bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of dietary fibre‐enriched ready‐to‐eat extruded snacks on the postprandial glycaemic response of non‐diabetic patients
Authors: Brennan Margaret A. , Derbyshire Emma J. , Brennan Charles S. , Tiwari Brijesh K.
Published: May 2012

Food intervention is a financially sensible way for prevention and treatment of diabetes. Extruded snack foods are considered high glycaemic products. Our previous research illustrated that postprandial glycaemic responses to snacks are manipulated by altering dietary fibre and starch contents. The current research assessed the effect of psyllium and oat bran on postprandial glycaemia and in vitro digestibility. Addition of psyllium fibre to extruded snack products significantly reduced both the in vitro and in vivo glycaemic responses of products compared to a control snack product recipe. Oat bran inclusion reduced in vitro starch digestibility but not in vivo glycaemic response. The inclusion of oat bran into the snack products appeared to extend the glycaemic response of individuals compared to the control snack, suggesting a possibility of prolonging glucose release and potentially affecting satiety responses. The positive effect in attenuating glucose response means that psyllium fibre could be a target for inclusion by the snack food industry to effectively manipulate postprandial glucose response of individuals.
A novel Bayesian strategy for the identification of spatially varying material properties and model validation: an application to static elastography
Authors: Koutsourelakis Phaedon‐Stelios
Published: May 2012

The present paper proposes a novel Bayesian, a computational strategy in the context of model‐based inverse problems in elastostatics. On one hand, we attempt to provide probabilistic estimates of the material properties and their spatial variability that account for the various sources of uncertainty. On the other hand, we attempt to address the question of model fidelity in relation to the experimental reality and particularly in the context of the material constitutive law adopted. This is especially important in biomedical settings when the inferred material properties will be used to make decisions/diagnoses. We propose an expanded parametrization that enables the quantification of model discrepancies in addition to the constitutive parameters. We propose scalable computational strategies for carrying out inference and learning tasks and demonstrate their effectiveness in numerical examples with noiseless and noisy synthetic data. Copyright © 2012 John Wiley & Sons, Ltd.
Three‐dimensional meshfree‐enriched finite element formulation for micromechanical hyperelastic modeling of particulate rubber composites
Authors: Wu C.T. , Koishi M.
Published: May 2012

A three‐dimensional microstructure‐based finite element framework is presented for modeling the mechanical response of rubber composites in the microscopic level. This framework introduces a novel finite element formulation, the meshfree‐enriched FEM, to overcome the volumetric locking and pressure oscillation problems that normally arise in the numerical simulation of rubber composites using conventional displacement‐based FEM. The three‐dimensional meshfree‐enriched FEM is composed of five‐noded tetrahedral elements with a volume‐weighted smoothing of deformation gradient between neighboring elements. The L2‐orthogonality property of the smoothing operator enables the employed Hu–Washizu–de Veubeke functional to be degenerated to an assumed strain method, which leads to a displacement‐based formulation that is easily incorporated with the periodic boundary conditions imposed on the unit cell. Two numerical examples are analyzed to demonstrate the effectiveness of the proposed approach. Copyright © 2012 John Wiley & Sons, Ltd.
Rheological behaviors of glass bead‐ and wollastonite‐filled polypropylene composites modified with thermoplastic elastomers
Authors: Balkan Onur , Ezdeşir Ayhan
Published: May 2012

Steady‐ and oscillatory‐shear rheological behaviors of polypropylene/glass bead (PP/GB) and PP/wollastonite (PP/W) melts modified with thermoplastic elastomers, poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) copolymer (SEBS) and the corresponding block copolymer grafted with maleic anhydride (SEBS‐g‐MA), were examined by means of a parallel‐plate rheometer. With adding the elastomers (SEBS and SEBS‐g‐MA) and fillers (spherical GB and acicular W) to PP, viscosity especially at low shear rates and shear‐thinning flow behavior at high shear rates were pronounced as evidenced quantitatively by Carreau–Yasuda (CY) parameters, but Cox–Merz analogy became weakened. Besides, melt‐elasticity in terminal region and relaxation time (tc) in crossing point increased, indicating an enhancement in quasi‐solid behavior of molten PP. Comparing with the elastomers, rheological behaviors of molten PP were more influenced with adding the rigid fillers, especially with W due to distinct acicular shape of W particles. SEBS‐g‐MA elastomer more affected rheological behaviors of the ternary composites than SEBS elastomer, implying that SEBS elastomer and the filler particles behaved individually (i.e., development of separate microstructure) in (PP/GB)/SEBS and (PP/W)/SEBS ternary composites, but core‐shell microstructure developed with strong interfacial adhesion by adding SEBS‐g‐MA elastomer, and the filler particles encapsulated with the thick SEBS‐g‐MA elastomer interlayer (i.e., core‐shell particles) acted like neither big elastomer particles nor like individual rigid particles in melt‐state. Moreover, effects of SEBS‐g‐MA elastomer reached a maximum on rheological behaviors of (PP/W)/SEBS‐g‐MA ternary composite, indicating a synergy between core‐shell microstructure and acicular W particles. Correlations between oscillatory‐shear flow properties and microstructures of the blends and composites were evaluated using Cole–Cole (CC), Han–Chuang (HC), and van Gurp–Palmen (vGP) plots. COMPOS., 2012. © 2012 Society of Plastics
Structure and properties of peroxide dynamically vulcanized polypropylene/ethylene–propylene–diene/zinc dimethacrylate composites
Authors: Chen Yukun , Xu Chuanhui , Cao Liming , Wang Yanpeng
Published: May 2012

Peroxide dynamically vulcanized thermoplastic olefin (TPO) based on polypropylene (PP)/ethylene–propylene–diene (EPDM) loaded with zinc dimethacrylate (ZDMA) was prepared. The addition of ZDMA improved the complex viscosity of the resulting materials in the melt state significantly, as determined from oscillatory rheology analyses. Dynamic mechanical analysis (DMA) and transmission electron microscopy (TEM) examinations were performed to evaluate the structure of the PP/EPDM/ZDMA composite. Atomic force microscope (AFM) and scanning electron microscopy (SEM) were used to study the morphology. The degree of crystallinity was evaluated using X‐ray diffraction method (XRD). The results revealed that incorporation of ZDMA resulted in a size reduction of the rubber droplets and improved the compatibility between rubber and PP phases. The nanoparticles of the polymerized ZDMA (PZDMA) served as an effective nucleating agent for the crystallization of PP. The rheological properties and mechanical properties were improved by ZDMA. Particularly, the izod impact strength of the PP/EPDM/ZDMA (80/20/6, w/w) composite is nearly 2 times higher than the PP/EPDM (80/20, w/w) and 12 times higher than the PP; besides, the elongation at break of the PP/EPDM/ZDMA (80/20/6, w/w) is 3 times higher than that of the PP/EPDM (80/20, w/w) and 6 times higher than the PP. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Preparation of chitosan‐nanohydroxyapatite composite scaffolds by a supercritical CO2 assisted process
Authors: Karakeçili Ayşe , Arıkan Ayşegül
Published: May 2012

In this study, chitosan‐nanohydroxyapatite composite scaffolds were prepared by a supercritical fluid assisted process. For this purpose, different amounts of nanohydroxyapatite particles, that is, 0.25, 0.50, and 1.00 wt% were added to chitosan (deacetylation degree: DD 75–85%) solution (2%, w/v, in acetic acid). The gels were then frozen at −20°C, treated in acetone and dried in a supercritical fluid extractor under a constant CO2 flow of 15 g/min at 35°C and 200 bar for 5 h to obtain porous scaffolds. Scanning electron microscope views showed that the drying of gels under supercritical CO2 lead to the formation of microporous scaffolds with a pore size distribution of 30–150 μm. Addition of nanohydroxyapatite particles did not significantly affect the pore size distribution. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy and X‐Ray diffraction analyses supported the successful incorporation of nanohydroxyapatite particles in the scaffold. An increase in water uptake and mechanical strength were observed in composite scaffolds. The results obtained from this study indicated that chitosan‐nanohydroxyapatite scaffolds prepared by using supercritical CO2 shall be considered as a potential candidate for bone tissue engineering applications. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Life cycle assessment of high‐concentration photovoltaic systems
Authors: Fthenakis Vasilis M. , Kim Hyung Chul
Published: May 2012

The environmental profiles of photovoltaic (PV) systems are becoming better as materials are used more efficiently in their production, and overall system performance improves. Our analysis details the material and energy inventories in the life cycle of high‐concentration PV systems, and, based on measured field‐performances, evaluates their energy payback times, life cycle greenhouse gas emissions, and usage of land and water. Although operating high‐concentration PV systems require considerable maintenance, their life cycle environmental burden is much lower than that of the flat‐plate c‐Si systems operating in the same high‐insolation regions. The estimated energy payback times of the Amonix 7700 PV system in operation at Phoenix, AZ, is only 0.9 year, and its estimated greenhouse gas emissions are 27 g CO2‐eq./kWh over 30 years, or approximately 16 g CO2‐eq./kWh over 50 years. Copyright © 2012 John Wiley & Sons, Ltd.
Plasma Directed Organization of Nanodots on Polymers: Effects of Polymer Type and Etching Time on Morphology and Order
Authors: Kontziampasis Dimitrios , Constantoudis Vassilios , Gogolides Evangelos
Published: May 2012

Oxygen plasma etching of poly(methyl methacrylate) (PMMA), poly(ethylene terephthalate) (PET), and polystyrene (PS) leads to the formation of organized nanodots on the surfaces of the polymers. In this paper, we describe the metrological characterization of these nanodots and compare their morphology as a function of the polymer type. We study the evolution of the surface morphology with etching time and observe a transition point where dual scale roughness develops, order is lost, and sudden increase in the surface roughness is observed. Possible mechanisms are discussed.

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Cost Effective Deposition System for Nitrogen Incorporated Diamond‐like Carbon Coatings
Authors: Kumar Sushil , Dwivedi Neeraj , Kumar Dalai Manas
Published: May 2012

Nitrogen incorporated diamond‐like carbon (N‐DLC) thin films were grown, at high base pressure of 5 × 10−3 Torr, under varied nitrogen gas pressure (NGP) (variation from 55 to 85 mTorr) and varied negative self‐bias (NSB) (variation from 35 to 190 V), using primary pump (rotary pump) processed radio frequency‐plasma enhanced chemical vapour deposition technique. These films then studied for their structural compositional and nanomechanical properties. Time of flight‐secondary ion mass spectroscopy was used to confirm the presence of nitrogen and to investigate the depth profile of these N‐DLC films, whereas energy dispersive X‐ray analysis measurement was carried to analyze the atomic concentration of constituents of film. Micro‐Raman analysis reveals change in D and G peak positions and ID/IG ratio with the change in NSB as well as NGP. It is worth noting that N‐DLC film grown at NGP and NSB of 55 mTorr and 100 V, respectively, exhibited very high hardness as 40.3 GPa. Hence, due to better nanomechanical properties by simpler, high deposition rate and cost effective process, which yielded very high throughput may leads these N‐DLC films to their wide industrial applications such as hard and protective coating on cutting tools, automobile parts, bio‐implants or wear resistant coating on magnetic hard disk.

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High quality p‐type chemical vapor deposited {111}‐oriented diamonds: Growth and fabrication of related electrical devices
Authors: Lazea Andrada , Garino Yiuri , Teraji Tokuyuki , Koizumi Satoshi
Published: May 2012

In this paper the quality of boron‐doped diamond films grown by microwave (MW) plasma activated chemical vapor deposition on high pressure high temperature synthetic type Ib {111}‐oriented diamond substrates is estimated from the correlations between low‐temperature cathodoluminescence analyses and Hall measurements. The layers attributes, obtained in the low methane concentration regime (0.05% [CH4]/[H2] ratio) and using low plasma powers (450–500 W), are completed by impurities incorporation investigations (secondary ion mass spectroscopy). Hall mobility values exceeding 550 cm2 V−1 s−1 at room temperature and characteristic excitonic luminescence peaks were obtained, indicating towards the high crystalline quality of our {111}‐oriented diamond films. Based on these B‐doped samples, Schottky junctions were fabricated and analyzed, presenting the highest rectification ratio when compared with similar devices.
On analytical properties of the diamagnetic permeability in the presence of the spatial dispersion
Authors: Pitaevskii L. P.
Published: May 2012

It is well known that the usual assumptions about analytical properties of the magnetic permeability μ result in a contradiction in the case of a diamagnetic. It occurs, that the permeability, as a function of the complex frequency ω, decreases monotonically along the imaginary half‐axis in the upper half of the ω‐plane and, consequently, can not reach the limiting value μ = 1 at |ω| → ∞ as it must do. It is discussed how the presence of the spatial dispersion may solve this paradox. © 2012 Wiley Periodicals, Inc.
Non‐convex model for sensor network localization based on connectivity
Authors: Qiao Dapeng , Pang Grantham K.H.
Published: May 2012

In this paper, a new model utilizing all the information derived from connectivity‐based sensor network localization is introduced. The connectivity information between any pair of nodes is modeled as convex and non‐convex constraints. The localization problem is solved by searching for a solution that would satisfy all the constraints established in the problem. A two‐objective evolutionary algorithm called Pareto Archived Evolution Strategy (PAES) is used to solve the localization problem. The solution can reach the most suitable configuration of the unknown nodes because the information on both convex and non‐convex constraints related to connectivity has been utilized. From simulation results, a relationship between the communication range and accuracy is obtained. Furthermore, a two‐level range connectivity‐based sensor network localization method is proposed to enrich the connectivity information. The two‐level range/indication of connectivity between each pair of nodes would indicate three levels of connectivity: strong, weak, or nil. A comparison on accuracy between the one‐level and two‐level ranges of connectivity is carried out by simulation using six different topological networks all containing 100 nodes. Simulation results have shown that better solution can be obtained by using two‐level range connectivity compared with the usual one‐level range connectivity‐based localization. Copyright © 2012 John Wiley & Sons, Ltd.
A systematic approach to exosome‐based translational nanomedicine
Authors: Hood Joshua L. , Wickline Samuel A.
Published: May 2012

Exosomes are a type of cell‐derived extracellular nanovesicle. They relay information between cells. Some known exosome functions include immune modulation, promotion of angiogenesis, and tumor metastasis. To date, clinical use of exosomes has focused predominantly on evaluating their efficacy as cancer vaccines or diagnostically as biomarker containers. However, few investigations have explored their potential to serve as a platform for the development of semi‐synthetic nanovesicles. Given their nanoscale size, potential to express targeting ligands in native conformations and deformable structure, exosomes offer a logical biological vesicle platform for adapting and producing semi‐synthetic vesicles with excellent potential for nanomedicine applications. However, there are obstacles associated with realizing this potential that must be addressed. Thus, a systematic approach to isolating, modifying, and testing exosomes is presented to facilitate the introduction of exosome‐based translational nanomedicine. WIREs Nanomed Nanobiotechnol 2012, 4:458–467. doi: 10.1002/wnan.1174

This article is categorized under:

Diagnostic Tools > Diagnostic Nanodevices

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
Correction for the effect of soil moisture on in situ XRF analysis using low‐energy background
Authors: Bastos R. O. , Melquiades F. L. , Biasi G. E. V.
Published: May 2012

X‐ray fluorescence (XRF) analyses are affected by many matrix and geometrical factors that, generally, are possible to handle in laboratory conditions. However, when in situ analyses are considered, constraints in the measurement conditions make more difficult to handle some factors, such as moisture, affecting the measurement accuracy. Efforts have been made to correct some of the effects by inserting some steps in the sample preparation process. The problem is that each step added in this process, aiming a better precision and accuracy, makes the in situ measurement harder and longer to accomplish, influencing negatively the intrinsic advantages of the in situ measurement. In this work, we propose a method to correct the effect of soil moisture on in situ XRF analysis using low‐energy background. The method demands a simple calibration, after which a long drying procedure is not necessary before measuring the samples. Copyright © 2012 John Wiley & Sons, Ltd.
Effects of Second Language Usage on Genetic Counseling Training and Supervision
Authors: Vanneste Rachel , Chiu Sui Mei , Russell Laura , Fitzpatrick Jennifer
Published: May 2012

We conducted an exploratory study of the experiences of genetic counselors who have either trained or supervised in a second language to assess the relevance of this issue to genetic counseling training and supervision. Two hundred‐thirty NSGC members, CAGC members and genetic counseling students completed the online questionnaire. Many of the respondents reported that training and supervision differed when another language was involved. Supervisors reported difficulty in assessing students’ counseling skills and discomfort with an incomplete understanding of session content. Students described a greater focus on vocabulary at the expense of psychosocial dimensions. Despite this, most felt that using another language enhanced their training experience. As such, training programs might consider increasing support to these learners and supervisors by explicitly acknowledging the challenges they face, providing students with language tools to aid in their acquisition of basic skills and providing supervisors with new methods for assessing student counseling skills when using other languages.
Chapter 9: Options for Summarizing Medical Test Performance in the Absence of a “Gold Standard”
Authors: Trikalinos Thomas A. , Balion Cynthia M.
Published: May 2012

The classical paradigm for evaluating test performance compares the results of an index test with a reference test. When the reference test does not mirror the “truth” adequately well (e.g. is an “imperfect” reference standard), the typical (“naïve”) estimates of sensitivity and specificity are biased. One has at least four options when performing a systematic review of test performance when the reference standard is “imperfect”: (a) to forgo the classical paradigm and assess the index test’s ability to predict patient relevant outcomes instead of test accuracy (i.e., treat the index test as a predictive instrument); (b) to assess whether the results of the two tests (index and reference) agree or disagree (i.e., treat them as two alternative measurement methods); (c) to calculate “naïve” estimates of the index test’s sensitivity and specificity from each study included in the review and discuss in which direction they are biased; (d) mathematically adjust the “naïve” estimates of sensitivity and specificity of the index test to account for the imperfect reference standard. We discuss these options and illustrate some of them through examples.
Cancer cachexia is associated with a decrease in skeletal muscle mitochondrial oxidative capacities without alteration of ATP production efficiency
Authors: Julienne Cloé M. , Dumas Jean‐François , Goupille Caroline , Pinault Michelle , Berri Cécile , Collin Anne , Tesseraud Sophie , Couet Charles , Servais Stephane
Published: May 2012

Background

Cancer cachexia is a complex syndrome related to a negative energy balance resulting in muscle wasting. Implication of muscle mitochondrial bioenergetics alterations during cancer cachexia was suggested. Therefore, the aim of this study was to explore the efficiency of oxidative phosphorylation in skeletal muscle mitochondria in a preclinical model of cancer cachexia.

Methods

Berlin–Druckrey IX rats with peritoneal carcinosis (PC) were used as a model of cancer cachexia with healthy pair‐fed rats (PF) as control. Hindlimb muscle morphology and fibre type composition were analysed in parallel with ubiquitin ligases and UCP gene expression. Oxidative phosphorylation was investigated in isolated muscle mitochondria by measuring oxygen consumption and ATP synthesis rate.

Results

PC rats underwent significant muscle wasting affecting fast glycolytic muscles due to a reduction in fibre cross‐sectional area. MuRF1 and MAFbx gene expression were significantly increased (9‐ and 3.5‐fold, respectively) in the muscle of PC compared to PF rats. Oxygen consumption in non‐phosphorylating state and the ATP/O were similar in both groups. Muscle UCP2 gene was overexpressed in PC rats. State III and the uncoupled state were significantly lower in muscle mitochondria from PC rats with a parallel reduction in complex IV activity (−30 %).

Conclusion

This study demonstrated that there was neither alteration in ATP synthesis efficiency nor mitochondrial uncoupling in skeletal muscle of cachectic rats despite UCP2 gene overexpression. Muscle mitochondrial oxidative capacities were reduced due to a decrease in complex IV activity. This mitochondrial bioenergetics alteration could participate to insulin resistance, lipid droplet accumulation and lactate production.
Effect of colon cancer and surgical resection on skeletal muscle mitochondrial enzyme activity in colon cancer patients: a pilot study
Authors: Phillips Bethan E. , Smith Kenneth , Liptrot Sarah , Atherton Philip J. , Varadhan Krishna , Rennie Michael J. , Larvin Mike , Lund Jonathan N. , Williams John P.
Published: May 2012

Background

Colon cancer (CC) patients commonly suffer declines in muscle mass and aerobic function. We hypothesised that CC would be associated with reduced muscle mass and mitochondrial enzyme activity and that curative resection would exacerbate these changes.

Methods

We followed age‐matched healthy controls and CC patients without distant metastasis on radiological imaging before and 6 weeks after hemi‐colectomy surgery. Body composition was analysed using dual energy X‐ray absorptiometry. Mitochondrial enzyme activity and protein concentrations were analysed in vastus lateralis muscle biopsies.

Results

In pre‐surgery, there were no differences in lean mass between CC patients and age‐matched controls (46.1 + 32.5 vs. 46.1 + 37.3 kg). Post‐resection lean mass was reduced in CC patients (43.8 + 30.3 kg, P < 0.01). When comparing markers of mitochondrial function, the following were observed: pyruvate dehydrogenase (PDH) activity was lower in CC patients pre‐surgery (P < 0.001) but normalized post‐resection and cytochrome c oxidase and pyruvate dehydrogenase E2 subunit protein expression were lower in CC patients pre‐surgery and not restored to control values post‐resection (P < 0.001). Nuclear factor kappa‐B, an inflammatory marker, was higher in CC patients pre‐surgery compared to controls (P < 0.01), returning to control levels post‐resection.

Conclusion

Muscle mass was affected by surgery rather than cancer per se. PDH activity was however lower in cancer patients, suggesting that muscle mass and mitochondrial enzyme activity are not inextricably linked. This reduction in mitochondrial enzyme activity may well contribute to the significant risks of major surgery to which CC patients are exposed.
Comparison of PET/CT with other imaging modalities in women with genital tuberculosis
Authors: Sharma Jai B. , Karmakar Debjyoti , Kumar Rakesh , Shamim Shamim A. , Kumar Sunesh , Singh Neeta , Roy Kallol K. , Reddy Rama M.
Published: May 2012

Objective

To compare findings with 2‐deoxy‐2‐(18F)fluoro‐D‐glucose positron emission tomography combined with computed tomography (18F‐FDG‐PET/CT) with findings obtained using ultrasound (US), magnetic resonance imaging (MRI), and CT in patients with proven tubercular tubo‐ovarian masses.

Methods

Seventeen patients with proven tubercular tubo‐ovarian masses underwent 18F‐FDG‐PET/CT imaging and the findings were compared with US (for all patients), MRI (for 9 patients), CT (for 4 patients), and laparotomy or laparoscopic findings (for 14 patients).

Results

Eleven patients (64.7%) had unilateral tubo‐ovarian masses, with activity in 6 masses (35.3%); 4 patients (23.5%) had bilateral tubo‐ovarian masses, with activity in all masses; and 2 patients (11.76%) had unilateral space‐occupying lesions, with activity in 1 lesion. The detection rates of tubo‐ovarian masses with 18F‐FDG‐PET/CT were similar to, but the characterization of adnexal masses was less than, those obtained with CT or MRI. Finally, 18F‐FDG‐PET/CT was equally accurate as laparoscopy or laparotomy in detecting the presence, laterality, and activity of tubo‐ovarian masses.

Conclusion

Imaging with 18F‐FDG‐PET/CT is noninvasive and appears to be clinically useful for the diagnosis of tubercular tubo‐ovarian masses.
Mastodon herbivory in mid-latitude late-Pleistocene boreal forests of eastern North America
Authors: Teale Chelsea L. , Miller Norton G.
Published: May 2012

Skeletal remains of the extinct American mastodon have often been found with deposits of short, decorticated twigs intermixed with plant fragments presumed to be gastrointestinal or fecal material. If such deposits are digesta, paleobotanical evidence may be used to analyze mastodon foraging strategy, with implications for assessing habitat selection, ecological roles, and response to environmental change. To identify components of mastodon diet in mid-latitude late-Pleistocene boreall forests of eastern North America, plant macrofossils and pollen from a molar socket (Hyde Park site, New York) were compared with dispersed deposits associated with skeletal remains (Hiscock and Chemung sites, New York). Similar macrofossil condition and twig morphology among samples, but difference from a modern boreal fen analog, confirmed the deposits were digesta. Comparison of twigs with material from other paleontological sites and modern elephants suggested dimensions generally indicative of digesta. Picea formed the bulk of each sample but Pinus may have been locally important. Wintertime browsing of Salix and Populus, and springtime consumption of Alnus, were indicated. Evidence for Cyperaceae, Gramineae, and Compositae was ambiguous. If conifers, broadleaf trees, shrubs, and herbs were necessary to fulfill dietary requirements, mastodons would have been nutritionally stressed by rapid late-Pleistocene decrease in vegetational diversity.
Species and sexual differences in behavioural responses of a specialist and generalist parasitoid species to host-related volatiles
Authors: Ngumbi E. , Fadamiro H.
Published: May 2012

The relationship between the degree of specialization of parasitoids and their responses to host-related volatiles is an important and current evolutionary question. Specialist parasitoids which have evolved to attack fewer host species are predicted to be more responsive to host-related volatiles than generalists. We tested the above prediction by comparing behavioural responses of both sexes of two parasitoids (Hymenoptera: Braconidae) with different degrees of host specificity, Microplitis croceipes (Cresson) (specialist) and Cotesia marginiventris (generalist), to different suites of synthetic host-related volatile compounds. The compounds tested at two doses (1 and 100μg) include two green leaf volatiles (GLVs: hexanal and (Z)-3-hexen-1-ol) and four herbivore-induced plant volatiles (HIPVs: (Z)-3-hexenyl acetate, linalool, (Z)-3-hexenyl butyrate and (E,E)-α-farnesene). Two hypotheses were tested: (i) M. croceipes (specialist) would show relatively greater behavioural responses to the HIPVs, whereas C. marginiventris (generalist) would show greater behavioural responses to the GLVs, and (ii) females of both species would show greater responses than conspecific males to the host-related volatiles. At the low dose (1μg), females of the specialist showed significantly greater responses than females of the generalist to three of the tested HIPVs, (Z)-3-hexenyl acetate, linalool and (Z)-3-hexenyl butyrate. In contrast, females of the generalist showed relatively greater responses to the GLVs. The same trends were recorded at the high dose but fewer significant differences were detected. In general, similar results were recorded for males, with the exception of linalool (an HIPV) which elicited significantly greater response in the generalist than the specialist. Comparing the sexes, females of both species showed greater responses than conspecific males to most of the tested volatiles. The ecological significance of these findings is discussed.
Impact of fertility transmission and other sociodemographic factors on reproductive success and coalescent trees
Authors: BRANDENBURG JEAN-TRISTAN , AUSTERLITZ FRÉDÉRIC , TOUPANCE BRUNO
Published: May 2012

Fertility transmission (FT) is a phenomenon with a cultural and/or genetic basis, whereby a positive correlation exists between the number of offspring of an individual and that of his/her parents. Theoretical studies using a haploid individual-based model have shown that FT increases the variance and intergenerational correlation in reproductive success and results in an imbalance in the coalescent tree of sampled genes. This phenomenon has been documented in several demographic studies conducted on the correlation in fertility between generations, or through the reconstruction of the genealogical trees of mitochondrial DNA sequences. However, as mtDNA is a single locus, potentially subject to other forces (e.g. natural selection), it is of interest to extend the theory of FT to nuclear loci. We show that because random mating between individuals leads to a mixing of their fertility profiles, FT in these cases will have less influence on the variance and intergenerational correlation of reproductive success. This, in turn, results in less impact on the shape of the coalescent trees. Nevertheless, in the presence of FT, high heterogeneity in reproductive success and homogamy for family size will increase the imbalance in the coalescent tree. Thus, FT should be easier to detect when occurring in conjunction with these other factors. We also show the utility of analysing different kinds of loci (X-linked, Y-linked, mitochondrial and autosomal) to assess whether FT is matrilineal, patrilineal or biparental. Finally, we demonstrate that the shape of the coalescent tree depends upon population size, in contrast to the classical Kingman's model.
Promoting a Culture of Driving: Rationing, Car Sharing, and Propaganda in World War II
Authors: FROHARDT-LANE SARAH
Published: May 2012

World War II, some scholars have argued, interrupted Americans’ “love affair” with the automobile. According to this school of thought, gasoline rationing temporarily curtailed car driving and suspended car culture before both surged in the postwar era. This essay argues that World War II strengthened, rather than interrupted, Americans’ attachment to the automobile and solidified driving as a fundamental part of American culture. Ration boards distinguished between “essential” and “nonessential” driving and justified gasoline rationing as the only method to preserve civilian driving when supplies of gasoline were low. Thus at the same time as government and private industry were encouraging Americans to limit their driving, they were sending a strong message that Americans needed to drive and that foregoing driving whenever one wanted was a true, if temporary, hardship. Advertisements and government propaganda conflated car ownership with citizenship and portrayed driving as integral to the American way of life. But this mode of citizenship was not available to all: posters, pamphlets, and advertisements portrayed the American driver almost exclusively as white and most often as male. Such depictions implied that the mobility and independence that driving afforded were the sole domain of white American men.
Oil Culture: Guest Editors' Introduction
Authors: BARRETT ROSS , WORDEN DANIEL
Published: May 2012

This special issue advances the first comprehensive account of “oil culture,” the broad field of cultural representations and symbolic forms that have taken shape around the fugacious material of oil in the 150 years since the inception of the US petroleum industry. Exploring the cultural life of oil from a variety of methodological perspectives, the essays in this special issue seek to elucidate the complex role that imaginative representations have played in establishing and contesting oil's status as the primary commodity underpinning modern economic expansion and a fundamental ontological construct shaping social and political life in the United States and beyond. By addressing the rise of oil as a cultural problem, this issue aims to fill a significant gap in oil scholarship and to intervene in what has become an epochal and highly charged moment in the history of petro-capitalism.
Mixing Oil and Water: Naturalizing Offshore Oil Platforms in Gulf Coast Aquariums
Authors: JØRGENSEN DOLLY
Published: May 2012

On 26 June 2010, the brand new Gulf of Mexico exhibit at the National Mississippi River Museum & Aquarium in Dubuque, Iowa opened devoid of life. The tanks were purposefully left empty, rather than showing the vibrant aquatic life of the Gulf, to highlight the oil spill associated with BP's Deepwater Horizon offshore drilling incident earlier in 2010. According to the museum's press release, the museum wanted

to open a Gulf exhibit recognizing the crisis that is happening on the Gulf Coast … The exhibit, without fish, now has the opportunity to make a bold statement related to the oil spill in the Gulf Coast by asking Museum & Aquarium visitors to imagine a lifeless Gulf.1
Malthus, Wages, and Preindustrial Growth
Authors: CLARK GREGORY , CUMMINS JOSEPH , SMITH BROCK
Published: May 2012

Gregory Clark argued inA Farewell to Alms thatpreindustrial societies, including England, were Malthusian. Day wages show incomes were trendless: as high in Europe in the medieval era as in 1800, even in England. The opposed view is that England and the Netherlands grew substantially from 1200 to 1800. Early day wages overestimate living standards. Here we show that preindustrial farm employment shares can be estimated from probate occupation reports. These imply only 60 percent employed in farming in England in 1560–1579 and 1653–1660, consistent with the high incomes indicated by wages. Day wages do measure preindustrial living standards.
Instability of the isolated spectrum for W-shaped maps
Authors: LI ZHENYANG , GÓRA PAWEŁ
Published: May 2012

In this note we consider the W-shaped map $W_0=W_{s_1,s_2}$ with ${1}/{s_1}+{1}/{s_2}=1$ and show that the eigenvalue $1$ is not stable. We do this in a constructive way. For each perturbing map $W_a$ we show the existence of a ‘second’ eigenvalue $\lambda _a$, such that $\lambda _a\to 1$ as $a\to 0$, which proves instability of the isolated spectrum of $W_0$. At the same time, the existence of second eigenvalues close to 1 causes the maps $W_a$to behave in a metastable way. There are two almost-invariant sets, and the system spends long periods of consecutive iterations in each of them, with infrequent jumps from one to the other.
Older job seekers' job search intensity: the interplay of proactive personality, age and occupational future time perspective
Authors: ZACHER HANNES
Published: May 2012

Long-term unemployment of older people can have severe consequences for individuals, communities and ultimately economies, and is therefore a serious concern in countries with an ageing population. However, the interplay of chronological age and other individual difference characteristics in predicting older job seekers' job search is so far not well understood. This study investigated relationships among age, proactive personality, occupational future time perspective (FTP) and job search intensity of 182 job seekers between 43 and 77 years in Australia. Results were mostly consistent with expectations based on a combination of socio-emotional selectivity theory and the notion of compensatory psychological resources. Proactive personality was positively related to job search intensity and age was negatively related to job search intensity. Age moderated the relationship between proactive personality and job search intensity, such that the relationship was stronger at higher compared to lower ages. One dimension of occupational FTP (perceived remaining time left in the occupational context) mediated this moderating effect, but not the overall relationship between age and job search intensity. Implications for future research, including the interplay of occupational FTP and proactive personality, and some tentative practical implications are discussed.
High prevalence of nasal carriage of β-lactamase-negative ampicillin-resistantHaemophilus influenzaein healthy children in Korea
Authors: BAE S. M. , LEE J. H. , LEE S. K. , YU J. Y. , LEE S. H. , KANG Y. H.
Published: May 2012

This study investigated the carriage of antimicrobial resistantHaemophilus influenzaein 582 healthy children attending kindergarten or elementary school at four intervals over a 9-month period in Seoul, Korea. Diverse colonization patterns and a lower level of long-term persistent carriage byH. influenzaestatus were evident in this study. ColonizingH. influenzaeisolates showed a high rate of resistance to β-lactams including ampicillin (51·9%), cefaclor (52·1%), and amoxicillin/clavulanate (16·3%). Based on the ampicillin resistance mechanism,H. influenzaeisolates were categorized as β-lactamase-negative, ampicillin-susceptible (BLNAS) (48·1%), β-lactamase-positive, ampicillin-resistant (BLPAR) (22·6%), β-lactamase-negative, ampicillin-resistant (BLNAR) (22·8%), and β-lactamase-positive, amoxicillin/clavulanate-resistant (BLPACR) strains (6·5%). This study provides the first evidence of a high prevalence (22·8%) of BLNAR strains ofH. influenzaenasal carriage in healthy children attending kindergarten or the first 2 years of elementary school in Korea. The high carriage of these resistant strains in overcrowded urban settings may create reservoirs for development ofH. influenzae-resistant strains.
Changes in the modulation of retinocollicular transmission through group III mGluRs long after an increase in intraocular pressure in a rat model of glaucoma
Authors: GEORGIOU ANNE L. , GUO LI , CORDEIRO M. FRANCESCA , SALT THOMAS E.
Published: May 2012

Metabotropic glutamate receptors (mGluRs) have been shown to be involved in the modulation of retinocollicular neurotransmission. In glaucoma, retinal ganglion cells (RGCs) degenerate, which may have an implication on this transmission as the superior colliculus is their major central target in the much-used rodent models of the disease. We have investigated this using anin vitroslice preparation of the superior colliculus by eliciting field excitatory postsynaptic potentials (fEPSPs) through optic tract stimulation in a rat ocular hypertension model of glaucoma. Application of the group III mGluR agonist L-AP4 reduced the peak amplitude of the fEPSP in superior colliculus slices through presynaptic mechanisms as previously shown in our lab. At 3 and 16 weeks after surgery, there were no significant differences in the effect of L-AP4 on fEPSP peak amplitude in the superior colliculus slices receiving input from the glaucomatous eyes [elevated intraocular pressure (IOP)] compared to those with input from the unoperated eyes (normal IOP). However, at 32 weeks, the fEPSP peak amplitude was reduced to a significantly greater degree during L-AP4 application in the elevated IOP slices compared to normal IOP slices. At all time points, there were no significant changes in the baseline amplitudes of fEPSPs or the stimulus intensities required to evoke fEPSPs. These results suggest that the modulation of synaptic transmission through group III mGluRs on RGC terminals to the superior colliculus is changed at later stages due to RGC degeneration through IOP elevation. These changes may be compensatory changes possibly through plasticity in the RGC terminals of surviving cells, which may be due to increases in the numbers of group III mGluRs. This result may have implications on further treatment studies carried out using these models of glaucoma as changes in the central visual system may need to be considered along with the retinal changes that occur.
Oxytocin enhances resting-state connectivity between amygdala and medial frontal cortex
Authors: Sripada Chandra Sekhar , Phan K. Luan , Labuschagne Izelle , Welsh Robert , Nathan Pradeep J. , Wood Amanda G.
Published: May 2012

The neuropeptide oxytocin (OXT) plays an important role in complex socio-affective behaviours such as affiliation, attachment, stress and anxiety. Previous studies have focused on the amygdala as an important target of OXT's effects. However, the effects of OXT on connectivity of the amygdala with cortical regions such as medial frontal cortex, an important mediator of social cognition and emotion regulation, remain unexplored. In a randomized, double-blind, cross-over design, 15 volunteers received intranasal OXT or placebo prior to resting-state functional magnetic resonance imaging. OXT significantly increased connectivity between both amygdalae and rostral medial frontal cortex (rmFC), while having only negligible effects on coupling with other brain regions. These results demonstrate that OXT is a robust and highly selective enhancer of amygdala connectivity with rmFC, a region critical to social cognition and emotion regulation, and add to our understanding of the neural mechanisms by which OXT modulates complex social and cognitive behaviours.
Assessing sources of uncertainty in formaldehyde air mass factors over tropical South America: Implications for top‐down isoprene emission estimates
Authors: Barkley Michael P. , Kurosu Thomas P. , Chance Kelly , De Smedt Isabelle , Van Roozendael Michel , Arneth Almut , Hagberg Daniel , Guenther Alex
Published: May 2012

We use a nested‐grid version of the GEOS‐Chem chemistry transport model, constrained by isoprene emissions from the Model of Emissions of Gases and Aerosols from Nature (MEGAN), and the Lund‐Potsdam‐Jena General Ecosystem Simulator (LPJ‐GUESS) bottom‐up inventories, to evaluate the impact that surface isoprene emissions have on formaldehyde (HCHO) air‐mass factors (AMFs) and vertical column densities (VCDs) over tropical South America during 2006, as observed by the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) and Ozone Monitoring Instrument (OMI). Although the large‐scale seasonal variability of monthly mean HCHO VCDs is typically unaffected by the choice of bottom‐up inventory, large relative differences of up to ±45% in the HCHO VCD can occur for individual regions and months, but typically most VCD differences are of order ±20%. These relative changes are comparable to those produced by other sources of uncertainty in the AMF including aerosols and surface albedo, but less than those from clouds. In a sensitivity test, we find that top‐down annual isoprene emissions inferred from SCIAMACHY and OMI HCHO vertical columns can vary by as much as ±30–50% for each instrument respectively, depending on the region studied and the a priori isoprene emissions used. Our analysis suggests that the influence of the a priori isoprene emissions on HCHO AMFs and VCDs is therefore non‐negligible and must be carefully considered when inferring top‐down isoprene emissions estimates over this, or potentially any other, region.
Variations in seawater Sr/Ca recorded in deep‐sea bamboo corals
Authors: Hill T. M. , LaVigne M. , Spero H. J. , Guilderson T. , Gaylord B. , Clague D.
Published: May 2012

A depth transect of deep‐sea bamboo corals along the California margin provides evidence that coral strontium to calcium ratios (Sr/Cacoral) record seawater Sr/Ca ratios (Sr/Casw). A calibration was constructed utilizing Sr/Cacoral ratios and previously published Pacific Sr/Casw data (R2 = 0.53, n = 12, p < 0.01): Sr/Cacoral (mmol/mol) = 4.62*Sr/Casw (mmol/mol) − 36.64. Sr/Casw is ultimately governed by the remineralization of Sr‐containing shells of surface water‐derived marine organisms (e.g., Acantharia) at intermediate water depths. California margin Sr/Cacoral records from 792 and 1295 m document fluctuations in Sr/Casw that appear decadal‐scale. These results suggest that Sr/Casw may not be as stable as previously assumed and may be influenced by surface productivity on short timescales.
Importance of data assimilation technique in defining the model drivers for the space weather specification of the high‐latitude ionosphere
Authors: Zhu L. , Schunk R. , Scherliess L. , Eccles V.
Published: May 2012

The high‐latitude ionosphere is a dynamic region in the solar‐terrestrial system. The disturbances in this region can adversely affect numerous military and civilian systems, and the accurate specification and forecast of its plasma and electrodynamic structures are important for space weather research. Presently, most of the space weather models use limited observations and/or indices to define a set of empirical drivers for physical models forward in time. The empirical drivers have a “climatological” nature, and there are significant physical inconsistencies among various empirical drivers. Therefore, the specifications of high‐latitude environment from these space weather models cannot truthfully reflect the weather features. Utah State University (USU) has developed a data assimilation model for the high‐latitude ionosphere plasma dynamics and electrodynamics to overcome these hurdles. With a set of physical models and an ensemble Kalman filter, the model can define the drivers that are most truthful to the real space environment by ingesting data from multiple observations. In this paper, we will provide the details on how the model drivers truthful to real space weather are defined in the developed USU data assimilation model and show the space weather variability of the model outputs driven by these model drivers for various seasonal and geomagnetic conditions. Also, we will present preliminary results of validation and comparison studies to demonstrate that the model results with the optimal magnetospheric drivers determined by data assimilation are the better representations of real space environment.