bluuebunny/crossref_metadata_2025 huggingface dataset:
Wetting of amorphous and nanocrystalline Ni75B15Si10 substrates by molten Sn
Authors: Shen Ping , Yang Jun , Yin Zhongfa , Sun Jianxin , Jiang Qichuan
Published: August 2012

The wetting behavior and interfacial microstructures of molten Sn on the amorphous and annealing‐induced nanocrystalline Ni75B15Si10 ribbons were investigated using a modified sessile‐drop method. The results show that the amorphous structure favors the wettability, while the structural relaxation and primary crystallization remarkably deteriorate it. The wetting is essentially attributed to the strong chemical affinity between liquid Sn and Ni in the substrate. Precipitation of the nanocrystallites like Ni3B and Ni3Si weakens the wettability by decreasing the atomic activity of Ni. However, the reduced oxidation of the substrate surface after higher temperature annealing and the alleviated diffusion of Sn towards the bulk of the substrate as well as possible capillarity assistance of the liquid movement along the grain or phase boundaries ahead of the triple line may help to facilitate the wetting to some extent. Copyright © 2012 John Wiley & Sons, Ltd.
High‐Interstitial Stainless Austenitic Steel Castings
Authors: Berns Hans , Nabiran Nilofar , Mujica Laís
Published: August 2012

Interstitial atoms are most effective in strengthening austenitic steels. In stainless grades, chromium strongly reduces the solubility limit of carbon. High‐nitrogen contents require costly pressure or powder metallurgy to dissolve N in the melt. The combination of both elements comes with a high‐interstitial solubility at normal pressure of air. Sand casting with 18 mass% Cr and Mn each and 0.85 mass% (C + N) were industrially produced. The investigation revealed: proof strength Rp0.2 = 457 [MPa], true fracture strength R = 1714 [MPa], fracture elongation A = 44%, notch impact toughness KV = 290 J combined with a DBTT of −94°C, an impact wear resistance comparable to Hadfield steel X120Mn12 but combined with a good corrosion resistance. Deep freezing and cold working does not effect the low relative magnetic permeability. This unique combination of properties offers advantages in application.
Effect of Heat Treatment on Microstructure and Mechanical Properties of 2.25Cr–1Mo Steel
Authors: Wang Wei , Zhao Wengui , Qu Jinbo
Published: August 2012

The effect of heat treatment on microstructure and mechanical properties of a ferritic heat‐resistant steel, 2.25Cr–1Mo, was investigated. The characteristics of carbides, i.e., size, morphology, distribution, and composition, in different stages of heat treatment were examined by using transmission electron microscopy (TEM) and energy dispersive X‐ray (EDX). As the heat treatment proceeded from normalizing and tempering (NT, the delivery state), simulated post‐welding heat treatment (PWHT), to step cooling (SC), the carbides evolved from M3C, Mo2C to M7C3, M23C6. The uniformly dispersed carbides, e.g., Mo2C, M7C3, and M23C6, are responsible for the excellent mechanical properties and creep resistance of the steel. The result demonstrates that the coarsening of carbides deteriorates impact toughness and the morphology, crystal structure, and chemical composition of carbides are also important influencing factors.
In Situ Observation of Surface Electrochemical Activities of Lean Duplex Stainless Steel LDX 2101
Authors: Li Xuyan , Guo Lifang , Han Dong , Li Jin , Jiang Yiming
Published: August 2012

The surface electrochemical corrosion activity of the economic lean duplex stainless steel LDX2101 was investigated in situ in chloride solution with a combination of long working distance microscope (LWDM) and electrochemical techniques. In addition, the site and chemical composition of the electrochemical active points on the specimen surface were also determined with integrated scanning electron microscope/energy dispersive X‐ray spectroscope (SEM/EDS) system. The results demonstrated that: (i) The reaction of α → Cr2N + γ2 precedes that of α → σ + γ2 when LDX2101 was aged at 700°C. (ii) The initiation sites of electrochemical active points could be determined by LWDM in combination with potentiostatic pulse technique (PPT). (iii) The sites of electrochemical active points were found to change from inclusions (MnS/Al2O3) to secondary austenite phase (γ2), with the increase of aging time at 700°C.
The holographic quantum effective potential at finite temperature and density
Authors: Kiritsis Elias , Niarchos Vasilis
Published: August 2012

Abstract

We develop a formalism that allows the computation of the quantum effective potential of a scalar order parameter in a class of holographic theories at finite temperature and charge density. The effective potential is a valuable tool for studying the ground state of the theory, symmetry breaking patterns and phase transitions. We derive general formulae for the effective potential and apply them to determine the phase transition temperature and density in the scaling region.
Viruses in Biology
Authors: López-García Purificación , Moreira David
Published: August 2012

During the first half of the twentieth century, many scientists considered viruses the smallest living entities and primitive life forms somehow placed between the inert world and highly evolved cells. The development of molecular biology in the second half of the century showed that viruses are strict molecular parasites of cells, putting an end to previous virocentric debates that gave viruses a primeval role in the origin of life. Recent advances in comparative genomics and metagenomics have uncovered a vast viral diversity and have shown that viruses are active regulators of cell populations and that they can influence cell evolution by acting as vectors for gene transfer among cells. They have also fostered a revival of old virocentric ideas. These ideas are heterogeneous, extending from proposals that consider viruses functionally as living beings and/or as descendants of viral lineages that preceded cell evolution to other claims that consider viruses and/or some viral families a fourth domain of life. In this article, we revisit these virocentric ideas and analyze the place of viruses in biology in light of the long-standing dichotomic debate between metabolist and geneticist views which hold, respectively, that self-maintenance (metabolism) or self-replication and evolution are the primeval features of life. We argue that whereas the epistemological discussion about whether viruses are alive or not and whether some virus-like replicators precede the first cells is a matter of debate that can be understood within the metabolism-versus-genes dialectic; the claim that viruses form a fourth domain in the tree of life can be solidly refuted by proper molecular phylogenetic analyses and needs to be removed from this debate.
Structural considerations for chromatin state models with transcription as a functional readout
Authors: Chen Haodong , Monte Emma , Parvatiyar Michelle S. , Rosa-Garrido Manuel , Franklin Sarah , Vondriska Thomas M.
Published: August 2012

Lacking from the rapidly evolving field of chromatin regulation is a discrete model of chromatin states. We propose that each state in such a model should meet two conditions: a structural component and a quantifiable effect on transcription. The practical benefits to the field of a model with greater than two states (including one with six states, as described herein) would be to improve interpretation of data from disparate organ systems, to reflect temporal and developmental dynamics and to integrate the, at present, conceptually and experimentally disparate analyses of individual genetic loci (in vitro or using single gene approaches) and genome‐wide features (including ChlP‐seq, chromosomal capture and mRNA expression via microarrays/sequencing).
Contraceptive counseling in Turkey after induced abortion
Authors: Günyeli Ilker , Abike Faruk , Bingöl Banu , Ornek Turkan
Published: August 2012

Objective

To determine the effectiveness of post‐abortion contraceptive counseling to women with unwanted pregnancy and to investigate use of modern contraceptive methods among Turkish women.

Methods

A prospective case–control study was conducted at 3 Turkish centers between March 23, 2008, and January 10, 2011. A total of 333 women enrolled in the study were divided into 2 groups. Women in group 1 (n = 140) presented with unwanted pregnancy requiring induced abortion whereas women in group 2 (n = 193) had requested contraception counseling.

Results

The use of coitus interruptus or condoms was significantly more frequent in group 1 than in group 2 (P < 0.001). No statistically significant differences were detected between the 2 groups in their use of oral contraceptives, intrauterine devices, injection methods, calendar methods, and other methods. The education level attained by women in group 1 was lower than that of women in group 2 (P = 0.041).

Conclusion

Increased effort is required to ensure that sufficient education about family planning is provided to Turkish women for the prevention of unwanted pregnancies and induced abortions.
On the unique features of post‐disaster humanitarian logistics
Authors: Holguín‐Veras José , Jaller Miguel , Van Wassenhove Luk N. , Pérez Noel , Wachtendorf Tricia
Published: August 2012

Logistic activity can be thought of as a socio‐technical process whereby a social network of individuals orchestrates a series of technical activities using supporting systems such as transportation and communications. To understand the functioning of the entire system requires proper consideration of all its components. We identify seven key components: the objectives being pursued, the origin of the commodity flows to be transported, knowledge of demand, the decision‐making structure, periodicity and volume of logistic activities, and the state of the social networks and supporting systems. Based on our analysis of the differences between commercial and humanitarian logistics, we pinpoint research gaps that need to be filled to enhance both the efficiency of humanitarian logistics and the realism of the mathematical models designed to support it.

We argue that humanitarian logistics is too broad a field to fit neatly into a single definition of operational conditions. At one end of the spectrum we find humanitarian logistic efforts of the kind conducted in long‐term disaster recovery and humanitarian assistance, where operational efficiency – akin to commercial logistics – is a prime consideration. At the other, post‐disaster humanitarian logistic operations involved in disaster response and short‐term recovery activities represent a vastly different operational environment, often in chaotic settings where urgent needs, life‐or‐death decisions and scarce resources are the norm. The huge contrast between these operational environments requires that they be treated separately.
Rational weak mixing in infinite measure spaces
Authors: AARONSON JON
Published: August 2012

Rational weak mixing is a measure theoretic version of Krickeberg’s strong ratio mixing property for infinite measure preserving transformations. It requires ‘density’ ratio convergence for every pair of measurable sets in a dense hereditary ring. Rational weak mixing implies weak rational ergodicity and (spectral) weak mixing. It is enjoyed for example by Markov shifts with Orey’s strong ratio limit property. The power, subsequence version of the property is generic.
Measure-theoretic chaos
Authors: DOWNAROWICZ TOMASZ , LACROIX YVES
Published: August 2012

We define new isomorphism invariants for ergodic measure-preserving systems on standard probability spaces, called measure-theoretic chaos and measure-theoretic$^+$ chaos. These notions are analogs of the topological chaos DC2 and its slightly stronger version (which we denote by $\text {DC}1\frac 12$). We prove that: (1) if a topological system is measure-theoretically (measure-theoretically$^+$) chaotic with respect to at least one of its ergodic measures then it is topologically DC2 $(\text {DC}1\frac 12)$ chaotic; (2) every ergodic system with positive Kolmogorov–Sinai entropy is measure-theoretically$^+$ chaotic (even in a slightly stronger uniform sense). We provide an example showing that the latter statement cannot be reversed, that is, of a system of entropy zero with uniform measure-theoretic$^+$chaos.
High-speed granular chute flows
Authors: Holyoake Alex J. , McElwaine Jim N.
Published: August 2012

This paper reports experimental findings on the flow of sand down a steep chute. Nearly all granular flow models have a maximum value for the friction and therefore predict that flows on steep slopes will accelerate at a constant rate until the interaction with the ambient fluid becomes important. This prediction has not been tested by previous work, which has focused on relatively low slope angles where steady, fully developed flows occur after short distances. We test this by investigating flows over a much greater range of slope angles (30–50${}^{\ensuremath{\circ} } $) and flow depths (4–130 particle diameters). We examine flows with two basal conditions, one flat and frictional, the other bumpy. The latter imposes a no-slip condition for slow, deep flows, but permits some degree of slip for high flow velocities. The data suggests that friction can be much larger than theories such as the $\ensuremath{\mu} (I)$ rheology proposed by Jop, Forterre & Pouliquen (Nature, vol. 441, 2006) suggest and that there may be constant velocity states above the angle of vanishing ${h}_{\mathit{stop}} $. Although these flows do not vary in time, all but the flows on the bumpy base at low inclinations accelerate down the slope. A recirculation mechanism sustains flows with a maximum mass flux of $20~\mathrm{kg} ~{\mathrm{s} }^{\ensuremath{-} 1} $, allowing observations to be made at multiple points for each flow for an indefinite period. Flows with Froude number in the range 0.1–25 and bulk inertial number 0.1–2.7 were observed in the dense regime, with surface velocities in the range 0.2–5.6 $\mathrm{m} ~{\mathrm{s} }^{\ensuremath{-} 1} $. Previous studies have focused on $I\lessapprox 0. 5$. We show that a numerical implementation of the $\ensuremath{\mu} (I)$ rheology does not fully capture the accelerating dynamics or the transverse velocity profile on the bumpy base. We also observe the transverse separation of the flow into a dense core flanked by dilute regions and the formation of longitudinal vortices.
On the acoustic levitation stability behaviour of spherical and ellipsoidal particles
Authors: Foresti D. , Nabavi M. , Poulikakos D.
Published: August 2012

We present here an in-depth analysis of particle levitation stability and the role of the radial and axial forces exerted on fixed spherical and ellipsoidal particles levitated in an axisymmetric acoustic levitator, over a wide range of particle sizes and surrounding medium viscosities. We show that the stability behaviour of a levitated particle in an axisymmetric levitator is unequivocally connected to the radial forces: the loss of levitation stability is always due to the change of the radial force sign from positive to negative. It is found that the axial force exerted on a sphere of radius ${R}_{s} $ increases with increasing viscosity for ${R}_{s} / \lambda \lt 0. 0125$ ($\lambda $ is the acoustic wavelength), with the viscous contribution of this force scaling with the inverse of the sphere radius. The axial force decreases with increasing viscosity for spheres with ${R}_{s} / \lambda \gt 0. 0125$. The radial force, on the other hand, decreases monotonically with increasing viscosity. The radial and axial forces exerted on an ellipsoidal particle are larger than those exerted on a volume-equivalent sphere, up to the point where the ellipsoid starts to act as an obstacle to the formation of the standing wave in the levitator chamber.
The interaction between flow-induced vibration mechanisms of a square cylinder with varying angles of attack
Authors: Nemes András , Zhao Jisheng , Lo Jacono David , Sheridan John
Published: August 2012

This study examines the influence of angle of attack of a square section cylinder on the cylinder’s flow-induced vibration, where the direction of the vibration is transverse to the oncoming flow. Our experiments, which traversed the velocity–angle of attack parameter space in considerable breadth and depth, show that a low-mass ratio body can undergo combinations of both vortex-induced vibration and galloping. When the body has an angle of attack that makes it symmetric to the flow, such as when it assumes the square or diamond orientation, the two mechanisms remain independent. However, when symmetry is lost we find a mixed mode response with a new branch of vortex-induced oscillations that exceeds the amplitudes resulting from the two phenomena independently. The oscillations of this higher branch have amplitudes larger than the ‘upper branch’ of vortex-induced vibrations and at half the frequency. For velocities above this resonant region, the frequency splits into two diverging branches. Analysis of the amplitude response reveals that the transition between galloping and vortex-induced vibrations occurs over a narrow range of angle of incidence. Despite the rich set of states found in the parameter space the vortex shedding modes remain very similar to those found previously in vortex-induced vibration.
Non-modal stability in sliding Couette flow
Authors: Liu R. , Liu Q. S.
Published: August 2012

The problem of an incompressible flow between two coaxial cylinders with radii$a$and$b$subjected to a sliding motion of the inner cylinder in the axial direction is considered. The energy stability and the non-modal stability have been investigated for both axisymmetric and non-axisymmetric disturbances. For the non-modal stability, we focus on two problems: response to external excitations and response to initial conditions. The former is studied by examining the$\epsilon $-pseudospectrum, and the latter by examining the energy growth function$G(t)$. Unlike the results of the modal analysis in which the stability of sliding Couette flow is determined by axisymmetric disturbances, the energy analysis shows that a non-axisymmetric disturbance has a critical energy Reynolds number for all radius ratios$\eta = a/ b$. The results for non-modal stability show that rather large transient growth occurs over a wide range of azimuthal wavenumber$n$and streamwise wavenumber$\ensuremath{\alpha} $, even though the Reynolds number is far below its critical value. For the problem of response to external excitations, the response is sensitive to low-frequency external excitations. For all values of the radius ratio, the maximum response is achieved by non-axisymmetric and streamwise-independent disturbances when the frequency of external forcing$\omega = 0$. For the problem of response to initial conditions, the optimal disturbance is in the form of helical streaks at low Reynolds numbers. With the increase of$\mathit{Re}$, the optimal disturbance becomes very close to straight streaks. For each$\eta $, the maximum energy growth of streamwise-independent disturbances is of the order of${\mathit{Re}}^{2} $, and the optimal time is of the order of$\mathit{Re}$. This relation is qualitatively similar to that for plane Couette flow, plane Poiseuille flow and pipe Poiseuille flow. Direct numerical simulations are applied to investigate the transition of the streamwise vortex (SV) scenario at$\mathit{Re}= 1000$and 1500 for various$\eta $. The initial disturbances are the optimal streamwise vortices predicted by the non-modal analysis. We studied the streak breakdown phase of the SV scenarios by examining the instability of streaks. Moreover, we have investigated the sustainment of the energy of disturbances in the SV scenario.
Kolmogorov laws for stratified turbulence
Authors: Augier Pierre , Galtier Sébastien , Billant Paul
Published: August 2012

Following the Kolmogorov technique, an exact relation for a vector third-order moment $\mathbi{J}$ is derived for three-dimensional incompressible stably stratified turbulence under the Boussinesq approximation. In the limit of a small Brunt–Väisälä frequency, isotropy may be assumed which allows us to find a generalized $4/ 3$-law. For strong stratification, we make the ansatz that $\mathbi{J}$ is directed along axisymmetric surfaces parameterized by a scaling law relating horizontal and vertical coordinates. An integration of the exact relation under this hypothesis leads to a generalized Kolmogorov law which depends on the intensity of anisotropy parameterized by a single coefficient. By using a scaling relation between large horizontal and vertical length scales we fix this coefficient and propose a unique law.
Reynolds number effects on lipid vesicles
Authors: Salac David , Miksis Michael J.
Published: August 2012

Vesicles exposed to the human circulatory system experience a wide range of flows and Reynolds numbers. Previous investigations of vesicles in fluid flow have focused on the Stokes flow regime. In this work the influence of inertia on the dynamics of a vesicle in a shearing flow is investigated using a novel level-set computational method in two dimensions. A detailed analysis of the behaviour of a single vesicle at finite Reynolds number is presented. At low Reynolds numbers the results recover vesicle behaviour previously observed for Stokes flow. At moderate Reynolds numbers the classical tumbling behaviour of highly viscous vesicles is no longer observed. Instead, the vesicle is observed to tank-tread, with an equilibrium angle dependent on the Reynolds number and the reduced area of the vesicle. It is shown that a vesicle with an inner/outer fluid viscosity ratio as high as 200 will not tumble if the Reynolds number is as low as 10. A new damped tank-treading behaviour, where the vesicle will briefly oscillate about the equilibrium inclination angle, is also observed. This behaviour is explained by an investigation on the torque acting on a vesicle in shear flow. Scaling laws for vesicles in inertial flows have also been determined. It is observed that quantities such as vesicle tumbling period follow square-root scaling with respect to the Reynolds number. Finally, the maximum tension as a function of the Reynolds number is also determined. It is observed that, as the Reynolds number increases, the maximum tension on the vesicle membrane also increases. This could play a role in the creation of stable pores in vesicle membranes or for the premature destruction of vesicles exposed to the human circulatory system.
Thermal and viscous boundary layers in turbulent Rayleigh–Bénard convection
Authors: Scheel J. D. , Kim E. , White K. R.
Published: August 2012

We present the results from numerical simulations of turbulent Rayleigh–Bénard convection for an aspect ratio (diameter/height) of 1.0, Prandtl numbers of 0.4 and 0.7, and Rayleigh numbers from $1\ensuremath{\times} 1{0}^{5} $ to $1\ensuremath{\times} 1{0}^{9} $. Detailed measurements of the thermal and viscous boundary layer profiles are made and compared to experimental and theoretical (Prandtl–Blasius) results. We find that the thermal boundary layer profiles disagree by more than 10 % when scaled with the similarity variable (boundary layer thickness) and likewise disagree with the Prandtl–Blasius results. In contrast, the viscous boundary profiles collapse well and do agree (within 10 %) with the Prandtl–Blasius profile, but with worsening agreement as the Rayleigh number increases. We have also investigated the scaling of the boundary layer thicknesses with Rayleigh number, and again compare to experiments and theory. We find that the scaling laws are very robust with respect to method of analysis and they mostly agree with the Grossmann–Lohse predictions coupled with laminar boundary layer theory within our numerical uncertainty.
Intake of polyphenol-rich pomegranate pure juice influences urinary glucocorticoids, blood pressure and homeostasis model assessment of insulin resistance in human volunteers
Authors: Tsang Catherine , Smail Nacer F. , Almoosawi S. , Davidson I. , Al-Dujaili Emad A. S.
Published: August 2012

Pomegranate juice (PJ; also known as pomegreat pure juice) provides a rich and varied source of polyphenolic compounds that may offer cardioprotective, anti-atherogenic and antihypertensive effects. The aim of this study was to investigate the effect of PJ consumption on glucocorticoids levels, blood pressure (BP) and insulin resistance in volunteers at high CVD risk. Subjects (twelve males and sixteen females) participated in a randomised, placebo-controlled cross-over study (BMI: 26·77 (sd3·36) kg/m2; mean age: 50·4 (sd6·1) years). Volunteers were assessed at baseline, and at weeks 2 and 4 for anthropometry, BP and pulse wave velocity. Cortisol and cortisone levels in urine and saliva were determined by specific ELISA methods, and the cortisol/cortisone ratio was calculated. Fasting blood samples were obtained to assess plasma lipids, glucose, insulin and insulin resistance (homeostasis model assessment of insulin resistance). Volunteers consumed 500 ml of PJ or 500 ml of a placebo drink containing a similar amount of energy. Cortisol urinary output was reduced but not significant. However, cortisol/cortisone ratios in urine (P = 0·009) and saliva (P = 0·024) were significantly decreased. Systolic BP decreased from 136·4 (sd 6·3) to 128·9 (sd 5·1) mmHg (P = 0·034), and diastolic BP from 80·3 (sd 4·29) to 75·5 (sd 5·17) mmHg (P = 0·031) after 4 weeks of fruit juice consumption. Pulse wave velocity decreased from 7·5 (sd 0·86) to 7·44 (sd 0·94) m/s (P = 0·035). There was also a significant reduction in fasting plasma insulin from 9·36 (sd 5·8) to 7·53 (sd 4·12) mIU/l (P = 0·025) and of homeostasis model assessment of insulin resistance (from 2·216 (sd 1·43) to 1·82 (sd 1·12),P= 0·028). No significant changes were seen in the placebo arm of the study. These results suggest that PJ consumption can alleviate key cardiovascular risk factors in overweight and obese subjects that might be due to a reduction in both systolic and diastolic BP, possibly through the inhibition of 11β-hydroxysteroid dehydrogenase type 1 enzyme activity as evidenced by the reduction in the cortisol/cortisone ratio. The reduction in insulin resistance might have therapeutic benefits for patients with non-insulin-dependent diabetes, obesity and the metabolic syndrome.
Molecular mechanisms of the cardiovascular protective effects of polyphenols
Authors: Andriantsitohaina Ramaroson , Auger Cyril , Chataigneau Thierry , Étienne-Selloum Nelly , Li Huige , Martínez M. Carmen , Schini-Kerth Valérie B. , Laher Ismail
Published: August 2012

Epidemiological studies have reported a greater reduction in cardiovascular risk and metabolic disorders associated with diets rich in polyphenols. The antioxidant effects of polyphenols are attributed to the regulation of redox enzymes by reducing reactive oxygen species production from mitochondria, NADPH oxidases and uncoupled endothelial NO synthase in addition to also up-regulating multiple antioxidant enzymes. Although data supporting the effects of polyphenols in reducing oxidative stress are promising, several studies have suggested additional mechanisms in the health benefits of polyphenols. Polyphenols from red wine increase endothelial NO production leading to endothelium-dependent relaxation in conditions such as hypertension, stroke or the metabolic syndrome. Numerous molecules contained in fruits and vegetables can activate sirtuins to increase lifespan and silence metabolic and physiological disturbances associated with endothelial NO dysfunction. Although intracellular pathways involved in the endothelial effects of polyphenols are partially described, the molecular targets of these polyphenols are not completely elucidated. We review the novel aspects of polyphenols on several targets that could trigger the health benefits of polyphenols in conditions such as metabolic and cardiovascular disturbances.
The gut microbiome of kittens is affected by dietary protein:carbohydrate ratio and associated with blood metabolite and hormone concentrations
Authors: Hooda Seema , Vester Boler Brittany M. , Kerr Katherine R. , Dowd Scot E. , Swanson Kelly S.
Published: August 2012

High-protein, low-carbohydrate (HPLC) diets are common in cats, but their effect on the gut microbiome has been ignored. The present study was conducted to test the effects of dietary protein:carbohydrate ratio on the gut microbiota of growing kittens. Male domestic shorthair kittens were raised by mothers fed moderate-protein, moderate-carbohydrate (MPMC; n 7) or HPLC (n 7) diets, and then weaned at 8 weeks onto the same diet. Fresh faeces were collected at 8, 12 and 16 weeks; DNA was extracted, followed by amplification of the V4–V6 region of the 16S rRNA gene using 454 pyrosequencing. A total of 384 588 sequences (average of 9374 per sample) were generated. Dual hierarchical clustering indicated distinct clustering based on the protein:carbohydrate ratio regardless of age. The protein:carbohydrate ratio affected faecal bacteria. Faecal Actinobacteria were greater (P< 0·05) and Fusobacteria were lower (P< 0·05) in MPMC-fed kittens. Faecal Clostridium, Faecalibacterium, Ruminococcus, Blautia and Eubacterium were greater (P< 0·05) in HPLC-fed kittens, while Dialister, Acidaminococcus, Bifidobacterium, Megasphaera and Mitsuokella were greater (P< 0·05) in MPMC-fed kittens. Principal component analysis of faecal bacteria and blood metabolites and hormones resulted in distinct clusters. Of particular interest was the clustering of blood TAG with faecal Clostridiaceae, Eubacteriaceae, Ruminococcaceae, Fusobacteriaceae and Lachnospiraceae; blood ghrelin with faecal Coriobacteriaceae, Bifidobacteriaceae and Veillonellaceae; and blood glucose, cholesterol and leptin with faecal Lactobacillaceae. The present results demonstrate that the protein:carbohydrate ratio affects the faecal microbiome, and highlight the associations between faecal microbes and circulating hormones and metabolites that may be important in terms of satiety and host metabolism.
The citrus flavanone naringenin suppresses CYP1B1 transactivation through antagonising xenobiotic-responsive element binding
Authors: Poon Ching Ho , Wong Tsz Yan , Wang Yanfei , Tsuchiya Yuki , Nakajima Miki , Yokoi Tsuyoshi , Leung Lai K.
Published: August 2012

Exposure to environmental toxicants or exogenous oestrogen increases the risk of cancer. Some toxicants such as polycyclic aromatic hydrocarbons (PAH) undergo biotransformation to become genotoxic agents. Cytochrome p450 (CYP) 1B1 is an enzyme catalysing this transformation. Consumption of fruit and vegetables is considered to be protective against carcinogenesis, and naringenin can be found abundantly in citrus fruits. In the present study, the effect of naringenin on the regulation of CYP1B1 was investigated in MCF-7 cells. Enzyme inhibition assays revealed that naringenin inhibited CYP1B1 at or above 5 μm but not CYP1A1 activity. Quantitative PCR analysis also demonstrated that 1 μm-naringenin reduced CYP1B1 mRNA expression induced by 7,12-dimethylbenz(α)anthracene (DMBA). Further study illustrated that the suppression was at the transcriptional level. Since previous studies have shown that oestrogen response element (ERE) and xenobiotic-responsive element (XRE) are functional binding sequences in the promoter region of CYP1B1, interference of DNA binding on these two elements was pursued. Employing reporter gene assays as well as the electromobility shift assay, we verified that naringenin counteracted DMBA-induced XRE binding at − 1675. These results supported the notion that fruit consumption could be a protective measure against PAH biotransformation.
Hydration biomarkers in free-living adults with different levels of habitual fluid consumption
Authors: Perrier Erica , Vergne Sébastien , Klein Alexis , Poupin Marie , Rondeau Pascale , Le Bellego Laurent , Armstrong Lawrence E. , Lang Florian , Stookey Jodi , Tack Ivan
Published: August 2012

Little is known about the impact of habitual fluid intake on physiology. Specifically, biomarkers of hydration status and body water regulation have not been adequately explored in adults who consume different fluid volumes in everyday conditions, without prolonged exercise or environmental exposure. The purpose of the present study was to compare adults with habitually different fluid intakes with respect to biomarkers implicated in the assessment of hydration status, the regulation of total body water and the risk of kidney pathologies. In the present cross-sectional study, seventy-one adults (thirty-two men, thirty-nine women, age 25–40 years) were classified according to daily fluid intake: thirty-nine low drinkers (LD; ≤ 1·2 litres/d) and thirty-two high drinkers (HD; 2–4 litres/d). During four consecutive days, urinary parameters (first morning urine (FMU) on day 1 and subsequent 24 h urine (24hU) collections), blood parameters, and food and beverage intake were assessed. ANOVA and non-parametric comparisons revealed significant differences between the LD and HD groups in 24hU volume (1·0 (se 0·1) v. 2·4 (se 0·1) litres), specific gravity (median 1·023 v. 1·010), osmolality (767 (se 27) v. 371 (se 33) mOsm/kg) and colour (3·1 (se 0·2) v. 1·8 (se 0·2)). Similarly, in the FMU, the LD group produced a smaller amount of more concentrated urine. Plasma cortisol, creatinine and arginine vasopressin concentrations were significantly higher among the LD. Plasma osmolality was similar between the groups, suggesting physiological adaptations to preserve plasma osmolality despite low fluid intake. The long-term impact of adaptations to preserve plasma osmolality must be examined, particularly in the context of renal health.
Consumption of blueberries with a high-carbohydrate, low-fat breakfast decreases postprandial serum markers of oxidation
Authors: Blacker Bryan C. , Snyder Shannon M. , Eggett Dennis L. , Parker Tory L.
Published: August 2012

We sought to determine whether consumption of blueberries could reduce postprandial oxidation when consumed with a typical high-carbohydrate, low-fat breakfast. Participants (n14) received each of the three treatments over 3 weeks in a cross-over design. Treatments consisted of a high blueberry dose (75 g), a low blueberry dose (35 g) and a control (ascorbic acid and sugar content matching that of the high blueberry dose). Serum oxygen radical absorbance capacity (ORAC), serum lipoprotein oxidation (LO) and serum ascorbate, urate and glucose were measured at fasting, and at 1, 2 and 3 h after sample consumption. The mean serum ORAC was significantly higher in the 75 g group than in the control group during the first 2 h postprandially, while serum LO lag time showed a significant trend over the 3 h for both blueberry doses. Changes in serum ascorbate, urate and glucose were not significantly different among the groups. To our knowledge, this is the first report that has demonstrated that increased serum antioxidant capacity is not attributable to the fructose or ascorbate content of blueberries. In summary, a practically consumable quantity of blueberries (75 g) can provide statistically significant oxidative protectionin vivoafter a high-carbohydrate, low-fat breakfast. Though not tested directly, it is likely that the effects are due to phenolic compounds, either directly or indirectly, as they are a major family of compounds in blueberries with potential bioactive activity.
“The Master-Key of Our Theme”: Master Betty and the Politics of Theatricality in Herman Melville's “The Fiddler”
Authors: COLLINS MICHAEL JAMES
Published: August 2012

In what is by now among the more famous personal histories in American studies, by 1852 Herman Melville was facing bankruptcy and personal ruin after the financial failures ofMoby-DickandPierre. Under the guidance of the new editor ofPutnam's Magazine, Charles Briggs, Melville turned to writing magazine fiction. Building upon work that seeks to show how Melville in his short stories negotiated the terrain between the riotous world of the popular press and the sanctified realm of high art, this article looks at a frequently neglected work by Melville from 1854, “The Fiddler,” as a response to this personal crisis. I show how Melville's story resurrects a forgotten transatlantic history (the life of the Irish actor Master William Henry West Betty) as a means to explore his own search for an aesthetic that could adequately serve both the demands of the spectacular world of antebellum publishing and his own high literary ambitions.
Bruce Catton, Middlebrow Culture, and the Liberal Search for Purpose in Cold War America
Authors: COOK ROBERT
Published: August 2012

This essay provides a case study of one man's transition from the reform-oriented liberalism of the New Deal period to the burgeoning rights-focussed liberalism of the 1960s. It contends that Bruce Catton, the most popular Civil War historian of his generation, played an influential role in forging the culture of Cold War America. He did so in his capacity as a prominent “middlebrow” intellectual who sought to instil his legions of adoring fans with a sense of moral purpose at a time when political elites were fretting about ordinary Americans' ability to fight the Cold War effectively. While his finely crafted narratives of the Civil War demonstrated the courage and conviction of nineteenth-century Americans, his many public appearances in the 1950s enabled him to disseminate further his conviction that the timeless values of American democracy remained as relevant in the disturbing present as they had been in the country's divided past. Catton's characteristically middlebrow commitment to antiracism as a contribution to the Cold War struggle was by no means unfaltering but an assessment of his writings and actions during the Civil War centennial reveals his continuing determination to render American democracy sufficiently vigorous to counter the ongoing communist threat.
The Memorialization of Southern Poor White Men's Labor in Rick Bragg's Memoir Trilogy
Authors: ROBERTSON SARAH
Published: August 2012

This article explores the ways that Rick Bragg memorializes poor white men's labor across his memoir trilogy, examining the tensions that arise as he attempts to bring poor whites into the center of the southern community. I consider the neo-Agrarian strains within his work, as well as Bragg's responses to the globalization of the region. The work addresses the absences within the South's memorial landscape, and questions the extent to which Bragg's work addresses those gaps.
Foraging dives of sperm whales in the north-western Mediterranean Sea
Authors: Gannier Alexandre , Petiau Estelle , Dulau Violaine , Rendell Luke
Published: August 2012

Oceanic odontocetes rely on echolocation to forage on pelagic or benthic prey, but their feeding ecology is difficult to study. We studied sperm whale foraging dives during summer in the north-western Mediterranean, using visual and passive acoustic observations. Clicking and creaking activities were recorded during dives of focal whales, at distances <3000 m using a towed hydrophone and DAT recorder. A total of 52 sperm whales were recorded over at least one full dive cycle. Data were obtained for 156 complete dives in total, including sequences of up to nine consecutive dives. Various dive and environmental variables were entered in multiple linear regression and principal components analysis, as well as estimated mass of whales. Creak rate was 0.80 creak/minute on average, with moderate variance. Bigger whales tended to dive longer at greater depths (as suggested by ascent durations), and emitted more creaks during a dive: 20.2 creaks/dive on average for individuals <24 tons, compared to 25.6 creaks/dive for animals >24 tons of estimated mass. For individual whales, creak rates did not vary significantly with size (range 0.78–0.80 creak/minute), but decreased with time of the day, and increased for shorter foraging phases. For different dives, higher creak rates were also observed earlier in the day, and linked to shorter foraging phases and surface durations. Although the exact significance of creak emissions (i.e. foraging attempt or prey capture) is not precisely determined, creak rates may be reliably used to quantify sperm whale foraging when single animal dives can be followed acoustically.
Surface anatomical profile of the cerebral cortex in obsessive–compulsive disorder: a study of cortical thickness, folding and surface area
Authors: Fan Q. , Palaniyappan L. , Tan L. , Wang J. , Wang X. , Li C. , Zhang T. , Jiang K. , Xiao Z. , Liddle P. F.
Published: August 2012

Background

Studying the distribution of anatomical abnormalities over the entire cortical surface can help to identify key neural circuits implicated in generating symptoms of neuropsychiatric disorders. There is a significant inconsistency among studies investigating the neuroanatomy of obsessive–compulsive disorder (OCD) because of the confounding influence of co-morbid depression and medication use and the lack of unbiased estimation of whole-brain morphometric changes. It is also unknown whether the distinct surface anatomical properties of thickness, surface area and gyrification, which collectively contribute to grey matter volume (GMV), are independently affected in OCD.

Method

The cortical maps of thickness, gyrification and surface areal change were acquired from 23 unmedicated OCD patients and 20 healthy controls using an unbiased whole-brain surface-based morphometric (SBM) method to detect regional changes in OCD. Subcortical structures were not assessed in this study.

Results

Patients showed a significant increase in the right inferior parietal cortical thickness. Significant increases in gyrification were also noted in the left insula, left middle frontal and left lateral occipital regions extending to the precuneus and right supramarginal gyrus in OCD. Areal contraction/expansion maps revealed no significant regional differences between the patients and controls. In patients, gyrification of the insula significantly predicted the symptom severity measured using Yale–Brown Obsessive–Compulsive Scale (YBOCS).

Conclusions

An alteration in the cortical surface anatomy is an important feature of OCD seen in unmedicated samples that relates to the severity of the illness. The results underscore the presence of a neurodevelopmental aberration underlying the pathophysiology of OCD.
Persistence of cognitive impairment and its negative impact on psychosocial functioning in lithium-treated, euthymic bipolar patients: a 6-year follow-up study
Authors: Mora E. , Portella M. J. , Forcada I. , Vieta E. , Mur M.
Published: August 2012

Background

Previous cross-sectional studies report that cognitive impairment is associated with poor psychosocial functioning in euthymic bipolar patients. There is a lack of long-term studies to determine the course of cognitive impairment and its impact on functional outcome.

Method

A total of 54 subjects were assessed at baseline and 6 years later; 28 had DSM-IV TR bipolar I or II disorder (recruited, at baseline, from a Lithium Clinic Program) and 26 were healthy matched controls. They were all assessed with a cognitive battery tapping into the main cognitive domains (executive function, attention, processing speed, verbal memory and visual memory) twice over a 6-year follow-up period. All patients were euthymic (Hamilton Rating Scale for Depression score lower than 8 and Young mania rating scale score lower than 6) for at least 3 months before both evaluations. At the end of follow-up, psychosocial functioning was also evaluated by means of the Functioning Assessment Short Test.

Results

Repeated-measures multivariate analysis of covariance showed that there were main effects of group in the executive domain, in the inhibition domain, in the processing speed domain, and in the verbal memory domain (p<0.04). Among the clinical factors, only longer illness duration was significantly related to slow processing (p=0.01), whereas strong relationships were observed between impoverished cognition along time and poorer psychosocial functioning (p<0.05).

Conclusions

Executive functioning, inhibition, processing speed and verbal memory were impaired in euthymic bipolar out-patients. Although cognitive deficits remained stable on average throughout the follow-up, they had enduring negative effects on psychosocial adaptation of patients.
Ruelle operator with weakly contractive iterated function systems
Authors: YE YUAN-LING
Published: August 2012

The Ruelle operator has been studied extensively both in dynamical systems and iterated function systems (IFSs). Given a weakly contractive IFS $(X, \{w_j\}_{j=1}^m)$ and an associated family of positive continuous potential functions $\{p_j\}_{j=1}^m$, a triple system $(X, \{w_j\}_{j=1}^m, \{p_j\}_{j=1}^m)$is set up. In this paper we study Ruelle operators associated with the triple systems. The paper presents an easily verified condition. Under this condition, the Ruelle operator theorem holds provided that the potential functions are Dini continuous. Under the same condition, the Ruelle operator is quasi-compact, and the iterations sequence of the Ruelle operator converges with a specific geometric rate, if the potential functions are Lipschitz continuous.
A new variable structure controller for robot manipulators with a nonlinear PID sliding surface
Authors: Atia Khaled R.
Published: August 2012

In this paper a new sliding mode controller for set-point control of robot manipulators is proposed. The controller does not use any part of the robot dynamics in the control law. Thus, it is structurally simpler than other sliding mode controllers where the control law uses a nominal model of the robot dynamics. The controller uses a new nonlinear Proportional-Integral-Derivative (PID) sliding surface. The stability of the controlled robot dynamics is proved. On applying the boundary-layer approach to remove chattering, a nonlinear PID controller exists inside the boundary layer. This PID controller ensures that the error tend to zero asymptotically if there is no disturbances applied to the robot dynamics.
Embodied Memory: Body-Memory in the Performance Research of Jerzy Grotowski
Authors: Laster Dominika
Published: August 2012

In this article Dominika Laster examines the embodied-memory work undertaken by the Polish theatre director and performance researcher Jerzy Grotowski. While Grotowski approached work with memory – which in his practice necessarily implied body-memory – in a variety of ways, it was often as a mode of inquiry. For Grotowski, there were at least two different types of memory work, which emerge in two distinct phases of his research. The first was the use of body-memory undertaken during the Theatre of Production phase. Here, the work with body-memory was used as a tool in the actor's process of self-penetration and opening, serving as an instrument in the rediscovery of impulses and intentions of a past moment. This process of rediscovery is integral to the freeing of creativity and tapping into the obstructed internal resources of the actor. Another use of memory work, which became articulated in the phase of Grotowski's research known as Art as Vehicle, is that which facilitates the rediscovery of essence. Grotowski's practice of ‘active remembering’ functioned as a tool in the search for one's essence, understood as the most intimate, pre-cultural aspect of the self, which precedes difference and is at once the most singular and universal aspect of being. Dominika Laster is a Lecturer in Theatre. Her book A Bridge Made of Memory: Embodied Memory, Witnessing, and Transmission in the Grotowski Work and her edition of Loose Screws: Nine New Plays from Poland, are forthcoming from Seagull Press (distributed globally by the University of Chicago Press).