bluuebunny/crossref_metadata_2025 huggingface dataset:
Hepatitis E Virus Replication Requires an Active Ubiquitin-Proteasome System
Authors: Karpe Yogesh A. , Meng Xiang-Jin
Published: March 2012

The mechanism of hepatitis E virus (HEV) replication remains largely unknown. Here we demonstrate that HEV replication requires an active ubiquitin-proteasome system and that proteasome inhibitors affect HEV replication, possibly by inhibition of viral transcription or/and translation without a significant effect on cellular translation. Overexpression of ubiquitin in inhibitor-treated cells partially reverses the inhibitor effect on HEV replication. The results suggest that HEV replication requires interactions with proteasome machinery, which could be a potential therapeutic target against HEV.
Abuse of medication during international football competition in 2010 – lesson not learned
Authors: Tscholl Philippe Matthias , Dvorak Jiri
Published: March 2012

Background

The use of medication in professional football has previously been shown to defy clinical guidelines.

Materials and methods

Physicians of the teams who participated at the 2010 FIFA World Cup provided the list of medications used by each player within the 72 h preceding every match.

Results

During the tournament 71.7% of all players took medication, and 60.3% (444 of 736 players) took painkilling agents at least once. Over a third of players (39.0%) took a painkilling agent before every game. More medications were used during the finals than during the qualifying round of matches (pool games) (0.87±0.09 vs 0.77±0.03, p<0.01). Players from North and South America took almost twice the number of medications than did players from other continents (1.18±0.08 vs 0.64±0.03; p<0.01).

Conclusion

The use of medication reported by the team physicians in international football competition is increasing. Systematic use – medication for every match – appeared to be the norm in certain teams. This has implications for player health. These data encourage efforts to better understand, and to address, this potential disastrous practice in professional sports.
Geriatric consultation service in emergency department: how does it work?
Authors: Yuen Terry Man Yue , Lee Larry Lap Yip , Or Ikea Lai Chun , Yeung Kwai Lin , Chan Jimmy Tak Shing , Chui Catherine Pui Yuk , Kun Emily Wai Lin
Published: March 2012

Background

Hong Kong is having a significant prevalence of geriatric patients who usually require admission after presentation to the hospital through emergency departments. The geriatric consultation programme ‘We Care’ aims at lowering acute geriatric medical admission.

Objectives

The study aims at analysing the impact of the geriatric consultation service on the acute medical admission, and to study the characteristics and outcome of geriatric patients.

Methods

Retrospective study. Patients who received geriatric consultations during 1 January 2009 to 1 March 2011 were enrolled. The demographic information, diseases case mix, venue of discharge, clinical severity, community nursing service referrals and adverse outcomes were retrieved and analysed. The incidence of adverse outcomes under the presence of each factor was studied.

Results

2202 geriatric patients were referred. Their age ranged from 45 to 99 (mean 79.91, SD 7.45, median 80). These cases were categorised into: (1) chronic pulmonary disease (n=673; 30.6%), (2) debilitating cardiac disease (n=526; 23.9%), (3) geriatric syndromes (n=147; 6.7%), (4) neurological problems (n=416; 18.9%), (5) diabetes-related problems (n=146; 6.6%), (6) terminal malignancy (n=39; 1.8%), (7) electrolyte or input/output disturbance (n=137; 6.2%), (8) non-respiratory infections (n=36, 1.6%) and (9) others (n=82; 3.7%). Acute medical admission was evaded in 84.7% of all consultations with 1039 (47.2%) patients discharged home and 825 patients (37.5%) admitted to convalescent hospital. The incidence rate of adverse outcomes was 1.6%.

Conclusion

Programme ‘We Care’ provided comprehensive geriatric assessment to suitable geriatric patients, resulting in an effective reduction of acute geriatric hospital admission.
SEXUAL REPRODUCTION IN A SIMPLE GROWTH POPULATION MODEL
Authors: LEMOS CARLOS GENTIL ORO , SANTOS MARCIO
Published: March 2012

One of the most important characteristics in the survival of a species is related to the kind of reproduction responsible for the offspring generation. However, only in the last years the role played by sexual reproduction has been investigated. Then, for a better understanding of this kind of process we introduce, in this work, a surface reaction model that describes the role of the sexual reproduction. In our model two different elements of the species, representing male and female, can interact to reproduce a new element. The sex of this new element is chosen with a given probability and in order to take into account the mortality rate we introduce another kind of individual. The value of the spatial density of this element remains constant during the time evolution of the system. The model is studied using Monte Carlo simulations and mean field approximation. Depending on the values of the control parameters of the model, the system can attain two stationary states: In one of them the population survives and in the other it can be extinguished. Besides, accordingly to our results, the phase diagram of the model shows a discontinuous transition between these two states.
MODELING TIME-VARYING DARK ENERGY WITH CONSTRAINTS FROM LATEST OBSERVATIONS
Authors: ZHANG QING-JUN , WU YUE-LIANG
Published: March 2012

We introduce a set of two-parameter models for the dark energy equation of state (EOS) w(z) to investigate time-varying dark energy. The models are classified into two types according to their boundary behaviors at the redshift z = (0, ∞) and their local extremum properties. A joint analysis based on four observations ( SNe + BAO + CMB + H0) is carried out to constrain all the models. It is shown that all models get almost the same [Formula: see text] and the cosmological parameters (ΩM, h, Ωbh2) with the best-fit results (0.28, 0.70, 2.24), although the constraint results on two parameters (w0, w1) and the allowed regions for the EOS w(z) are sensitive to different models and a given extra model parameter. For three of Type I models which have similar functional behaviors with the so-called CPL model, the constrained two parameters w0 and w1 have negative correlation and are compatible with the ones in CPL model, and the allowed regions of w(z) get a narrow node at z~0.2. The best-fit results from the most stringent constraints in Model Ia give [Formula: see text] which may compare with the best-fit results [Formula: see text] in the CPL model. For four of Type II models which have logarithmic function forms and an extremum point, the allowed regions of w(z) are found to be sensitive to different models and a given extra parameter. It is interesting to obtain two models in which two parameters w0 and w1 are strongly correlative and appropriately reduced to one parameter by a linear relation w1∝(1+w0).
VECTOR MESON DOMINANCE AND RADIATIVE DECAYS OF HEAVY SPIN-3/2 BARYONS TO HEAVY SPIN-1/2 BARYONS
Authors: ALIEV T. M. , SAVCI M. , ZAMIRALOV V. S.
Published: March 2012

Using the calculated values of the strong coupling constants of the heavy sextet spin-3/2 baryons to sextet and antitriplet heavy spin-1/2 baryons with light vector mesons within the light cone QCD sum rules method, and vector meson dominance assumption, the radiative decay widths are calculated. These widths are compared with the "direct" radiative decay widths predicted in the framework of the light cone QCD sum rules.
CORNELL AND KRATZER POTENTIALS WITHIN THE SEMIRELATIVISTIC TREATMENT
Authors: HASSANABADI S. , RAJABI A. A. , ZARRINKAMAR S.
Published: March 2012

We obtain approximate analytical solutions of the two-body Spinless Salpeter equation under both Cornell (Funnel) and Kratzer potentials and thereby provide a basis to study semirelativistic two-body systems which frequently appear in physics. Apart from the physical significance, the work is mathematically appealing as we have actually reported approximate analytical solutions of the corresponding Heun equations which appear as one of the most challenging differential equations of mathematical physics.
USING PATTERNS FOR THE ANALYSIS AND RESOLUTION OF COMPLIANCE VIOLATIONS
Authors: ELGAMMAL AMAL , TURETKEN OKTAY , VAN DEN HEUVEL WILLEM-JAN
Published: March 2012

Today's enterprises demand a high degree of compliance of business processes to meet laws and regulations, such as Sarbanes-Oxley and Basel II. Compliance should be enforced during all phases of business process lifecycle, from the phases of analysis and design to deployment, monitoring and evaluation. In this paper, a taxonomy of compliance constraints for business processes is introduced based on the notion of compliance patterns. Patterns facilitate the formal specification of compliance constraints that enable their verification and analysis against business process models. This taxonomy serves as the backbone of the root-cause analysis, which is conducted to reason about and eventually to resolve design-time compliance violations, by providing appropriate guidelines as remedies to alleviate design-time compliance deviations. We have developed and integrated a set of tools to observe and evaluate the applicability of our approach, and experiment with it in case studies.
Minority Carrier Lifetime Behavior in Crystalline Silicon in Rapid Laser Heating
Authors: Sameshima Toshiyuki , Betsuin Koichi , Mizuno Tomohisa , Sano Naoki
Published: March 2012

We report changes in the light-induced minority carrier effective lifetime τeff of crystalline silicon caused by rapid laser heating. The top surface of n- and p-type silicon substrates with thicknesses of 520 and 150 µm coated with thermally grown SiO2 layers were heated by a 940 nm semiconductor laser for 4 ms. τeff was measured by a method of microwave absorption caused by carriers induced by 620 nm light illumination at 1.5 mW/cm2. τeff for light illumination of the top surfaces was decreased to 1.0×10-5 and 4.8×10-6 s by laser heating at 5.0×104 W/cm2 for n- and p-type 520-µm-thick silicon substrates, respectively. It was decreased to 1.5×10-6 and 6.7×10-6 s by laser heating at 4.2×104 W/cm2 for n- and p-type 150-µm-thick silicon substrates, respectively. The decrease in τeff resulted from the generation of defect states associated with the carrier recombination velocity at the top surface region, S
top. Laser heating increased S
top to 6000 and 10000 cm/s for n- and p-type 520-µm-thick silicon substrates, respectively and to 9200 and 2150 cm/s for n- and p-type 150-µm-thick silicon substrates, respectively. Heat treatment at 400 °C for 4 h markedly decreased S
top to 21 and 120 cm/s respectively for 520-µm-thick n- and p-type silicon samples heated at 5.0×104 W/cm2. The heat treatment also decreased, 10 and 35 cm/s, respectively, for 150-µm-thick n- and p-type silicon substrates heated at 4.2×104 W/cm2.
High-Performance Thin Film Transistor with Amorphous In2O3–SnO2–ZnO Channel Layer
Authors: Tomai Shigekazu , Nishimura Mami , Itose Masayuki , Matuura Masahide , Kasami Masashi , Matsuzaki Shigeo , Kawashima Hirokazu , Utsuno Futoshi , Yano Koki
Published: March 2012

We have developed a high-mobility and high-processability oxide semiconductor using amorphous In2O3–SnO2–ZnO (a-ITZO) as the channel material. An a-ITZO thin-film transistor (TFT) was fabricated by a back-channel-etch process. Its field effect mobility was more than 20 cm2 V-1 s-1 and its subthreshold swing was 0.4 V s-1, which makes it a promising candidate for next-generation TFTs.
Effect of Channel Length on the Reliability of Amorphous Indium–Gallium–Zinc Oxide Thin Film Transistors
Authors: Lee Soo-Yeon , Kim Sun-Jae , Lee Young Wook , Lee Woo-Geun , Yoon Kap-Soo , Han Min-Koo
Published: March 2012

We investigated the effect of the channel length on the reliability of amorphous indium–gallium–zinc oxide (IGZO) thin-film transistors (TFTs) under the negative and positive gate bias stress. The threshold voltage (V
th) was barely changed at the channel length of 8 µm under the negative bias stress. When the channel length was 10 and 15 µm, V
th shifted negatively about 0.7 and 2.5 V. However, V
th shift did not depend on the channel length under the positive bias stress. Under the negative gate bias stress, the holes might not be accumulated uniformly at the channel. Because the band gap of IGZO is large, the effect of negative gate bias is decreased when the back interface is fixed by source/drain electrode. When the channel length decreases, the amount of accumulated hole decreases and V
th shift decreases.
An 8-bit Data Driving Scheme Based on Two-Step Digital-to-Analog Conversion for Integrated Data Drivers of Active-Matrix Organic Light-Emitting Diodes
Authors: Kim Tae-Wook , Choi Byong-Deok
Published: March 2012

The two-step digital-to-analog conversion (DAC) scheme has been reported to be very area-efficient for thin-film transistor-liquid crystal display (TFT-LCD) data driver ICs, but it is not as well suited as it is for polycrystalline silicon (poly-Si) TFT integrated circuits. The charge redistribution in the two-step DAC process requires an operational amplifier in principle, which is most challenging for poly-Si TFT circuits. The proposed two-step DAC for active-matrix organic light-emitting diodes (AMOLEDs) makes the operational amplifier unnecessary by appropriately exploiting the preexisting capacitors in the pixel to compensate for the characteristic variations of TFTs. Moreover, the second-step DAC occurs at the same time as threshold voltage compensation, and it does not require additional time. By thoroughly analyzing area efficiency depending on the resolution decomposition between the first- and second-step DACs, we found that 5-bit coarse plus 3-bit fine DACs are best in terms of circuit area. When we designed a layout of the proposed 8-bit DAC on the basis of the 4 µm design rules, the DAC circuit area is no more than 72×637 µm2, which, to the best of our knowledge, is the most compact to date.
Oxidation of Silicon Utilizing a Microwave Plasma System: Electric-Stress Hardening of SiO2 Films by Controlling the Surface and Interface Roughness
Authors: Kabe Yoshiro , Hasunuma Ryu , Yamabe Kikuo
Published: March 2012

Electric-stress hardening of silicon dioxide (SiO2) films under high electric field stresses was studied. SiO2 films were formed by two-step oxidation utilizing thermal oxidation and plasma oxidation. This process has the advantages of both oxidation processes: the low degradation rate of thermal oxidation and the flat SiO2 surface and SiO2/Si interface obtained by plasma oxidation. Time-dependent dielectric breakdown and stress-induced leakage current were measured to evaluate the degradation rate and the breakdown lifetime of the oxides. Atomic force microscopy was used to evaluate the roughnesses of the SiO2 surface and interface. The two-dimensional degradation distribution under a current stress was investigated by the stress-induced etched-oxide surface roughness method. Atomically uniform SiO2 was found to suppress the generation of local weak spots under current stress. We conclude that using an appropriate combination of the oxidation processes can reduce the degradation and enhance the breakdown lifetimes of SiO2 films.
Space Charge Trapping and Conduction in Low-Density Polyethylene/Silica Nanocomposite
Authors: Wu Wu , Jiandong Jiandong , Yin Yin , Yi Yi , Lan Lan , Li Li , Wang Wang , Qiaohua Qiaohua , Li Li , Xuguang Xuguang , Xiao Xiao , Dengming Dengming
Published: March 2012

The high field conduction and space charge distribution were investigated in low-density polyethylene (LDPE) and LDPE/silica nanocomposites filled with various concentrations of nanosilica. The results indicate that nanosilica could effectively suppress space charge accumulation at nanofiller concentrations from 0.1 to 5.0 wt %. However, the conduction current at a high field significantly increases at low concentrations from 0.1 to 0.5 wt % and remarkably reduces at high concentrations from 0.5 to 5.0 wt %. It is shown that the trap depth corresponding to the time from 2 to 3600 s significantly decreases at low nanofiller concentrations from 0.1 to 0.5 wt %. However, the depth of deep traps corresponding to the time from 100 to 3600 s increases with the increase in nanofiller concentration from 0.5 to 5.0 wt %. Moreover, the depth of shallow traps corresponding to the time from 2 to 100 s increases at concentrations from 0.5 to 2.0 wt %, and then it decreases at concentrations from 2.0 to 5.0 wt %. In addition, the apparent mobility varies with the modification of trap depth caused by the introduction of nanofiller. The threshold field E
Ω–t for remarkable charge injection and E
t–c proportional to the total trap density H are significantly lower in the nanocomposite with a low nanosilica concentration, i.e., 0.1 and 0.5 wt %, while both of them increase at concentrations from 0.5 to 5.0 wt %. It is considered that the impurity effect is greater than the nanofiller effect at a low nanofiller concentration. The deep trap is speculated as the chemical trap in the interface of the nanofiller bonding strongly with the polymer chain, while the shallow trap may be related to the chemical trap in the weakly bonded interface. It is clear that the space charge behavior and conduction are significantly affected by modification of the trap depth and density distribution owing to the introduction of nanofiller.
Acid Generation Mechanism for Extreme Ultraviolet Resists Containing Pinanediol Monosulfonate Acid Amplifiers: A Pulse Radiolysis Study
Authors: Enomoto Kazuyuki , Arimitsu Koji , Yoshizawa Atsutaro , Joshi Ravi , Yamamoto Hiroki , Oshima Akihiro , Kozawa Takahiro , Tagawa Seiichi
Published: March 2012

Very highly sensitive resists are required for extreme ultraviolet (EUV, 13.5 nm) lithography, which is regarded as the most promising next-generation lithography. Chemically amplified resists have been proposed to increase acid yield and sensitivity through the use of an acid amplifier. There are two steps for acid generation in chemically amplified resists: initial acid generation and acid amplification. The first systematic research on the acid generation mechanisms of chemically amplified resists showing the involvement of acid amplifiers has been performed by both time-resolved pulse radiolysis and spectrophotometric titration methods. The role of acid amplifiers in acid generation processes, initiated by exposure, has been clarified using toluene and trifluoromethylbenzene derivatives of pinanediol monosulfonate.
Mesoproterozoic emplacement and enriched mantle derivation of the Racherla alkali syenite, Palaeo-Mesoproterozoic Cuddapah Basin, southern India: insights from
in situ
Sr–Nd isotopic analysis on apatite
Authors: Chalapathi Rao N. V. , Wu Fu-Yuan , Srinivas M.
Published: March 2012

We report an
in situ
Sm–Nd isochron age of 1326±73 Ma, determined by LA-MC-ICP-MS (laser ablation-multiple collector-inductively coupled plasma-mass spectrometry), on crystalline apatite grains from the Racherla alkali syenite occurring in the Palaeo-Mesoproterozoic Cuddapah Basin, southern India. The obtained Mesoproterozoic age necessitates the Racherla syenite to be an intrusive into the sedimentary rocks of the Cuddapah Basin contrary to some previous suggestion that it represents an inlier of the basement pluton. Age of the dated syenite, within its error limits, is also coeval with that of the nearby Chelima lamproite (1354±52 Ma) and other syenite complexes (
c
. 1352 Ma) located elsewhere within the Eastern Ghats Mobile Belt, southern India, thereby implying a common geotectonic control in all of their generation. Incompatible trace element signatures (high La/Nb, Zr/Nb and La/Yb),
87
Sr/
86
Sr (0.70432±10) and the lower Nd isotopic ratio (

ε

Nd
(t) −8.9) of the apatite suggest derivation of the Racherla syenite parent magma from an enriched mantle source. Our findings provide compelling evidence for the existence of ancient (
c
. 2.6 Ga) metasomatized lithospheric mantle, at the Archaean–Palaeoproterozoic boundary, beneath the Cuddapah Basin. This enriched mantle appears to have had played a dominant role in the generation of co-spatial and coeval lamproites within and around the Cuddapah Basin and a plethora of alkaline and sub-alkaline syenites within the Eastern Ghats Mobile Belt. Implications of our study in the context of Indo-Antarctic collisional tectonics are also explored.
Palaeoproterozoic sedimentation on the Singhbhum Craton: global context and comparison with Kaapvaal
Authors: Mazumder R. , Eriksson P. G. , De S. , Bumby A. J. , Lenhardt N.
Published: March 2012

The Singhbhum Craton has a limited Palaeoproterozoic supracrustal record, which suggests a three-part history, comprising: a long period of high freeboard and palaeosol formation on granitoids; subsequent rift-related mafic–ultramafic volcanism and subordinate sedimentation (
c.
2.25–2.1 Ga: Dhanjori and Jagannathpur basin-fills; possibly also Simlipal, Malangtoli and Ongarbira basin-fills), which overlapped locally with mafic soil formation; and a major regression at around 2.0 Ga. Following a long hiatus, the approximately 1.6 Ga Dhalbhum–Dalma succession was laid down, probably under continental conditions. This rather truncated record stands in contrast to the chronologically and geographically much more widespread supracrustal basin-fills of the Kaapvaal Craton, and there appears to be an overall poor comparison between these two early Precambrian crustal blocks. However, on Kaapvaal, three analogous events are identified: widespread approximately 2.2 Ga mafic volcanism, followed by a well-developed palaeosol and a major transgression prior to 2.05 Ga. The three shared events between the two cratons are compatible with the postulate of a global, approximate 2.45–2.2 Ga shutdown of magmatic and tectonic geodynamics, with the origin of the triumvirate directly reflecting its resumption again after about 2.2 Ga. We recognize here that a large diversity of views on Singhbhum's geodynamic history exists, predicated on a lack of precise geochronology and commonly poor outcrops, and the current hypotheses are presented with these factors in mind.
CPU DB
Authors: Danowitz Andrew , Kelley Kyle , Mao James , Stevenson John P. , Horowitz Mark
Published: March 2012

With this open database, you can mine microprocessor trends over the past 40 years.
Sample size in usability studies
Authors: Schmettow Martin
Published: March 2012

Magic numbers are strictly hocus-pocus, so usability studies must test many more subjects than is usually assumed.
Searching the village
Authors: Horowitz Damon , Kamvar Sepandar D.
Published: March 2012

We describe Aardvark, a social search engine. With Aardvark, users ask a question, either by instant message, e-mail, Web input, text message, or voice. Aardvark then routes the question to the person in the user's extended social network most likely to be able to answer that question. As compared to a traditional Web search engine, where the challenge lies in finding the right
document
to satisfy a user's information need, the challenge in a social search engine like Aardvark lies in finding the right
person
to satisfy a user's information need. Further, while trust in a traditional search engine is based on authority, in a social search engine like Aardvark, trust is based on intimacy. We describe how these considerations inform the architecture, algorithms, and user interface of Aardvark, and how they are reflected in the behavior of Aardvark users.
Role of 20-HETE in the antihypertensive effect of transfer of chromosome 5 from Brown Norway to Dahl salt-sensitive rats
Authors: Williams Jan M. , Fan Fan , Murphy Sydney , Schreck Carlos , Lazar Jozef , Jacob Howard J. , Roman Richard J.
Published: March 2012

This study examined whether substitution of chromosome 5 containing the CYP4A genes from Brown Norway rat onto the Dahl S salt-sensitive (SS) genetic background upregulates the renal production of 20-HETE and attenuates the development of hypertension. The expression of CYP4A protein and the production of 20-HETE were significantly higher in the renal cortex and outer medulla of SS.5BN(chromosome 5-substituted Brown Norway rat) consomic rats fed either a low-salt (LS) or high-salt (HS) diet than that seen in SS rats. The increase in the renal production of 20-HETE in SS.5BNrats was associated with elevated expression of CYP4A2 mRNA. MAP measured by telemetry rose from 117 ± 1 to 183 ± 5 mmHg in SS rats fed a HS diet for 21 days, but only increased to 151 ± 5 mmHg in SS.5BNrats. The pressure-natriuretic and diuretic responses were twofold higher in SS.5BNrats compared with SS rats. Protein excretion rose to 354 ± 17 mg/day in SS rats fed a HS diet for 21 days compared with 205 ± 13 mg/day in the SS.5BNrats, and the degree of glomerular injury was reduced. Baseline glomerular capillary pressure (Pgc) was similar in SS.5BNrats (43 ± 1 mmHg) and Dahl S (44 ± 2 mmHg) rats. However, Pgc increased to 59 ± 3 mmHg in SS rats fed a HS diet for 7 days, while it remained unaltered in SS.5BNrats (43 ± 2 mmHg). Chronic administration of an inhibitor of the synthesis of 20-HETE (HET0016, 10 mg·kg−1·day−1iv) reversed the antihypertensive phenotype seen in the SS.5BNrats. These findings indicate that the transfer of chromosome 5 from the BN rat onto the SS genetic background increases the renal expression of CYP4A protein and the production of 20-HETE and that 20-HETE contributes to the antihypertensive and renoprotective effects seen in the SS.5BNconsomic strain.
Cyclooxygenase inhibition abolishes age-related differences in cerebral vasodilator responses to hypercapnia
Authors: Barnes Jill N. , Schmidt John E. , Nicholson Wayne T. , Joyner Michael J.
Published: March 2012

Blood flow and vasodilatory responses are altered by age in a number of vascular beds, including the cerebral circulation. To test the role of prostaglandins as regulators of cerebral vascular function, we examined cerebral vasodilator responses to CO2 (cerebrovascular reactivity) in young (26 ± 5 yr; 6 males/6 females) and older (65 ± 6 yr, 5 males/5 females) healthy humans before and after cyclooxygenase inhibition (using indomethacin). Middle cerebral artery velocity (MCAv) responses to stepped hypercapnia were measured before and 90 min after indomethacin. Changes in MCAv during the recovery from hypercapnia (vasoconstrictor responses) were also evaluated before and after indomethacin. Cerebrovascular reactivity was calculated using linear regression between MCAv and end-tidal CO2. Young adults demonstrated greater MCAv (55 ± 6 vs. 39 ± 5 cm/s: P < 0.05) and MCAv reactivity (1.67 ± 0.20 vs. 1.09 ± 0.19 cm·s−1·mmHg−1; P < 0.05) to hypercapnia compared with older adults ( P < 0.05). In both groups MCAv and MCAv reactivity decreased between control and indomethacin. Furthermore, the age-related differences in these cerebrovascular variables were abolished by indomethacin. During the recovery from hypercapnia, there were no age-related differences in MCAv reactivity; however, indomethacin significantly reduced the MCAv reactivity in both groups. Taken together, these results suggest that cerebral blood flow velocity and cerebrovascular reactivity are attenuated in aging humans, and may be due to a loss of prostaglandin-mediated vasodilation.
Discharge properties of motor units during steady isometric contractions performed with the dorsiflexor muscles
Authors: Jesunathadas Mark , Klass Malgorzata , Duchateau Jacques , Enoka Roger M.
Published: March 2012

The purpose of this study was to record the discharge characteristics of tibialis anterior motor units over a range of target forces and to import these data, along with previously reported observations, into a computational model to compare experimental and simulated measures of torque variability during isometric contractions with the dorsiflexor muscles. The discharge characteristics of 44 motor units were quantified during brief isometric contractions at torques that ranged from recruitment threshold to an average of 22 ± 14.4% maximal voluntary contraction (MVC) torque above recruitment threshold. The minimal [range: 5.8–19.8 pulses per second (pps)] and peak (range: 8.6–37.5 pps) discharge rates of motor units were positively related to the recruitment threshold torque ( R2 ≥ 0.266; P < 0.001). The coefficient of variation for interspike interval at recruitment was positively associated with recruitment threshold torque ( R2 = 0.443; P < 0.001) and either decreased exponentially or remained constant as target torque increased above recruitment threshold torque. The variability in the simulated torque did not differ from the experimental values once the recruitment range was set to ∼85% MVC torque, and the association between motor twitch contraction times and peak twitch torque was defined as a weak linear association ( R2 = 0.096; P < 0.001). These results indicate that the steadiness of isometric contractions performed with the dorsiflexor muscle depended more on the distributions of mechanical properties than discharge properties across the population of motor units in the tibialis anterior.
Visual gravity influences arm movement planning
Authors: Sciutti Alessandra , Demougeot Laurent , Berret Bastien , Toma Simone , Sandini Giulio , Papaxanthis Charalambos , Pozzo Thierry
Published: March 2012

When submitted to a visuomotor rotation, subjects show rapid adaptation of visually guided arm reaching movements, indicated by a progressive reduction in reaching errors. In this study, we wanted to make a step forward by investigating to what extent this adaptation also implies changes into the motor plan. Up to now, classical visuomotor rotation paradigms have been performed on the horizontal plane, where the reaching motor plan in general requires the same kinematics (i.e., straight path and symmetric velocity profile). To overcome this limitation, we considered vertical and horizontal movement directions requiring specific velocity profiles. This way, a change in the motor plan due to the visuomotor conflict would be measurable in terms of a modification in the velocity profile of the reaching movement. Ten subjects performed horizontal and vertical reaching movements while observing a rotated visual feedback of their motion. We found that adaptation to a visuomotor rotation produces a significant change in the motor plan, i.e., changes to the symmetry of velocity profiles. This suggests that the central nervous system takes into account the visual information to plan a future motion, even if this causes the adoption of nonoptimal motor plans in terms of energy consumption. However, the influence of vision on arm movement planning is not fixed, but rather changes as a function of the visual orientation of the movement. Indeed, a clear influence on motion planning can be observed only when the movement is visually presented as oriented along the vertical direction. Thus vision contributes differently to the planning of arm pointing movements depending on motion orientation in space.
TRPV4 channels mediate the infrared laser-evoked response in sensory neurons
Authors: Albert E. S. , Bec J. M. , Desmadryl G. , Chekroud K. , Travo C. , Gaboyard S. , Bardin F. , Marc I. , Dumas M. , Lenaers G. , Hamel C. , Muller A. , Chabbert C.
Published: March 2012

Infrared laser irradiation has been established as an appropriate stimulus for primary sensory neurons under conditions where sensory receptor cells are impaired or lost. Yet, development of clinical applications has been impeded by lack of information about the molecular mechanisms underlying the laser-induced neural response. Here, we directly address this question through pharmacological characterization of the biological response evoked by midinfrared irradiation of isolated retinal and vestibular ganglion cells from rodents. Whole cell patch-clamp recordings reveal that both voltage-gated calcium and sodium channels contribute to the laser-evoked neuronal voltage variations (LEVV). In addition, selective blockade of the LEVV by micromolar concentrations of ruthenium red and RN 1734 identifies thermosensitive transient receptor potential vanilloid channels as the primary effectors of the chain reaction triggered by midinfrared laser irradiation. These results have the potential to facilitate greatly the design of future prosthetic devices aimed at restoring neurosensory capacities in disabled patients.
Effects of Combined Opioids on Pain and Mood in Mammals
Authors: Rech Richard H. , Mokler David J. , Briggs Shannon L.
Published: March 2012

The authors review the opioid literature for evidence of increased analgesia and reduced adverse side effects by combining mu-opioid-receptor (MOR) agonists, kappa-opioid-receptor (KOR) agonists, and nonselective low-dose-opioid antagonists (LD-Ant). We tested fentanyl (MOR agonist) and spiradoline (KOR agonist), singly and combined, against somatic and visceral pain models. Combined agonists induced additive analgesia in somatic pain and synergistic analgesia in visceral pain. Other investigators report similar effects and reduced tolerance and dependence with combined MOR agonist and KOR agonist. LD-Ant added to either a MOR agonist or KOR agonist markedly enhanced analgesia of either agonist. In accordance with other place-conditioning (PC) studies, our PC investigations showed fentanyl-induced place preference (CPP) and spiradoline-induced place aversion (CPA). We reduced fentanyl CPP with a low dose of spiradoline and reduced spiradoline CPA with a low dose of fentanyl. We propose combined MOR agonist, KOR agonist, and LD-Ant to produce superior analgesia with reduced adverse side effects, particularly for visceral pain.
Conditional Expression of Human PPARδand a Dominant Negative Variant of hPPARδ In Vivo
Authors: Higgins Larry G. , Garbacz Wojciech G. , Gustafsson Mattias C. U. , Nainamalai Sitheswaran , Ashby Peter R. , Wolf C. Roland , Palmer Colin N. A.
Published: March 2012

The nuclear receptor, NR1C2 or peroxisome proliferator-activated receptor (PPAR)-δ, is ubiquitously expressed and important for placental development, fatty acid metabolism, wound healing, inflammation, and tumour development. PPARδhas been hypothesized to function as both a ligand activated transcription factor and a repressor of transcription in the absence of agonist. In this paper, treatment of mice conditionally expressing human PPARδwith GW501516 resulted in a marked loss in body weight that was not evident in nontransgenic animals or animals expressing a dominant negative derivative of PPARδ. Expression of either functional or dominant negative hPPARδblocked bezafibrate-induced PPARα-dependent hepatomegaly and blocked the effect of bezafibrate on the transcription of PPARαtarget genes. These data demonstrate, for the first time, that PPARδcould inhibit the activation of PPARα in vivoand provide novel models for the investigation of the role of PPARδin pathophysiology.
Factors of the Lectin Pathway of Complement Activation and Their Clinical Associations in Neonates
Authors: Cedzynski Maciej , Swierzko Anna St. , Kilpatrick David C.
Published: March 2012

This paper summarizes the data concerning soluble defense lectins (mannan-binding lectin, M-ficolin, L-ficolin, and H-ficolin) with the unique ability to activate complement and their associated serine proteases (MASPs) in neonates. The clinical importance of deficiencies of these immune factors is presented in aspects of perinatal mortality, premature births, and low birthweight. Prenatal serum concentrations of L-ficolin, H-ficolin, and MASP-2 (and probably M-ficolin) correlate with gestational age and birthweight. The relationship of serum MBL to gestational age is controversial. TheMBL2genotypes XA/O and O/O (associated with low-serum MBL) are associated with perinatal infections, whereas the high serum MBL-conferring A/A genotypes may be associated with prematurity. Low-serum L-ficolin concentrations, but not low-serum H-ficolin concentrations, are also associated with perinatal infections. Much of the literature is inconsistent, and the relationships reported so far require independent confirmation at both gene and protein levels. Our preliminary conclusion is that these soluble defense lectins play a protective role in the neonate, and that insufficiency of such factors contributes to the adverse consequences of prematurity and low birthweight.
On Stabilization of PVPA/PVA Electrospun Nanofiber Membrane and Its Effect on Material Properties and Biocompatibility
Authors: Franco Rose Ann , Min Young-Ki , Yang Hun-Mo , Lee Byong-Taek
Published: March 2012

A novel nanofiber membrane was fabricated by electrospinning composed of polyvinyl phosphonic acid (PVPA) and polyvinyl alcohol (PVA). Stabilization was done due to the high dissolvability of the membrane when in contact with water. Physical treatment was done by exposure to heat at 150°C in a vacuum environment at different periods of time. Chemical crosslinking was done by immersion in methanol and methanol/ glutaraldehyde. A heat‐exposed membrane was also further crosslinked chemically. All conditions were compared with regards to its effect on the material properties of the membranes and its biological response in vitro with MG‐63 osteoblast‐like cell line. Visual examination and dimensional analyses showed that heat treatment produced discoloration on the membrane surface and chemical crosslinking reduced membrane dimensions. Tensile strength and strain improved in crosslinked membranes compared to noncrosslinked counterpart. Swelling and degradation was also investigated and was seen to vary depending on the crosslinking condition. Biocompatibility was observed to be more favorable in heat‐treated membranes.
Aphids: A Model for Polyphenism and Epigenetics
Authors: Srinivasan Dayalan G. , Brisson Jennifer A.
Published: March 2012

Environmental conditions can alter the form, function, and behavior of organisms over short and long timescales, and even over generations. Aphid females respond to specific environmental cues by transmitting signals that have the effect of altering the development of their offspring. These epigenetic phenomena have positioned aphids as a model for the study of phenotypic plasticity. The molecular basis for this epigenetic inheritance in aphids and how this type of inheritance system could have evolved are still unanswered questions. With the availability of the pea aphid genome sequence, new genomics technologies, and ongoing genomics projects in aphids, these questions can now be addressed. Here, we review epigenetic phenomena in aphids and recent progress toward elucidating the molecular basis of epigenetics in aphids. The discovery of a functional DNA methylation system, functional small RNA system, and expanded set of chromatin modifying genes provides a platform for analyzing these pathways in the context of aphid plasticity. With these tools and further research, aphids are an emerging model system for studying the molecular epigenetics of polyphenisms.
Controlling Complex Dynamics in a Protected Area Discrete‐Time Model
Authors: Russu Paolo
Published: March 2012

This paper investigates how the introduction of user fees and defensive expenditures changes the complex dynamics of a discrete‐time model, which represents the interaction between visitors and environmental quality in an open‐access protected‐area (OAPA). To investigate this issue more deeply, we begin by studying in great detail the OAPA model, and then we introduce the user fee (β) and the defensive expenditures (ρβ) specifically directed towards at the protection of the environmental resource. We observed that some values of β can generate a chaotic regime from a stable dynamic of the OAPA model. Finally, to eliminate the chaotic regime, we design a controller by OGY method, assuming the user fee as a controller parameter.
Taxonomic Position of the Oriental Species ofMesosa(Mesosa) (Coleoptera, Cerambycidae, Lamiinae, Mesosini)
Authors: Yamasako Junsuke , Ohbayashi Nobuo
Published: March 2012

Twelve oriental mesosine species which had been belonged to the nominotypical subgenus of the genusMesosaLatreille, 1829, are transferred to the subgenusDissosiraPascoe, 1865 of the genusAgelastaNewman, 1842, as follows:A. (D.) perplexa(Pascoe, 1858);A. (D.) columba(Pascoe, 1859);A. (D.) rufa(Breuning, 1935);A. (D.) catenatoidesYamasako and N. Ohbayashi, nom. nov. [replacement name forA. (D.) laosensis(Breuning, 1935) already occupied by Pic (1925)];A. (D.) gardneri(Breuning, 1938);A. (D.) nigropunctata(Breuning, 1938);A. (D.) konoi(Hayashi, 1956);A. (D.) yonaguni(Hayashi, 1962);A. (D.) nigrostictica(Breuning, 1967);A. (D.) siamana(Breuning, 1974);A. (D.) praelongipes(Kusama and Irie, 1976);A. (D.) kumei(Takakuwa, 1991).
A New and Fast Multiphase Image Segmentation Model for Color Images
Authors: Yang Yunyun , Wu Boying
Published: March 2012

This paper presents a new and fast multiphase image segmentation model for color images. We propose our model by incorporating the globally convex image segmentation method and the split Bregman method into the piecewise constant multiphase Vese‐Chan model for color images. We have applied our model to many synthetic and real color images. Numerical results show that our model can segment color images with multiple regions and represent boundaries with complex topologies, including triple junctions. Comparison with the Vese‐Chan model demonstrates the efficiency of our model. Besides, our model does not require a priori denoising step and is robust with respect to noise.
Simulation for Sludge Flocculation I: Brownian Dynamic Simulation for Perikinetic Flocculation of Charged Particle
Authors: Liu Linshuang , Yang Guolu , Yu Minghui
Published: March 2012

To investigate sludge drying process, a numerical simulation based on Brownian dynamic for the floc with uncharged and charged particles was conducted. The Langevin equation is used as dynamical equation for tracking each particle in a floc. An initial condition and periodic boundary condition which well conformed to reality is used for calculating the floc growth process. Each cell consists of 1000 primary particles with diameter 0.1 ~ 4 μm. Floc growth is related to the thermal force and the electrostatic force. The electrostatic force on a particle in the simulation cell is considered as the sum of electrostatic forces from other particles in the original cell and its replicate cells. It is assumed that flocs are charged with precharged primary particles in dispersion system by ionization. By the analysis of the simulation figures, on one hand, the effects of initial particle size and sludge density on floc smashing time, floc radius of gyration, and fractal dimension were discussed. On the other hand, the effects of ionization on floc smashing time and floc structure were presented. This study has important practical value in the high‐turbidity water treatment, especially for sludge drying.
Static Electric Force and Measurement Principle of Material Constants in Electrostrictive Material
Authors: Kuang Zhen-Bang
Published: March 2012

Electrostrictive materials convert electrical energy into mechanical energy and vice versa. They are extensive applied as intelligent materials in the engineering structures. The governing equations in electrostrictive media under the quasistatic electric field are very important for the measurement of material constants and the research on the strength and function. But some theoretical problems should be further clarified. In this paper, the electric force acting on the material is studied and the complete governing equations will be given. In this paper a possible method to measure electrostrictive coefficients is also discussed.
Hybrid Anion Exchange Hollow Fiber Membrane for Delivery of Ionic Drugs
Authors: Wang Na , Cui Mengbing , Wu Cuiming , Cheng Yiyun , Xu Tongwen
Published: March 2012

Hybrid anion exchange hollow fiber membranes (HAEHFMs) based on bromomethylated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) are proposed as potential drug carriers for four anionic model drugs, including the sodium salts of benzoate (NaBS), salicylate (NaSA), meta-amino salicylate (NaMAS), and loxoprofen (NaLS). The results of the static loading and release experiments suggest that electrostatic interaction, hydrogen bonding, and hydrophobic interaction are the main interaction patterns between the membrane and the drugs. And they are directly influenced by the external phase conditions and the drug physicochemical characteristics, such as structure, molecular weight, dissociation (pKa), and hydrogen bonding capability. Among the four different drugs, NaSA and NaMAS appear to be the most suitable for controlled release by the HAEHFM due to their excellent adsorption/release behaviors.
High-Temperature Photovoltaic Effect in Heterojunction
Authors: Ni Hao , Zhao Kun , Liu Xiaojin , Xiang Wenfeng , Zhao Songqing , Kong Yu-Chau , Wong Hong-Kuen
Published: March 2012

We fabricated a heterojunction of /n-Si and investigated its electronic transport and ultraviolet photovoltaic properties at higher temperature up to 673 K. The rectifying behaviors vanished with the energy-band structure evolvement from 300 to 673 K. Under irradiation of a 248 nm pulse laser, the peak values of open-circuit photovoltage and short-circuit photocurrent decreased drastically. This understanding of the temperature-related current-voltage behavior and ultraviolet photodetection of oxide heterostructures should open a route for devising future microelectronic devices working at high temperature. PACS: 73.40.Lq, 71.27.+ a, 73.50.Pz.
Study of Tool Wear and Overcut in EDM Process with Rotary Tool and Magnetic Field
Authors: Teimouri Reza , Baseri Hamid
Published: March 2012

Tool wear and workpiece overcut have been studied in electrical discharge machining process with rotational external magnetic field and rotational electrode. Experiments have been divided to three main regimes, namely, low-energy regime, middle-energy regime, and high-energy regime. The influence of process parameters were investigated on electrode wear rate and overcut. Results indicate that applying a magnetic field around the machining gap increases the electrode wear rate and overcut. Also, rotation of the tool has negative effect on overcut.