bluuebunny/crossref_metadata_2025 huggingface dataset:
Pd‐Catalyzed Reaction of Allyl Carbonate with Polyols: The Role of CO2 in Transesterification versus Etherification of Glycerol
Authors: Gordillo Alvaro , Lloyd‐Jones Guy C.
Published: January 2012

An intermolecular Pd/PPh3‐catalyzed transesterification of diallyl carbonate with glycerol to generate glycerol carbonate has been developed. Analysis of the reaction kinetics in THF indicates a first‐order dependence on Pd and diallyl carbonate, that the Pd bears two phosphines during the turnover limiting event, and that increasing the glycerol concentration inhibits reaction, possibly via change in the polarity of the medium. 13C isotopic labeling studies demonstrate that the Pd‐catalyzed transesterification requires at least one allyl carbonate moiety and that there is rapid equilibrium of the allyl carbonate with CO2 in solution, even when present only at low concentrations. A mechanism that is consistent with these results involves oxidative addition of the allyl carbonate to Pd followed by reversible decarboxylation, with the intermediate η1‐ and η3‐allyl Pd alkoxides mediating direct and indirect transesterification reactions with the glycerol. Using this model, successful simulations of the kinetics of reactions conducted under atmospheres of N2 or CO2 could be achieved, including switching in selectivity between etherification and transesterification in the early stages of reaction. Reactions with the higher polyols threitol and erythritol are also efficient, generating the terminal (1,2) monocarbonates with high selectivity.
Pathway of Oxygen Incorporation from O2 in TiO2 Photocatalytic Hydroxylation of Aromatics: Oxygen Isotope Labeling Studies
Authors: Li Yue , Wen Bo , Yu Cailan , Chen Chuncheng , Ji Hongwei , Ma Wanhong , Zhao Jincai
Published: January 2012

The hydroxylation process is the primary, and even the rate‐determining step of the photocatalytic degradation of aromatic compounds. To make clear the hydroxylation pathway of aromatics, the TiO2 photocatalytic hydroxylation of several model substrates, such as benzoic acid, benzene, nitrobenzene, and benzonitrile, has been studied by an oxygen‐isotope‐labeling method, which can definitively assign the origin of the O atoms (from oxidant O2 or solvent H2O) in the hydroxyl groups of the hydroxylated products. It is found that the oxygen source of the hydroxylated products depends markedly on the reaction conditions. The percentage of the products with O2‐derived hydroxyl O atoms increases with the irradiation time, while it decreases with the increase of substrate concentration. More intriguingly, when photogenerated valence‐band holes (hvb+) are removed, nearly all the O atoms (>97 %) in the hydroxyl groups of the hydroxylated products of benzoic acid come from O2, whereas the scavenging of conduction‐band electrons (ecb−) makes almost all the hydroxyl O atoms (>95 %) originate from solvent H2O. In the photocatalytic oxidation system with benzoic acid and benzene coexisting in the same dispersion, the percentage of O2‐derived hydroxyl O atoms in the hydroxylated products of strongly adsorbed benzoic acid (ca. 30 %) is much less than in that of weakly adsorbed benzene (phenol) (>60 %). Such dependences provide unique clues to uncover the photocatalytic hydroxylation pathway. Our experiments show that the main O2‐incorporation pathway involves the reduction of O2 by ecb− and the subsequent formation of free .OH via H2O2, which was usually overlooked in the past photocatalytic studies. Moreover, in the hydroxylation initiated by hvb+, unlike the conventional mechanism, the O atom in O2 cannot incorporate into the product through the direct coupling between molecular O2 and the substrate‐based radicals.
The σ‐Hole Phenomenon of Halogen Atoms Forms the Structural Basis of the Strong Inhibitory Potency of C5 Halogen Substituted Glucopyranosyl Nucleosides towards Glycogen Phosphorylase b
Authors: Kantsadi Anastasia L. , Hayes Joseph M. , Manta Stella , Skamnaki Vicky T. , Kiritsis Christos , Psarra Anna‐Maria G. , Koutsogiannis Zissis , Dimopoulou Athina , Theofanous Stavroula , Nikoleousakos Nikolaos , Zoumpoulakis Panagiotis , Kontou Maria , Papadopoulos George , Zographos Spyros E. , Komiotis Dimitris , Leonidas Demetres D.
Published: January 2012

C5 halogen substituted glucopyranosyl nucleosides (1‐(β‐D‐glucopyranosyl)‐5‐X‐uracil; X=Cl, Br, I) have been discovered as some of the most potent active site inhibitors of glycogen phosphorylase (GP), with respective Ki values of 1.02, 3.27, and 1.94 μM. The ability of the halogen atom to form intermolecular electrostatic interactions through the σ‐hole phenomenon rather than through steric effects alone forms the structural basis of their improved inhibitory potential relative to the unsubstituted 1‐(β‐D‐glucopyranosyl)uracil (Ki=12.39 μM), as revealed by X‐ray crystallography and modeling calculations exploiting quantum mechanics methods. Good agreement was obtained between kinetics results and relative binding affinities calculated by QM/MM‐PBSA methodology for various substitutions at C5. Ex vivo experiments demonstrated that the most potent derivative (X=Cl) toward purified GP has no cytotoxicity and moderate inhibitory potency at the cellular level. In accordance, ADMET property predictions were performed, and suggest decreased polar surface areas as a potential means of improving activity in the cell.
NMR Investigation of Imidazolium‐Based Ionic Liquids and Their Aqueous Mixtures
Authors: Cesare Marincola Flaminia , Piras Cristina , Russina Olga , Gontrani Lorenzo , Saba Giuseppe , Lai Adolfo
Published: January 2012

1H and 13C NMR spectroscopy is employed to investigate the interaction of water with two imidazolium‐based ionic liquids (ILs), 1‐hexyl‐3‐methylimidazolium bromide ([C6mim]Br) and 1‐octyl‐3‐methylimidazolium bromide ([C8mim]Br), at IL concentrations well above the critical aggregation concentration (CAC). The results are compared with those of the neat samples. To this aim, a detailed analysis of the changes in the 1H chemical shifts, 13C relaxation parameters, and 2D ROESY data due to the presence of water is performed. The results for both neat ILs are consistent with a packed structure where head‐to‐head, head‐to‐tail, and tail‐to‐tail contacts occur and where the site of maximal mobility restriction is at the polar head. At the lowest investigated water content, the presence of water influences mainly the environment around the IL polar head, slowing down the motional dynamics of the aromatic ring with respect to the alkyl chain. At higher water contents this difference diminishes, the motional freedom of the whole molecule increasing. The presence of ROESY cross‐peaks between protons in the polar and apolar IL regions, as well as between protons in non‐neighboring alkyl groups, at all investigated water contents suggests that the alkyl tails are not fully segregated in hydrophobic domains, as expected for micelle‐like structures.
1,2,4‐Oxadiazole 4‐Oxides as Nitrones in 1,3‐Dipolar Cycloaddition Reactions to Vinyl Ethers
Authors: Quadrelli Paolo , Lunghi Fabio , Bovio Bruna , Gautschi William , Caramella Pierluigi
Published: January 2012

1,2,4‐Oxadiazole 4‐oxides display nitronic reactivity and selectivities identical to those of N‐methyl‐C‐phenyl nitrone, which is a typical acyclic nitrone, affording comparable amounts of endo‐ and exo‐5‐alkoxyisoxazolidines. The exo stereoisomers undergo an easy rearrangement under the reaction conditions to yield oxadiazolinic esters. The structures of the adducts have been confirmed by X‐ray structures and spectroscopic data. A donor p‐methoxyphenyl at the nitronic carbon slows down the cycloaddition rate, while an acceptor p‐nitrophenyl retards the rearrangement of the exo adduct.
Malleable disc base for direct infiltration measurements using the tension infiltrometry technique
Authors: Moret‐Fernández David , Blanco Nuria , Martínez‐Chueca Victor , Bielsa Ana
Published: January 2012

The correct use of the tension disc infiltrometer requires the membrane of the disc base to be completely in contact with the soil surface. To achieve this contact, a thick layer of sand is commonly placed between the soil surface and the disc base. This paper presents an alternative disc (MDB), which, by incorporating a malleable membrane, allows direct infiltration measurements without using a contact sand layer. Infiltration curves obtained with this new design in a soil under three different tillage management treatments were compared with the corresponding curves obtained with a conventional disc (CDB) that uses a contact sand layer. The cumulative infiltration curves measured with CDB were analysed by the differentiated linearization (DL) method, and the corresponding curves obtained with MDB were analysed using both the DL and the cumulative linearization (CL) models. The values of hydraulic conductivity (K0) and sorptivity (S0) estimated with CDB were also compared with those obtained with MDB. Finally, the cumulative infiltration curves measured with CDB and MDB were compared with the corresponding modelled function for the respective K0 and S0 values calculated with the CL and DL models. The results show that, compared with CDB without a contact sand layer, MDB allows complete soil surface wetting even when non‐smoothed soil surfaces are used. The CDB, which yielded average K0 values 18% lower than those estimated with MDB, gave the highest values of standard error for the hydraulic parameters calculated. Furthermore, the subjective method employed in the CDB‐DL technique, which requires the first points of the differential infiltration line corresponding to the sand layer to be manually removed, introduces additional uncertainties in estimating S0 and K0. Comparison between the modelled and measured infiltration curves demonstrates that the DL or CL methods applied to MDB gave excellent estimates of S0 and K0. Copyright © 2012 John Wiley & Sons, Ltd.
Concentrations and loads of dissolved xenobiotics and hormones in two small river catchments of different land use in Luxembourg
Authors: Krein A. , Keßler S. , Meyer B. , Pailler J.‐Y. , Guignard C. , Hoffmann L.
Published: January 2012

The investigation focuses on the analysis of dissolved sulfonamides, tetracyclines, analgesics, anticonvulsants and hormones in surface water. Runoff event and baseflow samples were analysed in two small river catchments of different land use in Luxembourg. For most of the flood events, similar pollutant loads to those transported during 1 day with average baseflow discharge were observed. The maximum contents during flood events and the event mean concentrations are controlled by pre‐event hydro‐climatological conditions. For all substances under investigation, maximum concentrations and event mean concentrations show a decrease with raising antecedent rainfall. In addition, the interstorm and intrastorm variability of the pollutant transport was determined. Runoff generation and corresponding transport of xenobiotic compounds show a complex pattern with many interrelated processes, taking place within bedrock, soil, anthropogenic facilities and channel and in different parts of the basins under investigation. Different sources of pollutants can be identified and related to particular locations in the basin. The influence of the sewer systems is obvious. In the agricultural Mess basin, higher rainfall amounts lead to greater quantities of laterally inflowing soil water with higher concentrations of dissolved oxytetracycline. This originates from veterinary medicines administered to livestock and enters the environment through the application of organic fertilisers, especially by slurry that is applied to the fields. Copyright © 2012 John Wiley & Sons, Ltd.
Multiparametric MRI maps for detection and grading of dominant prostate tumors
Authors: Moradi Mehdi , Salcudean Septimiu E. , Chang Silvia D. , Jones Edward C. , Buchan Nicholas , Casey Rowan G. , Goldenberg S. Larry , Kozlowski Piotr
Published: January 2012

Purpose:

To develop an image‐based technique capable of detection and grading of prostate cancer, which combines features extracted from multiparametric MRI into a single parameter map of cancer probability.

Materials and Methods:

A combination of features extracted from diffusion tensor MRI and dynamic contrast enhanced MRI was used to characterize biopsy samples from 29 patients. Support vector machines were used to separate the cancerous samples from normal biopsy samples and to compute a measure of cancer probability, presented in the form of a cancer colormap. The classification results were compared with the biopsy results and the classifier was tuned to provide the largest area under the receiver operating characteristic (ROC) curve. Based solely on the tuning of the classifier on the biopsy data, cancer colormaps were also created for whole‐mount histopathology slices from four radical prostatectomy patients.

Results:

An area under ROC curve of 0.96 was obtained on the biopsy dataset and was validated by a “leave‐one‐patient‐out” procedure. The proposed measure of cancer probability shows a positive correlation with Gleason score. The cancer colormaps created for the histopathology patients do display the dominant tumors. The colormap accuracy increases with measured tumor area and Gleason score.

Conclusion:

Dynamic contrast enhanced imaging and diffusion tensor imaging, when used within the framework of supervised classification, can play a role in characterizing prostate cancer. J. Magn. Reson. Imaging 2012;35:1403–1413. © 2012 Wiley Periodicals, Inc.
Quality improvement of microsurgery through telecommunication—the postoperative care after microvascular transfer of intestine
Authors: Chen Hung‐Chi , Kuo Hsin‐Chih , Chung Kuo‐Piao , Chen Shih‐Heng , Tang Yueh‐Bih , Su Syi
Published: January 2012

The purpose of this report is to describe the use of telecommunication to improve the quality of postoperative care following microsurgery, especially following microvascular transfer of intestinal transfer for which shortening of ischemia time is of utmost importance to achieve high success rate. From 2003 to 2009 microvascular transfer of intestinal flaps had been performed in 112 patients. After surgery the patients were put in intensive care unit and the flaps were checked every 1 hour. The image for circulatory status of the flaps was sent directly to the attending surgeon for judgment. The information was sent through intranet and the surgeon can get access to the intranet through internet if necessary. Among the 112 cases, there were 9 cases of reexploration. The average duration between the time of problem detection and the time of starting reexploration was 54 min in 7 cases, and other 2 cases were delayed to enter the operating room which had been occupied by other cases of major trauma. Only two flaps were lost completely, two patients developed narrowing at the junction of cervical esophagus and thoracic esophagus. The rate of salvage for intestinal flap is apparently higher than those reported in the literature. In the postoperative management of microsurgery in ICU, telecommunication can help to reduce the ischemia time after vascular compromise in the transfer of free intestinal flap. Telecommunication is really an easy and effective tool in improving the outcome of reconstructive surgery. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
Single‐stage reconstruction of oral and hypopharyngeal double cancer with a free jejunal flap
Authors: Hirano Takashi , Tateyama Kaori , Kodama Satoru , Takeno Shinsuke , Suzuki Masashi
Published: January 2012

Multiple primary tumors are a known phenomenon in head and neck cancer. However, the incidence of simultaneous oral and hypopharyngeal double cancer is extremely rare. In light of this, the surgical treatment for oral and hypopharyngeal double cancer has not been established. Here we present a case of oral and hypopharyngeal double cancer in which we successfully used a free jejunal flap to reconstruct an oral and hypopharyngeal defect. When the oral tumor is limited to the mucosal surface, a single‐stage reconstruction with a free jejunal flap is a suitable option because it is simple and causes less morbidity than using additional flap reconstruction. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
Autonomization of free flaps in the oral cavity: A prospective clinical study
Authors: Mücke Thomas , Wolff Klaus‐D. , Rau Andrea , Kehl Victoria , Mitchell David A. , Steiner Timm
Published: January 2012

Controversy exists over how long a free flap is dependent on its pedicle and if neovascularization is different between flap types, recipient sites, and irradiated and nonirradiated patients. An understanding of the timing of this process should optimize the safety of secondary procedures involving the flap. In a prospective clinical study, hemoglobin oxygenation and capillary flow were measured in 50 flaps (25 forearm flaps, 15 osteocutaneous fibula flaps, and 10 anterolateral thigh flaps) 4 and 12 weeks postoperatively. The flaps were located at the floor of the mouth, cheek, or tongue (n = 39) or at the hard or soft palate (n = 11). Measurements were carried out using the O2C monitoring system under temporary digital occlusion of the pedicle. After 4 weeks, 17 free flaps were found to be autonomized indicated by the O2C measurements comparing both values before and after digital compression of the vascular pedicle. After 12 weeks, 41 patients had completion of free flap autonomization, as indicated by the HbO2 and CF before and after pedicle compression. The location of free flap in the lower jaw (P < 0.0001 after 4 weeks, P = 0.013 after 12 weeks), fasciocutaneous radial forearm flaps after 4 weeks (P < 0.0001), and not irradiated recipient site after 4 weeks (P = 0.014) were found to be positive factors significantly influencing autonomization. In conclusion, free flap autonomization depends on several variables which should be considered before further surgery after free flap reconstruction as the transferred tissue can be still dependent on its pedicle. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012.
An 8‐ to 12‐GHz wideband negative resistance reflection amplifier
Authors: Chan Pak , Fusco V.
Published: January 2012

This article describes the design and characterization of a wideband, 40% bandwidth microwave one port reflection amplifier.Experimental and simulation results are presented. The one port reflection amplifier uses a silicon bipolar transistor and demonstrates a return gain of better than 10 dB from 8 to 11.5 GHz. The gain of the refection amplifier can be easily DC modulated. In addition, a pair of reflection amplifiers is used to create a wideband bidirectional amplifier. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:553–555, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26597
Building communities of philanthropy in higher education: contextual influences
Authors: McAlexander James H. , F. Koenig Harold
Published: January 2012

In this era of constrained and declining economic resources, institutions of higher education are turning to advancement professionals to identify and cultivate the financial resources that are becoming an increasing and larger portion of the fundamental funding of the institution. In this high stakes arena, advancement professionals have a need for the tools that can assist them in cultivating philanthropic relationships more effectively and efficiently. To that purpose, this research empirically explores ways in which the brand community construct can be adapted to philanthropic intent for non‐profit organizations to aid in the cultivation process. This paper presents the results of a survey of college alumni drawn from a commercially provided online panel, and examines the potential impact that institutional size may have upon the relationships of an alumni brand community and the community's expressed willingness to offer financial donations to the alma mater. From a theoretic perspective, this paper reveals that brand community is a significant contributor to this expression of philanthropic intent across universities of differing size. As a practical consideration, our findings produce additional evidence to affirm the notion that brand community is a robust construct that can be of value to development professionals who seek to build financial support for both small and large universities. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of graphene doping of holographic polymer‐dispersed liquid crystals
Authors: Kim Byung Kyu , Jang Min Woo , Park Hong Chae , Jeong Han Mo , Kim Eun Young
Published: January 2012

Doping a polymer matrix with a minute amount of graphene (0.05–0.25%) had significant effects on the grating formation kinetics and electro‐optical performance of a holographic polymer‐dispersed liquid crystal. Low graphene contents (≤0.1%) reduced the viscosity and induced rapid diffusion, curing, grating formation, and high diffraction efficiency with a diffraction overshoot of 0.05%. Conversely, high graphene contents increased the compound viscosity, and the entire process proceeded slowly. Graphene increased the polymer conductivity and local electric field, reduced the operating voltage from 65 to 25–50 V, and increased the contrast ratio from 7 to 8–23 with a concomitant decrease in rise time. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Luminescence quenching of porous silicon nanoparticles in presence of ascorbic acid
Authors: La Ferrara Vera , Fiorentino Giuseppe , Rametta Gabriella , Di Francia Girolamo
Published: January 2012

In this work, the effect of ascorbic acid on luminescence of porous silicon nanoparticles is studied. Porous nanoparticles with a multi‐sized distribution are produced from a porous silicon free standing film and filtered through a 450 nm membrane. The highly luminescent and water‐soluble nanoparticles are dispersed in deionized water. The stability of photoluminescence signal and the dimensions of porous silicon nanoparticles are characterized before adding ascorbic acid into the porous nanoparticles solution. The increasing of photoluminescence, before stabilization, has been correlated to oxidation of nanoparticles in water, evaluated by the technique of Attenuated Total Reflection. Once the nanoparticle photoluminescence signal is stabilized, ascorbic acid is loaded into the solution and its presence and real absorption onto the porous silicon nanoparticles are evaluated from their emission quenching. The quenching of photoluminescence is studied with different concentrations of ascorbic acid by Stern–Volmer plot for confirming the quenching law. This study shows that luminescence quenching of porous nanoparticles could be used for determining the presence of ascorbic acid in a solution.
Induction of Osteogenesis in Mesenchymal Stem Cells by Activated Monocytes/Macrophages Depends on Oncostatin M Signaling
Authors: Guihard Pierre , Danger Yannic , Brounais Bénédicte , David Emmanuelle , Brion Régis , Delecrin Joël , Richards Carl D. , Chevalier Sylvie , Rédini Françoise , Heymann Dominique , Gascan Hugues , Blanchard Frédéric
Published: January 2012

Bone resorption by osteoclasts and bone formation by osteoblasts are tightly coupled processes implicating factors in TNF, bone morphogenetic protein, and Wnt families. In osteoimmunology, macrophages were described as another critical cell population regulating bone formation by osteoblasts but the coupling factors were not identified. Using a high-throughput approach, we identified here Oncostatin M (OSM), a cytokine of the IL-6 family, as a major coupling factor produced by activated circulating CD14+ or bone marrow CD11b+ monocytes/macrophages that induce osteoblast differentiation and matrix mineralization from human mesenchymal stem cells while inhibiting adipogenesis. Upon activation of toll-like receptors (TLRs) by lipopolysaccharide or endogenous ligands, OSM was produced in classically activated inflammatory M1 and not M2 macrophages, through a cyclooxygenase-2 and prostaglandin-E2 regulatory loop. Stimulation of osteogenesis by activated monocytes/macrophages was prevented using neutralizing antibodies or siRNA to OSM, OSM receptor subunits gp130 and OSMR, or to the downstream transcription factor STAT3. The induced osteoblast differentiation program culminated with enhanced expression of CCAAT-enhancer-binding protein δ, Cbfa1, and alkaline phosphatase. Overexpression of OSM in the tibia of mice has led to new bone apposition with no sign of bone resorption. Two other cytokines have also a potent role in bone formation induced by monocytes/macrophages and activation of TLRs: IL-6 and leukemia inhibitory factor. We propose that during bone inflammation, infection, or injury, the IL-6 family signaling network activated by macrophages and TLR ligands stimulates bone formation that is largely uncoupled from bone resorption and is thus an important target for anabolic bone therapies.

Disclosure of potential conflicts of interest is found at the end of this article.
PKA/CREB Signaling Triggers Initiation of Endothelial and Hematopoietic Cell Differentiation via Etv2 Induction
Authors: Yamamizu Kohei , Matsunaga Taichi , Katayama Shiori , Kataoka Hiroshi , Takayama Naoya , Eto Koji , Nishikawa Shin-Ichi , Yamashita Jun K.
Published: January 2012

Ets family protein Etv2 (also called ER71 or Etsrp) is a key factor for initiation of vascular and blood development from mesodermal cells. However, regulatory mechanisms and inducing signals for Etv2 expression have been largely unknown. Previously, we revealed that cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling enhanced differentiation of vascular progenitors into endothelial cells (ECs) and hematopoietic cells (HPCs) using an embryonic stem cell (ESC) differentiation system. Here, we show that PKA activation in an earlier differentiation stage can trigger EC/HPC differentiation through Etv2 induction. We found Etv2 was markedly upregulated by PKA activation preceding EC and HPC differentiation. We identified two cAMP response element (CRE) sequences in the Etv2 promoter and 5′-untranslated region and confirmed that CRE-binding protein (CREB) directly binds to the CRE sites and activates Etv2 transcription. Expression of a dominant negative form of CREB completely inhibited PKA-elicited Etv2 expression and induction of EC/HPCs from ESCs. Furthermore, blockade of PKA significantly inhibited Etv2 expression in ex vivo whole-embryo culture using Etv2-Venus knockin mice. These data indicated that PKA/CREB pathway is a critical regulator for the initiation of EC/HPC differentiation via Etv2 transcription. This early-stage molecular linkage between a triggering signal and transcriptional cascades for differentiation would provide novel insights in vascular and blood development and cell fate determination.

Disclosure of potential conflicts of interest is found at the end of this article.
Abstract convex optimal antiderivatives
Authors: Reich Simeon , Bartz Sedi
Published: January 2012

Having studied families of antiderivatives and their envelopes in the setting of classical convex analysis, we now extend and apply these notions and results in settings of abstract convex analysis. Given partial data regarding a
c
-subdifferential, we consider the set of all
c
-convex
c
-antiderivatives that comply with the given data. Under a certain assumption, this set is not empty and contains both its lower and upper envelopes. We represent these optimal antiderivatives by explicit formulae. Some well known functions are, in fact, optimal
c
-convex
c
-antiderivatives. In one application, we point out a natural minimality property of the Fitzpatrick function of a
c
-monotone mapping, namely that it is a minimal antiderivative. In another application, in metric spaces, a constrained Lipschitz extension problem fits naturally the convexity notions we discuss here. It turns out that the optimal Lipschitz extensions are precisely the optimal antiderivatives. This approach yields explicit formulae for these extensions, the most particular case of which recovers the well known extensions due to McShane and Whitney.
Evaluation of the long-term effects of gastric inhibitory polypeptide–ovalbumin conjugates on insulin resistance, metabolic dysfunction, energy balance and cognition in high-fat-fed mice
Authors: Irwin Nigel , Montgomery Ian A. , Flatt Peter R.
Published: January 2012

The effects of active immunisation with gastric inhibitory polypeptide (GIP) or (proline3)GIP–ovalbumin conjugates on insulin resistance, metabolic dysfunction, energy expenditure and cognition were examined in high-fat-fed mice. Normal mice were injected (subcutaneously) once every 14 d for 98 d with GIP–ovalbumin conjugates, with transfer to a high-fat diet on day 21. Active immunisation resulted in GIP antibody generation and significantly (P < 0·01 to P < 0·001) reduced circulating non-fasting plasma insulin concentrations compared to high-fat control mice from day 70 onwards. The glycaemic responses to intraperitoneal glucose or nutrient ingestion were significantly improved in all treated mice, with corresponding stimulated plasma insulin levels depressed compared to high-fat controls. These changes were associated with substantially (P < 0·001) improved glucose-lowering responses to exogenous insulin and decreases of muscle and fat TAG, pancreatic insulin, circulating total and LDL-cholesterol levels (P < 0·01 to P < 0·001). Treatment with GIP–ovalbumin conjugates was not associated with alterations in energy expenditure, indirect calorimetry or aspects of cognitive function. The observed changes were almost identical in GIP and (Pro3)GIP immunised mice and were independent of any effects on food intake or body weight. Further tests established that coupling of GIP peptides to ovalbumin abolished any intrinsic insulin-releasing or glucose-lowering activity. These results suggest that induction of GIP-neutralising antibodies with GIP–ovalbumin conjugates is an effective means of countering the metabolic abnormalities induced by high-fat feeding and does not adversely have an impact on a marker of cognition function or energy expenditure.
Spatial–temporal variation ofAchiruslarvae (Actinopterygii: Achiridae) in mangrove, beach and reef habitats in north-eastern Brazil
Authors: Silva-Falcão Elisabeth Cabral , Severi William , De Araújo Maria Elisabeth
Published: January 2012

The genusAchirusis made up of demersal fish that have a close relationship with the substrate and exhibit peculiar aspects during their larval stage. The aim of the present study was to determine whether the abundance ofAchiruslarvae differed among a set of habitats in the estuary of the Formoso River in the State of Pernambuco (north-eastern Brazil). Sampling was performed monthly between April 2009 and March 2010, and comprised horizontal hauls with plankton net during the day and night in mangrove, beach and reef habitats. Fish larvae were sorted, identified, measured and larval stage recorded. Density and body length values were used in a non-parametric analysis of variance for the determination of variations between seasons, habitats and diel periods. A total of 204 larvae were collected, with an average density of 2.1 larvae.100 m−3. Density was greater in the nocturnal samplings, with no differences found between habitats. The larvae occurred in the yolk-sac to post-flexion stage, with pre-flexion the most abundant stage (78%). Size segregation was observed. Larger larvae were captured at night and in the mangrove. The smallest larvae were caught on the reef, with length increasing toward the mangrove. The results indicate thatAchiruslarvae come from deeper regions near reefs, where spawning probably occurs, and perform ontogenetic migration towards the shallow waters of mangrove, where they settle.
Putting singular and plural morphology in context
Authors: DISPALDRO MARCO , BENELLI BEATRICE
Published: January 2012

This study explores the development of children's knowledge of linguistic and pragmatic aspects of singular and plural in Italian, for definite articles (Experiment 1) and verbs (Experiment 2). Participants aged three to adult were asked to pick objects from two dishes, each with a different number of items on them (one vs. two), following the morphological information. Results show that children understand that singular forms refer to ‘one’ at about age four, whereas they understand that plural forms refer to ‘more than one’ when they are older than six. Moreover, children use singular and plural knowledge in appropriate relation with the referential context only when they are about six.
Non-typhoidal Salmonella bacteraemia in elderly patients: an increased risk for endovascular infections, osteomyelitis and mortality
Authors: CHEN P. L. , LEE H. C. , LEE N. Y. , WU C. J. , LIN S. H. , SHIH H. I. , LEE C. C. , KO W. C. , CHANG C. M.
Published: January 2012

Non-typhoidal Salmonella (NTS) is a common pathogen causing foodborne infections, bacteraemia, and extra-intestinal focal infections (EFIs) in humans. The study compares the clinical characteristics of elderly patients with NTS bacteraemia with those of young adults. Of 272 adults with NTS bacteraemia identified in this study, 162 (59·6%) were aged ⩾55 years. EFIs were observed in 36% of the 162 patients. The most common EFIs in the elderly patients (⩾55 years) was mycotic aneurysm, followed by pulmonary infections and bone/joint infections. Elderly patients more often had chronic heart, lung, renal and malignant diseases, had more EFIs, and a higher 30-day mortality rate. Independent factors of 30-day mortality in elderly patients were solid-organ tumour [adjusted odds ratio (aOR) 4·4, P=0·003], mycotic aneurysm (aOR 3·7, P=0·023) and shock (aOR 12·1, P<0·0001). HIV infection, autoimmune diseases, and receipt of immunosuppressive therapy were more often observed in young patients.
The Size of a Hypergraph and its Matching Number
Authors: HUANG HAO , LOH PO-SHEN , SUDAKOV BENNY
Published: January 2012

More than forty years ago, Erdős conjectured that for any $t \leq \frac{n}{k}$, every k-uniform hypergraph on n vertices without t disjoint edges has at most max${\binom{kt-1}{k}, \binom{n}{k}-\binom{n-t+1}{k}\}$ edges. Although this appears to be a basic instance of the hypergraph Turán problem (with a t-edge matching as the excluded hypergraph), progress on this question has remained elusive. In this paper, we verify this conjecture for all $t < \frac{n}{3k^2}$. This improves upon the best previously known range $t = O\bigl(\frac{n}{k^3}\bigr)$, which dates back to the 1970s.
Observational bounds on atmospheric heating by aerosol absorption: Radiative signature of transatlantic dust
Authors: Davidi Amit , Kostinski Alex B. , Koren Ilan , Lehahn Yoav
Published: January 2012

Aerosols absorb solar radiation thus changing the atmospheric temperature profile but the overall magnitude of this effect is not known. To that end, Saharan dust emissions over the Atlantic Ocean provide an opportunity to examine aerosol‐related heating via satellite imaging. A major difficulty, however, is disentangling a straightforward heating signal caused by the absorbing dust from a meteorological signal, which originates from correlation between dust concentration and air temperature. To tackle the problem, we combine temperature (T) soundings, from the atmospheric infrared sounder (AIRS), with aerosol optical depth (τ) measurements, from the moderate resolution imaging spectroradiometer (MODIS), and data assimilation results from the global data assimilation system (GDAS). We introduce the quantity β(P) ≡ ∂TP/∂τ, the subscript indicating temperature at a given pressure, and study the observed (AIRS) vs. modeled (GDAS) vertical profiles of β(P). Using the vertical as well as horizontal patterns of β(P) and Δβ(P) ≡ βobs. − βmodl., we avoid instrumental and geographic artifacts and extract a remarkably robust radiative heating signal of about 2–4 K within the dust layer. The extracted signal peaks over the mid‐Atlantic Ocean, as a result of competing trends: “memory” of the dust source in the east, and mixing with transparent aerosol in the west.
Observed and modeled solar cycle variation in geocoronal hydrogen using NRLMSISE‐00 thermosphere conditions and the Bishop analytic exosphere model
Authors: Nossal S. M. , Mierkiewicz E. J. , Roesler F. L.
Published: January 2012

High precision observations during Solar Cycle 23 using the Wisconsin H‐alpha Mapper (WHAM) Fabry‐Perot quantify a factor of 1.5 ± 0.15 higher Balmer α column emission intensity during near‐solar‐maximum than during solar minimum conditions. An unresolved question is how does the observed solar cycle variation in the hydrogen column emission compare with that calculated from the hydrogen distribution in atmospheric models? We have compared WHAM solar minimum and near‐solar‐maximum column intensity observations with calculations using the thermospheric hydrogen density profile and background thermospheric conditions from the Mass Spectrometer Incoherent Scatter (NRLMSISE‐00) empirical model extended to exospheric altitudes using the analytic exosphere model of Bishop (1991). Using this distribution, we apply the lyao_rt global resonance radiative transfer code of Bishop (1999) to calculate expected intensities that would be observed from the ground for the viewing conditions of the observations. The observed intensities are brighter than those calculated for the corresponding conditions, indicating that when MSIS is used as the thermospheric hydrogen distribution the derived intensities are too low. Additionally, both the observed and calculated WHAM hydrogen column emission intensities are higher for near‐solar‐maximum than for solar minimum conditions. There is better agreement between observations and intensities calculated using the evaporative analytic exosphere model at solar maximum, suggesting an underestimation of modeled satellite atoms at high altitudes. This result is consistent with sensitivity studies using the option for a quasi‐exobase for satellite atoms to account for the creation of satellite orbits from charge exchange collisions.
First remote sensing observations of trifluoromethane (HFC‐23) in the upper troposphere and lower stratosphere
Authors: Harrison Jeremy J. , Boone Christopher D. , Brown Alexander T. , Allen Nicholas D. C. , Toon Geoffrey C. , Bernath Peter F.
Published: January 2012

This work reports the first remote sensing measurements of atmospheric HFC‐23 (CHF3) using solar occultation measurements made by the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE‐FTS) and the Jet Propulsion Laboratory Mark IV (MkIV) balloon interferometer. A total of 8809 ACE occultations measured between 2004 and 2010 have been processed, along with 24 MkIV occultations measured between 1989 and 2007. ACE data (yearly averages over the 10–25 km altitude range) in the tropics/subtropics (40°S–40°N) reveal a trend of 4.0 ± 1.6% per year in the growth of HFC‐23 for 2004–2009 (or 3.9 ± 1.2% per year for 2004–2010), slightly smaller than surface measurements from Cape Grim air archive samples over the same time period (4.7 ± 0.3% per year). The northern midlatitude and high‐latitude MkIV data (averaged over the 10–25 km altitude range) indicate a growth rate of 5.8 ± 0.3% per year over the period 1989–2007 (5.3 ± 0.4% per year for just the midlatitude data), similar to the Cape Grim surface trend of 5.7 ± 0.1% per year over the same period. The absolute HFC‐23 volume mixing ratios measured by ACE and MkIV in the upper troposphere/lower stratosphere are in good agreement (<5% bias) with each other but are ∼30% larger than ground‐based measurements. The source of this bias has not been definitively ascertained; however, spectroscopic errors are the most likely cause.
Incorporating numerical modeling into estimates of the detection capability of the IMS infrasound network
Authors: Le Pichon A. , Ceranna L. , Vergoz J.
Published: January 2012

To monitor compliance with the Comprehensive Nuclear‐Test ban Treaty (CTBT), a dedicated International Monitoring System (IMS) is being deployed. Recent global scale observations recorded by this network confirm that its detection capability is highly variable in space and time. Previous studies estimated the radiated source energy from remote observations using empirical yield‐scaling relations which account for the along‐path stratospheric winds. Although the empirical wind correction reduces the variance in the explosive energy versus pressure relationship, strong variability remains in the yield estimate. Today, numerical modeling techniques provide a basis to better understand the role of different factors describing the source and the atmosphere that influence propagation predictions. In this study, the effects of the source frequency and the stratospheric wind speed are simulated. In order to characterize fine‐scale atmospheric structures which are excluded from the current atmospheric specifications, model predictions are further enhanced by the addition of perturbation terms. A theoretical attenuation relation is thus developed from massive numerical simulations using the Parabolic Equation method. Compared with previous studies, our approach provides a more realistic physical description of long‐range infrasound propagation. We obtain a new relation combining a near‐field and a far‐field term, which account for the effects of both geometrical spreading and absorption. In the context of the future verification of the CTBT, the derived attenuation relation quantifies the spatial and temporal variability of the IMS infrasound network performance in higher resolution, and will be helpful for the design and prioritizing maintenance of any arbitrary infrasound monitoring network.
Formation and growth of ultrafine particles from secondary sources in Bakersfield, California
Authors: Ahlm Lars , Liu Shang , Day Douglas A. , Russell Lynn M. , Weber Robin , Gentner Drew R. , Goldstein Allen H. , DiGangi Josh P. , Henry Samuel B. , Keutsch Frank N. , VandenBoer Trevor C. , Markovic Milos Z. , Murphy Jennifer G. , Ren Xinrong , Scheller Scott
Published: January 2012

In this study, physical and chemical properties of ultrafine aerosol particles are investigated at an urban site in Bakersfield, California, during the CalNex 2010 (California Research at the Nexus of Air Quality and Climate Change) campaign in May and June. Ultrafine particle measurements include particle number size distributions by a scanning Differential Mobility Analyzer (DMA) and size resolved aerosol chemical composition determined with a High‐Resolution Time‐of‐Flight Aerosol Mass Spectrometer (HR‐ToF‐AMS). Growth events of ultrafine particles were observed on most days and had a very regular pattern. A nucleation mode centered at ∼20 nm appeared in the morning and grew to 40–100 nm throughout the day. Microphysical modeling and size‐resolved HR‐ToF‐AMS concentrations showed that organic components provided most of the particle growth in the ultrafine mode, and sulfate provided on most days only a minor contribution to the mass of this mode. The ultrafine particle mass was largely dominated by organics (77%), and was at maximum during the afternoon. Elemental carbon (EC) and the AMS tracer C4H9+ for hydrocarbon‐like organic aerosol (HOA) peaked in the early morning during rush hour, indicative of primary emissions. The fact that the particle number concentration peaked in the afternoon, when EC was at minimum, indicates that the midday increase in number concentration was likely due to new particle formation. The potential importance of solar radiation, the condensation sink of vapor on existing particles, concentrations of OH, O3, SO2, NH3, and VOCs for both condensational growth and new particle formation is evaluated based on the covariation of these parameters with ultrafine mass. The results suggest that the ultrafine particles are from secondary sources that are co‐emitted or co‐produced with glyoxal and formaldehyde.
Suppression of Rac1 activity at the apical membrane of MDCK cells is essential for cyst structure maintenance
Authors: Yagi Shunsuke , Matsuda Michiyuki , Kiyokawa Etsuko
Published: January 2012

Using MDCK cells that constitutively express a Förster resonance energy transfer biosensor, we found that Rac1 activity is homogenous at the entire plasma membrane in early stages of cystogenesis, whereas in later stages Rac1 activity is higher at the lateral membrane than at the apical plasma membrane. If Rac1 is activated at the apical membrane in later stages, however, the monolayer cells move into the luminal space. In these cells, tight junctions are disrupted, accompanied by mislocalization of polarization markers and disorientation of cell division. These observations indicate that Rac1 suppression at the apical membrane is essential for the maintenance of cyst structure.
Toxicology of Insecticides—Introductory Considerations
Authors: Marrs Timothy C
Published: January 2012

This chapter deals with some issues not covered by the remaining chapters in the book. These issues include the classification and regulation of pesticides and exposure (including exposure to mixtures of pesticides). Newer developments such as developmental neurotoxicity and probabilistic risk assessment are also examined. The complicated and confusing issue of nomenclature of pesticides is discussed as well as issues such as purity.
Comparative Metabolism and Toxicology of Pyrethroids in Mammals
Authors: Gammon Derek W , Chandrasekaran Appavu , ElNaggar Shaaban F
Published: January 2012

Pyrethroid insecticides are toxic to insects and mammals through effects on ion channels in the nervous system, with probable additional sites in muscle. Voltage-gated sodium channels (VGSCs) have been studied most extensively as target sites and there is evidence for two toxicity syndromes (types I and II), associated with different effects on VGSCs, based on the absence or presence of a cyano group in the alcohol moiety. Pyrethroids also have agonist effects on voltage-gated calcium channel subtype(s), which tend to show type I/II differences. There is also evidence for antagonist effects of type II pyrethroids on voltage and GABA-gated chloride channels. Correlations have been made between some ion channel effects and motor activity reductions and effects on the acoustic startle response in the rat. The former is non-specific for type I and II structures but the latter provides some evidence of separation of type I and II. Metabolic transformation of pyrethroids in mammals explains some of the relatively low toxicity of these insecticides in mammals versus insects. Pyrethroids are neurotoxic as the parent; oxidative and hydrolytic metabolites are considered to have little or no toxicity. A wide range of metabolic stability for commercial pyrethroids has been shown. The clinical signs of neurotoxicity following oral gavage dosing in rodents generally correlate with peak blood/plasma concentrations. Similarly, reversibility of neurotoxicity after oral gavage dosing usually occurs within 24h and correlates with large decreases in blood/plasma concentrations.
Toxicology of Some Insecticides Not Discussed Elsewhere
Authors: Marrs Timothy C , Dewhurst Ian C
Published: January 2012

The insecticides discussed in this chapter comprise a group of insecticides that are not covered elsewhere in this book, with the exception of fipronil which is discussed in detail in Chapter 12. The phenylpyrazoles (fipronil and ethiprole) are antagonists at the γ-aminobutyric acid A (GABAA) receptor. Indoxacarb is anoxadiazine, which exerts its insecticidal action at voltage-dependent sodium channels. Amitraz is an amidine acaricide and insecticide used on crops and farm animals and is thought to act via the octopamine receptors in insects. The mode of action of pyridalyl on insects is unclear. Unsurprisingly, in view of their disparate mode of actions in insects, the insecticides discussed in this chapter have differing toxicities in mammals.