bluuebunny/crossref_metadata_2025 huggingface dataset:
Unified measurement system with suction control for measuring hysteresis in soil‐gas transport parameters
Authors: Rouf Md Abdur , Hamamoto Shoichiro , Kawamoto Ken , Sakaki Toshihiro , Komatsu Toshiko , Moldrup Per
Published: January 2012

A unified measurement system with suction control (UMS_SC) was developed for measuring soil water characteristics curves (SWCC) and gas transport parameters under alternating drying and wetting cycles. The new system consists of a diffusion chamber, sample ring, porous plate, tensiometer, moisture sensor, oxygen electrodes, and air pressure gauges. The SWCC and gas transport parameters [gas diffusion coefficient (Dp) and air permeability (ka)] for two different porous materials, Toyoura sand and granulated slag, were simultaneously measured under drying and wetting cycles. The SWCC and gas transport parameters measured by UMS_SC were consistent with recent models and independently measured data on exactly the same materials using standard experimental setups from literature. For an applied water suction head of less than 50 cm and corresponding water saturation of around 0.3–0.5, the UMS_SC data documented hysteretic (nonsingular) behavior in both measured Dp and ka under repeated drying and wetting cycles. The hysteretic behavior was insignificant for water and air contents but large for both gas transport parameters when applying suction, and hysteretic effects were larger for air permeability than for gas diffusivity. Additionally, hysteresis in the percolation threshold (soil‐air content where gas transport ceases due to interconnected water‐filled pores) for both gas diffusion and air permeability was insignificant for both materials. These findings should be taken into account when developing models for diffusive and convective gas transport and their parameters in variably saturated porous media.
Stochastic simulation of nonstationary oscillation hydroclimatic processes using empirical mode decomposition
Authors: Lee T. , Ouarda T. B. M. J.
Published: January 2012

Nonstationary oscillation (NSO) processes are observed in a number of hydroclimatic data series. Stochastic simulation models are useful to study the impacts of the climatic variations induced by NSO processes into hydroclimatic regimes. Reproducing NSO processes in a stochastic time series model is, however, a difficult task because of the complexity of the nonstationary behaviors. In the current study, a novel stochastic simulation technique that reproduces the NSO processes embedded in hydroclimatic data series is presented. The proposed model reproduces NSO processes by utilizing empirical mode decomposition (EMD) and nonparametric simulation techniques (i.e., k‐nearest‐neighbor resampling and block bootstrapping). The model was first tested with synthetic data sets from trigonometric functions and the Rössler system. The North Atlantic Oscillation (NAO) index was then examined as a real case study. This NAO index was then employed as an exogenous variable for the stochastic simulation of streamflows at the Romaine River in the province of Quebec, Canada. The results of the application to the synthetic data sets and the real‐world case studies indicate that the proposed model preserves well the NSO processes along with the key statistical characteristics of the observations. It was concluded that the proposed model possesses a reasonable simulation capacity and a high potential as a stochastic model, especially for hydroclimatic data sets that embed NSO processes.
Assessment of post-fire changes in land surface temperature and surface albedo, and their relation with fire - burn severity using multitemporal MODIS imagery
Authors: Veraverbeke Sander , Verstraeten Willem W. , Lhermitte Stefaan , Van De Kerchove Ruben , Goossens Rudi
Published: January 2012

This study evaluates the effects of the large 2007 Peloponnese (Greece) wildfires on changes in broadband surface albedo (α), daytime land surface temperature (LSTd) and night-time LST (LSTn) using a 2-year post-fire time series of Moderate Resolution Imaging Spectroradiometer satellite data. In addition, it assesses the potential of remotely sensed α and LST as indicators for fire–burn severity. Immediately after the fire event, mean α dropped up to 0.039 (standard deviation = 0.012) (P < 0.001), mean LSTd increased up to 8.4 (3.0) K (P < 0.001), and mean LSTn decreased up to –1.2 (1.5) K (P < 0.001) for high-severity plots (P < 0.001). After this initial alteration, fire-induced changes become clearly smaller and seasonality starts governing the α and LST time series. Compared with the fire-induced changes in α and LST, the post-fire NDVI drop was more persistent in time. This temporal constraint restricts the utility of remotely sensed α and LST as indicators for fire–burn severity. For the times when changes in α and LST were significant, the magnitude of changes was related to fire–burn severity, revealing the importance of vegetation as a regulator of land surface energy fluxes.
Do Behavioral Syndromes Affect Foraging Strategy and Risk‐Taking in a Juvenile Fish Predator?
Authors: Nannini Michael A. , Parkos Joseph , Wahl David H.
Published: January 2012

Behavioral syndromes often have individuals varying along a continuum of personality traits. Some individuals exhibit bold or aggressive behaviors and are willing to explore novel stimuli, whereas others are shy and tend to avoid novel stimuli. Species that undergo an ontogenetic diet shift may experience a particularly important benefit if the shift to more‐profitable prey is linked to this willingness to explore novel stimuli. However, actively selecting more‐evasive prey can make these predators more vulnerable to predation themselves. We used largemouth bass Micropterus salmoides as a model to examine the role of behavioral syndromes in structuring predator strategies for dealing with these conflicting environmental pressures. Exploration behavior was first determined by testing willingness to explore a novel environment. Behaviors were then measured in two other contexts where exploration and boldness could potentially have fitness consequences: (1) the likelihood of consuming a novel prey item and (2) movement in the presence of a predator. Fish that tended to be exploratory consumed more total prey biomass than did fish that avoided a novel environment; however, the nonexploratory fish were more discriminating and targeted novel fish prey to a greater extent than did bold fish. Activity in the presence of a predator was not related to any other factor measured. Although our results provide no evidence that behavioral syndromes influence the predator avoidance behavior of largemouth bass, these syndromes do appear to play an important role in prey selection. Our study indicates that although behavioral syndromes do not necessarily affect behavior across all environmental contexts, they may influence feeding strategies and thus could potentially affect the timing of dietary shifts.
Patterns of Hybridization of Nonnative Cutthroat Trout and Hatchery Rainbow Trout with Native Redband Trout in the Boise River, Idaho
Authors: Neville Helen M. , Dunham Jason B.
Published: January 2012

Hybridization is one of the greatest threats to native fishes. Threats from hybridization are particularly important for native trout species as stocking of nonnative trout has been widespread within the ranges of native species, thus increasing the potential for hybridization. While many studies have documented hybridization between native cutthroat trout Oncorhynchus clarkii and nonnative rainbow trout O. mykiss, fewer have focused on this issue in native rainbow trout despite widespread threats from introductions of both nonnative cutthroat trout and hatchery rainbow trout. Here, we describe the current genetic (i.e., hybridization) status of native redband trout O. mykiss gairdneri populations in the upper Boise River, Idaho. Interspecific hybridization was widespread (detected at 14 of the 41 sampled locations), but high levels of hybridization between nonnative cutthroat trout and redband trout were detected in only a few streams. Intraspecific hybridization was considerably more widespread (almost 40% of sampled locations), and several local populations of native redband trout have been almost completely replaced with hatchery coastal rainbow trout O. mykiss irideus; other populations exist as hybrid swarms, some are in the process of being actively invaded, and some are maintaining genetic characteristics of native populations. The persistence of some redband trout populations with high genetic integrity provides some opportunity to conserve native genomes, but our findings also highlight the complex decisions facing managers today. Effective management strategies in this system may include analysis of the specific attributes of each site and population to evaluate the relative risks posed by isolation versus maintaining connectivity, identifying potential sites for control or eradication of nonnative trout, and long-term monitoring of the genetic integrity of remaining redband trout populations to track changes in their status.

Received February 24, 2011; accepted August 4, 2011
Combustion waves in hydraulically resisted systems
Authors: Brailovsky I. , Kagan L. , Sivashinsky G.
Published: January 2012

The effects of hydraulic resistance on the burning of confined/obstacle-laden gaseous and gas-permeable solid explosives are discussed on the basis of recent research. Hydraulic resistance is found to induce a new powerful mechanism for the reaction spread (diffusion of pressure) allowing for both fast subsonic as well as supersonic propagation. Hydraulic resistance appears to be of relevance also for the multiplicity of detonation regimes as well as for the transitions from slow conductive to fast convective, choked or detonative burning. A quasi-one-dimensional Fanno-type model for premixed gas combustion in an obstructed channel open at the ignition end is discussed. It is shown that, similar to the closed-end case studied earlier, the hydraulic resistance causes a gradual precompression and preheating of the unburned gas adjacent to the advancing deflagration, which leads (after an extended induction period) to a localized autoignition that triggers an abrupt transition from deflagrative to detonative combustion. In line with the experimental observations, the ignition at the open end greatly encumbers the transition (compared with the closed-end case), and the deflagration practically does not accelerate up to the very transition point. Shchelkin's effect, that ignition at a small distance from the closed end of a tube facilitates the transition, is described.
Gas-phase detonation propagation in mixture composition gradients
Authors: Kessler D. A. , Gamezo V. N. , Oran E. S.
Published: January 2012

The propagation of detonations through several fuel–air mixtures with spatially varying fuel concentrations is examined numerically. The detonations propagate through two-dimensional channels, inside of which the gradient of mixture composition is oriented normal to the direction of propagation. The simulations are performed using a two-component, single-step reaction model calibrated so that one-dimensional detonation properties of model low- and high-activation-energy mixtures are similar to those observed in a typical hydrocarbon–air mixture. In the low-activation-energy mixture, the reaction zone structure is complex, consisting of curved fuel-lean and fuel-rich detonations near the line of stoichiometry that transition to decoupled shocks and turbulent deflagrations near the channel walls where the mixture is extremely fuel-lean or fuel-rich. Reactants that are not consumed by the leading detonation combine downstream and burn in a diffusion flame. Detonation cells produced by the unstable reaction front vary in size across the channel, growing larger away from the line of stoichiometry. As the size of the channel decreases relative to the size of a detonation cell, the effect of the mixture composition gradient is lessened and cells of similar sizes form. In the high-activation-energy mixture, detonations propagate more slowly as the magnitude of the mixture composition gradient is increased and can be quenched in a large enough gradient.
Plasma-assisted ignition and deflagration-to-detonation transition
Authors: Starikovskiy Andrey , Aleksandrov Nickolay , Rakitin Aleksandr
Published: January 2012

Non-equilibrium plasma demonstrates great potential to control ultra-lean, ultra-fast, low-temperature flames and to become an extremely promising technology for a wide range of applications, including aviation gas turbine engines, piston engines, RAMjets, SCRAMjets and detonation initiation for pulsed detonation engines. The analysis of discharge processes shows that the discharge energy can be deposited into the desired internal degrees of freedom of molecules when varying the reduced electric field,
E
/
n
, at which the discharge is maintained. The amount of deposited energy is controlled by other discharge and gas parameters, including electric pulse duration, discharge current, gas number density, gas temperature, etc. As a rule, the dominant mechanism of the effect of non-equilibrium plasma on ignition and combustion is associated with the generation of active particles in the discharge plasma. For plasma-assisted ignition and combustion in mixtures containing air, the most promising active species are O atoms and, to a smaller extent, some other neutral atoms and radicals. These active particles are efficiently produced in high-voltage, nanosecond, pulse discharges owing to electron-impact dissociation of molecules and electron-impact excitation of N
2
electronic states, followed by collisional quenching of these states to dissociate the molecules. Mechanisms of deflagration-to-detonation transition (DDT) initiation by non-equilibrium plasma were analysed. For longitudinal discharges with a high power density in a plasma channel, two fast DDT mechanisms have been observed. When initiated by a spark or a transient discharge, the mixture ignited simultaneously over the volume of the discharge channel, producing a shock wave with a Mach number greater than 2 and a flame. A gradient mechanism of DDT similar to that proposed by Zeldovich has been observed experimentally under streamer initiation.
Analytical studies of the dynamics of gaseous detonations
Authors: Clavin Paul , Williams Forman A.
Published: January 2012

The dynamics of gaseous detonation is revisited on the basis of analytical studies. Problems of initiation, quenching, pulsation and cellular structures are addressed. The objective is to improve our physical understanding of the development, stability and structure of gaseous detonations. New insights that have been gained from analytical investigations are emphasized. Specific problems discussed are the direct initiation of detonations in spherical geometry, the spontaneous soft initiation and quenching of detonations in a temperature gradient, the stability threshold and dynamics of galloping detonations, and the multi-dimensional instability threshold and cellular structures of both overdriven and near-Chapman–Jouguet detonations. It will be seen that, although there have been many accomplishments, some outstanding questions remain.
Explosion propagation in inert porous media
Authors: Ciccarelli G.
Published: January 2012

Porous media are often used in flame arresters because of the high surface area to volume ratio that is required for flame quenching. However, if the flame is not quenched, the flow obstruction within the porous media can promote explosion escalation, which is a well-known phenomenon in obstacle-laden channels. There are many parallels between explosion propagation through porous media and obstacle-laden channels. In both cases, the obstructions play a duel role. On the one hand, the obstruction enhances explosion propagation through an early shear-driven turbulence production mechanism and then later by shock–flame interactions that occur from lead shock reflections. On the other hand, the presence of an obstruction can suppress explosion propagation through momentum and heat losses, which both impede the unburned gas flow and extract energy from the expanding combustion products. In obstacle-laden channels, there are well-defined propagation regimes that are easily distinguished by abrupt changes in velocity. In porous media, the propagation regimes are not as distinguishable. In porous media the entire flamefront is affected, and the effects of heat loss, turbulence and compressibility are smoothly blended over most of the propagation velocity range. At low subsonic propagation speeds, heat loss to the porous media dominates, whereas at higher supersonic speeds turbulence and compressibility are important. This blending of the important phenomena results in no clear transition in propagation mechanism that is characterized by an abrupt change in propagation velocity. This is especially true for propagation velocities above the speed of sound where many experiments performed with fuel–air mixtures show a smooth increase in the propagation velocity with mixture reactivity up to the theoretical detonation wave velocity.
Astrophysical explosions: from solar flares to cosmic gamma-ray bursts
Authors: Wheeler J. Craig
Published: January 2012

Astrophysical explosions result from the release of magnetic, gravitational or thermonuclear energy on dynamical time scales, typically the sound-crossing time for the system. These explosions include solar and stellar flares, eruptive phenomena in accretion discs, thermonuclear combustion on the surfaces of white dwarfs and neutron stars, violent magnetic reconnection in neutron stars, thermonuclear and gravitational collapse supernovae and cosmic gamma-ray bursts, each representing a different type and amount of energy release. This paper summarizes the properties of these explosions and describes new research on thermonuclear explosions and explosions in extended circumstellar media. Parallels are drawn between studies of terrestrial and astrophysical explosions, especially the physics of the transition from deflagration-to-detonation.
Autoignitions and detonations in engines and ducts
Authors: Bradley Derek
Published: January 2012

The origins of autoignition at hot spots are analysed and the pressure pulses that arise from them are related to knock in gasoline engines and to developing detonations in ducts. In controlled autoignition engines, autoignition is benign with little knock. There are several modes of autoignition and the existence of an operational peninsula, within which detonations can develop at a hot spot, helps to explain the performance of various engines. Earlier studies by Urtiew and Oppenheim of the development of autoignitions and detonations ahead of a deflagration in ducts are interpreted further, using a simple one-dimensional theory of the generation of shock waves ahead of a turbulent flame. The theory is able to indicate entry into the domain of autoignition in an ‘explosion in the explosion’. Importantly, it shows the influence of the turbulent burning velocity, and particularly its maximum attainable value, upon autoignition. This value is governed by localized flame extinctions for both turbulent and laminar flames. The theory cannot show any details of the transition to a detonation, but regimes of eventually stable or unstable detonations can be identified on the operational peninsula. Both regimes exhibit transverse waves, triple points and a cellular structure. In the case of unstable detonations, transverse waves are essential to the continuing propagation. For hazard assessment, more needs to be known about the survival, or otherwise, of detonations that emerge from a duct into the same mixture at atmospheric pressure.
The physics, chemistry and dynamics of explosions
Authors: Oran Elaine S. , Williams Forman A.
Published: January 2012

The motivation for devoting a Theme Issue to explosions is discussed. As subsequent articles in the issue are written with the assumption that the reader has had a certain amount of previous exposure to the subject, some of the history and necessary background information are presented here. The topics on explosions that will be encountered in the remaining articles are previewed. Finally, several important future outstanding research problems, beyond those addressed in the following articles, are discussed, with the objective of complementing the coverage of explosions in this issue.
Large vapour cloud explosions, with particular reference to that at Buncefield
Authors: Bradley D. , Chamberlain G. A. , Drysdale D. D.
Published: January 2012

This paper first briefly surveys the energy releases in some major accidents. It then examines the analyses of the explosion at the Buncefield fuel storage site in the UK, one of the most intense accidental explosions in recent times. This followed the release of approximately 300 tonnes of winter-grade gasoline, when a 15 m high storage tank was overfilled for about 40 min before ignition of the resulting flammable mixture. The ensuing explosion was of a severity that had not been identified previously in a major hazard assessment of this type of facility. It was therefore imperative to investigate the event thoroughly and develop an understanding of the underlying mechanisms to inform future prevention, mitigation and land-use planning issues. The investigation of the incident was overseen by the Buncefield Major Incident Investigation Board. A separate Explosion Mechanism Advisory Group examined the evidence and reported on the severity of the explosion. It concluded that additional work was necessary and recommended that a two-stage project be initiated, phase 1 of which has been completed. The analyses of the damage and the derivation of explosion over-pressures are described. Possible explosion mechanisms and the evidence for them at Buncefield are discussed, in the light of other major incidents. Mechanisms that are reviewed include high-speed turbulent combustion, quasi-detonations, fully developed detonations, the generation of fireballs, flame instabilites, radiative heat transfer and aspects of two-phase burning. Of particular importance is the acceleration of turbulent flames along the line of trees and hedgerows. A number of conclusions are drawn and suggestions made for further research.
Air Monitoring: New Advances in Sampling and Detection
Authors: Watson Nicola , Davies Stephen , Wevill David
Published: January 2012

As the harmful effects of low-level exposure to hazardous organic air pollutants become more evident, there is constant pressure to improve the detection limits of indoor and ambient air monitoring methods, for example, by collecting larger air volumes and by optimising the sensitivity of the analytical detector. However, at the other end of the scale, rapid industrialisation in the developing world and growing pressure to reclaim derelict industrial land for house building is driving the need for air monitoring methods that can reliably accommodate very-high-concentration samples in potentially aggressive matrices. This paper investigates the potential of a combination of two powerful gas chromatography—based analytical enhancements—sample preconcentration/thermal desorption and time-of-flight mass spectrometry—to improve quantitative and qualitative measurement of very-low-(ppt) level organic chemicals, even in the most complex air samples. It also describes new, practical monitoring options for addressing equally challenging high-concentration industrial samples.
EnteropathogenicEscherichia coliAssociated with Diarrhea in Children in Cairo, Egypt
Authors: Behiry Iman K. , Abada Emad A. , Ahmed Entsar A. , Labeeb Rania S.
Published: January 2012

In this study we isolate and identify the EnteropathogenicEscherichia coli(EPEC) causing diarrhea in children less than five years in Cairo, Egypt, during different seasons. Children younger than five years with diarrhea, attending the Pediatric Gastroenterology Intensive Care Unit of the Cairo University Pediatric Hospital in one year period were our group of study. Our control group was age and sex matched concurrent healthy children. The identifiedE. coliisolates were subjected to antimicrobial disc diffusion susceptibility test and further identified for EPEC serotype by slide agglutination test, using antiserumE. colisomatic trivalent I (O111, O55, O26) according to the instructions of the manufacturer. Out of 134 patients 5.2% of them revealed EPEC in the fecal sample, while the 20 children control group showed no EPEC isolates in their samples. Our EPEC frequency showed variations from the compared results of other studies. Higher rate of EPEC (18.7%) was found in patients between 2 to 3 years, while EPEC rate was (7.5%) in patients less than 6 months old, with . EPEC was identified from fecal specimens as a unique pathogen or associated with other pathogens in acute and chronic diarrhea in children. EPEC were detected in all seasons except in winter, and was predominant in summer season. Four (57%) EPEC isolates were resistant to ampicillin, ticarcillin, and cotrimoxazole, and (14.3%) to the third generation cephalosporins.
Regulatory Immunotherapy in Bone Marrow Transplantation
Authors: Morales-Tirado Vanessa , Luszczek Wioleta , van der Merwe Marié , Pillai Asha
Published: January 2012

Every year individuals receive hematopoietic stem cell transplantation (HSCT) to eradicate malignant and nonmalignant disease. The immunobiology of allotransplantation is an area of ongoing discovery, from the recipient's conditioning treatment prior to the transplant to the donor cell populations responsible for engraftment, graft-versus-host disease, and graft-versus-tumor effect. In this review, we focus on donor-type immunoregulatory T cells, namely, natural killer T cells (NKT) and regulatory T cells (Treg), and their current and potential roles in tolerance induction after allogeneic HSCT.
Na+–K+–2Cl− cotransporter type 2 trafficking and activity: The role of interacting proteins
Authors: Carmosino Monica , Procino Giuseppe , Svelto Maria
Published: January 2012

The central role of Na+–K+–2Cl− cotransporter type 2 (NKCC2) in vectorial transepithelial salt reabsorption in thick ascending limb cells from Henle's loop in the kidney is evidenced by the effects of loop diuretics, the pharmacological inhibitors of NKCC2, that are amongst the most powerful antihypertensive drugs available to date. Moreover, genetic mutations of the NKCC2 encoding gene resulting in impaired apical targeting and function of NKCC2 transporter give rise to a pathological phenotype known as type I Bartter syndrome, characterised by a severe volume depletion, hypokalaemia and metabolic alkalosis with high prenatal mortality. On the contrary, excessive NKCC2 activity has been linked with inherited hypertension in humans and in rodent models. Interestingly, in animal models of hypertension, NKCC2 upregulation is achieved by post‐translational mechanisms underlining the need to analyse the molecular mechanisms involved in the regulation of NKCC2 trafficking and activity to gain insights in the pathogenesis of hypertension.
A role for microtubules in endothelial cell protrusion in three‐dimensional matrices
Authors: Martins Gabriel G. , Kolega John
Published: January 2012

Background information

Most cells reside in vivo in a three‐dimensional (3D) environment surrounded by extracellular matrix and other neighbouring cells, conditions that are different from those found by cells cultured in vitro on two‐dimensional (2D) substrata. Cell morphology and behaviour are very different under these two different conditions, but the structural basis for these differences is still not understood, especially the role of microtubules (MTs). To address this issue, we studied the early spreading behaviour of bovine aortic endothelial cells (BAECs) cultured in 3D collagen matrices and on 2D substrata, in the presence of MT‐disrupting drugs.

Results

We found that depolymerisation of MTs greatly reduces the ability of BAECs to form large and stable protrusions inside 3D collagen matrices, an effect that is less pronounced when the cells are cultured on 2D substrata. Colcemid‐treated BAECs inside 3D matrices begin assembling protrusions and pull on the matrix, but they fail to extend those protrusions deep into the matrix. It has been previously reported that MT disruption affects Rho signalling which may result in increased cell rigidity and adhesiveness to 2D matrices. Accordingly, we demonstrate that colcemid treatment indeed leads to activation of Rho‐kinase (ROCK) targets, which in turn results in activation of regulatory myosin light chains, and that blocking of ROCK mitigates some of the effects of MT disruption in cell spreading in 3D.

Conclusions

Our results show that MT depolymerisation is particularly disruptive when cells interact with pliable 3D matrices, suggesting a role for MTs and the Rho pathway in the fine‐tuning of contractile and adhesive forces necessary to sustain cell motility in vivo.
Timing of gonadectomy in adult women with complete androgen insensitivity syndrome (CAIS): patient preferences and clinical evidence
Authors: Deans Rebecca , Creighton Sarah M. , Liao Lih‐Mei , Conway Gerard S.
Published: January 2012

Objective  Adult women with complete androgen insensitivity syndrome (CAIS) are increasingly likely to defer or decline gonadectomy despite counselling about malignancy risk. The objectives of this study were to review the evidence on the risk of gonadal malignancy in adult women with CAIS and to explore women’s reasons for deferring gonadectomy.

Study Design  A case series and literature review.

Patients  Sixteen women with CAIS over the age of 18 years who have elected to defer gonadectomy.

Results  Sixty‐two relevant papers were identified. Of these, 14 confirmed that tumours had been reported in 98 adults. Taking into account the limitations of combining historic case series, this review estimates a risk of gonadal malignancy of 14% (range 0% and 22%) in adults with CAIS. The most common reasons women offered for deferring gonadectomy included inconvenience of surgery, concern about surgical risk and reluctance to take hormone replacement therapy.

Conclusions  Perceived benefits for retaining gonads in women with CAIS are prompting more women to keep their gonads in situ. An accurate estimate for adult malignancy risk is unavailable, and the risks currently quoted may be falsely reassuring.
Integrin signalling and function in immune cells
Authors: Zhang Yanbo , Wang Hongyan
Published: January 2012

Integrins not only mediate cell–cell and cell–extracellular matrix adhesion, but also affect the multitude of signal transduction cascades in control of cell survival, proliferation, differentiation and organ development. Mutations in integrins or the major effectors of integrin signalling pathways cause defective organ development, immunodeficiency, cancer or autoimmune disease. Understanding of the signalling events that drive integrin activation and signalling is therefore crucial to uncover the molecular mechanisms of these diseases. This review discusses the key signalling complexes regulating integrin activation and function in both ‘inside‐out’ and ‘outside‐in’ pathways in T lymphocytes, including kinases, SLP‐76, VAV1, ADAP, SKAP‐55, RapL, RIAM, Rap1, Talin and Kindlin.
Estimation of tissue osteopontin levels before and after different traditional therapeutic modalities in psoriatic patients
Authors: El‐Eishi N.H. , Kadry D. , Hegazy R.A. , Rashed L.
Published: January 2012

Background  Several lines of evidences support a major role for Th1 cells in psoriasis. Treatment of psoriasis with cyclosporine, methotrexate and psoralen plus ultraviolet A (PUVA) is associated with clinical improvement and decrease in epidermal hyperplasia. Osteopontin (OPN) exerts a T‐helper type 1 (Th1) cytokine function, regulating inflammatory cell accumulation and function.

Objective  To detect the effects of methotrexate, cyclosporine and PUVA on OPN expression in psoriatic plaques, and whether these changes correlate with clinical response.

Methods  For three groups of psoriatic patients (each including 12 patients), the Psoriasis Area Severity Index (PASI) and levels of lesional skin OPN were determined using enzyme‐linked immunosorbent assays before and after treatment with methotrexate, cyclosporine or PUVA. Skin biopsies from 20 healthy volunteers served as control for OPN levels in normal skin.

Results  Baseline lesional skin of psoriatic patients showed a statistically significant elevation of OPN levels in comparison to controls. Three months after therapy, the three therapeutic modalities were associated with a significant decrease in the mean levels of PASI and tissue OPN, with the PUVA group showing the highest level of reduction in OPN levels and cyclosporine group showing the highest level of reduction in PASI.

Conclusion  Our study points to the possible role played by OPN in the pathogenesis of psoriasis and in reflecting disease severity. These standard therapeutic modalities used in the current study were associated with a significant decrease in PASI and OPN levels. They constitute highly effective therapeutic modalities for psoriasis, which might exert their anti‐psoriatic activity partially through altering the expression of OPN.
Status of oxidative stress on lesional skin surface of plantar warts
Authors: Arican O. , Ozturk P. , Kurutas E.B. , Unsal V.
Published: January 2012

Background  Warts are abnormal skin growths caused by human papilloma virus (HPV) infections within the skin of the patients. Sometimes the disease is difficult to treatment, and also, the relationship between HPV and some forms of skin cancers is important. The cutaneous oxidative stress status of warts is absent in the literature.

Objectives  To evaluate the role of oxidative stress in affected skin areas in a group of patients with plantar warts.

Methods  Thirty‐six consecutive patients with a diagnosis of plantar warts were enrolled. The samples were obtained by scraping the skin surface. Superoxide dismutase (SOD) and catalase (CAT) activities and malondialdehyde (MDA) levels were measured spectrophotometrically at samples.

Results  The SOD activity was significantly lower, and the MDA level was significantly higher on the lesional area than on the non‐lesional area (P < 0.001 for each), and there was no significant difference in the CAT activity between both areas (P = 0.11).

Conclusion  Cutaneous oxidative stress in patients with plantar warts may play a role in pathogenesis of the disease. The addition of topical drugs with antioxidative effects may be valuable in the treatment of warts.
Ca2+ signals of astrocytes are modulated by the NAD+/NADH redox state
Authors: Requardt Robert P. , Hirrlinger Petra G. , Wilhelm Franziska , Winkler Ulrike , Besser Stefanie , Hirrlinger Johannes
Published: January 2012

J. Neurochem. (2012) 120, 1014–1025.

Astrocytes are important glial cells in the brain providing metabolic support to neurons as well as contributing to brain signaling. These different functional levels have to be highly coordinated to allow for proper cell and brain function. In this study, we show that in astrocytes the NAD+/NADH redox state modulates dopamine‐induced Ca2+ signals thereby connecting metabolism and Ca2+ signaling. Application of dopamine induced a dose‐dependent increase in Ca2+ signal frequency in these cells, which was dependent on D1‐receptor signaling, glycolytic activity, an increase in cytosolic NADH and inositol 1,4,5‐triphosphate receptor operated intracellular Ca2+ stores. Application of dopamine at a low concentration (1 μM) did not induce an increase in Ca2+ signal frequency by itself. However, simultaneously increasing cytosolic NADH content either by direct application of NADH or by application of lactate resulted in a pronounced increase in Ca2+ signal frequency. This increase could be blocked by co‐application of pyruvate, suggesting that indeed the NAD+/NADH redox state is regulating Ca2+ signals. We conclude that at the NAD+/NADH redox state metabolic and signaling information is integrated in astrocytes, thereby most likely contributing to precisely coordinate these different tasks of astrocytes.
Identification of F‐box only protein 7 as a negative regulator of NF‐kappaB signalling
Authors: Kuiken Hendrik J. , Egan David A. , Laman Heike , Bernards Rene , Beijersbergen Roderick L. , Dirac Annette M.
Published: January 2012

The nuclear factor κB (NF‐κB) signalling pathway controls important cellular events such as cell proliferation, differentiation, apoptosis and immune responses. Pathway activation occurs rapidly upon TNFα stimulation and is highly dependent on ubiquitination events. Using cytoplasmic to nuclear translocation of the NF‐κB transcription factor family member p65 as a read‐out, we screened a synthetic siRNA library targeting enzymes involved in ubiquitin conjugation and de‐conjugation for modifiers of regulatory ubiquitination events in NF‐κB signalling. We identified F‐box protein only 7 (FBXO7), a component of Skp, Cullin, F‐box (SCF)‐ubiquitin ligase complexes, as a negative regulator of NF‐κB signalling. F‐box protein only 7 binds to, and mediates ubiquitin conjugation to cIAP1 and TRAF2, resulting in decreased RIP1 ubiquitination and lowered NF‐κB signalling activity.
Using ESTs database to predict and validate single polymorphisms at the HLA system
Authors: Figueiredo T. C. , de Oliveira J. R. M.
Published: January 2012

We propose a bioinformatics pipeline in which we use an ESTs database to predict and validate single‐nucleotide polymorphisms (SNPs) directly linked to gene‐coding regions at the HLA class I genes (HLA‐A, HLA‐B and HLA‐C). Annotation originated from our analysis revealed various classes of possible new variations that may indicate possible new alleles. Thus, bioinformatics pipelines seem to be useful approaches to help screening for novel genetic variations at the HLA panel, and further analysis will foster this aim to provide celerity at the massive analysis of data currently generated in large‐scale high‐throughput experiments.
Polymorphisms of NOD2 and the risk of tuberculosis: a validation study in the Chinese population
Authors: Pan H. , Dai Y. , Tang S. , Wang J.
Published: January 2012

A genome‐wide association study (GWAS) of leprosy reported four specific genetic polymorphisms of NOD2 that were associated with susceptibility to Mycobacterium leprae in China. Considering the role of NOD2 in innate immune defence, we performed a study in a Chinese population to determine whether the same SNPs of NOD2 that were associated with disease caused by M. leprae were also associated with disease caused by Mycobacterium tuberculosis. We performed a frequency‐matched case–control study in 1043 patients with pulmonary tuberculosis and 808 unaffected controls. All subjects were >15 years old and were Han Chinese from Jiangsu Province. We extracted DNA from a blood sample from each study participant. SNPs of rs3135499, rs7194886, rs8057341 and rs9302752 in the NOD2 gene were genotyped using a TaqMan‐based allelic discrimination system. Using all possible patients with tuberculosis as cases, no significant association was found between the four specific SNPs and the risk of tuberculosis. In a subgroup analysis restricted to cases with bacteriologically confirmed tuberculosis (sputum culture positive), the variant genotype of rs7194886 was significantly associated with an altered risk of tuberculosis. Compared with the CC genotype, individuals carrying the CT/TT genotype of rs7194886 had an increased risk [odds ratio (OR) 1.35, 95% confidence interval (CI) (1.05–1.72)]. The association was stronger among tobacco smokers and males. By haplotype analysis, rs9302752C–rs7194886T was associated with an increased risk of bacteriologically confirmed tuberculosis (sputum culture positive) (P = 0.039), but it was not significant after correcting for multiple comparisons. In summary, genetic polymorphisms of the SNP rs7194886 in the NOD2 gene, which were discovered in the GWAS of leprosy, might also be associated with the pulmonary tuberculosis in the Chinese population.
The influence of age and aerobic fitness: effects on mitochondrial respiration in skeletal muscle
Authors: Larsen S. , Hey‐Mogensen M. , Rabøl R. , Stride N. , Helge J. W. , Dela F.
Published: January 2012

Aim:

Mitochondrial function has previously been studied in ageing, but never in humans matched for maximal oxygen uptake (). Furthermore, the influence of ageing on mitochondrial substrate sensitivity is not known.

Methods:

Skeletal muscle mitochondrial respiratory capacity and mitochondrial substrate sensitivity were measured by respirometry in young (23 ± 3 years) and middle‐aged (53 ± 3 years) male subjects with similar . Protocols for respirometry included titration of substrates for complex I (glutamate), complex II (succinate) and both (octanoyl carnitine) for calculation of substrate sensitivity (C50). Myosin heavy chain (MHC) isoforms, citrate synthase (CS) and β‐hydroxy‐acyl‐CoA‐dehydrogenase (HAD) activity, mitochondrial DNA (mtDNA) content, protein levels of complexes I–V and antioxidant defence system [manganese superoxide dismutase (MnSOD)] were measured.

Results:

No differences were found in maximal mitochondrial respiration or C50 with glutamate (2.0 ± 0.3 and 1.8 ± 0.3 mm), succinate (3.7 ± 0.2 and 3.8 ± 0.4 mm) or octanoyl carnitine (47 ± 8 and 56 ± 7 μm) in young and middle‐aged subjects respectively. Normalizing mitochondrial respiration to mtDNA young subjects had a higher (P < 0.05) respiratory capacity per mitochondrion compared to middle‐aged subjects. HAD activity and mtDNA per mg tissue were higher in middle‐aged compared to young subjects. Middle‐aged had a higher MHC I isoform and a lower MHC IIX isoform content compared to young subjects.

Conclusion:

Mitochondrial substrate sensitivity is not affected by ageing. When young and middle‐aged men are carefully matched for , mitochondrial respiratory capacity is also similar. However, per mitochondrion respiratory capacity was lower in middle‐aged compared to young subjects. Thus, when matched for , middle‐aged seem to require a higher mitochondrial content than young subjects.
The impact of pandemic influenza A (H1N1) 2009 on the circulation of respiratory viruses 2009–2011
Authors: Mak Gannon C. , Wong Ann H. , Ho Winnie Y. Y. , Lim Wilina
Published: January 2012

Please cite this paper as: Mak et al. (2012) The impact of pandemic influenza A (H1N1) 2009 on the circulation of respiratory viruses 2009–2011. Influenza and Other Respiratory Viruses 6(3), e6–e10.

Surveillance of respiratory viruses has been conducted for many years at the public health laboratory in Hong Kong. With the occurrence of pandemic influenza A (H1N1) 2009, we observed a change in the seasonality of influenza activity with a seemingly corresponding change in the activity of respiratory syncytial virus, parainfluenza virus, and adenovirus during 2009–2011. This phenomenon could most likely be explained by virus interference.
OPTIMAL MANAGEMENT OF INVASIVE SPECIES WITH DIFFERENT REPRODUCTION AND SURVIVAL STRATEGIES
Authors: ELOFSSON KATARINA , BENGTSSON GÖRAN , GREN ING‐MARIE
Published: January 2012

Abstract In this paper, a numerical model is developed for analyzing the role of species life history and age structure for the optimal management of a commercial resident species that is exposed to an invasive species. It is shown that reproduction and mortality characteristics of both species ands age structure of the invader at the time of invasion are important for the costs of invasions when the invader and resident species compete for scarce resources. Commercially harvested species with low juvenile survival and high reproduction are found to be economically more robust against invasions. Species with these life‐history traits are also the most damaging as invaders. Properties of the harvesting cost function and the discount rate are shown to be of importance for the development of the invader population over time. Hence, it is possible to identify specific combinations of life‐history characteristics and economic conditions under which invasions cause particularly large economic damage.
NOVEL IMPLANT DEVICE TRACKING ALGORITHM FOR WIRELESS HEALTH MONITORING IN WBAN
Authors: LEE CHONG HYUN , BAE JINHO , KIM JOON-YOUNG
Published: January 2012

Positioning implant device in WBAN(Wireless Body Area Network) becomes difficult since signal strength varies in different human tissues and shadowing noise due to body movement. We propose a novel tracking algorithm in WBAN. To estimate position under various human tissues, we adopt a sliding linear window using past position information. By adjusting window parameters, the proposed algorithm is to reduce noise and to track position. The proposed algorithm has little computational increment as compared to the α-β tracker. Throughout simulations, we verify outstanding position tracking performance and insensitivity of initial parameters.
PREPARATION OF CDTE FILMS BY SPRAY PYROLYSIS TECHNIQUE AND THEIR CHARACTERIZATIONS
Authors: GUNJAL S. D. , KHOLLAM Y. B. , SHELKE P. N. , UDAWANT R. R. , TAKWALE M. G. , MOHITE K. C. , KOINKAR PANKAJ
Published: January 2012

In present paper, we report the preparation of CdTe films on thoroughly cleaned glass substrates by using the novel spray pyrolysis technique with CdCl 2. H 2 O and TeO 2 as precursor materials. The films were deposited on glass substrates by using the parameters: (a) spray nozzle - substrate distance = 30 cm, (b) sparing solution conc. = 0.02 M, (c) carrier N 2 gas flow rate = 15 lpm, (d) substrate temperature = 350°C, (e) deposition time = 15 min. (f) N 2 gas purging time for deposition chamber = 45 min. and (g) amount of spray solution = 50 ml solution. The resultant films were characterized by using physical techniques: XRD, FTIR, EDAX and SEM. The characterization results showed that the resultant films are having material purity and cubic CdTe phase purity with zinc blend symmetry. The SEM study revealed the nano-rod morphological feature of CdTe films with rod diameter in range of 100 - 250 nm and average rod length ~ 5μm. The values of absorptance (α) and band gap energy ( E g ) for these films are found to be 0.91 and ~ 1.42 eV respectively. These results indicated the high potential of CdTe films prepared in the present work for solar cell applications.
DEVELOPMENT OF ELEMENTAL AND ISOTOPIC ANALYSIS OF URANIUM AND THORIUM IN MATERIAL USING AN AUTOMATIC SPE INJECTION EQUIPMENT COUPLED TO ICP-DRC-MS
Authors: SAKAMA MINORU , SAZE TAKUYA , KITADE TAKASHI , SHIKINO OSAMU
Published: January 2012

We have investigated to elucidate the relationship between specific activities of radionuclides and elemental concentrations of trace elements in environment and materials. In 2010 the funding for bigger equipment cost of ICPMS (Inductively Coupled Plasma Mass Spectrometry) and automated SPE (Solid Phase Elution) was allowed to insert it in the national revised budget for The University of Tokushima. In this paper, we have briefly introduced a new integrated instrumental system based on ICPMS and SPE for radiation measurement and multi trace elemental analysis.
TENSILE PROPERTIES OF CARBON NANOFIBERS USING NANO-MANIPULATOR INSIDE SCANNING ELECTRON MICROSCOPE
Authors: JANG HOON-SIK , NAHM SEUNG HOON , KIM JUNG HAN , OH KYU HWAN
Published: January 2012

We performed the tensile test of an individual carbon nanofiber (CNF) inside a scanning electron microscope. The mechanical testing system was installed in a scanning electron microscope (SEM). The nano-manipulator was set up in the SEM, and the force sensor, which is formed as a cantilever, was mounted on the nano-manipulator. Then, the force sensor can be controlled by using the nano-manipulator. The CNFs were dispersed on the transmission electron microscope (TEM) grid, and the both end of the CNFs were welded on the TEM grid and the tip of force sensor by exposing electron-beam of the SEM. The tensile test of the CNFs was performed by controlling the nano-manipulator. The load response during the tensile test was obtained by force sensor. Stess-strain curve was obtained from force-displacement curve of CNF after tensile test. The elastic modulus of CNFs was calculated at ~12.5 GPa.