bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature dependence of magnetic anisotropy constant in iron chalcogenide Fe3Se4: Excellent agreement with theories
Authors: Wang Jun , Duan Hongyan , Lin Xiong , Aguilar Victor , Mosqueda Aaron , Zhao Guo-meng 
Published: November 2012

Magnetic hysteresis loops were measured for ferrimagnetic iron chalcogenide Fe3Se4 nanoparticles in the whole temperature range below the Curie temperature TC (315 K). The coercivity of the material is huge, reaching about 40 kOe at 10 K. The magnetic anisotropy constant K was determined from the magnetic hysteresis loop using the law of approach to saturation. The deduced anisotropy constant at 10 K is 5.22×106 erg/cm3, which is over one order of magnitude larger than that of Fe3O4. We also demonstrated that the experimental magnetic hysteresis loop is in good agreement with the theoretical curve calculated by Stoner and Wohlfarth for a noninteracting randomly oriented uniaxial single-domain particle system. Moreover, we show that K is proportional to the cube of the saturation magnetization Ms, which confirms earlier theoretical models for uniaxial magnets.
Underwater radiated noise measurements of a noise-reduced fisheries research vessel
Authors: De Robertis Alex , Wilson Christopher D. , Furnish Scott R. , Dahl Peter H. 
Published: November 2012

Abstract
De Robertis, A., Wilson, C. D., Furnish, S. R., and Dahl, P. H. 2013. Underwater radiated noise measurements of a noise-reduced fisheries research vessel. – ICES Journal of Marine Science, 70: 480–484. Vessel-radiated noise is traditionally measured at naval acoustic ranges, but lower-cost options are desirable for routine monitoring of research vessels. Measurements of a noise-reduced research vessel made at a naval noise range are compared to those made using an experimental mooring equipped with commercially available instrumentation. The measurements from the mooring were precise and within 2.5 dB of those from the noise range at third-octave bands <500 Hz. At higher frequencies, direct comparisons were precluded by an intermittent shaft-related noise present only during the mooring measurements, but previously observed at the navy range. The agreement between the two methods suggests that simplified, field-deployable hydrophone systems can be used to accurately characterize the noise signatures of research vessels.
Lower Extremity Predominant Stiff-Person Syndrome and Limbic Encephalitis With Amphiphysin Antibodies in Breast Cancer
Authors: Krishna Vivek R. , Knievel Kerry , Ladha Shafeeq , Sivakumar Kumaraswamy 
Published: November 2012

Abstract
A 54-year-old woman presented with several weeks of psychiatric symptoms, partial-onset seizures, and painful spasms of the lower extremities. On examination, she exhibited severe stiffness and intermittent extensor spasms of the lower extremities. Magnetic resonance imaging of the brain showed T2 hyperintensity in the left temporal lobe with enhancement after gadolinium administration on T1-weighted images. Amphiphysin antibodies were present in the serum. Radiographic screening for malignancy disclosed a metastatic breast cancer. The case is a unique example of amphiphysin autoimmunity, illustrating the possibility of paraneoplastic stiff-person syndrome and limbic encephalitis coexisting in a patient with a “classical” presentation of stiff-person syndrome confined to the lower extremities.
Quantifying individual variation in behaviour: mixed‐effect modelling approaches
Authors: Dingemanse Niels J. , Dochtermann Ned A. 
Published: November 2012

Summary

Growing interest in proximate and ultimate causes and consequences of between‐ and within‐individual variation in labile components of the phenotype – such as behaviour or physiology – characterizes current research in evolutionary ecology.
The study of individual variation requires tools for quantification and decomposition of phenotypic variation into between‐ and within‐individual components. This is essential as variance components differ in their ecological and evolutionary implications.
We provide an overview of how mixed‐effect models can be used to partition variation in, and correlations among, phenotypic attributes into between‐ and within‐individual variance components.
Optimal sampling schemes to accurately estimate (with sufficient power) a wide range of repeatabilities and key (co)variance components, such as between‐ and within‐individual correlations, are detailed.
Mixed‐effect models enable the usage of unambiguous terminology for patterns of biological variation that currently lack a formal statistical definition (e.g. ‘animal personality’ or ‘behavioural syndromes’), and facilitate cross‐fertilisation between disciplines such as behavioural ecology, ecological physiology and quantitative genetics.
Vegetation dynamics drive segregation by body size in Galapagos tortoises migrating across altitudinal gradients
Authors: Blake Stephen , Yackulic Charles B. , Cabrera Fredy , Tapia Washington , Gibbs James P. , Kümmeth Franz , Wikelski Martin 
Published: November 2012

Summary

Seasonal migration has evolved in many taxa as a response to predictable spatial and temporal variation in the environment. Individual traits, physiology and social state interact with environmental factors to increase the complexity of migratory systems. Despite a huge body of research, the ultimate causes of migration remain unclear.
A relatively simple, tractable system – giant tortoises on Santa Cruz Island, Galapagos, was studied to elucidate the roles of environmental variation and individual traits in a partial migratory system. Specifically, we asked: (i) do Galapagos tortoises undergo long‐distance seasonal migrations? (ii) is tortoise migration ultimately driven by gradients in forage quality or temperature; and (iii) how do sex and body size influence migration patterns?
We recorded the daily locations of 17 GPS‐tagged tortoises and walked a monthly survey along the altitudinal gradient to characterize the movements and distribution of tortoises of different sizes and sexes. Monthly temperature and rainfall data were obtained from weather stations deployed at various altitudes, and the Normalized Difference Vegetation Index was used as a proxy for forage quality.
Analyses using net displacement or daily movement characteristics did not agree on assigning individuals as either migratory or non‐migratory; however, both methods suggested that some individuals were migratory. Adult tortoises of both sexes move up and down an altitudinal gradient in response to changes in vegetation dynamics, not temperature. The largest tagged individuals all moved, whereas only some mid‐sized individuals moved, and the smallest individuals never left lowland areas. The timing of movements varied with body size: large individuals moved upward (as lowland forage quality declined) earlier in the year than did mid‐sized individuals, while the timing of downward movements was unrelated to body size and occurred as lowland vegetation productivity peaked.
Giant tortoises are unlikely candidates for forage‐driven migration as they are well buffered against environmental fluctuations by large body size and a slow metabolism. Notably the largest, and presumably most dominant, individuals were most likely to migrate. This characteristic and the lack of sex‐based differences in movement behaviour distinguish Galapagos tortoise movement from previously described partial migratory systems.
Probucol prevents blood–brain barrier dysfunction in wild‐type mice induced by saturated fat or cholesterol feeding
Authors: Takechi Ryusuke , Galloway Susan , Pallebage‐Gamarallage Menuka M , Lam Virginie , Dhaliwal Satvinder S , Mamo John C 
Published: November 2012

Summary

Dysfunction of the blood–brain barrier (BBB) is an early pathological feature of vascular dementia and Alzheimer's disease (AD) and is triggered by inflammatory stimuli. Probucol is a lipid‐lowering agent with potent anti‐oxidant properties once commonly used for the treatment of cardiovascular disease. Probucol therapy was found to stabilize cognitive symptoms in elderly AD patients, whereas in amyloid transgenic mice probucol was shown to attenuate amyloidosis. However, the mechanisms underlying the effects of probucol have note been determined.

In the present study we investigated whether probucol can prevent BBB disturbances induced by chronic ingestion of proinflammatory diets enriched with either 20% (w/w) saturated fats (SFA) or 1% (w/w) cholesterol. Mice were fed the diets for 12 weeks before they were killed and BBB integrity was measured.

Mice maintained on either the SFA‐ or cholesterol‐supplemented diets were found to have a 30‐ and sevenfold greater likelihood of BBB dysfunction, respectively, as determined by the parenchymal extravasation of plasma‐derived immunoglobulins and endogenous lipoprotein enrichment with β‐amyloid. In contrast, mice fed the SFA‐ or cholesterol‐enriched diets that also contained 1% (w/w) probucol showed no evidence of BBB disturbance. The parenchymal expression of glial fibrillary acidic protein, a marker of cerebrovascular inflammation, was significantly greater in mice fed the SFA‐enriched diet. Plasma lipid, β‐amyloid and apolipoprotein B levels were not increased by feeding of the SFA‐ or cholesterol‐enriched diets. However, mice fed the SFA‐ or cholesterol‐enriched diets did exhibit increased plasma non‐esterified fatty acid levels that were not reduced by probucol.

The data suggest that probucol prevents disturbances of BBB induced by chronic ingestion of diets enriched in SFA or cholesterol by suppressing inflammatory pathways rather than by modulating plasma lipid homeostasis.
Reward for Bdellovibrio bacteriovorus for preying on a polyhydroxyalkanoate producer
Authors: Martínez Virginia , Jurkevitch Edouard , García José Luis , Prieto María Auxiliadora 
Published: November 2012

SummaryBdellovibrio bacteriovorus HD100 is an obligate predator that invades and grows within the periplasm of Gram‐negative bacteria, including mcl‐polyhydroxyalkanoate (PHA) producers such as Pseudomonas putida. We investigated the impact of prey PHA content on the predator fitness and the potential advantages for preying on a PHA producer. Using a new procedure to control P. putida KT2442 cell size we demonstrated that the number of Bdellovibrio progeny depends on the prey biomass and not on the viable prey cell number or PHA content. The presence of mcl‐PHA hydrolysed products in the culture supernatant after predation on P. putida KT42Z, a PHA producing strain lacking PhaZ depolymerase, confirmed the ability of Bdellovibrio to degrade the prey's PHA. Predator motility was higher when growing on PHA accumulating prey. External addition of PHA polymer (latex suspension) to Bdellovibrio preying on the PHA minus mutant P. putida KT42C1 restored predator movement, suggesting that PHA is a key prey component to sustain predator swimming speed. High velocities observed in Bdellovibrio preying on the PHA producing strain were correlated to high intracellular ATP levels of the predator. These effects brought Bdellovibrio fitness benefits as predation on PHA producers was more efficient than predation on non‐producing bacteria.
Vfm a new quorum sensing system controls the virulence of Dickeya dadantii
Authors: Nasser William , Dorel Corinne , Wawrzyniak Julien , Van Gijsegem Frédérique , Groleau Marie‐Christine , Déziel Eric , Reverchon Sylvie 
Published: November 2012

SummaryDickeya dadantii is a plant pathogen that secretes cell wall‐degrading enzymes (CWDE) that are responsible for soft‐rot symptoms. Virulence genes are expressed in a concerted manner and culminate when bacterial multiplication slows. We identify a 25 kb vfm cluster required for D. dadantii CWDE production and pathogenesis. The vfm cluster encodes proteins displaying similarities both with enzymes involved in amino acid activation and with enzymes involved in fatty acid biosynthesis. These similarities suggest that the vfm genes direct the production of a metabolite. Cell‐free supernatant from the D. dadantii wild‐type strain restores CWDE production in vfm mutants. Collectively, our results indicate that vfm genes direct the synthesis of an extracellular signal and constitute a new quorum sensing system. Perception of the signal is achieved by the two‐component system VfmH–VfmI, which activates the expression of the vfmE gene encoding an AraC regulator. VfmE then activates both the transcription of the CWDE genes and the expression of the vfm operons. The vfm gene cluster does not seem to be widespread among bacterial species but is conserved in other Dickeya species and could have been laterally transferred to Rahnella. This work highlights that entirely new families of bacterial languages remain to be discovered.
Endoscopic papillary large‐balloon dilation following limited sphincterotomy for the removal of refractory bile duct stones: Experience of 169 cases in a single Chinese center
Authors: Yang Xiao Ming , Hu Bing , Pan Ya Min , Gao Dao Jian , Wang Tian Tian , Wu Jun , Ye Xin 
Published: November 2012

ObjectiveTo evaluate the efficacy and safety of endoscopic papillary large‐balloon dilation (EPLBD) combined with limited endoscopic sphincterotomy (EST) for the removal of large biliary duct stones (≥10 mm).MethodsData of patients who underwent an attempted removal of large bile duct stones by limited EST followed by EPLBD (≥12 mm in diameter) from April 2006 to October 2011 in our center were reviewed. Clinical characteristics, endoscopic methods and outcomes of the patients were collected and analyzed.ResultsA total of 169 patients with a mean age of 69.3 years (range 19–97 years) underwent 171 procedures. Median stone size and balloon diameter was 15 mm and 13 mm, respectively. Complete stone removal in a single session was achieved in 163 procedures (95.3%) with mechanical lithotripsy (ML) used in 66 (38.6%). Patients with a larger stone size required more frequent use of ML with a comparable success rate (P < 0.01). There were no significant differences between patients with and without periampullary diverticula in stone clearance (97.3% vs 93.8%), ML requirement (36.5% vs 40.2%) and complications (2.7% vs 6.2%) (all P > 0.05). Seven patients had eight procedure‐related complications including moderate or mild bleeding (n = 4), minor perforation (n = 1), mild pancreatitis (n = 2) and cholangitis (n = 1).ConclusionEPLBD following limited EST is an effective and safe approach for the removal of large biliary duct stones, especially for those refractory cases.
Improving rigour and efficiency of use‐availability habitat selection analyses with systematic estimation of availability
Authors: Benson John F. 
Published: November 2012

Summary

Animal habitat selection analyses often rely on comparisons of habitat use and availability to infer selection. Random locations are commonly used to assess availability despite inefficiency and potential uncertainty associated with random sampling. Herein, I propose a systematic approach to estimate habitat availability to reduce sampling error and computing time associated with GIS‐based estimation of habitat availability using random locations.

I used Euclidean distance analysis (EDA) as a model technique to demonstrate the sensitivity of use‐availability analyses to insufficient random sampling and to evaluate the proposed systematic approach. I re‐analysed data from a previous study of habitat selection of Florida panthers (Puma concolor coryi) and compared results of analyses in which distance‐based habitat availability (i.e. expected distance) was estimated with a range in sample sizes of random locations, and also systematically.

My results demonstrate that expected distances and statistical results of EDA based on random sampling can be unreliable with low and arbitrary numbers of random points, vary if increasing numbers of points are used, and approach results obtained systematically at greater numbers of points (i.e. with sufficient sampling).

The systematic approach efficiently measures habitat availability by making calculations from all possible locations, at a specified resolution, across the scale of interest. Thus, it eliminates uncertainty due to sampling error and is considerably faster. The systematic approach improves rigour and efficiency of animal habitat selection analyses that rely on comparisons of habitat use and availability and ensures repeatability of results for practical and theoretical applications.
Intensive buffering can keep pH above 7.2 for over 4 h during apnea: an experimental porcine study
Authors: HÖSTMAN S. , ENGSTRÖM J. , HEDENSTIERNA G. , LARSSON A. 
Published: November 2012

BackgroundVentilation with low tidal volumes reduces mortality in acute respiratory distress syndrome. A further reduction of tidal volumes might be beneficial, and it is known that apneic oxygenation (no tidal volumes) with arteriovenous CO2 removal can keep acid‐base balance and oxygenation normal for at least 7 h in an acute lung injury model. We hypothesized that adequate buffering might be another approach and tested whether tris‐hydroxymethyl aminomethane (THAM) alone could keep pH at a physiological level during apneic oxygenation for 4 h.MethodsSix pigs were anesthetized, muscle relaxed, and normoventilated. The lungs were recruited, and apneic oxygenation as well as administration of THAM, 20 mmol/kg/h, was initiated. The experiment ended after 270 min, except one that was studied for 6 h.ResultsTwo animals died before the end of the experiment. Arterial pH and arterial carbon dioxide tension (PaCO2) changed from 7.5 (7.5, 7.5) to 7.3 (7.2, 7.3) kPa, P < 0.001 at 270 min, and from 4.5 (4.3, 4.7) to 25 (22, 28) kPa, P < 0.001, respectively. Base excess increased from 5 (3, 6) to 54 (51, 57) mM, P < 0.001. Cardiac output and arterial pressure were well maintained. The pig, which was studied for 6 h, had pH 7.27 and PaCO2 27 kPa at that time.ConclusionWith intensive buffering using THAM, pH can be kept in a physiologically acceptable range for 4 h during apnea.
Vital dysfunctions after intensive care discharge: prevalence and impact on patient outcome
Authors: TIRKKONEN J. , OLKKOLA K. T. , HUHTALA H. , TENHUNEN J. , HOPPU S. 
Published: November 2012

BackgroundPatients discharged from the intensive care unit (ICU) are at increased risk for serious adverse events (SAEs). Recording vital functions and comprehending the consequences of altered vitals on general wards may be suboptimal. This potentially endangers recovery after successful intensive care. We aimed to determine the prevalence of vital dysfunctions after ICU discharge and their effect on patient outcome.MethodsA prospective observational study. Adult patients discharged from a tertiary referral hospital ICU to general wards without treatment limitations were visited 24 h afterwards; their vitals were measured and reported to ward staff. Attending ward nurse responsible for patient was interviewed.ResultsThe cohort consisted of 184 patients who had survived the first 24 h on the ward without complications (age: 57 ± 16 years; male: 68%). The prevalence of objectively measured vital dysfunctions was 15%, and the attending nurse had been unusually concerned about the patient in 19% of cases. Of the 184 patients, 9.8% subsequently suffered an SAE. In a multivariate logistic regression model, only vital dysfunctions (odds ratio 3.79; 95% confidence interval 1.18–12.2) and nurse concern (3.63; 1.17–11.3) were independently associated with an increased incidence of SAE. Medical emergency team (MET) assistance was never considered necessary by ward staff. Sensitivity of observed altered vitals on SAEs was 50% and specificity 89%. Sensitivity of nurse concern was 26%, specificity 84%.ConclusionsSimple vital function measurement and attending ward nurse's subjective assessment facilitate early detection of post‐ICU patients at risk. The threshold in seeking assistance through MET remains high.
PaO2 oscillations caused by cyclic alveolar recruitment can be monitored in pig buccal mucosa microcirculation
Authors: KLEIN K. U. , HARTMANN E. K. , BOEHME S. , SZCZYRBA M. , HEYLEN L. , LIU T. , DAVID M. , WERNER C. , MARKSTALLER K. , ENGELHARD K. 
Published: November 2012

BackgroundCyclic alveolar recruitment and derecruitment play a role in the pathomechanism of acute lung injury and may lead to arterial partial pressure of oxygen (PaO2) oscillations within the respiratory cycle. It remains unknown, however, if these PaO2 oscillations are transmitted to the microcirculation. The present study investigates if PaO2 oscillations can be detected in the pig buccal mucosa microcirculation.MethodsRespiratory failure was induced by surfactant depletion in seven pigs. PaO2 oscillations caused by cyclic recruitment and derecruitment were measured in the thoracic aorta by fast fluorescence quenching of oxygen technology. Haemoglobin oxygen saturation, haemoglobin amount and blood flow in the buccal mucosa microcirculation were determined by combined fast white light spectrometry and laser Doppler flowmetry additionally to systolic arterial pressure. Measurements were performed during baseline conditions and during cyclic recruitment and derecruitment.ResultsMeasurements remained stable during baseline. Respiratory‐dependent oscillations occurred in the systemic circulation [PaO2 oscillations 92 (69–172) mmHg; systolic arterial pressure oscillations 33 (13–35) %] and were related to the respiratory rate (5.0 ± 0.2/min) as confirmed by Fourier analysis. Synchronised oscillations were detected to the pig buccal mucosa microcirculation [haemoglobin oxygen saturation oscillations 3.4 (2.7–4.9) %; haemoglobin amount oscillations 8.5 (2.3–13.3) %; blood flow oscillations 66 (18–87) %]. The delay between PaO2‐\ and microcirculatory oxygen oscillations was 7.2 ± 2.8 s.ConclusionThe present study suggests that PaO2 oscillations caused by cyclic recruitment and derecruitment were transmitted to the buccal mucosa microcirculation. This non‐invasive approach of measuring oxygen waves as a surrogate parameter of cyclic recruitment and derecruitment could be used to monitor PaO2 oscillations at the bedside.
Phasic transition from goal‐directed to habitual control over drug‐seeking produced by conflicting reinforcer expectancy
Authors: Hogarth Lee , Field Matt , Rose Abigail K. 
Published: November 2012

AbstractThe transition from goal‐directed to habitual control over drug‐seeking has been experimentally demonstrated in animals, but there have been no comparable reports in humans. Following a recent animal design, the current study employed an outcome‐devaluation procedure to test whether goal‐directed control over tobacco seeking would be abolished by alcohol expectancy. Eighty smokers first learned that two responses earned tobacco or chocolate points, respectively, before tobacco was devalued by health warnings and smoking satiety. Participants were then presented with either a glass of beer/wine or water with instructions that this item could be consumed after the task (alternative reward). Then choice between the tobacco and chocolate response was measured in extinction to assess goal‐directed control of tobacco seeking, in a nominal Pavlovian to instrumental transfer (PIT) test to assess stimulus control of tobacco seeking, and in a reacquisition test to assess the impact of direct feedback from the outcomes. The results showed that alcohol expectancy selectively abolished goal‐directed control of tobacco seeking but not stimulus control or the impact of feedback from outcomes. These data suggest that ‘endogenous’ retrieval of low drug value governing goal‐directed regulation of drug seeking is disrupted by conflicting appraisal of an alternative reinforcer, promoting habitual control, which may play a role in relapse.