bluuebunny/crossref_metadata_2025 huggingface dataset:
From agricultural geology to hydropedology: forging links within the twenty-first-century geoscience community
Authors: Landa Edward R.
Published: December 2007

Despite historical linkages, the fields of geology and soil science have developed along largely divergent paths in the United States during much of the mid- to late-twentieth century. The shift in recent decades within both disciplines, towards greater emphasis on environmental-quality issues and a systems approach, has created new opportunities for collaboration and cross-training. Because of the importance of the soil as a dynamic interface between the hydrosphere, biosphere, atmosphere and lithosphere, introductory and advanced soil-science classes are now taught in a number of Earth and environmental science departments. The National Research Council's recent report,
Basic Research Opportunities in Earth Science
, highlights the soil zone as part of the land surface to groundwater ‘critical zone’ requiring additional investigation. To better prepare geology undergraduates to deal with complex environmental problems, their training should include a fundamental understanding of the nature and properties of soils. Those undergraduate geology students with an interest in this area should be encouraged to view soil science as a viable Earth-science specialty area for graduate study.
Policies for a sustainable use of soil resources
Authors: Montanarella Luca
Published: December 2007

Soil protection policies have been developed at National level in a number of countries. The US Soil Conservation Act, the German Federal Soil Protection Act, and the Soil Action Plan for England are just some examples of such policies. International policies for a sustainable use of soil resources have been developed both at regional level and at global level. The Alpine Convention and the upcoming EU Thematic Strategy for Soil Protection are two examples of regional policies addressing soil protection. No specific binding global policy exists for soil protection. Nevertheless, a number of environmental protection policies address soil-protection aspects, like the climate-change convention, the biodiversity convention and the desertification convention. Further development of the EU Thematic Strategy for Soil Protection will make it possible to explore new methods of international cooperation in this field.
Nutrient balances for improving the use-efficiency of non-renewable resources: experiences from Switzerland and Southeast Asia
Authors: Menzi H. , Gerber P.
Published: December 2007

Simple nutrient balances can be a valuable tool to assess and visualize whether farming systems are in equilibrium or not with respect to nutrient inputs and outputs. Thus, they can raise awareness about environmental risks of agricultural production, and especially intensive livestock production. They are also a valuable tool for policy development and implementation processes. In this paper, we discuss how a nutrient-balance approach can help to improve the awareness of different stakeholders about the ecological impacts of agriculture and the efficient use of nutrients. While the example from Switzerland demonstrates the potential ecological benefits of compulsory nutrient balancing, the examples from Asia demonstrate how a combination of nutrient balancing and geographic information system (GIS) was used to identify hot-spots with respect to insufficient and excessive P input, and we will discuss a nutrient-balance method developed to improve nutrient management in the rapidly growing intensive livestock-production sector.
Parameterization of meander-belt elements in high-resolution three-dimensional seismic data using the GeoTime cube and modern analogues
Authors: Rabelo I. R. , Luthi S. M. , Van Vliet L. J.
Published: December 2007

The parametric quantification of geological bodies from high-resolution seismic data helps in understanding and predicting their occurrences, but is often hampered by layer distortions caused by post-depositional processes. A method called GeoTime cube is presented that overcomes this by creating a seismic volume between two near-isochronous geological markers in which the vertical axis corresponds approximately to relative geologic time. This volume is no longer affected by post-depositional deformations, a feature that greatly facilitates the extraction of sedimentary elements of interest. A case study of a fluvio-estuarine reservoir from Suriname demonstrates how fluvial point bars, channel fills and crevasse splays can be extracted from the GeoTime cube. Their geometries are quantified with the help of recent analogues. Meandering rivers are found to show relatively constant curvatures and a characteristic spacing of their meander loops. Cubic splines are suitable parametric descriptors of such river paths. Point bars are their main depositional product and can be approximated by two intersecting circle segments, representing the initial and the final position of the meander loop. The axis joining the circle centres corresponds to the direction of accretion, and the normals to these axes describe the drainage trend. Knowledge of these parameters from a limited area can be used to stochastically model the meander belt in the up- and downstream direction.
Seismic geomorphology of Palaeozoic collapse features in the Fort Worth Basin (USA)
Authors: Sullivan E. C. , Marfurt K. J. , Blumentritt C. , Ammerman M.
Published: December 2007

Modern multi-trace geometric attributes produce three-dimensional volumes that can facilitate the recognition of karst geomorphology by avoiding the need to pre-interpret irregular horizons and by enhancing subseismic lateral variations in reflectivity. These geometric attributes include the well-established coherence technology, coupled with recent developments in spectrally limited estimates of volumetric curvature. Coherence measures lateral changes in waveform, and as such, is often sensitive to joints, small faults, sinkholes and collapse features. The many components of reflector curvature, including the most negative, most positive, Gaussian curvature and related shape indices (e.g. valleys, saddles, domes), are complimentary to coherence measures. Short wavelength estimates of curvature will illuminate small-scale lineaments while longer wavelength estimates of curvature illuminate more subtle flexures and compaction features. We show the results of applying a variety of multi-trace geometric attributes to a three-dimensional seismic volume from the Fort Worth Basin, where a collapse system extends vertically some 800m from the Ordovician Ellenburger carbonates through the dominantly siliciclastic Mississippian— Pennsylvanian interval. The collapse features in our data set appear as rounded, sinkhole-like appearances on time and horizon slices in the Pennsylvanian Marble Falls Limestones and the Ellenburger horizon displays features that can be interpreted as cockpit karst, dolines and frying pan valleys. Although a variety of palaeocave breccia facies in core and image logs indicate that the Ellenburger surface has been karsted, these breccias are not confined to the mega collapse features visible in seismic. The large (up to 700 m diameter) collapse chimneys can be shown in multi-spectral curvature attributes to have elongate rhombohedral shapes associated with intersections of Pennsylvanian age, field-scale to basin-scale, basement lineaments and faults. Isochores indicate greatest tectonic growth on faults from Mississippian until early Pennsylvanian, coincident with thickest fill of collapse features. Thus we interpret the origin of the chimneys to be primarily tectonic. The multi-trace geometric attributes permit better imaging of the three-dimensional shapes of the collapse features, provide better constraints on timing of their formation, allow us to begin to separate karst processes from tectonic processes and provide a means of predicting most likely locations of fluid movement along faults.
Fluvial seismic geomorphology: a view from the surface
Authors: Ethridge F. G. , Schumm S. A.
Published: December 2007

Three-dimensional seismic data enable geoscientists to image the stratigraphic record along selected stratal or time slices. These slices provide detailed images of the planform geometry of ancient depositional systems and environments. In this presentation we attempt to provide a partial answer to the question: what kind of information do nonmarine channel and valley patterns and parameters convey regarding sediment load, channel stability, structural or climatic history of the area, and palaeochannel and reservoir architecture? Geomorphologists have long recognized four basic channel patterns: straight, meandering, braided and anastomosing. They have also developed a classification based on aerial pattern and sediment load. This relationship seems straightforward; however the patterns form a continuum with a great deal of complexity related to degree and character of sinuosity, braiding and anabranching. For example an equal- width sinuous pattern suggests moderate to high lateral stability, and low bed load to suspended load deposits. A wide bend sinuous pattern suggests low to moderate lateral stability, and higher bed load to suspended load deposits. Because of convergence and divergence, interpretation of controls on palaeochannel patterns is difficult. Nevertheless, a better understanding of the various controls on modem river morphology and dynamics can produce useful information regarding palaeo-systems. For example, river type (straight, braided, meandering and anastomosing) depends upon upstream controls such as geologic history (glaciated v. non-glaciated systems), tectonics (relief), lithology (sediment type) and climate (hydrology and vegetation), and downstream controls such as base-level (up and down) and length (avulsion). In addition, factors such as bedrock, active tectonics, floods and vegetation cause considerable pattern variability. Only by taking into account the effect of these controls and by using all available data can there be more predictive and interpretive explanations of seismic data.
Seismic expression of turbidity-current and bottom-current processes on the Northern Mauritanian continental slope
Authors: Schwab A. M. , Tremblay S. , Hurst A.
Published: December 2007

The architectural framework of the Mauritanian continental slope is characterized by a complex mixture of gravity and bottom current deposits that modify the pelagic background sedimentation. Since the Neogene, the Mauritanian passive margin bottom-currents have been the main control on the construction and topography of the slope. On the lower slope, numerous sediment waves and contourites occur. Turbidity-current channel incisions and slope failures are responsible for the destructive remodelling of the slope. The upper-slope incisions have a dendritic pattern, and converge into highly sinuous main channels in the lower slope, where the channels become constructional with levees and lateral accretion packages. Subsurface data exhibit older slope failures, which guide the location of later turbidity-current channel pathways. The seabed and shallow seismic expression of deep-water slope deposits generated by variable gravity-transport and bottom-current processes in offshore Northern Mauritania can be compared with analogous settings in lower resolution, deeper subsurface seismic data to gain a better understanding of the slope environment and deposits.
Repeatable evaluation of search services in dynamic environments
Authors: Jensen Eric C. , Beitzel Steven M. , Chowdhury Abdur , Frieder Ophir
Published: December 2007

In dynamic environments, such as the World Wide Web, a changing document collection, query population, and set of search services demands frequent repetition of search effectiveness (relevance) evaluations. Reconstructing static test collections, such as in TREC, requires considerable human effort, as large collection sizes demand judgments deep into retrieved pools. In practice it is common to perform shallow evaluations over small numbers of live engines (often pairwise, engine A vs. engine B) without system pooling. Although these evaluations are not intended to construct reusable test collections, their utility depends on conclusions generalizing to the query population as a whole. We leverage the bootstrap estimate of the reproducibility probability of hypothesis tests in determining the query sample sizes required to ensure this, finding they are much larger than those required for static collections. We propose a semiautomatic evaluation framework to reduce this effort. We validate this framework against a manual evaluation of the top ten results of ten Web search engines across 896 queries in navigational and informational tasks. Augmenting manual judgments with pseudo-relevance judgments mined from Web taxonomies reduces both the chances of missing a correct pairwise conclusion, and those of finding an errant conclusion, by approximately 50%.
Frequency-based identification of correct translation equivalents (FITE) obtained through transformation rules
Authors: Pirkola Ari , Toivonen Jarmo , Keskustalo Heikki , Järvelin Kalervo
Published: December 2007

We devised a novel statistical technique for the identification of the translation equivalents of source words obtained by transformation rule based translation (TRT). The effectiveness of the technique called
frequency-based identification of translation equivalents
(
FITE
) was tested using biological and medical cross-lingual spelling variants and out-of-vocabulary (OOV) words in Spanish-English and Finnish-English TRT. The results showed that, depending on the source language and frequency corpus, FITE-TRT (the identification of translation equivalents from TRT's translation set by means of the FITE technique) may achieve high translation recall. In the case of the Web as the frequency corpus, translation recall was 89.2%--91.0% for Spanish-English FITE-TRT. For both language pairs FITE-TRT achieved high translation precision: 95.0%--98.8%. The technique also reliably identified native source language words: source words that cannot be correctly translated by TRT. Dictionary-based CLIR augmented with FITE-TRT performed substantially better than basic dictionary-based CLIR where OOV keys were kept intact. FITE-TRT with Web document frequencies was the best technique among several fuzzy translation/matching approaches tested in cross-language retrieval experiments. We also discuss the application of FITE-TRT in the automatic construction of multilingual dictionaries.
RIC
Authors: Böhm Christian , Faloutsos Christos , Pan Jia-Yu , Plant Claudia
Published: December 2007

How do we find a
natural
clustering of a real-world point set which contains an unknown number of clusters with different shapes, and which may be contaminated by noise? As most clustering algorithms were designed with certain assumptions (Gaussianity), they often require the user to give input parameters, and are sensitive to noise. In this article, we propose a robust framework for determining a natural clustering of a given dataset, based on the minimum description length (MDL) principle. The proposed framework,
robust information-theoretic clustering (RIC)
, is orthogonal to any known clustering algorithm: Given a preliminary clustering, RIC purifies these clusters from noise, and adjusts the clusterings such that it simultaneously determines the most natural amount and shape (subspace) of the clusters. Our RIC method can be combined with any clustering technique ranging from K-means and K-medoids to advanced methods such as spectral clustering. In fact, RIC is even able to purify and improve an initial coarse clustering, even if we start with very simple methods. In an extension, we propose a fully automatic stand-alone clustering method and efficiency improvements. RIC scales well with the dataset size. Extensive experiments on synthetic and real-world datasets validate the proposed RIC framework.
Database research opportunities in computer games
Authors: White Walker , Koch Christoph , Gupta Nitin , Gehrke Johannes , Demers Alan
Published: December 2007

In this paper, we outline several ways in which the database community can contribute to the development of technology for computer games. We outline the architecture of different types of computer games, and show how database technology plays a role in their design. From this, we identify several new research directions to improve the utilization of this technology in computer games.
Delayed password disclosure
Authors: Jakobsson Markus , Myers Steven
Published: December 2007

We present a new authentication protocol called Delayed Password Disclosure. Based on the traditional username and password paradigm, the protocol's goal is aimed at reducing the effectiveness of phishing/spoofing attacks that are becoming increasingly problematic for Internet users. This is done by providing the user with dynamic feedback while password entry occurs. While this is a process that would normally be frowned upon by the cryptographic community, we argue that it may result in more effective security than that offered by currently proposed "cryptographically acceptable" alternatives. While the protocol cannot prevent
partial
disclosure of one's password to the phisher, it does provide a user with the tools necessary to recognize an ongoing phishing attack, and prevent the disclosure of his/her entire password, providing graceful security degradation.
Competitiveness via primal-dual
Authors: Chrobak Marek
Published: December 2007

From the editor:
So you are reading this paper on online algorithms. At first the paper reads well, and you get through the first few pages in no time -- until the authors pull a rabbit out of a hat: the online algorithm. Fine, you say to yourself, patience, it all will start making sense when I get to the analysis, just keep reading. But it doesn't -- the proof is by an even more mysterious trick, and this time out of the hat comes a humpback whale: yes, a potential function. Sound familiar?
Modulation of ileal bile acid transporter (ASBT) activity by depletion of plasma membrane cholesterol: association with lipid rafts
Authors: Annaba Fadi , Sarwar Zaheer , Kumar Pradeep , Saksena Seema , Turner Jerrold R. , Dudeja Pradeep K. , Gill Ravinder K. , Alrefai Waddah A.
Published: December 2007

Apical sodium-dependent bile acid transporter (ASBT) represents a highly efficient conservation mechanism of bile acids via mediation of their active transport across the luminal membrane of terminal ileum. To gain insight into the cellular regulation of ASBT, we investigated the association of ASBT with cholesterol and sphingolipid-enriched specialized plasma membrane microdomains known as lipid rafts and examined the role of membrane cholesterol in maintaining ASBT function. Human embryonic kidney (HEK)-293 cells stably transfected with human ASBT, human ileal brush-border membrane vesicles, and human intestinal epithelial Caco-2 cells were utilized for these studies. Floatation experiments on Optiprep density gradients demonstrated the association of ASBT protein with lipid rafts. Disruption of lipid rafts by depletion of membrane cholesterol with methyl-β-cyclodextrin (MβCD) significantly reduced the association of ASBT with lipid rafts, which was paralleled by a decrease in ASBT activity in Caco-2 and HEK-293 cells treated with MβCD. The inhibition in ASBT activity by MβCD was blocked in the cells treated with MβCD-cholesterol complexes. Kinetic analysis revealed that MβCD treatment decreased the Vmaxof the transporter, which was not associated with alteration in the plasma membrane expression of ASBT. Our study illustrates that cholesterol content of lipid rafts is essential for the optimal activity of ASBT and support the association of ASBT with lipid rafts. These findings suggest a novel mechanism by which ASBT activity may be rapidly modulated by alterations in cholesterol content of plasma membrane and thus have important implications in processes related to maintenance of bile acid and cholesterol homeostasis.
The Adventures of Sonic Hedgehog in Development and Repair. I. Hedgehog signaling in gastrointestinal development and disease
Authors: Parkin Caroline A. , Ingham Philip W.
Published: December 2007

Hedgehog (Hh) proteins are members of a family of secreted signaling factors that orchestrate the development of many organs and tissues including those of the gastrointestinal (GI) tract. The requirement for Hh activity is not limited to early development but underlies the homeostasis of a number of tissues, and abnormal activity of the Hh pathway is associated with several GI malignancies. Understanding the roles and mechanisms of action of Hh signaling both in development and postnatally should thus give novel insights into potential treatments for these diseases. Here we focus on the Hh signaling pathway and its role in GI tract development and maintenance and consider the diseases resulting from aberrant Hh activity.
Role played by P2X and P2Y receptors in evoking the muscle chemoreflex
Authors: Hayes Shawn G. , McCord Jennifer L. , Kaufman Marc P.
Published: December 2007

The role played by purinergic 2Y receptors in evoking the muscle chemoreflex is not well defined. To shed light on this issue, we compared the pressor responses with popliteal arterial injection of UTP (1 mg/kg), a selective P2Y agonist, with those to popliteal arterial injection of ATP (1 mg/kg), a P2X and P2Y agonist, and to α,β-methylene ATP (50 μg/kg), a selective P2X1 and P2X3 agonist, in decerebrate unanesthetized cats. We found that injection of ATP and α,β-methylene ATP increased mean arterial pressure by 19 ± 2 and 15 ± 4 mmHg, whereas UTP had no affect on arterial pressure. In addition, the pressor responses to injection of ATP and α,β-methylene ATP were abolished by section of the sciatic nerve, demonstrating that they were reflex in origin. We conclude that P2Y receptors on thin fiber muscle afferents play no role in evoking the muscle chemoreflex.
Importance of hemodynamic forces as signals for exercise-induced changes in endothelial cell phenotype
Authors: Laughlin M. Harold , Newcomer Sean C. , Bender Shawn B.
Published: December 2007

Current evidence indicates that the ability of physical activity to sustain a normal phenotype of arterial endothelial cells (ECs) plays a central role in the beneficial effects of exercise (Ex) on atherosclerotic disease. Here we evaluate the strength of evidence that shear stress (SS) and/or circumferential wall stress (stretch) are the primary signals, produced by bouts of Ex, that signal altered gene expression in arterial ECs, thereby resulting in a less atherogenic EC phenotype. Current literature indicates that SS is a signal for expression of antiatherogenic genes in cultured ECs, in ECs of isolated arteries, and in ECs of arteries in intact animals. Furthermore, SS levels in the arteries of humans during Ex are in the range that produces beneficial changes. In contrast, complex flow profiles within recirculation zones and/or oscillatory flow patterns can cause proatherogenic gene expression in ECs. In vivo evidence indicates that Ex decreases oscillatory flow/SS in some portions of the arterial tree but may increase oscillatory flow in other areas of the arterial tree. Circumferential wall stress can increase expression of some beneficial EC genes as well, but circumferential wall stress also increases production of reactive oxygen species and increases the expression of adhesion factors and other proatherogenic genes. Interactions of arterial pressure and fluid SS play an important role in arterial vascular health and likely contribute to how Ex bouts signal changes in EC gene expression. It is also clear that other local and circulating factors interact with these hemodynamic signals during Ex to produce the healthy arterial EC phenotype. We conclude that available evidence suggests that exercise signals formation of beneficial endothelial cell phenotype at least in part through changes in SS and wall stretch in the arteries.
Tea Consumption Is Inversely Associated With Carotid Plaques in Women
Authors: Debette Stéphanie , Courbon Dominique , Leone Nathalie , Gariépy Jérôme , Tzourio Christophe , Dartigues Jean-François , Barberger-Gateau Pascale , Ritchie Karen , Alpérovitch Annick , Amouyel Philippe , Ducimetière Pierre , Zureik Mahmoud
Published: December 2007

Objective—

The aim of this study was to assess the relationship of tea consumption with common carotid artery intima-media thickness (CCA-IMT) and carotid plaques.

Methods and Results—

The study was performed on 6597 subjects aged ≥65 years, recruited in the French population for the Three-City Study. Atherosclerotic plaques in the extracranial carotid arteries and CCA-IMT were measured using a standardized protocol. Results were tested for replication in another, younger, French population sample (EVA-Study, 1123 subjects). In the Three-City Study, increasing daily tea consumption was associated with a lower prevalence of carotid plaques in women: 44.0%, 42.5%, and 33.7% in women drinking no tea, 1 to 2 cups/d, and ≥3 cups/d (
P
=0.0001). This association was independent of age, center, major vascular risk factors, educational level, and dietary habits (adjOR=0.68[95%CI:0.54 to 0.86] for women drinking ≥3 cups/d compared with none). There was no association of tea consumption with carotid plaques in men, or CCA-IMT in both genders. In the EVA-Study, carotid plaque frequency was 18.8%, 18.5%, and 8.9% in women drinking no tea, 1 to 2 cups/d, and ≥3 cups/d (
P
=0.08).

Conclusion—

In a large sample of elderly community subjects we showed for the first time that carotid plaques were less frequent with increasing tea consumption in women.
Are Steroids Useful to Treat Cerebral Venous Thrombosis?
Authors: Canhão Patrícia , Cortesão Ana , Cabral Marta , Ferro José M. , Stam Jan , Bousser Marie-Germaine , Barinagarrementeria Fernando
Published: December 2007

Background and Purpose—

No randomized controlled trial has evaluated the efficacy of steroids in acute cerebral venous thrombosis (CVT). We aimed to analyze the effect of steroids on the outcome of patients in the International Study on Cerebral Veins and Dural Sinus Thrombosis (ISCVT).

Methods—

ISCVT is a prospective observational study that included 624 CVT patients. Death or dependence at 6 months was compared between cases (patients treated with steroids) and controls (patients not treated with steroids), using 3 designs: (1) Matched case–control study (each case matched with a control for prognostic factors); (2) Nonmatched case–control study of the ISCVT cohort; (3) Case–control study in different strata according to the number of poor prognostic variables in each patient.

Results—

One hundred and fifty (24%) patients were treated with steroids. (1) In the matched case–control study, poor outcome was similar in the two groups of patients (26/146 versus 17/149, OR=1.7; 95% CI 0.9 to 3.3,
P
=0.119). (2) In the ISCVT cohort, no significant difference in poor outcomes was found whether patients were treated with steroids or not (26/146 versus 60/469, OR=1.5; 95% CI 0.9 to 2.4). Patients without parenchymal lesions treated with steroids had worse prognosis than those treated without steroids (8/45 versus 9/184, OR=4.2, 95% CI 1.6 to 11.6,
P
=0.008). (3) Treatment with steroids was not associated with a better outcome in any strata of patients according to the number of poor prognostic factors.

Conclusions—

Steroids in the acute phase of CVT were not useful and were detrimental in patients without parenchymal cerebral lesions. These results do not support the use of steroids in CVT (evidence level III).
Level and Value of Circulating Endothelial Progenitor Cells in Patients After Acute Ischemic Stroke
Authors: Yip Hon-Kan , Chang Li-Teh , Chang Wen-Neng , Lu Cheng-Hsien , Liou Chia-Wei , Lan Min-Yu , Liu Josef S. , Youssef Ali A. , Chang Hsueh-Wen
Published: December 2007

Background and Purpose—

Endothelial progenitor cells (EPCs) migrate from bone marrow to systemic circulation in response to tissue ischemia where they differentiate into mature endothelial cells for angiogenesis in situ. This study tested the hypothesis that the level of circulating EPCs is substantially increased and predictive of prognostic outcomes after acute ischemic stroke (IS).

Methods—

The level of circulating EPCs (staining markers: CD31/CD34 [E
1
], CD62E/CD34 [E
2
], and KDR/CD34 [E
3
]) were examined using flow cytometry at 48 hours after acute IS in 138 consecutive patients. The EPC level was also evaluated once in 20 healthy volunteers and in 40 at-risk control subjects.

Results—

Level of circulating EPCs (E
1–3
) was significantly higher in patients with IS than in at-risk control subjects (
P
<0.05). Additionally, EPC (E
1–3
) level was significantly lower in patients with severe neurological impairment (defined as a score ≥12 on the National Institutes of Health Stroke Scale) than in patients with less severe impairment (National Institutes of Health Stroke Scale < score 12) at 48 hours after IS (
P
<0.0001). Moreover, the EPC (E
3
) level was strongly correlated with improved National Institutes of Health Stroke Scale ≥4 on day 21 after IS (
P
=0.0004). Furthermore, low circulating EPC level was independently predictive of severe neurological impairment (National Institutes of Health Stroke Scale ≥12) at 48 hours (E
1–3
) and combined major adverse clinical outcomes (defined as recurrent IS, any cause of death, or National Institutes of Health Stroke Scale of ≥12) on day 90 (E
1
) after IS (
P
<0.001).

Conclusions—

Level of circulating EPCs is independently predictive of prognosis after IS.
Overexpression of Dimethylarginine Dimethylaminohydrolase Inhibits Asymmetric Dimethylarginine–Induced Endothelial Dysfunction in the Cerebral Circulation
Authors: Dayoub Hayan , Rodionov Roman N. , Lynch Cynthia , Cooke John P. , Arning Erland , Bottiglieri Teodoro , Lentz Steven R. , Faraci Frank M.
Published: December 2007

Background and Purpose—

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase (NOS). An elevation of plasma ADMA levels is associated with cardiovascular disease. ADMA is hydrolyzed by dimethylarginine dimethylaminohydrolases (DDAHs). The goal of this study was to determine whether overexpression of human DDAH-1 in transgenic (DDAH-1–Tg) mice inhibits the vascular effects of ADMA.

Methods—

Using nontransgenic (non-Tg) and DDAH-1–Tg mice, we compared responses of the carotid artery and aorta (in vitro) and of the cerebral arterioles (in vivo) in the absence or presence of ADMA. DDAH-1 expression and plasma levels of ADMA were also measured.

Results—

Western blotting indicated that vascular expression of DDAH-1 was increased markedly in DDAH-1–Tg mice. Plasma levels of ADMA were reduced by ≈50% in DDAH-1–Tg mice compared with non-Tg mice (0.19±0.02 vs 0.37±0.04 μmol/L,
P
<0.05). Contraction of the aorta to nitro-
l
-arginine methyl ester (an inhibitor of NOS), an index of basal production of NO, was increased in DDAH-1–Tg mice compared with controls (50±4% vs 34±4%,
P
<0.05). Relaxation of the carotid artery to acetylcholine (an endothelium-dependent agonist) was enhanced in DDAH-1–Tg animals compared with control mice (relaxation of 74±6% vs 59±5%, respectively, in response to 10 μmol/L acetylcholine,
P
<0.05). ADMA (100 μmol/L) impaired the vascular response to acetylcholine in both non-Tg and DDAH-1–Tg mice, but the relative difference between the 2 strains remained. Responses to the endothelium-independent NO donor nitroprusside were similar in all groups. In vivo, ADMA (10 μmol/L) reduced responses of the cerebral arterioles to acetylcholine by ≈70% in non-Tg mice (
P
<0.05), and this inhibitory effect was largely absent in DDAH-1–Tg mice.

Conclusions—

These findings provide the first evidence that overexpression of DDAH-1 increases basal levels of vascular NO and protects against ADMA-induced endothelial dysfunction in the cerebral circulation.
Stroke Incidence and Survival in the Beginning of the 21st Century in Southern Sweden
Authors: Hallström Björn , Jönsson Ann-Cathrin , Nerbrand Christina , Norrving Bo , Lindgren Arne
Published: December 2007

Background and Purpose—

We report trends of stroke incidence and survival up to year 2001/2002 in Lund-Orup, Sweden, and projections of future stroke incidence in Sweden.

Methods—

Lund Stroke Register, a prospective population-based study, included all first-ever stroke patients, between March 1, 2001 and February 28, 2002, in the Lund-Orup health care district. Institution-based studies for 1983 to 1985 and 1993 to 1995 were used for comparison. We calculated age-standardized incidence and Cox proportional hazards analysis of survival (stroke subtype, sex, age group, and study period in the analysis). Minimum follow-up was 46 months. Based on our register’s stroke incidence and the official Swedish population projection, a projection for future stroke incidence on a national basis was calculated.

Results—

We included 456 patients with first-ever stroke in 2001/2002. The age-standardized incidence (to the European population) was 144 per 100 000 person-years (95%CI 130 to 158) in 2001/2002, 158 (95%CI 149 to 168) in 1993 to 1995, and 134 (95%CI 126 to 143) in 1983 to 1985. Cox proportional hazard analysis indicated decreased risk of death after stroke in 2001/2002 (hazard ratio 0.80; 95%CI 0.67 to 0.94) compared with 1993 to 1995. Up to year 2050, the annual number of new stroke patients in Sweden may increase by 59% based solely on demographic changes.

Conclusions—

Despite possible underestimation of stroke incidence during the previous institution-based studies, the increased stroke incidence between 1983 to 1985 and 1993 to 1995 did not continue in 2001/2002. The long-term survival after stroke continues to improve. As the elderly population is growing in Sweden, stable incidence and increasing survival will result in a rapidly increasing prevalence of stroke patients in Sweden.
Emboli Formation Rather Than Inflammatory Mediators Are Responsible for Increased Cerebral Water Content After Conventional and Assisted Beating-Heart Myocardial Revascularization in a Porcine Model
Authors: Bierbach Benjamin , Meier Matthias , Kasper-König Walter , Heimann Axel , Alessandri Beat , Horstick Georg , Oelert Hellmut , Kempski Oliver
Published: December 2007

Background and Purpose—

Emboli and proinflammatory mediators are suspected of generating cerebral edema after coronary surgery. In contrast to cardiopulmonary bypass (CPB), off-pump coronary artery bypass surgery (OPCAB) reduces microemboli count and proinflammatory mediator release but carries the risk of hemodynamic instability. A microaxial blood pump can augment cardiac output.

Methods—

Coronary bypasses were constructed in pigs with CPB and cardioplegia (n=9), OPCAB (n=9), or blood-pump support CAB (n=9). Nine animals underwent sham operation. Embolus count was monitored and regional cerebral blood flow was assessed with microspheres in 21 brain specimens per animal (n=189 per group). Interleukins 6 and 8 and tumor necrosis factor-α concentrations were determined. These variables were studied before, during, and for 4 hours after surgery. Finally, cerebral water content was determined.

Results—

During CPB and blood-pump CAB, a significant number of emboli were counted in contrast to OPCAB and controls (
P
<0.05). During CPB, regional cerebral blood flow was affected (32 of 189) and showed reactive hyperemia except in 10 specimens after aortic cross-clamp release. This impairment persisted in 20 specimens. During and after OPCAB, regional cerebral blood flow remained nearly unchanged but showed low flow during (58 of 189) and after (35 of 189) the blood-pump run. A significant increase in proinflammatory mediators was observed only in the CPB group. CPB and blood-pump CAB significantly increased cerebral water content (
P
<0.05). A strong correlation between embolic load and cerebral water content was observed in all groups. No correlation between proinflammatory mediator release and cerebral water content was detected.

Conclusions—

Emboli formation rather than inflammatory mediators are responsible for increased cerebral water content after conventional and assisted beating-heart myocardial revascularization.
Doing Theology: Engaging the Public
Authors: Elliot Alison
Published: December 2007

This article examines the characteristics of some of the contexts in which public theology is done. Examples are taken from Scotland and particularly the experience of representatives of the Church of Scotland. Three publics are identified as target audiences: an institutional public in which official positions are debated and defended; a constructed public in which theological understanding is developed in the company of others; and a personal public which characterizes some forms of broadcasting. Discourse in each public has different characteristics, drawing on distinctive theological assumptions about church and faith. The article examines how public theology can draw strength from practice in each context.
Faith in, with and under Gordon Brown: A Scottish Presbyterian/Calvinist Reflection
Authors: Gay Doug
Published: December 2007

Profiles of the UK Prime Minister Gordon Brown repeatedly characterize him by means of the terms 'Presbyterian' and 'Calvinist'. This article explores the cultural and theological background to how such terms are habitually used within the British media and offers a critical reflection, based on Brown's speeches, as to how religious terms, themes and identifications are in play in his public and political discourse. It identifies two dominant themes in Brown's recent public discourse: 'narrating Britishness' and 'the moral sense'. In reflection on these, the article suggests that Brown is intellectually estranged from Calvinist and Presbyterian theological traditions, defining his faith as 'a private matter' and rooting his moral sense in the traditions of the British and Scottish Enlightenments.
Reflections on How and Why We Go Public
Authors: Stackhouse Max
Published: December 2007

Whereas many think of public theology as it addresses public policy directly, this article seeks to chart the major non-political, indirect ways in which religions go public and thereby influence the common life and civil society. In addition to sketching out how religions generally shape their cultural and civilizational ethos, and thus personal character and social polity, it identifies how Christianity does so in distinctive directions and why it does so in comparison and contrast with other great traditions. Finally, it offers a set of suggestions as to why, for all its failures and blunders, a Christian public theology engenders a distinctive ethic which is good for humanity.
Public Theology—a Latin Captivity of the Church: Violence and Public Theology in the Asia-Pacific Context
Authors: Haire James
Published: December 2007

This article looks at public theology from the perspective of the Asia-Pacific context. Thus, the focus is on theology from the standpoint of Christianity as a minority faith, seeking to do theology in a world outside that of the western church. The article considers the activity of public theology through the engagement of theology with a world of violence. It begins by looking at violence and the transformed communities of peace in the New Testament, through examining the milieu of violence, the transformed communities of peace and the dynamics which created those transformed communities. It then goes on to observe the dynamics of peace and violence in the intercultural history of Christianity, by looking historically at cyclic culture and word culture and the interaction between the two, particularly as they relate to peace and violence. From this, the article draws out conclusions on the Christian experience of peace and violence in relation to cultures, and looks at how Christians are called to engage in public theology in such a world.
X-ray crystal structure of the fibrinolysis inhibitor α2-antiplasmin
Authors: Law Ruby H. P. , Sofian Trifina , Kan Wan-Ting , Horvath Anita J. , Hitchen Corinne R. , Langendorf Christopher G. , Buckle Ashley M. , Whisstock James C. , Coughlin Paul B.
Published: December 2007

The serpin α2-antiplasmin (SERPINF2) is the principal inhibitor of plasmin and inhibits fibrinolysis. Accordingly, α2-antiplasmin deficiency in humans results in uncontrolled fibrinolysis and a bleeding disorder. α2-antiplasmin is an unusual serpin, in that it contains extensive N- and C-terminal sequences flanking the serpin domain. The N-terminal sequence is crosslinked to fibrin by factor XIIIa, whereas the C-terminal region mediates the initial interaction with plasmin. To understand how this may happen, we have determined the 2.65Å X-ray crystal structure of an N-terminal truncated murine α2-antiplasmin. The structure reveals that part of the C-terminal sequence is tightly associated with the body of the serpin. This would be anticipated to position the flexible plasmin-binding portion of the C-terminus in close proximity to the serpin Reactive Center Loop where it may act as a template to accelerate serpin/protease interactions.
Databases as policy instruments. About extending networks as evidence-based policy
Authors: de Bont Antoinette , Stoevelaar Herman , Bal Roland
Published: December 2007

Background

This article seeks to identify the role of databases in health policy. Access to information and communication technologies has changed traditional relationships between the state and professionals, creating new systems of surveillance and control. As a result, databases may have a profound effect on controlling clinical practice.

Methods

We conducted three case studies to reconstruct the development and use of databases as policy instruments. Each database was intended to be employed to control the use of one particular pharmaceutical in the Netherlands (growth hormone, antiretroviral drugs for HIV and Taxol, respectively). We studied the archives of the Dutch Health Insurance Board, conducted in-depth interviews with key informants and organized two focus groups, all focused on the use of databases both in policy circles and in clinical practice.

Results

Our results demonstrate that policy makers hardly used the databases, neither for cost control nor for quality assurance. Further analysis revealed that these databases facilitated self-regulation and quality assurance by (national) bodies of professionals, resulting in restrictive prescription behavior amongst physicians.

Conclusion

The databases fulfill control functions that were formerly located within the policy realm. The databases facilitate collaboration between policy makers and physicians, since they enable quality assurance by professionals. Delegating regulatory authority downwards into a network of physicians who control the use of pharmaceuticals seems to be a good alternative for centralized control on the basis of monitoring data.
Clinical effectiveness of usual care with or without antidepressant medication for primary care patients with minor or mild-major depression: a randomized equivalence trial
Authors: Hermens Marleen LM , van Hout Hein PJ , Terluin Berend , Adèr Herman J , Penninx Brenda WJH , van Marwijk Harm WJ , Bosmans Judith E , van Dyck Richard , de Haan Marten
Published: December 2007

Background

Minor and mild-major depression are highly prevalent in primary care. There is insufficient evidence for the effectiveness of antidepressants in the treatment of minor and mild-major depression. We compared the effectiveness of usual primary care treatment, with or without antidepressants, in minor and mild-major depression.

Methods

A pragmatic patient-randomized equivalence trial with 52 weeks follow-up was conducted in The Netherlands. In total, 59 primary care physicians (PCPs) recruited and treated 181 adult patients with minor or mild-major depression. Patients were randomized to four consultations within 3 months of usual care plus antidepressants (UCandAD) or usual care alone (UCnoAD). The Montgomery Åsberg Depression Rating Scale (MADRS) was used to assess changes in severity of depressive symptoms. The predefined equivalence margin was set at five points. Multilevel analysis was used to analyze the data. Secondary outcome measures were the Short-Form 36 (SF-36), and the Client Satisfaction Questionnaire (CSQ-8).

Results

Patients received on average 3.0 (SD 1.4) 15-min consultations within 3 months with (n = 85) or without paroxetine (n = 96). Equivalence of UCandAD and UCnoAD was demonstrated in the intention-to-treat analyses as well as the per-protocol analysis after 6 weeks, but not at 13, 26 and 52 weeks follow-up. No statistical differences in effectiveness between treatment groups were found in the intention-to-treat analysis. No differences in the physical and mental functioning (SF-36) were found between the treatment groups. Patients allocated to UCandAD were slightly more satisfied with their treatment at 13 weeks follow-up (but not at 52 weeks follow-up) than patients allocated to UCnoAD. Preliminary analyses suggested that subgroups such as patients with mild-major (instead of a minor) depression might benefit from antidepressant treatment. Patients who were assigned to their preferred treatment (in particular to UCnoAD) were more often compliant and had better clinical outcomes.

Conclusion

UCandAD was as effective as UCnoAD over the first 6 weeks, but not at 13, 26, and 52 weeks. However, superiority of either treatment could not be demonstrated either. The question whether antidepressants add any clinical effect to usual care remains unresolved. We recommend future studies to look for subgroups of patients who may benefit from antidepressants.

Trial registration

Dutch Trial Registry ISRCN03007807.
Vitamin D receptor polymorphisms and breast cancer risk in a large population-based case-control study of Caucasian and African-American women
Authors: Trabert Britton , Malone Kathleen E , Daling Janet R , Doody David R , Bernstein Leslie , Ursin Giske , Marchbanks Polly A , Strom Brian L , Humphrey Mariela C , Ostrander Elaine A
Published: December 2007

Introduction

The involvement of vitamin D receptor (VDR), which is a key mediator in the vitamin D pathway, in breast cancer etiology has long been of interest.

Methods

We examined the association between polymorphisms in the 3' end of the VDR gene, specifically BsmI and Poly(A), and breast cancer risk within a large, population-based, case-control study of breast cancer. Cases (n = 1,631) were Caucasian and African-American women, aged 35 to 64 years, who were diagnosed with incident, invasive breast cancer between July 1994 and April 1998. Control individuals (n = 1,435) were women without breast cancer ascertained through random digit dialing.

Results

Accounting for age, study site, and sampling weights, we observed a significantly increased risk for breast cancer among Caucasian, postmenopausal carriers of the bb genotype of BsmI (odds ratio = 1.53, 95% confidence interval = 1.04 to 2.27). However, no associations with the bb genotype were observed in African-American women. Overall, there were no significant associations between the Poly(A) genotype and breast cancer risk in either racial group. Smoking status (ever/never) modified the association between both the BsmI and Poly(A) genotypes and breast cancer risk. The respective associations between these genotypes and breast cancer risk did not significantly vary by oral contraceptive use, hormone replacement therapy, or body mass index.

Conclusion

Our results provide additional support for an increased risk for breast cancer in postmenopausal Caucasian women with the BsmI bb genotype and shed light on possible differential effects by menopausal status and race.