bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of Si and REE on the Corrosion Resistance of ZnAl40Cu3 Alloy
Authors: Michalik Rafał
Published: December 2013

The corrosion resistance of ZnAl40Cu3 alloy are presented in the paper. Base alloy, alloy with silicon and alloy with silicon and rare earth elements were tested. The scope of the examination included: potentiodynamic and potentiostatic examinations, studies of the alloy surface condition after corrosion tests. The studies have shown, that the addition of rare earth elements improves the corrosion resistance of the ZnAl40Cu3 alloy in 3% NaCl environment. The presence of the silicon precipitates does not decrease the corrosion resistance of the ZnAl40Cu3 alloy in the 3% NaCl environment
Influence of the Type of Medical Sterilisation on Electrochemical Properties of Passive Layer Created on X10CrNi 18-8 Steel
Authors: Przondziono Joanna , Walke Witold
Published: December 2013

The study presents results of impedance tests performed for wires made of X10CrNi 18-8 steel after electrochemical polishing and chemical passivation, subject to medical sterilisation with pressurised water steam or ethylene oxide. In order to determine the impact of sterilising agent on electrochemical characteristics of the passive layer, impedance measurements were made. Measurements were made with application of measurement system Auto Lab PGSTAT 302N equipped with FRA2 (Frequency Response Analyser) module. Impedance spectra of the system were determined in the tests and data obtained in the measurement was matched to the equivalent system. It made the ground for determination of numerical values of resistance and capacitance of the analysed systems. Impedance spectra of the tested system are presented in the form of Nyquist diagrams for various values of frequency, and as Bode diagrams. On the ground of performed test it was explicitly proved that application of steam sterilisation and sterilisation with ethylene oxide of wires made of X10CrNi 18-8 steel after chemical passivation used for urological guide wires has a favourable impact on their electrochemical characteristics.
Technological Effects of Metallurgical Industry Restructuring in Poland
Authors: Gajdzik Bożena , Janiszewski Krystian
Published: December 2013

The publication presents changes occurring in technological processes of producing steel after transformation of economic system in Poland after year 1989 and conducted repair programs within restructuring of metallurgical industry of iron and steel. Changes were based on withdrawals of economically unprofitable technologies, including open hearth furnaces through expansion of electrical and converter technologies of steel manufacturing up to activities which were connected with changing the profile of manufactured assortment.
Evaluation of the Applicability of Sanicro 25 Steel in Supercritical Boilers
Authors: Jamrozik Przemysław , Sozańska Maria
Published: December 2013

We examine the mechanical and physical properties of Sanicro 25 steel that are relevant to the performance requirements of supercritical boilers (e.g., resistance to high-temperature corrosion). Sanicro 25 is mainly used in the construction of power plant components. Materials research has demonstrated the stability of properties at elevated temperatures (700 to 750°C) during long-term use. We conducted tests of corrosion resistance for Sanicro 25 steel, and confirmed its resistance to oxidation in steam and exhaust gas heat .
Metallurgical Quality of Feed Ingots and Castings Made from Nickel and Cobalt Superalloys
Authors: Binczyk Franciszek , Cwajna Jan , Gradoń Paweł , Sozańska Maria , Cieśla Marek
Published: December 2013

The paper presents the results of ATD thermal analysis of feed ingots (master heat) and castings made from IN-713C, MAR-247 and MAR-509 superalloys. Metallurgical quality assessment was made based on the analysis of dT/dt curve in rage from Teutto Tsol. Furthermore, impurities (oxides of Al, Zr, Hf, Cr etc.) have been identified inside the shrinkage cavities of feed ingots and castings. Significant similarities has been observed between impurities found in ingots, ATD test samples and finished castings. It has been demonstrated that ATD analysis of samples taken from different parts of feed ingot can be effective method of metallurgical quality assessment for these ingots.
Production Methods of Thin, Narrow and Profiled Steel Strips
Authors: Herian Jerzy , Aniołek Krzystof
Published: December 2013

This paper is a synthetic presentation of the current state of knowledge on the fundamentals of cold production of thin and narrow steel strips. Such strips are semi-finished products used to manufacture final products which are widely used in a number of industries. The production devices are characterised and methods as well as technologies of their manufacture are discussed. For cases where wire is flattened to obtain strips with naturally rounded edges, the deformation phases with a uniform and non-uniform draft across the width of the strip have been identified. Changes in the widening coefficient and the rounding radius of the strip edge are described for these phases as a function of draft.
Influence of Copper Addition on Structure and Hardness of the ZnAl40Cu3 Alloy after Heat Treatment
Authors: Michalik Rafał , Tomaszewska Agnieszka
Published: December 2013

The effect of heat treatment on the structure and hardness of the ZnAl240Cu3 alloy is presented in the paper. ZnAl40 and ZnAl40Cu3 alloys were tested. The scope of the examination included: dilatometry, structural and hardness tests. There are two transformations taking place during the heating and the reverse transformation during cooling. Most important for the alloy is the first transormation which occurs at lower temperatures (from 104°C to 131°C). There are found, that long-term soaking at 185°C results in a significant decrease in the hardness of the ZnAl40Cu3.alloy. The reason for the observed decrease in the hardness of the ZnAl40Cu3 alloy by soaking at a temperature of 185°C is primarily disappearance of dendrites.
Role for σ38 in Prolonged Survival of Escherichia coli in Drosophila melanogaster
Authors: Shiratsuchi Akiko , Shimamoto Naoto , Nitta Mao , Tuan Tran Quoc , Firdausi Afwa , Gawasawa Mitsuko , Yamamoto Kaneyoshi , Ishihama Akira , Nakanishi Yoshinobu
Published: December 2013

Bacteria adapt themselves to host environments by altering the pattern of gene expression. The promoter-recognizing subunit σ of bacterial RNA polymerase plays a major role in the selection of genes to be transcribed. Among seven σ factors of Escherichia coli, σ38 is responsible for the transcription of genes in the stationary phase and under stressful conditions. We found a transient increase of σ38 when E. coli was injected into the hemocoel of Drosophila melanogaster. The loss of σ38 made E. coli rapidly eliminated in flies, and flies infected with σ38-lacking E. coli stayed alive longer than those infected with the parental strain. This was also observed in fly lines defective in humoral immune responses, but not in flies in which phagocytosis was impaired. The lack of σ38 did not influence the susceptibility of E. coli to phagocytosis, but made them vulnerable to killing after engulfment. The changes caused by the loss of σ38 were recovered by the forced expression of σ38-encoding rpoS as well as σ38-regulated katE and katG coding for enzymes that detoxify reactive oxygen species. These results collectively suggested that σ38 contributes to the prolonged survival of E. coli in Drosophila by inducing the production of enzymes that protect bacteria from killing in phagocytes. Considering the similarity in the mechanism of innate immunity against invading bacteria between fruit flies and humans, the products of these genes could be new targets for the development of more effective antibacterial remedies.
ADAM17-Mediated Shedding of FcγRIIIA on Human NK Cells: Identification of the Cleavage Site and Relationship with Activation
Authors: Lajoie Laurie , Congy-Jolivet Nicolas , Bolzec Armelle , Gouilleux-Gruart Valérie , Sicard Elodie , Sung Hsueh Cheng , Peiretti Frank , Moreau Thierry , Vié Henri , Clémenceau Béatrice , Thibault Gilles
Published: December 2013

FcγRIIIA/CD16A, the low-affinity receptor for the IgG Fc portion expressed on human CD56dim NK cells and involved in Ab-dependent cell cytotoxicity, is shed upon NK cell activation. We found that recombinant a disintegrin and metalloprotease (ADAM) 17 cleaved the ectodomain of FcγRIIIA/CD16A and a peptide for which the sequence encompasses aa 191–201 of the FcγRIIIA/CD16A stalk region but not ADAM10. MALDI-TOF analysis revealed that the peptide was cleaved between Ala195 and Val196 (i.e., 1 aa upstream of the expected position). This location of the cleavage site was confirmed by the finding that ADAM17 failed to cleave a peptide in which Ala and Val were reversed. ADAM17 was found to be expressed on NK cells, and stimulation with PMA or N-ethyl-maleimide resulted in the shedding of FcγRIIIA/CD16A and CD62L, a specific substrate of ADAM17. Selective inhibition of ADAM17 prevented the shedding of both molecules. Moreover, the shedding of FcγRIIIA/CD16A was strongly correlated with degranulation when a wide range of CD56dim NK cell activating receptors were stimulated, whereas both ADAM17-dependent shedding and internalization were involved in FcγRIIIA/CD16A downmodulation when the latter was engaged. Finally, the shedding of FcγRIIIA/CD16A was restricted to activated cells, suggesting that ADAM17 acts mainly, if not exclusively, in cis. Taken together, our results demonstrated for the first time, to our knowledge, at the molecular level that ADAM17 cleaves the stalk region of FcγRIIIA/CD16A and identified its cleavage site. The shedding of FcγRIIIA/CD16A was at least partially ADAM17 dependent, and it may be considered as a marker of FcγRIIIA/CD16A-independent NK cell activation highly correlated with degranulation.
Arsenic Trioxide and Other Arsenical Compounds Inhibit the NLRP1, NLRP3, and NAIP5/NLRC4 Inflammasomes
Authors: Maier Nolan K. , Crown Devorah , Liu Jie , Leppla Stephen H. , Moayeri Mahtab
Published: December 2013

Inflammasomes are large cytoplasmic multiprotein complexes that activate caspase-1 in response to diverse intracellular danger signals. Inflammasome components termed nucleotide-binding oligomerization domain–like receptor (NLR) proteins act as sensors for pathogen-associated molecular patterns, stress, or danger stimuli. We discovered that arsenicals, including arsenic trioxide and sodium arsenite, inhibited activation of the NLRP1, NLRP3, and NAIP5/NLRC4 inflammasomes by their respective activating signals, anthrax lethal toxin, nigericin, and flagellin. These compounds prevented the autoproteolytic activation of caspase-1 and the processing and secretion of IL-1β from macrophages. Inhibition was independent of protein synthesis induction, proteasome-mediated protein breakdown, or kinase signaling pathways. Arsenic trioxide and sodium arsenite did not directly modify or inhibit the activity of preactivated recombinant caspase-1. Rather, they induced a cellular state inhibitory to both the autoproteolytic and substrate cleavage activities of caspase-1, which was reversed by the reactive oxygen species scavenger N-acetylcysteine but not by reducing agents or NO pathway inhibitors. Arsenicals provided protection against NLRP1-dependent anthrax lethal toxin–mediated cell death and prevented NLRP3-dependent neutrophil recruitment in a monosodium urate crystal inflammatory murine peritonitis model. These findings suggest a novel role in inhibition of the innate immune response for arsenical compounds that have been used as therapeutics for a few hundred years.
Aged Mice Are Unable To Mount an Effective Myeloid Response to Sepsis
Authors: Nacionales Dina C. , Gentile Lori F. , Vanzant Erin , Lopez M. Cecilia , Cuenca Angela , Cuenca Alex G. , Ungaro Ricardo , Li Yi , Baslanti Tezcan Ozrazgat , Bihorac Azra , Moore Frederick A. , Baker Henry V. , Leeuwenburgh Christiaan , Moldawer Lyle L. , Efron Philip A.
Published: December 2013

The elderly have increased morbidity and mortality following sepsis; however, the cause(s) remains unclear. We hypothesized that these poor outcomes are due in part to defects in innate immunity, rather than to an exaggerated early inflammatory response. Young (6–12 wk) or aged (20–24 mo) mice underwent polymicrobial sepsis, and subsequently, the aged mice had increased mortality and defective peritoneal bacterial clearance compared with young mice. No differences were found in the magnitude of the plasma cytokine responses. Although septic aged mice displayed equivalent or increased numbers of circulating, splenic, and bone marrow myeloid cells, some of these cells exhibited decreased phagocytosis, reactive oxygen species production, and chemotaxis. Blood leukocyte gene expression was less altered in aged versus young mice 1 d after sepsis. Aged mice had a relative inability to upregulate gene expression of pathways related to neutrophil-mediated protective immunity, chemokine/chemokine receptor binding, and responses to exogenous molecules. Expression of most MHC genes remained more downregulated in aged mice at day 3. Despite their increased myeloid response to sepsis, the increased susceptibility of aged mice to sepsis appears not to be due to an exaggerated inflammatory response, but rather, a failure to mount an effective innate immune response.
Cutting Edge: DNAX Accessory Molecule 1–Deficient CD8+ T Cells Display Immunological Synapse Defects That Impair Antitumor Immunity
Authors: Ramsbottom Kelly M. , Hawkins Edwin D. , Shimoni Raz , McGrath Mairi , Chan Christopher J. , Russell Sarah M. , Smyth Mark J. , Oliaro Jane
Published: December 2013

DNAX accessory molecule 1 (DNAM-1) is expressed on all CD8+ T cells and promotes their activation and effector function. DNAM-1 interacts with LFA-1, a critical molecule for immunological synapse formation between T cells and APCs, and for cytotoxic killing of target cells. Mice that lack DNAM-1 display abnormal T cell responses and antitumor activity; however, the mechanism involved is unclear. In this article, we show that DNAM-1 deficiency results in reduced proliferation of CD8+ T cells after Ag presentation and impaired cytotoxic activity. We also demonstrate that DNAM-1–deficient T cells show reduced conjugations with tumor cells and decreased recruitment of both LFA-1 and lipid rafts to the immunological synapse, which correlates with reduced tumor cell killing in vitro. This synapse defect may explain why DNAM-1–deficient mice cannot clear tumors in vivo, and highlights the importance of DNAM-1 and the immunological synapse in T cell–mediated antitumor immunity.
Cytosolic Group IVA and Calcium-Independent Group VIA Phospholipase A2s Act on Distinct Phospholipid Pools in Zymosan-Stimulated Mouse Peritoneal Macrophages
Authors: Gil-de-Gómez Luis , Astudillo Alma M. , Guijas Carlos , Magrioti Victoria , Kokotos George , Balboa María A. , Balsinde Jesús
Published: December 2013

Phospholipase A2s generate lipid mediators that constitute an important component of the integrated response of macrophages to stimuli of the innate immune response. Because these cells contain multiple phospholipase A2 forms, the challenge is to elucidate the roles that each of these forms plays in regulating normal cellular processes and in disease pathogenesis. A major issue is to precisely determine the phospholipid substrates that these enzymes use for generating lipid mediators. There is compelling evidence that group IVA cytosolic phospholipase A2 (cPLA2α) targets arachidonic acid–containing phospholipids but the role of the other cytosolic enzyme present in macrophages, the Ca2+-independent group VIA phospholipase A2 (iPLA2β) has not been clearly defined. We applied mass spectrometry–based lipid profiling to study the substrate specificities of these two enzymes during inflammatory activation of macrophages with zymosan. Using selective inhibitors, we find that, contrary to cPLA2α, iPLA2β spares arachidonate-containing phospholipids and hydrolyzes only those that do not contain arachidonate. Analyses of the lysophospholipids generated during activation reveal that one of the major species produced, palmitoyl-glycerophosphocholine, is generated by iPLA2β, with minimal or no involvement of cPLA2α. The other major species produced, stearoyl-glycerophosphocholine, is generated primarily by cPLA2α. Collectively, these findings suggest that cPLA2α and iPLA2β act on different phospholipids during zymosan stimulation of macrophages and that iPLA2β shows a hitherto unrecognized preference for choline phospholipids containing palmitic acid at the sn-1 position that could be exploited for the design of selective inhibitors of this enzyme with therapeutic potential.
Lack of Galactosylation Enhances the Pathogenic Activity of IgG1 but Not IgG2a Anti-Erythrocyte Autoantibodies
Authors: Ito Kiyoaki , Furukawa Jun-ichi , Yamada Kazunori , Tran Ngoc Lan , Shinohara Yasuro , Izui Shozo
Published: December 2013

IgG bears asparagine-linked oligosaccharide side chains in the Fc region. Variations in their extent of galactosylation and sialylation could modulate IgG Fc-dependent effector functions, and hence Ab activity. However, it has not yet been clarified whether the pathogenic potential of IgG autoantibodies is consistently enhanced by the absence of galactose residues per se or the lack of terminal sialylation, which is dependent on galactosylation. Moreover, it remains to be defined whether the increased pathogenicity of agalactosylated IgG is related to activation of the complement pathway by mannose-binding lectin, as suggested by in vitro studies. Using a murine model of autoimmune hemolytic anemia, we defined the contribution of galactosylation or sialylation to the pathogenic activity of IgG1 and IgG2a anti-erythrocyte class-switch variants of 34-3C monoclonal autoantibody. We generated their degalactosylated or highly sialylated glycovariants and compared their pathogenic effects with those of highly galactosylated or desialylated counterparts. Our results demonstrated that lack of galactosylation, but not sialylation, enhanced the pathogenic activity of 34-3C IgG1, but not IgG2a autoantibodies. Moreover, analysis of in vivo complement activation and of the pathogenic activity in mice deficient in C3 or IgG FcRs excluded the implication of mannose-binding lectin-mediated complement activation in the enhanced pathogenic effect of agalactosylated IgG1 anti-erythrocyte autoantibodies.
Thymic Medullary Epithelium and Thymocyte Self-Tolerance Require Cooperation between CD28–CD80/86 and CD40–CD40L Costimulatory Pathways
Authors: Williams Joy A. , Zhang Jingjing , Jeon Hyein , Nitta Takeshi , Ohigashi Izumi , Klug David , Kruhlak Michael J. , Choudhury Baishakhi , Sharrow Susan O. , Granger Larry , Adams Anthony , Eckhaus Michael A. , Jenkinson S. Rhiannon , Richie Ellen R. , Gress Ronald E. , Takahama Yousuke , Hodes Richard J.
Published: December 2013

A critical process during thymic development of the T cell repertoire is the induction of self-tolerance. Tolerance in developing T cells is highly dependent on medullary thymic epithelial cells (mTEC), and mTEC development in turn requires signals from mature single-positive thymocytes, a bidirectional relationship termed thymus crosstalk. We show that CD28–CD80/86 and CD40–CD40L costimulatory interactions, which mediate negative selection and self-tolerance, upregulate expression of LTα, LTβ, and receptor activator for NF-κB in the thymus and are necessary for medullary development. Combined absence of CD28–CD80/86 and CD40–CD40L results in profound deficiency in mTEC development comparable to that observed in the absence of single-positive thymocytes. This requirement for costimulatory signaling is maintained even in a TCR transgenic model of high-affinity TCR–ligand interactions. CD4 thymocytes maturing in the altered thymic epithelial environment of CD40/CD80/86 knockout mice are highly autoreactive in vitro and are lethal in congenic adoptive transfer in vivo, demonstrating a critical role for these costimulatory pathways in self-tolerance as well as thymic epithelial development. These findings demonstrate that cooperativity between CD28–CD80/86 and CD40–CD40L pathways is required for normal medullary epithelium and for maintenance of self-tolerance in thymocyte development.
T Cell Ig and Mucin Domain–Containing Protein 3 Is Recruited to the Immune Synapse, Disrupts Stable Synapse Formation, and Associates with Receptor Phosphatases
Authors: Clayton Kiera L. , Haaland Matthew S. , Douglas-Vail Matthew B. , Mujib Shariq , Chew Glen M. , Ndhlovu Lishomwa C. , Ostrowski Mario A.
Published: December 2013

CD8+ CTLs are adept at killing virally infected cells and cancer cells and releasing cytokines (e.g., IFN-γ) to aid this response. However, during cancer and chronic viral infections, such as with HIV, this CTL response is progressively impaired due to a process called T cell exhaustion. Previous work has shown that the glycoprotein T cell Ig and mucin domain–containing protein 3 (Tim-3) plays a functional role in establishing T cell exhaustion. Tim-3 is highly upregulated on virus and tumor Ag-specific CD8+ T cells, and antagonizing Tim-3 helps restore function of CD8+ T cells. However, very little is known of how Tim-3 signals in CTLs. In this study, we assessed the role of Tim-3 at the immunological synapse as well as its interaction with proximal TCR signaling molecules in primary human CD8+ T cells. Tim-3 was found within CD8+ T cell lipid rafts at the immunological synapse. Blocking Tim-3 resulted in a significantly greater number of stable synapses being formed between Tim-3hiCD8+ T cells and target cells, suggesting that Tim-3 plays a functional role in synapse formation. Further, we confirmed that Tim-3 interacts with Lck, but not the phospho-active form of Lck. Finally, Tim-3 colocalizes with receptor phosphatases CD45 and CD148, an interaction that is enhanced in the presence of the Tim-3 ligand, galectin-9. Thus, Tim-3 interacts with multiple signaling molecules at the immunological synapse, and characterizing these interactions could aid in the development of therapeutics to restore Tim-3–mediated immune dysfunction.
Aerosol seasonal variations over urban sites in Ukraine and Belarus according to AERONET and POLDER measurements
Authors: Milinevsky G. , Danylevsky V. , Bovchaliuk V. , Bovchaliuk A. , Goloub Ph. , Dubovik O. , Kabashnikov V. , Chaikovsky A. , Mishchenko M. , Sosonkin M.
Published: December 2013

Abstract. The paper presents an investigation of aerosol seasonal variations in several urban sites in the East European region. Our analysis of seasonal variations of optical and physical aerosol parameters is based on the sun-photometer 2008–2012 data from three urban ground-based AERONET sites in Ukraine (Kyiv, Kyiv-AO, and Lugansk) and one site in Belarus (Minsk), as well as on satellite POLDER instrument data for urban areas in Ukraine. Aerosol amount and optical thickness values exhibit peaks in the spring (April–May) and late summer (August), whereas minimum values are seen in late autumn over the Kyiv and Minsk sites. The results show that aerosol fine mode particles are most frequently detected during the spring and late summer seasons. The seasonal variation similarity in the two regions points to the resemblance in basic aerosol sources which are closely related to properties of aerosol particles. However the aerosol amount and properties change noticeably from year to year and from region to region. The analysis of seasonal aerosol optical thickness variations over the urban sites in the eastern and western parts of Ukraine according to both ground-based and POLDER data exhibits the same traits. In particular, over Kyiv, the values of the Angstrom exponent are lower in April of 2011 than in 2009 and 2010, while aerosol optical thickness values are almost the same, which can be explained by an increase in the amount of coarse mode particles in the atmosphere, such as Saharan dust. Moreover, the coarse mode particles prevailed over suburbs and the center of Kyiv during a third of all available days of observation in 2012. In general, the fine and coarse mode particles' modal radii averaged over 2008–2012 range from 0.1 to 0.2 μm and 2 to 5 μm, respectively, during the period from April to September. The single scattering albedo and refractive index values of these particles correspond to a mix of urban-industrial, biomass burning, and dust aerosols. In addition, strongly absorbing particles were observed in the period from October to March, and the modal radius of fine and coarse mode particles changed from month to month widely.
The role of iron species on the competition of two coastal diatoms, Skeletonema costatum and Thalassosira weissflogii
Authors: Li S.-X. , Liu F.-J. , Zheng F.-Y. , Zuo Y.-G. , Huang X.-G.
Published: December 2013

Abstract. Coastal diatoms are often exposed to macronutrient (N and P) and Fe enrichment. However, how these exposures influence on Fe biogeochemical cycle and then on diatom interspecific competition is unknown. In this study, two non-toxic coastal diatoms, Skeletonema costatum and Thalassosira weissflogii were exposed to N, P, and Fe enrichment for four-day. The growth of algae was co-controlled by macronutrient and Fe species (Fe (III)-EDTA, Fe(OH)3, dissolved, colloidal, and particulate Fe from culture medium). The influence of Fe species on algal cell density was more significant than macronutrient. When S. costatum coexisted with T. weissflogii, their cell density ratios were ranged between 5.57–7.03 times, indicating that S. costatum was more competitive than T. weissflogii. There were not significant correlation between cell density ratio and iron requirement, including iron adsorption and absorption per cell, iron adsorption and absorption by all algal cells. As Fe complexing ligands, algal exudates can promote diatom growth itself and such promotion on S. costatum was more obvious than that on T. weissflogii. Iron species was a key determinant on interspecific competition of coastal diatom, and the degree of bioavailability was described as follows: dissolved iron from own exudates > colloidal iron from own exudates > particulate iron from own exudates > particulate iron from another algal exudates > colloidal iron from another algal exudates > dissolved iron from another algal exudates > Fe (III)-EDTA> Fe (OH)3.
The East Asian winter monsoon variability in response to precession during the past 150 000 yr
Authors: Yamamoto M. , Sai H. , Chen M.-T. , Zhao M.
Published: December 2013

Abstract. The response of the East Asian winter monsoon variability to orbital forcing is still unclear, and hypotheses are controversial. We present a 150 000 yr record of sea surface temperature difference (ΔSST) between the South China Sea and other Western Pacific Warm Pool regions as a proxy for the intensity of the Asian winter monsoon, because the winter cooling of the South China Sea is caused by the cooling of surface water at the northern margin and the southward advection of cooled water due to winter monsoon winds. The ΔSST showed dominant precession cycles during the past 150 000 yr. The ΔSST varies at precessional band and supports the hypothesis that monsoon is regulated by insolation changes at low-latitudes (Kutzbach, 1981), but contradicts previous suggestions based on marine and loess records that eccentricity controls variability on glacial–interglacial timescales. Maximum winter monsoon intensity corresponds to the May perihelion at precessional band, which is not fully consistent with the Kutzbach model of maximum winter monsoon at the June perihelion. Variation in the East Asian winter monsoon was anti-phased with the Indian summer monsoon, suggesting a linkage of dynamics between these two monsoon systems on an orbital timescale.
Effects of land-conversion in a biosphere–atmosphere model of Northern South America – Part 2: Case studies on the mechanisms of differential hydrometeorology
Authors: Knox R. G. , Longo M. , Swann A. L. S. , Zhang K. , Levine N. M. , Moorcroft P. R. , Bras R. L.
Published: December 2013

Abstract. A physical model of the terrestrial biosphere (Ecosystem Demography Model) is combined with an atmospheric model (Brazilian Regional Atmospheric Modeling System) to investigate how land conversion in the Amazon and Northern South America have changed the hydrology of the region. Two numerical realizations of the structure and composition of terrestrial vegetation are used as boundary conditions in a simulation of the regional land surface and atmosphere. One realization seeks to capture the present day vegetation condition that includes human deforestation and land-conversion, the other is an estimate of the potential structure and composition of the region without human influence. Two focus areas, one in the Brazilian state of Pará, and one in the Bolivian Chaco, are selected to scrutinize the basis of differential hydrology and hydrometeorology manifested by the two scenarios. In both cases, deforestation led to increases in total surface albedo, driving decreases in net-radiation, boundary layer moist static energy and ultimately convective precipitation. In the case of the Bolivian Chaco, decreased precipitation was also a result of decreased advective moisture transport, indicating that differences in local hydrometeorology may manifest via teleconnections with the greater region.
Trends and variability in extreme precipitation indices over Maghreb countries
Authors: Tramblay Y. , El Adlouni S. , Servat E.
Published: December 2013

Abstract. Maghreb countries are highly vulnerable to extreme hydrological events, such as floods and droughts, driven by the strong variability of precipitation. While several studies have analyzed the presence of trends in precipitation records for the Euro-Mediterranean basin, this study provides a regional assessment of trends on its southernmost shores. A database of 22 stations located in Algeria, Morocco and Tunisia with between 33 and 59 yr of daily precipitation records is considered. The change points and trends are analyzed for eleven climate indices, describing several features of the precipitation regime. The issue of conducting multiple hypothesis tests is addressed through the implementation of a false discovery rate procedure. The spatial and interannual variability of the precipitation indices at the different stations are analyzed and compared with large-scale atmospheric circulation patterns, including the North Atlantic Oscillation (NAO), western Mediterranean Oscillation (WEMO), Mediterranean Oscillation (MO) and El Niño–Southern Oscillation (ENSO). Results show a strong tendency towards a decrease of precipitation totals and wet days together with an increase in the duration of dry periods, mainly for Morocco and western Algeria. On the other hand, only a few significant trends are detected for heavy precipitation indices. The NAO and MO patterns are well correlated with precipitation indices describing precipitation amounts, the number of dry days and the length of wet and dry periods, whereas heavy precipitation indices exhibit a strong spatial variability and are only moderately correlated with large-scale atmospheric circulation patterns.
Simulating global and local surface temperature changes due to Holocene anthropogenic land cover change
Authors: He Feng , Vavrus Steve J. , Kutzbach John E. , Ruddiman William F. , Kaplan Jed O. , Krumhardt Kristen M.
Published: December 2013

Surface albedo changes from anthropogenic land cover change (ALCC) represent the second largest negative radiative forcing behind aerosol during the industrial era. Using a new reconstruction of ALCC during the Holocene era by Kaplan et al. (2011), we quantify the local and global temperature response induced by Holocene ALCC in the Community Climate System Model, version 4. We find that Holocene ALCC causes a global cooling of 0.17°C due to the biogeophysical effects of land‐atmosphere exchange of momentum, moisture, and radiative and heat fluxes. On the global scale, the biogeochemical effects of Holocene ALCC from carbon emissions dominate the biogeophysical effects by causing 0.9°C global warming. The net effects of Holocene ALCC amount to a global warming of 0.73°C during the preindustrial era, which is comparable to the ~0.8°C warming during industrial times. On local to regional scales, such as parts of Europe, North America, and Asia, the biogeophysical effects of Holocene ALCC are significant and comparable to the biogeochemical effect.
Effects of waves on coastal water dispersion in a small estuarine bay
Authors: Delpey M. T. , Ardhuin F. , Otheguy P. , Jouon A.
Published: December 2013

A three‐dimensional wave‐current model is used to investigate wave‐induced circulations in a small estuarine bay and its impact on freshwater exchanges with the inner shelf, related to stratified river plume dispersion. Modeled salinity fields exhibit a lower salinity surface layer due to river outflows, with typical depth of 1 m inside the bay. The asymmetric wave forcing on the bay circulation, related to the local bathymetry, significantly impacts the river plumes. It is found that the transport initiated in the surf zone by the longshore current can oppose and thus reduce the primary outflow of freshwater through the bay inlets. Using the model to examine a high river runoff event occurring during a high‐energy wave episode, waves are found to induce a 24 h delay in freshwater evacuation. At the end of the runoff event, waves have reduced the freshwater flux to the ocean by a factor 5, and the total freshwater volume inside the bay is increased by 40%. According to the model, and for this event, the effect of the surf zone current on the bay flushing is larger than that of the wind. The freshwater balance is sensitive to incident wave conditions. Maximum freshwater retention is found for intermediate offshore wave heights 1 m < Hs < 2 m. For higher‐energy waves, the increase in the longshore current reduces the retention, which is two times lower for Hs = 4 m than for Hs = 2 m.
A sampling method for improving the representation of spatially varying precipitation and soil moisture using the Simple Biosphere Model
Authors: Medina Isaac D. , Denning A. Scott , Baker Ian T. , Ramirez Jorge A. , Randall David A.
Published: December 2013

Representing spatially varying precipitation for current grid length scales used in General Circulation Models (GCMs) is a continuing challenge. Furthermore, to fully capture the hydrologic effects of nonuniform precipitation, a representation of soil moisture heterogeneity and distribution of spatially varying precipitation must exist within the same framework. For this study, the explicit and sampling methods of Sellers et al. (2007) are tested off‐line using the Simple Biosphere Model (SiB3) in an arid, semiarid, and wet site, and are numerically compared to the bulk method, which is currently used in GCMs. To carry out the numerical experiments, an arbitrary grid area was defined by (1) a single instance of SiB3 (bulk method), (2) 100 instances of SiB3 (explicit method), and (3) less than 100 instances of SiB3 (sampling method). Precipitation was randomly distributed over fractions of the grid area for the explicit and sampling methods, while the standard SiB3 exponential distribution relating precipitation intensity to the grid area wet fraction was used in the bulk method. Comparing the sampling and bulk method to the explicit method indicates that 10 instances of SiB3 in the sampling method better captures the spatial variability in soil moisture and grid area flux calculations produced by the explicit method, and deals realistically with spatially varying precipitation at little additional computational cost to the bulk method.
Carbon Nanotube and Graphene‐based Bioinspired Electrochemical Actuators
Authors: Kong Lirong , Chen Wei
Published: December 2013

Bio‐inspired actuation materials, also called artificial muscles, have attracted great attention in recent decades for their potential application in intelligent robots, biomedical devices, and micro‐electro‐mechanical systems. Among them, ionic polymer metal composite (IPMC) actuator has been intensively studied for their impressive high‐strain under low voltage stimulation and air‐working capability. A typical IPMC actuator is composed of one ion‐conductive electrolyte membrane laminated by two electron‐conductive metal electrode membranes, which can bend back and forth due to the electrode expansion and contraction induced by ion motion under alternating applied voltage. As its actuation performance is mainly dominated by electrochemical and electromechanical process of the electrode layer, the electrode material and structure become to be more crucial to higher performance. The recent discovery of one dimensional carbon nanotube and two dimensional graphene has created a revolution in functional nanomaterials. Their unique structures render them intriguing electrical and mechanical properties, which makes them ideal flexible electrode materials for IPMC actuators in stead of conventional metal electrodes. Currently although the detailed effect caused by those carbon nanomaterial electrodes is not very clear, the presented outstanding actuation performance gives us tremendous motivation to meet the challenge in understanding the mechanism and thus developing more advanced actuator materials. Therefore, in this review IPMC actuators prepared with different kinds of carbon nanomaterials based electrodes or electrolytes are addressed. Key parameters which may generate important influence on actuation process are discussed in order to shed light on possible future research and application of the novel carbon nanomateials based bio‐inspired electrochemical actuators.
Welche anorganischen Strukturen sind am komplexesten?
Authors: Krivovichev Sergey V.
Published: December 2013

Die Entdeckung, dass Röntgenstrahlen an Kristallen gebeugt werden, markierte den Beginn einer neuen wissenschaftlichen Ära, die eine Vielzahl von erstaunlichen Entdeckungen über die Strukturen und Funktionen von Materie auf atomarer und molekularer Skala hervorgebracht hat. Über die letzten hundert Jahre wurden ungefähr 150 000 anorganische Kristallstrukturen aufgeklärt und bildlich dargestellt. Das Aufkommen neuer Technologien wie Flächendetektoren und Synchrotronstrahlung führte zur Strukturlösung von kristallinen Verbindungen nie dagewesener Komplexität. Allerdings fehlt bis heute eine klare quantitative Definition der strukturellen Komplexität von Kristallen. In diesem Kurzaufsatz nutzen wir die mathematische Informationstheorie, um den Komplexitätsgrad anorganischer Strukturen in Form ihres Informationsgehaltes zu charakterisieren.
Rheology and morphology of polyester/thermoplastic flour blends
Authors: Démé Florian , Peuvrel‐Disdier Edith , Vergnes Bruno
Published: December 2013

Two maize flours (standard and waxy grades) were plasticized in an internal mixer with a constant amount of water and two glycerol contents. The resulting thermoplastic flours (TPFs) were characterized in dynamic oscillatory shear and creep/recovery rheometry. They displayed two different behaviors: the viscoelastic behavior of a high‐molecular‐weight polymer for the first one and a gel‐like behavior for the second one. The TPFs were then mixed with a copolyester [poly(butylene adipate–terephtalate)]. All of the blends contained the same volume fractions and were prepared with the same mixing conditions. The morphology and rheological behavior of each blend were characterized. Different morphologies, ranging from cocontinuous to nodular, were observed. In fixed mixing conditions, the blend morphology was shown to be governed by the rheological behavior of the starchy phase and the plasticizer content. The gel‐like behavior of the second TPF seemed to prevent droplet coalescence; this led to a very fine dispersion. The rheological behavior of each blend appeared to be linked to both the morphology and the rheological behavior of the two phases. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40222.
Reactive compatibilization of an immiscible polyester/polyolefin blend with PP‐g‐MAH and PMPI dual compatibilizers
Authors: Shin Ji Hee , Lee Hyun Kyu , Kim Kyung Moon , Lee Kwang Hee
Published: December 2013

Blends of a polyester hot melt resin and a poly‐α‐olefin hot melt resin were modified using the reactive compounding technique. The effects of the compatibilizers were evaluated by studying the mechanical properties, the morphology, and the thermal properties of the modified blends. A pronounced compatibilizing effect was obtained with dual compatibilizers composed of maleated polypropylene and poly[methylene (phenylene isocyanate)] (PMPI). The addition of 1 phr of PMPI was sufficient to improve the elongation and tensile strength. From the results, it is anticipated that PMPI can be used as an efficient coupler to enhance the compatibility of immiscible polyester/polyolefin blends. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40232.
Feldspar/titanium dioxide/chitosan as a biophotocatalyst hybrid for the removal of organic dyes from aquatic phases
Authors: Yazdani Maryam , Bahrami Hajir , Arami Mokhtar
Published: December 2013

Feldspar/titanium dioxide/chitosan hybrid, a photoactive biocompatible adsorbent for anionic dyes, was synthesized, characterized, and successfully tested. The adsorbent characterization, pH role, adsorbent dose effect, equilibrium data, kinetic plats, and thermodynamic parameters are reported. The point of zero charge for the hybrid was measured to be 8.3, and the most favorable pH range for the adsorption process was found to be below this pH value. The adsorption equilibrium study demonstrated that the Freundlich model was best fitted to the experimental data. Without UV light exposure, the prepared adsorbent adsorbed 72 mg of Acid Black 1 (AB1)/g of sorbent (86% removal) from a 100‐mL solution with an initial dye concentration of 50 mg/L, whereas UV irradiation resulted in an increase in the elimination of AB1 dye (97% removal). The kinetic data was depicted well by the pseudo‐second‐order model. The thermodynamic parameters indicated that the reaction between the hybrid and the dye was exothermic and also spontaneous at lower temperatures. In the batch desorption process, several aqueous solutions adjusted to different pH values were tested, and the best desorption performance (90% desorption) was achieved at pH 11. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40247.
CHITIN SYNTHASE B: A MIDGUT‐SPECIFIC GENE INDUCED BY INSECT HORMONES AND INVOLVED IN FOOD INTAKE IN Bombyx mori LARVAE
Authors: Zhuo Weiwei , Chu Feng , Kong Lingfei , Tao Hui , Sima Yanghu , Xu Shiqing
Published: December 2013

Chitin synthase (CHS) is the key regulatory enzyme in chitin synthesis and excretion in insects, and a specific target of insecticides. We cloned a CHS B gene of Bombyx mori (BmChsB) and showed it to be midgut specific, highly expressed during the feeding process in the larva. Knockdown of BmChsB expression in the third‐instar larvae increased the number of nonmolting and abnormally molting larvae. Exposure to nikkomycin Z, a CHS inhibitor, reduced the amount of chitin in the peritrophic membrane of molted larvae, whereas abnormally elevated BmChsB mRNA levels were readily detected from the end of molting and in the newly molted larvae. Exogenous 20‐hydroxyecdysone (20E) and methoprene, a juvenile hormone analogue, significantly upregulated the expression of BmChsB when the levels of endogenous molting hormone (MH) were low and the levels of endogenous juvenile hormone (JH) were high immediately after molting. When levels of endogenous MH were high and those of endogenous JH were low during the molting stage, exogenous 20E did not upregulate BmChsB expression and exogenous methoprene upregulated it negligibly. When the endogenous hormone levels were low during the mulberry‐leaf intake process, BmChsB expression was upregulated by exogenous methoprene. We conclude that the expression of BmChsB is regulated by insect hormones, and directly affects the chitin‐synthesis‐dependent form of the peritrophic membrane and protects the food intake and molting process of silkworm larvae.
DIFFERENTIAL GENE EXPRESSION IN MALE AND FEMALE FAT BODY IN THE ORIENTAL FRUIT FLY, Bactrocera dorsalis
Authors: Zuo Yu‐Han , Chen Mei‐Er
Published: December 2013

The sexual difference in gene expression in fat body between 8‐ and 10‐day‐old male and female Bactrocera dorsalis was examined using suppression subtractive hybridization. A total of 952 clones were sequenced and searched using BLAST from the subtracted cDNA library. About 22% of these clones showed homology with detoxification enzymes including cytochrome P450 monooxygenases (CYPs) and glutathione S‐transferase. NADH dehydrogenases, distributed to energy metabolism, constituted about 9% of these clones. About 10% of these clones were cecropin, an antimicrobial peptide. Real‐time quantitative polymerase chain reaction (qPCR) analysis showed that four transcripts were expressed at a higher level in fat body of males, compared to females. Bactrocera dorsalis cyp6g2 (Bdcyp6g2) was cloned (accession number KF469179) and the temporal profile of transcriptional expression showed that Bdcyp6g2 mRNA increased with age in males from day 3 after eclosion, but only on days 0–3 in females. Compared to females, the susceptibility of 9‐day‐old males to three insecticides was significantly less. These results suggested the genes expressed at a higher level in male act in its survival.
Efficient production of fermentable sugars from oil palm empty fruit bunch by combined use of acid and whole cell culture–catalyzed hydrolyses
Authors: Li Qingxin , Ng Wei Ting , Puah Sze Min , Bhaskar Ravindran Vijay , Soh Loon Siong , MacBeath Calum , Parakattil Pius , Green Phil , Wu Jin Chuan
Published: December 2013

Empty fruit bunch (EFB) of oil palm trees was converted to fermentable sugars by the combined use of dilute acids and whole fungal cell culture–catalyzed hydrolyses. EFB (5%, w/v) was hydrolyzed in the presence of 0.5% H2SO4 and 0.2% H3PO4 at 160 °C for 10 Min. The solid fraction was separated from the acid hydrolysate by filtration and subjected to enzymatic hydrolysis at 50 °C using the whole cell culture of Trichoderma reesei RUT‐C30 (2%, w/v), which was prepared by cultivation at 30 °C for 7 days to reach its maximal cellulase activity. The combined hydrolyses of EFB gave a total sugar yield of 82.0%. When used as carbon sources for cultivating Escherichia coli in M9 medium at 37 °C, the combined EFB hydrolysates were shown to be more favorable or at least as good as pure glucose for cell growth in terms of the higher (1.1 times) optical density of E. coli cells. The by‐products generated during the acid‐catalyzed hydrolysis did not seem to obviously affect cell growth. The combined use of acid and whole cell culture hydrolyses might be a commercially promising method for pretreatment of lignocellulose to get fermentable sugars.