bluuebunny/crossref_metadata_2025 huggingface dataset:
P2X7 Receptors in Neurohypophysial Terminals: Evidence for their Role in Arginine‐Vasopressin Secretion
Authors: Cuadra Adolfo E. , Custer Edward E. , Bosworth Elizabeth L. , Lemos José R.
Published: August 2013

Arginine‐vasopressin (AVP) plays a major role in maintaining cardiovascular function and related pathologies. The mechanism involved in its release into the circulation is complex and highly regulated. Recent work has implicated the purinergic receptor, P2X7R, in a role for catecholamine‐enhanced AVP release in the rat hypothalamic‐neurohypophysial (NH) system. However, the site of P2X7R action in this endocrine system, and whether or not it directly mediates release in secretory neurons have not been determined. We hypothesized that the P2X7R is expressed and mediates AVP release in NH terminals. P2X7R function was first examined by patch‐clamp recordings in isolated NH terminals. Results revealed that subpopulations of isolated terminals displayed either high ATP‐sensitivity or low ATP‐sensitivity, the latter of which was characteristic of the rat P2X7R. Additional recordings showed that terminals showing sensitivity to the P2X7R‐selective agonist, BzATP, were further inhibited by P2X7R selective antagonists, AZ10606120 and brilliant blue‐G. In confocal micrographs from tissue sections and isolated terminals of the NH P2X7R‐immunoreactivity was found to be localized in plasma membranes. Lastly, the role of P2X7R on AVP release was tested. Our results showed that BzATP evoked sustained AVP release in NH terminals, which was inhibited by AZ10606120. Taken together, our data lead us to conclude that the P2X7R is expressed in NH terminals and corroborates its role in AVP secretion. J. Cell. Physiol. 229: 333–342, 2014. © 2013 Wiley Periodicals, Inc.
Nitric Oxide Regulation of Na, K‐ATPase Activity in Ocular Ciliary Epithelium Involves Src Family Kinase
Authors: Shahidullah Mohammad , Mandal Amritlal , Wei Guojun , Delamere Nicholas A.
Published: August 2013

The nitric oxide (NO) donor sodium nitroprusside (SNP) is known to reduce aqueous humor (AH) secretion in the isolated porcine eye. Previously, SNP was found to inhibit Na,K‐ATPase activity in nonpigmented ciliary epithelium (NPE), AH‐secreting cells, through a cGMP/protein kinase G (PKG)‐mediated pathway. Here we show Src family kinase (SFK) activation in the Na,K‐ATPase activity response to SNP. Ouabain‐sensitive 86Rb uptake was reduced by >35% in cultured NPE cells exposed to SNP (100 µM) or exogenously added cGMP (8‐Br‐cGMP) (100 µM) and the SFK inhibitor PP2 (10 µM) prevented the response. Ouabain‐sensitive ATP hydrolysis was reduced by ∼40% in samples detected in material obtained from SNP‐ and 8‐Br‐cGMP‐treated cells following homogenization, pointing to an intrinsic change of Na,K‐ATPase activity. Tyrosine‐10 phosphorylation of Na,K‐ATPase α1 subunit was detected in SNP and L‐arginine‐treated cells and the response prevented by PP2. SNP elicited an increase in cell cGMP. Cells exposed to 8‐Br‐cGMP displayed SFK activation (phosphorylation) and inhibition of both ouabain‐sensitive 86Rb uptake and Na,K‐ATPase activity that was prevented by PP2. SFK activation, which also occurred in SNP‐treated cells, was suppressed by inhibitors of soluble guanylate cyclase (ODQ; 10 µM) and PKG (KT5823; 1 µM). SNP and 8‐Br‐cGMP also increased phosphorylation of ERK1/2 and p38 MAPK and the response prevented by PP2. However, U0126 did not prevent SNP or 8‐Br‐cGMP‐induced inhibition of Na,K‐ATPase activity. Taken together, the results suggest that NO activates guanylate cyclase to cause a rise in cGMP and subsequent PKG‐dependent SFK activation. Inhibition of Na,K‐ATPase activity depends on SFK activation. J. Cell. Physiol. 229: 343–352, 2014. © 2013 Wiley Periodicals, Inc.
Role of Hippo Signaling in Cancer Stem Cells
Authors: Hao Jin , Zhang Yueling , Jing Dian , Li Yu , Li Juan , Zhao Zhihe
Published: August 2013

Cancer stem cells (CSCs) have been proposed and evidenced as the initiator of tumor formation and the seeds of metastases. Thereby, the molecular mechanisms regarding modulation of CSCs have been widely explored, aimed to improve treatment for cancer patients. Recent progress has highlighted the effects of Hippo signaling in tumorigenesis and cancer development, including its crucial role in CSC regulation. Although the kernel Hippo signaling cascade has been well studied, its upstream inputs and downstream transcriptional regulation still remain elusive. In this review, we summarize the current understanding of the mechanism and regulatory function of Hippo signaling in CSCs, with emphasis on its possible roles in regulation of CSC self‐renewal, differentiation and tumorigenesis. J. Cell. Physiol. 229: 266–270, 2014. © 2013 Wiley Periodicals, Inc.
Advances in Androgen Receptor Targeted Therapy for Prostate Cancer
Authors: Ahmed Alia , Ali Shadan , Sarkar Fazlul H.
Published: August 2013

Prostate cancer (PCa) is the second leading cause of cancer death in men. Current research findings suggest that the androgen receptor (AR) and its signaling pathway contribute significantly to the progression of metastatic PCa. The AR is a ligand activated transcription factor, where androgens such as testosterone (T) and dihydroxytestosterone (DHT) act as the activating ligands. However in many metastatic PCa, the AR functions promiscuously and is constitutively active through multiple mechanisms. Inhibition of enzymes that take part in androgen synthesis or synthesizing antiandrogens that can inhibit the AR are two popular methods of impeding the androgen receptor signaling axis; however, the inhibition of androgen‐independent activated AR function has not yet been fully exploited. This article focuses on the development of emerging novel agents that act at different steps along the androgen‐AR signaling pathway to help improve the poor prognosis of PCa patients. J. Cell. Physiol. 229: 271–276, 2014. © 2013 Wiley Periodicals, Inc.
Measurement of ATP in Single Oocytes: Impact of Maturation and Cumulus Cells on Levels and Consumption
Authors: Dalton Caroline M. , Szabadkai Gyorgy , Carroll John
Published: August 2013

Mitochondria provide the primary source of ATP in the oocyte and early embryo and mitochondrial dysfunction and deficit of mitochondria‐derived ATP has been linked to suboptimal developmental competence. We have undertaken a study of ATP in the maturing mouse oocyte using a novel recombinant FRET based probe, AT1.03. We show that AT1.03 can be successfully used to monitor cytosolic ATP levels in single live oocytes over extended time periods. We find that ATP levels undergo dynamic changes associated with specific maturational events and that oocytes display altered rates of ATP consumption at different stages of maturation. Cumulus enclosed oocytes have a higher ATP level during maturation than denuded oocytes and this can be abolished by inhibition of gap junctional communication between the oocyte and cumulus cells. Our work uses a new approach to shed light on regulation of ATP levels and ATP consumption during oocyte maturation. J. Cell. Physiol. 229: 353–361, 2014. © 2013 The Authors. Journal of Cellular Physiology published by Wiley Periodicals, Inc.
The effects of low levels of light at night upon the endocrine physiology of western scrub‐jays (Aphelocoma californica)
Authors: Schoech Stephan J. , Bowman Reed , Hahn Thomas P. , Goymann Wolfgang , Schwabl Ingrid , Bridge Eli S.
Published: August 2013

Florida scrub‐jays (Aphelocoma coerulescens) in the suburbs breed earlier than jays in native habitat. Amongst the possible factors that influence this advance (e.g., food availability, microclimate, predator regime, etc.), is exposure to artificial lights at night (LAN). LAN could stimulate the reproductive axis of the suburban jays. Alternatively, LAN could inhibit pineal melatonin (MEL), thus removing its inhibitory influence on the reproductive axis. Because Florida scrub‐jays are a threatened species, we used western scrub‐jays (Aphelocoma californica) to investigate the effects of LAN upon reproductive hormones and melatonin. Jays were held under conditions in which the dark‐phase of the light:dark cycle was without illumination and then under low levels of LAN. Under both conditions, birds were exposed first to short‐days (9.5L:14.5D) that were gradually increased to long‐days (14.5L:9.5D). At various times, blood samples were collected during the light part of the cycle to measure reproductive hormones (luteinizing hormone, LH; testosterone, T; and estradiol, E2). Similarly, samples to assess melatonin were collected during the dark. In males, LAN caused a depression in LH levels and levels were ∼4× greater under long‐ than short‐days. In females, there was no effect of LAN or photoperiod upon LH. LAN resulted in depressed T levels in females, although there was no effect on T in males. E2 levels in both sexes were lower under LAN than under an unlighted dark‐phase. Paradoxically, MEL was higher in jays under LAN, and under long‐days. MEL did not differ by sex. LAN disrupted the extraordinarily strong correlation between T and E2 that existed under unlighted nocturnal conditions. Overall, our findings fail to support the hypothesis that LAN stimulates the reproductive axis. Rather, the data demonstrate that LAN tends to inhibit reproductive hormone secretion, although not in a consistent fashion between the sexes. J. Exp. Zool. 319A: 527–538, 2013. © 2013 Wiley Periodicals, Inc.
Caspase 3 in molluscan tissues: Localization and possible function
Authors: Motta Chiara M. , Frezza Vincenzo , Simoniello Palma
Published: August 2013

The presence and localization of caspase 3, a master enzyme in apoptosis, have been analyzed in tissues of four species of Molluscs: the Bivalves Callista chione and Adamussium colbecki and the Gastropods Helix pomatia and Neobuccinum eatoni. Western blotting and immunocytochemical analyses show that a 32 kDa caspase 3 is present in guts, in gill lamellae and in digestive glands during digestion but not in heart tissue or in resting digestive glands. The enzyme is also found in gonads of both sexes but there are significant differences between Bivalves and Gastropods and between male and female germ cells, especially in late stages of differentiation. In particular, caspase 3 is abundant in Bivalves oocytes and in Gastropods spermatozoa but not in Gastropods oocytes; in Callista spermatozoa it appears only after sea water activation. TUNEL staining and PCNA immunolocalization, carried out on C. chione and H. pomatia tissues, suggest that caspase 3 is primarily associated with degenerative processes in gut, digestive gland and early stage germ cells while in gills, oocytes and mature spermatozoa it is primarily correlated with cell function and/or differentiation. J. Exp. Zool. 319A: 548–559, 2013. © 2013 Wiley Periodicals, Inc.
The effects of ionospheric outflow on ICME and SIR driven sawtooth events
Authors: Brambles O. J. , Lotko W. , Zhang B. , Ouellette J. , Lyon J. , Wiltberger M.
Published: August 2013

Magnetosphere sawtooth oscillations have been observed during interplanetary coronal mass ejection (ICME) events, when the solar wind conditions are relatively steady, and during periods when the interplanetary magnetic field (IMF) fluctuates between northward and southward, as during interplanetary stream interaction regions (SIR). The impact of ionospheric outflow on the ICME‐driven 18 April 2002 and SIR‐driven 24 October 2002 sawtooth events is investigated using a multifluid adaptation of the Lyon‐Fedder‐Mobarry global simulation. The mechanisms that generate the sawtooth oscillations are investigated by comparing a baseline simulation without outflow and a simulation that includes an O+ outflow model. The ionospheric outflow is regulated by a statistical relationship between Alfvénic Poynting flux and O+ ion outflow flux. In the baseline simulation for the 18 April 2002 ICME‐driven event, one substorm is observed that is generated by the southward turning of the IMF, after which the magnetosphere‐ionosphere system settles into a quasi‐steady convection mode. When outflow is included, quasi‐periodic substorms are observed suggesting that the sawtooth oscillations are generated internally by the effects of the O+ ions. In contrast, during the 24 October 2002 SIR‐driven event, quasi‐periodic substorms are generated regardless of whether outflow is included or not. For this event, the generation and triggering of the substorms is controlled by the external driving of the solar wind. For both events, when outflow is included, the signatures of the substorms are more intense and are more noticeable across a wider range of local times than in the baseline simulations.
The differences between storms driven by helmet streamer CIRs and storms driven by pseudostreamer CIRs
Authors: Borovsky Joseph E. , Denton Michael H.
Published: August 2013

A corotating interaction region (CIR) is formed when fast coronal hole origin solar wind overtakes slow solar wind and forms a region of compressed plasma and magnetic field. The slow wind upstream of the coronal hole fast wind can be either of helmet streamer origin or pseudostreamer origin. For a collection of 125 CIR‐driven geomagnetic storms, the slow wind ahead of each CIR is examined; for those storm not containing ejecta, each CIR is categorized as a helmet streamer CIR (74 of the 125 storms) or a pseudostreamer CIR (11 of the 125 storms). Separate superposed epoch studies are performed on the two groups to discern the differences between storms driven by pseudostreamer CIRs and those driven by helmet streamer CIRs. A major difference is that pseudostreamer CIR storms tend not to have a calm before the storm, so the outer plasmasphere does not refill before storm onset, and the outer electron radiation belt does not exhibit a pre‐storm decay. The superdense plasma sheet is weaker for pseudostreamer CIR storms, and the dropout of the electron radiation belt is weaker. Pseudostreamer CIR storms and helmet streamer CIR storms tend to be of the same strength as measured by the magnitude of Kp, MBI (midnight boundary index), or Dst.
Oxygen and carbon stable isotopes in coast redwood tree rings respond to spring and summer climate signals
Authors: Johnstone James A. , Roden John S. , Dawson Todd E.
Published: August 2013

Interannual variability in the oxygen and carbon isotope composition of tree ring cellulose was investigated in coast redwood (Sequoia sempervirens) from three sites in coastal Northern California. Middle and late wood samples from annual tree rings were compared to regional climate indices and gridded ocean‐atmosphere fields for the years 1952–2003. The strongest climate‐isotope relationship (r = 0.72) was found with summer (June–September) daily maximum temperature and middle wood δ13, which also responds positively to coastal sea surface temperature and negatively to summer low cloud frequency. Late wood δ18O reflects a balance between 18O‐enriched summer fog drip and depleted summer rainwater, while a combined analysis of late wood δ18O and δ13C revealed sensitivity to the sign of summer precipitation anomalies. Empirical orthogonal function analysis of regional summer climate indices and coast redwood stable isotopes identified multivariate isotopic responses to summer fog and drought that correspond to atmospheric circulation anomalies over the NE Pacific and NW U.S. The presence of regional climate signals in coast redwood stable isotope composition, consistent with known mechanistic processes and prior studies, offers the potential for high‐resolution paleoclimate reconstructions of the California current system from this long‐lived tree species.
Identity Orientation, Organizational Identification, and Leadership Involvement
Authors: Gonzalez Jorge A. , Chakraborty Subhajit
Published: August 2013

The present study relies on theories of authentic and relational leadership, as well as the identity orientation model, to study leadership involvement in volunteer organizations. We propose that self‐expression and social cohesion—the opportunity organizational membership provides people to express who they are and to develop social relationships—are related to organizational identification and leadership involvement. We posit that self‐expression and social cohesion satisfy personal and relational identification motives and increase organizational identification—a form of identification with a collective—which in turn affect leadership involvement. The hypotheses are tested using structural equations modeling using a sample of 210 professional association members, a nonwork sample that reduces the influence of extrinsic rewards on leadership involvement.
Understanding Leadership Through Leadership Understandings
Authors: Stuke Kurt B.
Published: August 2013

In 1992, Margaret Wheatley urged leadership scholars to search for “new ways of understanding” (Wheatley, 1992/2006, p. 160). The search, with some exception, has stalled. Leadership studies remains mired in a philosophical understanding grounded in positivism. Within the current paper, an exploration of how an understanding is informed by its core philosophical assumptions is presented. An alternative framing for understandings is explored through the reconstruction of these same core philosophical assumptions. The benefits of dwelling within the alternative framing are sketched.
Effects of heme oxygenase‐1 on bacterial antigen‐induced articular chondrocyte catabolism in vitro
Authors: Mawatari Taro , Nakamichi Ikuo , Suenaga Eiji , Maloney William J. , Smith Robert L.
Published: August 2013

This study tested the hypothesis that heme oxygenase‐1 (HO‐1) expression counteracts bacterial antigen‐induced catabolic metabolism in human articular chondrocytes. HO‐1 expression was induced in chondrocytes by the iron‐containing porphoryin, hemin. Anti‐catabolic and anti‐apoptotic effects of HO‐1 expression were evaluated following bacterial antigen (lipopolysaccharides, LPS) activation of chondrocytes by quantification of cytokine and cartilage matrix protein expression. Effects of HO‐1 over‐expression on chondrocyte matrix metabolism were evaluated using plasmid‐driven protein synthesis. Hemin increased HO‐1 expression and LPS increased interleukin‐1beta and interleukin‐6 gene and protein expression in chondrocytes. Hemin‐induced HO‐1 decreased LPS‐induced interleukin‐1beta and interleukin‐6 gene and protein expression. Increased HO‐1 expression partially reversed LPS‐suppression of aggrecan and type II collagen gene expression and suppressed LPS‐induced gene expression of IL‐6, inducible nitric oxide synthase (iNOS), matrix metalloproteinases (MMPs), and IL‐1beta. HO‐1 induction was inversely correlated with LPS‐induced chondrocyte apoptosis. HO‐1 over‐expression in chondrocytes decreased matrix protein gene expression. With LPS activation, increased HO‐1 expression decreased chondrocyte catabolism, partially reversed LPS‐dependent inhibition of cartilage matrix protein expression and protected against apoptosis. Without LPS, hemin‐induced HO‐1 and plasmid‐based over‐expression of HO‐1 inhibited cartilage matrix gene expression. The results suggest that elevated HO‐1 expression in chondrocytes is protective of cartilage in inflamed joints but may otherwise suppress matrix turn over. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1943–1949, 2013
Median nerve deformation and displacement in the carpal tunnel during finger motion
Authors: Yoshii Yuichi , Ishii Tomoo , Tung Wen‐Lin , Sakai Shinsuke , Amadio Peter C.
Published: August 2013

The objective of this study was to evaluate the correlations between deformation and displacement of median nerve and flexor tendons during finger motion in the carpal tunnel for both carpal tunnel syndrome (CTS) patients and healthy controls. Sixty‐two wrists of 31 asymptomatic volunteers and fifty‐one wrists of 28 idiopathic CTS patients were evaluated by ultrasound. The displacement of the median nerve and the middle finger flexor digitorum superficialis (FDS) tendon, as well as area, perimeter, aspect ratio of a minimum enclosing rectangle, and circularity of the median nerve were measured in finger extension and flexion positions. Deformation indices were defined as the ratios of indices in finger extension and flexion positions. The correlations between displacement and deformation indices were evaluated. There were significant correlations between nerve palmar–dorsal displacement and deformation indices (p < 0.05). The aspect ratio deformation index showed the strongest correlation to palmar–dorsal displacement of the nerve (−0.572, p < 0.01). This study showed that there is a relationship between median nerve deformation indices and nerve palmar–dorsal displacement in the carpal tunnel. Since the highest correlations were between palmar–dorsal nerve displacement direction and aspect ratio deformation index, these parameters may be helpful to understand the pathophysiology of CTS. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1876–1880, 2013
Understanding the impact of crop and food production on the water environment—using sugar as a model
Authors: Hess Tim , Aldaya Maite , Fawell John , Franceschini Helen , Ober Eric , Schaub Ruediger , Schulze‐Aurich Jochen
Published: August 2013

The availability of fresh water and the quality of aquatic ecosystems are important global concerns, and agriculture plays a major role. Consumers and manufacturers are increasingly sensitive to sustainability issues related to processed food products and drinks. The present study examines the production of sugar from the growing cycle through to processing to the factory gate, and identifies the potential impacts on water scarcity and quality and the ways in which the impact of water use can be minimised. We have reviewed the production phases and processing steps, and how calculations of water use can be complicated, or in some cases how assessments can be relatively straightforward. Finally, we outline several ways that growers and sugar processors are improving the efficiency of water use and reducing environmental impact, and where further advances can be made. This provides a template for the assessment of other crops. © 2013 Society of Chemical Industry
Subwavelength grating Fourier‐transform interferometer array in silicon‐on‐insulator
Authors: Bock Przemek J. , Cheben Pavel , Velasco Aitor V. , Schmid Jens H. , Delâge André , Florjańczyk Mirosław , Lapointe Jean , Xu Dan‐Xia , Vachon Martin , Janz Siegfried , Calvo María L.
Published: August 2013

A planar waveguide Fourier‐transform spectrometer with densely arrayed Mach‐Zehnder interferometers is demonstrated. Subwavelength gratings are used to produce an optical path difference without waveguide bends. The fabricated device comprises of an array of 32 Mach‐Zehnder interferometers, which produce a spatial interferogram without any moving parts, yielding a spectral resolution of 50 pm and a free‐spectral range of 0.78 nm. As a result of similar propagation losses in subwavelength grating waveguides and conventional strip waveguides, loss imbalance is minimized and high interferometic extinction ratio of −25 to −30 dB is obtained. Furthermore, phase and amplitude errors arising from normal fabrication variation are compensated by the spectral retrieval process using calibration measurements.
Investigation of the Competition Between Cell/Surface and Cell/Cell Interactions During Neuronal Cell Culture on a Micro‐Engineered Surface
Authors: Béduer Amélie , Gonzales‐Calvo Inès , Vieu Christophe , Loubinoux Isabelle , Vaysse Laurence
Published: August 2013

To investigate the respective roles of topography and cell/cell interactions in the development of a guided neuronal network on an engineered surface, micropatterned PDMS substrates were generated with different microgrooves geometry and investigated for the influence of cell density on neurite outgrowth and alignment. Through this systematic investigation, using a human neuronal stem cell line, the rules of neuronal network development and guiding could be learned. The results show that when cell density is increased the influence on neuritic outgrowth and alignment is very different for the various grooves geometries. The data emphasized the competition, in neurite development, between physical cues brought by surface topographical features and cell to cell communications. These results can be of particular interest for designing functional neuronal networks with a controlled architecture.
Evaluation of Warfarin Management with International Normalized Ratio Self‐Testing and Online Remote Monitoring and Management Plus Low‐Dose Vitamin K with Genomic Considerations: A Pilot Study
Authors: Bussey Henry I. , Bussey Marie , Bussey‐Smith Kristin L. , Frei Christopher R.
Published: August 2013

Study Objectives

As better international normalized ratio (INR) control and self‐testing reduce events in warfarin‐treated patients, and vitamin K supplementation may improve INR control, our primary objective was to evaluate the effect of a system combining frequent INR self‐testing with online remote monitoring and management (STORM2) and low‐dose vitamin K supplementation on INR control; our secondary objectives were to assess the impact of STORM2 on clinician time and to evaluate the influence of pharmacogenomics on INR stability and warfarin dose after vitamin K supplementation.

Design

Prospective pre‐ and postintervention study.

Setting

Freestanding clinical research center.

Patients

Fifty‐five patients treated with long‐term warfarin therapy who were referred from four anticoagulation clinics and seven medical practices.

Intervention

All patients performed weekly INR self‐testing and received vitamin K 100 µg/day and online anticoagulation management for 1 year.

Measurements and Main Results

INR control and time required for anticoagulation management were assessed, and an analysis of warfarin dosing and INR stability by genetic polymorphism subgroup (vitamin K epoxide reductase complex 1 [VKORC1] and cytochrome P450 2C9 isoenzyme) was performed; vitamin K product content was also analyzed. The percentage of time that the INR is within the time in therapeutic range (TTR) improved from 56% before the intervention to 81% after the intervention (p<0.0001), and time spent at extreme INR values of lower than 1.5 or higher than 5 was reduced from 3.1% to 0.4% (p=0.01). Clinician time was less than 10 minutes per four patient visits per month. Genetic polymorphisms did not correlate with INR stability or the increase in warfarin dose after vitamin K supplementation. The content of the vitamin K product, however, was only 34–76% of the labeled amount. Patients with the GG VKORC1 genotype required a higher warfarin dose than predicted by the genomic‐based dosing chart in the warfarin package insert.

Conclusion

The 25% point improvement in TTR with STORM2 is a greater improvement than reported previously with other efforts to improve TTR. STORM2 required a minimum amount of clinician time. Pharmacogenomics were not predictive of improved INR control or the magnitude of the warfarin dose after vitamin K supplementation, although the content of the product was unreliable. Patients with the GG VKORC1 genotype required a higher warfarin dose than predicted by the product information. The potential clinical impact of improved INR control with this method warrants comparisons with conventionally managed warfarin and with the new oral anticoagulants.
Designing cooperativity into the designed protein Top7
Authors: Yadahalli Shilpa , Gosavi Shachi
Published: August 2013

The topology of the designed protein Top7 is not found in natural proteins. Top7 shows signatures of non‐cooperative folding in both experimental studies and computer simulations. In particular, molecular dynamics of coarse‐grained structure‐based models of Top7 show a well‐populated C‐terminal folding‐intermediate. Since most similarly sized globular proteins are cooperative folders, the non‐natural topology of Top7 has been suggested as a reason for its non‐cooperative folding. Here, we computationally examine the folding of Top7 with the intent of making it cooperative. We find that its folding cooperativity can be increased in two ways: (a) Optimization of packing interactions in the N‐terminal half of the protein enables further folding of the C‐terminal intermediate. (b) Reduction in the packing density of the C‐terminal region destabilizes the intermediate. In practice, these strategies are implemented in our Top7 model through modifications to the contact‐map. These modifications do not alter the topology of Top7 but result in cooperative folding. Amino‐acid mutations that mimic these modifications also lead to a significant increase in folding cooperativity. Finally, we devise a method to randomize the sizes of amino‐acids within the same topology, and confirm that the structure of Top7 makes its folding sensitive to packing interactions. In contrast, the ribosomal protein S6, which has secondary structure similar to Top7, has folding which is much less sensitive to packing perturbations. Thus, it should be possible to make a sequence fold cooperatively to the structure of Top7, but to do so its side‐chain packing needs to be carefully designed. Proteins 2014; 82:364–374. © 2013 Wiley Periodicals, Inc.
Predicting protein–DNA interactions by full search computational docking
Authors: Roberts Victoria A. , Pique Michael E. , Ten Eyck Lynn F. , Li Sheng
Published: August 2013

Protein–DNA interactions are essential for many biological processes. X‐ray crystallography can provide high‐resolution structures, but protein‐DNA complexes are difficult to crystallize and typically contain only small DNA fragments. Thus, there is a need for computational methods that can provide useful predictions to give insights into mechanisms and guide the design of new experiments. We used the program DOT, which performs an exhaustive, rigid‐body search between two macromolecules, to investigate four diverse protein–DNA interactions. Here, we compare our computational results with subsequent experimental data on related systems. In all cases, the experimental data strongly supported our structural hypotheses from the docking calculations: a mechanism for weak, nonsequence‐specific DNA binding by a transcription factor, a large DNA‐binding footprint on the surface of the DNA‐repair enzyme uracil‐DNA glycosylase (UNG), viral and host DNA‐binding sites on the catalytic domain of HIV integrase, and a three‐DNA‐contact model of the linker histone bound to the nucleosome. In the case of UNG, the experimental design was based on the DNA‐binding surface found by docking, rather than the much smaller surface observed in the crystallographic structure. These comparisons demonstrate that the DOT electrostatic energy gives a good representation of the distinctive electrostatic properties of DNA and DNA‐binding proteins. The large, favourably ranked clusters resulting from the dockings identify active sites, map out large DNA‐binding sites, and reveal multiple DNA contacts with a protein. Thus, computational docking can not only help to identify protein–DNA interactions in the absence of a crystal structure, but also expand structural understanding beyond known crystallographic structures. Proteins 2013; 81:2106–2118. © 2013 Wiley Periodicals, Inc.
Spatially resolved diagnostic methods for polymer electrolyte fuel cells: a review
Authors: Kalyvas Christos , Kucernak Anthony , Brett Dan , Hinds Gareth , Atkins Steve , Brandon Nigel
Published: August 2013

This review discusses the range of diagnostic techniques reported in the literature for spatially resolved studies of operating fuel cells. In situ diagnostic techniques continue to reveal more about the working of fuel cells and in so doing allow for improved cell hardware design, materials selection, and choice of operating conditions to realize advanced electrochemical performance and longevity. These techniques also allow us to scrutinize the validity of conventional bulk electrical measurements and develop detailed models of fuel cell operation.

This article is categorized under:

Fuel Cells and Hydrogen > Science and Materials
Computational fluid dynamics for concentrating solar power systems
Authors: Ho Clifford K.
Published: August 2013

Computational fluid dynamics (CFD) can be used to better understand complex processes and to improve designs and system performance in concentrating solar power (CSP) applications. Applications presented in this paper include CFD simulations for collectors, thermal receivers, and thermal storage technologies. CFD simulations of wind flow around collectors such as parabolic troughs and heliostats have been used to determine wind loads, which impact the design and requirements of the support structure. Simulations of the heat transfer and heat loss in solar thermal receivers have been performed to identify designs that optimize thermal efficiency, and to better understand radiative, convective, and conductive heat losses. CFD models have also been developed to understand processes in thermal storage systems, including mixing in thermoclines, heat transfer in solid media, and melting and solidification processes in phase‐change materials. Researchers have generally concluded that CFD modeling is a useful and cost‐effective tool to understand processes and improve designs for CSP systems.

This article is categorized under:

Concentrating Solar Power > Science and Materials

Concentrating Solar Power > Systems and Infrastructure
Beliefs About Faith and Work: Development and Validation of Honoring God and Prosperity Gospel Scales
Authors: Neubert Mitchell J. , Dougherty Kevin D. , Park Jerry Z. , Griebel Jenna
Published: August 2013

Disputes over the connection between beliefs and behaviors, coupled with the relative paucity of survey measures of specific theological beliefs related to work and its association with financial success, motivated the development of two beliefs scales: beliefs about work as a means to honor God and beliefs about God promising prosperity for believers. Analyses demonstrated these two scales to be distinct from one another and reliable. Using a national sample of over 1,000 working adults, we assessed the relationship of the specific belief scales to Lynn et al.'s (J Bus Ethics 85(2):227–241, 2009 ) faith at work scale, Mirels and Garrett's (J Consul Clin Psychol 36(1):40–44, 1971) Protestant Work Ethic scale, two personality scales (Conscientiousness and Neuroticism), entrepreneurial behavior, helping behavior, and religious tradition. Results indicate convergent and divergent validity and demonstrate the potential utility of these beliefs scales for predicting work-related attitudes and practices.
Grappling with “That Awkward Sex Stuff”: Encountering themes of sexual violence in the formal curriculum
Authors: Engebretson Kathryn E.
Published: August 2013

This qualitative study examines the discourses that 25 preservice secondary social studies teachers create surrounding whether to include themes of sexual violence in the formal curriculum. As part of their first methods course, the participants read Harriet Jacobs's 1861 memoir Incidents in the Life of a Slave Girl and planned a unit using it as the central text. Using discourse analysis and feminist poststructural theory, the author finds that no singular discourse prevails but that the participants struggled with whether to include or exclude historical accounts of sexual violence in the formal curriculum. Implications for researchers, teacher educators, and teachers are discussed.
Risk Factors for Discharge to an Acute Care Hospital From Inpatient Rehabilitation Among Stroke Patients
Authors: Roberts Pamela S. , DiVita Margaret A. , Riggs Richard V. , Niewczyk Paulette , Bergquist Brittany , Granger Carl V.
Published: August 2013

Objective

To identify medical and functional health risk factors for being discharged directly to an acute‐care hospital from an inpatient rehabilitation facility among patients who have had a stroke.

Design

Retrospective cohort study.

Setting

Academic medical center.

Participants

A total of 783 patients with a primary diagnosis of stroke seen from 2008 to 2012; 60 were discharged directly to an acute‐care hospital and 723 were discharged to other settings, including community and other institutional settings.

Methods or Interventions

Logistic regression analysis.

Main Outcome Measurements

Direct discharge to an acute care hospital compared with other discharge settings from the inpatient rehabilitation unit.

Results

No significant differences in demographic characteristics were found between the 2 groups. The adjusted logistic regression model revealed 2 significant risk factors for being discharged to an acute care hospital: admission motor Functional Independence Measure total score (odds ratio 0.97, 95% confidence interval 0.95‐0.99) and enteral feeding at admission (odds ratio 2.87, 95% confidence interval 1.34‐6.13). The presence of a Centers for Medicare and Medicaid−tiered comorbidity trended toward significance.

Conclusion

Based on this research, we identified specific medical and functional health risk factors in the stroke population that affect the rate of discharge to an acute‐care hospital. With active medical and functional management, early identification of these critical components may lead to the prevention of stroke patients from being discharged to an acute‐care hospital from the inpatient rehabilitation setting.
Binary sources of loess on the Chinese Loess Plateau revealed by U–Pb ages of zircon
Authors: Che Xudong , Li Gaojun
Published: August 2013

The age distribution of detrital zircon has been used to trace sediment sources. Existing datasets show great similarity of zircon ages between the loess on the Chinese Loess Plateau (CLP) and the sediments from the North Tibetan Plateau (NTP), implying that eolian dust is delivered from the NTP to the CLP by westerly winds or via the Yellow River. However, NTP dust can also be transported by northwesterly winds from the Alxa arid lands (AALs), where materials are received from both the NTP and the Gobi Altay Mountains (GAMs). Here we report U–Pb zircon ages for AALs sands and NTP and CLP loess. The results show that the zircons in the AALs are mixed from NTP and GAMs zircons. NTP loess is mainly derived from local sources. Mixing of materials from the NTP and GAMs defines the zircon ages of the loess on the CLP better than the pure NTP source. No temporal and spatial heterogeneities of zircon ages have been observed for the loess on the CLP, which suggests that the well-mixed materials in the AALs likely have an eolian source.
Changes in the source of nutrients associated with oceanographic dynamics offshore southern Chile (41°S) over the last 25,000 years
Authors: Verleye Thomas J. , Martinez Philippe , Robinson Rebecca S. , Louwye Stephen
Published: August 2013

In order to obtain a better knowledge of past oceanographic variability offshore southern Chile, this study reappraises the changes in the sources of nutrients over the last 25 ka based on a detailed comparison of previously published nitrogen isotope and microfossil records (dinoflagellate cysts, coccoliths and diatoms) from ODP Site 1233 (41°S). Our findings support the main conclusions of Martinez et al. (2006) in the sense that both the Subantarctic Surface Water and the Gunther Undercurrent are potential sources for the recorded late Quaternary sedimentary δ15N signatures at Site 1233, with variable contributions of both sources during different time periods. This study indicates that Subantarctic Surface Water forms the main source for nutrients during the last glacial maximum (25–18.6 cal ka BP), the first part of the deglaciation (18.6–15.7 cal ka BP) and the Holocene (9.8 cal ka BP until present). An increased contribution of Equatorial Subsurface Water as a source of nutrients to the photic zone offshore southern Chile is observed between 14.4 and 9.8 cal ka BP, which is indicative for upwelling conditions at least after 13.2 cal ka BP as indicated by the microfossil data.
Feasibility of an Interdisciplinary Early Intervention for Patients with Low Levels of Responsiveness Following an Acquired Brain Injury
Authors: Seeto Treena , Kuys Suzanne , Budden Cassandra , Griffin Erin , Kajewski Haylee , McPhail Steven
Published: August 2013

There is a scarcity of research investigating interdisciplinary early rehabilitation intervention models for people with low levels of responsiveness following acquired brain injury. This is particularly problematic for service models in acute hospital settings where early rehabilitation of such patients may be assigned a low priority in comparison to other competing demands. This pilot study investigated the feasibility of implementing an interdisciplinary early rehabilitation intervention in an acute neurosciences ward within existing staffing, and describes clinical changes among intervention participants. A prospective longitudinal study, with a matched historical control (individually matched by Glasgow Coma Scale) was undertaken. Prospective intervention participants (n= 13) received up to twice-weekly interdisciplinary intervention in addition to usual care. Matched historical controls (n= 13) received only usual care. Implementing an interdisciplinary early intervention proved feasible in this acute care setting. Significant improvement (alpha = .05) among the patients receiving the interdisciplinary intervention was observed across all clinical outcomes, including: Coma Recovery Scale-Revised, Glasgow Coma Scale, Mental Status Questionnaire, Royal Brisbane Hospital Outcome Measure for Swallowing, selected subtests of the Functional Independence Measure, Acquired Brain Injury Physiotherapy Assessment and the Clinical Outcomes Variable Scale. A future randomised clinical trial is warranted.
Which Factors Determine Who is Referred for Community Rehabilitation Following Traumatic Brain Injury?
Authors: Ta'eed Gillian , Skilbeck Clive E. , Slatyer Mark
Published: August 2013

Primary objective: To investigate which variables predict referral for rehabilitation in the participants of the Tasmanian Neurotrauma Register (TNTR), a large (N = 1226) prospective population-based study of adult traumatic brain injury (TBI) in southern Tasmania.

Method: Over a 3-year period, only 54 TBI patients were referred by hospital or local health services for public community rehabilitation, with 121 referred by TNTR research assistants. A further 247 accessed private rehabilitation and 804 received no rehabilitation. These four groups were compared on a range of variables to identify which factors determine referral.

Results: Those referred by hospital or community services and those receiving private rehabilitation had more severe TBI (p < .001), greater disability (p < .001) and were more likely to have been hospitalised post-injury (p < .001). The TNTR-referred group reported more post-concussion symptoms (PCS; p < .001), anxiety (p < .001) and depression (p < .001). TNTR-referral was more likely (p < .001) following assault, compared with other causes of injury. Sixteen per cent of those not referred for rehabilitation had suffered moderate or severe TBI.

Conclusions: These results indicate that no recognised pathway existed for non-hospitalised TBI patients to access public rehabilitation, even if they were reporting high levels of PCS and psychological distress. Furthermore, routine follow-up to assess rehabilitation needs was not occurring in Tasmania, even for some with moderate and severe TBI.
Protein and amino acid digestion characteristics of two forms of preserved lucerne forage fed to mature horses
Authors: Stowers N.L. , Waldron L.A. , Thomas D.G. , Pryor I.D.
Published: August 2013

A trial was conducted, using 12 mature thoroughbred horses in a cross-over design, to compare the protein and amino acid digestibility of dry lucerne chaff (LC) against a controlled fermented lucerne (CFL) product (HNF Fiber®; Fiber Fresh Feeds Ltd, Reporoa, New Zealand). Crude protein levels were higher in CFL compared to LC, and when individual amino acids were analysed, the majority (88%) of these were also higher. Crude protein digestibility was significantly (18%) higher in CFL diets (P < 0.001) compared to LC. Significant differences (P < 0.05) were seen in individual amino acid digestibility in favour of the CFL diet for lysine (24%) and methionine (30%), as well as threonine, histidine, tyrosine, leucine, isoleucine, valine, alanine, proline, serine and aspartamine. Although amino acid requirements in horses are still poorly defined, the higher availability of amino acids in CFL compared to LC should be taken into account when formulating horse diets including these feedstuffs.
Preliminary investigation of the influence of long-term dietary isoflavone intake on reproductive tract histology and sex steroid receptor expression in female domestic cats (Felis catus)
Authors: Whitehouse-Tedd Katherine M. , Cave Nicholas J. , Roe Wendi D. , Ugarte Claudia E. , Thomas David G.
Published: August 2013

Genistein and daidzein are isoflavones which are reported to influence the reproductive system in a variety of mammalian species. This pilot study aimed to determine if dietary isoflavones could potentially influence reproductive tract histology or morphology in domestic cats, when consumed during the postnatal development period. Cats were maintained on either treatment (150 µg/g DM genistein and 150 µg/g DM daidzein, n = 4) or control (isoflavone free, n = 8) diets from weaning, up to 414 (±17.2) days post-weaning. Reproductive tissues were collected during routine ovario-hysterectomy and examined for histology and sex steroid receptor expression. Findings indicate that these dietary isoflavones influenced the expression of oestrogen receptor α (ERα) and oestrogen receptor β (ERβ), and progesterone receptor in feline reproductive tissues. One cat in the treatment group developed suppurative endometritis, but no evidence of uterotrophic or histological changes were found in any other cats. The potential to alter expression of hormone receptors in the reproductive tract of domestic cats exposed to genistein and daidzein warrants further investigation.
Leisure Type, Leisure Satisfaction and Adolescents’ Psychological Wellbeing
Authors: Shin Kyulee , You Sukkyung
Published: August 2013

This study examined the impact of leisure type on leisure satisfaction, along with its subsequent effects on adolescents’ psychological wellbeing, using a longitudinal sample of 3,449 Korean adolescents at two time points (2003 and 2004). The results indicated that the type of leisure activity (measured in 10th grade) had differential effects on students’ long-term psychological wellbeing (measured in 11th grade) according to sex. Specifically, for male students, only active leisure (i.e., sports activities) had a positive effect on leisure satisfaction. By contrast, for female students, although active leisure activities exerted positive effects on leisure satisfaction, passive leisure (i.e., sedentary activities) and social leisure (i.e., spending time with friends) had a negative impact on students’ leisure satisfaction. For both male and female students, leisure satisfaction had longitudinal effects on their psychological wellbeing, with increasing life satisfaction and decreasing stress.
REMARKS ON THE UNIVALENCE CRITERION OF PASCU AND PASCU
Authors: BHARANEDHAR VAIDHYANATHAN , PONNUSAMY SAMINATHAN
Published: August 2013

We consider a recent work of Pascu and Pascu [‘Neighbourhoods of univalent functions’,Bull. Aust. Math. Soc. 83(2) (2011), 210–219] and rectify an error that appears in their work. In addition, we study certain analogous results for sense-preserving harmonic mappings in the unit disc$\vert z\vert \lt 1$. As a corollary to this result, we derive a coefficient condition for a sense-preserving harmonic mapping to be univalent in$\vert z\vert \lt 1$.