bluuebunny/crossref_metadata_2025 huggingface dataset:
Body mass index, prognosis and mode of death in chronic heart failure: Results from the Valsartan Heart Failure Trial
Authors: Cicoira Mariantonietta , Maggioni Aldo Pietro , Latini Roberto , Barlera Simona , Carretta Elisa , Janosi Andras , Soler Jordi Soler , Anand Inder , Cohn Jay N. ,   Val‐HeFT Investigators
Published: December 2006

Aims:

To assess the relationship between body mass index (BMI), mortality and mode of death in chronic heart failure (CHF) patients; to define the shape of the relationship between BMI and mortality.

Methods and results:

We performed a post‐hoc analysis of 5010 patients from the Valsartan Heart Failure Trial. The end‐points of the study were all‐cause and cardiovascular mortality. Mortality rate was 27.2% in underweight patients (BMI<22 kg/m2), 21.7% in normal weight patients (BMI 22–24.9 kg/m2), 17.9% in overweight patients (BMI 25–29.9 kg/m2) and 16.5% in obese patients (BMI>30 kg/m2) (p<0.0001). The rates of non‐cardiovascular death did not differ among groups. The risk of death due to progressive heart failure was 3.4‐fold higher in the underweight than in the obese patients (p<0.0001). Normal weight, overweight and obese patients had lower risk of death as compared with underweight patients (p=0.019, HR 0.76, 95% CI 0.61–0.96; p=0.0005, HR 0.68, 95% CI 0.55–0.84; p=0.003, HR 0.67, 95% CI 0.52–0.88, respectively) independently of symptoms, ventricular function, beta‐blocker use, C‐reactive protein and brain natriuretic peptide levels.

Conclusions:

In CHF patients a higher BMI is associated with a better prognosis independently of other clinical variables. The relationship between mortality and BMI is monotonically decreasing.
Myocardial viability estimation during the recovery phase of stress echocardiography after acute beta‐blocker administration
Authors: Karagiannis Stefanos E. , Feringa Harm H.H. , Bax Jeroen J. , Elhendy Abdu , Dunkelgrun Martin , Vidakovic Radosav , Hoeks S.E. , van Domburg Ron , Valhema Roelf , Cokkinos Dennis V. , Poldermans Don
Published: December 2006

Background:

Myocardial viability assessment in severely dysfunctional segments by dobutamine stress echocardiography (DSE) is less sensitive than nuclear scanning.

Aim:

To assess the additional value of using the recovery phase of DSE after acute beta‐blocker administration for identifying viable myocardium.

Methods:

The study included 49 consecutive patients with ejection fraction (LVEF) ≤35%. All patients underwent DSE evaluation at low–high dose and during recovery phase, and dual‐isotope single photon emission tomography (DISA‐SPECT) evaluation for viability of severely dysfunctional segments. Patients with ≥4 viable segments were considered viable. Coronary revascularization followed within 3 months in all patients. Radionuclide evaluation of LVEF was performed before and 12 months after revascularization.

Results:

Viability with DISA‐SPECT was detected in 463 (59%) segments, while 154 (19.7%) segments presented as scar. The number of viable segments increased from 415 (53%) at DSE to 463 (59%) at DSE and recovery, and the number of viable patients increased from 43 to 49 respectively. LVEF improved by ≥5% in 27 patients. Multivariate regression analysis showed that, DSE with recovery phase was the only independent predictor of ≥5% LVEF improvement after revascularization (OR 14.6, CI 1.4–133.7).

Conclusion:

In this study, we demonstrate that the recovery phase of DSE has an increased sensitivity for viability estimation compared to low–high dose DSE.
d‐pinitol regulates Th1/Th2 balance via suppressing Th2 immune response in ovalbumin‐induced asthma
Authors: Lee Jun Sik , Lee Chang-Min , Jeong Young-Il , Jung In Duk , Kim Bo-Hye , Seong Eun-Young , Kim Jong-Il , Choi Il-Whan , Chung Hae Young , Park Yeong-Min
Published: December 2006

d‐pinitol has been demonstrated to exert insulin‐like and anti‐inflammatory activities. However, its anti‐allergic effect in the Th1/Th2 immune response is poorly understood. Recently, it was shown that T‐bet and GATA‐3 are master Th1 and Th2 regulatory transcription factors. In this study, we have attempted to determine whether d‐pinitol regulates Th1/Th2 cytokine production, T‐bet and GATA‐3 gene expression in OVA‐induced asthma model mice. We also examined to ascertain whether d‐pinitol could influence eosinophil peroxidase (EPO) activity. After being sensitized and challenged with ovalbumin (OVA) showed typical asthmatic reactions. These reactions included an increase in the number of eosinophils in bronchoalveolar lavage (BAL) fluid, an increase in inflammatory cell infiltration into the lung tissue around blood vessels and airways, airway luminal narrowing, and the development of airway hyper‐responsiveness (AHR). The administration of d‐pinitol before the last airway OVA challenge resulted in a significant inhibition of all asthmatic reactions. Accordingly, this study may provide evidence that d‐pinitol plays a critical role in the amelioration of the pathogenetic process of asthma in mice. These findings provide new insight into the immunopharmacological role of d‐pinitol in terms of its effects in a murine model of asthma, and also broaden current perspectives in our understanding of the immunopharmacological functions of d‐pinitol.
Identification of proteins whose expression is up‐ or down‐regulated in the mushroom bodies in the honeybee brain using proteomics
Authors: Uno Yuko , Fujiyuki Tomoko , Morioka Mizue , Takeuchi Hideaki , Kubo Takeo
Published: December 2006

To identify protein(s) with different expression patterns in the mushroom bodies (MBs) in the honeybee brain, we compared the protein profiles of MBs and optic lobes (OLs) using proteomics. Two‐dimensional gel electrophoresis revealed that five and three spots were selectively expressed in the MBs or OLs, respectively. Liquid chromatography tandem mass spectrometry analysis identified juvenile hormone diol kinase and glyceraldehyde‐3‐phosphate dehydrogenase as MB‐ and OL‐selective proteins, respectively. In situ hybridization revealed that jhdk expression was upregulated in MB neuron subsets, whereas gapdh expression was downregulated, indicating that MBs have a distinct gene and protein expression profile in the honeybee brain.
Characterisation of lipofuscin‐like lysosomal inclusion bodies from human placenta
Authors: Schröder Bernd , Elsässer Hans-Peter , Schmidt Bernhard , Hasilik Andrej
Published: December 2006

Here we show that human term placenta contains lipofuscin‐like lysosomal inclusions, a phenomenon usually associated with senescence in postmitotic cells. These findings imply that a simple pelleting of a lysosomal lysate is not appropriate for the isolation of lysosomal membranes, as the inclusions tend to be sedimented with the membranes.
Credible Keynesianism? New Labour Macroeconomic Policy and the Political Economy of Coarse Tuning
Authors: CLIFT BEN , TOMLINSON JIM
Published: December 2006

This article questions prevailing interpretations of New Labour's political economy and challenges the assumption within the comparative and international political economy literatures of the exhaustion of the Keynesian political economic paradigm. New Labour's doctrinal statements are analysed to establish to what extent these doctrinal positions involve a repudiation of Keynesianism. Although New Labour has explicitly renounced the ‘fine tuning’ often (somewhat problematically) associated with post-war Keynesian political economy, we argue that they have carved out policy space in which to engage in macroeconomic ‘coarse tuning’ inspired by Keynesian thinking. This capacity to ‘coarse tune’ is precisely what is being sought in New Labour's quest for credibility through the redesign of British macroeconomic policy framework and institutions. Our empirical focus on New Labour in government since 1997 offers considerable evidence that this search for the capacity to ‘coarse tune’ has been successful.
The PM and the Pendulum: Dynamic Forecasting of British Elections
Authors: LEBO MATTHEW J. , NORPOTH HELMUT
Published: December 2006

We apply a dynamic perspective to forecasting votes and seats in British elections. Our vote model captures the swing of the electoral pendulum between the two major parties while using prime ministerial approval as the (sole) short-run predictor of vote choice. The seat model incorporates the inertia of the previous seat distribution while translating votes into seats. The models forecast the lead of one major party over the other (percentage for votes and number for seats). The statistical estimation includes data on British elections since 1945, although the test for cycles (swing of the electoral pendulum) goes as far back as 1832. The vote model picks the winner of every one of the 1945–2005 elections (out-of-sample forecasts) and is rarely off by more than 2 percentage points. The seat model does almost as well, rarely missing the seat lead by more than 25.
Post-operative complications of cochlear implantation in adults and children: five years' experience in Maastricht
Authors: Postelmans J T F , Cleffken B , Stokroos R J
Published: December 2006

Although cochlear implantation is considered a safe method of rehabilitation for profoundly deaf individuals, a number of these patients suffer complications after surgery. To evaluate post-operative complications after cochlear implantation, a retrospective chart review was performed for 112 patients who had undergone implantation in the Maastricht Academic Hospital. Minor complications were defined as those that could be overcome by medical or audiological management. These occurred in 36 patients (32 per cent) and all were managed successfully. Major complications were defined as device extrusion and those requiring further surgery, and these were identified in four patients (3.6 per cent). These complications included wound infection and device failure mediated by middle-ear pathology. In cases of chronic otitis media, we recommend performance of cochlear implantation as a staged procedure. In order to reduce the post-operative incidence of acute otitis media, we recommend adenoidectomy, placement of ventilation tubes and early antibiotic treatment.
Standard Georgian
Authors: Shosted Ryan K. , Chikovani Vakhtang
Published: December 2006

Georgian is a Kartvelian (South Caucasian) language spoken by 4 to 5 million people in the Republic of Georgia, with small diaspora communities spread out in a few republics of the former Soviet Union, Iran, and Turkey. Shanidze (1973) distinguishes six groups of Georgian dialects: Dasavluri (Imeruli, Guruli, Rachuli, Lechkhumuri); Ingilouri; Kartlur-Kakhuri (Kartluri, Kakhuri, Javakhuri, Meskhuri, Kizikuri); Mtiulur-Pshauri (Mtiulur-Gudamakruli, Pshauri); Pkhouri (Khevsuruli, Mokheuri, Tushuri); and Samkhret-Dasavluri (Acharuli, Imerkheuli). The Kartluri dialect is considered the basis of standard or literary Georgian. It is spoken in Kartli, an eastern Georgian province where Tbilisi, the Georgian capital, is located. Standard literary Georgian is discussed here. One male speaker from Tbilisi (the second author) was consulted for all the data presented in the illustration.
A randomized controlled clinical trial of a psychosocial and communication intervention carried out by GPs for patients with medically unexplained symptoms
Authors: AIARZAGUENA JOSÉ M. , GRANDES GONZALO , GAMINDE IDOIA , SALAZAR AGUSTÍN , SÁNCHEZ ÁLVARO , ARIÑO JULEN
Published: December 2006

Background. Somatizing patients are a challenge to general practitioners (GPs). A cluster randomized controlled trial was conducted to asses the effect of specific communication techniques delivered by GPs on somatizing patients' self-perceived health.

Method. Thirty-nine GPs were assigned randomly to two parallel groups. GPs in the intervention group treated somatic patients according to specific communication techniques focused on offering a physical explanation – release of hormones – and approaching sensitive topics in the patient's experience indirectly. Control GPs used the standard Goldberg reattribution technique. A total of 156 patients, aged 18–65 years, were selected randomly from a list of 468 patients with six or more active symptoms for women and four or more for men. All patients had six programmed 30-min consultations. Health-related quality of life (assessed with the 36-item Short-Form Health Survey, SF-36) and a summary utility index were used as outcome measures. Patients were interviewed at home at baseline and at 3, 8 and 12 months after the beginning of the intervention.

Results. Patients in both groups improved in all dimensions of the SF-36. The time course of the quality of life was significantly better for the intervention group in five of the eight scales of the SF-36 (bodily pain, mental health, physical functioning, vitality, and social functioning) and in the utility index (p<0·039).

Conclusions. Communication techniques were found to have a clinically relevant impact on body pain. This finding, together with a trend towards better scores in the remaining scales, justifies the use of these techniques in psychosocial interventions delivered to patients with medically unexplained symptoms.
Reducing medication-related adverse events in elderly patients
Authors: Fernando Bernard , McKinstry Brian , Sheikh Aziz
Published: December 2006

‘The current care systems cannot do the job. Trying harder will not work. If we want safer, higher-quality care, we will need to have redesigned systems of care, including the use of information technology to support clinical and administrative processes.’
Severe decline of large birds in the Northern Sahel of West Africa: a long-term assessment
Authors: THIOLLAY JEAN-MARC
Published: December 2006

The current status of most West African birds is little known and may change quickly with increasing human population pressure and agriculture, road, tourism, hunting and mining developments. Following documented declines of raptors in Sudan and the Southern Sahel zones, I compared the number of birds counted along the same eight extensive transect counts in 1971–1973 (3,703 km) and 2004 (3,688 km) in arid steppes, acacia woodlands and desert mountains of northern Mali and Niger (Adrar des Iforhas, Aïr, Ténéré). The once widespread Ostrich Struthio camelus is now extinct west of Chad. No Arabian Ardeotis arabs and Nubian Bustards Neotis nuba were seen in 2004 (216 in 1970s) nor any Rüppell's Griffon Gyps rueppellii and Lappet-faced Vultures Torgos tracheliotus (114 and 96 respectively recorded in the 1970s). From Adrar to Ténéré, just one Egyptian Vulture Neophron percnopterus was recorded in 2004 (vs 75 in 1970s), but it was still common in the oases of Kawar (27 vs 38). These data are exploratory and the current status of the species involved should be further documented. Nevertheless, they are a serious warning about the future of several taxa. Overhunting, aggravated by overgrazing and degradation of acacia woodlands are obvious causes of the collapse of Ostrich and bustards. The near-extinction of wild ungulates, intensified use of cattle, increased disturbance and poisoning of predators may have been critical in the dramatic decline of vultures. An effective hunting ban, updates on the status of threatened species, reintroduction of Ostrich, enforcement of existing nature reserves and design of a new one in northern Mali are among the most urgent steps to take if the large birds of the vast subdesert areas of West Africa are to be conserved.
Kinetics of cell death of frozen-thawed human embryonic stem cell colonies is reversibly slowed down by exposure to low temperature
Authors: Heng B.C. , Ye C.P. , Liu H. , Toh W.S. , Rufaihah A.J. , Cao T.
Published: December 2006

A major challenge in the widespread application of hES (human embryonic stem) cells in clinical therapy and basic scientific research is the development of efficient cryopreservation protocols. Conventional slow-cooling protocols utilizing standard cryoprotectant concentrations i.e. 10% (v/v) DMSO, yield extremely low survival rates of less than 5% as reported by previous studies. This study characterized cell death in frozen-thawed hES colonies that were cryopreserved under standard conditions. Surprisingly, our results showed that immediately after post-thaw washing, the overwhelming majority of hES cells were viable (approximately 98%), as assessed by the trypan blue exclusion test. However, when the freshly thawed hES colonies were placed in a 37 °C incubator, there was a gradual reduction in cell viability over time. The kinetics of cell death was drastically slowed down by keeping the freshly thawed hES colonies at 4 °C, with more than 90% of cells remaining viable after 90 min of incubation at 4 °C. This effect was reversible upon re-exposing the cells to physiological temperatures. The vast majority of low temperature-exposed hES colonies gradually underwent cell death upon incubation for a further 90 min at 37 °C. Hence, our observations would strongly suggest involvement of a self-induced apoptotic mechanism, as opposed to cellular necrosis arising from cryoinjury.
THE LAW AS A SOCIAL PRACTICE: Are Shared Activities at the Foundations of Law?
Authors: Smith Matthew Noah
Published: December 2006

A central tenet of positivism is that social practices are at the foundations of law. This has been cashed out in a variety of ways. For example, Austin argues that, among other practices, a habit of obedience to a sovereign is at the foundations of law, and Hart argues that at the foundations of law is the converging attitudes and behaviors of a class of relevant officials. Since Hart, some prominent positivists have employed either David Lewis's analysis of conventions or Michael Bratman's theory of shared cooperative activities to develop new accounts of the social practices that are at the foundations of law, whatever those foundations might be. In this paper, I identify five features characteristic of the Lewisean and Bratmanian models of social facts—models of what I call hypercommittal social practices. I then show that models of social facts that have these features ought not to be used to explain the way in which a social practice is at the foundations the law. I conclude that hypercommittal social practices such as Lewisean conventions or Bratmanian shared activities are not at the foundations of law.
Truth commissions: a schematic overview
Authors: Hayner Priscilla B.
Published: December 2006

Numerous truth commissions of different types are being created around the world. The purpose of this schematic overview is to study the variety and to sketch out the differences and similarities between the different truth commissions established since the Truth and Reconciliation Commission of South Africa launched in 1995.
Gleichzeitiger Gesichtsfelddefekt und Libidoverlust – Zufall?
Authors: Jenni  , Seiler  , Christ  , Stettler
Published: December 2006

Wir stellen einen 60-jährigen Patienten vor, bei dem anlässlich einer Routineuntersuchung eine Visuseinschränkung mit homonymen Gesichtsfeldausfällen festgestellt wurde, was letztlich zur Diagnose eines infiltrativen Makroprolaktinoms führte. Anamnestisch war ein Hypogonadismus bereits seit mehreren Jahren manifest. Unter medikamentöser Therapie mit Cabergolin gingen die ophthalmologischen Symptome rasch zurück und bildgebend wurde ein Rückgang der Tumorgrösse dokumentiert. Gerade bei Männern werden Prolaktinome meist erst bei erheblicher Tumorgrösse und bei entsprechenden Kompressionssymptomen diagnostiziert; sie gelangen häufig auf Umwegen an den Endokrinologen. Die Behandlung weicht insofern von derjenigen der übrigen Hypophysenadenome ab, als die Symptome und die Tumorgrösse rein medikamentös wirksam beeinflusst werden können.
Impact of the Eastern Weddell Ice Shelves on water masses in the eastern Weddell Sea
Authors: Thoma Malte , Grosfeld Klaus , Lange Manfred A.
Published: December 2006

We use a primitive equation Ocean General Circulation Model to simulate the ocean circulation regime in the Eastern Weddell Sea. The computer model ROMBAX (Revisited Ocean Model based on Bryan And Cox) is an improved version of an earlier ocean model, which has been developed to allow the simulation of the flow regime in ice shelf covered regions. The Eastern Weddell Ice Shelf (EWIS) region is of particular importance because of its narrow continental shelf and its location at the inflow of water masses from the east into the southern Weddell Sea. We have compared the simulated flow pattern and water properties in the EWIS region with the available sparse observations. While the general observed structure of temperature and salinity is reproduced, the model tends to overestimate the on‐shore flow of warm deep waters. This discrepancy is not large enough to seriously influence the ice shelf – ocean interaction, which is in good agreement with estimates based on field observations. The mean net melt rate is found to be 0.88 m yr−1 (2.1 mSv) and has a strong seasonal cycle. Sensitivity studies with different ice shelf configurations (no melting, no ice shelf, closed cavity) show strong impacts on the water mass properties in the EWIS region, with up to 0.7°C difference in temperature and 0.05 in salinity relative to the control run. Our results suggest that the EWIS region is of substantial importance to water mass preconditioning and formation in the Weddell Sea, although no deep or bottom water formation occurs in the eastern Weddell Sea directly.
A climatology of tides in the Antarctic mesosphere and lower thermosphere
Authors: Murphy D. J. , Forbes J. M. , Walterscheid R. L. , Hagan M. E. , Avery S. K. , Aso T. , Fraser G. J. , Fritts D. C. , Jarvis M. J. , McDonald A. J. , Riggin D. M. , Tsutsumi M. , Vincent R. A.
Published: December 2006

A function that approximates atmospheric tidal behavior in the polar regions is described. This function is fitted to multistation radar measurements of wind in the mesosphere and lower thermosphere with the aim of obtaining a latitude‐longitude‐height description of the variation of tides over the whole Antarctic continent. Archival wind data sets are combined with present‐day ones to fill the spatial distribution of the observations and to reduce the potential effects of spatial aliasing. Multiple years are combined through the compilation of monthly station composite days, yielding results for each month of the year. Despite potential problems associated with year‐to‐year variations in the tidal phase, a useful climatology of Antarctic zonal and meridional tidal wind components is compiled. The results of the fits reproduce the major features of the high‐latitude tidal wind field: the dominance of the semidiurnal migrating mode in the winter months and the presence of a semidiurnal zonal wave number one component in the summer months. It is also found that the summer semidiurnal tide contains a zonal wave number zero component.
Surface tension of atmospheric humic‐like substances in connection with relaxation, dilution, and solution pH
Authors: Salma Imre , Ocskay Rita , Varga Imre , Maenhaut Willy
Published: December 2006

Humic‐like substances (HULIS) were isolated by a solid‐phase extraction procedure from PM2.5 fraction urban‐type atmospheric aerosol samples collected in downtown Budapest, Hungary, in the nonheating season. Their amount was derived, and the surface tension properties of their pure solutions were investigated. Carbon content of HULIS accounted for 54% of the water‐soluble organic carbon and for 19% of organic carbon in the aerosol. Solution of pure HULIS in concentrations corresponding to real incipient cloud droplets decreased the surface tension of water by about 30%, and the major decrease occurred within several tens of seconds. In diluted solutions, however, the thermodynamic equilibrium in surface tension was only reached after several hours, but the equilibrium depression value was still remarkable, about 18%. Detailed analysis of the relaxation curves implied that the kinetics of the surface tension depression should be regarded as and described by a diffusion‐controlled process. The surface tension curves as a function of the HULIS concentration after an elapsed time of up to about 100 s resembled the curves observed earlier, but the shape of and tendency in the equilibrium curve (the isotherm) was rather different. The deviations were linked to physicochemical properties of certain classes of compounds within the HULIS. The surface tension depended on the solution pH as well; the smallest depression was observed at about pH = 5, and it was increased by an additional 13% for strong acidic or basic conditions; hence the role of surface tension in cloud droplet formation under acid rain conditions is further amplified.
Role of mantle flow at the North Fiji Basin: Insights from anomalous topography
Authors: Zhang Nan , Pysklywec Russell N.
Published: December 2006

The North Fiji Basin is a complex back‐arc system situated between the opposite‐verging Tonga and New Hebrides subduction zones. On the basis of two independent calculations, we find that the back‐arc region is anomalously high with topography residuals reaching up to 2000 m above what should be isostatically supported. Our study aims to test whether a hot buoyant upwelling is required beneath the North Fiji Basin to support the observed high elevation. The mantle thermal structure beneath the North Fiji Basin is inferred from the global tomographic model S20RTS, where seismic velocity anomalies are converted to density/temperature anomalies. This thermal structure is input into a three‐dimensional mantle convection code, CitcomS, and the flow‐induced surface topography is calculated and compared with the observed anomalous topography. In a series of experiments, we eliminate various portions of the mantle structure to consider what type of mantle flow can support the anomalous topography. The experiments suggest that the observed topography in the North Fiji Basin is consistent with the support of hot buoyant upper mantle upwelling, and specifically rising material in the depth range from 70 to 120 km is the most critical component. A relatively thin/weak lithosphere is required to produce the high‐amplitude and short‐wavelength topography residuals, and the presence of discrete breaks in the plate produces further localization of flow‐induced topography.
Role of bathymetry in Agulhas Current configuration and behaviour
Authors: Speich S. , Lutjeharms J. R. E. , Penven P. , Blanke B.
Published: December 2006

The Agulhas Current forms an important link in the global ocean thermohaline circulation by its role in the inter‐ocean exchange of water south of Africa. This process of ring shedding at the current's retroflection is dependent on perturbations to its trajectory that are sensitive to bathymetry. These perturbations may furthermore force the current to intersect shallow regions resulting in substantial changes to its path. A number of other flow characteristics of the system have also been deemed to be influenced by bathymetry. How dependent is Agulhas Current behaviour therefore on the bottom topography? We have used a regional, primitive equation model for initial experimentation. Removing the Agulhas Bank leads to enhanced inter‐ocean flux, indicating its importance for inter‐ocean exchange. Excising the Agulhas Plateau causes meridional meanders in the Agulhas Return Current to be unlocked from the bathymetry. Smoothing the continental slope weakens the current and substantially increases the direct inter‐ocean flux.
Geologic constraints on the existence and distribution of West Antarctic subglacial volcanism
Authors: Vogel S. W. , Tulaczyk S. , Carter S. , Renne P. , Turrin B. , Grunow A.
Published: December 2006

Strong and abundant magnetic anomalies imaged beneath the West Antarctic Ice Sheet by aerogeophysical surveys have been interpreted as evidence of widespread Late Cenozoic basaltic volcanism, perhaps even a large igneous province. Petrological and geochemical composition of subglacial sediment samples from West Antarctica supports crustal provenance and does not provide positive evidence for the existence of the proposed mafic Late Cenozoic large igneous province. The only two identified basaltic pebbles, out of a total of >500 examined pebbles, are of Mesozoic to Cambrian age. We conjecture that the subglacial large igneous province does not exist or is blanketed by an at least Miocene age sedimentary drape.
Does the Arctic sea ice have a tipping point?
Authors: Winton Michael
Published: December 2006

Two IPCC fourth assessment report climate models have Arctic Ocean simulations that become sea‐ice‐free year around in 1%/year CO2 increase to quadrupling experiments. These runs are examined for evidence of accelerated climate change associated with the removal of sea ice, particularly due to increasing surface albedo feedback. Both models become seasonally ice‐free at an annual mean polar temperature of −9°C without registering much impact on the surface albedo feedback or disturbing the linear relationship between Arctic Ocean climate change and that of the surrounding region. When the polar temperature rises above −5°C, however, there is a sharp increase in the surface albedo feedback of one of the models, driving an abrupt elimination of Arctic ice and an increase in temperature above that expected from warming of the surrounding region. The transition to ice‐free conditions is more linear in the other model, with ocean heat flux playing the primary driving role.
Future abrupt reductions in the summer Arctic sea ice
Authors: Holland Marika M. , Bitz Cecilia M. , Tremblay Bruno
Published: December 2006

We examine the trajectory of Arctic summer sea ice in seven projections from the Community Climate System Model and find that abrupt reductions are a common feature of these 21st century simulations. These events have decreasing September ice extent trends that are typically 4 times larger than comparable observed trends. One event exhibits a decrease from 6 million km2 to 2 million km2 in a decade, reaching near ice‐free September conditions by 2040. In the simulations, ice retreat accelerates as thinning increases the open water formation efficiency for a given melt rate and the ice‐albedo feedback increases shortwave absorption. The retreat is abrupt when ocean heat transport to the Arctic is rapidly increasing. Analysis from multiple climate models and three forcing scenarios indicates that abrupt reductions occur in simulations from over 50% of the models and suggests that reductions in future greenhouse gas emissions moderate the likelihood of these events.
Role of void space geometry in permeability evolution in crustal rocks at elevated pressure
Authors: Benson Philip M. , Meredith Philip G. , Schubnel Alexandre
Published: December 2006

A key consequence of the presence of void space within rock is their significant influence upon fluid transport properties. In this study, we measure changes in elastic wave velocities (P and S) contemporaneously with changes in permeability and porosity at elevated pressure for three rock types with widely different void space geometries: a high‐porosity sandstone (Bentheim), a tight sandstone (Crab Orchard), and a microcracked granodiorite (Takidani). Laboratory data are then used with the permeability models of Guéguen and Dienes and Kozeny‐Carman to investigate the characteristics that different void space geometries impart to measured permeabilities. Using the Kachanov effective medium theory, elastic wave velocities are inverted, permitting the recovery of crack density evolution with increasing effective pressure. The crack densities are then used as input to the microcrack permeability model of Guéguen and Dienes. The classic Kozeny‐Carman approach of Walsh and Brace is also applied to the measured permeability data via a least squares fit in order to extract tortuosity data. We successfully predict the evolution of permeability with increasing effective pressure, as directly measured in experiments, and report the contrast between permeability changes observed in rock where microcracks or equant pores dominate the microstructure. Additionally, we show how these properties are affected by anisotropy of the rock types via the measured anisotropic fabrics in each rock. The combined experimental and modeling results illustrate the importance of understanding the details of how rock microstructure changes in response to an external stimulus in predicting the simultaneous evolution of different rock physical properties.
Theoretical aspects of dipolar interactions and their appearance in first‐order reversal curves of thermally activated single‐domain particles
Authors: Egli R.
Published: December 2006

Recently, the study of interacting particles was driven by the modeling effort undertaken to interpret first‐order reversal curve (FORC) diagrams of natural rocks and sediments. Understanding the effect of magnetostatic interactions is of primary importance in rock magnetism and paleomagnetism, and FORCs can provide useful information for this purpose. However, fully quantitative theories of FORC measurements have not been formulated yet. The goal of this paper is to fill this gap for the case of interacting single‐domain (SD) particles. First, a general analytical expression is obtained for the local interaction field produced by a random set of magnetic dipoles. This expression is then used to formulate a general theory that explains the effect of the local interaction field on FORCs. Exact solutions are obtained for the case of weakly interacting single‐domain particles, whereby the effect of thermal activations is considered as well. These solutions show that a rigorous analysis of the FORC function and its relationship with the distributions of coercivities and interaction fields is possible.
Impacts of sources and aging on submicrometer aerosol properties in the marine boundary layer across the Gulf of Maine
Authors: Quinn P. K. , Bates T. S. , Coffman D. , Onasch T. B. , Worsnop D. , Baynard T. , de Gouw J. A. , Goldan P. D. , Kuster W. C. , Williams E. , Roberts J. M. , Lerner B. , Stohl A. , Pettersson A. , Lovejoy E. R.
Published: December 2006

Measurements were made on board the NOAA RV Ronald H. Brown during the second New England Air Quality Study (NEAQS 2004) to determine the source of the aerosol in the region and how sources and aging processes affect submicrometer aerosol chemical composition and optical properties. Using the Lagrangian particle dispersion model FLEXPART in combination with gas phase tracer compounds, local (urban), regional (NE U.S. urban corridor of Washington, D.C.; New York; and Boston), and distant (midwest industries and North American forest fires) sources were identified. Submicrometer aerosol measured near the source region (Boston Harbor) had a molar equivalence ratio near one with respect to NH4+, NO3−, and SO4=, had a large mass fraction of particulate organic matter (POM) relative to SO4=, and had relatively unoxidized POM. As distance from the source region increased, the submicrometer aerosol measured in the marine boundary layer became more acidic and had a lower POM mass fraction, and the POM became more oxidized. The relative humidity dependence of light extinction reflected the change in aerosol composition being lower for the near‐source aerosol and higher for the more processed aerosol. A factor analysis performed on a combined data set of aerosol and gas phase parameters showed that the POM measured during the experiment was predominantly of secondary anthropogenic origin.
International Consortium for Atmospheric Research on Transport and Transformation (ICARTT): North America to Europe—Overview of the 2004 summer field study
Authors: Fehsenfeld F. C. , Ancellet G. , Bates T. S. , Goldstein A. H. , Hardesty R. M. , Honrath R. , Law K. S. , Lewis A. C. , Leaitch R. , McKeen S. , Meagher J. , Parrish D. D. , Pszenny A. A. P. , Russell P. B. , Schlager H. , Seinfeld J. , Talbot R. , Zbinden R.
Published: December 2006

In the summer of 2004 several separate field programs intensively studied the photochemical, heterogeneous chemical and radiative environment of the troposphere over North America, the North Atlantic Ocean, and western Europe. Previous studies have indicated that the transport of continental emissions, particularly from North America, influences the concentrations of trace species in the troposphere over the North Atlantic and Europe. An international team of scientists, representing over 100 laboratories, collaborated under the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) umbrella to coordinate the separate field programs in order to maximize the resulting advances in our understanding of regional air quality, the transport, chemical transformation and removal of aerosols, ozone, and their precursors during intercontinental transport, and the radiation balance of the troposphere. Participants utilized nine aircraft, one research vessel, several ground‐based sites in North America and the Azores, a network of aerosol‐ozone lidars in Europe, satellites, balloon borne sondes, and routine commercial aircraft measurements. In this special section, the results from a major fraction of those platforms are presented. This overview is aimed at providing operational and logistical information for those platforms, summarizing the principal findings and conclusions that have been drawn from the results, and directing readers to specific papers for further details.
Reliable conjunctive use rules for sustainable irrigated agriculture and reservoir spill control
Authors: Schoups Gerrit , Addams C. Lee , Minjares Jose Luis , Gorelick Steven M.
Published: December 2006

We develop optimal conjunctive use water management strategies that balance two potentially conflicting objectives: sustaining irrigated agriculture during droughts and minimizing unnecessary spills and resulting water losses from the reservoir during wet periods. Conjunctive use is specified by a linear operating rule, which determines the maximum surface water release as a function of initial reservoir storage. Optimal strategies are identified using multiobjective interannual optimization for sustainability and spill control, combined with gradient‐based annual profit maximization. Application to historical conditions in the irrigated system of the Yaqui Valley, Mexico, yields a Pareto curve of solutions illustrating the trade‐off between sustaining agriculture and minimizing spills and water losses. Minimal water losses are obtained by maximizing surface water use and limiting groundwater pumping, such that reservoir levels are kept sufficiently low. Maximum agricultural sustainability, on the other hand, results from increased groundwater use and keeping surface water reservoir levels high during wet periods. Selected optimal operating rules from the multiobjective optimization are tested over a large number of equally probable streamflow time series, generated with a stochastic time series model. In this manner, statistical properties, such as the mean sustainability and sustainability percentiles, are determined for each optimal rule. These statistical properties can be used to select rules for water management that are reliable over a wide range of streamflow conditions.
Modulation of protein kinase C by curcumin; inhibition and activation switched by calcium ions
Authors: Mahmmoud Y A
Published: December 2006

Background and purpose:

Previous studies have identified the natural polyphenol curcumin as a protein kinase C (PKC) inhibitor. In contrast, we found significant stimulation of PKC activity following curcumin treatment. Thus, the mechanism of curcumin interaction with PKC was investigated.

Experimental approach:

We employed phosphorylation assays in the presence of soluble or membrane‐bound PKC substrates, followed by SDS–PAGE, autoradiography and phosphorylation intensity measurements.

Key results:

Curcumin inhibited PKC in the absence of membranes whereas stimulation was observed in the presence of membranes. Further analysis indicated that curcumin decreased PKC activity by competition with Ca2+ stimulation of the kinase, resulting in inhibition of activity at lower Ca2+ concentrations and stimulation at higher Ca2+ concentrations. The role of the membrane is likely to be facilitation of Ca2+‐binding to the kinase, thus relieving the curcumin inhibition observed at limited Ca2+ concentrations. Curcumin was found to mildly stimulate the catalytic subunit of PKC, which does not require Ca2+ for activation. In addition, studies on Ca2+‐independent PKC isoforms as well as another curcumin target (the sarcoplasmic reticulum Ca2+‐ATPase) confirmed a correlation between Ca2+ concentration and the curcumin effects.

Conclusions and Implications:

Curcumin competes with Ca2+ for the regulatory domain of PKC, resulting in a Ca2+‐dependent dual effect on the kinase. We propose that curcumin interacts with the Ca2+‐binding domains in target proteins. To our knowledge, this is the first study that defines an interaction domain for curcumin, and provides a rationale for the broad specificity of this polyphenol as a chemopreventive drug.

British Journal of Pharmacology (2007) 150, 200–208. doi:10.1038/sj.bjp.0706970
Activation of peripheral cannabinoid CB1and CB2receptors suppresses the maintenance of inflammatory nociception: a comparative analysis
Authors: Gutierrez T , Farthing J N , Zvonok A M , Makriyannis A , Hohmann A G
Published: December 2006

Background and Purpose:

Effects of locally administered agonists and antagonists for cannabinoid CB1and CB2receptors on mechanical and thermal hypersensitivity were compared after the establishment of chronic inflammation.

Experimental approach:

Carrageenan was administered unilaterally to the rat hindpaw on day 1. Prophylactic efficacy of locally administered CB1‐ and CB2‐selective agonists −arachidonyl‐2‐chloroethylamide (ACEA) and (R,S)‐(2‐iodo‐5‐nitro‐phenyl)‐[l‐(l‐methyl‐piperidin‐2‐ylmethyl)‐lH‐ubdik‐3‐yl]‐methanone ((R,S)‐AM1241), respectively− on mechanical and thermal hypersensitivity were compared on day 2. Pharmacological specificity was evaluated using locally administered CB1and CB2‐selective antagonists −N‐(piperidin‐1‐yl)‐5‐(4‐chlorophenyl)‐1‐(2,4‐dichlorophenyl)‐4‐methyl‐1H‐pyrazole‐3‐carboxamidehydrochloride (SR141716A) andN‐[(1S)‐endo‐1,3,3‐trimethyl bicycle [2.2.1] heptan‐2‐yl]‐5‐(4‐chloro‐3‐methylphenyl)‐1‐(4‐methylbenzyl)‐pyrazole‐3‐carboxamide (SR144528), respectively.

Key Results:

Administration of either ACEA or AM1241 to the inflamed but not noninflamed paw suppressed the maintenance of carrageenan‐evoked mechanical hyperalgesia and tactile allodynia and attenuated thermal hyperalgesia. The ACEA‐induced suppression of mechanical and thermal hypersensitivity was blocked by local injection of SR141716A but not SR144528. AM1241 suppressed mechanical hypersensitivity with the reverse pharmacological specificity. The AM1241‐induced suppression of thermal hyperalgesia was blocked by SR144528 and to a lesser extent by SR14176A. Co‐administration of ACEA with AM1241 in the inflamed paw increased the magnitude but not the duration of thermal antihyperalgesia compared to intraplantar administration of either agonist alone.

Conclusions and Implications:

Cannabinoids act locally through distinct CB1and CB2mechanisms to suppress mechanical hypersensitivity after the establishment of chronic inflammation, at doses that produced modest changes in thermal hyperalgesia. Additive antihyperalgesic effects were observed following prophylactic co‐administration of the CB1‐ and CB2‐selective agonists. Our results suggest that peripheral cannabinoid antihyperalgesic actions may be exploited for treatment of inflammatory pain states.

British Journal of Pharmacology(2007)150, 153–163. doi:10.1038/sj.bjp.0706984
Insulin induces airway smooth muscle contraction
Authors: Schaafsma D , Gosens R , Ris J M , Zaagsma J , Meurs H , Nelemans S A
Published: December 2006

Background and purpose:

Recently, the use of inhaled insulin formulations for the treatment of type I and type II diabetes has been approved in Europe and in the United States. For regular use, it is critical that airway function remains unimpaired in response to insulin exposure.

Experimental approach:

We investigated the effects of insulin on airway smooth muscle (ASM) contraction and contractile prostaglandin (PG) production, using guinea‐pig open‐ring tracheal smooth muscle preparations.

Key results:

It was found that insulin (1 nM‐1 μM) induced a concentration‐dependent contraction that was insensitive to epithelium removal. These sustained contractions were susceptible to inhibitors of cyclooxygenase (indomethacin, 3 μM), Rho‐kinase (Y‐27632, 1 μM) and p42/44 MAP kinase (PD‐98059, 30 μM and U‐0126, 3 μM), but not of PI‐3‐kinase (LY‐294002,10 μM). In addition, insulin significantly increased PGF2α‐production which was inhibited by indomethacin, but not Y‐27632. Moreover, the FP‐receptor antagonist AL‐8810 (10 μM) and the EP1‐receptor antagonist AH‐6809 (10 μM) strongly reduced insulin‐induced contractions, supporting a pivotal role for contractile prostaglandins.

Conclusions and implications:

Collectively, the results show that insulin induces guinea‐pig ASM contraction presumably through the production of contractile prostaglandins, which in turn are dependent on Rho‐kinase for their contractile effects. The data suggest that administration of insulin as an aerosol could result in some acute adverse effects on ASM function.

British Journal of Pharmacology(2007)150, 136–142. doi:10.1038/sj.bjp.0706985
Mouse testicular hyaluronidase-like proteins SPAM1 and HYAL5 but not HYALP1 degrade hyaluronan
Authors: Reitinger Stephan , Laschober Gerhard Thomas , Fehrer Christine , Greiderer Brigitte , Lepperdinger Günter
Published: December 2006

Besides SPAM1 (sperm adhesion molecule 1; formerly named PH-20), further hyaluronidase-like proteins, HYAL5 (hyaluronoglucosaminidase 5) and HYALP1 (hyaluronoglucosaminidase pseudogene 1) are also expressed in murine testicular tissue. As they share a high degree of sequence similarity with known hyaluronidases, all three polypeptides could potentially exhibit hyaluronidase activity, a function that is beneficial for spermatozoa in order to penetrate the hyaluronan-rich cumulus, which surrounds the oocyte. Recently, it was reported that SPAM1-deficient mice are fertile and spermatozoa derived from mutant mice still exhibit hyaluronidase activity [Baba, Kashiwabara, Honda, Yamagata, Wu, Ikawa, Okabe and Baba (2002) J. Biol. Chem. 277, 30310–30314]. We have now recombinantly expressed mouse SPAM1, HYAL5 and HYALP1 in Xenopus laevis oocytes and determined their respective expression pattern in testis. Transcripts of all three genes are expressed in seminiferous tubules in regions where maturing spermatogenic cells reside. SPAM1 and HYAL5 but not HYALP1 proteins exhibit hyaluronidase activity at neutral pH. The two active hyaluronidases are both bound to the cell surface via a glycosylphosphatidylinositol anchor. Furthermore, structural characteristics are discussed that are necessary for hyaluronidases in order to exhibit hyaluronan cleavage.