bluuebunny/crossref_metadata_2025 huggingface dataset:
The zebrafish mutants for the V-ATPase subunits d, ac45, E, H and c and their variable pigment dilution phenotype
Authors: Ramos-Balderas Jose L , Carrillo-Rosas Samantha , Guzman Aida , Navarro Rosa E , Maldonado Ernesto
Published: February 2013

Background

The V-ATPase is a proton pump that creates an acidic medium, necessary for lysosome function and vesicular traffic. It is also essential for several developmental processes. Many enzymes, like the V-ATPase, are assemblies of multiple subunits, in which each one performs a specific function required to achieve full activity. In the zebrafish V-ATPase 15 different subunits form this multimeric complex and mutations in any of these subunits induce hypopigmentation or pigment dilution phenotype. We have previously found variability in the pigment dilution phenotype among five of the V-ATPase zebrafish mutants. This work presents additional information about such differences and is an update from a previous report.

Findings

We describe the variable phenotype severity observed among zebrafish V-ATPase pigment dilution mutants studying mRNA expression levels from their corresponding genes. At the same time we carried out phylogenetic analysis for this genes.

Conclusions

Based in the similarities between different pigment dilution mutants we suggest that there is an essential role for V-ATPases in melanosome biogenesis and melanocyte survival. Neither variable expression levels for the different V-ATPase subunits studied here or the presence of duplicated genes seems to account for the variable phenotype severity from this group of mutants. We believe there are some similarities between the pigment dilution phenotype from zebrafish V-ATPase insertional mutants and pigment mutants obtained in a chemical screening (“Tubingen pigmentation mutants”). As for some of these “Tubingen mutants” the mutated gene has not been found we suggest that mutations in V-ATPase genes may be inducing their defects.
Can otoplasty impact hearing? A prospective randomized controlled study examining the effects of pinna position on speech reception and intelligibility
Authors: McNeil Michael L , Aiken Steve J , Bance Manohar , Leadbetter Jeff R , Hong Paul
Published: February 2013

Objectives

Otoplasty is a commonly performed surgical procedure that restores the ideal position of the pinna. Although the pinna is a well-recognized component of the auditory apparatus, no studies have assessed the audiological effects of this procedure. We sought to quantify the impact of pinna repositioning on speech intelligibility and reception.

Methods

Eighteen adults with normal hearing and pinnae were recruited and the pinna positions were randomized in each participant. Intracanal acoustical analysis was performed to calculate the Speech Intelligibility Index (SII). Hearing In Noise Test (HINT) with two azimuth speaker arrangement was also performed. The outcome measures were compared using paired; t-tests for both pinna positions.

Results

The SII significantly improved with the pinna in forward position (49.3 vs. 45.8, p<0.001). HINT thresholds also improved with the pinna forward (-6.43dB vs. -5.08dB, p=0.0003).

Conclusions

Pinna position affects audiological performance, in both speech intelligibility and speech reception in noise. These are novel findings that may impact the informed consent process and decision to treat for patients undergoing otoplasty.
Fibrolipoma of the nasal septum; report of the first case
Authors: Ozturk Murat , Ila Kadri , Kara Ahmet , Iseri Mete
Published: February 2013

Background/Objective

Fibrolipomas are a rare subtype of lipomas and very rare in the oral and maxillofacial region. Lipomas affecting the central nervous system are even more infrequent occurring with a frequency of 0.1%.

Study design, methods

Case report.

Case presentation

This report includes a patient who had a nasal septal fibrolipoma and an accompanying corpus callosum lipoma.

Conclusions

To our knowledge, this is the first reported nasal septal fibrolipoma case in the literature. The diagnostic and surgical features of this case and the unity of septal fibrolipoma and intracranial lipomas are discussed.
The constant beat: cardiomyocytes adapt their forces by equal contraction upon environmental stiffening
Authors: Hersch Nils , Wolters Benjamin , Dreissen Georg , Springer Ronald , Kirchgeßner Norbert , Merkel Rudolf , Hoffmann Bernd
Published: February 2013

Cardiomyocytes are responsible for the permanent blood flow by coordinated heart contractions. This vital function is accomplished over a long period of time with almost the same performance, although heart properties, as its elasticity, change drastically upon aging or as a result of diseases like myocardial infarction. In this paper we have analyzed late rat embryonic heart muscle cells' morphology, sarcomere/costamere formation and force generation patterns on substrates of various elasticities ranging from ∼1 to 500 kPa, which covers physiological and pathological heart stiffnesses. Furthermore, adhesion behaviour, as well as single myofibril/sarcomere contraction patterns, was characterized with high spatial resolution in the range of physiological stiffnesses (15 kPa to 90 kPa). Here, sarcomere units generate an almost stable contraction of ∼4%. On stiffened substrates the contraction amplitude remains stable, which in turn leads to increased force levels allowing cells to adapt almost instantaneously to changing environmental stiffness. Furthermore, our data strongly indicate specific adhesion to flat substrates via both costameric and focal adhesions. The general appearance of the contractile and adhesion apparatus remains almost unaffected by substrate stiffness.
Motor neurons and glia exhibit specific individualized responses to TDP-43 expression in a Drosophila model of amyotrophic lateral sclerosis
Authors: Estes Patricia S. , Daniel Scott G. , Mccallum Abigail P. , Boehringer Ashley V. , Sukhina Alona S. , Zwick Rebecca A. , Zarnescu Daniela C.
Published: February 2013

Amyotrophic lateral sclerosis (ALS) is a fatal disease characterized by complex neuronal and glial phenotypes. Recently, RNA-based mechanisms have been linked to ALS via RNA-binding proteins such as TDP-43, which has been studied in vivo using models ranging from yeast to rodents. We have developed a Drosophila model of ALS based on TDP-43 that recapitulates several aspects of pathology, including motor neuron loss, locomotor dysfunction and reduced survival. Here we report the phenotypic consequences of expressing wild-type and four different ALS-linked TDP-43 mutations in neurons and glia. We show that TDP-43-driven neurodegeneration phenotypes are dose- and age-dependent. In motor neurons, TDP-43 appears restricted to nuclei, which are significantly misshapen due to mutant but not wild-type protein expression. In glia and in the developing neuroepithelium, TDP-43 associates with cytoplasmic puncta. TDP-43-containing RNA granules are motile in cultured motor neurons, although wild-type and mutant variants exhibit different kinetic properties. At the neuromuscular junction, the expression of TDP-43 in motor neurons versus glia leads to seemingly opposite synaptic phenotypes that, surprisingly, translate into comparable locomotor defects. Finally, we explore sleep as a behavioral readout of TDP-43 expression and find evidence of sleep fragmentation consistent with hyperexcitability, a suggested mechanism in ALS. These findings support the notion that although motor neurons and glia are both involved in ALS pathology, at the cellular level they can exhibit different responses to TDP-43. In addition, our data suggest that individual TDP-43 alleles utilize distinct molecular mechanisms, which will be important for developing therapeutic strategies.
Transmembrane voltage potential is an essential cellular parameter for the detection and control of tumor development in aXenopusmodel
Authors: Chernet Brook T. , Levin Michael
Published: February 2013

Understanding mechanisms that orchestrate cell behavior into appropriately patterned tissues and organs within the organism is an essential element of preventing, detecting and treating cancer. Bioelectric signals (resting transmembrane voltage potential gradients in all cells) underlie an important and broadly conserved set of control mechanisms that regulate pattern formation. We tested the role of transmembrane potential in tumorigenesis mediated by canonical oncogenes in Xenopus laevis. Depolarized membrane potential (Vmem) was a characteristic of induced tumor-like structures (ITLSs) generated by overexpression of Gli1, KrasG12D, Xrel3 or p53Trp248. This bioelectric signature was also present in precursor ITLS sites. Vmem is a bioelectric marker that reveals ITLSs before they become histologically and morphologically apparent. Moreover, voltage was functionally important: overexpression of hyperpolarizing ion transporters caused a return to normal Vmem and significantly reduced ITLS formation in vivo. To characterize the molecular mechanism by which Vmem change regulates ITLS phenotypes, we performed a suppression screen. Vmem hyperpolarization was transduced into downstream events via Vmem-regulated activity of SLC5A8, a sodium-butyrate exchanger previously implicated in human cancer. These data indicate that butyrate, a histone deacetylase (HDAC) inhibitor, might be responsible for transcriptional events that mediate suppression of ITLSs by hyperpolarization. Vmem is a convenient cellular parameter by which tumors induced by human oncogenes can be detected in vivo and represents a new diagnostic modality. Moreover, control of resting membrane potential is functionally involved in the process by which oncogene-bearing cells depart from normal morphogenesis programs to form tumors. Modulation of Vmem levels is a novel and promising strategy for tumor normalization.
Vertebrate Spt2 is a novel nucleolar histone chaperone that assists in ribosomal DNA transcription
Authors: Osakabe Akihisa , Tachiwana Hiroaki , Takaku Motoki , Hori Tetsuya , Obuse Chikashi , Kimura Hiroshi , Fukagawa Tatsuo , Kurumizaka Hitoshi
Published: February 2013

In eukaryotes, transcription occurs in the chromatin context with the assistance of histone binding proteins, such as chromatin/nucleosome remodeling factors and histone chaperones. However, it is unclear how each remodeling factor or histone chaperone functions in transcription. Here, we identified a novel histone-binding protein, Spt2, in higher eukaryotes. Recombinant human Spt2 binds to histones and DNA, and promotes nucleosome assembly in vitro. Spt2 accumulates in nucleoli and interacts with RNA polymerase I in chicken DT40 cells, suggesting its involvement in ribosomal RNA transcription. Consistently, Spt2-deficient chicken DT40 cells are sensitive to RNA polymerase I inhibitors and exhibit decreased transcription activity, based on a transcription run-on assay. Domain analyses of Spt2 revealed that the C-terminal region, containing the region homologous to yeast Spt2, is responsible for histone binding, while the central region is essential for nucleolar localization and DNA binding. Based on these results, we conclude that vertebrate Spt2 is a novel histone chaperone with a separate DNA binding domain, facilitating ribosomal DNA transcription through chromatin remodeling during transcription.
A GEF-to-phospholipase molecular switch caused by PA, RAC and jak tyrosine kinase, that explains leukocyte cell migration
Authors: Mahankali Madhu , Henkels Karen M. , Gomez-Cambronero Julian
Published: February 2013

Phospholipase D2 (PLD2) is a cell-signaling molecule that bears two activities: a Guanine-nucleotide Exchange Factor (GEF) and a lipase that reside in the PX/PH domains and in two HKD domains, respectively. Upon cell stimulation, the GEF activity yields Rac2-GTP and the lipase activity yields phosphatidic acid (PA). We present here for the first that these activities regulate one another. Upon cell stimulation, both GEF and lipase activities are quickly (∼3 min) elevated. As soon as it is produced, PA positively feeds back on the GEF and further activates it. Rac2-GTP, on the other hand, is inhibitory to the lipase activity. PLD2 lipase would remain downregulated if it was not for the contribution of the tyrosine kinase Janus Kinase 3 (JAK3) that restores lipase action. Conversely, the GEF is inhibited upon phosphorylation by JAK3 and is effectively terminated by this action and by the increasing accumulation of PA at >15 min of cell stimulation. This PA interferes with the ability of the GEF to bind to its substrate (Rac2-GTP). Thus, both temporal inter-regulation and phosphorylation-dependent mechanisms are involved in determining a GEF/lipase switch within the same molecule. Human neutrophils stimulated by IL-8 follow a biphasic pattern of GEF and lipase activation that can be explained by such an intramolecular switch. This is the first report of a temporal inter-regulation of two enzymatic activities that reside in the same molecule with profound biological consequences in leukocyte cell migration.
Endothelial cell and model membranes respond to shear stress by rapidly decreasing the order of their lipid phases
Authors: Yamamoto Kimiko , Ando Joji
Published: February 2013

Endothelial cells (ECs) sense shear stress and transduce blood flow information into functional responses that play important roles in vascular homeostasis and pathophysiology. A unique feature of shear-stress-sensing is the involvement of many different types of membrane-bound molecules, including receptors, ion channels and adhesion proteins, but the mechanisms remain unknown. Because cell membrane properties affect the activities of membrane-bound proteins, shear stress might activate various membrane-bound molecules by altering the physical properties of EC membranes. To determine how shear stress influences the cell membrane, cultured human pulmonary artery ECs were exposed to shear stress and examined for changes in membrane lipid order and fluidity by Laurdan two-photon imaging and FRAP measurements. Upon shear stress stimulation, the lipid order of EC membranes rapidly decreased in an intensity-dependent manner, and caveolar membrane domains changed from the liquid-ordered state to the liquid-disordered state. Notably, a similar decrease in lipid order occurred when the artificial membranes of giant unilamellar vesicles were exposed to shear stress, suggesting that this is a physical phenomenon. Membrane fluidity increased over the entire EC membranes in response to shear stress. Addition of cholesterol to ECs abolished the effects of shear stress on membrane lipid order and fluidity and markedly suppressed ATP release, which is a well-known EC response to shear stress and is involved in shear-stress Ca2+ signaling. These findings indicate that EC membranes directly respond to shear stress by rapidly decreasing their lipid phase order and increasing their fluidity; these changes could be linked to shear-stress-sensing and response mechanisms.
Depletion of PtdIns(4,5)P2 underlies retinal degeneration in Drosophila trp mutants
Authors: Sengupta Sukanya , Barber Thomas R. , Xia Hongai , Ready Donald F. , Hardie Roger C.
Published: February 2013

The prototypical transient receptor potential (TRP) channel is the major light-sensitive, and Ca2+-permeable channel in the microvillar photoreceptors of Drosophila. TRP channels are activated following hydrolysis of phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] by the key effector enzyme phospholipase C (PLC). Mutants lacking TRP channels undergo light-dependent retinal degeneration, as a consequence of the reduced Ca2+ influx. It has been proposed that degeneration is caused by defects in the Ca2+-dependent visual pigment cycle, which result in accumulation of toxic phosphorylated metarhodopsin–arrestin complexes (MPP–Arr2). Here we show that two interventions, which prevent accumulation of MPP–Arr2, namely rearing under red light or eliminating the C-terminal rhodopsin phosphorylation sites, failed to rescue degeneration in trp mutants. Instead, degeneration in trp mutants reared under red light was rescued by mutation of PLC. Degeneration correlated closely with the light-induced depletion of PtdIns(4,5)P2 that occurs in trp mutants due to failure of Ca2+-dependent inhibition of PLC. Severe retinal degeneration was also induced in the dark in otherwise wild-type flies by overexpression of a bacterial PtdInsPn phosphatase (SigD) to deplete PtdIns(4,5)P2. In degenerating trp photoreceptors, phosphorylated Moesin, a PtdIns(4,5)P2-regulated membrane–cytoskeleton linker essential for normal microvillar morphology, was found to delocalize from the rhabdomere and there was extensive microvillar actin depolymerisation. The results suggest that compromised light-induced Ca2+ influx, due to loss of TRP channels, leads to PtdIns(4,5)P2 depletion, resulting in dephosphorylation of Moesin, actin depolymerisation and disintegration of photoreceptor structure.
The ER Ca2+ sensor STIM1 regulates actomyosin contractility of migratory cells
Authors: Chen Ying-Ting , Chen Yih-Fung , Chiu Wen-Tai , Wang Yang-Kao , Chang Hsien-Chang , Shen Meng-Ru
Published: February 2013

Stromal interaction molecule 1 (STIM1) is an endoplasmic reticulum (ER) Ca2+ sensor that triggers the store-operated Ca2+ entry (SOCE). The clinical relevance of STIM1 has been highlighted in breast and cervical cancer, but the molecular mechanism by which STIM1 promotes cancer progression remains unclear. This study explores the regulatory mechanisms by which STIM1-dependent Ca2+ signaling controls cancer cell migration. Three different SOCE inhibitors, SKF96365, 2-APB and YM-58483, significantly inhibited cervical cancer cell migration to a similar extent to that of STIM1 silencing. In contrast, STIM1 overexpression significantly enhanced cervical cancer cell migration. Live cell confocal images and three-dimensional tomograms showed that STIM1 formed aggregates and translocated towards the plasma membranes of migratory cells, and this was accompanied by increasing cytosolic Ca2+ spikes. STIM1 silencing also inhibited the recruitment and association of active focal adhesion kinase (pTyr397-FAK) and talin at focal adhesions, indicating the blockade of force transduction from integrin signaling. Epidermal growth factor-induced phosphorylation of myosin II regulatory light chains was abolished by STIM1 knockdown and SOCE inhibition. Dual immunostaining of activated myosin II (pSer19-MLC) and actin revealed that actomyosin formation depended on STIM1-mediated Ca2+ entry. Most importantly, STIM1 expression levels as well as SOCE activity controlled the generation of cell contractile force, as measured by the microfabricated post-array-detector system. These results highlight the unique role of STIM1-dependent Ca2+ signaling in controlling cell migration by the regulation of actomyosin reorganization in conjunction with enhanced contractile forces.
The presence of a truncated base excision repair pathway in human spermatozoa, Mediated by OGG1
Authors: Smith T. B. , Dun M. D. , Smith N. D. , Curry B. J. , Connaughton H. S. , Aitken R. J.
Published: February 2013

DNA repair has long been considered impossible in human spermatozoa due to the high level of DNA compaction observed in these cells. However, detailed examination of the base excision repair pathway in human spermatozoa has revealed the presence of an enzyme critical to this pathway, OGG1. This glycosylase was associated with the sperm nucleus and mitochondria and could actively excise 8-hydrdoxy, 2′-deoxyguanosine, releasing this adduct into the extracellular space. This activity was significantly reduced in the presence of cadmium (II), a recognized inhibitor of OGG1, in a time- and dose- dependent manner (P<0.001). Remarkably, spermatozoa do not possess the downstream components of the base excision repair pathway, APE1 and XRCC1. The absence of these proteins was particularly significant, as APE1 is required to create a 3′-hydroxyl (3′-OH) terminus at the apurinic site created by OGG1, which would be recognized by the TUNEL assay. As a result, TUNEL was unable to detect oxidatively induced DNA damage in spermatozoa following exposure to hydrogen peroxide. In the same cells, intracellular and extracellular 8OHdG could be clearly detected in a manner that was highly correlated with the outcome of SCSA (Sperm Chromatin Structure Assay). However, incubation of these cells for 48 hours revealed a time-dependent increase in TUNEL positivity, suggesting the perimortem activation of a nuclease. These results emphasize the limited capacity of mature spermatozoa to mount a DNA repair response to oxidative stress, and highlight the importance of such mechanisms in the oocyte in order to protect the embryo from paternally mediated genetic damage.
Rapid Removal of o-Phthalaldehyde from Water by Polyallylamine-Conjugated Thermoresponsive Polymer-Mediated Extraction
Authors: Saitoh Tohru , Fukushima Kotaro , Hiraide Masataka
Published: February 2013

A high-level disinfectant, o-phthalaldehyde (OPA), was rapidly removed from water by a thermoresponsive polymer-mediated extraction using polyallylamine-conjugated poly(N-isopropylacrylamide). The use of 1 g of the thermoresponsive polymer allowed nearly complete removal of 130 mg of OPA.
F–CN Bond Cleavage by Iron Silyl Complex and Electronic Effect of the Group or Atom Attached to Cyano Group: A Theoretical DFT Study
Authors: Dahy AbdelRahman A , Koga Nobuaki
Published: February 2013

The cleavage of F–CN bond in the presence of Fe(II) silyl complex, [Cp(CO)FeSiMe3], was studied using density functional theory calculations and compared with the mechanisms for E–CN (E = C, N, and O) bond cleavages, which have previously been clarified to be a silyl-migration-induced reaction.
Synthesis of Water-Soluble Cyclophane Pentamers Using Click Chemistry as a Multivalent Host for Daunorubicin and Doxorubicin
Authors: Hayashida Osamu , Nakamura Yuki
Published: February 2013

Cationic cyclophane pentamer 1 has been prepared from a tetraazide-functionalized cyclophane derivative and four acetylene-functionalized cyclophane derivatives by Cu(I)-catalyzed 1,3-dipolar cycloadditions (click chemistry) in a 87% yield, followed by a treatment with trifluoroacetic acid. Cationic host 1 showed effective guest-binding behavior toward fluorescent guests such as 6-p-toluidinonaphthalene-2-sulfonate, in comparison with those of monomeric cyclophane. On the other hand, anionic cyclophane pentamer 2, which was derived from 1 by a reaction with succinic anhydride, showed enhanced guest-binding affinity toward anticancer drugs such as daunorubicin hydrochloride, in comparison with those of the monomeric cyclophane.
A Simple Synthetic Route for the Preparation of Tetramethylglycolide from Lactic Acid
Authors: Watanabe Kohtaro , Andou Yoshito , Shirai Yoshihito , Nishida Haruo
Published: February 2013

Poly(tetramethylglycolide), a chemical recyclable polymer, is currently attracting a lot of interest as a substitute for poly(l-lactic acid). We report here a simple and convenient route for the synthesis of tetramethylglycolide (TMG) from lactic acid. This method involves three steps: (1) one-step protection of lactic acid by cyclic acetalization employing acetone; (2) α-methylation of the obtained 2,2,5-trimethyl-1,3-dioxolan-4-one; and (3) one-pot synthesis of TMG including the hydrolysis of 2,2,5,5-tetramethyl-1,3-dioxolan-4-one. We found significant advantages of the incorporation of existing reactions in the synthesis of TMG.
Molecular Iodine in Aqueous Ammonia: Oxidative Fragmentation of Oxiranes to Nitriles
Authors: Jadhav Ravindra R , Akamanchi Krishnacharya G
Published: February 2013

Oxiranes undergo oxidative fragmentation, when treated with iodine in aqueous ammonia, to give nitriles. The reaction goes via formation of 1,2-amino alcohols as intermediates followed by C–C bond cleavage. Advantages of the method are use of off-the-shelf nonexplosive, unlike previously used potentially explosive o-iodoxybenzoic acid, reagents, mild reaction conditions, and easy work-up procedure.
Production of Oxidation-resistant Copper Nanoparticles on Carbon Nanotubes by Photoreduction
Authors: Nishida Naoki , Miyashita Akira , Tsukuda Tatsuya , Tanaka Hideki
Published: February 2013

Copper nanoparticles (Cu NPs) were produced through photoreduction of a mixture of copper acetate solution and carbon nanotubes (CNTs) at room temperature. The diameter of the NPs could be controlled by the photoirradiation time. HRTEM and XRD measurements revealed that the NPs were composed of a metallic Cu core and a Cu2O shell that acts as a passive layer.
Shape-controlled Synthesis of ZnS–CuInS2–AgInS2 Solid Solution Nanoparticles and Their Photoluminescence Properties
Authors: Dai Meilin , Uematsu Taro , Kuwabata Susumu , Torimoto Tsukasa
Published: February 2013

Nanoparticles of a ZnS–CuInS2–AgInS2 (Z-CAIS) solid solution were prepared successfully via the thermal decomposition of single precursors in a hot oleylamine solution, their band gap being controlled by varying the chemical composition of the precursors. The morphologies of the nanoparticles changed from spheres to rods with an increase in the ZnS content in the particles. The photoluminescence intensity of Z-CAIS was relatively large, while ZnS–CuInS2 and ZnS nanorods prepared under the same reaction conditions exhibited no photoluminescence.
Facile Solubilization and Photovoltaic Application of C60 Fullerene–Ethylenediamine Adduct
Authors: Akiyama Tsuyoshi , Ueda Taiki , Ono Yuji , Kimura Kento , Matsuoka Ken-ichi , Yamada Sunao , Oku Takeo
Published: February 2013

Fullerene C60–ethylenediamine adduct particles were solubilized in toluene by the addition of acyl chloride. An inverted-type bulk-heterojunction organic thin-film solar cell using polythiophene and the solubilized C60–ethylenediamine adduct as the photoactive layer was fabricated, and the layer generated a photocurrent via the photoexcitation of polythiophene. The solar-cell performance suggested that the solubilized C60–ethylenediamine adduct works as an n-type semiconductor for polythiophene.
Ligand-controlled Iron-catalyzed Cross Coupling of Benzylic Chlorides with Aryl Grignard Reagents
Authors: Kawamura Shintaro , Nakamura Masaharu
Published: February 2013

The selective cross coupling of benzylic chlorides with aryl Grignard reagents has been achieved by using catalytic amounts of FeCl2 and electronically tuned ortho-phenylenebisphosphine ligands. Although electron-deficient ligands promoted the reductive homocoupling of benzylic halides, electron-rich ligands effectively promoted the desired cross-coupling reaction to afford the corresponding diarylmethanes in good to excellent yields.
Synthesis of Mordenite Nanocrystals by Using a Hydrophobic Structure-directing Agent
Authors: Inagaki Satoshi , Watanabe Yasuhiro , Nishita Yuji , Kubota Yoshihiro
Published: February 2013

Mordenite nanocrystals of around 80 nm in length along the c axis were synthesized successfully by using a hydrophobic structure-directing agent (SDA). The nanometer-sized mordenite catalyst showed higher activity than the micron- or submicron-sized versions in cumene cracking.
Solubilization of Chemically Reduced Graphene Oxide Using Coffee Catechol
Authors: Lee Jang Mi , Jeong Geumbi , Lee Mi Yeon , Kim So Yeon , Park Young Ho , Park Sung Young , Kim Sang Chun , Min Byung-Gak , In Insik
Published: February 2013

Stable aqueous dispersion of chemically reduced graphene oxide (RGO) was prepared through simple “catechol-induced reduction and functionalization” with a coffee catechol, chlorogenic acid (CA) or real Americano coffee. Prepared CA/RGO or coffee/RGO assembly was optically clear and stable for more than 6 months. This coffee catechol based approach for the formulation of soluble RGO can be easily extended to other “green chemistry” where catechol-rich fruits such as wine or beverages such as berry juice can be used for the formulation of soluble graphene.
Poly(dimethylsiloxane)-protected Silver Nanowire Network for Transparent Conductor with Enhanced Oxidation Resistance and Adhesion Properties
Authors: Lee Won Jin , Lee Mi Yeon , Roy Arup Kumer , Lee Kang Seok , Park Sung Young , In Insik
Published: February 2013

A highly electrically conducting and optically transparent silver nanowire (AgNW) network with enhanced oxidation resistance and adhesion properties was formulated through poly(dimethylsiloxane) (PDMS) protection on top of the AgNW network on a poly(ethylene terephthalate) (PET) substrate. The PDMS-protected AgNW network would prevent device malfunction in AgNW-based devices owing to its high resistance to oxidation by oxygen from the air and its enhanced adhesion to the PET substrate, while minimizing any decrease in optical transmittance and increase in sheet resistance of the AgNW network in the presence of the PDMS protection layer.
Facile Synthesis of Oligosaccharide–Poly(l-lactide) Conjugates Forming Nanoparticles with Saccharide Core and Shell
Authors: Tanaka Tomonari , Fukuhara Hiroyuki , Shoda Shin-ichiro , Kimura Yoshiharu
Published: February 2013

Various oligosaccharide–poly(l-lactide) conjugates (Sac-PLLAs) were synthesized readily through the direct azidation of unprotected saccharides followed by click chemistry with acetylene-terminated poly(l-lactide)s. The Sac-PLLAs were found to form aggregates with the saccharide moieties as the core and shell in nonpolar and polar solvents, respectively.
Trade Promotion Decisions Under Demand Uncertainty: A Market Experiment Approach
Authors: Yuan Hong , Gómez Miguel I. , Rao Vithala R.
Published: February 2013

In this paper, we examine trade promotion decisions in manufacturer–retailer channels where retailers face consumer demand uncertainty. We first present the theoretical analysis for two types of markets where trade promotion discounts are offered either as off-invoices or as scan-backs. We derive propositions by comparing wholesale and retail prices, retailer order quantities, and profits given the same trade promotion discount. Next, we extend the basic model so that the amount of trade promotion discount influences market expansion and solve for the optimal discount level. To test our theory, we then employ market experiments where we manipulate demand uncertainty and market expansion. Consistent with our theoretical predictions, we find that wholesale and retail prices are higher and retailer order quantities lower when the same amount of trade promotion discount is allocated to scan-backs versus off-invoices. In the market expansion condition, we find that manufacturers offer deeper discounts when trade promotions are allocated to off-invoices versus scan-backs. Overall, our research suggests that market experiments can shed light on trade promotion outcomes for which industry data are sparse or nonexistent.

This paper was accepted by Teck Ho, behavioral economics.
Importance of the Efficiency of Double-Stranded DNA Formation in cDNA Synthesis for the Imprecision of Microarray Expression Analysis
Authors: Thormar Hans G , Gudmundsson Bjarki , Eiriksdottir Freyja , Kil Siyoen , Gunnarsson Gudmundur H , Magnusson Magnus Karl , Hsu Jason C , Jonsson Jon J
Published: February 2013

BACKGROUND

The causes of imprecision in microarray expression analysis are poorly understood, limiting the use of this technology in molecular diagnostics. Two-dimensional strandness-dependent electrophoresis (2D-SDE) separates nucleic acid molecules on the basis of length and strandness, i.e., double-stranded DNA (dsDNA), single-stranded DNA (ssDNA), and RNA·DNA hybrids.

METHODS

We used 2D-SDE to measure the efficiency of cDNA synthesis and its importance for the imprecision of an in vitro transcription–based microarray expression analysis.

RESULTS

The relative amount of double-stranded cDNA formed in replicate experiments that used the same RNA sample template was highly variable, ranging between 0% and 72% of the total DNA. Microarray experiments showed an inverse relationship between the difference between sample pairs in probe variance and the relative amount of dsDNA. Approximately 15% of probes showed between-sample variation (P < 0.05) when the dsDNA percentage was between 12% and 35%. In contrast, only 3% of probes showed between-sample variation when the dsDNA percentage was 69% and 72%. Replication experiments of the 35% dsDNA and 72% dsDNA samples were used to separate sample variation from probe replication variation. The estimated SD of the sample-to-sample variation and of the probe replicates was lower in 72% dsDNA samples than in 35% dsDNA samples.

CONCLUSIONS

Variation in the relative amount of double-stranded cDNA synthesized can be an important component of the imprecision in T7 RNA polymerase–based microarray expression analysis.
Laboratory Assessment of Novel Oral Anticoagulants: Method Suitability and Variability between Coagulation Laboratories
Authors: Helin Tuukka A , Pakkanen Anja , Lassila Riitta , Joutsi-Korhonen Lotta
Published: February 2013

BACKGROUND

Laboratory tests to assess novel oral anticoagulants (NOACs) are under evaluation. Routine monitoring is unnecessary, but under special circumstances bioactivity assessment becomes crucial. We analyzed the effects of NOACs on coagulation tests and the availability of specific assays at different laboratories.

METHODS

Plasma samples spiked with dabigatran (Dabi; 120 and 300 μg/L) or rivaroxaban (Riva; 60, 146, and 305 μg/L) were sent to 115 and 38 European laboratories, respectively. International normalized ratio (INR) and activated partial thromboplastin time (APTT) were analyzed for all samples; thrombin time (TT) was analyzed specifically for Dabi and calibrated anti–activated factor X (anti-Xa) activity for Riva. We compared the results with patient samples.

RESULTS

Results of Dabi samples were reported by 73 laboratories (13 INR and 9 APTT reagents) and Riva samples by 22 laboratories (5 INR and 4 APTT reagents). Both NOACs increased INR values; the increase was modest, albeit larger, for Dabi, with higher CV, especially with Quick (vs Owren) methods. Both NOACs dose-dependently prolonged the APTT. Again, the prolongation and CVs were larger for Dabi. The INR and APTT results varied reagent-dependently (P < 0.005), with less prolongation in patient samples. TT results (Dabi) and calibrated anti-Xa results (Riva) were reported by only 11 and 8 laboratories, respectively.

CONCLUSIONS

The screening tests INR and APTT are suboptimal in assessing NOACs, having high reagent dependence and low sensitivity and specificity. They may provide information, if laboratories recognize their limitations. The variation will likely increase and the sensitivity differ in clinical samples. Specific assays measure NOACs accurately; however, few laboratories applied them.
Reconsidering Heathenry
Authors: Snook Jennifer
Published: February 2013

This article is the result of ethnographic fieldwork among American practitioners of Heathenry, a reconstructionist religious movement whose practitioners align themselves with ancient Germanic and Norse cosmology. In this article, I respond to previous representations of Heathenry as racist by exploring the intricacies and nuances of members' co-construction of their own ethnic folkway. I show that Heathens construct group boundaries by distinguishing between categories of folkish and universalist, while mostly living between racial exclusivity and complete inclusivity. In other words, Heathens self-consciously establish symbolically meaningful categories to distinguish between practitioners' understandings of who gets to be Heathen, of racial/ethnic exclusivity, and complete inclusivity. While some American Heathens find race or ancestry irrelevant, most do not and all must participate in the conversations that seek to define Heathenry as an indigenous tradition, purely a system of faith, or a complex folkway struggling to be ethnic while resisting racist labels.
Contemporary Mormon Religiosity and the Legacy of “Gathering”
Authors: Phillips Rick , Cragun Ryan
Published: February 2013

The Church of Jesus Christ of Latter-day Saints—the LDS, or Mormon church—has dominated the state of Utah both culturally and politically since joining the Union in 1896. Scholars note that LDS majorities in Utah and other parts of the Intermountain West foster a religious subculture that has promoted higher levels of Mormon church attendance and member retention than in other parts of the nation. However, after rising throughout most of the twentieth century, the percentage of Utah's population belonging to the church began declining in 1989. Some sources assert Utah is now less Mormon than at any time in the state's history. This article examines the degree to which this decline has affected LDS church activity and retention in Utah and adjacent environs. We find evidence suggesting church attendance rates may be falling, and clear evidence that rates of apostasy among Mormons have risen over the past decade.
Testosterone: a metabolic hormone in health and disease
Authors: Kelly Daniel M , Jones T Hugh
Published: February 2013

Testosterone is a hormone that plays a key role in carbohydrate, fat and protein metabolism. It has been known for some time that testosterone has a major influence on body fat composition and muscle mass in the male. Testosterone deficiency is associated with an increased fat mass (in particular central adiposity), reduced insulin sensitivity, impaired glucose tolerance, elevated triglycerides and cholesterol and low HDL-cholesterol. All these factors are found in the metabolic syndrome (MetS) and type 2 diabetes, contributing to cardiovascular risk. Clinical trials demonstrate that testosterone replacement therapy improves the insulin resistance found in these conditions as well as glycaemic control and also reduces body fat mass, in particular truncal adiposity, cholesterol and triglycerides. The mechanisms by which testosterone acts on pathways to control metabolism are not fully clear. There is, however, an increasing body of evidence from animal, cell and clinical studies that testosterone at the molecular level controls the expression of important regulatory proteins involved in glycolysis, glycogen synthesis and lipid and cholesterol metabolism. The effects of testosterone differ in the major tissues involved in insulin action, which include liver, muscle and fat, suggesting a complex regulatory influence on metabolism. The cumulative effects of testosterone on these biochemical pathways would account for the overall benefit on insulin sensitivity observed in clinical trials. This review discusses the current knowledge of the metabolic actions of testosterone and how testosterone deficiency contributes to the clinical disease states of obesity, MetS and type 2 diabetes and the role of testosterone replacement.
Stable Gene Silencing in Zebrafish with Spatiotemporally Targetable RNA Interference
Authors: Dong Zhiqiang , Peng Jisong , Guo Su
Published: February 2013

The ability to regulate gene activity in a spatiotemporally controllable manner is vital for biological discovery that will impact disease diagnosis and treatment. While conditional gene silencing is possible in other genetic model organisms, this technology is largely unavailable in zebrafish, an important vertebrate model organism for functional gene discovery. Here, using short hairpin RNAs (shRNAs) designed in the microRNA-30 backbone, which have been shown to mimic natural microRNA primary transcripts and be more effective than simple shRNAs, we report stable RNA interference-mediated gene silencing in zebrafish employing the yeast Gal4-UAS system. Using this approach, we reveal at single-cell resolution the role of atypical protein kinase Cλ (aPKCλ) in regulating neural progenitor/stem cell division. We also show effective silencing of the one-eyed-pinhead and no-tail/brachyury genes. Furthermore, we demonstrate stable integration and germ-line transmission of the UAS-miR-shRNAs for aPKCλ, the expressivity of which is controllable by the strength and expression of Gal4. This technology shall significantly advance the utility of zebrafish for understanding fundamental vertebrate biology and for the identification and evaluation of important therapeutic targets.
Novel Connections Between DNA Replication, Telomere Homeostasis, and the DNA Damage Response Revealed by a Genome-Wide Screen for TEL1/ATM Interactions in Saccharomyces cerevisiae
Authors: Piening Brian D , Huang Dongqing , Paulovich Amanda G
Published: February 2013

Tel1 is the budding yeast ortholog of the mammalian tumor suppressor and DNA damage response (DDR) kinase ATM. However, tel1-Δ cells, unlike ATM-deficient cells, do not exhibit sensitivity to DNA-damaging agents, but do display shortened (but stably maintained) telomere lengths. Neither the extent to which Tel1p functions in the DDR nor the mechanism by which Tel1 contributes to telomere metabolism is well understood. To address the first question, we present the results from a comprehensive genome-wide screen for genetic interactions with tel1-Δ that cause sensitivity to methyl methanesulfonate (MMS) and/or ionizing radiation, along with follow-up characterizations of the 13 interactions yielded by this screen. Surprisingly, many of the tel1-Δ interactions that confer DNA damage sensitivity also exacerbate the short telomere phenotype, suggesting a connection between these two phenomena. Restoration of normal telomere length in the tel1-Δ xxx-Δ mutants results in only minor suppression of the DNA damage sensitivity, demonstrating that the sensitivity of these mutants must also involve mechanisms independent of telomere length. In support of a model for increased replication stress in the tel1-Δ xxx-Δ mutants, we show that depletion of dNTP pools through pretreatment with hydroxyurea renders tel1-Δ cells (but not wild type) MMS-sensitive, demonstrating that, under certain conditions, Tel1p does indeed play a critical role in the DDR.
Capacidade combinatória em mamoeiro para resistência a oídio
Authors: Vivas Marcelo , Silveira Silvaldo Felipe da , Cardoso Deisy Lúcia , Pereira Messias Gonzaga , Vivas Janieli Maganha Silva , Ferreguetti Geraldo Antônio
Published: February 2013

A resistência genética constitui alternativa sustentável para o controle do oídio. Objetivando indicar possíveis combinações híbridas que contribuam para a redução da severidade de oídio em folha de mamoeiro, foi realizado um cruzamento dialélico envolvendo oito genótipos, sendo quatro do grupo 'Solo' e quatro do grupo 'Formosa'. Os 56 híbridos (F1's e recíprocos) juntamente com seus genitores foram avaliados em blocos casualizados com quatro repetições. A severidade do oídio na folha foi quantificada em março e maio de 2010, respectivamente, aos 11 e 13 meses após o plantio. Com a média de cada tratamento foram estimadas as capacidades geral e específica de combinação. Assim, considerando as estimativas da capacidade combinatória obtidas com base na média das duas avaliações, as melhores combinações para os genitores avaliados quanto à severidade do oídio foram 'Maradol x Waimanalo', 'Maradol x Sunrise Solo 72/12', 'JS 12-4 x São Mateus', 'Sekati x Waimanalo', 'Sekati x Golden', 'Sekati x Sunrise Solo 72/12', 'Sekati x São Mateus', 'Waimanalo x São Mateus' e 'Golden x São Mateus'. Os resultados evidenciam ainda a possibilidade de obtenção de híbridos com potencial para redução da severidade do oídio provenientes de cruzamentos entre genótipos dos grupos 'Solo' e 'Formosa' e também em cruzamentos dentro do grupo 'Solo'.
Variabilidade espacial de atributos químicos do solo sob cafeeiro Conilon: relação com textura, matéria orgânica e relevo
Authors: Burak Diego Lang , Passos Renato Ribeiro , Andrade Felipe Vaz
Published: February 2013

Atributos químicos do solo têm relação com outros atributos, inclusive os geomorfológicos, constituindo fatores que controlam sua variabilidade espacial. Dentro desta premissa, delineou-se o objetivo deste trabalho: avaliar a variabilidade dos atributos químicos do solo e sua inter-relação com as frações granulométricas e componentes da matéria orgânica do solo, contextualizando a influência do relevo, utilizando-se a geoestatística e a análise de componentes principais (ACP). A variabilidade espacial dos atributos químicos em menor profundidade foi mais influenciada pelo relevo. Pela ACP, atributos relacionados com a reação do solo (pH, Ca, Mg, Al, m e V) contribuíram com o primeiro componente principal (CP1) nas duas profundidades. Contudo, somente o CP1 na profundidade de 0,0 - 0,1 m foi correlacionado com o relevo: maiores altitudes e menores declividades favoreceram o maior teor da fração argila e menor teor de areia grossa, aumentando a retenção de cátions básicos no solo. Substâncias húmicas da matéria orgânica tiveram fraca influência na variabilidade dos atributos químicos, ressalvando a maior relação entre Ca e Mg com ácidos húmicos em locais de textura mais arenosa. Zonas homogêneas e correlatas com atributos geomorfológicos nas duas profundidades foram melhores obtidas para os teores de K, em comparação aos demais atributos. Dessa forma, o uso da análise espacial para segmentação da paisagem em regiões homogêneas visando otimizar o manejo da adubação depende não somente da topografia, mas também dos atributos químicos e da profundidade de amostragem.
Enfrentamento da violência infligida pelo parceiro íntimo por mulheres em área urbana da região Nordeste do Brasil
Authors: Silva Raquel de Aquino , Araújo Thália Velho Barreto de , Valongueiro Sandra , Ludermir Ana Bernarda
Published: February 2013

OBJETIVO: Descrever as formas de enfrentamento à violência física adotadas por mulheres agredidas por parceiro íntimo. MÉTODOS: Estudo transversal realizado na linha de base de estudo de coorte, com gestantes cadastradas no Programa Saúde da Família, entre julho de 2005 e março de 2006, em Recife, PE. Foram selecionadas 283 gestantes de 18 a 49 anos com histórico de violência física pelo parceiro de então ou mais recente antes e/ou durante a gestação. As entrevistas foram realizadas face a face, com questionário estruturado e pré-codificado, e realizou-se análise descritiva. Foi coletada informação sobre características sociodemográficas das mulheres, tipos e gravidade da violência física cometida pelo parceiro, formas de enfrentamento da violência, pessoas e serviços de apoio procurados pelas mulheres, motivos para a mulher ter alguma vez abandonado e retornado a casa em razão da violência. RESULTADOS: Das mulheres que sofreram violência física pelo parceiro íntimo, 57,6% conversaram com alguém, 3,5% procuraram ajuda institucionalizada, 17,3% conversaram e procuraram ajuda institucionalizada e 21,6% não procuraram nenhuma forma de ajuda. As pessoas mais procuradas foram os pais (42,0%), amigo/amiga (31,6%) e irmão/irmã (21,2%). Os serviços mais procurados pelas mulheres foram: polícia/delegacia (57,6%), serviços de saúde (27,1%) e instituições religiosas (25,4%). Relataram não ter obtido qualquer tipo de ajuda 44,8% das mulheres; 32,1% disseram ter saído de casa alguma vez na vida, pelo menos por uma noite, das quais 5,9% não retornaram a casa. Foram motivos para deixar a casa: a exacerbação da violência e o medo de ser morta; para o retorno: a esperança de mudança do parceiro e o desejo de preservar a família. CONCLUSÕES: Grande parte das mulheres que sofriam violência por parceiro íntimo buscou alguma forma de ajuda. A rede social primária (familiares e amigos) foi a mais procurada pelas mulheres para romper o ciclo violento. Os resultados apontam a necessidade de maior divulgação dos serviços de apoio e a importância da ampliação e qualificação da rede de serviços (polícia, justiça, saúde, assistência psicossocial) para que estes possam acolher e apoiar as mulheres, dando-lhes suporte efetivo para romper com a situação de VPI.