bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estrogen Treatment and Estrogen Suppression: Metabolic Effects in Adolescence
Authors: Mauras Nelly , Hayes Valerie , O’Brien Kimberly O. 
Published: July 2014

ABSTRACT
The metabolic consequences of reaching full reproductive maturity in humans involve not only growth hormone (GH) and insulin-like growth factor-I, but also the collaborative interaction of the gonadal sex steroids. Estrogen is critical for completing linear growth. It also inhibits bone resorption, decreases plasma lipid levels and serves as an antiatherosclerotic agent. Our studies show that, in low doses, estrogen increases GH production, increases calcium absorption and decreases bone turnover; however, unlike testosterone, estrogen has no effects as a protein-anabolic agent, at least at the whole body level. Studies of selective estrogen suppression, achieved using a potent aromatase inhibitor, show that estrogen is the main regulator of the gonadotropin axis. In boys, selective aromatase blockade may have a role in delaying epiphyseal fusion. Large placebo-controlled trials will be required to study this effect further.
Comparative Mapping Between Coho Salmon (Oncorhynchus kisutch) and Three Other Salmonids Suggests a Role for Chromosomal Rearrangements in the Retention of Duplicated Regions Following a Whole Genome Duplication Event
Authors: Kodama Miyako , Brieuc Marine S O , Devlin Robert H , Hard Jeffrey J , Naish Kerry A 
Published: July 2014

Abstract
Whole genome duplication has been implicated in evolutionary innovation and rapid diversification. In salmonid fishes, however, whole genome duplication significantly pre-dates major transitions across the family, and re-diploidization has been a gradual process between genomes that have remained essentially collinear. Nevertheless, pairs of duplicated chromosome arms have diverged at different rates from each other, suggesting that the retention of duplicated regions through occasional pairing between homeologous chromosomes may have played an evolutionary role across species pairs. Extensive chromosomal arm rearrangements have been a key mechanism involved in re-dipliodization of the salmonid genome; therefore, we investigated their influence on degree of differentiation between homeologs across salmon species. We derived a linkage map for coho salmon and performed comparative mapping across syntenic arms within the genus Oncorhynchus, and with the genus Salmo, to determine the phylogenetic relationship between chromosome arrangements and the retention of undifferentiated duplicated regions. A 6596.7 cM female coho salmon map, comprising 30 linkage groups with 7415 and 1266 nonduplicated and duplicated loci, respectively, revealed uneven distribution of duplicated loci along and between chromosome arms. These duplicated regions were conserved across syntenic arms across Oncorhynchus species and were identified in metacentric chromosomes likely formed ancestrally to the divergence of Oncorhynchus from Salmo. These findings support previous studies in which observed pairings involved at least one metacentric chromosome. Re-diploidization in salmon may have been prevented or retarded by the formation of metacentric chromosomes after the whole genome duplication event and may explain lineage-specific innovations in salmon species if functional genes are found in these regions.
Position Effect Variegation and Viability Are Both Sensitive to Dosage of Constitutive Heterochromatin inDrosophila
Authors: Berloco Maria , Palumbo Gioacchino , Piacentini Lucia , Pimpinelli Sergio , Fanti Laura 
Published: July 2014

AbstractThe dosage effect of Y-chromosome heterochromatin on suppression of position effect variegation (PEV) has long been well-known in Drosophila. The phenotypic effects of increasing the overall dosage of Y heterochromatin have also been demonstrated; hyperploidy of the Y chromosome produces male sterility and many somatic defects including variegation and abnormal legs and wings. This work addresses whether the suppression of position effect variegation (PEV) is a general feature of the heterochromatin (independent of the chromosome of origin) and whether a hyperdosage of heterochromatin can affect viability. The results show that the suppression of PEV is a general feature of any type of constitutive heterochromatin and that the intensity of suppression depends on its amount instead of some mappable factor on it. We also describe a clear dosage effect of Y heterochromatin on the viability of otherwise wild-type embryos and the modification of that effect by a specific gene mutation. Together, our results indicate that the correct balance between heterochromatin and euchromatin is essential for the normal genome expression and that this balance is genetically controlled.
DNA Helicase HIM-6/BLM Both Promotes MutSγ-Dependent Crossovers and Antagonizes MutSγ-Independent Interhomolog Associations During Caenorhabditis elegans Meiosis
Authors: Schvarzstein Mara , Pattabiraman Divya , Libuda Diana E , Ramadugu Ajit , Tam Angela , Martinez-Perez Enrique , Roelens Baptiste , Zawadzki Karl A , Yokoo Rayka , Rosu Simona , Severson Aaron F , Meyer Barbara J , Nabeshima Kentaro , Villeneuve Anne M 
Published: July 2014

Abstract
Meiotic recombination is initiated by the programmed induction of double-strand DNA breaks (DSBs), lesions that pose a potential threat to the genome. A subset of the DSBs induced during meiotic prophase become designated to be repaired by a pathway that specifically yields interhomolog crossovers (COs), which mature into chiasmata that temporarily connect the homologs to ensure their proper segregation at meiosis I. The remaining DSBs must be repaired by other mechanisms to restore genomic integrity prior to the meiotic divisions. Here we show that HIM-6, the Caenorhabditis elegans ortholog of the RecQ family DNA helicase BLM, functions in both of these processes. We show that him-6 mutants are competent to load the MutSγ complex at multiple potential CO sites, to generate intermediates that fulfill the requirements of monitoring mechanisms that enable meiotic progression, and to accomplish and robustly regulate CO designation. However, recombination events at a subset of CO-designated sites fail to mature into COs and chiasmata, indicating a pro-CO role for HIM-6/BLM that manifests itself late in the CO pathway. Moreover, we find that in addition to promoting COs, HIM-6 plays a role in eliminating and/or preventing the formation of persistent MutSγ-independent associations between homologous chromosomes. We propose that HIM-6/BLM enforces biased outcomes of recombination events to ensure that both (a) CO-designated recombination intermediates are reliably resolved as COs and (b) other recombination intermediates reliably mature into noncrossovers in a timely manner.
Microscopic Analysis of Organic Solar Cells by Simultaneous Measurements of ESR and Device Performance
Authors: Marumoto Kazuhiro , Nagamori Tatsuya , Yabusaki Masaki 
Published: July 2014

ABSTRACTLight-induced electron spin resonance (LESR) study of polymer solar cells has been performed to investigate accumulated hole carriers in these devices under device operation. We analyzed clear correlation between the number of accumulated holes in regioregular poly(3-hexylthiophene) (P3HT) evaluated by LESR and the deterioration of device performance (Voc, Jsc) observed using the same device under simulated solar irradiation. The effects of hole accumulation with deep trapping levels formed in P3HT at the organic interfaces on the performance are examined by considering interfacial electric dipole layers and charge-carrier scattering by accumulated holes.
Effect of Annealing on Microstructure in (Doped and Undoped) Hydrogenated Amorphous Silicon Films
Authors: Beyer W. , Hilgers W. , Lennartz D. , Maier F.C. , Nickel N.H. , Pennartz F. , Prunici P. 
Published: July 2014

ABSTRACTLaser heating and annealing of hydrogenated amorphous silicon (a-Si:H) films is of interest for improved material properties. Due to the variety of possible laser treatments with regard to wavelength, pulse duration, scan time etc., the definition of laser impact on the material is a challenge which we try to approach by comparing properties of laser and oven treated materials. Here we report on the effect of oven heat treatment (up to TA= 575°C) on microstructure and hydrogen content of hydrogenated amorphous silicon films, as detected by measurements of infrared absorption and of effusion of hydrogen as well as of implanted helium. The latter technique has been found to measure isolated voids (cavities) of the size of silicon divacancies and larger. Undoped as well as phosphorus and boron doped plasma-deposited a-Si:H films of various hydrogen content (< 15 at.%) were investigated, including undoped device grade a-Si:H. The results show little indication for void-related microstructure in the as-deposited and annealed state for material with a concentration of silicon bonded hydrogen below 5 at. %. At higher hydrogen concentration, evidence is found that hydrogen out-diffusion due to annealing causes isolated voids in concentrations up to about 1020 cm-3. A possible mechanism for the annealing induced (micro-)void generation is discussed.
Defect Management of High Efficiency Multijunction, Space and Concentrator Solar Cells
Authors: Yamaguchi Masafumi , Kojima Nobuaki , Ikeda Kazuma , Ohshita Yoshio 
Published: July 2014

ABSTRACTIII-V compound multi-junction solar cells have high efficiency potential of more than 50% due to wide photo response, while limiting efficiencies of single-junction solar cells are 31-32%. In order to realize high efficiency III-V compound multi-junction solar cells, understanding and controlling imperfections (defects) are very important. This paper reviews fundamentals of defects and defect management for III-V compound materials, single-junction, multi-junction, space and concentrator solar cells.
Increased sensitivity in a-SiC pinpin multilayers in the VIS-NIR range under UV light
Authors: Silva V. , Rodrigues I. , Vieira M. A , Louro P. , Vieira M. 
Published: July 2014

ABSTRACTIn this paper we experimentally demonstrate the use of near-ultraviolet steady state illumination to increase the spectral sensitivity of a double a-SiC/Si pi’n/pin photodiode beyond the visible spectrum (400 nm-880 nm). The concept is extended to implement a one by four wavelength division multiplexer with channel separation in the visible/near infrared range. Optoelectronic characterization of the device is presented and shows the feasibility of tailoring the wavelength and bandwidth of a polychromatic mixture. Several monochromatic pulsed lights in the VIS/NIR range, separately or in a polychromatic mixture illuminated the device. Independent tuning of the wavelengths is performed by steady state 390 nm optical bias superimposed from front and back sides. Results show that, front background enhances the light-to-dark sensitivity of the medium, long and infrared wavelength channels, and quench strongly the shorter wavelengths. Back background has the opposite effect; it only enhances the channel magnitude in short wavelength range and strongly reduces it in the long ones. This nonlinearity provides the possibility for selective tuning a specific wavelength. A capacitive optoelectronic model supports the experimental results. A numerical simulation is presented.
Optical Characterization of Si Nanowires: Dependence with Substrate Orientation and Light Polarization
Authors: Badán Juan A. , Marotti Ricardo E. , Dalchiele Enrique A. , Ariosa Daniel , Martín Francisco , Leinen Dietmar , Ramos-Barrado José R. 
Published: July 2014

ABSTRACTOptical properties of Si nanowire arrays (SiNWs) prepared on p-doped Si(111) and Si(100) substrates are studied. The SiNWs were synthesized by self-assembly electroless metal deposition nanoelectrochemistry in an ionic silver HF solution through selective etching. Total reflectance (Rt) and total diffuse reflectance (Rdt) of SiNWs change drastically in comparison to polished Si. To understand these changes diffuse reflectance (Rd) with polarized incident light was studied. For samples prepared on Si(111), the wavelength integrated Rd (wIRd) shows maxima at certain angle of incidence θ and it does not depend on light polarization. Moreover, Rdt of SiNWs prepared on Si(111) can be modeled as an ensemble of diffuse reflectors. For samples prepared on Si(100) wIRd increases with θ, being greater when the light electric field is parallel to the plane of incidence. Also, Rd spectra show structures due to interference effects. For these reasons SiNWs prepared on Si(100) can be considered as a thin film whose refractive index depends on light polarization.
Exfoliated Clay Nanoplatelets as Gelator and Oxidizing Agent for Ionic Liquid Electrolyte to Enhance Photovoltaic Performance of Dye-Sensitized Solar Cells
Authors: Cheng You-Chun , Lee Chia-Hsin , Tsai Chun Kai , Lin King-Fu 
Published: July 2014

ABSTRACTExfoliated montmorillonite (exMMT) nanoplatelets are a two-dimensional electrolyte carrying ∼1.78 dissociable monovalent cations per nanometer square. They were fabricated through soap-free emulsion polymerization of poly(methyl methacrylate) in the presence of MMT. Because the dissociated exMMTs are anionic, they were not only capable of gelatinizing 1-methyl-3-propylimidazolium iodide (MPII) ionic liquid-based electrolyte, but also increased the power conversion efficiency of resulting dye-sensitized solar cell (DSSC) from 6 to 7.77%. Recently, we investigated the ionic conductive mechanism of exMMT-gelled MPII ionic liquid-based electrolyte and found that the exMMTs acted like an oxidizing agent for iodide ions (I-). As exMMTs were mixed with MPII, I-ions readily oxidized to I3-and even to I5-ions by losing the electrons. Consequently, the ionic conductivity was significantly increased due to the fact that I-, I3-, and I5-tended to form redox couples that transported faster by way of the Grothus/exchange reaction process.
Perovskite Based Hybrid Solar Cells with Transparent Carbon Nanotube electrodes
Authors: Mielczarek Kamil , Zakhidov Anvar A. 
Published: July 2014

ABSTRACTRecently, major advances have been made in electrolytic and solid state DSSCs through the use of perovskite nanocrystals as a sensitizing agent where power conversion efficiencies of over 12% have been realized [1–3]. Moreover the planar DSSC/PV devices with perovskites used as photoactive absorbers sandwiched between selective electron and hole transport layers have demonstrated record performances. Additionally, the uses of carbon nanotubes (CNTs) as a flexible, transparent, lightweight and robust electrode material have been demonstrated in both DSSC as well as OPV devices. The application of CNTs as a charge collector with perovskite sensitized solid state planar PV and DSSCs is discussed. Performance characteristics of CNTs within perovskite based hybrid OPVs are investigated and the role of CNTs as an efficient charge collector is extended to the inverted geometry.
The Improvement of Dental Composite Properties with Electromagnetically Aligned Nanofiber
Authors: Uyar Tansel , Cokeliler Dilek 
Published: July 2014

ABSTRACTBecause of the aesthetics, handy and low cost features, acrylic resin is the main material in denture fabrication last 40 years. The purpose of this study is to improve mechanical properties of acrylic based dental composites used in dentistry by applying nanofiber approaches. Polymethylmethacrylate (PMMA) is commonly used as a base acrylic denture material with benefits of rapid and easy handling but sometime this material can be fractured or cracked in clinical use because of the strength issues that is frequently used in restorative dentistry in recent years. A wide variety of fillers that are used to produce PMMA composites draw the attention in literature. Using PMMA composite resins with electrospun polyvinylalcohol (PVA) nanofiber fillers is our first novelty. Also the producing and using aligned electrospun fibers as a filler is our second novelty of this practice. PVA was selected as composite filler because of biocompatibility and preparing easily also has non-toxic solvent. Electrospinning system is manufactured that allows manipulation of electric field used in the application of alignment in lab scale. Various auxillary electrode systems are used for different patterns of alignment with the manufactured device and electrode systems produce fibers in different range of diameter. Scanning electron microscopy (SEM) is used for physical characterization and determined the range of fiber diameters. After the optimization of concentration step non-woven and aligned fibers are also analyzed. Non-woven fiber has no unique pattern because of the nature of electrospinning but aligned fibers has crossed lines. These produced fibers structured as layer-by-layer form with different features are used in producing PMMA dental composites with different volume ratios. In the last part of the research, PMMA dental composites are produced with aligned and formless fibers that are characterized with three-point bending test. The maximum flexural strength figure shows that fiber load by weight %0.25 and above improves the maximum. The change of flexural strength, elastic modulus values and toughness are obtained and compared with formless and aligned PVA nanofiber included composite specimens. As a result, mechanical properties of PMMA dental composites are improved with using PVA nanofibers as a filler also with the usage of aligned fibers instead of the formless ones the effects of improvement gets better with maximum values as 5.1 MPa (flexural strength), 0.8 GPa (elastic modulus), 170kJ/m3 (toughness).
Phase Transitions in Multiferroic BiFeO3
Authors: Gavriliuk Alexander G. , Struzhkin Viktor , Lyubutin Igor S. , Trojan Ivan A. , Hu Michael Y. , Chow Paul 
Published: July 2014

AbstractThe multiferroic BiFeO3 crystals were studied under high pressures up to 70 GPa created in diamond anvil cells. Electronic, magnetic and structural transformations were found in the region 40-55 GPa. Electronic transition with high-to-low spin crossover of Fe3+ ion, suppression of magnetism and metallization were carefully investigated and documented. All transitions are completely reversible. The proposed theoretical consideration explains some details of the high-pressure magnetic, optical and electronic properties.
Computational Alchemy: The Search for New Superhard Materials
Authors: Teter David M. 
Published: July 2014

A central challenge to modern materials science is the rational design and synthesis of new materials possessing exceptional properties. Recent advances in first-principles modeling methods and the availability of increasingly powerful computational resources make this goal increasingly achievable. The strength of these modeling methods lies in their predictive ability. They are able to reproduce the crystal structures and elastic properties of a large class of materials to within 2–3% of experimental values and have predicted a number of phase transitions that have been verified experimentally.Despite the power of these methods, the process of designing materials from first principles is not usually a straight-forward or simple one. It requires overcoming a number of obstacles, some of them quite formidable. First a calculable figure of merit that correlates well with the desired property must be identified. While this may be straightforward in some cases, in others—such as predicting the ability of a material to isolate radionuclides over million-year time scales—the process of reducing complex properties to a few calculable variables can be rather difficult. Next a promising chemical system and a realistic set of crystal structures must be selected. This is not trivial because predicting the structures that can crystallize in a given system can be exceedingly challenging. However a wide variety of methods are available to aid in the generation of promising structures — comparative crystallography, algorithms based upon the concepts of crystalline nets and close packing, modern alloy theory methods, and simulated annealing strategies being some examples.
LiNbO3: A Paradigm for Photorefractive Materials
Authors: Arizmendi L. , Agulló-López F. 
Published: July 2014

Lithium niobate (LiNbO3) is a paradigmatic photorefractive (PR) material. It provided the first experimental evidence of the PR effect and still maintains a key position in the field. This position is fostered by the fact that large congruent single crystals with good optical quality are routinely grown, enabling technological applications. A remarkable example, a PR narrow-band interference filter has recently been developed and put on the market.A relevant property of LiNbO3, the high electrooptic figure of merit,n3r, assures efficient PR performance. Another unique feature is the occurrence of a bulk photovoltaic (PV) effect, i.e., the generation of a voltage (in an open circuit) or a current (in a short circuit) as a consequence of homogeneous illumination. The bulk PV effect acts, in a way, like an internal electric field, enhancing the PR effect. On the other hand, thermal fixing or stabilization of PR gratings has been successfully accomplished through an interplay between proton and electron dynamics. LiNbO3is also the choice substrate for the commercial fabrication of waveguide devices such as modulators, wavelength filters, multiplexers, and demultiplexers. Moreover, lasing action as well as nonlinear effects have been achieved due to the marked inhibition of the PR effect caused by heavy Mg doping. This illustrates the intimate connection between PR behavior and defect structure, i.e., between optics and materials science.
Biological Parameters ofPodisus nigrispinus(Hemiptera: Pentatomidae) Fed with Different Soybean Insect Pests
Authors: Denez Marlon Dias , Bueno Adeney De Freitas , Pasini Amarildo , Bortolotto Orcial Ceolin , Stecca Cristiane Dos Santos 
Published: July 2014

AbstractBiological parameters of Podisus nigrispinus (Dallas) fed with third-instar Lepidoptera larvae of Spodoptera frugiperda J.E. Smith, Spodoptera cosmioides (Walker, 1858), and Anticarsiagemmatalis (Hübner, 1818), as well as eggs of Euschistus heros (F., 1798), the brown stink bug, were evaluated. Experiments were performed under controlled conditions (25 ± 1°C; 70 ± 10% relative humidity, and a photoperiod of 16:8 [L:D] h). P. nigrispinus had good nymphal development with &gt;87% larval survival (viability), as well as high fecundity in adults, when fed with A. gemmatalis, S.frugiperda, and S. cosmioides larvae. Differently, adults of P. nigrispinus originating from nymphs fed with eggs of E. heros completed their life cycle; however, larval survival (viability) was reduced to 45.7%. Furthermore, these adults did not oviposit, and their body mass was from 50 to 73% lower than in individuals originating from nymphs fed with other tested prey. Taking into consideration that neither E. heros nor Spodoptera spp. are controlled by Bt soybean varieties expressing the Cry 1Ac protein, it can be assumed that the predator P. nigrispinus will still find prey species to feed in soybean fields even after the adoption of this pest control technology. This might help lower any potential negative impact of Bt soybean adoption above this insect predator. Moreover, the studied caterpillars proved to be potential prey for the predator's mass rearing, similarly to what is presently being done with coleopteran larvae.
CSR and Assurance Services: A Research Agenda
Authors: Cohen Jeffrey R. , Simnett Roger 
Published: July 2014

SUMMARY
This paper describes the current environment for assurance services for corporate social responsibility (CSR) performance. It then discusses opportunities for research, and highlights areas that are evolving as significant research opportunities and areas of significance that have been under-researched in the past. Finally, the paper reviews the five papers in the forum and highlights how multiple methodologies may be appropriate to examine different aspects of assuring CSR reporting from both internal and external assurance perspectives.