bluuebunny/crossref_metadata_2025 huggingface dataset:
IMPEDANCE SPECTROSCOPY STUDY OF THE FERROELECTRIC Pb0.8K0.1Dy0.1Nb2O6 CERAMICS
Authors: RAO K. SAMBASIVA , LATHA T. SWARNA , KRISHNA P. MURALI , PRASAD D. MADHAVA
Published: May 2008

Polycrystalline Dy -modified Pb 1-x K 2x Nb 2 O 6 (PKN) ferroelectric ceramic with a general formula Pb 1-x K 2x-3y M y Nb 2 O 6 for x=0.20, y=0.10 and M = Dy , have been prepared by the solid-state reaction route. The X-ray diffraction (XRD) studies of the material at room temperature revealed orthorhombic structure with lattice parameters a=17.701 Å, b=17.958 Å and c=3.883 Å. The dielectric anomaly with a sharp peak is observed at 430°C. The impedance plots are used as a tool to analyze the sample behavior as a function of frequency. The grain and grain boundary contributions are estimated. The modulus mechanism indicates the non-Debye type relaxation. The activation energy value near the phase transition temperature has been found to be different in the above TC from AC conductivity measurements.
ENCRYPTION AND DECRYPTION FOR QUANTUM SECRET SHARING PROTOCOL WITH HOT TRAPPED IONS
Authors: YANG WEN-XING , CHEN AI-XI
Published: May 2008

In this letter, a efficient scheme is proposed for the quantum secret encryption and decryption implementation for quantum secret sharing protocol with trapped ions in thermal motion, in which the effective Hamiltonian does not involve the external degree of freedom and thus the scheme is insensitive to the external state, allowing it to be thermal state. The proposed scheme requires no auxiliary states to assist intermediate atomic transitions and conditional quantum dynamics for quantum phase flip and quantum state diffusion. Besides, secret transmission using entanglement swapping also has been presented.
THE VIRTUAL CROSSING NUMBER OF 2-COMPONENT FLAT VIRTUAL LINKS WITH THE SUPPORTING GENUS ONE
Authors: KADOKAMI TERUHISA
Published: May 2008

We introduce a method to estimate the virtual crossing number of a 2-component flat virtual link. In particular, we give an estimation for the case that a surface realization of the link is expressed by two non-homologous simple loops on the torus (whose supporting genus is one automatically), and determine for some special cases. To know estimations, it is important to consider "realizing problem".
COLORING ALGEBRAIC KNOTS AND LINKS
Authors: DAMIANO DAVID B. , SENNOTT ELIZABETH M.
Published: May 2008

Let K be a knot or link and let p = det (K). Using integral colorings of rational tangles, Kauffman and Lambropoulou showed that every rational K has a mod p coloring with distinct colors. If p is prime this holds for all mod p colorings. Harary and Kauffman conjectured that this should hold for prime, alternating knot diagrams without nugatory crossings for p prime. Asaeda, Przyticki and Sikora proved the conjecture for Montesinos knots. In this paper, we use an elementary combinatorial argument to prove the conjecture for prime alternating algebraic knots with prime determinant. We also give a procedure for coloring any prime alternating knot or link diagram and demonstrate the conjecture for non-algebraic examples.
Why are we shaped differently, and why does it matter?
Authors: Santosa Sylvia , Jensen Michael D.
Published: May 2008

Body fat distribution is an important predictor of metabolic abnormalities in obese humans. Dysregulation of free fatty acid (FFA) release, especially from upper body subcutaneous adipose tissue, appears to contribute substantially to these metabolic disturbances. Why different individuals preferentially store fat in upper vs. lower body subcutaneous fat or subcutaneous vs. visceral fat is not completely understood. Current evidence suggests that defects in regional lipolysis are not the cause of net fat retention in larger fat depots. Regional variations in the storage of fatty acids, both meal derived and direct reuptake, and storage of circulating FFAs that may help to explain why some depots expand at the expense of others have been reported. We review the quantitative data on regional lipolysis, meal, and FFA storage in adults to provide an overview of fat balance differences in adults with different fat distribution patterns.
Intraoperative IGS/CT Updates for Complex Endoscopic Frontal Sinus Surgery
Authors: Chennupati Sri Kiran , Woodworth Bradford A. , Palmer James N. , Cohen Noam A. , Kennedy David W. , Chiu Alexander G.
Published: May 2008

Introduction: Computer-aided surgery (CAS) systems integrate endoscopic visualization with real-time localization based on preoperative imaging. One short-coming of the current systems is the lack of real-time, radiographic assessment of surgical changes. We describe the potential applications of xCAT™, a new intraoperative mobile volume CT scanner and its utility in providing surgical navigation updates in the operating room. Methods: A case report is presented describing how intraoperative CT updates were used in a complicated, revision endoscopic frontal sinus surgery. Results: A 53-year-old male with Samter’s triad and a history of multiple previous endoscopic sinus surgeries presented with recurrent, symptomatic nasal polyposis and right-sided frontal headaches. Preoperative CT scans showed a large type III frontal recess cell obstructing the frontal sinus. He underwent revision endoscopic surgery with the use of CAS and the xCAT intraoperative CT scanner. Use of the intraoperative CT scanner to update preoperative images was extremely helpful in the endoscopic dissection of the frontal recess cell and in assessing completeness of dissection along the anterior skull base. Conclusion: The xCAT intraoperative mobile volume CT scanner shows promise in providing real-time updates to surgical navigation. This may prove to be a valuable tool in endoscopic sinus surgery, especially in complex revision and frontal sinus cases.
Gene-Environment Interactions and Familial Relative Risks
Authors: Bermejo J.Lorenzo
Published: May 2008

Objectives: Parents share genes and environmental exposures with their offspring. Spouses are often unrelated and their excess of genetic sharing is low, but the similar lifestyles of spouses regarding, for example, tobacco consumption may also result in a familial clustering of disease. This study investigates the influence of gene-environment interactions on the relative risks of disease for the offspring and the spouses of affected individuals. Methods: Theoretical models were developed to explore the dependence of familial relative risks on environmental parameters (exposure frequency, relative risk of disease for exposed versus unexposed individuals, extent of environmental sharing), on genetic parameters (allele frequency, genotype relative risk and mode of inheritance), on the number of descendants in exposed versus unexposed individuals, and on the model of gene-environment interaction. Lung cancer was used as an example of a complex disease with smoking as a known risk factor. Results: The parent-offspring and the spouse-spouse relative risks of disease varied widely in the strength of the environmental and genetic components and their degree of interaction. The familial relative risk of lung cancer decreased with increasing smoking prevalence. The relationship between exposure frequency and relative risk was markedly different when genes and environment had similar effects on disease susceptibility. Conclusions: Estimates of the relative risk of disease for varying exposure frequencies may help to assess the relevance of genetic effects in disease etiology. In particular, a positive association between offspring relative risk and exposure frequency may be indicative of genes interacting with environmental factors of similar effect sizes, with the corresponding implications for gene identification studies.
A Multi-Center Prospective, Randomized, Double-Blind Trial Studying the Effect of Misoprostol on the Outcome of Intrauterine Insemination
Authors: Billiet Kelly , Dhont Marc , Vervaet Chris , Vermeire An , Gerris Jan , De Neubourg Diane , Delbeke Luc , Ombelet Willem , De Sutter Petra
Published: May 2008

Background: Because seminal prostaglandins play a role at natural fertilization, it was hypothesized that vaginal supplementation of prostaglandins at the time of intrauterine insemination (IUI) might enhance chances of conception. We investigated the effect of misoprostol, a prostaglandin analogue, on the success rate of IUI. Methods: A multi-center double-blind randomized controlled trial, using a cross-over design with alternating sequence, was designed. Vaginal tablets of misoprostol or placebo were used in conjunction to intrauterine insemination. In total, 199 women, comprising 466 cycles, were analyzed. Main outcome measures were pregnancy rate and prevalence of vaginal bleeding and uterine cramps. Results: The misoprostol group accounted for 146 cycles with 19 pregnancies, whereas the placebo group cycles totaled 164 cycles with 21 pregnancies (13.0 vs. 12.8%, not significant). There was a statistically significant increase in vaginal bleeding (12.3 vs. 1.8%; OR 7.55; 95% CI 2.31–24.48) and abdominal cramping rates (15.1 vs. 4.3%; OR 3.98; 95% CI 1.68–9.39) after application of misoprostol. Due to these severe adverse events the study was prematurely terminated. Conclusion: Although prostaglandins surely play a role in natural human reproduction, vaginal administration of misoprostol at the time of IUI is associated with a high rate of side effects and does not seem to enhance the outcome.
Association of High-Molecular-Weight to Total Adiponectin Ratio with Pulse Wave Velocity in Hemodialysis Patients
Authors: Kato Akihiko , Odamaki Mari , Ishida Junko , Hishida Akira
Published: May 2008

High-molecular-weight adiponectin (HMW ADPN) plays an important role in the regulation of insulin action and atherogenic processes, but the role of HMW ADPN remains to be determined in hemodialysis (HD) patients. In this study, we measured serum total and HMW ADPN in 67 HD patients (age: 67 ± 14 years, time on HD: 75 ± 68 months, male/female = 39/28), and examined an association between HMW ADPN and arteriosclerotic parameters such as aortic pulse wave velocity (PWV), cardio-ankle vascular index (CAVI) and ankle-brachial pressure index (ABI). PWV was significantly correlated positively with log-transformed IL-6 (r = 0.33, p < 0.01). CAVI was significantly related to the percentile of aortic calcification area (%ACA) (r = 0.28, p = 0.03) and log-transformed IL-6 (r = 0.25, p = 0.05). ABI was associated negatively with log-transformed IL-6 (r = –0.35, p < 0.01) and %ACA (r = –0.36, p < 0.01), but positively with albumin (r = 0.33, p < 0.01). The HMW-to-total ADPN ratio, a better predictor for insulin resistance, was significantly and positively correlated with PWV (r = 0.34, p < 0.01) and CAVI (r = 0.24, p = 0.05). A multiple stepwise regression analysis revealed that the HMW-to-total ADPN ratio was an independent determinant for PWV and CAVI but not for ABI. The findings suggest that HMW-to-total ADPN ratio may be positively associated with aortic stiffness in HD patients.
+P5 (D1S3309E), a novel target binding site for the Wilms’ tumour suppressor 1 (WT1) gene, maps to human chromosome 1q21→q22
Authors: Negus K. , Holmes G.H. , Wicking C. , Wainwright B.J. , Little M.H.
Published: May 2008

The Wilms’ tumour suppressor 1 gene (WT1) encodes a zinc finger transcription factor critical for normal urogenital development. We have previously isolated a DNA fragment, +P5 (D1S3309E), to which all WT1 protein isoforms bind. Using PCR of a human × rodent somatic cell hybrid mapping panel, together with two-color fluorescence in situ hybridisation of +P5-containing cosmids and previously localised human chromosome 1q cosmids, we have mapped the +P5 fragment to chromosome 1q21→q22.
Localization of ZNF164, ZNF146, GGTA1, SOX2, PRLR and EEF2 on homoeologous cattle, sheep and goat chromosomes by fluorescent in situ hybridization and comparison with the human gene map
Authors: Hayes H. , Le Chalony C. , Goubin G. , Mercier D. , Payen E. , Bignon C. , Kohno K.
Published: May 2008

The six following genes: zinc finger proteins 164 (ZNF164) and 146 (ZNF146), alpha-galactosyltransferase 1 (GGTA1), SRY-related HMG-box 2 (SOX2), prolactin receptor (PRLR) and elongation factor 2 (EEF2) have been localized by fluorescent in situ hybridization respectively on bovine and caprine chromosomes 17, 18, 11, 1, 20 and 7 and on sheep chromosomes 17, 14, 3, 1, 16, and 5. The comparison of the results with the locations of these genes in man (except for ZNF164) confirm the correspondences between human and bovine chromosomes established from heterologous chromosome painting data.
Angiotensin II Relaxations of Bovine Adrenal Cortical Arteries
Authors: Gauthier Kathryn M. , Zhang David X. , Cui Lijie , Nithipatikom Kasem , Campbell William B.
Published: May 2008

Angiotensin (Ang) II regulates adrenal steroidogenesis and adrenal cortical arterial tone. Vascular metabolism could decrease Ang II concentrations and produce metabolites with vascular activity. Our goals were to study adrenal artery Ang II metabolism and to characterize metabolite vascular activity. Bovine adrenal cortical arteries were incubated with Ang II (100 nmol/L) for 10 and 30 minutes. Metabolites were analyzed by mass spectrometry. Ang (1-7), Ang III, and Ang IV concentrations were 146±21, 173±42 and 58±11 pg/mg at 10 minutes and 845±163, 70±14, and 31±3 pg/mg at 30 minutes, respectively. Concentration-related relaxations of U46619-preconstricted cortical arteries to Ang II (maximum relaxation=29±3%; EC
50
=3.4 pmol/L) were eliminated by endothelium removal and inhibited by the NO synthase inhibitor, nitro-
l
-arginine (30 μmol/L; maximum relaxation=14±7%). Ang II relaxations were enhanced by the angiotensin type-1 receptor antagonist losartan (1 μmol/L; maximum relaxation=41±3%; EC
50
=11 pmol/L). Losartan-enhanced Ang II relaxations were inhibited by nitro-
l
-arginine (maximum relaxation=18±5%) and the angiotensin type-2 receptor antagonist PD123319 (10 μmol/L; maximum relaxation=27±5%). Ang (1-7) and Ang III caused concentration-related relaxations with less potency (EC
50
=43 and 24 nmol/L, respectively) but similar efficacy (maximum relaxations=39±3% and 48±5%, respectively) as losartan-enhanced Ang II relaxations. Ang (1-7) relaxations were inhibited by nitro-
l
-arginine (maximum relaxation=16±4%) and the Ang (1-7) receptor antagonist 7
D
-Ala-Ang (1-7) (1 μmol/L; maximum relaxation=10±3%) and eliminated by endothelium removal. Thus, Ang II metabolism by adrenal cortical arteries to metabolites with decreased vascular activity represents an inactivation pathway possibly decreasing Ang II presentation to adrenal steroidogenic cells and limits Ang II vascular effects.
Effects of Aliskiren on Blood Pressure, Albuminuria, and (Pro)Renin Receptor Expression in Diabetic TG(mRen-2)27 Rats
Authors: Feldman David L. , Jin Liang , Xuan Hong , Contrepas Aurelie , Zhou Yinong , Webb Randy L. , Mueller Dominik N. , Feldt Sandra , Cumin Frederick , Maniara Wieslawa , Persohn Elke , Schuetz Helmut , Jan Danser A.H. , Nguyen Genevieve
Published: May 2008

The aim of this study was to explore the effects of the renin inhibitor aliskiren in streptozotocin-diabetic TG(mRen-2)27 rats. Furthermore, we investigated in vitro the effect of aliskiren on the interactions between renin and the (pro)renin receptor and between aliskiren and prorenin. Aliskiren distributed extensively to the kidneys of normotensive (non)diabetic rats, localizing in the glomeruli and vessel walls after 2 hours exposure. In diabetic TG(mRen-2)27 rats, aliskiren (10 or 30 mg/kg per day, 10 weeks) lowered blood pressure, prevented albuminuria, and suppressed renal transforming growth factor-β and collagen I expression versus vehicle. Aliskiren reduced (pro)renin receptor expression in glomeruli, tubules, and cortical vessels compared to vehicle (in situ hybridization). In human mesangial cells, aliskiren (0.1 μmol/L to 10 μmol/L) did not inhibit binding of
125
I-renin to the (pro)renin receptor, nor did it alter the activation of extracellular signal-regulated kinase 1/2 by renin (20 nmol/L) preincubated with aliskiren (100 nmol/L) or affect gene expression of the (pro)renin receptor. Evidence was obtained that aliskiren binds to the active site of prorenin. The above results demonstrate the antihypertensive and renoprotective effects of aliskiren in experimental diabetic nephropathy. The evidence that aliskiren can reduce in vivo gene expression for the (pro)renin receptor and that it may block prorenin-induced angiotensin generation supports the need for additional work to reveal the mechanism of the observed renoprotection by this renin inhibitor.
On the Gradual Evolution of Complexity and the Sudden Emergence of Complex Features
Authors: Ofria Charles , Huang Wei , Torng Eric
Published: May 2008

Evolutionary theory explains the origin of complex organismal features through a combination of reusing and extending information from less-complex traits, and by needing to exploit only one of many unlikely pathways to a viable solution. While the appearance of a new trait may seem sudden, we show that the underlying information associated with each trait evolves gradually. We study this process using digital organisms, self-replicating computer programs that mutate and evolve novel traits, including complex logic operations. When a new complex trait first appears, its proper function immediately requires the coordinated operation of many genomic positions. As the information associated with a trait increases, the probability of its simultaneous introduction drops exponentially, so it is nearly impossible for a significantly complex trait to appear without reusing existing information. We show that the total information stored in the genome increases only marginally when a trait first appears. Furthermore, most of the information associated with a new trait is either correlated with existing traits or co-opted from traits that were lost in conjunction with the appearance of the new trait. Thus, while total genomic information increases incrementally, traits that require much more information can still arise during the evolutionary process.
Criteria for Conceptual and Operational Notions of Complexity
Authors: Chu Dominique
Published: May 2008

While complex systems have been studied now for more than two decades, there still is no agreement on what complexity actually is. This lack of a definition might be a problem when asking questions about the evolution of complexity. In this article criteria against which candidate measures of complexity can be assessed are discussed. The main conclusion of this article is that because of the absence of a basic consensus on what complexity is, there is no criterion that can be used to decide whether or not a proposed measure actually measures complexity. The main recommendation is to abandon complexity as a formal notion; instead, research into the evolution of complexity should use well-understood proxy notions (as is sometimes done in the literature). For the time being “complexity” should remain an informal notion. Research into evolutionary trends of these proxy notions might eventually lead to an emergent community consensus on what complexity is.
Modeling the Contribution of the Brussels Heat Island to a Long Temperature Time Series
Authors: Van Weverberg K. , De Ridder K. , Van Rompaey A.
Published: May 2008

A mesoscale meteorological model containing a detailed land surface model is used to assess the contribution of urban heating to the temperature record of the national recording station of Belgium in Uccle, near Brussels. The Advanced Regional Prediction System (ARPS) was applied over a domain of 60 km × 60 km with a horizontal resolution of 1 km. Four meteorological episodes were selected, and, for each of these, the model was integrated using two different land cover situations. The first consisted of a detailed reconstruction of the early nineteenth-century setting of Brussels and its wide surroundings, while the second corresponded to the present-day land cover. Since the nineteenth century, when the recording station of Uccle was established, a major land cover change from an agricultural area to a built surface has taken place. The temperature difference between the simulations at the site of Uccle was assumed to represent the urban effect on the site since the beginning of recording. The urban heat island (UHI) of Brussels was found to have a significant impact on the temperature record in Uccle. The urban–rural temperature difference was found to build up during the evening, gradually decreasing during the night and becoming zero during the day. By analyzing the surface energy balance it was revealed that the UHI is mainly caused by a greater storage of energy in the urban fabric during the day and a release of this heat in the evening. The UHI had a significant average impact on the Uccle temperature record during two of the four selected weather situations. The effect amounted to 0.77°C in a cloudy weather situation with westerly winds and to 1.13°C in a clear and calm weather situation.
Drought Recurrence and Seasonal Rainfall Prediction in the Río Yaqui Basin, Mexico
Authors: Nicholas Robert E. , Battisti David S.
Published: May 2008

A statistical approach is used to explore the variability of precipitation and meteorological drought in Mexico’s Río Yaqui basin on seasonal-to-decadal time scales. For this purpose, a number of custom datasets have been developed, including a monthly 1900–2004 precipitation index for the Yaqui basin created by merging two gridded land surface precipitation products, a 349-yr tree-ring-based proxy for Yaqui wintertime rainfall, and a variety of large-scale climate indices derived from gridded SST records. Although significantly more rain falls during the summer (June–September) than during the winter (November–April), wintertime rainfall is over 3 times as variable relative to the climatological mean. Summertime rainfall appears to be unrelated to any large-scale patterns of variability, but a strong relationship between ENSO and Yaqui rainfall during the winter months offers the possibility of meaningful statistical prediction for this season’s precipitation. Analysis of both historical and reconstructed rainfall data suggests that meteorological droughts as severe as the 1994–2002 Yaqui drought occur about 2 times per century, droughts of even greater severity have occurred in the past, and such droughts are generally associated with wintertime anomalies. Whereas summertime reservoir inflow is larger in the Yaqui basin, wintertime inflow is more variable (in both relative and absolute terms) and is much more strongly correlated with same-season rainfall. Using the identified wintertime ENSO–rainfall relationship, two simple empirical forecast models for possible use by irrigation planners are demonstrated.
An Urban Parameterization for a Global Climate Model. Part II: Sensitivity to Input Parameters and the Simulated Urban Heat Island in Offline Simulations
Authors: Oleson K. W. , Bonan G. B. , Feddema J. , Vertenstein M.
Published: May 2008

In a companion paper, the authors presented a formulation and evaluation of an urban parameterization designed to represent the urban energy balance in the Community Land Model. Here the robustness of the model is tested through sensitivity studies and the model’s ability to simulate urban heat islands in different environments is evaluated. Findings show that heat storage and sensible heat flux are most sensitive to uncertainties in the input parameters within the atmospheric and surface conditions considered here. The sensitivity studies suggest that attention should be paid not only to characterizing accurately the structure of the urban area (e.g., height-to-width ratio) but also to ensuring that the input data reflect the thermal admittance properties of each of the city surfaces. Simulations of the urban heat island show that the urban model is able to capture typical observed characteristics of urban climates qualitatively. In particular, the model produces a significant heat island that increases with height-to-width ratio. In urban areas, daily minimum temperatures increase more than daily maximum temperatures, resulting in a reduced diurnal temperature range relative to equivalent rural environments. The magnitude and timing of the heat island vary tremendously depending on the prevailing meteorological conditions and the characteristics of surrounding rural environments. The model also correctly increases the Bowen ratio and canopy air temperatures of urban systems as impervious fraction increases. In general, these findings are in agreement with those observed for real urban ecosystems. Thus, the model appears to be a useful tool for examining the nature of the urban climate within the framework of global climate models.
Hurricane “Rainfall Potential” Derived from Satellite Observations Aids Overland Rainfall Prediction
Authors: Jiang Haiyan , Halverson Jeffrey B. , Simpson Joanne , Zipser Edward J.
Published: May 2008

The Tropical Rainfall Measuring Mission–based National Aeronautics and Space Administration Goddard Multisatellite Precipitation Analysis (MPA) product is used to quantify the rainfall distribution in tropical cyclones that made landfall in the United States during 1998–2004. A total of 37 tropical cyclones (TC) are examined, including 2680 three-hourly MPA precipitation observations. Rainfall distributions for overland and overocean observations are compared. It is found that the TC rainfall over ocean bears a strong relationship with the TC maximum wind, whereas the relationship for overland conditions is much weaker. The rainfall potential is defined by using the satellite-derived rain rate, the satellite-derived storm size, and the storm translation speed. This study examines the capability of the overocean rainfall potential to predict a storm’s likelihood of producing heavy rain over land. High correlations between rain potentials before landfall and the maximum storm total rain over land are found using the dataset of the 37 landfalling TCs. Correlations are higher with the average rain potential on the day prior to landfall than with averages over any other time period. A TC overland rainfall index is introduced based on the rainfall potential study. This index can be used to predict the storm peak rainfall accumulation over land. Six landfalling storms during the 2005 Atlantic Ocean hurricane season are examined to verify the capability of using this index to forecast the maximum storm total rain over land in the United States. The range of the maximum storm overland rain forecast error for these six storms is between 2.5% and 24.8%.
Volcanic Ash Transport from Mount Asama to the Tokyo Metropolitan Area Influenced by Large-Scale Local Wind Circulation
Authors: Tsunematsu Nobumitsu , Nagai Tomohiro , Murayama Toshiyuki , Adachi Ahoro , Murayama Yasuhiro
Published: May 2008

The eruption of the Mount Asama volcano on 16 September 2004 produced an ash cloud and led to ashfall in the Tokyo metropolitan area that lies on the Kanto Plain. Satellite images showed the ash cloud drifting toward the south in the morning but to the southeast in the afternoon. An aerosol lidar and a ceilometer, installed in the metropolitan area, continuously observed the southeastward-transported ash particles passing at altitudes of 2.6–4.5 km above mean sea level (MSL) in the nighttime. Results of meteorological analyses and numerical experiments showed that the south-to-southeasterly sea breezes and valley winds prevailed at altitudes below 1.5 km MSL over the Kanto Plain in the afternoon and the compensatory return flow (CRF) was formed aloft at altitudes of 1.5–4.5 km MSL as strong northwesterly winds, which were encouraged by a synoptic wind. The numerical experiments also showed that the direction of the ash transport turned from the south to the southeast following the formation of the northwesterly CRF. This demonstrates that the daytime ash transport was influenced by the CRF. The nocturnal ash transport, however, depended on the intensified synoptic wind. Thus, in addition to synoptic winds, the large-scale local wind circulation prevailing over the Kanto Plain can determine the direction of ash transport originating from the Mount Asama volcano and increase the possibility of ashfall in the Tokyo metropolitan area.
MODIS Global Cloud-Top Pressure and Amount Estimation: Algorithm Description and Results
Authors: Menzel W. Paul , Frey Richard A. , Zhang Hong , Wylie Donald P. , Moeller Chris C. , Holz Robert E. , Maddux Brent , Baum Bryan A. , Strabala Kathy I. , Gumley Liam E.
Published: May 2008

The Moderate Resolution Imaging Spectroradiometer (MODIS) on the NASA Earth Observing System (EOS) Terra and Aqua platforms provides unique measurements for deriving global and regional cloud properties. MODIS has spectral coverage combined with spatial resolution in key atmospheric bands, which is not available on previous imagers and sounders. This increased spectral coverage/spatial resolution, along with improved onboard calibration, enhances the capability for global cloud property retrievals. MODIS operational cloud products are derived globally at spatial resolutions of 5 km (referred to as level-2 products) and are aggregated to a 1° equal-angle grid (referred to as level-3 product), available for daily, 8-day, and monthly time periods. The MODIS cloud algorithm produces cloud-top pressures that are found to be within 50 hPa of lidar determinations in single-layer cloud situations. In multilayer clouds, where the upper-layer cloud is semitransparent, the MODIS cloud pressure is representative of the radiative mean between the two cloud layers. In atmospheres prone to temperature inversions, the MODIS cloud algorithm places the cloud above the inversion and hence is as much as 200 hPa off its true location. The wealth of new information available from the MODIS operational cloud products offers the promise of improved cloud climatologies. This paper 1) describes the cloud-top pressure and amount algorithm that has evolved through collection 5 as experience has been gained with in-flight data from NASA Terra and Aqua platforms; 2) compares the MODIS cloud-top pressures, converted to cloud-top heights, with similar measurements from airborne and space-based lidars; and 3) introduces global maps of MODIS and High Resolution Infrared Sounder (HIRS) cloud-top products.
Does Air Pollution Really Suppress Precipitation in Israel?
Authors: Alpert P. , Halfon N. , Levin Z.
Published: May 2008

Trends in the orographic rainfall ratio R0 over Israel are reevaluated. It is shown that the rainfall has not changed significantly over most of the mountainous stations, with some significant increases over the central mountains. The overall evaluation of R0 for all potential station pairs, calculating the ratio of each mountain station separately over each coastal or seashore station, indicates that about 50% of all pairs show a positive trend in R0. The high spatial variability, especially over the mountains, allows for finding orographic rainfall ratio trends that are significant in both the positive and negative directions. The correct definition of R0 in the Israeli case requires the use of a seashore cluster of stations. If some of the seashore stations are replaced by inland stations, and in particular stations that are right over the region of maximum positive rainfall urban enhancement due to the thermal heat island or other urban effects, a seemingly decreasing “orographic ratio” is unavoidable. In such a case, urban dynamical positive effects on coastal rainfall can be erroneously interpreted as pollution suppression of orographic rainfall. When seashore stations are selected as required by a proper definition of the orographic ratio, increasing R0 is obtained over central Israel and an insignificant trend over the north is found. Furthermore, evaluation of the ratio of rainfall for the upwind in comparison with the downwind side of the Galilee Mountains exhibits an increasing trend, opposite to the recent findings of Givati and Rosenfeld. The rainfall analysis shows no evidence of any suppression of rainfall over the mountains due to pollution, and at least in Israel other factors besides aerosols are predominant in defining the trends in the orographic rainfall ratio.
Applications of an Infrared Doppler Lidar in Detection of Wind Shear
Authors: Shun C. M. , Chan P. W.
Published: May 2008

In December 2005, operational wind shear alerting at the Hong Kong International Airport (HKIA) reached an important milestone with the launch of the automatic Lidar (light detection and ranging) Windshear Alerting System (LIWAS). This signifies that the anemometer-based and radar-based wind shear detection technologies deployed worldwide in the twentieth century have been further advanced by the addition of the lidar—a step closer to all-weather coverage.

Unlike the microburst and gust front, which have a well-defined coherent vertical structure in the lowest several hundred meters of the atmosphere, terrain-induced wind shear tends to have high spatial and temporal variability. To detect the highly changeable winds to be encountered by the aircraft under terrain-induced wind shear situations, the Hong Kong Observatory devises an innovative glide path scan (GPScan) strategy for the lidar, pointing the laser beam toward the approach and departure glide paths, with the changes in azimuth and elevation angles concerted. The purpose of the GPScans is to derive the headwind profiles and hence the wind shear along the glide paths. Developed based on these GPScans, LIWAS is able to capture about 76% of the wind shear events reported by pilots over the most-used approach corridor under clear-air conditions. During the past two years, further developments of the lidar took place at HKIA, including the use of runway-specific lidar to further enhance the wind shear detection performance.
Optimizing Performance of a Microwave Salinity Mapper: STARRS L-Band Radiometer Enhancements*
Authors: Burrage Derek M. , Wesson Joel C. , Goodberlet Mark A. , Miller Jerry L.
Published: May 2008

Airborne microwave radiometers for salinity remote sensing have advanced to a point where operational surveys can be conducted over the inner continental shelf to observe the evolution of freshwater plumes emanating from rivers and estuaries. To determine seawater microwave emissivity, and hence conductivity and salinity, precisely and accurately demands high instrument sensitivity, stability, and sampling rates; such requirements involve significant design trade-offs. The Salinity, Temperature, and Roughness Remote Scanner (STARRS) was developed to enhance these features relative to existing instruments. The authors describe here key elements of the STARRS design and the results of early performance assessments and deployments. During early deployments, the instrument performed well in areas of moderate to high salinity signal-to-noise ratio, but more homogenous areas revealed band-limited random signal fluctuations on the order of a 6-min period and ∼1-K amplitude that were of internal origin. Detailed analyses of laboratory and field tests revealed that internal “flicker,” or 1/f noise (having spectral roll-off proportional to the reciprocal of frequency f ), was the main source of these fluctuations. The instrument was modified to eliminate the random fluctuations and to further enhance sensitivity and stability. Laboratory tests and recent field deployments show that the upgrade improved instrument performance dramatically, to the extent that continental shelf scale areas with relatively homogenous salinity distributions can now be surveyed reliably using STARRS.
Potential Vorticity Diagnosis of the Severe Convective Regime. Part II: The Impact of Idealized PV Anomalies
Authors: Nielsen-Gammon John W. , Gold David A.
Published: May 2008

Idealized numerical experiments are conducted to understand the effect of upper-tropospheric potential vorticity (PV) anomalies on an environment conducive to severe weather. Anomalies are specified as a single isolated vortex, a string of vortices analogous to a negatively tilted trough, and a pair of string vortices analogous to a position error in a negatively tilted trough. The anomalies are placed adjacent to the tropopause along a strong upper-level jet at a time just prior to a major tornado outbreak and inverted using the nonlinear balance equations.

In addition to the expected destabilization beneath and adjacent to a cyclonic PV anomaly, the spatial pattern of the inverted balanced streamfunction and height fields is distorted by the presence of the horizontal PV gradient along the upper-tropospheric jet stream. Streamfunction anomalies are elongated in the cross-jet direction, while height and temperature anomalies are elongated in the along-jet direction. The amplitude of the inverted fields, as well as the changes in CAPE associated with the inverted temperature perturbations, are linearly proportional to the amplitudes of the PV anomalies themselves, and the responses to complex PV perturbation structures are approximated by the sum of the responses to individual simple PV anomalies. This is true for the range of PV amplitudes tested, which was designed to mimic typical 6-h forecast or analysis errors and produced changes in CAPE beneath the trough of well over 100 J kg−1. Impacts on inverted fields are largest when the PV anomaly is on the anticyclonic shear side of the jet, where background PV is small, compared with the cyclonic shear side of the jet, where background PV is large.
Potential Vorticity Diagnosis of the Severe Convective Regime. Part IV: Comparison with Modeling Simulations of the Moore Tornado Outbreak
Authors: Gold David A. , Nielsen-Gammon John W.
Published: May 2008

A potential vorticity (PV) diagnostic framework is used to explore the sensitivity of the 3 May 1999 Oklahoma City tornado outbreak to the strength of a particular PV anomaly proximate to the geographical region experiencing the tornado outbreak. The results derived from the balanced PV diagnosis agree broadly with those obtained previously in a numerical simulation of the same event, while offering additional insight into the nature of the sensitivity. Similar to the findings of other cases, the balanced diagnosis demonstrates that intensifying (removing) the PV anomaly of interest increases (decreases) the balanced CAPE over the southwestern portion of the outbreak region, reduces (increases) the storm-relative helicity, and increases (reduces) ascent. The latter finding, coupled with the results of the modeling study, demonstrates that intensifying a PV anomaly proximate to an outbreak environment can increase the likelihood that more widespread and possibly less tornadic convection will ensue. The overall results of the balanced diagnosis complement those of other case studies, leading to the formulation of a conceptual model that broadly anticipates how the convective regime will respond to changes in intensity of upper-tropospheric weather features.
Low-Frequency Modulation of Intraseasonal Equatorial Kelvin Wave Activity in the Pacific from SODA: 1958–2001
Authors: Dewitte Boris , Purca Sara , Illig Serena , Renault Lionel , Giese Benjamin S.
Published: May 2008

Intraseasonal equatorial Kelvin wave activity (IEKW) at a low frequency in the Pacific is investigated using the Simple Ocean Data Assimilation (SODA) oceanic reanalyses. A vertical and horizontal mode decomposition of SODA variability allows estimation of the Kelvin wave amplitude according to the most energetic baroclinic modes. A wavenumber–frequency analysis is then performed on the time series to derive indices of modulation of the IEKW at various frequency bands. The results indicate that the IEKW activity undergoes a significant modulation that projects onto baroclinic modes and is not related in a straightforward manner to the low-frequency climate variability in the Pacific. Linear model experiments corroborate that part of the modulation of the IEKW is tightly linked to change in oceanic mean state rather than to the low-frequency change of atmospheric equatorial variability.
Effects of Multiple Scattering on Attenuation-Based Retrievals of Stratiform Rainfall from CloudSat
Authors: Matrosov Sergey Y. , Battaglia Alessandro , Rodriguez Peter
Published: May 2008

An attenuation-based method to retrieve vertical profiles of rainfall rates from height derivatives/gradients of CloudSat nadir-pointing W-band reflectivity measurements is discussed. This method takes advantage of the high attenuation of W-band frequency signals in rain and the low variability of nonattenuated reflectivity due to strong non-Rayleigh scattering from rain drops. The retrieval uncertainties could reach 40%–50%. The suggested method is generally applicable to rainfall rates (R) in an approximate range from about 2–3 to about 20–25 mm h−1. Multiple scattering noticeably affects the gradients of CloudSat measurements for R values greater than about 5 mm h−1. To avoid a retrieval bias caused by multiple-scattering effects, a special correction for retrievals is introduced. For rainfall rates greater than about 25 mm h−1, the influence of multiple scattering gets overwhelming, and the retrievals become problematic, especially for rainfalls with higher freezing-level altitudes. The attenuation-based retrieval method was applied to experimental data from CloudSat covering the range of rainfall rates. CloudSat retrievals were compared to the rainfall estimates available from a National Weather Service ground-based scanning precipitation radar operating at S band. Comparisons between spaceborne and conventional radar rainfall retrievals were generally in good agreement and indicated the mutual consistency of both quantitative precipitation estimate types. The suggested CloudSat rainfall retrieval method is immune to the absolute calibration of the radar and to attenuation caused by the melting layer and snow regions. Since it does not require surface returns, it is applicable to measurements above both land and water surfaces.
Scale-Selective Digital-Filtering Initialization
Authors: Termonia Piet
Published: May 2008

Digital-filtering initialization (DFI) of atmospheric models relies on the fact that the gravity–inertia waves have higher frequencies than the meteorologically relevant rotational modes and assumes that a frequency exists that separates them. This note shows that a Doppler effect of fast-propagating storms may “shift” the frequencies of the small-scale rotational modes into the frequency categories that are deemed to be the ones of the gravity–inertia waves. A forecast is presented in which the impact of this on DFI manifests itself to a substantial extent (i.e., a reduction the depth of the eye of the storm by about 6–7 hPa). As a cure it is proposed to make the filtering scale selective (i.e., filtering the large spatial scales more than the small ones). It is shown that, not only does this leave the storm almost intact, but it also leads to a more balanced initial state. The implementation of such a filter is straightforward in a spectral limited-area model.
A real break or reluctant parting? France, the United States and the Spanish Question, 1946
Authors: Messenger David A.
Published: May 2008

In 1946, the French government imposed sanctions on the authoritarian Franco regime in Spain. France was the only western state to take action on Spain that moved beyond rhetorical condemnation. This action was preceded and followed by intense private and public efforts to convince the United States and Great Britain to impose sanctions too. Why could France not accept the western alliance's commitment to the status quo when it was evident this was the preferred policy of the Foreign Minister Georges Bidault? When it came to the Spanish Question, the significance of Resistance rhetoric and imagery about an idealized new world competed with a realistic assessment of France's new role tied to the United States. The result was an awkwardly constructed French policy which undermined, at least for a moment, France's place in the emerging Cold War alliance.
Jean-Paul Sartre, John Steinbeck and the liability of liberty in the post-war period
Authors: Stephens Bradley
Published: May 2008

The polarities of the Cold War impelled many intellectuals on both sides of the Atlantic to take sides either with capitalism or communism. Both Jean-Paul Sartre and John Steinbeck famously attempted to respond to this ideological choice and would differ in their political leanings: Sartre was an outspoken critic of American capitalist hegemony, whereas Steinbeck became an avid opponent of the communist bloc. They nonetheless shared a dedication to engaging with the social issues of their time, becoming arguably the pre-eminent proletarian writers of the period and eventual Nobel Prize winners. Sartre believed Steinbeck to be `the most rebellious, perhaps' of American writers, whilst Steinbeck so admired the French intellectual scene typified by Sartre that he spent nearly a year in Paris writing for Le Figaro. Their pivotal promotion of individual freedom may have nudged them towards both ends of the political spectrum respectively; yet their emphasis on the changeability of human existence constantly destabilized any position they approached. In this article I argue for a productive return to their writing in order to underline the alternations both encounter when seeking to put the libertarian ideal of individuality into practice. In their novels L'Âge de raison (1945) and East of Eden (1952), as well as in their journals, we can observe how their mutual emphasis on man's indeterminism as an autonomous subject inevitably dissolves the foundation of any normative political ethos. As such, it is crucial to reiterate that their engagement with the post-war period in fact deeply complicates the drive for totalization and systemization implied in the strict allegiances of the Cold War political terrain.
Effects of Aliskiren, a Direct Renin Inhibitor, on Cardiac Repolarization and Conduction in Healthy Subjects
Authors: Ayalasomayajula Surya , Yeh Ching‐Ming , Vaidyanathan Sujata , Flannery Brian , Dieterich Hans Armin , Howard Dan , Bedigian Martin P. , Dole William P.
Published: May 2008

This multicenter, double‐blind study evaluated the effects of aliskiren, a direct renin inhibitor approved for hypertension, on cardiac repolarization and conduction. Healthy volunteers (n = 298) were randomized to aliskiren 300 mg, aliskiren 1200 mg, moxifloxacin 400 mg (positive control), or placebo once daily for 7 days. Digitized electrocardiograms were obtained at baseline and day 7 of treatment over 23 hours postdose. Placebo‐adjusted mean changes from baseline in QTcF (Fridericia corrected), QTcI (individualized correction), PR, and QRS intervals were compared at each time point (time‐matched analysis) and for values averaged across the dosing period (baseline‐averaged analysis). In time‐matched analysis, mean changes in QTcF with aliskiren were below predefined limits for QTc prolongation (mean increase <5 milliseconds; upper 90% confidence interval [CI] <1 0 milliseconds) except aliskiren 1200 mg at 23 hours (5.2 milliseconds; 90% CI 2.2, 8.1). With moxifloxacin, significant QTcF prolongation occurred at most time points, confirming the sensitivity of the assay. Baseline‐averaged analysis was consistent with time‐matched analysis. Instances of QTcF interval >450 milliseconds or a >30‐millisecond increase from baseline with aliskiren (≤1%) were similar or lower than placebo (≤4%). Results were similar for QTcI. Aliskiren had no effect on PR or QRS duration. In conclusion, aliskiren at the highest approved dose (300 mg) and a 4‐fold higher dose had no effect on cardiac repolarization or conduction in healthy volunteers.