bluuebunny/crossref_metadata_2025_split huggingface dataset:
Silent Infarcts and Cerebral Microbleeds Modify the Associations of White Matter Lesions With Gait and Postural Stability
Authors: Choi Philip , Ren Mandy , Phan Thanh G. , Callisaya Michele , Ly John V. , Beare Richard , Chong Winston , Srikanth Velandai 
Published: March 2012

Background and Purpose—
Although cerebral white matter lesions (WMLs), silent infarcts (SIs), and microbleeds (MBs) are individually associated with poorer gait and balance, it is unknown if they interact. We studied the interactions of WML volume with SI and MB on gait and postural stability.

Methods—
Participants in a population-based study aged 60 to 86 years underwent brain MRI, computerized gait measurement, and a physiological profile assessment of postural stability. Segmentation procedures and standard rating methods were used to measure WML, SI, and MB. Linear regression was used to test interactions between lesions on gait and postural stability, adjusting for age, sex, and total intracranial volume.

Results—

There were 395 participants (mean age, 72 years; SD, 7.0). SIs were predominantly located in subcortical frontal white matter and in deep gray structures, and MBs were largely lobar. Participants with SI or MB had higher WML volumes than those without (
P
<0.001 and
P
=0.05, respectively). The presence of SI (
P
for interaction=0.01) or MB (
P
for interaction <0.01) magnified the adverse association of WML volume with gait. SI (
P
for interaction=0.02), but not MB, magnified the adverse association of WML volume with postural stability.

Conclusions—
Subclinical cerebrovascular lesions are adversely associated with gait and postural stability in older people in a cumulative fashion.
Changes in Western Pacific Tropical Cyclones Associated with the El Niño–Southern Oscillation Cycle
Authors: Li Richard C. Y. , Zhou Wen 
Published: March 2012

Abstract
This study examines the interannual variability of three groups of tropical cyclones (TCs)—super typhoons (STYs), typhoons (TYs), and tropical storms and tropical depressions (TSTDs)—and their relationship with the El Niño–Southern Oscillation (ENSO). Both wavelet analysis and correlation studies of upper-ocean heat content reveal significant differences for the three types of TCs. In particular, an increase (decrease) in the frequency of STYs is usually associated with the mature phase of El Niño (La Niña) events, while the converse is true for TSTDs. In contrast, the frequency of TYs increases (decreases) during the transition period from La Niña to El Niño (El Niño to La Niña) events. The results suggest that the timing with which ENSO impacts STYs, TYs, and TSTDs varies and that their corresponding changes in frequency closely follow the evolution of the ENSO cycle.
Empirical orthogonal function analysis is also conducted to investigate the impact of different environmental factors influenced by ENSO on TCs. The vertical wind shear and moist static energy associated with ENSO are identified as the dominant factors that control the frequency of STYs. In comparison, the frequency of TYs is found to be closely related to the relative vorticity and vertical wind shear associated with both the transition phase of ENSO and with other types of climate variability.
The Role of Windward-Side Diabatic Heating in Sierra Nevada Spillover Precipitation
Authors: Kaplan Michael L. , Vellore Ramesh K. , Marzette Phillip J. , Lewis John M. 
Published: March 2012

Abstract
This study focuses on the meso-α- and meso-β-scale manifestations of the latent-heat-induced reduction of windward-side blocking to two flood-producing precipitation events on the leeside of the Sierra Nevada. Two simulations were performed—one employing full microphysics [control (CTRL)] and a second in which the latent heating terms are turned off in the microphysics [no latent heating (NLH)]. The differences between the CTRL and NLH are consistent with upstream latent heating—the moist, divergent, and ascending flow dominates the leeside of the mountain range in the CTRL producing copious spillover precipitation while dry high-momentum/downslope-descending flow dominates the NLH simulation on the leeside. A comprehensive sequence of events for spillover precipitation is formulated as follows: 1) Ascent within the exit region of a polar jet streak develops in response to velocity divergence aloft. 2) This ascent phases with ascent from the windward-side flow to create a mesoscale region of heavy upslope precipitation. 3) The latent heat release from the upslope precipitation reduces the upstream static stability and blocking. 4) A mesoscale ridge in the thickness field builds in the upper troposphere and induces subgeostrophic flow in the jet’s exit region above the mountain range. 5) Adjustments to this ridge result in a cross-mountain midlevel jet that facilitates a river of midlevel moisture advected over to the leeside. 6) Stretching of moist isentropic surfaces in proximity to the plume of moisture fluxes causes destabilization on the leeside and formation of a leeside mesolow. 7) Boundary layer air accelerates into the leeside mesolow to form a mountain-parallel low-level flow.
Inertial Oscillations in Geostrophic Flow: Is the Inertial Frequency Shifted by ζ/2 or by ζ?
Authors: Chavanne Cédric P. , Firing Eric , Ascani François 
Published: March 2012

Abstract
The short answer to the question posed in the title is that it depends on the frame of reference chosen to describe the motions. In the inertial limit, the frequency in a rotating frame of reference corresponds to the rotation rate of the inertial current vectors relative to that frame. When described in a reference frame rotating with a geostrophic flow having a relative vertical vorticity ζ, inertial oscillations have a frequency f + ζ, equal to twice the fluid’s rotation rate around the local vertical axis. From a nonrotating frame of reference, one would measure only half this frequency; the other half arises from describing inertial motions in a reference frame rotating with the background flow. However, when described in a reference frame rotating with Earth, hence rotating at −ζ/2 relative to the geostrophic frame, inertial oscillations have a frequency reduced to f + ζ/2.
Relationships between Rain Characteristics and Environment. Part II: Atmospheric Disturbances Associated with Shallow Convection over the Eastern Tropical Pacific
Authors: Yokoyama Chie , Takayabu Yukari N. 
Published: March 2012

Abstract
Synoptic-scale westward-propagating disturbances over the eastern Pacific (EP) are analyzed in boreal autumn, utilizing spectral analysis, composite analysis, and energy budget analysis. The results are compared with those over the western Pacific (WP).
Spectral peaks of total precipitable water (TPW) and vertical velocity at 850 hPa (ω850), and outgoing longwave radiation (OLR) are detected at periods of ~3–7 days over the EP. Meanwhile over the WP, a spectral peak of OLR is pronounced, but peaks of TPW and ω850 are not detected. Composite analysis reveals that disturbances that have a coupled structure, with a vortex at its center near ~9°N and a mixed Rossby–gravity (MRG) wave–type disturbance, frequently exist over the EP. At the same time, the disturbances have a double-deck structure associated with divergence both in the upper and in the middle to lower troposphere. These disturbances are associated with both deep convection and congestus, which generate kinetic energy of the disturbance in the upper and in the lower troposphere, respectively.
Examining diabatic heating in relation to the coupled disturbances, deep heating with the peak at the height of ~7.5 km is greatest in the northeastern part of the vortex. The coupled MRG wave–type disturbance provides a relatively deep cross-equatorial southerly flow into the northeastern part of the vortex. It is suggested that deep rain is maintained with the existence of deep convergence produced by the coupled disturbances over the EP, where a very shallow convergence field exists on average.
Generating and Calibrating Probabilistic Quantitative Precipitation Forecasts from the High-Resolution NWP Model COSMO-DE
Authors: Bentzien Sabrina , Friederichs Petra 
Published: March 2012

Abstract
Statistical postprocessing is an integral part of an ensemble prediction system. This study compares methods used to derive probabilistic quantitative precipitation forecasts based on the high-resolution version of the German-focused Consortium for Small-Scale Modeling (COSMO-DE) time-lagged ensemble (COSMO-DE-TLE). The investigation covers the period from July 2008 to June 2011 for a region over northern Germany with rain gauge measurements from 445 stations. The investigated methods provide pointwise estimates of the predictive distribution using logistic and quantile regression, and full predictive distributions using parametric mixture models. All mixture models use a point mass at zero to represent the probability of precipitation. The amount of precipitation is modeled by either a gamma, lognormal, or inverse Gaussian distribution. Furthermore, an adaptive tail using a generalized Pareto distribution (GPD) accounts for a better representation of extreme precipitation. The predictive probabilities, quantiles, and distributions are evaluated using the Brier, the quantile verification, and the continuous ranked probability scores. Baseline predictions and covariates are based on first-guess estimates from the COSMO-DE-TLE. Predictive performance is largely improved by statistical postprocessing due to an increase in reliability and resolution. The mixture models show some deficiencies. The inverse Gaussian fails to provide calibrated predictive distributions, whereas the lognormal and gamma mixtures perform well within the bulk of the distribution. Both mixtures provide significantly less skill for the extremal quantiles (0.99–0.999). Their representation is largely improved by incorporating an adaptive GPD tail. Even more stable estimates are obtained if the annual cycle is included in the postprocessing and training is performed on almost 3 yr of data.
Effect of ethylene vinyl acetate on physico-mechanical and thermal properties of polypropylene and starch biocomposites
Authors: Ramaraj B. , Shit Subhas C. , Nayak Sanjay K. 
Published: March 2012

The aim of this research is to investigate the effects of ethylene vinyl acetate (EVA) as compatibilizer on physico-mechanical and thermal properties of polypropylene (PP)/starch composites. PP/starch composites were prepared by the extrusion of PP resin with potato starch in co-rotating twin-screw extruder by varying starch content from 5 to 20%, where the EVA content was 10 wt% based upon potato starch. It was found that with the increase in starch content from 0 to 20% in the PP matrix, the tensile elongation increased from 19.77 to 32.0%, moisture content increased from 0.013 to 0.062%, water absorption increased from 0.035 to 0.181% and density increased from 0.912 to 0.985 g/cm3, however, the tensile, flexural and impact properties, Rockwell hardness, melt flow index and vicat softening point were found to decrease linearly. Similarly, the incorporation of starch with EVA has reduced the melting temperature of PP matrix from 162.3 to 158.55°C, the heat of fusion (▵ Hf) of PP matrix decreased from 66.52 to 27.05 J/g and so is the percentage crystallization, decreased from 31.83 to 21.45% with increase in starch content from 0 to 20 wt% in the PP matrix.
The production of space in metropolitan regions: A Lefebvrian analysis of governance and spatial change
Authors: Buser Michael 
Published: March 2012

The language of relational geography now permeates the field and literature of planning, with phrases such as ‘fuzzy boundaries’ and ‘flows and networks’ being commonly used to express the complexity of socio-economic and governance relations. However, recent research suggests the so-called ‘relational turn’ is not only far from complete, but is unable to account for the bounded reality of urban processes. Following from these debates, this article seeks to redirect the study of urban change away from relational and absolute interpretations of space in favour of a more robust consideration and critical reflection on the social production of city-regions. Towards this objective, the author introduces an approach situated within Lefebvre’s The Production of Space to examine strategies of metropolitan regionalism in the Capital District, New York (United States). Interpreting the city-region as a social product reflecting the co-constitutive relationship of conceived, perceived and lived space spatial elements, the paper argues that the silences of lived space within metropolitan regionalism are indicative of a post-political condition where hegemonic vision, discourse and ideology deny a robust urban democracy. It is this ability to engage with the dynamism of social change and the relationships between spaces which makes Lefebvre’s spatial theory immensely valuable for the study of emerging and shifting structures of governance.
Mutation of the receptor tyrosine phosphatase PTPRC (CD45) in T-cell acute lymphoblastic leukemia
Authors: Porcu Michaël , Kleppe Maria , Gianfelici Valentina , Geerdens Ellen , De Keersmaecker Kim , Tartaglia Marco , Foà Robin , Soulier Jean , Cauwelier Barbara , Uyttebroeck Anne , Macintyre Elizabeth , Vandenberghe Peter , Asnafi Vahid , Cools Jan 
Published: March 2012

Abstract
The protein tyrosine phosphatase CD45, encoded by the PTPRC gene, is well known as a regulator of B- and T-cell receptor signaling. In addition, CD45 negatively regulates JAK family kinases downstream of cytokine receptors. Here, we report the presence of CD45 inactivating mutations in T-cell acute lymphoblastic leukemia. Loss-of-function mutations of CD45 were detected in combination with activating mutations in IL-7R, JAK1, or LCK, and down-regulation of CD45 expression caused increased signaling downstream of these oncoproteins. Furthermore, we demonstrate that down-regulation of CD45 expression sensitizes T cells to cytokine stimulation, as observed by increased JAK/STAT signaling, whereas overexpression of CD45 decreases cytokine-induced signaling. Taken together, our data identify a tumor suppressor role for CD45 in T-cell acute lymphoblastic leukemia.
PKC-δ mediates interferon-α-induced apoptosis through c-Jun NH2-terminal kinase activation
Authors: Yanase Noriko , Hayashida Miho , Kanetaka-Naka Yuki , Hoshika Akinori , Mizuguchi Junichiro 
Published: March 2012

Abstract

Background
Interferon-α (IFN-α) exerts an anti-tumor effect at least through induction of apoptosis in a variety of types including B lymphoma cells. We recently found that IFN-α induced a sustained activation of c-Jun NH2-terminal kinase1 (JNK1), which is implicated in activation of the tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) promoter. In the present study, we explored upstream component(s) of the prolonged IFN-α-initiated activation of JNK1.

Results
IFN-α caused activation of PKC-δ in Daudi B lymphoma cells and myeloma U266 cells, as detected by Western blotting using a monoclonal antibody specific for the phosphorylated form of PKC-δ. The dominant-negative form of mutant PKC-δ (dnPKC-δ) reduced the IFN-α-induced JNK1 activation, TRAIL promoter activity, loss of mitochondrial membrane potential (ΔΨm), and increase in propidium iodide (PI) positive cells. The IFN-α-induced activation of JNK1 and the TRAIL promoter was also attenuated by the PKC-δ inhibitor rottlerin. Moreover, a constitutively active form of mutant PKC-δ enhanced the IFN-α-induced TRAIL promoter activity and loss of ΔΨm in Daudi B lymphoma cells. In addition, IFN-α-induced Ser727 phosphorylation of Stat1 was also abrogated by dnPKC-δ.

Conclusions
IFN-α induced JNK1 activation via PKC-δ, leading to upregulation of TRAIL. The interaction of the consequent enhanced TRAIL expression with TRAIL-receptor results in a loss of ΔΨm and increase in PI positive cells. The IFN-α-induced apoptotic events may also be affected by the Ser727-Stat1 induced by PKC-δ-mediated signaling component(s).
Identification of genes expressed in cultures of E. coli lysogens carrying the Shiga toxin-encoding prophage Φ24B
Authors: Riley Laura M , Veses-Garcia Marta , Hillman Jeffrey D , Handfield Martin , McCarthy Alan J , Allison Heather E 
Published: March 2012

Abstract

Background
Shigatoxigenic E. coli are a global and emerging health concern. Shiga toxin, Stx, is encoded on the genome of temperate, lambdoid Stx phages. Genes essential for phage maintenance and replication are encoded on approximately 50% of the genome, while most of the remaining genes are of unknown function nor is it known if these annotated hypothetical genes are even expressed. It is hypothesized that many of the latter have been maintained due to positive selection pressure, and that some, expressed in the lysogen host, have a role in pathogenicity. This study used Change Mediated Antigen Technology (CMAT)™ and 2D-PAGE, in combination with RT-qPCR, to identify Stx phage genes that are expressed in E. coli during the lysogenic cycle.

Results
Lysogen cultures propagated for 5-6 hours produced a high cell density with a low proportion of spontaneous prophage induction events. The expression of 26 phage genes was detected in these cultures by differential 2D-PAGE of expressed proteins and CMAT. Detailed analyses of 10 of these genes revealed that three were unequivocally expressed in the lysogen, two expressed from a known lysogenic cycle promoter and one uncoupled from the phage regulatory network.

Conclusion
Propagation of a lysogen culture in which no cells at all are undergoing spontaneous lysis is impossible. To overcome this, RT-qPCR was used to determine gene expression profiles associated with the growth phase of lysogens. This enabled the definitive identification of three lambdoid Stx phage genes that are expressed in the lysogen and seven that are expressed during lysis. Conservation of these genes in this phage genome, and other Stx phages where they have been identified as present, indicates their importance in the phage/lysogen life cycle, with possible implications for the biology and pathogenicity of the bacterial host.
Activation of the RpoN-RpoS regulatory pathway during the enzootic life cycle of Borrelia burgdorferi
Authors: Ouyang Zhiming , Narasimhan Sukanya , Neelakanta Girish , Kumar Manish , Pal Utpal , Fikrig Erol , Norgard Michael V 
Published: March 2012

Abstract

Background
The maintenance of Borrelia burgdorferi in its complex tick-mammalian enzootic life cycle is dependent on the organism's adaptation to its diverse niches. To this end, the RpoN-RpoS regulatory pathway in B. burgdorferi plays a central role in microbial survival and Lyme disease pathogenesis by up- or down-regulating the expression of a number of virulence-associated outer membrane lipoproteins in response to key environmental stimuli. Whereas a number of studies have reported on the expression of RpoS and its target genes, a more comprehensive understanding of when activation of the RpoN-RpoS pathway occurs, and when induction of the pathway is most relevant to specific stage(s) in the life cycle of B. burgdorferi, has been lacking.

Results
Herein, we examined the expression of rpoS and key lipoprotein genes regulated by RpoS, including ospC, ospA, and dbpA, throughout the entire tick-mammal infectious cycle of B. burgdorferi. Our data revealed that transcription of rpoS, ospC, and dbpA is highly induced in nymphal ticks when taking a blood meal. The RpoN-RpoS pathway remains active during the mammalian infection phase, as indicated by the sustained transcription of rpoS and dbpA in B. burgdorferi within mouse tissues following borrelial dissemination. However, dbpA transcription levels in fed larvae and intermolt larvae suggested that an additional layer of control likely is involved in the expression of the dbpBA operon. Our results also provide further evidence for the downregulation of ospA expression during mammalian infection, and the repression of ospC at later phases of mammalian infection by B. burgdorferi.

Conclusion
Our study demonstrates that the RpoN-RpoS regulatory pathway is initially activated during the tick transmission of B. burgdorferi to its mammalian host, and is sustained during mammalian infection.
Acetylcholine content and viability of cholinergic neurons are influenced by the activity of protein histidine phosphatase
Authors: Eißing Anna , Fischer Daniel , Rauch Ilka , Baumann Anne , Schebb Nils-Helge , Karst Uwe , Rose Karsten , Klumpp Susanne , Krieglstein Josef 
Published: March 2012

Abstract

Background
The first mammalian protein histidine phosphatase (PHP) was discovered in the late 90s of the last century. One of the known substrates of PHP is ATP-citrate lyase (ACL), which is responsible - amongst other functions - for providing acetyl-CoA for acetylcholine synthesis in neuronal tissues. It has been shown in previous studies that PHP downregulates the activity of ACL by dephosphorylation. According to this our present work focused on the influence of PHP activity on the acetylcholine level in cholinergic neurons.

Results
The amount of PHP in SN56 cholinergic neuroblastoma cells was increased after overexpression of PHP by using pIRES2-AcGFP1-PHP as a vector. We demonstrated that PHP overexpression reduced the acetylcholine level and induced cell death. The acetylcholine content of SN56 cells was measured by fast liquid chromatography-tandem mass spectrometry method. Overexpression of the inactive H53A-PHP mutant also induced cell damage, but in a significantly reduced manner. However, this overexpression of the inactive PHP mutant did not change the acetylcholine content of SN56 cells significantly. In contrast, PHP downregulation, performed by RNAi-technique, did not induce cell death, but significantly increased the acetylcholine content in SN56 cells.

Conclusions
We could show for the first time that PHP downregulation increased the acetylcholine level in SN56 cells. This might be a potential therapeutic strategy for diseases involving cholinergic deficits like Alzheimer's disease.
KRAS rs61764370 is associated with HER2-overexpressed and poorly-differentiated breast cancer in hormone replacement therapy users: a case control study
Authors: Cerne Jasmina-Ziva , Stegel Vida , Gersak Ksenija , Novakovic Srdjan 
Published: March 2012

Abstract

Background
A single nucleotide polymorphism located in the 3'-untranslated region of the KRAS oncogene (KRAS variant; rs61764370) disrupts a let-7 miRNA binding and was recently reported to act as a genetic marker for increased risk of developing human cancers. We aimed to investigate an association of the KRAS variant with sporadic and familial breast cancer and breast tumor characteristics.

Methods
Genotyping was accomplished in 530 sporadic postmenopausal breast cancer cases, 165 familial breast cancer cases (including N = 29, who test positive for BRCA1/2 mutations) and 270 postmenopausal control women using the flurogenic 5' nuclease assay. Information on hormone replacement therapy (HRT) use and tumor characteristics in sporadic breast cancer cases was ascertained from a postal questionnaire and pathology reports, respectively. Associations between the KRAS genotype and breast cancer or breast tumor characteristics were assessed using chi-square test and logistic regression models.

Results
No evidence of association was observed between the KRAS variant and risk of sporadic and familial breast cancer - either among BRCA carriers or non-BRCA carriers. The KRAS variant was statistically significantly more often associated with human epidermal growth factor receptor 2 (HER2) - positive tumors and tumors of higher histopathologic grade. However, both associations were detected only in HRT users.

Conclusion
Our data do not support the hypothesis that the KRAS variant rs61764370 is implicated in the aetiology of sporadic or of familial breast cancer. In postmenopausal women using HRT, the KRAS variant might lead to HER2 overexpressed and poorly-differentiated breast tumors, both indicators of a worse prognosis.