bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing the importance of burrows through behavioral observations of Parastacus brasiliensis, a Neotropical burrowing crayfish (Crustacea), in laboratory conditions
Authors: Palaoro Alexandre V , Dalosto Marcelo M , Coutinho Cadidja , Santos Sandro
Published: August 2013

Background

Crayfish from the Neotropical region comprise a unique group among crustaceans. Their burrowing habits have severe consequences for many ecological, morphological, and behavioral traits. Although they are all considered true burrowers, the degree of these adaptations and their relationships to the behavioral repertoires of these crustaceans have been discussed for a long time, although with no consensus.

Results

To address this situation, we performed behavioral observations of Parastacus brasiliensis in a laboratory environment. Animals (n = 7) were isolated and acclimated in experimental aquaria according to their size (two large and five smaller aquaria) and observed for seven days at four different times of the day (twice during the day and twice at night). Their behaviors were qualified and quantified. The time spent inside and outside the burrow was also observed and analyzed with a t test for paired samples. Their circadian activity was analyzed using Rayleigh's Z test. Animals spent 54.9% of the time hiding within the burrow and also remained longer in it during the day than at night. They spent more time active outside the burrow during the night.

Conclusions

These results suggest that these crayfish are nocturnal and are definitely not a part of the lotic species group. This species appears to be closely associated with its burrow but can exhibit considerable activity outside of it and can therefore be classified as a secondary burrower. Although this is a laboratory study, the results may stimulate further studies on the importance of burrows to these animals and provide basic background information for new studies on these cryptic crustaceans.
Synthesis and biological evaluation of novel benzyl piperazine derivatives of 5-(5-nitroaryl)-1,3,4-thiadiazoles as Anti-Helicobacter pylo ri agents
Authors: Mohammadhosseini Negar , Saniee Parastoo , Ghamaripour Ameneh , Aryapour Hassan , Afshar Farzaneh , Edraki Najmeh , Siavoshi Farideh , Foroumadi Alireza , Shafiee Abbas
Published: August 2013

Background and the purpose of the study

Helicobacter pylori is recognized as the main cause of gastritis and gastroduodenal ulcers and classified as class 1 carcinogen pathogen. Different 1,3,4-thiadiazole derivatives bearing 5-nitroaryl moiety have been shown considerable anti- H. pylori activity. In attempt to find new and potent derivatives of described scaffold, a new series of 1-(substituted benzyl)-4-(5-(5-nitroaryl-2-yl)-1,3,4-thiadiazol-2-yl)piperazine derivatives were synthesized and evaluated against three metronidazole-resistant isolates of H. pylori using paper disk diffusion bioassay test.

Methods

The title compounds were prepared through the reaction of 1-(5-(5-nitroaryl-2-yl)-1,3,4-thiadiazol-2-yl) piperazine 5a-b and substituted benzyl chloride in DMF. The inhibitory activity of the new derivatives 6a-q against three metronidazole-resistant isolates of H. pylori was evaluated by the disc diffusion method and compared with the commercially available standard drug metronidazole.

Results and discussion

The results of SAR study indicated that the potency and anti-H. pylori activity profile of synthesized derivatives is mainly attributed to the substituted nitroaryl moiety at the C-5 position of 1,3,4-thiadiazole ring. Most of 1,3,4-thiadiazole derivatives bearing 5-nitrofuran moiety at C-5 position of central thiadiazole ring, demonstrated more promising anti-H. pylori than the 5-nitrothiophen counterpart.

Conclusion

The most potent nitrofuran derivative containing 3-methoxybenzyl piperazine pendant at the C-2 position of 1,3,4-thiadiazole ring (compound 6i), demonstrated strong anti-H. pylori potential at studied concentrations 100-25 μg/disk (IZD > 20 mm) against all studied metronidazole- resistant isolates of H. pylori.
Combi-protein coated microcrystals of lipases for production of biodiesel from oil from spent coffee grounds
Authors: Banerjee Aditi , Singh Veena , Solanki Kusum , Mukherjee Joyeeta , Gupta Munishwar Nath
Published: August 2013

Background

Replacing chemical catalysts with biocatalysts is a widely recognized goal of white biotechnology. For biocatalytic processes requiring low water containing media, enzymes for example commercial preparations of lipases, show low catalytic efficiencies. Some high activity preparations for addressing this concern have been described. Protein coated microcrystals (PCMC) constitute one such preparation. The present work describes a Combi-PCMC for synthesis of biodiesel from the oil extracted from spent coffee grounds.

Results

Different lipases were screened for biodiesel synthesis from crude coffee oil out of which Novozym 435 gave the best conversion of 60% in 4 h. Optimization of reaction conditions i.e. % water, temperature and purification of coffee oil further enhanced conversion upto 88% in 24 h. A mixture of Novozym 435 and a cheap commercially available 1,3-specific lipase RMIM (from Mucor miehei) was used in different ratios and 1:1 was found to be the best trade-off between conversion and cost. The commercial preparations then were replaced by a novel biocatalyst design called Combi-Protein coated microcrystals (Combi-PCMC) wherein CAL B and Palatase were co-immobilized with K2SO4 as the core and this performed equivalent to the commercial preparations giving 83% conversion in 48 h.

Conclusion

Coffee oil extracted from spent coffee grounds could be used for the synthesis of biodiesel by using appropriate commercial preparations of lipases. The expensive commercially immobilized preparations can also be replaced by a simpler and inexpensive immobilization design called combi-PCMC which synergizes the catalytic action of a nonspecific lipase CAL B and a free form of 1,3-specific lipase from Mucor miehei.
Effects of creep feeding and supplemental glutamine or glutamine plus glutamate (Aminogut) on pre- and post-weaning growth performance and intestinal health of piglets
Authors: Cabrera Rafael A , Usry James L , Arrellano Consuelo , Nogueira Eduardo T , Kutschenko Marianne , Moeser Adam J , Odle Jack
Published: August 2013

Background

Creep feeding is used to stimulate piglet post-weaning feed consumption. L-Glutamine (GLN) is an important source of fuel for intestinal epithelial cells. The objective of this study was to determine the impact of creep feeding and adding GLN or AminoGut (AG; containing glutamine + glutamate) to pre- and post-weaning diets on pig performance and intestinal health. Litters (N = 120) were allotted to four treatments during 14–21 d of lactation: 1) No creep feed (NC, n = 45); 2) creep fed control diet (CFCD, n = 45); 3) creep fed 1% GLN (CFGLN, n = 15); 4) creep fed .88% AG (CFAG, n = 15). After weaning, the NC and CFCD groups were sub-divided into three groups (n = 15 each), receiving either a control nursery diet (NC-CD, CFCD-CD) or a diet supplemented with either GLN (NC-GLN, CFCD-GLN) or with AG (NC-AG, CFCD-AG). Litters that were creep fed with diets containing GLN or AG also were supplemented with those amino acids in the nursery diets (CFGLN-GLN, CFAG-AG). Glutamine was added at 1% in all three post-weaning diet phases and AG was added at .88% in phase 1 and 2 and at .66% in phase 3.

Results

Feed conversion (feed/gain) showed means among treatment means close to significance (P = 0.056) and Tukey’s test for pairwise mean comparisons showed that Pigs in the CFGLN-GLN group had the best feed conversion (feed/gain) in the first three-week period post-weaning, exceeding (P = 0.044) controls (CFCD-CD) by 34%. The NC-AG group had (P = 0.02) the greatest feed intake in the last three week of the study, exceeding controls (CFCD-CD) by 12%. CFGLN-GLN, CFCD-GLN and sow reared (SR) pigs had the greatest (P = 0.049) villi height exceeding the CFCD-AG group by 18%, 20% and 19% respectively. The CFAG-AG group had the deepest (P = 0.001) crypts among all treatments. CFGLN-GLN, CFCD-GLN and SR groups had the greatest (P = 0.001) number of cells proliferating (PCNA) exceeding those in the NC-CD group by 43%, 54% and 63% respectively. Sow reared pigs showed the greatest (P = 0.001) intestinal absorption capacity for xylose and mannitol.

Conclusion

Supplementation of creep feed and nursery diets with GLN and/or AminoGut in the first three week improved feed conversion possibly due to improved intestinal health.
Neuropathology of brain and spinal malformations in a case of monosomy 1p36
Authors: Shiba Naoko , Daza Ray AM , Shaffer Lisa G , Barkovich A James , Dobyns William B , Hevner Robert F
Published: August 2013

Monosomy 1p36 is the most common subtelomeric chromosomal deletion linked to mental retardation and seizures. Neuroimaging studies suggest that monosomy 1p36 is associated with brain malformations including polymicrogyria and nodular heterotopia, but the histopathology of these lesions is unknown. Here we present postmortem neuropathological findings from a 10 year-old girl with monosomy 1p36, who died of respiratory complications. The findings included micrencephaly, periventricular nodular heterotopia in occipitotemporal lobes, cortical dysgenesis resembling polymicrogyria in dorsolateral frontal lobes, hippocampal malrotation, callosal hypoplasia, superiorly rotated cerebellum with small vermis, and lumbosacral hydromyelia. The abnormal cortex exhibited “festooned” (undulating) supragranular layers, but no significant fusion of the molecular layer. Deletion mapping demonstrated single copy loss of a contiguous 1p36 terminal region encompassing many important neurodevelopmental genes, among them four HES genes implicated in regulating neural stem cell differentiation, and TP73, a monoallelically expressed gene. Our results suggest that brain and spinal malformations in monosomy 1p36 may be more extensive than previously recognized, and may depend on the parental origin of deleted genes. More broadly, our results suggest that specific genetic disorders may cause distinct forms of cortical dysgenesis.
Characterization of erythrose reductases from filamentous fungi
Authors: Jovanović Birgit , Mach Robert L , Mach-Aigner Astrid R
Published: August 2013

Proteins with putative erythrose reductase activity have been identified in the filamentous fungi Trichoderma reesei, Aspergillus niger, and Fusarium graminearum by in silico analysis. The proteins found in T. reesei and A. niger had earlier been characterized as glycerol dehydrogenase and aldehyde reductase, respectively. Corresponding genes from all three fungi were cloned, heterologously expressed in Escherichia coli, and purified. Subsequently, they were used to establish optimal enzyme assay conditions. All three enzymes strictly require NADPH as cofactor, whereas with NADH no activity could be observed. The enzymatic characterization of the three enzymes using ten substrates revealed high substrate specificity and activity with D-erythrose and D-threose. The enzymes from T. reesei and A. niger herein showed comparable activities, whereas the one from F. graminearum reached only about a tenth of it for all tested substrates. In order to proof in vivo the proposed enzyme function, we overexpressed the erythrose reductase-encoding gene in T. reesei. An increased production of erythritol by the recombinant strain compared to the parental strain could be detected.
Composting of selected organic wastes from peri-urban areas of Harare, Zimbabwe
Authors: Mhindu Rangarirayi L , Wuta Menas , Ngorima Esther
Published: August 2013

Background

The composting process of peri-urban household wastes, changes that occur during composting, and the properties of the composting products that are of importance for use as soil amendments were studied. Seven different composting mixtures were made in large piles consisting of fallen tree leaves and fresh vegetable leaves mixed with grass or maize straw (0%, 10%, 30% and 50% w/w), wastes common in peri-urban areas of Harare.

Results

The highest temperature peaks of the mixtures with 0% and 10% straw were in the range of 68°C to 72°C. Mixtures with 30% straw had temperature peaks of 50°C (maize) and 52°C (grass). The mixture with 50% grass straw reached a peak of 50°C, while the corresponding mixture with maize straw did not reach thermophilic temperatures. pH ranged from between 6.2 and 6.8 before composting to between 7.4 and 7.8 after composting. The ammonium concentration peaked at various times but declined to negligible concentrations at day 140. The concentration of nitrates increased with composting up to day 97 and decreased gradually thereafter. There was a general increase in nitrogen concentration from 0.9% to 2.3% as composting progressed. Decreases in organic C% and C/N ratio with composting were also observed, signifying mass loss.

Conclusion

The results of this study indicated that household wastes with 50% straw or less can be composted but with measures being taken to achieve temperatures greater than 55°C for at least 3 days to destroy weed seeds and pathogens. The composts with 30% straw mixture had the greatest potential as a soil amendment in peri-urban areas of Harare as they effectively reduced nitrogen losses.
Seismic data analysis by adaptive sparse time-frequency decomposition
Authors: Sattari Hamid , Gholami Ali , Siahkoohi Hamid R.
Published: August 2013

The variation of frequency content of a seismic trace with time carries information about the properties of the subsurface reflectivity sequence. Time-frequency (TF) analysis is a significant tool to extract such information for seismostratigraphic interpretation purposes. However, several TF transforms have been reported in the literature; higher resolution and sensitivity to local changes of the signal have always mattered. We have developed an adaptive high-resolution TF transform that is performed in two sequential steps: First, the window length is adaptively determined for each sample of the signal such that it leads to maximum compactness of energy in the resulting TF plane. Second, the generated nonstationary windows are used to inversely decompose the signal under study via a convex constrained sparse optimization, where a mixed norm of the TF coefficients is minimized subject to invertibility of the transform. Later on, the optimized transform is used as an efficient tool for seismic data analysis such as thin-bed characterization and thin-bedded gas reservoir detection. In the case of gas reservoir detection, based on amplitude versus offset analysis in the TF domain, a simple new method called the difference section was evaluated. The results of various numerical examples from synthetic and field data revealed a remarkable performance of the proposed method compared with the state-of-the-art TF transforms.
The PACAP-Regulated Gene Selenoprotein T Is Abundantly Expressed in Mouse and Human β-Cells and Its Targeted Inactivation Impairs Glucose Tolerance
Authors: Prevost Gaëtan , Arabo Arnaud , Jian Long , Quelennec Eddy , Cartier Dorthe , Hassan Sahar , Falluel-Morel Anthony , Tanguy Yannick , Gargani Sophia , Lihrmann Isabelle , Kerr-Conte Julie , Lefebvre Hervé , Pattou François , Anouar Youssef
Published: August 2013

Selenoproteins are involved in the regulation of redox status, which affects several cellular processes, including cell survival and homeostasis. Considerable interest has arisen recently concerning the role of selenoproteins in the regulation of glucose metabolism. Here, we found that selenoprotein T (SelT), a new thioredoxin-like protein of the endoplasmic reticulum, is present at high levels in human and mouse pancreas as revealed by immunofluorescence and quantitative PCR. Confocal immunohistochemistry studies revealed that SelT is mostly confined to insulin- and somatostatin-producing cells in mouse and human islets. To elucidate the role of SelT in β-cells, we generated, using a Cre-Lox strategy, a conditional pancreatic β-cell SelT-knockout C57BL/6J mice (SelT-insKO) in which SelT gene disruption is under the control of the rat insulin promoter Cre gene. Glucose administration revealed that male SelT-insKO mice display impaired glucose tolerance. Although insulin sensitivity was not modified in the mutant mice, the ratio of glucose to insulin was significantly higher in the SelT-insKO mice compared with wild-type littermates, pointing to a deficit in insulin production/secretion in mutant mice. In addition, morphometric analysis showed that islets from SelT-insKO mice were smaller and that their number was significantly increased compared with islets from their wild-type littermates. Finally, we found that SelT is up-regulated by pituitary adenylate cyclase-activating polypeptide (PACAP) in β-pancreatic cells and that SelT could act by facilitating a feed-forward mechanism to potentiate insulin secretion induced by the neuropeptide. Our findings are the first to show that the PACAP-regulated SelT is localized in pancreatic β- and δ-cells and is involved in the control of glucose homeostasis.
Growth Hormone Is Necessary for the p53-Mediated, Obesity-Induced Insulin Resistance in Male C57BL/6J × CBA Mice
Authors: Bogazzi Fausto , Raggi Francesco , Russo Dania , Bohlooly-Y Mohammad , Sardella Chiara , Urbani Claudio , Lombardi Martina , Manetti Luca , Lupi Isabella , Tornell Jan , Martino Enio
Published: August 2013

Insulin resistance is a key marker of both obesity and GH excess. The purpose of the study was to assess the role of GH on p53-mediated insulin resistance of male mice with obesity due to a high-fat diet. C57BL/6J × CBA male mice fed on a high-fat diet (Obe) were studied; male mice fed a normal diet (Lean) or transgenic mice for bovine GH under the same genetic background (Acro) served as controls. The convergence of p53 and GH pathways was evaluated by Western blot. Obe mice had insulin resistance, which was sustained by a selective increased expression of p53 in adipose tissue. Normal insulin sensitivity was restored, and adipose p53 expression normalized when the GH pathway was blocked. Only the adipose p53 expression was sensitive to the GH blockage, which occurred through the p38 pathway. Adipose tissue of Obe mice had a coordinate overexpression of suppressors of cytokine signal 1–3 and signal transducers and activators of transcription-1, -3, and -5b, not different from that of Acro mice, suggesting an increased sensitivity of adipose tissue to GH. On the contrary, Lean mice were unaffected by changes of GH action. GH seems to be necessary for the increased adipose p53 expression and for insulin resistance of obese mice.
Characterization of the Gonadotropin Releasing Hormone Receptor (GnRHR) Expression and Activity in the Female Mouse Ovary
Authors: Torrealday Saioa , Lalioti Maria D. , Guzeloglu-Kayisli Ozlem , Seli Emre
Published: August 2013

GnRH agonists (GnRHa) are increasingly used for fertility preservation in women undergoing gonadotoxic chemotherapy. However, the protective mechanisms of action for these compounds have not yet been elucidated. In this study, we aimed to determine whether GnRHa have a direct effect on ovarian granulosa cells. GnRH receptor (GnRHR) expression was determined in mouse somatic and gonadal tissues including granulosa/cumulus cells and oocytes using quantitative RT-PCR and immunohistochemistry. Granulosa cells were isolated from mouse ovaries primed with pregnant mare serum gonadotropin. Response to GnRHa in cultured granulosa cells was assessed by determining the increase of intracellular cAMP and by assessing phosphorylation of downstream mediators of GnRH signaling: ERK and p38. To measure intracellular cAMP in our system, the cells were transfected with a cAMP-responsive luciferase reporter plasmid and stimulated with GnRHa. For all experiments, pituitary tissue and/or the αT3–1 mouse pituitary cell line were used as controls. GnRHR mRNA and protein were detected in mouse ovaries, granulosa/cumulus cells, and oocytes. After GnRHa stimulation at various time intervals, we were unable to detect a cAMP increase or activation of the ERK or p38 signaling pathway in cultured primary mouse granulosa cells, whereas activation was detected in the control αT3–1 mouse pituitary cells. In this study, we have not detected activation of the canonical GnRH signaling pathways in mouse ovarian somatic cells. Our findings suggest that the mechanism of action of GnRHa in the ovary is either below the detection level of our experimental design or is different from that in the pituitary.
Central ventilatory and cardiovascular actions of trout gastrin-releasing peptide (GRP) in the unanesthetized trout
Authors: Le Mével Jean-Claude , Lancien Frédéric , Mimassi Nagi , Kermorgant Marc , Conlon J. Michael
Published: August 2013

Gastrin-releasing peptide (GRP), a neuropeptide initially isolated from porcine stomach, shares sequence similarity with bombesin. GRP and its receptors are present in the brains and peripheral tissues of several species of teleost fish, but little is known about the ventilatory and cardiovascular effects of this peptide in these vertebrates. The goal of this study was to compare the central and peripheral actions of picomolar doses of trout GRP on ventilatory and cardiovascular variables in the unanesthetized rainbow trout. Compared to vehicle, intracerebroventricular (ICV) injection of GRP (1–50 pmol) significantly elevated the ventilation rate (ƒV) and the ventilation amplitude (VAMP), and consequently the total ventilation (VTOT). The maximum hyperventilatory effect of GRP (VTOT: +225%), observed at a dose of 50 pmol, was mostly due to its stimulatory action on VAMP (+170%) rather than ƒV (+20%). In addition, ICV GRP (50 pmol) produced a significant increase in mean dorsal aortic blood pressure (PDA) (+35%) and in heart rate (ƒH) (+25%). Intra-arterial injections of GRP (5–100 pmol) were without sustained effect on the ventilatory variables but produced sporadic and transient increases in ventilatory movement at doses of 50 and 100 pmol. At these doses, GRP elevated PDA by +20% but only the 50 pmol dose significantly increased HR (+15%). In conclusion, our study suggests that endogenous GRP within the brain of the trout may act as a potent neurotransmitter and/or neuromodulator in the regulation of cardio-ventilatory functions. In the periphery, endogenous GRP may act as locally-acting and/or circulating neurohormone with an involvement in vasoregulatory mechanisms.
GDNF-independent ureteric budding: role of PI3K-independent activation of AKT and FOSB/JUN/AP-1 signaling
Authors: Tee James B. , Choi Yohan , Dnyanmote Ankur , Decambre Marvalyn , Ito Chiharu , Bush Kevin T. , Nigam Sanjay K.
Published: August 2013

A significant fraction of mice deficient in either glial cell-derived neurotrophic factor (GDNF) or its co-receptors (Gfrα1, Ret), undergoes ureteric bud (UB) outgrowth leading to the formation of a rudimentary kidney. Previous studies using the isolated Wolffian duct (WD) culture indicate that activation of fibroblast growth factor (FGF) receptor signaling, together with suppression of BMP/Activin signaling, is critical for GDNF-independent WD budding (Maeshima et al., 2007). By expression analysis of embryonic kidney from Ret(−/−) mice, we found the upregulation of several FGFs, including FGF7. To examine the intracellular pathways, we then analyzed GDNF-dependent and GDNF-independent budding in the isolated WD culture. In both conditions, Akt activation was found to be important; however, whereas this occurred through PI3-kinase in GDNF-dependent budding, in the case of GDNF-independent budding, Akt activation was apparently via a PI3-kinase independent mechanism. Jnk signaling and the AP-1 transcription factor complex were also implicated in GDNF-independent budding. FosB, a binding partner of c-Jun in the formation of AP-1, was the most highly upregulated gene in the ret knockout kidney (in which budding had still occurred), and we found that its siRNA-mediated knockdown in isolated WDs also blocked GDNF-independent budding. Taken together with the finding that inhibition of Jnk signaling does not block Akt activation/phosphorylation in GDNF-independent budding, the data support necessary roles for both FosB/Jun/AP-1 signaling and PI3-kinase-independent activation of Akt in GDNF-independent budding. A model is proposed for signaling events that involve Akt and JNK working to regulate GDNF-independent WD budding.
Pocket proteins critically regulate cell cycle exit of the trabecular myocardium and the ventricular conduction system
Authors: Park David S. , Tompkins Rose O. , Liu Fangyu , Zhang Jie , Phoon Colin K. L. , Zavadil Jiri , Fishman Glenn I.
Published: August 2013

During development, the ventricular conduction system (VCS) arises from the trabecular or spongy myocardium. VCS and trabecular myocytes proliferate at a significantly slower rate than compact zone myocardial cells, establishing a transmural cell cycle gradient. The molecular determinants of VCS/trabecular myocyte cell cycle arrest are not known. Given the importance of pocket proteins (Rb, p107 and p130) in mediating G0/G1 arrest in many cell types, we examined the role of this gene family in regulating cell cycle exit of the trabecular myocardium and ventricular conduction system. Using a combinatorial knockout strategy, we found that graded loss of pocket proteins results in a spectrum of heart and lung defects. p107/p130 double knockout (dKO) hearts manifest dysregulated proliferation within the compact myocardium and trabecular bases, while the remaining trabecular region cell cycle exits normally. Consequently, dKO hearts exhibit defective cardiac compaction, septal hyperplasia and biventricular outflow tract obstruction, while the VCS appears relatively normal. Loss of all three pocket proteins (3KO) is necessary to completely disrupt the transmural cell cycle gradient. 3KO hearts exhibit massive overgrowth of the trabecular myocardium and ventricular conduction system, which leads to fetal heart failure and death. Hearts carrying a single pocket protein allele are able to maintain the transmural cell cycle gradient. These results demonstrate the exquisite sensitivity of trabecular and conduction myocytes to pocket protein function during ventricular chamber development.
Cold exposure increases intestinal paracellular permeability to nutrients in the mouse
Authors: Price Edwin R. , Ruff Lisa J. , Guerra Alberto , Karasov William H.
Published: August 2013

In situations of increased energy demand/food intake, animals can often acclimate within several days. The intestine generally responds to elevated digestive demand by increasing in size. However, there is likely a limit to how quickly the intestine can grow to meet the new demand. We investigated the immediate and longer term changes to intestinal properties of the mouse when suddenly exposed to 4°C. We hypothesized that paracellular permeability to nutrients would increase as part of an immediate response to elevated absorptive demand. We measured absorption of L-arabinose, intestinal size, and gene expression of several tight junction proteins (claudin-2, claudin-4, claudin-15, and ZO-1) at 3 timepoints: pre-exposure, 1 d, and 2 wks of cold exposure. Cold exposure increased food intake 62% after 2 wks but intake was not significantly increased after 1 d. Intestinal wet mass was elevated after 1 day and throughout the experiment. Absorption of arabinose rose 20% after 1 day in the cold and was 33% higher after 2 wks. Expression of claudin-2 increased after 1 day of cold exposure, but there were no changes in expression of any claudin genes when normalized to ZO-1 expression. Our results indicate that intestinal mass can respond rapidly to increased energy demand and that increased paracellular permeability is also part of that response. Increased paracellular permeability may be a consequence of enterocyte hyperplasia resulting in more tight junctions across which molecules can absorb.
Preparation of Monodisperse Hydrogel Particles by Membrane Emulsification Using Highly Ordered Anodic Porous Alumina
Authors: Yanagishita Takashi , Kawamoto Midori , Nishio Kazuyuki , Masuda Hideki
Published: August 2013

Monodisperse hydrogel particles were prepared by membrane emulsification using ordered anodic porous alumina. The size of the obtained hydrogel particles could be controlled by changing the pore size in the anodic porous alumina. The average diameter of the obtained hydrogel particles showed a good linear relationship with the pore size of anodic porous alumina used for membrane emulsification. The process is simple and allows for the high-throughput preparation of monodisperse hydrogel particles with controlled sizes.
What Is European Integration Really About? A Political Guide for Economists
Authors: Spolaore Enrico
Published: August 2013

Europe's monetary union is part of a broader process of integration that started in the aftermath of World War II. In this “political guide for economists,” we look at the creation of the euro within the bigger picture of European integration. How and why were European institutions established? What is European integration really about? We address these questions from a political-economy perspective, building on ideas and results from the economic literature on the formation of states and political unions. Specifically, we look at the motivations, assumptions, and limitations of the European strategy initiated by Jean Monnet and his collaborators of partially integrating policy functions in a few areas with the expectation that more integration will follow in other areas in a sort of chain reaction toward an “ever-closer union.” The euro with its current problems is a child of that strategy and its limits.
Cross of Euros
Authors: O'Rourke Kevin H , Taylor Alan M
Published: August 2013

The eurozone currently confronts severe short-run macroeconomic adjustment problems and a deficient institutional architecture that has to be reformed in the longer run. Europe's efforts at economic and monetary union are historically unprecedented. However, the gold standard provides lessons regarding what will and won't work, macroeconomically and politically, in the short run, while US history provides long-run lessons regarding appropriate institutional structures. The latter also suggests that institutional reform only happens at times of great crisis, and that it cannot be taken for granted. The eurozone's leaders may therefore ultimately have to take heed of the lessons of history regarding currency union breakups.
How Video Rental Patterns Change as Consumers Move Online
Authors: Zentner Alejandro , Smith Michael , Kaya Cuneyd
Published: August 2013

How will consumption patterns for popular and “long-tail” products change when consumers move from brick-and-mortar to Internet markets? We address this question using customer-level panel data obtained from a national video rental chain as it was closing many of its local stores. These data allow us to use the closure of a consumer's local video store as an instrument, breaking the inherent endogeneity between channel choice and product choice. Our results suggest that when consumers move from brick-and-mortar to online channels, they are significantly more likely to rent “niche” titles relative to “blockbusters.” This suggests that a significant amount of niche product consumption online is due to the direct influence of the channel on consumer behavior, not just due to selection effects from the types of consumers who decide to use the Internet channel or the types of products that consumers decide to purchase online.

This paper was accepted by Pradeep Chintagunta, marketing.
Entrepreneurial Spawning and Firm Characteristics
Authors: Habib Michel A. , Hege Ulrich , Mella-Barral Pierre
Published: August 2013

We analyze the implications of the decision to spawn or to retain a new product for the nature and evolution of the firm. In our model, a new product is spawned if the fit between the product and its parent firm organization is not adequate. We focus on the impact of the firm's history of spawning decisions on firm characteristics such as size, focus, profitability, and innovativeness, and analyze its role in shaping firm dynamics. In accordance with the empirical literature, our model predicts that older firms innovate less, spawn less, are more diversified and less profitable, and that firms with more valuable general or specialized resources innovate and spawn more. Echoing seemingly contradictory empirical findings, our model predicts that small, focused firms (large, diversified firms) innovate and spawn more, and are more profitable when sample heterogeneity is driven by the importance of organizational fit (the value of general resources).

This paper was accepted by Bruno Cassiman, business strategy.
The Dark Side of Competition for Status
Authors: Charness Gary , Masclet David , Villeval Marie Claire
Published: August 2013

Unethical behavior within organizations is not rare. We investigate experimentally the role of status-seeking behavior in sabotage and cheating activities aiming at improving one's performance ranking in a flat-wage environment. We find that average effort is higher when individuals are informed about their relative performance. However, ranking feedback also favors disreputable behavior. Some individuals do not hesitate to incur a cost to improve their rank by sabotaging others' work or by increasing artificially their own performance. Introducing sabotage opportunities has a strong detrimental effect on performance. Therefore, ranking incentives should be used with care. Inducing group identity discourages sabotage among peers but increases in-group rivalry.

Data, as supplemental material, are available at http://dx.doi.org/10.1287/mnsc.2013.1747 .

This paper was accepted by John List, behavioral economics.
Matthew: Effect or Fable?
Authors: Azoulay Pierre , Stuart Toby , Wang Yanbo
Published: August 2013

In a market context, a status effect occurs when actors are accorded differential recognition for their efforts depending on their location in a status ordering, holding constant the quality of these efforts. In practice, because it is very difficult to measure quality, this ceteris paribus proviso often precludes convincing empirical assessments of the magnitude of status effects. We address this problem by examining the impact of a major status-conferring prize that shifts actors' positions in a prestige ordering. Specifically, using a precisely constructed matched sample, we estimate the effect of a scientist becoming a Howard Hughes Medical Institute (HHMI) Investigator on citations to articles the scientist published before the prize was awarded. We do find evidence of a postappointment citation boost, but the effect is small and limited to a short window of time. Consistent with theories of status, however, the effect of the prize is significantly larger when there is uncertainty about article quality, and when prize winners are of (relatively) low status at the time of election to the HHMI Investigator Program.

This paper was accepted by David Hsu, entrepreneurship and innovation.
Forward-Looking Market Risk Premium
Authors: Duan Jin-Chuan , Zhang Weiqi
Published: August 2013

A method for computing forward-looking market risk premium is developed in this paper. We first derive a theoretical expression that links forward-looking risk premium to investors' risk aversion and forward-looking volatility, skewness, and kurtosis of cumulative return. In addition, investors' risk aversion is theoretically linked to volatility spread, defined as the gap between the risk-neutral volatility deduced from option data and the physical return volatility exhibited by return data. The volatility spread formula serves as the basis for using the generalized method of moments to estimate investors' risk aversion. We adopt the generalized autoregressive conditional heteroskedasticity model for the physical return process and estimate the model using the S&P 500 daily index returns and then deduce the forward-looking variance, skewness, and kurtosis of the corresponding cumulative return. The forward-looking risk premiums are estimated monthly over the sample period of 2001–2010, and all are found to be positive. Furthermore, two asset pricing tests are conducted. First, change in forward-looking risk premiums is negatively related to the S&P 500 holding period return, reflecting that an increase in discount rate reduces current stock prices. Second, market illiquidity positively affects forward-looking risk premium, indicating that forward-looking risk premium contains an illiquidity risk premium component.

Data, as supplemental material, are available at http://dx.doi.org/10.1287/mnsc.2013.1758

This paper was accepted by Wei Jiang, finance.
Broken Circle &/ Spiral Hill?: Smithson’s spirals, pataphysics, syzygy and survival
Authors: Shanken Edward A.
Published: August 2013

The copious literature on the work of artist Robert Smithson has made very little of the many parallels between the inventor of earthworks and the nineteenth-century author of pataphysics, despite the established fact that the artist read and made notes from Alfred Jarry’s Dr. Faustroll (1898) while working on the Spiral Jetty in 1970, which undoubtedly influenced the subsequent Broken Circle &/ Spiral Hill (1971, Emmen). Given the insightful literature reassessing Jarry’s influence on twentieth-century artists including Marcel Duchamp, John Cage and Rodney Graham, a consideration of Smithson’s spiral earthworks in connection with Jarry is long overdue. In contrast to prevailing art research practices today, Smithson’s work is much more aligned with the pataphysical pursuit of ‘imaginary solutions’ that examine ‘the laws governing exceptions’ and describe ‘a universe which can be – and perhaps should be – envisaged in place of the traditional one’. Art historian Jack Burnham’s interprets Smithson’s earthworks as a ‘time-bound web of man-nature interactions … didactic exercises … [that] show a desperate need for environmental sensibility’. In this respect, the work of both Jarry and Smithson can provide a useful corrective to an overly rationalistic approach to art research, offering the field – and contemporary art in general – potentially valuable tools for forms of practice that challenge rather than adopt conventional academic models and epistemological constructs.
Intertextuality of retrieval database artworks
Authors: Hsu Wun-Ting , Lai Wen-Shu
Published: August 2013

Retrieval database artwork, unlike other artwork, does not present fixed, preset and stable contents; it is formed as external data are retrieved from different sociocultural contexts and combined into the artworks’ content. This article aims to address the intertextual relationships between retrieval database artworks and the mass-produced texts from which the database artworks retrieve their data. After briefly discussing the difference between retrieval database artwork and participatory database artwork, and exploring the main concept of intertextuality, we address why intertextuality is essential and beneficial in understanding retrieval database artworks. Two selected works are used to demonstrate that, as the artwork is executed, the meanings and relationships of retrieval database artwork are ever-changing, and the authorship is constantly shifting due to the viewer’s participation. Shifting authorship in retrieval database artwork is caused by the daily mass cultural production of original text, which might or might not be retrieved by the database to be incorporated into the artwork. We conclude that retrieval database artworks cannot separate themselves from mass data. The dynamic intertextual relationships between the work and its ongoing retrieval of content from other cultural productions, as well as the viewers’ contributions to the work, simultaneously shape and reshape the work and its authorship.
The Neural String Network
Authors: Sermon Paul
Published: August 2013

An interactive collaborative drawing ‘machine’ designed on the concept of a neural network, allowing participants to experience a shared creative process, using the principles of open-source and social networked communication through an analogue string system. The underlying concept of the String Neural Network is to introduce participants to the idea of collaborative-shared drawing practice, as a dispersed collective that alludes to Roland Barthes The Death of the Author (1967) whereby each participant plays an equal role as both viewer and artist. Played out like a surrealist Exquisite Corpse game of consequences or as a piece of Haiku poetry, the drawing participants contribute marks, signs and signifiers to an open-content drawing, akin to the development of open-source software. The string network consists of five drawing table ‘nodes’ within a room/studio space measuring eight by eight metres square. Each node is linked to the other four via pulleys and washing lines, making it possible to peg a sheet of A4 paper to a line and winch it across to any one of the other nodes. The network system uses ten string connections between the five drawing tables, creating a pentagram within a pentagon neural network design. Representing the interconnected synapses and neurons of the brain, the role of each participant is that of cause and effect. A single instruction initiates a series of consequences that unfold in drawings, marks and patterns that are created whilst being hoisted simultaneously across the room in quick succession. The Neural String Network project was first set up in March 2012 to coincide with ‘DecodeRecode’, a telematic art project undertaken by students at MediaCityUK Salford University, as part of the centenary celebration of Alan Turing. Each participating student was given a single word drawn from the Turing theme, such as machine, brain, code and apple that were interpreted and communicated as a drawing by a collective consciousness.
Contribution of distinct platelet integrins to binding, unfolding, and assembly of fibronectin
Authors: Huynh Khon C. , Stoldt Volker R. , Scharf Rudiger E.
Published: August 2013

Fibronectin (FN) fibrillogenesis depends on the binding of FN to cellular receptors and subsequent unfolding of bound FN. Integrins αIIbβ3, αvβ3, and α5β1 are known to assemble FN fibrils on platelets. In our study, we examined the contribution of these integrins to FN binding, unfolding, and assembly on platelets in suspension and adherent platelets in the presence or absence of agonists. Phorbol 12-myristate 13-acetate (PMA), but not adenosine diphosphate (ADP), induced binding of FN to platelets in suspension. In contrast, adherent platelets were able to deposit FN on their surfaces in the absence of agonists. β3 integrins had a major impact on the interaction of FN on platelets. αvβ3 showed a similar contribution to the binding of FN as αIIbβ3 on PMA-stimulated platelets in suspension but had a lesser contribution to unfolding and deposition of FN on adherent platelets. α5β1 also participated in the interaction of FN with platelets by mediating the unfolding and assembly of FN, but to a lesser extent than β3 integrins. None of the distinct antibodies directed against one of the three integrins caused a complete inhibition of binding, unfolding, and assembly of FN by platelets. Thus, it is likely that αIIbβ3, αvβ3, and α5β1 or another still unknown receptor can be substituted.
Effect of Reductants on Valuable Metals Separation and Recovery from Copper Cliff Converter Slag
Authors: Mitrašinović Aleksandar M. , Wolf Anton
Published: August 2013

The aim of the project is to investigate new material as a reductant in nickel extraction and purification processes. The analyzed reductants were coke, pig iron, ferrosilicon and two copper-silicon alloys. The mixture with the slag and reductant was poured into a cylindrical alumina crucible and kept in a furnace for one hour at 1573 K (1300 °C). After settling, the solidified sample consisted of the matte settled at the bottom of the sample separated from the slag at the top. Ferrosilicon was found to be the most effective reductant for cobalt recovery while 70wt%Cu-30wt%Si alloy facilitated 72% copper and 87% nickel recovery. The highest copper recovery is achieved with 90wt%Cu-10wt%Si reductant. Due to low melting point, high exothermicity and suitable density, Cu-Si alloys could be an ideal choice for the pyrometallurgical converting processes.
The emerging role of the molecular marker p27 in the differential diagnosis of adrenocortical tumors
Authors: Pereira Sofia S , Morais Tiago , Costa Madalena M , Monteiro Mariana P , Pignatelli Duarte
Published: August 2013

Malignant adrenocortical tumors (ACTs) are rare and highly aggressive; conversely, benign tumors are common and frequently found incidentally (the so-called incidentalomas). Currently, the use of molecular markers in the diagnosis of ACTs is still controversial. The aim of this study was to analyze the molecular profile of different ACTs with the purpose of identifying markers useful for differentiating between these tumors. The ACTs that were studied (n=31) included nonfunctioning adenomas (ACAn)/incidentalomas (n=13), functioning adenomas with Cushing's syndrome (ACAc) (n=7), and carcinomas (n=11); normal adrenal glands (n=12) were used as controls. For each sample, the percentage area stained for the markers StAR, IGF2, IGF1R, p53, MDM2, p21, p27, cyclin D1, Ki-67, β-catenin, and E-cadherin was quantified using a morphometric computerized tool. IGF2, p27, cyclin D1, and Ki-67 were the markers for which the percentage of stained area was significantly higher in carcinoma samples than in adenoma samples. Ki-67 and p27 were the markers that exhibited the highest discriminative power for differential diagnosis between carcinomas and all type of adenomas, while IGF2 and StAR were only found to be useful for differentiating between carcinomas and ACAn and between carcinomas and ACAc respectively. The usefulness of Ki-67 has been recognized before in the differential diagnosis of malignant tumors. The additional use of p27 as an elective marker to distinguish benign ACTs from malignant ACTs should be considered.
Optimal bone mechanical and material properties require a functional glucagon-like peptide-1 receptor
Authors: Mabilleau Guillaume , Mieczkowska Aleksandra , Irwin Nigel , Flatt Peter R , Chappard Daniel
Published: August 2013

Bone is permanently remodeled by a complex network of local, hormonal, and neuronal factors that affect osteoclast and osteoblast biology. Among these factors, a role for gastrointestinal hormones has been proposed based on the evidence that bone resorption dramatically falls after a meal. Glucagon-like peptide-1 (GLP1) is one of these gut hormones, and despite several reports suggesting an anabolic effect of GLP1, or its stable analogs, on bone mass, little is known about the effects of GLP1/GLP1 receptor on bone strength. In this study, we investigated by three-point bending, quantitative X-ray microradiography, microcomputed tomography, qBEI, and FTIRI bone strength and bone quality in male Glp1r knockout (Glp1r KO) mice when compared with control WT animals. Animals with a deletion of Glp1r presented with a significant reduction in ultimate load, yield load, stiffness, and total absorbed and post-yield energies when compared with WT animals. Furthermore, cortical thickness and bone outer diameter were significantly decreased in deficient animals. The mineral quantity and quality were not significantly different between Glp1r KO and WT animals. On the other hand, the maturity of the collagen matrix was significantly reduced in deficient animals and associated with lowered material properties. Taken together, these data support a positive effect of GLP1R on bone strength and quality.