bluuebunny/crossref_metadata_2025 huggingface dataset:
Steady and non-steady state kinetics describe polychlorinated biphenyl bioaccumulation in natural populations of bluegill (Lepomis macrochirus) and cisco (Coregonus artedi)
Authors: Burtnyk Michael D. , Paterson Gordon , Drouillard Kenneth G. , Haffner G. Douglas
Published: December 2009

This study investigated polychlorinated biphenyl (PCB) bioaccumulation patterns across age classes of bluegill ( Lepomis macrochirus ) and cisco ( Coregonus artedi ) collected from Sharbot Lake, Ontario. For bluegill, lipid normalized concentrations of PCB congeners of log Kow < 6.8 did not demonstrate any significant increases across individuals 2–5 years of age. In similarly aged cisco, however, significant age-related increases in lipid normalized PCB concentrations were observed for the majority of these congeners. For PCBs of log Kow > 6.8, these congeners demonstrated significant and similar age-related fugacity increases in both species. These patterns indicated that the bioaccumulation of less hydrophobic PCB congeners in bluegill suggest quicker growth kinetics and demonstrate the potential of this species to achieve steady state within their lifetime. In contrast, PCB bioaccumulation patterns in cisco demonstrated that biomagnification and non-steady state kinetics better reflect the capacity of this species to bioaccumulate PCBs. These results demonstrated that for pollutants of log Kow < 6.8, growth dilution and age-specific metabolic rates are critical for understanding their bioaccumulation by freshwater fish. However, for increasingly hydrophobic pollutants, their bioaccumulation reflects the biology and ecology of these species in their respective warm- and cold-water habitats.
Differentiating mortality from delayed migration in subyearling fall Chinook salmon (Oncorhynchus tshawytscha)
Authors: Buchanan Rebecca A. , Skalski John R. , McMichael Geoffrey A.
Published: December 2009

A total of 1154 acoustic-tagged subyearling fall Chinook salmon ( Oncorhynchus tshawytscha ) were monitored during their movement through Lower Monumental Reservoir, Snake River, Washington, USA. A release–recapture design was developed to partition their fates into migration, delayed migration (i.e., holdover or temporary residualization), and mortality using a series of standard detection arrays augmented with individual intrareach autonomous receivers. The standard detection arrays were used in conjunction with traditional release–recapture models to estimate the joint probabilities of migrating and surviving through the reservoir. Closed population estimators were used to estimate the abundance of tagged fish still alive in the river reaches and to differentiate mortality from delayed migration. Over the course of the study from 15 August to 14 November 2007, delayed migration rates increased and mortality rates generally declined. A minimum of 10.6% of the fish were estimated to have delayed migration in the reservoir during the study period.
DKP oscillator in noncommutative phase space
Authors: Guo Guangjie , Long Chaoyun , Yang Zuhua , Qin Shuijie
Published: December 2009

The exact solutions of the Duffin–Kemmer–Petiau (DKP) oscillator for spin-0 particles have been studied in noncommutative phase space. The results show that due to the noncommutative effect, the energy spectrum of the DKP oscillator for spin-0 particles is no longer degenerate. In addition, we obtain the nonrelativistic limit of the energy spectrum.
Optimal entanglement generation in cavity QED with dissipation
Authors: Zhang Jian-Song , Xu Jing-Bo
Published: December 2009

We investigate a two-level atom coupled to a cavity with a strong classical driving field in a dissipative environment and find an analytical expression for the time evolution density matrix for the system. The analytical density operator is then used to study the entanglement between the atom and cavity by considering the competing process between the atom–field interactions and the field–environment interactions. It is shown that there is an optimal interaction time for generating atom–cavity entanglement.
Calculation of charge-state distributions of accelerated ions in gas media
Authors: Negri Agustín E. , Arazi Andrés
Published: December 2009

Charge-state distributions of medium-mass ions passing through H2 or He gas targets were calculated by means of a Monte Carlo code that only uses semiempirical formulae for electron-capture and electron-loss cross sections as inputs. A good agreement with experimental data was achieved. In this paper, we suggest the use of these calculations to study the effect of nuclear fusion reactions on the atomic electrons of the reactants, and on the ionic charge state of the products.
A method to create disordered vortex arrays in atomic Bose–Einstein condensates
Authors: Madarassy Enikö J.M.
Published: December 2009

We suggest a method to create quantum turbulence (QT) in a trapped atomic Bose–Einstein condensate (BEC). By replacing in the upper half of our box the wave function, Ψ, with its complex conjugate, Ψ*, new negative vortices are introduced into the system. The simulations are performed by solving the two-dimensional Gross–Pitaevskii equation (2D GPE). We study the successive dynamics of the wave function by monitoring the evolution of density and phase profile.
Generalization of Einstein’s synchronization for the case of anisotropic light speed
Authors: Sfarti A.
Published: December 2009

The current paper derives a generalized version of Einstein’s clock synchronization rule for the case of inertial frames in which light speed is assumed to be anisotropic. The current paper is the result of a discussion started with Professor N.D. Mermin. We show how we can construct the theory of relativity from only one base principle: the postulate of relativity. The postulate of relativity is the requirement that the equations, describing the laws of physics, have the same form (are covariant) in all admissible frames of reference.
Relative abundance and species richness of cerambycid beetles in partial cut and uncut bottomland hardwood forests
Authors: Newell Patti , King Sammy
Published: December 2009

Partial cutting techniques are increasingly advocated and used to create habitat for priority wildlife. However, partial cutting may or may not benefit species dependent on deadwood; harvesting can supplement coarse woody debris in the form of logging slash, but standing dead trees may be targeted for removal. We sampled cerambycid beetles during the spring and summer of 2006 and 2007 with canopy malaise traps in 1- and 2-year-old partial cut and uncut bottomland hardwood forests of Louisiana. We captured a total of 4195 cerambycid beetles representing 65 species. Relative abundance was higher in recent partial cuts than in uncut controls and with more dead trees in a plot. Total species richness and species composition were not different between treatments. The results suggest partial cuts with logging slash left on site increase the abundance of cerambycid beetles in the first few years after partial cutting and that both partial cuts and uncut forest should be included in the bottomland hardwood forest landscape.
Black spruce reforestation in Kalmia heath: seedling response to forest floor mixing and mycorrhizal inoculation with Paxillus involutus
Authors: Walker Gregg R. , Mallik Azim U.
Published: December 2009

In the boreal forests of eastern Canada, black spruce ( Picea mariana (Mill.) Britton, Sterns, Poggenb.) regeneration often fails in nutrient-poor sites dominated by Kalmia angustifolia L. occurring after nonsevere forest fire, clearcut harvesting, and insect defoliation. Traditional silvicultural treatments have limited success in regenerating these sites. We tested whether forest floor mixing and planting black spruce seedlings preinoculated with an ectomycorrhizal (ECM) fungus, Paxillus involutus (Batsch) Fr., has potential to improve black spruce growth in Kalmia -dominated sites. We measured growth and foliar nutrient concentrations of ECM-inoculated and control black spruce seedlings planted in burned and insect-defoliated sites after forest floor mixing in Terra Nova National Park, Newfoundland. We also measured soil moisture, temperature, pH, total phenol and nutrient concentrations, litter decomposition, and soil respiration in those sites. Seedlings in soil-mixed plots had significantly higher growth and foliar nutrient concentrations than nonmixed plots, likely because soil mixing improved the substrate conditions by increased soil moisture, pH, and litter decomposition. Seedlings in insect-defoliated sites had significantly higher increases in height and foliar nutrient concentrations than those in the burned sites. Inoculated seedlings had significantly higher initial ECM formation than the control seedlings, but they failed to achieve higher growth.
Impact of temperature on the linear viscoelastic region of wood
Authors: Jiang Jiali , Lu Jianxiong
Published: December 2009

The impact of temperature on the linear viscoelastic region, which is characterized by critical strain, of Chinese fir ( Cunninghamia lanceolata (Lamb.) Hook.) was investigated at various temperatures between –100 and 220 °C for specimens with a moisture content of approximately 0.6%. The effect of oscillation frequency on the linear viscoelastic region under various constant temperatures was also examined. The results indicated that critical strain generally decreased with increasing temperature except at –80, –20, 40, 120, and 220 °C. These five exceptions were attributed to the occurrence of relaxation processes. With an increase in testing frequency from 1 to 20 Hz, the critical strain decreased slightly at all temperatures. It is suggested that the stored elastic energy and yield stress, which were obtained at critical strain, could be indicators to predict wood mechanical performance.
Decomposition of pure and mixed foliage litter in a young lodgepole pine – Sitka alder stand in the central interior of British Columbia
Authors: Sanborn P.T. , Brockley R.P.
Published: December 2009

A 7-year litterbag experiment examined mass loss dynamics of Sitka alder ( Alnus viridis (Chaix) DC. subsp. sinuata (Regel) A. Löve & D. Löve) and lodgepole pine ( Pinus contorta Dougl. ex Loud. var. latifolia Engelm. ex S. Watson) foliage litter in a young stand dominated by these species in the Sub-Boreal Spruce biogeoclimatic zone of central British Columbia. Although mass loss was initially faster for alder litter, the amounts of mass remaining for alder, pine, and mixed pine–alder (50:50 by mass) litter began to converge after 2 years. Mass loss by the mixed litter differed significantly from that predicted from the behaviour of its pure components, but the mechanisms responsible could not be determined from this experiment. Limit values for the projected maximum extent of mass loss ranged from 63.5% (alder) to 76.9% (pine), with the latter value considerably below estimates reported for lodgepole pine in Scandinavia. Despite these differing limit values, forest floor mass measurements prior to the experiment did not show significantly higher organic matter accumulations under long-established alder clumps on this site.
PION TRANSITION FORM FACTOR AT THE TWO-LOOP LEVEL VIS-À-VIS EXPERIMENTAL DATA
Authors: MIKHAILOV S. V. , STEFANIS N. G.
Published: December 2009

We use light-cone QCD sum rules to calculate the pion-photon transition form factor, taking into account radiative corrections up to the next-to-next-to-leading order of perturbation theory. We compare the obtained predictions with all available experimental data from the CELLO, CLEO, and the BaBar Collaborations. We point out that the BaBar data are incompatible with the convolution scheme of QCD, on which our predictions are based, and can possibly be explained only with a violation of the factorization theorem. We pull together recent theoretical results and comment on their significance.
RENORMALIZATION-GROUP ANATOMY OF TRANSVERSE-MOMENTUM DEPENDENT PARTON DISTRIBUTION FUNCTIONS IN QCD
Authors: STEFANIS N. G. , CHEREDNIKOV I. O.
Published: December 2009

The ultraviolet and rapidity divergences of transverse-momentum dependent parton distribution functions with lightlike and transverse gauge links is studied, also incorporating a soft eikonal factor. We find that in the light-cone gauge with q--independent pole prescriptions extra divergences appear which amount, at one-loop, to a cusp-like anomalous-dimension. We show that such contributions are absent when the Mandelstam-Leibbrandt prescription is used. In the first case, the soft factor cancels the anomalous dimension defect, while in the second case its ultraviolet-divergent part reduces to unity.
EXCLUSIVE PRODUCTION OF SOFT PIONS IN DIS
Authors: BRAUN V. M. , IVANOV D. YU. , LENZ A. , PETERS A.
Published: December 2009

We consider pion electroproduction close to threshold for Q2 in the region 1–10 GeV2 on a nucleon target. The momentum transfer dependence of the S-wave multipoles at threshold, E0+ and L0+, is calculated in the chiral limit using light-cone sum rules. Predictions for the cross sections in the threshold region, both for π0p and π+n channels, are given that include P-wave contributions that, as we argue, are model independent to a large extent. The results are compared with the SLAC E136 data on the structure function F2(W,Q2) in the threshold region.
RENORMALIZATION OF TWIST FOUR OPERATORS IN QCD
Authors: MANASHOV ALEXANDER
Published: December 2009

I review a new technique for calculation of higher twist evolution equations in Quantum Chromodynamics.
META-STABLE BRANE CONFIGURATIONS BY QUARTIC SUPERPOTENTIAL FOR BIFUNDAMENTALS
Authors: AHN CHANGHYUN
Published: December 2009

The type IIA nonsupersymmetric meta-stable brane configuration consisting of three NS5-branes, D4-branes and anti-D4-branes where the electric gauge theory superpotential has a quartic term for the bifundamentals besides a mass term is constructed. By adding the orientifold 4-plane and 6-plane to this brane configuration, we also describe the intersecting brane configurations of type IIA string theory corresponding to the meta-stable nonsupersymmetric vacua of corresponding gauge theories.
CYCLIC MAGNETIC UNIVERSE
Authors: NOVELLO M. , ARAUJO ALINE N. , SALIM J. M.
Published: December 2009

Recent works have shown the important role nonlinear electrodynamics (NLED) can have in two crucial questions of cosmology, concerning particular moments of its evolution for very large and for low-curvature regimes, that is for very condensed phase and at the present period of acceleration. We present here a toy model of a complete cosmological scenario in which the main factor responsible for the geometry is a nonlinear magnetic field which produces a Friedmann–Robertson–Walker homogeneous and isotropic geometry. In this scenario we distinguish four distinct phases: a bouncing period, a radiation era, an acceleration era, and a re-bouncing period. It has already been shown that in NLED a strong magnetic field can overcome the inevitability of a singular region typical of linear Maxwell theory; on the other extreme situation, that is for very weak magnetic field it can accelerate the expansion. The present model goes one step further: after the acceleration phase the universe re-bounces and enters into a collapse era. This behavior is a manifestation of the invariance under the dual map of the scale factor a(t) → 1/a(t), a consequence of the corresponding inverse symmetry of the electromagnetic field (F → 1/F, where F ≡ FμνFμν) of the NLED theory presented here. Such sequence collapse–bouncing–expansion–acceleration–re-bouncing–collapse constitutes a basic unitary element for the structure of the universe that can be repeated indefinitely yielding what we call a cyclic magnetic universe.
ON THE ORIGIN OF APPROXIMATE CUSTODIAL SYMMETRY IN THE TWO-HIGGS DOUBLET MODEL
Authors: FROGGATT C. D. , NEVZOROV R. , NIELSEN H. B. , THOMPSON D.
Published: December 2009

We argue that the consistent implementation of the multiple point principle (MPP) in the general nonsupersymmetric two-Higgs doublet model (2HDM) can lead to a set of approximate global custodial symmetries that ensure CP conservation in the Higgs sector and the absence of flavor changing neutral currents (FCNC) in the considered model. In particular, the existence of a large set of degenerate vacua at some high energy scale Λ caused by the MPP can result in approximate U(1) and Z2 symmetries that suppress FCNC and CP-violating interactions in the 2HDM. We explore the renormalization group (RG) flow of the Yukawa and Higgs couplings within the MPP inspired 2HDM with approximate custodial symmetries and show that the solutions to the RG equations are focused near quasifixed points at low energies if the MPP scale Λ is relatively high. We study the Higgs spectrum and couplings near the quasifixed point at moderate values of tan β and compute a theoretical upper bound on the lightest Higgs boson mass. If Λ ≳ 1010 GeV the lightest CP-even Higgs boson is always lighter than 125 GeV. When the MPP scale is low, the mass of the lightest Higgs particle can reach 180–220 GeV while its coupling to the top quark can be significantly larger than in the SM, resulting in the enhanced production of Higgs bosons at the LHC. Other possible scenarios that appear as a result of the implementation of the MPP in the 2HDM are also discussed.
ONE-LOOP ELECTROWEAK EFFECTS ON STOP-CHARGINO PRODUCTION AT LHC
Authors: BECCARIA M. , MACORINI G. , MIRABELLA E. , PANIZZI L. , RENARD F. M. , VERZEGNASSI C.
Published: December 2009

The process of stop-chargino production at LHC has been calculated in the Minimal Supersymmetric Standard Model at the complete electroweak one-loop level, assuming a mSUGRA symmetry breaking scheme. Several properties of the angular and invariant mass distributions of the basic [Formula: see text] amplitudes have been derived. For a meaningful collection of different benchmark points the overall electroweak one-loop effects are at most of the order of a few percent. At the realistically expected LHC accuracy, the main supersymmetric electroweak features of the process can be therefore essentially derived in this theoretical scheme from the simple Born level expressions.
The Effect of Submarine Groundwater Discharge on the Ocean
Authors: Moore Willard S.
Published: December 2009

The exchange of groundwater between land and sea is a major component of the hydrological cycle. This exchange, called submarine groundwater discharge (SGD), is comprised of terrestrial water mixed with sea water that has infiltrated coastal aquifers. The composition of SGD differs from that predicted by simple mixing because biogeochemical reactions in the aquifer modify its chemistry. To emphasize the importance of mixing and chemical reaction, these coastal aquifers are called subterranean estuaries. Geologists recognize this mixing zone as a site of carbonate diagenesis and dolomite formation. Biologists have recognized that terrestrial inputs of nutrients to the coastal ocean may occur through subterranean processes. Further evidence of SGD comes from the distribution of chemical tracers in the coastal ocean. These tracers originate within coastal aquifers and reach the ocean through SGD. Tracer studies reveal that SGD provides globally important fluxes of nutrients, carbon, and metals to coastal waters.
Bioluminescence in the Sea
Authors: Haddock Steven H.D. , Moline Mark A. , Case James F.
Published: December 2009

Bioluminescence spans all oceanic dimensions and has evolved many times—from bacteria to fish—to powerfully influence behavioral and ecosystem dynamics. New methods and technology have brought great advances in understanding of the molecular basis of bioluminescence, its physiological control, and its significance in marine communities. Novel tools derived from understanding the chemistry of natural light-producing molecules have led to countless valuable applications, culminating recently in a related Nobel Prize. Marine organisms utilize bioluminescence for vital functions ranging from defense to reproduction. To understand these interactions and the distributions of luminous organisms, new instruments and platforms allow observations on individual to oceanographic scales. This review explores recent advances, including the chemical and molecular, phylogenetic and functional, community and oceanographic aspects of bioluminescence.
Treatment of Panic
Authors: Schmidt Norman B. , Keough Meghan E.
Published: December 2009

The present review summarizes empirical developments in the psychosocial treatment of panic and panic disorder by focusing on four key themes that have been emphasized in this literature: (a) treatment efficacy, effectiveness, and innovation; (b) modulating and process variables in treatment; (c) effective dissemination of treatment; and (d) prevention of panic. Cognitive behavioral treatments (CBTs) for panic are very good, even in the context of comorbidity, but the level of efficacy does not appear to be increasing over time. Unfortunately, there have been relatively few substantive innovations in CBT protocols since the 1980s, and despite progress in the use of computer technology, dissemination of these treatments is lagging. The prevention of panic-spectrum psychopathology is a promising area linked with advances in the identification of panic-relevant risk factors that appear to modulate CBT outcomes.
Age-dependent alterations in fibrillar collagen content and myocardial diastolic function: role of SPARC in post-synthetic procollagen processing
Authors: Bradshaw Amy D. , Baicu Catalin F. , Rentz Tyler J. , Van Laer An O. , Bonnema D. Dirk , Zile Michael R.
Published: December 2009

Advanced age, independent of concurrent cardiovascular disease, can be associated with increased extracellular matrix (ECM) fibrillar collagen content and abnormal diastolic function. However, the mechanisms causing this left ventricular (LV) remodeling remain incompletely defined. We hypothesized that one determinant of age-dependent remodeling is a change in the extent to which newly synthesized procollagen is processed into mature collagen fibrils. We further hypothesized that secreted protein acidic and rich in cysteine (SPARC) plays a key role in the changes in post-synthetic procollagen processing that occur in the aged myocardium. Young (3 mo old) and old (18–24 mo old) wild-type (WT) and SPARC-null mice were studied. LV collagen content was measured histologically by collagen volume fraction, collagen composition was measured by hydroxyproline assay as soluble collagen (1 M NaCl extractable) versus insoluble collagen (mature cross-linked), and collagen morphological structure was examined by scanning electron microscopy. SPARC expression was measured by immunoblot analysis. LV and myocardial structure and function were assessed using echocardiographic and papillary muscle experiments. In WT mice, advanced age increased SPARC expression, myocardial diastolic stiffness, fibrillar collagen content, and insoluble collagen. In SPARC-null mice, advanced age also increased myocardial diastolic stiffness, fibrillar collagen content, and insoluble collagen but significantly less than those seen in WT old mice. As a result, insoluble collagen and myocardial diastolic stiffness were lower in old SPARC-null mice (1.36 ± 0.08 mg hydroxyproline/g dry wt and 0.04 ± 0.005) than in old WT mice (1.70 ± 0.10 mg hydroxyproline/g dry wt and 0.07 ± 0.005, P < 0.05). In conclusion, the absence of SPARC reduced age-dependent alterations in ECM fibrillar collagen and diastolic function. These data support the hypothesis that SPARC plays a key role in post-synthetic procollagen processing and contributes to the increase in collagen content found in the aged myocardium.
Autophagy and protein kinase C are required for cardioprotection by sulfaphenazole
Authors: Huang Chengqun , Liu Wayne , Perry Cynthia N. , Yitzhaki Smadar , Lee Youngil , Yuan Hua , Tsukada Yayoi Tetsuo , Hamacher-Brady Anne , Mentzer Robert M. , Gottlieb Roberta A.
Published: December 2009

Previously, we showed that sulfaphenazole (SUL), an antimicrobial agent that is a potent inhibitor of cytochrome P4502C9, is protective against ischemia-reperfusion (I/R) injury (Ref. 15 ). The mechanism, however, underlying this cardioprotection, is largely unknown. With evidence that activation of autophagy is protective against simulated I/R in HL-1 cells, and evidence that autophagy is upregulated in preconditioned hearts, we hypothesized that SUL-mediated cardioprotection might resemble ischemic preconditioning with respect to activation of protein kinase C and autophagy. We used the Langendorff model of global ischemia to assess the role of autophagy and protein kinase C in myocardial protection by SUL during I/R. We show that SUL enhanced recovery of function, reduced creatine kinase release, decreased infarct size, and induced autophagy. SUL also triggered PKC translocation, whereas inhibition of PKC with chelerythrine blocked the activation of autophagy in adult rat cardiomyocytes. In the Langendorff model, chelerythrine suppressed autophagy and abolished the protection mediated by SUL. SUL increased autophagy in adult rat cardiomyocytes infected with GFP-LC3 adenovirus, in isolated perfused rat hearts, and in mCherry-LC3 transgenic mice. To establish the role of autophagy in cardioprotection, we used the cell-permeable dominant-negative inhibitor of autophagy, Tat-Atg5K130R. Autophagy and cardioprotection were abolished in rat hearts perfused with recombinant Tat-Atg5K130R. Taken together, these studies indicate that cardioprotection mediated by SUL involves a PKC-dependent induction of autophagy. The findings suggest that autophagy may be a fundamental process that enhances the heart's tolerance to ischemia.
Involvement of calcium-calmodulin-dependent protein kinase II in endothelin receptor expression in rat cerebral arteries
Authors: Waldsee Roya , Ahnstedt Hilda , Eftekhari Sajedeh , Edvinsson Lars
Published: December 2009

Experimental cerebral ischemia and organ culture of cerebral arteries result in the enhanced expression of endothelin ETBreceptors in smooth muscle cells via increased transcription. The present study was designed to evaluate the involvement of calcium-calmodulin-dependent protein kinase (CAMK) in the transcriptional expression of endothelin receptors after organ culture. Rat basilar arteries were incubated for 24 h with or without the CAMK inhibitor KN93 or ERK1/2 inhibitor U0126. The contractile responses to endothelin-1 (ET-1; ETAand ETBreceptor agonist) and sarafotoxin 6c (S6c; ETBreceptor agonist) were studied using a sensitive myograph. The mRNA levels of the ETAand ETBreceptors and CAMKII were determined by real-time PCR, and their protein levels were evaluated by immunohistochemistry and Western blot. The mRNA levels of CAMKII and the ETBreceptor increased during organ culture, but there was no change in the expression of the ETAreceptor. This effect was abolished by coincubation with KN93 or U0126. In functional studies, both inhibitors attenuated the S6c-induced contraction. Incubating the arteries with KN93, but not U0126, decreased the amount of phosphorylated CAMKII. The inhibitors had no effect on the levels of myosin light chain during organ culture, as measured by Western blot. CAMKII is involved in the upregulation of the endothelin ETBreceptor and interacts with the ERK1/2 pathway to enhance receptor expression. CAMKII has no effect on the contractile apparatus in rat cerebral arteries.
Baroreflex control of muscle sympathetic nerve activity: a nonpharmacological measure of baroreflex sensitivity
Authors: Hart Emma C. , Joyner Michael J. , Wallin B. Gunnar , Karlsson Tomas , Curry Timothy B. , Charkoudian Nisha
Published: December 2009

The sensitivity of baroreflex control of sympathetic nerve activity (SNA) represents the responsiveness of SNA to changes in blood pressure. In a slightly different analysis, the baroreflex threshold measures the probability of whether a sympathetic burst will occur at a given diastolic blood pressure. We hypothesized that baroreflex threshold analysis could be used to estimate the sensitivity of the sympathetic baroreflex measured by the pharmacological modified Oxford test. We compared four measures of sympathetic baroreflex sensitivity in 25 young healthy participants: the “gold standard” modified Oxford analysis (nitroprusside and phenylephrine), nonbinned spontaneous baroreflex analysis, binned spontaneous baroreflex analysis, and threshold analysis. The latter three were performed during a quiet baseline period before pharmacological intervention. The modified Oxford baroreflex sensitivity was significantly related to the threshold slope ( r = 0.71, P < 0.05) but not to the binned (1 mmHg bins) and the nonbinned spontaneous baroreflex sensitivity ( r = 0.22 and 0.36, respectively, P > 0.05), which included burst area. The threshold analysis was also performed during the modified Oxford manipulation. Interestingly, we found that the threshold analysis results were not altered by the vasoactive drugs infused for the modified Oxford. We conclude that the noninvasive threshold analysis technique can be used as an indicator of muscle SNA baroreflex sensitivity as assessed by the modified Oxford technique. Furthermore, the modified Oxford method does not appear to alter the properties of the baroreflex.
Chronic urotensin-II infusion induces diastolic dysfunction and enhances collagen production in rats
Authors: Tran Lavinia , Kompa Andrew R. , Kemp Will , Phrommintikul Arintaya , Wang Bing H. , Krum Henry
Published: December 2009

The vasoactive peptide urotensin-II (U-II) is likely to play a key causal role in cardiac remodeling that ultimately leads to heart failure. Its contribution, specifically to the development of diastolic dysfunction and the downstream intracellular signaling, however, remains unresolved. This study interrogates the effect of chronic U-II infusion in normal rats on cardiac structure and function. The contribution of Rho kinase (ROCK) signaling to these pathophysiological changes is evaluated in cell culture studies. Chronic high-dose U-II infusion over 4 wk significantly impaired diastolic function in rats on echocardiography-derived Doppler indexes, including E-wave deceleration time (vehicle 56.7 ± 3.3 ms, U-II 118.0 ± 21.5 ms; P < 0.01) and mitral valve annulus peak early/late diastolic tissue velocity (vehicle 2.01 ± 0.19 ms, U-II 1.04 ± 0.25 ms; P < 0.01). A lower dose of U-II infusion (1 nmol·kg−1·h−1) yielded comparable changes. Diastolic dysfunction was accompanied by molecular [significant increases in procollagen-α1(I) gene expression on real-time PCR] and morphological (increases in total collagen, P < 0.05, and collagen type-I protein deposition, P < 0.001) evidence of left ventricular (LV) fibrosis following high-dose U-II infusion. The ROCK inhibitor GSK-576371 (10−7 to 10−5 M) elicited concentration-dependent inhibition of U-II (10−7 M)-stimulated cardiac fibroblast collagen synthesis and cardiac myocyte protein synthesis. Chronic U-II infusion causes diastolic dysfunction, caused by fibrosis of the LV. The in vitro data suggest that this may be in part occurring via a ROCK-dependent pathway.
Protein kinases A and C regulate receptor-mediated increases in cAMP in rabbit erythrocytes
Authors: Adderley Shaquria P. , Sridharan Meera , Bowles Elizabeth A. , Stephenson Alan H. , Ellsworth Mary L. , Sprague Randy S.
Published: December 2009

Activation of the β-adrenergic receptor (β-AR) or the prostacyclin receptor (IPR) results in increases in cAMP and ATP release from erythrocytes. cAMP levels depend on a balance between synthesis via adenylyl cyclase and hydrolysis by phosphodiesterases (PDEs). Previously, we reported that cAMP increases associated with activation of the β-AR and IPR in rabbit and human erythrocytes are tightly regulated by distinct PDEs ( 1 ). Importantly, inhibitors of these PDEs potentiated both increases in cAMP and ATP release. It has been shown that increases in protein kinase (PK) activity can activate PDE3 and PDE4. Both PKA and PKC are present in the erythrocyte and can phosphorylate and activate these PDEs. Here we investigate the hypothesis that PKA regulates PDE activity associated with the β-AR and both PKA and PKC regulate the PDE activity associated with the IPR in rabbit erythrocytes. Pretreatment of erythrocytes with the PKA inhibitor, H89 (10 μM), in the presence of the PDE4 inhibitor, rolipram (10 μM), augmented isoproterenol (1 μM)-induced cAMP increases. In contrast, in the presence of the PDE3 inhibitor, cilostazol (10 μM), pretreatment of erythrocytes with either H89 (1 μM) or two chemically dissimilar inhibitors of PKC, calphostin C (1 μM) or GFX109203X (1 μM), potentiated iloprost (1 μM)-induced cAMP increases. Furthermore, pretreatment of erythrocytes with both H89 and GFX109203X in the presence of cilostazol augmented the iloprost-induced increases in cAMP to a greater extent than either PK inhibitor individually. These results support the hypothesis that PDEs associated with receptor-mediated increases in cAMP in rabbit erythrocytes are regulated by kinases specific to the receptor's signaling pathway.
Modulation of endocytic trafficking and apical stability of CFTR in primary human airway epithelial cultures
Authors: Cholon Deborah M. , O'Neal Wanda K. , Randell Scott H. , Riordan John R. , Gentzsch Martina
Published: December 2009

CFTR is a highly regulated apical chloride channel of epithelial cells that is mutated in cystic fibrosis (CF). In this study, we characterized the apical stability and intracellular trafficking of wild-type and mutant CFTR in its native environment, i.e., highly differentiated primary human airway epithelial (HAE) cultures. We labeled the apical pool of CFTR and subsequently visualized the protein in intracellular compartments. CFTR moved from the apical surface to endosomes and then efficiently recycled back to the surface. CFTR endocytosis occurred more slowly in polarized than in nonpolarized HAE cells or in a polarized epithelial cell line. The most common mutation in CF, ΔF508 CFTR, was rescued from endoplasmic reticulum retention by low-temperature incubation but transited from the apical membrane to endocytic compartments more rapidly and recycled less efficiently than wild-type CFTR. Incubation with small-molecule correctors resulted in ΔF508 CFTR at the apical membrane but did not restore apical stability. To stabilize the mutant protein at the apical membrane, we found that the dynamin inhibitor Dynasore and the cholesterol-extracting agent cyclodextrin dramatically reduced internalization of ΔF508, whereas the proteasomal inhibitor MG-132 completely blocked endocytosis of ΔF508. On examination of intrinsic properties of CFTR that may affect its apical stability, we found that N-linked oligosaccharides were not necessary for transport to the apical membrane but were required for efficient apical recycling and, therefore, influenced the turnover of surface CFTR. Thus apical stability of CFTR in its native environment is affected by properties of the protein and modulation of endocytic trafficking.
Bone marrow-derived angiogenic cells restore lung alveolar and vascular structure after neonatal hyperoxia in infant mice
Authors: Balasubramaniam Vivek , Ryan Sharon L. , Seedorf Gregory J. , Roth Emily V. , Heumann Thatcher R. , Yoder Mervin C. , Ingram David A. , Hogan Christopher J. , Markham Neil E. , Abman Steven H.
Published: December 2009

Neonatal hyperoxia impairs vascular and alveolar growth in mice and decreases endothelial progenitor cells. To determine the role of bone marrow-derived cells in restoration of neonatal lung structure after injury, we studied a novel bone marrow myeloid progenitor cell population from Tie2-green fluorescent protein (GFP) transgenic mice (bone marrow-derived angiogenic cells; BMDAC). We hypothesized that treatment with BMDAC would restore normal lung structure in infant mice during recovery from neonatal hyperoxia. Neonatal mice (1-day-old) were exposed to 80% oxygen for 10 days. BMDACs (1 × 105), embryonic endothelial progenitor cells, mouse embryonic fibroblasts (control), or saline were then injected into the pulmonary circulation. At 21 days of age, saline-treated mice had enlarged alveoli, reduced septation, and a reduction in vascular density. In contrast, mice treated with BMDAC had complete restoration of lung structure that was indistinguishable from room air controls. BMDAC comprised 12% of distal lung cells localized to pulmonary vessels or alveolar type II (AT2) cells and persist (8.8%) for 8 wk postinjection. Coculture of AT2 cells or lung endothelial cells (luEC) with BMDAC augmented AT2 and luEC cell growth in vitro. We conclude that treatment with BMDAC after neonatal hyperoxia restores lung structure in this model of bronchopulmonary dysplasia.
Increase in passive stiffness at reduced airway smooth muscle length: potential impact on airway responsiveness
Authors: Bossé Ynuk , Solomon Dennis , Chin Leslie Y. M. , Lian Kevin , Paré Peter D. , Seow Chun Y.
Published: December 2009

The amplitude of strain in airway smooth muscle (ASM) produced by oscillatory perturbations such as tidal breathing or deep inspiration (DI) influences the force loss in the muscle and is therefore a key determinant of the bronchoprotective and bronchodilatory effects of these breathing maneuvers. The stiffness of unstimulated ASM (passive stiffness) directly influences the amplitude of strain. The nature of the passive stiffness is, however, not clear. In this study, we measured the passive stiffness of ovine ASM at different muscle lengths (relative to in situ length, which was used as a reference length, Lref) and states of adaptation to gain insights into the origin of this muscle property. The results showed that the passive stiffness was relatively independent of muscle length, possessing a constant plateau value over a length range from 0.62 to 1.25 Lref. Following a halving of ASM length, passive stiffness decreased substantially (by 71%) but redeveloped over time (∼30 min) at the shorter length to reach 65% of the stiffness value at Lref, provided that the muscle was stimulated to contract at least once over a ∼30-min period. The redevelopment and maintenance of passive stiffness were dependent on the presence of Ca2+ but unaffected by latrunculin B, an inhibitor of actin filament polymerization. The maintenance of passive stiffness was also not affected by blocking myosin cross-bridge cycling using a myosin light chain kinase inhibitor or by blocking the Rho-Rho kinase (RhoK) pathway using a RhoK inhibitor. Our results suggest that the passive stiffness of ASM is labile and capable of redevelopment following length reduction. Redevelopment and maintenance of passive stiffness following muscle shortening could contribute to airway hyperresponsiveness by attenuating the airway wall strain induced by tidal breathing and DI.
Design of Carborane Molecular Architectures via Electronic Structure Computations
Authors: Oliva Josep M. , Serrano-Andrés Luis , Klein Douglas J. , Schleyer Paul von Ragué , Michl Josef
Published: December 2009

Quantum‐mechanical electronic structure computations were employed to explore initial steps towards a comprehensive design of polycarborane architectures through assembly of molecular units. Aspects considered were (i) the striking modification of geometrical parameters through substitution, (ii) endohedral carboranes and proposed ejection mechanisms for energy/ion/atom/energy storage/transport, (iii) the excited state character in single and dimeric molecular units, and (iv) higher architectural constructs. A goal of this work is to find optimal architectures where atom/ion/energy/spin transport within carborane superclusters is feasible in order to modernize and improve future photoenergy processes.
Plasma-Induced Damage on the Reliability of Hf-Based High-k/Dual Metal-Gates Complementary Metal Oxide Semiconductor Technology
Authors: Weng Wu-Te , Lee Yao-Jen , Lin Horng-Chih , Huang Tiao-Yuan
Published: December 2009

This study examines the effects of plasma-induced damage (PID) on Hf-based high-k/dual metal-gates transistors processed with advanced complementary metal-oxide-semiconductor (CMOS) technology. In addition to the gate dielectric degradations, this study demonstrates that thinning the gate dielectric reduces the impact of damage on transistor reliability including the positive bias temperature instability (PBTI) of n-channel metal-oxide-semiconductor field-effect transistors (NMOSFETs) and the negative bias temperature instability (NBTI) of p-channel MOSFETs. This study shows that high-k/metal-gate transistors are more robust against PID than conventionalSiO2/poly-gate transistors with similar physical thickness. Finally this study proposes a model that successfully explains the observed experimental trends in the presence of PID for high-k/metal-gate CMOS technology.
Surgical Approach to a Large Left Adrenocortical Mass with Associated Tumour Thrombosis of the Left Renal Vein: Preservation of the Ipsilateral Kidney
Authors: Pérez Utrilla Manuel , Nuñez Mora Carlos , Rojo Sebastián Alejandro , Cabrera Castillo Pedro M. , García Mediero José M.
Published: December 2009

A sixty-years-old male with diagnosis of a left adrenal mass ( mm) with associated tumour thrombosis of the left renal vein with no clear signs of thrombosis of the inferior vena cava was admitted for elective surgery Finally an adrenalectomy and excision of tumour thrombus preserving the ipsilateral kidney was made. Despite of the complex vascular management, this kind of approaches allow to preserve normal renal function in patients with future nephrotoxic treatment like cisplatin.
Current‐Mode Third‐Order Quadrature Oscillator Using CDTAs
Authors: Horng Jiun-Wei
Published: December 2009

This paper describes a current‐mode third‐order quadrature oscillator based on current differencing transconductance amplifiers (CDTAs). Outputs of two current‐mode sinusoids with 90° phase difference are available in the quadrature oscillator circuit. The oscillation condition and oscillation frequency are orthogonal controllable. The proposed circuit employs only grounded capacitors and is ideal for integration. Simulation results are included to confirm the theoretical analysis.
Improved Method for In Vitro Secondary Amastigogenesis ofTrypanosoma cruzi: Morphometrical and Molecular Analysis of Intermediate Developmental Forms
Authors: Hernández-Osorio L. A. , Márquez-Dueñas C. , Florencio-Martínez L. E. , Ballesteros-Rodea G. , Martínez-Calvillo S. , Manning-Cela R. G.
Published: December 2009

Trypanosoma cruziundergoes a biphasic life cycle that consists of four alternate developmental stages. In vitro conditions to obtain a synchronic transformation and efficient rates of pure intermediate forms (IFs), which are indispensable for further biochemical, biological, and molecular studies, have not been reported. In the present study, we established an improved method to obtain IFs from secondary amastigogenesis. During the transformation kinetics, we observed progressive decreases in the size of the parasite body, undulating membrane and flagellum that were concomitant with nucleus remodeling and kinetoplast displacement. In addition, a gradual reduction in parasite movement and acquisition of the amastigote-specific Ssp4 antigen were observed. Therefore, our results showed that the in vitro conditions used obtained large quantities of highly synchronous and pure IFs that were clearly distinguished by morphometrical and molecular analyses. Obtaining these IFs represents the first step towards an understanding of the molecular mechanisms involved in amastigogenesis.
Genetic Association Analysis of Functional Polymorphisms in Neuronal Nitric Oxide Synthase 1 Gene (NOS1) and Mood Disorders and Fluvoxamine Response in Major Depressive Disorder in the Japanese Population
Authors: Okumura Takenori , Kishi Taro , Okochi Tomo , Ikeda Masashi , Kitajima Tsuyoshi , Yamanouchi Yoshio , Kinoshita Yoko , Kawashima Kunihiro , Tsunoka Tomoko , Inada Toshiya , Ozaki Norio , Iwata Nakao
Published: December 2009

Background/Aim: Nitric oxide has been reported to play a role in neural transmitter release and N-methyl-D-aspartate receptor activation, as well as to be related to oxidative stress. Abnormalities in both of these mechanisms are thought to be involved in the pathophysiology of mood disorders including major depressive disorder (MDD) and bipolar disorder (BP). In addition, several lines of evidence support an association between abnormalities in neuronal nitric oxide synthases (nNOS) and mood disorders. Therefore, we studied the association of nNOS gene (NOS1) and mood disorders and the efficacy of fluvoxamine treatment in Japanese MDD patients. Materials and Methods: Using a single nucleotide polymorphism (SNP; rs41279104, also called ex1c), we conducted a genetic association analysis of case-control samples (325 MDD patients, 154 BP patients and 807 controls) in the Japanese population. In addition, we performed an association analysis between NOS1 and the efficacy of fluvoxamine treatment in 117 MDD patients. We defined a clinical response as a decrease of more than 50% in baseline SIGH-D (Structured Interview Guide for the Hamilton Rating Scale for Depression) score within 8 weeks, and clinical remission as an SIGH-D score of less than 7 at 8 weeks. Results: We did not detect a significant association between NOS1 and MDD, BP or the fluvoxamine therapeutic response in MDD in allele/genotype-wise analysis. Conclusions: We did not detect an association between only one marker (rs41279104) in NOS1 and Japanese mood disorder patients and fluvoxamine response, but sample sizes were probably too small to allow a meaningful test. Moreover, because we did not perform an association analysis based on linkage disequilibrium and a mutation scan of NOS1, a replication of the study using a larger sample and based on linkage disequilibrium may be required for conclusive results.
ECG Criteria to Identify Epicardial Ventricular Tachycardia in Nonischemic Cardiomyopathy
Authors: Vallès Ermengol , Bazan Victor , Marchlinski Francis E.
Published: December 2009

Background—

ECG criteria identifying epicardial (EPI) origin for ventricular tachycardia (VT) in nonischemic cardiomyopathy have not been determined. Endocardial (ENDO) and EPI basal left ventricle fibrosis characterizes the VT substrate.

Methods and Results—

We assessed the QRS from 102 basal-superior/lateral EPI and 67 comparable ENDO pace maps in 14 patients with nonischemic cardiomyopathy. Pace mapping focused on low bipolar voltage areas. Published morphology criteria: q wave in lead I (QWLI) and no q waves in inferior leads and interval criteria: pseudo-delta wave ≥34 ms, intrinsicoid deflection time ≥85 ms, shortest RS complex ≥121 ms, and maximum deflection index ≥0.55 were assessed for ability to identify EPI origin. Sixteen EPI and 8 ENDO of the 34 mapped VTs (71%) in the study population and 14 EPI and 7 ENDO VTs from an 11-patient validation cohort were localized to basal-superior/lateral left ventricle and corroborated pacing data. A QWL1 was seen in EPI but not ENDO pace maps (91% versus 4%;
P
<0.001), identified 14 of 16 EPI VTs (sensitivity, 88%), and was seen in 1 of 8 ENDO VTs (specificity, 88%). None of the remaining criteria achieved similar sensitivity without specificity <50%. We identified 4 criteria (q waves in inferior leads, pseudo-delta wave ≥75 ms, maximum deflection index ≥0.59, and QWL1) having ≥95% specificity and ≥20% sensitivity in identifying EPI/ENDO origin for pace maps. This 4-step algorithm identified the origin in 109 of 115 pace maps (95%), 21 of 24 VTs (88%) in the study population, and 19 of 21 VTs (90%) in validation cohort.

Conclusions—

Morphological ECG features that describe the initial QRS vector can help identify basal-superior/lateral EPI VTs in nonischemic cardiomyopathy.