bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitric oxide modulation of ETB receptor-induced vasopressin release by rat and mouse hypothalamo-neurohypophyseal explants
Authors: Rossi Noreen F. , Beierwaltes William H.
Published: December 2005

Endothelin (ET) peptides stimulate vasopressin (AVP) secretion via ETB receptors at hypothalamic loci. Nitric oxide modulates the actions of ET in the cardiovascular system and also influences neurotransmission and specifically suppresses firing of magnocellular neurons. The purpose of these studies was to ascertain whether nitric oxide, generated in response to ETB receptor stimulation, buffers the stimulatory effect of ET and suppresses AVP release. Studies were performed using a pharmacological approach in hypothalamo-neurohypophyseal explants from rats, and an alternative strategy using explants from mice with an inactivating mutation of neuronal NOS (nNOS−/−) and their wild-type parent strain. Whole explants in standard culture or only the hypothalamus of compartmentalized explants was exposed to the ETB selective agonist, IRL 1620 (10−13 to 10−8 M). Rat and wild-type mouse explants displayed similar responses, although absolute basal release rates were higher from murine explants. Maximal AVP release at 0.1 nM IRL 1620 was 311 ± 63 (rat) and 422 ± 112% basal·explant−1·h−1 (mouse). Sodium nitroprusside (SNP; 0.1 mM) suppressed maximal AVP release to basal values. Nω-nitro-l-arginine methyl ester (l-NAME, 0.1 μM), which did not itself stimulate AVP secretion, more than doubled the response to 1 pM IRL 1620, from 136 ± 28 to 295 ± 49% basal·explant−1·h−1 ( P < 0.05) by rat explants. Explants from wild-type mice responded similarly. Explants from nNOS−/− mice had higher basal AVP secretory rate in response to 1 pM IRL 1620: 271 ± 48 compared with 150 ± 24% basal·explant−1·h−1 ( P < 0.05) from wild-type murine explants. In the nNOS−/−, SNP suppressed stimulated release, and l-NAME exerted no additional stimulatory effect: 243 ± 38% basal·explant−1·h−1. Thus nitric oxide inhibits the AVP secretory response induced by ETB receptor activation within the hypothalamo-neurohypophyseal system and is generated primarily by the nNOS isoform. The modulation of AVP secretion by ET and also nitric oxide can take place independently from their effects on cerebral blood flow, systemic hemodynamics, or the arterial baroreflex.
Hemodynamic and neuroendocrine responses to changes in sodium intake in compensated heart failure
Authors: Damgaard Morten , Norsk Peter , Gustafsson Finn , Kanters Jørgen K. , Christensen Niels Juel , Bie Peter , Friberg Lars , Gadsbøll Niels
Published: December 2005

Patients with untreated heart failure (HF) exhibit a blunted hemodynamic and neuroendocrine response to a high sodium intake, leading to excessive sodium and water retention. However, it is not known whether this is the case for patients with compensated HF receiving angiotensin-converting enzyme inhibitors and β-adrenoreceptor blockers. Therefore, we determined the hemodynamic and neuroendocrine responses to 1 wk of a low-sodium diet (70 mmol/day) and 1 wk of a high-sodium diet (250 mmol/day) in 12 HF patients and 12 age-matched controls in a randomized, balanced fashion. During steady-state conditions, hemodynamic and neuroendocrine examinations were performed at rest and during bicycle exercise. In seated HF patients, high sodium intake increased body weight (1.6 ± 0.4%), plasma volume (9 ± 2%), cardiac index (14 ± 6%), and stroke volume index (21 ± 5%), whereas mean arterial pressure was unchanged. Therefore, the total peripheral resistance decreased by 10 ± 4%. Similar hemodynamic changes were observed during an incremental bicycle exercise test. Plasma concentrations of angiotensin II and norepinephrine were suppressed, whereas plasma pro-B-type natriuretic peptide remained unchanged. In conclusion, high sodium intake was tolerated without any excessive sodium and water retention in medically treated patients with compensated HF. The observation that high sodium intake improves cardiac performance, induces peripheral vasodilatation, and suppresses the release of vasoconstrictor hormones does not support the advice for HF patients to restrict dietary sodium.
Agonist and hypertonic saline-induced trafficking of the NK3-receptors on vasopressin neurons within the paraventricular nucleus of the hypothalamus
Authors: Haley Gwendolen E. , Flynn Francis W.
Published: December 2005

The neurokinin 3 receptor (NK3R) is colocalized with vasopressinergic neurons within the hypothalamic paraventricular nucleus (PVN) and intraventricular injections of NK3R agonists stimulate vasopressin (VP) release. Our objectives were to test the hypotheses that intraventricular injections of the selective NK3R agonist, succinyl-[Asp6, N-Me-Phe8] substance P (senktide), activate NK3R expressed by vasopressinergic neurons within the PVN, and see whether NK3R expressed by vasopressinergic neurons in the PVN are activated by hyperosmolarity. NK3R internalization was used as a marker of receptor activation. Immunohistochemistry revealed that NK3Rs were membrane-bound on VP immunoreactive neurons in control rats. Following senktide injection, there was a significant increase in the appearance of NK3R immunoreactivity within the cytoplasm and a morphological rearrangement of the dendrites, indicating receptor internalization, which was reversible. Furthermore, pretreatment with a selective NK3R antagonist, SB-222200, blocked the senktide-induced VP release and internalization of the NK3R in the PVN. These results show that the trafficking of the NK3R is due to ligand binding the NK3R. In a subsequent experiment, rats were administered intragastric loads of 2 or 0.15 M NaCl, and NK3R immunohistochemistry was used to track activation of the receptor. In contrast to control rats, 2 M NaCl significantly increased plasma VP levels and caused the internalization of the NK3R on VP neurons. Also, NK3R immunoreactivity was located in the nuclei of vasopressinergic neurons after senktide and 2 M NaCl treatment. These results show that hyperosmolarity stimulates the local release of an endogenous ligand in the PVN to bind to and activate NK3R on vasopressinergic neurons.
Effect of voluntary exercise on peripheral tissue glucocorticoid receptor content and the expression and activity of 11β-HSD1 in the Syrian hamster
Authors: Coutinho Agnes E. , Campbell Jonathan E. , Fediuc Sergiu , Riddell Michael C.
Published: December 2005

Recent findings indicate that elevated levels of glucocorticoids (GC), governed by the expression of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) and GC receptors (GR), in visceral adipose tissue and skeletal muscle lead to increased insulin resistance and the metabolic syndrome. Paradoxically, evidence indicates that aerobic exercise attenuates the development of the metabolic syndrome even though it stimulates acute increases in circulating GC levels. To investigate the hypothesis that training alters peripheral GC action to maintain insulin sensitivity, young male hamsters were randomly divided into sedentary (S) and trained (T) groups ( n = 8 in each). The T group had 24-h access to running wheels over 4 wk of study. In muscle, T hamsters had lower 11β-HSD1 protein expression (19.2 ± 1.40 vs. 22.2 ± 0.96 optical density, P < 0.05), similar 11β-HSD1 enzyme activity (0.9 ± 0.27% vs. 1.1 ± 0.26), and lower GR protein expression (9.7 ± 1.86 vs. 15.1 ± 1.78 optical density, P < 0.01) than S hamsters. In liver, 11β-HSD1 protein expression tended to be lower in T compared with S (19.2 ± 0.56 vs. 21.4 ± 1.05, P = 0.07), whereas both enzyme activity and GR protein expression were similar. In contrast, visceral adipose tissue contained ∼2.7-fold higher 11β-HSD1 enzyme activity in T compared with S (12.9 ± 3.3 vs. 4.8 ± 1.5% conversion, P < 0.05) but was considerably smaller in mass (0.24 ± 0.02 vs. 0.71 ± 0.06 g). Thus the intracellular adaptation of GC regulators to exercise is tissue specific, resulting in decreases in GC action in skeletal muscle and increases in GC action in visceral fat. These adaptations may have important implications in explaining the protective effects of aerobic exercise on insulin resistance and other symptoms of the metabolic syndrome.
Dual-wavelength phosphorimetry for determination of cortical and subcortical microvascular oxygenation in rat kidney
Authors: Johannes Tanja , Mik Egbert G. , Ince Can
Published: December 2005

This study presents a dual-wavelength phosphorimeter developed to measure microvascular Po2(μPo2) in different depths in tissue and demonstrates its use in rat kidney. The used phosphorescent dye is Oxyphor G2 with excitation bands at 440 and 632 nm. The broad spectral gap between the excitation bands combined with a relatively low light absorption of 632 nm light by tissue results in a marked difference in penetration depths of both excitation wavelengths. In rat kidney, we determine the catchments depth of the 440-nm excitation to be 700 μm, whereas the catchments depth of 632 nm is as much as 4 mm. Therefore, the measurements differentiate between cortex and outer medulla, respectively. In vitro, no difference in Po2readings between both channels was found. On the rat kidney in vivo, the measured cortical μPo2was on average 20 Torr higher than the medullary μPo2over a wide Po2range induced by variations in inspired oxygen fraction. Examples provided from endotoxemia and resuscitation show differences in responses of mean cortical and medullary Po2readings as well as in the shape of the Po2histograms. It can be concluded that oxygen-dependent quenching of phosphorescence of Oxyphor G2 allows quantitative measurement of μPo2noninvasively in two different depths in vivo. Oxygen levels measured by this technique in the rat renal cortex and outer medulla are consistent with previously published values detected by Clark-type oxygen electrodes. Dual-wavelength phosphorimetry is excellently suited for monitoring μPo2changes in two different anatomical layers under pathophysiological conditions with the characteristics of providing oxygen histograms from two depths and having a penetration depth of several millimeters.
Occupation, Marital Status, and Low-Grade Inflammation
Authors: Engström Gunnar , Hedblad Bo , Rosvall Maria , Janzon Lars , Lindgärde Folke
Published: December 2005

Objective—

We explored the relationships between inflammatory proteins, occupation, and marital status, and their independent associations with incidence of cardiovascular disease (CVD).

Methods and Results—

Five inflammation-sensitive proteins (ISPs) (fibrinogen, ceruloplasmin, haptoglobin, α1-antitrypsin, orosomucoid) were measured in 6075 apparently healthy men. Incidence of coronary events and stroke was followed over 18 years in relation to occupation and marital status. All ISPs showed higher concentrations in divorced men and in manual workers. Except for fibrinogen, this remained significant after adjustments for confounding factors. Adjusted for traditional cardiovascular risk factors, incidence of coronary events was significantly increased in unskilled manual workers and in divorced men. The relative risks were slightly reduced after further adjustments for ISPs (from 1.79 to 1.70 in unskilled manual workers; from 1.58 to 1.51 in divorced men). All ISPs were significantly associated with incidence of coronary events, after adjustments for traditional risk factors. This relationship was essentially unchanged after further adjustments for occupation and marital status.

Conclusion—

Inflammation could contribute to, but not fully explain, the increased cardiovascular risk in manual workers and divorced men. Although the ISPs vary greatly by occupational and marital status, this does not confound the relationship between ISPs and incidence of CVD.
18
F-Choline Images Murine Atherosclerotic Plaques Ex Vivo
Authors: Matter Christian M. , Wyss Matthias T. , Meier Patricia , Späth Nicolas , von Lukowicz Tobias , Lohmann Christine , Weber Bruno , de Molina Ana Ramirez , Lacal Juan Carlos , Ametamey Simon M. , von Schulthess Gustav K. , Lüscher Thomas F. , Kaufmann Philipp A. , Buck Alfred
Published: December 2005

Objective—

Current imaging modalities of atherosclerosis mainly visualize plaque morphology. Valuable insight into plaque biology was achieved by visualizing enhanced metabolism in plaque-derived macrophages using
18
F-fluorodeoxyglucose (
18
F-FDG). Similarly, enhanced uptake of
18
F-fluorocholine (
18
F-FCH) was associated with macrophages surrounding an abscess. As macrophages are important determinants of plaque vulnerability, we tested
18
F-FCH for plaque imaging.

Methods and Results—

We injected
18
F-FCH (n=5) or
18
F-FDG (n=5) intravenously into atherosclerotic apolipoprotein E-deficient mice. En face measurements of aortae isolated 20 minutes after
18
F-FCH injections demonstrated an excellent correlation between fat stainings and autoradiographies (
r
=0.842,
P
<0.0001), achieving a sensitivity of 84% to detect plaques by
18
F-FCH. In contrast, radiotracer uptake 20 minutes after
18
F-FDG injections correlated less with en face fat stainings (
r
=0.261,
P
<0.05), reaching a sensitivity of 64%. Histological analyses of cross-sections 20 minutes after coinjections of
18
F-FCH and
14
C-FDG (n=3) showed that
18
F-FCH uptake correlated better with fat staining (
r
=0.740,
P
<0.0001) and macrophage-positive areas (
r
=0.740,
P
<0.0001) than
14
C-FDG (fat:
r
=0.236,
P
=0.29 and CD68 staining:
r
=0.352,
P
=0.11), respectively.

Conclusions—

18
F-FCH identifies murine plaques better than
18
F-FDG using ex vivo imaging. Enhanced
18
F-FCH uptake into macrophages may render this tracer a promising candidate for imaging plaques in patients.
Reduced Immunoregulatory CD31
+
T Cells in Patients With Atherosclerotic Abdominal Aortic Aneurysm
Authors: Caligiuri Giuseppina , Rossignol Patrick , Julia Pierre , Groyer Emilie , Mouradian Dikran , Urbain Dominique , Misra Namita , Ollivier Véronique , Sapoval Marc , Boutouyrie Pierre , Kaveri Srini V. , Nicoletti Antonino , Lafont Antoine
Published: December 2005

Background—

Cell-mediated immunity is considered to contribute to the pathogenesis of abdominal aortic aneurysms (AAA). In particular, infiltrating macrophages and CD8
+
T lymphocytes participate in the destruction of the aortic wall extracellular matrix and smooth muscle cells. We surmise that these pathological events are controlled by circulating regulatory lymphocytes.

Methods and Results—

Circulating CD4
+
/CD31
+
cells were reduced in AAA patients (n=80, 8.9±0.6%) as compared with controls (n=69, 13.7±0.8%;
P
<0.001) and inversely proportional to AAA size. Exclusion of the aneurysm by an endoprothesis did not affect CD31
+
T cell values. Reduction of blood CD4
+
/CD31
+
cells was not attributable to their enrichment in AAA tissue. In contrast, CD8
+
/CD31
+
cells were slightly reduced in the blood while increased in the aneurysmal tissue (29.2±0.5 versus 20.2±4.7% in blood, n=6;
P
<0.05). Remarkably, high percentages of CD4
+
/CD31
+
cells were able to regulate proliferation and cytokine production of CD8
+
lymphocytes, as well as CD8
+
cell-mediated cytotoxicity of aortic smooth muscle cells (
P
<0.01). Finally, CD4
+
/CD31
+
cells reduced the production and activity of metalloproteinase-9 by lipopolysaccharide-stimulated macrophages.

Conclusions—

Circulating CD4
+
/CD31
+
T cells regulate macrophage and CD8
+
T cell activation and effector function in the arterial wall. Their reduction might promote the development of AAA.
Glycoprotein Ibα–Mediated Platelet Adhesion and Aggregation to Immobilized Thrombin Under Conditions of Flow
Authors: Weeterings Cees , Adelmeijer Jelle , Myles Timothy , de Groot Philip G. , Lisman Ton
Published: December 2005

Objectives—

Thrombin interacts with platelets via the protease-activated receptors (PARs) 1 and 4, and via glycoprotein Ibα (GPIbα). Recently, it was shown that platelets are able to adhere to immobilized thrombin under static conditions via GPIbα.

Methods and Results—

Here, we show that platelets are also able to adhere to and form stable aggregates on immobilized thrombin under conditions of flow. Adhesion and aggregation to thrombin was dependent on the interaction with GPIbα, as addition of glycocalicin or an antibody blocking the interaction between thrombin and GPIbα inhibited platelet adhesion. Additionally, platelet adhesion to recombinant thrombin mutants, which are unable to bind GPIbα, was severely suppressed. Furthermore, platelet adhesion to thrombin was dependent on activation of PARs, and partly on granule secretion and thromboxane-A2 synthesis. Immobilization of thrombin on a fibrin network resulted in substantially increased adhesion compared with fibrin alone. The adhesion to fibrin alone was completely abolished by addition of dRGDW, whereas fibrin-bound thrombin still showed substantial platelet adhesion in the presence of dRGDW, indicating that fibrin-bound thrombin is able to directly capture platelets under flow.

Conclusion—

These results indicate that platelets are able to adhere to thrombin under flow conditions, which is dependent on the interaction with GPIbα.
Xanthine Oxidoreductase Inhibition Causes Reverse Remodeling in Rats With Dilated Cardiomyopathy
Authors: Minhas Khalid M. , Saraiva Roberto M. , Schuleri Karl H. , Lehrke Stephanie , Zheng Meizi , Saliaris Anastasios P. , Berry Cristine E. , Vandegaer Konrad M. , Li Dechun , Hare Joshua M.
Published: December 2005

Increased reactive oxygen species (ROS) generation is implicated in cardiac remodeling in heart failure (HF). As xanthine oxidoreductase (XOR) is 1 of the major sources of ROS, we tested whether XOR inhibition could improve cardiac performance and induce reverse remodeling in a model of established HF, the spontaneously hypertensive/HF (SHHF) rat. We randomized Wistar Kyoto (WKY, controls, 18 to 21 months) and SHHF (19 to 21 months) rats to oxypurinol (1 mmol/L; n=4 and n=15, respectively) or placebo (n=3 and n=10, respectively) orally for 4 weeks. At baseline, SHHF rats had decreased fractional shortening (FS) (31±3% versus 67±3% in WKY,
P
<0.0001) and increased left-ventricular (LV) end-diastolic dimension (9.7±0.2 mm versus 7.0±0.4 mm in WKY,
P
<0.0001). Whereas placebo and oxypurinol did not change cardiac architecture in WKY, oxypurinol attenuated decreased FS and elevated LV end-diastolic dimension, LV end-systolic dimension, and LV mass in SHHF. Increased myocyte width in SHHF was reduced by oxypurinol. Additionally, fetal gene activation, altered calcium cycling proteins, and upregulated phospho–extracellular signal–regulated kinase were restored toward normal by oxypurinol (
P
<0.05 versus placebo-SHHF). Importantly, SHHF rats exhibited increased XOR mRNA expression and activity, and oxypurinol treatment reduced XOR activity and superoxide production toward normal, but not expression. On the other hand, NADPH oxidase activity remained unchanged, despite elevated subunit protein abundance in treated and untreated SHHF rats. Together these data demonstrate that chronic XOR inhibition restores cardiac structure and function and offsets alterations in fetal gene expression/Ca
2+
handling pathways, supporting the idea that inhibiting XOR-derived oxidative stress substantially improves the HF phenotype.
Downregulation of Endothelin-1 by Farnesoid X Receptor in Vascular Endothelial Cells
Authors: He Fengtian , Li Jiang , Mu Ying , Kuruba Ramalinga , Ma Zheng , Wilson Annette , Alber Sean , Jiang Yu , Stevens Troy , Watkins Simon , Pitt Bruce , Xie Wen , Li Song
Published: December 2005

The farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily that is highly expressed in liver, kidney, adrenals, and intestine. FXR may play an important role in the pathogenesis of cardiovascular diseases via regulating the metabolism and transport of cholesterol. In this study, we report that FXR is also expressed in rat pulmonary artery endothelial cells (EC), a “nonclassical” bile acid target tissue. FXR is functional in EC, as demonstrated by induction of its target genes such as small heterodimer partner (SHP) after treatment with chenodeoxycholic acid, a FXR agonist. Interestingly, activation of FXR in EC led to downregulation of endothelin (ET)-1 expression. Reporter assays showed that activation of FXR inhibited transcriptional activation of the human ET-1 gene promoter and also repressed the activity of a heterologous promoter driven by activator protein (AP)-1 response elements. Electrophoretic mobility-shift and chromatin immunoprecipitation assays indicated that FXR reduced the binding activity of AP-1 transcriptional factors, suggesting that FXR may suppress ET-1 expression via negatively interfering with AP-1 signaling. These studies suggest that FXR may play a role in endothelial homeostasis and may serve as a novel molecular target for manipulating ET-1 expression in vascular EC.
Selective Rac-1 Inhibition Protects From Diabetes-Induced Vascular Injury
Authors: Vecchione Carmine , Aretini Alessandra , Marino Gennaro , Bettarini Umberto , Poulet Roberta , Maffei Angelo , Sbroggiò Mauro , Pastore Lucio , Gentile Maria Teresa , Notte Antonella , Iorio Luca , Hirsch Emilio , Tarone Guido , Lembo Giuseppe
Published: December 2005

Diabetes mellitus is a main risk factor for vascular diseases. Vascular injury induced by diabetes mellitus is characterized by endothelial dysfunction attributable to an increased oxidative stress. So far, the molecular mechanisms involved in the vasculotoxic effects of diabetes are only partially known. We examined the effect of diabetes mellitus on oxidative stress and Rac-1 activation, a small G-protein involved in the activation of NADPH oxidase. Our results show that oxidative stress in vessels of different murine models of diabetes mellitus and in endothelial cells treated with high glucose is associated with an increased Rac-1/PAK binding and Rac-1 translocation from cytosol to plasma membrane, thus demonstrating an enhanced Rac-1 activity. More important, selective Rac-1 inhibition by an adenoviral vector carrying a dominant negative mutant of Rac-1 protected from oxidative stress and vascular dysfunction induced by diabetes mellitus. Our study demonstrates that Rac-1 plays a crucial role in diabetes-induced vascular injury, and it could be a target of novel therapeutic approaches to reduce vascular risk in diabetes mellitus.
Application of Satellite-Derived Atmospheric Motion Vectors for Estimating Mesoscale Flows
Authors: Bedka Kristopher M. , Mecikalski John R.
Published: December 2005

This study demonstrates methods to obtain high-density, satellite-derived atmospheric motion vectors (AMV) that contain both synoptic-scale and mesoscale flow components associated with and induced by cumuliform clouds through adjustments made to the University of Wisconsin—Madison Cooperative Institute for Meteorological Satellite Studies (UW-CIMSS) AMV processing algorithm. Operational AMV processing is geared toward the identification of synoptic-scale motions in geostrophic balance, which are useful in data assimilation applications. AMVs identified in the vicinity of deep convection are often rejected by quality-control checks used in the production of operational AMV datasets. Few users of these data have considered the use of AMVs with ageostrophic flow components, which often fail checks that assure both spatial coherence between neighboring AMVs and a strong correlation to an NWP-model first-guess wind field. The UW-CIMSS algorithm identifies coherent cloud and water vapor features (i.e., targets) that can be tracked within a sequence of geostationary visible (VIS) and infrared (IR) imagery. AMVs are derived through the combined use of satellite feature tracking and an NWP-model first guess. Reducing the impact of the NWP-model first guess on the final AMV field, in addition to adjusting the target selection and vector-editing schemes, is found to result in greater than a 20-fold increase in the number of AMVs obtained from the UW-CIMSS algorithm for one convective storm case examined here. Over a three-image sequence of Geostationary Operational Environmental Satellite (GOES)-12 VIS and IR data, 3516 AMVs are obtained, most of which contain flow components that deviate considerably from geostrophy. In comparison, 152 AMVs are derived when a tighter NWP-model constraint and no targeting adjustments were imposed, similar to settings used with operational AMV production algorithms. A detailed analysis reveals that many of these 3516 vectors contain low-level (100–70 kPa) convergent and midlevel (70–40 kPa) to upper-level (40–10 kPa) divergent motion components consistent with localized mesoscale flow patterns. The applicability of AMVs for estimating cloud-top cooling rates at the 1-km pixel scale is demonstrated with excellent correspondence to rates identified by a human expert.
Climate Variability and Sugarcane Yield in Louisiana
Authors: Greenland David
Published: December 2005

This paper seeks to understand the role that climate variability has on annual yield of sugarcane in Louisiana. Unique features of sugarcane growth in Louisiana and nonclimatic, yield-influencing factors make this goal an interesting and challenging one. Several methods of seeking and establishing the relations between yield and climate variables are employed. First, yield–climate relations were investigated at a single research station where crop variety and growing conditions could be held constant and yield relations could be established between a predominant older crop variety and a newer one. Interviews with crop experts and a literature survey were used to identify potential climatic factors that control yield. A statistical analysis was performed using statewide yield data from the American Sugar Cane League from 1963 to 2002 and a climate database. Yield values for later years were adjusted downward to form an adjusted yield dataset. The climate database was principally constructed from daily and monthly values of maximum and minimum temperature and daily and monthly total precipitation for six cooperative weather-reporting stations representative of the area of sugarcane production. The influence of 74 different, though not independent, climate-related variables on sugarcane yield was investigated. The fact that a climate signal exists is demonstrated by comparing mean values of the climate variables corresponding to the upper and lower third of adjusted yield values. Most of these mean-value differences show an intuitively plausible difference between the high- and low-yield years. The difference between means of the climate variables for years corresponding to the upper and lower third of annual yield values for 13 of the variables is statistically significant at or above the 90% level. A correlation matrix was used to identify the variables that had the largest influence on annual yield. Four variables [called here critical climatic variables (CCV)], mean maximum August temperature, mean minimum February temperature, soil water surplus between April and September, and occurrence of autumn (fall) hurricanes, were built into a model to simulate adjusted yield values. The CCV model simulates the yield value with an rmse of 5.1 t ha−1. The mean of the adjusted yield data over the study period was 60.4 t ha−1, with values for the highest and lowest years being 73.1 and 50.6 t ha−1, respectively, and a standard deviation of 5.9 t ha−1. Presumably because of the almost constant high water table and soil water availability, higher precipitation totals, which are inversely related to radiation and temperature, tend to have a negative effect on the yields. Past trends in the values of critical climatic variables and general projections of future climate suggest that, with respect to the climatic environment and as long as land drainage is continued and maintained, future levels of sugarcane yield will rise in Louisiana.
The Characteristics of the Chicago Lake Breeze and Its Effects on Trace Particle Transport: Results from an Episodic Event Simulation
Authors: Harris Lucas , Kotamarthi V. Rao
Published: December 2005

The lake-breeze circulation that forms over Lake Michigan during the summer influences the Chicago, Illinois, metropolitan area’s weather in several ways. Of particular significance is the circulation’s effect on the dispersion of pollutants such as ozone and aerosols produced in and around the city. To investigate these effects, the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5) was used to perform numerical simulations for two lake-breeze events—one in July 1999 and another in July 2002. The model runs were verified with data from several locations around the Chicago area. The simulated breeze circulation decreased the rate of increase in air temperature while penetrating roughly 12 km inland and lasting about 8 h, in reasonable agreement with observations. Furthermore, the inland penetration distance was related to the strength of the maximum vertical velocity within the front. Calculations of trajectories and transport of particles showed that the breeze tended to transport particles trapped within it to the north when release occurred before the circulation came ashore, whereas particles released at the time of the breeze’s landfall or afterward moved more northeasterly, in the direction of the prevailing wind. Thirty-four percent of all released particles were trapped by the circulation and raised to a height of at least 300 m, and 20% of the particles remained in the lowest 100 m above the surface. In addition, sensitivity tests showed little change in the modeled breeze when measured surface temperatures for Lake Michigan were used as initial conditions and boundary conditions in the place of surface skin temperature (as derived by the National Centers for Environmental Prediction). Raising the lake temperatures significantly in the simulation yielded a more elongated vertical circulation and a briefer lake-breeze event that did not reach as far inland.
Rainfall Estimation in the Sahel. Part I: Error Function
Authors: Ali Abdou , Lebel Thierry , Amani Abou
Published: December 2005

Rainfall estimation in semiarid regions remains a challenging issue because it displays great spatial and temporal variability and networks available for monitoring are often of low density. This is especially the case in the Sahel, a region of 3 million km2 where the life of populations is still heavily dependent on rain for agriculture. Whatever the data and sensors available for rainfall estimation—including satellite IR and microwave data and possibly weather radar systems—it is necessary to define objective error functions to be used in comparing various rainfall products. This first of two papers presents a theoretical framework for the development of such an error function and the optimization of its parameters for the Sahel. A range of time scales—from rain event to annual—are considered, using two datasets covering two different spatial scales. The mesoscale [Estimation des Pluies par Satellite (EPSAT)-Niger (E-N)] is documented over a period of 13 yr (1990–2002) on an area of 16 000 km2 covered by 30 recording rain gauges; the regional scale is documented by the Centre Regional Agrometeorologie–Hydrologie–Meteorologie (AGRHYMET) (CRA) dataset, with an annual average of between 600 and 650 rain gauges available over a period of 8 yr. The data analysis showed that the spatial structure of the Sahelian rain fields is markedly anisotropic, nonstationary, and dominated by the nesting of two elementary structures. A cross-validation procedure on point rainfall values leads to the identification of an optimal interpolation algorithm. Using the error variances computed from this algorithm on 1° × 1° and 2.5° × 2.5° cells, an error function is derived, allowing the calculation of standard errors of estimation for the region. Typical standard errors for monthly rainfall estimation are 11% (10%) for a 10-station network on a 2.5° × 2.5° (1° × 1°) grid, and 40% (30%) for a single station on a 2.5° × 2.5° (1° × 1°) grid. In a companion paper, this error function is used to investigate the differences between satellite rainfall products and how they compare with ground-based estimates.
Rainfall Estimation in the Sahel. Part II: Evaluation of Rain Gauge Networks in the CILSS Countries and Objective Intercomparison of Rainfall Products
Authors: Ali Abdou , Amani Abou , Diedhiou Arona , Lebel Thierry
Published: December 2005

This study investigates the accuracy of various precipitation products for the Sahel. A first set of products is made of three ground-based precipitation estimates elaborated regionally from the gauge data collected by Centre Regional Agrometeorologie–Hydrologie–Meteorologie (AGRHYMET). The second set is made of four global products elaborated by various international data centers. The comparison between these two sets covers the period of 1986–2000. The evaluation of the entire operational network of the Sahelian countries indicates that on average the monthly estimation error for the July–September period is around 12% at a spatial scale of 2.5° × 2.5°. The estimation error increases from south to north and remains below 10% for the area south of 15°N and west of 11°E (representing 42% of the region studied). In the southern Sahel (south of 15°N), the rain gauge density needs to be at least 10 gauges per 2.5° × 2.5° grid cell for a monthly error of less than 10%. In the northern Sahel, this density increases to more than 20 gauges because of the large intermittency of rainfall. In contrast, for other continental regions outside Africa, some authors have found that only five gauges per 2.5° × 2.5° grid cell are needed to give a monthly error of less than 10%. The global products considered in this comparison are the Climate Prediction Center (CPC) merged analysis of precipitation (CMAP), Global Precipitation Climatology Project (GPCP), Global Precipitation Climatology Center (GPCC), and Geostationary Operational Environmental Satellite (GOES) precipitation index (GPI). Several methods (scatterplots, distribution comparisons, root-mean-square error, bias, Nash index, significance test for the mean, variance, and distribution function, and the standard deviation approach for the kriging interval) are first used for the intercomparison. All of these methods lead to the same conclusion that CMAP is slightly the better product overall, followed by GPCC, GPCP, and GPI, with large errors for GPI. However, based on the root-mean-square error, it is found that the regional rainfall product obtained from the synoptic network is better than the four global products. Based on the error function developed in a companion paper, an approach is proposed to take into account the uncertainty resulting from the fact that the reference values are not the real ground truth. This method was applied to the most densely sampled region in the Sahel and led to a significant decrease of the raw evaluation errors. The reevaluated error is independent of the gauge references.
Ambient Sulfate Trends and the Influence of Meteorology
Authors: Mueller Stephen F.
Published: December 2005

Data on atmospheric levels of sulfur dioxide (SO2) and sulfate were examined to quantify changes since 1989. Changes in sulfur species were adjusted to account for meteorological variability. Adjustments were made using meteorological variables expressed in terms of their principal components that were used as predictors in statistical models. Several models were tested. A generalized additive model (GAM)—based in part on nonparametric, locally smoothed predictor functions—computed the greatest association between sulfate and the meteorological predictors. Sulfate trends estimated after a GAM-based adjustment for weather-related influences were found to be primarily downward across the eastern United States by as much as 6.7% per year (average of −2.6% per year), but large spatial variability was noted. The most conspicuous characteristic in the trends was over portions of the Appalachian Mountains where very small (average = −1.6% per year) and often insignificant sulfate changes were found. The Appalachian region also experienced a tendency, after removing meteorological influences, for increases in the ratio RS of sulfate sulfur to total sulfur. Before 1991, this ratio averaged 0.33 across all sites. Appalachian increases in RS were equivalent to 0.07 during 1989–2001 (significant for most sites at the 0.05 level), or nearly 2 times the average change at the other sites. This suggests that conditions over the Appalachians became notably more efficient at oxidizing SO2 into sulfate. Alternatively, subtle changes in local deposition patterns occurred, preferentially in and near mountainous monitoring sites, that changed the SO2–sulfate balance.
Metaphorical images of organization: How organizational researchers develop and select organizational metaphors
Authors: Cornelissen Joep P. , Kafouros Mario , Lock Andrew R.
Published: December 2005

The article examines how metaphors are developed and selected within organizational theorizing and research. The issue addressed is not whether metaphors exist and play a part in organizational theorizing – as this is now widely accepted – but to draw out how metaphors are actually used and are of conceptual value, particularly as such insights may aid organizational researchers in a better use of them.Working from this position, the article reviews the extant theoretical literature on metaphor, surveys the organizational literature to document past and contemporary metaphors-in-use (1993–2003), and identifies the heuristics (i.e. judgmental rules) that have been used by organizational researchers in developing and selecting these metaphors. The identified heuristics are the integration, relational, connection, availability, distance and concreteness heuristics. On the basis of these identified heuristics, and the biases and errors associated with them, the article also posits a number of governing rules that can guide organizational researchers in their continued development and selection of metaphors in the organizational field.
When the inferior candidate is offered the job: The selection interview as a political and power game
Authors: Bozionelos Nikos
Published: December 2005

The article seeks to advance the view that the selection interview frequently serves as a political arena for various power networks in the organization whose interests may be conflicting. Members of the interview panel try to advance the interests of the power networks to which they belong by lobbying for the candidates whose background and values concur most with those interests. The notion of the interview as a political and power game is illustrated with a case from the academic environment. It is concluded that there is a need for systematic investigation to establish the prevalence of the phenomenon, develop taxonomies, and examine its relationship with variables and outcomes of importance to organizations.
People, service and trust: is there a public sector service value chain?
Authors: Heintzman Ralph , Marson Brian
Published: December 2005

This article reviews the evidence for the existence of a ‘public sector service value chain’, offering a new way of thinking about what Bouckaert and his colleagues have called the micro-performance approach to improving trust and confidence in public institutions (Bouckaert et al., 2002). In particular, the article focuses on the role of service delivery in enhancing citizen trust and confidence. But it does so in the context of a broader model, one that links service delivery to other important aspects of management performance, especially people management. The article refers to this model as the ‘public sector service value chain’, drawing on work by Heskett and others in the private sector (Heskett et al., 1994, 1997). The article reviews evidence for links between employee engagement (satisfaction and commitment) and client satisfaction in the public sector, and between public sector client satisfaction and citizen trust and confidence. The article identifies the five main ‘drivers’ of service satisfaction in the public sector, and reviews both purported ‘drivers’ of employee engagement as well as data documenting the influence service delivery appears to have on citizens’ trust and confidence in Canada. The article outlines a forward research agenda, to identify the drivers of staff satisfaction and commitment, as well as drivers of trust and confidence in public institutions, and to determine whether the proposed links in the ‘public sector service value chain’ can be empirically validated.
The issues involved in the reform of the Bulgarian judicial system
Authors: Frison-Roche François , Sodev Spas-Dimitrov
Published: December 2005

The reform of the judicial systems of the post-Communist European countries has been and still is one of the essential criteria for admission to the European Union. These reforms have proved to be more long-drawn-out and more difficult than could be expected and the case of Bulgaria, in 2005, is no exception to this. This article presents, on the one hand, the legislative and constitutional aspects of the reform of the Bulgarian judicial system and, on the other, the historic and political context. It shows that the introduction of the democratic principle of the separation and independence of the judiciary can have certain negative consequences for the workings of the judicial system, now subject to the control of a body emanating from it, the Higher Judicial Council, which is too corporatist to exercise that effective self-regulation which would make it possible to eliminate the endemic politicization and corruption of the magistrates. It also shows the distinction that must be made and must be accepted between the independence of the judiciary in the exercising of its judicial functions and the necessity of introducing hierarchical regulation, by administrative means, of the effective functioning of the judicial system and the management of its resources.
Good governance and market-based reforms: a study of Bangladesh
Authors: Azmat Fara , Coghill Ken
Published: December 2005

‘Good governance’ is increasingly regarded as pivotal to development in developing countries. The six indicators recognized as the most effective measurement tools of ‘good governance’ across the world are: voice and accountability; political stability and absence of violence; government effectiveness; regulatory quality; rule of law and control of corruption (Kaufmann, Kraay and Lobaton, 2003: 8–9). This paper investigates how lack of ‘good governance’ affects the success and sustainability of the market-based reforms undertaken in the agriculture sector of Bangladesh. The reforms have been associated with increased food grain production, improved food security conditions and easy access by farmers to agricultural inputs. However, a significant problem has arisen recently: the sale of low quality and underweight agricultural inputs sometimes at higher prices has become common. Not only is this problem undermining the positive impact of the reforms, it is also threatening their sustainability. The paper argues that the problems with regulatory quality, rule of law and control of corruption – indicators of good governance – are the underlying reasons for this problem. In the context of increasing pressures from donors to pursue market-based reforms, this paper stresses the need for integrated governance linking government, business and civil society as paramount for promoting good governance for the success and sustainability of the reforms.
Generations of interactive policy-making in the Netherlands
Authors: de Vries Michiel S.
Published: December 2005

In two previous articles in this journal, I posed the hypothesis that policy generations exist and are able to explain policy changes (De Vries, 1999, 2002). Those articles argued that shifts in the dominant policy goals and the policy instruments being dominant in public policy-making processes occur periodically and simultaneously, congruent with the predictions derived from a model on policy generations. This article completes the trilogy by analyzing shifts in the relations between policy-makers and various societal actors. It argues that these shifts also reflect the periodical changes in the design of policy-making processes and that they occur simultaneously with the shifts in policy goals and the dominant policy instruments used. This supports the hypothesis that major policy change can be understood as a shift in attention simultaneously visible in the policy goals, the instruments used and the role of societal actors; that it is a periodical change; and that such change can be theoretically explained and predicted by the necessary neglect of aspects of policy-making not addressed in the previous period.
Race, Location, and Education
Authors: Gilbert Michele A.
Published: December 2005

Throughout the 1990s, unprecedented numbers of Black mayors were elected in large American cities. Previous explanatory factors for Black mayoral success based on the 1970s and 1980s may no longer be adequate given the economic transformations to cities in the 1990s. This study examines structural demographic data to investigate the trends in Black mayoral success. The author finds that the proportion of the Black population, educational attainment, and regional location affect the electoral success of Black mayors.
The Dualism of Good and Evil and East Indian Insecurity in Guyana
Authors: Gibson Kean
Published: December 2005

Both of the major ethnic groups in Guyana—Africans and East Indians—show a normal concern for the well-being of their ethnic group. They both also fear being dominated by the other—a fear that is due to the human instinct of self-preservation. But for East Indians in Guyana, fear is motivated and justified by the belief that “Black” people are evil by nature. This belief is legitimized in the Hindu scriptures in the caste system that is based on the dualism of good and evil. This article looks at the caste system, its reconstitution in Guyana, and the violent consequences due to East Indian need to justify their perception of themselves as the morally superior “good” group who are therefore entitled to rule.
Enslaved Africans’ Rivalry with White Overseers in Plantation Culture
Authors: Wiethoff William E.
Published: December 2005

Conventional wisdom about the Old South excludes slaves from the ranks of plantation overseers. However, a preference for restrictive types of evidence and a race-sensitive system for assigning titles in plantation culture raise questions about the accuracy of conventional wisdom. Reexamining conventional scholarship and supplementing it with slave narratives and legal resources suggest that slaves served as overseers more frequently and more competently than previously reported. First, an analysis of both Black and White narratives across the Old South reveals many instances where slaves performed the duties of overseers without carrying that title. Second, drawing on a comparison with the rivalry between Black and White urban workers, an analysis of salary data for White overseers suggests that their competition for work with slaves contributed to other factors that depressed their value to planters.
Capitalism and the Culture of Hate in Granfield’s Amazing Grace: The Story of the Hymn
Authors: Yenika-Agbaw Vivian
Published: December 2005

In this article, I argue that hateful practices that are prevalent in society are, for the most part linked to our excessive quest for materialism. To demonstrate this, I discuss different ways John Newton, author of the popular hymn, Amazing Grace, justified why he became a slaver in Granfield’s non fiction picture book, Amazing Grace: The Story of the Hymn. Knowing fully well that slavery was wrong, Newton willingly participated in the triangular trade business, because he believed it was truly the only he could make a living.