications is Ti‐6Al‐4V, but some studies associate the vanadium (V) with the cytotoxic effects and adverse reactions in tissues, while aluminum (Al) has been associated with neurological disorders. Ti‐Nb alloys belong to a new class of Ti‐based alloys with no presence of Al and V and with elasticity modulus values that are very attractive for use as a biomaterial. It is well known that the presence of interstitial elements (such as oxygen, for example) changes the mechanical properties of alloys significantly, particularly the elastic properties, the same way that heat treatments can change the microstructure of these alloys. This article presents the effect of heat treatment and oxygen doping in some mechanical properties and the biocompatibility of three alloys of the Ti‐Nb system, characterized by density measurements, X‐ray diffraction, optical microscopy, Vickers microhardness, in vitro cytotoxicity, and mechanical spectroscopy.
Reliability of capillary hemoglobin screening under routine conditions
Authors: Ziemann Malte , Lizardo Bettina , Geusendam Geert , Schlenke Peter
Published: May 2011

BACKGROUND: Capillary hemoglobin (Hb) measurement before admission for whole blood donation is performed in many blood donation services, in spite of several studies reporting many donors with low Hb values being missed by capillary Hb screening.

STUDY DESIGN AND METHODS: Predonation capillary and venous Hb levels of 9209 first‐time donors presenting for whole blood donation were compared. Hb testing was conducted by photometric determination of finger‐stick samples with a photometric method (Donor Checker, HemoCue) and using a hematology analyzer for venous samples.

RESULTS: Both capillary and venous Hb measurements were available for 8910 donors (96.8%). The arithmetic mean deviation of the capillary Hb from the venous sample was +1.5 ± 6.8 g/L, and the mean deviation was 5.4 ± 4.5 g/L. In 7865 donors (88%), capillary and venous Hb values differed less than 10 g/L from each other, but in 86 donors (1.0%) the difference was at least 20 g/L, and in 10 donors (0.1%), even 30 g/L or more. In 93.3% of females and 98.7% of males, the categorization as having sufficient or too low Hb for blood donation was concordant between capillary and venous measurements. A total of 34.4% of donors with too low results of capillary Hb screening had sufficient venous Hb levels. Only one donor (0.01%) passed the capillary Hb screening despite venous Hb values below 110 g/L.

CONCLUSION: The currently available methods for capillary Hb screening allow reliable determination of predonation Hb values under routine conditions. Additional venous Hb measurements in donors with too low capillary Hb values might reduce the rate of deferred donors by approximately one‐third.
Uprooted but Stable: Chilean Parties and the Concept of Party System Institutionalization
Authors: Luna Juan Pablo , Altman David
Published: May 2011

Mainwaring and Scully's concept of party system institutionalization (PSI) has greatly influenced the literature on parties and party systems. This article contributes to the “revisionist” literature on PSI by exploring the recent evolution of the concept's four dimensions in Chile. It finds that the Chilean party system is not homogenously institutionalized (as conventionally argued) but is simultaneously frozen at the elite level and increasingly disconnected from civil society. In this regard, it approaches some recent descriptions of the Brazilian party system, a prototypical example of an “inchoate” party system that has gained stability over time without developing roots in society. This article argues that the current operationalization of the concept of PSI is problematic. Not only should all four dimensions of the concept be simultaneously measured, probably through multiple indicators for each one, but their trends across time and space should also be better integrated into the concept's theoretical structure.
Quantification of the impact of the hoverfly, Metasyrphus corollae on the cereal aphid, Sitobion avenae, in winter wheat: laboratory rates of kill
Authors: Adams T. H. L. , Chambers R. J. , Dixon A. F. G.
Published: May 2011

The rate of kill of cereal aphids by larvae of Metasyrphus corollae (F.) (Diptera: Syrphidae) was measured in the laboratory with the aim of assessing the impact of this predator on field populations of cereal aphids. Daily measurements were taken of changes in both the larval weight and the biomass of aphids killed by M. corollae in conditions of constant temperature and humidity. A mean relative kill rate was defined and calculated for each larval instar of the predator from which estimates of field daily rates of kill can be made.

Quantification de l'impact de Metasyrphus corollae sur Sitobion avenae sur blé d'hiver: taux de mortalité au laboratoire

Le taux de mortalité de S. avenae provoqué par les larves de M. corollae a été mesureé au laboratoire pour évaluer l'impact de ce prédateur sur les populations de ce puceron dans la nature. L'évolution du poids des larves et de la biomasse de pucerons tués a été suivie tous les jours dans des conditions de température et humidité constantes. Un taux moyen de mortalité a été déterminé pour chaque stade larvaire du prédateur, il a servi à déduire les niveaux de mortalité quotidienne dans les champs.
Host selection by ovipositing cowpea weevils: Patterning of input from separate sense organs
Authors: Messina Frank J. , Barmore Joyce L. , Renwick J. A. A.
Published: May 2011

Ablations were performed to identify the sense organs used in host selection by ovipositing cowpea weevils, Callosobruchus maculatus. Antennae, foretarsi and palpi (maxillary + labial) were removed singly or in combination, and females were offered pairwise choices of four host species. Removal of the palpi consistently had the greatest effect on host choice, whereas the relative importance of other organs depended on the pair of hosts tested. Different organs may provide conflicting input as to the ‘preferred’ host; certain ablations led to a complete reversal in preference (as opposed to a simple loss of discrimination). Input from separate organs appeared to be received in a dominance hierarchy.

Sélection de l'hǒte lors de la ponte de Callosobruchus maculatus: modélisation des influx provenant séparément des divers organes sensoriels

Les ablations ont servi d'éttape nitiale lors de la détermination des organes sensoriels impliqués dans la sélection du lieu de ponte par C. maculatus. Les antennes, les tarses antérieurs, les palpes (maxillaires et labiaux) ont été retirés seuls ou en combinaison. Les femelles ont eu des choix binaires entre les graines de 4 légumineuses: Cicer arietinum, Glycine max, Phaseolus vulgaris, Vigna unguiculata. Chaque combinaison d'ablations était accompagnée d'un témoin chez lequel les měmes ablations étaient unilatérales. C'est l'ablation des palpes qui a le plus modifié le choix de l'hǒte; l'influence relative des autres organes dépendait des paires d'hǒtes offerts. Différents organes peuvent fournir des influx opposés quant à l'hǒte préféré; certaines ablations ont conduit à une inversion complète des préférences. Il semble que les influx sensoriels formaient une gamma avec hiérarchie dominante. Dans les choix binaires, les préférences initiales des femelles intactes ont été supprimées avec l'ablation des palpes seuls, cependant elles n'avaient pas été modifiées par l'ablation conjointe des palpes et des tarses. Dans ces expériences, l'influx antennaire ne devenait dominant qu'après ablation des deux autres organes sensoriels. Les préférences des femelles avec ablations unilatérales ne différaient pas de celles des femelles intactes.
Sex pheromone discrimination by male aphids of a biotype of Schizaphis graminum
Authors: Eisenbach J. , Mittler T. E.
Published: May 2011

The ability of male aphids of two different biotypes (C & E) of the greenbug, Schizaphis graminum (Rondani), to distinguish ovipara‐produced sex pheromone of their own biotype from that of the other biotype was examined using an arena olfactometer. Biotype E males showed a strong preference for biotype E oviparae; the preference of biotype C males for biotype C oviparae was less marked. These behavioral findings indicate a potential biochemical reproductive isolating mechanism for these biotypes.

Unterscheidung der weiblichen Geschlechtspheromone zweier Biotypen der Aphide Schizaphis graminum durch die Männchen

Die Reaktion der Männchen von zwei Biotypen (C & E) der Aphide Schizaphis graminum auf die Geschlechtspheromone der Oviparen ihres eigenen und des anderen Biotyps wurde mit Hilfe einer Olfaktometer‐Arena untersucht. Biotyp E Männchen zeigten eine starke Präferenz für Biotyp E Ovipare, während die Präferenz von Biotyp C Männchen für Biotyp C Ovipare weniger stark ausgeprägt war. Diese Resultate deuten auf einen möglichen verhaltensbiologischen Isolationsmechanismus der beiden Biotypen dieser Blattlausart in der Natur hin.
Molecular profiling indicates orthotopic xenograft of glioma cell lines simulate a subclass of human glioblastoma
Authors: Shankavaram Uma T. , Bredel Markus , Burgan William E. , Carter Donna , Tofilon Philip , Camphausen Kevin
Published: May 2011

Cell line models have been widely used to investigate glioblastoma multiforme (GBM) pathobiology and in the development of targeted therapies. However, GBM tumours are molecularly heterogeneous and how cell lines can best model that diversity is unknown. In this report, we investigated gene expression profiles of three preclinical growth models of glioma cell lines, in vitro and in vivo as subcutaneous and intracerebral xenografts to examine which cell line model most resembles the clinical samples. Whole genome DNA microarrays were used to profile gene expression in a collection of 25 high‐grade glioblastomas, and comparisons were made to profiles of cell lines under three different growth models. Hierarchical clustering revealed three molecular subtypes of the glioblastoma patient samples. Supervised learning algorithm, trained on glioma subtypes predicted the intracerebral cell line model with one glioma subtype (r = 0.68; 95% bootstrap CI –0.41, 0.46). Survival analysis of enriched gene sets (P < 0.05) revealed 19 biological categories (146 genes) belonging to neuronal, signal transduction, apoptosis‐ and glutamate‐mediated neurotransmitter activation signals that are associated with poor prognosis in this glioma subclass. We validated the expression profiles of these gene categories in an independent cohort of patients from ‘The Cancer Genome Atlas’ project (r = 0.62, 95% bootstrap CI: –0.42, 0.43). We then used these data to select and inhibit a novel target (glutamate receptor) and showed that LY341595, a glutamate receptor specific antagonist, could prolong survival in intracerebral tumour‐implanted mice in combination with irradiation, providing an in vivo cell line system of preclinical studies.
Oral Lichen Planus and Dental Implants – A Retrospective Study
Authors: Czerninski Rakefet , Eliezer Meizi , Wilensky Asaf , Soskolne Aubrey
Published: May 2011

Objectives: To examine whether oral lichen planus (OLP) affects the success rate of dental implants and if the manifestations of OLP are altered by implant‐borne prostheses.

Materials and Methods: OLP patients, treated in the oral medicine department, with (the study group) and without (control group) dental implants were included. Pocket depth, mobility, bleeding on probing, erythema, pain and radiolucency around the implants, as well as clinical findings and OLP symptoms were recorded. Follow‐up ranged from 12–24 months. Ordinal variables and visual analog scale score were compared using the Mann–Whitney test. The significance of the trend within each of the groups was assed using the Friedman test. Categorical variables were compared using Pearson chi‐squared test and Fisher's exact test.

Results: Fourteen patients in the study group with 1–15 implants per patient and 15 in the control group were included. No implant failures were recorded. Comparison between the clinical manifestations of OLP in both groups did not reveal any significant differences.

Conclusions: Success of implant rehabilitation among treated OLP patients does not seem to be different from the success rate in the general population. Nor does implant placement influence the disease manifestations.
The Effects of Cortical Bone Thickness and Trabecular Bone Strength on Noninvasive Measures of the Implant Primary Stability Using Synthetic Bone Models
Authors: Hsu Jui‐Ting , Fuh Lih‐Jyh , Tu Ming‐Gene , Li Yu‐Fen , Chen Kuan‐Ting , Huang Heng‐Li
Published: May 2011

Purpose: This study investigated how the primary stability of a dental implant as measured by the insertion torque value (ITV), Periotest value (PTV), and implant stability quotient (ISQ) is affected by varying thicknesses of cortical bone and strengths of trabecular bone using synthetic bone models.

Materials and Methods: Four synthetic cortical shells (with thicknesses of 0, 1, 2, and 3 mm) were attached to four cellular rigid polyurethane foams (with elastic moduli of 137, 47.5, 23, and 12.4 MPa) and one open‐cell rigid polyurethane foam which mimic the osteoporotic bone (with an elastic modulus 6.5 MPa), to represent the jawbones with various cortical bone thicknesses and strengths of trabecular bone. A total of 60 bone specimens accompanied with implants was examined by a torque meter, Osstell resonance frequency analyzer, and Periotest electronic device. All data were statistically analyzed by two‐way analysis of variance. In addition, second‐order nonlinear regression was utilized to assess the correlations of the primary implant stability with the four cortex thicknesses and five strengths of trabecular bone.

Results: ITV, ISQ, and PTV differed significantly (p < .05) and were strongly correlated with the thickness of cortical bone (R2 > 0.9) and the elastic modulus of trabecular bone (R2 = 0.74–0.99).

Conclusions: The initial stability at the time of implant placement is influenced by both the cortical bone thickness and the strength of trabecular bone; however, these factors are mostly nonlinearly correlated with ITV, PTV, and ISQ. Using ITV and PTV seems more suitable for identifying the primary implant stability in osteoporotic bone with a thin cortex.
Peri‐Implant Bone Density in Senile Osteoporosis‐Changes from Implant Placement to Osseointegration
Authors: Beppu Kensuke , Kido Hirofumi , Watazu Akira , Teraoka Kay , Matsuura Masaro
Published: May 2011

Purpose: The aim of this study was to examine healing over time after implant body placement in a senile osteoporosis model and a control group.

Materials and Methods: In this study, 16‐week‐old male mice were used. The senile osteoporosis model consisted of senescence‐accelerated prone 6 mice and the control group consisted of senescence‐accelerated resistant 1 mice. Titanium‐coated plastic implants were used as experimental implants whose dimensions were 3.0 mm in length, 1.1 mm in apical diameter, and 1.2 mm in coronal diameter. Bone samples were collected at 5, 7, 14, 21, and 28 days after implant placement. A micro‐quantitative computed tomography (QCT) system was used to scan these samples and a phantom in order to quantitate bone mineral measurements. Bone mineral density (BMD) of each sample was measured. Each sample was also examined by light microscopy after QCT imaging. At 14 and 28 days after implant placement, the bone‐implant contact (BIC) ratios were calculated from light microscopy images and were divided into cortical bone and bone marrow regions.

Results: When BMD was compared between the osteoporosis and control groups using micro‐QCT, the osteoporosis group had a significantly lower BMD in the region 0–20 µm from the implant surface in the bone marrow region at 14 days onward after implant placement. Compared with the control group, the osteoporosis model also had significantly lower BMD in all regions 0–100 µm from the implant surface in the bone marrow region at 14 days after placement. However, in the cortical bone region, no statistically significant difference was observed in the regions at the bone‐implant interface. Light microscopy revealed osseointegration for all implants 28 days after implant placement. The osteoporosis model tended to have lower BICs compared with that of the control group, although this did not reach statistical significance.

Discussion: Our results showed that osseointegration was achieved in the osteoporosis model. However, the BMD was 30–40% lower than that of the control group in the region closest to the implant surface in bone marrow region. Peri‐implant BMD was lower in a relatively large area in the osteoporosis model during an important time for osseointegration. Therefore, this result suggests that osteoporosis might be considered as a risk factor in implant therapy.

Conclusion: The osteoporosis model had a lower BMD than the control group in the region closest to the implant during an important time for osseointegration. This result suggests that senile osteoporosis might be a risk factor in implant therapy. However, the osteoporosis model and the control group had no difference in peri‐implant BMD in the cortical bone region. This suggests that risk might be avoided by implant placement that effectively uses the cortical bone.
Insight into the phosphodiesterase mechanism from combined QM/MM free energy simulations
Authors: Wong Kin‐Yiu , Gao Jiali
Published: May 2011

Molecular dynamics simulations employing a combined quantum mechanical and molecular mechanical potential have been carried out to elucidate the reaction mechanism of the hydrolysis of a cyclic nucleotide cAMP substrate by phosphodiesterase 4B (PDE4B). PDE4B is a member of the PDE superfamily of enzymes that play crucial roles in cellular signal transduction. We have determined a two‐dimensional potential of mean force (PMF) for the coupled phosphoryl bond cleavage and proton transfer through a general acid catalysis mechanism in PDE4B. The results indicate that the ring‐opening process takes place through an SN2 reaction mechanism, followed by a proton transfer to stabilize the leaving group. The computed free energy of activation for the PDE4B‐catalyzed cAMP hydrolysis is about 13 kcal·mol−1 and an overall reaction free energy is about −17 kcal·mol−1, both in accord with experimental results. In comparison with the uncatalyzed reaction in water, the enzyme PDE4B provides a strong stabilization of the transition state, lowering the free energy barrier by 14 kcal·mol−1. We found that the proton transfer from the general acid residue His234 to the O3′ oxyanion of the ribosyl leaving group lags behind the nucleophilic attack, resulting in a shallow minimum on the free energy surface. A key contributing factor to transition state stabilization is the elongation of the distance between the divalent metal ions Zn2+ and Mg2+ in the active site as the reaction proceeds from the Michaelis complex to the transition state.
Tertiary Hyperparathyroidism Resistant to Cinacalcet Treatment
Authors: Okada Manabu , Tominaga Yoshihiro , Izumi Kumiko , Nobata Hironobu , Yamamoto Takayuki , Hiramitsu Takahisa , Tsujita Makoto , Goto Norihiko , Nanmoku Koji , Watarai Toshihiko , Uchida Kazuharu
Published: May 2011

Cinacalcet hydrochloride (cinacalcet) has been reported to be efficacious for patients with tertiary hyperparathyroidism (THPT). We experienced five patients with THPT requiring parathyroidectomy (PTx) because of resistance to cinacalcet treatment and investigated their clinical characteristics and clinical course. The maximum diameter of the parathyroid gland estimated by ultrasonography before renal transplantation was evaluated. Serum total calcium, phosphorus, intact parathyroid hormone (iPTH), alkaline phosphatase (ALP), and creatinine (Cr) levels were investigated every three months after the administration of cinacalcet and at PTx. After surgery, the Cr levels were followed. In all five patients, at least one parathyroid gland had a largest diameter of more than 1 cm, and the mean diameter was 18.7 mm (range 14.9–24.1 mm). Intact PTH and ALP levels gradually increased after the initiation of cinacalcet and the Cr levels transiently increased after PTx. These findings suggest that the existence of a severely enlarged nodular hyperplastic gland is a main factor involved in resistance to cinacalcet.
Parathyroidectomy Markedly Reduces Oxidative Stress in a Patient with Primary Hyperparathyroidism
Authors: Tanaka Motoko , Tokunaga Koki , Maruyama Toru , Otagiri Masaki , Tominaga Yoshihiro , Itoh Kazuko , Matsushita Kazutaka , Komaba Hirotaka , Fukagawa Masafumi
Published: May 2011

Parathyroidectomy for hyperparathyroidism has been associated with a survival benefit, but the mechanisms remain unclear. We are reporting on an 88‐year‐old female patient who had high serum calcium and intact parathyroid hormone levels associated with an enlarged parathyroid gland. A parathyroidectomy was performed due to a diagnosis of primary hyperparathyroidism. After the surgery, there was a marked decrease in the oxidative stress markers, such as the ratios of oxidized to unoxidized albumin and advanced oxidation protein products. These results suggest that parathyroidectomy reduces oxidative stress in patients with primary hyperparathyroidism, which may in part explain the reduced risk for cardiovascular and all‐cause mortality after parathyroidectomy.
Parathyroid Hormone Control Survey to Determine Inter‐method and Inter‐lab Variations in Japan
Authors: Kakuta Takatoshi , Kato Hitoshi , Komaba Hirotaka , Akizawa Tadao ,   Japanese PTH Control Survey Committee
Published: May 2011

For uremic patients, Kidney Disease: Improving Global Outcomes suggest that parathyroid hormone (PTH) levels should be maintained within approximately 2–9 times the upper normal limit for the assay. One of reasons for the lack of definite approximate PTH values is the inability to use the Allegro Intact PTH assay from Nicols. We aimed to evaluate whether other parathyroid hormone assays were suitable for these assessments. We compared the parathyroid hormone concentrations measured with five commercial immunoassays by using three serum pools and seven artificially spiked samples of parathyroid hormone; the Total Intact parathyroid hormone assay was used as the reference assay. Although the results of parathyroid hormone assays showed high correlation, the concentrations differed from Yamasa's assay to another. And the third/second‐generation assay ratio was approximately 60%. Further, the Immulite assay overestimated the levels of 1–84 PTH. We showed important inter‐method variations in the parathyroid hormone assays used in Japan.
Effects of Raloxifene on Bone Mineral Metabolism in Postmenopausal Japanese Women on Hemodialysis
Authors: Tanaka Motoko , Itoh Kazuko , Matsushita Kazunori , Matsushita Kazutaka , Moriishi Misaki , Kawanishi Hideki , Fukagawa Masafumi
Published: May 2011

In addition to renal osteodystrophy, postmenopausal women on hemodialysis are at high risk for osteoporosis. Recent studies reported the effects of raloxifene, a selective estrogen receptor modulator for osteoporosis, in postmenopausal women. The present study evaluated the efficacy of raloxifene and its effects on bone mineral metabolism in postmenopausal Japanese patients on dialysis. In a prospective, multicentre study, 17 postmenopausal women on chronic hemodialysis with severe osteoporosis (bone mineral density [BMD]≤2 SD by bone densitometry) were treated with 60 mg/day raloxifene hydrochloride for 12 months. The study also included 10 age‐matched control women. Vitamin D and calcium salts were not changed during the study. Intact parathyroid hormone (iPTH), serum calcium and phosphorus, and bone resorption marker (NTx) were measured, and BMD were determined by DEXA, at 0, 6, and 12 months after administration of raloxifene. The mean lumbar spine BMD at baseline was similar in the two groups. Raloxifene therapy (for 12 months) improved lumbar spine BMD (by 2.6%) in 53% of the patients, while 70% of the control group showed a reduction in BMD (by 4.0%). Raloxifene significantly decreased serum calcium and increased iPTH. Our results suggested that raloxifene improved trabecular BMD in postmenopausal Japanese women on hemodialysis. The effects of raloxifene on serum calcium and serum iPTH level suggest it improves bone resorption. Vitamin D and/or calcium salts should be added to raloxifene treatment to avoid secondary hyperparathyroidism.
Interaction Between the Antibiotic Tetracycline and the Elongation Factor 1α from the Archaeon Sulfolobus solfataricus
Authors: Lamberti Anna , Martucci Nicola M. , Ruggiero Immacolata , Arcari Paolo , Masullo Mariorosario
Published: May 2011

The interaction between tetracycline and the archaeal elongation factor 1α from Sulfolobus solfataricus was investigated. The effects produced by this eubacterial antibiotic indicated that this interaction involved the G‐domain of the elongation factor 1α from S. solfataricus, although also the M‐domain was required. In fact, in the presence of the antibiotic, an increase in the fluorescence quantum yield of the aromatic region was observed for elongation factor 1α from S. solfataricus and its truncated form lacking the C‐terminal domain, but not for that lacking also the M‐domain. The increase in quantum yield was restored when the G‐domain of elongation factor 1α from S. solfataricus was fused to the M and the C‐domains of the eubacterial analogue elongation factor Tu. Tetracycline inhibits protein synthesis catalysed by elongation factor 1α from S. solfataricus; this is accompanied by an increase in the GDP/GTP exchange rate and a slight inhibition of the intrinsic GTPase, suggesting that a main effect of the antibiotic was exerted on the GTP‐bound form of the enzyme. Furthermore, the mixed inhibition observed for GTPase confirmed that the interaction, besides the G‐domain, involved also other region(s) of elongation factor 1α from S. solfataricus. These results can be useful for studying potential side effects arising from the interaction between tetracycline and eukaryotic elongation factors.
Exploring QSARs for 5‐Lipoxygenase (5‐LO) Inhibitory Activity of 2‐Substituted 5‐Hydroxyindole‐3‐Carboxylates by CoMFA and CoMSIA
Authors: Zheng Junxia , Xiao Gaokeng , Guo Jialiang , Zheng Yang , Gao Hao , Zhao Suqing , Zhang Kun , Sun Pinghua
Published: May 2011

A series of indole and related benzo[g]indole compounds displaying potent activities against 5‐lipoxygenase were selected to establish three‐dimensional quantitative structure–activity relationships using comparative molecular field analysis and comparative molecular similarity indices analysis methods. A training set of 37 active compounds was used to develop the models, which were then valuated by a series of internal and external cross‐validation techniques. A test set of seven compounds was used for the external validation. Models with greater than 70% predictive ability, as determined by external validation, and high internal validity (cross‐validated q2 > 0.5) have been developed. The satisfactory comparative molecular field analysis model predicted a q2 value of 0.779 and an r2 value of 0.957 and revealed that electrostatic and steric properties play a significant role in potency. The best comparative molecular similarity indices analysis model, based on a combination of steric, hydrophobic, and H‐bond donor effects, predicted a q2 value of 0.816 and an r2 value of 0.953. The models were graphically interpreted using comparative molecular field analysis and comparative molecular similarity indices analysis contour plots that provided insight into the structural requirements for increasing the activity of a compound. The results obtained from this study provide a solid basis for future rational design of more active 5‐lipoxygenase inhibitors.
Transformations of 3‐Hydroxy Steroids with Lewis and Anhydrous Protic Acids: The Case of Pregn‐4‐en‐3β,17α,20β‐Triol
Authors: De Marco Rosaria , Leggio Antonella , Liguori Angelo , Perri Francesca , Siciliano Carlo
Published: May 2011

The acid‐catalyzed dehydration is one of the most important processes, which transforms 3‐hydroxy steroids into their corresponding unsaturated derivatives. This reaction is of great importance because it can produce molecules that play a key role in the understanding of the natural metabolism of steroids. Sterol dehydration is generally performed with aqueous acidic systems, and the treatment often affords low yields of the desired compounds and/or complex mixtures of by‐products. In this paper, we report the results obtained from the study of the structural and stereochemical effects of the acid‐induced reaction of pregn‐4‐en‐3β,17α,20β‐triol in anhydrous systems. In particular, the treatment of this trihydroxy steroid model with Lewis acids leads to the corresponding Δ3,5‐steradiene as the only product and in very high yields. With Lewis acids, no modifications of the 1,2‐diol function on the D‐ring are observed, even when the reactions are performed at high temperatures. Protic acid catalysis in non‐aqueous organic solvents causes the formation of an epimeric mixture of the corresponding Δ3,5‐steradiene derivatives by a partial stereochemical inversion of the asymmetric C‐17. The reactivity of the 17α,20β‐diolic residue is also evaluated by exposing pregn‐4‐en‐3β,17α,20β‐triol and the corresponding Δ3,5‐steradiene to the prolonged action of anhydrous protic acid systems under thermal conditions.
Collectibles and collections for comparative and evolutionary neurobiological research in Africa
Authors: Manger Paul R.
Published: May 2011

The scientific investigation of brains of different vertebrates, both extant and extinct, is of interest for several reasons: for translating medical research on rodent models into practice, for understanding the animals investigated in order to improve conservation and management strategies, and for understanding the evolution of the human brain. The African continent has vast resources that are incredibly valuable to this endeavor, including an enormous variety of extant species, as well as a rich fossil record covering human evolution and many aspects of vertebrate evolution. This paper briefly outlines the current situation in terms of collections in Africa, most of which are found in South Africa. It is hoped that these brief descriptions will increase international scientific interest in the available collections.
The importance of scientific collecting and natural history museums for comparative neuroanatomy
Authors: Iwaniuk Andrew N.
Published: May 2011

The comparative study of vertebrate brains is inherently dependent upon access to a sufficient number of species and specimens to perform meaningful comparisons. Although many studies rely on compiling published information, continued specimen collection, in addition to more extensive use of existing brain collections and natural history museums, are crucial for detailed neuroanatomical comparisons across species. This review highlights the importance of collecting species through a variety of means, details a marsupial brain collection, and stresses the potential of natural history museums as a resource for comparative neuroanatomy. By taking advantage of as many of these resources as possible, researchers can rapidly increase species coverage and generate a better understanding of how the brain evolves.
Brain collections at the National Museum of Health and Medicine
Authors: Fobbs, Jr. Archibald J. , Johnson John I.
Published: May 2011

Owing in large part to the foresight and efforts of Wally Welker, the National Museum of Health and Medicine has become a major repository for collections of brain specimens vital to the study of neurobehavioral evolution. From its origins in the Armed Forces Institute of Pathology, with the collection of largely pathological specimens assembled by Paul Yakovlev, the museum has added to its resources four additional extensive collections, largely consisting of specimens acquired specifically for comparative and evolutionary studies: Welker's collection from the University of Wisconsin‐Madison, John I. Johnson's collection from Michigan State University, the Adolf Meyer Collection from the Johns Hopkins University, and the Elizabeth Crosby collections from the University of Michigan. We describe here the history and contents of each of these five collections, to inform the scientific field of the extent and details of these remarkable resources.
Methicillin‐resistantStaphylococcus aureusin a population of horses in Australia
Authors: Axon JE , Carrick JB , Barton MD , Collins NM , Russell CM , Kiehne J , Coombs G
Published: May 2011

Objective To evaluate if methicillin‐resistantStaphylococcus aureus(MRSA) is present in the horse population in Australia.

Design A two‐part retrospective study of laboratory submissions of microbial culture results from horses.

Methods Part A: medical records of 216 horses that had MRSA screening performed on nasal swabs collected over a 30‐day period at admission to the Scone Equine Hospital Clovelly Intensive Care Unit were retrieved. Part B: laboratory records from 2004 to 2009 of culture submissions to the Scone Veterinary Laboratory were reviewed and cultures that grew MRSA were identified. The MRSA isolates from Parts A and B were genotyped over an 18‐month period.

Results MRSA screening of 216 horses identified eight (3.7%) positive samples. MRSA was isolated from cultures of 80 (0.002%) clinical bacteriology samples over a 6‐year period. Genotypic analysis was performed on 36 isolates. All MRSA characterised had the same pulse field gel electrophoresis pattern (type 1), with eight closely related subtypes identified (subtypes A–F and H) and 66% of isolates classified as subtype D, which multilocus sequence and staphylococcal cassette chromosomemectyping analysis identified as ST612‐MRSA‐IVa, a clonal complex (CC) 8S. aureusstrain. Antimicrobial resistance to more than two classes of antimicrobials was common.

Conclusions MRSA was present in a population of horses in Australia. Genotypic analysis of the isolates identified the MRSA strain as CC8S. aureus. Further research needs to be undertaken to evaluate MRSA infection and colonisation of horses and personnel in Australia.