bluuebunny/crossref_metadata_2025_split huggingface dataset:
Processes Controlling the Mean Tropical Pacific Precipitation Pattern. Part I: The Andes and the Eastern Pacific ITCZ
Authors: Takahashi Ken , Battisti David S. 
Published: August 2007

Abstract
The question of why the intertropical convergence zone (ITCZ) is generally north of the equator in the tropical Pacific is addressed. Experiments with an atmospheric general circulation model coupled to idealized representations of the ocean show that the presence of the Andes is enough to lower sea surface temperature (SST) off the west coast of South America through evaporation, thus promoting a north–south asymmetry, with the ITCZ north of the equator, which is amplified by interactions between the ocean and the atmosphere. The evaporative cooling results mainly from the subsidence of low specific humidity air, which is due in turn to the mechanical effect of the Andes on the zonal mean flow. The positive feedback from low-level clouds on SST is an important factor for the efficiency of the mechanism described.
West of 120°W, the presence of the Rockies and Himalayas produces a comparable forcing to that of the Andes, but this is not enough to reverse or neutralize the north–south asymmetry set by the Andes. It is shown that the longitudinal offset between the forcings in both hemispheres allows the Andes to preferentially set the north–south asymmetry, which propagates westward into the rest of the Pacific.
Asymmetry in the observed ocean heat transports (more heat transport convergence in the Northern Hemisphere) associated with the Kuroshio was found to reinforce the effect of the Andes, although it is not a strong forcing by itself. Sensitivity experiments indicate that the north–south asymmetry of the ITCZ caused (evaporatively) by the Andes is robust to the presence of a strong equatorial cold tongue and to seasonality in insolation.
Cluster Analysis of Typhoon Tracks. Part II: Large-Scale Circulation and ENSO
Authors: Camargo Suzana J. , Robertson Andrew W. , Gaffney Scott J. , Smyth Padhraic , Ghil Michael 
Published: August 2007

Abstract
A new probabilistic clustering method, based on a regression mixture model, is used to describe tropical cyclone (TC) propagation in the western North Pacific (WNP). Seven clusters were obtained and described in Part I of this two-part study. In Part II, the present paper, the large-scale patterns of atmospheric circulation and sea surface temperature associated with each of the clusters are investigated, as well as associations with the phase of the El Niño–Southern Oscillation (ENSO). Composite wind field maps over the WNP provide a physically consistent picture of each TC type, and of its seasonality. Anomalous vorticity and outgoing longwave radiation indicate changes in the monsoon trough associated with different types of TC genesis and trajectory. The steering winds at 500 hPa are more zonal in the straight-moving clusters, with larger meridional components in the recurving ones. Higher values of vertical wind shear in the midlatitudes also accompany the straight-moving tracks, compared to the recurving ones.
The influence of ENSO on TC activity over the WNP is clearly discerned in specific clusters. Two of the seven clusters are typical of El Niño events; their genesis locations are shifted southeastward and they are more intense. The largest cluster is recurving, located northwestward, and occurs more often during La Niña events. Two types of recurving and one of straight-moving tracks occur preferentially when the Madden–Julian oscillation is active over the WNP region.
The Tropical Atmospheric El Niño Signal in Satellite Precipitation Data and a Global Climate Model
Authors: Chen Yonghua , Del Genio Anthony D. , Chen Junye 
Published: August 2007

AbstractAspects of the tropical atmospheric response to El Niño related to the global energy and water cycle are examined using satellite retrievals from the Tropical Rainfall Measuring Mission and the Advanced Microwave Scanning Radiometer-E and simulations from the Goddard Institute for Space Studies (GISS) general circulation model (GCM). The El Niño signal is extracted from climate fields using a linear cross-correlation technique that captures local and remote in-phase and lagged responses. Passive microwave and radar precipitation anomalies for the 1997/98 and 2002/03 El Niños and the intervening La Niña are highly correlated, but anomalies in stratiform–convective rainfall partitioning in the two datasets are not. The GISS GCM produces too much rainfall in general over ocean and too little over land. Its atmospheric response to El Niño is weaker and decays a season too early. Underestimated stratiform rainfall fraction (SRF) and convective downdraft mass flux in the GISS GCM and excessive shallow convective and low stratiform cloud result in latent heating that peaks at lower altitudes than inferred from the data. The GISS GCM also underestimates the column water vapor content throughout the Tropics, which causes it to overestimate outgoing longwave radiation. The response of both quantities to interannual Hadley circulation anomalies is too weak. The GISS GCM’s Walker circulation also exhibits a weak remote response to El Niño, especially over the Maritime Continent and western Indian Ocean. This appears to be a consequence of weak static stability due to the model’s lack of upper-level stratiform anvil heating, excessive low-level heating, and excessive dissipation due to cumulus momentum mixing. Our results suggest that parameterizations of mesoscale updrafts, convective downdrafts, and cumulus-scale pressure gradient effects on momentum transport are keys to a reasonable GISS GCM simulation of tropical interannual variability.
Intravenous immunoglobulins suppress T-cell priming by modulating the bidirectional interaction between dendritic cells and natural killer cells
Authors: Tha-In Thanyalak , Metselaar Herold J. , Tilanus Hugo W. , Groothuismink Zwier M. A. , Kuipers Ernst J. , de Man Robert A. , Kwekkeboom Jaap 
Published: August 2007

AbstractThe modes of action of intravenous immunoglobulins (IVIgs) in exerting their immunomodulatory properties are broad and not fully understood. IVIgs can modulate the function of various immune cells, including suppressing the capacity of dendritic cells (DCs) to stimulate T cells. In the present study, we showed that DCs matured in the presence of IVIgs (IVIg-DCs) activated NK cells, and increased their interferon-γ production and degranulation. The activated NK cells induced apoptosis of the majority of IVIg-DCs. In consequence, only in the presence of NK cells, IVIg-DCs were 4-fold impaired in their T-cell priming capacity. This was due to NK-cell–mediated antibody-dependent cellular cytotoxicity (ADCC) to IVIg-DCs, probably induced by IgG multimers, which could be abrogated by blockade of CD16 on NK cells. Furthermore, IVIg-DCs down-regulated the expression of NKp30 and KIR receptors, and induced the generation of CD56brightCD16−CCR7+ lymph node–type NK cells. Our results identify a novel pathway, in which IVIgs induce ADCC of mature DCs by NK cells, which downsizes the antigen-presenting pool and inhibits T-cell priming. By influencing the interaction between DCs and NK cells, IVIgs modulate the ability of the innate immunity to trigger T-cell activation, a mechanism that can “cool down” the immune system at times of activation.
Gambogic acid, a novel ligand for transferrin receptor, potentiates TNF-induced apoptosis through modulation of the nuclear factor-κB signaling pathway
Authors: Pandey Manoj K. , Sung Bokyung , Ahn Kwang Seok , Kunnumakkara Ajaikumar B. , Chaturvedi Madan M. , Aggarwal Bharat B. 
Published: August 2007

AbstractGambogic acid (GA), a xanthone derived from the resin of the Garcinia hanburyi, has been recently demonstrated to bind transferrin receptor and exhibit potential anticancer effects through a signaling mechanism that is not fully understood. Because of the critical role of NF-κB signaling pathway, we investigated the effects of GA on NF-κB–mediated cellular responses and NF-κB–regulated gene products in human leukemia cancer cells. Treatment of cells with GA enhanced apoptosis induced by tumor necrosis factor (TNF) and chemotherapeutic agents, inhibited the expression of gene products involved in antiapoptosis (IAP1 and IAP2, Bcl-2, Bcl-xL, and TRAF1), proliferation (cyclin D1 and c-Myc), invasion (COX-2 and MMP-9), and angiogenesis (VEGF), all of which are known to be regulated by NF-κB. GA suppressed NF-κB activation induced by various inflammatory agents and carcinogens and this, accompanied by the inhibition of TAK1/TAB1-mediated IKK activation, inhibited IκBα phosphorylation and degradation, suppressed p65 phosphorylation and nuclear translocation, and finally abrogated NF-κB–dependent reporter gene expression. The NF-κB activation induced by TNFR1, TRADD, TRAF2, NIK, TAK1/TAB1, and IKKβ was also inhibited. The effect of GA mediated through transferrin receptor as down-regulation of the receptor by RNA interference reversed its effects on NF-κB and apoptosis. Overall our results demonstrate that GA inhibits NF-κB signaling pathway and potentiates apoptosis through its interaction with the transferrin receptor.
Glycogen synthase kinase 3α and 3β have distinct functions during cardiogenesis of zebrafish embryo
Authors: Lee Huang-Chieh , Tsai Jen-Ning , Liao Pei-Yin , Tsai Wei-Yuan , Lin Kai-Yen , Chuang Chung-Cheng , Sun Chi-Kuang , Chang Wen-Chang , Tsai Huai-Jen 
Published: August 2007

Abstract

Background
Glycogen synthase kinase 3 (GSK3) encodes a serine/threonine protein kinase, is known to play roles in many biological processes. Two closely related GSK3 isoforms encoded by distinct genes: GSK3α (51 kDa) and GSK3β (47 kDa). In previously studies, most GSK3 inhibitors are not only inhibiting GSK3, but are also affecting many other kinases. In addition, because of highly similarity in amino acid sequence between GSK3α and GSK3β, making it difficult to identify an inhibitor that can be selective against GSK3α or GSK3β. Thus, it is relatively difficult to address the functions of GSK3 isoforms during embryogenesis. At this study, we attempt to specifically inhibit either GSK3α or GSK3β and uncover the isoform-specific roles that GSK3 plays during cardiogenesis.

Results
We blocked gsk3α and gsk3β translations by injection of morpholino antisense oligonucleotides (MO). Both gsk3α- and gsk3β-MO-injected embryos displayed similar morphological defects, with a thin, string-like shaped heart and pericardial edema at 72 hours post-fertilization. However, when detailed analysis of the gsk3α- and gsk3β-MO-induced heart defects, we found that the reduced number of cardiomyocytes in gsk3α morphants during the heart-ring stage was due to apoptosis. On the contrary, gsk3β morphants did not exhibit significant apoptosis in the cardiomyocytes, and the heart developed normally during the heart-ring stage. Later, however, the heart positioning was severely disrupted in gsk3β morphants. bmp4 expression in gsk3β morphants was up-regulated and disrupted the asymmetry pattern in the heart. The cardiac valve defects in gsk3β morphants were similar to those observed in axin1 and apc

mcr
mutants, suggesting that GSK3β might play a role in cardiac valve development through the Wnt/β-catenin pathway. Finally, the phenotypes of gsk3α mutant embryos cannot be rescued by gsk3β mRNA, and vice versa, demonstrating that GSK3α and GSK3β are not functionally redundant.

Conclusion
We conclude that (1) GSK3α, but not GSK3β, is necessary in cardiomyocyte survival; (2) the GSK3β plays important roles in modulating the left-right asymmetry and affecting heart positioning; and (3) GSK3α and GSK3β play distinct roles during zebrafish cardiogenesis.
Influence of maternal and social factors as predictors of low birth weight in Italy
Authors: Nobile Carmelo GA , Raffaele Gianluca , Altomare Carlo , Pavia Maria 
Published: August 2007

Abstract

Background
The purpose of this study is to provide insight into the determinants of low birth weight (LBW) in Italy.

Methods
The study was carried out in a non-teaching hospital in Catanzaro (Italy). All LBW and very LBW newborns (200) were included in the study and a random sample of 400 newborns weighing ≥ 2500 g was selected. Data were collected from the delivery certificates during one year. Smoking activity of mother and familiar and/or social support during pregnancy was gathered through telephone interviews.

Results
Overall annual LBW rate was 11.8%. Among LBW newborn there were 125 preterm and 75 term. Younger mothers, those who smoked during pregnancy, and had fewer prenatal care visits were more likely to deliver a LBW child; moreover, preterm newborns, delivered by caesarean section, and twin or multiple birth were significantly more likely to have a LBW. The comparison of very LBW (<1500 g) to LBW newborns showed that a very LBW was significantly more likely in newborns delivered by less educated mothers, those who work outside the home, live in smaller towns, and had less echographies; moreover, as expected, very LBW newborns were more likely to be preterm.

Conclusion
Several modifiable factors affect the risk of LBW, even when universal access to health care is freely available, but socio-economic status appears to correlate only to very LBW.
ABO blood group phenotypes influence parity specific immunity to Plasmodium falciparum malaria in Malawian women
Authors: Senga Edward , Loscertales Maria-Paz , Makwakwa KEB , Liomba George N , Dzamalala Charles , Kazembe Peter N , Brabin Bernard J 
Published: August 2007

Abstract

Background
Blood group O has been significantly associated with increased placental malaria infection in primiparae and reduced risk of infection in multiparae in the Gambia, an area with markedly seasonal malaria transmission. This study analyses the association between ABO blood group phenotypes in relation to placental malaria pathology and birth outcomes in southern Malawi, an area with perennial malaria transmission.

Methods
A cross-sectional study of 647 mother/child pairs delivering in Montfort Hospital, Chikwawa District between February-June 2004 and January-July 2005 was undertaken. Maternal peripheral and cord blood samples were obtained at delivery. Placental tissue was obtained and malaria histology classified as active, past or no malaria infection. Birth anthropometry was recorded. ABO blood group was measured by agglutination.

Results
In primiparae, blood group O was significantly associated with increased risk of active placental infection (OR 2.18, 95% CI 1.15–4.6, p = 0.02) and an increased foetal-placental weight ratio compared to non-O phenotypes (5.68 versus 5.45, p = 0.03) In multiparae blood group O was significantly associated with less frequent active placental infection (OR 0.59, 95% CI 0.36–0.98, p = 0.04), and a higher newborn ponderal index compared to non-O phenotypes (2.65 versus 2.55, p = 0.007). In multivariate regression parity was independently associated with increased risk of placental malaria (active andpast infection) in primiparae with blood group O (p = 0.034) and reduced risk in multiparae with the same phenotype (p = 0.015).

Conclusion
Parity related susceptibility to placental malaria is associated with the mothers ABO phenotype. This interaction influences foetal and placental growth and could be an important modifying factor for pregnancy outcomes. The biological explanation could relate to sialic acid dependent placental membrane differences which vary with ABO blood group.
Dermoid cyst of the pancreas: presentation and management
Authors: Tucci Gianfranco , Muzi Marco Gallinella , Nigro Casimiro , Cadeddu Federica , Amabile Dalia , Servadei Francesca , Farinon Attilio M 
Published: August 2007

Abstract

Background
Dermoid cyst of the pancreas is a benign, well-differentiated, extremely rare germ cell neoplasm. Published data indicate that differential diagnosis of cystic lesions of the pancreas is challenging and although ultrasonography, computed tomography and magnetic resonance may be useful, radiological findings are often inconclusive and the diagnosis is intraoperative. We report a case of a dermoid cyst of the tail of the pancreas intraoperatively diagnosed and successfully treated with left pancreatectomy. Further, characteristics, preoperative detection and differential diagnosis of this rare pathology are also discussed.

Case presentation
This report documents the findings of a 64-year-old male presenting with a well defined echogenic pancreatic mass on ultrasonography. Computerized Tomography (CT) showed a 5 cm cystic tumor arising from pancreatic tail and Magnetic Resonance Imaging (MRI) suggested a tumor extension to the middle side of the stomach without defined margins. A left pancreatectomy was performed. On surgical specimen, histological evaluation revealed a dermoid cyst of the tail of the pancreas measuring 8.5 × 3.0 cm.

Conclusion
Given the benign nature of the dermoid cyst, surgical resection most likely represents the definitive treatment and cure. In addition, resection is indicated in consideration of the difficulty in diagnosing dermoid cyst preoperatively. However, endoscopic ultrasound and fine needle aspiration cytology have recently been shown to be effective, safe, reliable and cost-saving preoperative diagnostic tools. Therefore, until more cases of dermoid cyst are identified to further elucidate its natural history and improve the reliability of the preoperative diagnostic tools, surgical resection should be considered the standard therapy in order to exclude malignancy.
The global role of ppGpp synthesis in morphological differentiation and antibiotic production in Streptomyces coelicolor A3(2)
Authors: Hesketh Andrew , Chen Wenqiong Joan , Ryding Jamie , Chang Sherman , Bibb Mervyn 
Published: August 2007

Abstract
Background
Regulation of production of the translational apparatus via the stringent factor ppGpp in response to amino acid starvation is conserved in many bacteria. However, in addition to this core function, it is clear that ppGpp also exhibits genus-specific regulatory effects. In this study we used Affymetrix GeneChips to more fully characterize the regulatory influence of ppGpp synthesis on the biology of Streptomyces coelicolor A3(2), with emphasis on the control of antibiotic biosynthesis and morphological differentiation.

Results
Induction of ppGpp synthesis repressed transcription of the major sigma factor hrdB, genes with functions associated with active growth, and six of the thirteen conservons present in the S. coelicolor genome. Genes induced following ppGpp synthesis included the alternative sigma factor SCO4005, many for production of the antibiotics CDA and actinorhodin, the regulatory genes SCO4198 and SCO4336, and two alternative ribosomal proteins. Induction of the CDA and actinorhodin clusters was accompanied by an increase in transcription of the pathway regulators cdaR and actII-ORF4, respectively. Comparison of transcriptome profiles of a relA null strain, M570, incapable of ppGpp synthesis with its parent M600 suggested the occurrence of metabolic stress in the mutant. The failure of M570 to sporulate was associated with a stalling between production of the surfactant peptide SapB, and of the hydrophobins: it overproduced SapB but failed to express the chaplin and rodlin genes.

Conclusion
In S. coelicolor, ppGpp synthesis influences the expression of several genomic elements that are particularly characteristic of streptomycete biology, notably antibiotic gene clusters, conservons, and morphogenetic proteins.
Aktuelle Entwicklungen im vorgeburtlichen Screening auf chromosomale Störungen / Recent developments in antenatal screening for chromosomal abnormalities
Authors: Knippel Alexander-Johannes , Kozlowski Peter , Stressig Rüdiger 
Published: August 2007

Zusammenfassung
Das klassische Ersttrimesterscreening (ETS) liefert eine durch unabhängige prospektive Studien validierte Nachweisrate für ein fetales Down-Syndrom von 86–90% bei einer falsch-positiv Rate von 5%. Durch eine Kombination von Erst- und Zweittrimestermarkern (Integrated Screening) kann eine Verbesserung der Nachweisrate auf 94–96% erreicht werden, wenn das Gesamttestergebnis erst nach Vorliegen der Zweittrimesterwerte mitgeteilt wird. Die frühe Diagnostik des klassischen Ersttrimesterscreenings und die bessere Testgenauigkeit des Integrierten Screenings können durch ein sequentielles Screening kombiniert werden, bei dem man in Fällen mittlerer Risiken eine zusätzliche Zweittrimesterbiochemie durchführt. Patientinnen mit hohen Risiken im Ersttrimesterscreening würde direkt eine invasive Diagnostik empfohlen, Patientinnen mit sehr niedrigen Risiken benötigten keine weitere Untersuchung. Genaue Zahlen für einen Risikogrenzwert ab dem eine Zweittrimesterbiochemie empfohlen wird und prospektive Studien zu diesem sequentiellen Screening liegen jedoch noch nicht vor. Sind über die Risikoangabe für eine fetale Trisomie 21 hinaus weitere Informationen zum Gesundheitszustand des Kindes gewünscht, ist ein erweitertes Ultraschallscreening im ersten Trimenon eine gute Alternative. Quantitative Aussagen zur Screeningperformance des erweiterten Ultraschallscreenings für ein fetales Down-Syndrom sind zurzeit noch nicht möglich.
Invasive Pränataldiagnostik / Invasive methods in prenatal diagnostics
Authors: Rost Imma , Schiessl Barbara , Heinrich Uwe , Rupprecht Wolfgang , Wagner Annett , Klein Hanns-Georg 
Published: August 2007

Zusammenfassung
Unter den Begriff der Invasiven Pränataldiagnostik fallen Eingriffe bzw. Verfahren, die auf der Untersuchung von Zellen des Ungeborenen, Fruchtwasser- bzw. Blutproben basieren. Die Eingriffe zur Gewinnung dieser Zellen bzw. Flüssigkeiten beinhalten ein Eingriffsrisiko, vor allem das einer Fehlgeburt bzw. eines intrauterinen Fruchttodes. Daher ist die Invasive Pränataldiagnostik im Gegensatz zu den nicht-invasiven Screeningmethoden, die zum Teil auch Bestandteil der allgemeinen Mutterschaftsrichtlinien sind, grundsätzlich an eine Indikation gebunden. Diese Indikation ergibt sich in der Regel aus einem individuellen Risiko für eine bestimmte Erkrankung beim Ungeborenen.
Nicht-invasive Pränataldiagnostik durch Analyse fetaler DNA im mütterlichen Blut / Non-invasive prenatal diagnosis by genetic analysis of maternal blood
Authors: Zimmermann Bernhard G. 
Published: August 2007

Zusammenfassung
Seit Jahrzehnten gab es Bestrebungen Informationen aus dem Blut der werdenden Mutter zur nicht-invasiven Schwangerschaftsdiagnostik zu nutzen. Das Ziel waren in den Neunzigerjahren fetale Zellen und deren Anreicherung; die hochgesteckten Hoffnungen haben sich jedoch nicht erfüllt. Eine routinemäßige Anwendung der entwickelten Methoden ist nicht absehbar. Mit der Entdeckung fetaler DNS und RNS im mütterlichen Plasma boten sich diagnostische Anwendungen an. Die auf DNS-Tests basierende Bestimmung des Rhesus-Genotyps und des Geschlechts des Kindes halten europaweit Einzug in die klinische Praxis. Zudem kann das Risiko von bestimmten Erbkrankheiten durch den Nachweis der väterlich vererbten Mutationen vorbestimmt werden und wird in Zukunft helfen, invasive Eingriffe zur Fruchtwasser- oder Chorionentnahme zu reduzieren. Die Forschung kommt dem Ziel des nicht-invasiven Nachweises fetaler Aneuploidien immer näher, dennoch ist es bis zur routinemäßigen Anwendung noch ein weiter Weg.