bluuebunny/crossref_metadata_2025 huggingface dataset:
Low-Temperature Degradation of Zirconia and Implications for Biomedical Implants
Authors: Chevalier Jérôme , Gremillard Laurent , Deville Sylvain
Published: June 2007

This review describes the mechanisms responsible for low-temperature degradation (LTD) of zirconia ceramics and its detrimental consequences for biomedical devices. Special emphasis is given to the critical issue of zirconia degradation actually observed for hip prostheses. Experimental methods to accurately measure and predict LTD in a given zirconia ceramic are presented. Different solutions to inhibit LTD or at least reduce its kinetics are reviewed, with the objective of highlighting alternative options for the generation of new zirconia-based biomedical ceramic devices.
The Last Word: Books as a Statistical Metaphor for Microbial Communities
Authors: Schloss Patrick D. , Handelsman Jo
Published: June 2007

Microbial communities contain unparalleled complexity, making them difficult to describe and compare. Characterizing this complexity will contribute to understanding the ecological processes that drive microbe-host interactions, bioremediation, and biogeochemistry. Moreover, an estimate of species richness will provide an indication of the completeness of a community profile. Such estimates are difficult, however, because community structure rarely fits a well-defined distribution. We present a model based on the word usage in books to illustrate the power of statistical tools in describing microbial communities and suggesting biological hypotheses. The model also generates data to test these methods when there are insufficient data in the literature. For example, by simulating the word distribution in books, we can predict the number of words that must be read to estimate the size of the vocabulary used to write the book. Combined with other models that have been used to make inaccessible problems tractable, our book model offers a unique approach to the complex problem of describing microbial diversity.
The Impact of Genome Analyses on Our Understanding of Ammonia-Oxidizing Bacteria
Authors: Arp Daniel J. , Chain Patrick S.G. , Klotz Martin G.
Published: June 2007

The availability of whole-genome sequences for ammonia-oxidizing bacteria (AOB) has led to dramatic increases in our understanding of these environmentally important microorganisms. Their genomes are smaller than many other members of the proteobacteria and may indicate genome reductions consistent with their limited lifestyle. The genomes have a surprising level of gene repetition including genes for ammonia catabolism, iron acquisition, and insertion sequences. The gene profiles reveal limited genes for catabolism and transport of complex organic compounds, but complete pathways for some other compounds. This led to the observation of chemolithoheterotrophic growth of Nitrosomonas europaea. Genes for sucrose synthesis/degradation were identified. The core metabolic module of aerobic ammonia oxidation, the extraction of electrons from hydroxylamine to generate proton-motive force and reductant, has evolutionary roots in the denitrification inventory of anaerobic sulfur-dependent bacteria. The extension by ammonia monooxygenase provides a mechanism to feed this module using ammonia and O2.
Toward a Hyperstructure Taxonomy
Authors: Norris Vic , Blaauwen Tanneke den , Doi Roy H. , Harshey Rasika M. , Janniere Laurent , Jiménez-Sánchez Alfonso , Jin Ding Jun , Levin Petra Anne , Mileykovskaya Eugenia , Minsky Abraham , Misevic Gradimir , Ripoll Camille , Saier Milton , Skarstad Jr., Kirsten , Thellier Michel
Published: June 2007

Bacterial cells contain many large, spatially extended assemblies of ions, molecules, and macromolecules, called hyperstructures, that are implicated in functions that range from DNA replication and cell division to chemotaxis and secretion. Interactions between these hyperstructures would create a level of organization intermediate between macromolecules and the cell itself. To explore this level, a taxonomy is needed. Here, we describe classification criteria based on the form of the hyperstructure and on the processes responsible for this form. These processes include those dependent on coupled transcription-translation, protein-protein affinities, chromosome site-binding by protein, and membrane structures. Various combinations of processes determine the formation, maturation, and demise of many hyperstructures that therefore follow a trajectory within the space of classification by form/process. Hence a taxonomy by trajectory may be desirable. Finally, we suggest that working toward a taxonomy based on speculative interactions between hyperstructures promises most insight into life at this level.
The Impact of Human Rights Trials in Latin America
Authors: Sikkink Kathryn , Walling Carrie Booth
Published: June 2007

Since the 1980s, states have been increasingly addressing past human rights violations using multiple transitional justice mechanisms including domestic and international human rights trials. In the mid-1980s, scholars of transitions to democracy generally concluded that trials for past human rights violations were politically untenable and likely to undermine new democracies. More recently, some international relations experts have echoed the pessimistic claims of the early `trial skeptics' and added new concerns about the impact of trials. Yet, relatively little multicountry empirical work has been done to test such claims, in part because no database on trials was available. The authors have created a new dataset of two main transitional justice mechanisms: truth commissions and trials for past human rights violations. With the new data, they document the emergence and dramatic growth of the use of truth commissions and domestic, foreign, and international human rights trials in the world. The authors then explore the impact that human rights trials have on human rights, conflict, democracy, and rule of law in Latin America. Their analysis suggests that the pessimistic claims of skeptics that human rights trials threaten democracy, increase human rights violations, and exacerbate conflict are not supported by empirical evidence from Latin America.
Hypertonic hydroxyethyl starch solution for hypovolaemia correction following heart surgery
Authors: Sirvinskas Edmundas , Sneider Edvin , Svagzdiene Milda , Vaskelyte Jolanta , Raliene Laima , Marchertiene Irena , Adukauskiene Dalia
Published: June 2007

Background. The aim of the study was to evaluate the effect of hypertonic NaCl hydroxyethyl starch solution on haemodynamics and cardiovascular parameters in the early postoperative period in patients for correction of hypovolaemia after heart surgery. Methods. Eighty patients undergoing myocardial revascularisation at the Clinic of Cardiac Surgery of the Heart Centre (Kaunas University of Medicine) were randomly divided into two groups. The HyperHaes® group (n = 40) received 250 ml 7.2% NaCl/6% HES solution and the control Ringer's acetate group (n = 40) received placebo (500ml Ringer's acetate solution) for volume correction after the surgery. Results. After infusion of HyperHaes® solution, cardiac index increased from 2.69 (0.7) to 3.52 (0.8)l/min/m2, systemic vascular resistance index, pulmonary vascular resistance index and the gradient between central and peripheral temperature decreased, and oxygen transport parameters improved. Ringer's group patients needed more intensive infusion therapy (4050.0 (1102.2) ml in the Ringer's group, 3513.7(762.5) ml in the HyperHaes® group). During the first 24 hours postoperatively, diuresis was significantly higher in the HyperHaes® group (3640.0 (1122.9) ml and 2736.0 (900.7) ml), total fluid balance was lower in HyperHaes® group (1405.6 (1519.0) ml and 2718.3 (1508.0) ml, respectively). After the infusion of HyperHaes ® solution, no adverse events were noted. Conclusions. HyperHaes ® solution had a positive effect on haemodynamic parameters and microcirculation. Oxygen transport was more effective after HyperHaes® solution infusion. Higher diuresis, lower need for the infusion therapy for the first 24 hours and lower total fluid balance were determined in the HyperHaes® group. No adverse effects were observed after HyperHaes® solution infusion. Perfusion (2007) 22, 121—127.
Perfusionists in the world of tissue engineering — a quick and easy method for safe isolation of huge quantities of porcine cardiomyocytes
Authors: Neumann Bernd , Guo Ketai , Paul Angela , Greiner Tim O. , Graessle Angelika , Walter Christian , Walker Tobias , Scheule Albertus , Ziemer Gerhard , Wendel Hans P.
Published: June 2007

Isolation of huge quantities of primary cells from whole organs like the heart becomes increasingly important, especially for the emerging research field of tissue engineering and regenerative medicine. This study deals with the isolation of pig cardiomyocytes, in contrast to the standard mouse or rat models, because we aimed to draw attention to the species, which are genetically more closely related to the human organism.

The bigger operative and veterinary expenditure of the pig-heart model can only be justified by a technique that supplies a big amount of qualitative high-grade cardiomyocytes. In our model, the quality is guaranteed by protection of the heart, already in situ, by a cardioplegia and a careful application of collagenase to soften the tissue. The construction of a new apparatus which includes enormous costs was not necessary, since the perfusion equipment was realized from two commercially available HLMsets, which were modified and connected to each other. Our model makes it possible to rinse the whole myocardium, which leads to a better output than models that only prepare a part of the myocardium around a coronary artery.

The careful harvesting of high-grade cardiomyocytes is an important source of successful cell cultures to be used for numerous experimental applications, may reduce animal experiments and, additionally, represents a chance for perfusionists to become an important partner in interdisciplinary research projects. Perfusion (2007) 22, 137—142.
Review Article: Comparison of perfusion modes on microcirculation during acute and chronic cardiac support: is there a difference?
Authors: Ji Bingyang , Ündar Akif
Published: June 2007

Although heart-lung machines and cardiac assist devices have been used successfully for acute and chronic cardiac support for decades, controversies still remain concerning the benefits of pulsatile and non-pulsatile perfusion. The core of the debate is whether enough energy is generated by the artificial pulse to keep capillary beds open and cell metabolism stabilized during acute or chronic cardiac support. In other words, does artificial pulsatility exist in the microcirculation: small vessels of less than 100 μm in diameter? Many investigators have tried to use different tools and biomarkers to reflect directly or indirectly the state of the microcirculation when comparing the two different perfusion modes during acute and chronic cardiac support. However, the results are controversial. First, direct observation of the state of the microcirculation during acute and chronic cardiac support is limited; and reports concerning direct observation of the microcirculation with different perfusion modes in contemporary literature are rare. Secondly, different investigators have used their own criteria to define pulsatile flow. Therefore, it is necessary to develop more efficient methodologies, enabling direct observation of the microcirculation during acute and chronic cardiac support and also establish common criteria that will precisely quantify the pulsatile flow in terms of energy equivalent pressure (EEP) and surplus hemodynamic energy (SHE) levels. Using these critical parameters may explain how excess energy is created by pulsatile flow and maintains perfusion through the microcirculation by ensuring capillary patency. Perfusion (2007) 22, 115—119.
Tissue and plasma concentrations of cephuroxime during cardiac surgery in cardiopulmonary bypass — a microdialysis study
Authors: Mand'ák J. , Pojar M. , Maláková J. , Lonsky V. , Palička V. , Zivný P.
Published: June 2007

Aim: Wound and mediastinal infections are still very serious complications of open-heart surgery, in spite of the use of prophylactic antibiotics. The use of cardiopulmonary bypass (CPB) is associated with profound physiological changes affecting the pharmacokinetic behaviour of antibiotics.

The aim of this pilot study was to monitor the tissue concentrations of cephuroxime (prophylactic antibiotic) in skeletal muscle during cardiac surgery using CPB by interstitial microdialysis. These concentrations were compared with plasma concentrations of cephuroxime.

Material and methods: Nine adult patients operated on using CPB were enrolled in this study. Cephuroxime was used as a prophylactic antibiotic (1st dose — 3 g of cefuroxime i.v. with anesthesia induction, 2nd dose — 1.5 g i.v. after CPB with protamine sulphate, 3rd dose — 1.5 g i.v. 8 hours after the surgery).

Interstitial microdialysis was performed by probe CMA 60 (CMA Microdialysis AB, Sweden) inserted into the patient's deltoid muscle. Concentrations of cephuroxime in dialysates and in plasma were determined by the modified fluid chromatography method. The unbound cephuroxime fraction in plasma was obtained by using an ultrafiltration method. Samples of dialysates were collected at the following intervals: before CPB, each 30 minutes of CPB, at the end of CPB. Samples of blood were collected at these intervals: incision, start of CPB, each 30 minutes of CPB, at the end of CPB, at the end of surgery. Concentrations of cephuroxime in tissue were corrected by in vivo recoveries of the microdialysis probes.

Results: Plasma concentrations of cephuroxime were 163.5 ± 40.1, 79.3 ± 17.4, 73.7 ± 16.8, 66.1 ± 18.3, 57.0 ± 10.9, 120.7 ± 29.9 (mg . L—1) and concentrations of free plasma fraction of cephuroxime were 119.5 ± 35.2, 67.8 ± 15.5, 66.0 ± 12.5, 54.8 ± 12.2, 49.6 ± 9.8, 102.6 ± 26.0 (mg . L—1).

The concentrations of cephuroxime in dialysates were 44.3 ± 15.7, 36.1 ± 11.6, 31.9 ± 9.3, 34.6 ± 12.3, 27.6 ± 12.9, 56.7 ± 17.6 (mg . L—1).

The mean in vivo recovery of cephuroxime in this study was 30%.

Corrected concentrations (calculated by in vivo recovery) of cephuroxime in skeletal muscle were 148, 120, 106, 115, 92, 189 (mg . L—1).

Conclusion: Our preliminary results show that CPB can modify the time course of cephuroxime plasma and tissue concentrations. A decrease in plasma drug concentrations occurred at the start of CPB and lasted until CPB ended. An increase in plasma concentrations corresponds to the second drug dose after CPB. The concentrations of cephuroxime in skeletal muscle (corrected by recovery) during CPB are higher than plasma concentrations. It is influenced by important changes during CPB; closely associated with hemodilution, a shift of intravascular volume, solutes and albumin to the extravascular space and inconstant protein binding of cephuroxime during operation. Perfusion (2007) 22, 129—136.
Prepulse inhibition of the startle reflex and its attentional modulation in the human S-ketamine and N,N-dimethyltryptamine (DMT) models of psychosis
Authors: Heekeren K. , Neukirch A. , Daumann J. , Stoll M. , Obradovic M. , Kovar K.-A. , Geyer M.A. , GouzouLis-Mayfrank E.
Published: June 2007

Patients with schizophrenia exhibit diminished prepuLse inhibition (PPI) of the acoustic startle reflex and deficits in the attentional moduLation of PPI. Pharmacological challenges with hallucinogens are used as models for psychosis in both humans and animals. RemarkabLy, in contrast to the findings in schizophrenic patients and in animal hallucinogen modeLs of psychosis, previous studies with healthy volunteers demonstrated increased levels of PPI after administration of low to moderate doses of either the antiglutamatergic hallucinogen ketamine or the serotonergic hallucinogen psilocybin. The aim of the present study was to investigate the influence of moderate and high doses of the serotonergic hallucinogen N,N-dimethyltryptamine (DMT) and the N-methyl-D-aspartate antagonist S-ketamine on PPI and its attentional modulation in humans. Fifteen healthy volunteers were included in a double-blind cross-over study with two doses of DMT and S-ketamine. Effects on PPI and its attentional modulation were investigated. Nine subjects completed both experimental days with the two doses of both drugs. S-ketamine increased PPI in both dosages, whereas DMT had no significant effects on PPI. S-ketamine decreased and DMT tended to decrease startle magnitude. There were no significant effects of either drug on the attentional modulation of PPI. In human experimental hallucinogen psychoses, and even with high, clearly psychotogenic doses of DMT or S-ketamine, healthy subjects failed to exhibit the predicted attenuation of PPI. In contrast, PPI was augmented and the startle magnitude was decreased after S-ketamine. These data point to important differences between human hallucinogen models and both animal hallucinogen models of psychosis and naturally occurring schizophrenia.
Impaired tight junction sealing and precocious involution in mammary glands ofPKN1transgenic mice
Authors: Fischer Andreas , Stuckas Heiko , Gluth Markus , Russell Tanya D. , Rudolph Michael C. , Beeman Neal E. , Bachmann Sebastian , Umemura Shinobu , Ohashi Yasuhiro , Neville Margaret C. , Theuring Franz
Published: June 2007

The mammary gland undergoes a complex set of changes to establish copious milk secretion at parturition. To test the hypothesis that signaling through the Rho pathway plays a role in secretory activation, transgenic mice expressing a constitutively activated form of the Rho effector protein PKN1 in the mammary epithelium were generated. PKN1 activation had no effect in late pregnancy but inhibited milk secretion after parturition, diminishing the ability of transgenic dams to support a litter. Mammary gland morphology as well as increased apoptosis and expression of IFGBP5 and TGFβ3 suggest precocious involution in these animals. Furthermore, tight junction sealing at parturition was impaired in transgenic mammary glands as demonstrated by intraductal injection of [14C]sucrose. Consistent with this finding, tight junction sealing in response to glucocorticoid stimulation was highly impaired in EpH4 mammary epithelial cells expressing constitutively activated PKN1, whereas expression of a dominant-negative PKN1 mutant resulted in accelerated tight junction sealing in vitro. Tight junction formation was not impaired as demonstrated by the correct localization of occludin and ZO1 at the apical cell borders. Our results provide evidence that PKN1 participates in the regulation of tight junction sealing in the mammary gland by interfering with glucocorticoid signaling.
Relationships between Productivity, Physical Habitat, and Aquatic Invertebrate and Vertebrate Populations of Forest Streams: An Information‐Theoretic Approach
Authors: Kiffney P. M. , Roni P.
Published: June 2007

Freshwater ecosystems worldwide are threatened by habitat degradation resulting in widespread population declines or extinction of invertebrate and vertebrate taxa. Millions of dollars are spent annually on efforts to restore the physical complexity of degraded habitats, such as adding wood to streams. The efficacy of these efforts may be limited, however, because basal productivity (availability of nutrients, algae, bacteria, and organic matter) and predation also constrain the abundance and diversity of stream biota. Using light input as a surrogate for basal productivity, we examined the relative importance of predation, productivity, and physical habitat in explaining the variation in invertebrate and vertebrate populations in small forest streams of coastal Oregon. Our results suggest that aquatic populations are limited by these factors individually and in combination as well as by their interactive effects. For example, invertebrate taxa richness was best predicted by basal productivity, and richness was positively correlated with light. Total vertebrate biomass was positively related to both basal productivity and physical habitat, and the top‐ranked model included light input and velocity. The top‐ranked model explaining variation in the biomass of the coastal giant salamander Dicamptodon tenebrosus was a single‐variable model that included the interaction of basal productivity with channel slope. Streams are dynamic environments, and species living within these ecosystems are probably affected by multiple, interacting factors. Our results support this notion and suggest that, in some cases, restoring physical habitat may have minimal effect on stream communities if productivity at lower trophic levels is also limiting.
Versão brasileira da Escala de Estresse Percebido: tradução e validação para idosos
Authors: Luft Caroline Di Bernardi , Sanches Sabrina de Oliveira , Mazo Giovana Zarpellon , Andrade Alexandro
Published: June 2007

OBJETIVO: Traduzir a Escala de Estresse Percebido para a língua portuguesa do Brasil e verificar sua validade para mensurar o estresse percebido de idosos brasileiros. MÉTODOS: A escala foi traduzida e testada em sua versão completa, com 14 questões e na reduzida, com dez questões. A tradução obedeceu às etapas de tradução, tradução reversa e revisão por um comitê. A escala traduzida foi aplicada, por meio de entrevista, a 76 idosos com idade média de 70,04 anos (DP=6,34; mín: 60; máx: 84). A consistência interna foi verificada por meio do coeficiente alfa de Cronbach e a validade de construto, por análise fatorial exploratória com rotação ortogonal pelo método varimax. As médias das versões completa e reduzida foram analisadas comparando o estresse percebido em função da auto-avaliação da saúde, nível econômico percebido, estado civil, condições de residência, entre outras. RESULTADOS: Quanto à confiabilidade, a versão completa apresentou consistência interna semelhante (r=0,82) à reduzida (r=0,83). A análise fatorial revelou a existência de dois fatores para a completa e um para a reduzida. A questão 12 apresentou as menores cargas fatoriais. Ao analisar a possibilidade de a escala diferenciar o estresse percebido em função das variáveis, verificou-se que a versão completa obteve maiores diferenças no estresse do que a reduzida. CONCLUSÕES: A Escala de Estresse Percebido mostrou-se clara e confiável para mensurar o estresse percebido de idosos brasileiros, apresentando qualidades psicométricas adequadas.
Desigualdad socioeconómica y salud mental: revisión de la literatura latinoamericana
Authors: Ortiz-Hernández Luis , López-Moreno Sergio , Borges Guilherme
Published: June 2007

El objetivo fue analizar la producción científica realizada en América Latina que indaga el impacto de la condición socioeconómica sobre los trastornos mentales y el uso o dependencia a sustancias. Se revisaron bases de datos internacionales y regionales. En la mayoría de los estudios se ha observado que en adultos y adolescentes pertenecer a estratos socioeconómicos bajos se asocia con mayor riesgo de trastornos mentales. El consumo de alcohol es mayor entre las personas con mejores condiciones socioeconómicas; en el caso del abuso y la dependencia al alcohol se observa una tendencia opuesta, aunque la evidencia para los últimos es menos contundente. En adolescentes el tabaquismo es más frecuente entre los que provienen de hogares con mejores condiciones socioeconómicas; sin embargo, entre los adultos la mayor probabilidad se encuentra entre los de peor situación económica. En adultos el consumo de drogas ilegales es más frecuente entre las personas de nivel socioeconómico inferior. Las drogas médicas tienden a ser más consumidas por adultos y adolescentes con mejor situación socioeconómica. El uso de solventes es más frecuente entre adolescentes de estratos bajos.
Healthcare organizations, linguistic communities, and the emblematic model of palliative care
Authors: Vasconcellos-Silva Paulo R. , Rivera Francisco Javier Uribe , Siebeneichler Flávio Beno
Published: June 2007

The linguistic-communicative paradigm offers some interesting perspectives in a context where the perception of patient needs is considered a critical step in high-quality care. This study describes healthcare organizations as linguistic communities based on the conceptual framework of Habermas' communicative action theory. Four communicative models are present in healthcare settings: objectifying-instrumental (hegemonic model), where elements of interaction are objectified for clinical purposes; dialogic model with strategic perspectives, in which conversations are used unilaterally as tools to access subjective states; non-dialogic-transmissional model, in which linguistic exchanges are replaced with artifacts to transmit information; and full communicative model (present in palliative care based in homecare and informal caregivers, emphasizing health team/family interactions). Based on these premises, we considered palliative care an emblematic communicative model based on multidisciplinary teams devoted to transdisciplinary collaboration. In these settings, linguistic interaction with patients and their families could provide a solid basis for organization of healthcare networks.
Targeted Radiotherapy: Microgray Doses and the Bystander Effect
Authors: Mairs Robert J. , Fullerton Natasha E. , Zalutsky Michael R. , Boyd Marie
Published: June 2007

Indirect effects may contribute to the efficacy of radiotherapy by sterilizing malignant cells that are not directly irradiated. However, little is known of the influence of indirect effects in targeted radionuclide treatment. We compared γ-radiation-induced bystander effects with those resulting from exposure to three radiohaloanalogues of meta-iodobenzylguanidine (MIBG): [131I]MIBG (low linear energy transfer (LET) β-emitter), [123I]MIBG (high LET Auger electron emitter), and meta-[211At]astatobenzylguanidine ([211At]MABG) (high LET α-emitter). Cells exposed to media from γ-irradiated cells exhibited a dose-dependent reduction in survival fraction at low dosage and a plateau in cell kill at > 2 Gy. Cells treated with media from [131I]MIBG demonstrated a dose-response relationship with respect to clonogenic cell death and no annihilation of this effect at high radiopharmaceutical dosage. In contrast, cells receiving media from cultures treated with [211At]MABG or [123I]MIBG exhibited dose-dependent toxicity at low dose but elimination of cytotoxicity with increasing radiation dose (i.e. U-shaped survival curves). Therefore radionuclides emitting high LET radiation may elicit toxic or protective effects on neighboring untargeted cells at low and high dose respectively. We conclude that radiopharmaceutical-induced bystander effects may depend on LET and be distinct from those elicited by conventional radiotherapy.
Morphological variation in the Weberian apparatus of Cypriniformes
Authors: Bird Nathan C. , Hernandez L. Patricia
Published: June 2007

Cypriniformes (which includes the minnows, carps, loaches, algae‐eaters, stone loaches, and suckers) is a morphologically diverse and incredibly speciose order of teleosts. It has been suggested that a number of evolutionary innovations, key to improved hearing and feeding, have played an important role in cypriniform fishes' success. One such innovation, the Weberian apparatus, is a novel assemblage of vertebral elements and modified ribs that relay and amplify sound pressure changes from the gas bladder to the inner ear. The Weberian apparatus unites Cypriniformes with other major orders into an extremely species‐rich group of fishes, the Otophysi. Together, otophysan fishes comprise one of the largest groups of fishes in the world, as well as the majority of freshwater fishes. Here we present a detailed comparison of the Weberian apparatus in a number of cypriniform families using cleared and stained specimens. We present data regarding inter‐ and intrafamilial morphological variation within Cypriniformes. With few, but evolutionarily important, exceptions we find that diagnostic features of the Weberian apparatus characterize each family. Interspecific variation within each of the families Balitoridae, Gyrinocheilidae, and Catostomidae is only slight, whereas variation among subfamilies within Cyprinidae and Cobitidae is far more significant. This comparative study identifies a number of distinct morphologies, some of which appear highly correlated with ecological niche. For example, inhabiting swift‐moving waters appears to be a key factor in the encapsulation of the anterior gas bladder in some cobitids, balitorids, and gobionin cyprinids. J. Morphol., 2007. © 2007 Wiley‐Liss, Inc.
Skeletal muscle fiber type conversion during the repair of mouse soleus: Potential implications for muscle healing after injury
Authors: Matsuura Tetsuya , Li Yong , Giacobino Jean‐Paul , Fu Freddie H. , Huard Johnny
Published: June 2007

We used a mouse model of cardiotoxin injury to examine fiber type conversion during muscle repair. We evaluated the soleus muscles of 37 wild‐type mice at 2, 4, 8, and 12 weeks after injury. We also used antibodies (fMHC and sMHC) against fast and slow myosin heavy chain to classify the myofibers into three categories: fast‐, slow‐, and mixed (hybrid)‐type myofibers (myofibers expressing both fMHC and sMHC). Our results revealed an increase in the percentage of slow‐type myofibers and a decrease in the percentage of fast‐type myofibers during the repair process. The percentage of hybrid‐type myofibers increased 2 weeks after injury, then gradually decreased over the following 6 weeks. Similarly, our analysis of centronucleated myofibers showed an increase in the percentage of slow‐type myofibers and decreases in the percentages of fast‐ and hybrid‐type myofibers. We also investigated the relationship between myofiber type conversion and peroxisome proliferator‐activated receptor‐γ coactivator‐1α (PGC‐1α). The expression of both PGC‐1α protein, which is expressed in both the nucleus and the cytoplasm of regenerating myofibers, and sMHC protein increased with time after cardiotoxin injection, but we observed no significant differential expression of fMHC protein in regenerating muscle fibers during muscle repair. PGC‐1α‐positive myofibers underwent fast to slow myofiber type conversion during the repair process. These results suggest that PGC‐1α contributes to myofiber type conversion after muscle injury and that this phenomenon could influence the recovery of the injured muscle. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1534–1540, 2007
Reserve mobilisation in mesquite (Prosopis juliflora) seed (Leguminosae)
Authors: Gallão Maria I , Vieira Ícaro GP , Mendes Francisca NP , de Souza Alex SN , de Brito Edy S
Published: June 2007

The seeds of Prosopis juliflora (mesquite) have a water barrier composed of the palisade layer present in the seed tegument and galactomannans in the endosperm. Changes in the morphological and physiological states of seeds are usually accompanied by changes in their metabolism. The aim of this study was to detect and characterise the main reserves and their mobilisation during and following germination of P. juliflora seeds. Sections of seeds 0, 24, 48 and 72 h after the onset of the imbibing process were evaluated by light microscopy, and seed reserves were extracted and quantified. Polysaccharides were isolated and characterised by 1H nuclear magnetic resonance (NMR) spectroscopy. In mesquite seeds a well‐developed endosperm, consisting largely of the storage carbohydrate (galactomannans), lies between the seed coat and the cotyledons. Germination was complete after 24 h of imbibition. At this time, morphological changes were observed in stained protein bodies. Chemical analysis showed a decrease in protein levels until 48 h. After 48 h, globular structures were observed in the cotyledon cells, but after 72 h these grains were smaller and their content was reduced. Polarisation microscopy confirmed that this material was composed of starch grains. The 1H NMR spectrum of P. juliflora seeds showed that sucrose was used following germination. Apparently, sucrose is the transport sugar mobilised from reserve stocks for seedling growth. Parallel to endosperm galactomannan degradation, starch is produced transitorily in the cotyledon. Copyright © 2007 Society of Chemical Industry
Dose dependency between cigarette consumption and reduced maternal serum PAPP‐A levels at 11–13+6 weeks of gestation
Authors: Kagan K. O. , Frisova V. , Nicolaides K. H. , Spencer K.
Published: June 2007

Objective

To examine whether in smokers there is a significant dose dependency between the number of cigarettes per day and levels of free ß‐hCG and pregnancy‐associated plasma protein A (PAPP‐A) at 11–13+6 weeks of gestation.

Methods

This was a retrospective analysis of the maternal serum free ß‐hCG and PAPP‐A levels in relation to the maternal smoking status in 109 263 chromosomally normal singleton pregnancies that had undergone first‐trimester screening for Down syndrome by a combination of fetal nuchal translucency thickness and maternal serum biochemistry.

Results

There were 95 287 nonsmokers and 13 976 cigarette smokers. The overall median PAPP‐A MoM among cigarette smokers was 0.827, which was 19.6% lower than the value of 1.029 in nonsmokers (p < 0.0001 for log10 MoM). The respective values for β‐hCG MoM were 1.003 for smokers and 1.035 for nonsmokers (p < 0.0001 for log10 MoM) which corresponds to a reduction of 3.1%. There was a significant inverse relationship between the number of cigarettes per day and the level of PAPP‐A MoM (r = 0.989, p < 0.0001) but not the level of free β‐hCG MoM (r = 0.733; p = 0.098). Using a statistical modeling approach we found that the screen‐positive rate when correcting the PAPP‐A MoM by an all or nil smoking factor was reduced by only 0.1% (3.75 vs 3.85%) when compared to correcting with a factor related to the smoking dose per day.

Conclusion

In first‐trimester screening for Down syndrome by maternal serum PAPP‐A and free β‐hCG the impact of correcting for the dose dependant rather than the all or nil effect of smoking is marginal. However, a dose dependent correction improves the accuracy of the individual patient‐specific risk. Copyright © 2007 John Wiley & Sons, Ltd.
Whistler scattering of suprathermal electrons in the solar wind: Particle‐in‐cell simulations
Authors: Saito Shinji , Gary S. Peter
Published: June 2007

Solar wind observations sometimes show that suprathermal, magnetic field‐aligned, strahl electrons have pitch angle distributions which become broader in width as electron kinetic energy increases. Magnetosonic‐whistler waves propagating sunward at k × Bo = 0 where Bo is the background magnetic field and k is the wave number have a cyclotron resonance with electrons propagating in the anti‐sunward direction. This resonance leads to pitch angle scattering which increases strahl electron energy perpendicular to Bo. The strahl response to a broadband whistler fluctuation spectrum was studied using Particle‐In‐Cell (PIC) simulations in a magnetized, homogeneous, collisionless plasma. The simulations show that enhanced whistler waves with finite damping lead to strahl pitch angle distributions which broaden in width with increasing kinetic energy, in agreement with certain observations. Results from the simulations show how the strahl is broadened as a function of wave amplitude and relative strahl density.
Divergence of hypertrophic growth and fetal gene profile: the influence of β‐blockers
Authors: Du X‐J
Published: June 2007

While the expression patterns of cardiac hypertrophy‐related genes have been well documented and widely used as markers for hypertrophy, recent research has revealed uncoupling of hypertrophy‐related gene profiles and hypertrophic growth. The role of β‐adrenergic signalling in the development of hypertrophy is incompletely understood. The finding of an upregulated expression of hypertrophy‐related genes but a suppressed hypertrophy following β‐blockade reveals previously unrecognized sympatho‐adrenergic mechanisms of hypertrophic growth.

British Journal of Pharmacology (2007) 152, 169–171; doi:10.1038/sj.bjp.0707353
Extrapolating to the one-electron basis-set limit in electronic structure calculations
Authors: Varandas A. J. C.
Published: June 2007

A simple, yet reliable, scheme based on treating uniformly singlet-pair and triplet-pair interactions is suggested to extrapolate atomic and molecular electron correlation energies calculated at two basis-set levels of ab initio theory to the infinite one-electron basis-set limit. The novel dual-level method is first tested on extrapolating the full correlation in single-reference coupled-cluster singles and doubles energies for the closed-shell systems CH2(A11), H2O, HF, N2, CO, Ne, and F2 with correlation-consistent basis sets of the type cc-pVXZ (X=D,T,Q,5,6) reported by Klopper [Mol. Phys. 6, 481 (2001)] against his own benchmark calculations with large uncontracted basis sets obtained from explicit correlated singles and doubles coupled-cluster theory. Comparisons are also reported for the same data set but using both single-reference Møller-Plesset and coupled-cluster doubles methods. The results show a similar, often better, accordance with the target results than Klopper’s extrapolations where singlet-pair and triplet-pair energies are extrapolated separately using the popular X−3 and X−5 dual-level laws, respectively. Applications to the extrapolation of the dynamical correlation in multireference configuration interaction calculations carried out anew for He, H2, HeH+, He2++, H3+(1A′1), H3+(1A′3), BH, CH, NH, OH, FH, B2, C2, N2, O2, F2, BO, CO, NO, BN, CN, SH, H2O, and NH3 with standard augmented correlation-consistent basis sets of the type aug-cc-pVXZ (X=D,T,Q,5,6) are also reported. Despite lacking accurate theoretical or experimental data for comparison in the case of most diatomic systems, the new method also shows in this case a good performance when judged from the results obtained with the traditional schemes which extrapolate using the two largest affordable basis sets. For the Hartree-Fock and complete-active space self-consistent field energies, a simple pragmatic extrapolation rule is examined whose results are shown to compare well with the ones obtained from the best reported schemes.
Optical properties of vacancies in thermochemically reduced Mg-doped sapphire single crystals
Authors: Ramírez R. , Tardío M. , González R. , Muñoz Santiuste J. E. , Kokta M. R.
Published: June 2007

Optical absorption and emission experiments were used to characterize defects and defect aggregates in Mg-doped Al2O3 crystals due to thermochemical reduction at high temperatures. Oxygen vacancies and higher-order defects are produced much more readily in Mg-doped than in undoped Al2O3 crystals. F+ and F centers (oxygen vacancies with one or two electrons, respectively) were monitored by their optical absorption bands at about 4.8 and 6.0eV, respectively. In contrast with undoped crystals, where the reduction produces primarily F centers and a small amount of F+ centers, in Mg-doped crystals both F and F+ centers are created in comparable concentrations. These thermally generated F and F+ centers are much more stable than those produced in undoped crystals irradiated with neutrons. Clustering of individual oxygen vacancies forming higher-order defects, such as anion divacancy F22+ and F2+ centers, was investigated by low temperature absorption and luminescence experiments, in conjunction with UV irradiation and thermal treatments. The strong absorption bands at 2.87 and 3.69eV were shown to be due to Mg-perturbed F22+ and F2+ centers, respectively. In addition, photoconversion of F22+ and F2+ centers was observed. In crystals containing large concentrations of F22+ centers, electrons excited by 5.0eV light are trapped by F22+ and F2+ centers resulting in the conversion of F22+ centers into F2+. A model of F-type centers was extended to F22+ and F2+ centers. The calculated optical parameters are in very good agreement with those determined experimentally. A simple analysis of the lattice energy suggests that the environments of the F2-type centers are different in TCR Al2O3 crystals and in n-irradiated undoped crystals.
Direct measurement of the group index of photonic crystal waveguides via Fourier transform spectral interferometry
Authors: Gomez-Iglesias Alvaro , O’Brien David , O’Faolain Liam , Miller Alan , Krauss Thomas F.
Published: June 2007

The authors report a direct, single-shot measurement of the group index profile of photonic crystal waveguides, combining spectral interferometry with Fourier transform analysis. This technique’s versatility allows them to resolve subtle changes in dispersion and to quantify the “slow light” effect at the photonic crystal waveguide mode cutoff. For a waveguide 99μm long, they measure a group index up to 85, whereas for lengths of 397 and 695μm, they measure maximum values of 30 and 25, respectively. These results show the relationship between transmission characteristics and the maximum group delay observed in photonic crystals.
From Source Material to News Story in New Zealand Print Media: A Prospective Study of the Stigmatizing Processes in Depicting Mental Illness
Authors: Nairn Raymond , Coverdale John , Claasen Donna
Published: June 2007

Objective: The aim of this study was to analyse how newspaper articles that depict mental illnesses are generated from source materials.

Method: From a prospectively collected national sample of print materials involving mental illness, 50 published items that related to the Privacy Commissioner's opinion about disclosure of a psychiatric patient's health information were identified. A copy of the Privacy Commissioner's original Case Note and three news stories about the Case Note distributed by the New Zealand Press Association constituted the database. These materials were subjected to discourse analysis. We identified themes and their transformation from the Case Note through the news stories and examined the impact of these transformations on the stigmatization of mental illness.

Results: Four themes were identified: human rights, vulnerability, risk of dangerousness and threat, and mental illness/psychiatric patient. The only potentially positive theme, human rights, was limited both by being fragmented in the source material, and by being utilized, in the published news stories to undermine the legitimacy of the patient's right to privacy. Use of the other themes was consistent with stereotypes about mental illness.

Conclusions: Although there were no inaccuracies in the content of the news stories they were substantially more negative than the source material in their depiction of the identified patient. A potentially positive discourse (human rights) was not by itself sufficient to ensure a positive portrayal of mental illness. An understanding of the transformations is important for efforts to effectively combat the stigmatization of those with mental illness.
Mania Pre-Lithium
Authors: Cawte John
Published: June 2007

The changes that lithium brought are most fully understood when we grasp the difficulties for management that acute mania presented. Restraint in canvas camisoles, padded cells, paraldehyde, water-baths and salts—Epsom, not Lithium—met mania in echos of Bedlam still heard in the early 1950s. It is a part of psychiatric history important to remember.
A Psychological Approach to Research on Teachers' Classroom Decision‐making
Authors: Calderhead James
Published: June 2007

A number of different approaches to research on teachers' classroom decision‐making have developed over recent years. This paper outlines a psychological approach, and points out that several exploratory studies of teachers' thoughts and decision‐making indicate that, in the classroom, teachers rarely make decisions in the sense of making choices amongst alternatives at all. It would appear instead that they respond in a rule‐fashioned manner to particular configurations of cues, many of which concern attributes of their pupils. In addition, decision‐making research suggests that several commonly found classroom interaction patterns serve managerial, as opposed to instructional, functions. Whether this is due to inadequacies of the research methods and research designs employed or to the very nature of teaching is problematic. However, differences found between experienced and probationer teachers in both cognitive and behavioural variables would suggest that decision‐making research may make a useful contribution to teacher training.
Practical Work in 11‐13 Science: the context, type and aims of current practice
Authors: Beatty J.W. , Woolnough B.E.
Published: June 2007

It is common experience that a very large amount of science teaching for 11‐13‐year‐olds in the schools of England and Wales is practically based, but little work seems to have been done to investigate it more fully — to analyse the amount, the type and the aims of practical work which science teachers have. This article describes the findings of some research done in 1978 and 79 to study the amount and type of science being taught to the 11‐13‐year‐olds and the aims that their teachers had for doing practical work in it. The results are discussed, and the changes of science teachers aims to practical work since 1962 are considered.
Middle School Attitude Survey
Authors: Taylor Graham , Sayer Brian
Published: June 2007

The investigation explored some aspects of attitudes held by teachers towards the 9‐13 Middle School. The data were obtained from teachers working in 9‐13 Middle Schools within one northern Metropolitan District. The sample consisted of 708 Middle School teachers, from a total Middle School teaching population of 1063 teachers. The data were collected during the period November 1980 to March 1981. Findings indicated that a majority of these practising teachers held positive attitudes towards the 9‐13 Middle School. Separate ratings were obtained for a variety of subgroups within the total population based on age, sex, status in school and previous training and experience.

A questionnaire, in addition to the attitude questionnaire, produced data indicating almost a 2:1 preference for the 9‐13 as opposed to the 8‐12 Middle School. Even accepting the fact that some teachers may prefer the status quo when asked to state a preference in an unstable educational climate such as we have now, it is still felt to be revealing that such a large majority indicated favour for the 9‐13 Middle School. It was also found that over 70% of all the sample teachers found working in a 9‐13 Middle School a satisfying experience.
Teacher Receptivity to System‐wide Change
Authors: Waugh Russell F. , Punch Keith F.
Published: June 2007

This study is concerned with the receptivity of teachers in Western Australia towards the recently implemented Certificate of Secondary Education System, a new method of certifying student achievement using teachers' assessments. A general model of teacher receptivity towards system‐wide educational change is developed, and forms the basis for an empirical investigation with a large and representative sample of teachers. Using correlation and regression techniques, the results show a clear pattern of relationships between the independent variables and teacher receptivity.
Denominational Schools and Pupil Attitude Towards Christianity
Authors: Francis L. J.
Published: June 2007

Summary The 1944 Education Act enables the churches in England to provide voluntary aided schools. The Roman Catholic church currently provides 9.9% of state maintained primary school places and the Church of England provides 7.9% through voluntary aided schools. In order to evaluate the influence of church voluntary aided schools on pupil attitudes towards Christianity, an attitude scale was administered to three generations of third and fourth year junior pupils in the same 15 county schools, 10 Church of England aided schools and five Roman Catholic aided schools in 1974, 1978 and 1982. After controlling for a range of other influences, the data demonstrate the positive influence of Roman Catholic schools on pupil attitude towards Christianity and the negative influence of Church of England Schools. The direction of the school influence on pupil attitude is consistent for all three samples.