bluuebunny/crossref_metadata_2025 huggingface dataset:
Digestion, milk production and milk fatty acid profile of dairy cows fed flax hulls and infused with flax oil in the abomasum
Authors: Côrtes Cristiano , Kazama Ricardo , da Silva-Kazama Daniele , Benchaar Chaouki , Zeoula Lucia M , Santos Geraldo TD , Petit Hélène V
Published: July 2011

Flax hull, a co-product obtained from flax processing, is a rich source of n-3 fatty acids (FA) but there is little information on digestion of flax hull based diets and nutritive value of flax hull for dairy production. Flax oil is rich in α-linolenic acid (LNA) and rumen bypass of flax oil contributes to increase n-3 FA proportions in milk. Therefore, the main objective of the experiment was to determine the effects of abomasal infusion of increasing amounts of flax oil on apparent digestibility, dry matter (DM) intake, milk production, milk composition, and milk FA profile with emphasis on the proportion of LNA when cows were supplemented or not with another source of LNA such as flax hull. Six multiparous Holstein cows averaging 650±36 kg body weight and 95±20 d in milk were assigned to a 6×6 Latin square design (21-d experimental periods) with a 2×3 factorial arrangement of treatments. Treatments were: 1) control, neither flax hull nor flax oil (CON), 2) diet containing (DM basis) 15·9% flaxseed hull (FHU); 3) CON with abomasal infusion of 250 g/d flax oil; 4) CON with abomasal infusion of 500 g/d flax oil; 5) FHU with abomasal infusion of 250 g/d flax oil; 6) FHU with abomasal infusion of 500 g/d flax oil. Infusion of flax oil in the abomasum resulted in a more pronounce decrease in DM intake for cows fed the CON diets than for those fed the FHU diets. Abomasal infusion of flax oil had little effect on digestibility and FHU supplementation increased digestibility of DM and crude protein. Milk yield was not changed by abomasal infusion of flax oil where it was decreased with FHU supplementation. Cows fed FHU had higher proportions of 18:0, cis9-18:1, trans dienes, trans monoenes and total trans in milk fat than those fed CON. Proportion of LNA was similar in milk fat of cows infused with 250 and 500 g/d flax oil in the abomasum. Independently of the basal diet, abomasal infusion of flax oil resulted in the lowest n-6:n-3 FA ratio in milk fat, suggesting that the most important factor for modification of milk FA profile was the amount of n-3 FA bypassing the rumen and not the amount of flax hull fed to dairy cows. Moreover, these data suggest that there is no advantage to supply more than 250 g/d of flax oil in the abomasum to increase the proportion of LNA in milk fat.
Relationships between milking frequency, lactation persistency and milk yield in Swedish Red heifers and cows milked in a voluntary attendance automatic milking system
Authors: Pettersson Gunnar , Svennersten-Sjaunja Kerstin , Knight Christopher H
Published: July 2011

A large dataset comprising output from an automatic milking (AM) system between 1999 and 2006 was examined and a total of 172 cow lactation curves and 68 heifer lactation curves were identified for further analysis. Relationships between milking frequency at different stages of lactation and lactation persistency and total lactation yield were determined. Cows had higher peak and total milk yields than heifers, but heifers had higher persistency (defined as the rate of decline in milk yield between days 100 and 300 post calving). Milking frequency did not differ significantly between cows and heifers in early lactation, but thereafter decreased significantly more in cows than in heifers. The effect of milking frequency on yield characteristics was analysed by comparing the highest and lowest quartiles for milking frequency. High milking frequency in early lactation was consistently associated with increased peak yield. High milking frequency averaged across the whole lactation was associated with increased peak yield in both cows and heifers, and with improved lactation persistency in cows only. This resulted in total lactation yield that was 21% greater in the high quartile cows compared with the low.
Ectopic, submandibular thyroid causing hyperthyroidism
Authors: Eli S U , Marnane C , Peter R , Winter S
Published: July 2011

Background:

Ectopic thyroid tissue in the submandibular region is exceptionally rare. Nevertheless, the treating physician should consider this condition within the differential diagnosis of a submandibular mass.

Method:

Case report of ectopic thyroid tissue presenting as a submandibular mass in a patient with hyperthyroidism, together with a review of the English-literature concerning ectopic thyroid tissue.

Conclusion:

To our knowledge, this is the first report of ectopic thyroid tissue presenting as a submandibular mass and causing hyperthyroidism. Removal of the submandibular mass resulted in normalisation of thyroid function, and subsequent reduction in the patient's antithyroid medication dosage. Ectopic thyroid tissue should be suspected in any patient with a submandibular mass. Prior to resection of such a lesion, it is essential to ensure that normal, functioning thyroid tissue is present elsewhere. Ectopic thyroid tissue can also present with pathology similar to that affecting the normal thyroid gland.
Is undergraduate medical education working for ENT surgery? A survey of UK medical school graduates
Authors: Powell J , Cooles F A H , Carrie S , Paleri V
Published: July 2011

Background:

Despite the patient numbers and scope of ENT surgery, it is under-represented in most undergraduate medical curricula.

Method:

An online questionnaire was e-mailed, at National Health Service trust level, to 3544 newly qualified doctors from 30 UK medical schools. Undergraduate ENT exposure, confidence and educational value were measured on a Likert scale.

Results:

We received 444 eligible responses. The mean undergraduate ENT exposure was 3.4 days of pre-clinical teaching plus 5.0 days of ENT departmental experience. However, 15.8 per cent of respondents reported no formal departmental ENT experience, and 65.8 per cent would have liked further undergraduate experience. Teaching modalities with a lower perceived educational value were generally offered more frequently than those with a higher perceived educational value. Graduates felt significantly less confident with ENT history-taking, examination and management, compared with their cardiology clinical competencies (p < 0.001).

Conclusion:

These results highlight the lack of UK ENT undergraduate education, and the significant effect this has on junior doctors’ clinical confidence. In addition, commonly used teaching methods may not be optimally effective.
Selected plasma fatty acid levels in subsistence fed sled dogs along the Yukon River: a pilot study for biomonitoring
Authors: Dunlap Kriya L. , Reynolds Arleigh J. , Duffy Lawrence K. , Gerlach S. Craig , Loring Philip A. , Cleroux Marilyn , Godin Jean Philippe
Published: July 2011

The introduction of the ‘western diet’ marked a decline in omega–3 fatty acids rich foods and a concurrent increase in saturated and omega–6 fatty acids that persists today. Historically, circumpolar people have had a low incidence of obesity, diabetes and cardiovascular disease and this has been largely attributed to polyphenolic compounds and omega–3 fatty acids offered from subsistence foods. In this report, we studied sled dogs as an Arctic sentinel species for monitoring the effect of a changing diet on lipid profiles along the Yukon River. Subsistence fed village sled dogs along the Yukon River, maintained largely on salmon were compared with a control kennel maintained on commercial food. Profiles showed higher levels for long chain omega–3 fatty acids in village subsistence fed dogs compared to control dogs and an opposite trend for omega–6 fatty acids, establishing baseline levels for follow up studies. A comparison with data for previously published mercury levels from the same cohort of dogs revealed a positive correlation with alpha–linolenic fatty acid and a negative correlation with linoleic fatty acid. Food and nutritional security is a concern in the Arctic as the impacts of climate change and transport of contaminants become obvious. This study supports not only the nutritional value of a subsistence diet but also the utility of sled dogs as a sentinel for human dietary change.
AGING PROPERTIES OF SEQUENTIAL ORDER STATISTICS
Authors: Burkschat M. , Navarro J.
Published: July 2011

Sequential order statistics describe the ordered failure times in a k-out-of-n system, where the failures of components might affect the performance of remaining working components. In this article aging properties of sequential order statistics are examined and conditions are given such that the distribution of a sequential order statistic is ILR, IFR, IFRA, or NBU. Moreover, conditions for aging properties of spacings of sequential order statistics are obtained.
STOCHASTIC SEQUENTIAL ASSIGNMENT PROBLEM WITH ARRIVALS
Authors: Righter Rhonda
Published: July 2011

We extend the classic sequential stochastic assignment problem to include arrivals of workers. When workers are all of the same type, we show that the socially optimal policy is the same as the individually optimal policy for which workers are given priority according to last come–first served. This result also holds under several variants in the model assumptions. When workers have different types, we show that the socially optimal policy is determined by thresholds such that more valuable jobs are given to more valuable workers, but now the individually optimal policy is no longer socially optimal. We also show that the overall value increases when worker or job values become more variable.
THE M/G/1-TYPE MARKOV CHAIN WITH RESTRICTED TRANSITIONS AND ITS APPLICATION TO QUEUES WITH BATCH ARRIVALS
Authors: Pérez Juan F. , Van Houdt Benny
Published: July 2011

We consider M/G/1-type Markov chains where a transition that decreases the value of the level triggers the phase to a small subset of the phase space. We show how this structure—referred to as restricted downward transitions—can be exploited to speed up the computation of the stationary probability vector of the chain. To this end we define a new M/G/1-type Markov chain with a smaller block size, the G matrix of which is used to find the original chain's G matrix. This approach is then used to analyze the BMAP/PH/1 queue and the BMAP[2]/PH[2]/1 preemptive priority queue, yielding significant reductions in computation time.
A “Triumph of Freedom” After All?Prigg v. PennsylvaniaRe-examined
Authors: Goldstein Leslie Friedman
Published: July 2011

Prigg v. Pennsylvania(1842), has puzzled scholars for generations. Law professor David Currie has called it “perplexing.” It is a case over which scholars have come to a wide array of conflicting conclusions.
Gerard Manley Hopkins' sprung rhythm: corpus study and stochastic grammar
Authors: Hayes Bruce , Moore-Cantwell Claire
Published: July 2011

Sprung rhythm is a complex poetic metre invented and used by Gerard Manley Hopkins. We re-examine and amplify a seminal analysis of this metre by Kiparsky (1989). We coded the sprung rhythm corpus for stress, weight and phrasing, then used a computer program to locate every scansion compatible with Kiparsky's analysis. The analysis appears to be nearly exceptionless. However, it is incomplete in that it permits dozens or even hundreds of scansions for certain lines. We propose a Parsability Principle for metrics mandating that ambiguity of scansion be minimised, and suggest that under this proposal, the Kiparskyan system is not a possible metre. Our own revised analysis adds ten new constraints and is cast in the form of a stochastic maxent grammar. It produces an acceptably low level of ambiguity in metrical parsing, and is supported by a good match to the diacritics Hopkins employed to mark his intended scansion.
Chronic hypobaric hypoxia, patent arterial duct and a new interventional technique to close it
Authors: Freudenthal Franz P. , Heath Alexandra , Villanueva Jorge , Mendes Janne , Vicente Ximena , von Alvensleben Inge , Echazú Gabriel , Navarro Joaquin , Lang Nora , Kozlik-Feldmann Rainer
Published: July 2011

Background

Interventional closure of patent arterial duct has become an accepted alternative to surgical closure. Clinical trial with “Nit-Occlud®PDA-R”.

Methods and results

To assess the safety and efficacy of the device, we performed a prospective clinical study between June, 2009 and December, 2010 in La Paz, Bolivia. In all, 29 – 22 female patients and 7 male patients – out of 59 patients were selected on the basis of inclusion criteria. The procedures were performed under sedation at an age and weight of 5.7 years and 22.7 kilograms, respectively, with 4–6 French arterial sheaths and 5–7 French venous sheaths. The minimal diameter of the duct was 3.5 millimetres. The procedure, fluoroscopy, and hospitalisation times were 96.4 minutes (55 to 145), 13.1 minutes (3 to 25.2), and 24 hours, respectively. The “Nit-Occlud®PDA-R” was successfully deployed in all patients. Immediate, 24-hour, 1-, 3-, and 6-month closure rates were 65.5%, 79.3%, 96.5%, and 100%, respectively. The systolic pulmonary pressure diminished from 37 millimetres of mercury (21 to 57) before the intervention to 31 millimetres of mercury (21 to 45) after the intervention. No early or late embolisation, haemolysis, left pulmonary artery, or descending aorta obstruction occurred.

Conclusions

We conclude that the “Nit-Occlud®PDA-R” device is safe and effective in closing patent arterial duct up to a diameter of 8 millimetres.
Prenatal complex congenital heart disease with Loeys–Dietz syndrome
Authors: Kawazu Yukiko , Inamura Noboru , Kayatani Futoshi , Okamoto Nobuhiko , Morisaki Hiroko
Published: July 2011

We report an infantile case of Loeys–Dietz syndrome prenatally diagnosed with congenital complex heart disease – double outlet right ventricle and interruption of the aortic arch. The patient also showed prominent dilatation of the main pulmonary artery. Emergency bilateral pulmonary artery banding was performed on the 9th day. However, on the 21st day, the patient died of massive bleeding due to rupture of the right pulmonary artery. Subsequently, a mutation of the TGFBR1 gene was detected. As cardiovascular lesions of Loeys–Dietz syndrome appear early and progress rapidly, the prognosis is generally poor. Patients require periodic examination and early intervention with medical therapy such as Losartan administration and surgical therapy. Early genetic screening is thought to be useful for the prediction of complications as well as vascular disease.
New CNES‐CLS09 global mean dynamic topography computed from the combination of GRACE data, altimetry, and in situ measurements
Authors: Rio M. H. , Guinehut S. , Larnicol G.
Published: July 2011

An accurate knowledge of the ocean mean dynamic topography (MDT) is mandatory for the optimal use of altimetric data, including their assimilation into operational ocean forecasting systems. A new global 1/4° resolution MDT was computed for the 1993–1999 time period with improved data and methodology compared to the previous RIO05 MDT field. First, a large‐scale MDT is obtained from the CLS01 altimetric Mean Sea Surface and a recent geoid model computed from 4.5 years of GRACE (Gravity Recovery and Climate Experiment) data. Altimetric sea level anomalies and in situ measurements are then combined to compute synthetic estimates of the MDT and the corresponding mean currents. While the RIO05 MDT was based on 10 years of in situ dynamic heights and drifting buoy velocities, the new field benefits from an enlarged data set of in situ measurements ranging from 1993 to 2008 and includes all hydrological profiles from the Argo array. Moreover, the processing of the in situ data has been updated. A new Ekman model was developed to extract the geostrophic velocity component from the drifting buoy measurements. The handling of hydrologic measurements has also been revisited. Compared to the previous RIO05 solution, the new global MDT resolves much stronger gradients in western boundary currents, with mean velocities being doubled in some places. Moreover, in comparison to several other recent MDT estimates, we find that the new CNES‐CLS09 MDT is in better agreement with independent in situ observations.
Vertical tectonics at a continental crust‐oceanic plateau plate boundary zone: Fission track thermochronology of the Sierra Nevada de Santa Marta, Colombia
Authors: Villagómez Diego , Spikings Richard , Mora Andrés , Guzmán Georgina , Ojeda Germán , Cortés Elizabeth , van der Lelij Roelant
Published: July 2011

The topographically prominent Sierra Nevada de Santa Marta forms part of a faulted block of continental crust located along the northern boundary of the South American Plate, hosts the highest elevation in the world (∼5.75 km) whose local base is at sea level, and juxtaposes oceanic plateau rocks of the Caribbean Plate. Quantification of the amount and timing of exhumation constrains interpretations of the history of the plate boundary, and the driving forces of rock uplift along the active margin. The Sierra Nevada Province of the southernmost Sierra Nevada de Santa Marta exhumed at elevated rates (≥0.2 Km/My) during 65–58 Ma in response to the collision of the Caribbean Plateau with northwestern South America. A second pulse of exhumation (≥0.32 Km/My) during 50–40 Ma was driven by underthrusting of the Caribbean Plate beneath northern South America. Subsequent exhumation at 40–25 Ma (≥0.15 Km/My) is recorded proximal to the Santa Marta‐Bucaramanga Fault. More northerly regions of the Sierra Nevada Province exhumed rapidly during 26–29 Ma (∼0.7 Km/My). Further northward, the Santa Marta Province exhumed at elevated rates during 30–25 Ma and 25–16 Ma. The highest exhumation rates within the Sierra Nevada de Santa Marta progressed toward the northwest via the propagation of NW verging thrusts. Exhumation is not recorded after ∼16 Ma, which is unexpected given the high elevation and high erosive power of the climate, implying that rock and surface uplift that gave rise to the current topography was very recent (i.e., ≤1 Ma?), and there has been insufficient time to expose the fossil apatite partial annealing zone.
Genome-scale analysis of anaerobic benzoate and phenol metabolism in the hyperthermophilic archaeon Ferroglobus placidus
Authors: Holmes Dawn E , Risso Carla , Smith Jessica A , Lovley Derek R
Published: July 2011

Insight into the mechanisms for the anaerobic metabolism of aromatic compounds by the hyperthermophilic archaeon Ferroglobus placidus is expected to improve understanding of the degradation of aromatics in hot (>80° C) environments and to identify enzymes that might have biotechnological applications. Analysis of the F. placidus genome revealed genes predicted to encode enzymes homologous to those previously identified as having a role in benzoate and phenol metabolism in mesophilic bacteria. Surprisingly, F. placidus lacks genes for an ATP-independent class II benzoyl-CoA (coenzyme A) reductase (BCR) found in all strictly anaerobic bacteria, but has instead genes coding for a bzd-type ATP-consuming class I BCR, similar to those found in facultative bacteria. The lower portion of the benzoate degradation pathway appears to be more similar to that found in the phototroph Rhodopseudomonas palustris, than the pathway reported for all heterotrophic anaerobic benzoate degraders. Many of the genes predicted to be involved in benzoate metabolism were found in one of two gene clusters. Genes for phenol carboxylation proceeding through a phenylphosphate intermediate were identified in a single gene cluster. Analysis of transcript abundance with a whole-genome microarray and quantitative reverse transcriptase polymerase chain reaction demonstrated that most of the genes predicted to be involved in benzoate or phenol metabolism had higher transcript abundance during growth on those substrates vs growth on acetate. These results suggest that the general strategies for benzoate and phenol metabolism are highly conserved between microorganisms living in moderate and hot environments, and that anaerobic metabolism of aromatic compounds might be analyzed in a wide range of environments with similar molecular targets.
Measuring unbiased metatranscriptomics in suboxic waters of the central Baltic Sea using a new in situ fixation system
Authors: Feike Janie , Jürgens Klaus , Hollibaugh James T , Krüger Siegfried , Jost Günter , Labrenz Matthias
Published: July 2011

An analysis of the microbial metabolism is fundamental to understanding globally important element transformations. One culture-independent approach to deduce those prokaryotic metabolic functions is to analyze metatranscriptomes. Unfortunately, since mRNA is extremely labile, it is unclear whether the abundance patterns detected in nature are vulnerable to considerable modification in situ simply due to sampling procedures. Exemplified on comparisons of metatranscriptomes retrieved from pelagic suboxic zones of the central Baltic Sea (70–120 m depth), earlier identified as areas of high aerobic ammonium oxidation activity, and quantification of specific transcripts in them, we show that different sampling techniques significantly influence the relative abundance of transcripts presumably diagnostic of the habitat. In situ fixation using our newly developed automatic flow injection sampler resulted in an abundance of thaumarchaeal ammonia monooxygenase transcripts that was up to 30-fold higher than that detected in samples obtained using standard oceanographic sampling systems. By contrast, the abundance of transcripts indicative of cellular stress was significantly greater in non-fixed samples. Thus, the importance of in situ fixation in the reliable evaluation of distinct microbial activities in the ecosystem based on metatranscriptomics is obvious. In consequence, our data indicate that the significance of thaumarchaeota to aerobic ammonium oxidation could yet have been considerably underestimated. Taken these results, this could in general also be the case in attempts aimed at an unbiased gene expression analysis of areas below the epipelagic zone, which cover 90% of the world's oceans.
A ‘universal’ type II chaperonin PCR detection system for the investigation of Archaea in complex microbial communities
Authors: Chaban Bonnie , Hill Janet E
Published: July 2011

Bacteria and Archaea are evolutionarily and biochemically distinct domains found together in many environments. Robust ‘universal’ PCR primer sets targeting both the bacterial 16S rRNA gene and the type I chaperonin gene have been established. However, ‘universal’ PCR primers for Archaea are currently limited to the 16S rRNA gene. We investigated the type II chaperonin (known as the thermosome, TF55, CCT or TCP-1) as a potential universal target (UT) for Archaea. Reproducible amplification of thermosome gene sequences from all major phyla tested was achieved through the application of a mixture or ‘cocktail’ of two forward and two reverse primers. Phylogenies based on the ∼750-bp thermosome UT were congruent with 16S rRNA gene phylogenies while exhibiting longer branch lengths, improving resolution of closely related taxa. ‘Universal’ thermosome primers were applied to profiling the archaeal community of dairy cow rumen and results compared with profiles based on the 16S rRNA gene and methyl co-enzyme M reductase (methanogen-specific) gene. Clone libraries generated from each target gene, as well as a pyrosequencing profile of one thermosome rumen library, revealed that all three targets consistently detected Methanobrevibacter smithii, Methanobrevibacter ruminantium and Methanosphaera stadtmanae as the dominant constituents; however, thermosome gene sequences were more diverse than either of the other targets providing a higher resolution description of the archaeal community. These findings demonstrate that a ‘universal’ thermosome PCR protocol is a powerful metagenomic tool for detecting and characterizing Archaea and archaeal communities.
Novel magnetite-producing magnetotactic bacteria belonging to the Gammaproteobacteria
Authors: Lefèvre Christopher T , Viloria Nathan , Schmidt Marian L , Pósfai Mihály , Frankel Richard B , Bazylinski Dennis A
Published: July 2011

Two novel magnetotactic bacteria (MTB) were isolated from sediment and water collected from the Badwater Basin, Death Valley National Park and southeastern shore of the Salton Sea, respectively, and were designated as strains BW-2 and SS-5, respectively. Both organisms are rod-shaped, biomineralize magnetite, and are motile by means of flagella. The strains grow chemolithoautotrophically oxidizing thiosulfate and sulfide microaerobically as electron donors, with thiosulfate oxidized stoichiometrically to sulfate. They appear to utilize the Calvin–Benson–Bassham cycle for autotrophy based on ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) activity and the presence of partial sequences of RubisCO genes. Strains BW-2 and SS-5 biomineralize chains of octahedral magnetite crystals, although the crystals of SS-5 are elongated. Based on 16S rRNA gene sequences, both strains are phylogenetically affiliated with the Gammaproteobacteria class. Strain SS-5 belongs to the order Chromatiales; the cultured bacterium with the highest 16S rRNA gene sequence identity to SS-5 is Thiohalocapsa marina (93.0%). Strain BW-2 clearly belongs to the Thiotrichales; interestingly, the organism with the highest 16S rRNA gene sequence identity to this strain is Thiohalospira alkaliphila (90.2%), which belongs to the Chromatiales. Each strain represents a new genus. This is the first report of magnetite-producing MTB phylogenetically associated with the Gammaproteobacteria. This finding is important in that it significantly expands the phylogenetic diversity of the MTB. Physiology of these strains is similar to other MTB and continues to demonstrate their potential in nitrogen, iron, carbon and sulfur cycling in natural environments.
The Extent to Which Adiposity Markers Explain the Association Between Sedentary Behavior and Cardiometabolic Risk Factors
Authors: Stamatakis Emmanuel , Hamer Mark
Published: July 2011

An emerging body of evidence suggests that sedentary behavior (SB) is an independent risk factor for cardiometabolic disease. Recent data suggest that multi‐domain SB has detrimental associations with BMI, waist circumference (WC), and nonadiposity‐related (total cholesterol, high density lipoprotein cholesterol (HDL‐C), systolic (SBP) and diastolic (DBP) blood pressure) cardiometabolic risk markers. The aim of this cross‐sectional study was to examine the extent to which the associations between SB and nonadiposity‐related cardiometabolic risk markers are explained by adiposity markers. Subjects were 5,067 Health Survey for England (HSE) 2008 respondents (2,552 men) aged 16–65 years. The measurements protocol involved self‐reports of television time, other recreational sitting, occupational sitting/standing, physical activity and objective measures of weight, height, WC, total cholesterol, HDL cholesterol, SBP, and DBP. BMI or WC adjustments of the multivariable models looking at the associations between SB and nonadiposity markers attenuated all associations towards the null. Using established logistic regression‐based algorithms we calculated that a large percentage of the associations between SB time and nonadiposity risk factors is explained by BMI or WC (range: 27.3–95.9%). Future longitudinal studies should further examine the mediatory role of adiposity in explaining the associations between SB and cardiometabolic risk.
Brown Fat Activity Is not Apparent in Subjects With HIV Lipodystrophy and Increased Resting Energy Expenditure
Authors: Kosmiski Lisa A. , Sage‐El Adrienne , Kealey Elizabeth H. , Bessesen Daniel H.
Published: July 2011

The HIV lipodystrophy (LD) syndrome is associated with increased resting energy expenditure (REE), but the basis of this hypermetabolism has not been determined. The objective of this pilot study was to determine if brown fat is activated in subjects with HIV LD and increased REE. In this descriptive study of four subjects with HIV LD and marked hypermetabolism, REE was measured by indirect calorimetry and brown fat activity was determined by 18F‐fluorodeoxyglucose (FDG) positron‐emission tomography (PET) combined with anatomic computed tomography (CT). Brown fat activity was not apparent in any subject with HIV LD and resting hypermetabolism. Therefore, brown fat activation is unlikely to be the principal cause of the increased REE associated with the HIV LD syndrome. Evidence of adaptive thermogenesis has been demonstrated in this syndrome, but this study suggests that tissues other than brown adipose tissue (BAT) are responsible. Further understanding of the chronic hypermetabolism associated with HIV LD could provide new insights into the regulation of energy balance.
Acute Effect of Alginate‐Based Preload on Satiety Feelings, Energy Intake, and Gastric Emptying Rate in Healthy Subjects
Authors: Georg Morten Georg , Kristensen Mette , Belza Anita , Knudsen Jes C. , Astrup Arne
Published: July 2011

Viscous dietary fibers such as sodium alginate extracted from brown seaweed have received much attention lately for their potential role in energy regulation through the inhibition of energy intake and increase of satiety feelings. The aim of our study was to investigate the effect on postprandial satiety feelings, energy intake, and gastric emptying rate (GER), by the paracetamol method, of two different volumes of an alginate‐based preload in normal‐weight subjects. In a four‐way placebo‐controlled, double‐blind, crossover trial, 20 subjects (age: 25.9 ± 3.4 years; BMI: 23.5 ± 1.7 kg/m2) were randomly assigned to receive a 3% preload concentration of either low volume (LV; 9.9 g alginate in 330 ml) or high volume (HV; 15.0 g alginate in 500 ml) alginate‐based beverage, or an iso‐volume placebo beverage. The preloads were ingested 30 min before a fixed breakfast and again before an ad libitum lunch. Consumption of LV‐alginate preload induced a significantly lower (8.0%) energy intake than the placebo beverage (P = 0.040) at the following lunch meal, without differences in satiety feelings or paracetamol concentrations. The HV alginate significantly increased satiety feelings (P = 0.038), reduced hunger (P = 0.042) and the feeling of prospective food consumption (P = 0.027), and reduced area under the curve (iAUC) paracetamol concentrations compared to the placebo (P = 0.05). However, only a 5.5% reduction in energy intake was observed for HV alginate (P = 0.20). Although they are somewhat contradictory, our results suggest that alginate consumption does affect satiety feelings and energy intake. However, further investigation on the volume of alginate administered is needed before inferring that this fiber has a possible role in short‐term energy regulation.
Complete chaotic mixing in an electro-osmotic flow by destabilization of key periodic pathlines
Authors: Chabreyrie R. , Chandre C. , Aubry N.
Published: July 2011

The ability to generate complete, or almost complete, chaotic mixing is of great interest in numerous applications, particularly for microfluidics. For this purpose, we propose a strategy that allows us to quickly target the parameter values at which complete mixing occurs. The technique is applied to a time periodic, two-dimensional electro-osmotic flow with spatially and temporally varying Helmholtz-Smoluchowski slip boundary conditions. The strategy consists of following the linear stability of some key periodic pathlines in parameter space (i.e., amplitude and frequency of the forcing), particularly through the bifurcation points at which such pathlines become unstable.
Particle image velocimetry measurements of massively separated turbulent flows with rotation
Authors: Visscher Jan , Andersson Helge I.
Published: July 2011

Measurements of instantaneous velocity fields in the separated flow downstream of a backward-facing step in a rotating channel are presented for the first time. Particle image velocimetry (PIV) measurements were made for 13 different rotation numbers Ro at a bulk flow Reynolds number of about 5600. The expansion ratio 2:1 was the same as in the flow visualization study by Rothe and Johnston [ASME J. Fluids Eng. 101, 117 (1979)] which covered about the same range of Ro. The measured mean flow pattern exhibited substantial variations with the rate of system rotation. In particular, the length of the primary separation bubble decreased monotonically with increasing anti-cyclonic rotation and increased with increasing rate of cyclonic rotation, in keeping with the earlier observations. At the highest anti-cyclonic rotation rate, the flow field also separated from the planar wall where the shear layer flow was subjected to cyclonic rotation. The PIV data for the in-plane components of the Reynolds stress tensor were severely affected by the imposed system rotation. Almost all the striking affects of the Coriolis force observed herein could be explained by means of the exact production terms in the transport equation for the second-moments of the velocity fluctuations. These changes were in turn consistent with the observed alterations of the mean flow field.
Numerical study of flow characteristics behind a stationary circular cylinder with a flapping plate
Authors: Wu J. , Shu C.
Published: July 2011

The laminar flow over a stationary circular cylinder with a flapping plate is simulated in this study to investigate the flow characteristics by using our recently developed boundary condition-enforced immersed boundary-lattice Boltzmann method [Wu and Shu, J. Comput. Phys. 228, 1963 (2009); Wu et al., Int. J. Numer. Methods Fluids 62, 327 (2010); Wu and Shu, Comm. Comp. Phys. 7, 793 (2010)]. The purpose of this work is to study the flow control behind a bluff body by an alternative way different from the rotationally oscillating motion. The idea is in fact from the tadpole locomotion, where the bluff head-body is modeled by a circular cylinder, and the thin tail is simplified by a rigid plate with flapping motion. In this work, only the laminar flow is considered and thus the Reynolds number is chosen as 100. Similar to the case of rotationally oscillating cylinder, the flow wake behind the cylinder and flapping plate is strongly affected by the flapping amplitude and frequency of plate. On the other hand, because of the existence of flapping plate, the length of plate can also modify the flow structures. Due to flapping motion of plate, some typical flow patterns and drag reduction are found, and two different vortex interaction modes, known as constructive interaction and destructive interaction, are observed.
Behavior of water molecules near monolayer-protected clusters with different terminal segments of ligand
Authors: Yang An-Cheng , Weng Cheng-I , Chen Tei-Chen
Published: July 2011

Molecular dynamics simulations are performed to investigate the behavior of water molecules near gold monolayer protected clusters (MPCs) with two different types of surfactant, HS(CH2)5(OCH2CH2)2COOH (type1) and HS(CH2)11COOH (type2). The effects of the different moieties of the two ligands on the local structure of the water molecules are quantified by means of the reduced density profiles of oxygen and hydrogen atoms, and the hydrogen bond statistics. The adsorption characteristics of water molecules are evaluated by means of their residence time near the MPCs. The results show that the hydrophilic oligo (ethylene glycol) segment increases the number of water molecules, which penetrate the protective layer of MPC. As a result, the inter-water hydrogen bond network in the protective layer of type1 MPC is stronger than that in the protective layer of the type2 MPC. It is shown that the presence of interfacial hydrogen bonds increases the adsorption of water molecules near the MPCs and therefore constrains the motion of MPCs. As a result, the residence time of the water molecules adjacent to the type1 MPC is longer than that of the molecules adjacent to the type2 MPC.
Magnetotransport properties of Pr0.5Ca0.5MnO3 thin films grown by a solution route
Authors: Staruch M. , Stan L. , Lee J. H. , Wang H. , Budnick J. I. , Jain M.
Published: July 2011

Thin films of Pr0.5Ca0.5MnO3 were fabricated on (001) oriented SrLaAlO4, NdGaO3, and SrTiO3 substrates using a hybrid solution route and spin coating techniques. Good crystalline and epitaxial quality of the films was confirmed with X-ray diffraction and transmission electron microscopy studies. Strain in the film grown on NdGaO3 substrate did not relax during annealing process and the film exhibited charge-ordered insulator phase at low temperatures even with magnetic fields up to 9 T. However, the films on SrLaAlO4 and SrTiO3 substrates (with partially relaxed compressive and tensile strain, respectively) displayed melting of the charge-ordered phase with applied magnetic fields of less than 5 T. The results suggest that strain-relaxation rather than only the type of strain plays an important role in lowering critical melting magnetic fields in these films.
Exact solution of the spectrum and magneto-optics of multilayer hexagonal graphene
Authors: Chang C. P.
Published: July 2011

We demonstrate that by decoupling the interlayer interactions, N-layer hexagonal graphene is decomposed into the N independent subsystems. Each subsystem, exactly described by a 2 × 2 matrix, is treated as a renormalized graphene with the renormalized site energy and intralayer interaction. The analytical form of the energy dispersions and wave functions of each renormalized graphene is easily obtained. The study reveals the origin of electron-hole asymmetry, and how it is caused by the interlayer interaction between different sublattices at adjacent layers. The monolayer-graphene-like characteristics allow us to describe Landau-level energies and magneto-optical absorption spectra of each renormalized graphene based on the effective mass model. There are N sets of Landau levels in the energy spectra of the N-layer hexagonal graphene. The magneto-optical spectra exhibit N groups of Landau-peaks. Each group of Landau-peaks follows the same optical selection as that of a monolayer graphene.
Magnitude and time response of electronic and topographical changes during hydrogen sensing in size selected palladium nanoparticles
Authors: Khanuja M. , Shrestha S. , Mehta B. R. , Kala S. , Kruis F. E.
Published: July 2011

In this study, size dependence of electronic and topographical effects during Pd-H interaction has been investigated by studying H sensing in thin films of size selected and monosized nanoparticles having 15, 20, and 25 nm diameter. By separating the contributions of electronic changes due to H adsorption and topographical changes due to lattice expansion to hydrogen sensing, it has been shown that the magnitude and response time of these changes are sensitive functions of nanoparticle size and measurement temperature. The temperature dependence of saturated resistance corresponding to these changes provides important information about the nature of electronic and topographical changes.
Scanning capacitance spectroscopy on n+-p asymmetrical junctions in multicrystalline Si solar cells
Authors: Jiang C.-S. , Heath J. T. , Moutinho H. R. , Al-Jassim M. M.
Published: July 2011

We report on a scanning capacitance spectroscopy (SCS) study on the n+-p junction of multicrystalline silicon solar cells. We found that the spectra taken at space intervals of ∼10 nm exhibit characteristic features that depend strongly on the location relative to the junction. The capacitance-voltage spectra exhibit a local minimum capacitance value at the electrical junction, which allows the junction to be identified with ∼10-nm resolution. The spectra also show complicated transitions from the junction to the n-region with two local capacitance minima on the capacitance-voltage curves; similar spectra to that have not been previously reported in the literature. These distinctive spectra are due to uneven carrier-flow from both the n- and p-sides. Our results contribute significantly to the SCS study on asymmetrical junctions.
Tailoring magnetic anisotropy in epitaxial half metallic La0.7Sr0.3MnO3 thin films
Authors: Perna P. , Rodrigo C. , Jiménez E. , Teran F. J. , Mikuszeit N. , Méchin L. , Camarero J. , Miranda R.
Published: July 2011

We present a detailed study on the magnetic properties, including anisotropy, reversal fields, and magnetization reversal processes, of well characterized half-metallic epitaxial La0.7Sr0.3MnO3 (LSMO) thin films grown onto SrTiO3 (STO) substrates with three different surface orientations, i.e., (001), (110), and (11−8). The latter shows step edges oriented parallel to the [110] (in-plane) crystallographic direction. Room temperature high resolution vectorial Kerr magnetometry measurements have been performed at different applied magnetic field directions in the whole angular range. In general, the magnetic properties of the LSMO films can be interpreted with just the uniaxial term, with the anisotropy axis given by the film morphology, whereas the strength of this anisotropy depends on both structure and film thickness. In particular, LSMO films grown on nominally flat (110)-oriented STO substrates presents a well defined uniaxial anisotropy originated from the existence of elongated in-plane [001]-oriented structures, whereas LSMO films grown on nominally flat (001)-oriented STO substrates show a weak uniaxial magnetic anisotropy, with the easy axis direction aligned parallel to residual substrate step edges. Elongated structures are also found for LSMO films grown on vicinal STO(001) substrates. These films present a well-defined uniaxial magnetic anisotropy, with the easy axis lying along the step edges, and its strength increases with the LSMO thickness. It is remarkable that this step-induced uniaxial anisotropy has been found for LSMO films up to 120 nm thickness. Our results are promising for engineering novel half-metallic magnetic devices that exploit tailored magnetic anisotropy.
Coherent hypersonic closed-pipe organ like modes in supported polymer films
Authors: Akimov A. V. , Young E. S. K. , Sharp J. S. , Gusev V. , Kent A. J.
Published: July 2011

Hypersonic wavepackets were injected into polymer films of various thicknesses on a crystalline substrate, and quantized vibrational modes were detected. The acoustic spectrum showed up to six localized modes with frequencies determined by the boundary conditions for acoustic modes similar to those obtained in closed organ pipes. The decay rate of the modes was found to increase linearly with frequency in the gigahertz range.
Re-entrant phase behaviour of network fluids: A patchy particle model with temperature-dependent valence
Authors: Russo J. , Tavares J. M. , Teixeira P. I. C. , da Gama M. M. Telo , Sciortino F.
Published: July 2011

We study a model consisting of particles with dissimilar bonding sites (“patches”), which exhibits self-assembly into chains connected by Y-junctions, and investigate its phase behaviour by both simulations and theory. We show that, as the energy cost εj of forming Y-junctions increases, the extent of the liquid-vapour coexistence region at lower temperatures and densities is reduced. The phase diagram thus acquires a characteristic “pinched” shape in which the liquid branch density decreases as the temperature is lowered. To our knowledge, this is the first model in which the predicted topological phase transition between a fluid composed of short chains and a fluid rich in Y-junctions is actually observed. Above a certain threshold for εj, condensation ceases to exist because the entropy gain of forming Y-junctions can no longer offset their energy cost. We also show that the properties of these phase diagrams can be understood in terms of a temperature-dependent effective valence of the patchy particles.
Onset of fast reconnection in Hall magnetohydrodynamics mediated by the plasmoid instability
Authors: Huang Yi-Min , Bhattacharjee A. , Sullivan Brian P.
Published: July 2011

The role of a super-Alfvénic plasmoid instability in the onset of fast reconnection is studied by means of the largest Hall magnetohydrodynamics simulations to date, with system sizes up to 104 ion skin depths (di). It is demonstrated that the plasmoid instability can facilitate the onset of rapid Hall reconnection, in a regime where the onset would otherwise be inaccessible because the Sweet–Parker width is significantly above di. However, the topology of Hall reconnection is not inevitably a single stable X-point. There exists an intermediate regime where the single X-point topology itself exhibits instability, causing the system to alternate between a single X-point geometry and an extended current sheet with multiple X-points produced by the plasmoid instability. Through a series of simulations with various system sizes relative to di, it is shown that system size affects the accessibility of the intermediate regime. The larger the system size is, the easier it is to realize the intermediate regime. Although our Hall magnetohydrodynamics (MHD) model lacks many important physical effects included in fully kinetic models, the fact that a single X-point geometry is not inevitable raises the interesting possibility for the first time that Hall MHD simulations may have the potential to realize reconnection with geometrical features similar to those seen in fully kinetic simulations, namely, extended current sheets and plasmoid formation.
Temperature and field dependent magnetic Compton scattering study of Heusler alloy Co2MnSi
Authors: Dashora Alpa , Ahuja B. L. , Vinesh A. , Lakshmi N. , Itou M. , Sakurai Y.
Published: July 2011

Temperature and field dependent spin polarized electron momentum distributions in ternary Heusler compound Co2MnSi have been measured using the magnetic Compton spectrometer at SPring-8, Japan. The experimental magnetic Compton profile at 10 K reconciles well with the theoretical profile computed using the spin polarized relativistic (SPR) Korringa–Kohn–Rostoker (KKR) method. The temperature and field dependent experimental magnetic profiles have been mainly analyzed to check the role of Mn 3d electrons in the formation of magnetic moments in Co2MnSi. The diffuse contribution from conduction electrons is antiferromagnetically coupled to the spin moment arising from 3d electrons of Co and Mn. The spin moments calculated using SPR-KKR calculations are in good agreement with the present measurements.
Nonlocality and the critical Reynolds numbers of the minimum state magnetohydrodynamic turbulence
Authors: Zhou Ye , Oughton Sean
Published: July 2011

Magnetohydrodynamic (MHD) systems can be strongly nonlinear (turbulent) when their kinetic and magnetic Reynolds numbers are high, as is the case in many astrophysical and space plasma flows. Unfortunately these high Reynolds numbers are typically much greater than those currently attainable in numerical simulations of MHD turbulence. A natural question to ask is how can researchers be sure that their simulations have reproduced all of the most influential physics of the flows and magnetic fields? In this paper, a metric is defined to indicate whether the necessary physics of interest has been captured. It is found that current computing resources will typically not be sufficient to achieve this minimum state metric.