bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thrifty Genotypes and Phenotypes in the Pathogenesis of Type 2 Diabetes Mellitus
Authors: Ong Ken K.L. , Dunger David B. 
Published: July 2014

ABSTRACT
Dramatically high rates of type 2 diabetes mellitus (DM) have been observed in historically undernourished, recently urbanized populations. A comparable model is the high risk of DM in individuals who were growth restrained in utero and subsequently catch up in size. While it is proposed that undernutrition may somehow adversely program metabolism, both models could also be explained by genotypes that promoted survival during earlier nutritional adversity but later add to the risk of DM. Our recent studies in a contemporary birth cohort have identified two different candidate thrifty genotypes. The insulin gene VNTR ΙII/ΙΙΙ genotype promotes fetal growth and historically could thereby have enhanced survival during infancy. In contrast, the maternally inherited 16189 mitochondrial DNA variant is associated with restrained fetal growth and may therefore enhance the likelihood of maternal survival. Both genotypes are associated with an increased risk of adult type 2 DM in historical cohorts. However, the development of DM in individuals from contemporary birth cohorts may prove to be influenced more by genetic and other early determinants of childhood obesity.
Route-Dependent Endocrine and Metabolic Effects of Estrogen Replacement Therapy
Authors: O’Sullivan Anthony J. , Ho Ken K.Y. 
Published: July 2014

ABSTRACT
The route of estrogen replacement therapy has a major impact on the growth hormone (GH)-insulin-like growth factor-I (IGF-I) axis. Estrogen administration by the oral, but not the transdermal, route reduces IGF-I and increases GH levels in postmenopausal women. This perturbation of the GH-IGF-I axis occurs with different forms of estrogen treatment, indicating that the dissociation of the somatotropic axis and concomitant increase in GH-binding protein levels are intrinsic effects of the oral route of estrogen administration. In clinical studies, oral estrogen reduced postprandial lipid oxidation, compared with transdermal estrogen. Oral estrogen was also associated with a reduction in lean body mass and an increase in fat mass, compared with transdermal estrogen. In contrast, the route of estrogen therapy had no impact on carbohydrate metabolism or the estrogen-induced increase in bone mineral density. The findings of route-dependent changes in body composition add a new dimension to health considerations concerning estrogen therapy in postmenopausal women and may have significant implications for estrogen replacement therapy in young hypogonadal females.
Telomerase and the Cellular Lifespan: Implications for the Aging Process
Authors: Ostler Elizabeth L. , Wallis Corrin V. , Aboalchamat Bilal , Faragher Richard G.A. 
Published: July 2014

ABSTRACT
The aging process has multiple causes. However, there is now substantial evidence consistent with the hypothesis that (i) all normal mammalian somatic cells have a finite capacity to replicate and (ii) that gradual cell turnover throughout the lifespan of a mammal eventually exhausts this finite capacity. This results in a gradual accumulation of senescent (irreversibly post-mitotic) cells with increasing age. These cells display a radically different phenotype to their growing counterparts, which has the potential to compromise tissue function. Perhaps the best evidence for this is seen in Werner’s syndrome, a rare genetic disease, in which patients display most of the features of accelerated aging, together with a profoundly compromised replicative lifespan in certain tissue lineages. Several classes of human cells are now known to count divisions by monitoring the progressive attrition of chromosomal ends (telomeres), leading to the activation of a p53-p21waf - dependent G1 checkpoint. Ectopic expression of telomerase has been shown to prevent senescence in several cell types and offers the potential for interventions in the aging process based on tissue engineering, gene therapy or homeografts. However, this telomere-driven senescence mechanism seems to be absent from rodents, which use telomere-independent means (perhaps based upon p14arf) to count divisions. Similar senescence pathways are now being reported in humans, and this, coupled with the demonstration of tissue-specific telomeric loss rates, has the potential to render strategies based on the use of telomerase dependent on the characteristics of the target tissue. Werner’s syndrome may provide strong clues regarding the potential limitations and prospects of such future treatments.
A Role for the Somatotropic Axis in Neural Development, Injury and Disease
Authors: Scheepens Arjan , Williams Chris E. , Breier Bernhard Η. , Guan Jian , Gluckman Peter D. 
Published: July 2014

ABSTRACT
This review article discusses the roles of the somatotropic axis in the growth and development of the normal central nervous system (CNS) and during recovery from brain injury. Classically, the actions of pituitary-derived growth hormone (GH) have been reported to be primarily mediated via the induction of hepatic insulin-like growth factor-I (IGF-I). GH receptors (GHRs), however, have now been identified in many body tissues and shown to have both endocrine and local actions, some of which are IGF-I independent. Within the brain, GHRs are widely located across a range of cellular phenotypes, yet little is known regarding their function or endogenous ligand. It is now becoming accepted that GH, like IGF-I, is integrally involved in the growth and development of the normal CNS. Following brain injury, IGF-I mRNA is induced, primarily within reactive microglia. The resultant IGF-I protein appears to have a dual role, first as an endogenous neurotropic and anti-apoptotic agent acting directly on stressed cells, and second as a prohormone for generation of the N-terminal tripeptide of IGF-I, glycine-proline-glutamate (GPE), and the resulting des-N-(l-3)-IGF-I, both of which have specific neuroprotective properties. Our work on deciphering the upstream regulators of injury-induced IGF-I has revealed that a GH-like substance is strongly upregulated after brain injury and specifically associated with stressed neurons and glia. Subsequent to this finding, GH administered centrally 2 hours after a hypoxic-ischemic brain injury in juvenile rats was found to provide significant neuroprotection, interestingly, in a spatiotemporal pattern distinct from the neuroprotection offered by IGF-I. The implications of these findings in regard to the growth, development and injury response of the CNS are discussed.
Hypothalamic Growth Hormone-Insulin-like Growth Factor-I Axis across the Human Life Span
Authors: Ghigo Ezio , Arvat Emanuela , Gianotti Laura , Lanfranco Fabio , Broglio Fabio , Aimaretti Gianluca , Maccario Mauro , Camanni Franco 
Published: July 2014

ABSTRACT
The activity of the growth hormone (GH)- insulin-like growth factor-I (IGF-I) axis undergoes marked variations across the human life span, mainly reflecting age-related changes in the neural control of somatotroph function. IGF-I secretion generally reflects GH status, except in newborns, who secrete high levels of GH but low levels of IGF-I. Changes in the gonadal steroid milieu, particularly estradiol, play a major role in the enhanced activity of the GH-IGF-I axis at puberty and probably reflect further changes in the neuroendocrine control of somatotroph secretion. The change in responsiveness of somatotrophs to various stimuli, including GHRH, is not as marked as the spontaneous secretion of GH at puberty. However, in childhood, somatotrophs are unusually refractory to the somatostatin-mediated negative GH autofeedback mechanism. Normal children show normal responsiveness to the stimulatory influence of α-adrenergic and cholinergic agonists, galanin and arginine, but the activating effect of these stimuli on somatotroph secretion is reduced in elderly individuals, with the notable exception of arginine. Arginine potentiates both spontaneous and GHRH-induced GH secretion to the same extent in normally growing children, adults and elderly individuals, indicating that the releasable pool of GH is generally preserved across the human life span. Thus, the reduction in spontaneous and GHRH-induced GH secretion in the elderly probably reflects age-related changes in neurotransmitter control, leading to GHRH hypoactivity and absolute or relative somatostatin hyperactivity in the aged hypothalamus. Cholinergic impairment in the aging brain probably involves hypothalamic pathways and leads to decreased activity of the GH-IGF-I axis in normal and elderly individuals, as well as in individuals with premature brain aging. However, there is evidence indicating that age-related variations in the activity of the natural GH-secretagogue ligand(s) at the hypothalamic level could also play a role in the age-dependent changes in the GH-IGF-I axis.
Trennbankensystem – ein Weg zu mehr Finanzstabilität in Deutschland?
Authors: Dombret Andreas , Liebig Thilo , Stein Ingrid 
Published: July 2014

AbstractThis article examines how the introduction of a specialised banking system is likely to impact banks and the real economy in Germany, in particular from a financial stability perspective. This study is motivated by a recently passed law in Germany on a specialised banking system (Trennbankengesetz), current reforms in the US and UK and proposals for the EU. We focus on the consequences of a separation of the savings & loan business and proprietary trading.
We conclude that proprietary trading plays a significant role only for large, systemically important banks in Germany. The latter act as universal banks and grant a considerable fraction of all loans that go to domestic enterprises and consumers. Costs for customers, however, are likely to be moderate. In contrast, a specialised banking system may provide the important advantage that insolvent trading units can be separated more easily from the savings & loan business arm and eventually liquidated. In this way, implicit state guarantees may be reduced.
Fairer Systemwettbewerb zwischen gesetzlicher und privater Krankenversicherung
Authors: Kifmann Mathias , Nell Martin 
Published: July 2014

ZusammenfassungWir entwickeln einen Reformvorschlag, der den problematischen Selektions­wettbewerb zwischen GKV und PKV beendet und zu einem fairen Systemwettbewerb führt. Jeder Bürger leistet einen einkommensabhängigen Beitrag zum Gesundheitsfonds und hat bei einem Wechsel in die PKV Anspruch auf risikogerechte Zahlungen aus dem Gesundheitsfonds. Die Versicherungspflichtgrenze wird gesenkt und langfristig abgeschafft. Private Versicherungen können nicht mehr allein deshalb mit Versicherten rechnen, weil diese durch einen Wechsel Solidarbeiträge vermeiden können. Die Nachhaltigkeit unseres Reformvorschlags wird durch eine Kapitalbildung gesichert. JEL-Klassifikation: I13, I18
Reproducing Stories: Strategic Narratives of Teen Pregnancy and Motherhood
Authors: Barcelos Chris A , Gubrium Aline C 
Published: July 2014

Abstract
Pregnant and parenting young women are simultaneously silenced and overrepresented by raced and classed social narratives on adolescent childbearing in the United States. These narratives posit teen childbearing as an unequivocal social, health, and economic problem, although some scholars and policy makers construct alternative narratives that focus on inequalities and propose different perspectives on causes and consequences. Narrative inquiry that analyzes how stories are produced and utilized can enable a more nuanced approach to complex social problems. We conducted 19 individual, in-depth, and semistructured interviews with young mothers ages 16 to 21 who attend a community-based alternative education program in a low-income northeastern city. Interviews were analyzed using thematic narrative techniques. The young mothers we interviewed used a process of strategic negotiation to distance themselves from prevailing social and cultural stories about the problem of teen motherhood. Participants demonstrated this strategic process through their attempts to assuage stigma and construct unproblematic identities. Young mothers reproduced and reinterpreted a variety of circulating narratives on teen childbearing. They reproduced dominant narratives through pathology, missed adolescence, and redemption stories, and reinterpreted dominant narratives through stories of stratified reproduction, sexual health education, and stigmatization and surveillance. Our participants' narratives illustrate the need to think broadly about the meanings of early pregnancy and motherhood in terms of how they play out in research and policymaking. We call for a discursive shift in ways of knowing about and doing research and policy surrounding teen childbearing.
Whole-Genome Sequence of the C57L/J Mouse Inbred Strain
Authors: Ananda Guruprasad , Takemon Yuka , Hinerfeld Douglas , Korstanje Ron 
Published: July 2014

AbstractWe sequenced the complete genome of the widely used C57L/J mouse inbred strain. With 40× average coverage, we compared the C57L/J sequence with that of the C57BL/6J and identified many known as well as novel private variants. This genome sequence adds another strain to the growing number of mouse inbred strains with complete genome sequences and is a valuable resource to the scientific community.
Self-energy Models for Scattering in Semiconductor Nanoscale Devices: Causality Considerations and the Spectral Sum Rule
Authors: Barker John R. , Martinez Antonio 
Published: July 2014

ABSTRACTThe modelling of of silicon gate-all-around nanowire transistors by non-equilibrium Green function methods requires the computation of self-energies for inelastic electron-phonon interactions. It is shown that many approximations designed to reduce numerical complexityto these self-energies in fact fail because they do not satisfy appropriate causality conditions. Four familiar approximations are discussed and their failures resolved. It is also shown that a condition for the spectral density sum rule to hold (and hence accurate density of states in energy) depends on a simple causality condition.
The Structure and the Mechanical Properties of a Newly Fabricated Cellulose-Nanofiber/Polyvinyl-Alcohol Composite
Authors: Oishi Yukako , Hotta Atsushi 
Published: July 2014

ABSTRACTCellulose nanofibers (Cel-F) were extracted by a simple and harmless Star Burst (SB) method, which produced aqueous cellulose-nanofiber solution just by running original cellulose beads under a high pressure of water in the synthetic SB chamber. By optimizing the SB process conditions, the cellulose nanofibers with high aspect ratios and the small diameter of ∼23 nm were obtained, which was confirmed by transmission electron microscopy (TEM). From the structural analysis of the Cel-F/PVA composite by the scanning electron microscopy (SEM), it was found that the Cel-F were homogeneously dispersed in the PVA matrix. Considering the high molecular compatibility of the cellulose and PVA due to the hydrogen bonding, a good adhesive interface could be expected for the Cel-F and the PVA matrix. The influences of the morphological change in Cel-F on the mechanical properties of the composites were analysed. The Young’s modulus rapidly increased from 2.2 GPa to 2.9 GPa up to 40 SB treatments (represented by the unit Pass), whereas the Young’s modulus remained virtually constant above 40 Pass. Due to the uniform dispersibility of the Cel-F, the Young’s modulus of the 100 Pass composite at the concentration of 5 wt% increased up to 3.2 GPa. The experimental results corresponded well with the general theory of the composites with dispersed short-fiber fillers, which clearly indicated that the potential of the cellulose nanofibers as reinforcement materials for hydrophilic polymers was sufficiently confirmed.
Direct gap Group IV semiconductors for next generation Si-based IR photonics
Authors: Kouvetakis John , Gallagher James , Menéndez José 
Published: July 2014

ABSTRACTThis paper presents synthesis and optical properties of mono-crystalline Ge1-ySny and Ge1-x-ySixSny semiconductor alloys grown on Si/Ge platforms via purposely designed CVD routes using highly reactive Si/Ge/Sn hydrides including Ge3H8, Ge4H10, Si4H10 and SnD4. The Ge1-ySny materials are shown to exhibit strong and tunable photoluminescence induced by the substitution of sizable Sn concentrations in the Ge diamond lattice ultimately leading to an indirect-to-direct band gap crossover at y= 0.08-0.09. The optical data indicate that the IR coverage of the alloy extends well beyond that of elemental Ge into the broader long wavelength range suggesting a variety of applications in Si-based photonics. Ge1-x-ySixSny alloys represent the first viable ternary semiconductor among group IV elements with independently tunable lattice parameter and electronic structure. Studies of the compositional dependence of direct and indirect edges in these alloys using photoluminescence and photocurrent measurements are reviewed. The optical results show band gap variation over a wide range above and below that of Ge from 1.1 to 0.5 eV and provide the first demonstration of direct gap behavior in this semiconductor system.
Pulsed–light Crystallization of Thin Film Silicon, Germanium, and Silicon Germanium Alloy
Authors: Yan Baojie , Toner William , Dubey Mukul , Fan Qihua , Jiang Chun-Sheng , Stevenson David 
Published: July 2014

ABSTRACTWe report the recent progress of crystallization of amorphous silicon (a-Si), amorphous germanium (a-Ge) and amorphous silicon germanium alloy (a-SiGe) using a pulsed-Xenon-lamp system with multiple lamps. The precursor materials were deposited using a sputtering machine on display glass substrates maintained on a rotary holder. The RF powers on the silicon and germanium targets were varied to control the Ge/Si ratio in the materials. The film thickness was in the range of 50-100 nm, targeting the application in thin film transistors (TFT). The samples were pre-heated to 350-450°C in a conveyer chamber with nitrogen flow before the crystallization. The materials were characterized using AFM, Raman and Spectroscopic Ellipsometry. We demonstrated that we can uniformly crystallize a-Si, a-SiGe, and a-Ge with a single-pulse or multiple-pulse process on 10×5 cm2 glass substrates. We found that the required crystallization power for a-Ge is much lower than for a-Si. The power needed to crystallize a-SiGe is between the power required for a-Ge and a-Si crystallizations, and it increased with increasing Si fraction. No Raman signal was measurable in the as-deposited films. Strong Raman peaks at 520 cm-1 and 290 cm-1 were observed in the pulsed-lamp crystallized poly-Si and poly-Ge films, respectively. Distinct Ge-Ge, Si-Ge, and Si-Si vibration modes were observed at ~285 cm-1, ~390 cm-1, and ~470 cm-1, respectively, in the poly-SiGe films formed after the pulsed-light treatments. Their intensity ratios and the peak positions depended on the Ge/Si ratio and the light intensity used for the crystallization. AFM images showed the formation of large grains with increased surface roughness.
High quality kerfless silicon mono-crystalline wafers and cells by high throughput epitaxial growth
Authors: Hao R. , Ravi T.S. , Siva V. , Vatus J. , Miller D. , Custodio J. , Moyers K. 
Published: July 2014

ABSTRACTCrystalline silicon based photovoltaics continues to be the dominant technology for large scale deployment of solar energy. While impressive cost gains in silicon based PV have come with scale, there remains a strong push for increased efficiencies and further lowering of manufacturing costs to achieve true grid parity. So far, however, there has not been a production proven approach that reduces the cost while maintaining or increasing the efficiency. Attempts to reduce the amount of silicon used, for example, have led to development of various kerfless wafer manufacturing approaches. While some of these approaches have shown the potential for reduced costs, they also compromise the efficiency mainly due to the inferior quality of the material.Epitaxy based kerfless silicon wafers, on the other hand, has shown the potential to reverse this trend offering lower manufacturing costs while maintaining or even enhancing the efficiency due to the high quality of the n-type and p-type silicon epitaxial (Epi) wafers. In this work, we present key aspects of Crystal Solar’s patented high throughput production silicon epitaxial reactor and its use in the manufacture of standard thickness N and P wafers. Besides the advantage of having significantly reduced cost, these Epi wafers have high quality, better mechanical strength and resistance to light inducted degradation due to significantly reduced oxygen content.
Optimization of the protocrystalline p-layer in a-Si:H-based n-i-p photodiodes
Authors: Vygranenko Y. , Fernandes M. , Vieira M. , Sazonov A. 
Published: July 2014

ABSTRACTThis work reports a carbon-free, blue-enhanced a-Si:H n-i-p photodiode with an optimized protocrystalline p-layer. Although the used deposition conditions for the p-layer correspond to the microcrystalline regime, thin layers are mostly protocrystalline due to the amorphous underlying undoped layer. This conclusion is supported by Raman spectroscopy measurements. We have also found that the optical band gap of the p-layer can be varied by adjusting the rf power. By widening the band gap and tuning the impurity concentration in the p-layer, absorption and recombination losses at the p-i interface were reduced. The current-voltage, capacitance-voltage, and spectral-response characteristics of fabricated photodiodes are correlated with the doping level, optical band gap, and deposition conditions for p-layers. The optimized device exhibits a leakage current of about ∼80 pA/cm2 at 5 V reverse bias. The external quantum efficiency reaches a peak value of 92% at a wavelength of 510 nm, and, at shorter wavelengths, decreases down to 66%@400nm.
Control of Y2O3 nano-islands density to introduce artificial pinning centers in YBCO thin films
Authors: Mele P. , Matsumoto K. , Horide T. , Miura O. , Ichinose A. , Mukaida M. , Yoshida Y. , Horii S. 
Published: July 2014

AbstractWe successfully introduced high-density linear defects as artificial pinning centers (APCs) of the quantized vortices into YBCO films, during the film deposition procedure. APCs were introduced perpendicular to the film surface by using the distributed nano-sized Y2O3 islands prepared on SrTiO3(100) substrates. It is possible to induce strong changes on the shape and density of the Y2O3 islands by varying the deposition and annealing conditions. The highest Y2O3 islands density, 226/μm2, was obtained with fifteen laser pulses at 800°C of substrate temperature, and applying an annealing temperature of 800°C. Even if only a small fraction of the induced defects act as effective pinning centers, Jc of YBCO film grown on the Y2O3 nanoislands/SrTiO3 substrate increased to 1.8 107 A/cm2 (20 K, B//c, 0 T), which is 1.5 times higher than that of the pure YBCO film.
Porous Metals
Authors: Shapovalov Vladimir 
Published: July 2014

Porous metals are engineered materials; they are designed for special properties. Technological progress necessitates expanding the choices of such materials, making the development of new porous metals a relevant challenge for materials scientists.Although a wealth of information has already been accumulated on these materials, new results are published every year, extending the engineer's capability to manufacture porous metals and revealing their unknown and often unusual properties. This survey describes the state of the art and some recent accomplishments in the field. This article discusses manufacturing practices, structure, properties, and applications of porous metals. Promising new research issues are also highlighted. Materials whose pores were not formed in situ, like honeycomb structures made by high-energy beams etc., are not covered.