bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of sodium cellulose sulphate/poly‐dimethyl‐diallyl‐ammonium chloride biological capsules for immobilized cultivation of microalgae
Authors: Zeng Xianhai , Danquah Michael K. , Potumarthi Ravichandra , Cao Jia , Chen Xiao Dong , Lu Yinghua 
Published: June 2012

AbstractBACKGROUND: Microalgae continue to be a focus of industrial bioprocess sustainability practice owing to the numerous biofuels and bioproducts that can be obtained with simultaneous environmental bioremediation applications. However, the extremely dilute nature of large volume microalgal cultures and the small particle size of single‐cell microalgae present technological and economic problems of effective dewatering, thus affecting the application of microalgae in process industries. Microalgae immobilization using biocompatible polymeric systems has proved to be an effective strategy to circumvent the heavy dewatering requirement, as this approach provides physical separation between the solid microalgal cells and the liquid medium.RESULTS: In this work, a novel microalgae immobilization carrier, sodium cellulose sulphate/poly‐dimethyl‐diallyl‐ammonium chloride (NaCS‐PDMDAAC) capsule, was synthesized and the resulting polymeric capsules were characterized using physicochemical techniques such as Fourier transform infrared spectroscopy (FT‐IR), scanning electron microscopy equipped with energy dispersive X‐ray spectroscopy (SEM‐EDX) and nuclear magnetic resonance spectroscopy (NMR). Experimental results showed that the unique properties of NaCS‐PDMDAAC capsules, such as pore size, capsule size, mechanical strength, and structural and compositional homogeneity, relevant to microalgae cultivation with batch or continuous nutrient removal can be accurately controlled.CONCLUSION: These polymeric capsules find applications not only with microalgae cultivation but also for other microorganisms. © 2012 Society of Chemical Industry
Feedback Vertex Sets in Tournaments
Authors: Gaspers Serge , Mnich Matthias 
Published: June 2012

AbstractWe study combinatorial and algorithmic questions around minimal feedback vertex sets (FVS) in tournament graphs. On the combinatorial side, we derive upper and lower bounds on the maximum number of minimal FVSs in an n‐vertex tournament. We prove that every tournament on n vertices has at most 1.6740n minimal FVSs, and that there is an infinite family of tournaments, all having at least 1.5448n minimal FVSs. This improves and extends the bounds of Moon (1971). On the algorithmic side, we design the first polynomial space algorithm that enumerates the minimal FVSs of a tournament with polynomial delay. The combination of our results yields the fastest known algorithm for finding a minimum‐sized FVS in a tournament.
Cardiovascular effects of the microinjection of L‐proline into the third ventricle or the paraventricular nucleus of the hypothalamus in unanesthetized rats
Authors: Lopes‐Azevedo Silvana , Scopinho América Augusto , Busnardo Cristiane , Aguiar Corrêa Fernando Morgan 
Published: June 2012

AbstractWe investigated the cardiovascular effects of the microinjection of L‐proline (L‐Pro) into the third ventricle (3V) and its peripheral mechanisms. Different doses of L‐Pro into the 3V caused dose‐related pressor and bradycardiac responses. The pressor response to L‐Pro injected into the 3V was potentiated by intravenous pretreatment with the ganglion blocker pentolinium (5 mg/kg), thus excluding any significant involvement of the sympathetic nervous system. Because the response to the microinjection of L‐Pro into the 3V was blocked by intravenous pretreatment with the V1‐vasopressin receptor antagonist dTyr(CH2)5(Me)AVP (50μg/kg), it is suggested that these cardiovascular responses are mediated by a vasopressin release. The pressor response to the microinjection of L‐Pro into the 3V was found to be mediated by circulating vasopressin, so, given that the paraventricular nucleus of the hypothalamus (PVN) is readily accessible from the 3V, we investigated whether the PVN could be a site of action for the L‐Pro microinjected in the 3V. The microinjection of L‐Pro (0.033 μmoles/0.1 μl) into the PVN caused cardiovascular responses similar to those of injection of the 3V and were also shown to be mediated by vasopressin release. In conclusion, these results show that the microinjection of L‐Pro into the 3V causes pressor and bradycardiac responses that could involve stimulation of the magnocellular cells of the PVN and release of vasopressin into the systemic circulation. Also, because the microinjection of L‐Pro into the PVN caused a pressor response, this is the first evidence of cardiovascular effects caused by its injection in a supramedullary structure. © 2012 Wiley Periodicals, Inc.
Activity‐dependent energy budget for neocortical signaling: Effect of short‐term synaptic plasticity on the energy expended by spiking and synaptic activity
Authors: DiNuzzo Mauro , Giove Federico 
Published: June 2012

AbstractThe available estimate of the energy expended for signaling in rat neocortex is refined to examine the separate contribution of spiking and synaptic activity as a function of average neuronal firing rate. By taking into account a phenomenological model of short‐term synaptic plasticity, we show that the transition from low to high cortical activity is accompanied by a substantial increase in relative energy consumed by action potentials vs. synaptic potentials. This consideration might be important for a deeper understanding of how information is represented in the cortex and which metabolic pathways are upregulated to sustain cortical activity. © 2012 Wiley Periodicals, Inc.
Differential effects of distinct central nervous system regions on cell migration and axonal extension of neural precursor transplants
Authors: Jin Ying , Sura Karna , Fischer Itzhak 
Published: June 2012

AbstractTransplantation of neural precursor cells (NPCs) is a promising therapeutic strategy in CNS injury. However, the adult CNS lacks instructive signals present during development and, depending on the region and type of transplant, may be inhibitory for neuron generation and axonal growth. We examined the effects of the white matter in different regions of the adult CNS on the properties of NPC transplants with respect to cell survival, differentiation, migration, and axonal growth. NPCs were prepared from day 13.5 embryonic spinal cord of transgenic rats that express the human placental alkaline phosphatase (AP) reporter. These NPCs were injected unilaterally into the cervical spinal cord white matter and into the corpus callosum of adult rats and were analyzed immunohistochemically 2 weeks later. NPCs survived in both regions and differentiated into astrocytes, oligodendrocytes, and neurons, with no apparent differences in survival or phenotypic composition. However, in the spinal cord white matter, graft‐derived cells, identified as precursors and glial cells, migrated from the injection site rostrally and caudally, whereas, in the corpus callosum, graft‐derived cells did not migrate and remained at the injection site. Importantly, graft‐derived neurons extended axons from the grafting site along the corpus callosum past the midline, entering into the contralateral side of the corpus callosum. These results demonstrate dramatic differences between white matter regions in the spinal cord and brain with respect to cell migration and axonal growth and underscore the importance of considering the effects of the local CNS environment in the design of effective transplantation strategies. © 2012 Wiley Periodicals, Inc.
LARGE‐WOOD LOADING FROM NATURAL AND ENGINEERED PROCESSES AT THE WATERSHED SCALE
Authors: Lawrence J. E. , Resh V. H. , Cover M. R. 
Published: June 2012

ABSTRACTLarge wood, both live and dead, is essential for producing complex habitat in many streams, especially in forested watersheds that support salmonid populations. The addition of engineered wood structures is a common approach taken in many streams where past watershed management practices have resulted in reduced wood loading. We examined six 300‐m stream reaches in the Lagunitas Creek watershed, Northern California, to determine (i) the distribution of large wood in the bankfull channel and 10‐year floodplain, (ii) the influence of large wood on the size and distribution of pools and (iii) whether streams with engineered wood structures had greater diversity of pool habitat to support salmonid populations. We found that the amount of large wood in the bankfull channel and the amount available for recruitment from the 10‐year floodplain were highly variable among and within reaches examined and largely dependent on the local geomorphic setting. Stream reaches with engineered wood structures had elevated pool frequencies relative to reaches without these structures, suggesting a higher capacity to support salmonids during critical life stages. Among large wood pieces that had a strong influence on pool formation, 23% had an attached root wad and 66% were part of a cluster. All of the study reaches we examined had lower volumes of large wood in their bankfull channels than similar stream types with natural wood‐loading levels, suggesting that increased additions of large wood could provide ecosystem benefits over time. These principles can be understood and transferred effectively to other watersheds using a framework of wood‐loading process domains. Copyright © 2012 John Wiley & Sons, Ltd.
Analysis on the generalization of proxy signature
Authors: Tiwari Namita , Padhye Sahadeo 
Published: June 2012

ABSTRACTProxy signature is a specific digital signature, which allows an original signer to delegate her signing capability to proxy signer and then, the later can perform message signing on behalf of the former. Authentication is a desired property in cryptographic protocols. The proxy signature provides this property. In this article, we cover the research progress made on proxy signature and investigate its relationships with other existing signature schemes having continuous progress until now. We also provide real‐world scenarios, to understand better the situations, where these schemes are applicable for security purposes. We analyze the security properties of existing schemes and make a comparison among them on the basis of different number theoretic problems. Some open problems are also discussed, to the best of our knowledge. In addition, we provide some future directions, which can be used as a hint to work further in the area of proxy signature. We hope that this article will provide a ready reference to work in the related area. Copyright © 2012 John Wiley & Sons, Ltd.
Indicial lift response function: an empirical relation for finite‐thickness airfoils, and effects on aeroelastic simulations
Authors: Bergami Leonardo , Gaunaa Mac , Heinz Joachim 
Published: June 2012

ABSTRACTThe aeroelastic response of wind turbines is often simulated in the time domain by using indicial response techniques. Unsteady aerodynamics in attached flow are usually based on Jones's approximation of the flat plate indicial response, although the response for finite‐thickness airfoils differs from the flat plate one.The indicial lift response of finite‐thickness airfoils is simulated with a panel code, and an empirical relation is outlined connecting the airfoil indicial response to its geometric characteristics. The effects of different indicial approximations are evaluated on a 2D profile undergoing harmonic pitching motion in the attached flow region; the resulting lift forces are compared with computational fluid dynamics (CFD) simulations. The relevance for aeroelastic simulations of a wind turbine is also evaluated, and the effects are quantified in terms of variations of equivalent fatigue loads, ultimate loads, and stability limits.The agreement with CFD computations of a 2D profile in harmonic motion is improved by the indicial function accounting for the finite‐thickness of the airfoil. Concerning the full wind turbine aeroelastic behavior, the differences between simulations on the basis of Jones's and finite‐thickness indicial response functions are rather small; Jones's flat‐plate approximation results in only slightly larger fatigue and ultimate loads, and lower stability limits. Copyright © 2012 John Wiley & Sons, Ltd.
Fatigue distribution optimization for offshore wind farms using intelligent agent control
Authors: Zhao Rongyong , Shen Wenzhong , Knudsen Torben , Bak Thomas 
Published: June 2012

ABSTRACTA novel control approach is proposed to optimize the fatigue distribution of wind turbines in a large‐scale offshore wind farm on the basis of an intelligent agent theory. In this approach, each wind turbine is considered to be an intelligent agent. The turbine at the farm boundary communicates with its neighbouring downwind turbines and organizes them adaptively into a wind delivery group along the wind direction. The agent attributes and the event structure are designed on the basis of the intelligent agent theory by using the unified modelling language. The control strategy of the intelligent agent is studied using topology models. The reference power of an individual wind turbine from the wind farm controller is re‐dispatched to balance the turbine fatigue in the power dispatch intervals. In the fatigue optimization, the goal function is to minimize the standard deviation of the fatigue coefficient for every wind turbine. The optimization is constrained such that the average fatigue for every turbine is smaller than what would be achieved by conventional dispatch and such that the total power loss of the wind farm is restricted to a few percent of the total power. This intelligent agent control approach is verified through the simulation of wind data from the Horns Rev offshore wind farm. The results illustrate that intelligent agent control is a feasible way to optimize fatigue distribution in wind farms, which may reduce the maintenance frequency and extend the service life of large‐scale wind farms. Copyright © 2012 John Wiley & Sons, Ltd.
Has the situation of the ‘have‐nots’ improved?
Authors: Jannuzzi Gilberto De Martino , Goldemberg José 
Published: June 2012

AbstractThe need to promote significant changes in the production and use of energy in the direction of cleaner fuels and greater energy efficiency provide opportunities to reduce this gap of energy consumption indices between the rich and poor, both in developing and developed countries. Wide disparities in the access and consumption levels of modern fuels and electricity still persist between developing and developed countries, in spite of increased international awareness and efforts. This paper shows that progress has been made in order to increase access to electricity and cleaner cooking fuels and this has improved the standards of living of poor population. However, more efforts are necessary in order to speed up the reduction of the energy gap and eliminate energy poverty. Greater investments in energy efficiency are an essential part of this strategy and some countries are pursuing it.This article is categorized under:

Energy Policy and Planning > Economics and Policy
Energy and Development > Climate and Environment
New Rare‐Earth Metal Germanides RE2Ge9 (RE = Nd, Sm) by Thermal Decomposition of High‐Pressure Phases REGe5
Authors: Meier Katrin , Wosylus Aron , Cardoso‐Gil Raul , Burkhardt Ulrich , Curfs Caroline , Hanfland Michael , Grin Yuri , Schwarz Ulrich 
Published: June 2012

AbstractThe rare‐earth metal germanides RE2Ge9 (RE = Nd, Sm) have been prepared by thermal decomposition of the metastable high‐pressure phases REGe5 at ambient pressure. The compounds adopt an orthorhombic unit cell with a = 396.34(4) pm; b = 954.05(8) pm and c = 1238.4(1) pm for Nd2Ge9 and a = 395.46(7) pm; b = 946.4(2) pm and c = 1232.1(3) pm for Sm2Ge9. Crystal structure refinements reveal space group Pmmn (No. 59) for Nd2Ge9. The atomic pattern resembles an ordered defect variety of the pentagermanide motif REGe5 (RE = La; Nd, Sm, Gd, Tb) comprising corrugated germanium layers. These condense into a three‐dimensional network interconnected by eight‐coordinated germanium atoms. The resulting framework channels along [100] enclose the neodymium atoms. With respect to the atomic arrangement of the pentagermanides, half of the interlayer germanium atoms are eliminated in an ordered way so that occupied and empty germanium columns alternate along [001]. The rare‐earth metal atoms of both types of compounds, REGe5 and RE2Ge9, exhibit the electronic states 4f 3 and 4f 5 (oxidation state +3) for neodymium and samarium, respectively, evidencing that the modification of the germanium network leaves the electron configuration of the metal atoms unaffected.
Projected changes in water availability in the United Kingdom
Authors: Sanderson Michael G. , Wiltshire Andrew J. , Betts Richard A. 
Published: June 2012

There is evidence for a change in the seasonality of UK rainfall consistent with projections from climate models, which could have a significant impact on water availability. This paper describes an analysis of seasonal mean runoff in the UK calculated directly within an ensemble of regional climate models. Both surface and subsurface runoff have been analyzed, and the times at which a climate change signal in the runoff could be detected have also been calculated. Runoff is projected to increase in winter in all regions of the UK, by 5–25% by the 2080s, but remain the same or decrease in the other seasons. We find that a climate change signal could be detected in runoff in winter in western parts of the UK as early as the 2020s, but much later in eastern areas of England. In summer, detection times (2040–2060 s) are generally later than those in winter (2020–2040 s). Our results imply water resources in the southeast of the UK could be reduced during the twenty‐first century, and adaptation may be needed long before a formal detection of a climate change signal is made.
Characterization of cytoskeletal protein 4.1R interaction with NHE1 (Na+/H+ exchanger isoform 1)
Authors: Nunomura Wataru , Denker Sheryl P. , Barber Diane L. , Takakuwa Yuichi , Gascard Philippe 
Published: June 2012

NHE1 (Na+/H+ exchanger isoform 1) has been reported to be hyperactive in 4.1R-null erythrocytes [Rivera, De Franceschi, Peters, Gascard, Mohandas and Brugnara (2006) Am. J. Physiol. Cell Physiol. 291, C880–C886], supporting a functional interaction between NHE1 and 4.1R. In the present paper we demonstrate that 4.1R binds directly to the NHE1cd (cytoplasmic domain of NHE1) through the interaction of an EED motif in the 4.1R FERM (4.1/ezrin/radixin/moesin) domain with two clusters of basic amino acids in the NHE1cd, K519R and R556FNKKYVKK, previously shown to mediate PIP2 (phosphatidylinositol 4,5-bisphosphate) binding [Aharonovitz, Zaun, Balla, York, Orlowski and Grinstein (2000) J. Cell. Biol. 150, 213–224]. The affinity of this interaction (Kd=100–200 nM) is reduced in hypertonic and acidic conditions, demonstrating that this interaction is of an electrostatic nature. The binding affinity is also reduced upon binding of Ca2+/CaM (Ca2+-saturated calmodulin) to the 4.1R FERM domain. We propose that 4.1R regulates NHE1 activity through a direct protein–protein interaction that can be modulated by intracellular pH and Na+ and Ca2+ concentrations.
Surface phonons, elastic response, and conformal invariance in twisted kagome lattices
Authors: Sun Kai , Souslov Anton , Mao Xiaoming , Lubensky T. C. 
Published: June 2012

Model lattices consisting of balls connected by central-force springs provide much of our understanding of mechanical response and phonon structure of real materials. Their stability depends critically on their coordination number
z
.
d
-dimensional lattices with
z
= 2
d
are at the threshold of mechanical stability and are isostatic. Lattices with
z
< 2
d
exhibit zero-frequency “floppy” modes that provide avenues for lattice collapse. The physics of systems as diverse as architectural structures, network glasses, randomly packed spheres, and biopolymer networks is strongly influenced by a nearby isostatic lattice. We explore elasticity and phonons of a special class of two-dimensional isostatic lattices constructed by distorting the kagome lattice. We show that the phonon structure of these lattices, characterized by vanishing bulk moduli and thus negative Poisson ratios (equivalently, auxetic elasticity), depends sensitively on boundary conditions and on the nature of the kagome distortions. We construct lattices that under free boundary conditions exhibit surface floppy modes only or a combination of both surface and bulk floppy modes; and we show that bulk floppy modes present under free boundary conditions are also present under periodic boundary conditions but that surface modes are not. In the long-wavelength limit, the elastic theory of all these lattices is a conformally invariant field theory with holographic properties (characteristics of the bulk are encoded on the sample boundary), and the surface waves are Rayleigh waves. We discuss our results in relation to recent work on jammed systems. Our results highlight the importance of network architecture in determining floppy-mode structure.
Sleep perception and the multiple sleep latency test in patients with primary insomnia
Authors: HUANG LILI , ZHOU JUNYING , LI ZHE , LEI FEI , TANG XIANGDONG 
Published: June 2012

SummaryThe purpose of this study was to examine the relationship between overnight sleep perception and the daytime multiple sleep latency test (MSLT) among individuals who were primary insomnia patients (PIPs) or good sleeper controls (GSCs). We collected overnight sleep data via polysomnography (PSG), subjective sleep data via a morning questionnaire (self‐evaluated) and MSLT data via four 20‐min naps over 8 h. Subjects included 122 PIPs and 48 GSCs. Sleep perception was calculated as subjective sleep time/objective sleep time × 100%. PIPs showed a significant difference (P < 0.001) between sleep time, as determined by PSG (387.8 ± 100 min) and self‐report (226.3 ± 160 min), but no difference was obtained for GSCs (440.6 ± 53 versus 435.4 ± 65 min). The means for sleep perception were 56.4 ± 38.8% for the PIPs and 99.3 ± 13.6% for the GSCs (P < 0.001). In the PIPs group, weak but statistically significant negative correlations (r: −0.20 to −0.25) were found for MSLT versus sleep perception and versus self‐ and PSG‐evaluated sleep time. Compared to PIPs with low scores on the MSLT, those with high scores had less sleep perception (%), less self‐ and PSG‐evaluated sleep time and greater sleep misperception time. GSCs did not show significant correlations between MSLT and sleep measures or differences in comparisons between individuals with high and low scores on the MSLT. These results add novel data to the literature by suggesting that 24‐h hyperarousal potentially plays a key role in the pathophysiological issues of insomnia.