bluuebunny/crossref_metadata_2025 huggingface dataset:
Doping control analysis of tricyclic tetrahydroquinoline‐derived selective androgen receptor modulators using liquid chromatography/electrospray ionization tandem mass spectrometry
Authors: Thevis Mario , Kohler Maxie , Thomas Andreas , Schlörer Nils , Schänzer Wilhelm
Published: July 2008

Selective androgen receptor modulators represent an emerging class of therapeutics to counteract various diseases such as osteoporosis and muscle wasting. Numerous drug candidates have been developed and investigated including a group that comprises a tricyclic tetrahydroquinoline nucleus such as 2‐methyl‐2‐(8‐nitro‐3a,4,5,9b‐tetrahydro‐3H‐cyclopenta[c]chinolin‐4‐yl)propan‐1‐ol. Due to their novelty and medicinal purpose, these compounds also possess great potential for misuse in sports, and studies on the mass spectrometric behavior of three synthesized model substances and drug candidates were conducted to provide information on typical dissociation pathways following electrospray ionization and collision‐induced dissociation. Product ion mass spectra derived from protonated molecules were studied using high resolution/high accuracy orbitrap mass spectrometry, and characteristic fragmentation routes and product ions were elucidated. Major and general findings include the elimination of a hydroxyl radical from [M+H]+, the elimination of the 2‐substituted side chain, and the gas‐phase rearrangement of the investigated tricyclic tetrahydroquinolines to 6‐nitroquinoline yielding a common product ion at m/z 175. Knowledge of these dissociation pathways supports the identification of related substances as well as metabolic products, which is of utmost importance to drug testing laboratories. The compounds were implemented into existing screening procedures, and detection limits (0.2–0.6 ng/mL), recoveries (92–97%), and intraday and interday precision (<22%) were evaluated. Copyright © 2008 John Wiley & Sons, Ltd.
A new approach to the giant component problem
Authors: Janson Svante , Luczak Malwina J.
Published: July 2008

We study the largest component of a random (multi)graph on n vertices with a given degree sequence. We let n → ∞. Then, under some regularity conditions on the degree sequences, we give conditions on the asymptotic shape of the degree sequence that imply that with high probability all the components are small, and other conditions that imply that with high probability there is a giant component and the sizes of its vertex and edge sets satisfy a law of large numbers; under suitable assumptions these are the only two possibilities. In particular, we recover the results by Molloy and Reed on the size of the largest component in a random graph with a given degree sequence.

We further obtain a new sharp result for the giant component just above the threshold, generalizing the case of G(n,p) with np = 1 + ω(n)n−1/3, where ω(n) → ∞ arbitrarily slowly.

Our method is based on the properties of empirical distributions of independent random variables, and leads to simple proofs. © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2009
Automatic identification of key classes in a software system using webmining techniques
Authors: Zaidman Andy , Demeyer Serge
Published: July 2008

Software engineers new to a project are often stuck sorting through hundreds of classes in order to find those few classes that offer a significant insight into the inner workings of the software project. To help stimulate this process, we propose a technique that can identify the most important classes in a system or the key classes of that system. Software engineers can use these classes to focus their understanding efforts when starting to work on a new software project. Those key classes are typically characterized with having a lot of ‘control’ within the application. In order to find these controlling classes, we present a detection approach that is based on dynamic coupling and webmining. We demonstrate the potential of our technique using two open‐source software systems that have a rich documentation set. During the case studies we use dynamically gathered coupling information that vary between a number of coupling metrics. The case studies show that we are able to retrieve 90% of the classes deemed important by the original maintainers of the systems, while maintaining a level of precision of around 50%. Copyright © 2008 John Wiley & Sons, Ltd.
Semi‐automatic segmentation of fetal cardiac cavities: progress towards an automated fetal echocardiogram
Authors: Tutschek B. , Sahn D. J.
Published: July 2008

Objective

To develop a novel application of a tool for semi‐automatic volume segmentation and adapt it for analysis of fetal cardiac cavities and vessels from heart volume datasets.

Methods

We studied retrospectively virtual cardiac volume cycles obtained with spatiotemporal image correlation (STIC) from six fetuses with postnatally confirmed diagnoses: four with normal hearts between 19 and 29 completed gestational weeks, one with d‐transposition of the great arteries and one with hypoplastic left heart syndrome. The volumes were analyzed offline using a commercially available segmentation algorithm designed for ovarian folliculometry. Using this software, individual ‘cavities’ in a static volume are selected and assigned individual colors in cross‐sections and in 3D‐rendered views, and their dimensions (diameters and volumes) can be calculated.

Results

Individual segments of fetal cardiac cavities could be separated, adjacent segments merged and the resulting electronic casts studied in their spatial context. Volume measurements could also be performed. Exemplary images and interactive videoclips showing the segmented digital casts were generated.

Conclusion

The approach presented here is an important step towards an automated fetal volume echocardiogram. It has the potential both to help in obtaining a correct structural diagnosis, and to generate exemplary visual displays of cardiac anatomy in normal and structurally abnormal cases for consultation and teaching. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Osteopontin Expression in Squamous Cell Cancer of the Esophagus
Authors: Wu I‐Chen , Wu Ming‐Tsang , Chou Shah‐Hwa , Yang Sheau‐Fang , Goan Yih‐Gang , Lee Jang‐Ming , Chou Yi‐Pin , Bair Ming‐Jong , Wang Tsang‐En , Chen Angela , Chang Wen‐Hsiung , Kuo Fu‐Chen , Wu Deng‐Chyang
Published: July 2008

Background

The purpose of this study was to better understand the role of osteopontin (OPN) in esophageal squamous cell carcinoma (ESCC) by comparing the OPN mRNA level in ESCC tumor tissue and matched normal tissue and by determining the prognostic significance of the gene expression.

Methods

Initially, by an oligo‐nucleotide microarray hybridization technique, OPN expressions were found to consistently elevate at least twofold in three ESCC tissues compared with their adjacent normal ones. Subsequently, the expression of OPN mRNA was detected by real‐time QRT‐PCR among the 58 fresh surgical ESCC specimens. The clinical information was obtained by chart review.

Results

OPN mRNA expression was detectable in 58 of 58 (100%) tumor specimens and 57 of 58 (98.3%) nonmalignant esophageal specimens. OPN expression was higher in tumor tissue than in the matched normal tissue in 54 of 58 (93.1%) individual cases. The overall median mRNA expression level of OPN was approximately 8.8‐fold higher in tumor tissues (4.1; range: 0.02–247) compared with matched normal esophageal tissues (0.5; range, 0.0–21.4; p < 0.001). Overexpression of OPN mRNA was significantly associated with clinical stage (p = 0.01). The more severe the clinical stage (from I‐II, III, to IV) was the higher frequency of overexpression of OPN mRNA. No significant associations were found between overexpression of OPN mRNA and the patients’ survival (p = 0.27).

Discussion

Our findings suggest OPN is associated with esophageal tumorigenesis and progression, but not patients’ survival.
Center and periphery: The expansion and metamorphosis of Han culture
Authors: Wei HUO
Published: July 2008

The cave reliefs of Mahao in Leshan City, Sichuan Province, have been world-famous for containing an early Buddhist statue. Yet, little attention has been paid to the co-existent stone reliefs sharing the tomb cave and the cultural significance thereof. Through the Qin and Han dynasties (221 BC–220 AD), the ancient Ba and Shu civilizations in what is Sichuan today gradually merged into the Chinese civilization, of which the Han civilization is the main body, on the one hand, the Han civilization exerted a strong influence on its south-western counterparts, as is revealed by the stone reliefs in the tomb cave; on the other hand, the south-western region was apparently assimilated into the Chinese civilization while concurrently absorbing elements of even farther civilizations (e.g., those in Central and South Asia). The early image of Buddha appeared against a wide cultural background.
Bedeutung von Polymorphismen für venöse und arterielle Thrombosen
Authors: Seidel H.
Published: July 2008

Die Polymorphismen der thrombozytären Glykoproteine Ia-IIa (GP Ia C807T) und HPA-1a/1b (GP IIIa T1565C), des Fibrinolyseinhibitors PAI-1 675 4G/5G sowie der Methylentetrahydrofolatreduktase MTHFR C677T werden immer wieder als Risikofaktoren für arterielle und venöse Thrombembolien diskutiert. Ihr prädiktiver Wert für das Auftreten von thrombembolischen Ereignissen ist jedoch aufgrund einer widersprüchlichen Datenlage unklar. Nach derzeitigem Kenntnisstand gehen die genannten Polymorphismen nicht gesichert mit einem erhöhten Thrombembolierisiko einher. Daher ist ihre Untersuchung zurzeit weder in der arteriellen noch in der venösen Thrombophiliediagnostik indiziert. Aufgrund der hohen Prävalenzen dieser genetischen Merkmale bedarf es weiterer Untersuchungen, um die Grenzen zwischen Confoundereffekt und Risikofaktor zu definieren.
Identification of potential genes/proteins regulated by Tiam1 in colorectal cancer by microarray analysis and proteome analysis
Authors: Liu Li , Wang Shuang , Zhang Qingling , Ding Yanqing
Published: July 2008

Tiam1 (T‐cell lymphoma invasion and metastasis‐inducing protein 1), a guanine nucleotide exchange factor that activates Rac, is a colorectal cancer metastasis‐related gene. In this study, we aimed to better understand the mechanism underlying Tiam1‐mediated metastasis. We applied gene microarray and proteome analysis and compared expression of genes and proteins in a stable Tiam1‐silencing colorectal cancer cell line and in a control cell line. Our analysis identified three genes, high‐mobility group box1 (HMGB1), annexin IV (ANXA4) and phosphoglycerate mutase 1 (PGAM1) that were associated with Tiam1. Analysis of these proteins, which may be directly or indirectly regulated by Tiam1, may provide insight into the role and mechanism of Tiam1 in colorectal cancer metastasis.
Deletion of the autoregulatory insert modulates intraprotein electron transfer in rat neuronal nitric oxide synthase
Authors: Feng Changjian , Roman Linda J. , Hazzard James T. , Ghosh Dipak K. , Tollin Gordon , Masters Bettie Sue S.
Published: July 2008

Comparative CO photolysis kinetics studies on wild‐type and autoregulatory (AR) insert‐deletion mutant of rat nNOS holoenzyme were conducted to directly investigate the role of the unique AR insert in the catalytically significant FMN–heme intraprotein electron transfer (IET). Although the amplitude of the IET kinetic traces was decreased two‐ to three‐fold, the AR deletion did not change the rate constant for the calmodulin‐controlled IET. This suggests that the rate‐limiting conversion of the electron‐accepting state to a new electron‐donating (output) state does not involve interactions with the AR insert, but that AR may stabilize the output state once it is formed.
Mutagenesis of Gln294 of the reverse transcriptase of human immunodeficiency virus type‐2 and its effects on the ribonuclease H activity
Authors: Bochner R. , Duvshani A. , Adir N. , Hizi A.
Published: July 2008

Despite the high homology between human immunodeficiency virus type‐1 (HIV‐1) and human immunodeficiency virus type‐2 (HIV‐2) reverse transcriptases (RTs), the ribonuclease H (RNase H) level of HIV‐2 RT is lower than that of HIV‐1 RT, while the DNA polymerase of both RTs is similar. We conducted mutagenesis of HIV‐2 RT Gln294 (shown to control the RNase H activity level when modified to a Pro in the smaller p54 subunit and not in the larger p68 subunit) to various residues, and assayed the activities of all mutants. All exhibited an RNase H that is higher than the wild‐type (WT) HIV‐2 RT level, although the DNA polymerase of all mutants equals WT HIV‐2 RT level. These results represent a unique case, where every mutation induces an increase rather than a decrease in an enzyme's activity.
Safety networks: fishery barometers and the outsourcing of judgement at the early Meteorological Department
Authors: DRY SARAH
Published: July 2008

In 1854 Admiral FitzRoy, acting as the first head of the Meteorological Department of the Board of Trade, initiated a project to distribute fishery barometers to poor fishing communities. Over the next eleven years until his untimely death in 1865, FitzRoy oversaw the distribution of dozens of barometers. The distribution continued after his death and many of the original barometers are still in place. FitzRoy's tenure at the Met Department is today remembered for his innovative and controversial development of weather forecasts, the first of their kind in Britain, which were telegraphed to coastal towns to warn of impending storms. Against the backdrop of this dramatic attempt to predict the weather using the tools of telegraphy and synoptic mapping, the barometer distribution project looks like an unexceptional piece of administration, a routine shuttling of correspondence and instruments. Closer inspection reveals a case study in Victorian governance that shows how individuals could contribute to elite forms of science by remaining independent of them in key respects. Rather than providing disciplined and trustworthy registrations of nature's language, the fishery barometers distributed by FitzRoy and the Met Department were explicitly excluded from the wider project to map British and global weather. By being thus excluded, they helped augment the autonomy of their intended users, the poor fishermen who were thereby made into better, more independent, interpreters of the Met Office forecasts. By revealing the potential for an instrument to be useful when not registering, this episode suggests that instruments could augment as well as replace the autonomous judgements of individuals.
Raising the aerocompass in early twentieth-century Britain
Authors: DAVIS SOPHIA
Published: July 2008

This paper concerns the movement of the old navigational instrument, the compass, into the new situation of the aeroplane in the early part of the twentieth century. In order for the technology that had so long resided on ships or in the hand to continue to function in new contexts, a huge amount of work was required. Relationships were forged and made fraught, inventions were made to contest and succeed one another, new scientific and technical knowledge was produced. Throughout, the perceived nature of compasses and magnetic fields underwent subtle but significant shifts. Until recently histories dealing with the emergence of the aerocompass have largely black-boxed the technological changes, with only superficial treatment of issues lying beyond the compass itself.1 John Bradley's exploration of the feud between the Admiralty and military compass designers, and the sections in both Bradley's and A. E. Fanning's work on lawsuits over originality,2 go some way towards rectifying this imbalance. This paper extends that work further. It focuses on events in Britain, particularly those centred on two institutions, the Admiralty Compass Observatory at Ditton Park, Slough, and the Royal Aircraft Factory (later the Royal Aircraft Establishment) at Farnborough.
Bipartisan politics and practical knowledge: advertising of public science in two London newspapers, 1695–1720
Authors: WIGELSWORTH JEFFREY R.
Published: July 2008

This article explores the enticement of consumers for natural philosophy (buyers of books, audiences at public lectures and purchasers of instruments) in London between 1695 and 1720 through advertisements placed in two political newspapers. This twenty-five-year period witnessed both the birth of public science and the rage of party politics. A consideration of public science adverts within the Whig-leaning Post Man and the Tory-leaning Post Boy reveals that members of both the Whig and Tory parties were equally targeted and that natural philosophy was sold to London's reading population in bipartisan fashion. In the process of integrating natural philosophy into the wider culture through commercial sales, political allegiances were not imprinted on the advertising process. This conclusion raises questions regarding the historiographical assertion of Whig-supported public science and Tory opposition to it at the level of consumers.
Presbyterians and science in the north of Ireland before 1874
Authors: HOLMES ANDREW R.
Published: July 2008

In his presidential address to the Belfast meeting of the British Association for the Advancement of Science in 1874, John Tyndall launched what David Livingstone has called a ‘frontal assault on teleology and Christian theism’. Using Tyndall's intervention as a starting point, this paper seeks to understand the attitudes of Presbyterians in the north of Ireland to science in the first three-quarters of the nineteenth century. The first section outlines some background, including the attitude of Presbyterians to science in the eighteenth century, the development of educational facilities in Ireland for the training of Presbyterian ministers, and the specific cultural and political circumstances in Ireland that influenced Presbyterian responses to science more generally. The next two sections examine two specific applications by Irish Presbyterians of the term ‘science’: first, the emergence of a distinctive Presbyterian theology of nature and the application of inductive scientific methodology to the study of theology, and second, the Presbyterian conviction that mind had ascendancy over matter which underpinned their commitment to the development of a science of the mind. The final two sections examine, in turn, the relationship between science and an eschatological reading of the signs of the times, and attitudes to Darwinian evolution in the fifteen years between the publication ofThe Origin of Speciesin 1859 and Tyndall's speech in 1874.
Analysis of the impact of fortified food consumption on overall dietary quality in Irish adults
Authors: Joyce Triona , Hannon Evelyn M. , Kiely Mairead , Flynn Albert
Published: July 2008

The aim of the present study was to assess the impact of fortified food (FF) consumption on overall dietary quality in Irish adults. Data for this analysis was based on the North/South Ireland Food Consumption Survey w7/15/2008hich used a 7 d food diary to collect food and beverage intake data in a representative sample of 1379 Irish adults (662 men and 717 women) aged 18–64 years. Foods contained in the database that are fortified were identified from the presence of vitamins and/or minerals in the ingredient list on the label. The results showed that an increased level of FF consumption was associated with lower intakes (percentage food energy) of total fat and saturated fat (women only) and higher intakes of total carbohydrate, total sugars (but not added sugars) and starch. Increased consumption was associated with a more micronutrient-dense diet and a reduced prevalence of dietary inadequacies of Ca, Fe, riboflavin and folate, particularly in women. Higher FF consumption was associated with higher intakes of fruit, lower intakes of alcohol and a lower likelihood of smoking in men and women. Thus it appears that FF consumption is a marker of both better dietary quality and healthy lifestyle behaviours.
Whole-grain consumption and transcription factor-7-like 2 (TCF7L2) rs7903146: gene–diet interaction in modulating type 2 diabetes risk
Authors: Fisher Eva , Boeing Heiner , Fritsche Andreas , Doering Frank , Joost Hans-Georg , Schulze Matthias B.
Published: July 2008

Whole grains are known to influence postprandial glucose response and insulin demand and are inversely associated with diabetes risk. Genetic variation of the transcription factor-7-like 2 encoding gene (TCF7L2) is assumed to promote an early insulin secretory defect and has been consistently attributed to the risk of developing type 2 diabetes. The present study examined the hypothesis that the protective effect of whole grains might be attenuated in the presence of the rs7903146 risk-conferring T-allele. We employed a case–cohort study of 2318 randomised individuals and 724 incident type 2 diabetes cases from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam cohort. Multivariate Cox regression was used to estimate relative risks of diabetes including product terms testing for the genotype-specific effect modification of dietary whole grain. Dietary intake of whole grains was assessed by a validated FFQ. The TCF7L2 rs7903146 T-allele was associated with type 2 diabetes (hazard ratio = 1·51; 95 % CI 1·21, 1·87) and modified the inverse association between whole-grain intake and diabetes risk (P = 0·016 for interaction). While whole-grain intake was inversely associated with diabetes risk among rs7903146 CC homozygote carriers (hazard ratio for 50 g portion per d = 0·86; 95 % CI 0·75, 0·99), the T-allele negated the protective effect of whole-grain intake (hazard ratio among T-allele carriers for 50 g portion per d = 1·08; 95 % CI 0·96, 1·23). These data provide evidence that the beneficial effect of whole-grain intake on diabetes risk is modified by TCF7L2 rs7903146.
Anti-inflammatory effects of long-chainn-3 PUFA in rhinovirus-infected cultured airway epithelial cells
Authors: Saedisomeolia Ahmad , Wood Lisa G. , Garg Manohar L. , Gibson Peter G. , Wark Peter A. B.
Published: July 2008

Long-chainn-3 PUFA (LCn-3PUFA) including DHA and EPA, are known to decrease inflammation by inhibiting arachidonic acid (AA) metabolism to eicosanoids, decreasing the production of pro-inflammatory cytokines and reducing immune cell function. The aim of this study was to determine if EPA and DHA reduced the release of inflammatory mediators from airway epithelial cells infected with rhinovirus (RV). Airway epithelial cells (Calu-3) were incubated with EPA, DHA and AA for 24 h, followed by rhinovirus infection for 48 h. IL-6, IL-8 and interferon-γ-induced protein-10 (IP-10) released by cells were measured using ELISA. Viral replication was measured by serial titration assays. The fatty acid content of cells was analysed using GC. Cellular viability was determined by visual inspection of cells and lactate dehydrogenase release. DHA (400 μm) resulted in a significant 16 % reduction in IL-6 release after RV-43 infection, 29 % reduction in IL-6 release after RV-1B infection, 28 % reduction in IP-10 release after RV-43 infection and 23 % reduction in IP-10 release after RV-1B infection. Cellular DHA content negatively correlated with IL-6 and IP-10 release. None of the fatty acids significantly modified rhinovirus replication. DHA supplementation resulted in increased cellular content of DHA at the cost of AA, which may explain the decreased inflammatory response of cells. EPA and AA did not change the release of inflammatory biomarkers significantly. It is concluded that DHA has a potential role in suppressing RV-induced airway inflammation.
Analysis of fat and muscle mass in patients with inflammatory bowel disease during remission and active phase
Authors: Rocha Raquel , Santana Genoile Oliveira , Almeida Neogélia , Lyra Andre Castro
Published: July 2008

Inflammatory bowel disease (IBD) is often associated with malnutrition. The aim of this study was to compare the body composition of outpatients with IBD during remission and active phase. In order to evaluate disease activity we used Crohn's Disease Activity Index for Crohn's disease (CD) patients and Lichtiger's Index for ulcerative colitis (UC) patients. All patients underwent the analysis of BMI, arm muscle area (AMA) and triceps plus subscapula skinfold thickness (TST+SST) to identify total, muscle and fat mass, respectively. In total 102 patients were evaluated (CD,n50; UC,n52) and the majority was young women. Malnutrition according to BMI was found in 14·0 % of patients with CD and 5·7 % of UC patients. Muscle mass depletion was detected in more than half of the CD and UC patients. The BMI, TST+SST and AMA values were lower in the active phase only in CD patients (P < 0·05). Fat mass depletion was associated with active phase in both CD and UC patients. Body composition parameters obtained using BMI, TST+SST and AMA were not correlated with the presence of fistula in CD patients (P>0·05). In conclusion, patients without signs of malnutrition had fat mass depletion especially in the active phase and muscle mass depletion occurred both in CD and UC patients.
Hepatitis B vaccination and changes in sexual risk behaviour among men who have sex with men in Amsterdam
Authors: XIRIDOU M. , WALLINGA J. , DUKERS-MUIJERS N. , COUTINHO R.
Published: July 2008

The impact of hepatitis B vaccination in men having sex with men in Amsterdam has been marginal until now, possibly because of increases in sexual risk behaviour counterbalancing the effect of vaccination. A mathematical model is used to describe the hepatitis B epidemic. The model shows that, with the current vaccination coverage, the decrease in incidence is small in the beginning. However, the number of infections prevented per vaccine administered rises over time. Nevertheless, increased risk behaviour reduces the benefit of vaccination. Targeting high-risk men is more successful in reducing and containing the epidemic than targeting low-risk men. In conclusion, the vaccination campaign is effective and should be intensified. High-risk men should be targeted for vaccination and for risk reduction.
Warm, wet weather associated with increased Legionnaires' disease incidence in The Netherlands
Authors: KARAGIANNIS I. , BRANDSEMA P. , VAN DER SANDE M.
Published: July 2008

It has been suggested that warm and humid weather is related to a high incidence of Legionnaires' disease (LD), but no data on this association existed in The Netherlands. The objective of this study was to investigate the short-term effects of the weather on LD in The Netherlands. National LD surveillance and meteorological data were obtained. We analysed the data using Poisson regression, adjusting for long-term trends, and using principal components analysis. The highest weekly incidence of LD occurred when the mean weekly temperature was +17·5°C. Mean weekly relative humidity, temperature and precipitation intensity were associated with LD incidence in the multivariable model. Warm, humid and showery summer weather was found to be associated with higher incidence of LD in The Netherlands. These results may be used to predict an increase in the number of cases of LD in The Netherlands during the summer.
Long-Range Percolation Mixing Time
Authors: BENJAMINI ITAI , BERGER NOAM , YADIN ARIEL
Published: July 2008

We provide an estimate, sharp up to poly-logarithmic factors, of the asymptotic almost sure mixing time of the graph created by long-range percolation on the cycle of length N ($\Integer/N\Integer$). While it is known that the asymptotic almost sure diameter drops from linear to poly-logarithmic as the exponent s decreases below 2 [4, 9], the asymptotic almost sure mixing time drops from N2 only to Ns-1 (up to poly-logarithmic factors).
Delineation of carbonate dust, aluminous dust, and sea salt deposition in a Greenland glaciochemical array using positive matrix factorization
Authors: Banta J. Ryan , McConnell Joseph R. , Edwards Ross , Engelbrecht Johann P.
Published: July 2008

High‐resolution trace element records from polar ice cores are fundamental to identifying spatial and temporal variability in dust and sea salt aerosols. Here, we developed high temporal resolution glaciochemical records over recent centuries from an array of seven recently collected Greenland ice cores. Positive matrix factorization (PMF) was used to assess apportionment of trace elements between three unique sources, which were identified as proxies of carbonate dust, aluminous dust, and sea salt. The three PMF factors agree well with literature values and represent the first time carbonate and aluminous dust sources have been quantifiably differentiated using high‐resolution glaciochemistry. The concentrations of all three sources varied with ice core site. However, the large array of ice cores provided a regional‐scale understanding of the sources and magnitude of dust and sea salt impurities deposited on the Greenland ice sheet. At the regional level, all three sources varied on seasonal, annual, and multiyear timescales. The seasonal deposition of sea salt impurities reached a maximum in the winter, followed by spring peaks of carbonate and aluminous dust. Over the 331 year composite record, only aluminous dust exhibited a long‐term increasing trend that peaked in the 1930s and was followed by a 20% decline in recent decades.
Impacts of chromophoric dissolved organic material on surface ocean heating in the Chukchi Sea
Authors: Hill Victoria J.
Published: July 2008

Recent observations show visible light attenuation in the Arctic Ocean to be greater than previously assumed. High attenuation observed during the period prior to ice melt and increased phytoplankton production, was attributed primarily to the high levels of absorption by chromophoric dissolved organic material (CDOM) present in these waters. Preliminary evidence suggests this material is produced by ice algae in the early spring. Optical data from the Chukchi shelf system collected in the spring and summer of 2002, were used to model energy absorption in the mixed layer by both dissolved and particulate material. In the spring, absorption by CDOM was responsible for increasing the energy absorbed in the mixed layer by 40% over pure seawater. Thus CDOM absorption represents a significant factor in the heating budget of Arctic surface waters. The energy absorbed by CDOM has the potential to account for 48% of the springtime ice melt driven by water column heating. With continued warming, negative feedback due to loss of ice algae habitat could slow down heating effects in the spring. However, terrestrial input of CDOM to the Arctic is postulated to increase due to the release of organic carbon from thawing permafrost. Coupled with the loss of the highly reflective sea ice cover during the spring and summer, CDOM absorption may become increasingly influential in the heating budget of Arctic surface waters.
Uncertainties in atmospheric surface pressure fields from global analyses
Authors: Salstein David A. , Ponte Rui M. , Cady‐Pereira Karen
Published: July 2008

Operational analyses from the U.S. National Centers for Environmental Prediction (NCEP) and the European Centre for Medium‐Range Weather Forecasts (ECMWF) provide, among other quantities, atmospheric surface pressure. This field is especially useful for data processing and interpretation of altimeter and gravity satellite missions like Jason‐1 and GRACE (Gravity Recovery and Climate Experiment). Quantitative use of this pressure field, however, requires knowledge of its uncertainties. To assess these uncertainties, we compare NCEP and ECMWF analyses of surface pressure to an extensive set of surface barometric observations for the period 2001–2005, both land‐ and ocean‐based, as well as to each other. Differences between each analysis and the observations are quite similar, indicating that both analyses generally fit the station observations equally well. Such differences, including both bias and variance about the bias, are largest over parts of the Southern Ocean, and over Asia, central Africa, and Antarctica. These bias and variance differences between the NCEP and ECMWF surface pressure fields change only slightly over the period of study. More importantly, though, such differences are substantially smaller than those found by previous studies for an earlier period (1993–1995), suggesting recent improvements in both analyses. The largest differences are found over high latitudes, particularly over Antarctica, and in the respective winter hemisphere. Much of the differences occur on rapid timescales, though with a significant portion at timescales longer than 1–2 months. The potential impact of such uncertainties on de‐aliasing and interpreting sea level and gravity data from altimeter and GRACE missions is discussed.
Enhancement and evaluation of the AIRPACT ozone and PM2.5 forecast system for the Pacific Northwest
Authors: Chen Jack , Vaughan Joe , Avise Jeremy , O'Neill Susan , Lamb Brian
Published: July 2008

The Air Indicator Report for Public Access and Community Tracking (AIRPACT) real‐time numerical air quality forecast system operates daily in the Pacific Northwest region to predict hourly ozone, PM2.5 and related precursor and pollutant species. In an update to the existing AIRPACT forecast system, the MM5/SMOKE/CMAQ Eulerian modeling system replaces the MM5/CALMET/CALGRID model framework. The new system, AIRPACT‐3, has a larger domain that encompasses Washington, Oregon, Idaho, and bordering areas. The system includes a highly dynamic emission processing subsystem which incorporates anthropogenic and biogenic emissions, as well as real‐time wildfire emission estimates, and a dynamic dairy ammonia emissions module. As an initial evaluation of the system, forecast results were compared against measurement data for the August–November 2004 period. Analyses showed that the system is skillful in predicting episodic ozone conditions (8‐h daily maxima) above 50 ppbv, but systematically over‐predicts levels less than 40 ppbv. For fine particulate matter, PM2.5, the system captures the concentration differences between urban and rural regions, and captures qualitatively the speciated distribution of fine PM2.5 component concentrations. A separate emission sensitivity study shows the system can adequately simulate the PM pollution impacts from fire events; however, the new dairy ammonia emission module has lesser impact on the overall PM2.5 forecast performance.
Impact of the microstructure of snow on its temperature: A model validation with measurements from Summit, Greenland
Authors: Dadic R. , Schneebeli M. , Lehning M. , Hutterli M. A. , Ohmura A.
Published: July 2008

The influence of snow microstructure on thermal and radiative transfer in snow has not been thoroughly investigated as the tools necessary to efficiently measure microstructural geometry at millimeter resolution have not yet been available. Here we investigate the impact of snow microstructure on the thermal and radiative properties of snow and specifically determine the depth resolution of snow stratigraphy measurements needed to adequately model snow temperatures. To address this subject, detailed information on physical properties of the snow cover was collected at Summit, Greenland, in summer 2003. We present a new set of snow microstructure data, measured with a high‐resolution penetrometer (SnowMicroPen (SMP)). The penetration resistance can be used to estimate the thickness of individual layers but also reflects the thickness and the number of bonds in the snowpack. SMP is a motor‐driven, constant speed micropenetrometer acquiring 256 hardness measurements per millimeter. The data were used to describe the physical properties of snow and to compute snow temperatures in the topmost meter of the snowpack using the snow cover model SNOWPACK. The spatial resolution of the snow microstructure and the subsequent parametrization of SMP‐estimated density strongly affected the modeled temperature and temperature gradients. The SMP‐estimated density was used as an input to SNOWPACK and affected the thermal conductivity and radiative transfer in the snowpack. Our results thus show that highly resolved stratigraphic input data on the order of at least 1 cm are necessary to adequately simulate snow temperatures and snow metamorphism, including the observed formation of subsurface hoar in the high Arctic snow cover.
Lidar on the Phoenix mission to Mars
Authors: Whiteway James , Daly Michael , Carswell Allan , Duck Thomas , Dickinson Cameron , Komguem Leonce , Cook Clive
Published: July 2008

A lidar system for atmospheric measurements will operate from the surface of Mars as part of the Phoenix mission. This will measure the height profile of backscattered laser light from airborne dust and clouds. These observations will be coordinated with solar radiation measurements and in situ sampling to study the climate and the water cycle. The design and testing of the lidar system are described, and measurements are presented that demonstrate the analysis methods and the performance characteristics.
Comparison of different objective functions for parameterization of simple respiration models
Authors: van Wijk M. T. , van Putten B. , Hollinger D. Y. , Richardson A. D.
Published: July 2008

The eddy covariance measurements of carbon dioxide fluxes collected around the world offer a rich source for detailed data analysis. Simple, aggregated models are attractive tools for gap filling, budget calculation, and upscaling in space and time. Key in the application of these models is their parameterization and a robust estimate of the uncertainty and reliability of their predictions. In this study we compared the use of ordinary least squares (OLS) and weighted absolute deviations (WAD, which is the objective function yielding maximum likelihood parameter estimates with a double exponential error distribution) as objective functions within the annual parameterization of two respiration models: the Q10 model and the Lloyd and Taylor model. We introduce a new parameterization method based on two nonparametric tests in which model deviation (Wilcoxon test) and residual trend analyses (Spearman test) are combined. A data set of 9 years of flux measurements was used for this study. The analysis showed that the choice of the objective function is crucial, resulting in differences in the estimated annual respiration budget of up to 40%. The objective function should be tested thoroughly to determine whether it is appropriate for the application for which the model will be used. If simple models are used to estimate a respiration budget, a trend test is essential to achieve unbiased estimates over the year. The analyses also showed that the parameters of the Lloyd and Taylor model are highly correlated and difficult to determine precisely, thereby limiting the physiological interpretability of the parameters.
Rain‐induced subsurface airflow and Lisse effect
Authors: Guo Haipeng , Jiao Jiu J. , Weeks Edwin P.
Published: July 2008

Water‐level increase after rainfall is usually indicative of rainfall recharge to groundwater. This, however, may not be true if the Lisse effect occurs. This effect represents the water‐level increase in a well driven by airflow induced by an advancing wetting front during highly intensive rains. The rainwater, which may behave like a low‐permeability lid, seals the ground surface so that the air pressure beneath the wetting front is increased because of air compression due to downward movement of the wetting front. A rapid and substantial rise of the water level in the well screened below water table, which bears no relationship to groundwater recharge, can be induced when various factors such as soil properties and the rain‐runoff condition combine favorably. A transient, three‐dimensional and variably saturated flow model was employed to study the air and groundwater flows in the soil under rain conditions. The objectives of this paper are two‐fold: to evaluate the reliability of the theory of the Lisse effect presented by Weeks to predict its magnitude in modeled situations that mimic the physical complexity of real aquifers, and to conduct parametric studies on the sensitivity of the water‐level rise in the well to soil properties and the rain event. The simulation results reveal that the magnitude of the Lisse effect increases with the ponding depth. Soil permeability plays a key role in generating the Lisse effect. The water‐level rise in the well is delayed relative to the air‐pressure rise in the unsaturated zone when the soil permeability is low, and the maximum water‐level rise is less than the maximum air pressure induced by rain infiltration. The simulation also explores the sensitivity of the Lisse effect to the van Genuchten parameters and the water table depth.
Spatiotemporal evolution of upwelling regime along the western coast of the Iberian Peninsula
Authors: Alvarez Ines , Gomez‐Gesteira Moncho , deCastro Maite , Dias João Miguel
Published: July 2008

The spatial and temporal variability of upwelling regime along the western coast of the Iberian Peninsula (IP) has been analyzed by means of two different but complementary databases: QuikSCAT satellite database, which is available from mid‐1999 with a high spatial resolution (0.25° × 0.25°); and Pacific Fisheries Environmental Laboratory (PFEL) database, with a coarser spatial resolution (1° × 1°) but extending back to 1967. The combined use of both databases allows determination of the spatial variability of Ekman transport and pumping, and identification of temporal trends in upwelling signal. Upwelling‐favorable conditions are observed during spring and summer. Apart from this well‐known seasonality on upwelling regime along the western coast of the IP, some other features have been identified: (1) Upwelling occurs simultaneously along the entire western coast of the IP, but is undoubtedly more complex closer to particular features of the shoreline. (2) Positive Ekman pumping is more intense near Capes Sao Vicente and Rocha during spring‐summer and near Cape Finisterre all over the year. (3) More favorable upwelling conditions have been observed in February and November during the last decade. This result is corroborated by Sea Level Pressure composites, which show the existence of abnormally high pressures close to the IP during the last decade compared to the historical records (1948–2006). (4) The decadal variability of UI is higher in autumn‐winter than in spring‐summer. (5) Monthly upwelling trends indicate a weakening in upwelling intensity during most of the year with the exception of February, June, and July.
Heritability of Hyperphagic Eating Behavior and Appetite‐Related Hormones among Hispanic Children
Authors: Fisher Jennifer O. , Cai Guowen , Jaramillo Sandra J. , Cole Shelly A. , Comuzzie Anthony G. , Butte Nancy F.
Published: July 2008

Objective: Eating in the absence of hunger (EAH) may be a genetically influenced phenotype of overweight children, but evidence is limited. This research evaluated the heritability (h2) of EAH and its association with overweight among Hispanic children 5 to 18 years old. Genetic and environmental associations of EAH with overweight, fat mass, and key hormonal regulators of food intake were also evaluated.

Research Methods and Procedures: A family design was used to study 801 children from 300 Hispanic families. Weighed food intakes were used to measure EAH after an ad libitum dinner providing 50% of estimated energy needs. Fasting ghrelin, amylin, insulin, and leptin were measured by immunoassays. Measured heights, weights, and fat mass (using DXA) were obtained. Total energy expenditure (TEE) was measured by room respiration calorimetry.

Results: On average, children consumed 41% of TEE at the dinner meal, followed by an additional 19% of TEE in the absence of hunger. Overweight children consumed 6.5% more energy at dinner (p < 0.001) and 14% more energy in the absence of hunger (p < 0.001) than non‐overweight children. Significant heritabilities were seen for EAH (h2 = 0.51) and dinner intake (h2 = 0.52) and for fasting levels of ghrelin (h2 = 0.67), amylin (h2 = 0.37), insulin (h2 = 0.37), and leptin (h2 = 0.34). Genetic correlations were seen between eating behavior and fasting hormones, suggesting common underlying genes affecting their expression.

Discussion: This research provides new evidence that overweight Hispanic children exhibit elevated levels of hyperphagic eating behaviors that are influenced by genetic endowment.
Adult Obesity Does Not Predict 6‐Year Weight Gain in Men: The Aerobics Center Longitudinal Study
Authors: Van Wye Gretchen , Dubin Joel A. , Blair Steven N. , DiPietro Loretta
Published: July 2008

Objective: To determine the longitudinal relation between history of adult obesity and the 6‐year trajectory of weight change in men.

Research Methods and Procedures: Subjects were healthy, affluent men (n = 761) between the ages of 20 and 78 years who completed at least four comprehensive medical exams at the Cooper Clinic between 1987 and 2003. Maximum adult weight was reported, and current height was measured at baseline. Body weight and cardiorespiratory fitness were measured at all examinations. Adult obesity status was determined from self‐reported maximum weight and measured height at baseline as BMI ≥ 30 kg/m2. Weight at all examinations was regressed on a history of adult obesity using linear mixed effects modeling.

Results: At baseline, men reporting a history of adult obesity were significantly heavier than men reporting no such history (BMI 29.8 vs. 25.0 kg/m2; p < 0.05). However, the rate of weight gain among men with a history of obesity was slower than among men without a history of adult obesity (0.04 vs. 0.18 kg/yr; p = 0.09), although this difference was only marginally significant. Fitness modulated the relationship between history of obesity and weight change over time, and both higher levels of fitness and greater frequency of dieting were associated with attenuated weight gain. In contrast, chronic disease and depression were associated with accelerated weight gain.

Discussion: Although a history of obesity was associated with higher weight, it did not seem to result in accelerated weight gain over time. Additionally, dieting and fitness were important for minimizing weight gain.
Cardiorespiratory Fitness and Sedentary Activities Are Associated with Adiposity in Adolescents
Authors: Ortega Francisco B. , Tresaco Beatriz , Ruiz Jonatan R. , Moreno Luis A. , Martin‐Matillas Miguel , Mesa Jose L. , Warnberg Julia , Bueno Manuel , Tercedor Pablo , Gutiérrez Ángel , Castillo Manuel J. ,   AVENA Study Group
Published: July 2008

Objective: To determine whether physical activity, sedentary activities, and/or cardiorespiratory fitness are related to waist circumference in adolescents, as previously reported in adults.

Research Methods and Procedures: The study subjects were a representative sample of Spanish adolescents (N = 2859; 1357 boys, 1502 girls; age, 13 to 18.5 years), all of whom were involved in the AVENA (Food and Assessment of the Nutritional Status of Adolescents) study. BMI, waist circumference, pubertal maturation status, and cardiorespiratory fitness were measured in all. Leisure‐time physical activity, sedentary activities, active commuting to school, and socioeconomic status were assessed by self‐reported questionnaires.

Results: No relationship was found between leisure‐time physical activity and BMI or waist circumference. In contrast, and in both boys and girls and after adjustment for confounding variables, cardiorespiratory fitness was found to be inversely associated with waist circumference and BMI, independent of sedentary activities or physical activity (p ≤ 0.001). The maximum oxygen consumption explained 13% of the variance in waist circumference in boys and 16% in girls. Sedentary activities were independently and directly related to waist circumference in both boys and girls (p ≤ 0.05) and to BMI in boys (p ≤ 0.05). Sedentary activities explained 10% of the variance in waist circumference in boys and 18% in girls. The BMI‐adjusted waist circumference was inversely correlated with cardiorespiratory fitness in overweight‐obese boys (p ≤ 0.05) and showed a trend toward significance in girls (p ≤ 0.1).

Discussion: Both moderate to high levels of cardiorespiratory fitness and sedentary activities, but not physical activity, are associated with lower abdominal adiposity, as measured by waist circumference.