bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of tissue type-plasminogen activator deletion and associated fibrin(ogen) deposition on macrophage localization in peritoneal inflammation
Authors: Massa Christine , Braine Emma , Lenzo Jason , Turner Amanda , Way Kerrie , Hamilton John , Cook Andrew , Vlahos Ross
Published: March 2006

There are two plasminogen activators (PAs), urokinase type-PA (u-PA) and tissue type-PA (t-PA). While u-PA is considered to be involved in cellular migration and tissue remodeling and t-PA in fibrinolysis, this distinction is not always clear-cut. With the use of u-PA and t-PA gene deficient mice (u-PA-/and t-PA-/mice, respectively) we have assessed the role of each PA in acute peritonitis. The cellular infiltrate in both thioglycolateand antigen-induced peritoneal exudates was unaffected in u-PA-/mice; in contrast, in t-PA-/mice, the macrophage numbers, particularly of the Mac-1hi population, in the peritoneal cavity by day4 were significantly reduced compared to wild-type mice. However, examination of the peritoneal wall revealed in fact increased numbers of macrophages adhering on/in the cavity lining at all time points studied; in addition, increased fibrin(ogen) staining was observed for these mice. The reduced macrophage numbers in the peritoneal cavities of t-PA-/mice could be increased by administration of plasmin or t-PA prior to harvesting the thioglycolate-elicited exudates. These results suggest that t-PA and not u-PA is the PA controlling fibrinolysis in murine peritonitis. In its absence macrophages adhere to the accumulated fibrin(ogen) on/in the cavity wall lining, most likely via Mac-1 binding, thus affecting migration into and/or out of the peritoneal cavity. They also highlight the need to examine both the peritoneal cavity and wall in order to monitor accurately the extent of a peritoneal inflammatory reaction. Peritoneal inflammation in t-PA-/mice represents a useful model to study the progression of intra-abdominal adhesions during surgery and clinical peritonitis.
High urokinase expression contributes to the angiogenic properties of endothelial cells derived from circulating progenitors
Authors: Basire Agnès , Sabatier Florence , Ravet Sophie , Lamy Edouard , Mialhe Agnès , Zabouo Gwladys , Paul Pascale , Gurewich Victor , Sampol José , Dignat-George Françoise
Published: March 2006

Endothelial progenitor cells (EPC) displaya unique ability to repair vascular injury and promote neovascularization although the underlying molecular mechanisms remain poorly understood. Urokinase-type plasminogen activator (uPA) and its receptor (uPAR) play a critical role in cell migration and angiogenesis by facilitating proteolysis of extracellular matrix.The aim of the present study was to characterize the uPA/uPAR-dependent proteolytic potential of EPC outgrown from human umbilical cord blood and to analyze its contribution to their angiogenic properties in vitro. Cells derived from EPC (EPDC), presenting typical features of late outgrowth endothelial cells, were compared to mature endothelial cells, represented by human umbilical vein endothelial cells (HUVEC). Using quantitative flow cytometry, enzyme-linked immunosorbent assays and zymography, we demonstrated that EPDC displayed higher levels of uPA and uPAR. In conditioned culture media, uPA-dependant proteolytic activity was also found to be significantly increased in EPDC.This activity was paralleled bya higher secretion of pro-metalloproteinase-2 (pro-MMP-2). Inhibition of EPDC-associated uPA by monoclonal antibodies that block either uPA activity or receptor binding, significantly reduced proliferation, migration and capillary like tube formation. Moreover, tumor necrosis factoralpha and vascular endothelial growth factor,known to be locally secreted in ischemic areas, further increased the proteolytic potential of EPDC by up-regulating uPA and uPAR expression respectively.The EPDC response to these factors was found to be more pronounced than that of HUVEC. In conclusion, these findings indicated that EPDC are characterized by high intrinsic uPA/uPAR-dependent proteolytic potential that could contribute to their invasive and angiogenic behaviour.
Effect of nitric oxide synthase (NOS) inhibition on macro- and microcirculation in a model of rat endotoxic shock
Authors: Pullamsetti Soni , Maring Daniel , Ghofrani Hossein , Mayer Konstantin , Weissmann Norbert , Rosengarten Bernhard , Lehner Martin , Schudt Christian , Boer Rainer , Grimminger Friedrich , Seeger Werner , Schermuly Ralph
Published: March 2006

Treatment of hemodynamic instability in septic shock often demands the administration of vasopressor agents, although these may have deleterious effects on microcirculatory homeostasis. Inhibition of nitric oxide synthase (NOS) has been suggested as an alternative therapeutic approach, as NO formation may be excessively increased in sepsis. To compare the effects of epinephrine titration, non-selective NOS inhibition by L-NMMA and selective inhibition of inducible NOS (iNOS) by 1400W on hemodynamics and on the regulation of microcirculation in a rat model of endotoxic shock, we intravenously injected endotoxin (LPS) or saline to male Wist ar rats and after 2 hours randomized LPS treated rats into four different groups that received either saline, norepinephrine, L-NMMA or 1400W (n=6 per group). Three hours after LPS administration, rats presented with severe systemic arterial hypotension (64 ± 3 vs. 115 ± 4 mmHg, p<0.001), unresponsiveness to volume treatment, lactate acidosis and a marked increase in plasmatic nitrite and nitrate levels (15 ±8 vs. 263 ± 47 µM, p<0.001). Measurement of the tissue oxygenation in the ileum mucosal layer by the Erlangen micro-lightguide spectrophotometer (EMPHO) technique demonstrated marked heterogeneity of hemoglobin saturation, with appearance of low oxygenated areas. Norepinephrine, usually stabilizing blood pressure (99 ±7 vs. 67 ±4 mmHg 60 min after infusion, p<0.01), increased lactate formation (7.9± 0.2 vs. 3.7 ± 0.5 mM, p<0.001) and drastically increased low oxygenated regions in the ileum mucosal layer. L-NMMA similarly increased blood pressure (92 ±6 vs. 67 ±4 mmHg 60 min after infusion, p<0.05), but did not enhance lactate acidosis. However, some further deterioration of mucosa oxygenation was again noted. 1400W forwarded stabilization of blood pressure (88 ± 5 vs. 67 ±4 mmHg 60 min after injection, p<0.05), reduced plasmatic nitrite and nitrate levels similar to L-NMMA, without an aggravation of lactate acidosis. In addition, mucosal oxygenation did not deteriorate in response to this agent. Thereby, we conclude that in a rat model of endotoxic shock selective iNOS inhibitors are superior to non-specific NOS inhibitors and in particular to norepinephrine for the treatment of macro-and microcirculatory abnormalities in experimental septic shock.
Association of factor V gene polymorphisms (Leiden; Cambridge; Hong Kong and HR2 haplotype) with recurrent idiopathic pregnancy loss in Tunisia
Authors: Zammiti Walid , Mtiraoui Nabil , Mercier Eric , Abboud Nesrine , Saidi Sarra , Mahjoub Touhami , Almawi Wassim , Gris Jean-Christophe
Published: March 2006

Inherited thrombophilia has been shown to be linked with fetal loss. We performed a case-control study on the association between thrombosis-related polymorphisms in the factor V (FV) gene (Leiden, Cambridge, Hong Kong; HR2 haplotype) and idiopathic recurrent pregnancy loss (RPL) in Tunisian women. A total of 348 women with RPL, and 203 control women were studied, corresponding to 1,250 pregnancy losses and 1,200 successful pregnancies. FV Leiden was seen in 19.4% of patients (4.3% in the homozygous state) and in 5.5% of controls. The prevalence of the FV HR2 haplotype was similar in patients and controls, but with 7 homozygous patients for 1 control. FV Cambridge and Hong Kong were absent from both patients and controls. The study of all pregnancy losses evidenced that the frequency of the factor V Leiden polymorphism was zero in women who had miscarried before7 weeks of gestation, and then sharply increased to a plateau. After categorization of pregnancy losses (before8 weeks of gestation; weeks 8 and 9; weeks 10 to 12; from the 13th week of gestation onwards), heterozygous and homozygous factor V Leiden polymorphisms, and homozygous FV HR2 haplotype, were associated with significant and independent risks of pregnancy loss during weeks 8 and 9, which increased during weeks 10 to 12, then culminated after week 12. In Tunisian women with idiopathic RPL, factor V Leiden polymorphism and homozygous FV HR2 haplotype are not a risk factor for very early pregnancy loss, before 8 weeks of gestation, but are thereafter associated with significant clinical risks, which gradually increase from the 8th week onwards.
Thrombophilic risk factors and homocysteine levels in Behçet’s disease in eastern Spain and their association with thrombotic events
Authors: Ricart José , Todolí José , Calvo Javier , Villa Piedad , Estellés Amparo , España Francisco , Santaolaria Marisa , Corella Dolores , Aznar Justo , Vayá Amparo
Published: March 2006

Behçet’s disease (BD) is a chronic inflammatory disorder in which thrombosis occurs in about 30% of patients. The prothrombotic mechanisms are unknown. Thrombophilic defects and hyperhomocysteinaemia may be involved in the pathogenesis of thrombotic events, although results have been controversial. Moreover, no information is available on this issue for eastern Spain.We studied the prevalence of inherited and acquired thrombophilic risk factors in 79 patients with BD (43 men, 36 women) who had (n = 23) or did not have (n = 56) thrombosis, and in 84 healthy control subjects (42 men, 42 women). Risk factors examined were antithrombin, protein C and protein S levels, factor V Leiden, the prothrombin G20210A mutation, the methylenetetrahydrofolate reductase C677T polymorphism, and acquired thrombophilic risk factors, including anticardiolipin antibodies, lupus anticoagulant, and serum homocysteine levels. There were no differences between patients and controls in any of the parameters studied.When we studied BD patients with and without thrombotic events, the only thrombophilic defect that differed was the prothrombin G20210A mutation: Three out of 23 patients with thrombosis were carriers, compared with none of 56 patients without thrombosis (p = 0.022).Two of the three carriers developed catastrophic or recurrent thrombotic episodes; one wasa homozygous carrier of the G20210A prothrombin mutation and the other was doubly heterozygous for the G20210A prothrombin mutation and factor V Leiden. A meta-analysis demonstrated an association of factor V Leiden and prothrombin mutation with thrombosis in BD. When studies from Turkey were excluded from the meta-analysis, only the prothrombin G20210A mutation was associated with thrombosis.
Tenilsetam prevents early diabetic retinopathy without correcting pericyte loss
Authors: Hoffmann Jennifer , Alt Alex , Lin Jihong , Lochnit Günther , Schubert Uwe , Schleicher Erwin , Chavakis Triantaphyllos , Brownlee Michael , Van der Woude Fokko , Preissner Klaus , Hammes Hans-Peter
Published: March 2006

Hyperglycemia-induced mitochondrial overproduction of reactive oxygen species leads to the activation of different biochemical pathways involved in endothelial damage of the diabetic retina. Tenilsetam [(±)-3-(2-thienyl)-2-piperazinone] is a dicarbonyl scavenger in the millimolar range anda transition metal ion chelator in the micromolar range. We tested its effect on experimental diabetic retinopathy, and on endothelial cell characteristics in vitro. Streptozotocin diabetic male Wistar rats (60 mg/ kg BW) received 50 mg/kg BW tenilsetam (D-T) for 36 weeks, or no treatment (D).The impact of tenilsetam (0–30 mM) on endothelial proliferation, apoptosis, sprouting, cytokine-induced leucocyte-endothelial interaction, and VEGF expression was tested in vitro.Tenilsetam did not affect glycemic control or body weight in diabetic animals. The 3.7 fold increase in acellular capillaries in diabetic rats [p<0.001 vs. non-diabetic controls (N)] was reduced by 70% (p<0.001) through treatment, but pericyte loss (D vs. N –33%; p<0.001) remained unaffected. In vitro, tenilsetam inhibited endothelial proliferation at lower doses, while inducing apoptosis at high doses. Leucocyte adhesion was only inhibited at high doses. Sprouting angiogenesis of bovine retinal endothelial cells was promoted at lower doses (≤ 10 mM). At micromolar concentrations, endothelial VEGF expression was upregulated by 100%. Long-term treatment with the AGEinhibitor and iron-chelating compound tenilsetam inhibits the formation of acellular capillaries without correcting pericyte loss. The compound has dose-dependent effects on endothelial cell function. These data suggest that, independent of known properties, tenilsetam shows important rescue functions on endothelial cells which could be useful for the treatment of early diabetic retinopathy.
Clinical usefulness of D-dimer testing in cancer patients with suspected pulmonary embolism
Authors: Le Gal Grégoire , De Lucia Sylvain , Roy Pierre-Marie , Meyer Guy , Aujesky Drahomir , Bounameaux Henri , Perrier Arnaud , Righini Marc
Published: March 2006

Limited data are available about the diagnostic value of D-dimer testing in cancer patients with clinically suspected pulmonary embolism (PE).Therefore, we evaluated i) the safety and clinical usefulness of an ELISA D-dimer test to rule out PE in cancer patients compared with non-cancer patients and ii) whether adopting a higher D-dimer cut-off value might increase the usefulness of D-dimer in cancer patients. We analysed data from two outcome studies which enrolled 1,721 consecutive patients presenting in the emergency department with clinically suspected PE. Presence of an active malignancy was abstracted from the database. All patients underwent a sequential diagnostic work-up including an ELISA D-dimer test and a 3-month followup. Sensitivity and predictive value (NPV) were 100% in both cancer and non-cancer patients. PE was ruled out by a negative D-dimer test in 494/1,554 (32%) patients without cancer, and in 18/164 (11%) patients witha malignancy. At cut-off values varying from 500 to 900 µg/l, the sensitivity was unchanged (100%, 95% CI: 93% to 100%) and the specificity increased from 16% (95% CI:11% to 24%) to 30% (95% CI:22% to 39%).The 3-month thromboembolic risk was 0% (95 % CI: 0% to 18%) in cancer patients witha negative D-dimer test. ELISA D-dimer appears safe to rule out pulmonary embolism in cancer patients but it is negative in only one of ten patients at the usual cut-off value. Increasing the cut-off value of D-dimer in cancer patients might increase the test’s clinical usefulness.
Interleukin-4 differentially regulates osteoprotegerin expression and induces calcification in vascular smooth muscle cells
Authors: Schrader Jörg , Niebergall Ute , Viereck Volker , Burchert Andreas , Hörsch Dieter , Preissner Klaus , Schoppet Michael , Hofbauer Lorenz
Published: March 2006

Vascular calcification is characterized by cellular transdifferentiation and expression of bone-related matrix proteins that result in the presence of bone-like structures in the vascular wall. Interleukin (IL)-4, a pleiotropic cytokine, and osteoprotegerin (OPG), an essential regulator of osteoclast biology, have both been linked to vascular disease. Here, we assessed the role of IL-4 and OPG in vascular calcification in vitro. IL-4 induced OPG mRNA levels and protein secretion by 5-fold in a dose-and time-dependent fashion in human coronary artery smooth muscle cells (CASMC). Activation of the transcription factor STAT6 preceded IL-4-induced OPG expression, and blockade of IL-4-induced STAT6 activation by the phospholipase C inhibitor D609 decreased OPG expression. Long-term exposure of IL-4 for 4 weeks resulted in transformation of CASMC towards an osteoblastic phenotype, based on the expression of the transcription factor Cbfa1 and increased mineral deposition. Notably, calcification of CASMC was inhibited by gene silencing of Cbfa1. During osteogenic transformation, IL-4 down-regulated OPG production in CASMC. IL-4 has differential effects in CASMC: While short-term exposure enhances OPG production through a STAT6-dependent mechanism, long-term exposure causes Cbfa1-dependent osteogenic transformation anda decreased production of OPG, an inhibitor of bone resorption.
Towards a European Foreign Policy
Authors: Crowe Brian
Published: March 2006

The Balkans have been the crucible of the EU's Common Foreign and Security Policy (CFSP). In the 1990s the appointment of David (Lord) Owen as a strong representative to manage the EU's Bosnian policy, the sidelining of the EU itself by the Contact Group, and American dominance at Dayton (what price 'this is the hour of Europe'?) and over Kosovo were important precursors to the important European Council decisions in June 1999 to appoint a high-profile international statesman as High Representative for the CFSP and to create the EU's own military capability in European Security and Defence Policy (ESDP). The Constitutional Treaty's further provisions, notably replacing the Presidency in external relations, will be sorely missed and will need to be brought back.ESDP is developing well, if modestly, and making a genuine contribution, mostly with a strong civ-mil component, in several parts of the world. The CFSP itself seems to be managing quite well. But the EU is not yet set up for serious 'events' or crisis management. Experience shows, and greater recognition is needed, that the EU (probably even with an EU Foreign Minister) needs to be represented by member states that carry conviction to outside interlocutors: some member states are inevitably more equal and carry greater weight than others, even if all have an equal voice. Since EU foreign policy is in large measure inescapably a function of US foreign policy, member states need to have a better common understanding among themselves about the nature of the transatlantic relationship. It will take confidence in the efficacy of the CFSP, to which all must give greater priority, before those member states that have alternatives will accept being bound to conducting their foreign policy (or being represented in the UN Security Council) through Brussels. at will take time and effort.
Singapore's Diplomacy: Vulnerability into Strength
Authors: Rana Kishan S.
Published: March 2006

Singapore is a practitioner of focused, innovative diplomacy, constantly in search of the political space for itself that would overcome its sense of vulnerability resulting from its geopolitical location. This has entailed involving other states in its well-being, constantly searching for ways to make itself relevant to the international community, through niche diplomacy and a proactive style.It has been creative in its use of regional diplomacy. It runs a relatively small network of embassies, with strong centralized control through its foreign ministry; it has economized on its scarce resource — skilled manpower — through extensive use of 'non-resident ambassadors'. Poor accountability to publics, attrition of talent and gender inequality are among its few weaknesses. Some, but not all, of its methods are relevant to other small states.
Diplomacy's Possible Futures
Authors: Henrikson Alan K.
Published: March 2006

In an attempt to think beyond the immediate horizon for diplomacy, five possible futures are envisioned. 'Disintermediation' suggests that diplomats, in competition with a dynamic private sector, may need to adopt business methods and use the internet — or be bypassed. 'Europeanization' could largely subordinate bilateral diplomacy within the regional European Union framework, although space might be left for 'public diplomatic' functions. International 'democratization' would accord a larger role to states hitherto excluded from decision-making within multilateral institutions, and also to civil society. 'Thematization' would require a higher degree of flexibility from diplomats as they engage in crusade-like efforts against terrorism, disease and other such threats. 'Americanization' implies the adjustment by diplomats to a world in which 'international relations' are conducted along the lines of US domestic politics, with lobbying and advocacy becoming major activities. The need to win greater public support, if not necessarily to involve the people directly in diplomacy, is evident in all of these 'projective visions'.
The Diplomacy of Proximity and Specialness: Enhancing Canada's Representation in the United States
Authors: Hocking Brian , Lee Donna
Published: March 2006

Diplomatic representation, both as a concept and in terms of its structures and processes, does not receive the attention that it deserves. This is surprising given that it forms a central concern for both analysts and practitioners of diplomacy, with the latter confronting multiple challenges in adapting modes of representation to changes in their international and domestic political environments. One facet of this can be identified in responses to factors that have assumed a significant place in the development of diplomacy — namely distance and proximity. To the growth of proximity in both spatial and issue-oriented terms, the challenge of the 'special relationship' is added in specific contexts. Both factors come together in the case of Canada's attempts to manage its policies towards the United States. Here, strategies have moved through distinct phases responding to domestic and international changes. The latest phase, which is associated with substantial rethinking of the role and structure of Foreign Affairs Canada, assumes the form of what has been labelled the Enhanced Representation Initiative (ERI). The ERI is interesting not only in the Canadian-US context, but because it reveals more general problems for governments seeking to manage the pressures of proximity and a growing number of relationships that assume aspects of 'specialness'.
The Impact of Land Cover Change on a Simulated Storm Event in the Sydney Basin
Authors: Gero A. F. , Pitman A. J.
Published: March 2006

The Regional Atmospheric Modeling System (RAMS) was run at a 1-km grid spacing over the Sydney basin in Australia to assess the impact of land cover change on a simulated storm event. The simulated storm used NCEP–NCAR reanalysis data, first with natural (i.e., pre-European settlement in 1788) land cover and then with satellite-derived land cover representing Sydney's current land use pattern. An intense convective storm develops in the model in close proximity to Sydney's dense urban central business district under current land cover. The storm is absent under natural land cover conditions. A detailed investigation of why the change in land cover generates a storm was performed using factorial analysis, which revealed the storm to be sensitive to the presence of agricultural land in the southwest of the domain. This area interacts with the sea breeze and affects the horizontal divergence and moisture convergence—the triggering mechanisms of the storm. The existence of the storm over the dense urban area of Sydney is therefore coincidental. The results herein support efforts to develop parameterization of urban surfaces in high-resolution simulations of Sydney's meteorological environment but also highlight the need to improve the parameterization of other types of land cover change at the periphery of the urban area, given that these types dominate the explanation of the results.
Impact of New Solar Radiation Parameterization in the Eta Model on the Simulation of Summer Climate over South America
Authors: Tarasova T. A. , Fernandez J. P. R. , Pisnichenko I. A. , Marengo J. A. , Ceballos J. C. , Bottino M. J.
Published: March 2006

The regional Eta workstation (WS) model with horizontal resolution of 40 km has been integrated over South America for January 2003. The NCEP–DOE Reanalysis II was used for initial and lateral boundary conditions. The comparison of the model-simulated and satellite-derived values of monthly mean incident solar radiation at the surface demonstrates that the former values are larger by 20%–30% over the entire region. To improve the surface flux representation in the model, a new solar radiation scheme has been implemented in it. An offline comparison of the original and the new radiation schemes with the detailed line-by-line method demonstrates a higher accuracy for the new scheme. With the new scheme, the model-simulated incident solar radiation at the surface is in a better agreement with the satellite-derived data. Nevertheless, a noticeable systematic difference of 10%–20% still remains, probably because of the incorrect description of cloud parameters in the model. The lower incident solar radiation in the new version of the model causes a decrease of near-surface air temperature by 0.1°–1°C and a decrease of precipitation rate by up to 20%–30% over most of the continent. The increase in the simulated incident solar radiation and temperature is found in the region of the South Atlantic convergence zone, which is responsible for the enhanced cloudiness and precipitation in the central and southeastern parts of Brazil during summer. The model results are compared with observational data of meteorological stations, the Global Precipitation Climatology Project (GPCP), and the South American Low-Level Jet Experiment (SALLJEX) and are discussed.
Understanding Precipitation Changes in Iberia in Early Spring: Weather Typing and Storm-Tracking Approaches
Authors: Paredes Daniel , Trigo Ricardo M. , Garcia-Herrera Ricardo , Trigo Isabel Franco
Published: March 2006

March monthly accumulated precipitation in the central and western regions of the Iberian Peninsula presents a clear continuous decline of 50% during the 1960–97 period. A finer analysis using daily data reveals that this trend is exactly confined to the month of March. However, this is merely the most visible aspect of a larger phenomenon over the North Atlantic/European sector. The European precipitation trends in March for the period 1960–2000 show a clear distribution of increasing precipitation in the northern regions (the British Isles and parts of Scandinavia) together with decreasing trends throughout the western Mediterranean Basin.

Relevant circulation changes over the North Atlantic and European sectors explain these precipitation trends. First, a regional Eulerian approach by means of a weather-type (WT) classification shows that the major rainfall contributors in March display significantly decreasing frequencies for the Iberian Peninsula, in contrast to the corresponding “wet” weather types for the U.K./Ireland sector, which display increasing frequencies. Within a larger context, a Lagrangian approach, based on the analysis of storm tracks over Europe and the North Atlantic region, reveals dramatic changes in the location of cyclones in the last four decades that coincide with the corresponding precipitation trends in Europe. The North Atlantic Oscillation is suggested to be the most important large-scale factor controlling both the circulation changes and the precipitation trends over the Euro–Atlantic area in March. Finally, the potential impact of reduced precipitation for rivers and water resources in the Iberian Peninsula is considered.
Using TRMM/TMI to Retrieve Surface Soil Moisture over the Southern United States from 1998 to 2002
Authors: Gao H. , Wood E. F. , Jackson T. J. , Drusch M. , Bindlish R.
Published: March 2006

Passive microwave remote sensing has been recognized as a potential method for measuring soil moisture. Combined with field observations and hydrological modeling brightness temperatures can be used to infer soil moisture states and fluxes in real time at large scales. However, operationally acquiring reliable soil moisture products from satellite observations has been hindered by three limitations: suitable low-frequency passive radiometric sensors that are sensitive to soil moisture and its changes; a retrieval model (parameterization) that provides operational estimates of soil moisture from top-of-atmosphere (TOA) microwave brightness temperature measurements at continental scales; and suitable, large-scale validation datasets. In this paper, soil moisture is retrieved across the southern United States using measurements from the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) X-band (10.65 GHz) radiometer with a land surface microwave emission model (LSMEM) developed by the authors. Surface temperatures required for the retrieval algorithm were obtained from the Variable Infiltration Capacity (VIC) hydrological model using North American Land Data Assimilation System (NLDAS) forcing data. Because of the limited information content on soil moisture in the observed brightness temperatures over regions characterized by heavy vegetation, active precipitation, snow, and frozen ground, quality control flags for the retrieved soil moisture are provided. The resulting retrieved soil moisture database will be available through the NASA Goddard Space Flight Center (GSFC) Distributed Active Archive Center (DAAC) at a 1/8° spatial resolution across the southern United States for the 5-yr period of January 1998 through December 2002. Initial comparisons with in situ observations obtained from the Oklahoma Mesonet resulted in seasonal correlation coefficients exceeding 0.7 for half of the time covered by the dataset. The dynamic range of the satellite-derived soil moisture dataset is considerably higher compared to the in situ data. The spatial pattern of the TMI soil moisture product is consistent with the corresponding precipitation fields.
Probabilistic Quantitative Precipitation Estimation in Complex Terrain
Authors: Clark Martyn P. , Slater Andrew G.
Published: March 2006

This paper describes a flexible method to generate ensemble gridded fields of precipitation in complex terrain. The method is based on locally weighted regression, in which spatial attributes from station locations are used as explanatory variables to predict spatial variability in precipitation. For each time step, regression models are used to estimate the conditional cumulative distribution function (cdf) of precipitation at each grid cell (conditional on daily precipitation totals from a sparse station network), and ensembles are generated by using realizations from correlated random fields to extract values from the gridded precipitation cdfs. Daily high-resolution precipitation ensembles are generated for a 300 km × 300 km section of western Colorado (dx = 2 km) for the period 1980–2003. The ensemble precipitation grids reproduce the climatological precipitation gradients and observed spatial correlation structure. Probabilistic verification shows that the precipitation estimates are reliable, in the sense that there is close agreement between the frequency of occurrence of specific precipitation events in different probability categories and the probability that is estimated from the ensemble. The probabilistic estimates have good discrimination in the sense that the estimated probabilities differ significantly between cases when specific precipitation events occur and when they do not. The method may be improved by merging the gauge-based precipitation ensembles with remotely sensed precipitation estimates from ground-based radar and satellites, or with precipitation and wind fields from numerical weather prediction models. The stochastic modeling framework developed in this study is flexible and can easily accommodate additional modifications and improvements.
The Relationship between Intermodel Differences and Surface Energy Balance Complexity in the Rhône-Aggregation Intercomparison Project
Authors: Fox S. , Pitman A. J. , Boone A. , Habets F.
Published: March 2006

Six modes of complexity of the Chameleon land surface model (CHASM) are used to explore the relationship between the complexity of the surface energy balance (SEB) formulation and the capacity of the model to explain intermodel variations in results from the Rhône-Aggregation Intercomparison Project (Rhône-AGG). At an annual time scale, differences between models identified in the Rhône-AGG experiments in the partitioning of available energy and water at the spatial scale of the Rhône Basin can be reproduced by CHASM via variations in the SEB complexity. Only two changes in the SEB complexity in the model generate statistically significant differences in the mean latent heat flux. These are the addition of a constant surface resistance to the simplest mode of CHASM and the addition of tiling and temporally and spatially variable surface resistance to produce the most complex model. Further, the only statistically significant differences in runoff occur following the addition of a constant surface resistance to the simplest mode of CHASM. As the time scale is reduced from annual to monthly, specific mechanisms begin to dominate the simulations produced by each Rhône-AGG model and introduce parameterization-specific behavior that depends on the time evolution of processes operating on longer time scales. CHASM cannot capture all this behavior by varying the SEB complexity, demonstrating the contribution to intermodel differences by hydrology and snow-related processes. Despite the increasing role of hydrology and snow in simulating processes at finer time scales, provided the constant surface resistance is included, CHASM's modes perform within the range of uncertainty illustrated by other Rhône-AGG models on seasonal and annual time scales.
Numerical Simulation of Heavy Precipitation in Northern Baja California and Southern California
Authors: Cerezo-Mota Ruth , Cavazos Tereza , Farfán Luis M.
Published: March 2006

The fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) was used to simulate the heavy-precipitation events of 6–21 January 1993 during a moderate El Niño that produced severe flooding, landslides, and the loss of many lives near the border of California and Baja California, Mexico. The mean synoptic-scale condition consisted of a strong upper-level subtropical westerly jet over the U.S.–Mexico western border and the passage of three surface fronts, along with intense low-level advection of tropical moisture and convective activity over the region. The MM5 reproduced the mean observed circulation patterns of the study period but with less intensity. During the first extreme event on 6 January, the model sounding profile in San Diego, California, was more unstable and saturated than observed, the horizontal winds were weaker in the lower troposphere, and the simulated precipitation was slightly underestimated. The model precipitation was verified with hourly and daily precipitation records in California and Baja California, respectively, and regional errors were obtained for the 16-day period. The simulation showed an improvement when the resolution increased from 90 to 30 km, but there was not a significant improvement from 30 to 10 km; however, extreme rainfall events (>10 mm day−1) were better resolved by the 10-km grid, possibly due to the finer-scale topography.
Daily Precipitation over Southern Africa: A New Resource for Climate Studies
Authors: Layberry R. , Kniveton D. R. , Todd M. C. , Kidd C. , Bellerby T. J.
Published: March 2006

This paper describes a new high-resolution multiplatform multisensor satellite rainfall product for southern Africa covering the period 1993–2002. The microwave infrared rainfall algorithm (MIRA) employed to generate the rainfall estimates combines high spatial and temporal resolution Meteosat infrared data with infrequent Special Sensor Microwave Imager (SSM/I) overpasses. A transfer function relating Meteosat thermal infrared cloud brightness temperatures to SSM/I rainfall estimates is derived using collocated data from the two instruments and then applied to the full coverage of the Meteosat data. An extensive continental-scale validation against synoptic station data of both the daily MIRA precipitation product and a normalized geostationary IR-only Geostationary Operational Environmental Satellite (GOES) precipitation index (GPI) demonstrates a consistent advantage using the former over the latter for rain delineation. Potential uses for the resulting high-resolution daily rainfall dataset are discussed.
Neural Error Regression Diagnosis (NERD): A Tool for Model Bias Identification and Prognostic Data Assimilation
Authors: Abramowitz Gab , Gupta Hoshin , Pitman Andy , Wang Yingping , Leuning Ray , Cleugh Helen , Hsu Kuo-lin
Published: March 2006

Data assimilation in the field of predictive land surface modeling is generally limited to using observational data to estimate optimal model states or restrict model parameter ranges. To date, very little work has attempted to systematically define and quantify error resulting from a model's inherent inability to simulate the natural system. This paper introduces a data assimilation technique that moves toward this goal by accounting for those deficiencies in the model itself that lead to systematic errors in model output. This is done using a supervised artificial neural network to “learn” and simulate systematic trends in the model output error. These simulations in turn are used to correct the model's output each time step. The technique is applied in two case studies, using fluxes of latent heat flux at one site and net ecosystem exchange (NEE) of carbon dioxide at another. Root-mean-square error (rmse) in latent heat flux per time step was reduced from 27.5 to 18.6 W m−2 (32%) and monthly from 9.91 to 3.08 W m−2 (68%). For NEE, rmse per time step was reduced from 3.71 to 2.70 μmol m−2 s−1 (27%) and annually from 2.24 to 0.11 μmol m−2 s−1 (95%). In both cases the correction provided significantly greater gains than single criteria parameter estimation on the same flux.
Seasonal Variations in Terrestrial Water Storage for Major Midlatitude River Basins
Authors: Hirschi Martin , Seneviratne Sonia I. , Schär Christoph
Published: March 2006

This paper presents a new diagnostic dataset of monthly variations in terrestrial water storage for 37 midlatitude river basins in Europe, Asia, North America, and Australia. Terrestrial water storage is the sum of all forms of water storage on land surfaces, and its seasonal and interannual variations are in principle determined by soil moisture, groundwater, snow cover, and surface water. The dataset is derived with the combined atmospheric and terrestrial water-balance approach using conventional streamflow measurements and atmospheric moisture convergence data from the ECMWF 40-yr Re-Analysis (ERA-40). A recent study for the Mississippi River basin (Seneviratne et al. 2004) has demonstrated the validity of this diagnostic approach and found that it agreed well with in situ observations in Illinois. The present study extends this previous analysis to other regions of the midlatitudes.

A systematic analysis is presented of the slow drift that occurs with the water-balance approach. It is shown that the drift not only depends on the size of the catchment under consideration, but also on the geographical region and the underlying topography. The drift is in general not constant in time, but artificial inhomogeneities may result from changes in the global observing system used in the 44 yr of the reanalysis. To remove this time-dependent drift, a simple high-pass filter is applied. Validation of the results is conducted for several catchments with an appreciable coverage of in situ soil moisture and snow cover depth observations in the former Soviet Union, Mongolia, and China. Although the groundwater component is not accounted for in these observations, encouraging correlations are found between diagnostic and in situ estimates of terrestrial water storage, both for seasonal and interannual variations. Comparisons conducted against simulated ERA-40 terrestrial water storage variations suggest that the reanalysis substantially underestimates the amplitude of the seasonal cycle.

The basin-scale water-balance (BSWB) dataset is available for download over the Internet. It constitutes a useful tool for the validation of climate models, large-scale land surface data assimilation systems, and indirect observations of terrestrial water storage variations.
Evaluation of RadVil, a Radar-Based Very Short-Term Rainfall Forecasting Model
Authors: Boudevillain Brice , Andrieu Hervé , Chaumerliac Nadine
Published: March 2006

A very short-term rainfall forecast model is tested on actual radar data. This model, called RadVil, takes advantages of voluminal radar data through vertically integrated liquid (VIL) water content measurements. The model is tested on a dataset collected during the intensive observation period of the Mesoscale Alpine Program (MAP). Five rain events have been studied during this experiment. The results confirm the interest of VIL for quantitative precipitation forecasting at very short lead time. The evaluation is carried out in qualitative and quantitative ways according to Nash and correlation criteria on forecasting times ranging from 10 to 90 min and spatial scales from 4 to 169 km2. It attempts to be consistent with the hydrological requirements concerning the rainfall forecasting, for instance, by taking account of the relation between the catchments' size, their response time, and the required forecasting time. Several versions of RadVil corresponding to several VIL measurement strategies have been tested. Improvements offered by RadVil depend on meteorological situations. They are related to the spatial and temporal evolution of the VIL field structure and the validity of the models assumptions. Finally, a relationship between the temporal structure of VIL fields and forecast quality is established.
The Use of an Automated Nowcasting System to Forecast Flash Floods in an Urban Watershed
Authors: Sharif Hatim O. , Yates David , Roberts Rita , Mueller Cynthia
Published: March 2006

Flash flooding represents a significant hazard to human safety and a threat to property. Simulation and prediction of floods in complex urban settings requires high-resolution precipitation estimates and distributed hydrologic modeling. The need for reliable flash flood forecasting has increased in recent years, especially in urban communities, because of the high costs associated with flood occurrences. Several storm nowcast systems use radar to provide quantitative precipitation forecasts that can potentially afford great benefits to flood warning and short-term forecasting in urban settings. In this paper, the potential benefits of high-resolution weather radar data, physically based distributed hydrologic modeling, and quantitative precipitation nowcasting for urban hydrology and flash flood prediction were demonstrated by forcing a physically based distributed hydrologic model with precipitation forecasts made by a convective storm nowcast system to predict flash floods in a small, highly urbanized catchment in Denver, Colorado. Two rainfall events on 5 and 8 July 2001 in the Harvard Gulch watershed are presented that correspond to times during which the storm nowcast system was operated. Results clearly indicate that high-resolution radar-rainfall estimates and advanced nowcasting can potentially lead to improvements in flood warning and forecasting in urban watersheds, even for short-lived events on small catchments. At lead times of 70 min before the occurrence of peak discharge, forecast accuracies of approximately 17% in peak discharge and 10 min in peak timing were achieved for a 10 km2 highly urbanized catchment.
Estimating the Long-Term Hydrological Budget over Heterogeneous Surfaces
Authors: Song J. , Wesely M. L. , Holdridge D. J. , Cook D. R. , Klazura J.
Published: March 2006

Estimates of the hydrological budget in the Walnut River Watershed (WRW; ∼5000 km2) of southern Kansas were made with a parameterized subgrid-scale surface (PASS) model for the period 1996–2002. With its subgrid-scale distribution scheme, the PASS model couples surface meteorological observations with satellite remote sensing data to update root-zone available moisture and to simulate surface evapotranspiration rates at high resolution over extended areas. The PASS model is observationally driven, making use of extensive parameterizations of surface properties and processes. Heterogeneities in surface conditions are spatially resolved to an extent determined primarily by the satellite data pixel size. The purpose of modeling the spatial and interannual variability of water budget components at the regional scale is to evaluate the PASS model's ability to bridge a large grid cell of a climate model with its subgrid-scale variation. Modeled results indicate that annual total evapotranspiration at the WRW is about 66%–88% of annual precipitation—reasonable values for southeastern Kansas—and that it varies spatially and temporally. Seasonal distribution of precipitation plays an important role in evapotranspiration estimates. Comparison of modeled runoff with stream gauge measurements demonstrated close agreement and verified the accuracy of modeled evapotranspiration at the regional scale. In situ measurements of energy fluxes compare favorably with the modeled values for corresponding grid cells, and measured surface soil moisture corresponds with modeled root-zone available moisture in terms of temporal variability despite very heterogeneous surface conditions. With its ability to couple remote sensing data with surface meteorology data and its computational efficiency, PASS is easily used for modeling surface hydrological components over an extended region and in real time. Thus, it can fill a gap in evaluations of climate model output using limited field observations.
Communication Proficiency and Future Training Needs of the Female Professional: Self-Assessment vs. Supervisors' Evaluations
Authors: Staley Constance Courtney , Shockley-Zalabak Pamela
Published: March 2006

This research investigates the perceptions supervisors have of their female employees' communication proficiency, assuming, as has been repeatedly discussed in the literature, that communication skills are a critical component of organizational effectiveness and promotability. In particular, comparisons were made between evaluations of supervisors on a variety of communication competencies and female employees' self-evaluations. Similar comparisons were made between the supervisors' assessment of the importance of future training in each skill and the females' own assessment of their need for future training. While this research is exploratory in nature, the results demonstrate striking and potentially important differences between the perceptions of female professionals and their supervisors.
Professional Models vs. Patient Models in Rehabilitation after Heart Attack
Authors: Bar-On Dan
Published: March 2006

Two problems were identified in the professional treatment of rehabilitation after acute myocardial infarction (MI): (1) “Tower of Babel”—the physician, the social worker, and the psychologist use competing models to diagnose, intervene in, and evaluate a rehabilitation process, while each of them accounts for a fraction of the variance of the rehabilitation outcomes. (2) Asymmetry of relations-all three models overlook the possibility that the patients themselves have their own models, and that these models should be considered in the rehabilitation process. In a recent study, 89 male patients, ages 34-60, admitted to the Intensive Coronary Care Unit of the Soroka Medical Center in the south of Israel, were interviewed after their first acute MI. Their choices from a special Q-sort were factor-analyzed, and five consistent models were identified. Two of these patient models accounted for 35% of the variance in a regression analysis of the rehabilitation measures (return to work and physical and sexual functioning) after half a year. Only one of the patient models was based on a professional model. The physicians' model, based predominantly on physical cues, did not account significantly for the rehabilitation measures. Furthermore, when interviewed, most of the physicians were not aware that their patients had such models, and that they should be considered in the rehabilitation process. The results call for a redefinition of the social scientists' role in this medical setting. A system approach is proposed as a possible solution for the “Tower of Babel” problem and the asymmetry of relations between the professionals and their patients.