bluuebunny/crossref_metadata_2025 huggingface dataset:
Compaction bands and the formation of slot-shaped breakouts in St. Peter sandstone
Authors: Haimson B. , Klaetsch A.
Published: December 2007

Drilling of vertical wellbores in sandstone often results in stress-induced failed zones called breakouts. In the laboratory, miniature drilling under simulated far-field crustal stress conditions above a certain threshold produces breakouts that can be studied to enhance our understanding of deformation and failure mechanisms in rock. We report on drilling experiments in St. Peter sandstone, an Ordovician aeolian rock consisting of well-rounded bimodal quartz grains held together by sutured contacts. Breakouts here are slot-shaped and oriented at right angles to the far-field maximum stress direction (σ
H
), resembling emptied compaction bands. We distinguish between two porosity ranges in this rock. In the high-porosity variety (16–22%), grains are bonded through narrow sutures. In the vicinity of the borehole at points aligned with the far-field least horizontal principal stress (σ
h
) direction, where the maximum compressive stress concentrates, grain sutures sever at relatively low stress levels, leading to intergranular cracking. Debonded intact grains repack and produce a reduced-porosity narrow compaction band. Loose grains in the band abutting the borehole wall are then flushed out, assisted by the circulating drilling fluid. This intensifies the stress concentration ahead of the breakout tip, advancing the compaction band and lengthening the slot-shaped breakout. The process continues sequentially. Grains in the lower-porosity sandstone (11–12%) are more substantially sutured over much larger surface areas. This makes the sutures nearly as strong as the grains themselves; hence, failure requires considerably higher stresses, sufficient to bring about intragranular cracking. Consequently, and in contrast to the high-porosity sandstone, breakouts here are preceded by compaction bands of shattered and crushed grains. Both types of compaction bands have been encountered in the field and in independent laboratory experiments.
Models for compaction band propagation
Authors: Rudnicki J. W.
Published: December 2007

A compaction band is modelled as a thin, ellipsoidal heterogeneity with an imposed inelastic compactive strain and different elastic moduli from the surrounding matrix. Previously published results are used to determine the stress state in the band. For a wide variation of properties, stress conditions, and inelastic strain, the stress state in the band for aspect ratios observed in the field, 10
−3
–10
−4
, is indistinguishable from the result in the zero aspect ratio limit. In this limit, the compressive stress immediately adjacent to the band tip is roughly 10–100 times the far-field stress for parameters representative of field conditions. This value is relatively insensitive to the elastic mismatch between the band and the surrounding material, and is primarily controlled by the ratio of the far-field stress to twice the shear modulus times the inelastic compactive strain. This ratio is inferred to be about 0.02–0.05 from published field results, but may be several times larger for laboratory specimens. The ratio of tip to far-field stress increases with decrease of band shear modulus and becomes unbounded if both the shear modulus and aspect ratio go to zero. A combined anti-crack–dislocation model, in which a compactive relative displacement 2
h
is specified in the centre of the band and uniform traction elsewhere, predicts that for growth at constant energy release rate
h
is proportional to

L

where
L
is the half-length of the band. For an energy release rate of 40 kJ m
−2
, inferred in an earlier study from field observations and comparable with compaction energies inferred from laboratory tests on circumferentially notched compression samples, the constant of proportionality is consistent with that inferred from laboratory observations and earlier field data.
The geodynamic evolution of the Alpine orogen in the Cyclades (Aegean Sea, Greece): insights from diverse origins and modes of emplacement of ultramafic rocks
Authors: Katzir Y. , Garfunkel Z. , Avigad D. , Matthews A.
Published: December 2007

The Alpine orogen in the Cyclades, wherein both high-pressure metamorphic rocks and ultramafic rocks co-occur, is a key area in studying the emplacement of mantle rocks into the crust. Within the Cyclades three distinct ultramafic associations occur: (1) HP–LT ophiolitic mélanges of the Cycladic Blueschist Unit (CBU) on Evia and Syros; (2) meta-peridotites associated with migmatized leucogneisses on Naxos, which represent the deepest exposed levels of the CBU; (3) a greenschist-facies metamorphosed dismembered ophiolite juxtaposed on top of the CBU by an extensional detachment on Tinos. Most of the Cycladic ultramafic rocks were serpentinized prior to Alpine metamorphism, suggesting denudation prior to reburial. The Naxos meta-peridotites preserve, however, relict mantle assemblage and mantle-like oxygen isotope ratios, and thus indicate direct emplacement from the mantle into an underthrust continent during collision and HP metamorphism (M
1
). Thus conditions for M
1
in the Naxos leucogneiss core are constrained by ultramafic assemblages to 550–650 °C and ≥14 kbar. Mafic blocks of the ophiolitic mélanges in the NW Cyclades span a wide range of chemical compositions indicating derivation from variable oceanic settings and sequential events of alteration and metasomatism. Given the comparable geochemical heterogeneity in the Syros and Evian mélange intervals, the garnet-bearing meta-basites of the Syros mélange record higher M
1
temperatures (450–500 °C) than the garnet-free epidote blueschists of the Evian mélanges (400–430 °C). It follows that going southeastwards from Evia progressively deeper (i.e. hotter) levels of the subducted plate are exposed. Correspondingly, temperatures of the M
2
overprint also increase from pumpellyite-bearing assemblages on southern Evia, through greenschists on Syros to upper-amphibolite, sillimanite-bearing gneisses on Naxos. The diverse
P
–
T
paths of the CBU form an array wherein the deeper a rock sequence is buried, the ‘hotter’ is its exhumation path. Such a pattern is predicted by thermal modelling of tectonically thickened crust unroofed by either erosion or uniform extension.
Structural evolution of Andros (Cyclades, Greece): a key to the behaviour of a (flat) detachment within an extending continental crust
Authors: Mehl C. , Jolivet L. , Lacombe O. , Labrousse L. , Rimmele G.
Published: December 2007

The continental crust extends in a brittle manner in its upper part and in more distributed (ductile) manner in its lower part. During exhumation of HP metamorphic rocks, brittle features superimpose on earlier ductile ones as a result of the progressive localization of deformation. The islands of Tinos and Andros are part of the numerous metamorphic core complexes exhumed in the Aegean domain. They illustrate two steps of a gradient of finite extension along a transect between Mt. Olympos and Naxos. This study confirms the main role of boudinage as an initial localizing factor at the brittle–ductile transition and emphasizes the continuum of strain from ductile to brittle during exhumation. Early low-angle semi-brittle shear planes superimpose onto precursory ductile shear bands, whereas steeply dipping late brittle planes develop by progressive steepening of structures or sliding across en echelon arrays of veins. The comparison between Tinos and Andros allows us to propose a complete dynamic section of the Aegean extending continental crust and emphasizes that the strain localization process depends on both its rheological stratification and its compositional heterogeneity.
Late Miocene igneous rocks of Samos: the role of tectonism in petrogenesis in the southeastern Aegean
Authors: Pe-Piper G. , Piper D. J. W.
Published: December 2007

Late Miocene igneous rocks of Samos, in the southeastern Aegean Sea, comprise monzodiorite and minor granite of the Katavasis complex, trachyte and rhyolite of the Ambelos volcanic centre, and bimodal basalt–rhyolite at basin margins. Six new K–Ar ages, together with existing geochronology and biostratigraphy, show that the Katavasis complex and Ambelos centre date from 10–11 Ma and basalt–rhyolite from 8 Ma, correlating with cooling ages for the Katavasis complex and an unconformity in the basin fill. Monzodiorite, granite, trachyte and basalt all have similar radiogenic isotopes. Monzodiorite and basalt have similar trace element compositions and could result from 5–10% partial melting of enriched garnet lherzolite in the subcontinental lithosphere. Variations in trace elements suggest that trachyte and monzodiorite evolved by fractional crystallization from a parental magma similar to the younger basalt. The Katavasis and Ambelos rocks were synchronous with regional extension and listric faulting, which created opportunities for mid-crustal magma chambers and magma fractionation. Basalt extrusion was synchronous with the onset of north–south strike-slip faulting, which permitted more rapid transfer of magma to the surface. Late Miocene strike-slip faulting propagated from north to south in western Anatolia and the southeastern Aegean Sea, providing pathways for different types of mantle melts.
From syn- to post-orogenic Tertiary extension in the north Aegean region: constraints on the kinematics in the eastern Rhodope–Thrace, Bulgaria–Greece and the Biga Peninsula, NW Turkey
Authors: Bonev N. , Beccaletto L.
Published: December 2007

The Aegean region experienced back-are extension related to the Hellenic subduction system at least from the latest Oligocene to the present. We document Tertiary extension-related kinematics in the north Aegean, in the eastern Rhodope–Thrace of Bulgaria–Greece and the Biga Peninsula of NW Turkey. A regionally consistent NNE–SSW- to NE–SW-oriented kinematic direction, delineated in both areas by stretching lineations and associated ductile–brittle shear fabrics in exhumed metamorphic domes beneath detachments, suggests that they were kinematically coupled during the Tertiary extension. This kinematic framework, combined with regional geochronological data and the stratigraphic record in hanging-wall supradetachment basins, defines an extensional history that includes syn- and post-orogenic episodes from Paleocene to Miocene times. Paleocene–early Eocene synorogenic extension in the Kemer micaschists of the northern Biga Peninsula and in the Kesebir–Kardamos dome in Rhodope–Thrace accommodated gravitationally induced hinterland-directed exhumation of the orogenic stack, coeval with the closure of the Vardar Ocean. Then, following collision within the region, it was succeeded by latest Oligocene–Early Miocene extension as recorded in the Kazdaǧ Massif in the southern Biga Peninsula, which overlaps the Aegean back-arc post-orogenic extension, widely recognized in the central Aegean and southern Greek Rhodope. The protracted record of extension is interpreted to reflect progressive exhumation of the orogenic wedge along the Eurasian plate margin. Southward migration of extension and magmatism across the study areas accounts for sequential shift and roll-back of the subduction boundary at that margin, from the latest Cretaceous in the Rhodope to its present position at the Hellenic trench. The results allow recognition of the investigated areas as an important extensional domain in the north Aegean region, which underwent Tertiary syn- and post-orogenic extension.
Geodetic constraints on kinematics of southwestern Bulgaria from GPS and levelling data
Authors: Georgiev I. , Dimitrov D. , Belijashki T. , Pashova L. , Shanov S. , Nikolov G.
Published: December 2007

Southwestern Bulgaria belongs to the southern marginal parts of the central Balkan neotectonic region and borders the northern side of the highly seismic north Aegean region. The recent horizontal and vertical motion of the tectonic structures is controlled primarily by the collision stage, caused by continuing ENE palaeosubduction in the Ionian and Adriatic seas and extensional processes northwards of the North Aegean Trough. The present-day generation of small to moderate seismicity and crustal faulting suggests that the complex tectonic processes in the SW Bulgaria region are active. To monitor and study the tectonic deformation in SW Bulgaria, a global positioning system (GPS) network was established in early 2001. Analysis of GPS data from 1996 to 2004 resulted in a horizontal velocity field representing active surface deformations. Horizontal velocities at 38 GPS sites with respect to stable Eurasia are obtained. A new map of the recent vertical velocities is compiled, based on recomputed data from the repeated precise levelling for the period 1929–1991. We obtained evidence of recent active faulting. Based on the geological and geodetic data the SW Bulgaria is separated into five blocks with homogeneous kinematic behaviour. The average motion of each block varies from 1.3 to 3.4 mm a
−1
, and the whole region velocity is
c
. 1.8±0.7 mm a
−1
in a direction N154° with respect to stable Eurasia. Geodetic data correlate well with the geological data on neotectonic motions in SW Bulgaria.
Shear velocity structure in the Aegean region obtained by joint inversion of Rayleigh and Love waves
Authors: Karagianni E. E. , Papazachos C. B.
Published: December 2007

We present a shear velocity model of the crust and uppermost mantle under the Aegean region by simultaneous inversion of Rayleigh and Love waves. The database consists of regional earthquakes recorded by portable broadband three-component digital stations that were installed for a period of 6 months in the broader Aegean region. For each epicentre–station ray path group velocity dispersion curves are measured using appropriate frequency time analysis (FTAN). The dispersion measurements for more than 600 Love wave paths have been used. We have also incorporated previous results for
c
. 700 Rayleigh wave paths for the study area. The single-path dispersion curves of both waves were inverted to regional group velocity maps for different values of period (6–32 s) via a tomographic method. The local dispersion curves of discrete grid points for both surface waves were inverted nonlinearly to construct 1D models of shear-wave velocity v. depth. In most cases the joint inversion of Rayleigh and Love waves resulted in a single model (from the multiple models compatible with the data) that could interpret both Rayleigh and Love wave data. Around 60 local dispersion curves for both Rayleigh and Love waves were finally jointly inverted. As expected, because of the complex tectonic environment of the Aegean region the results show strong lateral variations of the S-wave velocities for the crust and uppermost mantle. Our results confirm the presence of a thin crust typically less than 28–30 km in the whole Aegean Sea, which in some parts of the southern and central Aegean Sea becomes significantly thinner (20–22 km). In contrast, a large crustal thickness of about 40–45 km exists in western Greece, and the remaining part of continental Greece is characterized by a mean crustal thickness of about 35 km. A significant sub-Moho upper mantle low-velocity zone (LVLmantle) with velocities as low as 3.7 km s
−1
, is clearly identified in the southern and central Aegean Sea, correlated with the high heat flow in the mantle wedge above the subducted slab and the related active volcanism in the region. The results obtained results are compared with independent body-wave tomographic information on the velocity structure of the study area and exhibit a generally good agreement, although significant small-scale differences are also identified.
A model for the Hellenic subduction zone in the area of Crete based on seismological investigations
Authors: Meier T. , Becker D. , Endrun B. , Rische M. , Bohnhoff M. , Stöckhert B. , Harjes H.-P.
Published: December 2007

The island of Crete represents a horst structure located in the central forearc of the retreating Hellenic subduction zone. The structure and dynamics of the plate boundary in the area of Crete are investigated by receiver function, surface wave and microseismicity using temporary seismic networks. Here the results are summarized and implications for geodynamic models are discussed. The oceanic Moho of the subducted African plate is situated at a depth of about 50–60 km beneath Crete. The continental crust of the overriding Aegean lithosphere is about 35 km thick in eastern and central Crete, and typical crustal velocities are observed down to the upper surface of the downgoing slab beneath western Crete. A negative phase at about 4 s in receiver functions occurring in stripes parallel to the trend of the island points to low-velocity slices within the Aegean lithosphere. Interplate seismicity is spread out about 100 km updip from the southern coastline of Crete. To the south of western Crete, this seismically active zone corresponds to the inferred rupture plane of the magnitude 8 earthquake of
ad
365. In contrast, interplate motion appears to be largely aseismic beneath the island. The coastline of Crete mimics the shape of a microseismically quiet realm in the Aegean lithosphere at 20–40 km depth, suggesting a relation between active processes at this depth range and uplift. The peculiar properties of the lithosphere and the plate interface beneath Crete are tentatively attributed to extrusion of material from a subduction channel, driving differential uplift of the island by several kilometres since about 4 Ma.
Body Fat Distribution and Risk of Coronary Heart Disease in Men and Women in the European Prospective Investigation Into Cancer and Nutrition in Norfolk Cohort
Authors: Canoy Dexter , Boekholdt S. Matthijs , Wareham Nicholas , Luben Robert , Welch Ailsa , Bingham Sheila , Buchan Iain , Day Nicholas , Khaw Kay-Tee
Published: December 2007

Background—

Body fat distribution has been cross-sectionally associated with atherosclerotic disease risk factors, but the prospective relation with coronary heart disease remains uncertain.

Methods and Results—

We examined the prospective relation between fat distribution indices and coronary heart disease among 24 508 men and women 45 to 79 years of age using proportional hazards regression. During a mean 9.1 years of follow-up, 1708 men and 892 women developed coronary heart disease. The risk for developing subsequent coronary heart disease increased continuously across the range of waist-hip ratio. Hazard ratios (95% CI) of the top versus bottom fifth of waist-hip ratio were 1.55 (1.28 to 1.73) in men and 1.91 (1.44 to 2.54) in women after adjustment for body mass index and other coronary heart disease risk factors. Hazard ratios increased with waist circumference, but risk estimates for waist circumference without hip circumference adjustment were lower by 10% to 18%. After adjustment for waist circumference, body mass index, and coronary heart disease risk factors, hazard ratios for 1-SD increase in hip circumference were 0.80 (95% CI, 0.74 to 0.87) in men and 0.80 (95% CI, 0.69 to 0.93) in women. Hazard ratios for body mass index were greatly attenuated when we adjusted for waist-hip ratio or waist circumference and other covariates.

Conclusions—

Indices of abdominal obesity were more consistently and strongly predictive of coronary heart disease than body mass index. These simple and inexpensive measurements could be used to assess obesity-related coronary heart disease risk in relatively healthy men and women.
Survival Is Similar After Standard Treatment and Chest Compression Only in Out-of-Hospital Bystander Cardiopulmonary Resuscitation
Authors: Bohm Katarina , Rosenqvist Mårten , Herlitz Johan , Hollenberg Jacob , Svensson Leif
Published: December 2007

Background—

We sought to compare the 1-month survival rates among patients after out-of-hospital cardiac arrest who had been given bystander cardiopulmonary resuscitation (CPR) in relation to whether they had received standard CPR with chest compression plus mouth-to-mouth ventilation or chest compression only.

Methods and Results—

All patients with out-of-hospital cardiac arrest who received bystander CPR and who were reported to the Swedish Cardiac Arrest Register between 1990 and 2005 were included. Crew-witnessed cases were excluded. Among 11 275 patients, 73% (n=8209) received standard CPR, and 10% (n=1145) received chest compression only. There was no significant difference in 1-month survival between patients who received standard CPR (1-month survival=7.2%) and those who received chest compression only (1-month survival=6.7%).

Conclusions—

Among patients with out-of-hospital cardiac arrest who received bystander CPR, there was no significant difference in 1-month survival between a standard CPR program with chest compression plus mouth-to-mouth ventilation and a simplified version of CPR with chest compression only.
Which Hospitals Have Significantly Better or Worse Than Expected Mortality Rates for Acute Myocardial Infarction Patients?
Authors: Stukenborg George J. , Wagner Douglas P. , Harrell Frank E. , Oliver M. Norman , Heim Steven W. , Price Amy L. , Han Caroline Kim , Wolf Andrew M. D. , Connors Alfred F.
Published: December 2007

Background—

Public reports that compare hospital mortality rates for patients with acute myocardial infarction are commonly used strategies for improving the quality of care delivered to these patients. Fair comparisons of hospital mortality rates require thorough adjustments for differences among patients in baseline mortality risk. This study examines the effect on hospital mortality rate comparisons of improved risk adjustment methods using diagnoses reported as present-at-admission.

Methods and Results—

Logistic regression models and related methods originally used by California to compare hospital mortality rates for patients with acute myocardial infarction are replicated. These results are contrasted with results obtained for the same hospitals by patient-level mortality risk adjustment models using present-at-admission diagnoses, using 3 statistical methods of identifying hospitals with higher or lower than expected mortality: indirect standardization, adjusted odds ratios, and hierarchical models. Models using present-at-admission diagnoses identified substantially fewer hospitals as outliers than did California model A for each of the 3 statistical methods considered.

Conclusions—

Large improvements in statistical performance can be achieved with the use of present-at-admission diagnoses to characterize baseline mortality risk. These improvements are important because models with better statistical performance identify different hospitals as having better or worse than expected mortality.
C1-Esterase Inhibitor Protects Against Neointima Formation After Arterial Injury in Atherosclerosis-Prone Mice
Authors: Shagdarsuren Erdenechimeg , Bidzhekov Kiril , Djalali-Talab Yassin , Liehn Elisa A. , Hristov Mihail , Matthijsen Robert A. , Buurman Wim A. , Zernecke Alma , Weber Christian
Published: December 2007

Background—Although activation of the complement system has been implicated in the progression of human atherosclerosis, its function during arterial remodeling after injury has not been investigated. Here, we examined the contribution of the complement cascade to neointima formation in apolipoprotein E–deficient mice using a C1-esterase inhibitor (C1-inhibitor).

Methods and Results—Apolipoprotein E–deficient mice fed an atherogenic diet were subjected to wire-induced endothelial denudation of the carotid artery and treated with C1-inhibitor (Berinert; 15 IU IV) or vehicle perioperatively and subsequently every 2 days. The effectiveness of C1-inhibitor treatment was confirmed by measurement of plasma C1-inhibitor activity. A significant reduction in serum triglyceride levels was observed in C1-inhibitor–treated mice, whereas cholesterol levels did not differ. After 3 weeks, neointimal area was significantly reduced in C1-inhibitor–treated mice versus controls, whereas medial area was unaltered. This was associated with a significant decrease in neointimal and medial macrophage and CD3+T-cell content. Expression of C3 mRNA was significantly reduced in plaques of C1-inhibitor–treated mice 10 days after injury, as assessed by reverse-transcription polymerase chain reaction. The peak in serum C3 levels after injury was markedly downregulated by C1-inhibitor, as evidenced by ELISA. Immunohistochemistry revealed strong expression of C3 and C3c, which colocalized to plaque macrophages and was reduced in C1-inhibitor–treated mice. C1-inhibitor impaired monocyte arrest on activated endothelium and platelets under flow conditions in vitro and leukocyte recruitment to carotid arteries 1 day after injury in vivo.

Conclusions—C1-inhibitor limits neointimal plaque formation and inflammation. This may involve blockade of complement activation, inhibition of leukocyte recruitment, and reduced triglyceride levels, thus providing a multimodal approach to treat arterial disease.
Utility of Currently Recommended Pediatric Dyslipidemia Classifications in Predicting Dyslipidemia in Adulthood
Authors: Magnussen Costan G. , Raitakari Olli T. , Thomson Russell , Juonala Markus , Patel Dharmendrakumar A. , Viikari Jorma S.A. , Marniemi Jukka , Srinivasan Sathanur R. , Berenson Gerald S. , Dwyer Terence , Venn Alison
Published: December 2007

Background—

New age- and sex-specific lipoprotein cut points developed from National Health and Nutrition Examination Survey (NHANES) data are considered to be a more accurate classification of a high-risk lipoprotein level in adolescents compared with existing cut points established by the National Cholesterol Education Program (NCEP). The aim of this study was to determine which of the NHANES or NCEP adolescent lipoprotein classifications was most effective for predicting abnormal levels in adulthood.

Methods and Results—

Adolescent and adult measures of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides were collected in 365 Australian, 1185 Finnish, and 273 US subjects participating in 3 population-based prospective cohort studies. Lipoprotein variables in adolescence were classified according to NCEP and NHANES cut points and compared for their ability to predict abnormal levels in adulthood. With the use of diagnostic performance statistics (sensitivity, specificity, positive predictive value, negative predictive value, area under receiver operating characteristic curve) in pooled and cohort-stratified data, the NHANES cut points (compared with NCEP cut points) were more strongly predictive of low high-density lipoprotein cholesterol in adults but less predictive of high total cholesterol, high low-density lipoprotein cholesterol, and high triglyceride levels in adults. We identified heterogeneity in the relative usefulness of each classification between cohorts.

Conclusions—

The separate use of NHANES cut points for high-density lipoprotein cholesterol and NCEP cut points for total cholesterol, low-density lipoprotein cholesterol, and triglycerides yielded the most accurate classification of adolescents who developed dyslipidemia in adulthood.
Platelet Sarcoplasmic Endoplasmic Reticulum Ca
2+
-ATPase and μ-Calpain Activity Are Altered in Type 2 Diabetes Mellitus and Restored by Rosiglitazone
Authors: Randriamboavonjy Voahanginirina , Pistrosch Frank , Bölck Birgit , Schwinger Robert H.G. , Dixit Madhulika , Badenhoop Klaus , Cohen Richard A. , Busse Rudi , Fleming Ingrid
Published: December 2007

Background—

Platelets from patients with type 2 diabetes mellitus display hyperaggregability and increased thrombogenic potential.

Methods and Results—

In platelets from patients with type 2 diabetes mellitus, we found enhanced tyrosine nitration and inactivation of the sarcoplasmic endoplasmic reticulum Ca
2+
-ATPase (SERCA-2), elevated platelet [Ca
2+
]
i
, and activation of μ-calpain. The tyrosine nitration of SERCA-2 and the activation of μ-calpain in vitro in platelets from healthy volunteers could be evoked in vitro by peroxynitrite. Platelet endothelial cell adhesion molecule-1 was identified as a μ-calpain substrate; its in vitro degradation was stimulated by peroxynitrite and prevented by calpain inhibitors. Calpain activation also was linked to hyperresponsiveness to thrombin and the loss of platelet sensitivity to nitric oxide synthase inhibitors. Platelets from patients with type 2 diabetes mellitus (hemoglobin A
1c
>6.6%) contained little or no intact platelet endothelial cell adhesion molecule-1, whereas degradation products were detectable. The peroxisome proliferator–activated receptor-γ agonist rosiglitazone increased SERCA-2 expression in megakaryocytes, and treating patients with type 2 diabetes mellitus with rosiglitazone for 12 weeks increased platelet SERCA-2 expression and Ca
2+
-ATPase activity, decreased SERCA-2 tyrosine nitration, and normalized platelet [Ca
2+
]
i
. Rosiglitazone also reduced μ-calpain activity, normalized platelet endothelial cell adhesion molecule-1 levels, and partially restored platelet sensitivity to nitric oxide synthase inhibition.

Conclusion—

These data identify megakaryocytes/platelets as additional cellular targets for peroxisome proliferator–activated receptor-γ agonists and highlight potential benefits of rosiglitazone therapy in cardiovascular diseases.
Diastolic Stiffness of the Failing Diabetic Heart
Authors: van Heerebeek Loek , Hamdani Nazha , Handoko M. Louis , Falcao-Pires Ines , Musters René J. , Kupreishvili Koba , Ijsselmuiden Alexander J.J. , Schalkwijk Casper G. , Bronzwaer Jean G.F. , Diamant Michaela , Borbély Attila , van der Velden Jolanda , Stienen Ger J.M. , Laarman Gerrit J. , Niessen Hans W.M. , Paulus Walter J.
Published: December 2007

Background—

Excessive diastolic left ventricular stiffness is an important contributor to heart failure in patients with diabetes mellitus. Diabetes is presumed to increase stiffness through myocardial deposition of collagen and advanced glycation end products (AGEs). Cardiomyocyte resting tension also elevates stiffness, especially in heart failure with normal left ventricular ejection fraction (LVEF). The contribution to diastolic stiffness of fibrosis, AGEs, and cardiomyocyte resting tension was assessed in diabetic heart failure patients with normal or reduced LVEF.

Methods and Results—

Left ventricular endomyocardial biopsy samples were procured in 28 patients with normal LVEF and 36 patients with reduced LVEF, all without coronary artery disease. Sixteen patients with normal LVEF and 10 with reduced LVEF had diabetes mellitus. Biopsy samples were used for quantification of collagen and AGEs and for isolation of cardiomyocytes to measure resting tension. Diabetic heart failure patients had higher diastolic left ventricular stiffness irrespective of LVEF. Diabetes mellitus increased the myocardial collagen volume fraction only in patients with reduced LVEF (from 14.6±1.0% to 22.4±2.2%,
P
<0.001) and increased cardiomyocyte resting tension only in patients with normal LVEF (from 5.1±0.7 to 8.5±0.9 kN/m
2
,
P
=0.006). Diabetes increased myocardial AGE deposition in patients with reduced LVEF (from 8.8±2.5 to 24.1±3.8 score/mm
2
;
P
=0.005) and less so in patients with normal LVEF (from 8.2±2.5 to 15.7±2.7 score/mm
2
,
P
=NS).

Conclusions—

Mechanisms responsible for the increased diastolic stiffness of the diabetic heart differ in heart failure with reduced and normal LVEF: Fibrosis and AGEs are more important when LVEF is reduced, whereas cardiomyocyte resting tension is more important when LVEF is normal.
Adenylyl Cyclase Type 6 Deletion Decreases Left Ventricular Function via Impaired Calcium Handling
Authors: Tang Tong , Gao Mei Hua , Lai N. Chin , Firth Amy L. , Takahashi Toshiyuki , Guo Tracy , Yuan Jason X.-J. , Roth David M. , Hammond H. Kirk
Published: December 2007

Background—

Adenylyl cyclases (ACs) are a family of effector molecules for G-protein–coupled receptors. The 2 ACs most abundantly expressed in cardiac myocytes are types 5 (AC5) and 6 (AC6), which have 65% amino acid homology. It has been speculated that coexpression of 2 AC types in cardiac myocytes represents redundancy, but the specific role of AC6 in cardiac physiology and its differences from AC5 remain to be defined.

Methods and Results—

We generated transgenic mice with targeted deletion of AC6. Deletion of AC6 was associated with reduced left ventricular contractile function (
P
=0.026) and relaxation (
P
=0.041). The absence of AC6 was associated with a 48% decay in β-adrenergic receptor–stimulated cAMP production in cardiac myocytes (
P
=0.003) and reduced protein kinase A activity (
P
=0.015). In addition, phospholamban phosphorylation was reduced (
P
=0.015), sarcoplasmic reticulum Ca
2+
-ATPase activity was impaired (
P
<0.0001), and cardiac myocytes showed marked abnormalities in calcium transient formation (
P
=0.001).

Conclusions—

The combination of impaired cardiac cAMP generation and calcium handling that result from AC6 deletion underlies abnormalities in left ventricular function. The biochemical and physiological consequences of AC6 deletion reveal it to be an important effector molecule in the adult heart, serving unique biological functions not replicated by AC5.
Long-Term Survival, Modes of Death, and Predictors of Mortality in Patients With Fontan Surgery
Authors: Khairy Paul , Fernandes Susan M. , Mayer John E. , Triedman John K. , Walsh Edward P. , Lock James E. , Landzberg Michael J.
Published: December 2007

Background—

To better define determinants of mortality in patients with univentricular physiology, a database registry was created of patients born in 1985 or earlier with Fontan surgery who were followed up at Children’s Hospital Boston.

Methods and Results—

A total of 261 patients, 121 of whom (46.4%) were women, had a first Fontan surgery at a median age of 7.9 years: right atrium–to–pulmonary artery connection in 135 (51.7%); right atrium to right ventricle in 25 (9.6%); and total cavopulmonary connection in 101 (38.7%). Over a median of 12.2 years, 76 (29.1%) died, 5 (1.9%) had cardiac transplantation, 5 (1.9%) had Fontan revision, and 21 (8.0%) had Fontan conversion. Perioperative mortality decreased steadily over time and accounted for 68.4% of all deaths. In early survivors, actuarial freedom from death or transplantation was 93.7%, 89.9%, 87.3%, and 82.6% at 5, 10, 15, and 20 years, respectively, with no significant difference between right atrium to pulmonary artery versus total cavopulmonary connection. Late deaths were classified as sudden in 7 patients (9.2%), thromboembolic in 6 (7.9%), heart failure–related in 5 (6.7%), sepsis in 2 (2.6%), and other in 4 (5.2%). Most sudden deaths were of presumed arrhythmic origin with no identifiable predictor. Independent risk factors for thromboembolic death were lack of antiplatelet or anticoagulant therapy (hazard ratio [HR], 91.6;
P
=0.0041) and clinically diagnosed intracardiac thrombus (HR, 22.7;
P
=0.0002). Independent predictors of heart failure death were protein-losing enteropathy (HR, 7.1;
P
=0.0043), single morphologically right ventricle (HR, 10.5;
P
=0.0429), and higher right atrial pressure (HR, 1.3 per 1 mm Hg;
P
=0.0016).

Conclusion—

In perioperative survivors of Fontan surgery, gradual attrition occurs predominantly from thromboembolic, heart failure–related, and sudden deaths.
Ethnic and Genetic Determinants of Cardiovascular Response to the Selective α
2
-Adrenoceptor Agonist Dexmedetomidine
Authors: Kurnik Daniel , Muszkat Mordechai , Sofowora Gbenga G. , Friedman Eitan A. , Dupont William D. , Scheinin Mika , Wood Alastair J.J. , Stein C. Michael
Published: December 2007

The α
2
-adrenoceptor agonist clonidine reduces blood pressure more effectively in White than Black Americans despite similar degrees of sympatholysis. Functional genetic variation in receptor signaling mechanisms, for example in the β3 G-protein subunit (
GNB3
C825T) and in the α
2C
-adrenoceptor subtype (
ADRA2C
del322–325), may affect drug responses. We examined the hypothesis that there are ethnic differences in the responses to the highly selective α
2
-agonist, dexmedetomidine, and that these genetic variants contribute to interindividual variability in drug responses. In a placebo-controlled, single-masked study, 73 healthy subjects (37 whites and 36 blacks) received 3 placebo infusions and then 3 incremental doses of dexmedetomidine (cumulative dose, 0.4 μg/kg), each separated by 30 minutes. Blood pressure, heart rate, and plasma catecholamine concentrations were determined after each infusion. We measured dexmedetomidine concentrations after the last infusion and determined
ADRA2C
del322–325 and
GNB3
C825T genotypes. Dexmedetomidine lowered blood pressure and plasma catecholamine concentrations significantly (all
P
<0.001). There was substantial interindividual variability in the reduction of systolic blood pressure (range, 1 to 34 mm Hg) and plasma norepinephrine concentrations (range, 24 to 424 pg/mL). However, there were no differences between black and white subjects in dexmedetomidine responses (
P
>0.16 for all outcomes) before or after adjustment for covariates. Neither
ADRA2C
del322–325 nor
GNB3
C825T genotypes affected the responses to dexmedetomidine (all
P
>0.66). There is large interindividual variability in response to the selective α
2
-AR agonist dexmedetomidine, and neither ethnicity nor
ADRA2C
and
GNB3
genotypes contribute to it. Further studies to identify determinants of α
2
-AR–mediated responses will be of interest.
Jean Delville's La Mission de l'Art: Hegelian Echoes in fin-de-siècle Idealism
Authors: Cole Brendan
Published: December 2007

Jean Delville was not only a gifted painter, but also a prolific author, poet and polemicist. He is unique amongst his artistic contemporaries for having written extensively on the subject of Idealism in art. Idealist philosophy, as an intellectual influence, was fairly pervasive amongst contemporary non-realist authors, poets and painters; the core nineteenth-century influence in this regard was the writings of Arthur Schopenhauer. Delville, however, took a different path, particularly in his seminal book, La Mission de l'Art, and his various polemical essays on the subject, which reflect, rather, key ideas derived from the writings of the German Idealist, G.W.F. Hegel. Hegel's influence on late-nineteenth century non-realist art is understated in the literature. This paper analyses the main ideas of Delville's La Mission de l'Art in the context of Hegelian Idealism. It focuses on key areas of this tradition, specifically with regard to the nature of the Idea and the Ideal, the relation of the Ideal to the natural world, the relation between the Idea and the notion of Beauty and the special role of the artist in revealing the Idea in physical form.
From Lateness To Waning To Crisis: the Burden of the Later Middle Ages
Authors: Kaminsky Howard
Published: December 2007

The common view of the Late Middle Ages as a time of decay is due to the very lateness imposed on this period by the idea of a Middle Ages, especially in the form of the "Waning model" created by Johan Huizinga in The Waning of the Middle Ages. The consequent "crises" predicated of most late-medieval phenomena, including the whole period, appear under critical analysis either as phantoms or as moments of progressive development. This discredits both the Waning model and the "Middle Ages" out of which it proceeds; they can best be replaced by the scheme that posits an "Old Europe" from the eleventh century to the eighteenth. Here the Middle Ages vanish and the fourteenth and fifteenth centuries, redeemed from the curse of lateness, appear with the twelfth and thirteenth as Early Old Europe.
The Use of Positron Emission Tomography With (18)F-Fluorodeoxyglucose for the Diagnosis of Vascular Graft Infection
Authors: Lauwers Patrick , Van den Broeck Sylvie , Carp Laurens , Hendriks Jeroen , Van Schil Paul , Blockx Pierre
Published: December 2007

Vascular graft infection is associated with a high morbidity and mortality rate. Diagnosis is difficult, as there is no single diagnostic criterion that has a 100% accuracy. A combination of physical examination, laboratory tests, and several imaging techniques is mandatory. Beside a wide range of indications in the oncological field, positron emission tomography with (18)F-fluorodeoxyglucose (FDG-PET) has a well-known role in the diagnosis of bone and soft-tissue infections. Some authors have recently reported on the potential use of FDG-PET in the diagnosis of vascular graft infections. The aim of this study is to review personal experience. Five consecutive patients with a suspected prosthetic infection (1 aortobifemoral bypass, 3 femoropopliteal bypasses, and 1 femorofemoral bypass) underwent FDG-PET. All prostheses showed a moderate or intense FDG tracer uptake. All 3 patients with an intense FDG uptake proved to have a prosthetic infection (based on microbiologic examination). These preliminary results suggest that FDG-PET might be an interesting tool to confirm vascular graft infection.
Does Lower-Extremity Arterial Disease Predict Future Falling Among Older Men and Women?
Authors: Arseven Adnan , Guralnik Jack M. , O'Brien Kaleba Erin , Liu Kiang , Chan Cheeling , McGrae McDermott Mary
Published: December 2007

The purpose of this study was to determine whether lower-extremity peripheral arterial disease (PAD) is an independent risk factor for falls among older persons. Men and women 55 years old and older participated. Subjects with PAD (n = 86) were identified from a noninvasive vascular laboratory and a general medicine practice. Randomly selected controls without PAD (n = 82) were identified from the same medicine practice. Subjects were categorized into PAD (ankle brachial index, <0.90) or controls (ankle brachial index, 0.90 to 1.50). Subjects underwent a comprehensive baseline evaluation for fall risk. Prospective fall data were obtained using monthly mail-in postcards and structured telephone interviews over a mean follow-up of 9.6 ± 2.9 months. Two independent investigators blinded to PAD status reviewed each fall incident for its eligibility. A total of 37 subjects (22%) had at least 1 eligible fall. In an unadjusted Cox regression model, the relative risk of falling was lower among PAD subjects than among controls (relative risk, 0.54; 95% confidence interval, 0.28 to 1.06). After adjustment for age, gender, history of frequent falls in the last year, number of comorbidities, and balance and gait abnormalities, PAD was significantly associated with a lower risk of falling (relative risk, 0.43; 95% confidence interval, 0.21 to 0.87) as compared with controls. PAD is associated with a lower risk of falling as compared with persons without PAD among older men and women. Future study is needed to determine whether reduced levels of physical activity among patients with PAD account for the lower rate of falling observed here.
Corporate Social Responsibility Orientation, Goals, and Behavior
Authors: Burton Brian K. , Goldsby Michael
Published: December 2007

Corporate social responsibility orientation (CSRO) remains an important topic of researchers. However, one aspect of CSRO that has not been well researched is how it relates to behaviors and goals of managers. In this article, the authors explore that relationship, testing whether emphasis on a particular domain of social responsibility affects time spent dealing with specific stakeholder groups and whether firm size affects that relationship. Results from a survey of small business owners indicate that the emphasis a manager places on a domain does affect behavior and that firm size has little impact on this relationship. Implications of these findings are discussed.
Corporate Responsiveness to Community Stakeholders
Authors: Kobeissi Nada , Damanpour Fariborz
Published: December 2007

Corporate community responsiveness relates to business activities that are integral parts of a firm’s operations and are designed to benefit the firm through benefiting the local communities. Using data from commercial banks in the United States between 1997 and 2000, the authors measured banks’ corporate community responsiveness by their Community Reinvestment Act (CRA) lending activities and their performance ratings by CRA examiners. The authors developed and tested eight hypotheses on the influence of contextual (community income, minority population, and competition) and organizational (age, profitability, risk, institutional ownership, and mergers and acquisitions) factors on the two measures of corporate community responsiveness. The authors found a negative effect for minority population; a positive effect for banks’ profitability; and partial support for community income, competition, and risk factors. The results show no effects for institutional ownership or mergers and acquisitions. The implications of these results for the instrumental aspect of stakeholder theory are discussed.
Economic and Social Roles of Companies in the Mass Media
Authors: Capriotti Paul
Published: December 2007

Businesses play an important social role in society that goes beyond their traditional economic role. The way in which these roles are carried out and communicated to the stakeholders can influence the company's corporate reputation. The first step in constructing a corporate reputation is corporate visibility. The mass media plays an important role in developing corporate visibility. Media visibility has a significant influence on public opinion and contributes strongly to forming companies' corporate reputation. The main aim of this article is to test the level of visibility of companies in the media as well as the attributes (economic and/or social) assigned to the companies. The author presents the results of the research done on the media visibility of companies belonging to the Spanish Stock Exchange in the four most important newspapers in Spain. Two basic results were obtained: Larger companies, with good reputations and oriented to mass consumption, have more visibility in newspapers, and companies are basically presented as economic and not social actors in society.
Disquiet on the island
Authors: Xavier Ângela Barreto
Published: December 2007

This article seeks to address the social and religious changes brought about in Goa during the first century of Portuguese conquest. It studies how the ‘negative’ effects of the Christian presence were overcome and transformed into an acceptable situation by the people involved in the process of Christianisation, and relates it to the durability of the Portuguese imperial presence. I argue that a careful study of the local society of two villages where conversion processes took place allows us to avoid easy answers and stereotypes about conversion, providing altogether more complex images of the Portuguese colonisation of Goa.
South Asian ways of seeing, Muslim ways of knowing
Authors: Freitag Sandria B.
Published: December 2007

The new ‘visual turn’ in history invites us, through new evidence and related methodologies, to look beyond middle-class issues and concerns in reconstructing the civil society that emerged in twentieth-century South Asia. The case study presented here addresses fundamental questions of how the emerging civil society scrutinized the state (both the imperial form and its independent heir), as well as how claims to authority and legitimacy continued to exist outside as well as within the state. New visual modes of communicating created a number of markets for groups of consumers in which both the shared cultural practices of South Asians, and group-specific meanings elaborated for those practices, helped individuals to define identities and to mobilise their passionate commitments on behalf of their respective group interests. This article examines one such group of consumers—South Asian Muslims—within the larger South Asian context. Thus, the ‘visual turn’ enables us to move from the specifics of particular posters (and how those changed over time) to the broader implications for the creation of a new public, and its concerns around abstracted values and issues.