bluuebunny/crossref_metadata_2025 huggingface dataset:
Changing Neighborhoods—Neighborhoods Changing
Authors: O'Sullivan David
Published: May 2009

The nature of urban neighborhoods, neighborhood effects, and the dynamics of residential segregation are important themes in contemporary sociological inquiry. Agent-based models of social systems have been widely applied in this context. However, both applied and model-based research in these areas suffer from weaknesses in underlying conceptualizations and representations of spatial context. Drawing on human geography and the sociospatial perspective in urban sociology, a framework that enables richer and more realistic representation of urban neighborhoods in agent-based simulation models is proposed and outlined. The framework relies on a graph representation of the spatial relations among spatial locations and can accommodate welldefined administrative zones, vague or ill-defined neighborhoods, hierarchically nested spatial zoning systems, overlapping neighborhoods, and changing relations among neighborhoods. Results from a preliminary application of the framework demonstrate its utility and possibilities for research into the effects of neighborhood structure on social processes.
Name-Based Cluster Sampling
Authors: Ferguson Douglas A.
Published: May 2009

An innovative method is proposed for generating valid national samples of online e-mail addresses that are proportionate to the population. Although multistage cluster sampling is not new, this particular application using first names and/or surnames has not been previously published or presented. This article outlines the method in detail and presents a number of advantages over other forms of samples. Limitations are also discussed.
Ethanol versus Gasoline
Authors: Carolan Michael S.
Published: May 2009

A variety of forces aligned at the turn of the last century to make ethyl alcohol — what is today known as ethanol — inefficient and uneconomical as a fuel alternative. Rather than a case of inevitable technological unfolding, the transition from King Coal to Big Oil was a sociologically contingent event. As a controversy study, this paper seeks to avoid the reductionist tendencies of past historical analyses of fuel. The author also seeks to redress a fundamental gap within the STS literature on the subject of automobile/fuel socio-technical systems, where the story of ethyl alcohol remains conspicuously absent. Among studies that examine how/why the automobile became locked in, little is said about ethyl alcohol, even though, as this paper details, it remained part of the fuel landscape well into the 20th century. The paper begins with an overview of the landscape developments of fuel during the later decades of the 19th century. Attention then turns to examining the various factors that went into shaping the automobile/fuel socio-technical system within the US during the first half of the 20th century.
Gender and geography II: bridging the gap — feminist, queer, and the geographical imaginary
Authors: Wright Melissa W.
Published: May 2009

Within geography, the flourishing of studies on sexuality indicate the vibrancy of scholarship that approaches sexuality as a nexus of the global and the intimate, where the most private and introspective experiences of embodied self meet with the multiscalar processes of identity and power across the local—global continuum. Certainly, recent publications in sexual, queer and feminist geographies leave no room for doubt that sexuality and gender are axes of multiscalar activity for developing meaning, power and politics in the most personal and public of settings around the world. Consequently, geographers have illustrated how any politics by and in support of those who subvert normative gendered and sexual subjectivities requires geographical imaginations that bridge methodological approaches. In this report, I focus on such geographical imaginaries by examining the efforts of those who work within and across the diverse fields of queer and feminist theories to create synergistic efforts for investigating the everyday life of power, identity and place.
Effect of Laminate Tapering on Strain Distribution in Adhesive Joints: Experimental Investigation
Authors: Haghani Reza , Al-Emrani Mohammad , Kliger Robert
Published: May 2009

Strain distribution in adhesive joints with untapered and normal-tapered laminates has been investigated using an experimental method. An optic measurement system, ARAMIS, was used to monitor the strain field in the adhesive layer. The results indicated that normal tapering of the laminate did not affect the shear and principal strain components, but it increased the maximum peeling strain in the joint for the tapering length examined in this study. The strength and failure mode of joints were also studied. It was found that normal tapering of the laminate did not improve the strength of the joint in comparison to joints with untapered laminates. Failure took place at the steel—adhesive interface in both configurations.
Effect of Surface Modification of Jute with Acrylic Monomers on the Performance of Polypropylene Composites
Authors: Khan Mubarak A. , Khan Ruhul A. , Zaman Haydar U. , Noor-A Alam M. , Hoque M.A.
Published: May 2009

Jute fabrics reinforced polypropylene (PP) composites (40% fiber by weight) are prepared using compression molding. Different formulations using oligomer urethane diacrylate (M-1100), monomers 2-ethyl hexyl acrylate (EHA), 1-vinyl 2-pyrrolidone (NVP), and photo-initiator (Irgacure-369) in methanol were prepared in order to modify the surface of jute fabrics. Jute fabrics are soaked in the prepared formulations and then cured by UV radiation source of varying intensities. The formulation containing 5% NVP, 5% EHA, 2.5% oligomer, and 2% photo-initiator and cured at 15 UV passes perform the highest mechanical properties. Tensile strength (TS), bending strength (BS), tensile modulus (TM), and bending modulus (BM) of the composites are found to be 54, 62, 915, and 2030 MPa, respectively. To investigate the effect of thermal initiator, benzyl peroxide is used in the optimized formulation instead of the Irgacure-369 photo-initiator. The TS, BS, TM, and BM of the composites are found to be 54, 63, 998, and 2150 MPa, respectively by treating jute with 2% benzoyl peroxide as the thermal initiator.
HSP90, a Capacitor of Behavioral Variation
Authors: Hung Hsiu-Cheng , Kay Steve A. , Weber Frank
Published: May 2009

Many aspects of behavior such as aggression, courtship, sexual orientation, and the sleep-wake cycle are determined by specific genes. Although point mutations in these genes predictably change characteristics of behavior, substantial variation can be observed among a population as well as during the lifetime of individuals. The origin of variation in behavior, however, is largely unknown. Here the authors investigated the role of HSP90 for the circadian control of behavior in Drosophila. They found that a partial loss of HSP90 function, either by mutagenesis or by pharmacological inhibition, did not affect the circadian clock itself, but the translation of molecular oscillations into behavioral rhythms. In HSP90-deficient flies behavioral activity was no longer stringently coupled to molecular oscillations giving rise to a large variation in individual behavioral activity patterns. The results show that HSP90 is a potent capacitor of behavioral variation, analogous to its role in morphology. Decreased HSP90 activity not only increases behavioral variability among a population, but interestingly also during the lifetime of individuals.
Chronotype Influences Diurnal Variations in the Excitability of the Human Motor Cortex and the Ability to Generate Torque during a Maximum Voluntary Contraction
Authors: Tamm Alexander S. , Lagerquist Olle , Ley Alejandro L. , Collins David F.
Published: May 2009

The ability to generate torque during a maximum voluntary contraction (MVC) changes over the day. The present experiments were designed to determine the influence of an individual's chronotype on this diurnal rhythm and on cortical, spinal, and peripheral mechanisms that may be related to torque production. After completing a questionnaire to determine chronotype, 18 subjects (9 morning people, 9 evening people) participated in 4 data collection sessions (at 09:00, 13:00, 17:00, and 21:00) over 1 day. We used magnetic stimulation of the cortex, electrical stimulation of the tibial nerve, electromyographic (EMG) recordings of muscle activity, and isometric torque measurements to evaluate the excitability of the motor cortex, the spinal cord, and the torque-generating capacity of the triceps surae (TS) muscles. We found that for morning people, cortical excitability was highest at 09:00, spinal excitability was highest at 21:00, and there were no significant differences in TS EMG or torque produced during MVCs over the day. In contrast, evening people showed parallel increases in cortical and spinal excitability over the day, and these were associated with increased TS EMG and MVC torque. There were no differences at the level of the muscle over the day between morning and evening people. We propose that the simultaneous increases in cortical and spinal excitability increased central nervous system drive to the muscles of evening people, thus increasing torque production over the day. These differences in cortical excitability and performance of a motor task between morning and evening people have implications for maximizing human performance and highlight the influence of chronotype on an individual's diurnal rhythms.
Under Cover of Darkness: Nocturnal Life of Diurnal Birds
Authors: Mukhin Andrey , Grinkevich Vitaly , Helm Barbara
Published: May 2009

Songbirds are generally considered diurnal, although many species show periodic nocturnal activity during migration seasons. From a breeding-range perspective, such migratory species appear to be diurnal because they are observed to nest and feed their young during the day. But are they really exclusively diurnal? The authors tested how a passerine long-distance migrant, the Eurasian reed warbler, schedules movements during the breeding period by tracking birds in 2 experimental situations: 1) Birds experienced simulated nest loss and were monitored during their search for alternative locations, and 2) birds were translocated to reed beds at distances from 2 to 21 km and tracked during homing. The simulated unpredictable events disrupted normal breeding, forced birds to move over relatively long distances, and triggered rapid change in diel activity. In all but 1 case, birds resorted to nocturnality to find their way home and to search for new places to breed. Nocturnality during the breeding season indicates that songbird schedules are far more flexible than previously assumed. The reasons for nocturnal movements are poorly understood. Among the presumed advantages, the reduced predation pressure at night stands out because it is advantageous for movements on local as well as global scales. Predation may be particularly relevant for inhabitants of fragmented habitats, which encounter unfavorable conditions when crossing gaps in their preferred habitat. Therefore, similar selection pressures around the year may have favored the evolution of a general circadian mechanism for switches to nocturnality. Furthermore, the novel finding of homing and dispersal at night may give leads toward understanding the still enigmatic navigational abilities of songbirds.
Health Benefits of Using Red Palm Oil in Deep-frying Potatoes: Low Acrolein Emissions and High Intake of Carotenoids
Authors: Andreu-Sevilla A.J. , Hartmann A. , Burló F. , Poquet N. , Carbonell-Barrachina A.A.
Published: May 2009

Palm oil is the second largest vegetable oil in terms of world production. Besides, red palm oil (RPO) is nonhydrogenated, has a high oxidative stability and contains high levels of natural antioxidants, such as carotenoids. The main objectives of this study were to study acrolein emissions during deep-frying operations, as an indicator of potentially toxic volatile compounds, and to evaluate the importance of French fries (fried with red palm oil) as an extra source of carotenoids in the diet. The acrolein emission rates from mono-unsaturated oils, such as red palm and olive oils, were much lower than that of poly-unsaturated oils, sunflower. The total carotenoid content of red palm oil, 480 mg/L, makes this oil perfect for developing functional foods round the world and gives the oil a high oxidative stability and long shelf life. Sensory tests proved that RPO French fries were scored positively by regular consumers. Their color was initially considered unusual and got low scores; however, when the flavor was evaluated RPO fries got higher scores than olive or sunflower fries. RPO proved to generate low amounts of potentially toxic volatiles, acrolein, and be an excellent source carotenoids.
Quality of Red Sweet Pepper Fruit Treated with 1-MCP during a Simulated Post-harvest Handling Chain
Authors: Fernández-Trujillo J.P. , Serrano J.M. , Martínez J.A.
Published: May 2009

Red pepper fruit (Capsicum annuum L. cv Setubal) were treated with air (control) or 900 ppb 1-methylcyclopropene (1-MCP) for 24 h at 20°C. The fruit were packed in perforated polypropylene and stored for 4.5 days at 8°C (storage), 3 days at 20°C (simulated retail display), and 4.5 days in domestic refrigerator at 5.6°C. Fruit stored continuously at 20°C served as reference of respiration rate and ethylene production. The fruit quality, storage disorders, and physiological behavior in this simplified post-harvest handling chain and the possible effects of the CO2 accumulated during 1-MCP treatments were particularly studied. The critical points of the simulated post-harvest chain as regards fruit quality were the retail display stage at 20°C, the inhibition of ethylene as a side effect of 1-MCP, and, to a lesser extent the domestic refrigeration phase. Simulated retail display exacerbated shriveling and weight loss, and negatively affected aroma, finger texture and, to a lesser extent, fruit taste, and mouth texture. The 3% increase in the CO2 accumulated in both treatments resulted in a transient increase in the respiration rate, flesh and juice hue angle, glutamic and ascorbic acids; an increase in succinic acid (higher in 1-MCP treated fruit), and a transient decrease in citric acid, juice lightness and chroma. Compared with the control, the 1-MCP prevented the increase in skin chroma during the storage phase, the upsurge of ethylene production during the retail display phase, and doubled the fumaric acid levels in the refrigerator phase. 1-MCP may have increased the fruit susceptibility to shriveling and weight loss and, to a greater extent, pitting and gray mold rot in the domestic refrigerator. In brief, 1-MCP cannot be recommended for extending non-climacteric pepper shelf-life.
From the Sword to Schindler: A Saga of Gastroscopy
Authors: Morgenstern Leon
Published: May 2009

Gastroscopy is an art as well as a science. The art is getting the instrument down; the science is the instrument itself. Rudolf Schindler was a master of both and is properly called “The Father Of Gastroscopy”. He can also be called a renaissance man, so varied were his interests. Sword-swallowing played a minor but interesting role in the development of gastroscopy. It is still alive and well.
Angiostatin regulates the expression of antiangiogenic and proapoptotic pathways via targeted inhibition of mitochondrial proteins
Authors: Lee Tong-Young , Muschal Stefan , Pravda Elke A. , Folkman Judah , Abdollahi Amir , Javaherian Kashi
Published: May 2009

Angiostatin, a proteolytic fragment of plasminogen, is a potent endogenous antiangiogenic agent. The molecular mechanisms governing angiostatin's antiangiogenic and antitumor effects are not well understood. Here, we report the identification of mitochondrial compartment as the ultimate target of angiostatin. After internalization of angiostatin into the cell, at least 2 proteins within the mitochondria bind this molecule: malate dehydrogenase, a member of Krebs cycle, and adenosine triphosphate synthase. In vitro and in vivo studies revealed differential regulation of key prosurvival and angiogenesis-related proteins in angiostatin-treated tumors and tumor-endothelium. Angiostatin induced apoptosis via down-regulation of mitochondrial BCL-2. Angiostatin treatment led to down-regulation of c-Myc and elevated levels of another key antiangiogenic protein, thrombospondin-1, reinforcing its antitumor and antiangiogenic effects. Further evidence is provided for reduced recruitment and infiltration of bone marrow–derived macrophages in angiostatin-treated tumors. The observed effects of angiostatin were restricted to the tumor site and were not observed in other major organs of the mice, indicating unique tumor specific bioavailability. Together, our data suggest mitochondria as a novel target for antiangiogenic therapy and provide mechanistic insights to the antiangiogenic and antitumor effects of angiostatin.
Phenotype, distribution, generation, and functional and clinical relevance of Th17 cells in the human tumor environments
Authors: Kryczek Ilona , Banerjee Mousumi , Cheng Pui , Vatan Linhua , Szeliga Wojciech , Wei Shuang , Huang Emina , Finlayson Emily , Simeone Diane , Welling Theodore H. , Chang Alfred , Coukos George , Liu Rebecca , Zou Weiping
Published: May 2009

Th17 cells play an active role in autoimmune diseases. However, the nature of Th17 cells is poorly understood in cancer patients. We studied Th17 cells, the associated mechanisms, and clinical significance in 201 ovarian cancer patients. Tumor-infiltrating Th17 cells exhibit a polyfunctional effector T-cell phenotype, are positively associated with effector cells, and are negatively associated with tumor-infiltrating regulatory T cells. Tumor-associated macrophages promote Th17 cells through interleukin-1β (IL-1β), whereas tumor-infiltrating regulatory T cells inhibit Th17 cells through an adenosinergic pathway. Furthermore, through synergistic action between IL-17 and interferon-γ, Th17 cells stimulate CXCL9 and CXCL10 production to recruit effector T cells to the tumor microenvironment. The levels of CXCL9 and CXCL10 are associated with tumor-infiltrating effector T cells. The levels of tumor-infiltrating Th17 cells and the levels of ascites IL-17 are reduced in more advanced diseases and positively predict patient outcome. Altogether, Th17 cells may contribute to protective human tumor immunity through inducing Th1-type chemokines and recruiting effector cells to the tumor microenvironment. Inhibition of Th17 cells represents a novel immune evasion mechanism. This study thus provides scientific and clinical rationale for developing novel immune-boosting strategies based on promoting the Th17 cell population in cancer patients.
Evaluation of NIH consensus criteria for classification of late acute and chronic GVHD
Authors: Vigorito Afonso C. , Campregher Paulo V. , Storer Barry E. , Carpenter Paul A. , Moravec Carina K. , Kiem Hans-Peter , Fero Matthew L. , Warren Edus H. , Lee Stephanie J. , Appelbaum Frederick R. , Martin Paul J. , Flowers Mary E. D.
Published: May 2009

Historically, graft-versus-host disease (GVHD) beyond 100 days after hematopoietic cell transplantation (HCT) was called chronic GVHD, even if the clinical manifestations were indistinguishable from acute GVHD. In 2005, the National Institutes of Health (NIH) sponsored a consensus conference that proposed new criteria for diagnosis and classification of chronic GVHD for clinical trials. According to the consensus criteria, clinical manifestations rather than time after transplantation should be used in clinical trials to distinguish chronic GVHD from late acute GVHD, which includes persistent, recurrent, or late-onset acute GVHD. We evaluated major outcomes according to the presence or absence of NIH criteria for chronic GVHD in a retrospective study of 740 patients diagnosed with historically defined chronic GVHD after allogeneic HCT between 1994 and 2000. The presence or absence of NIH criteria for chronic GVHD showed no statistically significant association with survival, risks of nonrelapse mortality or recurrent malignancy, or duration of systemic treatment. Antecedent late acute GVHD was associated with an increased risk of nonrelapse mortality and prolonged treatment among patients with NIH chronic GVHD. Our results support the consensus recommendation that, with appropriate stratification, clinical trials can include patients with late acute GVHD as well as those with NIH chronic GVHD.
Predictors of defaulting from completion of child immunization in south Ethiopia, May 2008 – A case control study
Authors: Tadesse Henoke , Deribew Amare , Woldie Mirkuzie
Published: May 2009

Background

Epidemiological investigations of recent outbreaks of vaccine preventable diseases have indicated that incomplete immunization was the major reason for the outbreaks. In Ethiopia, full immunization rate is low and reasons for defaulting from immunization are not studied well. The objective of the study was to identify the predictors of defaulting from completion of child immunization among children between ages 9–23 months in Wonago district, South Ethiopia.

Methods

Unmatched case control study was conducted in eight Kebeles (lowest administrative unit) of Wonago district in south Ethiopia. Census was done to identify all cases and controls. A total of 266 samples (133 cases and 133 controls) were selected by simple random sampling technique. Cases were children in the age group of 9 to 23 months who did not complete the recommended immunization schedule. Pre-tested structured questionnaire were used for data collection. Data was analyzed using SPSS 15.0 statistical software.

Results

Four hundred eighteen (41.7%) of the children were fully vaccinated and four hundred twelve (41.2%) of the children were partially vaccinated. The BCG: measles defaulter rate was 76.2%. Knowledge of the mothers about child immunization, monthly family income, postponing child immunization and perceived health institution support were the best predictors of defaulting from completion of child immunization.

Conclusion

Mothers should be educated about the benefits of vaccination and the timely administration of vaccines.
Chronic Intermittent Hypoxia Induces 11β-Hydroxysteroid Dehydrogenase in Rat Heart
Authors: Klusoňová Petra , Řeháková Lenka , Borchert Gudrun , Vagnerová Karla , Neckář Jan , Ergang Peter , Mikšík Ivan , Kolář František , Pácha Jiří
Published: May 2009

Corticosteroids are known to not only regulate electrolyte homeostasis but also play a role in the cardiovascular system, including myocardial remodeling. Because transgenic mice that overexpress 11β-hydroxysteroid dehydrogenase (11HSD) type 2 in cardiomyocytes have been shown to spontaneously develop cardiac hypertrophy and fibrosis, we investigated whether changes in the cardiac metabolism of glucocorticoids accompany remodeling of the heart under physiological conditions. In the present study, glucocorticoid metabolism and 11HSD2 were explored in the hearts of rats exposed to chronic intermittent hypobaric hypoxia (CIH), which induces hypertrophy and fibrosis of the right and less of the left ventricle. We first demonstrated that adaptation to CIH led to a significant increase in 11HSD2 transcript levels and activity in the myocardium. In contrast, neither 11HSD1 activity and mRNA level nor the abundance of mineralocorticoid and glucocorticoid receptor mRNA were up-regulated. The adaptation to CIH also led to an increase of 11HSD2 mRNA in isolated cardiomyocytes, whereas 11HSD1, glucocorticoid receptor, and mineralocorticoid receptor mRNA levels were not changed in comparison with the cardiomyocytes of control normoxic rats. The changes in cardiac metabolism of glucocorticoids were accompanied by inflammatory responses. The expression levels of the proinflammatory markers cyclooxygenase-2 and osteopontin were significantly increased in both the myocardium and the cardiomyocytes isolated from rats exposed to CIH. These findings suggest that myocardial remodeling induced by CIH is associated with the up-regulation of cardiac 11HSD2. Consequently, local metabolism of glucocorticoids could indeed play a role in cardiac hypertrophy and fibrosis.
Regulation of Food Intake and Gonadotropin-Releasing Hormone/Luteinizing Hormone during Lactation: Role of Insulin and Leptin
Authors: Xu Jing , Kirigiti Melissa A. , Grove Kevin L. , Smith M. Susan
Published: May 2009

Negative energy balance during lactation is reflected by low levels of insulin and leptin and is associated with chronic hyperphagia and suppressed GnRH/LH activity. We studied whether restoration of insulin and/or leptin to physiological levels would reverse the lactation-associated hyperphagia, changes in hypothalamic neuropeptide expression [increased neuropeptide Y (NPY) and agouti-related protein (AGRP) and decreased proopiomelanocortin (POMC), kisspeptin (Kiss1), and neurokinin B (NKB)] and suppression of LH. Ovariectomized lactating rats (eight pups) were treated for 48 h with sc minipumps containing saline, human insulin, or rat leptin. The arcuate nucleus (ARH) was analyzed for NPY, AGRP, POMC, Kiss1, and NKB mRNA expression; the dorsal medial hypothalamus (DMH) was analyzed for NPY mRNA. Insulin replacement reversed the increase in ARH NPY/AGRP mRNAs, partially recovered POMC, but had no effect on recovering Kiss1/NKB. Leptin replacement only affected POMC, which was fully recovered. Insulin/leptin dual replacement had similar effects as insulin replacement alone but with a slight increase in Kiss1/NKB. The lactation-induced increase in DMH NPY was unchanged after treatments. Restoration of insulin and/or leptin had no effect on food intake, body weight, serum glucose or serum LH. These results suggest that the negative energy balance of lactation is not required for the hyperphagic drive, although it is involved in the orexigenic changes in the ARH. The chronic hyperphagia of lactation is most likely sustained by the induction of NPY in the DMH. The negative energy balance also does not appear to be a necessary prerequisite for the suppression of GnRH/LH activity.
Salt-Inducible Kinase 1 in the Rat Pinealocyte: Adrenergic Regulation and Role in Arylalkylamine N-Acetyltransferase Gene Transcription
Authors: Kanyo R. , Price D. M. , Chik C. L. , Ho A. K.
Published: May 2009

The recognition of the basic leucine zipper domain in the regulation of transcriptional activity of cAMP response element-binding protein by salt-inducible kinase (SIK) prompted our investigation of the regulatory role of this kinase in the induction of Aa-nat and other cAMP-regulated genes in the rat pineal gland. Here we report Sik1 expression was induced by norepinephrine (NE) in rat pinealocytes primarily through activation of β-adrenergic receptors, with a minor contribution from activation of α-adrenergic receptors. Treatments with dibutyryl cAMP, and to a lesser extent, agents that elevate intracellular Ca2+ mimicked the effect of NE on Sik1 expression. In parallel to the results of the pineal cell culture studies, a marked nocturnal induction of Sik1 transcription was found in whole-animal studies. Knockdown of Sik1 by short hairpin RNA amplified the NE-stimulated Aa-nat transcription and other adrenergic-regulated genes, including Mapk phosphatase 1, inducible cAMP repressor, and type 2 iodothyronine deiodinase in a time-dependent manner. In contrast, overexpressing Sik1 had an inhibitory effect on the NE induction of Aa-nat and other adrenergic-regulated genes. Together, our results indicate that the adrenergic induction of Sik1 in the rat pineal gland is primarily through the β-adrenergic receptor → protein kinase A pathway. SIK1 appears to function as part of an endogenous repressive mechanism that regulates the peak and indirectly the duration of expression of Aa-nat and other cAMP-regulated genes. These findings support a role for SIK1 in framing the temporal expression profile of Aa-nat and other adrenergic-regulated genes in the rat pineal gland.
Expression of retinoic acid receptor alpha in the germline is essential for proper cellular association and spermiogenesis during spermatogenesis
Authors: Chung Sanny S. W. , Wang Xiangyuan , Wolgemuth Debra J.
Published: May 2009

Signaling through vitamin A metabolites is indispensable for spermatogenesis, and disruption of retinoic acid receptor alpha (RARα)function resulted in male sterility and aberrant spermatogenesis, which resembled vitamin A deficiency. Here we investigated the lineage- and cell-specific role of RARα-mediated signaling during spermatogenesis using germ-cell transplantation and genetically manipulated mouse models. We demonstrated that RARα-deficient germ-cell stem cells were able to repopulate germ-cell-depleted wild-type testes and initiate spermatogenesis;however, improper cellular associations and abnormal sperm formation were observed. We further generated RARα-deficient mice that expressed RARα-EGFP fusion protein uniquely in haploid germ cells. Strikingly, spermatid orientation, alignment and release, as well as sperm morphology, were normal and there was a partial rescue of sterility. These data provide the first direct evidence for a distinct requirement of RARα-mediated retinoid signaling specifically in germ cells.
Selective plane illumination microscopy techniques in developmental biology
Authors: Huisken Jan , Stainier Didier Y. R.
Published: May 2009

Selective plane illumination microscopy (SPIM) and other fluorescence microscopy techniques in which a focused sheet of light serves to illuminate the sample have become increasingly popular in developmental studies. Fluorescence light-sheet microscopy bridges the gap in image quality between fluorescence stereomicroscopy and high-resolution imaging of fixed tissue sections. In addition, high depth penetration, low bleaching and high acquisition speeds make light-sheet microscopy ideally suited for extended time-lapse experiments in live embryos. This review compares the benefits and challenges of light-sheet microscopy with established fluorescence microscopy techniques such as confocal microscopy and discusses the different implementations and applications of this easily adaptable technology.
Coupling of zygotic transcription to mitotic control at theDrosophilamid-blastula transition
Authors: Lu Xuemin , Li Jennifer M. , Elemento Olivier , Tavazoie Saeed , Wieschaus Eric F.
Published: May 2009

One of the most prominent features at the mid-blastula transition (MBT)observed in most embryos is a pause in cell cycle regulated by the nucleocytoplasmic (N/C) ratio. By using chromosome rearrangements to manipulate the DNA content of embryos, we determined that the threshold for this cell cycle pause in Drosophila is about 70% of the DNA content normally present at cycle 14. Embryos with DNA contents around this value show intermediate cell cycle behaviors. Some pause at cycle 14, some at cycle 15,and some form patches arrested in different mitotic cycles. A second feature at MBT is a massive increase in zygotic transcription and a parallel degradation of maternally supplied RNAs. To determine whether these changes in gene expression are governed by the same N/C ratio that controls cell cycle pause, we compared gene expression in haploid and diploid Drosophilaembryos. We find that most maternal RNA degradation and most new transcription correlate with absolute time or developmental stage, and are timed independently of the N/C ratio. We identify a class of zygotically active genes whose expression depends on the N/C ratio and which are only expressed at cycle 15 in haploids. In embryos with patchy cell cycle behavior due to threshold DNA contents, the expression of these genes correlates tightly with the boundaries of the mitotic patches, suggesting either that the mechanism that pauses the mitotic cycle is the same as the one that measures the N/C ratio, or that it is tightly coupled to the mechanism controlling zygotic transcription of N/C ratio genes at the MBT.
A shift from kinesin 5-dependent metaphase spindle function during preimplantation development in mouse
Authors: FitzHarris Greg
Published: May 2009

Microtubules within meiotic and mitotic spindles continually move towards spindle poles in a process termed poleward flux, which is essential for spindle integrity and faithful chromosome segregation. Kinesin 5 is a longstanding candidate for a molecular motor that might drive poleward flux,and has been shown to drive flux and to be necessary for spindle bipolarity in Xenopus egg extracts. However, kinesin 5 is not necessary for poleward flux or for maintaining metaphase spindle bipolarity in intact mammalian cells, and the reason for the different results in these systems is unknown. The experiments presented here test the hypothesis that these results might reflect developmental differences in spindle function by examining the role of kinesin 5 in mouse eggs and preimplantation embryos. In contrast to cultured somatic cells, poleward flux in mouse eggs is critically dependent upon kinesin 5. Inhibition of poleward flux leads to spindle shortening as a result of continued microtubule depolymerisation at the pole, and eventual loss of spindle bipolarity. Spindle bipolarity is also dependent upon kinesin 5 during the first three embryonic cleavages, but becomes kinesin 5-independent in the majority of spindles by the blastocyst stage. This switch occurs asynchronously in different blastomeres but is independent of clonal cell heritage and of whether the blastomere is within the inner cell mass or the trophoectoderm. These experiments reveal a novel developmental switch in the requirements for spindle function and chromosome segregation during preimplantation development.
Seven-year-old children's perceptions of participating in a comprehensive clinical birth cohort study
Authors: Gammelgaard Anne , Bisgaard Hans
Published: May 2009

While several studies have explored parents' perceptions of their children's participation in research, very few studies have described the children's own perceptions of their participation in research. The aim of this study was to describe children's perceptions of their participation in a comprehensive longitudinal clinical study. Semi-structured qualitative interviews were conducted with 17 children aged seven participating in the Copenhagen Prospective Study on Asthma in Childhood. The interviews were audiotaped, transcribed and analysed using the template analysis method. The children rated their experiences with venepunctures on a Wong-Baker faces scale. The regular visits to the hospital and comprehensive clinical tests did not seem to have affected the children negatively. In particular, the children would happily engage themselves in medical tests mimicking play (moving, walking, running or playing with a computer). A majority of the children, however, disapproved of the venepunctures and some even refused to have it done. The results of this study indicate that participation in even comprehensive paediatric research can be a positive experience to the participants, with the most popular tests being those that required active participation from the children.
Obtaining consent from minors with parental responsibility
Authors: Macharia E , Milanovic D
Published: May 2009

Britain has the highest rate of pregnancies in Europe among young women aged 15–19 years. In girls under 16, the rates of pregnancy are rising: in 2006, there were 7.8 conceptions per 1000 girls; in 2007, there were 8.3 conceptions per 1000 girls. Where babies are born with conditions requiring treatment, the clinician may be faced with the task of obtaining consent from a parent who is also a minor. These situations present potential pitfalls. Guidance from legislative acts and case law is sparse. For example, the Children Act 1989 does not specify age limits for the assumption of parental responsibility. Legal precedents for assessing competence and capacity may not apply to minors. The Gillick principle for assessing competence does not extend to the competence of minors to take decisions as responsible parents. The Mental Capacity Act 2005 prescribes the limits of capacity but only in those aged over 16 years. Lastly, although a minor's parents will bear responsibility for the minor, this responsibility does not extend to the minor's child. This article explores these controversies through four case scenarios. These scenarios are loosely based on the authors' prior experiences as paediatric surgeons. In light of current statutory guidance, and the paucity of legal precedent, there are few answers to be offered. However, exploring the issues, enabling them to be thoughtfully considered by health professionals, is in itself valuable.
Why are physicians reluctant to use estrogens for anything – or do they prefer ‘PROFOX’?
Authors: Studd John
Published: May 2009

The reluctance of physicians to use estrogens in women with hormone responsive disorders is a tragic result of the 2002 WHI study. Although their hostility to estrogen therapy antedated these studies, the flawed data is now used as justification for the denial of estrogens for treatment of low bone density and various types of hormone responsive depression in women. Estrogens should be first choice therapy for osteoporosis in women under the age of 60 years, but in practice bisphosphonates, with its increasing number of long-term side-effects, has become first-line therapy for physicians. These side-effects include osteonecrosis of the jaw, mid-shaft femoral fractures and the need for proton pump inhibitors, which further reduce bone density and add to the fracture risk. Pyschiatrists fail to use transdermal estradiol for postnatal depression, premenstrual depression and perimenopausal depression in spite of randomized trials demonstrating their efficacy. Selective serotonin reuptake inhibitor therapy for depression independently decreases bone density and is also responsible for loss of libido, loss of mental acuity and dependence. Thus postmenopausal women with vasomotor symptoms, depression, loss of libido, vaginal dryness or low bone density are frequently denied effective estrogen therapy and given a combination of low-cost generic prozac and fosamax, which is in danger of becoming a post-WHI nightmare drug PROFOX (PROzacFOsamaX). This can only be avoided if advisory bodies review the reassuring evidence concerning estrogen therapy in women under the age of 60 years and advise accordingly.
Management of lymphoma in pregnancy
Authors: Hodby K , Fields P A
Published: May 2009

One in every thousand pregnancies is complicated by a concurrent diagnosis of cancer. Lymphoma is currently the fourth most common malignancy diagnosed during pregnancy and its incidence is rising. The diagnosis and management of any malignancy during pregnancy is clearly a clinical and emotional minefield for both patients and health-care professionals. The major challenge is to optimize medical treatment offered to the mother, while limiting the impact on the fetus. Given the relative rarity of the situation, current practice is guided by case reports and personal experience of management of similar patients. Our centre has a large and busy lymphoma practice, and has cared for several women diagnosed with a variety of subtypes of lymphoma over the years. This review aims to summarize current opinion about best practice regarding these patients and discusses options available from the current literature.
The Bombyx ovary-derived cell line endogenously expresses PIWI/PIWI-interacting RNA complexes
Authors: Kawaoka Shinpei , Hayashi Nobumitsu , Suzuki Yutaka , Abe Hiroaki , Sugano Sumio , Tomari Yukihide , Shimada Toru , Katsuma Susumu
Published: May 2009

Genetic studies and large-scale sequencing experiments have revealed that the PIWI subfamily proteins and PIWI-interacting RNAs (piRNAs) play an important role in germ line development and transposon control. Biochemical studies in vitro have greatly contributed to the understanding of small interfering RNA (siRNA) and microRNA (miRNA) pathways. However, in vitro analyses of the piRNA pathway have been thus far quite challenging, because their expression is largely restricted to the germ line. Here we report that Bombyx mori ovary-derived cultured cell line, BmN4, endogenously expresses two PIWI subfamily proteins, silkworm Piwi (Siwi) and Ago3 (BmAgo3), and piRNAs associated with them. Siwi-bound piRNAs have a strong bias for uridine at their 5′ end and BmAgo3-bound piRNAs are enriched for adenine at position 10. In addition, Siwi preferentially binds antisense piRNAs, whereas BmAgo3 binds sense piRNAs. Moreover, we identified many pairs in which Siwi-bound antisense and BmAgo3-bound sense piRNAs are overlapped by precisely 10 nt at their 5′ ends. These signatures are known to be important for secondary piRNA biogenesis in other organisms. Taken together, BmN4 is a unique cell line in which both primary and secondary steps of piRNA biogenesis pathways are active. This cell line would provide useful tools for analysis of piRNA biogenesis and function.
Identification of the chloroplast adenosine-to-inosine tRNA editing enzyme
Authors: Karcher Daniel , Bock Ralph
Published: May 2009

Plastids (chloroplasts) of higher plants exhibit two types of conversional RNA editing: cytidine-to-uridine editing in mRNAs and adenosine-to-inosine editing in at least one plastid genome-encoded tRNA, the tRNA-Arg(ACG). The enzymes catalyzing RNA editing reactions in plastids are unknown. Here we report the identification of the A-to-I tRNA editing enzyme from chloroplasts of the model plantArabidopsis thaliana. The protein (AtTadA) has an unusual structure in that it harbors a large N-terminal domain of >1000 amino acids, which is not required for catalytic activity. The C-terminal region of the protein displays sequence similarity to tadA, the tRNA adenosine deaminase fromEscherichia coli. We show that AtTadA is imported into chloroplasts in vivo and demonstrate that the in vitro translated protein triggers A-to-I editing in the anticodon of the plastid tRNA-Arg(ACG). Suppression ofAtTadAgene expression in transgenicArabidopsisplants by RNAi results in reduced A-to-I editing in the chloroplast tRNA-Arg(ACG). The RNAi lines display a mild growth phenotype, presumably due to reduced chloroplast translational efficiency upon limited availability of edited tRNA-Arg(ACG).
Computational identification of riboswitches based on RNA conserved functional sequences and conformations
Authors: Chang Tzu-Hao , Huang Hsien-Da , Wu Li-Ching , Yeh Chi-Ta , Liu Baw-Jhiune , Horng Jorng-Tzong
Published: May 2009

Riboswitches are cis-acting genetic regulatory elements within a specific mRNA that can regulate both transcription and translation by interacting with their corresponding metabolites. Recently, an increasing number of riboswitches have been identified in different species and investigated for their roles in regulatory functions. Both the sequence contexts and structural conformations are important characteristics of riboswitches. None of the previously developed tools, such as covariance models (CMs), Riboswitch finder, and RibEx, provide a web server for efficiently searching homologous instances of known riboswitches or considers two crucial characteristics of each riboswitch, such as the structural conformations and sequence contexts of functional regions. Therefore, we developed a systematic method for identifying 12 kinds of riboswitches. The method is implemented and provided as a web server, RiboSW, to efficiently and conveniently identify riboswitches within messenger RNA sequences. The predictive accuracy of the proposed method is comparable with other previous tools. The efficiency of the proposed method for identifying riboswitches was improved in order to achieve a reasonable computational time required for the prediction, which makes it possible to have an accurate and convenient web server for biologists to obtain the results of their analysis of a given mRNA sequence. RiboSW is now available on the web at http://RiboSW.mbc.nctu.edu.tw/.
A Prospect Theory Model of Resource Allocation
Authors: Bromiley Philip
Published: May 2009

Many papers in organization theory and strategy use prospect theory, but few derive their hypotheses from prospect theory's formal model. This paper develops a prospect theory model of resource allocation under risk where projects have both positive and negative adjusted payoffs. The model assumes consistent value (rather than profit) maximizing behavior and demonstrates how resources, risk propensity, and reference levels interact to determine allocations to risky projects. The analysis shows that prospect theory's parameters interact in complex ways to influence risk taking, which makes simple predictions difficult. Overall, loss aversion and the reference point dominate the results, with curvature of the value function playing a secondary role and the maximum risk aversion occurring for firms near their reference points, not for firms above their reference points.
Combining a Multiattribute Value Function with an Optimization Model: An Application to Dynamic Resource Allocation for Infrastructure Maintenance
Authors: Mild Pekka , Salo Ahti
Published: May 2009

A key decision in infrastructure management is the allocation of resources to maintenance activities that consist of periodic rehabilitation actions and routine day-to-day operations. These activities improve the quality of different assets and operations. They also differ in terms of their objectives, costs, and life-cycle characteristics; yet they all impact the same infrastructure system and compete for resources from the same budget. To support the allocation of resources to these activities, we present a generic resource allocation model that we developed for the Finnish Road Administration (Finnra) by building and interlinking (i) a preference model, which yields the aggregate value of maintenance activities by applying multiattribute value functions to the quality distributions of assets; (ii) a life-cycle model, which captures the deterioration-improvement dynamics associated with the maintenance activities; and (iii) an optimization model, which generates funding recommendations for maximizing the aggregate long-term value of maintenance investments. The optimization results were explored in facilitated workshops where “on-the-fly” computations gave senior managers insights into how the recommendations depended on preferences and budget levels. The case study was awarded for an outstanding achievement in Finnra's research program, and it was also recognized as a Finalist for the Decision Analysis Society Practice Award in 2007.