bluuebunny/crossref_metadata_2025 huggingface dataset:
Arachidonic acid metabolites follow the preferential course of cyclooxygenase pathway for the basal tone in the internal anal sphincter
Authors: de Godoy Márcio A. F. , Rattan Neeru , Rattan Satish
Published: February 2009

Present studies determined the roles of the cyclooxygenase (COX) versus the lipoxygenase (LO) pathways in the metabolic pathway of arachidonic acid (AA) in the internal anal sphincter (IAS) tone. Studies were performed in the rat IAS versus the nontonic rectal smooth muscle (RSM). Indomethacin, the dual COX inhibitor, but not nordihydroguaiaretic acid (NDGA), the LO inhibitor, produced a precipitous decrease in the IAS tone. However, when added in the background of indomethacin, NDGA caused significant reversal of the IAS tone. These inhibitors had no significant effect on the RSM. To follow the significance of COX versus LO pathways, we examined the effects of AA and its metabolites. In the IAS, AA caused an increase in the IAS tone (Emax= 38.8 ± 3.0% and pEC50= 3.4 ± 0.1). In the RSM, AA was significantly less efficacious and potent (Emax= 11.3 ± 3.5% and pEC50= 2.2 ± 0.3). The AA metabolites (via COXs) PGF2αand U-46619 (a stable analog of thromboxane A2) produced increases in the IAS tone and force in the RSM. Conversely, AA metabolites (via 5-LO) lipoxin A4, 5-HETE, and leukotriene C4decreased the IAS tone. Finally, the contractile effects of AA in the IAS were selectively attenuated by the COX-1 but not the COX-2 inhibitor. Collectively, the specific effects of AA and the COX inhibitor, the Western blot and RT-PCR analyses showing specifically higher levels of COX-1, suggest a preferential role of the COX (specifically COX-1) pathway versus the LO in the regulation of the IAS tone.
p38 MAP kinase inhibitor reverses stress-induced myocardial dysfunction in vivo
Authors: Chen Fangping , Kan Hong , Hobbs Gerry , Finkel Mitchell S.
Published: February 2009

Recent clinical reports strongly support the intriguing possibility that emotional stress alone is sufficient to cause reversible myocardial dysfunction in patients. We previously reported that a combination of prenatal stress followed by restraint stress (PS+R) results in echocardiographic evidence of myocardial dysfunction in anesthetized rats compared with control rats subjected to the same restraint stress (Control+R). We now report results of our catheter-based hemodynamic studies in both anesthetized and freely ambulatory awake rats, comparing PS+R vs. Control+R. Systolic function [positive rate of change in left ventricular pressure over time (+dP/d t)] was significantly depressed ( P < 0.01) in PS+R vs. Control+R both under anesthesia (6,287 ± 252 vs. 7,837 ± 453 mmHg/s) and awake (10,438 ± 741 vs. 12,111 ± 652 mmHg/s). Diastolic function (−dP/d t) was also significantly depressed ( P < 0.05) in PS+R vs. Control+R both under anesthesia (−5,686 ± 340 vs. −7,058 ± 458 mmHg/s) and awake (−8,287 ± 444 vs. 10,440 ± 364 mmHg/s). PS+R also demonstrated a significantly attenuated ( P < 0.05) hemodynamic response to increasing doses of the β-adrenergic agonist isoproterenol. Intraperitoneal injection of the p38 MAP kinase inhibitor SB-203580 reversed the baseline reduction in +dP/d t and −dP/d t as well as the blunted isoproterenol response. Intraperitoneal injection of SB-203580 also reversed p38 MAP kinase and troponin I phosphorylation in cardiac myocytes isolated from PS+R. Thus the combination of prenatal stress followed by restraint stress results in reversible depression in both systolic and diastolic function as well as defective β-adrenergic receptor signaling. Future studies in this animal model may provide insights into the basic mechanisms contributing to reversible myocardial dysfunction in patients with ischemic and nonischemic cardiomyopathies.
Autoresuscitation responses to hypoxia-induced apnea are delayed in newborn 5-HT-deficient Pet-1 homozygous mice
Authors: Erickson Jeffery T. , Sposato Brian C.
Published: February 2009

Autoresuscitation is a critical survival-promoting mechanism in mammals that allows recovery from primary apnea via hypoxia-induced gasping. Here we show, using head-out plethysmography, that gasping behavior is altered during autoresuscitation, and the autoresuscitation response is delayed, in neonatal 5-hydroxytryptamine (5-HT) neuron-deficient Pet-1 homozygous ( Pet-1−/−) mice. When exposed to 97% N2-3% CO2 on postnatal day 4.5, unanesthetized Pet-1−/− mice required over four times longer than age-matched wild-type controls to initiate gasping following primary apnea. When oxygen was made available before the first gasp, allowing autoresuscitation to occur, gasping frequency was decreased and the duration of the gasping period was extended in the Pet-1 mutants compared with wild type, resulting in a nearly threefold increase in the time needed for successful autoresuscitation. However, when the exposure to anoxia was unrelenting, gasping frequency, the form of the gasps, the total number of gasps produced, the duration of the gasping period, and time to last gasp were comparable to controls. Plethysmographic testing of the same mutants on postnatal day 9.5 revealed that their autoresuscitation responses, although improved compared with day 4.5, remained significantly longer than in wild-type controls. Our data indicate that despite a severe deficiency of central 5-HT neurons, Pet-1−/− neonatal mice are capable of gasping, but their gasping pattern is altered during autoresuscitation, leading to a prolongation of the time required to recover from hypoxia-induced apnea.
Cardiovascular and pulmonary consequences of airway recruitment in preterm lambs
Authors: Polglase Graeme R. , Hooper Stuart B. , Gill Andrew W. , Allison Beth J. , McLean Carryn J. , Nitsos Ilias , Pillow J. Jane , Kluckow Martin
Published: February 2009

Increases in positive end-expiratory pressure (PEEP) improve arterial oxygenation in preterm infants, but the effects on cardiopulmonary hemodynamics are understood poorly. We aimed to determine the effect of increased PEEP on cardiopulmonary hemodynamics and to compare measurements from indwelling flow probes with Doppler echocardiography. Preterm lambs (129 ± 1 days) were ventilated initially with a tidal volume of 7 ml/kg and 4 cmH2O of PEEP. In ramp lambs ( n = 7), PEEP was increased by 2-cmH2O increments to 10 cmH2O and then in decrements back to 4 cmH2O. PEEP was unchanged in controls ( n = 6). Doppler echocardiographic flow measurements in the left pulmonary artery (LPA) and ductus arteriosus (DA) were correlated with flow probe measurements. Compared with controls, high PEEP reduced LPA flow from baseline (10-cmH2O PEEP: 43 ± 8% vs. control: 83 ± 21%; P = 0.029). High PEEP increased the proportion of right-to-left (R-L) shunting through the DA, with a trend to an increased oxygenation index compared with controls (oxygenation index: 44.5 ± 13.5 at 10-cmH2O PEEP vs. 19.4 ± 4.5 in controls; P = 0.07). Increasing PEEP decreased heart rate (17 beats/min; P = 0.03) and tended to lower systolic arterial pressure (5.0 mmHg; P = 0.052) compared with controls. Doppler echocardiography measurement of LPA flows correlated strongly with indwelling flow probe ( r2 = 0.73, P < 0.001), except during highly turbulent flows. Increases in PEEP have significant cardiopulmonary consequences in preterm lambs, including reduced LPA flow and increased R-L shunt through the DA. These changes are likely due to the concomitant increase in downstream pulmonary vascular resistance and increased cardiovascular constraint induced by PEEP.
Protein Kinase Cδ Differentially Regulates Platelet Functional Responses
Authors: Chari Ramya , Getz Todd , Nagy Bela , Bhavaraju Kamala , Mao Yingying , Bynagari Yamini Saraswathy , Murugappan Swaminathan , Nakayama Keiko , Kunapuli Satya P.
Published: February 2009

Objective—

Protein Kinase C delta (PKCδ) is expressed in platelets and activated downstream of protease-activated receptors (PAR)s and glycoprotein VI (GPVI) receptors. The purpose of this study was to investigate the role of PKCδ in platelets.

Methods and Results—

We evaluated the role of PKCδ in platelets using two approaches—pharmacological and molecular genetic approach. In human platelets pretreated with isoform selective antagonistic RACK peptide (δ V1-1)TAT, and in the murine platelets lacking PKCδ, PAR4-mediated dense granule secretion was inhibited, whereas GPVI-mediated dense granule secretion was potentiated. These effects were statistically significant in the absence and presence of thromboxane A
2
(TXA
2
). Furthermore, TXA
2
generation was differentially regulated by PKCδ. However, PKCδ had a small effect on platelet P-selectin expression. Calcium- and PKC-dependent pathways independently activate fibrinogen receptor in platelets. When calcium pathways are blocked by dimethyl-BAPTA, AYPGKF-induced aggregation in PKCδ null mouse platelets and in human platelets pretreated with (δ V1-1)TAT, was inhibited. In a FeCl
3
-induced injury in vivo thrombosis model, PKCδ
−/−
mice occluded similar to their wild-type littermates.

Conclusions—

Hence, we conclude that PKCδ differentially regulates platelet functional responses such as dense granule secretion and TXA
2
generation downstream of PARs and GPVI receptors, but PKCδ deficiency does not affect the thrombus formation in vivo.
Signaling Hierarchy Regulating Human Endothelial Cell Development
Authors: Kelly Melissa A. , Hirschi Karen K.
Published: February 2009

Objective—

Our present knowledge of the regulation of mammalian endothelial cell differentiation has been largely derived from studies of mouse embryonic development. However, unique mechanisms and hierarchy of signals that govern human endothelial cell development are unknown and, thus, explored in these studies.

Methods and Results—

Using human embryonic stem cells as a model system, we were able to reproducibly and robustly generate differentiated endothelial cells via coculture on OP9 marrow stromal cells. We found that, in contrast to studies in the mouse, bFGF and VEGF had no specific effects on the initiation of human vasculogenesis. However, exogenous Ihh promoted endothelial cell differentiation, as evidenced by increased production of cells with cobblestone morphology that coexpress multiple endothelial-specific genes and proteins, form lumens, and exhibit DiI-AcLDL uptake. Inhibition of BMP signaling using Noggin or BMP4, specifically, using neutralizing antibodies suppressed endothelial cell formation; whereas, addition of rhBMP4 to cells treated with the hedgehog inhibitor cyclopamine rescued endothelial cell development.

Conclusions—

Our studies revealed that Ihh promoted human endothelial cell differentiation from pluripotent hES cells via BMP signaling, providing novel insights applicable to modulating human endothelial cell formation and vascular regeneration for human clinical therapies.
Sex-Specific Familial Clustering of Myocardial Infarction in Patients With Acute Coronary Syndromes
Authors: Banerjee Amitava , Silver Louise E. , Heneghan Carl , Welch Sarah J.V. , Bull Linda M. , Mehta Ziyah , Banning Adrian P. , Rothwell Peter M.
Published: February 2009

Background—

Family history of premature myocardial infarction (MI) in first-degree relatives is a risk factor for MI and an indication for primary prevention. Although excess mother-to-daughter “transmission” occurs in ischemic stroke, no published studies have considered sex-of-parent/sex-of-proband interactions in the heritability of MI.

Methods and Results—

In a population-based study (Oxford Vascular Study) of all patients with acute coronary syndromes (ACS), irrespective of age, family history of all acute vascular events and related risk factors were analyzed by sex and age of both probands and first-degree relatives. Premature events were categorized as occurring at age <65 years. Of 835 probands with 1 or more ACS, 623 (420 men) had incident events and complete family history data. In probands with premature ACS, maternal history of both MI and of all vascular events were more common in female than male probands (odds ratio [OR], 2.25; 95% CI, 1.02 to 4.94;
P
=0.04 and OR, 3.03; 95% CI, 1.47 to 6.26;
P
=0.002, respectively). No such effect existed for paternal history (OR, 1.00; 95% CI, 0.46 to 2.10;
P
=0.99 and OR, 1.19; 95% CI, 0.58 to 2.43;
P
=0.63, respectively). Age at ACS in probands was highly correlated with age at MI in mothers (
r
=0.46,
P
<0.001), regardless of the proband’s sex. Consequently, history of premature maternal MI was strongly associated with premature ACS and premature MI in female (OR, 10.52; 95% CI, 2.17 to 56.6;
P
=0.001 and OR, 7.31; 95% CI, 1.55 to 34.6;
P
=0.004, respectively) and male probands (OR, 3.88; 95% CI, 1.20 to 12.6;
P
=0.01 and OR, 3.63; 95% CI, 1.13 to 11.60;
P
=0.02, respectively).

Conclusions—

Important sex-of-parent/sex-of-proband interactions exist in the family history of MI in patients with ACS. Greater emphasis should be placed on maternal than paternal history of MI, particularly in women aged <65 years.
Association and Functional Analyses of
MEF2A
as a Susceptibility Gene for Premature Myocardial Infarction and Coronary Artery Disease
Authors: Guella Ilaria , Rimoldi Valeria , Asselta Rosanna , Ardissino Diego , Francolini Maura , Martinelli Nicola , Girelli Domenico , Peyvandi Flora , Tubaro Marco , Merlini Pier Angelica , Mannucci Pier Mannuccio , Duga Stefano
Published: February 2009

Background—

Mutations in the
MEF2A
gene, coding for a member of the myocyte enhancer factor 2 family of transcription factors, have been reported in patients with coronary artery disease and myocardial infarction (MI). In particular, a 21-bp deletion and 3 missense mutations were demonstrated either to reduce MEF2A transcriptional activity or to impair its nuclear translocation. However, the association of
MEF2A
with coronary artery disease/MI was not confirmed in other studies. We analyzed the role of
MEF2A
in the pathogenesis of MI in 2008 Italian patients with premature MI and in 2008 controls.

Methods and Results—

Mutational screening of exon 8 (containing all so-far reported point mutations) disclosed 5 novel and 2 previously described missense mutations. Microsatellite genotyping and sequencing revealed the presence of the 21-bp deletion (located in exon 12) in 5 cases and in none of the controls. Functional studies on mutant proteins showed no alteration, neither in the transactivating properties (all mutants) nor in the nuclear localization (21-bp deletion). Furthermore, an association analysis performed using 3 microsatellites at the
MEF2A
locus showed no significant association with MI. These results were confirmed in a replication study performed on an independent Italian population with coronary artery disease.

Conclusions—

All together, our data do not support
MEF2A
as a susceptibility gene for coronary artery disease/MI in the Italian population.
Common Genetic Variants on Chromosome 9p21 Confers Risk of Ischemic Stroke
Authors: Smith J. Gustav , Melander Olle , Lövkvist Håkan , Hedblad Bo , Engström Gunnar , Nilsson Peter , Carlson Joyce , Berglund Göran , Norrving Bo , Lindgren Arne
Published: February 2009

Background—

Epidemiological studies indicate a genetic contribution to ischemic stroke risk, but specific genetic variants remain unknown, with the exception of a few rare variants. Recent genome-wide association studies identified and replicated common genetic variants on chromosome 9p21 to confer risk of coronary heart disease. We examined whether these variants are associated with ischemic stroke.

Methods and Results—

We genotyped 6 common genetic variants on chromosome 9p21, previously associated with coronary artery disease in genome-wide association studies, in 2 population-based studies in southern Sweden, the Lund Stroke Register (n=1837 cases, 947 controls) and the Malmö Diet and Cancer study (MDC; n=888 cases, 893 controls). We examined association in each study and in the pooled dataset. Adjustments were made for cardiovascular risk factors and further for previous myocardial infarction in MDC. We found a modest increase in ischemic stroke risk for 2 common (minor allele frequencies 0.46 to 0.49) variants, rs2383207 (
P
=0.04 in Lund Stroke Register,
P
=0.01 in MDC) and rs10757274 (
P
=0.03 in Lund Stroke Register,
P
=0.03 in MDC), in each sample independently. The strength of the association increased when samples were pooled with an odds ratio of 1.15 (95% CI, 1.05 to 1.25;
P
=0.002) for the strongest variant rs2383207. Results were similar after adjustment for clinical covariates. rs1333049 also showed significant association in MDC, which increased in the pooled sample (
P
=0.004).

Conclusions—

In this large sample (n=4565), we detected common genetic determinants for ischemic stroke on chromosome 9p21. Our findings indicate that ischemic stroke shares pathophysiological determinants with coronary heart disease and other arterial diseases and highlight the need for large sample sizes in stroke genetics.
Substrate–Enzyme Competition Attenuates Upregulated Anaplerotic Flux Through Malic Enzyme in Hypertrophied Rat Heart and Restores Triacylglyceride Content
Authors: Pound Kayla M. , Sorokina Natalia , Ballal Kalpana , Berkich Deborah A. , Fasano Mathew , LaNoue Kathryn F. , Taegtmeyer Heinrich , O'Donnell J. Michael , Lewandowski E. Douglas
Published: February 2009

Recent work identifies the recruitment of alternate routes for carbohydrate oxidation, other than pyruvate dehydrogenase (PDH), in hypertrophied heart. Increased carboxylation of pyruvate via cytosolic malic enzyme (ME), producing malate, enables “anaplerotic” influx of carbon into the citric acid cycle. In addition to inefficient NADH production from pyruvate fueling this anaplerosis, ME also consumes NADPH necessary for lipogenesis. Thus, we tested the balance between PDH and ME fluxes in hypertrophied hearts and examined whether low triacylglyceride (TAG) was linked to ME-catalyzed anaplerosis. Sham-operated (SHAM) and aortic banded rat hearts (HYP) were perfused with buffer containing either
13
C-palmitate plus glucose or
13
C glucose plus palmitate for 30 minutes. Hearts remained untreated or received dichloroacetate (DCA) to activate PDH and increase substrate competition with ME. HYP showed a 13% to 26% reduction in rate pressure product (RPP) and impaired dP/dt versus SHAM (
P
<0.05). DCA did not affect RPP but normalized dP/dt in HYP. HYP had elevated ME expression with a 90% elevation in anaplerosis over SHAM. Increasing competition from PDH reduced anaplerosis in HYP+DCA by 18%. Correspondingly, malate was 2.2-fold greater in HYP than SHAM but was lowered with PDH activation: HYP=1419±220 nmol/g dry weight; HYP+DCA=343±56 nmol/g dry weight. TAG content in HYP (9.7±0.7 μmol/g dry weight) was lower than SHAM (13.5±1.0 μmol/g dry weight). Interestingly, reduced anaplerosis in HYP+DCA corresponded with normalized TAG (14.9±0.6 μmol/g dry weight) and improved contractility. Thus, we have determined partial reversibility of increased anaplerosis in HYP. The findings suggest anaplerosis through NADPH-dependent, cytosolic ME limits TAG formation in hypertrophied hearts.
Functional Cardiomyocytes Derived From Human Induced Pluripotent Stem Cells
Authors: Zhang Jianhua , Wilson Gisela F. , Soerens Andrew G. , Koonce Chad H. , Yu Junying , Palecek Sean P. , Thomson James A. , Kamp Timothy J.
Published: February 2009

Human induced pluripotent stem (iPS) cells hold great promise for cardiovascular research and therapeutic applications, but the ability of human iPS cells to differentiate into functional cardiomyocytes has not yet been demonstrated. The aim of this study was to characterize the cardiac differentiation potential of human iPS cells generated using
OCT4
,
SOX2
,
NANOG
, and
LIN28
transgenes compared to human embryonic stem (ES) cells. The iPS and ES cells were differentiated using the embryoid body (EB) method. The time course of developing contracting EBs was comparable for the iPS and ES cell lines, although the absolute percentages of contracting EBs differed. RT-PCR analyses of iPS and ES cell–derived cardiomyocytes demonstrated similar cardiac gene expression patterns. The pluripotency genes
OCT4
and
NANOG
were downregulated with cardiac differentiation, but the downregulation was blunted in the iPS cell lines because of residual transgene expression. Proliferation of iPS and ES cell–derived cardiomyocytes based on 5-bromodeoxyuridine labeling was similar, and immunocytochemistry of isolated cardiomyocytes revealed indistinguishable sarcomeric organizations. Electrophysiology studies indicated that iPS cells have a capacity like ES cells for differentiation into nodal-, atrial-, and ventricular-like phenotypes based on action potential characteristics. Both iPS and ES cell–derived cardiomyocytes exhibited responsiveness to β-adrenergic stimulation manifest by an increase in spontaneous rate and a decrease in action potential duration. We conclude that human iPS cells can differentiate into functional cardiomyocytes, and thus iPS cells are a viable option as an autologous cell source for cardiac repair and a powerful tool for cardiovascular research.
Ultrafast High-Resolution In Vivo Volume-CTA of Mice Cerebral Vessels
Authors: Schambach Sebastian J. , Bag Simona , Steil Volker , Isaza Cristina , Schilling Lothar , Groden Christoph , Brockmann Marc A.
Published: February 2009

Background and Purpose—

Animal models developed in rats and mice have become indispensable in preclinical cerebrovascular research. Points of interest include the investigation of the vascular bed and the morphology and function of the arterial, capillary, and venous vessels. Because of their extremely small caliber, in vivo examination of these vessels is extremely difficult. In the present study we have developed a method to provide fast 3D in vivo analysis of cerebral murine vessels using volume computed tomography-angiography (vCTA).

Methods—

Using an industrial
X-ray
inspection system equipped with a multifocus cone beam
X-ray
source and a 12-bit direct digital flatbed detector, high-speed vCTA (180° rotation in 40 s. at 30 fps) was performed in anesthetized mice. During the scan an iodinated contrast agent was infused via a tail vein. Images were reconstructed using a filtered backprojection algorithm. Image analysis was performed by maximum intensity projection (MIP) and 3D volume reconstruction.

Results—

All mice tolerated i.v. injection of the iodinated contrast agent well. Smallest achievable voxel size of raw data while scanning the whole neurocranium was 16 μm. Anatomy of cerebral vessels was assessable in all animals, and anatomic differences between mouse strains could easily be detected. Mean vessel diameter was measured in C57BL/6 and BALBc mice. Changes of vessel caliber were assessable by repeated vCTA.

Conclusions—

Ultra fast in vivo vCTA of murine cerebral vasculature is feasible at resolutions down to 16 μm. The technique allows the assessment of vessel caliber changes in living mice, thus providing an interesting tool to monitor different features such as vasospasm or vessel patency.
Subacute Stent Thrombosis in Intracranial Stenting
Authors: Riedel Christian H. , Tietke Marc , Alfke Karsten , Stingele Robert , Jansen Olav
Published: February 2009

Background and Purpose—

We sought to determine the safety of intracranial stenting with respect to subacute stent thrombosis in patients being treated with standardized antiplatelet therapy.

Methods—

We retrospectively evaluated the outcome of primary intracranial stenting of atherosclerotic stenoses and of stenting in coil embolization procedures in 67 patients. We focused on those cases that led to subacute stent thrombosis even though the patients had been treated with standardized antiplatelet therapy before, during, and after stent placement. Patient age ranged from 19 to 78 years. In 33 patients, stents were placed for treatment of atherosclerotic stenoses; in the remaining 34 patients, stents were placed to assist coiling of aneurysms. The patients in this study were treated between January 2003 and August 2007.

Results—

Of the total 67 patients initially treated successfully by intracranial stenting, 7 patients developed subacute stent thrombosis. Of these 7 patients, 3 received stent placement into the basilar artery because of an underlying stenosis; in 1 patient, a stenosis of the M1 segment of the middle cerebral artery was treated. In 3 patients, aneurysms of the anterior cerebral artery, the posterior inferior cerebellar artery, and the basilar artery were treated by stent-assisted coil embolization. In 4 of the 7 patients with subacute thrombosis, recanalization of stents by local application of recombinant tissue-type plasminogen activator was successful.

Conclusions—

Intracranial stenting can lead to subacute stent thrombosis, even in patients who are treated with standardized antiplatelet therapy. Such complications have been described for patients after coronary artery stenting, but to our knowledge, no one has reported on a comparable number of cases of intracranial stenting procedures. In certain clinical scenarios, local thrombolysis with recombinant tissue-type plasminogen activator is an important treatment option to deal with subacute stent thrombosis.
The Transition to Strong Convection
Authors: Neelin J. David , Peters Ole , Hales Katrina
Published: February 2009

Recent work has shown that observations of tropical precipitation conform to properties associated with critical phenomena in other systems. Here some of these universal properties are used to probe the physics of tropical convection empirically, providing potential tests for models and parameterizations. The power-law pickup of ensemble average precipitation as a function of column water vapor w occurs above a critical value wc whose temperature dependence is determined for layer-integrated tropospheric temperature or saturation value. This dependence differs from the simplest expectations based on column saturation. Rescaling w by wc permits a collapse of precipitation-related statistics to similar functional dependence for all temperatures. The sharp precipitation variance peak at wc, obtained without detailed vertical structure information, appears consistent with arguments that onset requires a deep moist layer. Sea surface temperature (SST) is found not to have a significant effect on the precipitation pickup. The effect of SST on the climatological precipitation occurs via the frequency of occurrence of w values as the system spends a larger fraction of time near criticality over regions of warm SST. Near and above criticality, where most precipitation occurs, the w distribution is highly constrained by the interaction with convection, with a characteristic sharp drop at criticality. For precipitating points, the distribution has a Gaussian core with an approximately exponential tail akin to forced advection–diffusion problems. The long tail above wc, implying relatively frequent strong events, remains similar through the range of tropospheric temperature and SST spanning tropical large-scale conditions. A simple empirical closure illustrates time decay properties.
Using Transformation and Formation Maps to Study the Role of Air–Sea Heat Fluxes in North Atlantic Eighteen Degree Water Formation
Authors: Maze Guillaume , Forget Gael , Buckley Martha , Marshall John , Cerovecki Ivana
Published: February 2009

The Walin water mass framework quantifies the rate at which water is transformed from one temperature class to another by air–sea heat fluxes (transformation). The divergence of the transformation rate yields the rate at which a given temperature range is created or destroyed by air–sea heat fluxes (formation). Walin’s framework provides a precise integral statement at the expense of losing spatial information. In this study the integrand of Walin’s expression to yield transformation and formation maps is plotted and used to study the role of air–sea heat fluxes in the cycle of formation–destruction of the 18° ± 1°C layer in the North Atlantic.

Using remotely sensed sea surface temperatures and air–sea heat flux estimates based on both analyzed meteorological fields and ocean data–model syntheses for the 3-yr period from 2004 to 2006, the authors find that Eighteen Degree Water (EDW) is formed by air–sea heat fluxes in the western part of the subtropical gyre, just south of the Gulf Stream. The formation rate peaks in February when the EDW layer is thickened by convection owing to buoyancy loss. EDW is destroyed by air–sea heat fluxes from spring to summer over the entire subtropical gyre. In the annual mean there is net EDW formation in the west to the south of the Gulf Stream, and net destruction over the eastern part of the gyre. Results suggest that annual mean formation rates of EDW associated with air–sea fluxes are in the range from 3 to 5 Sv (Sv ≡ 106 m3 s−1). Finally, error estimates are computed from sea surface temperature and heat flux data using an ensemble perturbation method. The transformation/formation patterns are found to be robust and errors mostly affect integral quantities.
The Intrusion Depth of Density Currents Flowing into Stratified Water Bodies
Authors: Wells Mathew , Nadarajah Parthiban
Published: February 2009

Theory and laboratory experiments are presented describing the depth at which a density current intrudes into a linearly stratified water column, as a function of the entrainment ratio E, the buoyancy flux in the dense current B, and the magnitude of the stratification N. The main result is that Z ∼ E−1/3B1/3/N. It is shown that the depth of the intrusion scales as Z ∼ (3 ± 1)B1/3/N for laboratory experiments, and as for oceanic density currents. The velocity of a large-scale density current is controlled by a geostrophic balance defined as Ugeo = 0.25g′s/f, where s is the slope and f is the Coriolis parameter. The geostrophic buoyancy flux is then defined by Bgeo = g′Ugeoh, with g′ the reduced gravity and h the thickness of the current. The scaling herein implies that the depth of an oceanic intrusion is relatively insensitive to changes in source water properties but is very sensitive to changes in the stratification of the water column, consistent with the previous scaling of Price and Baringer. For example, if the buoyancy flux of a dense current were to double while the stratification remained constant, then there would only be a 25% increase in the intrusion depth, whereas doubling the stratification would result in a 50% decrease of the intrusion depth.
Origin and Pathway of Equatorial 13°C Water in the Pacific Identified by a Simulated Passive Tracer and Its Adjoint*
Authors: Qu Tangdong , Gao Shan , Fukumori Ichiro , Fine Rana A. , Lindstrom Eric J.
Published: February 2009

The origin and pathway of the thermostad water in the eastern equatorial Pacific Ocean, often referred to as the equatorial 13°C Water, are investigated using a simulated passive tracer and its adjoint, based on circulation estimates of a global general circulation model. Results demonstrate that the source region of the 13°C Water lies well outside the tropics. In the South Pacific, some 13°C Water is formed northeast of New Zealand, confirming an earlier hypothesis on the water’s origin. The South Pacific origin of the 13°C Water is also related to the formation of the Eastern Subtropical Mode Water (ESTMW) and the Sub-Antarctic Mode Water (SAMW). The portion of the ESTMW and SAMW that eventually enters the density range of the 13°C Water (25.8 < σθ < 26.6 kg m−3) does so largely by mixing. Water formed in the subtropics enters the equatorial region predominantly through the western boundary, while its interior transport is relatively small. The fresher North Pacific ESTMW and Central Mode Water (CMW) are also important sources of the 13°C Water. The ratio of the southern versus the northern origins of the water mass is about 2 to 1 and tends to increase with time elapsed from its origin. Of the total volume of initially tracer-tagged water in the eastern equatorial Pacific, approximately 47.5% originates from depths above σθ = 25.8 kg m−3 and 34.6% from depths below σθ = 26.6 kg m−3, indicative of a dramatic impact of mixing on the route of subtropical water to becoming the 13°C Water. Still only a small portion of the water formed in the subtropics reaches the equatorial region, because most of the water is trapped and recirculates in the subtropical gyre.
A Fourier-Based Method for the Distribution of Breaking Crests from Video Observations
Authors: Thomson Jim , Jessup Andrew T.
Published: February 2009

A Fourier-based method is presented to process video observations of water waves and calculate the speed distribution of breaking crest lengths. The method has increased efficiency and robust statistics compared with conventional algorithms that assemble distributions from tracking individual crests in the time domain. The method is tested using field observations (video images of whitecaps) of fetch-limited breaking waves during case studies with low (6.7 m s−1), moderate (8.5 m s−1), and high (12.6 m s−1) wind speeds. The method gives distributions consistent with conventional algorithms, including breaking rates that are consistent with direct observations. Results are applied to obtain remote estimates of the energy dissipation associated with wave breaking.
How and Why Interaction Matters
Authors: Manea Maria-Gabriela
Published: February 2009

The aftermath of the Cold War has brought a shift in the West's position on the acceptance and promotion of international human rights standards in developing countries. In this context, the Association of Southeast Asian Nations (ASEAN) member countries challenge the West's position based on two contradictory principles — comprehensibility and cultural embedment of human rights. In this article, I argue that interactions with regard to human rights involving state and non-state actors in ASEAN have become part of the process of regional identity formation. How ASEAN has responded to external pressures in terms of compliance with international human rights norms, and how it has developed its own normative and procedural approach to human rights at the regional level, are inherent in the dynamics of `Self' definition. A mixed pattern of `rhetorical' and `communicative action' explains how interaction has led to different phases — differentiation, affirmation, contestation and re-orientation — in the dynamics of `Self' definition of ASEAN with regard to human rights.
Paying for Protection
Authors: Ringsmose Jens
Published: February 2009

Since the creation of the Atlantic Alliance in 1949, the Alliance's minor partners have persistently spent a smaller share of their Gross Domestic Product (GDP) on military measures than their larger brothers-in-arms do. Taking my cue from collective goods theory, I examine the factors shaping the armament behaviour and military spending patterns of the smaller allies. The article's main theoretical argument is that the smallest among allies tend to perceive their military instruments as the price of admission to a collective defence organization upheld by larger and more potent powers. In essence, military spending becomes the price of security guarantees and protection. Consequently, small allies raise their military expenditures when their security-guaranteeing senior partner threatens with sanctions that the small ally considers more costly than the requested increase in military expenditures and not as a response to rising threats. In the second section of the article, this theoretical claim is illustrated and assessed against Denmark's Cold War defence policies. The empirical findings corroborate the belief that the small allies' leading policy-makers view their armed forces as a necessary evil maintained in order to profit from their senior partners' capabilities.
Toddler feeding: Expectations and experiences of low-income African American mothers
Authors: Horodynski Mildred A , Brophy-Herb Holly , Henry Michelle , Smith Katharine A , Weatherspoon Lorraine
Published: February 2009

Objective To ascertain maternal expectations and experiences with mealtimes and feeding of toddlers among low-income African American mothers in two mid- to large-size cities in the United States.

Design Qualitative focus group study.

Setting Two Early Head Start programme sites in a Midwestern state which serve low income families.

Method Twenty-seven low-income African American mothers took part in two focus groups which were conducted by a facilitator, according to a semi-structured topic guide. Focus group data were supplemented with demographic family data.

Results Four major themes emerged: (1) maternal perceptions of healthy toddlers, (2) maternal food choices for toddlers, (3) maternal expectations about toddler autonomy and self-regulation of feeding, and (4) mealtime context and interaction.

Conclusions and implications Data provided examples of maternal expectations and experiences, suggesting the development of healthy feeding patterns among some toddlers and provided evidence of less healthy feeding patterns in others. Evidence of less healthy feeding patterns included limiting toddler autonomy and food regulation, and misinterpretation of normative toddler behaviours. Because parenting practices and perceptions have been reported to contribute to social and environmental influences of obesity, this research could aid development of culturally sensitive nutrition education interventions.
Effect of Dietary Fatty Acid Composition on Th1/Th2 Polarization in Lymphocytes
Authors: Mizota Takamitsu , Fujita‐Kambara Chiaki , Matsuya Nemu , Hamasaki Shinji , Fukudome Takayasu , Goto Hirofumi , Nakane Shunya , Kondo Takayuki , Matsuo Hidenori
Published: February 2009

Background: It has become increasingly clear that polyunsaturated fatty acids (PUFAs) have immunomodulatory effects. However, the intake of these fatty acids used in animal studies often greatly exceeds dietary human intake. Whether differences in the composition of fatty acids that are consumed in amounts consistent with normal dietary intake can influence immune function remains uncertain. Methods: We manufactured 3 types of liquid diet, related to modified fatty acid composition (ω‐6/ω‐3 = 0.25, 2.27 and 42.9), but excluding eicosapentaenoic acid and docosahexaenoic acid, based upon a liquid diet used clinically in humans. We assessed CD3‐stimulated cytokine production of splenocytes in female BALB/c mice (n = 4 per group) fed 1 of 3 liquid diets for 4 weeks. We also measured the cytokine production of peripheral blood mononuclear cells stimulated with phorbol myristate acetate and ionomycin in humans at the end of a 4‐week period of consumption of 2 different liquid diets (ω‐6/ω‐3 = 3 and 44). Results: We found that the ratio of interfero ω‐γ (IFN‐γ) / interleukin‐4 (IL‐4) was significantly higher in mice fed theω ‐3 rich diet than in others. In humans, IFN‐γ / IL‐4 was significantly higher after the ω‐3 versus the ω‐6 enhanced diet. Conclusions: Differences in the composition of ω‐3 andω ‐6 PUFAs induces a shift in the Th1/Th2 balance in both mouse and human lymphocytes, even when ingested in normal dietary amounts. An ω‐3 rich diet containing α‐linolenic acid modulates immune function.
Intergenerational Patterns of Union Formation and Relationship Quality
Authors: Sassler Sharon , Cunningham Anna , Lichter Daniel T.
Published: February 2009

The authors examine whether young adults who experienced their parents' divorce and new relationships have different relationship trajectories than those who spent their childhoods living with biological parents in married-couple families. The analysis is based on longitudinal reports from more than 1,500 children from Wave 1 of the 1987-1988 National Survey of Families and Households who were ages 18 to 34 at Wave 3 (in 2001-2002). The results suggest that parents' intimate relationships serve as templates for their children. Children of divorce had elevated rates of cohabitation as adults, relative to marriage. But union outcomes were not uniform for all children who experienced parental divorce. Those whose parents cohabited following divorce exhibited elevated odds of cohabiting themselves, compared to young adults whose parents remarried without first cohabiting or remained in stable marriages. Parental cohabitation also undermines relationship quality and stability among married or dating young adults.
Comparison of isokinetic exercise versus standard exercise training in patients with chronic low back pain: a randomized controlled study
Authors: Sertpoyraz Filiz , Eyigor Sibel , Karapolat Hale , Capaci Kazim , Kirazli Yeşim
Published: February 2009

Objective: To compare the effectiveness of an isokinetic exercise programme and a standard exercise programme in patients with chronic low back pain in terms of pain, mobility, disability, psychological status and muscle strength.

Design: A randomized controlled trial.

Setting: An outpatient rehabilitation clinic.

Subjects: A total of 40 patients with low back pain were included in the study.

Interventions: Patients with low back pain were randomly allocated into group 1 (n=20, isokinetic exercises) and group 2 (n=20, standard exercise).

Main measures: Outcome measures included a visual analogue scale (VAS) for pain, fingertip-to-floor test for spinal mobility, Modified Oswestry Low Back Disability Questionnaire (MOLBDQ), Beck Depression Inventory and isokinetic muscle testing.

Results: The isokinetic and standard exercise groups demonstrated significant improvement in the VAS, fingertip-to-floor test, MOLBDQ, Beck Depression Inventory scores, and muscle strength compared with the baseline that persisted until the end of the first month (P<0.05). Comparison of both exercise groups in terms of these parameters obtained at the end of the treatment and at the first month after treatment showed no significant difference (P>0.05).

Conclusion: Isokinetic and standard exercise programmes have an equal effect in the treatment of low back pain, with no statistically significant difference found between the two programmes. The standard exercise programme was easily performed and had a low cost, making it the preferred option for exercise.
Employees' Intentions to Retire Early
Authors: van Dam Karen , van der Vorst Janine D. M. , van der Heijden Beatrice I. J. M.
Published: February 2009

This study investigated the early retirement intentions of 346 older Dutch employees by extending the theory of planned behavior with anticipated work conditions. The results showed that employees who felt a pressure from their spouse to retire early had a strong intention to leave the work force before the official retirement age, that is 65. Also, employees' retirement attitude and perceived control over the retirement decision were related to early retirement intentions. Finally, the results indicated that employees might postpone early retirement when they anticipate working in a challenging and rewarding work environment. Together, our findings suggest a number of ways in which organizations can affect employees' early retirement decision making.
Academic libraries and social and learning space
Authors: Bryant Joanna , Matthews Graham , Walton Graham
Published: February 2009

A key area of debate within the public and academic library sectors across the world is use of physical space. Changing ideas about what a library should be, coupled with the growth of digital collections, has raised fundamental questions about how library buildings are used and the role of space in library services. Alongside these drivers is the need for libraries to produce data on services to inform their future development and design. This article is a case study from Loughborough University in the UK to evaluate the use of a large open learning/social space in the library. The investigation employs an ethnographic approach to gather data, a method little used in the field. Findings are explored under the following themes: collaborative study, individual study, social space, intrusions and interruptions, use of technology, diversity, library staff/library materials and spatial organization. The role of ethnographic studies within the library context is considered alongside the broader theoretical considerations of the use of physical space.
Information literacy in the workplace
Authors: Crawford John , Irving Christine
Published: February 2009

Although increasingly recognized as a future skills issue, the use of information in the workplace is a little studied area within library and information research. A substantial `pedagogic' literature of learning in the workplace exists, however, and this was critically reviewed to generate a repertoire of issues which could in turn be used to inform a research project. This repertoire was supplemented by advice from the Scottish Information Literacy Project's partners and contacts including those working in Adult Literacies. These issues were used to generate research questions for an interview-based project which, it was hoped, would generate both action points and further research questions. With the help of partners a range of interviewees was identified, mainly in the public sector. Information usage in the workplace, as the pedagogic literature predicted, proved to be a form of social interaction with people, both within and outside the organization, being generally the prime source of information. Other sources included intranets, electronic resource data management systems, a limited range of Internet sites and a small number of printed sources. Recommendations include the need to establish contacts with chambers of commerce, skills agencies and trade unions. Public libraries should explore the possibility of developing information literacy training programmes.
Nurses’ Perceptions of Factors Influencing Patient Decision Support for Place of Care at the End of Life
Authors: Murray Mary Ann , Wilson Keith , Kryworuchko Jennifer , Stacey Dawn , O'Connor Annette
Published: February 2009

Although patients have more choices about where to receive care as death approaches, they often need help with decision making. This study identified factors that influence nurses’ provision of decision support. A total of 22 nurses, from 3 health networks, participated in semistructured interviews. Overall, nurses held favorable attitudes toward providing decision support for place of care at end of life. Overlap between other professionals’ roles and nurses’ clinical experience affected nurses’ decision support behaviors. Although nurses considered decision support to be part of patient-centered care, they report a lack of skills, confidence, and tools to help them provide it. These findings confirm the need to develop practical postlicensure education strategies and ways to embed patient decision support tools into systems of care.
Views of Formal and Informal Crime Control and Their Correlates in China
Authors: Shanhe Jiang  , Lambert Eric G.
Published: February 2009

For thousands of years, traditional China relied on a morality-based system of informal, socially enforced control. After its 1978 economic reforms, China embraced a more Western model of social control, based on laws and enforced by official governmental controlling organizations. However, few studies have examined correlates of formal and informal social control in a quantitative manner. This study analyzed data from 109 purposively selected residents in Hubei province and found that increased mobility was related to a belief that formal control was more effective. Collectivism was inversely related to the attitude that formal sanctions are a powerful deterrent to crime. Finally, satisfaction with police was positively related both to the belief in the deterrent value of formal sanctions and of informal sanctions.