bluuebunny/crossref_metadata_2025 huggingface dataset:
An Adaptive Time-Stepping Strategy for the Cahn-Hilliard Equation
Authors: Zhang Zhengru , Qiao Zhonghua
Published: May 2012

This paper studies the numerical simulations for the Cahn-Hilliard equation which describes a phase separation phenomenon. The numerical simulation of the Cahn-Hilliard model needs very long time to reach the steady state, and therefore large time-stepping methods become useful. The main objective of this work is to construct the unconditionally energy stable finite difference scheme so that the large time steps can be used in the numerical simulations. The equation is discretized by the central difference scheme in space and fully implicit second-order scheme in time. The proposed scheme is proved to be unconditionally energy stable and mass-conservative. An error estimate for the numerical solution is also obtained with second order in both space and time. By using this energy stable scheme, an adaptive time-stepping strategy is proposed, which selects time steps adaptively based on the variation of the free energy against time. The numerical experiments are presented to demonstrate the effectiveness of the adaptive time-stepping approach.
Guitar increases male facebook attractiveness: Preliminary support for the sexual selection theory of music
Authors: Tifferet Sigal , Gaziel Ofir , Baram Yoav
Published: May 2012

Music is a universal phenomenon that has genetic and brain-localized features. As such, it warrants adaptive evolutionary explanations. While some scholars believe that music arose as a by-product of other adaptations, others argue that music is likely to have served some adaptive function, for example in coalition signaling or mother-child bonding. The sexual selection theory of music suggests that music serves as a signal in mate selection. While this claim is prevalent, it lacks empirical evidence. A facebook experiment revealed that women replied more positively to friendship requests from a man shown in a photo holding a guitar. These results offer initial support for the sexual selection theory of music.
How significant is submarine groundwater discharge and its associated dissolved inorganic carbon in a river-dominated shelf system?
Authors: Liu Q. , Dai M. , Chen W. , Huh C.-A. , Wang G. , Li Q. , Charette M. A.
Published: May 2012

Abstract. In order to assess the role of submarine groundwater discharge (SGD) and its impact on the carbonate system on the northern South China Sea (NSCS) shelf, we measured seawater concentrations of four radium isotopes 223,224,226,228Ra along with carbonate system parameters in June–July, 2008. Complementary groundwater sampling was conducted in coastal areas in December 2008 and October 2010 to constrain the groundwater end-members. The distribution of Ra isotopes in the NSCS was largely controlled by the Pearl River plume and coastal upwelling. Long-lived Ra isotopes (228Ra and 226Ra) were enriched in the river plume but low in the offshore surface water and subsurface water/upwelling zone. In contrast, short-lived Ra isotopes (224Ra and 223Ra) were elevated in the subsurface water/upwelling zone as well as in the river plume but depleted in the offshore surface water. In order to quantify SGD, we adopted two independent mathematical approaches. Using a three end-member mixing model with total alkalinity (TAlk) and Ra isotopes, we derived a SGD flux into the NSCS shelf of 2.3–3.7 × 108 m3 day−1. Our second approach involved a simple mass balance of 228Ra and 226Ra and resulted in a first order but consistent SGD flux estimate of 2.2–3.7 × 108 m3 day−1. These fluxes were equivalent to 12–21 % of the Pearl River discharge, but the source of the SGD was mostly recirculated seawater. Despite the relatively small SGD volume flow compared to the river, the associated material fluxes were substantial given their elevated concentrations of dissolved inorganic solutes. In this case, dissolved inorganic carbon (DIC) flux through SGD was 153–347 × 109 mol yr−1, or ~23–53 % of the riverine DIC export flux. Our estimates of the groundwater-derived phosphate flux ranged 3–68 × 107 mol yr−1, which may be responsible for new production on the shelf up to 0.3–6.3 mmol C m−2 d−1. This rate of new production would at most consume 11 % of the DIC contribution delivered by SGD. Hence, SGD may play an important role in the carbon balance over the NSCS shelf.
The magnesium isotope record of cave carbonate archives
Authors: Riechelmann S. , Buhl D. , Schröder-Ritzrau A. , Riechelmann D. F. C. , Richter D. K. , Vonhof H. B. , Wassenburg J. A. , Geske A. , Spötl C. , Immenhauser A.
Published: May 2012

Abstract. Here we explore the potential of time-series magnesium (δ26Mg) isotope data as continental climate proxies in speleothem calcite archives. For this purpose, a total of six Pleistocene and Holocene stalagmites from caves in Germany, Morocco and Peru and two flowstones from a cave in Austria were investigated. These caves represent the semi-arid to arid (Morocco), the warm-temperate (Germany), the equatorial-humid (Peru) and the cold-humid (Austria) climate zones. Changes in the calcite magnesium isotope signature with time are placed against carbon and oxygen isotope records from these speleothems. Similar to other proxies, the non-trivial interaction of a number of environmental, equilibrium and non-equilibrium processes governs the δ26Mg fractionation in continental settings. These include the different sources of magnesium isotopes such as rain water or snow as well as soil and hostrock, soil zone biogenic activity, shifts in silicate versus carbonate weathering ratios and residence time of water in the soil and karst zone. Pleistocene stalagmites from Morocco show the lowest mean δ26Mg values (GDA: −4.26 ± 0.07 ‰ and HK3: −4.17 ± 0.15 ‰) and the data are well explained in terms of changes in aridity over time. The Pleistocene to Holocene stalagmites from Peru show the highest mean value (NC-A and NC-B δ26Mg: −3.96 ± 0.04 ‰) but only minor variations in Mg-isotope composition, which is in concert with the rather stable equatorial climate at this site. Holocene stalagmites from Germany (AH-1 mean δ26Mg: −4.01 ± 0.07 ‰; BU 4 mean δ26Mg: −4.20 ± 0.10 ‰) record changes in outside air temperature as driving factor rather than rainfall amount. The alpine Pleistocene flowstones from Austria (SPA 52: −3.00 ± 0.73 ‰; SPA 59: −3.70 ± 0.43 ‰) are affected by glacial versus interglacial climate change with outside air temperature affecting soil zone activity and weathering balance. Several data points in the Austrian and two data points in the German speleothems are shifted to higher values due to sampling in detrital layers (Mg-bearing clay minerals) of the speleothems. The data and their interpretation shown here highlight the potential but also the limitations of the magnesium isotope proxy applied in continental climate research. An obvious potential lies in its sensitivity for even subtle changes in soil-zone parameters, a hitherto rather poorly understood but extremely important component in cave archive research. Limitations are most obvious in the low resolution and high sample amount needed for analysis. Future research should focus on experimental and conceptual aspects including quantitative and well calibrated leaching and precipitation experiments.
Modeling the climatic implications of the Guliya δ18O record during the past 130 ka
Authors: Xiao D. , Zhao P. , Wang Y. , Zhou X.
Published: May 2012

Abstract. Using an intermediate-complexity UVic Earth System Climate Model (UVic Model), the geographical and seasonal implications and an indicative sense of the historical climate found in the δ18O record of the Guliya ice core (hereinafter, the Guliya δ18O) are investigated under time-dependent orbital forcing with an acceleration factor of 100 over the past 130 ka. The results reveal that the simulated late-summer (August–September) Guliya surface air temperature (SAT) reproduces the 23-ka precession and 43-ka obliquity cycles in the Guliya δ18O. Furthermore, the Guliya δ18O is significantly correlated with the SAT over the Northern Hemisphere (NH), which suggests the Guliya δ18O is an indicator of the late-summer SAT in the NH. Corresponding to the warm and cold phases of the precession cycle in the Guliya temperature, there are two anomalous patterns in the SAT and sea surface temperature (SST) fields. The first anomalous pattern shows an increase in the SAT (SST) toward the Arctic, possibly associated with the joint effect of the precession and obliquity cycles, and the second anomalous pattern shows an increase in the SAT (SST) toward the equator, possibly due to the influence of the precession cycle. Additionally, the summer (winter) Guliya and NH temperatures are higher (lower) in the warm phases of Guliya late-summer SAT than in the cold phases. Furthermore, the Guliya SAT is closely related to the North Atlantic SST, in which the Guliya precipitation may act as a "bridge" linking the Guliya SAT and the North Atlantic SST.
Comparison of physically- and economically-based CO2-equivalences for methane
Authors: Boucher O.
Published: May 2012

Abstract. There is a controversy on the role methane (and other short-lived species) should play in climate mitigation policies, and there is no consensus on what an optimal methane CO2-equivalence should be. We revisit this question by discussing some aspects of physically-based (i.e. global- warming potential or GWP and global temperature change potential or GTP) and socio-economically-based climate metrics. To this effect we use a simplified global damage potential (GDP) that was introduced by earlier authors and investigate the uncertainties in the methane CO2-equivalence that arise from physical and socio-economic factors. The median value of the methane GDP comes out very close to the widely used methane 100-yr GWP because of various compensating effects. However, there is a large spread in possible methane CO2-equivalences from this metric (1–99% interval: 10.0–42.5; 5–95% interval: 12.5–38.0) that is essentially due to the choice in some socio-economic parameters (i.e. the damage cost function and the discount rate). The main factor differentiating the methane 100-yr GTP from the methane 100-yr GWP and the GDP is the fact that the former metric is an end-point metric, whereas the latter are cumulative metrics. There is some rationale for an increase in the methane CO2-equivalence in the future as global warming unfolds, as implied by a convex damage function in the case of the GDP metric. We also show that a methane CO2-equivalence based on a pulse emission is sufficient to inform multi-year climate policies and emissions reductions, as long as there is enough visibility on CO2 prices and CO2-equivalences for the stakeholders.
Modelling irrigated maize with a combination of coupled-model simulation and uncertainty analysis, in the northwest of China
Authors: Li Y. , Kinzelbach W. , Zhou J. , Cheng G. D. , Li X.
Published: May 2012

Abstract. The hydrologic model HYDRUS-1-D and the crop growth model WOFOST are coupled to efficiently manage water resources in agriculture and improve the prediction of crop production. The results of the coupled model are validated by experimental studies of irrigated-maize done in the middle reaches of northwest China's Heihe River, a semi-arid to arid region. Good agreement is achieved between the simulated evapotranspiration, soil moisture and crop production and their respective field measurements made under current maize irrigation and fertilization. Based on the calibrated model, the scenario analysis reveals that the most optimal amount of irrigation is 500–600 mm in this region. However, for regions without detailed observation, the results of the numerical simulation can be unreliable for irrigation decision making owing to the shortage of calibrated model boundary conditions and parameters. So, we develop a method of combining model ensemble simulations and uncertainty/sensitivity analysis to speculate the probability of crop production. In our studies, the uncertainty analysis is used to reveal the risk of facing a loss of crop production as irrigation decreases. The global sensitivity analysis is used to test the coupled model and further quantitatively analyse the impact of the uncertainty of coupled model parameters and environmental scenarios on crop production. This method can be used for estimation in regions with no or reduced data availability.
Reform in the General Education Movement:
Authors: Zayed Kevin S.
Published: May 2012

Using a historical methodology, this article posits that general education reform at Michigan State College operated in a matrix of influence involving educational research, philanthropy, and inter- and intra-institutional cooperation—rather than a top-down channeling of reform from “prestigious institutions”—and a cyclical interplay between national discussions and local implementation.
Informing Practice: Examples as Tools for Constructing Justifications
Authors: Bieda Kristen N. , Lepak Jerilynn
Published: May 2012

Research explores how to help students build from, instead of building with, examples when justifying mathematical ideas.
Functions and the Volume of Vases
Authors: McCoy Ann C. , Barger Rita H. , Barnett Joann , Combs Emily
Published: May 2012

While filling vases with water and observing volume and height relationships, students learn the fundamentals of functions.
Reading Visual Representations
Authors: Rubenstein Rheta N. , Thompson Denisse R.
Published: May 2012

A tool used in reading theory is adapted to help mathematics teachers ask good questions that help students interpret displays of information.
Quick Reads: Word Clouds in Math Classrooms
Authors: Nickell Jennifer
Published: May 2012

Word clouds, a new organizational and communication tool being used in classrooms, can easily be incorporated into math class.
Like: A Term of Endearment
Authors: Bray-Smith Kerri , Wayne McClung John
Published: May 2012

Like terms is a foundational algebra element that gives students insights to a commonsense view of adding fractions. Through four problems for each grade band (K–2, 3–4, 5–6), students make rulers and measure, sort, and record items.
Investigating Measurement Knowledge
Authors: McCool Jenni K. , Holland Carol
Published: May 2012

Collaborating with a researcher, this teacher uses two fifth graders' assessment results to inform her whole-class instruction and gain insight into all her students' conceptual knowledge.
A review of the humaneness of puntilla as a slaughter method
Authors: Limon G , Guitian J , Gregory NG
Published: May 2012

Puntilla is a traditional slaughter method in which a knife is plunged into the back of the neck to sever the spinal cord. The aim is to produce immediate collapse of the animal. Puntilla is not condoned as a stunning method by the World Animal Health Organisation (OIE) because there is concern that the animal could be conscious during and after the neck stab. Nonetheless, it is still used in some developing countries. The effectiveness and humaneness of puntilla followed by neck sticking was examined at two slaughterhouses in Bolivia. Twenty llamas (Lama glama) and 309 cattle were observed during routine puntilla without stunning. The number of neck stabs was recorded, and then brain and spinal functions (rhythmic breathing, palpebral reflex and eyeball rotation) were assessed. In addition, the presence of specific cognitive responses (such as responses to a threat stimulus and noise, as well as to flavours and odours), were also assessed in cattle. Breed, sex, live weight, body condition score and the slaughterman's experience were recorded. Repeat stabbing was needed to penetrate the foramen ovale in 45% of the llamas and two of them attempted to stand following collapse after the initial stab. All llamas showed rhythmic breathing movements at the flank following puntilla and before sticking, and 95% had a positive palpebral reflex at the same time. Twenty-four percent of the cattle needed repeat stabbing. Repeat stabbing was significantly less frequent with experienced slaughtermen, and more frequent in heavyweight animals (> 380 kg). Brain and spinal responses were present in 91% of the cattle following the stabs. When cattle attempted to stand after a neck stab they were more likely to have rhythmic breathing, positive palpebral response and responsiveness to threat, noise and brief air stimulus applied to the face. These findings indicate that it is difficult in practice to penetrate the spinal cord with a single puntilla stab. Some nerve pathways are often functional after the neck stab and therefore it is highly likely that the animals remain conscious in at least some modalities for the next part of the slaughter procedure. The challenge in developing countries, however, is to find a strategy that encourages use of a method which limits suffering whilst being accessible for routine slaughter practice.
WSPA and APSRI humane slaughter programme in China: STEPS®
Authors: Zili J , Kolesar R
Published: May 2012

The adoption of slaughter and pre-slaughter techniques to improve animal welfare and meat quality and safety is dependent on providing appropriate information, application and enforcement as well as information ownership by local people. The World Society for the Protection of Animals (WSPA) and Beijing Chaoyang Anhua Animal Product Safety Research Institute (APSRI) have been running a humane slaughter programme in China for more than three years. The aim of the programme is to improve the welfare of animals slaughtered in China through a three-pronged approach: i) train core-plant mid-level managers to be humane slaughter trainers; ii) provide guidance on legislation and codes of practice; and iii) develop and implement pre-slaughter and slaughter animal welfare curricula for undergraduate veterinarians. The production of in-country training material is based on a training-needs analysis conducted prior to the programme. Four Chinese trainers have completed the training and become national level trainers. In the last three years they have trained more than 5,000 staff from 800 slaughterhouses. Technical standards for slaughtering pigs, based on those of the OIE, have been adopted in China and the veterinary curriculum development is progressing. The programme has introduced many positive changes to the Chinese slaughter industry and the signs are positive for good progress.
Licensing poultry CO2gas-stunning systems with regard to animal welfare: investigations under practical conditions
Authors: von Holleben K , von Wenzlawowicz M , Eser E
Published: May 2012

Carbon dioxide stunning of broilers is not permitted in Germany. However, the competent authority can license a system for testing, during which scientific evaluation with regard to animal welfare is required. Between 2004 and 2011 several aspects of three systems have been evaluated in Germany and Italy under practical conditions including: (i) supply to the stunning system; (ii) induction conditions; (iii) stunning effectiveness; and (iv) process control. The systems were: (i) LINCO progressive gas-stunning system in which broilers in their transport crates are lowered stepwise into a pit filled with CO2and exposed to slowly increasing concentrations of CO2in air up to between 50 and 65% with total dwell times between 275 and 440 s depending on birds’ weight; (ii) Stork PMT two-phase gas-stunning system (40% CO2/30% O2/30%N2for 1 min/80% CO2for 2 min) in which broilers are tipped onto a belt, on which they pass through the gas atmospheres; and (iii) Anglia Autoflow two-phase CO2-stunning system, in which the birds are exposed to the atmosphere in their crates. Results on the third system are pending as the investigation is still ongoing. In systems (i) and (ii) analysis of behaviour showed that birds were only exposed to high CO2concentration (> 40%) after becoming unconscious. Stunning effectiveness was very high but, nevertheless, occasionally birds (0.027% LINCO system and 0.003% Stork PMT system) were able to regain consciousness. Examples of evaluation of behaviour during induction are presented in this paper and animal welfare aspects are compared. Controlled-atmosphere stunning systems for broilers using less than 40% CO2until animals are unconscious, show obvious advantages compared to electrical water-bath stunning, for example, the avoidance of shackling and achieving high stunning effectiveness.
Model for Railway Infrastructure Management Organization
Authors: Stojić Gordan , Vesković Slavko , Tanackov Ilija , Milinković Sanjin
Published: May 2012

The provision of appropriate quality rail services has an important role in terms of railway infrastructure: quality of infrastructure maintenance, regulation of railway traffic, line capacity, speed, safety, train station organization, the allowable lines load and other infrastructure parameters.The analysis of experiences in transforming the railway systems points to the conclusion that there is no unique solution in terms of choice for institutional rail infrastructure management modes, although more than nineteen years have passed from the beginning of the implementation of the Directive 91/440/EEC. Depending on the approach to the process of restructuring the national railway company, adopted regulations and caution in its implementation, the existence or absence of a clearly defined transport strategy, the willingness to liberalize the transport market, there are several different ways for institutional management of railway infrastructure.A hybrid model for selection of modes of institutional rail infrastructure management was developed based on the theory of artificial intelligence, theory of fuzzy sets and theory of multicriteria optimization.KEY WORDSmanagement, railway infrastructure, organizational structure, hybrid model
Simulation of a Collision between Passenger Car and Child Pedestrian
Authors: Schejbalová Zuzana , Kvášová Alžběta , Mičunek Tomáš , Marek Zdenč›k
Published: May 2012

The Department of Forensic Experts in Transportation at the Faculty of Transportation Sciences performed a second set of dynamic passive safety tests of a passenger car (M1 category - Škoda Octavia II) in a child pedestrian collision. The initial and test conditions were similar to those of the first set of tests in September 2009 (Škoda Roomster). The deformations of the contact zones on the frontal vehicle surface were analyzed by a 3D scanning technology (3D handy scanner). Head, thorax and pelvic resultant acceleration, acceleration of knee joint in sagittal direction and contact force on the femoral structure of the dummy (P6 dummy, 1.17m; 22kg) were measured. The aim of these tests is to provide a detailed description of pedestrian kinematics and comparison of primary and secondary impact seriousness.KEY WORDSpassenger car, child pedestrian, primary and secondary impact, dummy instrumentation, injury criteria, 3D scanning
Prevalence and heritability of skin picking in an adult community sample: A twin study
Authors: Monzani Benedetta , Rijsdijk Fruhling , Cherkas Lynn , Harris Juliette , Keuthen Nancy , Mataix‐Cols David
Published: May 2012

Skin‐picking disorder (SPD) is a disabling psychiatric condition that can lead to skin damage and other medical complications. Epidemiological data is scarce and its causes are unknown. The present study examined the prevalence and heritability of skin‐picking symptoms in a large sample of twins. A total of 2,518 twins completed a valid and reliable self‐report measure of skin‐picking behavior. The prevalence of clinically significant skin picking was established using empirically derived cut‐offs. Twin modeling methods were employed to decompose the variance in the liability to skin picking into additive genetic and shared and non‐shared environmental factors. A total of 1.2% of twins scored above the cut‐off, indicative of clinically significant skin picking. All these participants were women. Univariate model‐fitting analyses (female twins only, N = 2,191) showed that genetic factors accounted for approximately 40% (95% CI 19–58%) of the variance in skin picking, with non‐shared environmental factors and measurement error accounting for the remaining variance (60% [95% CI 42–81%]). Shared environmental factors were negligible. It is concluded that pathological skin picking is relatively prevalent problem, particularly among women, and that it tends to run in families primarily due to genetic factors. Non‐shared environmental factors are also likely to play an important role in its etiology. © 2012 Wiley Periodicals, Inc.
Quantum disc plus inverse square potential. An analytical model for two‐dimensional quantum rings: Study of nonlinear optical properties
Authors: Duque C.M. , Mora‐Ramos M.E. , Duque C.A.
Published: May 2012

The exact solutions for the two‐dimensional motion of a conduction band electron in a disc shaped quantum dot under the effect of an external magnetic field and parabolic and inverse square confining potentials are used to calculate the linear and nonlinear optical absorption as well as the linear and nonlinear corrections to the refractive index in the system. It is shown that this kind of structure may work well as a model for a quantum ring. Using the basic parameters typical of the GaAs, the results show that the influence of the normally oriented magnetic field induces a blueshift in both the first and third order peaks of the calculated optical quantities. In addition, total peak amplitudes are shown to be growing functions of the magnetic field strength. The increase in the strength of the inverse square potential function enhances significantly the contribution from the nonlinear third‐order terms in both the absorption and the relative correction to the refractive index.
Synthesis and swelling behavior of thermosensitive IPN hydrogels based on sodium acrylate and N‐isopropyl acrylamide by a two‐step method
Authors: Lee Wen‐Fu , Lu Hsiang‐Cheng
Published: May 2012

A series of interpenetrating polymer network (IPN) hydrogels having higher swelling ratio (SR) and thermosensitivity were synthesized from sodium acrylate (SA) and N‐isopropyl acrylamide (NIPAAm) by a two‐step method. A series of the porous poly(sodium acrylate ‐co‐1‐vinyl–2‐pyrrolidone) [poly(SA‐co‐VP)], (SV), hydrogels were prepared from acrylic acid having 90% degree of neutralization and VP monomer in the first step. The second step is to immerse the SV dried gels into the NIPAAm solution containing initiator, accelerator, and crosslinker to absorb NIPAAm solution and then polymerized to form the poly(SA‐co‐VP)/poly(NIPAAm) IPN hydrogels (SVN). The effect of the different molar ratios of SA/VP and the content of NIPAAm on the swelling behavior and physical properties of the SVN hydrogels was investigated. Results showed that the SVN hydrogels displayed an obviously thermoreversible behavior when the temperature turns across the critical gel transition temperature (CGTT) of poly(NIPAAm) hydrogel. The pore diameter distributions inside the hydrogel also indicated that the pore sizes inside the SVN hydrogels were smaller than those inside the SV hydrogels. At the same time, the more proportion of SA was added into the hydrogel, the larger pore diameter of the SV hydrogel was formed. The results also showed that the SR decreased with an increase of the VP content in the SV hydrogel and more obviously decreased in the SVN hydrogels. The SVN networks also showed stronger shear moduli than SV hydrogels. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Role of saturated solutions of chiral amino acids in synthesis and phase segregation within optically active polyaniline
Authors: Sudha  , Devendra Kumar , Mitsumasa Iwamoto
Published: May 2012

The saturated solutions of chiral amino acids as soft template have been shown to function as a platform for induction of optical activity through free radical polymerization reaction. The conductivity of optically active polyaniline changes with the variation in acidity of reaction medium and morphology of the material. Ultraviolet‐visible and circular dichroism spectra along with scanning electron microscopy and transmission electron microscopy micrographs evaluate discrete morphologies of polymers at different pH with phase segregation between unprotonated and fully protonated domains. Four probe method shows that the branched structure caused by the presence of phenazine units in polymer chain stabilizes different charge states in polymer with higher conductivity having higher dissymmetric g‐factor. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Zinc glycerolate with lanthanum stearate to inhibit the thermal degradation of poly(vinyl chloride)
Authors: Jiang Pingping , Song Yinyin , Dong Yuming , Yan Cuirong , Liu Peng
Published: May 2012

Zinc glycerolate (ZnGly) was prepared and used as a poly(vinyl chloride) (PVC) thermal stabilizer in this work. ZnGly was characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), thermogravimetry (TGA), and transmission electron microscopy (TEM). Visual color evolution and thermal stability time at 180°C were used to examine the stabilizing efficiency of the samples. The thermal stability of PVC was significantly enhanced through adding ZnGly or ZnGly with lanthanum stearate (LaSt3). Compared with zinc stearate (ZnSt2), it was demonstrated the initial color stability was markedly improved and the thermal stability time was obviously extended by adding ZnGly. The thermal stability time of ZnGly was threefold than ZnSt2. In comparison with CaSt2/ZnSt2, the extent of coloration of PVC samples was significantly inhibited though adding LaSt3/ZnGly. It was verified that the appropriate percents of ZnGly in the mixture were between 25 and 50%. A possible mechanism for the stabilizing efficiency of ZnGly was also proposed. The stabilizing efficiency was attributed to the stabilizer's ability to absorb hydrogen chloride and replace the labile chlorine atoms on PVC chains. Moreover, the dynamic thermogravimetric analysis was used to confirm that combination of LaSt3 with ZnGly presented an obvious improvement of stability on thermal degradation of PVC. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Comparative analysis of intracellular metabolites of Cephalosporium acremonium in pilot and industrial fermentation processes
Authors: Yang Yang , Lu Hua , Ding Ming‐Zhu , Jiang Jing , Chen Yao , Yuan Ying‐Jin
Published: May 2012

To get a better understanding of the characteristics of Cephalosporium acremonium with higher productivity, C. acremonium cells in pilot and industrial fermentation processes were analyzed using the profiles of metabolites. The different metabolic features of cells in pilot and industrial processes were caused by the different fermentation environments. The hierarchical cluster analysis of the data of metabolic profiling revealed that the concentrations of most of the metabolites were higher in the industrial process than in the pilot one, especially at the cephalosporin C accumulation stage. The analysis of important metabolites of primary metabolism indicated that the ability of the cephalosporin C biosynthesis was higher in the industrial process than that in the pilot one in C. acremonium. The analysis of the variations of cephalosporin C precursors and amino acids that were related to these precursors suggested that the metabolic flux changes of α‐aminoadipic acid and cysteine between the primary metabolism and cephalosporin biosynthetic pathway in the industrial process. Furthermore, metabolites of C. acremonium, such as proline, spermine, inositol phosphate, and glycerol, were shown to respond to the fermentation environmental stress. These findings provide insights into the intracellular metabolite characteristics and feasible regulation scheme to improve the titer of cephalosporin C in the industrial process.
Systematic review and meta-analysis of vein cuffs for below-knee synthetic bypass
Authors: Twine C P , Williams I M , Fligelstone L J
Published: May 2012

Background

The aim was to investigate the possible benefit of vein cuffs for femoral to below-knee popliteal and femorodistal vessel synthetic bypass grafts.

Methods

PubMed, the Cochrane library, Embase and ClinicalTrials.gov were searched for all studies on any clinical effect of vein cuffs on synthetic grafts. Outcomes were selected based on inclusion in two or more studies: primary patency and limb survival. The data were subjected to meta-analysis by outcome.

Results

Three cohort and two randomized studies were selected for inclusion, involving 885 patients. Meta-analysis of five studies examining below-knee popliteal bypass showed a significant improvement for primary patency in cuffed grafts at 2 years, but not at 1 or 3 years (odds ratio at 2 years 0·46, 95 per cent confidence interval 0·22 to 0·97; P = 0·04). Limb salvage was significantly improved in cuffed grafts up to 2 years. Limb survival was also improved for cuffed distal grafts at 2 years (odds ratio 0·29, 0·11 to 0·75; P = 0·01) but showed no difference at any other time interval. Study quality was generally poor, with conflicting results.

Conclusion

There was a small but significant benefit for vein cuffs on synthetic grafts used for femoral to below-knee popliteal anastomoses, but little benefit for femorodistal anastomoses.
Superstaging in colorectal cancer
Authors: Harris D A , Beynon J
Published: May 2012

Should be used to refine current management strategies
Analysis of 3‐methoxypterostilbene in biological fluids by high‐performance liquid chromatography: application to pre‐clinical pharmacokinetics
Authors: Martinez Stephanie E. , Sayre Casey L. , Davies Neal M.
Published: May 2012

A method of analysis for 3‐methoxypterostilbene [trans‐3,3′5‐trimethoxy‐4′hydroxystilbene] in biological fluids is necessary to study pharmacokinetics. A novel and simple high‐performance liquid chromatographic method was developed for the determination of 3‐methoxypterostilbene in rat serum and urine. The internal standard, pinosylvin, was added to 0.1 mL serum or urine (serum proteins were precipitated with cold acetonitrile at −20°C). Separation was achieved with a Phenomenex® C18 (2) (5 µm, 250 × 4.60 mm) column with ultraviolet detection at 327 nm. The calibration curves in both matrices were linear ranging from 0.05 to 100 µg/mL, and the mean extraction efficiency was >99%. Precision of the assay for both matrices was <12% (RSD) and was within 13% for all points on the calibration curve. The limit of quantification for this method was 0.05 µg/mL. The assay was successfully applied to a preliminary study of 3‐methoxypterostilbene pharmacokinetics in a rat. Copyright © 2012 John Wiley & Sons, Ltd.
Organocatalytic Michael Reaction of Nitroenamine Derivatives with Aldehydes: Short and Efficient Asymmetric Synthesis of (−)‐Oseltamivir
Authors: Weng Jiang , Li Yong‐Bo , Wang Rui‐Bin , Lu Gui
Published: May 2012

Nitroenamine derivatives were used as a new class of Michael acceptors in the organocatalytic Michael reaction of aldehydes. The addition products were obtained in good yields and very good to excellent enantioselectivities. Moreover, a highly efficient, enantioselective, and simple synthesis of (−)‐oseltamivir was accomplished in only five steps: two separate one‐pot operations and one purification step. This procedural simplicity demonstrated the power of the organocatalytic asymmetric Michael reaction of nitroenamine acceptors with aldehydes.
Controllable Self‐Assembly of Organic–Inorganic Amphiphiles Containing Dawson Polyoxometalate Clusters
Authors: Yin Panchao , Pradeep Chullikkattil P. , Zhang Baofang , Li Feng‐Yan , Lydon Claire , Rosnes Mali H. , Li Dong , Bitterlich Emily , Xu Lin , Cronin Leroy , Liu Tianbo
Published: May 2012

An organic–inorganic molecular hybrid containing the Dawson polyoxometalate, ((C4H9)4N)5H‐ [P2V3W15O59(OCH2)3CNHCOC15H31], was synthesized and its surfactant‐like amphiphilic properties, represented by the formation of bilayer vesicles, were studied in polar solvents. The vesicle size decreases with both decreasing hybrid concentration and with increasing polarity of the solvent, independently. The self‐assembly behavior of this hybrid can be controlled by introducing different counterions into the acetonitrile solutions. The addition of ZnCl2 and NaI can cause a gradual decrease and increase of vesicular sizes, respectively. Tetraalkylammonium bromide is found to disassemble the vesicle assemblies. Moreover, the original counterions of the hybrid can be replaced with protons, resulting in pH‐dependent formation of vesicles in aqueous solutions. The hybrid surfactant can further form micro‐needle structures in aqueous solutions upon addition of Ca2+ ions.
Chiral chemical absorption property of a cross‐linked poly(N‐isopropyl acrylamide‐co‐sodium acrylate) thermoresponsive smart gel
Authors: Bag Dibyendu S. , Alam Sarfaraz
Published: May 2012

This investigation leads to the chiral chemical absorption property of a thermoresponsive gel material. d‐(+)‐α‐phenyl ethyl amine was taken as the chiral chemical. The gel material was synthesized by polymerizing 1:1 mole ratio of N‐isopropyl acrylamide and Na‐acrylate along with methylene bisacrylamide (2 wt.% of total monomer) as a cross‐linker using ammonium persulfate as an initiator and N, N, N′, N′‐tetra‐methyl ethylene diamine as an accelerator. The microporous nature of the gel material is observed by scanning electron microscope as well as by surface analysis. It is a pH as well as thermoresponsive gel. The highest gel swelling is observed at around pH 8.2 at room temperature (30 °C). The gel contains carboxylate (―COO−) group in this slightly alkaline condition. In the ionic state, the mutual repulsion of the ionic groups helps in swelling the gel. The lower critical solution temperature (LCST) of the gel is observed to be about 38 °C, which is higher than that of poly N‐isopropyl acrylamide itself (32 °C). This corroborates with the theory and other reported results that LCST increases with the incorporation of ionic moiety in the cross‐linked copolymer. The chiral chemical absorption of the gel material was monitored by measuring circular dichroism of the chiral compound in the presence and absence of gel using a circular dichroism spectropolarimeter (J‐810 L) (JASCO International Co., Ltd., Tokyo, Japan). About 18% of d‐(+)‐α‐phenyl ethyl amine is absorbed from its aqueous solution by 0.01 g of dry gel material (particle size: 106–212 µm) at room temperature. The absorption of the chiral compound is reversible with temperature having a sudden jump at LCST (38 °C) of the gel material. Chirality 24:506–511, 2012. © 2012 Wiley Periodicals, Inc.
Simultaneous enantioselective separation of polychlorinated biphenyls and their methyl sulfone metabolites by heart‐cut MDGC: Determination of enantiomeric fractions in fish oils and cow liver samples
Authors: Pérez‐Fernández Virginia , Castro‐Puyana María , González María José , Marina María Luisa , García María Ángeles , Gómara Belén
Published: May 2012

The potential of three capillary columns based on β‐cyclodextrin (i.e., Chirasil‐Dex, BGB‐172, and BGB‐176SE) has been studied for the simultaneous enantiomeric separation of polychlorinated biphenyls (PCBs) and methylsulfonyl metabolites of PCBs (MeSO2‐PCBs) employing a heart‐cut multidimensional gas chromatographic system (heart‐cut MDGC). Among the columns studied, the BGB‐176SE capillary column provided the best results, allowing the simultaneous enantioselective resolution of six MeSO2‐PCBs and six chiral PCBs; the Chirasil‐Dex column did not resolve any of the studied MeSO2‐PCBs; and a poor resolution was obtained for three MeSO2‐PCBs when the BGB‐172 column was employed. The developed method was successfully applied to two fish oil and one cow liver samples commercially available, which showed different enantioselective pattern. PCBs 91 and 176 presented a clear enrichment of the second eluted atropisomer in codfish oil, whereas in fish oil sample, slight enrichment of the first eluted atropisomer of CB45 and the second eluted atropisomer of CB136 were observed. Chirality 24:577–583, 2012. © 2012 Wiley Periodicals, Inc.
DNA Photocleavage by a Cationic BODIPY Dye through Both Singlet Oxygen and Hydroxyl Radical: New Insight into the Photodynamic Mechanism of BODIPYs
Authors: Wang Jianguang , Hou Yuanjun , Lei Wanhua , Zhou Qianxiong , Li Chao , Zhang Baowen , Wang Xuesong
Published: May 2012

Two new NIR‐absorbing BODIPY dyes, each bearing two pyridinium groups, are synthesized and their DNA‐binding affinities and DNA photocleavage abilities examined in depth. While one BODIPY dye photocleaves DNA mainly through singlet oxygen, the other photocleaves DNA through both singlet oxygen and hydroxyl radical. To the best of our knowledge, this is the first example of a hydroxyl radical being involved in the photodynamic behavior of BODIPY‐type dyes. EPR experiments confirm the ability of these and several related BODIPYs to generate superoxide anion radical and hydroxyl radical. This finding may shed light on the mechanism of BODIPY‐based photodynamic therapy (PDT) and open a new avenue for development of more efficient BODIPY‐type PDT agents.
The diagnostic and research applications of flow cytometry in cytopathology
Authors: Davidson Ben , Dong Hiep Phuc , Berner Aasmund , Risberg Björn
Published: May 2012

Flow cytometry (FCM) is an established ancillary technique applied to the diagnosis of hematological malignancies and for measurement of DNA content. In recent years, the number of fluorochrome‐conjugated antibodies available for immnuofluorescence and FCM has greatly increased, making it possible to evaluate this technique in other diagnostic contexts, as well as to study a range of biological processes. Serous effusions are optimal for studies using FCM as they consist of viable cells in suspension. Molecules that have been studied for their expression and clinical role in effusions in recent years participate in central cellular functions, including adhesion, proliferation, cellular metabolism, and apoptosis, as well as intracellular signaling. FCM can further be applied to quantitative analysis of molecules related to chemotherapy response, which, together with apoptosis, may represent an important tool for evaluating treatment response and prognosis in advanced and/or recurrent cancer. As targeted therapy assumes an ever‐growing role in the treatment of metastatic cancer, the ability to study living cells in effusions or fine‐needle aspirates is becoming more important. This article reviews the currently available data in this area of cytopathology. Diagn. Cytopathol. 2012;40:525–535. © 2012 Wiley Periodicals, Inc.
Synthesis of Diverse Fused Pyrazoles through Palladium‐Mediated Heteroarylation of Heteroarene C–H Bonds
Authors: Nayak Maloy , Batra Sanjay
Published: May 2012

A facile and efficient synthesis of new fused pyrazoles through the Pd(OAc)2‐mediated heteroarylation of heteroarene C–H bonds in Morita–Baylis–Hillman derivatives of 4‐iodopyrazolecarbaldehydes is described.
Ecological risk assessment of parent and halogenated polycyclic aromatic hydrocarbons in surface sediments from an urban river in south China
Authors: Sun Jian-Lin , Ni Hong-Gang , Zeng Hui
Published: May 2012

In the present study, 16 priority polycyclic aromatic hydrocarbons (Σ16PAHs), including seven carcinogenic PAHs (Σ7PAHs) designated by the U.S. Environmental Protection Agency, in surface sediment from an urban river (Shenzhen, south China) were measured. The concentrations of Σ16PAHs and Σ7PAHs ranged from 27.92 to 7409 ng/g and 0.53 to 2326 ng/g, respectively. Source appointments indicated that the PAHs in surface sediments were mainly derived from coal combustion (36.6%), oil spills (22.2%), vehicle emission (19.5%), and waste incineration (12.1%). The ecological risks posed by PAHs and several halogenated PAHs in these sediment samples were assessed using two redefined guidelines incorporating the toxic equivalency quotients (TEQs) of individual PAH congeners: (1) TEQs effect range–low, and (2) TEQs effect range–median. The authors' results suggested that the PAHs they measured in most of the sediments in this urban river would not cause acute biological effects. On the contrary, the ecological risk posed by some halogenated PAHs was much higher than that of their corresponding parent PAHs. Finally, the relationships between PAH levels and catchment urbanization processes were examined. The results indicated that rapid urbanization has led to an obvious increase in PAH contamination in surface sediments. Environ. Toxicol. Chem. 2012; 31: 1867–1873. © 2012 SETAC
Toxic thresholds of cadmium and lead to oceanic phytoplankton: Cell size and ocean basin–dependent effects
Authors: Echeveste P. , Agustí S. , Tovar-Sánchez A.
Published: May 2012

Thresholds of cadmium (Cd) and lead (Pb) toxic to oceanic phytoplankton were examined in natural communities from the Mediterranean and Black Seas and the North East Atlantic Ocean. At concentrations of added Cd and Pb greater than 0.11 µg L−1, cell abundances and growth rates decreased with increasing addition of Cd and Pb, for all phytoplankton populations. The lethal concentrations at which populations decreased by half (LC50s), ranged from 0.23 to 498.7 µg L−1 Cd for Atlantic Prochlorococcus and Black Sea picoeukaryotes, respectively, and from 20 to 465.2 µg L−1 Pb for Mediterranean Synechococcus and Black Sea nanoplankton, respectively. These lethal concentrations were significantly lower than those previously reported for phytoplankton cultures. The LC50s were strongly related to population cell size, increasing as cell size increased, indicating that oceanic picocyanobacteria Prochlorococcus and Synechococcus populations were the most sensitive, and the largest phytoplankton cells the most resistant. Based on this relationship, differences in sensitivity to Cd across systems were detected, with Black Sea phytoplankton communities being more resistant (up to 100 times) than similar sized phytoplankton of the Mediterranean Sea and Atlantic Ocean. Environ. Toxicol. Chem. 2012; 31: 1887–1894. © 2012 SETAC
Occurrence of C8–C10 esters in Mediterranean Myrtus communis L. leaf essential oil
Authors: Bazzali Ophélie , Tomi Félix , Casanova Joseph , Bighelli Ange
Published: May 2012

Myrtus communis L. grows wild all around the Mediterranean basin and on the islands. Myrtle leaf essential oil has a characteristic pleasant odour although various compositions, which differ by the content of monoterpene esters, have been reported. Fractionation of an essential oil sample from Corsica, followed by analysis of the chromatographic fractions by GC(RI) and 13 C NMR allowed the identification of four C8–C10 esters, first identified 20 years ago in a Spanish essential oil sample and since that time very scarcely reported, despite the tremendous amount of work carried out on the composition of myrtle leaf essential oil. Therefore, the composition of 63 samples of M. communis L. leaf essential oil isolated from myrtle growing wild in various Mediterranean countries (Corsica, Sardinia, Portugal, Morocco, Algeria and Tunisia) has been investigated by GC(RI) and 13 C NMR and the four C8–C10 esters have been identified in all the samples. The occurrence of these esters merits great attention, since they contribute to the pleasant odour of the myrtle essential oil. In parallel, 3,3,5,5,8,8‐hexamethyl‐7‐oxabicyclo[4.3.0]non‐1(6)‐ene‐2,4‐dione has been identified in all the samples. Copyright © 2012 John Wiley & Sons, Ltd.