bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Multimoment Bulk Microphysics Parameterization. Part III: Control Simulation of a Hailstorm
Authors: Milbrandt J. A. , Yau M. K. 
Published: December 2006

With continuous increase in the resolution of operational numerical weather prediction models, grid-scale saturation schemes that model cloud microphysics are becoming increasingly important. In Parts I and II of this study, the importance of the relative dispersion of the hydrometeor size distribution in bulk microphysics parameterizations was demonstrated and a closure approach for a three-moment scheme was proposed. In this paper, the full three-moment version of the new multimoment scheme is tested in a 3D simulation of a severe hailstorm. The modeled microphysical fields are examined, with particular attention paid to the simulated hail fields including the maximum hail sizes at the ground. A mesoscale model was initialized using synoptic analyses and successively nested to a resolution of 1 km. When compared to observations of the real storm from a nearby radar, the simulated storm reproduced several of the observed characteristics including the direction and speed of propagation, a bounded weak echo region, hook echo, mesocyclone, and a suspended overhang region. The magnitudes of radar reflectivity and surface precipitation are also well simulated. The mass contents, total number concentrations, equivalent reflectivities, and mean mass diameters of each hydrometeor category in the model were examined. The spatial distributions of the various hydrometeors throughout the storm appeared realistic and their values were consistent with published observations from other storms. Using the three predicted parameters of the gamma size distribution for hail, a method was introduced to determine the maximum hail size simulated from a bulk scheme that is physically observable. The observed storm produced golf ball–sized hail while the simulation produced walnut-sized hail at approximately the same time and location. The results suggest that because of the additional information provided about the size distribution, there is added value in prognosing the relative dispersion parameter of a given hydrometeor category in a bulk scheme.
A Multimoment Bulk Microphysics Parameterization. Part IV: Sensitivity Experiments
Authors: Milbrandt J. A. , Yau M. K. 
Published: December 2006

This is the fourth in a series of papers exploring the effects of the number of predicted moments in bulk microphysics schemes. In Part III, the three-moment version of a new multimoment scheme was used to simulate a severe hailstorm. The model successfully reproduced many of the observed gross characteristics, including the reflectivity structure and the maximum hail sizes at the ground. In this paper, the authors compare a series of sensitivity experiments using various one- and two-moment versions of the scheme with the three-moment version to explore the effects of predicting additional moments on the simulated hydrometeor fields, precipitation, and storm dynamics. Six sensitivity runs were performed. They varied in their ability to reproduce the precipitation pattern, storm structure, and peak values of microphysical fields of the control simulation. The two-moment simulations, which used diagnostic relations to prescribe the relative dispersion parameter, α, closely reproduced the spatial pattern, quantity, and phase of the precipitation at the surface as well as the overall storm structure, propagation speed, and peak values of several hydrometeor fields. The two-moment simulations, which used fixed values of α, on the other hand, differed more from the control. The runs using one-moment versions of the scheme were considerably different from each other and were poor at reproducing the control simulation. The results suggest that there is a dramatic improvement in the simulation moving from one- to two-moment schemes. For the case studied, it was found that if maximum particle size is not of concern, a two-moment scheme with a diagnostic dispersion parameter can reproduce most of the important aspects in a hailstorm simulation with a three-moment scheme.
Eddy Influences on Hadley Circulations: Simulations with an Idealized GCM
Authors: Walker Christopher C. , Schneider Tapio 
Published: December 2006

An idealized GCM is used to investigate how the strength and meridional extent of the Hadley circulation depend on the planet radius, rotation rate, and thermal driving. Over wide parameter ranges, the strength and meridional extent of the Hadley circulation display clear scaling relations with regime transitions, which are not predicted by existing theories of axisymmetric Hadley circulations. For example, the scaling of the strength as a function of the radiative-equilibrium equator-to-pole temperature contrast exhibits a regime transition corresponding to a regime transition in scaling laws of baroclinic eddy fluxes. The scaling of the strength of the cross-equatorial Hadley cell as a function of the latitude of maximum radiative-equilibrium temperature exhibits a regime transition from a regime in which eddy momentum fluxes strongly influence the strength to a regime in which the influence of eddy momentum fluxes is weak. Over a wide range of flow parameters, albeit not always, the Hadley circulation strength is directly related to the eddy momentum flux divergence at the latitude of the streamfunction extremum. Simulations with hemispherically symmetric thermal driving span circulations with local Rossby numbers in the horizontal upper branch of the Hadley circulation between 0.1 and 0.8, indicating that neither nonlinear nearly inviscid theories, valid for Ro → 1, nor linear theories, valid for Ro → 0, of axisymmetric Hadley circulations can be expected to be generally adequate. Nonlinear theories of axisymmetric Hadley circulations may account for aspects of the circulation when the maximum radiative-equilibrium temperature is displaced sufficiently far away from the equator, which results in cross-equatorial Hadley cells with nearly angular momentum-conserving upper branches. The dependence of the Hadley circulation on eddy fluxes, which are themselves dependent on extratropical circulation characteristics such as meridional temperature gradients, suggests that tropical circulations depend on the extratropical climate.
Superrotation Maintained by Meridional Circulation and Waves in a Venus-Like AGCM
Authors: Yamamoto Masaru , Takahashi Masaaki 
Published: December 2006

Fully developed superrotation—60 times faster than the planetary rotation (243 days)—is simulated using a Venus-like atmospheric general circulation model (AGCM). The angular momentum of the superrotation is pumped up by the meridional circulation with the help of waves, which accelerate the equatorial zonal flow. The waves generated by solar heating and shear instability play a crucial role in the atmospheric dynamics of the Venusian superrotation. Vertical and horizontal momentum transports of thermal tides maintain the equatorial superrotation in the middle atmosphere, while equatorward eddy momentum flux due to shear instability raises the efficiency of upward angular momentum transport by the meridional circulation in the lower atmosphere. In addition to the superrotation, some waves simulated in the cloud layer are consistent with the observations. The planetary-scale Kelvin wave identified as the near-infrared (NIR) oscillation with periods of 5–6 days is generated by the shear instability near the cloud base, and the temperature structure of the diurnal tide is similar to the infrared (IR) observation near the cloud top. Sensitivities to the bottom boundary conditions are also examined in this paper, since the surface physical processes are still unknown. The decrease of the equator–pole temperature difference and the increase of the surface frictional time constant result in the weaknesses of the meridional circulation and superrotation. In the cases of the weak superrotation, the vertical angular momentum transport due to the meridional circulation is inefficient and the equatorward eddy angular momentum transport is absent near 60-km altitude.
Pathologic Characteristics of the Torn Human Meniscus
Authors: Mesiha Mena , Zurakowski David , Soriano Jamil , Nielson Jason H. , Zarins Bertram , Murray Martha M. 
Published: December 2006

Background Acellular meniscus tissue is at a high risk for degeneration and retear. Information that would help surgeons predict, preoperatively, or intraoperatively which torn menisci had few viable cells could be useful in deciding which patients might be at increased risk for retear and failure of surgical repair. Hypothesis Patient age, length of time since injury, and tear type are predictors of the cellularity of meniscus tissue. Study Design Descriptive laboratory study. Methods Gross and histologic evaluation of torn meniscus tissue from 44 patients and 10 control menisci was performed. Results The patient factors of age, time since injury, and tear type all had significant effects on the pathologic characteristics of the torn meniscus. Patients older than 40 years had lower cellularity in the torn menisci than did patients younger than 40 years (P < .01). As time since injury increased, so did the rates of DNA fragmentation in the midsubstance of the meniscus and rates of Outerbridge II changes in the adjacent cartilage. Worse meniscal histologic scores were found in menisci with degenerative and radial tear types. Conclusion Patient age had a significant effect on the cellularity of the torn meniscus, with patients older than 40 years having significantly fewer meniscus cells than did those younger than 40 years. Further studies are needed to define the relative importance of the individual histologic findings in the clinical setting of meniscus tear and repair. Clinical Relevance In light of their decreased cellularity, menisci from patients older than 40 years may be more vulnerable to degeneration and retear after repair than are menisci of younger patients.
Prolonged Superficial Local Cryotherapy Attenuates Microcirculatory Impairment, Regional Inflammation, and Muscle Necrosis after Closed Soft Tissue Injury in Rats
Authors: Schaser Klaus-Dieter , Disch Alexander C. , Stover John F. , Lauffer Annette , Bail Herman J. , Mittlmeier Thomas 
Published: December 2006

Background Closed soft tissue injury induces progressive microvascular dysfunction and regional inflammation. The authors tested the hypothesis that adverse trauma-induced effects can be reduced by local cooling. While superficial cooling reduces swelling, pain, and cellular oxygen demand, the effects of cryotherapy on posttraumatic microcirculation are incompletely understood. Study Design Controlled laboratory study. Methods After a standardized closed soft tissue injury to the left tibial compartment, male rats were randomly subjected to percutaneous perfusion for 6 hours with 0.9% NaCL (controls; room temperature) or cold NaCL (cryotherapy; 8°C) (n = 7 per group). Uninjured rats served as shams (n = 7). Microcirculatory changes and leukocyte adherence were determined by intravital microscopy. Intramuscular pressure was measured, and invasion of granulocytes and macrophages was assessed by immunohistochemistry. Edema and tissue damage was quantified by gravimetry and decreased desmin staining. Results Closed soft tissue injury significantly decreased functional capillary density (240 ± 12 cm-1); increased microvascular permeability (0.75 ± 0.03), endothelial leukocyte adherence (995 ± 77/cm2), granulocyte (182.0 ± 25.5/mm2) and macrophage infiltration, edema formation, and myonecrosis (ratio: 2.95 ± 0.45) within the left extensor digitorum longus muscle. Cryotherapy for 6 hours significantly restored diminished functional capillary density (393 ± 35), markedly decreased elevated intramuscular pressure, reduced the number of adhering (462 ± 188/cm2) and invading granulocytes (119 ± 28), and attenuated tissue damage (ratio: 1.7 ± 0.17). Conclusion The hypothesis that prolonged cooling reduces posttraumatic microvascular dysfunction, inflammation, and structural impairment was confirmed. Clinical Relevance These results may have therapeutic implications as cryotherapy after closed soft tissue injury is a valuable therapeutic approach to improve nutritive perfusion and attenuate leukocyte-mediated tissue destruction. The risk for evolving compartment syndrome may be reduced, thereby preventing further irreversible aggravation.
Integrated molecular profiling of SOD2 expression in multiple myeloma
Authors: Hurt Elaine M. , Thomas Suneetha B. , Peng Benjamin , Farrar William L. 
Published: December 2006

Abstract
Reactive oxygen species are known to be involved in several cellular processes, including cell signaling. SOD2 is a key enzyme in the conversion of reactive oxygen species and has been implicated in a host of disease states, including cancer. Using an integrated, whole-cell approach encompassing epigenetics, genomics, and proteomics, we have defined the role of SOD2 in multiple myeloma. We show that the SOD2 promoter is methylated in several cell lines and there is a correlative decrease in expression. Furthermore, myeloma patient samples have decreased SOD2 expression compared with healthy donors. Overexpression of SOD2 results in decreased proliferation and altered sensitivity to 2-methoxyestradiol–induced DNA damage and apoptosis. Genomic profiling revealed regulation of 65 genes, including genes involved in tumorigenesis, and proteomic analysis identified activation of the JAK/STAT pathway. Analysis of nearly 400 activated transcription factors identified 31 transcription factors with altered DNA binding activity, including XBP1, NFAT, forkhead, and GAS binding sites. Integration of data from our gestalt molecular analysis has defined a role for SOD2 in cellular proliferation, JAK/STAT signaling, and regulation of several transcription factors.
Sleep apnoea as an independent risk factor for cardiovascular disease: current evidence, basic mechanisms and research priorities: Fig. 1—
Authors: McNicholas W. T. , Bonsignore M. R. ,   the Management Committee of EU COST ACTION B26
Published: December 2006

Considerable evidence is available in support of an independent association between obstructive sleep apnoea syndrome (OSAS) and cardiovascular disease, which is particularly strong for systemic arterial hypertension and growing for ischaemic heart disease, stroke, heart failure, atrial fibrillation and cardiac sudden death.The pathogenesis of cardiovascular disease in OSAS is not completely understood but likely to be multifactorial, involving a diverse range of mechanisms including sympathetic nervous system overactivity, selective activation of inflammatory molecular pathways, endothelial dysfunction, abnormal coagulation and metabolic dysregulation, the latter particularly involving insulin resistance and disordered lipid metabolism.The present report, which arose out of a European Union Cooperation in the field of Scientific and Technical Research (COST) action on OSAS (COST B26), reviews the current evidence for an independent association and proposes research priorities to identify the underlying mechanisms involved, with a view to identifying novel therapeutic strategies.Large-scale collaborative studies of carefully defined patient populations with obstructive sleep apnoea syndrome, adequately controlled for potential confounders, are needed. Such studies carry the prospect of evaluating potential interactions between different basic mechanisms operating in obstructive sleep apnoea syndrome and cardiovascular disease, and interactions with other related disorders, such as obesity, diabetes and dyslipidaemia. Furthermore, translational studies involving cell culture and animal models linked to studies of obstructive sleep apnoea syndrome patients are necessary to integrate basic mechanisms with the clinical disorder.
Recommendations on the use of exercise testing in clinical practice
Authors: Palange P. , Ward S. A. , Carlsen K-H. , Casaburi R. , Gallagher C. G. , Gosselink R. , O'Donnell D. E. , Puente-Maestu L. , Schols A. M. , Singh S. , Whipp B. J. 
Published: December 2006

Evidence-based recommendations on the clinical use of cardiopulmonary exercise testing (CPET) in lung and heart disease are presented, with reference to the assessment of exercise intolerance, prognostic assessment and the evaluation of therapeutic interventions (e.g.drugs, supplemental oxygen, exercise training). A commonly used grading system for recommendations in evidence-based guidelines was applied, with the grade of recommendation ranging from A, the highest, to D, the lowest.For symptom-limited incremental exercise, CPET indices, such as peak O2uptake (V′O2),V′O2at lactate threshold, the slope of the ventilation–CO2output relationship and the presence of arterial O2desaturation, have all been shown to have power in prognostic evaluation. In addition, for assessment of interventions, the tolerable duration of symptom-limited high-intensity constant-load exercise often provides greater sensitivity to discriminate change than the classical incremental test. Field-testing paradigms (e.g.timed and shuttle walking tests) also prove valuable.In turn, these considerations allow the resolution of practical questions that often confront the clinician, such as: 1) “When should an evaluation of exercise intolerance be sought?”; 2) “Which particular form of test should be asked for?”; and 3) “What cluster of variables should be selected when evaluating prognosis for a particular disease or the effect of a particular intervention?”
A novel statistical method to estimate the effective SNP size in vertebrate genomes and categorized genomic regions
Authors: Seo Daekwan , Jiang Cizhong , Zhao Zhongming 
Published: December 2006

Abstract

Background
The local environment of single nucleotide polymorphisms (SNPs) contains abundant genetic information for the study of mechanisms of mutation, genome evolution, and causes of diseases. Recent studies revealed that neighboring-nucleotide biases on SNPs were strong and the genome-wide bias patterns could be represented by a small subset of the total SNPs. It remains unsolved for the estimation of the effective SNP size, the number of SNPs that are sufficient to represent the bias patterns observed from the whole SNP data.

Results
To estimate the effective SNP size, we developed a novel statistical method, SNPKS, which considers both the statistical and biological significances. SNPKS consists of two major steps: to obtain an initial effective size by the Kolmogorov-Smirnov test (KS test) and to find an intermediate effective size by interval evaluation. The SNPKS algorithm was implemented in computer programs and applied to the real SNP data. The effective SNP size was estimated to be 38,200, 39,300, 38,000, and 38,700 in the human, chimpanzee, dog, and mouse genomes, respectively, and 39,100, 39,600, 39,200, and 42,200 in human intergenic, genic, intronic, and CpG island regions, respectively.

Conclusion
SNPKS is the first statistical method to estimate the effective SNP size. It runs efficiently and greatly outperforms the algorithm implemented in SNPNB. The application of SNPKS to the real SNP data revealed the similar small effective SNP size (38,000 – 42,200) in the human, chimpanzee, dog, and mouse genomes as well as in human genomic regions. The findings suggest strong influence of genetic factors across vertebrate genomes.
Uptake of 3H-cAMP by retinal pigment epithelium isolated from bluegill sunfish (Lepomis macrochirus)
Authors: Keith Thomas A , Radhakrishnan Varsha , Moredock Steve , García Dana M 
Published: December 2006

Abstract

Background
In bluegill sunfish, the melanin-containing pigment granules of the retinal pigment epithelium undergo cyclic movements in response both to ambient lighting and circadian cues. Pigment granules aggregate into the cell body at night (in the dark), and disperse into apical processes during the day (in the light). Regulation of pigment granule aggregation in a number of fishes depends on modulating the intracellular levels of cyclic adenosine monophosphate.

Results
Here we show isolated RPE takes up cyclic adenosine monophosphate (cAMP) in a saturable manner, exogenously applied cAMP induces pigment granule aggregation in retinal pigment epithelium isolated from bluegill, and aggregation induced in this manner is inhibited by treatment with probenecid, an organic anion transport inhibitor.

Conclusion
Our results raise the possibility that cAMP functions as a messenger secreted from the neural retina to signal darkness to the RPE, which takes it up. It further suggests that organic anion transport systems are the route by which cAMP crosses RPE cell membranes since probenecid inhibits extracellular cAMP from causing pigment granule aggregation.
Lutein is needed for efficient chlorophyll triplet quenching in the major LHCII antenna complex of higher plants and effective photoprotection in vivounder strong light
Authors: Dall'Osto Luca , Lico Chiara , Alric Jean , Giuliano Giovanni , Havaux Michel , Bassi Roberto 
Published: December 2006

Abstract

Background
Lutein is the most abundant xanthophyll in the photosynthetic apparatus of higher plants. It binds to site L1 of all Lhc proteins, whose occupancy is indispensable for protein folding and quenching chlorophyll triplets. Thus, the lack of a visible phenotype in mutants lacking lutein has been surprising.

Results
We have re-assessed the lut2.1 phenotypes through biochemical and spectroscopic methods. Lhc proteins from the lut2.1 mutant compensate the lack of lutein by binding violaxanthin in sites L1 and L2. This substitution reduces the capacity for regulatory mechanisms such as NPQ, reduces antenna size, induces the compensatory synthesis of Antheraxanthin + Zeaxanthin, and prevents the trimerization of LHCII complexes. In vitro reconstitution shows that the lack of lutein per se is sufficient to prevent trimerization. lut2.1 showed a reduced capacity for state I – state II transitions, a selective degradation of Lhcb1 and 2, and a higher level of photodamage in high light and/or low temperature, suggesting that violaxanthin cannot fully restore chlorophyll triplet quenching. In vitro photobleaching experiments and time-resolved spectroscopy of carotenoid triplet formation confirmed this hypothesis. The npq1lut2.1 double mutant, lacking both zeaxanthin and lutein, is highly susceptible to light stress.

Conclusion
Lutein has the specific property of quenching harmful 3Chl* by binding at site L1 of the major LHCII complex and of other Lhc proteins of plants, thus preventing ROS formation. Substitution of lutein by violaxanthin decreases the efficiency of 3Chl* quenching and causes higher ROS yield. The phenotype of lut2.1 mutant in low light is weak only because rescuing mechanisms of photoprotection, namely zeaxanthin synthesis, compensate for the ROS production. We conclude that zeaxanthin is effective in photoprotection of plants lacking lutein due to the multiple effects of zeaxanthin in photoprotection, including ROS scavenging and direct quenching of Chl fluorescence by binding to the L2 allosteric site of Lhc proteins.