bluuebunny/crossref_metadata_2025 huggingface dataset:
Dietary supplementation with Bifidobacterium lactis NCC2818 from weaning reduces local immunoglobulin production in lymphoid-associated tissues but increases systemic antibodies in healthy neonates
Authors: Lewis Marie C. , Patel Dilip V. , Fowler Jenni , Duncker Swantje , Zuercher Adrian W. , Mercenier Annick , Bailey Mick
Published: March 2013

Weaning is associated with a major shift in the microbial community of the intestine, and this instability may make it more acquiescent than the adult microbiota to long-term changes. Modulation achieved through dietary interventions may have potentially beneficial effects on the developing immune system, which is driven primarily by the microbiota. The specific aim of the present study was to determine whether immune development could be modified by dietary supplementation with the human probiotic Bifidobacterium lactis NCC2818 in a tractable model of weaning in infants. Piglets were reared by their mothers before being weaned onto a solid diet supplemented with B. lactis NCC2818, while sibling controls did not receive supplementation. Probiotic supplementation resulted in a reduction in IgA (P< 0·0005) and IgM (P< 0·009) production by mucosal tissues but had no effect on IgG production (P>0·05). Probiotic-supplemented pigs had more mast cells than unsupplemented littermates (P< 0·0001), although numbers in both groups were low. In addition, the supplemented piglets made stronger serum IgG responses to fed and injected antigens (P< 0·05). The present findings are consistent with B. lactis NCC2818 reducing intestinal permeability induced by weaning, and suggest that the piglet is a valuable intermediate between rodent models and human infants. The results also strongly suggest that measures of the effect of probiotic supplementation on the immune system need to be interpreted carefully as proxy measures of health benefit. However, they are useful in developing an understanding of the mechanism of action of probiotic strains, an important factor in predicting favourable health outcomes of nutritional intervention.
The Ghost Dance and the Politics of Exclusion in Sherman Alexie's “Distances.”
Authors: FARRINGTON TOM
Published: March 2013

Critical responses to (Spokane/Coeur d'Alene) Sherman Alexie's stories of the Spokane Indian reservation and its (semi-)fictional inhabitants inThe Lone Ranger and Tonto Fistfight in Heaven(1993, hereinTLR) tend to polarize over the problem of the collection's cultural authenticity. The majority of these criticisms fall into one of two categories: those who condemn the author's prose for trafficking moribund Indian stereotypes, and those who defend his commitment to realistic portrayals of a struggling reservation community. In either case, it is the perceived capacity of the stories to develop a particular sense of indigenous community that typically functions as the measure of their cultural authenticity. One story fromTLRthat has received none of this critical attention is “Distances,” a contemporary, dystopian realization of Wovoka's late nineteenth-century Ghost Dance prophecy that shares none of the characters, settings or events common to the other stories. This apparent withdrawal from the collection's featured community and “reservation realist” aesthetic affords Alexie the critical distance to examine the exclusionary principles that underlay the formation of American Indian communities, and the value of these principles for the individual members. A close reading of “Distances” reveals Alexie's representations of contemporary Ghost Dances to be crucial interjections into the debates surrounding American Indian literary nationalism, as his writing seeks to dramatize the problems of a separatist agenda for urban Indian communities.
Preservative action of 11S (glycinin) and 7S (β-conglycinin) soy globulin on bovine raw milk stored either at 4 or 25 °C
Authors: Osman Ali O , Mahgoub Samir A , Sitohy Mahmoud Z
Published: March 2013

Considerable inhibitory antibacterial actions were exerted by the soybean 11S subunit comparable with nisin on the proliferation of total viable count, Pseudomonas count and Enterobacteriaceae count in bovine milk stored at 4 or 25 °C for 30 d and 48 h, while 7S and lysozyme were much less effective. The maximum magnitudes of bacterial reduction by 11S and nisin were in the range 2–4 log CFU/ml. The proliferation of 3 pathogenic bacteria (Listeria monocytogenes, Salmonella Enteritidis and Escherichia coli O157:H7) artificially inoculated into raw milk stored at 4 or 25 °C were particularly and significantly (P<0·05) reduced by 11S subunit and nisin (0·5% w/v), but only slightly by 7S and moderately by lysozyme. Lactose consumption, acidity development and casein degradation during storage of bovine raw milk were attenuated during storage at 4 or 25 °C and sensorial traits were better maintained by supplementation with 11S (0·5% w/v). 11S subunit may be used a safely food preservative, if permitted.
Crude glycerol as glycogenic precursor in feed; effects on milk coagulation properties and metabolic profiles of dairy cows
Authors: Harzia Hedi , Kilk Kalle , Ariko Tiia , Kass Marko , Soomets Ursel , Jõudu Ivi , Kaart Tanel , Arney David , Kärt Olav , Ots Meelis
Published: March 2013

As grain prices rise, the search for alternative glycogenic precursors in animal feed becomes increasingly important, and this study was conducted to determine if the replacement of starch with glycerol, as an alternative glycogenic precursor, affects the milk metabolic profile and milk coagulation ability, and therefore the quality of the milk. Eight primiparous mid-lactation Holstein cows were fed during a replicated 4 × 4 Latin square trial with four different isoenergetic rations: (1) control (T0) fed a total mixed ration (TMR) with barley meal; (2) group T1, decreased barley content, replaced isoenergetically with 1 kg crude glycerol; (3) group T2, the barley meal was replaced with 2 kg of crude glycerol; and (4) group T3 the barley meal was replaced with 3 kg of crude glycerol. Rumen, blood and milk samples were collected at the end of every 21-d treatment period. Rumen samples were analysed for proportion of total volatile fatty acid (VFA), blood samples for insulin and glucose, and milk for metabolites (e.g. citric-acid cycle compounds). The change in glycogenic precursors had a positive effect on rumen VFA proportions; the proportion of propionic acid increased (P < 0·001). Milk protein (P < 0·001) and curd firmness (P < 0·001) both increased. The increase in milk protein concentration may have been due to an increase in microbial protein. Regarding the milk metabolic profiles, different signals were positively associated with coagulation ability and change in the diet. Based on this study, changing the glycogenic precursor in animal diet in this way is possible, and may have no immediate deleterious consequences on milk quality or cow health. Indeed, there is evidence for benefits from this substitution.
Strategy for the reduction of Trichloromethane residue levels in farm bulk milk
Authors: Ryan Siobhan , Gleeson David , Jordan Kieran , Furey Ambrose , O'Sullivan Kathleen , O'Brien Bernadette
Published: March 2013

High fat dairy products, such as butter and margarine can be contaminated during the milk production process with a residue called Trichloromethane (TCM), which results from the use of chlorine based detergent solutions. Although, TCM concentrations in Irish products are not at levels that are a public health issue, such contamination can cause marketing difficulties in countries to which Irish products are being exported. In an attempt to reduce such milk residues, a template procedure was developed, tried and tested on 43 farms (from 3 processing companies). This involved identifying farms with high TCM milk, applying corrective action in the form of advice and recommendations to reduce TCM and re-measuring milks from these farms. Trichloromethane in milk was measured by head-space gas chromatography with electron capture detector. The TCM reduction strategy proved successful in significantly reducing the levels in milk in the farms tested, e.g. TCM was reduced from 0·006 to the target of 0·002 mg/kg (P < 0·05). The strategy was then applied to farms who supplied milk to six Irish dairy processors with the objective of reducing TCM in those milks to a level of ⩽0·002 mg/kg. Initially, milk tankers containing milks from approximately 10–15 individual farms were sampled and analysed and tankers with high TCM (>0·002 mg/kg) identified. Individual herd milks contributing to these tankers were subsequently sampled and analysed and farms supplying high TCM identified. Guidance and advice was provided to the high TCM milk suppliers and levels of TCM of these milk supplies were monitored subsequently. A significant reduction (minimum P < 0·05) in milk TCM was observed in 5 of the 6 dairy processor milks, while a numerical reduction in TCM was observed in the remaining processor milk.
Morphological awareness in dyslexic university students
Authors: MARTIN JENNIFER , FRAUENFELDER ULI H. , COLÉ PASCALE
Published: March 2013

This research assessed phonological and morphological awareness in dyslexic university students. We tested 44 dyslexic university students in phonological and morphological awareness tasks and compared their performances to those of both matched chronological age and matched reading level controls. In the phonological awareness tests, the dyslexic university students performed at the same level as their reading level controls. In contrast, they systematically outperformed their reading level controls in the morphological awareness tasks and almost reached the proficiency level of the chronological age controls. The results show that dyslexic university students develop their morphological awareness more than their phonological awareness. These findings add to the evidence indicating that morphological awareness is not deficient in dyslexia and could instead play a beneficial role in the development of literacy skills in this population.
Second language fluency: Speaking style or proficiency? Correcting measures of second language fluency for first language behavior
Authors: DE JONG NIVJA H. , GROENHOUT RACHEL , SCHOONEN ROB , HULSTIJN JAN H.
Published: March 2013

In second language (L2) research and testing, measures of oral fluency are used as diagnostics for proficiency. However, fluency is also determined by personality or speaking style, raising the question to what extent L2 fluency measures are valid indicators of L2 proficiency. In this study, we obtained a measure of L2 (Dutch) proficiency (vocabulary knowledge), L2 fluency measures, and fluency measures that were corrected for first language behavior from the same group of Turkish and English native speakers (N = 51). For most measures of fluency, except for silent pause duration, both the corrected and the uncorrected measures significantly predicted L2 proficiency. For syllable duration, the corrected measure was a stronger predictor of L2 proficiency than was the uncorrected measure. We conclude that for L2 research purposes, as well as for some types of L2 testing, it is useful to obtain corrected measures of syllable duration to measure L2-specific fluency.
An investigation of morphological awareness and processing in adults with low literacy
Authors: TIGHE ELIZABETH L. , BINDER KATHERINE S.
Published: March 2013

Morphological awareness, which is an understanding of how words can be broken down into smaller units of meaning such as roots, prefixes, and suffixes, has emerged as an important contributor to word reading and comprehension skills. The first aim of the current study was to investigate the contribution of morphological awareness independent of phonological awareness and decoding to the reading comprehension abilities of adults with low literacy. Results indicated that morphological awareness was a significant unique predictor of reading comprehension. A second aim of the study was to investigate the processing of morphologically complex words of adults with low literacy in both an oral reading passage and a single-word naming task. Adults’ accuracy and response times were measured on different types of morphologically complex words and compared with control words matched on frequency in both the passage and the naming tasks. Results revealed that adults were vulnerable to morphological complexity: they performed more accurately and faster on matched control words versus morphologically complex word types. The educational implications for Adult Basic Education programs are discussed.
A pooled analysis of six month comparative efficacy and tolerability in four randomized clinical trials: agomelatine versus escitalopram, fluoxetine, and sertraline
Authors: Demyttenaere Koen , Corruble Emanuelle , Hale Anthony , Quera-Salva Maria-Antonia , Picarel-Blanchot Françoise , Kasper Siegfried
Published: March 2013

Objective

A pooled-analysis on the long-term outcome in four head-to-head studies: agomelatine versus fluoxetine, sertraline, and (twice) escitalopram.

Method

A meta-analytic approach was used. Hamilton Depression Rating Scale (HAM-D) scores, response and remission rates, Clinical Global Impression of Improvement (CGI-I) scores, response and remission rates, and completion rates/discontinuation rates due to adverse events were analyzed.

Results

At the last post-baseline assessment on the 24-week treatment period, the final HAM-D-17 score was significantly lower in patients treated with agomelatine than in patients treated with selective serotonin reuptake inhibitors (SSRIs), as well in the total group of patients with severe depression (P = 0.014 and 0.040, respectively). HAM-D response rates at the end of 24 weeks were significantly higher in patients treated with agomelatine than in patients treated with SSRIs, as well in the total group of patients with severe depression (P = 0.031 and 0.048, respectively). HAM-D remission rates at the end of 24 weeks were numerically but not significantly higher in patients treated with agomelatine than in patients treated with SSRIs. Final CGI-I scores were significantly lower for agomelatine. CGI-I response as well as remission rates were numerically higher in patients treated with agomelatine, without statistical significance. The percentage of patients with at least one emergent adverse event leading to treatment discontinuation was 9.4% in patients treated with SSRIs and 6.6% in patients treated with agomelatine (P = 0.065).

Conclusion

The present pooled analysis shows that, from a clinical point of view, agomelatine is at least as efficacious as the investigated SSRIs with a trend to fewer discontinuations due to adverse events.
THE DYNAMIC PROPERTIES OF ENDOGENOUS GROWTH MODELS
Authors: Sedgley Norman , Elmslie Bruce
Published: March 2013

This paper explores the dynamics of semiendogenous versus fully endogenous growth models in “lab equipment” specifications of the models with expanding sectors. Capital is allowed to accumulate and is used, together with other inputs, to produce new knowledge. The stability of the steady state path is found to be determined by the inequality and/or knife-edge restrictions needed to produce steady state growth. This paper takes the ratio of the shadow price of capital to knowledge and the level of consumption as jump variables. Semiendogenous growth models lead to a 4 × 4 dynamic system where the sign of the coefficient matrix of the log linearized dynamic system is indefinite, leading to a potential for both stable and unstable equilibria. The knife-edge restrictions needed to generate policy influences on growth are shown to be restrictions that reduce the system to 3 × 3 with a positive definite coefficient matrix, thereby guaranteeing a globally stable equilibrium. Implications for empirical testing are addressed.
PERSONAL-BANKRUPTCY CYCLES
Authors: Garrett Thomas A. , Wall Howard J.
Published: March 2013

This paper estimates the dynamics of the personal-bankruptcy rate over the business cycle by exploiting large cross-state variation. We find that bankruptcy rates are significantly above trend during a recession and rise as a recession persists. After a recession ends, there is a hangover in which bankruptcy rates begin to fall but remain above trend for several more quarters. Recovery periods see a strong bounce-back effect, with bankruptcy rates significantly below trend for several quarters. Despite the significant increases in bankruptcies during recessions, the largest contributor to rising bankruptcies during these periods has tended to be the longstanding upward trend.
The association of breakfast skipping and television viewing at breakfast with weight status among parents of 10–12-year-olds in eight European countries; the ENERGY (EuropeaN Energy balance Research to prevent excessive weight Gain among Youth) cross-sectional study
Authors: Bjørnarå Helga Birgit , Vik Frøydis N , Brug Johannes , Manios Yannis , De Bourdeaudhuij Ilse , Jan Natasa , Maes Lea , Moreno Luis A , Dössegger Alain , Bere Elling
Published: March 2013

Objective

The main objective was to assess the relationship of breakfast skipping, television (TV) viewing at breakfast and breakfast without TV with weight status among parents of 10–12-year-olds in eight European countries.

Design

A cross-sectional survey assessed breakfast eating and TV viewing at breakfast by three frequency questions and parents were categorized into: (i) breakfast skippers; (ii) breakfast with TV (TV watchers at breakfast); and (iii) breakfast without TV (breakfast eaters who do not watch TV during breakfast). Self-reported weight and height were used to categorize weight status as underweight, normal weight, overweight and obese. Multinomial logistic regression analyses were conducted with weight status as the dependent variable and breakfast habits as predictors, adjusting for sex, ethnicity and level of education.

Setting

The survey was conducted in 2010 in 199 primary schools across eight European countries participating in the ENERGY (EuropeaN Energy balance Research to prevent excessive weight Gain among Youth) cross-sectional study.

Subjects

Parents (n 6512) of 10–12-year-olds responded to the questionnaire.

Results

In the total study sample, with breakfast without TV as the reference group and adjusting for sex, ethnicity and level of education, the OR of being respectively overweight or obese (compared with normal weight) was 1·2 (95 % CI 1·0, 1·4) or 1·8 (95 % CI 1·5, 2·3) for breakfast skippers. The OR of being respectively underweight or obese was 0·5 (95 % CI 0·2, 0·9) or 1·4 (95 % CI 1·1, 1·8) for breakfast with TV.

Conclusions

Breakfast skippers were significantly more likely to be overweight and obese, and those eating breakfast while watching TV were significantly more likely to be obese and less likely to be underweight.
X-ray Nano- and Micro-tomography in an SEM
Authors: Pauwels Bart , Sasov Alexander
Published: March 2013

X-ray microfocus computer tomography (μ-CT) is a non-destructive experimental technique that reveals the 3D internal microstructure of the sample under study. The experimental set-up consists of an X-ray source, an X-ray detector, and set in between is a sample that is placed on a rotation stage. With this set-up multiple X-ray projection images can be obtained from the sample at different angles. In between the acquisition of two successive images, the sample is rotated over a small angle, typically between 0.2° and 1°. This set of projection images is then used as input for the reconstruction algorithm, which calculates a reconstruction of the internal microstructure of the sample with (sub-) micrometer sensitivity.
Enhancing ecosystem services with no-till
Authors: Lal R.
Published: March 2013

Ecosystem functions and services provided by soils depend on land use and management. The objective of this article is to review and synthesize relevant information on the impacts of no-till (NT) management of croplands on ecosystem functions and services. Sustainable management of soil through NT involves: (i) replacing what is removed, (ii) restoring what has been degraded, and (iii) minimizing on-site and off-site effects. Despite its merits, NT is adopted on merely ∼9% of the 1.5 billion ha of global arable land area. Soil's ecosystem services depend on the natural capital (soil organic matter and clay contents, soil depth and water retention capacity) and its management. Soil management in various agro-ecosystems to enhance food production has some trade-offs/disservices (i.e., decline in biodiversity, accelerated erosion and non-point source pollution), which must be minimized by further developing agricultural complexity to mimic natural ecosystems. However, adoption of NT accentuates many ecosystem services: carbon sequestration, biodiversity, elemental cycling, and resilience to natural and anthropogenic perturbations, all of which can affect food security. Links exist among diverse ecosystem services, such that managing one can adversely impact others. For example, increasing agronomic production can reduce biodiversity and deplete soil organic carbon (SOC), harvesting crop residues for cellulosic ethanol can reduce SOC, etc. Undervaluing ecosystem services can jeopardize finite soil resources and aggravate disservices. Adoption of recommended management practices can be promoted through payments for ecosystem services by a market-based approach so that risks of disservices and negative costs can be reduced either through direct economic incentives or as performance payments.
High-performance digital predistortion test platform development for wideband RF power amplifiers
Authors: Guan Lei , Kearney Ray , Yu Chao , Zhu Anding
Published: March 2013

In this paper, a complete design procedure, together with robust system validation approaches, is presented for implementing a high-performance re-configurable digital predistortion (DPD) test platform for compensating for nonlinear distortion and memory effects induced by radio frequency (RF) power amplifiers (PAs) in the transmitters of modern wireless communication systems. This hardware and software co-operated test system not only enables effective validation for DPD algorithm development, but also provides a high-performance and reliable hardware-based linearization test platform. The experimental test was applied on a medium power Doherty amplifier, which was designed for 3 G/4 G wireless communication base stations. By applying our DPD algorithms on the proposed platform, more than 30 dB improvements in adjacent channel power ratio can be achieved for Universal Mobile Telecommunications System and long-term evolution signal excitations.
Rotational alignment effects in NO(X) + Ar inelastic collisions: A theoretical study
Authors: Brouard M. , Chadwick H. , Eyles C. J. , Hornung B. , Nichols B. , Aoiz F. J. , Jambrina P. G. , Stolte S. , de Miranda M. P.
Published: March 2013

Rotational angular momentum alignment effects in the rotational inelastic scattering of NO(X) with Ar have been investigated by means of close-coupled quantum mechanical, quasi-classical trajectory, and Monte Carlo hard shell scattering calculations. It has been shown that the hard shell nature of the interaction potential at a collision energy of Ecoll = 66 meV is primarily responsible for the rotational alignment of the NO(X) molecule after collision. By contrast, the alternating trend in the quantum mechanical parity resolved alignment parameters with change in rotational state Δj reflects differences in the differential cross sections for NO(X) parity conserving and changing collisions, rather than an underlying difference in the collision induced rotational alignment. This suggests that the rotational alignment and the differential cross sections are sensitive to rather different aspects of the scattering dynamics. The applicability of the kinematic apse model has also been tested and found to be in excellent agreement with exact quantum mechanical scattering theory provided the collision energy is in reasonable excess of the well depth of the NO(X)–Ar potential energy surface.
Rotational alignment effects in NO(X) + Ar inelastic collisions: An experimental study
Authors: Brouard M. , Chadwick H. , Eyles C. J. , Hornung B. , Nichols B. , Aoiz F. J. , Jambrina P. G. , Stolte S.
Published: March 2013

Rotational angular momentum alignment effects in the rotationally inelastic collisions of NO(X) with Ar have been investigated at a collision energy of 66 meV by means of hexapole electric field initial state selection coupled with velocity-map ion imaging final state detection. The fully quantum state resolved second rank renormalized polarization dependent differential cross sections determined experimentally are reported for a selection of spin-orbit conserving and changing transitions for the first time. The results are compared with the findings of previous theoretical investigations, and in particular with the results of exact quantum mechanical scattering calculations. The agreement between experiment and theory is generally found to be good throughout the entire scattering angle range. The results reveal that the hard shell nature of the interaction potential is predominantly responsible for the rotational alignment of the NO(X) upon collision with Ar.
Analytical energy gradients for second-order multireference perturbation theory using density fitting
Authors: Győrffy Werner , Shiozaki Toru , Knizia Gerald , Werner Hans-Joachim
Published: March 2013

We present algorithms for computing analytical energy gradients for multi-configuration self-consistent field methods and partially internally contracted complete active space second-order perturbation theory (CASPT2) using density fitting (DF). Our implementation is applicable to both single-state and multi-state CASPT2 analytical gradients. The accuracy of the new methods is demonstrated for structures and excitation energies of valence and Rydberg states of pyrrole, as well as for structures and adiabatic singlet-triplet energy splittings for the hydro-, the O,O′-formato-, and the N,N′-diiminato-copper-dioxygen complexes. It is shown that the effects of density fitting on optimized structures and relative energies are negligible. For cases in which the total cost is dominated by the integral evaluations and transformations, the DF-CASPT2 gradient calculations are found to be faster than the corresponding conventional calculations by typically a factor of three to five using triple-ζ basis sets, and by about a factor of ten using quadruple-ζ basis sets.
Exact solution of the Zwanzig-Lauritzen model of polymer crystallization under tension
Authors: Samanta Himadri S. , Thirumalai D.
Published: March 2013

We solve a two-dimensional model for polymer chain folding in the presence of mechanical pulling force (f) exactly using equilibrium statistical mechanics. Using analytically derived expression for the partition function we determine the phase diagram for the model in the f-temperature (T) plane. A square root singularity in the susceptibility indicates a second order phase transition from a folded to an unfolded state at a critical force (fc) in the thermodynamic limit of infinitely long polymer chain. The temperature dependence of fc shows a reentrant phase transition, which is reflected in an increase in fc as T increases below a threshold value. As a result, for a range of f values, the unfolded state is stable at both low and high temperatures. The high temperature unfolded state is stabilized by entropy whereas the low temperature unfolded state is dominated by favorable energy. The exact calculation could serve as a benchmark for testing approximate theories that are used in analyzing single molecule pulling experiments.
Novel patterns of torsion-inversion-rotation energy levels in the ν11 asymmetric CH-stretch spectrum of methylamine
Authors: Dawadi Mahesh B. , Michael Lindsay C. , Chirokolava Andrei , Perry David S. , Xu Li-Hong
Published: March 2013

The high-resolution infrared spectrum of methylamine (CH3NH2) has been recorded using slit-jet direct absorption spectroscopy in the ν11 CH-stretch region (2965–3005 cm−1) with a resolution of 0.0025 cm−1. The 621 lines assigned by ground state combination differences represent 27 substates with |K′| ≤ 2 for the A, B, E1, and E2 symmetries. The spectrum of CH3NH2 is complicated by torsion and inversion tunneling connecting six equivalent minima. The upper states K′ = 0, ± 1 for E1 and E2 are substantially perturbed by “dark” states. The result in the spectrum is multiplets of 2 or 3 states with mixed bright/dark character. The analysis of the spectrum reveals two qualitative differences in the energy level pattern relative to the vibrational ground state and relative to available data on the lower frequency vibrations (NH2 wag and CN stretch). First at J′ = 0, there is a different ordering of the levels connected by torsion-inversion tunneling. Second, the low-J splittings indicative of torsion-rotation coupling are greatly reduced in the ν11 excited state relative to the vibrational ground state for both the E1 and E2 species, suggesting the partial suppression of torsional tunneling in the ν11 CH-stretch excited state.
High resolution spectroscopy of the Ar-D2O and Ar-HDO molecular complexes in the near-infrared range
Authors: Didriche K. , Földes T.
Published: March 2013

Three rovibrational bands of Ar-D2O and two rovibrational bands of Ar-HDO were observed in the 1.5 μm range by continuous wave cavity ringdown spectroscopy. Their analyses led to the determination of rotational constants for the upper states and vibrational shifts indicating that the potential energy surface is only slightly affected by the vibrational excitation. Some Coriolis couplings were identified. The observed lines were fitted to retrieve a 3.5 ns lifetime of the upper state, showing that even with a triple or double excitation quanta in the water subunit, the Ar-D2O and Ar-HDO complexes are long-lived species.
Conformation and intramolecular relaxation dynamics of semiflexible randomly hyperbranched polymers
Authors: Kumar Amit , Rai Gobind Ji , Biswas Parbati
Published: March 2013

The conformational and dynamic properties of semiflexible randomly hyperbranched polymers are investigated in dilute solutions within the framework of optimized Rouse-Zimm formalism. Semiflexibility is incorporated by restricting the directions and orientations of the respective bond vectors, while hydrodynamic interactions are modeled through the preaveraged Oseen tensor. The effect of semiflexibility is typically reflected in the intermediate frequency regime of the viscoelastic relaxation moduli where the bond orientation angle restores the characteristic power-law scaling in fractal structures, as in randomly hyperbranched polymers. Despite the absence of this power-law scaling regime in flexible randomly hyperbranched polymers and in earlier models of semiflexible randomly branched polymers due to weak disorder [C. von Ferber and A. Blumen, J. Chem. Phys. 116, 8616 (2002)]10.1063/1.1470198, this power-law behavior may be reinstated by explicitly modeling hyperbranched polymers as a Vicsek fractals. The length of this power-law zone in the intermediate frequency region is a combined function of the number of monomers and the degree of semiflexibility. A clear conformational transition from compact to open structures is facilitated by changing the bond orientation angle, where the compressed conformations are compact, while the expanded ones are relatively non-compact. The extent of compactness in the compressed conformations are much less compared to the semiflexible dendrimers, which resemble hard spheres. The fractal dimensions of the compressed and expanded conformations calculated from the Porod's scaling law vary as a function of the bond orientation angle, spanning the entire range of three distinct scaling regimes of linear polymers in three-dimensions. The results confirm that semiflexibility exactly accounts for the excluded volume interactions which are expected to be significant for such polymers with complex topologies.
Thermoelectric performance of MX2 (M = Mo,W; X = S,Se) monolayers
Authors: Huang Wen , Da Haixia , Liang Gengchiau
Published: March 2013

Using ab-initio method and ballistic transport model, we study electron and phonon energy dispersion relations of monolayer transition-metal dichalcogenides: MoS2, MoSe2, WS2, and WSe2. Their electron and heat transports as well as their thermoelectric properties are also studied under linear response regime with different doping types, crystal orientations, and temperatures. Our results show that electron and phonon transports are not very sensitive to crystal orientations because the differences between group velocity and transmission of these carriers along different transport directions are not significant. Furthermore, as temperature increases, first peak values of thermoelectric figure of merit (ZT1st peak) increase linearly except for monolayer n-type WSe2/MoSe2 and p-type WS2, which have higher increasing rates when temperature is high due to the electron transport contribution from an additional valley. Among these various conditions, the results show that all monolayers have similar ZT1st peak at low temperatures below 100 K, and p-type monolayer MoS2 has the largest ZT1st peak at room temperature while n-type WSe2 has the largest ZT1st peak at high temperatures.
Study of sensitization process on mid-infrared uncooled PbSe photoconductive detectors leads to high detectivity
Authors: Qiu Jijun , Weng Binbin , Yuan Zijian , Shi Zhisheng
Published: March 2013

For nearly a century, oxygen has been widely accepted as the key element that triggers photo-response in polycrystalline PbSe photoconductive detectors. Our photoluminescence and responsivity studies on PbSe samples, however, suggest that oxygen only serves as an effective sensitization improver and it is iodine rather than oxygen that plays the key role in triggering the photo-response. These studies shed light on the sensitization process for detector applications and ways to passivate defects in IV–VI semiconductors. As a result, high peak detectivity of 2.8 × 1010 cm·Hz1/2·W−1 was achieved at room temperature.
Estimation of acoustic properties and of the representative volume element of random fibrous media
Authors: Peyrega Charles , Jeulin Dominique
Published: March 2013

This work focuses on the estimation of acoustic properties from numerical simulations, and on the determination of the representative volume element of random fibrous media. At the microscopic scale, both viscous and thermal dissipations of energy occur in the air saturating the pores of a porous medium. Thus, the thermoacoustic formalism was used to model the physical behavior of several periodic unit cells of random fibrous media. Their properties such as both harmonic acoustic velocity and temperature were homogenized at different scales, in order to estimate representative volume elements for different properties.
Laminar flow of two miscible fluids in a simple network
Authors: Karst Casey M. , Storey Brian D. , Geddes John B.
Published: March 2013

When a fluid comprised of multiple phases or constituents flows through a network, nonlinear phenomena such as multiple stable equilibrium states and spontaneous oscillations can occur. Such behavior has been observed or predicted in a number of networks including the flow of blood through the microcirculation, the flow of picoliter droplets through microfluidic devices, the flow of magma through lava tubes, and two-phase flow in refrigeration systems. While the existence of nonlinear phenomena in a network with many inter-connections containing fluids with complex rheology may seem unsurprising, this paper demonstrates that even simple networks containing Newtonian fluids in laminar flow can demonstrate multiple equilibria. The paper describes a theoretical and experimental investigation of the laminar flow of two miscible Newtonian fluids of different density and viscosity through a simple network. The fluids stratify due to gravity and remain as nearly distinct phases with some mixing occurring only by diffusion. This fluid system has the advantage that it is easily controlled and modeled, yet contains the key ingredients for network nonlinearities. Experiments and 3D simulations are first used to explore how phases distribute at a single T-junction. Once the phase separation at a single junction is known, a network model is developed which predicts multiple equilibria in the simplest of networks. The existence of multiple stable equilibria is confirmed experimentally and a criterion for existence is developed. The network results are generic and could be applied to or found in different physical systems.
Optical properties of extended and localized states in m-plane InGaN quantum wells
Authors: Marcinkevičius S. , Kelchner K. M. , Nakamura S. , DenBaars S. P. , Speck J. S.
Published: March 2013

Scanning near-field and time-resolved photoluminescence spectroscopy were applied to study potential fluctuations and photoexcited carrier dynamics in single m-plane InGaN quantum well structures. The far- and near-field spectra were found to have contributions from transitions to the first and second hole levels in the extended states, and transitions in the localized states. Correlations between parameters of the near-field spectra confirmed that extended state luminescence was prevailing. The localized states, which were found to be separated from the extended states by ∼10 meV barriers, were attributed to regions of a higher In content.
Compact circular polarizer based on chiral twisted double split-ring resonator
Authors: Yan Sen , Vandenbosch Guy A. E.
Published: March 2013

A compact circular polarizer is presented, which is based on a twisted double split-ring resonator (DSRR). The bottom DSRR is rotated 90° with respect to the top one. When the structure is illuminated by a normally incident linearly polarized wave, the two linear components of the transmitted wave have nearly equal amplitudes and 90° (−90°) phase difference around the resonant frequency. This means that the transmitted wave with left-handed circular polarization is much larger (smaller) than the one with right-handed circular polarization. The electric fields and currents on the structure are analyzed to illustrate this phenomenon. The size of each unit cell in this structure is extremely small compared with the wavelength in all three dimensions. Both simulations and measurements verify our design at microwave frequencies.
Electronic structure of a single-layer InN quantum well in a GaN matrix
Authors: Miao M. S. , Yan Q. M. , Van de Walle C. G.
Published: March 2013

Using first-principles methods and 8-band k·p simulations, we study the electronic structure of an ultrathin quantum-well system consisting of a single layer of InN inserted in GaN matrix. Experimental photoluminescence and electroluminescence emission peaks for such structures have been reported in the wavelength region between 380 to 450 nm. In contrast, our calculations show an energy difference between the electron and hole states around 2.17 eV (573 nm). Possible origins of the experimental light emission are examined. We suggest that the experimental emission may be due to recombination of electrons (holes) in GaN with holes (electrons) in the quantum well.
Effect of interfacial structures on anomalous Hall behavior in perpendicular Co/Pt multilayers
Authors: Zhang J. Y. , Wu Z. L. , Wang S. G. , Zhao C. J. , Yang G. , Zhang S. L. , Liu Y. , Liu S. , Teng J. , Yu G. H.
Published: March 2013

A large enhancement of anomalous Hall resistivity was obtained in the perpendicular [Co/Pt]3 multilayers sandwiched by MgO/CoO hybrid bilayers. For example, the saturation Hall resistivity (ρxy) is greatly increased, which is 250% and 67% larger than that in pure [Co/Pt]3 multilayers and that in [Co/Pt]3 multilayers sandwiched by pure MgO layers, respectively. Meanwhile, the perpendicular magnetic anisotropy in the multilayers with MgO/CoO hybrid bilayers was enhanced. The large enhancement of ρxy originates from the modified metal/oxide interfacial structures, together with improved crystallization of core [Co/Pt]3 multilayers, due to the insertion of hybrid bilayers.
Synthesis, Chemical Characterisation, and DNA Binding Studies of Ferrocene-Incorporated Selenoureas
Authors: Hussain Raja Azadar , Badshah Amin , Tahir Muhammad Nawaz , Lal Bhajan , Khan Inayat Ali
Published: March 2013

In this article we have presented the synthesis, chemical characterisation (by NMR and FTIR spectroscopy, atomic absorption spectrophotometry, elemental analysis, and single crystal X-ray diffraction), electrochemistry, and DNA binding studies (with cyclic voltammetry, viscometry, and UV-vis spectroscopy) of six new ferrocene incorporated selenoureas. All the six compounds interact electrostatically with DNA which was evident by a negative shift in the cyclic voltammetry peak potential of the drug–DNA adduct relative to the free drug. The drug–DNA binding constant was calculated by a decrease in peak current after the addition of DNA to the free drug. We have also reported binding site sizes and diffusion coefficients of the synthesised compounds.
B cells promote inflammation in obesity and type 2 diabetes through regulation of T-cell function and an inflammatory cytokine profile
Authors: DeFuria Jason , Belkina Anna C. , Jagannathan-Bogdan Madhumita , Snyder-Cappione Jennifer , Carr Jordan David , Nersesova Yanina R. , Markham Douglas , Strissel Katherine J. , Watkins Amanda A. , Zhu Min , Allen Jessica , Bouchard Jacqueline , Toraldo Gianluca , Jasuja Ravi , Obin Martin S. , McDonnell Marie E. , Apovian Caroline , Denis Gerald V. , Nikolajczyk Barbara S.
Published: March 2013

Patients with type 2 diabetes (T2D) have disease-associated changes in B-cell function, but the role these changes play in disease pathogenesis is not well established. Data herein show B cells from obese mice produce a proinflammatory cytokine profile compared with B cells from lean mice. Complementary in vivo studies show that obese B cell–null mice have decreased systemic inflammation, inflammatory B- and T-cell cytokines, adipose tissue inflammation, and insulin resistance (IR) compared with obese WT mice. Reduced inflammation in obese/insulin resistant B cell–null mice associates with an increased percentage of anti-inflammatory regulatory T cells (Tregs). This increase contrasts with the sharply decreased percentage of Tregs in obese compared with lean WT mice and suggests that B cells may be critical regulators of T-cell functions previously shown to play important roles in IR. We demonstrate that B cells from T2D (but not non-T2D) subjects support proinflammatory T-cell function in obesity/T2D through contact-dependent mechanisms. In contrast, human monocytes increase proinflammatory T-cell cytokines in both T2D and non-T2D analyses. These data support the conclusion that B cells are critical regulators of inflammation in T2D due to their direct ability to promote proinflammatory T-cell function and secrete a proinflammatory cytokine profile. Thus, B cells are potential therapeutic targets for T2D.
Cutting the mists of the Black Mountain:Cleavages in Montenegro's divide over statehood and identity
Authors: Dzankic Jelena
Published: March 2013

The two decades of Montenegro's transition that followed the disintegration of Yugoslavia were marked by the transformation of the ambitions of the ruling political elites, which pushed the republic that once sought to be a member in a federal state towards independence. The shift in the agendas of the political elites also changed the meaning of the notions of “Montenegrin” and “Serb”. Hence, this paper looks at the cleavages that emerged during Montenegro's divide over statehood and identity. It asserts that elite competition in unconsolidated states prompts the emergence of ethno-cultural cleavages, which are necessary for establishing the identities of political elites and of their followers. The study first identifies the critical junctures for the emergence of functional and structural cleavages in Montenegro and associates these cleavages with the changing political context. It proceeds with an analysis of ethno-cultural cleavages, arguing that these emerged from the politicization of historical narratives. The study concludes by arguing that different types of cleavages supported the division over statehood and identity, and that as a result of the changes in identity in Montenegro, the political reinforcement of overlapping cleavages was essential in order to cement the ethno-cultural identities of the two camps.
International Statebuilding as contentious politics: the case of post conflict Bosnia and Herzegovina
Authors: Keranen Outi
Published: March 2013

The post-conflict space in Bosnia and Herzegovina has been marked by a multiplicity of statebuilding projects: in addition to the much-analyzed internationally-led statebuilding process, parallel Bosniak, Bosnian Serb and Bosnian Croat statebuilding trajectories exist. They seek to undermine and challenge the international statebuilding venture by appropriating and adapting the liberal statebuilding processes. This is carried out through the institutions and processes of governance put in place by international statebuilders to subvert the statebuilding trajectory. Focusing on the local appropriation of processes and institutions of governance, the paper maps out the repertoires of contention entailing boycotts, walk-outs, protests and refusals to co-operate in an attempt to explain and understand how local contention vis-à-vis the international statebuilding trajectory is carried out.
Interleukin‐6: Possible biological roles during exercise
Authors: Reihmane Dace , Dela Flemming
Published: March 2013

Interleukin‐6 (IL‐6) is a multifunctional cytokine that exerts its modulatory effects on cells that express membrane bound IL‐6 receptors; however, IL‐6 in a complex with soluble IL‐6R can bind to any cell that express glycoprotein 130 (gp130). Thus, all cell types may respond to the pro‐ as well as anti‐inflammatory properties of IL‐6. Since the first report of acute exercise‐induced increase in plasma IL‐6 in the early 1990s, scientists have tried to elucidate the factors that influence the magnitude of change of plasma IL‐6, as well as the possible biological roles of this cytokine. Evidence suggests that exercise intensity and duration as well as the form of contraction (e.g. eccentric or concentric) and muscle damage all influence IL‐6 response to acute exercise. However, data on training status and performance on plasma IL‐6 concentration changes during exercise are more inconclusive, as discussed in this review. In the last decade, most of the studies have focused on IL‐6 as an ‘energy sensor’ possibly secreted by skeletal muscle that activates glycogenolysis in the liver and lipolysis in fat tissue in order to provide muscle with the growing energy demands during exercise.