bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioformulation of Burkholderia sp. MSSP with a multispecies consortium for growth promotion of Cajanus cajan
Authors: Pandey Piyush , Maheshwari D.K.
Published: May 2007

The present work was undertaken to formulate an effective bioformulation using Burkholderia sp. strain MSSP, a known plant-growth-promoting rhizobacterium. MSSP was tagged with the reporter gene of green fluorescent protein (gfp) to monitor its population in cost-effective solid carriers, including sugarcane–bagasse, sawdust, cocoa peat, rice husk, wheat bran, charcoal, and rock phosphate, and paneer–whey as liquid carrier. Physical and chemical properties of different low-cost carrier materials were studied. The viability of the green fluorescent tagged variant of MSSP was estimated in different sterile carrier materials. Whey and wheat bran proved to be efficient carrier materials for the bioformulation. Sawdust, rock phosphate, rice husk, and cocoa peat were average, while charcoal and sugarcane–bagasse proved to be inferior carriers. The viability of strain MSSP was also assessed in wheat bran and whey-based consortium, having three other bacterial strains, namely Sinorhizobium meliloti PP3, Rhizobium leguminosarum Pcc, and Bacillus sp. strain B1. Presence of other plant-growth-promoting bacteria did not have any detrimental effect on the viability of MSSP. Efficiency of the wheat-bran-based multispecies consortium was studied on the growth of pigeonpea in field conditions. A considerable increase in plant biomass, nodule number and weight, and number of pods was recorded as compared with individual trials and with the control.
Gene cloning and heterologous expression of a serine protease fromStreptomyces fradiaevar.k11
Authors: Meng Kun , Li Jiang , Cao Yanan , Shi Pengjun , Wu Bo , Han Xiaoyu , Bai Yingguo , Wu Ningfeng , Yao Bin
Published: May 2007

The gene sfp1, which encodes a predicted serine proteinase designated SFP1, was isolated by the screening of a gene library of the feather-degrading strain Streptomyces fradiae var.k11. The open reading frame of sfp1 encodes a protein of 454 amino acids with a calculated molecular mass of 46.19 kDa. Sequence analysis reveals that SFP1 possesses a typical pre-pro-mature organization that consists of a signal sequence, an N-terminal propeptide region, and a mature proteinase domain. The pre-enzyme of SFP1 was expressed in Escherichia coli and consequently purified. The 25.6 kDa fraction with protease activity separated by gel filtration chromatography indicated that the mature enzyme of SFP1 was formed by autolysis of the propeptide after its expression. The purified SFP1 is active under a broad range of pH and temperature. SFP1 has pH and temperature optima of pH 8.5 and 65 °C for its caseinolytic activity and pH 9 and 62 °C for its keratinolytic activity. SFP1 was sharply inhibited by the serine proteinase inhibitor phenylmethyl sulfonyl fluoride and exhibited a good stability to solvents, detergents, and salts. Comparison of the protease activity of SFP1 with other commercial proteases indicates that SFP1 has a considerable caseinolytic and keratinolytic activity as does proteinase K.
INTERMODULATION IN MICROWAVE RESONATORS ON THE BASIS OF HIGH-TEMPERATURE SUPERCONDUCTORS
Authors: STANCA IOAN
Published: May 2007

This paper is no longer available. Please contact mplb@wspc.com
Mitochondrial nitric oxide in the signaling of cell integrated responses
Authors: Carreras Maria Cecilia , Poderoso Juan José
Published: May 2007

Mitochondria are the specialized organelles for energy metabolism, but, as a typical example of system biology, they also activate a multiplicity of pathways that modulate cell proliferation and mitochondrial biogenesis or oppositely promote cell arrest and programmed cell death by a limited number of oxidative or nitrosative reactions. These reactions are influenced by matrix nitric oxide (NO) steady-state concentration, either from local production or by gas diffusion to mitochondria from the canonical sources. Likewise, in a range of ∼30–200 nM, NO turns mitochondrial O2 utilization down by binding to cytochrome oxidase and elicits a burst of superoxide anion and hydrogen peroxide that diffuses outside mitochondria. Depending on NO levels and antioxidant defenses, more or less H2O2 accumulates in cytosol and nucleus, and the resulting redox grading contributes to dual activation of proliferating and proapoptotic cascades, like ERK1/2 or p38 MAPK. Moreover, these sequential activating pathways participate in rat liver and brain development and in thyroid modulation of mitochondrial metabolism and contribute to hypothyroid phenotype through complex I nitration. On the contrary, lack of NO disrupts pathways like S-nitrosylation or H2O2 production and likewise is a gateway to disease in amyotrophic lateral sclerosis with superoxide dismutase 1 mutations or to cancer proliferation.
LPA2 (EDG4) mediates Rho-dependent chemotaxis with lower efficacy than LPA1 (EDG2) in breast carcinoma cells
Authors: Chen Min , Towers L. Nicole , O'Connor Kathleen L.
Published: May 2007

Lysophosphatidic acid (LPA) acts via binding to specific G protein-coupled receptors and has been implicated in the biology of breast cancer. Here, we characterize LPA receptor expression patterns in common established breast cancer cell lines and their contribution to breast cancer cell motility. By measuring expression of the LPA receptors LPA1, LPA2, and LPA3 with real-time quantitative PCR, we show that the breast cancer cell lines tested can be clustered into three main groups: cells that predominantly express LPA1 (BT-549, Hs578T, MDA-MB-157, MDA-MB-231, and T47D), cells that predominantly express LPA2 (BT-20, MCF-7, MDA-MB-453, and MDA-MB-468), and a third group that shows comparable expression level of these two receptors (MDA-MB-175 and MDA-MB-435). LPA3 expression was detected primarily in MDA-MB-157 cells. Using a Transwell chemotaxis assay to monitor dose response, we find that cells predominantly expressing LPA1 have a peak migration rate at 100 nM LPA that drops off dramatically at 1 μM LPA, whereas cells predominantly expressing LPA2 show the peak migration rate at 1 μM LPA, which remains high at 10 μM. Using BT-20 cells, LPA2-specific small interfering RNA, and C3 exotransferase, we demonstrate that LPA2 can mediate LPA-stimulated cell migration and activation of the small GTPase RhoA. Using LPA2 small interfering RNA, exogenous expression of LPA1, and treatment with Ki16425 LPA receptor antagonist in the BT-20 cells, we further find that LPA1 and LPA2 cooperate to promote LPA-stimulated chemotaxis. In summary, our results suggest that the expression of both LPA1 and LPA2 may contribute to chemotaxis and may permit cells to respond optimally to a wider range of LPA concentrations, thus revealing a new aspect of LPA signaling.
Immunofluorescence localization of the receptor Mas in cardiovascular-related areas of the rat brain
Authors: Becker Lenice K. , Etelvino Gisele M. , Walther Thomas , Santos Robson A. S. , Campagnole-Santos Maria J.
Published: May 2007

The G protein-coupled receptor Mas was recently described as an angiotensin-(1–7) [ANG-(1–7)] receptor. In the present study we evaluated the anatomical localization of Mas using immunofluorescence in the central nervous system of adult male Wistar rats. An abundant labeling was found in the hippocampus, amigdala, anterodorsal thalamic nucleus, cortex, and hypoglossal nucleus. More importantly, a dense ANG-(1–7) receptor Mas immunoreactivity was observed in cardiovascular-related areas of the medulla and forebrain, shown in several previous studies as sites for the action of ANG-(1–7) in the brain. A strong staining was found in the nucleus of the solitary tract, caudal and rostral ventrolateral medulla, inferior olive, parvo and magnocellular portions of the paraventricular hypothalamic nucleus, supraoptic nucleus, and lateral preoptic area. Furthermore, Mas staining was predominantly present in neurons. At the medullary sites, a specific and high-intensity binding for rhodamine-ANG-(1–7) was also shown. The specific ANG-(1–7) binding was completely displaced by the anti-Mas antibody or by the ANG-(1–7) antagonist, A-779. The data presented provide the first anatomical basis for the physiological role of ANG-(1–7)/Mas axis in the modulation of different cardiovascular functions and give new insights for clarifying the role of ANG-(1–7) in the central nervous system.
Angiotensin-(1–7) stimulates the phosphorylation of JAK2, IRS-1 and Akt in rat heart in vivo: role of the AT1 and Mas receptors
Authors: Giani Jorge F. , Gironacci Mariela M. , Muñoz Marina C. , Peña Clara , Turyn Daniel , Dominici Fernando P.
Published: May 2007

Angiotensin (ANG) II exerts a negative modulation on insulin signal transduction that might be involved in the pathogenesis of hypertension and insulin resistance. ANG-(1–7), an endogenous heptapeptide hormone formed by cleavage of ANG I and ANG II, counteracts many actions of ANG II. In the current study, we have explored the role of ANG-(1–7) in the signaling crosstalk that exists between ANG II and insulin. We demonstrated that ANG-(1–7) stimulates the phosphorylation of Janus kinase 2 (JAK2) and insulin receptor substrate (IRS)-1 in rat heart in vivo. This stimulating effect was blocked by administration of the selective ANG type 1 (AT1) receptor blocker losartan. In contrast to ANG II, ANG-(1–7) stimulated cardiac Akt phosphorylation, and this stimulation was blunted in presence of the receptor Mas antagonist A-779 or the phosphatidylinositol 3-kinase (PI3K) inhibitor wortmannin. The specific JAK2 inhibitor AG-490 blocked ANG-(1–7)-induced JAK2 and IRS-1 phosphorylation but had no effect on ANG-(1–7)-induced phosphorylation of Akt, indicating that activation of cardiac Akt by ANG-(1–7) appears not to involve the recruitment of JAK2 but proceeds through the receptor Mas and involves PI3K. Acute in vivo insulin-induced cardiac Akt phosphorylation was inhibited by ANG II. Interestingly, coadministration of insulin with an equimolar mixture of ANG II and ANG-(1–7) reverted this inhibitory effect. On the basis of our present results, we postulate that ANG-(1–7) could be a positive physiological contributor to the actions of insulin in heart and that the balance between ANG II and ANG-(1–7) could be relevant for the association among insulin resistance, hypertension, and cardiovascular disease.
Dyspnea and Symptom Amplification in Asthma
Authors: Lavietes Marc H. , Ameh Joseph , Cherniack Neil S.
Published: May 2007

Background: The severity of a patient’s asthma and the intensity with which he describes his dyspnea do not correlate. Objectives: There is an indirect relationship between airway function in asthma and the intensity of dyspnea; this relationship is found only when the measure of a patient’s general tendency to exaggerate the intensity of any somatic symptom is considered simultaneously. Methods: Lung function, including spirometry (forced expiratory volume in 1 s, FEV1) and plethysmography (airway resistance, Raw), dyspnea (Borg scale score) and the tendency to exaggerate (the somatosensory amplification scale score, SSAS) have been quantified in 42 stable asthmatic patients. Results: There was no correlation between the Borg score and any spirometric or plethysmographic measure in these subjects. By contrast, there was a moderate correlation between the Borg score and the SSAS (r = 0.36, p = 0.03). However, when FEV1 or Raw (abscissa) and Borg scores (ordinate) were converted to residuals, there was a moderate correlation between the residuals and the SSAS score (for FEV1, r = 0.33 and p = 0.05; for Raw, r = –0.36 and p = 0.03). Conclusion: A physician may make a reasonable estimate of an asthmatic patient’s lung function from the intensity of his complaint only if he – the physician – considers the patient’s tendency to symptom amplify as well.
Effect of Cell-Based Intercellular Delivery of Transcription Factor GATA4 on Ischemic Cardiomyopathy
Authors: Bian Jing , Popović Zoran B. , Benejam Carlos , Kiedrowski Matthew , Rodriguez L. Leonardo , Penn Marc S.
Published: May 2007

Recent loss-of-function studies highlight the importance of the transcription factor GATA4 in the myocardial response to injury in the adult heart. However, the potential effects of gain-in-function of GATA4 overexpression, and transcription factors in general, is hindered by the fact that transcription factors are neither secreted nor taken up by cells. Chimeric proteins incorporating motifs of cell-penetrating proteins are secreted from cells and internalized by surrounding cells. We engineered a chimeric protein consisting of GATA4 and the cell-penetrating protein VP22. Cardiac fibroblasts stably transfected with the GATA4:VP22, GFP:VP22, or green fluorescent protein (GFP) constructs were transplanted into Lewis rats 1 month after left anterior descending ligation. GATA4:VP22 expression in the border zone was associated with increased cardiac myosin expression and cardiac myocyte size (30 μm versus 19 μm,
P
<0.01). Compared with the GFP:VP22 control group, 6 weeks after cardiac fibroblast transplantation (10 weeks after myocardial infarction), animals that received GATA4:VP22-expressing cardiac fibroblasts demonstrated increased cardiac function and less negative remodeling. These data demonstrate a novel strategy for transcription factor delivery to injured myocardium and indicate that the delivery of GATA4 locally to the infarct border zone induces multiple local effects in the border zone cardiac myocytes resulting in beneficial ventricular remodeling and improved global left ventricular function.
Endothelial Outgrowth Cells Are Not Derived From CD133
+
Cells or CD45
+
Hematopoietic Precursors
Authors: Timmermans Frank , Van Hauwermeiren Filip , De Smedt Magda , Raedt Robrecht , Plasschaert Frank , De Buyzere Marc L. , Gillebert Thierry C. , Plum Jean , Vandekerckhove Bart
Published: May 2007

Objective—

Two types of endothelial progenitor cells (EPCs), early EPCs and late EPCs (also called endothelial outgrowth cells [EOCs]), were described in vitro previously. In this report, we dissect the phenotype of the precursor(s) that generate these cell types with focus on the markers CD34, CD133, and vascular endothelial growth factor receptor-2 (VEGFR2) that have been used to identify putative circulating endothelial precursors. We also included CD45 in the analysis to assess the relation between CD34
+
hematopoietic progenitors (HPC), CD34
+
endothelial precursors, and both in vitro generated EPC types. Addressing this issue might lead to a better understanding of the lineage and phenotype of the precursor(s) that give rise to both cell types in vitro and may contribute to a consensus on their flowcytometric enumeration.

Methods and Results—

Using cell sorting of human cord blood (UCB) and bone marrow (BM) cells, we demonstrate that EOC generating precursors are confined to a small CD34
+
CD45
−
cell fraction, but not to the CD34
+
CD45
+
HPC fraction, nor any other CD45
+
subpopulation. CD34
+
CD45
+
HPC generated monocytic cells that displayed characteristics typical for early EPCs. Phenotypic analysis showed that EOC generating CD34
+
CD45
−
cells express VEGFR2 but not CD133, whereas CD34
+
CD45
+
HPC express CD133 as expected, but not VEGFR2.

Conclusion—

EOCs are not derived from CD133
+
cells or CD45
+
hematopoietic precursors.
Cyclin A2 Induces Cardiac Regeneration After Myocardial Infarction and Prevents Heart Failure
Authors: Cheng Richard K. , Asai Tomohiro , Tang Haiying , Dashoush Nurin H. , Kara Rina J. , Costa Kevin D. , Naka Yoshifumi , Wu Ed X. , Wolgemuth Debra J. , Chaudhry Hina W.
Published: May 2007

Mammalian myocardial infarction is typically followed by scar formation with eventual ventricular dilation and heart failure. Here we present a novel model system in which mice constitutively expressing cyclin A2 in the myocardium elicit a regenerative response after infarction and exhibit significantly limited ventricular dilation with sustained and remarkably enhanced cardiac function. New cardiomyocyte formation was noted in the infarcted zones as well as cell cycle reentry of periinfarct myocardium with an increase in DNA synthesis and mitotic indices. The enhanced cardiac function was serially assessed over time by MRI. Furthermore, the constitutive expression of cyclin A2 appears to augment endogenous regenerative mechanisms via induction of side population cells with enhanced proliferative capacity. The ability of cultured transgenic cardiomyocytes to undergo cytokinesis provides mechanistic support for the regenerative capacity of cyclin A2.
Prognosis and Safety of Anticoagulation in Intracranial Artery Dissections in Adults
Authors: Metso Tiina M. , Metso Antti J. , Helenius Johanna , Haapaniemi Elena , Salonen Oili , Porras Matti , Hernesniemi Juha , Kaste Markku , Tatlisumak Turgut
Published: May 2007

Background and Purpose—

To characterize different forms of intracranial artery dissections (IADs), and to test the assumption that IADs are frequently associated with subarachnoid hemorrhage (SAH) and poor outcome, and that anticoagulant therapy is contraindicated in these patients.

Methods—

We studied 81 consecutive non-SAH IAD patients and 22 IAD patients with SAH, diagnosed between 1994 and 2004 and 1998 and 2004, respectively, and treated the former patients immediately with heparin, followed with at least 3 months of warfarin. Outcomes were recorded at 3 months.

Results—

Approximately one-third of all cervicocephalic artery dissections were identifiably either completely located intracranially or extended into the intracranial space. At 3 months, 64 of the 81 non-SAH patients (79%) had a favorable outcome (modified Rankin Scale, 0 to 2); 1 patient died of brain infarction in the acute stage. Only 1 aneurysm developed during follow-up in the non-SAH group, and no intracranial bleeding was observed during anticoagulant treatment. Those presenting with SAH formed ≈25% of all IADs, and 21 cases out of 22 (95%) were associated with ruptured fusiform dissecting aneurysm. This latter group displayed significantly worse outcomes: 7 died, and only 7 had modified Rankin Scale 0 to 2 at 3 months.

Conclusions—

Our results provide important information for clinical practice. IADs appear to polarize into 2 groups: (1) nonaneurysmatic IADs presenting without SAH that are associated with favorable outcomes and safe anticoagulant therapy; and (2) aneurysmatic IADs, characterized by SAH and poorer prognosis. Literature on IADs may have been biased toward group 2.
The Changing Metabolism of Cities
Authors: Kennedy Christopher , Cuddihy John , Engel‐Yan Joshua
Published: May 2007

Data from urban metabolism studies from eight metropolitan regions across five continents, conducted in various years since 1965, are assembled in consistent units and compared. Together with studies of water, materials, energy, and nutrient flows from additional cities, the comparison provides insights into the changing metabolism of cities. Most cities studied exhibit increasing per capita metabolism with respect to water, wastewater, energy, and materials, although one city showed increasing efficiency for energy and water over the 1990s. Changes in solid waste streams and air pollutant emissions are mixed.

The review also identifies metabolic processes that threaten the sustainability of cities. These include altered ground water levels, exhaustion of local materials, accumulation of toxic materials, summer heat islands, and irregular accumulation of nutrients. Beyond concerns over the sheer magnitudes of resource flows into cities, an understanding of these accumulation or storage processes in the urban metabolism is critical. Growth, which is inherently part of metabolism, causes changes in water stored in urban aquifers, materials in the building stock, heat stored in the urban canopy layer, and potentially useful nutrients in urban waste dumps.

Practical reasons exist for understanding urban metabolism. The vitality of cities depends on spatial relationships with surrounding hinterlands and global resource webs. Increasing metabolism implies greater loss of farmland, forests, and species diversity; plus more traffic and more pollution. Urban policy makers should consider to what extent their nearest resources are close to exhaustion and, if necessary, appropriate strategies to slow exploitation. It is apparent from this review that metabolism data have been established for only a few cities worldwide, and interpretation issues exist due to lack of common conventions. Further urban metabolism studies are required.
Service Sector Metabolism: Accounting for Energy Impacts of the Montjuic Urban Park in Barcelona
Authors: Oliver‐Solà Jordi , Núñez Montserrat , Gabarrell Xavier , Boada Martí , Rieradevall Joan
Published: May 2007

This article evaluates, from an industrial ecology (IE) perspective, the energy performance of the services inside an urban system and determines their global environmental impact. Additionally, this study determines which are the most energy demanding services and the efficiency of their energy use per visitor and per surface area unit.

The urban system under study is the Montjuïc urban park in Barcelona, Catalonia, Spain, which can be considered a services system. In this case study we distinguished the different patterns of consumption among the service fields and, by studying each field individually, found the most efficient facilities and identified the most critical services based on energy use per visitor or per square meter. These findings are based on the use of energy flow accounting (EFA), life‐cycle assessment (LCA), and the energy footprint to analyze the Park's technical energy consumption.

Electricity consumption represents nearly 70% of the total energy consumed by the services at Montjuïc Park. The forest surface area required to absorb the CO2‐equivalent emissions produced by the life cycle of the energy consumed at Montjuïc Park represents 12.2 times the Park's surface area. We conclude this article by proposing the incorporation of the methods of IE within the study of parks containing multiple services to improve energy management, and as a result, to raise the global environmental performance of the service sector.
Integrating Global Environmental Concerns into Urban Management: The Scale and Readiness Arguments
Authors: Bai Xuemei
Published: May 2007

Due to the growing numbers of cities and urban residents, cities have increasingly contributed to global environmental issues. Many studies have pointed out that the city administrative level is a crucial level at which to address global issues. Nevertheless, integrating global concerns into local management remains a difficult task for the majority of cities. Building on existing theoretical and empirical studies, this article explores the obstacles that impede cities from addressing global environmental concerns, the opportunities for removing the obstacles, and strategies for bringing global issues onto the local level. Many of the obstacles are reflections of contradictory perceptions, concerns, interests, and priorities, which are presented in the form of two arguments, namely the scale argument and the readiness argument, in this article. The close linkages between global and local environmental issues and the potential economic benefits arising from addressing global concerns at the local level may provide opportunities and incentives for cities to take action earlier. The author further argues that although empirical studies in developed cities suggest that the most effective way to get municipal governments to address global concerns is by not talking about the “global,” an overly localized policy might not always result in a net gain in a developing city setting.
A Spatial Analysis of Residential Greenhouse Gas Emissions in the Toronto Census Metropolitan Area
Authors: VandeWeghe Jared R. , Kennedy Christopher
Published: May 2007

Residential greenhouse gas (GHG) emissions in the Toronto Census Metropolitan Area are spatially analyzed to determine the impact of urban form on emission‐causing activities. The key finding is that over the entire region, emissions from private auto use are on par with those from fuel use for building heating. Once beyond the transit‐intensive central core, private auto emissions surpass the emissions from building operations. Variation in total auto‐ and building‐related emissions is quite significant between census tracts, ranging from 3.1 to 13.1 tonnes of carbon dioxide equivalents per year. Of all tracts, the top ten in terms of GHG emission are located in the lower‐density suburbs, and their high emissions were largely due to private auto use.
Urbanization in Southeast Asia: Assessing Policy Process and Progress toward Sustainability
Authors: Ooi Giok Ling
Published: May 2007

In investigating the relationship between urbanization and sustainability in cities of developing countries, many researchers have looked to rising incomes as a driver for environmental improvement. This article challenges the transition and evolutionary models of urban environmental development that suggest that as cities grow in per capita income, their local environmental problems will diminish. The transition model is outcomes‐based, and a competing model based on greater attention to participation in setting sustainability goals and assessing the progress toward those goals is presented.

Consensus on appropriate sustainability indicators is a key element, albeit a challenging one, in the task of pursuing urban sustainability. This is due to the contested nature of the concept of sustainability and also the fact that much of the work done on sustainability has been conducted among countries or on a national scale. A brief review of health, urban transport, air quality, and sewerage indicators suggests that cities do not necessarily see more progress as the per capita income increases. Low‐income cities in Southeast Asia that are performing well are likely to see a deterioration in standards with rapid economic and population growth.
Synthesis of Results from the North American Monsoon Experiment (NAME) Process Study
Authors: Higgins Wayne , Gochis David
Published: May 2007

An international team of scientists from the United States, Mexico, and Central America carried out a major field campaign during the summer of 2004 to develop an improved understanding of the North American monsoon system leading to improved precipitation forecasts. Results from this campaign, which is the centerpiece of the North American Monsoon Experiment (NAME) Process Study, are reported in this issue of the Journal of Climate. In addition to a synthesis of key findings, this brief overview article also raises some important unresolved issues that require further attention. More detailed background information on NAME, including motivating science questions, where NAME 2004 was conducted, when, and the experimental design, was published previously by Higgins et al.
Radar-Observed Characteristics of Precipitating Systems during NAME 2004
Authors: Lang Timothy J. , Ahijevych David A. , Nesbitt Stephen W. , Carbone Richard E. , Rutledge Steven A. , Cifelli Robert
Published: May 2007

A multiradar network, operated in the southern Gulf of California (GoC) region during the 2004 North American Monsoon Experiment, is used to analyze the spatial and temporal variabilities of local precipitation. Based on the initial findings of this analysis, it is found that terrain played a key role in this variability, as the diurnal cycle was dominated by convective triggering during the afternoon over the peaks and foothills of the Sierra Madre Occidental (SMO). Precipitating systems grew upscale and moved WNW toward the gulf. Distinct precipitation regimes within the monsoon are identified. The first, regime A, corresponded to enhanced precipitation over the southern portions of the coast and GoC, typically during the overnight and early morning hours. This was due to precipitating systems surviving the westward trip (∼7 m s−1; 3–4 m s−1 in excess of steering winds) from the SMO after sunset, likely because of enhanced environmental wind shear as diagnosed from local soundings. The second, regime B, corresponded to the significant northward/along-coast movement of systems (∼10 m s−1; 4–5 m s−1 in excess of steering winds) and often overlapped with regime A. The weak propagation is explainable by shallow–weak cold pools. Reanalysis data suggest that tropical easterly waves were associated with the occurrence of disturbed regimes. Gulf surges occurred during a small subset of these regimes, so they played a minor role during 2004. Mesoscale convective systems and other organized systems were responsible for most of the rainfall in this region, particularly during the disturbed regimes.
Long-Term Climate and Derived Surface Hydrology and Energy Flux Data for Mexico: 1925–2004
Authors: Zhu Chunmei , Lettenmaier Dennis P.
Published: May 2007

Studying the role of land surface conditions in the Mexican portion of the North American monsoon system (NAMS) region has been a challenge due to the paucity of long-term observations. A long-term gridded observation-based climate dataset suitable for forcing land surface models, as well as model-derived land surface states and fluxes for a domain consisting of all of Mexico, is described. The datasets span the period of January 1925–October 2004 at 1/8° spatial resolution at a subdaily (3 h) time step. The simulated runoff matches the observations plausibly over most of the 14 small river basins spanning all of Mexico, which suggests that long-term mean evapotranspiration is realistically reproduced. On this basis, and given the physically based model parameterizations of soil moisture and energy fluxes, the other surface fluxes and state variables such as soil moisture should be represented reasonably. In addition, a comparison of the surface fluxes from this study is performed with North American Regional Reanalysis (NARR) data on a seasonal mean basis. The results indicate that downward shortwave radiation is generally smaller than in the NARR data, especially in summer. Net radiation, on the other hand, is somewhat larger in the Variable Infiltration Capacity (VIC) hydrological model than in the NARR data for much of the year over much of the domain. The differences in radiative and turbulent fluxes are attributed to (i) the parameterization used in the VIC forcings for solar and downward longwave radiation, which links them to the daily temperature and temperature range, and (ii) differences in the land surface parameterizations used in VIC and the NCEP–Oregon State University–U.S. Air Force–NWS/Hydrologic Research Lab (Noah) land scheme used in NARR.
Seasonal Shifts in the North American Monsoon
Authors: Grantz Katrina , Rajagopalan Balaji , Clark Martyn , Zagona Edith
Published: May 2007

Analysis is performed on the spatiotemporal attributes of North American monsoon system (NAMS) rainfall in the southwestern United States. Trends in the timing and amount of monsoon rainfall for the period 1948–2004 are examined. The timing of the monsoon cycle is tracked by identifying the Julian day when the 10th, 25th, 50th, 75th, and 90th percentiles of the seasonal rainfall total have accumulated. Trends are assessed using the robust Spearman rank correlation analysis and the Kendall–Theil slope estimator. Principal component analysis is used to extract the dominant spatial patterns and these are correlated with antecedent land–ocean–atmosphere variables. Results show a significant delay in the beginning, peak, and closing stages of the monsoon in recent decades. The results also show a decrease in rainfall during July and a corresponding increase in rainfall during August and September. Relating these attributes of the summer rainfall to antecedent winter–spring land and ocean conditions leads to the proposal of the following hypothesis: warmer tropical Pacific sea surface temperatures (SSTs) and cooler northern Pacific SSTs in the antecedent winter–spring leads to wetter than normal conditions over the desert Southwest (and drier than normal conditions over the Pacific Northwest). This enhanced antecedent wetness delays the seasonal heating of the North American continent that is necessary to establish the monsoonal land–ocean temperature gradient. The delay in seasonal warming in turn delays the monsoon initiation, thus reducing rainfall during the typical early monsoon period (July) and increasing rainfall during the later months of the monsoon season (August and September). While the rainfall during the early monsoon appears to be most modulated by antecedent winter–spring Pacific SST patterns, the rainfall in the later part of the monsoon seems to be driven largely by the near-term SST conditions surrounding the monsoon region along the coast of California and the Gulf of California. The role of antecedent land and ocean conditions in modulating the following summer monsoon appears to be quite significant. This enhances the prospects for long-lead forecasts of monsoon rainfall over the southwestern United States, which could have significant implications for water resources planning and management in this water-scarce region.
Submesoscale Spatiotemporal Variability of North American Monsoon Rainfall over Complex Terrain
Authors: Gebremichael Mekonnen , Vivoni Enrique R. , Watts Christopher J. , Rodríguez Julio C.
Published: May 2007

The authors analyze information from rain gauges, geostationary infrared satellites, and low earth orbiting radar in order to describe and characterize the submesoscale (<75 km) spatial pattern and temporal dynamics of rainfall in a 50 km × 75 km study area located in Sonora, Mexico, in the periphery of the North American monsoon system core region. The temporal domain spans from 1 July to 31 August 2004, corresponding to one monsoon season. Results reveal that rainfall in the study region is characterized by high spatial and temporal variability, strong diurnal cycles in both frequency and intensity with maxima in the evening hours, and multiscaling behavior in both temporal and spatial fields. The scaling parameters of the spatial rainfall fields exhibit dependence on the rainfall rate at the synoptic scale. The rainfall intensity exhibits a slightly stronger diurnal cycle compared to the rainfall frequency, and the maximum lag time between the two diurnal peaks is within 2.4 h, with earlier peaks observed for rainfall intensity. The time of maximum cold cloud occurrence does not vary with the infrared threshold temperature used (215–235 K), while the amplitude of the diurnal cycle varies in such a way that deep convective cells have stronger diurnal cycles. Furthermore, the results indicate that the diurnal cycle of cold cloud occurrence can be used as a surrogate for some basic features of the diurnal cycle of rainfall. The spatial pattern and temporal dynamics of rainfall are modulated by topographic features and large-scale features (circulation and moisture fields as related to geographical location). As compared to valley areas, mountainous areas are characterized by an earlier diurnal peak, an earlier date of maximum precipitation, closely clustered rainy hours, frequent yet small rainfall events, and less dependence of precipitation accumulation on elevation. As compared to the northern section of the study area, the southern section is characterized by strong convective systems that peak late diurnally. The results of this study are important for understanding the physical processes involved, improving the representation of submesoscale variability in models, downscaling rainfall data from coarse meteorological models to smaller hydrological scales, and interpreting and validating remote sensing rainfall estimates.
Variation of Hydrometeorological Conditions along a Topographic Transect in Northwestern Mexico during the North American Monsoon
Authors: Vivoni Enrique R. , Gutiérrez-Jurado Hugo A. , Aragón Carlos A. , Méndez-Barroso Luis A. , Rinehart Alex J. , Wyckoff Robert L. , Rodríguez Julio C. , Watts Christopher J. , Bolten John D. , Lakshmi Venkataraman , Jackson Thomas J.
Published: May 2007

Relatively little is currently known about the spatiotemporal variability of land surface conditions during the North American monsoon, in particular for regions of complex topography. As a result, the role played by land–atmosphere interactions in generating convective rainfall over steep terrain and sustaining monsoon conditions is still poorly understood. In this study, the variation of hydrometeorological conditions along a large-scale topographic transect in northwestern Mexico is described. The transect field experiment consisted of daily sampling at 30 sites selected to represent variations in elevation and ecosystem distribution. Simultaneous soil and atmospheric variables were measured during a 2-week period in early August 2004. Transect observations were supplemented by a network of continuous sampling sites used to analyze the regional hydrometeorological conditions prior to and during the field experiment. Results reveal the strong control exerted by topography on the spatial and temporal variability in soil moisture, with distinct landscape regions experiencing different hydrologic regimes. Reduced variations at the plot and transect scale during a drydown period indicate that homogenization of hydrologic conditions occurred over the landscape. Furthermore, atmospheric variables are clearly linked to surface conditions, indicating that heating and moistening of the boundary layer closely follow spatial and temporal changes in hydrologic properties. Land–atmosphere interactions at the basin scale (∼100 km2), obtained via a technique accounting for topographic variability, further reveal the role played by the land surface in sustaining high atmospheric moisture conditions, with implications toward rainfall generation during the North American monsoon.
A Climatological Perspective of Transient Synoptic Features during NAME 2004
Authors: Douglas Arthur V. , Englehart Phillip J.
Published: May 2007

This note provides a first look at a recently developed long-term climatology of transient synoptic features in northern Mexico. Key features investigated include inverted troughs, cutoff lows, cold fronts, and open troughs (westerly short waves). This 35-yr analysis of transient systems crossing northern Mexico (1967–2001) was developed to help place the summer climatology of the 2004 North American Monsoon Experiment (NAME) into a broader perspective. Inverted troughs are found to be the most commonly occurring transient synoptic feature during the monsoon with a mean frequency of occurrence of 55 days per summer season (June–September). Inverted troughs are found to contribute from 20% to 25% of the average summer rainfall observed in northern Mexico. Rainfall doubles during inverted trough days compared to days without transient systems being present.

In 2004 the monsoon season was greatly shortened due to a poorly developed subtropical high. Compared to long-term means, inverted troughs contributed less rainfall to the region in 2004 and this was, in part, associated with the shortened monsoon season. In contrast, frontal penetration into the region was almost double the 35-yr mean. These climatologies are designed to provide NAME researchers with benchmarks to assess model performance relative to how these models handle these systems and their associated rainfall. The work presented is a small portion of a much larger study that aims to determine the impact of all of these rain-bearing transient systems on the monsoon in northern Mexico.
Water Vapor Fluxes over the Intra-Americas Sea: Seasonal and Interannual Variability and Associations with Rainfall
Authors: Mestas-Nuñez Alberto M. , Enfield David B. , Zhang Chidong
Published: May 2007

The seasonal and interannual variability of moisture transports over the Intra-Americas Sea (including the Gulf of Mexico and the Caribbean Sea) is evaluated using the NCEP–NCAR global reanalysis. The seasonal variability of these moisture transports is consistent with previous studies and shows distinctive winter and summer regimes. Boreal winter moisture is mainly delivered to the central United States from the Pacific with some contribution from the Gulf of Mexico. It is during the boreal summer that the moisture flow over the Intra-Americas Sea is most effective in supplying the water vapor to the central United States via the northern branch of the Caribbean low-level jet. The increase of intensity of this jet during July is associated with an increase in evaporation over the Intra-Americas Sea, consistent with midsummer drought conditions over this region.

During both summer and winter, the interannual variability of the inflow of moisture from the Intra-Americas Sea into central United States is associated with Caribbean low-level jet variability. The source of the varying moisture is mainly the Gulf of Mexico and the North Atlantic area just east of the Bahamas Islands and the sink is precipitation over east-central United States. The main teleconnection pattern for these interannual variations appears to be the Pacific–North American, although in boreal winter ENSO and possibly the North Atlantic Oscillation may also play a role. During boreal summer, associations with ENSO mainly involve the zonal moisture exchange between the Intra-Americas Sea/tropical Atlantic and the tropical Pacific.
Effects of Increased Horizontal Resolution on Simulation of the North American Monsoon in the NCAR CAM3: An Evaluation Based on Surface, Satellite, and Reanalysis Data
Authors: Collier J. Craig , Zhang Guang J.
Published: May 2007

Simulation of the North American monsoon system by the National Center for Atmospheric Research (NCAR) Community Atmosphere Model (CAM3) is evaluated in its sensitivity to increasing horizontal resolution. For two resolutions, T42 and T85, rainfall is compared to Tropical Rainfall Measuring Mission (TRMM) satellite-derived and surface gauge-based rainfall rates over the United States and northern Mexico as well as rainfall accumulations in gauges of the North American Monsoon Experiment (NAME) Enhanced Rain Gauge Network (NERN) in the Sierra Madre Occidental. Simulated upper-tropospheric mass and wind fields are compared to those from NCEP–NCAR reanalyses. The comparison presented herein demonstrates that tropospheric motions associated with the North American monsoon system are sensitive to increasing the horizontal resolution of the model. An increase in resolution from T42 to T85 results in changes to a region of large-scale midtropospheric descent found north and east of the monsoon anticyclone. Relative to its simulation at T42, this region extends farther south and west at T85. Additionally, at T85, the subsidence is stronger. Consistent with the differences in large-scale descent, the T85 simulation of CAM3 is anomalously dry over Texas and northeastern Mexico during the peak monsoon months. Meanwhile, the geographic distribution of rainfall over the Sierra Madre Occidental region of Mexico is more satisfactorily simulated at T85 than at T42 for July and August. Moisture import into this region is greater at T85 than at T42 during these months. A focused study of the Sierra Madre Occidental region in particular shows that, in the regional-average sense, the timing of the peak of the monsoon is relatively insensitive to the horizontal resolution of the model, while a phase bias in the diurnal cycle of monsoon season precipitation is somewhat reduced in the higher-resolution run. At both resolutions, CAM3 poorly simulates the month-to-month evolution of monsoon rainfall over extreme northwestern Mexico and Arizona, though biases are considerably improved at T85.
Vertical Structure of Precipitation and Related Microphysics Observed by NOAA Profilers and TRMM during NAME 2004
Authors: Williams Christopher R. , White Allen B. , Gage Kenneth S. , Ralph F. Martin
Published: May 2007

In support of the 2004 North American Monsoon Experiment (NAME) field campaign, NOAA established and maintained a field site about 100 km north of Mazatlán, Mexico, consisting of wind profilers, precipitation profilers, surface upward–downward-looking radiometers, and a 10-m meteorological tower to observe the environment within the North American monsoon. Three objectives of this NOAA project are discussed in this paper: 1) to observe the vertical structure of precipitating cloud systems as they passed over the NOAA profiler site, 2) to estimate the vertical air motion and the raindrop size distribution from near the surface to just below the melting layer, and 3) to better understand the microphysical processes associated with stratiform rain containing well-defined radar bright bands.

To provide a climatological context for the profiler observations at the field site, the profiler reflectivity distributions were compared with Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) reflectivity distributions from the 2004 season over the NAME domain as well as from the 1998–2005 seasons. This analysis places the NAME 2004 observations into the context of other monsoon seasons. It also provides a basis for evaluating the representativeness of the structure of the precipitation systems sampled at this location. The number of rain events observed by the TRMM PR is dependent on geography; the land region, which includes portions of the Sierra Madre Occidental, has more events than the coast and gulf regions. Conversely, from this study it is found that the frequencies of occurrence of stratiform rain and reflectivity profiles with radar bright bands are mostly independent of region. The analysis also revealed that the reflectivity distribution at each height has more year-to-year variability than region-to-region variability. These findings suggest that in cases with a well-defined bright band, the vertical profile of the reflectivity relative to the height of the bright band is similar over the gulf, coast, and land regions.
A Rasch Perspective
Authors: Schumacker Randall E. , Smith Everett V.
Published: May 2007

Measurement error is a common theme in classical measurement models used in testing and assessment. In classical measurement models, the definition of measurement error and the subsequent reliability coefficients differ on the basis of the test administration design. Internal consistency reliability specifies error due primarily to poor item sampling. Rater reliability indicates error due to inconsistency among raters. For estimates of test-retest reliability, error is attributed mainly to changes over time. In alternate-forms reliability, error is assumed to be due largely to variation between samples of items on test forms. Rasch models can also compute reliability estimates of scores under different test situations. The authors therefore present the Rasch perspective on calculating reliability (measurement error) and present Rasch measurement model programs to compute the various reliability estimates.
Complexity of Primary Lifetime Occupation and Cognition in Advanced Old Age
Authors: Andel Ross , Kåreholt Ingemar , Parker Marti G. , Thorslund Mats , Gatz Margaret
Published: May 2007

Objectives: The authors explored the association between complexity of primary lifetime occupation and cognition in older adulthood. Method: The study included 386 participants from the Swedish Panel Study of Living Conditions of the Oldest Old, a nationally representative sample aged 77 years or older. The authors examined complexity of work with data, people, and things in relation to cognitive functioning, measured with a shortened version of Mini-Mental State Examination (MMSE) and cognitive impairment based on MMSE score cutoff. Results: Complexity of work with data and people were associated with better MMSE scores, controlling for age, sex, childhood socioeconomic status, and education. The association between complexity of work with data and MMSE remained statistically significant when adult occupational status was substituted for education as a covariate. Discussion: Complexity of primary lifetime occupation may be reflected in cognitive functioning even in advanced old age. This effect may be independent of education or occupational status.