bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Pincer Complexes as Catalysts for Amine Borane Dehydrogenation
Authors: St. John Anthony , Goldberg Karen I. , Heinekey D. Michael
Published: March 2013

Review: 44 refs.
ChemInform Abstract: A Review of RedOx Cycling of Solid Oxide Fuel Cells Anode
Authors: Faes Antonin , Hessler‐Wyser Aicha , Zryd Amedee , Van Herle Jan
Published: March 2013

Review: 267 refs.
Relation Between Time of Symptom Onset of ST‐Segment Elevation Myocardial Infarction and Patient Baseline Characteristics: From the National Cardiovascular Data Registry
Authors: Mogabgab Owen , Wiviott Stephen D. , Antman Elliot M. , Foody Joanne M. , Wang Tracy Y. , Sabatine Marc S. , Cannon Christopher P. , Li Shuang , Giugliano Robert P.
Published: March 2013

Background

The presence of a morning excess of ST‐segment elevation myocardial infarction (STEMI) has been observed. The relation between patient characteristics and timing of STEMI may provide insight into the biological processes responsible for this phenomenon.

Hypothesis

Patient baseline characteristics will vary with timing of STEMI.

Methods

We performed an analysis using a large national registry of unselected patients with STEMI (N = 45 218). Patients were categorized by time of symptom onset: early (6 am–2 pm), late day (2 pm–10 pm), and overnight (10 pm–6 am) then evaluated for variations in characteristics.

Results

A circadian variation in the timing of symptom onset of STEMI was observed (early 41%, late day 32%, and overnight 26%, P < 0.001). Circadian variations in factors known to alter timing of events were seen, including lower rates of home β‐blocker use, smoking, and diabetes, with early onset of STEMI symptoms. In addition, patients in the 6 am to 2 pm subgroup were more likely older, white race, and male, with higher rates of home aspirin use and lower rates of obesity. Higher rates of coexisting cardiovascular disease, including prior heart failure, 3‐vessel coronary artery disease, and depressed left ventricular ejection fraction, were observed in the overnight group. More robust antiplatelet therapy with home clopidogrel use was not associated with a change in the timing of events.

Conclusions

A morning excess of STEMI continues to exist and represents a potential target for preventative strategies. Patient baseline characteristics vary with the onset of STEMI and may reflect a physiologic relationship between these factors and the timing of events.
Library Construction and Biological Evaluation of Enmein‐Type Diterpenoid Analogues as Potential Anticancer Agents
Authors: Li Dahong , Xu Shengtao , Cai Hao , Pei Lingling , Wang Lei , Wu Xiaoming , Yao Hequan , Jiang Jieyun , Sun Yijun , Xu Jinyi
Published: March 2013

A library of promising enmein‐type 14‐O‐diterpenoid derivatives was constructed from a commercially available kaurene‐type oridonin by practical and efficient synthetic methods. These synthetic derivatives were evaluated for their antiproliferative activities against a set of four human cancer cell lines. The IC50 values are similar to or improved over those of the parent molecule and paclitaxel, the latter of which was used as a positive control. Compound 29 was further investigated for its apoptotic properties against human hepatocarcinoma Bel‐7402 cells to better understand its mode of action. Moreover, compound 29 was shown to have potent antitumor activity in vivo in studies with a murine model of gastric cancer (MGC‐803 mice). These results warrant further preclinical investigations of these diterpenoid‐based analogues as potential novel anticancer chemotherapeutics.
Unique hues and their stimuli—state of the art
Authors: Kuehni Rolf G.
Published: March 2013

The relationship between the information the visual system gathers at its interface with the outside world and the perceptual reality of four primary hues and the resulting hue circle has been and remains of interest since the second half of the 19th century. Considerable effort has been expended over many decades in determining statistical mean choices of color stimuli that for individuals represent unique hues in given conditions of viewing. In this article, historical and recent data are used to show the present state of knowledge. To have a means of comparison, in this article spectral and display unit stimuli are converted to Munsell hues on basis of dominant or complementary wavelengths of highest chroma data. Relatively good agreement was found between spectral and color sample data, with display data being significantly different in case of unique green. The issue of significant interobserver variability found in all data and its implications are highlighted. Problems with generating simple psychophysical models, particularly related to unique red, are discussed and a brief survey of the current knowledge on neural processing that may lead to unique hue perception is presented. Data still required for a meaningful definition of mean unique hue stimulus data are listed. © 2013 Wiley Periodicals, Inc. Col Res Appl, 39, 279–287, 2014; Published Online 20 March 2013 in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/col.21793
Simulating Pump–Probe Photoelectron and Absorption Spectroscopy on the Attosecond Timescale with Time‐Dependent Density Functional Theory
Authors: De Giovannini Umberto , Brunetto Gustavo , Castro Alberto , Walkenhorst Jessica , Rubio Angel
Published: March 2013

Molecular absorption and photoelectron spectra can be efficiently predicted with real‐time time‐dependent density functional theory. We show herein how these techniques can be easily extended to study time‐resolved pump–probe experiments, in which a system response (absorption or electron emission) to a probe pulse is measured in an excited state. This simulation tool helps with the interpretation of fast‐evolving attosecond time‐resolved spectroscopic experiments, in which electronic motion must be followed at its natural timescale. We show how the extra degrees of freedom (pump‐pulse duration, intensity, frequency, and time delay), which are absent in a conventional steady‐state experiment, provide additional information about electronic structure and dynamics that improve characterization of a system. As an extension of this approach, time‐dependent 2D spectroscopy can also be simulated, in principle, for large‐scale structures and extended systems.
Angle‐Resolved Strong‐Field Ionization of Polyatomic Molecules: More than the Orbitals Matters
Authors: Njoya Oumarou , Matsika Spiridoula , Weinacht Thomas
Published: March 2013

We compare the time‐ and angle‐dependent strong‐field ionization yields of three molecules with very similar electronic structure. A pump pulse in the deep ultraviolet excites 1,3‐cyclohexadiene, α‐terpinene, and α‐phellandrene to their first excited state. The latter two molecules are alkyl‐substituted 1,3‐cyclohexadiene systems. We then measure the strong‐field ionization yield due to a near infrared probe pulse as a function of delay and angle between pump and probe polarization vectors. Ab initio electronic structure calculations allow us to associate the parent ion yields with removal of an electron from a LUMO orbital (occupied after excitation by the pump). Despite the fact that the LUMO orbitals for these molecules are very similar, the angle‐dependent yields are very different, indicating that it is not the orbital shape alone which determines angle‐dependent ionization yields.
A cross‐layer optimization for maximum‐revenue‐based multicast in multichannel multiradio wireless mesh networks
Authors: Yang Wen‐Lin , Hong Wan‐Ting
Published: March 2013

Given a video/audio streaming system installed on a multichannel multiradio wireless mesh network, we are interested in a problem concerning about how to construct a delay‐constrained multicast tree to support concurrent interference‐free transmissions so that the number of serviced mesh clients is maximized. In this paper, we propose a heuristic approach called cross‐layer and load‐oriented (CLLO) algorithm for the problem. On the basis of the cross‐layer design paradigm, our CLLO algorithm can consider application demands, multicast routing, and channel assignment jointly during the formation of a channel‐allocated multicast tree. The experimental results show that the proposed CLLO outperforms the layered approaches in terms of the number of serviced mesh clients and throughputs. This superiority is due to information from higher layers can be used to guide routing selection and channel allocation at the same time. As a result, the CLLO algorithm can explore more solution spaces than the traditional layered approaches. In addition to that, we also propose a channel adjusting procedure to enhance the quality of channel‐allocated multicast trees. According to our simulations, it is proved to be an effective method for improving the performance of the proposed CLLO algorithm. Copyright © 2013 John Wiley & Sons, Ltd.
Genetic evidence for male‐biased dispersal in theQinghai toad‐headed agamidPhrynocephalus vlangaliiand its potential link to individual social interactions
Authors: Qi Yin , Yang Weizhao , Lu Bin , Fu Jinzhong
Published: March 2013

Sex‐biased dispersal has profound impacts on a species' biology and several factors have been attributed to its evolution, including mating system, inbreeding avoidance, and social complexity. Sex‐biased dispersal and its potential link to individual social interactions were examined in theQinghai toad‐headed agamid (Phrynocephalus vlangalii). We first determined the pattern of sex‐biased dispersal using population genetic methods. A total of 345 specimens from 32 sites in theQaidamBasin were collected and genotyped for nine microsatelliteDNAloci. Both individual‐based assignment tests and allele frequency‐based analyses were conducted. Females revealed much more genetic structure than males and all results were consistent with male‐biased dispersal. First‐generation migrants were also identified by genetic data. We then examined eight social interaction‐related morphological traits and explored their potential link to sex‐biased dispersal. Female residents had larger heads and longer tails than female migrants. The well‐developed signal system among females, coupled with viviparity, might make remaining on natal sites beneficial, and hence promote female philopatry. Dominant females with larger heads were more likely to stay. Contrary to females, male migrants had larger heads and belly patches than residents, suggesting that dispersal might confer selective advantages for males. Such advantages may include opportunities for multiple mating and escaping from crowded sites. Large belly patches and several other morphological traits may assist their success in obtaining mates during dispersal. Furthermore, a relatively high relatedness (R = 0.06) among females suggested that this species might have rudimentary social structure. Case studies in “less” social species may provide important evidence for a better understanding of sex‐biased dispersal.
Mate choice for genetic compatibility in the house mouse
Authors: Lindholm Anna K. , Musolf Kerstin , Weidt Andrea , König Barbara
Published: March 2013

In house mice, genetic compatibility is influenced by the t haplotype, a driving selfish genetic element with a recessive lethal allele, imposing fundamental costs on mate choice decisions. Here, we evaluate the cost of genetic incompatibility and its implication for mate choice in a wild house mice population. In laboratory reared mice, we detected no fertility (number of embryos) or fecundity (ability to conceive) costs of the t, and yet we found a high cost of genetic incompatibility: heterozygote crosses produced 40% smaller birth litter sizes because of prenatal mortality. Surprisingly, transmission of t in crosses using +/t males was influenced by female genotype, consistent with postcopulatory female choice for + sperm in +/t females. Analysis of paternity patterns in a wild population of house mice showed that +/t females were more likely than +/+ females to have offspring sired by +/+ males, and unlike +/+ females, paternity of their offspring was not influenced by +/t male frequency, further supporting mate choice for genetic compatibility. As the major histocompatibility complex (MHC) is physically linked to the t, we investigated whether females could potentially use variation at the MHC to identify male genotype at the sperm or individual level. A unique MHC haplotype is linked to the t haplotype. This MHC haplotype could allow the recognition of t and enable pre‐ and postcopulatory mate choice for genetic compatibility. Alternatively, the MHC itself could be the target of mate choice for genetic compatibility. We predict that mate choice for genetic compatibility will be difficult to find in many systems, as only weak fertilization biases were found despite an exceptionally high cost of genetic incompatibility.
Ecohydrological analysis of Steelhead (Oncorhynchus mykiss) habitat in an effluent dependent stream in the Pacific Northwest, USA
Authors: Sánchez‐Murillo R. , Brooks E.S. , Sampson L. , Boll J. , Wilhelm F.
Published: March 2013

A conundrum exists in the US Pacific Northwest (PNW) whereby increasingly stringent federal environmental regulations governing the discharge of nutrients from wastewater treatment plants (WWTP) to low order streams may negatively impact salmonid species listed under the US Endangered Species Act (ESA). We examined baseflow, water chemistry, benthic algal biomass, macroinvertebrate diversity, and steelhead in the West Fork Little Bear Creek (WFLBC), Idaho, USA, above and below the city of Troy WWTP to explain why this creek is the most productive juvenile steelhead stream in the Potlatch River drainage. Discharge from the WWTP maintained 6 km of perennial flow during summer. Dissolved oxygen (DO) levels indicate that nitrification depressed DO below the Idaho state standard of 6 mg/L within the first 200 m downstream of the discharge. Because of rapid re‐aeration, DO concentrations recovered by 1.3 km. Despite high nitrate (0.12 – 4.3 mg/L) and total phosphorus (0.11 – 0.60 mg/L) concentrations 2.5 km downstream, benthic algal biomass remained below the US Environmental Protection Agency's ‘nuisance algae’ level (i.e., 150 mg/m2) throughout the stream. Family biotic index indicated good water quality conditions above and 2.5 km downstream of the discharge, although fairly poor condictions were found 200 m downstream from the effluent. The WFLBC ecosystem appears to have the capacity to accept and actually benefit from high nutrient loads from a WWTP. This work emphasizes the importance of developing a thorough understanding of the site‐specific biochemical functioning of an ecosystem before selecting and applying standard management practices. Copyright © 2013 John Wiley & Sons, Ltd.
Riparian evapotranspiration modelling: model description and implementation for predicting vegetation spatial distribution in semi‐arid environments
Authors: García‐Arias A. , Francés F. , Morales‐de la Cruz M. , Real J. , Vallés‐Morán F. , Garófano‐Gómez V. , Martínez‐Capel F.
Published: March 2013

Biotic and abiotic interactions between the riparian zone and the river determine relevant hydrological processes and exert control over riparian and bordering upland vegetation types. Vegetation growth and development are mainly controlled by water availability on semi‐arid regions, where a moisture gradient determines the transition between the densely vegetated riparian zone and the semi‐arid upland. To reproduce this spatial distribution, a mathematical model named RibAV is presented. Its conceptualization is based on the main ecohydrological modelling approaches and field expertise. The implementation of RibAV that is proposed in this paper allows the simulation of the distribution of three plant functional types [herbaceous riparian vegetation (HRV), woody riparian vegetation (WRV) and terrestrial vegetation (TV)] within the riparian zone. An evapotranspiration index (Eidx) obtained through RibAV is used as a criterion for plant absence/presence prediction. Two permanent river reaches of semi‐arid Mediterranean basins, the Terde reach (Mijares River, Spain) and the Lorcha reach (Serpis River, Spain), have been selected as case studies for the calibration and validation of the model, respectively. Several criteria based on the confusion matrix were used to analyse the efficiency of RibAV on the prediction of plant distribution. The satisfactory performance of the model establishing the distribution of the riparian vegetation types and the limit between this zone and the bordering upland are demonstrated in this paper; the strength of the Eidx to classify plant functional types in riparian semi‐arid environments is additionally proven. Copyright © 2013 John Wiley & Sons, Ltd.
Pathophysiological hypoxia affects the redox state and IL‐2 signalling of human CD4+ T cells and concomitantly impairs survival and proliferation
Authors: Gaber Timo , Tran Cam Loan , Schellmann Saskia , Hahne Martin , Strehl Cindy , Hoff Paula , Radbruch Andreas , Burmester Gerd‐Rüdiger , Buttgereit Frank
Published: March 2013

Inflamed areas are characterized by infiltration of immune cells, local hypoxia and alterations of cellular redox states. We investigated the impact of hypoxia on survival, proliferation, cytokine secretion, intracellular energy and redox state of human CD4+ T cells. We found that pathophysiological hypoxia (<2% O2) significantly decreased CD4+ T‐cell survival after mitogenic stimulation. This effect was not due to an increased caspase‐3/7‐mediated apoptosis or adenosine‐5′‐triphosphate (ATP) consumption/depletion. However, the ability of stimulated T cells to proliferate was reduced under hypoxic conditions, despite increased expression of CD25. Pathophysiological hypoxia was also found to modify intracellular ROS (iROS) levels in stimulated T cells over time as compared with levels found in normoxia. Physiological hypoxia (5% O2) did not decrease CD4+ T‐cell survival and proliferation or modify iROS levels as compared with normoxia. We conclude that pathophysiological hypoxia affects T‐cell proliferation and viability via disturbed IL‐2R signalling downstream of STAT5a phosphorylation, but not as a result of impaired cellular energy homeostasis. We suggest iROS links early events in T‐cell stimulation to the inhibition of the lymphoproliferative response under pathophysiological hypoxic conditions. The level of iROS may therefore act as a mediator of immune functions leading to down‐regulation of long‐term T‐cell activity in inflamed tissues.
Optimization and validation of a capillary electrophoresis laser‐induced fluorescence method for amino acids determination in human plasma: Application to bipolar disorder study
Authors: Lorenzo Ma Paz , Villaseñor Alma , Ramamoorthy Anuradha , Garcia Antonia
Published: March 2013

Quantitative and qualitative analysis of amino acids in biofluids offers relevant information in diagnosis of diseases, evaluation of nutritional state, and in elucidating metabolic influences on physiology. A simple, rapid, and robust procedure in terms of sample treatment, separation, and quantitation based on CE‐LIF has been optimized for use in human plasma samples. Time required for derivatization was 15 min and analysis time was 35 min. 4‐Fluoro‐7‐nitro‐2,1,3‐benzoxadiazole (NBD‐F) was the labeling agent used for obtaining fluorescent derivatives. Electrophoretic conditions were: 175 mM borate buffer at pH 10.25 prepared with 12.5 mM β‐cyclodextrin. The voltage applied was +21 kV. Fourteen amino acids could be quantified: l‐proline, l‐phenylalanine, l‐leucine, l‐isoleucine, l‐ornithine, d‐ornithine, l‐glutamine, l‐alanine, l‐threonine, glycine, l‐serine, d‐serine, taurine and l‐glutamate. With this chiral CE‐LIF method, l‐ and d‐amino acids are adequately separated. The method was validated for a representative group of amino acids in human plasma: l‐proline, l‐isoleucine, l‐ornithine, l‐glutamine, l‐alanine l‐threonine, glycine, l‐serine, d‐serine, and glutamate. The method has been successfully applied to human plasma from patients with bipolar disorder, all of whom were taking lithium as a mood stabilizer. Eleven amino acids were quantified in plasma from nine patients, aged 24–55 years. The results were in accordance to published values for the bipolar patients. The method is useful particularly in studies where plasma amino acid levels can be used as biomarkers for diagnosis of diseases, evaluating the disease progression, and monitoring response to drug therapy.
Detection of cerebral spinal fluid‐associated chemokines in birth traumatized premature babies by chip‐based immunoaffinity CE
Authors: Phillips Terry M. , Wellner Edward
Published: March 2013

A major concern in treating premature infants with birth‐associated head trauma is the rapid determination of reliable biomarkers of neuroinflammation. To this end a chip‐based immunoaffinity CE device has been applied to determine the concentrations of inflammation‐associated chemokines in samples of cerebral spinal fluid collected from such subjects. The chip utilizes replaceable immunoaffinity disks, to which reactive antibody fragments (FAb) of six antichemokine‐specific antibodies were immobilized. Following injection of a sample into the device, the analytes were captured by the immobilized FAbs, labeled in situ with a red laser dye, chemically released and separated by CE. Each resolved peak was measured on‐line by LIF detection and the results compared to standard curves produced by running known chemokine standards through the immunoaffinity system. The complete processing of a sample took 10 min with separation of all six analytes being achieved in less than 2 min. The system compared well to commercial ELISA, analysis of the results by linear regression demonstrating r2 values in the range of 0.903–0.978, and intra and interassay CV of the migration times and the measured peak areas being less than 2.3 and 5%, respectively. Application of the system to analysis of cerebrospinal fluid from head traumatized babies clearly indicated the group with mild trauma versus those with severe injury. Additionally, CE analysis demonstrated that the severe trauma group could be divided into individuals with good and poor prognosis, which correlated with the clinical finding for each patient.
Available energy assessment software
Authors: Shandilya Kaushik K. , Kumar Ashok
Published: March 2013

This article presents a summary of the available software for performing various aspects of energy assessments based on a review of the web and the literature. The software tools are broadly classified in four areas: residential building simulation software, regulatory application software, heating, ventilation and air conditioning related software, and life cycle/cost analysis software. The study found that the software development is moving at a rapid pace to meet the growing demand for reducing energy consumption. © 2013 American Institute of Chemical Engineers Environ Prog, 32: 170‐175, 2013
Evidence for fluid‐triggered slip in the 2009 Mount Rainier, Washington earthquake swarm
Authors: Shelly David R. , Moran Seth C. , Thelen Weston A.
Published: March 2013

A vigorous swarm of over 1000 small, shallow earthquakes occurred 20–22 September 2009 beneath Mount Rainier, Washington, including the largest number of events ever recorded in a single day at Rainier since seismic stations were installed on the edifice in 1989. Many events were only clearly recorded on one or two stations on the edifice, or they overlapped in time with other events, and thus only ~200 were locatable by manual phase picking. To partially overcome this limitation, we applied waveform‐based event detection integrated with precise double‐difference relative relocation. With this procedure, detection and location goals are accomplished in tandem, using cross‐correlation with continuous seismic data and waveform templates constructed from cataloged events. As a result, we obtained precise locations for 726 events, an improvement of almost a factor of 4. These event locations define a ~850 m long nearly vertical structure striking NNE, with episodic migration outward from the initial hypocenters. The activity front propagates in a manner consistent with a diffusional process. Double‐couple‐constrained focal mechanisms suggest dominantly near‐vertical strike‐slip motion on either NNW or ENE striking faults, more than 30° different than the strike of the event locations. This suggests the possibility of en echelon faulting, perhaps with a component of fault opening in a fracture‐mesh‐type geometry. We hypothesize that the swarm was initiated by a sudden release of high‐pressure fluid into preexisting fractures, with subsequent activity triggered by diffusing fluid pressure in combination with stress transfer from the preceding events.
Thermal structure and megathrust seismogenic potential of the Makran subduction zone
Authors: Smith Gemma L. , McNeill Lisa C. , Wang Kelin , He Jiangheng , Henstock Timothy J.
Published: March 2013

The Makran subduction zone experienced a tsunamigenic Mw 8.1 earthquake in 1945 and recent, smaller earthquakes also suggest seismicity on the megathrust; however, its historical record is limited and hazard potential enigmatic. We have developed a 2‐D thermal model of the subduction zone. The results are twofold: (1) The thick sediment cover on the incoming plate leads to high (~150°) plate boundary temperatures at the deformation front making the megathrust potentially seismogenic to a shallow depth, and (2) the shallow dip of the subducting plate leads to a wide potential seismogenic zone (up to ~350 km). Combining these results with along strike rupture scenarios indicates that Mw8.7–9.2 earthquakes are possible in the seaward Makran subduction zone. These results have important earthquake and tsunami hazard implications, particularly for the adjacent coastlines of Pakistan, Iran, Oman, and India, as the Makran has not been previously considered a likely candidate for a Mw > 9 earthquake.
Recent Voyager 1 data indicate that on 25 August 2012 at a distance of 121.7 AU from the Sun, sudden and unprecedented intensity changes were observed in anomalous and galactic cosmic rays
Authors: Webber W. R. , McDonald F. B.
Published: March 2013

At the Voyager 1 (V1) spacecraft in the outer heliosphere, the intensities of both anomalous cosmic rays and galactic cosmic rays (GCRs) changed suddenly and decisively on 25 August (121.7 AU from the Sun). Within a matter of a few days, the intensity of 1.9–2.7 MeV protons and helium nuclei had decreased to less than 0.1 of their previous value, and eventually the intensities decreased by factors of at least 300–500. Also, on 25 August, the GCR protons, helium, and electrons increased suddenly in just 2 or 3 days by a factor of up to 2. The intensities of the GCR nuclei of all energies from 2 to 400 MeV then remained essentially constant with intensity levels and spectra that may represent the local GCR. The suddenness of these intensity changes indicates that V1 has crossed a well‐defined boundary for energetic particles at this time possibly related to the heliopause.
Improving primary healthcare through accreditation: baseline assessment of readiness and challenges in lebanese context
Authors: El‐Jardali Fadi , Ammar Walid , Hemadeh Randa , Jamal Diana , Jaafar Maha
Published: March 2013

The quality of primary healthcare (PHC) has become of high importance. In 2009, the Lebanese Ministry of Public Health launched the PHC accreditation program to expand and improve quality across the continuum of care. This study will explore the readiness of PHC centers in Lebanon to implement the newly developed accreditation standards including challenges and required actions/strategies. Seventy‐two centers were sampled, and respondents were asked to complete a 65‐item questionnaire adapted from the national PHC accreditation standards and two open‐ended questions. Descriptive analysis was conducted to assess responses to each item. Thematic analysis was used to analyze open‐ended questions. Scale scores were considerably low, particularly for areas that relate to quality of service delivery. Most respondents (59.8%) indicated not having a strategic plan on the basis of community needs. Close to 70% of respondents indicated that they do not monitor and investigate trends in rates of sentinel events, near misses, and adverse events. Moreover, 76.2% indicated not having a system for incident and accident‐reporting, and only 22.3% reported using one. The PHC accreditation in Lebanon can potentially reform this essential health system component. Results provide insights for policymakers and managers to consider in their efforts to improve quality and performance of PHC centers in Lebanon. Copyright © 2013 John Wiley & Sons, Ltd.
Variation of stream temperature among mesoscale habitats within stream reaches: southern Appalachians
Authors: Lynsey Long S. , Rhett Jackson C.
Published: March 2013

Stream mesoscale habitats have systematic topographic relationships to hyporheic flow patterns, which may create predictable temperature variation between mesoscale habitat types. We investigated whether systematic differences in temperature metrics occurred between mesoscale habitats within reaches of small streams tributary to the upper Little Tennessee River, southern Appalachians. Surface water temperature was recorded over three or four mid‐summer days in four mesoscale habitat types: riffle, main riffle, pool and alcove in 44 stream segments (sites). Temperature metrics were calculated for each mesoscale habitat relative to the mean value of the metric over the stream: Δ maximum temperature, Δ average maximum temperature and Δ maximum daily variation and also for each site: standard deviation of the maximum temperature and average diurnal variation (ADV). Sites were categorized as fully or partially forested. Pool tailouts had statistically significantly lower Δ maximum temperature and Δ average maximum temperature than riffle tailouts in partially forested sites, although differences were small. This was the opposite of what was expected in the presence of hyporheic exchange, indicating hyporheic exchange is not a dominant driver of mesoscale habitat temperatures at these sites. Temperature differences between mesoscale habitat units were small and unlikely to have ecological significance. We also evaluated relationships between stream temperature and riparian condition, watershed % impervious surfaces, watershed % non‐forested and elevation. ADV and standard deviation of the maximum temperature were significantly higher in partially forested sites, indicating that partially forested sites have greater temperature ranges and spatial variation of maximum temperatures. ADV decreased with elevation and increased with % impervious surfaces. Copyright © 2013 John Wiley & Sons, Ltd.
Effect of projected changes in winter streamflow on stream turbidity, Esopus Creek watershed in New York, USA
Authors: Mukundan Rajith , Pierson Donald C. , Wang Lucien , Matonse Adao H. , Samal Nihar R. , Zion Mark S. , Schneiderman Elliot M.
Published: March 2013

This study focuses on the impact of changes in winter streamflow on in‐stream turbidity in the Esopus Creek watershed, one of the New York City water supply watersheds. Projected changes in daily precipitation and air temperature from a suite of five global climate models and three emission scenarios for future periods 2046–2065 and 2081–2100 were downscaled for the study region. The simulated climate scenarios were used to project future streamflows using the Generalized Watershed Loading Functions – Variable Source Area watershed model. Seasonal turbidity rating curves based on measured historical streamflow and stream turbidity were used in combination with the simulated streamflow for generating future stream turbidity scenarios. Results indicate an increase in future ambient stream turbidity from November to March and a decrease during April. These results are the effects of increased winter rainfall, reduced snowfall, and a shift to early timing of spring snowmelt runoff, causing an increase in streamflow during early winter. It also suggests a reduction in the traditional peak streamflow around April that is expected to occur in this region. As a result, our models simulate a consistent increase in the low to medium percentile range of turbidity values associated with low to medium range of streamflows and no apparent change in high‐percentile turbidity values associated with high streamflows. Our results may be applicable in regions where snowmelt runoff is an important process and turbidity caused by the suspension of fine clay particles is a water quality concern. Copyright © 2013 John Wiley & Sons, Ltd.
Fracture risk and height: An association partly accounted for by cortical porosity of relatively thinner cortices
Authors: Bjørnerem Åshild , Bui Quang Minh , Ghasem-Zadeh Ali , Hopper John L , Zebaze Roger , Seeman Ego
Published: March 2013

Taller women are at increased risk for fracture despite having wider bones that better tolerate bending. Because wider bones require less material to achieve a given bending strength, we hypothesized that taller women assemble bones with relatively thinner and more porous cortices because excavation of a larger medullary canal may be accompanied by excavation of more intracortical canals. Three-dimensional images of distal tibia, fibula, and radius were obtained in vivo using high-resolution peripheral quantitative computed tomography (HRpQCT) in a twin study of 345 females aged 40 to 61 years, 93 with at least one fracture. Cortical porosity <100 µm as well as >100 µm, and microarchitecture, were quantified using Strax1.0, a new algorithm. Multivariable linear and logistic regression using generalized estimating equation (GEE) methods quantified associations between height and microarchitecture and estimated the associations with fracture risk. Each standard deviation (SD) greater height was associated with a 0.69 SD larger tibia total cross-sectional area (CSA), 0.66 SD larger medullary CSA, 0.50 SD higher medullary CSA/total CSA (i.e., thinner cortices relative to the total CSA due to a proportionally larger medullary area), and 0.42 SD higher porosity (all p < 0.001). Cortical area was 0.45 SD larger in absolute terms but 0.50 SD smaller in relative terms. These observations were confirmed by examining trait correlations in twin pairs. Fracture risk was associated with height, total CSA, medullary CSA/total CSA, and porosity in univariate analyses. In multivariable analyses, distal tibia, medullary CSA/total CSA, and porosity predicted fracture independently; height was no longer significant. Each 1 SD greater porosity was associated with fracture; odds ratios (ORs) and 95% confidence intervals (CIs) are as follows: distal tibia, OR = 1.55 (95% CI, 1.11–2.15); distal fibula, OR = 1.47 (95% CI, 1.14–1.88); and distal radius, OR = 1.22 (95% CI, 0.96–1.55). Taller women assemble wider bones with relatively thinner and more porous cortices predisposing to fracture.
Suppressive effect of the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) on hepatitis C virus replication
Authors: Sato Ayami , Saito Yoshimasa , Sugiyama Kazuo , Sakasegawa Noriko , Muramatsu Toshihide , Fukuda Shinya , Yoneya Mikiko , Kimura Masaki , Ebinuma Hirotoshi , Hibi Toshifumi , Ikeda Masanori , Kato Nobuyuki , Saito Hidetsugu
Published: March 2013

The histone deacetylase (HDAC) inhibitor suberoylanilide hydroxamic acid (SAHA) has a clinical promise for treatment of cancer including hepatocellular carcinoma (HCC). To investigate effect of SAHA on hepatitis C virus (HCV) replication, we treated the HCV replicon cell OR6 with SAHA. HCV replication was significantly inhibited by SAHA at concentrations below 1 μM with no cellular toxicity. Another HDAC inhibitor, tricostatin A, also showed reduction of HCV replication. The microarray analysis and quantitative RT‐PCR demonstrated up‐regulation of osteopontin (OPN) and down‐regulation of apolipoprotein‐A1 (Apo‐A1) after SAHA treatment. Direct gene induction of OPN and knockdown of Apo‐A1 also showed reduction of HCV replication. The liver specific microRNA‐122, which is involved in HCV replication, was not affected by SAHA treatment. These results suggest that SAHA has suppressive effect on HCV replication through alterations of gene expression such as OPN and Apo‐A1 in host cells. Epigenetic treatment with HDAC inhibitors may be a novel therapeutic approach for diseases associated with HCV infection such as chronic hepatitis, liver cirrhosis, and HCC. J. Cell. Biochem. 114: 1987–1996, 2013. © 2013 Wiley Periodicals, Inc.
Sediment storage by vegetation in steep bedrock landscapes: Theory, experiments, and implications for postfire sediment yield
Authors: Lamb Michael P. , Levina Mariya , DiBiase Roman A. , Fuller Brian M.
Published: March 2013

Mechanistic models for sediment transport on hillslopes are needed for applications ranging from landscape evolution to debris‐flow hazards. Progress has been made for soil‐mantled landscapes; however, little is known about sediment production and transport in bedrock landscapes that often maintain a patchy soil mantle, even though slopes exceed the angle of repose. Herein we investigate the hypothesis that patchy soil cover is stable on steep slopes due to local roughness such as vegetation dams that trap sediment upslope. To quantify local sediment storage, we developed a new theory and tested it against tilt‐table experiments. Results show that trapped sediment volume scales with the cube of dam width. Where the dam width is less than about fifty grain diameters, particle force chains appear to enhance stability, resulting in greater trapped volumes and sediment‐pile slopes that exceed the angle of repose. Trapped volumes are greatest for hillslopes that just exceed the friction slope and are independent of hillslope gradient for gradients greater than about twice the friction slope. For neighboring dams spaced less than about five grain diameters apart, grain bridging results in a single sediment pile that is larger than the sum of individual piles. This work provides a mass‐conserving framework for quantifying sediment storage and nonlocal transport in bedrock landscapes. Results may explain the rapid increase in sediment yield following wildfire in steep terrain in the absence of rainfall; as sediment dams are incinerated, particles become gravitationally unstable and move rapidly downslope as dry ravel.
N‐cycling and balancing of the N‐deficit generated in the oxygen minimum zone over the Namibian shelf—An isotope‐based approach
Authors: Nagel Birgit , Emeis Kay‐Christian , Flohr Anita , Rixen Tim , Schlarbaum Tim , Mohrholz Volker , van der Plas Anja
Published: March 2013

The northern Benguela upwelling system is a nutrient‐replete region with high plankton biomass production and a seasonally changing oxygen minimum zone. Nitrate:phosphate ratios in fresh upwelling water are low due to denitrification in the near‐seafloor oxygen minimum zone and phosphate efflux from sediments. This makes the region a candidate for substantial dinitrogen fixation, for which evidence is scarce. Nutrient and oxygen data, N isotope data of nitrate, nitrogen isotope ratios of particulate matter, particulate organic carbon content, and suspended matter concentrations on a transect across the shelf and upper slope at 23°S illustrate N‐cycling processes and are the basis for estimating the contribution of N‐sources and N‐sinks to the reactive nitrogen pool. It appears that N‐removal due to denitrification exceeds N gain by N2 fixation and physical mixing processes by a factor of >6, although inorganic N:P ratios again increase as surface water is advected offshore. Nitrate and ammonium regeneration, nutrient assimilation with N:P < 16, shelf break mixing, atmospheric input, and N2 fixation all contribute to the restoration of inorganic N:P ratios back to Redfield conditions, but in seasonally changing proportions. The Benguela upwelling system thus is a nutrient source for the oceanic‐mixed layer where N‐sources and N‐sinks are not in balance and Redfield conditions can only re‐adjust by advection and mixing processes integrated over time.
Mixed electrolytes in hydrophobic interaction chromatography†
Authors: Müller Egbert , Vajda Judith , Josic Djuro , Schröder Tim , Dabre Romain , Frey Tim
Published: March 2013

An essential part of the modulation of protein‐binding capacity in hydrophobic interaction chromatography is the buffer‐salt system. Besides using “single” electrolytes, multicomponent electrolyte mixtures may be used as an additional tool. Both the protein solubility and the binding capacity depend on the position of a salt in the so‐called Hofmeister series. Specific interactions are observed for an individual protein‐salt combination. For salt mixtures, selectivity, recovery, and binding capacity do not behave like for the single salts that are positioned in between the two mixed components in the Hofmeister series, as the continuous correlation would suggest. Thus, finding strategies for mixed salts could potentially lead to improved capacities in hydrophobic interaction chromatography. Mixtures of ammonium sulfate, sodium citrate, sodium sulfate, sodium chloride, sodium acetate, and glycine were used to investigate the binding capacities for lysozyme and a monoclonal antibody on various hydrophobic resins. Resin capacity for two investigated proteins increases when mixtures consisting of a chaotropic and a kosmotropic salt are applied. It seems to be related to the rather basic isoelectric points of the proteins.
Fast simultaneous determination of trimethoprim and sulfamethoxazole by capillary zone electrophoresis with capacitively coupled contactless conductivity detection
Authors: da Silva Iranaldo Santos , Vidal Denis Tadeu Rajh , do Lago Claudimir Lucio , Angnes Lúcio
Published: March 2013

The association of trimethoprim and sulfamethoxazole is a very effective with antibiotic properties, and commonly used in the treatment of a variety of infections. Due to the importance in diseases treatment of humans and also of animals, the development of methods for their quantification in commercial formulations is highly desirable. In the present study, a rapid method for simultaneous determination of these compounds using CE with capacitively coupled contactless conductivity detection was developed. A favorable working region for both analytes was from 12.5 to 200 μmol/L (linear responses with R > 0.999 for N = 5). Other parameters calculated were sensitivity (1.28 ± 0.10/1.45 ± 0.11) min/(μmol L), RSD (4.5%/2.0%), and LOD (1.1/3.3) μmol/L for trimethoprim and sulfamethoxazole, respectively. Under this condition, the total run time was only 2.6 min. The proposed method was applied to the determination of trimethoprim and sulfamethoxazole in commercial samples and the results were compared to those obtained by using a HPLC pharmacopoeia method. This new method is advantageous for quality‐control analyses of trimethoprim and sulfamethoxazole in pharmaceuticals samples, because it is rapid and precise. Moreover, it is less laborious and demands minimum amounts of reagents in comparison to the recommended method.
Gradient elution method in centrifugal partition chromatography for the separation of a complex sophorolipid mixture obtained from Candida bombicola yeasts
Authors: Kotland Alexis , Hadef Imane , Renault Jean‐Hugues , Hamzaoui Mahmoud , Martinez Agathe , Borie Nicolas , Guilleret Arnaud , Reynaud Romain , Hubert Jane
Published: March 2013

Sophorolipids represent an important class of natural surfactants with a variety of environmental, cosmetic, and pharmaceutical applications. Despite their promising physicochemical and biological properties, the use of sophorolipids is hampered by the lack of information regarding their individual structure‐activity relationships. The major difficulty in isolating pure sophorolipids arises from the high complexity of crude fermentation media composition and from their strong structural similarities. In this work, a centrifugal partition chromatography method was developed in an original gradient elution mode for the separation of sophorolipids produced by the yeast Candida bombicola. Experiments were realized by using three sets of solvent systems composed of n‐heptane, ethyl acetate, n‐butanol, methanol, and water in different proportions. The separation was performed at 5 mL/min in the ascending mode by increasing progressively the polarity of the organic mobile phase. In these conditions, more than 80% of the sophorolipids present in the initial crude fermentation extract were eluted successively from the most hydrophobic lactone forms to the most hydrophilic acid forms. The structures of the isolated sophorolipids were further elucidated by HPLC and NMR analyses.
Ultimate Controllers, Ownership and the Probability of Insolvency in Financially Distressed Firms
Authors: Poletti‐Hughes Jannine , Ozkan Aydin
Published: March 2013

This paper investigates the impact of corporate ownership and control on the outcome of financial distress. It is argued that the likelihood of financial distress resulting in insolvency depends on whether firms have controllers, the type of controllers and their cash flow ownership. Using a sample of 484 UK firms, 81 of which filed for insolvency, we show that financially distressed firms with controllers are more likely to be insolvent than widely held firms, where the probability of insolvency is greater when controllers are family or financial institutions. However, the probability of insolvency reduces significantly as the controllers' cash flow ownership increases beyond 10%. Copyright © 2013 John Wiley & Sons, Ltd.
High‐resolution tracking of motor disorders in Parkinson's disease during unconstrained activity
Authors: Roy Serge H. , Cole Bryan T. , Gilmore L. Don , De Luca Carlo J. , Thomas Cathi A. , Saint‐Hilaire Marie M. , Nawab S. Hamid
Published: March 2013

Parkinson's disease (PD) can present with a variety of motor disorders that fluctuate throughout the day, making assessment a challenging task. Paper‐based measurement tools can be burdensome to the patient and clinician and lack the temporal resolution needed to accurately and objectively track changes in motor symptom severity throughout the day. Wearable sensor‐based systems that continuously monitor PD motor disorders may help to solve this problem, although critical shortcomings persist in identifying multiple disorders at high temporal resolution during unconstrained activity. The purpose of this study was to advance the current state of the art by (1) introducing hybrid sensor technology to concurrently acquire surface electromyographic (sEMG) and accelerometer data during unconstrained activity and (2) analyzing the data using dynamic neural network algorithms to capture the evolving temporal characteristics of the sensor data and improve motor disorder recognition of tremor and dyskinesia. Algorithms were trained (n = 11 patients) and tested (n = 8 patients; n = 4 controls) to recognize tremor and dyskinesia at 1‐second resolution based on sensor data features and expert annotation of video recording during 4‐hour monitoring periods of unconstrained daily activity. The algorithms were able to make accurate distinctions between tremor, dyskinesia, and normal movement despite the presence of diverse voluntary activity. Motor disorder severity classifications averaged 94.9% sensitivity and 97.1% specificity based on 1 sensor per symptomatic limb. These initial findings indicate that new sensor technology and software algorithms can be effective in enhancing wearable sensor‐based system performance for monitoring PD motor disorders during unconstrained activities. © 2013 Movement Disorder Society