bluuebunny/crossref_metadata_2025 huggingface dataset:
Heparin Modulates the Mitogenic Activity of Fibroblast Growth Factor by Inducing Dimerization of its Receptor. A 3D View by Using NMR
Authors: Nieto Lidia , Canales Ángeles , Fernández Israel S. , Santillana Elena , González‐Corrochano Rocío , Redondo‐Horcajo Mariano , Cañada F. Javier , Nieto Pedro , Martín‐Lomas Manuel , Giménez‐Gallego Guillermo , Jiménez‐Barbero Jesús
Published: August 2013

In vitro mitogenesis assays have shown that sulfated glycosaminoglycans (GAGs; heparin and heparan sulfate) cause an enhancement of the mitogenic activity of fibroblast growth factors (FGFs). Herein, we report that the simultaneous presence of FGF and the GAG is not an essential requisite for this event to take place. Indeed, preincubation with heparin (just before FGF addition) of cells lacking heparan sulfate produced an enhancing effect equivalent to that observed when the GAG and the protein are simultaneously added. A first structural characterization of this effect by analytical ultracentrifugation of a soluble preparation of the heparin‐binding domain of fibroblast growth factor receptor 2 (FGFR2) and a low molecular weight (3 kDa) heparin showed that the GAG induces dimerization of FGFR2. To derive a high resolution structural picture of this molecular recognition process, the interactions of a soluble heparin‐binding domain of FGFR2 with two different homogeneous, synthetic, and mitogenically active sulfated GAGs were analyzed by NMR spectroscopy. These studies, assisted by docking protocols and molecular dynamics simulations, have demonstrated that the interactions of these GAGs with the soluble heparin‐binding domain of FGFR induces formation of an FGFR dimer; its architecture is equivalent to that in one of the two distinct crystallographic structures of FGFR in complex with both heparin and FGF1. This preformation of the FGFR dimer (with similar topology to that of the signaling complex) should favor incorporation of the FGF component to form the final assemblage of the signaling complex, without major entropy penalty. This cascade of events is probably at the heart of the observed activating effect of heparin in FGF‐driven mitogenesis.
Beta Sheets with a Twist: The Conformation of Helical Polyisocyanopeptides Determined by Using Vibrational Circular Dichroism
Authors: Schwartz Erik , Liégeois Vincent , Koepf Matthieu , Bodis Pavol , Cornelissen Jeroen J. L. M. , Brocorens Patrick , Beljonne David , Nolte Roeland J. M. , Rowan Alan E. , Woutersen Sander , Champagne Benoît
Published: August 2013

Detailed information on the architecture of polyisocyanopeptides based on vibrational circular dichroism (VCD) spectroscopy in combination with DFT calculations is presented. It is demonstrated that the screw sense of the helical polyisocyanides can be determined directly from the CN‐stretch vibrational region of the VCD spectrum. Analysis of the VCD signals associated with the amide I and amide II modes provides detailed information on the peptide side‐chain arrangement in the polymer and indicates the presence of a helical β‐sheet architecture, in which the dihedral angles are slightly different to those of natural β‐sheet helices.
Determination of Enantioselectivity and Enantiomeric Excess by Mass Spectrometry in the Absence of Chiral Chromatographic Separation: An Overview
Authors: Piovesana Susy , Samperi Roberto , Laganà Aldo , Bella Marco
Published: August 2013

This review describes the principles and instrumentation for the screening of asymmetric reactions by mass spectrometry. These techniques witnessed a significant advancement in the last few years. Although some of them are still at the proof‐of‐concept development stage, several applications might be foreseen in the field of combinatorial, high‐throughput parallel catalyst screening.
α‐Oligofurans: A Computational Study
Authors: Sharma Sagar , Bendikov Michael
Published: August 2013

Recently, α‐oligofurans have emerged as interesting and promising organic electronic materials that have certain advantages over α‐oligothiophenes. In this work, α‐oligofurans were studied computationally, and their properties were compared systematically with those of the corresponding oligothiophenes. Although the two materials share similar electronic structures, overall, this study revealed important differences between α‐oligofurans and α‐oligothiophenes. Twisting studies on oligofurans revealed them to be significantly more rigid than oligothiophenes in the ground state and first excited state. Neutral α‐oligofurans have more quinoid character, higher frontier orbital energies, and higher HOMO–LUMO gaps than their α‐oligothiophene counterparts. The theoretical results suggest that oligofurans (and subsequently polyfuran) have lower ionization potentials than the corresponding oligothiophenes (and polythiophene), which in turn predicts that oligofurans can be lightly doped more easily than oligothiophenes. Oligofuran dications (8 F2+–14 F2+) of medium‐sized and longer chain lengths show a polaron‐pair character, and the polycations of α‐oligofurans cannot accommodate high positive charges as easily as their thiophene analogues.
Towards Molecular Ribbons of Corannulene
Authors: Furrer Fabienne , Linden Anthony , Stuparu Mihaiela C.
Published: August 2013

Herein, we explore the synthesis of corannulene‐based ribbon‐shaped molecules through a repetitive Diels–Alder strategy. For this, appropriate corannulene‐based dienes and dienophiles were identified and synthesized. These building blocks could be combined in a modular way to obtain the dimeric and trimeric segments of the hypothetical molecular ribbons. 1D and 2D NMR measurements, along with crystal‐structure analyses, allowed the structures and geometries of the synthesized compounds to be determined.
Regioselectivity and Competition of the Paternò–Büchi Reaction and Triplet–Triplet Energy Transfer between Triplet Benzophenones and Pyrimidines: Control by Triplet Energy Levels
Authors: Liu Xiu‐Ling , Wang Jian‐Bo , Tong Yao , Song Qin‐Hua
Published: August 2013

The photochemical reaction of a pyrimidine and a ketone occurs either as a Paternò–Büchi (PB) reaction or as energy transfer (ET) from the triplet ketone to the pyrimidine. It is rare for the two types of reactions to occur concurrently, and their competitive mechanism remains unknown. In this work, two classes of products, regioisomeric oxetane(s) (2, 3) from a PB reaction and three isomeric dimers of 5‐fluoro‐1,3‐dimethyl uracil (FDMU) (4–6) from a photosensitized dimerization of FDMU, are obtained through the UV irradiation of FDMU with various benzophenones (BPs). The ratio of the two products (oxetanes to dimers) reveals that the two competitive reactions depend strongly on the triplet energy levels (ET) of the BPs. The BPs with higher ET values lead to higher proportions of dimers, whereas those with lower ET values give higher proportions of oxetane(s), with the generation of just two regioisomeric oxetanes for the BP with the lowest ET of the eight BPs investigated. The ratio of the two oxetanes (2:3) decreases with the BP ET value. The competitive mechanism for the two types of photochemical reactions is demonstrated through quenching experiments and investigation of temperature effects. Kinetic analysis shows that the rate constants of the two [2+2] photocycloadditions are comparable. Furthermore, in combination with the results of previous studies, we have gained insight into the dependence of the photochemical type and the regioselectivity in the PB reaction on the triplet energy gaps (ΔE) between the pyrimidines and ketones. For ketones with higher ET values than the pyrimidines, the photochemical reaction is a photosensitized dimerization of the pyrimidine. In the opposite case, a PB reaction occurs, and the lower the ET of the ketones, the lower the ratio of oxetanes (2:3). When the ET of values of the ketones are close to those of the pyrimidines, the two reactions occur concurrently, and the higher the ET of the ketones, the higher the proportion of the dimers. The ratio of oxetanes (2:3) decreases with the ET value of the BPs.
Watching Orientational Ordering at the Nanoscale with Coherent Anti‐Stokes Raman Microscopy
Authors: Parekh Sapun H. , Domke Katrin F.
Published: August 2013

Whether in lipid membranes, liquid crystals or solid‐state catalysts, the orientational ordering of molecules greatly influences the overall system behaviour. However, watching molecular alignment is a huge technical challenge. This article introduces nonlinear Raman (coherent anti‐Stokes Raman scattering; CARS) microscopy as a promising tool for fast, label‐free 3D chemical and structural sample characterization at the nanoscale in real time.
Organocatalytic Triazole Formation, Followed by Oxidative Aromatization: Regioselective Metal‐Free Synthesis of Benzotriazoles
Authors: Ramachary Dhevalapally B. , Shashank Adluri B.
Published: August 2013

Herein we report on our studies on the sequential one‐pot combinations of amine‐catalyzed multicomponent reactions (MCRs). We have developed the copper‐free synthesis of functionalized bicyclic N‐aryl‐1,2,3‐triazole and N‐arylbenzotriazole products 4 and 5 from the simple unmodified starting materials through [3+2]‐cycloaddition ([3+2]‐CA) and oxidative aromatization reactions in one pot under amine catalysis. The sequential one‐pot reaction proceeds in good yields with high selectivity by using pyrrolidine as the catalyst from the simple unmodified substrates of enones, aryl azides, and 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ). Furthermore, we have demonstrated the medicinal applications of products 4 and 5 through simple organic reactions.
Mesoporous Core–Shell Fenton Nanocatalyst: A Mild, Operationally Simple Approach to the Synthesis of Adipic Acid
Authors: Patra Astam K. , Dutta Arghya , Bhaumik Asim
Published: August 2013

Mesoporous nanoparticles composed of γ‐Al2O3 cores and α‐Fe2O3 shells were synthesized in aqueous medium. The surface charge of γ‐Al2O3 helps to form the core–shell nanocrystals. The core–shell structure and formation mechanism have been investigated by wide‐angle XRD, energy‐dispersive X‐ray spectroscopy, and elemental mapping by ultrahigh‐resolution (UHR) TEM and X‐ray photoelectron spectroscopy. The N2 adsorption–desorption isotherm of this core–shell materials, which is of type IV, is characteristic of a mesoporous material having a BET surface area of 385 m2 g−1 and an average pore size of about 3.2 nm. The SEM images revealed that the mesoporosity in this core–shell material is due to self‐aggregation of tiny spherical nanocrystals with sizes of about 15–20 nm. Diffuse‐reflectance UV/Vis spectra, elemental mapping by UHRTEM, and wide‐angle XRD patterns indicate that the materials are composed of aluminum oxide cores and iron oxide shells. These Al2O3@Fe2O3 core–shell nanoparticles act as a heterogeneous Fenton nanocatalyst in the presence of hydrogen peroxide, and show high catalytic efficiency for the one‐pot conversion of cyclohexanone to adipic acid in water. The heterogeneous nature of the catalyst was confirmed by a hot filtration test and analysis of the reaction mixture by atomic absorption spectroscopy. The kinetics of the reaction was monitored by gas chromatography and 1H NMR spectroscopy. The new core–shell catalyst remained in a separate solid phase, which could easily be removed from the reaction mixture by simple filtration and the catalyst reused efficiently.
Insights into the Oxidative Dehydrogenation of Amines with Nanoparticulate Iridium Oxide
Authors: Hammond Ceri , Schümperli Martin T. , Hermans Ive
Published: August 2013

The aerobic oxidation of amines offers a promising route towards many versatile chemical compounds. Within this contribution, we extend our previous investigations of iridium oxide‐catalyzed alcohol oxidation to amine substrates. In addition to demonstrating the versatility of this catalyst, particular attention is focused on the mechanisms of the reaction. Herein, we demonstrate that although amines are oxidized slower than the corresponding alcohols, the catalyst has a preference for amine substrates, and oxidizes various amines at turnover frequencies greater than other systems found in the open literature. Furthermore, the competition between double amine dehydrogenation, to yield the corresponding nitrile, and amine–imine coupling, to yield the corresponding coupled imine, has been found to arise from a competitive reaction pathway, and stems from an effect of substrate‐to‐metal ratio. Finally, the mechanism responsible for the formation of N‐benzylidene‐1‐phenylmethanamine was examined, and attributed to the coupling of free benzyl amine substrate and benzaldehyde, formed in situ through hydrolysis of the primary reaction product, benzyl imine.
Biomimetic Synthesis of Equisetin and (+)‐Fusarisetin A
Authors: Yin Jun , Kong Lili , Wang Cheng , Shi Yingbo , Cai Shujun , Gao Shuanhu
Published: August 2013

(+)‐Fusarisetin A belongs to a group of acyl tetramic acid natural products that show potential anticancer activity. Equisetin, a biogenetically related acyl tetramic acid, contains the basic skeleton of (+)‐fusarisetin A. We proposed that equisetin and (+)‐fusarisetin A share a biosynthetic pathway that starts with naturally occurring (S)‐serine and an unsaturated fatty acid. In support of this hypothesis, we have demonstrated that a cyclization sequence involving an intramolecular Diels–Alder reaction followed by a Dieckmann cyclization of polyenoylamino acid yielded equisetin. The aerobic oxidation of equisetin, promoted by either MnIII/O2 or a reactive oxygen species (ROS) produced by visible‐light chemistry, gave peroxyfusarisetin, which could be easily reduced to (+)‐fusarisetin A. We report herein detailed information on the biogenetic synthesis of equisetin and (+)‐fusarisetin A.
Highly Photoluminescent Amino‐Functionalized Graphene Quantum Dots Used for Sensing Copper Ions
Authors: Sun Hanjun , Gao Nan , Wu Li , Ren Jinsong , Wei Weili , Qu Xiaogang
Published: August 2013

Herein, we report a new kind of highly fluorescent probe for Cu2+ sensing generated by hydrothermal treatment of graphene quantum dots (GQDs). After hydrothermal treatment in ammonia, the greenish‐yellow fluorescent GQDs (gGQDs) with a low quantum yield (QY, 2.5 %) are converted to amino‐functionalized GQDs (afGQDs) with a high QY (16.4 %). Due to the fact that Cu2+ ions have a higher binding affinity and faster chelating kinetics with N and O on the surface of afGQDs than other transition‐metal ions, the selectivity of afGQDs for Cu2+ is much higher than that of gGQDs. Furthermore, afGQDs are biocompatible and eco‐friendly, and the afGQDs with a positive charge can be easily taken up by cells, which makes it possible to sense Cu2+ in living cells. The strategy presented here is simple in design, economical, and offers a “mix‐and‐detect” protocol without dye‐modified oligonucleotides or complex chemical modification.
The factor aliased effect number pattern and its application in experimental planning
Authors: Zhou Qi , Balakrishnan Narayanaswamy , Zhang Runchu
Published: August 2013

Optimality criteria are usually used to choose fractional factorial designs in applications. Within an optimal design, the effects of factors assigned to different columns may be estimated with different precisions. Among factors to be investigated in an experiment, the user often has prior information on their relative importance. Thus, it is beneficial to assign most important factors to columns enabling most precise estimation. In this paper, we introduce a criterion to rank the columns of a regular design and use the criterion to GMC designs accordingly. We study the mathematical properties of the new ranking practice and provide concrete guidance on assigning factors in some GMC designs. The Canadian Journal of Statistics 41: 540–555; 2013 © 2013 Statistical Society of Canada
Cytological criteria of high‐grade epithelial atypia in the cyst fluid of pancreatic intraductal papillary mucinous neoplasms
Authors: Pitman Martha B. , Centeno Barbara A. , Daglilar Ebubekir S. , Brugge William R. , Mino‐Kenudson Mari
Published: August 2013

BACKGROUND

The recognition of epithelial cells with high‐grade atypia (HGA) in the cyst fluid of an intraductal papillary mucinous neoplasm (IPMN) identifies a cyst at high risk of invasive carcinoma. To the best of the authors' knowledge, the cytological features of HGA have not been systematically analyzed to define diagnostic criteria.

METHODS

Cell groups from patients with histologically confirmed branch‐duct IPMNs were evaluated by 2 cytopathologists with expertise in pancreatic cytology. A consensus interpretation categorized the cell groups as having either low‐grade (LG) or high‐grade (HG) morphology. Characteristics regarding cell size and architecture, nuclear and cytoplasmic features, and background necrosis were analyzed. Performance characteristics were assessed using the Fisher exact test at 95% confidence intervals.

RESULTS

Sixty cell groups yielded 27 LG and 25 HG morphological groups. No consensus was reached for 8 groups, which were excluded from statistical analysis. Five features that were found to be significantly different between the LG and HG groups included: 1) cell size <  a 12‐μm duodenal enterocyte for HG and size equal for LG; 2) an increased nuclear‐to‐cytoplasmic (N/C) ratio; 3) marked nuclear membrane abnormalities; 4) abnormal chromatin pattern; and 5) background necrosis. The 3 most accurate features for the identification of HGA were background necrosis (88%), abnormal chromatin pattern (84%), and an increased N/C ratio (82%).

CONCLUSIONS

IPMN cyst fluid at high‐risk of malignancy can be recognized most accurately by the presence of epithelial cells with HGA showing an increased N/C ratio, an abnormal chromatin pattern, and background necrosis. Cancer (Cancer Cytopathol) 2014;122:40–47. © 2013 American Cancer Society.
Connexin 35b expression in the spinal cord of Danio rerio embryos and larvae
Authors: Carlisle Tara C. , Ribera Angeles B.
Published: August 2013

Electrical synapses are expressed prominently in the developing and mature nervous systems. Unlike chemical synapses, little is known about the developmental role of electrical synapses, reflecting the limitations imposed by the lack of selective pharmacological blockers. At a molecular level, the building blocks of electrical synapses are connexin proteins. In this study, we report the expression pattern for neuronally expressed connexin 35b (cx35b), the zebrafish orthologue of mammalian connexin (Cx) 36. We find that cx35b is expressed at the time of neural induction, indicating a possible early role in neural progenitor cells. Additionally, cx35b localizes to the ventral spinal cord during embryonic and early larval stages. We detect cx35b mRNA in secondary motor neurons (SMNs) and interneurons. We identified the premotor circumferential descending (CiD) interneuron as one interneuron subtype expressing cx35b. In addition, cx35b is present in other ventral interneurons of unknown subtype(s). This early expression of cx35b in SMNs and CiDs suggests a possible role in motor network function during embryonic and larval stages. J. Comp. Neurol. 522:861–875, 2014. © 2013 Wiley Periodicals, Inc.
Laminar and subcellular heterogeneity of GLAST and GLT‐1 immunoreactivity in the developing postnatal mouse hippocampus
Authors: Schreiner Alexandra E. , Durry Simone , Aida Tomomi , Stock Martin C. , Rüther Ulrich , Tanaka Kohichi , Rose Christine R. , Kafitz Karl W.
Published: August 2013

Astrocytes express two sodium‐coupled transporters, glutamate–aspartate transporter (GLAST) and glutamate transporter‐1 (GLT‐1), which are essential for the maintenance of low extracellular glutamate levels. We performed a comparative analysis of the laminar and subcellular expression profile of GLAST and GLT‐1 in the developing postnatal mouse hippocampus by using immunohistochemistry and western blotting and employing high‐resolution fluorescence microscopy. Astrocytes were identified by costaining with glial fibrillary acidic protein (GFAP) or S100β. In CA1, the density of GFAP‐positive cells and GFAP expression rose during the first 2 weeks after birth, paralleled by a steady increase in GLAST immunoreactivity and protein content. Upregulation of GLT‐1 was completed only at postnatal days (P) P20–25 and was thus delayed by about 10 days. GLAST staining was highest along the stratum pyramidale and was especially prominent in astrocytes at P3–5. GLAST immunoreactivity indicated no preferential localization to a specific cellular compartment. GLT‐1 exhibited a laminar expression pattern from P10–15 on, with the highest immunoreactivity in the stratum lacunosum‐moleculare. At the cellular level, GLT‐1 immunoreactivity did not entirely cover astrocyte somata and exhibited clusters at processes. In neonatal and juvenile animals, discrete clusters of GLT‐1 were also detected at perivascular endfeet. From these results, we conclude there is a remarkable subcellular heterogeneity of GLAST and GLT‐1 expression in the developing hippocampus. The clustering of GLT‐1 at astrocyte endfeet indicates that it might serve a specialized functional role at the blood–brain barrier during formation of the hippocampal network. J. Comp. Neurol. 522:204–224, 2014. © 2013 Wiley Periodicals, Inc.
The Validity of the Instrument to Evaluate Social Network in the Ageing Population: The Collaborative Research on Ageing in Europe Social Network Index
Authors: Zawisza Katarzyna , Galas Aleksander , Tobiasz‐Adamczyk Beata , Chatterji Somnath , Haro Josep Maria , Miret Marta , Koskinen Seppo , Power Mick , Leonardi Matilde
Published: August 2013

The aim of the study was to create a simplified, easy implementable multidimensional instrument to assess all relevant elements of the structure and function of social network within individuals across different European countries and to provide the tool for health professionals and policy makers.

The analysis was based on the sample of 10 446 non‐institutionalized adult population from Finland, Poland and Spain. The Social Network Questionnaire Collaborative Research on Ageing in Europe Social Network Index (COURAGE‐SNI) was part of the COURAGE questionnaire. The indicators of the functioning of social network ties (close relations), frequency of direct contact and general support were evaluated. Functions were assess within the main structural components as spouse, parents, children, grandchildren, other relatives, friends, coworkers and neighbours.

The exploratory factor analysis revealed five main latent components of social network with one component composed of hierarchical part. The confirmatory factor analysis provided an acceptable fit for the model. The generalize partial credit model was used to calculate factor scores for five components of the COURAGE‐SNI considering the social networks of ‘spouse/partner’, ‘parents’, ‘other family members’, ‘neighbours’ and ‘friends and co‐workers’. The scores for every component were recalculated so as to provide the social network saturation ranged from 0 (the lowest) to 100% (the highest possible). Finally, the COURAGE‐SNI score was obtained as the sum of weighted information calculated by the item response theory procedure for every aforementioned component.

In summary, the COURAGE‐SNI showed good reliability and content validity and seems to be a promising tool for the assessment of the social network phenomenon across European countries. Copyright © 2013 John Wiley & Sons, Ltd.

Key Practitioner Message

The Courage‐SNI is a new tool to assess the construct of social network in population studies.

The Courage‐SNI is an instrument useful to identify high risk groups or populations whose social network is poorer.
Shape‐ and Size‐Controlled Nanomaterials for Artificial Photosynthesis
Authors: Fukuzumi Shunichi , Yamada Yusuke
Published: August 2013

Nanomaterials with various shapes and sizes have been developed to mimic functions of photosynthesis in which solar energy conversion is achieved by using nanosized proteins with controlled shapes and sizes. Artificial photosynthesis consists of light‐harvesting and charge‐separation processes together with catalytic units of water oxidation and reduction. Nanosized mesoporous silica–alumina was utilized to encapsulate organic charge‐separation molecules inside the nanospace to elongate the lifetimes of the charge‐separated states, as observed in the photosynthetic reaction centers. Metal nanoparticles with controlled shapes and sizes have also been utilized as efficient catalysts for photocatalytic hydrogen evolution from water with reductants by using electron donor–acceptor organic molecules as photocatalysts. The control of the shape and size of metal nanoparticles plays a very important role in achieving high catalytic performance in catalytic hydrogen evolution in water reduction and also in catalytic oxygen evolution in water oxidation.
Synthesis of Pt/SiO2 Catalyst Nanoparticles from a Continuous Aerosol Process using Novel Cyclo‐octadienylplatinum Precursors
Authors: Faust Matthias , Enders Mirja , Gao Kun , Reichenbach Linus , Muller Thierry , Gerlinger Wolfgang , Sachweh Bernd , Kasper Gerhard , Bruns Michael , Bräse Stefan , Seipenbusch Martin
Published: August 2013

Investigations on the metal‐organic (MO)CVD of platinum nanoparticles on spherical, chemical vapor synthesis (CVS)‐produced SiO2 substrates are discussed in this paper. Commercially available methylcyclopentadienyl trimethyl platinum (MeCpPtMe3) (1) and three newly synthesized cyclooctadienyl platinum precursors are chosen and tested during a continuous CVD/CVS process. The synthesis of this new class of stable, halogen‐free precursors for atmospheric pressure (AP)CVD is presented. The complexes [PtMe2(R‐COD)], where R = Et (2a), nBu (2b), and iBu (2c), are shown to be highly suitable for the preparation of platinum nanoparticles. The precursors are characterized and their thermal properties are studied by thermogravimetric analysis (TGA) and infrared (IR). Investigations of the precursor decomposition mechanism, the effect of oxygen, and the autocatalytic effect during CVD are also carried out. Finally, transmission electron microscopy (TEM) and X‐ray photoelectron spectroscopy (XPS) analyses prove that continuous CVS of gas‐borne support particles combined with MOCVD of these newly synthesized platinum precursors gives ordered, defined platinum nanocatalysts with high dispersion and narrow size distribution (2 − 3 nm).
Castration‐induced upregulation of muscle ERα supports estrogen sensitivity of motoneuron dendrites in a sexually dimorphic neuromuscular system
Authors: Rudolph Lauren M. , Sengelaub Dale R.
Published: August 2013

The spinal cord of rats contains the sexually dimorphic motoneurons of the spinal nucleus of the bulbocavernosus (SNB). In males, SNB dendrites fail to grow after castration, but androgen or estrogen treatment supports dendritic growth in castrated males. Estrogenic support of SNB dendrite growth is mediated by estrogen receptors (ER) in the target muscle. ERα expression in cells lacking a basal lamina (referred to as “extra‐muscle fiber cells”) of the SNB target musculature coincides with the period of estrogen‐dependent SNB dendrite growth. In the SNB target muscle, extra‐muscle fiber ERα expression declines with age and is typically absent after postnatal (P) day 21 (P21). Given that estradiol downregulates ERα in skeletal muscle, we tested the hypothesis that depleting gonadal hormones would prevent the postnatal decline in ERα expression in the SNB target musculature. We castrated male rats at P7 and assessed ERα immunolabeling at P21; ERα expression was significantly greater in castrated males compared with normal animals. Because ERα expression in SNB target muscles mediates estrogen‐dependent SNB dendrogenesis, we further hypothesized that the castration‐induced increase in muscle ERα would heighten the estrogen sensitivity of SNB dendrites. Male rats were castrated at P7 and treated with estradiol from P21 to P28; estradiol treatment in castrates resulted in dendritic hypertrophy in SNB motoneurons compared with normal males. We conclude that early castration results in an increase in ERα expression in the SNB target muscle, and this upregulation of ERα supports estrogen sensitivity of SNB dendrites, allowing for hypermasculinization of SNB dendritic arbors. © 2013 Wiley Periodicals, Inc. Develop Neurobiol 73: 921–935, 2013
TALE transcription factors during early development of the vertebrate brain and eye
Authors: Schulte Dorothea , Frank Dale
Published: August 2013

Our brain's cognitive performance arises from the coordinated activities of billions of nerve cells. Despite a high degree of morphological and functional differences, all neurons of the vertebrate central nervous system (CNS) arise from a common field of multipotent progenitors. Cell fate specification and differentiation are directed by multistep processes that include inductive/external cues, such as the extracellular matrix or growth factors, and cell‐intrinsic determinants, such as transcription factors and epigenetic modulators of proteins and DNA. Here we review recent findings implicating TALE‐homeodomain proteins in these processes. Although originally identified as HOX‐cofactors, TALE proteins also contribute to many physiological processes that do not require HOX‐activity. Particular focus is, therefore, given to HOX‐dependent and ‐independent functions of TALE proteins during early vertebrate brain development. Additionally, we provide an overview about known upstream and downstream factors of TALE proteins in the developing vertebrate brain and discuss general concepts of how TALE proteins function to modulate neuronal cell fate specification.Developmental Dynamics 243:99–116, 2014. © 2013 Wiley Periodicals, Inc.
Adipose tissue derived stromal stem cell therapy in murine ConA‐derived hepatitis is dependent on myeloid‐lineage and CD4+T‐cell suppression
Authors: Higashimoto Mami , Sakai Yoshio , Takamura Masayuki , Usui Soichiro , Nasti Alessandro , Yoshida Keiko , Seki Akihiro , Komura Takuya , Honda Masao , Wada Takashi , Furuichi Kengo , Ochiya Takahiro , Kaneko Shuichi
Published: August 2013

Mesenchymal stromal stem cells (MSCs) are an attractive therapeutic model for regenerative medicine due to their pluripotency. MSCs are used as a treatment for several inflammatory diseases, including hepatitis. However, the detailed immunopathological impact of MSC treatment on liver disease, particularly for adipose tissue derived stromal stem cells (ADSCs), has not been described. Here, we investigated the immuno‐modulatory effect of ADSCs on hepatitis using an acute ConA C57BL/6 murine hepatitis model. i.v. administration of ADSCs simultaneously or 3 h post injection prevented and treated ConA‐induced hepatitis. Immunohistochemical analysis revealed higher numbers of CD11b+, Gr‐1+, and F4/80+ cells in the liver of ConA‐induced hepatitis mice was ameliorated after the administration of ADSCs. Hepatic expression of genes affected by ADSC administration indicated tissue regeneration‐related biological processes, affecting myeloid‐lineage immune‐mediating Gr‐1+ and CD11b+ cells. Pathway analysis of the genes expressed in ADSC‐treated hepatic inflammatory cells revealed the possible involvement of T cells and macrophages. TNF‐α and IFN‐γ expression was downregulated in hepatic CD4+ T cells isolated from hepatitis livers co‐cultured with ADSCs. Thus, the immunosuppressive effect of ADSCs in a C57BL/6 murine ConA hepatitis model was dependent primarily on the suppression of myeloid‐lineage cells and, in part, of CD4+ T cells.
Dispersant and salinity effects on weathering and acute toxicity of South Louisiana crude oil
Authors: Kuhl Adam J. , Nyman J. Andrew , Kaller Michael D. , Green Christopher C.
Published: August 2013

Chemical dispersants are an important technology in the remediation of oil spills in the aquatic environment, facilitating degradation of crude oil and salinity is an important factor in dispersant effectiveness. The aim of the present study was to explore the role of salinity on the degradation chemistry of crude oil polycyclic aromatic hydrocarbons (PAHs) and acute toxicity of the water-accommodated fraction (WAF) of the dispersant COREXIT 9500A and chemically dispersed crude oil on a common estuarine fish. Laboratory microcosms were designed at salinities of 4 parts per thousand (ppt), 12 ppt, or 18 ppt and spiked with crude oil, COREXIT 9500A, or a combined exposure to crude oil and COREXIT and allowed to biodegrade for 1 wk, 4 wk, and 16 wk. The WAF was harvested for analytical PAH analysis and acute toxicity testing in juvenile Fundulus grandis. Compared with undispersed oil, COREXIT exponentially increased the PAH concentrations in the WAF for up to 16 wk; hopane-normalized concentrations indicated that biodegradation was slowed for the first 4 wk. Dispersed crude oil and COREXIT were acutely toxic following 1 wk of biodegradation with no correlation between PAH concentrations and crude oil WAF mortality. Both dispersant and dispersant oil mixtures remained toxic for at least 4 wk at the lowest salinity tested, suggesting increased sensitivity or reduced biodegradation of toxic components in low-saline environments. At the lowest salinity, oil dispersed with COREXIT was more toxic than either the COREXIT alone or oil alone, even after 16 wk of biodegradation. Environ Toxicol Chem 2013;32:2611–2620. © 2013 SETAC
Two new floral elements of steppe vegetation from the Pleistocene of Europe
Authors: Czaja Alexander
Published: August 2013

Two new species, Agrimonia repens L. and Onopordum davisii Rech., are reported from the Schöningen 13 II site (middle Pleistocene). Both are elements of halophilous steppes and are recorded for the first time for the Pleistocene of Europe. This is the first fossil record of both species, highlighting the relevance of this finding with respect to the species chorology. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A magnetic disturbance index for Mercury's magnetic field derived from MESSENGER Magnetometer data
Authors: Anderson Brian J. , Johnson Catherine L. , Korth Haje
Published: August 2013

We present a magnetic disturbance measure for Mercury derived from MESSENGER Magnetometer data. Magnetic field fluctuations were computed in three period bands: 0.1–2 s, 2–20 s, and 20–300 s. From these, we determined log average magnetic variability versus latitude and local time in Mercury's magnetosphere. The quietest regions are the southern tail lobe and the nightside poleward of 30° magnetic latitude, and the most disturbed regions are near magnetopause boundaries and the magnetospheric cusp. We used ratios at each location between the mean disturbance and that observed on each pass to compute normalized measures of magnetic disturbance for each orbit. Composite disturbance indices incorporate disturbance levels in all three bands. Percentile ranking of the composite indices provides a quantitative basis for selecting data from quiet to disturbed conditions.
Slab tears and intermediate‐depth seismicity
Authors: Meighan Hallie E. , ten Brink Uri , Pulliam Jay
Published: August 2013

Active tectonic regions where plate boundaries transition from subduction to strike slip can take several forms, such as triple junctions, acute, and obtuse corners. Well‐documented slab tears that are associated with high rates of intermediate‐depth seismicity are considered here: Gibraltar arc, the southern and northern ends of the Lesser Antilles arc, and the northern end of Tonga trench. Seismicity at each of these locations occurs, at times, in the form of swarms or clusters, and various authors have proposed that each marks an active locus of tear propagation. The swarms and clusters start at the top of the slab below the asthenospheric wedge and extend 30–60 km vertically downward within the slab. We propose that these swarms and clusters are generated by fluid‐related embrittlement of mantle rocks. Focal mechanisms of these swarms generally fit the shear motion that is thought to be associated with the tearing process.
Australia's unique influence on global sea level in 2010–2011
Authors: Fasullo John T. , Boening Carmen , Landerer Felix W. , Nerem R. Steven
Published: August 2013

In 2011, a significant drop in global sea level occurred that was unprecedented in the altimeter era and concurrent with an exceptionally strong La Niña. This analysis examines multiple data sets in exploring the physical basis for the drop's exceptional intensity and persistence. Australia's hydrologic surface mass anomaly is shown to have been a dominant contributor to the 2011 global total, and associated precipitation anomalies were among the highest on record. The persistence of Australia's mass anomaly is attributed to the continent's unique surface hydrology, which includes expansive arheic and endorheic basins that impede runoff to ocean. Based on Australia's key role, attribution of sea level variability is addressed. The modulating influences of the Indian Ocean Dipole and Southern Annular Mode on La Niña teleconnections are found to be key drivers of anomalous precipitation in the continent's interior and the associated surface mass and sea level responses.
Are recent Arctic ozone losses caused by increasing greenhouse gases?
Authors: Rieder Harald E. , Polvani Lorenzo M.
Published: August 2013

It has been suggested that the Arctic ozone losses observed in recent years might be a manifestation of climate change due to increasing greenhouse gases. We here offer evidence to the contrary, by focusing on the volume of polar stratospheric clouds (VPSC), a convenient proxy for polar ozone loss whose simplicity allows for easily reproducible results. First, we analyze the time series of VPSC in three reanalysis data sets and find no statistically significant trends in VPSC–nor changes in their probability density functions–over the period 1979–2011. Second, we analyze VPSC in a stratosphere‐resolving chemistry‐climate model forced uniquely with increasing greenhouse gases following the A1B scenario: here too, we find no significant changes in VPSC over the entire 21st century. Taken together, these results strongly suggest that the sporadic high ozone losses in recent years have not been caused by increasing greenhouse gases.
A new approach to retrieve cloud base height of marine boundary layer clouds
Authors: Li J. M. , Yi Y. H. , Stamnes K. , Ding X. D. , Wang T. H. , Jin H. C. , Wang S. S.
Published: August 2013

A novel approach for estimating marine boundary layer cloud base height (CBH) is proposed based on calculated boundary layer lapse rates, collocated cloud top height (CTH), cloud top, and ocean surface temperatures from the A‐Train satellite constellation. The method takes advantage of the assumption that decreases of temperature within and below water clouds may follow the different constant apparent lapse rates in the same region, respectively. The CBHs derived from the new method compare well with the coincident CBH product from the active sensors of Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and CloudSat. The correlation coefficient, the mean difference, and the standard deviation are 0.79 (0.54), 0.02 km (0.03 km), and ±0.35 km (±0.54 km), respectively, when CTH is derived from CALIPSO data (or Moderate Resolution Imaging Spectroradiometer retrieval). Besides the relatively small bias, the most important advantage of this method compared to previous CBH retrieval techniques is that it is independent of boundary layer cloud types, optical thickness, and illumination.
New ultrahigh‐resolution picture of Earth's gravity field
Authors: Hirt Christian , Claessens Sten , Fecher Thomas , Kuhn Michael , Pail Roland , Rexer Moritz
Published: August 2013

We provide an unprecedented ultrahigh resolution picture of Earth's gravity over all continents and numerous islands within ±60° latitude. This is achieved through augmentation of new satellite and terrestrial gravity with topography data and use of massive parallel computation techniques, delivering local detail at ~200 m spatial resolution. As such, our work is the first‐of‐its‐kind to model gravity at unprecedented fine scales yet with near‐global coverage. The new picture of Earth's gravity encompasses a suite of gridded estimates of gravity accelerations, radial and horizontal field components, and quasi‐geoid heights at over 3 billion points covering 80% of Earth's land masses. We identify new candidate locations of extreme gravity signals, suggesting that the Committee on Data for Science and Technology standard for peak‐to‐peak variations in free‐fall gravity is too low by about 40%. The new models are beneficial for a wide range of scientific and engineering applications and freely available to the public.
Wind‐induced equatorial bulge in Venus and Titan general circulation models: Implication for the simulation of superrotation
Authors: Tokano Tetsuya
Published: August 2013

The centrifugal force associated with the superrotation in Venus' and Titan's middle atmosphere reduces the effective gravity and thereby modifies the shape of the geopotential surface, which manifests itself as an equatorial bulge. General circulation models (GCMs) based on the hydrostatic primitive equations cannot correctly represent this dynamics since the vertical component of the centrifugal force does not appear in the hydrostatic equation. Consequently, they are likely to underestimate the poleward pressure gradient force and superrotation in gradient wind balance. This effect can be accounted for in nonhydrostatic GCMs or in quasi‐hydrostatic GCMs, in which the hydrostatic equation is supplemented by the vertical component of the centrifugal and Coriolis force and which do not make the shallow‐atmosphere approximation. A quasi‐hydrostatic GCM is shown to predict faster superrotation than a hydrostatic GCM run under otherwise identical conditions.
Rossby rip currents
Authors: Marshall David P. , Vogel Bendix , Zhai Xiaoming
Published: August 2013

Oceanic Rossby waves and eddies flux energy and fluid westward, the latter through the Stokes drift or bolus transport. While the wave energy is largely dissipated at the western boundary, mass conservation requires that the fluid be returned offshore through Rossby rip currents. The form and magnitude of these rip currents are investigated through linear Rossby wave theory, a nonlinear numerical model, and analysis of sea surface height satellite observations. The net eastward volume transport by Rossby rip currents over the global ocean is estimated to be of order 10 Sv (1 Sv ≡106 m3 s−1). In an eddying ocean, both the westward Stokes drift and eastward rip currents can assume the form of banded quasi‐zonal jets.
Observations of barrier island length explained using an exploratory morphodynamic model
Authors: Roos Pieter C. , Schuttelaars Henk M. , Brouwer Ronald L.
Published: August 2013

Barrier coasts display a chain of islands, separated by tidal inlets that connect a back‐barrier basin to a sea or ocean. Observations show that barrier island length generally decreases for increasing tidal range and increasing basin area. However, this has neither been reproduced in model studies nor explained from the underlying physics. This is the aim of our study. Here we simulate barrier coast dynamics by combining a widely used empirical relationship for inlet dynamics with a process‐based model of the tidal hydrodynamics. Our model results show stable inlet systems with more than one inlet open that support the observed qualitative relationships and fit in existing barrier coast classifications. To explain this, we identify a competition between a destabilizing mechanism (bottom friction in inlets, tending to reduce the number of open inlets) and a stabilizing one (spatially varying pressure gradients over the inlets, tending to keep the inlets open).
Direct temperature and salinity acoustic full waveform inversion
Authors: Bornstein G. , Biescas B. , Sallarès V. , Mojica J. F.
Published: August 2013

Recent work has shown that Full Waveform Inversion could be suitable to extract physical properties such as sound speed (c), density (ρ), temperature (T), and salinity (S) from the weak impedance contrasts associated with the ocean's thermohaline fine structure.The seismic inversion approaches proposed so far are based on the iterative inversion of c from multichannel seismic data, while the rest of parameters (T,S, and ρ) are determined in a second step using two equations of state and a local T‐S empirical relationship. In this work, we present an alternative to this approach. Using 1‐D synthetic seismic data, we demonstrate that the direct full waveform inversion of T and S using adjoint methods is feasible without the use of any local T‐S relationship and that the models of physical properties obtained with this approach are far more accurate than those inferred from c.
GETTING STUCK IN THE BLUES: PERSISTENCE OF MENTAL HEALTH PROBLEMS IN AUSTRALIA
Authors: Roy John , Schurer Stefanie
Published: August 2013

Do episodes of mental health (MH) problems cause future MH problems, and if yes, how strong are these dynamics? We quantify the degree of persistence in MH problems using nationally representative, longitudinal data from Australia and system generalized method of moments (GMM), and correlated random effects approaches are applied to separate true from spurious state dependence. Our results suggest only a moderate degree of persistence in MH problems when assuming that persistence is constant across the MH distribution once individual‐specific heterogeneity is accounted for. However, individuals who fell once below a threshold that indicates an episode of depression are up to five times more likely to experience such a low score again a year later, indicating a strong element of state dependence in depression. Low income is a strong risk factor in state dependence for both men and women, which has important policy implications. Copyright © 2013 John Wiley & Sons, Ltd.
Fibroblast growth factor signaling in liver carcinogenesis
Authors: Sandhu Dalbir S. , Baichoo Esha , Roberts Lewis R.
Published: August 2013

Fibroblast growth factors, or FGFs, are a large family of polypeptide cytokines exhibiting a pleiotropy of functions, from cell growth to angiogenesis, wound healing, and tissue repair. This review broadly covers the genetics and protein expression of the FGF family members and the signaling pathways involved in FGF-mediated growth regulation. We emphasize the role of FGFs in the pathogenesis of hepatocellular carcinoma (HCC), including their effects on regulation of the tumor microenvironment and angiogenesis. Finally, we present current views on FGF's potential role as a prognostic marker in clinical practice, as well as its potential as a therapeutic target in HCC. (HEPATOLOGY 2014;59:1166–1173)