bluuebunny/crossref_metadata_2025 huggingface dataset:
Base-line selection of black spruce by large-scale aerial photography
Authors: Parker William H. , Niejenhuis Annette van , Damme Laird Van
Published: January 2010

Following selection of black spruce (Piceamariana (Mill.) B.S.P.) for growing space efficiency using a base line of basal area increment vs. crown length × crown radius, the corresponding crown data were determined by large-scale (1:1250) aerial photography for 174 ground-measured trees to determine whether aerial photography would provide a more accurate and cost-effective alternative for plus-tree selection. Values obtained for ground- and photo-measured tree heights and crown lengths corresponded closely, but values of crown radii measured from the ground by a right-angle prism did not correspond in the same manner to values derived from crown horizontal projection areas on the photos. Nonetheless, the different base lines of basal area increments vs. various ground- and photo-measured crown parameters generally identified the same trees as having the greatest growing space efficiency. The inclusion of crown length together with crown radius did not improve the goodness of fit for regressions of basal area increments vs. crown parameters. Apparently, the two horizontal dimensions are adequate to describe growing space for black spruce, perhaps because its crown form is relatively constant. Our results indicate that large-scale aerial photography is well suited to plus-tree selections of black spruce if ground mesurements are not also required to establish base lines; the extra cost of the photos is offset by the greater speed in measuring tree heights or crown horizontal projection areas. Thus, while the technique is sufficiently accurate, it is not cost effective for establishing growing space efficiency base lines where the basal area increment is determined directly from increment cores.
15N CHEMICAL SHIFT CALCULATIONS AND NATURAL BONDING ORBITAL ANALYSES OF (BENZAMIDE)n = 1 - 6 CLUSTERS
Authors: ESRAFILI MEHDI D. , BEHESHTIAN JAVAD , HADIPOUR NASSER L.
Published: January 2010

A DFT/B3LYP study was performed to calculate 15 N chemical shielding tensors in ( benzamide )n = 1-6 clusters. We found that N–H⋯O hydrogen bonds around the benzamide molecule in crystalline lattice have significant influences on the 15 N chemical shielding tensors. For ( benzamide )n clusters, the n-dependent trend in 15 N chemical shielding appears to be correlated with cooperative effects in R [N–H⋯O ] bond distance. Natural bonding orbital (NBO) analysis was used to rationalize the chemical shielding results in terms of [Formula: see text] charge delocalization effects in the benzamide clusters. This suggests that 15 N chemical shielding measurements can provide a useful probe of electron delocalization phenomena in both gaseous and condensed media.
COMPUTER SIMULATIONS OF THE INTERACTION OF CIGUATOXIN 3C, BREVENAL AND ent-BREVENAL LADDER POLYETHERS WITH A HOMOLOGY MODEL OF THE VOLTAGE-GATED Kv1.5 POTASSIUM CHANNEL
Authors: PIETRA FRANCESCO
Published: January 2010

The interaction of ladder polyethers of marine origin, like ciguatoxin 3C and brevenal, as well as hypothetic ent-brevenal, with the human voltage-gated Kv1.5 potassium ion channel is investigated in this work using homology modeling, automated docking, and energy scoring from molecular dynamics (MD) simulations. A 3D homology model of the pore region of the Kv1.5 channel, previously developed from the 2.9 Å resolution crystal structure of the mammalian Kv1.2 channel — which has a very similar pore sequence — is used here. While ciguatoxin 3C did not enter the pore, both brevenal and ent-brevenal were found into the pore, the latter one with the best score. Binding is attended by notable strain in the ligands, and the corresponding energy increase was evaluated for ent-brevenal by self consistent field (SCF) and density functional theory (DFT) procedures. Egress of ent-brevenal from the pore, as a microscopical reversal of the ingress, was investigated by a smart form of biased MD simulations. While this study indicates ample room and attractive interactions for both brevenal and its enantiomer into the pore, whether these molecules will be found to inhibit voltage-gated potassium ion currents depends upon the barriers in the real system to access the pore, with their thermodynamic and kinetic requirements.
THEORETICAL STUDY OF PRODUCT POLARIZATION FOR THE REACTION Ba + CH3I → BaI + CH3
Authors: QI YAN , DUAN ZHI-XIN
Published: January 2010

Using quasi-classical trajectory (QCT) method, the vector correlation between products and reagents for the exothermic reaction Ba + CH3I → BaI + CH3 has been studied on the extended Lond–Eyring–Polanyi–Sato (LEPS) potential energy surface (PES) at three collision energies of 1.6, 3.3, and 5.6 kcal/mol. The P(θr) distribution of the products describing the k-j' correlation and the dihedral angle distribution P(ϕr) describing k-k'-j' correlation are calculated in center-of-mass (CM) frame. Four polarization dependent generalized differential cross-sections (2π/σ)(dσ00/dωt), (2π/σ)(dσ20/dωt), (2π/σ)(dσ22+/dωt), and (2π/σ)(dσ21-/dωt) have also been presented in the CM frame as well. The results indicate that the product rotational angular momentum j' is not only aligned, but also oriented along the direction perpendicular to the scattering plane. In addition, the alignment and the orientation of the BaI product rotational angular momentum depend very sensitively on the collision energy.
A TRAJECTORY-FOLLOWING METHOD FOR SOLVING THE STEADY STATE OF CHEMICAL REACTION RATE EQUATIONS
Authors: LUO XIN-LONG
Published: January 2010

This article gives a trajectory-following method for the steady state of chemical reaction rate equations. In order to avoid wasting unnecessary computing time during the steady-state phase and get roughly accurate solutions during the transient-state phase, this method is realized via adopting the semi-implicit Euler formula as the stepping direction and adaptively adjusting the time-step size by an analogous trust-region technique. Under some standard assumptions, its global convergence analysis and local superlinear convergence analysis are also given. Finally, some numerical experiments of this method, in comparison with the traditional optimization methods and ordinary differential equation methods, are reported. The numerical results show that this trajectory-following method is a promising solution for this class of problems.
IL-7 is expressed and secreted by human skeletal muscle cells
Authors: Haugen Fred , Norheim Frode , Lian Henrik , Wensaas Andreas J. , Dueland Svein , Berg Ole , Funderud Ane , Skålhegg Bjørn S. , Raastad Truls , Drevon Christian A.
Published: January 2010

In addition to generating movement, skeletal muscle may have a function as a secretory organ. The aim of the present study was to identify novel proteins with signaling capabilities secreted from skeletal muscle cells. IL-7 was detected in media conditioned by primary cultures of human myotubes differentiated from satellite cells, and concentrations increased with incubation time. By immunoblotting and real-time RT-PCR IL-7 expression was confirmed at both protein and mRNA levels. Furthermore, with immunofluorescence and specific antisera, multinucleated myotubes were found to coexpress IL-7 and myosin heavy chain. During differentiation of human myotubes from satellite cells, IL-7 expression increased at mRNA and protein levels. In contrast, mRNA expression of the IL-7 receptor was 80% lower in myotubes compared with satellite cells. Incubations with recombinant IL-7 under differentiation conditions caused ∼35% reduction in mRNA for the terminal myogenic markers myosin heavy chain 2 (MYH2) and myogenin (MYOG), suggesting that IL-7 may act on satellite cells to inhibit development of the muscle fiber phenotype. Alternative routes of cell development were investigated, and IL-7 increased migration of satellite cells by 40% after 48 h in a Transwell system, whereas cell proliferation remained unchanged. In vivo, real-time RT-PCR analysis of musculus vastus lateralis ( n = 10) and musculus trapezius ( n = 7) biopsies taken from male individuals undergoing a strength training program demonstrated that after 11 wk mean IL-7 mRNA increased by threefold ( P = 0.01) and fourfold ( P = 0.04), respectively. In conclusion, we have demonstrated that IL-7 is a novel myokine regulated both in vitro and in vivo, and it may play a role in the regulation of muscle cell development.
A preferential p110α/γ PI3K inhibitor attenuates experimental inflammation by suppressing the production of proinflammatory mediators in a NF-κB-dependent manner
Authors: Dagia Nilesh M. , Agarwal Gautam , Kamath Divya V. , Chetrapal-Kunwar Anshu , Gupte Ravindra D. , Jadhav Mahesh G. , Dadarkar Shruta S. , Trivedi Jacqueline , Kulkarni-Almeida Asha A. , Kharas Firuza , Fonseca Lyle C. , Kumar Sanjay , Bhonde Mandar R.
Published: January 2010

A promising therapeutic approach to diminish pathological inflammation is to inhibit the increased production and/or biological activity of proinflammatory cytokines (e.g., TNF-α, IL-6). The production of proinflammatory cytokines is controlled at the gene level by the activity of transcription factors, such as NF-κB. Phosphatidylinositol 3-kinase (PI3K), a lipid kinase, is known to induce the activation of NF-κB. Given this, we hypothesized that inhibitors of PI3K activation would demonstrate anti-inflammatory potential. Accordingly, we studied the effects of a preferential p110α/γ PI3K inhibitor (compound 8C; PIK-75) in inflammation-based assays. Mechanism-based assays utilizing human cells revealed that PIK-75-mediated inhibition of PI3K activation is associated with dramatic suppression of downstream signaling events, including AKT phosphorylation, IKK activation, and NF-κB transcription. Cell-based assays revealed that PIK-75 potently and dose dependently inhibits in vitro and in vivo production of TNF-α and IL-6, diminishes the induced expression of human endothelial cell adhesion molecules (E-selectin, ICAM-1, and VCAM-1), and blocks human monocyte-endothelial cell adhesion. Most importantly, PIK-75, when administered orally in a therapeutic regimen, significantly suppresses the macroscopic and histological abnormalities associated with dextran sulfate sodium-induced murine colitis. The efficacy of PIK-75 in attenuating experimental inflammation is mediated, at least in part, due to the downregulation of pertinent inflammatory mediators in the colon. Collectively, these results provide first evidence that PIK-75 possesses anti-inflammatory potential. Given that PIK-75 is known to exhibit anti-cancer activity, the findings from this study thus reinforce the cross-therapeutic functionality of potential drugs.
Autophagy in health and disease. 1. Regulation and significance of autophagy: an overview
Authors: Mehrpour Maryam , Esclatine Audrey , Beau Isabelle , Codogno Patrice
Published: January 2010

Macroautophagy is a vacuolar degradation pathway that terminates in the lysosomal compartment after formation of a cytoplasmic vacuole or autophagosome that engulfs macromolecules and organelles. The identification of ATG (autophagy-related) genes that are involved in the formation of autophagosomes has greatly increased our knowledge of the molecular basis of macroautophagy, and its roles in cell function, which extend far beyond degradation and quality control of the cytoplasm. Macroautophagy, which plays a major role in tissue homeostasis, is now recognized as contributing to innate and adaptive immune responses. Recently, several mediators of apoptosis have been shown to control macroautophagy. Deciphering the cross talk between macroautophagy and apoptosis probably should help increase understanding of the role of macroautophagy in human disease and is likely to be of therapeutic importance.
Autophagy in health and disease. 3. Involvement of autophagy in muscle atrophy
Authors: Sandri Marco
Published: January 2010

Loss of muscle mass aggravates a variety of diseases, and understanding the molecular mechanisms that control muscle wasting is critical for developing new therapeutic approaches. Weakness is caused by loss of muscle proteins, and recent studies have underlined a major role for the autophagy-lysosome system in regulating muscle mass. Some key components of the autophagy machinery are transcriptionally upregulated during muscle wasting, and their induction precedes muscle loss. However, it is unclear whether autophagy is detrimental, causing atrophy, or beneficial, promoting survival during catabolic conditions. This review discusses recent findings on signaling pathways regulating autophagy.
Ameliorating effects and mechanisms of electroacupuncture on gastric dysrhythmia, delayed emptying, and impaired accommodation in diabetic rats
Authors: Yin Jieyun , Chen Jie , Chen Jiande D. Z.
Published: January 2010

The aim of this study was to investigate the effects and mechanisms of electroacupuncture (EA) on gastric accommodation, gastric dysrhythmia, and gastric emptying (GE) in streptozotocin (STZ)-induced diabetic rats. Five experiments were performed in five groups of STZ-induced diabetic rats to study the effects of EA at ST-36 (Zusanli) on gastric slow-wave dysrhythmia, delayed GE and intestinal transit, impaired gastric accommodation, and the mechanisms of EA involving the autonomic and opioidergic pathways. We found the following: 1) EA improved gastric dysrhythmia in the diabetic rats. The normal percentage of slow waves was 55.4 ± 2.9% at baseline and significantly increased to 69.2 ± 2.2% with EA ( P = 0.01); this effect was blocked by naloxone. 2) EA resulted in a 21.4% increase in GE and 18.2% increase in small intestinal transit in the diabetic rats. 3) EA restored diabetes-induced impairment in gastric accommodation. Gastric accommodation was 0.98 ± 0.13 ml with sham EA and significantly increased to 1.21 ± 0.15 ml with EA ( P = 0.01), and this effect was blocked by naloxone. 4) EA increased vagal activity assessed by the spectral analysis of the heart rate variability. We concluded that EA at ST-36 improves gastric dysrhythmia, delayed GE and intestinal transit, and impaired accommodation in STZ-induced diabetic rats, and the improvement seems to be mainly mediated via the vagal pathway. EA may have a promising therapeutic potential for diabetic gastroparesis.
Chronic maternal hypertension characterized by renal dysfunction is associated with reduced placental blood flow during late gestation in rabbits
Authors: McArdle Adelle M. , Roberts Claire T. , Maduwegedera Devaki , Flower Rebecca L. , Denton Kate M.
Published: January 2010

Maternal hypertension associated with renal disease is a common pregnancy complication. Previously, we have shown in a rabbit model of mild hypertension that offspring from hypertensive mothers have increased blood pressure as adults. In human pregnancy, hypertension has been associated with decreased utero-placental blood flow. The aim of this study was to determine placental blood flow (PBF) in mild (2-kidney-1-wrapped; 2K-1W) and moderate (2-kidney-2-wrapped; 2K-2W) rabbit models of maternal hypertension. We hypothesized that PBF would be inversely related to the severity of the hypertension. PBF and renal blood flow (RBF) were measured using microspheres on day 28 of a 32-day gestation, in normotensive (sham), 2K-1W, and 2K-2W hypertensive groups. Mean arterial pressure (MAP, ∼7 mmHg, P < 0.05) was increased, and RBF (∼35%, P < 0.05) was reduced in the 2K-1W and 2K-2W (MAP ∼20 mmHg, P < 0.01; RBF ∼53%, P < 0.05) groups compared with the sham group. In the 2K-1W group, PBF fell by ∼12% ( P = 0.08) and fetal-to-placental weight ratio increased by ∼12% ( P < 0.01) compared with the sham group, reflecting an increase in the functional capacity of the placenta to deliver nutrients to the fetus. In the 2K-2W group, PBF decreased ∼51% ( P < 0.05) compared with the sham group, without changes in placental efficiency. Thus, in late gestation, placental blood flow was significantly reduced in the moderate hypertension group, without accompanying changes in fetal or placental weight or placental efficiency. In contrast, mild hypertension resulted in an increase in placental efficiency, without significant changes in placental blood flow. These findings suggest that mild and moderate hypertension may alter placental delivery of nutrients via differing mechanisms dependent upon the severity of the hypertension.
Low blood flow at onset of moderate-intensity exercise does not limit muscle oxygen uptake
Authors: Nyberg Michael , Mortensen Stefan P. , Saltin Bengt , Hellsten Ylva , Bangsbo Jens
Published: January 2010

The effect of low blood flow at onset of moderate-intensity exercise on the rate of rise in muscle oxygen uptake was examined. Seven male subjects performed a 3.5-min one-legged knee-extensor exercise bout (24 ± 1 W, mean ± SD) without (Con) and with (double blockade; DB) arterial infusion of inhibitors of nitric oxide synthase ( NG-monomethyl-l-arginine) and cyclooxygenase (indomethacin) to inhibit the synthesis of nitric oxide and prostanoids, respectively. Leg blood flow and leg oxygen delivery throughout exercise was 25–50% lower ( P < 0.05) in DB compared with Con. Leg oxygen extraction (arteriovenous O2 difference) was higher ( P < 0.05) in DB than in Con (5 s: 127 ± 3 vs. 56 ± 4 ml/l), and leg oxygen uptake was not different between Con and DB during exercise. The difference between leg oxygen delivery and leg oxygen uptake was smaller ( P < 0.05) during exercise in DB than in Con (5 s: 59 ± 12 vs. 262 ± 39 ml/min). The present data demonstrate that muscle blood flow and oxygen delivery can be markedly reduced without affecting muscle oxygen uptake in the initial phase of moderate-intensity exercise, suggesting that blood flow does not limit muscle oxygen uptake at the onset of exercise. Additionally, prostanoids and/or nitric oxide appear to play important roles in elevating skeletal muscle blood flow in the initial phase of exercise.
Cerebrovascular reactivity and dynamic autoregulation in tetraplegia
Authors: Wilson Luke C. , Cotter James D. , Fan Jui-Lin , Lucas Rebekah A. I. , Thomas Kate N. , Ainslie Philip N.
Published: January 2010

Humans with spinal cord injury have impaired cardiovascular function proportional to the level and completeness of the lesion. The effect on cerebrovascular function is unclear, especially for high-level lesions. The purpose of this study was to evaluate the integrity of dynamic cerebral autoregulation (CA) and the cerebrovascular reactivity in chronic tetraplegia (Tetra). After baseline, steady-state hypercapnia (5% CO2) and hypocapnia (controlled hyperventilation) were used to assess cerebrovascular reactivity in 6 men with Tetra (C5–C7 lesion) and 14 men without [able-bodied (AB)]. Middle cerebral artery blood flow velocity (MCAv), cerebral oxygenation, arterial blood pressure (BP), heart rate (HR), cardiac output (Q̇; model flow), partial pressure of end-tidal CO2 (PetCO2), and plasma catecholamines were measured. Dynamic CA was assessed by transfer function analysis of spontaneous fluctuations in BP and MCAv. MCAv pulsatility index (MCAv PI) was calculated as (MCAvsystolic − MCAvdiastolic)/MCAvmean and standardized by dividing by mean arterial pressure (MAP). Resting BP, total peripheral resistance, and catecholamines were lower in Tetra ( P < 0.05), and standardized MCAv PI was ∼36% higher in Tetra ( P = 0.003). Resting MCAv, cerebral oxygenation, HR, and PetCO2 were similar between groups ( P > 0.05). Although phase and transfer function gain relationships in dynamic CA were maintained with Tetra ( P > 0.05), coherence in the very low-frequency range (0.02–0.07 Hz) was ∼21% lower in Tetra ( P = 0.006). Full (hypo- and hypercapnic) cerebrovascular reactivity to CO2 was unchanged with Tetra ( P > 0.05). During hypercapnia, standardized MCAv PI reactivity was enhanced by ∼78% in Tetra ( P = 0.016). Despite impaired cardiovascular function, chronic Tetra involves subtle changes in dynamic CA and cerebrovascular reactivity to CO2. Changes are evident in coherence at baseline and MCAv PI during baseline and hypercapnic states in chronic Tetra, which may be indicative of cerebrovascular adaptation.
Blockade of endogenous tissue kallikrein aggravates renal injury by enhancing oxidative stress and inhibiting matrix degradation
Authors: Liu Yuying , Bledsoe Grant , Hagiwara Makato , Yang Zhi-Rong , Shen Bo , Chao Lee , Chao Julie
Published: January 2010

Levels of tissue kallikrein (TK) are significantly lower in the urine of patients with kidney failure, and TK expression is specifically diminished in rat kidney after recovery from ischemia-reperfusion injury. In this study, we investigated the functional consequence of blocking endogenous TK activity in a rat model of chronic kidney disease. Inhibition of endogenous TK levels for 10 days by neutralizing TK antibody injection in DOCA-salt rats caused a significant increase in blood urea nitrogen and urinary protein levels, and a decrease in creatinine clearance. Kidney sections from anti-TK antibody-treated rats displayed a marked rise in tubular dilation and protein cast accumulation as well as glomerular sclerosis and size. TK blockade also increased inflammatory cell infiltration, myofibroblast and collagen accumulation, and collagen fraction volume. Elevated renal inflammation and fibrosis by anti-TK antibody were associated with increased expression of tumor necrosis factor-α, intercellular adhesion molecule-1, tissue inhibitor of metalloproteinase-2 (TIMP-2), and plasminogen activator inhibitor-1 (PAI-1). Moreover, the detrimental effect of TK blockade resulted in reduced nitric oxide (NO) levels as well as increased serum lipid peroxidation, renal NADH oxidase activity, and superoxide formation. In cultured proximal tubular cells, TK inhibited angiotensin II-induced superoxide production and NADH oxidase activity via NO formation. In addition, TK markedly increased matrix metalloproteinase-2 activity with a parallel reduction of TIMP-2 and PAI-1 synthesis. These findings indicate that endogenous TK has the propensity to preserve kidney structure and function in rats with chronic renal disease by inhibiting oxidative stress and activating matrix degradation pathways.
Current ideas on central chemoreception by neurons and glial cells in the retrotrapezoid nucleus
Authors: Mulkey Daniel K. , Wenker Ian C. , Kréneisz Orsolya
Published: January 2010

Central chemoreception is the mechanism by which CO2/pH-sensitive neurons (i.e., chemoreceptors) regulate breathing in response to changes in tissue pH. A region of the brain stem called the retrotrapezoid nucleus (RTN) is thought to be an important site of chemoreception ( 23 ), and recent evidence suggests that RTN chemoreception involves two interrelated mechanisms: H+-mediated activation of pH-sensitive neurons ( 38 ) and purinergic signaling ( 19 ), possibly from pH-sensitive glial cells. A third, potentially important, aspect of RTN chemoreception is the regulation of blood flow, which is an important determinate of tissue pH and consequently chemoreceptor activity. It is well established in vivo that changes in cerebral blood flow can profoundly affect the chemoreflex ( 2 ); e.g., limiting blood flow by vasoconstriction acidifies tissue pH and increases the ventilatory response to CO2, whereas vasodilation can wash out metabolically produced CO2 from tissue to increase tissue pH and decrease the stimulus at chemoreceptors. In this review, we will summarize the defining characteristics of pH-sensitive neurons and discuss potential contributions of pH-sensitive glial cells as both a source of purinergic drive to pH-sensitive neurons and a modulator of vasculature tone.
Reverse Cochlear Propagation in the Intact Cochlea of the Gerbil: Evidence for Slow Traveling Waves
Authors: Meenderink Sebastiaan W. F. , van der Heijden Marcel
Published: January 2010

The inner ear can produce sounds, but how these otoacoustic emissions back-propagate through the cochlea is currently debated. Two opposing views exist: fast pressure waves in the cochlear fluids and slow traveling waves involving the basilar membrane. Resolving this issue requires measuring the travel times of emissions from their cochlear origin to the ear canal. This is problematic because the exact intracochlear location of emission generation is unknown and because the cochlea is vulnerable to invasive measurements. We employed a multi-tone stimulus optimized to measure reverse travel times. By exploiting the dispersive nature of the cochlea and by combining acoustic measurements in the ear canal with recordings of the cochlear-microphonic potential, we were able to determine the group delay between intracochlear emission-generation and their recording in the ear canal. These delays remained significant after compensating for middle-ear delay. The results contradict the hypothesis that the reverse propagation of emissions is exclusively by direct pressure waves.
Kinematic Strategies in Newly Walking Toddlers Stepping Over Different Support Surfaces
Authors: Dominici Nadia , Ivanenko Yuri P. , Cappellini Germana , Zampagni Maria Luisa , Lacquaniti Francesco
Published: January 2010

In adults, locomotor movements are accommodated to various support surface conditions by means of specific anticipatory locomotor adjustments and changes in the intersegmental coordination. Here we studied the kinematic strategies of toddlers at the onset of independent walking when negotiating various support surface conditions: stepping over an obstacle, walking on an inclined surface, and on a staircase. Generally, toddlers could perform these tasks only when supported by the arm. They exhibited strategies very different from those of the adults. Although adults maintained walking speed roughly constant, toddlers markedly accelerated when walking downhill or downstairs and decelerated when walking uphill or upstairs. Their coordination pattern of thigh–shank–foot elevation angles exhibited greater inter-trial variability than that in adults, but it did not undergo the systematic change as a function of task that was present in adults. Thus the intersegmental covariance plane rotated across tasks in adults, whereas its orientation remained roughly constant in toddlers. In contrast with the adults, the toddlers often tended to place the foot onto the obstacle or across the edges of the stairs. We interpret such foot placements as part of a haptic exploratory repertoire and we argue that the maintenance of a roughly constant planar covariance—irrespective of the surface inclination and height—may be functional to the exploratory behavior. The latter notion is consistent with the hypothesis proposed decades ago by Bernstein that, when humans start to learn a skill, they may restrict the number of degrees of freedom to reduce the size of the search space and simplify the coordination.
Flexibility of Motor Pattern Generation Across Stimulation Conditions by the Neonatal Rat Spinal Cord
Authors: Klein David A. , Patino Angelica , Tresch Matthew C.
Published: January 2010

Previous studies have demonstrated that “locomotor-like” rhythmic patterns can be evoked in the isolated neonatal rat spinal cord by several means, including pharmacological neuromodulation and electrical stimulation of various pathways. Recent studies have used stimulation of afferent pathways to evoke rhythmic patterns, relying on synaptic activation of interneuronal systems rather than global imposition of neuromodulatory state by pharmacological agents. We use the in vitro neonatal rat spinal cord with attached hindlimb to examine the muscle activation patterns evoked by stimulation of these different pathways and evaluate whether stimulation of these pathways all evoke the same patterns. We find that the patterns evoked by bath application of serotonin (5-HT) and N-methyl-d-aspartic acid (NMDA) consisted of alternation between hip flexors and extensors and similar alternation was observed in the patterns evoked by electrical stimulation of the cauda equina (CE) or contralateral fifth lumbar (L5) dorsal nerve root. In contrast, the knee extensor/hip flexor rectus femoris (RF) and knee flexor/hip extensor semitendinosus (ST) were activated differentially across stimulation conditions. In 5-HT/NMDA patterns, RF was active in late flexion and ST in late extension. In CE patterns, these two muscles switched places with RF typically active in late extension and ST active in flexion. In L5 patterns, ST was activated in extension and RF was silent or weakly active during flexion. There were also systematic differences in the consistency of rhythms evoked by each stimulation method: patterns evoked by electrical stimulation of CE or L5 were less consistently modulated with the rhythm when compared with 5-HT/NMDA-evoked patterns. All differences were preserved following deafferentation, demonstrating that they reflect intrinsic properties of spinal systems. These results highlight the intrinsic flexibility of motor pattern generation by spinal motor circuitry which is present from birth and provides important information to many studies examining spinal pattern generating networks.
Effects of Ankle and Hip Muscle Afferent Inputs on Rhythm Generation During Fictive Locomotion
Authors: Frigon Alain , Sirois Jennifer , Gossard Jean-Pierre
Published: January 2010

Hip position and loading of limb extensors are major sensory cues for the initiation and duration of different phases during walking. Although these inputs have pathways projecting to the locomotor rhythm generator, their effects may vary in different parts of the locomotor cycle. In the present study, the plantaris (Pl), sartorius (Sart), rectus femoris (RF), and caudal gluteal (cGlu) nerves were stimulated at group I and/or group II strength during spontaneous fictive locomotion in 16 adult decerebrate cats. These nerves supply muscles that extend the ankle (Pl), flex the hip (Sart, RF), or extend the hip (cGlu). Stimuli were given at six epochs of the locomotor cycle to evaluate when they access the rhythm generator. Group I afferents from Pl nerve always reset the locomotor rhythm; stimulation during extension prolonged cycle period and extension phase duration, while stimulation during flexion terminated flexion and initiated extension. On the other hand, stimulating RF and cGlu nerves only produced significant effects on the rhythm in precise epochs, particularly during mid-flexion and/or mid- to late extension. Stimulating the Sart nerve produced complex effects on the rhythm that were not distributed evenly to all extensor motor pools. The most consistent effect was reduced flexion phase duration with stimulation during flexion, particularly at group II strength, and prolongation of the extension phase but only in late extension. That hip muscle afferents reset the rhythm in only specific epochs of the locomotor cycle suggests that the rhythm generator operates with several subdivisions to determine phase and cycle durations.
Tree-Based Methods for Discovery of Association between Flow Cytometry Data and Clinical Endpoints
Authors: Eliot M. , Azzoni L. , Firnhaber C. , Stevens W. , Glencross D. K. , Sanne I. , Montaner L. J. , Foulkes A. S.
Published: January 2010

We demonstrate the application and comparative interpretations of three tree-based algorithms for the analysis of data arising from flow cytometry: classification and regression trees (CARTs), random forests (RFs), and logic regression (LR). Specifically, we consider the question of what best predicts CD4 T-cell recovery in HIV-1 infected persons starting antiretroviral therapy with CD4 count between 200 and 350 cell/μL. A comparison to a more standard contingency table analysis is provided. While contingency table analysis and RFs provide information on the importance of each potential predictor variable, CART and LR offer additional insight into the combinations of variables that together are predictive of the outcome. In all cases considered, baseline CD3-DR-CD56+CD16+ emerges as an important predictor variable, while the tree-based approaches identify additional variables as potentially informative. Application of tree-based methods to our data suggests that a combination of baseline immune activation states, with emphasis on CD8 T-cell activation, may be a better predictor than any single T-cell/innate cell subset analyzed. Taken together, we show that tree-based methods can be successfully applied to flow cytometry data to better inform and discover associations that may not emerge in the context of a univariate analysis.
Far-Field Reconstruction from Transient Near-Field Measurement Using Cylindrical Modal Development
Authors: Rammal R. , Lalande M. , Martinod E. , Feix N. , Jouvet M. , Andrieu J. , Jecko B.
Published: January 2010

The aim of this work is to get far field radiation patterns for any radiating source from transient acquisition, in a large frequency range. An outdoor transient Ultra-Wideband near-field measurement base will be installed, a single time pulse radiated by the source will cover the desired spectrum, and the accurate determination of far field radiations will be accomplished by means of cylindrical waves' modal development. This method uses simplified test equipments, easy to be installed, and it reduces measurement costs.
VHL Frameshift Mutation as Target of Nonsense‐Mediated mRNA Decay in Drosophila melanogaster and Human HEK293 Cell Line
Authors: Micale Lucia , Muscarella Lucia Anna , Marzulli Marco , Augello Bartolomeo , Tritto Patrizia , D′Agruma Leonardo , Zelante Leopoldo , Palumbo Gioacchino , Merla Giuseppe
Published: January 2010

There are many well‐studied examples of human phenotypes resulting from nonsense or frameshift mutations that are modulated by Nonsense‐Mediated mRNA Decay (NMD), a process that typically degrades transcripts containing premature termination codons (PTCs) in order to prevent translation of unnecessary or aberrant transcripts. Different types of germline mutations in the VHL gene cause the von Hippel‐Lindau disease, a dominantly inherited familial cancer syndrome with a marked phenotypic variability and age‐dependent penetrance. By generating the Drosophila UAS:Upf1D45B line we showed the possible involvement of NMD mechanism in the modulation of the c.172delG frameshift mutation located in the exon 1 of Vhl gene. Further, by Quantitative Real‐time PCR (QPCR) we demonstrated that the corresponding c.163delG human mutation is targeted by NMD in human HEK 293 cells. The UAS:Upf1D45B line represents a useful system to identify novel substrates of NMD pathway in Drosophila melanogaster. Finally, we suggest the possible role of NMD on the regulation of VHL mutations.
Identification of the Leishmania major Proteins LmjF07.0430, LmjF07.0440, and LmjF27.2440 as Components of Fatty Acid Synthase II
Authors: Gurvitz Aner
Published: January 2010

Leishmania major causes leishmaniasis and is grouped within the Trypanosomatidae family, which also includes the etiologic agent for African sleeping sickness, Trypanosoma brucei. Previous studies on T. brucei showed that acyl carrier protein (ACP) of mitochondrial fatty acid synthase type 2 (FASII) plays a crucial role in parasite survival. Additionally, 3‐oxoacyl‐ACP synthase TbKASIII as well as TbHTD2 representing 3‐hydroxyacyl‐ACP dehydratase were also identified; however, 3‐oxoacyl‐ACP reductase TbKAR1 has hitherto evaded positive identification. Here, potential Leishmania FASII components LmjF07.0440 and LmjF07.0430 were revealed as 3‐hydroxyacyl‐ACP dehydratases LmHTD2‐1 and LmHTD2‐2, respectively, whereas LmjF27.2440 was identified as LmKAR1. These Leishmania proteins were ectopically expressed in Saccharomyces cerevisiae htd2 Δ or oar1 Δ respiratory deficient cells lacking the corresponding mitochondrial FASII enzymes Htd2p and Oar1p. Yeast mutants producing mitochondrially targeted versions of the parasite proteins resembled the self‐complemented cells for respiratory growth. This is the first identification of a FASII‐like 3‐oxoacyl‐ACP reductase from a kinetoplastid parasite.
Strong and Weak Convergence of the Modified Proximal Point Algorithms in Hilbert Space
Authors: Chai Xinkuan , Li Bo , Song Yisheng
Published: January 2010

For a monotone operator "Equation missing", we shall show weak convergence of Rockafellar's proximal point algorithm to some zero of "Equation missing" and strong convergence of the perturbed version of Rockafellar's to "Equation missing" under some relaxed conditions, where "Equation missing" is the metric projection from "Equation missing" onto "Equation missing". Moreover, our proof techniques are simpler than some existed results.
The Role of Lipopeptidophosphoglycan in the Immune Response toEntamoeba histolytica
Authors: Wong-Baeza Isabel , Alcántara-Hernández Marcela , Mancilla-Herrera Ismael , Ramírez-Saldívar Itzmel , Arriaga-Pizano Lourdes , Ferat-Osorio Eduardo , López-Macías Constantino , Isibasi Armando
Published: January 2010

The sensing of Pathogen Associated Molecular Patterns (PAMPs) by innate immune receptors, such as Toll-like receptors (TLRs), is the first step in the inflammatory response to pathogens.Entamoeba histolytica, the etiological agent of amebiasis, has a surface molecule with the characteristics of a PAMP. This molecule, which was termed lipopeptidophosphoglycan (LPPG), is recognized through TLR2 and TLR4 and leads to the release of cytokines from human monocytes, macrophages, and dendritic cells; LPPG-activated dendritic cells have increased expression of costimulatory molecules. LPPG activates NKT cells in a CD1d-dependent manner, and this interaction limits amebic liver abscess development. LPPG also induces antibody production, and anti-LPPG antibodies prevent disease development in animal models of amebiasis. Because LPPG is recognized by both the innate and the adaptive immune system (it is a “Pamptigen”), it may be a good candidate to develop a vaccine againstE. histolyticainfection and an effective adjuvant.
A New MAP Kinase Protein Involved in Estradiol-Stimulated Reproduction of the Helminth ParasiteTaenia crassiceps
Authors: Escobedo Galileo , Soldevila Gloria , Ortega-Pierres Guadalupe , Chávez-Ríos Jesús Ramsés , Nava Karen , Fonseca-Liñán Rocío , López-Griego Lorena , Hallal-Calleros Claudia , Ostoa-Saloma Pedro , Morales-Montor Jorge
Published: January 2010

MAP kinases (MAPK) are involved in the regulation of cellular processes such as reproduction and growth. In parasites, the role of MAPK has been scarcely studied. Here, we describe the participation of an ERK-like protein in estrogen-dependent reproduction of the helminth parasiteTaenia crassiceps. Our results show that 17β-estradiol induces a concentration-dependent increase in the bud number of in vitro cultured cysticerci. If parasites are also incubated in presence of an ERK-inhibitor, the stimulatory effect of estrogen is blocked. The expression of ERK-like mRNA and its corresponding protein was detected in the parasite. The ERK-like protein was over-expressed by all treatments. Nevertheless, a strong induction of phosphorylation of this protein was observed only in response to 17β-estradiol. Cross-contamination by host cells was discarded by flow cytometry analysis. Parasite cells expressing the ERK-like protein were exclusively located at the subtegument tissue by confocal microscopy. Finally, the ERK-like protein was separated by bidimensional electrophoresis and then sequenced, showing the conserved TEY activation motif, typical of all known ERK 1/2 proteins. Our results show that an ERK-like protein is involved in the molecular signalling during the interaction between the host andT. crassiceps, and may be considered as target for anti-helminth drugs design.
Carotid Intima-Media Thickness in Asymptomatic Patients With Arterial Hypertension Without Clinical Cardiovascular Disease: Relation With Left Ventricular Geometry and Mass and Coexisting Risk Factors
Authors: Di Bello Vitantonio , Carerj Scipione , Perticone Francesco , Benedetto Frank , Palombo Carlo , Talini Enrica , Giannini Danilo , La Carrubba Salvatore , Antonini-Canterin Francesco , Di Salvo Giovanni , Bellieni Giancarlo , Pezzano Antonio , Romano Maria Francesca , Balbarini Alberto
Published: January 2010

We analyzed in NYHA I hypertensives the interactions between Carotid Intima-Media Thickness (IMT), Hypertension and Cardiovascular (CV) risk factors and relationships between IMT, CV risk factors and left ventricular (LV) geometric remodelling. 198 asymptomatic, never treated, essential hypertensives (age: 58.2 ± 13) and 67 (age-gender matched) healthy subjects, were studied. Complete clinical examination, 2D Doppler echocardiography and vascular echography were performed in all study subjects. Major values of IMT are present in concentric LVH. Distribution of IMT among risk factors groups shows an higher IMT respect to increasing number of risk factors (P < 0.001). Significant correlation are present between pulse pressure and IMT (P < 0.006; r = 0.19) and IMT and LVM (P < 0.0001; r = 0.35). Altered patterns of LV geometry and carotid structural changes occur in many patients with essential hypertension. LVH or carotid remodeling are greater in elderly, in patients with higher systolic BP and with associated CV risk factors.
Renal Cortical Thickness as a Predictor of Renal Function and Blood Pressure Status Post Renal Artery Stenting
Authors: Padigala Kiran K. , Hartle J. Edward , Kirchner H. Lester , Schultz Michael F.
Published: January 2010

Renal artery stenting is a widely performed procedure for atherosclerotic renal artery stenosis. It is very important to identify patients that will benefit from this procedure as this may involve potential risk and complications. Our study is a retrospective analysis aimed at evaluation of mid-pole renal cortical thickness at the time of stenting and correlating with renal function and blood pressure after the procedure. A total of 48 procedures were done on 31 patients evaluated in this study. The change in SBP was greater for the abnormal group compared to the normal group (-1.49 mmHg vs. -0.98 mmHg, P = 0.7813). The change in DBP was greater for the abnormal group compared to the normal group (-0.68 mmHg vs. 0.04 mmHg, P = 0.3809). The change in odds of having a GFR in higher categories was greater for the abnormal group compared to the normal group (OR =1.23 vs. 1.05, P = 0.3085). Our study did not show a significant association of renal cortical thickness and outcomes of BP and GFR following stenting of atherosclerotic renal artery stenosis. However, we did find a greater improvement in BP and GFR in patients with abnormal cortical thickness compared to those with normal cortical thickness.
Experiencing the Restorative Components of Wilderness Environments: Does Congestion Interfere and Does Length of Exposure Matter?
Authors: Cole David N. , Hall Troy E.
Published: January 2010

Wilderness should provide opportunities for stress reduction and restoration of mental fatigue. Visitors, surveyed as they exited wilderness trailheads, were asked for self-assessments of stress reduction and mental rejuvenation and the extent to which they experienced various restorative components of the environment—attributes deemed by attention restorative theory to be conducive to restoration. Day and overnight hikers on both very high use and moderate use trails were studied. Most respondents reported substantial stress reduction and mental rejuvenation and most experienced the environment in ways considered conducive to restoration. At the moderate to high use levels we studied, psychological restoration did not vary significantly with level of congestion, suggesting that concern about restorative experiences is not a valid rationale for limiting use on wilderness trails. Day trips reduced stress and allowed for mental rejuvenation to the same degree that overnight trips did. However, several of the restorative components of environment were experienced to a significantly greater degree as length of trip increased.
“An Inconvenient Truth” Increases Knowledge, Concern, and Willingness to Reduce Greenhouse Gases
Authors: Nolan Jessica M.
Published: January 2010

Since May 24, 2006 millions of people have seen the movie “An Inconvenient Truth.” Several countries have even proposed using the film as an educational tool in school classrooms. However, it is not yet clear that the movie accomplishes its apparent goals of increasing knowledge and concern, and motivating people to reduce their greenhouse gas emissions. Two studies are reported, one with a sample of community moviegoers, and one with a sample of students. Across the two studies, results show that watching “An Inconvenient Truth” does increase knowledge about the causes of global warming, concern for the environment, and willingness to reduce greenhouse gases. However, the results of Study 2 suggest that willingness to take action immediately following movie viewing does not necessarily translate into action 1 month later. Recommendations are made for how the movie could be used to create behavioral change.
‘Where Were You When I Laid the Foundation of the Earth?’ Climate Change and a Theology of Development
Authors: Clifford Paula
Published: January 2010

Stringent criticisms of the environmental movement’s failure to respond adequately to the climate change crisis highlight the importance of an appropriate theological response. This article argues that the security and developmental consequences of climate change call for a theology that is based on God’s power and justice, his relationship with his people through Jesus Christ and, in consequence, people’s relationship with one another. Unjust relationships between rich and poor are central to a theology of development, and it is the healing of those relationships that is key to tackling global warming and other issues that work to the detriment of the world’s poorest people.
An Experiment with a Hybrid Regime in Nepal (1990—2006)
Authors: Parajulee Ramjee
Published: January 2010

The purpose of this article is to examine the political transition in Nepal during a period of 16 years (1990—2006) when it operated under a multiparty parliamentary polity. It argues that if a system carries inherent contradictions despite the inclusion of some democratic provisions, it becomes a hybrid regime and encourages the non-democratic forces to be active. The political transformation in Nepal after the pro-democracy movement of 1990 embraced some democratic provisions but contained several inherent flaws, making it a hybrid regime and failing to produce any substantive transformation. Consequently, two extreme forces — an ultra leftist force known as Nepal Communist Party (Maoist) and an ultra rightist force under the leadership of King Gyanendra — emerged and sought to reverse the political gains made after 1990.
Resilient and Resourceful?
Authors: Thomas Bejoy K. , Muradian Roldan , de Groot Gerard , de Ruijter Arie
Published: January 2010

In the backdrop of the popularization of social capital, it has become fashionable in development circles to highlight the resilience of the poor in the midst of stresses and shocks as well as their resourcefulness. Expressing scepticism, this article argues that social capital is a ‘conditional’ resource for the poor, availability of which is dependent on the presence of a ‘critical mass’ of other resources. The State plays a pivotal role in creating this ‘critical mass’. Household level case studies from a village in Kerala, India, on how the poor cope with vulnerable situations, are used to illustrate this point.