bluuebunny/crossref_metadata_2025 huggingface dataset:
Can Overconfidence be Debiased by Low‐Probability/High‐Consequence Events?
Authors: Li Shu , Li Jin‐Zhen , Chen Yi‐Wen , Bai Xin‐Wen , Ren Xiao‐Peng , Zheng Rui , Rao Li‐Lin , Wang Zuo‐Jun , Liu Huan
Published: February 2010

During the first half of 2008, China suffered three natural disasters: a heavy snow storm, an outbreak of hand‐foot‐mouth disease, and a severe earthquake. The aim of the present study is to explore how low‐probability/high‐consequence events influence overconfidence. In Study 1, opportunity samples were obtained by recruiting residents in three different types of disaster‐hit areas to answer a peer‐comparison probability judgment questionnaire about 1 month after the corresponding disaster occurred. The performance of 539 participants in disaster‐hit areas was compared with that of 142 residents in a nondisaster area. The findings indicate that residents in disaster‐hit areas were less overconfident than those in the nondisaster area on both positive and negative events. In Study 2, we surveyed a total of 336 quake‐victims 4 and 11 months after the earthquake to examine whether the impact of disasters on overconfidence would decay with time. The resulting data indicate that the disaster victims became more overconfident as time elapsed. The overall findings suggest that low‐probability/high‐consequence events could make people less overconfident and more rational and seem to serve as a function of debiasing.
Estimation of Risk Assessment of Some Heavy Metals Intake Through Black Scabbardfish (Aphanopus carbo) Consumption in Portugal
Authors: Cardoso Carlos , Farias Inês , Costa Valentina , Nunes Maria , Gordo Leonel
Published: February 2010

The intake of Cd, methyl‐Hg, and Pb through consumption of black scabbardfish (BSF) (Aphanopus carbo) in Portugal as well as the associated probability of exceeding the respective provisional tolerable weekly intakes (PTWIs) was estimated. For this purpose, the contamination levels of heavy metals in this fish species were combined with constructed consumption scenarios or with a hypothesized consumption distribution. Whereas Cd and Pb posed no serious risk, the consumption of at least one portion of BSF per month as well as the hypothetical study in the Portuguese population produced nonnegligible probabilities of surpassing the PTWI for Me‐Hg. Risk assessment for Portuguese consumers revealed a higher risk regarding Me‐Hg, 1.19% and 1.81% with the plug‐in (PI) and the tail estimation (TE) estimators, respectively. On the other hand, the risk for Cd and Pb was less than 1 in 100,000. TE was more realistic and accurate for Cd and Pb. Concerning Me‐Hg, TE and PI estimators produced similar results. Furthermore, the limitations of a deterministic approach were shown.
Market Orientation, Ownership Type, and E‐Business Assimilation: Evidence from Chinese Firms
Authors: Li Dahui , Chau Patrick Y. K. , Lai Fujun
Published: February 2010

While more and more firms have implemented e‐business in business operations, a better understanding of the factors that successfully drive the assimilation of e‐business will provide insights for firm executives and practitioners to develop effective strategies for e‐business. Different from previous studies that focus on individual‐level factors related to business executives and top management teams, this study examines how firm‐level strategic and cultural factors shape e‐business assimilation. Based on the strategy and marketing literature on market orientation and firm ownership, we developed a research model to describe how a firm's market orientation impacts e‐business assimilation. The model also describes the moderating effect of firm ownership type on the relationship between market orientation and e‐business assimilation. Based on data from 301 Chinese international trade firms, we found that two dimensions of market orientation (i.e., customer orientation, competitor orientation) had significant effects on e‐business assimilation. However, the third dimension, interfunctional coordination, was only partially significant. In addition, ownership type was a significant moderator of the effects of customer orientation and competitor orientation on e‐business assimilation, although ownership type was not a moderator of interfunctional coordination. Being one of the first studies of the impact of market orientation and firm ownership type on e‐business assimilation, we conclude with a discussion of the implications for future research and practice.
The Politics of Regulation: Adolescent Mothers and the Social Context of Resiliency
Authors: Silver Lauren
Published: February 2010

Abstract: The experiences of adolescent mothers have too often been reduced to patterns of correlation linking teenage parenthood with low educational attainment, persistent poverty and continued welfare dependency. These analyses have reinforced representations of an “undeserving poor” and the tendency to “blame the victim” for her structural condition and her dependence on the state. Researchers in adolescent development have attempted to move beyond pathologizing frameworks by considering the “resiliency” of young mothers; yet their contributions have been limited by the tendency to reduce experience to the level of psychological coping mechanisms. In this article, I build upon more recent work as I explore the multifaceted ways in which resiliency can be interpreted. Drawing from the experiences of adolescent mothers within the care of the child welfare system, I illustrate empirically that resiliency is not an intrinsic, psychological characteristic but rather, shifts in relation to particular social contexts and policies.
Beyond Today and Pass Tomorrow: Self‐Efficacy Among African‐American Adolescent Mothers
Authors: Rodriguez Cheryl
Published: February 2010

Abstract: In the 21st century, African‐American youth continue to be negatively defined by the media, by educators, and even some youth‐focused organizations as either super‐predators or super‐breeders. Black teenage mothers, in particular, are held responsible for poverty, escalating school dropout rates, child abuse and neglect, welfare dependence, despair and crime. Despite the persistence of these negative portrayals, researchers who strive to understand the lives of African‐American girls find that there are both subtle and overt forms of resistance to negative stereotyping as well as nuanced and creative strategies for self‐definition. This paper describes a research project that allowed some brief glimpses into the lives of teenage mothers in two low‐income communities. I discuss expressions of self‐efficacy that emerged in interviews with these young women and the critical need for youth programs in low‐income communities. I also include some programmatic suggestions that are specific to teen mothers and discuss the importance of feminist anthropology in research on community‐based youth programs.
Climatic adaptation in an isolated and genetically impoverished amphibian population
Authors: Orizaola Germán , Quintela María , Laurila Anssi
Published: February 2010

The capacity of populations to respond adaptively to environmental change is essential for their persistence. Isolated populations often harbour reduced genetic variation, which is predicted to decrease adaptive potential, and can be detrimental under the current scenarios of global change. In this study, we examined climatic adaptation in larval life history traits in the pool frogRana lessonaealong a latitudinal gradient across the northern distribution area of the species, paying special attention to the isolated and genetically impoverished fringe populations in central Sweden. Larvae from eight populations within three geographic areas (Poland, Latvia and Sweden) were reared under three temperatures (19, 22 and 26°C) in a common garden laboratory experiment. We found clear evidence for latitudinal adaptation inR. lessonaepopulations, larvae from higher latitudes growing and developing faster than low‐latitude ones. Larvae from the Swedish populations were able to compensate for the effects of cooler temperatures and a shorter growth season with genetically higher growth and development rates (i.e. countergradient variation) in the two higher temperature treatments, but there was no difference among the populations at the lowest temperature treatment, which is likely to be close to the temperature limiting growth inR. lessonae. Our results demonstrate that isolated and genetically impoverished populations can be locally adapted, and identify the Swedish fringe populations as a significant conservation unit adapted to the northern environmental conditions.
Brain abscess in children – epidemiology, predisposing factors and management in the modern medicine era
Authors: Shachor‐Meyouhas Y , Bar‐Joseph G , Guilburd JN , Lorber A , Hadash A , Kassis I
Published: February 2010

Aims:  Brain abscess is rare in children. Predisposing factors are found in almost 85% of cases. Overall, 25% of brain abscesses develop in children, mostly in the 4–7 years age group. Our study aimed to characterize children with brain abscesses treated in our hospital, identify risk factors, pathogens and short‐term outcome.

Methods:  A retrospective cohort of 20 years period, (1989–2009) included 27children (0–18 years). Medical records were analysed for age, gender, presenting symptoms and signs, predisposing factors, laboratory tests, imaging, microbiology results, treatment and outcome.

Results:  Of all the children, 63% (17/27) were male patients; mean age was 7.9 years and 52% were referred from other hospitals. Predisposing factors were identified in 81%, congenital heart disease and otitis were rare and sinusitis was found in 22% of the children. Main symptoms and signs included headaches, fever, neurological signs convulsions, (41%, 81%, 78% and 41% respectively). In 30% of cases, cultures were sterile. All patients were operated in addition to antibiotic treatment. Outcome was good with low mortality rate (3.7%).

Conclusions:  Manifestations of brain abscess may be subtle. A high index of suspicion and early imaging are warranted, different predisposing factors may reflect early intervention for congenital heart diseases. Mortality is rare in the modern medicine era.
GDP RIP (1933–2010)
Authors: Marks Nic
Published: February 2010

When a nation's Gross Domestic Product goes up, politicians glow with pride. When it goes down, headlines shout doom. Yet GDP says nothing about the real health of a nation. It measures nobody's happiness; it tells no one how much we are destroying our environment or our children's future. It ignores all the important measures of human life. Nic Marks says it is time we replaced this outmoded measurement with something more useful.
The Politick Survey of a Kingdome: The First Statistical Template?
Authors: Lewin Chris
Published: February 2010

A chance discovery led Chris Lewin to a manuscript dated 1631. It seems to be a set of instructions for a budding statistician. Is this pioneer effort the first framework for statistics in English?
Genetic Toxicology of Dental Composite Resin Extracts in Somatic Cells In Vivo
Authors: Arossi Guilherme Anziliero , Dihl Rafael Rodrigues , Lehmann Mauricio , Reguly Maria Luiza , De Andrade Heloísa Helena Rodrigues
Published: February 2010

Abstract:  The aim of this study was to assess the potential genetic toxicity associated to nine aqueous extracts from dental composite resins (Charisma, Fill Magic, Fill Magic Flow, Durafill, TPH Spectrum, Concept, Natural Look, Filtek Z250 and Filtek P60) and one random extract. Homologous mitotic recombination, point and chromosomal mutation effects were determined in somatic proliferative cells of Drosophila melanogaster exposed to aqueous extracts of the clinically used composites. Reproducible increases in clone mutant spot frequencies induced by diluted extract of Fill Magic Flow were observed. These increments were exclusively associated to the induction of homologous recombination – a genetic phenomenon involved in the loss of heterozygosis. The other eight composite resins and the random extract had no statistically significant effect on total spot frequencies – suggesting that they are non‐genotoxic in the somatic mutation and recombination test assay, which agrees with the applications they have in dentistry. These findings – supported by numerous studies showing a positive correlation between carcinogenicity in man and genotoxicity in the Drosophila wing spot test – point to the potential risks some composite resins pose to the health of patients and dentistry personnel.
Flexural Strength, Fracture Toughness, and Hardness of Silicon Carbide and Boron Carbide Armor Ceramics
Authors: Vargas‐Gonzalez Lionel , Speyer Robert F. , Campbell James
Published: February 2010

Armor‐grade B4C and SiC specimens were analyzed for phase assemblage, microstructure, and mechanical properties. SiC–N showed the highest four‐point fracture strength, and an ∼50% higher notched beam fracture toughness than solid‐state sintered B4C and SiC. This was attributed to preferential crack propagation along a weaker amorphous aluminosilicate grain‐boundary interphase, which also attenuated the effect of surface flaws on bending strength. Verco B4C showed the highest hardness. That material was phase pure, fully dense, and of finer grain size as compared with pressure‐assisted densification (PAD)‐B4C (hot pressed). Verco SiC showed a hardness equal to (Vickers) or higher than (Knoop) PAD‐B4C, and a comparatively narrow distribution in measured hardnesses. This was attributed to a fine‐grained, fully dense, solid‐state sintered microstructure with a fine and well‐distributed graphite second phase. Hardness of all specimens decreased with increasing applied load.
Creep Rupture and Fatigue Behavior of a Notched Oxide/Oxide Ceramic Matrix Composite at an Elevated Temperature
Authors: Mall Shankar , Sullivan Mark A.
Published: February 2010

Oxide/oxide ceramic matrix composites (CMCs) have the potential to provide a longer lifetime and better strength when subjected to thermomechanical loads due to their inherent resistance to oxidation. Different notches are usually required during their applications. Their time‐dependent behavior in the presence of a notch must therefore be characterized. This study investigated the creep rupture and fatigue behavior of a woven oxide/oxide CMC (N720/A) consisting of Nextel™720 (metastable mullite) fibers in an alumina matrix with a 0°/90° fiber orientation having a hole diameter to width ratio of 0.33 at 1200°C in a laboratory air environment. Monotonic tensile tests at 1200°C were also conducted. Fracture surfaces were examined to analyze failure and damage mechanisms. Comparisons with unnotched data showed N720/A to be insensitive to the notch (hole) under monotonic tensile, creep, and fatigue‐loading conditions. Deformation under the cyclic loading condition was affected by fatigue and creep; however, the damage mechanisms were the same under creep and fatigue‐loading conditions.
DETERMINATION OF SUITABLE THIN LAYER MODEL FOR AIR DRYING OF MANGO SLICES (Mangifera indica L.) AT DIFFERENT AIR TEMPERATURES AND VELOCITIES
Authors: CORZO OTONIEL , BRACHO NELSON , ALVAREZ CARLOS
Published: February 2010

An air dryer was used for thin layer drying process of green and half‐ripe mango, and moisture ratios at any drying time were compared by 10 models (Newton, Page, Henderson and Pabis, modified Henderson and Pabis, logarithmic, two‐term, two‐term exponential, Wang and Singh, Verma et al. and Midilli and Kucuk). The Midilli and Kucuk model satisfactorily described the drying behavior of mango slices at different maturity stages with highest R2 values and lowest χ2. Parametersκ, n and b for the Midilli and Kucuk model were significantly different (P < 0.05) for both maturity stages and were affected by air velocity and temperature. Parameter κfor green mango was found to be the least temperature sensitive. Parameter n for green mango was found to be the most temperature sensitive. Temperature dependence of parameter b for both maturity stages did not follow a relation type Arrhenius.

PRACTICAL APPLICATIONS

This work is intended to provide a significant tool to predict the moisture content of the green and half‐ripe mango slices at any time of drying process, establish the air drying conditions in order to achieve given moisture content of mango slices, and optimize the design of thin layer drying process.
EVALUATION OF PROCESS PARAMETERS IN THE INDUSTRIAL SCALE PROCESS OF SOYBEAN OIL EXTRACTION USING EXPERIMENTAL DESIGN METHODOLOGY
Authors: VALDUGA EUNICE , TONEL ELISABETE , TATSCH PIHETRA OLIVEIRA , SILVA MARCELI FERNANDES , TREICHEL HELEN
Published: February 2010

This work reports the use of experimental design for the assessment of the effects of process parameters of the soybean oil extraction in an industrial environment. A central composite rotatable design was carried out and the independent variables were soyflakes (27 to 41 mm), miscella concentration (25 to 39%) and solvent temperature (57 to 63C). The lowest concentration of residual oil was obtained with soyflakes of 34 mm, 32% of miscella concentration and solvent temperature of 60C, resulting in an average level of residual oil of 0.69%, corresponding to a 31% reduction related to the previous average level obtained in the extraction. The responses acidity and peroxide indexes, as well as color, were not significantly affected (P < 0.05) by the independent variables evaluated, showing, therefore, that the efficiency of the soybean oil extraction was optimized without prejudice the quality of the soybean oil.

PRACTICAL APPLICATIONS

In the industrial process, also called conventional (extraction by hexane), a deep study of the operational conditions involved to obtain soybean oil and bran, aim to improve the yield of the process. The oil extraction makes possible for the industry to establish, the best operational conditions, that results in energy saving and improvement of hexane recovery. In this sense, the experimental design methodology was used in order to optimize the process of soybean oil extraction in an industrial environment.
The formation of the embryonic mouse heart
Authors: Watanabe Yusuke , Buckingham Margaret
Published: February 2010

During cardiogenesis in the mouse, the second heart field (SHF) is the source of the myocardium of the outflow tract and it contributes to other regions of the heart with the exception of the primitive left ventricle. This contribution corresponds with that of the second myocardial cell lineage, identified by retrospective clonal analysis. Gene regulatory networks, signaling pathways, and heterogeneity within the SHF are discussed, together with the question of regulation of myocardial progenitor cells within the first heart field. The extension of the SHF into the mesodermal core of the arches also gives rise to endothelial cells of the pharyngeal arch arteries. Knowledge about the origin and genetic regulation of cells that contribute to the heart and associated vasculature is important for the diagnosis and treatment of congenital heart malformations.
PI3K kinase and scaffold functions in heart
Authors: Damilano Federico , Perino Alessia , Hirsch Emilio
Published: February 2010

Signal transduction events are key modulators of cellular function and, in the cardiovascular system, an emerging role is played by phosphoinositide 3‐kinases (PI3Ks), a family of enzymes containing a 3‐phosphorylated phosphoinositide that produce lipid second messengers. In the heart, multiple PI3K isoforms are expressed, but play potentially distinct roles. Among cardiac PI3Ks, PI3Kα is triggered by tyrosine kinase receptors and plays a role in adaptive hypertrophy, while PI3Kγ is triggered by G protein–coupled receptors and is involved in maladaptive heart remodeling. This view has been recently complicated by the finding that PI3Ks can also be involved in protein–protein interactions and affect signaling independently of their kinase activity. This review will thus focus on the effects of these multiple signaling events, with particular emphasis on their involvement in cardiac hypertrophy and failure.
Multiscale modeling of metabolism, flows, and exchanges in heterogeneous organs
Authors: Bassingthwaighte James B. , Raymond Gary M. , Butterworth Erik , Alessio Adam , Caldwell James H.
Published: February 2010

Large‐scale models accounting for the processes supporting metabolism and function in an organ or tissue with a marked heterogeneity of flows and metabolic rates are computationally complex and tedious to compute. Their use in the analysis of data from positron emission tomography (PET) and magnetic resonance imaging (MRI) requires model reduction since the data are composed of concentration–time curves from hundreds of regions of interest (ROI) within the organ. Within each ROI, one must account for blood flow, intracapillary gradients in concentrations, transmembrane transport, and intracellular reactions. Using modular design, we configured a whole organ model, GENTEX, to allow adaptive usage for multiple reacting molecular species while omitting computation of unused components. The temporal and spatial resolution and the number of species are adaptable and the numerical accuracy and computational speed is adjustable during optimization runs, which increases accuracy and spatial resolution as convergence approaches. An application to the interpretation of PET image sequences after intravenous injection of 13NH3 provides functional image maps of regional myocardial blood flows.
Increase in endocardial rotation during doxorubicin treatment
Authors: Bachner Noa , Tsadok Yossi , Adam Dan
Published: February 2010

Treatment of cardiomyopathy, when detected early, may slow myocardial deterioration and even reverse its course. However, no efficient, noninvasive measure of cardiac function is yet able to detect the early signs of cardiomyopathy. The aim of this study was to determine whether ultrasound speckle tracking analysis is a more sensitive measure of early changes of cardiac function than standard echocardiographic parameters. Eight Wistar rats were injected with doxorubicin and scanned weekly by ultrasound in order to follow the early stages of cardiomyopathy. Apical short‐axis scans were analyzed by a novel speckle tracking imaging program, enabling layer‐specific assessment of myocardial function. Only four of eight rats survived the full treatment. They showed a significant elevation of endocardial apical rotation (P < 0.006) after 4 weeks of treatment (25.1 ± 3.7 deg) versus baseline values (8.0 ± 2.8 deg), while ejection fraction remained normal (78.5 ± 3.5%). Thus, in the rat model, layer‐specific assessment of myocardial function may detect cardiomyopathy at its early stages.
Developmental basis of adult cardiovascular diseases
Authors: Markwald Roger R. , Norris Russell A. , Moreno‐Rodriguez Ricardo , Levine Robert A.
Published: February 2010

In this chapter, we review the working hypothesis that the roots of adult valvular heart disease (VHD) lie in embryonic development. Valvulogenesis is a complex process in which growth factors signal the process of endocardium‐to‐mesenchyme transformation (EMT) resulting in formation of prevalvular “cushions.” The post‐EMT processes, whereby cushions are morphogenetically remolded into valve leaflets, are less well understood, but they require periostin. Mice with targeted deletion of periostin develop degenerative changes similar to human forms of VHD. Mitral valves are also abnormally elongated in hypertrophic cardiomyopathy (HCM), which plays an important role in clinical disease expression. However, the mechanism for this is unclear, but correlates with enhanced expression of periostin in a specific population of ventricular cells derived from the embryonic proepicardial organ, which accumulate at sites where valvular endocardial EMT is reactivated. Collectively, these findings suggest that developmental mechanisms underlie adult valve responses to genetic mutations in degenerative VHD and HCM.
Heat acclimation–mediated cross‐tolerance in cardioprotection
Authors: Horowitz Michal , Assadi Halla
Published: February 2010

Heat acclimation (AC) is an evolutionarily conserved feature allowing adjustment to persistent changes in ambient temperature. The mechanisms underlying acclimation involve a continuum of physiologic changes, determined by temperature‐adaptive shifts in gene expression. The AC heart generates greater pressure at lower O2 consumption, but at the expense of contractile velocity, and renders cytoprotection to a wide range of stressors (cross‐tolerance) via greater cytoprotective protein reserves, faster post‐injury molecular dynamic response, and post‐translational modifications. A greater abundance of HSP70 and HIF‐1α and its metabolic targeted genes (both nuclear and mitochondrial) are among the cytoprotective changes that occur. The cytoprotection profile provides a dual protective strategy—a constitutive availability of cytoprotective proteins without a need for de novo protein synthesis, together with an “alerted system” responding rapidly upon insult. Hence, cross‐tolerance is achieved via activation of “on‐call” constitutive cytoprotection shared by all stressors, together with organ‐specific functional remodeling and stress‐specific cross‐talk.
Photosensitizing Effect of Hematoporphyrin IX on Immature Stages of Ceratitis capitata (Diptera: Tephritidae)
Authors: Pujol‐Lereis Luciana Mercedes , Massaldi Ana , Rabossi Alejandro , Quesada‐Allué Luis Alberto
Published: February 2010

Immature stages of Ceratitis capitata were tested as a model for hematoporphyrin IX (HP IX) phototoxicity. The lethal concentration 50 (LC50) of HP IX in the food was determined during postembryonic development until adult emergence as 0.173 mm (95% CI: 0.138–0.209). The corresponding HP IX LC50 during the dispersal period alone was 0.536 mm (95% CI: 0.450–0.633). HP IX toxicity was compared against Phloxine B (PhB) (0.5 mm). HP IX elicited a mortality of 90.87%, which was mainly concentrated during prepupal and early pupal stages. PhB mortality was much lower (56.88%) and occurred mainly during the adult pharate stage. A direct correlation between light‐dependent HP IX mortality, evidence of reactive oxygen species (ROS) and lipid peroxidation (conjugated dienes and thiobarbituric acid reactive substances) was established in C. capitata larvae. ROS were found to be very significant in both the brain and in the gut.
REE, Mn, Fe, Mg and C, O Isotopic Geochemistry of Calcites from Furong Tin Deposit, South China: Evidence for the Genesis of the Hydrothermal Ore‐forming Fluids
Authors: Shuang Yan , Bi Xian‐Wu , Hu Rui‐Zhong , Peng Jian‐Tang , Li Hang , Li Da‐Hua , Zhu Chang‐Sheng
Published: February 2010

The Furong tin deposit in the central Nanling region, South China, consists of three main types of mineralization ores, i.e. skarn‐, altered granite‐ and greisen‐type ores, hosted in Carboniferous and Permian strata and Mesozoic granitic intrusions. Calcite is the dominant gangue mineral intergrown with ore bodies in the orefield. We have carried out REE, Mn, Fe, and Mg geochemical and C, and O isotopic studies on calcites to constrain the source and evolution of the ore‐forming fluids. The calcites from the Furong deposit exhibit middle negative Eu anomaly (Eu/Eu*= 0.311–0.921), except for one which has an Eu/Eu* of 1.10, with the total REE content of 5.49–133 ppm. The results show that the calcites are characterized by two types of REE distribution patterns: a LREE‐enriched pattern and a flat REE pattern. The LREE‐enriched pattern of calcites accompanying greisen‐type ore and skarn‐type ore are similar to those of Qitianling granite. The REE, Mn, Fe, and Mg abundances of calcites exhibit a decreasing tendency from granite rock mass to wall rock, i.e. these abundances of calcites associated with altered granite‐type and greisen‐type ores are higher than those associated with skarn‐type ores. The calcites from primary ores in the Furong deposit show large variation in carbon and oxygen isotopic compositions. The δ13C and δ18O of calcites are −0.4 to −12.7‰ and 2.8 to 16.4‰, respectively, and mainly fall within the range between mantle or magmatic carbon and marine carbonate. The calcites from greisen and altered granite ores in the Furong deposit display a negative correlation in the diagram of δ13C versus δ18O, probably owing to the CO2‐degassing of the ore‐forming fluids. From the intrusion to wall‐rock, the calcites display an increasing tendency with respect to δ13C values. This implies that the carbon isotopic compositions of the ore‐bearing fluids have progressively changed from domination by magmatic carbon to sedimentary carbonate carbon. In combination with other geological and geochemical data, we suggest that the ore‐forming fluids represent magmatic origin. We believe that the fluids exsolved from fractionation of the granitic magma, accompanying magmatism of the Qitianling granite complex, were involved in the mineralization of the Furong tin polymetallic deposit.
Characterization and Mineralization Potentials of Granitic Pegmatites of Komu area, Southwestern Nigeria
Authors: Adetunji Ademuyiwa , Ocan Ojok Onesimus
Published: February 2010

The geology of the Komu area, south‐western Nigeria was investigated in order to determine the nature of occurrence, petrography and chemical composition, and to evaluate the mineral potential of granitic pegmatites. The pegmatites are hosted by para‐gneisses, amphibolites and granitic rocks. These host rocks are characterized by low pressure mineral assemblages of upper greenschist to lower amphibolite facies grades. The pegmatites consist of four lithological units: alkali feldspar unit, graphic granite unit, quartz‐albite‐muscovite‐tourmaline unit and saccharroidal albite‐muscovite‐tourmaline‐garnet unit.

A K/Rb ratio of below 100 is indicative of a mineralization potential in most pegmatites, except for the saccharroidal albite‐muscovite‐tourmaline‐garnet unit which has exceptionally high ratios. The discrimination diagrams Rb versus K/Rb, Zn versus K/Rb and Th versus K/Rb show a limited range of fractionation, suggesting that the pegmatites belong to the barren muscovite and rare element classes. The rare element class is moderately enriched in beryl, tourmaline and niobium–tantalum minerals. The pegmatite has affinity for beryl columbite sub‐type and lithium–cesium–tantalum (LCT) family. The ores plot mainly in the field of mangano‐tantalite of tantalite‐columbite quadrilateral diagram. These results indicate that the pegmatites are promising hosts for Nb‐Ta ores.
Baseline Characteristics of the Nateglinide and Valsartan Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) Trial Population: Comparison with Other Diabetes Prevention Trials
Authors: Krum Henry , McMurray John J.V. , Horton Edward , Gerlock Teresa , Holzhauer Bjoern , Zuurman Lineke , Haffner Steven M. , Bethel M. Angelyn , Holman Rury R. , Califf Robert M.
Published: February 2010

The Nateglinide and Valsartan Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) trial is exploring two pharmacological strategies (nateglinide and valsartan, both alone and in combination) in the prevention of overt diabetes mellitus (DM) and the reduction of cardiovascular disease (CVD) in subjects at high risk for these events. In this analysis, we provide baseline characteristics of the randomized NAVIGATOR study population and contrast them with those from other trials of DM prevention. Key eligibility criteria include impaired glucose tolerance (IGT) and impaired fasting glucose (IFG), a history of CVD (in patients aged ≥50 years), and ≥1 cardiovascular risk factor (in patients aged ≥55 years). Baseline demographic characteristics, laboratory findings, cardiovascular risk factors, CVD history, and medication use are described and compared with other trials of DM prevention. The full analysis set of subjects (N = 9306) showed a clustering of risk factors consistent with the metabolic syndrome: high rates of hypertension (77.5%), dyslipidemia (44.7%), increased waist circumference (101.0 cm), and high body mass index (BMI) (47.5% with BMI ≥30 kg/m2). A minority of patients had a history of CVD (24.3%); of these, 11.7% had a history of myocardial infarction and most of the remainder had evidence of coronary artery disease. Subjects also had elevated blood pressure (BP) (predominantly systolic) (139.7/82.6 mm Hg), increased serum low‐density lipoproteins cholesterol levels (3.27 mmol/L), and borderline elevation of triglyceride levels (1.97 mmol/L). Demographic data, BP, and lipid profiles in NAVIGATOR were similar to those of previous DM prevention trials, which were also based largely on meeting criteria for IGT. Medication use at baseline among NAVIGATOR subjects, which frequently included aspirin, beta‐blockers, calcium channel blockers, diuretics, and lipid‐lowering agents, reflects enhanced CVD risk. However, little prescribing of renin–angiotensin–aldosterone system blockers was observed, likely due to protocol exclusion criteria. In conclusion, the NAVIGATOR study comprises prediabetic subjects who typically have concurrent BP and metabolic disturbances and an enhanced risk of CVD, and are thus at higher risk for cardiovascular events than subjects in previous DM prevention trials.
Depression during pregnancy: detection, comorbidity and treatment
Authors: Muzik Maria , Marcus Sheila Marie , Flynn Heather , Rosenblum Katherine Lisa
Published: February 2010

Depression during pregnancy is common (∼15%). Routine prenatal depression screening coupled with the use of physician collaborators to assist in connecting women with care is critical to facilitate treatment engagement with appropriate providers. Providers should be aware of risk factors for depression – including a previous history of depression, life events, and interpersonal conflict – and should appropriately screen for such conditions. Depression during pregnancy has been associated with poor pregnancy outcomes including preeclampsia, insufficient weight gain, decreased compliance with prenatal care, and premature labor. Current research has questioned the overall benefit of treating depression during pregnancy with antidepressants when compared to the risk of untreated depression for mother and child. Published guidelines favor psychotherapy above medication as the first line treatment for prenatal depression. Poor neonatal adaptation or withdrawal symptoms in the neonate may occur with fetal exposure in late pregnancy, but the symptoms are mild to moderate and transient. The majority of mothers who decide to stop taking their antidepressants during pregnancy suffer relapsing symptoms. If depression continues postpartum, there is an increased risk of poor mother–infant attachment, delayed cognitive and linguistic skills in the infant, impaired emotional development, and behavioral problems in later life. Bipolar depression, anxiety and substance use disorders, and/or presence of severe psychosocial stress can lead to treatment‐resistance. Modified and more complex treatment algorithms are then warranted. Psychiatric medications, interpersonal or cognitive‐behavioral therapy, and adjunctive parent–infant/family treatment, as well as social work support, are modalities often required to comprehensively address all issues surrounding the illness.
Anti-ulcer activity of IAC, a novel free-radical scavenger, in rats
Authors: Zavatti Manuela , Corsi Lorenzo , Zanoli Paola , Baraldi Mario
Published: February 2010

Objectives

We investigated the ability of a novel low-molecular-weight free-radical scavenger, bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)-decandioate (IAC), to protect the gastric mucosa from indometacin-induced ulceration.

Methods

The pharmacological effects of IAC, administered orally or by intraperitoneal injection, on the gastric mucosa were assessed in a rat model of gastric ulceration induced by indometacin. The effect of IAC on the level of prostaglandin PGE2 in the gastric mucosa was also investigated.

Results

IAC, which has no ulcerative activity per se, had a preventive and protective activity against indometacin-induced gastric ulceration. This effect could be only partially attributed to a modulatory effect of IAC on PGE2 levels; it is more likely to be due to the antioxidant activity of the compound.

Conclusions

Taking into account the properties of IAC and the mechanisms underlying gastric inflammation elicited by non-steroidal anti-inflammatory drugs, IAC may represent a novel anti-ulcer agent.
Effects of axial stretch on sarcolemmal BKCachannels in post‐hatch chick ventricular myocytes
Authors: Iribe Gentaro , Jin Honghua , Kaihara Keiko , Naruse Keiji
Published: February 2010

We have previously reported the electrophysiological properties of sarcolemmal stretch‐activated BKCa(SAKCA) channels cloned from cultured chick embryonic ventricular myocytes. However, the role of BKCachannels in the electrophysiology of the more mature heart is not clear. We have investigated the effects on the BKCacurrent of axial stretch in post‐hatch ventricular myocytes. Whole‐cell currents of ventricular myocytes isolated from 2‐week‐old chicks were recorded using the patch‐clamp technique, while the cells were either held at resting length or stretched to cause a 10% increase in sarcomere length using a pair of carbon fibres attached to opposite ends of the cell. Stretch did not affect whole‐cell currents immediately after the stretch was applied. However, sustained stretch for 3 min significantly increased outward currents. This stretch‐induced change was reversed by applying 10 nmiberiotoxin, a specific BKCachannel blocker, or a Na+–Ca2+‐free environment. These results were reproduced in a computer simulation study. The present study is the first report about the sarcolemmal BKCacurrent from post‐hatch ventricular myocytes. The present results suggest that axial stretch activates BKCachannels via a stretch‐induced increase in the cytosolic Na+concentration followed by an increased Ca2+influx.
Localized tyrosine or tetrahydrobiopterin supplementation corrects the age‐related decline in cutaneous vasoconstriction
Authors: Lang James A. , Holowatz Lacy A. , Kenney W. Larry
Published: February 2010

The attenuated reflex vasoconstriction in aged skin may be partly mediated by oxidant‐induced reduction in functional substrate and cofactor availability for noradrenaline biosynthesis. We hypothesized that localized supplementation of tyrosine and tetrahydrobiopterin (BH4) in aged human skin could augment reflex‐ (whole‐body cooling) and pharmacologically (tyramine, which displaces noradrenaline from axon terminals) induced vasoconstriction. Four microdialysis fibres were placed in the forearm skin of 10 young and 10 older subjects for infusion of (1) Ringer solution (control), (2) 0.5 mm l‐tyrosine, (3) 5 mmBH4, and (4) BH4+l‐tyrosine. Cutaneous vascular conductance (CVC) was calculated (laser Doppler flux/mean arterial pressure) and normalized to baseline (%ΔCVCbase). Vasoconstriction was attenuated at the control site in the older subjects during both whole‐body cooling (young: −39 ± 3, older: −17 ± 3%ΔCVCbase;P< 0.01) and tyramine infusion (young: −41 ± 3, older: −21 ± 4%ΔCVCbase;P< 0.01). BH4(cold, young: −37 ± 3, older: −36 ± 3; tyramine, young: −41 ± 2, older: −36 ± 3%ΔCVCbase) and tyrosine (cold, young: −37 ± 4, older: −34 ± 4; tyramine, young: −40 ± 4, older: −45 ± 4%ΔCVCbase) both resolved the age‐related decrease in cutaneous vasoconstriction, but BH4+ tyrosine did not further augment vasoconstriction (cold, young: −38 ± 4, older: −31 ± 3; tyramine, young: −36 ± 3, older: −36 ± 5%ΔCVCbase). These data are consistent with the concept that reduced bioavailability of BH4and/or tyrosine may impair noradrenaline synthesis and contribute to the attenuated vasoconstrictor response in aged skin.
Investigation Into the Similarity Solution for Boundary Layer Flows in Microsystems
Authors: Kiwan Suhil , Al-Nimr M. A.
Published: February 2010

An investigation toward the existence of a complete similarity solution for boundary layer flows under the velocity slip and temperature jump conditions is carried out. The study is limited to the boundary layer flows resulting from an arbitrary freestream velocity U(x)=Uoxm and wall temperature given by Tw−T∞=Cxn. It is found that a similar solution exists only for m=1 and n=0, which represents stagnation flow on isothermal surface. This case has been thoroughly investigated. The analysis showed that three parameters control the flow and heat transfer characteristics of the problem. These parameters are the velocity slip parameter K1, the temperature jump parameter K2, and Prandtl number. The effect of these parameters on the flow and heat transfer of the problem has been studied and presented. It is found that the slip velocity parameter affects both the flow and heat transfer characteristics of the problem. It is found that the skin friction coefficient decreases with increasing K1 and most of changes in the skin friction takes place in the range 0<K1<1. The skin friction coefficient is found to be related to K1 and Rex according to the relation: Cf=3.38Rex−0.5(K1+1.279)−0.8 for 0<K1<5 with an error of ±4%. On the other hand, the correlation between Nu, K1, K2, and Pr has been found by the equation Nu=[(0.449+1.142K11.06)∕(0.515+K11.06)](K2+1.489Pr−0.44)−1, for 0<K1, K2<5, 0.7≤Pr≤5 within a maximum error of ±3%.
Experimental Investigation of Single-Phase Microjet Array Heat Transfer
Authors: Browne Eric A. , Michna Gregory J. , Jensen Michael K. , Peles Yoav
Published: February 2010

The heat transfer performance of two microjet arrays was investigated using degassed deionized water and air. The inline jet arrays had diameters of 54 μm and 112 μm, a spacing of 250 μm, a standoff of 200 μm (S/d=2.2 and 4.6, H/d=1.8 and 3.7), and jet-to-heater area ratios from 0.036 to 0.16. Average heat transfer coefficients with deionized water were obtained for 150≤Red≤3300 and ranged from 80,000 W/m2 K to 414,000 W/m2 K. A heat flux of 1110 W/cm2 was attained with 23°C inlet water and an average surface temperature of 50°C. The Reynolds number range for the same arrays with air was 300≤Red≤4900 with average heat transfer coefficients of 2500 W/m2 K to 15,000 W/m2 K. The effect of the Mach number on the area-averaged Nusselt number was found to be negligible. The data were compared with available correlations for submerged jet array heat transfer.
Improving Pre-Operative Evaluation and Surgical Planning of Spine Deformity Surgeries Using 3D Printing
Authors: Pfeiffer Ferris M.
Published: February 2010

Visualization of spinal pathologies such as scoliosis is imperative to proper surgical treatment. Current visualization techniques use 2D representations of the anatomy in the form of radiographs, CT, or MRI. The ability to view patient anatomy in three dimensions prior to surgical intervention allows for a more thorough evaluation and planning of the surgical requirements. Manufacturing methods such as three dimensional printing can be employed to rapidly generate a physical 3D representation of patient anatomy which can be used for visualization and/or surgical planning.
A Novel Piezo-Driven Micro-Jet Injection System for Transdermal Drug Delivery
Authors: Chen Kai
Published: February 2010

A novel piezo-driven micro-jet injection system is presented for transdermal drug delivery. The system uses an amplified piezoelectric actuator and a precision ball screw to accumulate the displacement of each pulsed injection. The device effectively eliminates the flow restrictor in the ampoule.
Biomechanical Evaluation of an Expandable Cage in Single Segment Posterior Lumbar Interbody Fusion
Authors: Bhatia Nitin N. , Lee Kenneth H. , Bui Chris , Wahba George M. , Estess Allyson A. , Luna Mario , Lee Thay Q.
Published: February 2010

One of the popular methods of treating lumbar spine pathologies involves a posterior lumbar interbody fusion (PLIF) using bilateral interbody non-expandable cages. Due to the geometry of these cages, they can require extensive bony removal and nerve root retraction. Some resultant risks of the procedure include dural lacerations and post-operative neuropraxia. Expandable interbody cages may address some of these concerns and possibly decrease the risks associated with PLIF procedures. This is the first study to our knowledge evaluating the biomechanical characteristics of an expandable lumbar interbody device in a cadaveric human spine model. The objective of this study was to evaluate the biomechanical characteristics of a new expandable interbody cage in single segment posterior lumbar interbody fusion using cadaveric lumbar spines.
Paraffin Actuated Micromirror for Endoscopic OCT
Authors: Ayers Jessica A. , Tang William C. , Chen Zhongping
Published: February 2010

Microelectromechanical systems (MEMS) have great potential for use in gastrointestinal (GI) imaging. Ultrasound and magnetic resonant imaging can provide useful information about the GI tract, but only optical coherence tomography (OCT) delivered endoscopically can be used to perform an optical biopsy of the GI tissue. In monitoring a condition such as Barrett’s esophagus, which typically requires regular random biopsies, the ability to achieve an optical biopsy is indispensible. While the existing method for obtaining an optical biopsy of the GI tract tissue produces functional images, there are drawbacks that could be improved upon. The gear-and-shaft assembly used to couple force from the motor at the proximal end to the distal imaging end requires a complex design [1]. By introducing a rotational MEMS device into the distal imaging end, a rotating optical coupling joint is no longer required at the proximal end, there is no need to precisely align the fixed fiber with the rotational drive shaft, and the metallic reinforcement sleeve can be eliminated leaving a simpler, more flexible delivery method [2]. In order to produce 3D OCT images, displacement in the z-direction needs to be coupled with rotation. A MEMS device that can achieve both vertical displacement and rotation further increases the simplicity of the device and decreases potential alignment and coupling errors. Our MEMS devices needs to be able to bend an OCT beam of light 90°, rotate that beam of light 360°, and simultaneously scan in the z-direction in order to produce 3D OCT images. Also, the device must fit inside the 1 mm diameter available in the endoscope. To accomplish this, we have designed, and are continuing to develop, a paraffin actuated micro mirror. The thermal expansion properties of paraffin wax have often been utilized in MEMS devices [3, 4]. We have made use of these properties in designing a piston like actuator. Heat is applied to a reservoir of paraffin enclosed by a parylene membrane. The paraffin expands and pushes the post above it upward with the developed force from its expansion. The amount of paraffin in each reservoir is controlled by the reservoir’s geometry and so by controlling the amount of heat applied, we can control how far the post above it moves in the vertical direction. Each device has three heaters, three reservoirs, and three posts. All three posts are attached to a single mirror. By appropriately cycling the applied heat to each reservoir, we expect to be able to move the mirror in a spiral like fashion. This will bend an applied beam of light 90° and rotate it 360° while achieving displacement in the z-direction.
Fixation of Distal Humerus Fractures: Principles and Biomechanics
Authors: Zalavras Charalampos G. , Vercillo Michael T. , Jun Bong-Jae , Otarodifard Karimdad Amir , Itamura John M. , Lee Thay Q.
Published: February 2010

Satisfactory outcome of intraarticular distal humerus fractures depends on anatomic joint restoration and stable fracture fixation to allow early motion. Orthogonal constructs (medial plate on medial column and posterior plate on lateral column) and parallel constructs (medial plate on medial column and lateral plate on lateral column) have been proposed for fixation of these fractures. However, the optimal configuration remains controversial. There are no clinical studies comparing these constructs and existing biomechanical studies had methodological limitations and reported conflicting results.