bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancement of Visual Responsiveness by Spontaneous Local Network Activity In Vivo
Authors: Haider Bilal , Duque Alvaro , Hasenstaub Andrea R. , Yu Yuguo , McCormick David A.
Published: April 2007

Spontaneous activity within local circuits affects the integrative properties of neurons and networks. We have previously shown that neocortical network activity exhibits a balance between excitatory and inhibitory synaptic potentials, and such activity has significant effects on synaptic transmission, action potential generation, and spike timing. However, whether such activity facilitates or reduces sensory responses has yet to be clearly determined. We examined this hypothesis in the primary visual cortex in vivo during slow oscillations in ketamine-xylazine anesthetized cats. We measured network activity (Up states) with extracellular recording, while simultaneously recording postsynaptic potentials (PSPs) and action potentials in nearby cells. Stimulating the receptive field revealed that spiking responses of both simple and complex cells were significantly enhanced (>2-fold) during network activity, as were spiking responses to intracellular injection of varying amplitude artificial conductance stimuli. Visually evoked PSPs were not significantly different in amplitude during network activity or quiescence; instead, spontaneous depolarization caused by network activity brought these evoked PSPs closer to firing threshold. Further examination revealed that visual responsiveness was gradually enhanced by progressive membrane potential depolarization. These spontaneous depolarizations enhanced responsiveness to stimuli of varying contrasts, resulting in an upward (multiplicative) scaling of the contrast response function. Our results suggest that small increases in ongoing balanced network activity that result in depolarization may provide a rapid and generalized mechanism to control the responsiveness (gain) of cortical neurons, such as occurs during shifts in spatial attention.
The human reticulocyte transcriptome
Authors: Goh Sung-Ho , Josleyn Matthew , Lee Y. Terry , Danner Robert L. , Gherman Robert B. , Cam Maggie C. , Miller Jeffery L.
Published: April 2007

RNA from circulating blood reticulocytes was utilized to provide a robust description of genes transcribed at the final stages of erythroblast maturation. After depletion of leukocytes and platelets, Affymetrix HG-U133 arrays were hybridized with probe generated from the reticulocyte total RNA (blood obtained from 14 umbilical cords and 14 healthy adult humans). Among the cord and adult reticulocyte profiles, 698 probe sets (488 named genes) were detected in each of the 28 samples. Among the highly expressed genes, promoter analyses revealed a subset of transcription factor binding motifs encoded at higher than expected frequencies including the hypoxia-related arylhydrocarbon receptor repressor family. Over 100 probe sets demonstrated differential expression between the cord and adult reticulocyte samples. For verification, the array expression patterns for 21 genes were confirmed by real-time PCR (correlation coefficient 0.98). Only four transcripts (MAP17, FLJ32009 , ARRB2, and FLJ27365 ) were identified as being upregulated in the adult blood transcriptome. Further analysis revealed that the lipid-regulating protein MAP17 was present in the membrane fraction of adult erythrocytes, but not detected in cord blood erythrocytes. Combined with other clinical and experimental data, these reticulocyte transcriptome profiles should be useful to better understand the molecular bases of terminal erythroid differentiation, hemoglobin switching, iron metabolism and malarial pathogenesis.
Down-Regulation of CD9 Expression during Prostate Carcinoma Progression Is Associated with CD9 mRNA Modifications
Authors: Wang Jia-Chi , Bégin Louis R. , Bérubé Nathalie G. , Chevalier Simone , Aprikian Armen G. , Gourdeau Henriette , Chevrette Mario
Published: April 2007

Purpose: Cluster-of-differentiation antigen 9 (CD9) protein, a member of the tetraspanin family, has been implicated in carcinogenesis of various human tumors. Although decreased expression of the CD82 tetraspanin protein, a close CD9 relative, is associated with prostate cancer progression, CD9 expression has not been analyzed in this malignancy.

Experimental Design: CD9 expression in human prostatic adenocarcinoma was analyzed by immunohistochemistry on 167 primary tumors and 88 lymph node or bone metastases. CD9 cDNA was sequenced from two human prostate cancer cell lines, prostatic adenocarcinoma, high-grade prostatic intraepithelial neoplasia (PIN), and normal prostatic tissues.

Results: Although CD9 was detected in the epithelium of normal prostatic tissues, reduced or loss of CD9 expression within neoplastic cells was observed in 24% of 107 clinically localized primary adenocarcinomas, 85% of 60 clinically advanced primary adenocarcinomas, 85% of 65 lymph node metastases, and 65% of 23 bone metastases. Difference in CD9 expression between clinically localized and advanced diseases was highly significant (P < 1 × 10−7). Whereas there was no alteration of CD9 cDNA in normal tissues, all PC-3–derived cell lines, one PIN, and four prostatic adenocarcinomas harbored deletions in their CD9 cDNAs. Recurring CD9 point mutations were also found in PC-3M-LN4 cells, one PIN, and seven prostatic adenocarcinomas.

Conclusions: CD9 expression is significantly reduced and even lost during prostate cancer progression. Moreover, deletions and mutations of the CD9 mRNA may be associated with loss of protein expression observed in tumor cells. Our data suggest that CD9 inactivation may play an important role in prostate cancer progression.
Multiple Molecular Markers as Predictors of Colorectal Cancer in Patients with Normal Perioperative Serum Carcinoembryonic Antigen Levels
Authors: Wang Jaw-Yuan , Lin Shiu-Ru , Wu Deng-Chyang , Lu Chien-Yu , Yu Fang-Jung , Hsieh Jan-Sing , Cheng Tian-Lu , Koay Lok-Beng , Uen Yih-Huei
Published: April 2007

Purpose: In this study, a high-sensitivity colorimetric membrane array method was used to detect circulating tumor cells (CTC) in the peripheral blood of colorectal cancer (CRC) patients with normal perioperative serum carcinoembryonic antigen (CEA) levels. This membrane array method was evaluated as a potential diagnostic and postoperative surveillance tool.

Study Design: Membrane arrays consisting of a panel of mRNA markers that include human telomerase reverse transcriptase, cytokeratin-19, cytokeratin-20, and CEA mRNA were used to detect CTCs in the peripheral blood of 157 postoperative CRC patients with normal perioperative serum CEA levels and in 80 healthy individuals. Digoxigenin-labeled cDNA were amplified by reverse transcription-PCR from the peripheral blood samples, which were then hybridized to the membrane array. The sensitivity, specificity, and accuracy of membrane arrays for the detection of CTCs were then calculated.

Results: Using the four markers in combination, expression of any three markers or all the four markers in this panel was significantly correlated with the clinicopathologic characteristics, including depth of tumor invasion, lymph node metastasis, tumor-node-metastasis stage, and postoperative relapse (all P < 0.05). The interval between the detection of all four positive molecular markers and subsequent elevated CEA ranged from 3 to 8 months (median 6 months). The expression of all four mRNA markers was an independent predictor for postoperative relapse. CRC patients with all four mRNA markers expression showed a significantly poorer survival rate than those with less than four positive markers.

Conclusions: The constructed membrane array method was helpful in the early prediction of postoperative relapse in CRC patients with normal perioperative serum CEA levels.
Tumor-stroma interactions in pancreatic ductal adenocarcinoma
Authors: Mahadevan Daruka , Von Hoff Daniel D.
Published: April 2007

The host stromal response to an invasive epithelial carcinoma is frequently called a desmoplastic reaction (DR) and is a universal feature of pancreatic ductal adenocarcinoma (PDA). This DR is characterized by a complex interplay between the normal host epithelial cells, invading tumor cells, stromal fibroblasts, inflammatory cells, proliferating endothelial cells, an altered extracellular matrix, and growth factors activating oncogenic signaling pathways by autocrine and paracrine mechanisms. Hence, the tumor microenvironment is a dynamic process promoting tumor growth and invasion through mechanisms likely to include anoikis resistance, genomic instability, and drug resistance. Cell coculture models, murine models (xenograft and genetic), and gene expression profiling studies on human PDA biopsies have identified several key molecules, such as collagen type I, fibronectin, laminin, matrix metalloproteinases (MMP) and their inhibitors (tissue inhibitors of MMP), growth factors (transforming growth factor β, platelet-derived growth factor, connective tissue growth factor, and hepatocyte growth factor), chemokines, and integrins as constituents of the DR. Despite these findings, it is unclear which molecular-cellular events initiate and drive desmoplasia in PDA. Accumulating evidence indicates that pancreatic stellate cells when activated switch to a myofibroblast phenotype that produces components of the extracellular matrix, MMPs, and tissue inhibitors of MMPs by activating the mitogen-activated protein kinase (extracellular signal-regulated kinase 1/2) pathway. Based on current evidence, several therapeutic strategies are been evaluated on identified potential therapeutic targets. This review summarizes our current understanding of the mechanisms that potentially drive the DR in PDA and future possibilities for therapeutic targeting of this critical process. [Mol Cancer Ther 2007;6(4):1186–97]
Predicting gefitinib responsiveness in lung cancer by fluorescence in situ hybridization/chromogenic in situ hybridization analysis of EGFR and HER2 in biopsy and cytology specimens
Authors: Daniele Lorenzo , Macrì Luigia , Schena Marina , Dongiovanni Diego , Bonello Lisa , Armando Enrico , Ciuffreda Libero , Bertetto Oscar , Bussolati Gianni , Sapino Anna
Published: April 2007

In non–small cell lung cancer (NSCLC), epidermal growth factor receptor (EGFR) mutational analysis is an excellent predictor of responsiveness to treatment with tyrosine kinase inhibitors, such as gefitinib. In up to 80% of NSCLCs, cytologic samples or endoscopic biopsies are the only specimens available for molecular analysis, but PCR amplification of DNA from small fixed and paraffin-embedded samples may create artifactual mutations. Fluorescence in situ hybridization (FISH) of EGFR and HER2 has been proposed as an alternative method of analysis. This project aimed to determine the optimal scoring method for FISH or chromogenic in situ hybridization (CISH) assays when analyzing small NSCLC samples to predict response. FISH or CISH analysis of EGFR and HER2 genes was done on 42 small samples derived from NSCLC patients treated with gefitinib. EGFR mutational analysis was done after quantity and quality controls of DNA. In seven of seven cases, a balanced increase in EGFR gene and chromosome 7 number was found to correlate with the presence of specific EGFR mutations. In addition, seven of seven cases with balanced EGFR/HER2 polysomy and two of three cases with balanced EGFR/HER2 trisomy responded to gefitinib (75% of responders). Instead, the EGFR mutations predicted only 7 of 12 (58%) of gefitinib-responsive patients. When only endoscopic biopsies or cytologic specimens are available, we propose using FISH/CISH for EGFR and HER2 as the test of choice for selecting patients for treatment with gefitinib and to consider as negative predictive factor the absence of EGFR/HER2 gene gain. [Mol Cancer Ther 2007;6(4):1223–9]
MUC4 Mucin Potentiates Pancreatic Tumor Cell Proliferation, Survival, and Invasive Properties and Interferes with Its Interaction to Extracellular Matrix Proteins
Authors: Chaturvedi Pallavi , Singh Ajay P. , Moniaux Nicolas , Senapati Shantibhushan , Chakraborty Subhankar , Meza Jane L. , Batra Surinder K.
Published: April 2007

MUC4, a transmembrane mucin, is aberrantly expressed in pancreatic adenocarcinomas while remaining undetectable in the normal pancreas. Recent studies have shown that the expression of MUC4 is associated with the progression of pancreatic cancer and is inversely correlated with the prognosis of pancreatic cancer patients. In the present study, we have examined the phenotypic and molecular consequences of MUC4 silencing with an aim of establishing the mechanistic basis for its observed role in the pathogenesis of pancreatic cancer. The silencing of MUC4 expression was achieved by stable expression of a MUC4-specific short hairpin RNA in CD18/HPAF, a highly metastatic pancreatic adenocarcinoma cell line. A significant decrease in MUC4 expression was detected in MUC4-knockdown (CD18/HPAF-siMUC4) cells compared with the parental and scrambled short interfering RNA–transfected (CD18/HPAF-Scr) control cells by immunoblot analysis and immunofluorescence confocal microscopy. Consistent with our previous observation, inhibition of MUC4 expression restrained the pancreatic tumor cell growth and metastasis as shown in an orthotopic mouse model. Our in vitro studies revealed that MUC4-associated increase in tumor cell growth resulted from both the enhanced proliferation and reduced cell death. Furthermore, MUC4 expression was also associated with significantly increased invasiveness (P ≤ 0.05) and changes in actin organization. The presence of MUC4 on the cell surface was shown to interfere with the tumor cell-extracellular matrix interactions, in part, by inhibiting the integrin-mediated cell adhesion. An altered expression of growth- and metastasis-associated genes (LI-cadherin, CEACAM6, RAC1, AnnexinA1, thrombomodulin, epiregulin, S100A4, TP53, TP53BP, caspase-2, caspase-3, caspase-7, plakoglobin, and neuregulin-2) was also observed as a consequence of the silencing of MUC4. In conclusion, our study provides experimental evidence that supports the functional significance of MUC4 in pancreatic cancer progression and indicates a novel role for MUC4 in cancer cell signaling. (Mol Cancer Res 2007;5(4):309–20)
Metacognition of Problem-Solving Strategies in Brazil, India, and the United States
Authors: Güss C. Dominik , Wiley Brian
Published: April 2007

Metacognition, the observation of one's own thinking, is a key cognitive ability that allows humans to influence and restructure their own thought processes. The influence of culture on metacognitive strategies is a relatively new topic. Using Antonietti's, Ignazi's and Perego's questionnaire on metacognitive knowledge about problem-solving strategies (2000), five strategies in three life domains were assessed among student samples in Brazil, India, and the United States (N=317), regarding the frequency, facility, and efficacy of these strategies. To investigate cross-cultural similarities and differences in strategy use, nationality and uncertainty avoidance values were independent variables. Uncertainty avoidance was expected to lead to high frequency of decision strategies. However, results showed no effect of uncertainty avoidance on frequency, but an effect on facility of metacognitive strategies. Comparing the three cultural samples, all rated analogy as the most frequent strategy. Only in the U.S. sample, analogy was also rated as the most effective and easy to apply strategy. Every cultural group showed a different preference regarding what metacognitive strategy was most effective. Indian participants found the free production strategy to be more effective, and Indian and Brazilian participants found the combination strategy to be more effective compared to the U.S. participants. As key abilities for the five strategies, Indians rated speed, Brazilians rated synthesis, and U.S. participants rated critical thinking as more important than the other participants. These results reflect the embedded nature and functionality of problem solving strategies in specific cultural environments. The findings will be discussed referring to an eco-cultural framework.
Heart and Cognition in Ancient Chinese Philosophy
Authors: Yu Ning
Published: April 2007

Following the theory of conceptual metaphor in cognitive linguistics, this paper studies a predominant conceptual metaphor in the understanding of the heart in ancient Chinese philosophy: THE HEART IS THE RULER OF THE BODY. The most important conceptual mapping of this metaphor consists in the perceived correspondence between the mental power of the heart and the political power of the ruler. The Chinese heart is traditionally regarded as the organ of thinking and reasoning, as well as feeling. As such, it is conceptualized as the central faculty of cognition. This cultural conceptualization differs fundamentally from the Western dualism that upholds the reason-emotion dichotomy, as represented by the binary contrast between mind and heart in particular, and mind and body in general. It is found that the HEART AS RULER metaphor has a mirror image, namely THE RULER IS THE HEART OF THE COUNTRY. The ruler as the "heart" of the country leads his nation while guided by his own heart as the "ruler" of his body. It is argued that the two-way metaphorical mappings are based on the overarching beliefs of ancient Chinese philosophy in the unity and correspondence between the microcosm of man and the macrocosm of universe. It is suggested that the conceptualization of the heart in ancient Chinese philosophy, which is basically metaphorical in nature, is still spread widely across Chinese culture today.
Cognition, Algebra, and Culture in the Tongan Kinship Terminology
Authors: Bennardo Giovanni , Read Dwight
Published: April 2007

We present an algebraic account of the Tongan kinship terminology (TKT) that provides an insightful journey into the fabric of Tongan culture. We begin with the ethnographic account of a social event. e account provides us with the activities of that day and the centrality of kin relations in the event, but it does not inform us of the conceptual system that the participants bring with them. Rather, it is a slice in time of an ongoing dynamic process that links behavior with a conceptual system of kin relations and vice versa. To understand this interplay, we need an account of the underlying conceptual system that is being activated during the event. Thus, we introduce a formal, algebraically based account of TKT. is account brings to the fore the underlying logic of TKT and allows us to distinguish between features of the kinship system that arise from the logic of TKT as a generative structure and features that must have arisen through cultural intervention.
The role of attraction in cultural evolution
Authors: Claidière Nicolas , Sperber Dan
Published: April 2007

Henrich and Boyd (2002) were the first to propose a formal model of the role of attraction in cultural evolution. They came to the surprising conclusion that, when both attraction and selection are at work, final outcomes are determined by selection alone. This result is based on a determistic view of cultural attraction, different from the probabilistic view introduced in Sperber (1996). We defend this probabilistic view, show how to model it, and argue that, when both attraction and selection are at work, both affect final outcomes.
Does the basic color terms discussion su er from the stimulus error?
Authors: Kuehni Rolf
Published: April 2007

This commentary raises the possibility of recent discussion on the issue of basic color terms suffering from the "stimulus error," first described by the English psychologist E. B. Titchener. It refers to confusion of the psychological experience with the physical description of the stimulus. Such confusion is routine in everyday language in situations where private sensory experiences are involved that cannot be objectively described, but is harmful in fundamental discussions about experiences.
Considering the Prevalence of the "Stimulus Error" in Color Naming Research
Authors: Jameson Kimberly , Bimler David , Dedrick Don , Roberson Debi
Published: April 2007

In "Does the Basic Color Terms discussion suffer from the Stimulus Error?" Rolf Kuehni describes a research stumbling block known as the "stimulus error," and hints at the difficulties it causes for mainstream color naming research (Kuehni, is Issue). Among the issues intrinsic to Kuehni's "stimulus error" description is the important question of what can generally be inferred from color naming behaviors based on bounded samples of empirical stimuli. Here we examine some specifics of the color naming research issues that Kuehni raises. While we share Kuehni's view regarding potential problems caused by the "stimulus error" and his concern regarding its prevalence, Kuehni's commentary seems primarily aimed at stimulating a general discussion of color naming research implications, because the articles he critiques do not actually commit the "stimulus error" in any serious sense. Based on Kuehni's comments, we further examine some of the relevant empirical and theoretical implications for cross-cultural color naming research.
Rain-on-Snow Events in the Western United States
Authors: McCabe Gregory J. , Clark Martyn P. , Hay Lauren E.
Published: April 2007

Rain-on-snow events pose a significant flood hazard in the western United States. This study provides a description of the spatial and temporal variability of the frequency of rain-on-snow events for 4318 sites in the western United States during water years (October through September) 1949–2003. Rain-on-snow events are found to be most common during the months of October through May; however, at sites in the interior western United States, rain-on-snow events can occur in substantial numbers as late as June and as early as September. An examination of the temporal variability of October through May rain-on-snow events indicates a mixture of increasing and decreasing trends in rain-on-snow events across the western United States. Decreasing trends in rain-on-snow events are most pronounced at lower elevations and are associated with trends toward fewer snowfall days and fewer precipitation days with snow on the ground. Rain-on-snow events are more (less) frequent in the northwestern (southwestern) United States during La Niña (El Niño) conditions. Additionally, increases in temperature in the western United States appear to be contributing to decreases in the number of rain-on-snow events for many sites through effects on the number of days with snowfall and the number of days with snow on the ground.
THE JOINT CENTER FOR SATELLITE DATA ASSIMILATION
Authors: Le Marshall John , Uccellini Louis , Einaudi Franco , Colton Marie , Chang Simon , Weng Fuzhong , Uhart Michael , Lord Stephen , Riishojgaard Lars-Peters , Phoebus Patricia , Yoe James G.
Published: April 2007

The Joint Center for Satellite Data Assimilation (JCSDA) was established by NASA and NOAA in 2001, with Department of Defense (DoD) agencies becoming partners in 2002. The goal of JCSDA is to accelerate the use of observations from Earth-orbiting satellites in operational environmental analysis and prediction models for the purpose of improving weather, ocean, climate, and air quality forecasts and the accuracy of climate datasets. Advanced instruments of current and planned satellite missions do and will increasingly provide large volumes of data related to the atmospheric, oceanic, and land surface state. During this decade, this will result in a five order of magnitude increase in the volume of data available for use by the operational and research weather, ocean, and climate communities. These data will exhibit accuracies and spatial, spectral, and temporal resolutions never before achieved. JCSDA will help ensure that the maximum benefit from investment in the space-based global observation system is realized. JCSDA will accelerate the use of satellite data from both operational and experimental spacecraft for weather and climate prediction systems. To this end, the advancement of data assimilation science by JCSDA has included the establishment of the JCSDA Community Radiative Transfer Model (CRTM), which has continual upgrades to allow for the effective use of current and many future satellite instruments. This and other activity within JCSDA have been supported by both internal and external (generally university based) research. Another key activity within JCSDA has been to lay the groundwork for and to establish common NWP model and data assimilation infrastructure for accessing new satellite data and optimizing the use of these data in operational models. As a result of this activity, common assimilation infrastructure has been established at NOAA and NASA and this will assist in a coordinated and integrated move to four-dimensional assimilation among the partner agencies.

This paper discusses the establishment of JCSDA and its mission, goals, and science priorities. It also discusses recent advances made by JCSDA, and planned future developments.
The Coupled Boundary Layers and Air–Sea Transfer Experiment in Low Winds
Authors: Edson James , Crawford Timothy , Crescenti Jerry , Farrar Tom , Frew Nelson , Gerbi Greg , Helmis Costas , Hristov Tihomir , Khelif Djamal , Jessup Andrew , Jonsson Haf , Li Ming , Mahrt Larry , McGillis Wade , Plueddemann Albert , Shen Lian , Skyllingstad Eric , Stanton Tim , Sullivan Peter , Sun Jielun , Trowbridge John , Vickers Dean , Wang Shouping , Wang Qing , Weller Robert , Wilkin John , Williams Albert J. , Yue D. K. P. , Zappa Chris
Published: April 2007

The Office of Naval Research's Coupled Boundary Layers and Air–Sea Transfer (CBLAST) program is being conducted to investigate the processes that couple the marine boundary layers and govern the exchange of heat, mass, and momentum across the air–sea interface. CBLAST-LOW was designed to investigate these processes at the low-wind extreme where the processes are often driven or strongly modulated by buoyant forcing. The focus was on conditions ranging from negligible wind stress, where buoyant forcing dominates, up to wind speeds where wave breaking and Langmuir circulations play a significant role in the exchange processes. The field program provided observations from a suite of platforms deployed in the coastal ocean south of Martha's Vineyard. Highlights from the measurement campaigns include direct measurement of the momentum and heat fluxes on both sides of the air–sea interface using a specially constructed Air–Sea Interaction Tower (ASIT), and quantification of regional oceanic variability over scales of O(1–104 mm) using a mesoscale mooring array, aircraft-borne remote sensors, drifters, and ship surveys. To our knowledge, the former represents the first successful attempt to directly and simultaneously measure the heat and momentum exchange on both sides of the air–sea interface. The latter provided a 3D picture of the oceanic boundary layer during the month-long main experiment. These observations have been combined with numerical models and direct numerical and large-eddy simulations to investigate the processes that couple the atmosphere and ocean under these conditions. For example, the oceanic measurements have been used in the Regional Ocean Modeling System (ROMS) to investigate the 3D evolution of regional ocean thermal stratification. The ultimate goal of these investigations is to incorporate improved parameterizations of these processes in coupled models such as the Coupled Ocean–Atmosphere Mesoscale Prediction System (COAMPS) to improve marine forecasts of wind, waves, and currents.
Transferability Intercomparison: An Opportunity for New Insight on the Global Water Cycle and Energy Budget
Authors: Takle E. S. , Roads J. , Rockel B. , Gutowski W. J. , Arritt R. W. , Meinke I. , Jones C. G. , Zadra A.
Published: April 2007

A new approach, called transferability intercomparisons, is described for advancing both understanding and modeling of the global water cycle and energy budget. Under this approach, individual regional climate models perform simulations with all modeling parameters and parameterizations held constant over a specific period on several prescribed domains representing different climatic regions. The transferability framework goes beyond previous regional climate model intercomparisons to provide a global method for testing and improving model parameterizations by constraining the simulations within analyzed boundaries for several domains. Transferability intercomparisons expose the limits of our current regional modeling capacity by examining model accuracy on a wide range of climate conditions and realizations. Intercomparison of these individual model experiments provides a means for evaluating strengths and weaknesses of models outside their “home domains” (domain of development and testing). Reference sites that are conducting coordinated measurements under the continental-scale experiments under the Global Energy and Water Cycle Experiment (GEWEX) Hydrometeorology Panel provide data for evaluation of model abilities to simulate specific features of the water and energy cycles. A systematic intercomparison across models and domains more clearly exposes collective biases in the modeling process. By isolating particular regions and processes, regional model transferability intercomparisons can more effectively explore the spatial and temporal heterogeneity of predictability. A general improvement of model ability to simulate diverse climates will provide more confidence that models used for future climate scenarios might be able to simulate conditions on a particular domain that are beyond the range of previously observed climates.
Water Balance for the Ji-Paraná River Basin, Western Amazon, Using a Simple Method through Geographical Information Systems and Remote Sensing
Authors: Victoria Danielde Castro , Santiago Alailson Venceslau , Ballester Maria Victoria Ramos , Pereira Antonio Roberto , Victoria Reynaldo Luiz , Richey Jeffrey E.
Published: April 2007

The Thornthwaite–Mather climatological model integrated into a Geographic Information System (GIS) was used to simulate the monthly water balance for the Ji-Paraná river basin, in the western Amazonian state of Rondônia (RO), from February 1995 through December 1996. Model inputs were Advanced Very High Resolution Radar (AVHRR) images, rainfall from rain gauges within and around the basin, soils, and land cover maps. Mean monthly temperature images, estimated from AVHRR, were used to calculate monthly potential evapotranspiration images. Rainfall measurements were interpolated to obtain monthly rainfall images using the spline method. Results were compared with annual water mass balance for 10 internal subbasins. Model results underestimated basin evapotranspiration in −6% and water surplus was overestimated in +12%. Annual basin evapotranspiration was 1166 mm, or 3.2 mm day−1, with a minimum in the dry season (1.7 mm day−1 in July) and maximum in the beginning of the wet season (4.2 mm day−1 in October). Three distinct land cover scenarios were evaluated. Complete basin deforestation reduced basin evapotranspiration and increased water deficit and surplus in approximately 200 mm yr−1.
Comparison of CALIPSO-Like, LaRC, and MODIS Retrievals of Ice-Cloud Properties over SIRTA in France and Florida during CRYSTAL-FACE
Authors: Chiriaco M. , Chepfer H. , Minnis P. , Haeffelin M. , Platnick S. , Baumgardner D. , Dubuisson P. , McGill M. , Noël V. , Pelon J. , Spangenberg D. , Sun-Mack S. , Wind G.
Published: April 2007

This study compares cirrus-cloud properties and, in particular, particle effective radius retrieved by a Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO)-like method with two similar methods using Moderate-Resolution Imaging Spectroradiometer (MODIS), MODIS Airborne Simulator (MAS), and Geostationary Operational Environmental Satellite imagery. The CALIPSO-like method uses lidar measurements coupled with the split-window technique that uses the infrared spectral information contained at the 8.65-, 11.15-, and 12.05-μm bands to infer the microphysical properties of cirrus clouds. The two other methods, using passive remote sensing at visible and infrared wavelengths, are the operational MODIS cloud products (using 20 spectral bands from visible to infrared, referred to by its archival product identifier MOD06 for MODIS Terra) and MODIS retrievals performed by the Clouds and the Earth’s Radiant Energy System (CERES) team at Langley Research Center (LaRC) in support of CERES algorithms (using 0.65-, 3.75-, 10.8-, and 12.05-μm bands); the two algorithms will be referred to as the MOD06 and LaRC methods, respectively. The three techniques are compared at two different latitudes. The midlatitude ice-clouds study uses 16 days of observations at the Palaiseau ground-based site in France [Site Instrumental de Recherche par Télédétection Atmosphérique (SIRTA)], including a ground-based 532-nm lidar and the MODIS overpasses on the Terra platform. The tropical ice-clouds study uses 14 different flight legs of observations collected in Florida during the intensive field experiment known as the Cirrus Regional Study of Tropical Anvils and Cirrus Layers–Florida Area Cirrus Experiment (CRYSTAL-FACE), including the airborne cloud-physics lidar and the MAS. The comparison of the three methods gives consistent results for the particle effective radius and the optical thickness but discrepancies in cloud detection and altitudes. The study confirms the value of an active remote sensing method (CALIPSO like) for the study of subvisible ice clouds, in both the midlatitudes and Tropics. Nevertheless, this method is not reliable in optically very thick tropical ice clouds, because of their particular microphysical properties.
Source Characterization with a Genetic Algorithm–Coupled Dispersion–Backward Model Incorporating SCIPUFF
Authors: Allen Christopher T. , Haupt Sue Ellen , Young George S.
Published: April 2007

This paper extends the approach of coupling a forward-looking dispersion model with a backward model using a genetic algorithm (GA) by incorporating a more sophisticated dispersion model [the Second-Order Closure Integrated Puff (SCIPUFF) model] into a GA-coupled system. This coupled system is validated with synthetic and field experiment data to demonstrate the potential applicability of the coupled model to emission source characterization. The coupled model incorporating SCIPUFF is first validated with synthetic data produced by SCIPUFF to isolate issues related directly to SCIPUFF’s use in the coupled model. The coupled model is successful in characterizing sources even with a moderate amount of white noise introduced into the data. The similarity to corresponding results from previous studies using a more basic model suggests that the GA’s performance is not sensitive to the dispersion model used. The coupled model is then tested using data from the Dipole Pride 26 field tests to determine its ability to characterize actual pollutant measurements despite the stochastic scatter inherent in turbulent dispersion. Sensitivity studies are run on various input parameters to gain insight used to produce a multistage process capable of a higher-quality source characterization than that produced by a single pass. Overall, the coupled model performed well in identifying approximate locations, times, and amounts of pollutant emissions. These model runs demonstrate the coupled model’s potential application to source characterization for real-world problems.
An Automated Technique to Quality Control Radar Reflectivity Data
Authors: Lakshmanan Valliappa , Fritz Angela , Smith Travis , Hondl Kurt , Stumpf Gregory
Published: April 2007

Echoes in radar reflectivity data do not always correspond to precipitating particles. Echoes on radar may result from biological targets such as insects, birds, or wind-borne particles; from anomalous propagation or ground clutter; or from test and interference patterns that inadvertently seep into the final products. Although weather forecasters can usually identify and account for the presence of such contamination, automated weather-radar algorithms are drastically affected. Several horizontal and vertical features have been proposed to discriminate between precipitation echoes and echoes that do not correspond to precipitation. None of these features by themselves can discriminate between precipitating and nonprecipitating areas. In this paper, a neural network is used to combine the individual features, some of which have already been proposed in the literature and some of which are introduced in this paper, into a single discriminator that can distinguish between “good” and “bad” echoes (i.e., precipitation and nonprecipitation, respectively). The method of computing the horizontal features leads to statistical anomalies in their distributions near the edges of echoes. Also described is how to avoid presenting such range gates to the neural network. The gate-by-gate discrimination provided by the neural network is followed by more holistic postprocessing based on spatial contiguity constraints and object identification to yield quality-controlled radar reflectivity scans that have most of the bad echo removed while leaving most of the good echo untouched. A possible multisensor extension, utilizing satellite data and surface observations, to the radar-only technique is also demonstrated. It is demonstrated that the resulting technique is highly skilled and that its skill exceeds that of the currently operational algorithm.
Empirical Estimation of Attenuation from Differential Propagation Phase Measurements at C Band
Authors: Gourley Jonathan J. , Tabary Pierre , Parent du Chatelet Jacques
Published: April 2007

A polarimetric method is devised to correct for attenuation effects at C band on reflectivity ZH and differential reflectivity ZDR measurements. An operational cross-correlation analysis is used to derive advection vectors and to displace echoes over a 5-min time step. These advected echoes are then compared with observations valid at the same time. The method assumes that the mean change in the intrinsic ZH and ZDR over a 5-min period when considering 1–2 h of observations over the entire radar umbrella is approximately zero. Correction coefficients are retrieved through the minimization of a cost function that links observed decreases in ZH and ZDR due to attenuation effects with increases in differential phase shift (ΦDP). The retrieved coefficients are consistent with published values for the typical ranges of temperatures and drop sizes encountered at midlatitudes, even when Mie scattering effects are present. Measurements of ZH and ZDR corrected using retrieved coefficients are compared with raw measurements and to measurements adjusted by mean coefficients found in the literature. The empirical retrieval method shows improvement over using mean correction coefficients based on comparisons of ZH from neighboring, unattenuated radars, disdrometer measurements, and analysis of ZH and ZDR as a function of ΦDP.
Daily NDVI Relationship to Cloud Cover
Authors: Tang Qiuhong , Oki Taikan
Published: April 2007

A normalized difference vegetation index (NDVI) cloud index (NCI) was derived from Pathfinder Advanced Very High Resolution Radiometer (AVHRR) daily NDVI data and compared with observed cloud amounts and a sunshine duration–cloud index (SCI) over an area of diverse land cover. Ground observations from 120 meteorological stations were significantly related to the daily NCI and the SCI, with R2 values of 0.41 and 0.50, respectively. The daily NCI and interpolated cloud indices derived from ground observations over the 776 900 km2 study area were compared. The correlation coefficient between the NCI and the observed cloud amount was less than 0.6 for less than 20% of the area. The correlation coefficient between the NCI and the observed sunshine duration index was less than 0.6 for less than 10% of the area and less than 0.7 for 41% of the area. There were strong correlations for high elevations in summer, and correlations for low elevations in winter were weaker. A frozen soil surface or snow cover degrades the NDVI relationship to clouds. The NCI and observed cloud indices had high correlation coefficients in areas with diverse land uses, suggesting that the NCI may be useful in estimating cloudiness over a large region.
The Shear Layer above and in Urban Canopies
Authors: Huq Pablo , White Louis A. , Carrillo Alejandro , Redondo Jose , Dharmavaram Seshu , Hanna Steven R.
Published: April 2007

The nature and role of the shear layer, which occurs at the level of the average building height in urban canopies, are poorly understood. Velocity data are analyzed to determine the characteristics of the shear layer of the urban canopy, defined as the broad, linear segment of the mean velocity profile in a region of high shear. Particle image velocimetry measurements in a water tunnel were undertaken to resolve velocity profiles for urban canopies of two geometries typical of Los Angeles, California, and New York City, New York, for which the aspect ratios (average building height-to-width ratio) H/wb are 1 and 3, respectively. The shear layers evolve with distance differently: For H/wb = 1 the urban canopy shear layer extends quickly from above the building height to ground level, whereas for H/wb = 3 the urban canopy shear layer remains elevated at the vicinity of the building height, only reaching to a depth of z/H ∼ 0.5 far downstream. Profiles of the mean velocity gradient also differ from each other for urban canopies associated with H/wb of 1 or 3. Values of shear dU/dz increase toward ground level for an urban canopy associated with H/wb = 1. For an urban canopy associated with H/wb = 3, localized peaks of shear dU/dz exist at the building height and at ground level, with values of shear decreasing to zero at building midheight and far above the building height. A consequence of the different forms of the shear layers of the two urban canopies is that the ground-level dispersion coefficient is likely to be greater for urban canopies associated with H/wb = 1 than for those associated with H/wb = 3 because of an increased ventilation and exchange mechanism for cities such as Los Angeles relative to cities such as New York City that possess urban canyons.
Ten Commandments for Academic Talent Development
Authors: Gagné Françoys
Published: April 2007

This article describes a set of 10 positively stated commandments designed to guide professionals responsible for the academic talent development of K-12 students. The first four target identification procedures, the “who” of talent development; they ensue directly from the conceptual framework of my Differentiated Model of Giftedness and Talent. The next five pertain to intervention modalities, the “how” of talent development. The last one stands alone as a reminder of the need for realistic expectations and alternative life goals. Each of them includes detailed explanations aimed at clarifying its exact meaning as well as the reasons for its inclusion in that list.
The Impact of an Undergraduate Honors Program on Gifted University Students
Authors: Hébert Thomas P. , McBee Matthew T.
Published: April 2007

Through a qualitative research design, this study examined the experiences of seven gifted university students in an undergraduate honors program. The findings indicated the students as adolescents experienced a sense of isolation resulting from the differences between their abilities, interests, life goals, religious value systems, and the communities in which they lived. At the university, the participants discovered within the honors program an intellectual and social network with other gifted individuals like them. Together they recognized their strong desire for self-actualization. In advanced-level courses, they found intellectual stimulation and academic challenge. Through several components of the honors program they developed significant psychosocial growth. Throughout their experiences, the honors program director became a mentor and played an important role in facilitating experiences designed to address the diverse needs of these gifted young adults. Implications of the findings are presented along with suggestions for designing appropriate honors program experiences for gifted university students.
School Factors and the Underachievement of Gifted Students in a Talent Search Summer Program
Authors: Matthews Michael S. , McBee Matthew T.
Published: April 2007

The topic of underachievement and how to reverse it has received a great deal of attention in the gifted education literature. The present study sought to add to the knowledge base on this issue by investigating the occurrence of underachievement behaviors and their predictors in a population of highly gifted students attending a summer educational program based on the talent search model. A group of 440 students in Grades 8-10 were given the School Attitude Assessment Survey—Revised at the beginning of the program. Attitudes toward and grades obtained in students' regular schools had little to no predictive value on students' academic and behavioral performance during the summer program. Results support qualitative findings in the literature, suggesting that educational interventions can be extremely effective in reversing the expression of underachieving behaviors.
Costs of Rheumatoid Arthritis: New Estimates from the Human Capital Method and Comparison to the Willingness-to-Pay Method
Authors: Fautrel Bruno , Clarke Ann E. , Guillemin Francis , Adam Viviane , St-Pierre Yvan , Panaritis Tina , Fortin Paul R. , Menard Henri A. , Donaldson Cam , Penrod John R.
Published: April 2007

Background . Individuals' valuation of changes in health states in monetary terms have been measured by examining changes in the direct and indirect costs of disease and by the willingness-to-pay (WTP) methodology. Methods . In 2002, a 2-part study was conducted in Quebec. In one part of the study, 121 rheumatoid arthritis (RA) patients from the McGill University Health Centre were mailed the Stanford Cost Assessment Questionnaire, which enabled the elicitation of direct costs and indirect costs, according to the friction cost and the human capital methods. The other part was a phone survey conducted in a representative sample of the general population and in the same sample of patients, aiming to elicit the societal WTP for a complete cure of RA in the context of 2 different scenarios: a public coverage or private insurance. These estimates were then compared. Results . Estimates of the cost of illness of RA ranged from 11,717 to 28,498 Canadian Dollars (CAD) depending on the method. These estimates are higher than those previously published in Canada from the 1990s, which is partly due to the recent and costly biological therapies and to a change in the measurement of productivity losses. These estimates are somewhat lower than the societal WTP elicited from the WTP survey, that is, 26,717 and 36,817 CAD per RA case, depending on the public or private health insurance context in which the cure would be available. Conclusion . Given that neither method is ideal, data from both methods would provide an important sensitivity analysis when monetary estimates of health state changes are required.