bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observed Patterns of Month-to-Month Storm-Track Variability and Their Relationship to the Background Flow*
Authors: Wettstein Justin J. , Wallace John M. 
Published: December 2009

Abstract
Month-to-month storm-track variability is investigated via EOF analyses performed on ERA-40 monthly-averaged high-pass filtered daily 850-hPa meridional heat flux and the variances of 300-hPa meridional wind and 500-hPa height. The analysis is performed both in hemispheric and sectoral domains of the Northern and Southern Hemispheres. Patterns characterized as “pulsing” and “latitudinal shifting” of the climatological-mean storm tracks emerge as the leading sectoral patterns of variability. Based on the analysis presented, storm-track variability on the spatial scale of the two Northern Hemisphere sectors appears to be largely, but perhaps not completely, independent.
Pulsing and latitudinally shifting storm tracks are accompanied by zonal wind anomalies consistent with eddy-forced accelerations and geopotential height anomalies that project strongly on the dominant patterns of geopotential height variability. The North Atlantic Oscillation (NAO)–Northern Hemisphere annular mode (NAM) is associated with a pulsing of the Atlantic storm track and a meridional displacement of the upper-tropospheric jet exit region, whereas the eastern Atlantic (EA) pattern is associated with a latitudinally shifting storm track and an extension or retraction of the upper-tropospheric jet. Analogous patterns of storm-track and upper-tropospheric jet variability are associated with the western Pacific (WP) and Pacific–North America (PNA) patterns. Wave–mean flow relationships shown here are more clearly defined than in previous studies and are shown to extend through the depth of the troposphere. The Southern Hemisphere annular mode (SAM) is associated with a latitudinally shifting storm track over the South Atlantic and Indian Oceans and a pulsing South Pacific storm track. The patterns of storm-track variability are shown to be related to simple distortions of the climatological-mean upper-tropospheric jet.
Linear Response Functions of a Cumulus Ensemble to Temperature and Moisture Perturbations and Implications for the Dynamics of Convectively Coupled Waves
Authors: Kuang Zhiming 
Published: December 2009

Abstract
An approach is presented for the construction of linear response functions of a cumulus ensemble to large-scale temperature and moisture perturbations using a cloud system–resolving model (CSRM). A set of time-invariant, horizontally homogeneous, anomalous temperature and moisture tendencies is added, one at a time, to the forcing of the CSRM. By recording the departure of the equilibrium domain-averaged temperature and moisture profiles from those of a control experiment and through a matrix inversion, a sufficiently complete and accurate set of linear response functions is constructed for use as a parameterization of the cumulus ensemble around the reference mean state represented by the control experiment.
This approach is applied to two different mean state conditions in which the CSRM, when coupled with 2D gravity waves, exhibits interestingly different behaviors. With a more strongly convecting mean state forced by the large-scale vertical velocity profile taken from the Tropical Ocean and Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE), spontaneous development of convectively coupled waves requires moisture variations above the boundary layer, whereas with a mean state of radiative–convective equilibrium (RCE) not forced by large-scale vertical advection, the development of convectively coupled waves is stronger and persists even when moisture variations above the boundary layer are removed. The linear response functions were able to reproduce these behaviors of the full CSRM with some quantitative accuracy. The linear response functions show that both temperature and moisture perturbations at a range of heights can regulate convective heating. The ability for convection to remove temperature anomalies, thus maintaining convective neutrality, decreases considerably from the lower troposphere to the middle and upper troposphere. It is also found that the response of convective heating to a lower tropospheric temperature anomaly is more top-heavy in the RCE case than in the TOGA COARE case. Comparing the linear response functions with the treatment of convection in an earlier simple model by the present author indicates general consistency, lending confidence that the instability mechanisms identified in that model provide the correct explanation to the instability seen in the CSRM simulations and the instability’s dependence on the mean state.
North American Temperature, Snowfall, and Snow-Depth Response to Winter Climate Modes
Authors: Ghatak Debjani , Gong Gavin , Frei Allan 
Published: December 2009

Abstract
The snowpack is an important seasonal surface water storage reservoir that affects the availability of water resources during the spring and summer seasons in mid–high latitudes. Not surprisingly, interannual variations in snow cover extent and snow water equivalent have been extensively studied in arid regions such as western North America. This study broadens the focus by examining snow depth as an alternative snowpack metric, and considers its variability over different parts of North America. The authors use singular value decomposition (SVD) in conjunction with linear and partial correlation to show that regional snow-depth variations can be largely explained by the winter North Atlantic Oscillation (NAO) and the Pacific–North American (PNA) modes of atmospheric variability through distinct mechanistic pathways involving regional winter circulation patterns and hydrologic fluxes. The high index phase of the NAO generates positive winter air temperature anomalies over eastern parts of North America, causing thinning of the winter snowpack via snowmelt. Meanwhile, the high index phase of the PNA generates negative winter snowfall anomalies across midlatitudinal areas of North America, which also serve to thin the snowpack. Positive PNA anomalies have also been shown to increase temperatures and decrease snow depths over western North America. The PNA influence extends across the continent, whereas the NAO influence is limited to eastern North America. The winter snow-depth variations associated with all of these pathways exhibit seasonal persistence, which ultimately yield regional-scale spring snow-depth anomalies throughout much of North America.
An Interdecadal Change in Southern China Summer Rainfall around 1992/93
Authors: Wu Renguang , Wen Zhiping , Yang Song , Li Yueqing 
Published: December 2009

Abstract
The present study documents a pronounced interdecadal change in summer rainfall over southern China around 1992/93 and explores the plausible reasons for this change. The summer rainfall is persistently below normal during 1980–92 and above normal during 1993–2002. Coherent changes in atmospheric circulation are identified over East Asia and the South China Sea (SCS)–western North Pacific (WNP). The increase in rainfall is accompanied by an increase in lower-level convergence, midtropospheric ascent, and upper-level divergence over southern China. The changes in lower-level winds feature two anomalous anticyclones: one over the SCS–subtropical WNP, and the other over north China–Mongolia. The outflows from the two anomalous anticyclones converge over southern China, leading to anomalous moisture convergence, enhanced ascent, and increased rainfall. The development of the northern anticyclone is related to an increase in the Tibetan Plateau snow cover in the preceding winter–spring that leads to a contrast in temperature change between the plateau and the surrounding regions. The relatively small temperature change over the plateau, coupled with increases in temperature to the west and the east, leads to an increase in surface pressure extending northward from the plateau. The development of the southern anticyclone is related to an increase in sea surface temperature in the equatorial Indian Ocean that enhances lower-level convergence and ascent. The accompanying upper-level divergent flows from the tropical Indian Ocean to the SCS–WNP lead to the development of anomalous descent and lower-level anomalous anticyclone over the SCS–WNP.
Regional Precipitation Trends: Distinguishing Natural Variability from Anthropogenic Forcing
Authors: Hoerling Martin , Eischeid Jon , Perlwitz Judith 
Published: December 2009

Abstract
In this study, the nature and causes for observed regional precipitation trends during 1977–2006 are diagnosed. It is found that major features of regional trends in annual precipitation during 1977–2006 are consistent with an atmospheric response to observed sea surface temperature (SST) variability. This includes drying over the eastern Pacific Ocean that extends into western portions of the Americas related to a cooling of eastern Pacific SSTs, and broad increases in rainfall over the tropical Eastern Hemisphere, including a Sahelian rainfall recovery and increased wetness over the Indo–West Pacific related to North Atlantic and Indo–West Pacific ocean warming. It is further determined that these relationships between SST and rainfall change are generally not symptomatic of human-induced emissions of greenhouse gases (GHGs) and aerosols. The intensity of regional trends simulated in climate models using observed time variability in greenhouse gases, tropospheric sulfate aerosol, and solar and volcanic aerosol forcing are appreciably weaker than those observed and also weaker than those simulated in atmospheric models using only observed SST forcing. The pattern of rainfall trends occurring in response to such external radiative forcing also departs significantly from observations, especially a simulated increase in rainfall over the tropical Pacific and southeastern Australia that are opposite in sign to the actual drying in these areas.
Additional experiments illustrate that the discrepancy between observed and GHG-forced rainfall changes during 1977–2006 results mostly from the differences between observed and externally forced SST trends. Only weak rainfall sensitivity is found to occur in response to the uniform distribution of SST warming that is induced by GHG and aerosol forcing, whereas the particular pattern of the observed SST change that includes an increased SST contrast between the east Pacific and the Indian Ocean, and strong regional warming of the North Atlantic Ocean, was a key driver of regional rainfall trends. The results of this attribution study on the causes for 1977–2006 regional rainfall changes are used to discuss prediction challenges including the likelihood that recent rainfall trends might persist.
Controlling Noise in Ensemble Data Assimilation Schemes
Authors: Peña Malaquias , Toth Zoltan , Wei Mozheng 
Published: December 2009

Abstract
A variety of ad hoc procedures have been developed to prevent filter divergence in ensemble-based data assimilation schemes. These procedures are necessary to reduce the impacts of sampling errors in the background error covariance matrix derived from a limited-size ensemble. The procedures amount to the introduction of additional noise into the assimilation process, possibly reducing the accuracy of the resulting analyses. The effects of this noise on analysis and forecast performance are investigated in a perfect model scenario. Alternative schemes aimed at controlling the unintended injection of noise are proposed and compared. Improved analysis and forecast accuracy is observed in schemes with minimal alteration to the evolving ensemble-based covariance structure.
Determinants of platelet number and regulation of thrombopoiesis
Authors: Kaushansky Kenneth 
Published: December 2009

Abstract
Our understanding of thrombopoiesis has improved greatly in the last two decades with the availability of in vitro assays of megakaryocyte progenitor cell growth, with the cloning and characterization of stem cell factor (SCF) and thrombopoietin (Tpo), the latter the primary humoral regulator of this process, and with the generation of genetically altered murine models of thrombopoietic failure and excess. While SCF affects developmentally early aspects of megakaryocyte growth, Tpo affects nearly all aspects of platelet production, from hematopoietic stem cell (HSC) self-renewal and expansion, through stimulation of megakaryocyte progenitor cell proliferation, to supporting their maturation into platelet-producing cells. The molecular and cellular mechanisms through which the marrow microenvironment and humoral mediators affect platelet production provide new insights into the interplay between intrinsic and extrinsic influences on hematopoiesis, and highlight new opportunities to translate basic biology into clinical advances.
Transfusion in the age of molecular diagnostics
Authors: Reid Marion E. 
Published: December 2009

Abstract
DNA-based tests are increasingly being used to predict a blood group phenotype to improve transfusion medicine. This is possible because genes encoding 29 of the 30 blood group systems have been cloned and sequenced, and the molecular bases associated with most antigens have been determined. RBCs carrying a particular antigen, if introduced into the circulation of an individual who lacks that antigen (through transfusion or pregnancy), can elicit an immune response. It is the antibody from such an immune response that causes problems in clinical practice and the reason why antigen-negative blood is required for safe transfusion. The classical method of testing for blood group antigens and antibodies is hemagglutination; however, it has certain limitations, some of which can be overcome by testing DNA. Such testing allows conservation of antibodies for confirmation by hemagglutination of predicted antigen-negativity. High-throughput platforms provide a means to test relatively large numbers of donors, thereby opening the door to change the way antigen-negative blood is provided to patients and to prevent immunization. This review summarizes how molecular approaches, in conjunction with conventional hemagglutination, can be applied in transfusion medicine.
ASH evidence-based guidelines: is the IgG-specific anti-PF4/heparin ELISA superior to the polyspecific ELISA in the laboratory diagnosis of HIT?
Authors: Cuker Adam , Ortel Thomas L. 
Published: December 2009

Abstract
You are asked to consult on a 76-year-old man admitted to the hospital with pneumonia and thrombocytopenia. Ten days before the current admission, he had undergone surgery to repair a small bowel obstruction. A preoperative platelet count had been normal. Following surgery, he received subcutaneous unfractionated heparin thromboprophylaxis until his discharge on post-operative day 5. In your differential diagnosis for the patient’s thrombocytopenia, you consider heparin-induced thrombocytopenia (HIT) and wish to order laboratory testing. In addition to a polyspecific anti-PF4/heparin ELISA for the diagnosis of HIT, your laboratory has recently begun to offer an IgG-specific ELISA. You wonder which of these assays performs better in the diagnosis of HIT.
Risk of future arterial cardiovascular events in patients with idiopathic venous thromboembolism
Authors: Green David 
Published: December 2009

Abstract
Venous and arterial thromboses have traditionally been considered distinct pathophysiologic entities. However, the two disorders have many features in common, and there is evidence that persons with venous thrombosis may be at greater risk for arterial events. The pathogenesis of both disorders includes endothelial injury, platelet activation, elevated levels of intrinsic clotting factors and inflammatory markers, increased fibrinogen, and impaired fibrinolysis. In addition, older age, obesity, dyslipidemia, and smoking predispose to both venous and arterial thrombosis. While the evidence that arterial disease is a risk factor for venous thrombosis is inconclusive, arterial disease does appear to occur with a modestly increased frequency in patients with a history of venous thromboembolism. Reported odds ratios in such patients were 1.2 for myocardial infarction, 1.3 for stroke, 2.3 for carotid plaque, and 4.3 for coronary calcification. Of note, in persons under age 40 with unprovoked venous thrombosis, the odds ratio for acute myocardial infarction was as high as 3.9. In general, however, venous disease is considered to be a weak risk factor for arterial thrombosis, and the use of agents specifically targeted to the prevention of heart attack or stroke in the majority of persons with VTE cannot be recommended at present.
ASH evidence-based guidelines: is there a role for second allogeneic transplant after relapse?
Authors: Thakar Monica S. , Forman Stephen J. 
Published: December 2009

Abstract
A 35-year-old male with a FLT3+ AML underwent allogeneic peripheral blood stem cell transplant using a myeloablative non-total body irradiation (TBI) conditioning regimen from his HLA-matched sibling donor. Following transplantation, he developed grade II acute graft-versus-host disease (GVHD) that resolved with increasing immunosuppression. The medications were subsequently discontinued, and he did not develop any evidence of chronic GVHD. Eighteen months after transplant, while off all immunosuppression, he developed fatigue and a blood count showed circulating blasts consistent with relapse of his disease. Among the various therapeutic questions is whether there is a role for a second allogeneic transplant to treat his disease and if so, at what time, with what conditioning, and with which type of donor.
ASH evidence-based guidelines: what is the role of maintenance therapy in the treatment of multiple myeloma?
Authors: Ghobrial Irene M. , Stewart A. Keith 
Published: December 2009

Abstract
A 51-year-old male was diagnosed with an IgA multiple myeloma (MM) after having back pain for several months. His bone marrow showed 30% involvement with plasma cells and his cytogenetics showed t(4:14). His β2-microglobulin was 6.5 mg/dL at diagnosis and he had multiple lytic lesions, along with a creatinine of 2.3 mg/dL and significant anemia. Induction therapy with lenalidomide, bortezomib and dexamethasone was used, and he was able to achieve complete remission after 4 cycles of therapy. He then went on to receive high-dose chemotherapy with a single autologous stem cell transplant. He tolerated it well and now comes to discuss follow-up treatment plans. He wants to discuss maintenance therapy.
Retroviral insertional mutagenesis identifies Zeb2 activation as a novel leukemogenic collaborating event in CALM-AF10 transgenic mice
Authors: Caudell David , Harper David P. , Novak Rachel L. , Pierce Rachel M. , Slape Christopher , Wolff Linda , Aplan Peter D. 
Published: December 2009

AbstractThe t(10;11) translocation results in a CALM-AF10 fusion gene in a subset of leukemia patients. Expression of a CALM-AF10 transgene results in leukemia, with prolonged latency and incomplete penetrance, suggesting that additional events are necessary for leukemic transformation. CALM-AF10 mice infected with the MOL4070LTR retrovirus developed acute leukemia, and ligation-mediated polymerase chain reaction was used to identify retroviral insertions at 19 common insertion sites, including Zeb2, Nf1, Mn1, Evi1, Ift57, Mpl, Plag1, Kras, Erg, Vav1, and Gata1. A total of 26% (11 of 42) of the mice had retroviral integrations near Zeb2, a transcriptional corepressor leading to overexpression of the Zeb2-transcript. A total of 91% (10 of 11) of mice with Zeb2 insertions developed B-lineage acute lymphoblastic leukemia, suggesting that Zeb2 activation promotes the transformation of CALM-AF10 hematopoietic precursors toward B-lineage leukemias. More than half of the mice with Zeb2 integrations also had Nf1 integrations, suggesting cooperativity among CALM-AF10, Zeb2, and Ras pathway mutations. We searched for Nras, Kras, and Ptpn11 point mutations in the CALM-AF10 leukemic mice. Three mutations were identified, all of which occurred in mice with Zeb2 integrations, consistent with the hypothesis that Zeb2 and Ras pathway activation promotes B-lineage leukemic transformation in concert with CALM-AF10.
Interconnecting molecular pathways in the pathogenesis and drug sensitivity of T-cell acute lymphoblastic leukemia
Authors: Sanda Takaomi , Li Xiaoyu , Gutierrez Alejandro , Ahn Yebin , Neuberg Donna S. , O'Neil Jennifer , Strack Peter R. , Winter Christopher G. , Winter Stuart S. , Larson Richard S. , von Boehmer Harald , Look A. Thomas 
Published: December 2009

Abstract
To identify dysregulated pathways in distinct phases of NOTCH1-mediated T-cell leukemogenesis, as well as small-molecule inhibitors that could synergize with or substitute for γ-secretase inhibitors (GSIs) in T-cell acute lymphoblastic leukemia (T-ALL) therapy, we compared gene expression profiles in a Notch1-induced mouse model of T-ALL with those in human T-ALL. The overall patterns of NOTCH1-mediated gene expression in human and mouse T-ALLs were remarkably similar, as defined early in transformation in the mouse by the regulation of MYC and its target genes and activation of nuclear factor-κB and PI3K/AKT pathways. Later events in murine Notch1-mediated leukemogenesis included down-regulation of genes encoding tumor suppressors and negative cell cycle regulators. Gene set enrichment analysis and connectivity map algorithm predicted that small-molecule inhibitors, including heat-shock protein 90, histone deacetylase, PI3K/AKT, and proteasome inhibitors, could reverse the gene expression changes induced by NOTCH1. When tested in vitro, histone deacetylase, PI3K and proteasome inhibitors synergized with GSI in suppressing T-ALL cell growth in GSI-sensitive cells. Interestingly, alvespimycin, a potent inhibitor of the heat-shock protein 90 molecular chaperone, markedly inhibited the growth of both GSI-sensitive and -resistant T-ALL cells, suggesting that its loss disrupts signal transduction pathways crucial for the growth and survival of T-ALL cells.