bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in mesospheric dynamics at 78°N, 16°E and 70°N, 19°E: 2001–2012
Authors: Hall C. M. , Tsutsumi M. 
Published: April 2013

AbstractMesospheric wind data from meteor wind radars situated on Svalbard (78°N, 16°E) and the Norwegian mainland (70°N, 19°E) are examined for evidence of systematic change during the interval 2001–2012. For both locations, we find changes that suggest a strengthening of the summer westward jet, a weakening of the local winter eastward flow and, yet at the same time, weak evidence for any significant corresponding trend in the winter poleward flow. There is also a suggestion of an increase in the altitude of the summer polar jet, but more data will be required to confirm this. The main finding of a strengthening zonal flow is consistent with earlier studies and also with a contemporary scenario of progressive strengthening of the Brewer‐Dobson circulation. We show that inclusion of sudden stratospheric warmings strongly influences trends. There is no obvious causality between the changes detected over the 2001–2012 time interval and the solar cycle parameterized by total solar irradiance.
Validation of MOPITT Version 5 thermal‐infrared, near‐infrared, and multispectral carbon monoxide profile retrievals for 2000–2011
Authors: Deeter M. N. , Martínez‐Alonso S. , Edwards D. P. , Emmons L. K. , Gille J. C. , Worden H. M. , Pittman J. V. , Daube B. C. , Wofsy S. C. 
Published: April 2013

AbstractValidation results are reported for the MOPITT (Measurements of Pollution in the Troposphere) “Version 5” (V5) product for tropospheric carbon monoxide (CO) and are compared to results for the “Version 4” product. The V5 retrieval algorithm introduces (1) a method for reducing retrieval bias drift associated with long‐term instrumental degradation, (2) a more exact representation of the effects of random errors in the radiances and, for the first time, (3) the use of MOPITT's near‐infrared (NIR) radiances to complement the thermal‐infrared (TIR) radiances. Exploiting TIR and NIR radiances together facilitates retrievals of CO in the lowermost troposphere. V5 retrieval products based (1) solely on TIR measurements, (2) solely on NIR measurements and (3) on both TIR and NIR measurements are separately validated and analyzed. Actual retrieved CO profiles and total columns are compared with equivalent retrievals based on in situ measurements from (1) routine NOAA aircraft sampling mainly over North America and (2) the “HIAPER Pole to Pole Observations” (HIPPO) field campaign. Particular attention is focused on the long‐term stability and geographical uniformity of the retrieval errors. Results for the retrieved total column clearly indicate reduced temporal bias drift in the V5 products compared to the V4 product, and do not exhibit a positive bias in the Southern Hemisphere, which is evident in the V4 product.
Numerical simulations of dust fluxes to the eastern Qinghai‐Tibetan Plateau: Comparison of model results with a Holocene peat record of dust deposition
Authors: Ferrat Marion , Langmann Baerbel , Cui Xuefeng , Gomes Jefferson , Weiss Dominik J. 
Published: April 2013

AbstractNumerical model simulations provide a useful platform for investigating the interactions between the atmospheric dust cycle and environmental change in Asia. However, model validation is still limited by the scarcity of ground observations of past terrestrial dust deposition fluxes. Here we apply a regional atmosphere‐chemistry/aerosol climate model to simulate Asian dust emissions, transport, and deposition over East Asia during the years 1996–1998 and compare the present‐day deposition fluxes and dominant dust sources obtained from the numerical simulations to those measured in a high‐resolution Holocene palaeodust peat record on the eastern Qinghai‐Tibetan Plateau. The model was found to produce reasonable dust emission fluxes from the Chinese dust sources, with average annual emissions of 179 Mt y−1, and successfully reproduced both the dominant dust sources and average deposition fluxes to the peat core, with modeled and observed fluxes of 6.1 g m−2 y−1. Sensitivity tests show that modeled dust fluxes are sensitive to the parameterization of erodible surfaces, and future development of the regional model to simulate dust emissions in Asia should include an improved scheme for the soil surface properties. The results presented here suggest that the regional model holds the potential to study past and present dust cycles in Asia but evidence the need for both further refinement of the model's dust parameterizations in this region and more high‐resolution terrestrial validation data sets such as peat archives. This study demonstrates how present‐day simulations, for which reanalysis data is available as boundary conditions, are useful tools to explore the relationship between the dust cycle and environmental change during the Holocene.
Study of atmospheric CH4 mole fractions at three WMO/GAW stations in China
Authors: Fang Shuang‐Xi , Zhou Ling‐Xi , Masarie Kenneth A. , Xu Lin , Rella Chris W. 
Published: April 2013

AbstractAtmospheric CH4 mole fractions were continuously measured from 2009 to 2011 at three WMO/GAW stations in China (Lin'an, LAN; Longfengshan, LFS; and Waliguan, WLG) using three Cavity Ring Down Spectroscopy instruments. LAN and LFS are GAW regional measurement stations. LAN is located in China's most economically developed region, and LFS is in a rice production area (planting area > 40,000 km2). WLG is a global measurement station in remote northwest China. At LAN, high methane mole fractions are observed in all seasons. Surface winds from the northeast enhance CH4 values, with a maximum increase of 32 ± 15 ppb in summer. The peak to peak amplitude of the seasonal cycle is 77 ± 35 ppb. At LFS, the diurnal cycle amplitude is approximately constant throughout the year except summer, when a value of 196 ± 65 ppb is observed. CH4 values at LFS reach their peak in July, which is different from seasonal variations typically observed in the northern hemisphere. CH4 mole fractions at WLG show both the smallest values and the lowest variability. Maximum values occur during summer, which is different from other northern hemisphere WMO/GAW global stations. The seasonal cycle amplitude is 17 ± 11 ppb. The linear growth rates at LAN, LFS, and WLG are 8.0 ± 1.2, 7.9 ± 0.9, and 9.4 ± 0.2 ppb yr−1, respectively, which are all larger than the global mean over the same 3 year period. Results from this study attempt to improve our basic understanding of observed atmospheric CH4 in China.
Mid‐Holocene Asian summer climate and its responses to cold ocean surface simulated in the PMIP2 OAGCMs experiments
Authors: Wang Tao , Wang Huijun 
Published: April 2013

AbstractIn this study, the outputs from four Ocean‐Atmosphere Coupled General Circulation Model experiments within the Paleoclimate Modelling Intercomparison Project phase 2 and four sets of Atmospheric General Circulation Model experiments were used to analyze the Asian summer climate during the mid‐Holocene (6 ka, about 6000 years ago). Additionally, the role of the orbital forcings and the effects of a cold ocean surface for the 6 ka were investigated by comparing the Atmospheric General Circulation Model simulations forced by different combinations of forcing parameters. The results indicated that in the 6 ka summer, the orbital forcings were the prime drivers of the increased temperature and precipitation and the strengthened summer monsoon over the Asian continent. On the other hand, these different orbital forcings also resulted in a colder Indian Ocean‐northwestern Pacific during this period. Our results suggested that this cold ocean surface could reduce the warming amplitude and precipitation enhancement over the Asian monsoon area in the 6 ka summer. The changes caused by the different ocean surface conditions were comparable with simulated 6 ka climate changes. The cold ocean surface also suppressed the Asian summer monsoon circulations. Therefore, the influences from anomalous ocean surface conditions played an important role on regulating the Asian summer climate during the 6 ka. In addition, it was found that the summer climate in the South Asian monsoon area was more sensitive to the changes in the orbital forcings and ocean surface conditions than that in the East Asian monsoon area.
The representation of the TTL in a tropical channel version of the WRF model
Authors: Evan Stephanie , Rosenlof K. H. , Dudhia J. , Hassler B. , Davis S. M. 
Published: April 2013

AbstractIn this study, the Weather Research Forecast (WRF) model is used to investigate key physical processes controlling the Tropical Tropopause Layer (TTL) temperature and water vapor distributions in December 2005 to January–February 2006. The model domain is configured as a tropical channel with a horizontal grid spacing of 36 km, a vertical grid spacing of 500 m, and a top at 0.1 hPa. Initial and boundary conditions are set using the ERA‐Interim reanalysis data set. An ozone distribution computed from satellite and ozonesonde measurements is used for radiative forcing calculations. The model's ability to replicate observed TTL temperatures is evaluated via comparisons with radiosonde data and reanalyses (MERRA and ERA‐Interim). The Microwave Limb Sounder (MLS) water vapor measurements are used to evaluate WRF‐simulated water vapor in the TTL. Results of the simulations show that the model reproduces the mean temperature and its variability above 50 hPa as well as the tropical tropopause height. However, the model cold point tropopause temperature is colder than the reanalyses by ~1.2 K. The model captures the location of TTL water vapor minimum in the Western Pacific but is drier than the MLS observations in the TTL. To assess possible reasons for the tropopause temperature discrepancy, an additional WRF experiment was conducted using analysis nudging for water vapor. This experiment produces more tropical cirrus clouds in the upper troposphere and a warming of ~1.5 K of the cold point tropopause. This suggests that the radiative effects of cirrus clouds and water vapor must be considered for accurate temperature simulations in the TTL.
Drivers of projected change in arctic moist static energy transport
Authors: Skific Natasa , Francis Jennifer A. 
Published: April 2013

AbstractWe explore annual and seasonal changes in moist static energy transport (MSE) into the Arctic over the 21st century as projected by the National Center for Atmospheric Research Community Climate System Model, version 3. Self‐organizing maps are used to assess changes in MSE and its components—the latent heat flux and dry static energy flux (DSE)—across 70°N. These are computed from multilevel fields of specific humidity, meridional wind, geopotential, and temperature spanning periods in the 20th century (1960 to 1999) and the 21st century (2070 to 2089). The 21st century simulation incorporates the Special Report on Emission Scenarios A2 scenario. A strong decrease in tropospheric DSE of about 9% by the end of 21st century offsets an increase in latent heat flux of about 20% relative to its 20th century average. The combined changes result in a total annual decrease in tropospheric MSE of about 3% by the late 21st century. The difference, while statistically not significant, represents a weak negative feedback on Arctic amplification. Self‐organizing maps also allow an attribution of changes in MSE to factors related to varying atmospheric dynamics and/or thermodynamics. A positive contribution to the MSE related to more frequent low pressure systems in high latitudes (dynamic factor) occurs in all seasons, particularly in the summer. The decrease in DSE is mainly due to a weakened poleward temperature gradient (thermodynamic factor) during all seasons except summer, which in turn is caused by amplified warming at high latitudes as a result of increased greenhouse gases.
Long‐term ozone changes and associated climate impacts in CMIP5 simulations
Authors: Eyring V. , Arblaster J. M. , Cionni I. , Sedláček J. , Perlwitz J. , Young P. J. , Bekki S. , Bergmann D. , Cameron‐Smith P. , Collins W. J. , Faluvegi G. , Gottschaldt K.‐D. , Horowitz L. W. , Kinnison D. E. , Lamarque J.‐F. , Marsh D. R. , Saint‐Martin D. , Shindell D. T. , Sudo K. , Szopa S. , Watanabe S. 
Published: April 2013

AbstractOzone changes and associated climate impacts in the Coupled Model Intercomparison Project Phase 5 (CMIP5) simulations are analyzed over the historical (1960–2005) and future (2006–2100) period under four Representative Concentration Pathways (RCP). In contrast to CMIP3, where half of the models prescribed constant stratospheric ozone, CMIP5 models all consider past ozone depletion and future ozone recovery. Multimodel mean climatologies and long‐term changes in total and tropospheric column ozone calculated from CMIP5 models with either interactive or prescribed ozone are in reasonable agreement with observations. However, some large deviations from observations exist for individual models with interactive chemistry, and these models are excluded in the projections. Stratospheric ozone projections forced with a single halogen, but four greenhouse gas (GHG) scenarios show largest differences in the northern midlatitudes and in the Arctic in spring (~20 and 40 Dobson units (DU) by 2100, respectively). By 2050, these differences are much smaller and negligible over Antarctica in austral spring. Differences in future tropospheric column ozone are mainly caused by differences in methane concentrations and stratospheric input, leading to ~10 DU increases compared to 2000 in RCP 8.5. Large variations in stratospheric ozone particularly in CMIP5 models with interactive chemistry drive correspondingly large variations in lower stratospheric temperature trends. The results also illustrate that future Southern Hemisphere summertime circulation changes are controlled by both the ozone recovery rate and the rate of GHG increases, emphasizing the importance of simulating and taking into account ozone forcings when examining future climate projections.
Inertia‐gravity waves in Antarctica: A case study using simultaneous lidar and radar measurements at McMurdo/Scott Base (77.8°S, 166.7°E)
Authors: Chen Cao , Chu Xinzhao , McDonald Adrian J. , Vadas Sharon L. , Yu Zhibin , Fong Weichun , Lu Xian 
Published: April 2013

AbstractThis study presents the first coincident observation of inertia‐gravity waves (IGWs) by lidar and radar in the Antarctic mesopause region. This is also the first known observation of two simultaneous IGWs at the same location. An Fe Boltzmann lidar at Arrival Heights (77.8°S, 166.7°E) provides high‐resolution temperature data, and a co‐located MF radar provides wind data. On 29 June 2011, coherent wave structures are observed in both the Fe lidar temperature and MF radar winds. Two dominant waves are determined from the temperature data with apparent periods of 7.7 ± 0.2 and 5.0 ± 0.1 h and vertical wavelengths of 22 ± 2 and 23 ± 2 km, respectively. The simultaneous measurements of temperature and wind allow the intrinsic wave properties to be derived from hodograph analyses unambiguously. The analysis shows that the longer‐period wave propagates northward with an azimuth of θ = 11° ± 5° clockwise from north. This wave has a horizontal wavelength of λh = 2.2 ± 0.2 × 103 km and an intrinsic period of τI = 7.9 ± 0.3 h. The intrinsic horizontal phase speed (CIh) for this wave is 80 ± 4 m/s, while the horizontal and vertical group velocities (Cgh and Cgz) are 48 ± 3 m/s and 0.5 ± 0.1 m/s, respectively. The shorter‐period wave has τI = 4.5 ± 0.3 h and θ = 100° ± 4° with λh = 1.1 ± 0.1 × 103 km and CIh = 68 ± 5 m/s. Its group velocities are Cgh = 58 ± 5 m/s and Cgz = 1.1 ± 0.1 m/s. Therefore, both waves propagate with very shallow elevation angles from the horizon (ϕ = 0.6° ± 0.1° and ϕ = 1.1° ± 0.1° for the longer‐ and shorter‐period waves, respectively) but originate from different sources. Our analysis suggests that the longer‐period IGW most likely originates from the stratosphere in a region of unbalanced flow.
Using inpatient hospital discharge data to monitor patient safety events
Authors: Taylor Jennifer A. , Pandian Ravi S. , Mao Lu , Michael Yvonne L. 
Published: April 2013

AbstractThe development of systematic and sustainable surveillance systems is necessary for the creation of patient safety prevention programs and the evaluation of improvement resulting from innovations. To that end, inpatient hospital discharges collected by the Pennsylvania Health Care Cost Containment Council were used to investigate patient safety events (PSEs) in Pennsylvania in 2006. PSEs were identified using external cause of injury codes (E‐codes) in combination with the Agency for Healthcare Research and Quality's patient safety indicators (PSIs). Encounters with and without PSEs were compared with regard to patient age, sex, race, length of stay, and cost. Approximately 9% of all Pennsylvania inpatient discharges had a PSE in 2006. Patients with a PSE were on average older, male, and white. The average length of stay for a PSE was 3 days longer and $35 000 more expensive than a non‐PSE encounter. It was concluded that E‐codes and PSIs were useful tools for the surveillance of PSEs in Pennsylvania, and that administrative data from healthcare organizations provide a consistent source of standardized data related to patient encounters, creating an opportunity to describe PSEs at the population level.
β‐Mannanase production by Aspergillus niger BCC4525 and its efficacy on broiler performance
Authors: Sornlake Warasirin , Matetaviparee Panida , Rattanaphan Nakul , Tanapongpipat Sutipa , Eurwilaichitr Lily 
Published: April 2013

AbstractBACKGROUNDMannan is a hemicellulose constituent commonly found in plant‐derived feed ingredients. The gum‐like property of mannan can obstruct digestive enzymes and bile acids, resulting in impaired nutrient utilisation. In this study, β‐mannanase production by Aspergillus niger strain BCC4525 was investigated using several agricultural residues under solid state condition. The biochemical properties of the target enzyme and the effects of enzyme supplementation on broiler performance and energy utilisation were assessed.RESULTSAmong five carbon sources tested, copra meal was found to be the best carbon source for β‐mannanase production with the maximum yield of 1837.5 U g−1. The crude β‐mannanase exhibited maximum activity at 80 °C within a broad range of pH from 2 to 6. In vitro digestibility assay, which simulates the gastrointestinal tract system of broilers, showed that β‐mannanase could liberate reducing sugars from corn/soybean diet. Surprisingly, β‐mannanase supplementation had no significant effect on broiler feed intake, feed conversion rate or energy utilisation.CONCLUSIONA high level of β‐mannanase was produced by A. niger BCC4525 under solid state condition using copra meal as carbon source. Although the enzyme has the desired properties of an enzyme additive for improving broiler performance, it does not appear to be beneficial.© 2013 Society of Chemical Industry
Implications of the histological determination of microRNAs in the screening, diagnosis and prognosis of colorectal cancer
Authors: MenéNdez Pablo , Villarejo Pedro , Padilla David , Menéndez José María , Rodríguez‐Montes José Antonio 
Published: April 2013

AbstractMicroRNAs are short non‐coding RNA molecules that participate in the regulation of gene expression. Several studies have demonstrated the involvement of microRNAs in oncogenesis and a variety of physiological functions. We conducted a literature review of studies that evaluated histological microRNAs in colorectal cancer. Although additional clinical studies are required to substantiate the relationship between microRNAs and colorectal cancer, there is preliminary evidence that microRNAs are related to the diagnosis and prognosis of colorectal cancer. J. Surg. Oncol. 2013;108:70–73. © 2013 Wiley Periodicals, Inc.
Ocular motor characteristics of different subtypes of spinocerebellar ataxia: Distinguishing features
Authors: Kim Ji Sun , Kim Ji Soo , Youn Jinyoung , Seo Dae‐Won , Jeong Yuri , Kang Ji‐Hoon , Park Jeong Ho , Cho Jin Whan 
Published: April 2013

AbstractBecause of frequent involvement of the cerebellum and brainstem, ocular motor abnormalities are key features of spinocerebellar ataxias and may aid in differential diagnosis. Our objective for this study was to distinguish the subtypes by ophthalmologic features after head‐shaking and positional maneuvers, which are not yet recognized as differential diagnostic tools in most common forms of spinocerebellar ataxias. Of the 302 patients with a diagnosis of cerebellar ataxia in 3 Korean University Hospitals from June 2011 to June 2012, 48 patients with spinocerebellar ataxia types 1, 2, 3, 6, 7, or 8 or with undetermined spinocerebellar ataxias were enrolled. All patients underwent a video‐oculographic recording of fixation abnormalities, gaze‐evoked nystagmus, positional and head‐shaking nystagmus, and dysmetric saccades. Logistic regression analysis controlling for disease duration revealed that spontaneous and positional downbeat nystagmus and perverted head‐shaking nystagmus were strong predictors for spinocerebellar ataxia 6, whereas saccadic intrusions and oscillations were identified as positive indicators of spinocerebellar ataxia 3. In contrast, the presence of gaze‐evoked nystagmus and dysmetric saccades was a negative predictor of spinocerebellar ataxia 2. Positional maneuvers and horizontal head shaking occasionally induced or augmented saccadic intrusions/oscillations in patients with spinocerebellar ataxia types 1, 2, and 3 and undetermined spinocerebellar ataxia. The results indicated that perverted head‐shaking nystagmus may be the most sensitive parameter for SCA6, whereas saccadic intrusions/oscillations are the most sensitive for spinocerebellar ataxia 3. In contrast, a paucity of gaze‐evoked nystagmus and dysmetric saccades is more indicative of spinocerebellar ataxia 2. Head‐shaking and positional maneuvers aid in defining ocular motor characteristics in spinocerebellar ataxias. © 2013 Movement Disorder Society
Challenges of diagnostic exome sequencing in an inbred founder population
Authors: Azmanov Dimitar N. , Chamova Teodora , Tankard Rick , Gelev Vladimir , Bynevelt Michael , Florez Laura , Tzoneva Dochka , Zlatareva Dora , Guergueltcheva Velina , Bahlo Melanie , Tournev Ivailo , Kalaydjieva Luba 
Published: April 2013

AbstractExome sequencing was used as a diagnostic tool in a Roma/Gypsy family with three subjects (one deceased) affected by lissencephaly with cerebellar hypoplasia (LCH), a clinically and genetically heterogeneous diagnostic category. Data analysis identified high levels of unreported inbreeding, with multiple rare/novel “deleterious” variants occurring in the homozygous state in the affected individuals. Step‐wise filtering was facilitated by the inclusion of parental samples in the analysis and the availability of ethnically matched control exome data. We identified a novel mutation, p.Asp487Tyr, in the VLDLR gene involved in the Reelin developmental pathway and associated with a rare form of LCH, the Dysequilibrium Syndrome. p.Asp487Tyr is the third reported missense mutation in this gene and the first example of a change affecting directly the functionally crucial β‐propeller domain. An unexpected additional finding was a second unique mutation (p.Asn494His) with high scores of predicted pathogenicity in KCNV2, a gene implicated in a rare eye disorder, retinal cone dystrophy type 3B. This result raised diagnostic and counseling challenges that could be resolved through mutation screening of a large panel of healthy population controls. The strategy and findings of this study may inform the search for new disease mutations in the largest European genetic isolate.