bluuebunny/crossref_metadata_2025 huggingface dataset:
Deep Regolith Weathering on the Summit Surface of the Southern Mount Lofty Ranges, South Australia: a Contribution to the ‘Laterite’ Debate
Authors: BOURMAN ROBERT P.
Published: August 2007

Chemical and mineralogical analyses of samples from a 102 m deep borehole and from road cuts on the summit surface of the Mount Lofty Ranges near Willunga Hill, are used to assess critically the view that the regolith here developed as a result of tropical, so‐called ‘lateritic’ weathering processes that developed a standard ‘laterite’ profile of great antiquity. There is no evidence of a former surface crust that comprises the upper part of a ‘standard laterite profile’. Moreover, there is no dramatic variation in chemical composition down the profile, with largely in situ localised weathering transformations explaining mineralogical variability. The presence of 2:1 layer silicates and the absence of gibbsite do not favour the operation of former intense tropical weathering, but the possible presence of chloritised smectite may have inhibited gibbsite formation. An iron‐depleted pallid zone does not occur at depth in the profile, but is present on the plateau margin. Many of the weathering features exposed in the road cuts can be explained in terms of modifications and developments under environmental conditions similar to those of the present, arguing against the view that the summit surface and its associated weathering mantle have been preserved in pristine form since the Mesozoic.
Consciously Constructing Exclusivity in the Suburbs? Unpacking a Master Planned Estate Development in Western Sydney
Authors: KENNA THERESE E.
Published: August 2007

In Australia, master planned estates are emerging as a favoured form of residential development, finding support from urban planners and government. The proliferation of master planned estates has led urban researchers to comment on the socially exclusive nature of many of these new developments and their potential contribution to socio‐spatial polarisation in the urban landscape. Do master planned estates purposefully inculcate an image of exclusivity, and do these constructions result in socio‐spatial polarisation? A case study of the contribution of master planned estates to polarisation in the urban landscape is examined here. This research analysed the intentions, imagery and outcomes of a specific master planned estate in suburban Sydney – Glenmore Park. The established, socially constructed, and in some ways negative image of western Sydney has been used as a mirror against which an alternative – albeit exclusive and distinct – identity for Glenmore Park has been advanced. The intended image was for an exclusive and prestigious estate for white nuclear families. The developers and place marketers played a key role in the construction of this exclusivity, which ultimately superseded some of the more socially inclusive planning objectives for the area. The overriding conclusion from this research is that, in this case, there is an explicit connection between intentions and imagery, which encourages socio‐spatial polarisation.
Income Adequacy and Social Security Differences between the Foreign-Born and U.S.-Born
Authors: Cohen Lee , Iams Howard
Published: August 2007

This paper projects retirement income and Social Security taxes and benefits among the foreign-born and U.S.-born in the United States. Focusing on the Depression and the late baby boom birth cohorts, we find that foreign-born persons have higher poverty rates than the U.S.-born, and as a group do not receive higher lifetime net benefits from Social Security than do the U.S.-born. However, persons from the late baby boom cohort who immigrated after 1969 have higher projected rates of return in Social Security than do U.S.-born persons of the same birth cohort.
Are Immigrant Youth Faring Better in U.S. Schools?
Authors: Fry Richard
Published: August 2007

In spite of the growing numbers and geographic dispersion of foreign-born children, the school outcomes of foreign-born teens improved during the 1990s. Analysis of Decennial Census data reveals that fewer immigrant youth dropped out of school and their English language proficiency improved. Some of the improvement is due to compositional change in the foreign-born teen population. Levels of parental education increased over the decade. Poverty among foreign-born adolescents declined. Other youth background characteristics did not change in a favorable direction. Multivariate analysis reveals that there was a large decline in the likelihood of immigrant teens dropping out of school above and beyond the demographic changes over the decade. For example, the likelihood that a Mexican-born teen educated in U.S. schools drops out of school declined by an estimated 43 percent over the 1990s. There is little evidence, however, that U.S. schools have improved in their English language instruction over the decade.
Human Genetics Studies: The Case for Group Rights
Authors: Underkuffler Laura S.
Published: August 2007

During the past 20 years, the importance of human genetic information has exploded. Whether sought for medical treatment, disease prediction studies, cultural studies, or the general study of human origins, human genetic information is now viewed as crucial for scientific research and general attempts at human understanding.

With the importance of genetic information have come bitter battles over its control. The demonstrated power of human genetic information has moved the issue of its “ownership” from the realm of musty academic musings to protracted political and legal battles among “source” individuals, researchers, commercial concerns, government agencies, and others. Whether collected through targeted scientific studies, “discarded” biological tissue, initial charitable bequest, or other means, genetic information and the biological materials in which it is contained have become the subject of protracted legal battles for control and intense social and ethical controversy.
Consumer‐Based Optimization of a Third‐Generation Product Made from Peanut and Rice Flour
Authors: Choi I.‐D. , Phillips R.D. , Resurreccion A.V.A.
Published: August 2007

ABSTRACT:  Indirectly puffed snacks were produced by an extrusion process with partially defatted (12% fat) peanut flour (30%, 40%, 50%) at different levels of screw speed (200, 300, 400 rpm) and feed rate (4, 5, 6 kg/h). Extrudates were dried to obtain half‐products (11% to 12% MC) followed by puffing with deep‐fat frying. The puffed snack prototypes were subjected to consumer acceptance test. Consumers rated higher than 6.0 (= like slightly) for all products produced within the experimental factor ranges on the attributes of crispness and texture, whereas consumer scores for appearance, color, flavor, and overall liking were lower than 6.0 for the product containing 50% peanut flour regardless of screw speed and feed rate. The product extruded with 50% peanut flour at screw speed of 400 rpm and feed rate of 6 kg/h received the lowest score of 5.5 on overall liking in a 9‐point hedonic score. Predicted regression models indicated that feed rate had the largest effect on consumer attributes followed by peanut flour and screw speed. From the superimposed contour plot of individual contour plot of consumer attributes, the optimum region was identified as the area beginning at the 42.0% to 43.0% peanut flour and 4.0 kg/h feed rates, rising to a maximum at 45% peanut flour and 4.6 kg/h feed rates and decreasing to the 33.0% to 34.0% peanut flour and 6.0 kg/h feed rates. Verification confirmed the ability of predictive regression models to identify peanut‐based snacks, which would be scored higher than 6.0 by consumer evaluation.
Adenosine Kinase ofTrypanosoma bruceiand Its Role in Susceptibility to Adenosine Antimetabolites
Authors: Lüscher Alexandra , Önal Pinar , Schweingruber Anne-Marie , Mäser Pascal
Published: August 2007

Trypanosoma bruceicannot synthesize purines de novo and relies on purine salvage from its hosts to build nucleic acids. With adenosine being a preferred purine source of bloodstream-form trypanosomes, adenosine kinase (AK; EC 2.7.1.20) is likely to be a key player in purine salvage. Adenosine kinase is also of high pharmacological interest, since for many adenosine antimetabolites, phosphorylation is a prerequisite for activity. Here, we cloned and functionally characterized adenosine kinase fromT. brucei(TbAK). TbAKis a tandem gene, expressed in both procyclic- and bloodstream-form trypanosomes, whose product localized to the cytosol of the parasites. The RNA interference-mediated silencing of TbAKsuggested that the gene is nonessential under standard growth conditions. Inhibition or downregulation of TbAKrendered the trypanosomes resistant to cordycepin (3′-deoxyadenosine), demonstrating a role for TbAK in the activation of adenosine antimetabolites. The expression of TbAKinSaccharomyces cerevisiaecomplemented a null mutation in the adenosine kinase geneado1. The concomitant expression of TbAKwith theT. bruceiadenosine transporter gene TbAT1allowedS. cerevisiae ado1 ade2double mutants to grow on adenosine as the sole purine source and, at the same time, sensitized them to adenosine antimetabolites. The coexpression of TbAKand TbAT1inS. cerevisiae ado1 ade2double mutants proved to be a convenient tool for testing nucleoside analogues for uptake and activation byT. bruceiadenosine salvage enzymes.
Lipopolysaccharide fromSalmonella entericaActivates NF-κB through both Classical and Alternative Pathways in Primary B Lymphocytes
Authors: Souvannavong Vongthip , Saidji Nabila , Chaby Richard
Published: August 2007

Lipopolysaccharides (LPS) are potent polyclonal B-lymphocyte activators. Recently, we have shown that LPS inhibits both spontaneous and drug-induced apoptosis in mature B lymphocytes, through cytosolic retention of Bax, a proapoptotic protein of the Bcl-2 family, by preventing its translocation to mitochondria. Research within the last few years has revealed that members of the NF-κB transcription factor regulate cell viability by activating genes involved in mitochondrion-dependent apoptosis. In this report, we examined the effect of sustained LPS stimulation on cytosolic and nuclear proteins of the IκB/NF-κB family to determine which NF-κB pathway, canonical (classical) or noncanonical (alternative), is activated by this agent in mature B cells. Immunoblotting analyses showed that LPS induced a time-dependent degradation of the NF-κB inhibitors IκBβ and IκBε (preferentially to isoform IκBα), via IκB kinase β. In addition, we observed that LPS triggered the processing of NF-κB p105 to p50 and that of NF-κB p100 to p52 in parallel with nuclear translocation of active p50 and p52, as NF-κBp50/RelA and NF-κBp52/RelB heterodimers, respectively. These results suggest that sustained stimulation with LPS can activate NF-κB through both classical and alternative pathways.
Clinical Evaluation of the Microscopic Observation Drug Susceptibility Assay for Detection of
Mycobacterium tuberculosis
Resistance to Isoniazid or Rifampin
Authors: Mello Fernanda C. Q. , Arias Mayra S. , Rosales Senia , Marsico Anna Grazia , Pavón Ada , Alvarado-Gálvez Carlos , Pessôa Carlos Leonardo Carvalho , Pérez Melly , Andrade Monica K. , Kritski Afranio L. , Fonseca Leila S. , Chaisson Richard E. , Kimerling Michael E. , Dorman Susan E.
Published: August 2007

This prospective study evaluated the performance of the
m
icroscopic
o
bservation
d
rug
s
usceptibility (MODS) assay for the direct detection of
Mycobacterium tuberculosis
drug resistance. MODS assay sensitivity, specificity, and positive and negative predictive values were 96.7% (95% confidence interval [95% CI], 92.1 to 98.8%), 78.4% (95% CI, 73.5 to 80.6%), 82.4% (95% CI, 78.4 to 84.2%), and 95.8% (95% CI, 89.9 to 98.5%), respectively, for isoniazid resistance and 96.0% (95% CI, 90.3 to 98.6%), 82.9% (95% CI, 78.8 to 84.7%), 80.0% (95% CI, 75.2 to 82.1%), and 96.7% (95% CI, 91.9 to 98.8%), respectively, for rifampin resistance. For both rifampin and isoniazid testing, the likelihood ratio for a negative test was ≤0.05, indicating that the MODS assay may be useful for ruling out drug resistance.
Bacteremia Due to Clonally Derived Methicillin-Resistant, Gentamicin-Susceptible Isolates and Methicillin-Susceptible, Gentamicin-Resistant Isolates of
Staphylococcus aureus
Authors: Daskalaki Maria , Otero Joaquin R. , Sanz Francisca , Chaves Fernando
Published: August 2007

We report recurrent bacteremia due to mixed infection with two clonally derived isolates of
Staphylococcus aureus
in a patient with Sezary syndrome. The two isolates, one gentamicin resistant and methicillin susceptible and the other gentamicin susceptible and methicillin resistant, developed by the deletion of the
mecA, ant(4
′
)Ia
, and
aacA-aphD
genes from a common gentamicin-resistant and methicillin-susceptible ancestor.
The Topology of Hepatitis B Virus Pregenomic RNA Promotes Its Replication
Authors: Abraham Teresa M. , Loeb Daniel D.
Published: August 2007

Previous analysis of hepatitis B virus (HBV) indicated base pairing between two
cis
-acting sequences, the 5′ half of the upper stem of ε and φ, contributes to the synthesis of minus-strand DNA. Our goal was to identify other
cis
-acting sequences on the pregenomic RNA (pgRNA) involved in the synthesis of minus-strand DNA. We found that large portions of the pgRNA could be deleted or substituted without an appreciable decrease in the level of minus-strand DNA synthesized, indicating that most of the pgRNA is dispensable and that a specific size of the pgRNA is not required for this process. Our results indicated that the
cis
-acting sequences for the synthesis of minus-strand DNA are present near the 5′ and 3′ ends of the pgRNA. In addition, we found that the first-strand template switch could be directed to a new location when a 72-nucleotide (nt) fragment, which contained the
cis
-acting sequences present near the 3′ end of the pgRNA, was introduced at that location. Within this 72-nt region, we uncovered two new
cis
-acting sequences, which flank the acceptor site. We show that one of these sequences, named ω and located 3′ of the acceptor site, base pairs with φ to contribute to the synthesis of minus-strand DNA. Thus, base pairing between three
cis
-acting elements (5′ half of the upper stem of ε, φ, and ω) are necessary for the synthesis of HBV minus-strand DNA. We propose that this topology of pgRNA facilitates first-strand template switch and/or the initiation of synthesis of minus-strand DNA.
Protein Kinase CK2 Phosphorylation of EB2 Regulates Its Function in the Production of Epstein-Barr Virus Infectious Viral Particles
Authors: Medina-Palazon Cahora , Gruffat Henri , Mure Fabrice , Filhol Odile , Vingtdeux-Didier Valérie , Drobecq Hervé , Cochet Claude , Sergeant Nicolas , Sergeant Alain , Manet Evelyne
Published: August 2007

The Epstein-Barr Virus (EBV) early protein EB2 (also called BMLF1, Mta, or SM) promotes the nuclear export of a subset of early and late viral mRNAs and is essential for the production of infectious virions. We show here that in vitro, protein kinase CK2α and -β subunits bind both individually and, more efficiently, as a complex to the EB2 N terminus and that the CK2β regulatory subunit also interacts with the EB2 C terminus. Immunoprecipitated EB2 has CK2 activity that phosphorylates several sites within the 80 N-terminal amino acids of EB2, including Ser-55, -56, and -57, which are localized next to the nuclear export signal. EB2S3E, the phosphorylation-mimicking mutant of EB2 at these three serines, but not the phosphorylation ablation mutant EB2S3A, efficiently rescued the production of infectious EBV particles by HEK293
BMLF1-KO
cells harboring an EB2-defective EBV genome. The defect of EB2S3A in transcomplementing 293
BMLF1-KO
cells was not due to impaired nucleocytoplasmic shuttling of the mutated protein but was associated with a decrease in the cytoplasmic accumulation of several late viral mRNAs. Thus, EB2-mediated production of infectious EBV virions is regulated by CK2 phosphorylation at one or more of the serine residues Ser-55, -56, and -57.
GENERAL LOGARITHMIC CORRECTIONS TO BEKENSTEIN–HAWKING ENTROPY
Authors: ZHAO REN , ZHAO HAI-XIA , HU SHUANG-QI
Published: August 2007

Recently, there has been a lot of attention devoted to resolving the quantum corrections to the Bekenstein–Hawking entropy of the black hole. In particular, the coefficient of the logarithmic term in the black hole entropy correction has been of great interest. In this paper, the black hole is corresponded to a canonical ensemble in statistics by radiant spectrum, resulted from the black hole tunnelling effect studies and the partition function of ensemble is derived. Then the entropy of the black hole is calculated. When the first-order approximation is taken into account, the logarithmic term of entropy correction is consistent with the result of the generalized uncertainty principle. In our calculation, there are no uncertainty factors. The prefactor of the logarithmic correction and the one if fluctuation is considered are the same. Our result shows that if the thermal capacity is negative, there is no divergent term. We provide a general method for further discussion on quantum correction to Bekenstein–Hawking entropy. We also offer a theoretical basis for comparing string theory and loop quantum gravity and deciding which one is more reliable.
TOWARDS A NEW STANDARD THEORY FOR ASTROPHYSICAL DISK ACCRETION
Authors: KUNCIC ZDENKA , BICKNELL GEOFFREY V.
Published: August 2007

We briefly review recent developments in black hole accretion disk theory, placing new emphasis on the vital role played by magnetohydrodynamic (MHD) stresses in transporting angular momentum. The apparent universality of accretion-related outflow phenomena is a strong indicator that vertical transport of angular momentum by large-scale MHD torques is important and may even dominate radial transport by small-scale MHD turbulence. This leads to an enhanced overall rate of angular momentum transport and allows accretion of matter to proceed at an interesting rate. Furthermore, we argue that when vertical transport is important, the radial structure of the accretion disk is modified and this affects the disk emission spectrum. We present a simple model demonstrating that energetic, magnetically-driven outflows give rise to a disk spectrum that is dimmer and redder than a standard accretion disk accreting at the same rate. We briefly discuss the implications of this key result for accreting black holes in different astrophysical systems.
NEUTRINO ENERGY LOSS ON IRON GROUP NUCLEI BY ELECTRON CAPTURE IN STRONG MAGNETIC FIELD AT THE CRUSTS OF NEUTRON STARS
Authors: LIU JING-JING , LUO ZHI-QUAN , LIU HONG-LIN , LAI XIANG-JUN
Published: August 2007

The neutrino energy loss rates on iron group nuclei by electron capture are calculated in a strong magnetic field at the crusts of Neutron stars. The results show that the magnetic field has only a slight effect on the neutrino energy loss rates in a range of 108–1013 G on surfaces of the most neutron stars. Whereas for some magnetars which range of the magnetic field is 1013–1018 G, the neutrino energy loss rates of the most iron group nuclei would be debased greatly and may be even decreased for 4 orders of magnitude by the strong magnetic field.
Transepithelial bioelectrical properties of rabbit acinar cell monolayers on polyester membrane scaffolds
Authors: Selvam Shivaram , Thomas Padmaja B. , Gukasyan Hovhannes J. , Yu Alan S. , Stevenson Douglas , Trousdale Melvin D. , Mircheff Austin K. , Schechter Joel E. , Smith Ronald E. , Yiu Samuel C.
Published: August 2007

In our quest to develop a tissue-engineered tear secretory system, we have tried to demonstrate active transepithelial ion fluxes across rabbit lacrimal acinar cell monolayers on polyester membrane scaffolds to evaluate the bioelectrical properties of the cultured cells. Purified lacrimal gland acinar cells were seeded onto polyester membrane inserts and cultured to confluency. Morphological properties of the cell monolayers were evaluated by transmission electron microscopy and immunofluorescence staining for Na+,K+-ATPase and the tight junction-associated protein occludin. Sections revealed cell monolayers with well-maintained epithelial cell polarity, i.e., presence of apical (AP) secretory granules, microvilli, and junctional complexes. Na+,K+-ATPase was localized on both the basal-lateral and apical plasma membranes. The presence of tight cell junctions was demonstrated by a positive circumferential stain for occludin. Bioelectrical properties of the cell monolayers were studied in Ussing chambers under short-circuit conditions. Active ion fluxes were evaluated by inhibiting the short-circuit current ( Isc) with a Na+,K+-ATPase inhibitor, ouabain (100 μM; basal-lateral, BL), and under Cl−-free buffer conditions after carbachol stimulation (CCh; 100 μM). The directional apical secretion of Cl− was demonstrated through pharmacological analysis, using amiloride (1 mM; BL) and bumetanide (0.1 mM; BL), respectively. Regulated protein secretion was evaluated by measuring the β-hexosaminidase catalytic activity in the AP culture medium in response to 100 μM basal CCh. In summary, rabbit lacrimal acinar cell monolayers generate a Cl−-dependent, ouabain-sensitive AP → BL Isc in response to CCh, consistent with current models for Na+-dependent Cl− secretion.
Temporal extracellular matrix adaptations in ligament during wound healing and hindlimb unloading
Authors: Martinez D. A. , Vailas A. C. , Vanderby R. , Grindeland R. E.
Published: August 2007

Previous data from spaceflight studies indicate that injured muscle and bone heal slowly and abnormally compared with ground controls, strongly suggesting that ligaments or tendons may not repair optimally as well. Thus the objective of this study was to investigate the biochemical and molecular gene expression of the collagen extracellular matrix in response to medial collateral ligament (MCL) injury repair in hindlimb unloaded (HLU) rodents. Male rats were assigned to 3- and 7-wk treatment groups with three subgroups each: sham control, ambulatory healing (Amb-healing), and HLU-healing groups. Amb- and HLU-healing animals underwent bilateral surgical transection of their MCLs, whereas control animals were subjected to sham surgeries. All surgeries were performed under isoflurane anesthesia. After 3 wk or 7 wk of HLU, rats were euthanized and MCLs were surgically isolated and prepared for molecular or biochemical analyses. Hydroxyproline concentration and hydroxylysylpyridinoline collagen cross-link contents were measured by HPLC and showed a substantial decrement in surgical groups. MCL tissue cellularity, quantified by DNA content, remained significantly elevated in all HLU-healing groups vs. Amb-healing groups. MCL gene expression of collagen type I, collagen type III, collagen type V, fibronectin, decorin, biglycan, lysyl oxidase, matrix metalloproteinase-2, and tissue inhibitor of matrix metalloproteinase-1, measured by real-time quantitative PCR, demonstrated differential expression in the HLU-healing groups compared with Amb-healing groups at both the 3- and 7-wk time points. Together, these data suggest that HLU affects dense fibrous connective tissue wound healing and confirms previous morphological and biomechanical data that HLU inhibits the ligament repair processes.
Hydrogen peroxide stimulates chloride secretion in primary inner medullary collecting duct cells via mPGES-1-derived PGE2
Authors: Soodvilai Sunhapas , Jia Zhanjun , Yang Tianxin
Published: August 2007

We investigated the role and mechanism of H2O2 in regulation of NaCl transport in primary inner medullary collecting duct (IMCD) cells. IMCD cells were isolated from wild-type mice and grown onto semipermeable membranes, and short-circuit current ( Isc) was determined by Ussing chamber. Exposure of IMCD cells to H2O2 at a range of 100–300 μM caused a rapid increase in Isc in a time- and dose-dependent manner. This increase was almost abolished by the cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channel inhibitors diphenylamine-2-carboxylic acid (DPC) and CFTRinhibitor-172. In contrast, the magnitude of stimulation was unaffected by the epithelial Na+ channel (ENaC) inhibitor amiloride. The H2O2-induced Cl− secretion was significantly inhibited by indomethacin, as well as by microsomal PGE synthase-1 (mPGES-1) deficiency. Like H2O2, PGE2 treatment induced a twofold increase in Isc that was reduced by the protein kinase A (PKA) inhibitors H-89 and KT5720. These data suggest that H2O2 stimulates CFTR Cl− channel-mediated Cl− secretion through cyclooxygenase- and mPGES-1-dependent release of PGE2 and subsequent activation of PKA.
Computational Model Predicts a Role for ERG Current in Repolarizing Plateau Potentials in Dopamine Neurons: Implications for Modulation of Neuronal Activity
Authors: Canavier Carmen C. , Oprisan Sorinel A. , Callaway Joseph C. , Ji Huifang , Shepard Paul D.
Published: August 2007

Blocking the small-conductance (SK) calcium-activated potassium channel promotes burst firing in dopamine neurons both in vivo and in vitro. In vitro, the bursting is unusual in that spiking persists during the hyperpolarized trough and frequently terminates by depolarization block during the plateau. We focus on the underlying plateau potential oscillation generated in the presence of both apamin and TTX, so that action potentials are not considered. We find that although the plateau potentials are mediated by a voltage-gated Ca2+current, they do not depend on the accumulation of cytosolic Ca2+, then use a computational model to test the hypothesis that the slowly voltage-activated ether-a-go-go–related gene (ERG) potassium current repolarizes the plateaus. The model, which includes a material balance on calcium, is able to reproduce the time course of both membrane potential and somatic calcium concentration, and can also mimic the induction of plateau potentials by the calcium chelator BAPTA. The principle of separation of timescales was used to gain insight into the mechanisms of oscillation and its modulation using nullclines in the phase space. The model predicts that the plateau will be elongated and ultimately result in a persistent depolarization as the ERG current is reduced. This study suggests that the ERG current may play a role in burst termination and the relief of depolarization block in vivo.
Nicotinic Receptor Activation Occludes Purinergic Control of Central Cardiorespiratory Network Responses to Hypoxia/Hypercapnia
Authors: Huang Z. G. , Griffioen K. J. S. , Wang X. , Dergacheva O. , Kamendi H. , Gorini C. , Mendelowitz D.
Published: August 2007

Prenatal nicotine exposure alters the cardiorespiratory network responses to hypoxia/hypercapnia; however the mechanism(s) responsible for these cardiorespiratory network responses and their alteration by prenatal nicotine exposure are unknown. We used an in vitro medullary slice that allows simultaneous examination of rhythmic respiratory-related activity and excitatory synaptic neurotransmission to cardioinhibitory vagal neurons (CVNs). Respiratory related increases in glutamatergic neurotransmission only occurred on recovery from hypoxia/hypercapnia in unexposed animals. These responses were not altered by nicotinic antagonists but were mediated in part by activation of P2 purinergic receptors. Prenatal nicotine exposure transformed central cardiorespiratory responses to hypoxia/hypercapnia; CVNs received a respiratory related glutamatergic neurotransmission during periods of hypoxia and hypercapnia, whereas increases in glutamatergic neurotransmission during recovery were absent. The excitatory neurotransmission to CVNs during hypoxia/hypercapnia in prenatal nicotine-exposed animals were wholly dependent on nicotinic receptor activation. In the presence of nicotinic antagonists, the responses in prenatal nicotine animals reverted to the pattern of responses in unexposed animals in which an increase in glutamatergic neurotransmission occurred not during but only on recovery from hypoxia/hypercapnia, and this recruited excitatory pathway was blocked by P2 receptor antagonists. These data identify a new functional role for purinergic receptors in the cardiorespiratory responses to hypoxia/hypercapnia and their role in occluding nicotinic receptor activation with prenatal nicotine exposure.
Modulation of bcl-xL in Tumor Cells Regulates Angiogenesis through CXCL8 Expression
Authors: Giorgini Simona , Trisciuoglio Daniela , Gabellini Chiara , Desideri Marianna , Castellini Laura , Colarossi Cristina , Zangemeister-Wittke Uwe , Zupi Gabriella , Del Bufalo Donatella
Published: August 2007

In this paper, we investigated whether bcl-xL can be involved in the modulation of the angiogenic phenotype of human tumor cells. Using the ADF human glioblastoma and the M14 melanoma lines, and their derivative bcl-xL–overexpressing clones, we showed that the conditioned medium of bcl-xL transfectants increased in vitro endothelial cell functions, such as proliferation and morphogenesis, and in vivo vessel formation in Matrigel plugs, compared with the conditioned medium of control cells. Moreover, the overexpression of bcl-xL induced an increased expression of the proangiogenic interleukin-8 (CXCL8), both at the protein and mRNA levels, and an enhanced CXCL8 promoter activity. The role of CXCL8 on bcl-xL–induced angiogenesis was validated using CXCL8-neutralizing antibodies, whereas down-regulation of bcl-xL through antisense oligonucleotide or RNA interference strategies confirmed the involvement of bcl-xL on CXCL8 expression. Transient overexpression of bcl-xL led to extend this observation to other tumor cell lines with different origin, such as colon and prostate carcinoma. In conclusion, our results showed that CXCL8 modulation by bcl-xL regulates tumor angiogenesis, and they point to elucidate an additional function of bcl-xL protein. (Mol Cancer Res 2007;5(8):761–71)
Central Role of Calcium-Dependent Tyrosine Kinase PYK2 in Endothelial Nitric Oxide Synthase–Mediated Angiogenic Response and Vascular Function
Authors: Matsui Akihiro , Okigaki Mitsuhiko , Amano Katsuya , Adachi Yasushi , Jin Denan , Takai Shinji , Yamashita Tomoya , Kawashima Seinosuke , Kurihara Tatsuya , Miyazaki Mizuo , Tateishi Kento , Matsunaga Shinsaku , Katsume Asako , Honshou Shoken , Takahashi Tomosaburo , Matoba Satoaki , Kusaba Tetsuro , Tatsumi Tetsuya , Matsubara Hiroaki
Published: August 2007

Background—

The involvement of Ca
2+
-dependent tyrosine kinase PYK2 in the Akt/endothelial NO synthase pathway remains to be determined.

Methods and Results—

Blood flow recovery and neovessel formation after hind-limb ischemia were impaired in PYK2
−/−
mice with reduced mobilization of endothelial progenitors. Vascular endothelial growth factor (VEGF)–mediated cytoplasmic Ca
2+
mobilization and Ca
2+
-independent Akt activation were markedly decreased in the PYK2-deficient aortic endothelial cells, whereas the Ca
2+
-independent AMP-activated protein kinase/protein kinase-A pathway that phosphorylates endothelial NO synthase was not impaired. Acetylcholine-mediated aortic vasorelaxation and cGMP production were significantly decreased. Vascular endothelial growth factor–dependent migration, tube formation, and actin cytoskeletal reorganization associated with Rac1 activation were inhibited in PYK2-deficient endothelial cells. PI3-kinase is associated with vascular endothelial growth factor–induced PYK2/Src complex, and inhibition of Src blocked Akt activation. The vascular endothelial growth factor–mediated Src association with PLCγ1 and phosphorylation of
783
Tyr-PLCγ1 also were abolished by PYK2 deficiency.

Conclusion—

These findings demonstrate that PYK2 is closely involved in receptor- or ischemia-activated signaling events via Src/PLCγ1 and Src/PI3-kinase/Akt pathways, leading to endothelial NO synthase phosphorylation, and thus modulates endothelial NO synthase–mediated vasoactive function and angiogenic response.
Gating Properties of
SCN5A
Mutations and the Response to Mexiletine in Long-QT Syndrome Type 3 Patients
Authors: Ruan Yanfei , Liu Nian , Bloise Raffaella , Napolitano Carlo , Priori Silvia G.
Published: August 2007

Background—

Mexiletine (Mex) has been proposed as a gene-specific therapy for patients with long-QT syndrome type 3 (LQT3) caused by mutations in the cardiac sodium channel gene (
SCN5A
). The degree of QT shortening and the protection from arrhythmias vary among patients harboring different mutations. We tested whether the clinical response to Mex in LQT3 could be predicted by the biophysical properties of the different mutations.

Methods and Results—

We identified 4
SCN5A
mutations in 5 symptomatic LQT3 patients with different responses to Mex (6 to 8 mg · kg
−1
· d
−1
). We classified the mutations as sensitive to Mex (P1332L, R1626P; ≥10% of QTc shortening and QTc <500 ms or no arrhythmias) or insensitive to Mex (S941N, M1652R; negligible or no QTc shortening and sudden death). We measured Na
+
current from HEK 293 cells transfected with wild-type (WT) or mutant Nav1.5. All mutations showed impaired inactivation of Na
+
current, but the mutations identified in patient responders to Mex (P1332L, R1626P) showed a hyperpolarizing shift of V
1/2
of steady-state inactivation. Furthermore, Mex produced use-dependent block with the order R1626P=P1332L>S941N=WT>M1652R, suggesting that Mex-sensitive mutants present prolonged recovery from Mex block.

Conclusions—

We propose that voltage dependence of channel availability and shifts of V
1/2
of steady-state inactivation correlate with the clinical response observed in LQT3 patients. This supports the view that the response to Mex is mutation specific and that in vitro testing may help to predict the response to therapy in LQT3.
IR-Theory and Transformation in the Greater Middle East: the Role of the United States
Authors: Amineh Mehdi Parvizi , Houweling Henk
Published: August 2007

This article analyzes why post-Cold War American foreign policy regarding the Greater Middle East (GME) changed course and why the United States having a virtual military monopoly fails to achieve its war aim in Iraq. To that end, the authors consult realist and liberal theory in international relations. Realists have a security-driven policy agenda. They fail to create a micro-level foundation in political man for the posited collective interest at the level of the state. Realists therefore produce indeterminate results. Liberal theory in international relations does have a micro-foundation in explanations of foreign policy choices in the form of the economic man. Liberal scholars therefore inquire into domestic sources of foreign policy decisions. However, the liberal national interest is not just a summation of private actor interests. These dominant approaches therefore fail to explain US foreign policy choices and policy outcomes in the region under study.The three quotations below create the problematic of this study:Today we are presented with a unique strategic opportunity. For more than 50 years we were constrained by a bipolar rivalry with a superpower adversary. Today and tomorrow, we have an opportunity to pursue a strategy of engagement and to design a military force to help the strategy succeed. I fully agree with the defense strategy of helping to shape the environment to promote US interests abroad.John Shalikashvili, Clinton's Chairman of the Joint Chiefs of Staff (1997)[Y]ou live now in the Mohammedan nation which, if the traveler's accounts are to be believed, is intelligent and even refined. What is this irredeemable decadence dragging it down through the centuries? Is it possible that we have risen while they remain static? I do not think so. I rather think that the dual movement has occurred in opposite directions […] European races are often the greatest rogues, but at least they are rogues to whom God gave the will and the power and whom he seems to have destined for some time to be at the head of mankind […] the European is to other races of mankind what man himself is to the lower animals: he makes them subservient to his use, and when he cannot subdue he destroys them.Alexis de Tocqueville (1962: 75-76)Why is it that we did not complete our cultural journey, and how is it that we have ended up today in the very worst of times? What is it that made our predecessor pore over their desks, writing down and recording the marvels of mathematics and sciences and searching out the skies with the stars and constellations in order to discover their secrets, and driven by the love of knowledge, to study medicine and to devise medicaments even from the stomachs of bees […] Andalus became a lost place, then Palestine became Andalus.Mahmud Darwish (2004)
From Soviet Republics to Independent Countries: Challenges of Transition in Central Asia
Authors: Rahimov Mirzohid
Published: August 2007

In the twentieth century, the Central Asian countries of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan passed through a complex historical period. They were originally founded as republics of the Soviet Union in the 1920s-30s as a result of national and territorial state delimitation. The process of the creation of new national state formations began after the Soviet Union disintegrated and these republics achieved independence. At the same time, the region's nations are facing complex problems of transition and the creation of new societies. Nevertheless, these countries have to continue the process of political and economic reforms, as well as development of civic institutions. The Central Asian nations established contacts with foreign states and international organizations and started to form a system of interstate relations between the countries of the region. There are potentials for development of regional integration of Central Asia. Future integration will depend on the readiness of the nations to carry out political and economic reforms, introduce forms and methods of economic regulation compatible with global norms, and most important, international support of political reforms and regional integration.
Indian Power Projection in the Greater Middle East: Tools and Objectives
Authors: Mudiam Prithvi Ram
Published: August 2007

India's approach to the Middle East during the Cold War years was weighed down by the partition of the subcontinent and the creation of Pakistan on a religious basis, the dispute with Pakistan over the Muslim majority province of Jammu and Kashmir and its own large Muslim minority. Hence, its policy towards the region tended to be defensive and reactive, and a general policy of support to the Arab causes, particularly that of the Palestinians, and a non-relationship with Israel were considered necessary to serve India's broad interests in the region. India's projection of secularism into the region was meant to prevent Pakistan from organizing an anti-Indian Islamic bloc in the region, and its projection of nonalignment was meant to scuttle the Western attempts to build anti-communist alliances there. However, the transformation in the superpowers relations following the collapse of the Soviet Union, changes in the regional environment in the Greater Middle East (GME) as well as South Asia and changes in India's domestic sphere created a new strategic and economic context for India to pursue its interests in the GME in the 1990s. There is an increasing convergence of strategic interests between the two regions and a growing complementarity of their economies in the post-Cold War world. Iran and Israel have become the two lynchpins of India's policy toward the region and, as an emerging global player, India, unlike during the Cold War, is in a strong position to promote its own interests as well as those of the international system in the region, which largely seem to coincide in the post-Cold War milieu.
India–Pakistan Engagement with the Greater Middle East: Implications and Options
Authors: Jain
Published: August 2007

This article aims to examine Indo–Pakistan relations to assess their implications for the Greater Middle East (GME). Both countries are frantically engaged in deploying their military and nuclear capabilities, resources as well as extra-regional connections, with an intention to alter the balance of power in one's favor, as this is evident from their close contest for enhancing the level of strategic cooperation with the United States, especially after 9/11. Moreover, the deep-seated historic hostility between India and Pakistan has produced a peculiar geopsychology among ruling elites to outmaneuver the other in order to contain each country's political, economic, and strategic influences in GME rather than to contribute to peace, prosperity, and stability there. This article also aims to explore interaction and interconnectedness between the three core concepts—geopolitics, geoeconomics and geopsychology—while evaluating Indo–Pakistan engagement with GME to advance and safeguard their respective manifold national interests.
An Improved Canopy Integration Scheme for a Land Surface Model with Prognostic Canopy Structure
Authors: Thornton Peter E. , Zimmermann Niklaus E.
Published: August 2007

A new logical framework relating the structural and functional characteristics of a vegetation canopy is presented, based on the hypothesis that the ratio of leaf area to leaf mass (specific leaf area) varies linearly with overlying leaf area index within the canopy. Measurements of vertical gradients in specific leaf area and leaf carbon:nitrogen ratio for five species (two deciduous and three evergreen) in a temperate climate support this hypothesis. This new logic is combined with a two-leaf (sunlit and shaded) canopy model to arrive at a new canopy integration scheme for use in the land surface component of a climate system model. An inconsistency in the released model radiation code is identified and corrected. Also introduced here is a prognostic canopy model with coupled carbon and nitrogen cycle dynamics. The new scheme is implemented within the Community Land Model and tested in both diagnostic and prognostic canopy modes. The new scheme increases global gross primary production by 66% (from 65 to 108 Pg carbon yr−1) for diagnostic model simulations driven with reanalysis surface weather, with similar results (117 PgC yr−1) for the new prognostic model. Comparison of model predictions to global syntheses of observations shows generally good agreement for net primary productivity (NPP) across a range of vegetation types, with likely underestimation of NPP in tundra and larch communities. Vegetation carbon stocks are higher than observed in forest systems, but the ranking of stocks by vegetation type is accurately captured.
Validation Schemes for Tropical Cyclone Quantitative Precipitation Forecasts: Evaluation of Operational Models for U.S. Landfalling Cases
Authors: Marchok Timothy , Rogers Robert , Tuleya Robert
Published: August 2007

A scheme for validating quantitative precipitation forecasts (QPFs) for landfalling tropical cyclones is developed and presented here. This scheme takes advantage of the unique characteristics of tropical cyclone rainfall by evaluating the skill of rainfall forecasts in three attributes: the ability to match observed rainfall patterns, the ability to match the mean value and volume of observed rainfall, and the ability to produce the extreme amounts often observed in tropical cyclones. For some of these characteristics, track-relative analyses are employed that help to reduce the impact of model track forecast error on QPF skill. These characteristics are evaluated for storm-total rainfall forecasts of all U.S. landfalling tropical cyclones from 1998 to 2004 by the NCEP operational models, that is, the Global Forecast System (GFS), the Geophysical Fluid Dynamics Laboratory (GFDL) hurricane model, and the North American Mesoscale (NAM) model, as well as the benchmark Rainfall Climatology and Persistence (R-CLIPER) model. Compared to R-CLIPER, all of the numerical models showed comparable or greater skill for all of the attributes. The GFS performed the best of all of the models for each of the categories. The GFDL had a bias of predicting too much heavy rain, especially in the core of the tropical cyclones, while the NAM predicted too little of the heavy rain. The R-CLIPER performed well near the track of the core, but it predicted much too little rain at large distances from the track. Whereas a primary determinant of tropical cyclone QPF errors is track forecast error, possible physical causes of track-relative differences lie with the physical parameterizations and initialization schemes for each of the models. This validation scheme can be used to identify model limitations and biases and guide future efforts toward model development and improvement.
A Two-Season Impact Study of Satellite and In Situ Data in the NCEP Global Data Assimilation System
Authors: Zapotocny Tom H. , Jung James A. , Le Marshall John F. , Treadon Russ E.
Published: August 2007

Observing system experiments are used to quantify the contributions to the forecast made by conventional in situ and remotely sensed satellite data. The impact of each data type is assessed by comparing the analyses and forecasts based on an observing system using all data types. The analysis and forecast model used for these observing system experiments is the National Centers for Environmental Prediction (NCEP) Global Data Assimilation/Forecast System (GDAS/GFS). The case studies chosen consist of 45-day periods during January–February 2003 and August–September 2003. During these periods, a T254–64 layer version of NCEP’s Global Spectral Model was used. The control run utilizes NCEP’s operational database and consists of all data types routinely assimilated in the GDAS. The two experimental runs have either all the conventional in situ data denied (NoCon) or all the remotely sensed satellite data denied (NoSat). Differences between the control and experimental runs are accumulated over the 45-day periods and analyzed to demonstrate the forecast impact of these data types through 168 h. Anomaly correlations, forecast impacts, and hurricane track forecasts are evaluated for both experiments. Anomaly correlations of geopotential height are evaluated over the polar caps and midlatitudes of both the Northern and Southern Hemispheres for spectral waves 1–20. Forecast impacts related to conventional meteorological parameters are evaluated. The parameters examined include geopotential height, precipitable water, temperature, the u component of the wind, wind vector differences, and relative humidity. Comparisons are made on multiple pressure levels extending from 10 to 1000 hPa. Hurricane track forecasts are evaluated during August and September for both the Atlantic and eastern Pacific basins. The results demonstrate a positive forecast impact from both the conventional in situ and remotely sensed satellite data during both seasons in both hemispheres. The positive forecast impacts from the conventional and satellite data are of similar magnitude in the Northern Hemisphere; however, the contribution to forecast quality from satellite data is considerably larger than the conventional data in the Southern Hemisphere. The importance of satellite data also generally increases at longer forecast times relative to conventional data. Finally, the accuracy of hurricane track forecasts benefits from the inclusion of both conventional and satellite data.