bluuebunny/crossref_metadata_2025 huggingface dataset:
Marital therapy for couples facing advanced cancer: Case review
Authors: McLean Linda M. , Nissim Rinat
Published: September 2007

Objective: The purpose of this article is to provide a brief review of the empirical literature regarding the impact of advanced cancer on the marital relationship. The link between attachment, caregiving, and care-receiving behaviors are defined. Both are activated and challenged in this population because the continuity of the marital bond is threatened, as well as the balance of reciprocal caregiving, often resulting in heightened marital distress.

Methods: Emotionally focused therapy (EFT), based in a synthesis of systemic, experiential, and attachment theory, is introduced as a marital protocol to both conceptualize and potentially mitigate the level of increased marital distress, and to achieve reciprocal caregiving.

Results: Two case studies are presented and support the benefit of EFT for those couples facing end of life.

Significance of results: The findings from these case reviews advance the literature and offer an empirically validated marital therapy for this population. Such a protocol that emphasizes attachment theory and the inherent link to caregiving and care receiving may serve as a powerful tool to both explain and alleviate marital distress for couples facing end of life. Working models of attachment can contribute significantly to our understanding of why individuals' distress and their experience of emotional support from spouse caregivers vary in the context of end-stage cancer.
Growing season extension and its impact on terrestrial carbon cycle in the Northern Hemisphere over the past 2 decades
Authors: Piao Shilong , Friedlingstein Pierre , Ciais Philippe , Viovy Nicolas , Demarty Jérôme
Published: September 2007

A number of studies have suggested that the growing season duration has significantly lengthened during the past decades, but the connections between phenology variability and the terrestrial carbon (C) cycle are far from clear. In this study, we used the “ORganizing Carbon and Hydrology In Dynamic Ecosystems” (ORCHIDEE) process based ecosystem model together with observed climate data to investigate spatiotemporal changes in phenology and their impacts on carbon fluxes in the Northern Hemisphere (>25°N) during 1980–2002. We found that the growing season length (GSL) has increased by 0.30 days yr−1 (R2 = 0.27, P = 0.010), owing to the combination of an earlier onset in spring (0.16 days yr−1) and a later termination in autumn (0.14 days yr−1). Trends in the GSL are however highly variable across the regions. In Eurasia, there is a significant trend toward earlier vegetation green‐up with an overall advancement rate of 0.28 days yr−1 (R2 = 0.32, P = 0.005), while in North America there is a significantly delayed vegetation senescence by 0.28 days yr−1 (R2 = 0.26, P = 0.013) during the study period. Our results also suggested that the GSL strongly correlates with annual gross primary productivity (GPP) and net primary productivity (NPP), indicating that longer growing seasons may eventually enhance vegetation growth. A 1‐day extension in GSL leads to an increase in annual GPP of 5.8 gC m−2 yr−1 (or 0.6% per day), and an increase in NPP of 2.8 gC m−2 yr−1 per day. However, owing to enhanced soil carbon decomposition accompanying the GPP increase, a change in GSL correlates only poorly with a change in annual net ecosystem productivity (NEP).
Analysis of charge transport during lightning using balloon‐borne electric field sensors and Lightning Mapping Array
Authors: Hager William W. , Sonnenfeld Richard G. , Aslan Beyza Caliskan , Lu Gaopeng , Winn William P. , Boeck William L.
Published: September 2007

Recently, wide band measurements of the electric field near a lightning flash have been obtained by a balloon‐borne electric field sonde or Esonde. This paper develops new techniques for analyzing lightning‐associated charge transport in a thundercloud by using both the Esonde data and simultaneous Lightning Mapping Array (LMA) measurements of VHF pulses emitted during lightning breakdown processes. Innovations in this paper include the following: (1) A filtering procedure is developed to separate the background field associated with instrument rotation and cloud charging processes from the lightning‐induced electric field change. Because of the abrupt change in the signal caused by lightning, standard filtering techniques do not apply. A new mathematical procedure is developed to estimate the background electric field that would have existed if the lightning had not occurred. The estimated background field is subtracted from the measured field to obtain the lightning‐induced field change. (2) Techniques are developed to estimate the charge transport due to lightning. At any instant of time during a cloud‐to‐ground (CG) flash, we estimate the charge transport by a monopole. During an intracloud (IC) flash, we estimate the charge transport by a dipole. Since the location of the monopole and dipole changes with time, they are referred to as a dynamic monopole and a dynamic dipole. The following physical constraints are used to achieve a unique fit: charge conservation during an IC flash, separation (distance between the CG monopole charge center and the ground and separation between IC dipole charge centers both exceed a minimum threshold), location (charge is placed on lightning channel), and likelihood (after a statistical analysis based on instrument uncertainty, highly unlikely charge locations are excluded). To implement the constraint that the charge is located on the lightning channel, we develop a mathematical object called the “pulse graph.” Vertices in the graph are pulse locations obtained from the Lightning Mapping Array. Edges in the graph (that is, the pairs of vertices which are connected by line segments) are obtained by joining, in a systematic way, neighboring vertices. One CG and two IC flashes observed on 18 August 2004 near Langmuir Laboratory are analyzed. In the CG flash, initial strokes drained 12 C charge from an altitude of 5 km, while an intermediate stroke discharged 12 C from a higher charge center at 8 km. For the IC flashes, the current flow lagged behind the channel formation by time intervals on the order of 0.1 s, roughly the same time delay observed for lightning optical signals detected by NASA's Lightning Imaging Sensor.
Examining injection properties of boreal forest fires using surface and satellite measurements of CO transport
Authors: Hyer Edward J. , Allen Dale J. , Kasischke Eric S.
Published: September 2007

Boreal forest fires are highly variable in space and time and also have variable vertical injection properties. We compared a University of Maryland Chemistry and Transport Model (UMD‐CTM) simulation of boreal forest fire CO in the summer of 2000 to surface observations from the NOAA Cooperative Air Sampling Network and satellite observations of CO from the Measurement of Pollutants in the Troposphere (MOPITT) instrument to investigate the sensitivity of these measurements to injection height and to evaluate the bulk injection properties of the boreal fire source. Our results show that emissions at the surface produce more than twice the signal in surface CO measurements compared with emissions injected into the upper troposphere. Surface injection yielded the best agreement with surface observations, but high‐altitude injection resulted in very small variations at the surface, and so the statistical comparison with surface observations was inconclusive. Because of the vertical sensitivity of MOPITT, estimated total CO burden north of 30°N was 10% higher for upper tropospheric injection of boreal forest fire CO compared to surface release. We used a contrast filter to select the MOPITT retrievals most sensitive to boreal forest fire injection height and found that the best agreement between simulation results and MOPITT observations was obtained with midtropospheric injection of emissions and with pressure‐weighted distribution of emissions through the tropospheric column. Appendix A uses CTM output to examine quantitatively the bias and errors in calculations of total column CO and total CO burden using MOPITT CO retrievals.
Robotic ecological mapping: Habitats and the search for life in the Atacama Desert
Authors: Warren‐Rhodes K. , Weinstein S. , Piatek J. L. , Dohm J. , Hock A. , Minkley E. , Pane D. , Ernst L. A. , Fisher G. , Emani S. , Waggoner A. S. , Cabrol N. A. , Wettergreen D. S. , Grin E. , Coppin P. , Diaz Chong , Moersch J. , Oril G. G. , Smith T. , Stubbs K. , Thomas G. , Wagner M. , Wyatt M. , Boyle L. Ng
Published: September 2007

As part of the three‐year ‘Life in the Atacama’ (LITA) project, plant and microbial abundance were mapped within three sites in the Atacama Desert, Chile, using an automated robotic rover. On‐board fluorescence imaging of six biological signatures (e.g., chlorophyll, DNA, proteins) was used to assess abundance, based on a percent positive sample rating system and standardized robotic ecological transects. The percent positive rating system scored each sample based on the measured signal strength (0 for no signal to 2 for strong signal) for each biological signature relative to the total rating possible. The 2005 field experiment results show that percent positive ratings varied significantly across Site D (coastal site with fog), with patchy zones of high abundance correlated with orbital and microscale habitat types (heaved surface crust and gravel bars); alluvial fan habitats generally had lower abundance. Non‐random multi‐scale biological patchiness also characterized interior desert Sites E and F, with relatively high abundance associated with (paleo)aqueous habitats such as playas. Localized variables, including topography, played an important, albeit complex, role in microbial spatial distribution. Site D biosignature trends correlated with culturable soil bacteria, with MPN ranging from 10‐1000 CFU/g‐soil, and chlorophyll ratings accurately mapped lichen/moss abundance (Site D) and higher plant (Site F) distributions. Climate also affected biological patchiness, with significant correlation shown between abundance and (rover) air relative humidity, while lichen patterns were linked to the presence of fog. Rover biological mapping results across sites parallel longitudinal W‐E wet/dry/wet Atacama climate trends. Overall, the study highlights the success of targeting of aqueous‐associated habitats identifiable from orbital geology and mineralogy. The LITA experience also suggests the terrestrial study of life and its distribution, particularly the fields of landscape ecology and ecohydrology, hold critical lessons for the search for life on other planets. Their applications to robotic sampling strategies on Mars should be further exploited.
Elliptically bent conformal phased array of modified box‐horns for hyperthermia treatment of tumors
Authors: Gupta Ramesh Chandra , Singh Surya Pal
Published: September 2007

A novel and effective hyperthermia applicator utilizing an elliptically bent conformal phased array of modified box‐horns is analyzed using Fresnel‐Kirchhoff scalar diffraction field theory. This configuration is mainly intended as a specialized and very effective applicator for hyperthermia treatment of tumor within curved portions of human body such as abdomen, chest, neck, etc. It is proposed that the interior of the modified box‐horn as well as feeding device be filled with de‐ionized water to provide a better impedance match to the tissue. The contour distribution of specific absorption rate (SAR) in x‐y plane, SAR distribution in z‐direction, penetration depth, power absorption coefficient and effective field size (EFS) due to the conformal array as well as single modified box‐horn are evaluated and compared at 2450 MHz. The effect of change in phase and amplitude excitation of modified box‐horn of the array on SAR distribution is also investigated. Results demonstrate that conformal phased array of modified box‐horns offers marked improvement in SAR distribution and penetration depth over single modified box‐horn. The results obtained by the present analysis for linear array of four titanium dioxide loaded horns terminated in water are validated against published experimental results available in the literature.
Synconvergent ductile flow in variable‐strength continental crust: Numerical models with application to the western Grenville orogen
Authors: Jamieson R. A. , Beaumont C. , Nguyen M. H. , Culshaw N. G.
Published: September 2007

We present results from numerical models for a convergent orogen with laterally variable lower crustal strength, representing a simplified orogenic system in which a strong craton, flanked by progressively weaker terranes, collides with another continent. With progressive convergence, crustal thickening, and thermal relaxation, lower crust becomes decoupled from upper and middle crust, forming a ductile orogenic infrastructure beneath a stronger superstructure. Collision with strong external crust results in uplift and expulsion of ductile nappes from the orogenic core, creating allochthonous terranes overlying a lower crustal indentor. The extent of transport and exhumation of lower crustal nappes over the indentor reflects the amount of convergence and the erosion rate. The western Grenville orogen displays across‐strike variations in age, tectonic history, and protolith association, suggesting a systematic variation in precollision crustal strength. The Laurentian craton, margin, and accreted terranes were variably reworked at synorogenic depths of 25–35 km during the Ottawan orogeny. Deformation propagated from younger monocyclic rocks in the southeast into older polycyclic rocks flanking the craton on the northwest. A comparison between numerical model results and crustal‐scale cross sections from the Georgian Bay and Montreal–Val d'Or transects shows close correspondence between crustal structure and model geometry. This indicates that the models produce geologically realistic results and provides a context for interpreting the tectonic evolution of the western Grenville orogen. Contrasts between the results of homogeneous channel flow models and the present ductile nappe models suggest that the effects of different styles of ductile flow can be distinguished in the geologic record.
Regionalization of rainfall for broad‐scale modeling: An inverse approach
Authors: Pinault J.‐L. , Allier D.
Published: September 2007

A spatially consistent approach is used for the representation of rainfall at catchment scale for continuous rainfall‐streamflow simulation by using inverse modeling. Representing rainfall data at every location as the product of the mean rainfall by the rainfall series reduced to unit average, it is shown that the regionalization of both terms should follow different ways for broad‐scale modeling. Whereas the regionalization of the mean rainfall is based on its spatial continuity, it is demonstrated from the study of three French basins that are subject to different climates that the reduced rainfall data should be represented from a weighted sum of a small number of observed rainfall data (three to five) located both inside and outside the catchments to be as representative as possible at catchment scale. The reliability of peak flow modeling increases with the basin size as well as the return period of flood events provided that the rainfall is correctly regionalized, which is particularly important for real‐time forecasting of rainfall and flow. This contradicts the widespread assumption that for the distributed rainfall‐runoff model, the denser the network of rain samplers used as input in the models, the more accurate the broad‐scale flood model will be.
Temperature and humidity biases in global climate models and their impact on climate feedbacks
Authors: John V. O. , Soden B. J.
Published: September 2007

A comparison of AIRS and reanalysis temperature and humidity profiles to those simulated from climate models reveals large biases. The model simulated temperatures are systematically colder by 1–4 K throughout the troposphere. On average, current models also simulate a large moist bias in the free troposphere (more than 100%) but a dry bias in the boundary layer (up to 25%). While the overall pattern of biases is fairly common from model to model, the magnitude of these biases is not. In particular, the free tropospheric cold and moist bias varies significantly from one model to the next. In contrast, the response of water vapor and tropospheric temperature to a surface warming is shown to be remarkably consistent across models and uncorrelated to the bias in the mean state. We further show that these biases, while significant, have little direct impact on the models' simulation of water vapor and lapse‐rate feedbacks.
Physical interpretation of the correlation between multi‐angle spectral data and canopy height
Authors: Schull M. A. , Ganguly S. , Samanta A. , Huang D. , Shabanov N. V. , Jenkins J. P. , Chiu J. C. , Marshak A. , Blair J. B. , Myneni R. B. , Knyazikhin Y.
Published: September 2007

Recent empirical studies have shown that multi‐angle spectral data can be useful for predicting canopy height, but the physical reason for this correlation was not understood. We follow the concept of canopy spectral invariants, specifically escape probability, to gain insight into the observed correlation. Airborne Multi‐Angle Imaging Spectrometer (AirMISR) and airborne Laser Vegetation Imaging Sensor (LVIS) data acquired during a NASA Terrestrial Ecology Program aircraft campaign underlie our analysis. Two multivariate linear regression models were developed to estimate LVIS height measures from 28 AirMISR multi‐angle spectral reflectances and from the spectrally invariant escape probability at 7 AirMISR view angles. Both models achieved nearly the same accuracy, suggesting that canopy spectral invariant theory can explain the observed correlation. We hypothesize that the escape probability is sensitive to the aspect ratio (crown diameter to crown height). The multi‐angle spectral data alone therefore may not provide enough information to retrieve canopy height globally.
Modeling seasonal and diurnal effects on ionospheric conductances, region‐2 currents, and plasma convection in the inner magnetosphere
Authors: Hurtaud Y. , Peymirat C. , Richmond A. D.
Published: September 2007

The present study focuses on a modeling of the seasonal and diurnal effects on the dynamics of the coupled magnetosphere‐ionosphere system under different solar illumination conditions, to try to reproduce some of the observations concerning the region 2 (R2) field‐aligned currents (FAC). This is performed by introducing in the Ionosphere Magnetosphere Model (IMM) the Earth's rotation axis tilt, the dipole axis tilt and an eccentric dipole. The simulated patterns of the R2 FAC agree rather well with the observations. In particular the dayside FAC density is two times greater in the summer hemisphere than in the winter one. The results show that seasonal tilt of the dipole axis affects the distributions of the Pedersen conductances and FAC by 28.5–52.8% and do not have much influence on the distribution of the magnetospheric plasma, which is modified by only 0.9–3.9%. The diurnal variations induced by the tilt of the dipole axis are of the same order of magnitude, 5.5–29% for the Pedersen conductances and FAC and 0.4–7.1% for the magnetospheric plasma. They modulate the interhemispheric asymmetry of the FAC by 26–59%. The eccentric dipole induces an increase (decrease) of the daily variations of the conductances and the FAC by a factor 1.2–2.3 in the Southern (Northern) Hemisphere, irrespective of the season, which contributes to increase the asymmetry between the two hemispheres. This results in an increase of the daily variations of the ion maximum pressure and of the electron maximum energy flux at the December solstice and at the March and September equinoxes, but a decrease at the June solstice. The maximal variation of the magnetospheric plasma distribution amounts to 6.7% at December solstice. These results underline the importance of considering the three different effects at the same time.
Oblique rifting at Tempe Fossae, Mars
Authors: Fernández Carlos , Anguita Francisco
Published: September 2007

This work shows the results of a structural study of the faults observed at the Tempe Rift (northeastern Tharsis region), Mars. A new, detailed map of faults and fault systems was used to geometrically characterize the fracture architecture of the Tempe Rift and to measure fault length, displacement, and spacing data, to analyze the spatial distribution of fault centroids, and to investigate the fractal nature of fault trace maps. A comparison with analog models and the use of conventional techniques of fault population analysis show that the Tempe Rift was most probably generated under sinistral oblique‐rifting processes, which highlights the importance of the presence of inherited fractures in the tectonic evolution of the Noachian crust. The angle between the extension direction and the rift axis varies along the Tempe Rift, ranging from 50°–60° at its central southern part to 66°–88° to the southwest. Fault scaling relationships are similar to those found at mid‐ocean ridges on Earth with exponential fault length‐frequency distributions. Localized, inhomogeneous deformation generated weakly interacting faults, spanning the entire thickness of the mechanical layer. This thickness decreased from southwest to northeast along the rift, along with distance from the central part of the Tharsis dome.
Blockade of the chemokine receptor CXCR2 ameliorates adjuvant‐induced arthritis in rats
Authors: Barsante M M , Cunha T M , Allegretti M , Cattani F , Policani F , Bizzarri C , Tafuri W L , Poole S , Cunha F Q , Bertini R , Teixeira M M
Published: September 2007

Background and purpose:

Chemokine receptors CXCR1 and CXCR2 may mediate influx of neutrophils in models of acute and chronic inflammation. The potential benefits of oral administration of a CXCR1/2 inhibitor, DF 2162, in adjuvant‐induced polyarthritis (AIA) were investigated.

Experimental approach:

A model of AIA in rats was used to compare the therapeutic effects of the treatment with DF2162, anti‐TNF or anti‐CINC‐1 antibodies on joint inflammation and local production of cytokines and chemokines.

Key results:

DF2162 prevented chemotaxis of rat and human neutrophils induced by chemokines acting on CXCR1/2. DF2162 was orally bioavailable and metabolized to two major metabolites. Only metabolite 1 retained CXCR1/2 blocking activity. Treatment with DF2162 (15 mg kg−1, twice daily) or metabolite 1, but not metabolite 2, starting on day 10 after arthritis induction diminished histological score, the increase in paw volume, neutrophil influx and local production of TNF, IL‐1β, CCL2 and CCL5. The effects of DF2162 were similar to those of anti‐TNF, and more effective than those of anti‐CINC‐1, antibodies. DF2162 prevented disease progression even when started 13 days after arthritis induction.

Conclusions and implications:

DF 2162, a novel orally‐active non‐competitive allosteric inhibitor of CXCR1 and CXCR2, significantly ameliorates AIA in rats, an effect quantitatively and qualitatively similar to those of anti‐TNF antibody treatment. These findings highlight the contribution of CXCR2 in the pathophysiology of AIA and suggest that blockade of CXCR1/2 may be a valid therapeutic target for further studies aiming at the development of new drugs for treatment of rheumatoid arthritis.

British Journal of Pharmacology(2008)153, 992–1002; doi:10.1038/sj.bjp.0707462; published online 24 September 2007
Inhibition of 2‐arachidonoylglycerol catabolism modulates vasoconstriction of rat middle cerebral artery by the thromboxane mimetic, U‐46619
Authors: Hillard C J , Ho W‐Sv , Thompson J , Gauthier K M , Wheelock C E , Huang H , Hammock B D
Published: September 2007

Background and purpose:

Cerebrovascular smooth muscle cells express the CB1cannabinoid receptor and CB1agonists produce vasodilatation of the middle cerebral artery (MCA). The thromboxane A2mimetic, U‐46619, increased the content of the endocannabinoid, 2‐arachidonoylglycerol (2‐AG) in the MCA and 2‐AG moderated the vasoconstriction produced by U46619 in this tissue. The purposes of this study were to examine the extent to which 2‐AG is catabolized by cerebral arteries and to determine whether blockade of 2‐AG inactivation potentiates its feedback inhibition of U‐44619‐mediated vasoconstriction.

Experimental approach:

The diameters of isolated, perfused MCA from male rats were measured using videomicroscopy.

Key results:

Exogenous 2‐AG produces a CB1receptor‐dependent and concentration‐related increase in the diameter of MCA constricted with 5‐HT. TheEmaxfor 2‐AG dilation is increased 4‐fold in the presence of the metabolic inhibitors 3‐(decylthio)‐1,1,1‐trifluropropan‐2‐one (DETFP), URB754 and URB597. To examine the role of catabolism in the effects of endogenous 2‐AG, vasoconstriction induced by U‐46619 was studied. DETFP and URB754, but not the fatty acid amide hydrolase inhibitor, URB597, significantly increased the EC50for U‐46619. These data support a physiological role for endocannabinoid feedback inhibition in the effects of U‐46619 and indicate that endogenously produced 2‐AG is also efficiently catabolized within the MCA.

Conclusions and implications:

MCA express mechanisms for the efficient inactivation of 2‐AG, providing further support for an endocannabinoid feedback mechanism that opposes thromboxane‐mediated vasoconstriction. These data suggest that potentiation of endogenously produced 2‐AG could be a novel therapeutic approach to the treatment of thrombotic stroke.

British Journal of Pharmacology(2007)152, 691–698; doi:10.1038/sj.bjp.0707468; published online 24 September 2007
Cannabis reward: biased towards the fairer sex?
Authors: McGregor I S , Arnold J C
Published: September 2007

In contrast to drugs such as alcohol, amphetamine and cocaine, cannabis use in humans has proven difficult to model in laboratory animals. Recent breakthrough discoveries of intravenous THC self‐administration in rhesus monkeys and self‐administration of the synthetic cannabinoid agonist WIN 55,212‐2 in rats have allowed new studies of the genetic, neural and environmental determinants of cannabis use. In the present issue of BJP, Fattore and colleagues further demonstrate genetic (strain) differences in WIN 55,212‐2 self‐administration in rats, with Long Evans (LE) and Lister Hooded (LH), but not Sprague–Dawley, rats self‐administering this drug. They then show that female LE and LH rats self‐administer more WIN 55,212‐2 than male rats. Ovariectomy abolished this sex difference, suggesting a permissive role for oestrogen in cannabis reward. This accompanying Commentary reviews recent progress in animal models of cannabis use and highlights the role of genetic, developmental and endocrine factors in driving cannabis use and dependence.

British Journal of Pharmacology (2007) 152, 562–564; doi:10.1038/sj.bjp.0707469; published online 24 September 2007
PPARα agonists inhibit nitric oxide production by enhancing iNOS degradation in LPS‐treated macrophages
Authors: Paukkeri E‐L , Leppänen T , Sareila O , Vuolteenaho K , Kankaanranta H , Moilanen E
Published: September 2007

Background and purpose:

Nitric oxide (NO) production through the inducible nitric oxide synthase (iNOS) pathway is increased in response to pro‐inflammatory cytokines and bacterial products. In inflammation, NO has pro‐inflammatory and regulatory effects. Peroxisome proliferator‐activated receptors (PPARs), members of the nuclear steroid receptor superfamily, regulate not only metabolic but also inflammatory processes. The aim of the present study was to investigate the role of PPARα in the regulation of NO production and iNOS expression in activated macrophages.

Experimental approach:

The effects of PPARα agonists were investigated on iNOS mRNA and protein expression, on NO production and on the activation of transcription factors NF‐κB and STAT1 in J774 murine macrophages exposed to bacterial lipopolysaccharide (LPS).

Key results:

PPARα agonists GW7647 and WY14643 reduced LPS‐induced NO production in a dose‐dependent manner as measured by the accumulation of nitrite into the culture medium. However, PPARα agonists did not alter LPS‐induced iNOS mRNA expression or activation of NF‐κB or STAT1 which are important transcription factors for iNOS. Nevertheless, iNOS protein levels were reduced by PPARα agonists in a time‐dependent manner. The reduction was markedly greater after 24 h incubation than after 8 h incubation. Treatment with the proteasome inhibitors, lactacystin or MG132, reversed the decrease in iNOS protein levels caused by PPARα agonists.

Conclusions and implications:

The results suggest that PPARα agonists reduce LPS‐induced iNOS expression and NO production in macrophages by enhancing iNOS protein degradation through the proteasome pathway. The results offer an additional mechanism underlying the anti‐inflammatory effects of PPARα agonists.

British Journal of Pharmacology (2007) 152, 1081–1091; doi:10.1038/sj.bjp.0707477; published online 24 September 2007
Protein kinase G regulates the basal tension and plays a major role in nitrovasodilator‐induced relaxation of porcine coronary veins
Authors: Qi H , Zheng X , Qin X , Dou D , Xu H , Raj J U , Gao Y
Published: September 2007

Background and purpose:

Coronary venous activity is modulated by endogenous and exogenous nitrovasodilators. The present study was to determine the role of protein kinase G (PKG) in the regulation of the basal tension and nitrovasodilator‐induced relaxation of coronary veins.

Experimental approach:

Effects of a PKG inhibitor on the basal tension and responses induced by nitroglycerin, DETA NONOate, and 8‐Br‐cGMP in isolated porcine coronary veins were determined. Cyclic cGMP was measured with radioimmunoassay. PKG activity was determined by measuring the incorporation of 32P from γ‐32P‐ATP into the specific substrate BPDEtide.

Key results:

Rp‐8‐Br‐PET‐cGMPS, a specific PKG inhibitor, increased the basal tension of porcine coronary veins and decreased PKG activity. The increase in tension was 38% of that caused by nitro‐L‐arginine. Relaxation of the veins induced by nitroglycerin and DETA NONOate was accompanied with increases in cGMP content and PKG activity. These effects were largely eliminated by inhibiting soluble guanylyl cyclase with ODQ. The increase in PKG activity induced by the nitrovasodilators was abolished by Rp‐8‐Br‐PET‐cGMPS. The relaxation caused by these dilators and by 8‐Br‐cGMP at their EC50 was attenuated by the PKG inhibitor by 51–66%.

Conclusions and implications:

These results suggest that PKG is critically involved in nitric oxide‐mediated regulation of the basal tension in porcine coronary veins and that it plays a primary role in relaxation induced by nitrovasodilators. Since nitric oxide plays a key role in modulating coronary venous activity, augmentation of PKG may be a therapeutic target for improving coronary blood flow.

British Journal of Pharmacology (2007) 152, 1060–1069; doi:10.1038/sj.bjp.0707479; published online 24 September 2007
Cannabinoids and their actions
Authors: Alexander S P H , Randall M
Published: September 2007

British Journal of Pharmacology (2007) 152, 557–558; doi:10.1038/sj.bjp.0707483; published online 24 September 2007
Vascular adaptations to hypoxia: molecular and cellular mechanisms regulating vascular tone
Authors: Paffett Michael L. , Walker Benjimen R.
Published: September 2007

Several molecular and cellular adaptive mechanisms to hypoxia exist within the vasculature. Many of these processes involve oxygen sensing which is transduced into mediators of vasoconstriction in the pulmonary circulation and vasodilation in the systemic circulation. A variety of oxygen-responsive pathways, such as HIF (hypoxia-inducible factor)-1 and HOs (haem oxygenases), contribute to the overall adaptive process during hypoxia and are currently an area of intense research. Generation of ROS (reactive oxygen species) may also differentially regulate vascular tone in these circulations. Potential candidates underlying the divergent responses between the systemic and pulmonary circulations may include Nox (NADPH oxidase)-derived ROS and mitochondrial-derived ROS. In addition to alterations in ROS production governing vascular tone in the hypoxic setting, other vascular adaptations are likely to be involved. HPV (hypoxic pulmonary vasoconstriction) and CH (chronic hypoxia)-induced alterations in cellular proliferation, ionic conductances and changes in the contractile apparatus sensitivity to calcium, all occur as adaptive processes within the vasculature.
Effect of Age on F0Difference Limen and Concurrent Vowel Identification
Authors: Vongpaisal Tara , Pichora-Fuller Margaret Kathleen
Published: September 2007

Purpose

To investigate the effect of age on voice fundamental frequency (F0) difference limen (DL) and identification of concurrently presented vowels.

Method

Fifteen younger and 15 older adults with normal audiometric thresholds in the speech range participated in 2 experiments. In Experiment 1, F0DLs were measured for a synthesized vowel. In Experiment 2, accuracy in identifying concurrently presented vowel pairs was measured. Vowel pairs were formed from 5 synthesized vowels with F0separations ranging from 0 to 4 semitones.

Results

Younger adults had smaller (better) F0DLs than older adults. For the older group, age was significantly correlated with F0DLs. Younger adults identified concurrent vowels more accurately than older adults. When the vowels in the pairs had different formants, both age groups benefited similarly from F0separation. Interestingly, when both constituent vowels had identical formants, F0separation was deleterious, especially for older adults. Pure-tone average threshold did not correlate significantly with either F0DL or accuracy in concurrent vowel identification.

Conclusion

Age-related declines were confirmed for F0DLs, identification of concurrently spoken vowels, and benefit from F0separation between vowels with identical formants. This pattern of findings is consistent with age-related deficits in periodicity coding.
Effect of Digital Frequency Compression (DFC) on Speech Recognition in Candidates for Combined Electric and Acoustic Stimulation (EAS)
Authors: Gifford René H. , Dorman Michael F. , Spahr Anthony J. , McKarns Sharon A.
Published: September 2007

Purpose

To compare the effects of conventional amplification (CA) and digital frequency compression (DFC) amplification on the speech recognition abilities of candidates for a partial-insertion cochlear implant, that is, candidates for combined electric and acoustic stimulation (EAS).

Method

The participants were 6 patients whose audiometric thresholds at 500 Hz and below were ≤60 dB HL and whose thresholds at 2000 Hz and above were ≥80 dB HL. Six tests of speech understanding were administered with CA and DFC. The Abbreviated Profile of Hearing Aid Benefit (APHAB) was also administered following use of CA and DFC.

Results

Group mean scores were not statistically different in the CA and DFC conditions. However, 2 patients received substantial benefit in DFC conditions. APHAB scores suggested increased ease of communication, but also increased aversive sound quality.

Conclusion

Results suggest that a relatively small proportion of individuals who meet EAS candidacy will receive substantial benefit from a DFC hearing aid and that a larger proportion will receive at least a small benefit when speech is presented against a background of noise. This benefit, however, comes at a cost—aversive sound quality.
Talker Differences in Clear and Conversational Speech: Acoustic Characteristics of Vowels
Authors: Ferguson Sarah Hargus , Kewley-Port Diane
Published: September 2007

Purpose

To determine the specific acoustic changes that underlie improved vowel intelligibility in clear speech.

Method

Seven acoustic metrics were measured for conversational and clear vowels produced by 12 talkers—6 who previously were found (S. H. Ferguson, 2004) to produce a large clear speech vowel intelligibility effect for listeners with normal hearing identifying vowels in background noise (the
big benefit talkers
), and 6 who produced no clear speech vowel intelligibility benefit (the
no benefit talkers
).

Results

For vowel duration and for certain measures of the overall acoustic vowel space, the change from conversational to clear speech was significantly greater for big benefit talkers than for no benefit talkers. For measures of formant dynamics, in contrast, the clear speech effect was similar for the 2 groups.

Conclusion

These results suggest that acoustic vowel space expansion and large vowel duration increases improve vowel intelligibility. In contrast, changing the dynamic characteristics of vowels seems not to contribute to improved clear speech vowel intelligibility. However, talker variability suggested that improved vowel intelligibility can be achieved using a variety of clear speech strategies, including some apparently not measured here.
Pathways from postsocialism: ownership sequence and performance of firms in Hungary, 1991‐1999
Authors: Vedres Balazs
Published: September 2007

Corporate ownership structures were important means to navigate postsocialist uncertainties, and as relational structures, they were vulnerable to subsequent path dependencies. Organizational innovations might outlive their relevant environments, locking firms in to underperform. This article analyzes the ownership sequences and performance of the 200 largest Hungarian firms between 1991 and 1999. Hungary in the 1990s is a strategic historical case to understand turning points, sequencing and performance. Optimal matching analysis is used to identify pathways, and dynamic scaling analysis to delimit ownership regimes in time. Hypotheses about how sequences mattered are tested by regression models of performance. The findings indicate that network forms buffered uncertainties up to 1995, contributing to high labor and capital efficiency. After this period, domestic corporate coalitions locked firms in, leading to inferior performance compared to manager buy‐outs, domestic subsidiaries, and foreign‐owned firms. Joint ventures on the other hand provided protection and then later the option for concentrating ownership, outperforming other pathways of ownership.
Corporate strategy: an agent‐based approach
Authors: Caldart Adrián Atilio , Ricart Joan E
Published: September 2007

In this paper, we explore the application of the construct exploitation and exploration at the level of the corporate strategy of the firm. For that purpose, we operationalized and formalized the analysis through the development of a set of agent‐based simulations which capture and describe the evolution of firms led by exploitative and explorative corporate strategies in business environments showing different levels of complexity. Results indicate that the relative performances of exploitative strategies vs those characterized by an opportunistic combination of exploitation and exploration, are contingent on the characteristics of the environment in which the firm operates and the quality of the corporate strategic plans that determine the initial strategic positioning of the firm.
Airflow produced by dielectric barrier discharge between asymmetric parallel rod electrodes
Authors: Hayashi Kazuo , Tanaka Motofumi , Yasui Hiroyuki , Hashimoto Kiyoshi
Published: September 2007

We observed a novel type of airflow produced by an atmospheric rf discharge between asymmetric parallel rod electrodes. The electrodes were a bare metal rod 1mm in diameter and a glass-coated metal rod 3.2mm in diameter. The thrust, measured by a pendulum, increased with discharge input power.
Comment on “Relation between space charge limited current and power loss in open drift tubes” [Phys. Plasmas 13, 073101 (2006)]
Authors: Swanekamp S. B. , Schumer J. W.
Published: September 2007

In Phys Plasmas 13, 073101 (2006), the drop in the space-charge-limited (SCL) current for a beam injected into a space with an open boundary is analyzed with an electromagnetic particle-in-cell code. The authors explained the power loss observed at the open boundary as the loss of electromagnetic radiation created from the deceleration of electrons in the gap, and they developed an effective voltage theory to predict the drop in the SCL current observed in the simulations. In this Comment, we show that, provided the current remains below the SCL value, the electric and magnetic fields are constant in time so that power loss from the open boundary is a dc phenomenon with no rf power leaving through the boundary. We show that the electric and magnetic fields are static in time and static fields DO NOT RADIATE. Instead, the electron beam charges the collector plate, which causes a real electrostatic electric field to develop. The electron energy loss is not due to radiation but rather to the work done by this electrostatic field on the electrons as they move across the gap. This is precisely the energy dissipated in the matched resistance across the open boundary, which is a consequence of the boundary condition. Furthermore, since a real electrostatic potential develops, the voltage drop is real and there is no need to call the voltage drop an effective voltage.
Response to “Comment on ‘Relation between space charge limited current and power loss in open drift tubes' ” [Phys Plasmas 14, 094705 (2007)]
Authors: Biswas Debabrata , Kumar Raghwendra
Published: September 2007

It is pointed out in this Response that as the collector plate is a grounded conductor whose potential is held fixed at zero, it is incorrect to assume that it becomes negatively charged due to the accumulation of electron space-charge. Further, the connection between the collector potential due to the assumed accumulation of charges and the impedance of the open boundary appears tenuous. Moreover, the use of the impedance in evaluating the power loss while at the same time stating that “electromagnetic effects are not expected to play a key role” is in itself contradictory.
Colliding particles in highly turbulent flows
Authors: Mehlig Bernhard , Uski Ville , Wilkinson Michael
Published: September 2007

We discuss relative velocities and the collision rate of small particles suspended in a highly turbulent fluid. In the limit where the viscous damping is very weak, we estimate the relative velocities using the Kolmogorov cascade principle.
Stability analysis of neural networks with interval time-varying delays
Authors: Hou Yi-You , Liao Teh-Lu , Lien Chang-Hua , Yan Jun-Juh
Published: September 2007

The global exponential stability is investigated for neural networks with interval time-varying delays. Based on the Leibniz-Newton formula and linear matrix inequality technique, delay-dependent stability criteria are proposed to guarantee the exponential stability of neural networks with interval time-varying delays. Some numerical examples and comparisons are provided to show that the proposed results significantly improve the allowable upper and lower bounds of delays over some existing ones in the literature.
Generalized gradient-augmented harmonic Fourier beads method with multiple atomic and/or center-of-mass positional restraints
Authors: Khavrutskii Ilja V. , McCammon J. Andrew
Published: September 2007

We describe a generalization of the gradient-augmented harmonic Fourier beads method for finding minimum free-energy transition path ensembles and similarly minimum potential energy paths to allow positional restraints on the centers of mass of selected atoms. The generalized gradient-augmented harmonic Fourier beads (ggaHFB) method further extends the scope of the HFB methodology to studying molecule transport across various mobile phases such as lipid membranes. Furthermore, the new implementation improves the applicability of the HFB method to studies of ligand binding, protein folding, and enzyme catalysis as well as modeling equilibrium pulling experiments. Like its predecessor, the ggaHFB method provides accurate energy profiles along the specified paths and in certain simple cases avoids the need for path optimization. The utility of the ggaHFB method is demonstrated with an application to the water permeation through a single-wall (5,5) carbon nanotube with a diameter of 6.78Å and length of 16.0Å. We provide a simple rationale as to why water enters the hydrophobic nanotube and why it does so in pulses and in wire assembly.
Dianions of 7,7,8,8-tetracyano-p-quinodimethane and perfluorinated tetracyanoquinodimethane: Information on excited states from lifetime measurements in an electrostatic storage ring and optical absorption spectroscopy
Authors: Panja Subhasis , Kadhane Umesh , Andersen Jens Ulrik , Holm Anne I. S. , Hvelplund Preben , Kirketerp Maj-Britt Suhr , Nielsen Steen Brøndsted , Støchkel Kristian , Compton Robert N. , Forster James S. , Kilså Kristine , Nielsen Mogens Brøndsted
Published: September 2007

We have developed an experimental technique that allows us to study the physics of short lived molecular dianions in the gas phase. It is based on the formation of monoanions via electrospray ionization, acceleration of these ions to keV energies, and subsequent electron capture in a sodium vapor cell. The dianions are stored in an electrostatic ion storage ring in which they circulate with revolution times on the order of 100μs. This enables lifetime studies in a time regime covering five orders of magnitude, 10−5–1s. We have produced dianions of 7,7,8,8-tetracyano-p-quinodimethane and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-p-quinodimethane (TCNQ-F4) and measured their lifetimes with respect to electron autodetachment. Our data indicate that most of the dianions were initially formed in electronically excited states in the electron transfer process. Two levels of excitation were identified by spectroscopy on the dianion of TCNQ-F4, and the absorption spectrum was compared with spectra obtained from spectroelectrochemistry of TCNQ-F4 in acetonitrile solution.
Propagation of relativistic surface harmonics radiation in free space
Authors: an der Brügge Daniel , Pukhov Alexander
Published: September 2007

Relativistic high-harmonics generation from overdense plasma surfaces is studied using three-dimensional particle-in-cell simulations. It is shown that the simple vacuum propagation in the real three-dimensional geometry strongly affects the harmonics spectrum on the optical axis. It may even lead to the formation of attosecond pulses without any special optical filters. To make good use of these effects it is necessary to shape either the laser pulse focal spot, or the surface material in such a way that the S-number of the interaction [see Gordienko and Pukhov, Phys. Plasmas 12, 043109 (2005)] is preserved over the largest possible area. The three-dimensional simulations are carefully compared with the one-dimensional ones. It is shown that the one-dimensional models work well even in cases where the laser is focused to a quite small spot on the harmonics generating surface (σ≈λ).
Statistical properties of streamwise velocity in a supersonic turbulent boundary layer
Authors: Ganapathisubramani B.
Published: September 2007

Statistical properties of streamwise velocity fluctuations in a supersonic boundary layer are examined using particle image velocimetry data. The mean velocity profile reveals a logarithmic region that extends farther from the wall (compared to incompressible boundary layers), up to y∕δ≈0.5. The rms velocity profiles are consistent with previous measurements reported in the literature and indicates a plateau region between y∕δ=0.3 and 0.6 with a nominal second peak at y∕δ≈0.6. Contours of two-point correlations are forward leaning for reference locations near the wall and become more symmetric along both streamwise and wall-normal directions as the reference location moves away from the wall. The integral length scales (Lx) and the representative length scales (λxu) reveal an increasing-decreasing trend with distance from the wall, attaining a maximum within the logarithmic region at y∕δ≈0.4.