bluuebunny/crossref_metadata_2025 huggingface dataset:
A Tantalizing View of What Set Off Japan's Killer Quake
Authors: Kerr Richard A.
Published: January 2012

Japanese scientists combing through the vast jumble of seismic signals recorded in the days before the Tohoku earthquake have just sorted out more than 1000 newly recognized earthquakes.
Robotic Fish Point to Schooling Gene
Authors: Pennisi Elizabeth
Published: January 2012

Scientists studying schooling behavior with the aid of robotic fish reported at the meeting that they may have pinpointed a gene important for schooling.
Archaeologist of Sound
Authors: Cowen Ron
Published: January 2012

With near-obsessive determination, audio historian Patrick Feaster has been tracking down remnants of long-vanished voices and noises—and in some cases resurrecting them against the odds.
Cigarette Smoke Induction of Osteopontin (SPP1) Mediates T
H
17 Inflammation in Human and Experimental Emphysema
Authors: Shan Ming , Yuan Xiaoyi , Song Li-zhen , Roberts Luz , Zarinkamar Nazanin , Seryshev Alexander , Zhang Yiqun , Hilsenbeck Susan , Chang Seon-Hee , Dong Chen , Corry David B. , Kheradmand Farrah
Published: January 2012

The destruction of lung tissue in emphysema is orchestrated by antigen-presenting cells that have been activated by smoke.
Self-Association of Lymphocytic Choriomeningitis Virus Nucleoprotein Is Mediated by Its N-Terminal Region and Is Not Required for Its Anti-Interferon Function
Authors: Ortiz-Riaño Emilio , Cheng Benson Yee Hin , de la Torre Juan C. , Martínez-Sobrido Luis
Published: January 2012

Arenaviruses have a bisegmented, negative-strand RNA genome. Both the large (L) and small (S) genome segments use an ambisense coding strategy to direct the synthesis of two viral proteins. The L segment encodes the virus polymerase (L protein) and the matrix Z protein, whereas the S segment encodes the nucleoprotein (NP) and the glycoprotein precursor (GPC). NPs are the most abundant viral protein in infected cells and virions and encapsidate genomic RNA species to form an NP-RNA complex that, together with the virus L polymerase, forms the virus ribonucleoprotein (RNP) core capable of directing both replication and transcription of the viral genome. RNP formation predicts a self-association property of NPs. Here we document self-association (homotypic interaction) of the NP of the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV), as well as those of the hemorrhagic fever (HF) arenaviruses Lassa virus (LASV) and Machupo virus (MACV). We also show heterotypic interaction between NPs from both closely (LCMV and LASV) and distantly (LCMV and MACV) genetically related arenaviruses. LCMV NP self-association was dependent on the presence of single-stranded RNA and mediated by an N-terminal region of the NP that did not overlap with the previously described C-terminal NP domain involved in either counteracting the host type I interferon response or interacting with LCMV Z.
Combination of Biological Screening in a Cellular Model of Viral Latency and Virtual Screening Identifies Novel Compounds That Reactivate HIV-1
Authors: Gallastegui Edurne , Marshall Brett , Vidal David , Sanchez-Duffhues Gonzalo , Collado Juan A. , Alvarez-Fernández Carmen , Luque Neus , Terme Jean-Michel , Gatell Josep M. , Sánchez-Palomino Sonsoles , Muñoz Eduardo , Mestres Jordi , Verdin Eric , Jordan Albert
Published: January 2012

Although highly active antiretroviral therapy (HAART) has converted HIV into a chronic disease, a reservoir of HIV latently infected resting T cells prevents the eradication of the virus from patients. To achieve eradication, HAART must be combined with drugs that reactivate the dormant viruses. We examined this problem in an established model of HIV postintegration latency by screening a library of small molecules. Initially, we identified eight molecules that reactivated latent HIV. Using them as templates, additional hits were identified by means of similarity-based virtual screening. One of those hits, 8-methoxy-6-methylquinolin-4-ol (MMQO), proved to be useful to reactivate HIV-1 in different cellular models, especially in combination with other known reactivating agents, without causing T-cell activation and with lower toxicity than that of the initial hits. Interestingly, we have established that MMQO produces Jun N-terminal protein kinase (JNK) activation and enhances the T-cell receptor (TCR)/CD3 stimulation of HIV-1 reactivation from latency but inhibits CD3-induced interleukin-2 (IL-2) and tumor necrosis factor alpha (TNF-α) gene transcription. Moreover, MMQO prevents TCR-induced cell cycle progression and proliferation in primary T cells. The present study documents that the combination of biological screening in a cellular model of viral latency with virtual screening is useful for the identification of novel agents able to reactivate HIV-1. Moreover, we set the bases for a hypothetical therapy to reactivate latent HIV by combining MMQO with physiological or pharmacological TCR/CD3 stimulation.
Antiretroviral Therapy Reduces the Magnitude and T Cell Receptor Repertoire Diversity of HIV-Specific T Cell Responses without Changing T Cell Clonotype Dominance
Authors: Conrad Joseph A. , Ramalingam Ramesh K. , Duncan Coley B. , Smith Rita M. , Wei Jie , Barnett Louise , Simons Brenna C. , Lorey Shelly L. , Kalams Spyros A.
Published: January 2012

After initiation of antiretroviral therapy (ART), HIV loads and frequencies of HIV epitope-specific immune responses decrease. A diverse virus-specific T cell receptor (TCR) repertoire allows the host to respond to viral epitope diversity, but the effect of antigen reduction as a result of ART on the TCR repertoire of epitope-specific CD8+T cell populations has not been well defined. We determined the TCR repertoires of 14 HIV-specific CD8+T cell responses from 8 HIV-positive individuals before and after initiation of ART. We used multiparameter flow cytometry to measure the distribution of memory T cell subsets and the surface expression of PD-1 on T cell populations and T cell clonotypes within epitope-specific responses from these individuals. Post-ART, we noted decreases in the frequency of circulating epitope-specific T cells (P= 0.02), decreases in the number of T-cell clonotypes found within epitope-specific T cell receptor repertoires (P= 0.024), and an overall reduction in the amino acid diversity within these responses (P< 0.0001). Despite this narrowing of the T cell response to HIV, the overall hierarchy of dominant T cell receptor clonotypes remained stable compared to that pre-ART. CD8+T cells underwent redistributions in memory phenotypes and a reduction in CD38 and PD-1 expression post-ART. Despite extensive remodeling at the structural and phenotypic levels, PD-1 was expressed at higher levels on dominant clonotypes within epitope-specific responses before and after initiation of ART. These data suggest that the antigen burden may maintain TCR diversity and that dominant clonotypes are sensitive to antigen even after dramatic reductions after initiation of ART.
Retargeting of Rat Parvovirus H-1PV to Cancer Cells through Genetic Engineering of the Viral Capsid
Authors: Allaume Xavier , El-Andaloussi Nazim , Leuchs Barbara , Bonifati Serena , Kulkarni Amit , Marttila Tiina , Kaufmann Johanna K. , Nettelbeck Dirk M. , Kleinschmidt Jürgen , Rommelaere Jean , Marchini Antonio
Published: January 2012

The rat parvovirus H-1PV is a promising anticancer agent given its oncosuppressive properties and the absence of known side effects in humans. H-1PV replicates preferentially in transformed cells, but the virus can enter both normal and cancer cells. Uptake by normal cells sequesters a significant portion of the administered viral dose away from the tumor target. Hence, targeting H-1PV entry specifically to tumor cells is important to increase the efficacy of parvovirus-based treatments. In this study, we first found that sialic acid plays a key role in H-1PV entry. We then genetically engineered the H-1PV capsid to improve its affinity for human tumor cells. By analogy with the resolved crystal structure of the closely related parvovirus minute virus of mice, we developed anin silicothree-dimensional (3D) model of the H-1PV wild-type capsid. Based on this model, we identified putative amino acids involved in cell membrane recognition and virus entry at the level of the 2-fold axis of symmetry of the capsid, within the so-called dimple region.In situmutagenesis of these residues significantly reduced the binding and entry of H-1PV into permissive cells. We then engineered an entry-deficient viral capsid and inserted a cyclic RGD-4C peptide at the level of its 3-fold axis spike. This peptide binds αvβ3and αvβ5integrins, which are overexpressed in cancer cells and growing blood vessels. The insertion of the peptide rescued viral infectivity toward cells overexpressing αvβ5integrins, resulting in the efficient killing of these cells by the reengineered virus. This work demonstrates that H-1PV can be genetically retargeted through the modification of its capsid, showing great promise for a more efficient use of this virus in cancer therapy.
Comparison of clinical and pathological characteristics of isolated aortitis and Takayasu arteritis with ascending aorta involvement
Authors: Wang Hongyue , Li Li , Wang Linlin , Chang Qian , Pu Jielin
Published: January 2012

Aims

Isolated aortitis (IA) is a newly recognized condition, but its differentiation from Takayasu arteritis (TA) is still a challenge. This study aims to explore the characteristics of IA.

Methods

The clinical and pathological data of 965 cases with excised ascending aortas were obtained by chart and slide review. IA cases were compared with TA cases and examined for CD3, CD4, CD8, CD20, CD68, CD138 and IgG4 of the infiltrates using immunohistochemistry.

Results

24 cases of IA and eight cases of TA were identified. IA cases tended to be older than TA cases (mean 46.3 vs 33.9 years). Both groups had the same male/female ratio (1.0). IA cases tended to have a bigger aortic diameter (mean 59.7 vs 47.6 mm), statistically less intimal thickening (mean 678 vs 1101 μm), fewer lesions outside the ascending aorta (8% vs 100%), a lower erythrocyte sedimentation rate (mean 14.6 vs 27.0 mm/h) and more active aortitis (75.0% vs 62.5%) than TA cases. The number of CD3+ cells was equal to CD20+ cells in the media but fewer than CD20+ cells in the adventitia of IA cases. Their CD4/CD8+ ratio ranged from 1.0 to 1.8 while the number of CD68+ macrophages varied largely. IgG4+ cells ranged from 0 to 40 (mean 4) cells/HPF and the IgG4+/CD138+ ratio ranged from 0 to 0.36 (mean 0.06) in IA cases.

Conclusions

Cases of IA tend to have more histologically active inflammation except for a relatively normal erythrocyte sedimentation rate, localised lesions and milder intimal fibrosis than cases of TA. IgG4 abnormality may not be the main cause of IA.
Evaluation of inverse integral transforms for undergraduate physics students
Authors: Farrell Aaron , van Zyl Brandon P. , MacDonald Zachary
Published: January 2012

We provide a simple approach to the analytical evaluation of inverse integral transforms that does not require any knowledge of complex analysis. The central idea behind our method is to reduce the inverse transform to the solution of an ordinary differential equation. We illustrate the utility of our approach by providing examples of the evaluation of transforms without the use of tables. We also demonstrate how the method may be used to obtain a general representation of a function in the form of a series involving the Dirac delta distribution and its derivatives, which has applications in quantum mechanics, semiclassical, and nuclear physics.
Prediction of alpha-decay energy and decay half-life for unknown superheavy nuclei using resonances of exactly solvable α+nucleus potential
Authors: Devi Arati , Sahu Basudeb , Mehrotra I.
Published: January 2012

Predictions of the results of alpha-decay energy (Q-value) and decay half-life (t1/2) are made for experimentally unknown alpha decaying systems of superheavy nuclei. Following a theoretical method proposed recently by B. Sahu, the calculations are performed using the analytical expression of the potential that simulates the nuclear+Coulomb potential of the α + daughter nucleus system. The Q-value considered as resonance energy is calculated using the behavior of the wave function, and the t1/2 is expressed analytically using the exact solutions of the potential. A global formula for the potential parameter as a function of neutron number in a given isotopic chain of nuclei is developed for the calculation of Q and t1/2. Calculations of the latter two quantities are made for the decay chain of newly discovered superheavy elements 294117, 293117, and for the isotopic chains of Z = 74 and 102. Predictions of the same parameters are made for Z = 113 and some other still unknown superheavy nuclei. It is observed that the global formula works well in evaluating correct results of Q and t1/2 for various alpha emitters.
A NOVEL MODE AND ITS VERIFICATION OF PARALLEL MOLECULAR DYNAMICS SIMULATION WITH THE COUPLING OF GPU AND CPU
Authors: HOU CHAOFENG , GE WEI
Published: January 2012

Graphics processing unit (GPU) is becoming a powerful computational tool in scientific and engineering fields. In this paper, for the purpose of the full employment of computing capability, a novel mode for parallel molecular dynamics (MD) simulation is presented and implemented on basis of multiple GPUs and hybrids with central processing units (CPUs). Taking into account the interactions between CPUs, GPUs, and the threads on GPU in a multi-scale and multilevel computational architecture, several cases, such as polycrystalline silicon and heat transfer on the surface of silicon crystals, are provided and taken as model systems to verify the feasibility and validity of the mode. Furthermore, the mode can be extended to MD simulation of other areas such as biology, chemistry and so forth.
RECONSTRUCTING f(R, T) GRAVITY FROM HOLOGRAPHIC DARK ENERGY
Authors: HOUNDJO M. J. S. , PIATTELLA OLIVER F.
Published: January 2012

We consider cosmological scenarios based on f(R, T) theories of gravity (R is the Ricci scalar and T is the trace of the energy–momentum tensor) and numerically reconstruct the function f(R, T) which is able to reproduce the same expansion history generated, in the standard General Relativity theory, by dark matter and holographic dark energy. We consider two special f(R, T) models: in the first instance, we investigate the modification R + 2f(T), i.e. the usual Einstein–Hilbert term plus a f(T) correction. In the second instance, we consider a f(R) + λT theory, i.e. a T correction to the renown f(R) theory of gravity.
DERIVED SNP ALLELES ARE USED MORE FREQUENTLY THAN ANCESTRAL ALLELES AS RISK-ASSOCIATED VARIANTS IN COMMON HUMAN DISEASES
Authors: GORLOVA OLGA Y. , YING JUN , AMOS CHRISTOPHER I. , SPITZ MARGARET R. , PENG BO , GORLOV IVAN P.
Published: January 2012

Evolutionary aspects of the genetic architecture of common human diseases remain enigmatic. The results of more than 200 genome-wide association studies published to date were compiled in a catalog ( http://www.genome.gov/26525384/ ). We used cataloged data to determine whether derived (mutant) alleles are associated with higher risk of human disease more frequently than ancestral alleles. We placed all allelic variants into ten categories of population frequency (0%–100%) in 10% increments. We then analyzed the relationship between allelic frequency, evolutionary status of the polymorphic site (ancestral versus derived), and disease risk status (risk versus protection). Given the same population frequency, derived alleles are more likely to be risk associated than ancestral alleles, as are rarer alleles. The common interpretation of this association is that negative selection prevents fixation of the risk variants. However, disease stratification as early or late onset suggests that weak selection against risk-associated alleles is unlikely a major factor shaping genetic architecture of common diseases. Our results clearly suggest that the duration of existence of an allele in a population is more important. Alleles existing longer tend to show weaker linkage disequilibrium with neighboring alleles, including the causal alleles, and are less likely to tag a SNP-disease association.
Central infusion of aliskiren prevents sympathetic hyperactivity and hypertension in Dahl salt-sensitive rats on high salt intake
Authors: Huang Bing S. , White Roselyn A. , Bi Li , Leenen Frans H. H.
Published: January 2012

Central infusion of an angiotensin type 1 (AT1) receptor blocker prevents sympathetic hyperactivity and hypertension in Dahl salt-sensitive (S) rats on high salt. In the present study, we examined whether central infusion of a direct renin inhibitor exerts similar effects. Intracerebroventricular infusion of aliskiren at the rate of 0.05 mg/day markedly inhibited the increase in ANG II levels in the cerebrospinal fluid and in blood pressure (BP) caused by intracerebroventricular infusion of rat renin. In Dahl S rats on high salt, intracerebroventricular infusion of aliskiren at 0.05 and 0.25 mg/day for 2 wk similarly decreased resting BP in Dahl S rats on high salt. In other groups of Dahl S rats, high salt intake for 2 wk increased resting BP by ∼25 mmHg, enhanced pressor and sympathoexcitatory responses to air-stress, and desensitized arterial baroreflex function. All of these effects were largely prevented by intracerebroventricular infusion of aliskiren at 0.05 mg/day. Aliskiren had no effects in rats on regular salt. Neither high salt nor aliskiren affected hypothalamic ANG II content. These results indicate that intracerebroventricular infusions of aliskiren and an AT1 receptor blocker are similarly effective in preventing salt-induced sympathetic hyperactivity and hypertension in Dahl S rats, suggesting that renin in the brain plays an essential role in the salt-induced hypertension. The absence of an obvious increase in hypothalamic ANG II by high salt, or decrease in ANG II by aliskiren, suggests that tissue levels do not reflect renin-dependent ANG II production in sympathoexcitatory angiotensinergic neurons.
Myostatin stimulates myosatellite cell differentiation in a novel model system: evidence for gene subfunctionalization
Authors: Garikipati Dilip K. , Rodgers Buel D.
Published: January 2012

Myosatellite cells play an important role in mammalian muscle regeneration as they differentiate and fuse with mature fibers. In fish, they also contribute to postnatal growth and the formation of new fibers. The relative conservation of fish systems, however, is not well known nor are the underlying mechanisms that control myosatellite cell differentiation. We therefore characterized this process in primary cells from rainbow trout and determined the effects of two known regulators in mammalian systems: IGF-I and myostatin. Unlike mammalian cell lines, subconfluent and proliferating trout myosatellite cells differentiated spontaneously and at a rate proportional to serum concentration. The expression of key myogenic markers (Myf5, MyoD1, myogenin, and MLC) and of the different myostatin paralogs (MSTN-1a/1b/2a) increased with serum-stimulated differentiation, although MSTN-1a expression was consistently higher than that of the other paralogs. In addition, MSTN-2a was only expressed as an unprocessed transcript. In low serum, where differentiation is normally suppressed, recombinant myostatin stimulated myogenic marker expression over time. The opposite was true for IGF-I as it stimulated proliferation, not differentiation, and additionally antagonized myostatin. This includes myostatin's effects on marker expression and on the autoregulation of MSTN-1a and -1b expression. These results conflict with studies using mammalian cell lines and suggest, alternatively, that myostatin is a positive, not negative, regulator of myosatellite cell differentiation. Mammalian myoblasts differentiate when confluent and with serum withdrawal, which differs considerably from how myosatellite cells differentiate in vivo. Thus the primary rainbow trout myosatellite cell culture system appears to be more physiologically relevant.
Regulation of pendrin by cAMP: possible involvement in β-adrenergic-dependent NaCl retention
Authors: Azroyan Anie , Morla Luciana , Crambert Gilles , Laghmani Kamel , Ramakrishnan Sureshkrishna , Edwards Aurélie , Doucet Alain
Published: January 2012

The sodium-independent anion exchanger pendrin is expressed in several tissues including the kidney cortical collecting duct (CCD), where it acts as a chloride/bicarbonate exchanger and has been shown to participate in the regulation of acid-base homeostasis and blood pressure. The renal sympathetic nervous system is known to play a key role in the development of salt-induced hypertension. This study aimed to determine whether pendrin may partly mediate the effects of β adrenergic receptors (β-AR) on renal salt handling. We investigated the regulation of pendrin activity by the cAMP/protein kinase A (PKA) signaling pathway, both in vitro in opossum kidney proximal (OKP) cells stably transfected with pendrin cDNA and ex vivo in isolated microperfused CCDs stimulated by isoproterenol, a β-AR agonist. We found that stimulation of the cAMP/PKA pathway in OKP cells increased the amount of pendrin at the cell surface as well as its transport activity. These effects stemmed from increased exocytosis of pendrin and were associated with its phosphorylation. Furthermore, cAMP effects on the membrane expression and activity of pendrin were abolished by mutating the serine 49 located in the intracellular N-terminal domain of pendrin. Finally, we showed that isoproterenol increases pendrin trafficking to the apical membrane as well as the reabsorption of both Cl−and Na+in microperfused CCDs. All together, our results strongly suggest that pendrin activation by the cAMP/PKA pathway underlies isoproterenol-induced stimulation of NaCl reabsorption in the kidney collecting duct, a mechanism likely involved in the sodium-retaining effect of β-adrenergic agonists.
Urinary excretion of AQP2 and ENaC in autosomal dominant polycystic kidney disease during basal conditions and after a hypertonic saline infusion
Authors: Graffe Carolina Cannillo , Bech Jesper Nørgaard , Lauridsen Thomas Guldager , Pedersen Erling Bjerregaard
Published: January 2012

Renal handling of sodium and water is abnormal in chronic kidney diseases. To study the function and regulation of the aquaporin-2 water channel (AQP2) and the epithelial sodium channel (ENaC) in autosomal dominant polycystic kidney disease (ADPKD), we measured urinary excretion of AQP2 (u-AQP2), the β-subunit of ENaC (u-ENaCβ), cAMP (u-cAMP), and prostaglandin E2(u-PGE2); free water clearance (CH2O); fractional sodium excretion (FENa); and plasma vasopressin (p-AVP), renin (p-Renin), angiotensin II (p-ANG II), aldosterone (p-Aldo), and atrial and brain natriuretic peptide (p-ANP, p-BNP) in patients with ADPKD and healthy controls during 24-h urine collection and after hypertonic saline infusion during high sodium intake (HS; 300 mmol sodium/day) and low sodium intake (LS; 30 mmol sodium/day). No difference in u-AQP2, u-ENaCβ, u-cAMP, u-PGE2, CH2O, and vasoactive hormones was found between patients and controls at baseline, but during HS the patients had higher FENa. The saline caused higher increases in FENain patients than controls during LS, but the changes in u-ENaCβ, p-Aldo, p-ANP, p-BNP, p-Renin, and p-ANG II were similar. Higher increases in u-AQP2 and p-AVP were seen in patients during both diets. In conclusion, u-AQP2 and u-ENaCβwere comparable in patients with ADPKD and controls at baseline. In ADPKD, the larger increase in u-AQP2 and p-AVP in response to saline could reflect an abnormal water absorption in the distal nephron. During LS, the larger increase in FENain response to saline could reflect a defective renal sodium retaining capacity in ADPKD, unrelated to changes in u-ENaCβ.
Galvanic stimulation of the vestibular periphery in guinea pigs during passive whole body rotation and self-generated head movement
Authors: Shanidze N. , Lim K. , Dye J. , King W. M.
Published: January 2012

Irregular vestibular afferents exhibit significant phase leads with respect to angular velocity of the head in space. This characteristic and their connectivity with vestibulospinal neurons suggest a functionally important role for these afferents in producing the vestibulo-collic reflex (VCR). A goal of these experiments was to test this hypothesis with the use of weak galvanic stimulation of the vestibular periphery (GVS) to selectively activate or suppress irregular afferents during passive whole body rotation of guinea pigs that could freely move their heads. Both inhibitory and excitatory GVS had significant effects on compensatory head movements during sinusoidal and transient whole body rotations. Unexpectedly, GVS also strongly affected the vestibulo-ocular reflex (VOR) during passive whole body rotation. The effect of GVS on the VOR was comparable in light and darkness and whether the head was restrained or unrestrained. Significantly, there was no effect of GVS on compensatory eye and head movements during volitional head motion, a confirmation of our previous study that demonstrated the extravestibular nature of anticipatory eye movements that compensate for voluntary head movements.
Opposing modulatory effects of D1- and D2-like receptor activation on a spinal central pattern generator
Authors: Clemens S. , Belin-Rauscent A. , Simmers J. , Combes D.
Published: January 2012

The role of dopamine in regulating spinal cord function is receiving increasing attention, but its actions on spinal motor networks responsible for rhythmic behaviors remain poorly understood. Here, we have explored the modulatory influence of dopamine on locomotory central pattern generator (CPG) circuitry in the spinal cord of premetamorphic Xenopus laevis tadpoles. Bath application of exogenous dopamine to isolated brain stem-spinal cords exerted divergent dose-dependent effects on spontaneous episodic patterns of locomotory-related activity recorded extracellularly from spinal ventral roots. At low concentration (2 μM), dopamine reduced the occurrence of bursts and fictive swim episodes and increased episode cycle periods. In contrast, at high concentration (50 μM) dopamine reversed its actions on fictive swimming, now increasing both burst and swim episode occurrences while reducing episode periods. The low-dopamine effects were mimicked by the D2-like receptor agonists bromocriptine and quinpirole, whereas the D1-like receptor agonist SKF 38393 reproduced the effects of high dopamine. Furthermore, the motor response to the D1-like antagonist SCH 23390 resembled that to the D2 agonists, whereas the D2-like antagonist raclopride mimicked the effects of the D1 agonist. Together, these findings indicate that dopamine plays an important role in modulating spinal locomotor activity. Moreover, the transmitter's opposing influences on the same target CPG are likely to be accomplished by a specific, concentration-dependent recruitment of independent D2- and D1-like receptor signaling pathways that differentially mediate inhibitory and excitatory actions.
Influence fields: a quantitative framework for representation and analysis of active dendrites
Authors: Rathour Rahul Kumar , Narayanan Rishikesh
Published: January 2012

Neuronal dendrites express numerous voltage-gated ion channels (VGICs), typically with spatial gradients in their densities and properties. Dendritic VGICs, their gradients, and their plasticity endow neurons with information processing capabilities that are higher than those of neurons with passive dendrites. Despite this, frameworks that incorporate dendritic VGICs and their plasticity into neurophysiological and learning theory models have been far and few. Here, we develop a generalized quantitative framework to analyze the extent of influence of a spatially localized VGIC conductance on different physiological properties along the entire stretch of a neuron. Employing this framework, we show that the extent of influence of a VGIC conductance is largely independent of the conductance magnitude but is heavily dependent on the specific physiological property and background conductances. Morphologically, our analyses demonstrate that the influences of different VGIC conductances located on an oblique dendrite are confined within that oblique dendrite, thus providing further credence to the postulate that dendritic branches act as independent computational units. Furthermore, distinguishing between active and passive propagation of signals within a neuron, we demonstrate that the influence of a VGIC conductance is spatially confined only when propagation is active. Finally, we reconstruct functional gradients from VGIC conductance gradients using influence fields and demonstrate that the cumulative contribution of VGIC conductances in adjacent compartments plays a critical role in determining physiological properties at a given location. We suggest that our framework provides a quantitative basis for unraveling the roles of dendritic VGICs and their plasticity in neural coding, learning, and homeostasis.
Spillover Phenomena and Its Striking Impacts in Electrocatalysis for Hydrogen and Oxygen Electrode Reactions
Authors: Papakonstantinou Georgios D. , Jaksic Jelena M. , Labou Diamantoula , Siokou Angeliki , Jaksic Milan M.
Published: January 2012

The core subject of the present paper represents the interrelated spillover (effusion) phenomena both of the primary oxide and the H‐adatoms, their theory and practice, causes, appearances and consequences, and evidences of existence, their specific properties, and their alterpolar equilibria and kinetic behavior, structural, and resulting catalytic, and double layer charging features. The aim is to introduce electron conductive and d‐d interactive individual and composite (mixed valence) hypo‐d‐oxide compounds, of increased altervalent capacity, or their suboxides (Magnéli phases), as the interactive catalytic supports and therefrom provide (i) the strong metal‐support interaction (SMSI) catalytic effect and (ii) dynamic spillover interactive transfer of primary oxides (M‐OH) and free effusional H‐adatoms for further electrode reactions and thereby advance the overall electrocatalytic activity. Since hypo‐d‐oxides feature the exchange membrane properties, the higher the altervalent capacity, the higher the spillover effect. In fact, altervalent hypo‐d‐oxides impose spontaneous dissociative adsorption of water molecules and then spontaneously pronounced membrane spillover transferring properties instantaneously resulting with corresponding bronze type (Pt/HxWO3) under cathodic and/or its hydrated state (Pt/W(OH)6), responsible for Pt‐OH effusion, under anodic polarization, this way establishing instantaneous reversibly revertible alterpolar bronze features (Pt/H0.35WO3⇔ Pt/W(OH)6) and substantially advanced electrocatalytic properties of these composite interactive electrocatalysts. Such nanostructured‐type electrocatalysts, even of mixed‐valence hypo‐d‐oxide structures (Pt/H0.35WO3/TiO2/C, Pt/HxNbO3/TiO2/C), have for the first time been synthesized by the sol‐gel methods and shown rather high stability, electron conductivity, and nonexchanged initial pure monobronze spillover and catalytic properties. Such a unique electrocatalytic system, as the striking target issue of the present paper, has been shown to be the superior for substantiation of the revertible cell assembly for spontaneous reversible alterpolar interchanges between PEMFC and WE. The main target of the present thorough review study has been to throw some specific insight light on the overall spillover phenomena and their effects in electrocatalysis of oxygen and hydrogen electrode reactions from diverse angles of view and broad contemporary experimental methods and approaches (XPS, FTIR, DRIFT, XRD, potentiodynamic spectra, UHRTEM).
Dynamic Properties of a Differential‐Algebraic Biological Economic System
Authors: Zhang Hongyang , Zhang Chunrui
Published: January 2012

We analyze a differential‐algebraic biological economic system with time delay. The model has two different Holling functional responses. By considering time delay as bifurcation parameter, we find that there exists stability switches when delay varies, and the Hopf bifurcation occurs when delay passes through a sequence of critical values. Furthermore, we also consider the stability and direction of the Hopf bifurcation by applying the normal form theory and the center manifold theorem. Finally, using Matlab software, we do some numerical simulations to illustrate the effectiveness of our results.
Why Did Americans Reject Compulsory Health Insurance after WWI? An Application of the Lifecycle Model
Authors: Wilson Stuart J. , Emery J. C. Herbert
Published: January 2012

Progressive reformers failed to gain support to implement compulsory health insurance in the US after WWI. Modeling results presented in this paper, using a lifecycle model with sickness risk and precautionary savings, support the conclusion that existing voluntary insurance plans were adequate and welfare-enhancing in the US, that compulsory health insurance as proposed would not be welfare-enhancing, and that Americans' preference to self-insure during most of their working lives was rational, utility-maximizing behaviour.
Application of Integer and Fractional Models in Electrochemical Systems
Authors: Jesus Isabel S. , Tenreiro Machado J. A.
Published: January 2012

This paper describes the use of integer and fractional electrical elements, for modelling two electrochemical systems. A first type of system consists of botanical elements and a second type is implemented by electrolyte processes with fractal electrodes. Experimental results are analyzed in the frequency domain, and the pros and cons of adopting fractional‐order electrical components for modelling these systems are compared.
Gliclazide Does Not Fully Prevent 2-Deoxy-D-Ribose-Induced Oxidative Damage Because It Does Not Restore Glutathione Content in a Pancreaticβ-Cell Line
Authors: Koh Gwanpyo , Kim Min-Kyoung , Yang Eun-Jin , Lee Dae-Ho
Published: January 2012

We compared the effects of gliclazide, an antidiabetic agent with antioxidant properties, andN-acetyl-L-cysteine (NAC), a glutathione precursor, in protecting against 2-deoxy-D-ribose- (dRib-) induced oxidative damage in HIT-T15 cells. Using trypan blue staining and flow cytometry with annexin V/PI staining, gliclazide treatment slightly reversed dRib-induced cell death and apoptosis, and NAC treatment markedly reduced both measures. Likewise, flow cytometry using DHR 123 staining showed that the levels of dRib-induced reactive oxygen species (ROS) were partially suppressed by gliclazide and completely inhibited by NAC. Using electron spin resonance spectrometry, gliclazide and NAC scavenged hydroxyl radicals generated by Fenton reaction to a similar degree in a cell-free system. NAC, but not gliclazide, completely restored the intracellular glutathione depleted by dRib using monochlorobimane fluorescence and glutathione assays. Thus, gliclazide treatment suppressed dRib-induced oxidative damage in HIT-T15 cells less than NAC did because gliclazide did not restore the intracellular glutathione content as effectively as NAC. In addition, the elevation of intracellular glutathione rather than free radical scavenging might be an important mechanism for protecting against dRib-induced oxidative damage in aβ-cell line.
Using Basic Ethical Principles to Evaluate Safety Efforts in Transfusion Medicine
Authors: Brooks Jay P.
Published: January 2012

Pursuit of pharmaceutical purity of the blood in the bag has led to a shrinking donor base and a significantly more expensive product. Decisions regarding new infectious marker testing and donor deferrals have typically been made emphasizing decreasing one specific risk without considering the effect the intervention will have on the overall safety and availability of blood transfusion. Regulations have been formulated by governmental agencies with limited input from the medical community. The decision making process has lacked risk benefit analyses and has not had the robustness associated with spirited discussions. Policies made in this manner may result in certain risks being decreased but can also have adverse unintended consequences. Being guided by the ethical principles of nonmaleficence, beneficence, autonomy, and justice, we need to evaluate our actions in the context of overall blood safety rather than narrowly focusing on any one area.
Impulsive Perturbations of a Three‐Species Food Chain System with the Beddington‐DeAngelis Functional Response
Authors: Do Younghae , Baek Hunki , Kim Dongseok
Published: January 2012

The dynamics of an impulsively controlled three‐species food chain system with
the Beddington‐DeAngelis functional response are investigated using the Floquet
theory and a comparison method. In the system, three species are prey, mid‐predator,
and top‐predator. Under an integrated control strategy in sense of biological and
chemical controls, the condition for extinction of the prey and the mid‐predator
is investigated. In addition, the condition for extinction of only the mid‐predator is
examined. We provide numerical simulations to substantiate the theoretical results.
Subjective Logic-Based Anomaly Detection Framework in Wireless Sensor Networks
Authors: Yuan Jinhui , Zhou Hongwei , Chen Hong
Published: January 2012

In existing anomaly detection approaches, sensor node often turns to neighbors to further determine whether the data is normal while the node itself cannot decide. However, previous works consider neighbors' opinions being just normal and anomalous, and do not consider the uncertainty of neighbors to the data of the node. In this paper, we propose SLAD (subjective logic based anomaly detection) framework. It redefines opinion deriving from subjective logic theory which takes the uncertainty into account. Furthermore, it fuses the opinions of neighbors to get the quantitative anomaly score of the data. Simulation results show that SLAD framework improves the performance of anomaly detection compared with previous works.
The Importance of Velocity Acceleration to Flow-Mediated Dilation
Authors: Stoner Lee , Young Joanna M. , Fryer Simon , Sabatier Manning J.
Published: January 2012

The validity of the flow-mediated dilation test has been questioned due to the lack of normalization to the primary stimulus, shear stress. Shear stress can be calculated using Poiseuille's law. However, little attention has been given to the most appropriate blood velocity parameter(s) for calculating shear stress. The pulsatile nature of blood flow exposes the endothelial cells to two distinct shear stimuli during the cardiac cycle: a large rate of change in shear at the onset of flow (velocity acceleration), followed by a steady component. The parameter typically entered into the Poiseuille's law equation to determine shear stress is time-averaged blood velocity, with no regard for flow pulsatility. This paper will discuss (1) the limitations of using Posieuille's law to estimate shear stress and (2) the importance of the velocity profile—with emphasis on velocity acceleration—to endothelial function and vascular tone.
Protective Role of the ACE2/Ang-(1–9) Axis in Cardiovascular Remodeling
Authors: Ocaranza María Paz , Jalil Jorge E.
Published: January 2012

Despite reduction in cardiovascular (CV) events and end-organ damage with the current pharmacologic strategies, CV disease remains the primary cause of death in the world. Pharmacological therapies based on the renin angiotensin system (RAS) blockade are used extensively for the treatment of hypertension, heart failure, and CV remodeling but in spite of their success the prevalence of end-organ damage and residual risk remain still high. Novel approaches must be discovered for a more effective treatment of residual CV remodeling and risk. The ACE2/Ang-(1–9) axis is a new and important target to counterbalance the vasoconstrictive/proliferative RAS axis. Ang-(1–9) is hydrolyzed slower than Ang-(1–7) and is able to bind the Ang II type 2 receptor. We review here the current experimental evidence suggesting that activation of the ACE2/Ang-(1–9) axis protects the heart and vessels (and possibly the kidney) from adverse cardiovascular remodeling in hypertension as well as in heart failure.
Ethical Aspects of Blood Donors and the Recipients of Their Blood
Authors: van den Burg P. J. M. , Magnussen K.
Published: January 2012

To date medical care is inextricable based on blood donors and blood products. The continuing increase and intensification of tests and guidelines also results in a change in deferral and abnormal test results. Donors and recipients of their blood are faced with this information and are confronted with a kaleidoscope of thoughts and emotions. The discussion with respect to paid versus nonpaid donation is not new, but other aspects are less often discussed. We describe these other aspects for donors and recipients of their blood and hope to open the ethical discussion; if and to what extent we should have limits?
Variational-Like Inequalities and Equilibrium Problems with Generalized Monotonicity in Banach Spaces
Authors: Mahato N. K. , Nahak C.
Published: January 2012

We introduce the notion of relaxed (ρ-θ)-η-invariant pseudomonotone mappings, which is weaker than invariant pseudomonotone maps. Using the KKM technique, we establish the existence of solutions for variational-like inequality problems with relaxed (ρ-θ)-η-invariant pseudomonotone mappings in reflexive Banach spaces. We also introduce the concept of (ρ-θ)-pseudomonotonicity for bifunctions, and we consider some examples to show that (ρ-θ)-pseudomonotonicity generalizes both monotonicity and strong pseudomonotonicity. The existence of solution for equilibrium problem with (ρ-θ)-pseudomonotone mappings in reflexive Banach spaces are demonstrated by using the KKM technique.
Test Generation for Crosstalk‐Induced Delay Faults in VLSI Circuits Using Modified FAN Algorithm
Authors: Jayanthy S. , Bhuvaneswari M. C. , Sujitha Keesarapalli
Published: January 2012

As design trends move toward nanometer technology, new problems due to noise effects lead to a decrease in reliability and performance of VLSI circuits. Crosstalk is one such noise effect which affects the timing behaviour of circuits. In this paper, an efficient Automatic Test Pattern Generation (ATPG) method based on a modified Fanout Oriented (FAN) to detect crosstalk‐induced delay faults in VLSI circuits is presented. Tests are generated for ISCAS_85 and enhanced scan version of ISCAS_89 benchmark circuits. Experimental results demonstrate that the test program gives better fault coverage, less number of backtracks, and hence reduced test generation time for most of the benchmark circuits when compared to modified Path‐Oriented Decision Making (PODEM) based ATPG. The number of transitions is also reduced thus reducing the power dissipation of the circuit.
Analytical Solutions for Corrosion‐Induced Cohesive Concrete Cracking
Authors: Chen Hua-Peng , Xiao Nan
Published: January 2012

The paper presents a new analytical model to study the evolution of radial cracking around a corroding steel reinforcement bar embedded in concrete. The concrete cover for the corroding rebar is modelled as a thick‐walled cylinder subject to axisymmetrical displacement constraint at the internal boundary generated by expansive corrosion products. A bilinear softening curve reflecting realistic concrete property, together with the crack band theory for concrete fracture, is applied to model the residual tensile stress in the cracked concrete. A governing equation for directly solving the crack width in cover concrete is established for the proposed analytical model. Closed‐form solutions for crack width are then obtained at various stages during the evolution of cracking in cover concrete. The propagation of crack front with corrosion progress is studied, and the time to cracking on concrete cover surface is predicted. Mechanical parameters of the model including residual tensile strength, reduced tensile stiffness, and radial pressure at the bond interface are investigated during the evolution of cover concrete cracking. Finally, the analytical predictions are examined by comparing with the published experimental data, and mechanical parameters are analysed with the progress of reinforcement corrosion and through the concrete cover.
Mitochondrial DNA Variability withinUromastyx ornata philbyi(Agamidae: Squamata) from Southwestern Saudi Arabia
Authors: Amer Sayed A. M. , Ahmed Mohamed M. , Wilms Thomas M. , Shobrak Mohammed , Kumazawa Yoshinori
Published: January 2012

Approximately 2.4 kbp of mitochondrial DNA was sequenced from 9 individuals ofUromastyx ornata philbyioriginating from Taif, Namas, Al-Baha, and Jazan in southwestern Saudi Arabia. The sequenced regions cover eight tRNA genes (tRNAGln,tRNAIle,tRNAMet,tRNATrp,tRNAAla,tRNAAsn,tRNACys, andtRNATyr) and two protein-coding genes (NADH dehydrogenase subunit 2 and cytochromeb).U. ornata philbyihad an insertion of 170 bp length betweentRNAGlnandtRNAIlegenes. The first 128 bp of this insertion was similar to the one identified earlier inU. ornata ornataand can be folded into a stem-and-loop structure, which was less stable inU. ornata philbyithan inU. ornata ornata, or the secondtRNAGlngene. The next 42 bp of the insertion was unique inU. ornata philbyiand additionally retained a stable stem-and-loop structure. Most base substitutions found in the sequenced genes were synonymous transitions rather than transversions. Tree analyses supported the sister group relationship between the twoU. ornatasubspecies and dividedU. ornata philbyiinto two groups: Taif+Namas group in the east of Sarawat and Al-Baha+Jazan group in the west of Sarawat. These molecular data are in agreement with current classification ofU. ornata.
Creatinine-Based Estimations of Kidney Function Are Unreliable in Obese Kidney Donors
Authors: Aggarwal Nidhi , Porter Anna C. , Tang Ignatius Y. S. , Becker Bryan N. , Akkina Sanjeev K.
Published: January 2012

Accurate assessment of kidney function by measurement of glomerular filtration rate (GFR) is essential to the risk assessment of prospective living kidney donors. We evaluated the performance of various estimating equations for creatinine clearance (Cockcroft-Gault), GFR (Modification of Diet in Renal Disease, Chronic Kidney Disease Epidemiology Collaboration), and 24-hour urine collections for creatinine clearance in obese potential kidney donors. We evaluated 164 potential kidney donors including 49 with a BMI of 30–35 and 32 with a BMI >35 that have completed a routine living donor evaluation with a measured GFR. All the estimating equations performed poorly in obese donors. While 24-hour urine collections performed better, only 15% had an adequate 24-hour urine collection. Since obese kidney donors may be at higher than average risk for kidney failure, accurate assessment of kidney function in these donors is crucial to ensure their long-term health postdonation.
The Effect of Human and Mouse Fibroblast Feeder Cells on Cardiac Differentiation of Human Pluripotent Stem Cells
Authors: Pekkanen-Mattila Mari , Ojala Marisa , Kerkelä Erja , Rajala Kristiina , Skottman Heli , Aalto-Setälä Katriina
Published: January 2012

Mouse embryonic fibroblasts (MEFs) and human foreskin fibroblasts (hFFs) are commonly used as feeder cells to maintain the pluripotent state of stem cells. The aim of the present study was to evaluate the effect of MEF and hFF feeders on the cardiac differentiation. Two human embryonic and two induced pluripotent stem cell lines were cultured on MEF and hFF before cardiac differentiation. The expression of Brachyury T was higher in cell lines cultured on MEF, than if cultured on hFF, suggesting enhanced mesoderm formation. However, significant positive influence of MEF feeders on cardiac differentiation was only seen with one cell line. Further, the ability of hFF to maintain pluripotency of stem cells originally cultured on MEF was quite poor. In conclusion, the cells behaved differently whether cultured on hFF or MEF feeders. However, the influence of the feeder cells on differentiation was less than the difference observed between the cell lines.