bluuebunny/crossref_metadata_2025 huggingface dataset:
Combining tree height samples produced by airborne laser scanning and stand management records to estimate plot volume inEucalyptusplantations
Authors: Vauhkonen Jari , MehtÄtalo Lauri , Packalén Petteri
Published: August 2011

Regular stand structure and availability of precise silvicultural management data produce a special situation regarding remote sensing based assessments of plantation forests. This study tested the use of stand management records to improve single-tree detection in a Eucalyptus plantation. Combined airborne laser scanning (ALS) and planting distance data were used to detect trees and extract their heights. The extracted heights were used as an input for volume estimation using both existing plot-level functions and new tree-level models. The accuracies were evaluated in a test data set of 191 field reference plots in which the diameters of the Eucalyptus urograndis (E. grandis (Hill) Maiden × E. urophylla S.T. Blake) trees varied from 6 to 41 cm and tree heights varied from 12 to 41 m. The constructed mixed-effects model that predicted stem volume from tree height resulted in a root mean squared error (RMSE) of 68 dm3(15%) in a cross validation of the modeling data. The tree detection produced estimates of stem number with low bias (i.e., average difference between measured and estimated) and an RMSE of 6% of the mean, whereas plot-level mean and dominant heights were estimated with RMSEs of 1.5 m (5%) and 2 m (6%), respectively, using ALS data alone. The difference of about 60 cm observed between the ALS-based and field-measured dominant height was most likely caused by the penetration of the laser pulses through the canopy. A system of plot-level models that employed a small sample of calibration field data gave RMSEs of 1 m (3%) and 2.2 m2/ha (9%) for site index and basal area, respectively. The plot volume was estimated with an RMSE of 44 m3/ha (12%) at best. A similar residual variation was observed in the volume estimates of an area-based method applied to the same data set. The combined results suggest the feasibility of the proposed methodology in a plantation inventory using ALS data with a density of only 1.5 pulses/m2.
Assessment of armillaria root disease infection in stands in south-central British Columbia with varying levels of overstory retention, with and without pushover logging
Authors: Chapman William K. , Schellenberg Bruce , Newsome Teresa A.
Published: August 2011

This trial, conducted near Nakusp, British Columbia, compares pushover logging (combination tree felling and root removal technique using large machines to push trees out of the ground) with handfalling logging (no root removal) for effects on the incidence of armillaria root disease in postharvest regeneration. Pushover logging did not reduce levels of root disease, expressed as percentage tree mortality, over handfalling harvesting on this site. High variability of measured disease levels within some treatments and few replicates lowered the power of the trial. However, in addition to being statistically insignificant, the mean differences between the two main treatments were small and biologically uninteresting, and the response was inconsistent in direction. The trial also included three mature timber retention levels as treatments, and there seemed to be a trend of declining root disease with increased retention of stems. This phenomenon should be further investigated as current literature is not clear on the response of armillaria to partial harvesting. There was a strong suggestion of a difference between susceptibility of natural and planted seedlings to armillaria root disease, with natural regeneration being less susceptible. Thuja plicata Donn ex D. Don was less affected by armillaria root disease than other species in this trial, whether it was planted or naturally regenerated.
DECREASED REFRACTIVE INDEX OF NANOCRYSTALLINE ZIRCONIUM OXIDE THIN FILMS
Authors: ATUCHIN V. V. , ALIEV V. SH. , AYUPOV B. M. , KOROLKOV I. V.
Published: August 2011

Amorphous zirconium oxide (a- ZrO 2) thin films were prepared onto fuzzed quartz substrates by ion beam sputtering deposition (IBSD) method in ( Ar + O 2) gas mixture. Optical parameters of the films were evaluated by laser ellipsometry (λ = 632.8 nm ) and optical transmission measurements. Structural parameters were studied by XRD measurements. Variation of refractive index and film thickness have been defined as a function of time of high-temperature annealing at T = 900° C . Formation of monoclinic zirconium oxide (m- ZrO 2) nanocrystals with diameter of ~60 nm embedded into a- ZrO 2 matrix has been found by XRD analysis after long-time annealing.
A NEW DUALITY APPROACH TO ELASTICITY
Authors: CIARLET PHILIPPE G. , GEYMONAT GIUSEPPE , KRASUCKI FRANÇOISE
Published: August 2011

The displacement-traction problem of three-dimensional linearized elasticity can be posed as three different minimization problems, depending on whether the displacement vector field, or the stress tensor field, or the strain tensor field, is the unknown.

The objective of this paper is to put these three different formulations of the same problem in a new perspective, by means of Legendre–Fenchel duality theory. More specifically, we show that both the displacement and strain formulations can be viewed as Legendre–Fenchel dual problems to the stress formulation. We also show that each corresponding Lagrangian has a saddle-point, thus fully justifying this new duality approach to elasticity.
GROUND STATE PROPERTIES OF EXTREME NEUTRON RICH ISOTOPES OBSERVED: A RELATIVISTIC MEAN FIELD APPROACH
Authors: MALI PROVASH
Published: August 2011

The ground state properties namely the binding energy, the root mean square (rms) radius (neutron, proton and charge) and the deformation parameter of 45 newly identified neutron-rich isotopes in the A~71–152 mass region have been predicted in the relativistic mean filed (RMF) framework along with the Bardeen–Cooper–Schrieffer (BCS) type of pairing. Validity of the RMF results with the NL3 effective force are tested for odd-A Zn and Rh isotopic chains without taking the time reversal symmetry breaking effects into consideration. The RMF prediction on the binding energies are in good agreement with the empirical/finite-range droplet model calculation. The shell effects on the rms radii of odd-A Zn and Rh isotopes are nicely reproduced. The possibility of shape-coexistence in the newly identified nuclei is discussed.
Differential impact of mitochondrial positioning on mitochondrial Ca2+ uptake and Ca2+ spark suppression in skeletal muscle
Authors: Rossi Ann E. , Boncompagni Simona , Wei Lan , Protasi Feliciano , Dirksen Robert T.
Published: August 2011

Muscle contraction requires ATP and Ca2+ and, thus, is under direct control of mitochondria and the sarcoplasmic reticulum. During postnatal skeletal muscle maturation, the mitochondrial network exhibits a shift from a longitudinal (“longitudinal mitochondria”) to a mostly transversal orientation as a result of a progressive increase in mitochondrial association with Ca2+ release units (CRUs) or triads (“triadic mitochondria”). To determine the physiological implications of this shift in mitochondrial disposition, we used confocal microscopy to monitor activity-dependent changes in myoplasmic (fluo 4) and mitochondrial (rhod 2) Ca2+ in single flexor digitorum brevis (FDB) fibers from 1- to 4-mo-old mice. A robust and sustained Ca2+ accumulation in triadic mitochondria was triggered by repetitive tetanic stimulation (500 ms, 100 Hz, every 2.5 s) in FDB fibers from 4-mo-old mice. Specifically, mitochondrial rhod 2 fluorescence increased 272 ± 39% after a single tetanus and 412 ± 45% after five tetani and decayed slowly over 10 min following the final tetanus. Similar results were observed in fibers expressing mitochondrial pericam, a mitochondrial-targeted ratiometric Ca2+ indicator. Interestingly, sustained mitochondrial Ca2+ uptake following repetitive tetanic stimulation was similar for triadic and longitudinal mitochondria in FDB fibers from 1-mo-old mice, and both mitochondrial populations were found by electron microscopy to be continuous and structurally tethered to the sarcoplasmic reticulum. Conversely, the frequency of osmotic shock-induced Ca2+ sparks per CRU density decreased threefold (from 3.6 ± 0.2 to 1.2 ± 0.1 events·CRU−1·min−1·100 μm−2) during postnatal development in direct linear correspondence ( r2 = 0.95) to an increase in mitochondrion-CRU pairing. Together, these results indicate that mitochondrion-CRU association promotes Ca2+ spark suppression but does not significantly impact mitochondrial Ca2+ uptake.
Role of RhoA and its effectors ROCK and mDia1 in the modulation of deformation-induced FAK, ERK, p38, and MLC motogenic signals in human Caco-2 intestinal epithelial cells
Authors: Chaturvedi Lakshmi S. , Marsh Harold M. , Basson Marc D.
Published: August 2011

Repetitive deformation enhances intestinal epithelial migration across tissue fibronectin. We evaluated the contribution of RhoA and its effectors Rho-associated kinase (ROK/ROCK) and mammalian diaphanous formins (mDia1) to deformation-induced intestinal epithelial motility across fibronectin and the responsible focal adhesion kinase (FAK), extracellular signal-regulated kinase (ERK), p38, and myosin light chain (MLC) signaling. We reduced RhoA, ROCK1, ROCK2, and mDia1 by smart-pool double-stranded short-interfering RNAs (siRNA) and pharmacologically inhibited RhoA, ROCK, and FAK in human Caco-2 intestinal epithelial monolayers on fibronectin-coated membranes subjected to 10% repetitive deformation at 10 cycles/min. Migration was measured by wound closure. Stimulation of migration by deformation was prevented by exoenzyme C3, Y27632, or selective RhoA, ROCK1, and ROCK2 or mDia1 siRNAs. RhoA, ROCK inhibition, or RhoA, ROCK1, ROCK2, mDia1, and FAK reduction by siRNA blocked deformation-induced nuclear ERK phosphorylation without preventing ERK phosphorylation in the cytoplasmic protein fraction. Furthermore, RhoA, ROCK inhibition or RhoA, ROCK1, ROCK2, and mDia1 reduction by siRNA also blocked strain-induced FAK-Tyr925, p38, and MLC phosphorylation. These results suggest that RhoA, ROCK, mDia1, FAK, ERK, p38, and MLC all mediate the stimulation of intestinal epithelial migration by repetitive deformation. This pathway may be an important target for interventions to promote mechanotransduced mucosal healing during inflammation.
Augmented central nitric oxide production inhibits vasopressin release during hemorrhage in acute alcohol-intoxicated rodents
Authors: Whitaker Annie M. , Sulzer Jesse K. , Molina Patricia E.
Published: August 2011

Acute alcohol intoxication (AAI) attenuates the AVP response to hemorrhage, contributing to impaired hemodynamic counter-regulation. This can be restored by central cholinergic stimulation, implicating disrupted signaling regulating AVP release. AVP is released in response to hemorrhage and hyperosmolality. Studies have demonstrated nitric oxide (NO) to play an inhibitory role on AVP release. AAI has been shown to increase NO content in the paraventricular nucleus. We hypothesized that the attenuated AVP response to hemorrhage during AAI is the result of increased central NO inhibition. In addition, we predicted that the increased NO tone during AAI would impair the AVP response to hyperosmolality. Conscious male Sprague-Dawley rats (300–325 g) received a 15-h intragastric infusion of alcohol (2.5 g/kg + 300 mg·kg−1·h−1) or dextrose prior to a 60-min fixed-pressure hemorrhage (∼40 mmHg) or 5% hypertonic saline infusion (0.05 ml·kg−1·min−1). AAI attenuated the AVP response to hemorrhage, which was associated with increased paraventricular NO content. In contrast, AAI did not impair the AVP response to hyperosmolality. This was accompanied by decreased paraventricular NO content. To confirm the role of NO in the alcohol-induced inhibition of AVP release during hemorrhage, the nitric oxide synthase inhibitor, nitro-l-arginine methyl ester (l-NAME; 250 μg/5 μl), was administered centrally prior to hemorrhage. l-NAME did not further increase AVP levels during hemorrhage in dextrose-treated animals; however, it restored the AVP response during AAI. These results indicate that AAI impairs the AVP response to hemorrhage, while not affecting the response to hyperosmolality. Furthermore, these data demonstrate that the attenuated AVP response to hemorrhage is the result of augmented central NO inhibition.
Control of microvascular Po2kinetics following onset of muscle contractions: role for AMPK
Authors: Kano Yutaka , Poole David C. , Sudo Mizuki , Hirachi Toshiro , Miura Shinji , Ezaki Osamu
Published: August 2011

The microvascular partial pressure of oxygen (Pmvo2) kinetics following the onset of exercise reflects the relationship between muscle O2delivery and uptake (V̇o2). Although AMP-activated protein kinase (AMPK) is known as a regulator of mitochondria and nitric oxide metabolism, it is unclear whether the dynamic balance of O2delivery and V̇o2at exercise onset is dependent on AMPK activation level. We used transgenic mice with muscle-specific AMPK dominant-negative (AMPK-DN) to investigate a role for skeletal muscle AMPK on Pmvo2kinetics following onset of muscle contractions. Phosphorescence quenching techniques were used to measure Pmvo2at rest and across the transition to twitch (1 Hz) and tetanic (100 Hz, 3–5 V, 4-ms pulse duration, stimulus duration of 100 ms every 1 s for 1 min) contractions in gastrocnemius muscles (each group n = 6) of AMPK-DN mice and wild-type littermates (WT) under isoflurane anesthesia with 100% inspired O2to avoid hypoxemia. Baseline Pmvo2before contractions was not different between groups ( P > 0.05). Both muscle contraction conditions exhibited a delay followed by an exponential decrease in Pmvo2. However, compared with WT, AMPK-DN demonstrated 1) prolongation of the time delay before Pmvo2began to decline (1 Hz: WT, 3.2 ± 0.5 s; AMPK-DN, 6.5 ± 0.4 s; 100 Hz: WT, 4.4 ± 1.0 s; AMPK-DN, 6.5 ± 1.4 s; P < 0.05), 2) a faster response time (i.e., time constant; 1 Hz: WT, 19.4 ± 3.9 s; AMPK-DN, 12.4 ± 2.6 s; 100 Hz: WT, 15.1 ± 2.2 s; AMPK-DN, 9.0 ± 1.7 s; P < 0.05). These findings are consistent with the presence of substantial mitochondrial and microvascular dysfunction in AMPK-DN mice, which likely slows O2consumption kinetics (i.e., oxidative phosphorylation response) and impairs the hyperemic response at the onset of contractions thereby sowing the seeds for exercise intolerance.
Preactivation of AMPK by metformin may ameliorate the epithelial cell damage caused by renal ischemia
Authors: Seo-Mayer Patricia W. , Thulin Gunilla , Zhang Li , Alves Daiane S. , Ardito Thomas , Kashgarian Michael , Caplan Michael J.
Published: August 2011

Alterations in epithelial cell polarity and in the subcellular distributions of epithelial ion transport proteins are key molecular consequences of acute kidney injury and intracellular energy depletion. AMP-activated protein kinase (AMPK), a cellular energy sensor, is rapidly activated in response to renal ischemia, and we demonstrate that its activity is upregulated by energy depletion in Madin-Darby canine kidney (MDCK) cells. We hypothesized that AMPK activity may influence the maintenance or recovery of epithelial cell organization in mammalian renal epithelial cells subjected to energy depletion. MDCK cells were ATP depleted through a 1-h incubation with antimycin A and 2-deoxyglucose. Immunofluoresence localization demonstrated that this regimen induces mislocalization of the Na-K-ATPase from its normal residence at the basolateral plasma membrane to intracellular vesicular compartments. When cells were pretreated with the AMPK activator metformin before energy depletion, basolateral localization of Na-K-ATPase was preserved. In MDCK cells in which AMPK expression was stably knocked down with short hairpin RNA, preactivation of AMPK with metformin did not prevent Na-K-ATPase redistribution in response to energy depletion. In vivo studies demonstrate that metformin activated renal AMPK and that treatment with metformin before renal ischemia preserved cellular integrity, preserved Na-K-ATPase localization, and led to reduced levels of neutrophil gelatinase-associated lipocalin, a biomarker of tubular injury. Thus AMPK may play a role in preserving the functional integrity of epithelial plasma membrane domains in the face of energy depletion. Furthermore, pretreatment with an AMPK activator before ischemia may attenuate the severity of renal tubular injury in the context of acute kidney injury.
Neural correlates of evidence accumulation in a perceptual decision task
Authors: Liu Taosheng , Pleskac Timothy J.
Published: August 2011

Sequential sampling models provide a useful framework for understanding human decision making. A key component of these models is an evidence accumulation process in which information is accrued over time to a threshold, at which point a choice is made. Previous neurophysiological studies on perceptual decision making have suggested accumulation occurs only in sensorimotor areas involved in making the action for the choice. Here we investigated the neural correlates of evidence accumulation in the human brain using functional magnetic resonance imaging (fMRI) while manipulating the quality of sensory evidence, the response modality, and the foreknowledge of the response modality. We trained subjects to perform a random dot motion direction discrimination task by either moving their eyes or pressing buttons to make their responses. In addition, they were cued about the response modality either in advance of the stimulus or after a delay. We isolated fMRI responses for perceptual decisions in both independently defined sensorimotor areas and task-defined nonsensorimotor areas. We found neural signatures of evidence accumulation, a higher fMRI response on low coherence trials than high coherence trials, primarily in saccade-related sensorimotor areas (frontal eye field and intraparietal sulcus) and nonsensorimotor areas in anterior insula and inferior frontal sulcus. Critically, such neural signatures did not depend on response modality or foreknowledge. These results help establish human brain areas involved in evidence accumulation and suggest that the neural mechanism for evidence accumulation is not specific to effectors. Instead, the neural system might accumulate evidence for particular stimulus features relevant to a perceptual task.
Patterns of hypermetria and terminal cocontraction during point-to-point movements demonstrate independent action of trajectory and postural controllers
Authors: Scheidt Robert A. , Ghez Claude , Asnani Supriya
Published: August 2011

We examined elbow muscle activities and movement kinematics to determine how subjects combine elementary control actions in performing movements with one and two trajectory segments. In reaching, subjects made a rapid elbow flexion to a visual target before stabilizing the limb with either a low or a higher level of elbow flexor/extensor coactivity (CoA), which was cued by target diameter. Cursor diameter provided real-time biofeedback of actual muscle CoA. In reversing, the limb was to reverse direction within the target and return to the origin with minimal CoA. We previously reported that subjects overshoot the goal when attempting a reversal after first having learned to reach accurately to the same target. Here we test the hypothesis that this hypermetria results because reversals co-opt the initial feedforward control action from the preceding trained reach, thereby failing to account for task-dependent changes in limb impedance induced by differences in flexor/extensor coactivity as the target is acquired (higher in reaching than reversing). Instructed increases in elbow CoA began mid-reach, thus increasing elbow impedance and reducing transient oscillations present in low CoA movments. Flexor EMG alone increased at movement onset. Test reversals incorporated the initial agonist activity of previous reaches but not the increased coactivity at the target, thus leading to overshoot. Moreover, we observed elevated coactivity in reversals upon returning to the origin even though coactivity in reaching was centered at the goal target. These findings refute the idea that the brain necessarily invokes distinct unitary control actions for reaches and reversals made to the same target. Instead, reaches and reversals share a common control action that initiates trajectories toward their target and another later control action that terminates movement and stabilizes the limb about its final resting posture, which differs in the two tasks.
Examining Brain‐Cognition Effects of Ginkgo Biloba Extract: Brain Activation in the Left Temporal and Left Prefrontal Cortex in an Object Working Memory Task
Authors: Silberstein R. B. , Pipingas A. , Song J. , Camfield D. A. , Nathan P. J. , Stough C.
Published: August 2011

Ginkgo Biloba extract (GBE) is increasingly used to alleviate symptoms of age related cognitive impairment, with preclinical evidence pointing to a pro‐cholinergic effect. While a number of behavioral studies have reported improvements to working memory (WM) associated with GBE, electrophysiological studies of GBE have typically been limited to recordings during a resting state. The current study investigated the chronic effects of GBE on steady state visually evoked potential (SSVEP) topography in nineteen healthy middle‐aged (50‐61 year old) male participants whilst completing an object WM task. A randomized double‐blind crossover design was employed in which participants were allocated to receive 14 days GBE and 14 days placebo in random order. For both groups, SSVEP was recorded from 64 scalp electrode sites during the completion of an object WM task both pre‐ and 14 days post‐treatment. GBE was found to improve behavioural performance on the WM task. GBE was also found to increase the SSVEP amplitude at occipital and frontal sites and increase SSVEP latency at left temporal and left frontal sites during the hold component of the WM task. These SSVEP changes associated with GBE may represent more efficient processing during WM task completion.
Age-Related Deficits in Spatial Memory and Hippocampal Spines in Virgin, Female Fischer 344 Rats
Authors: Luine Victoria N. , Wallace Maureen E. , Frankfurt Maya
Published: August 2011

Effects of aging on memory and brain morphology were examined in aged, 21-month-old, and young, 4-month-old, Fischer 344 female rats. Spatial memory was assessed using the object placement task, and dendritic spine density was determined on pyramidal neurons in the hippocampus following Golgi impregnation. Consistent with previous studies, aged females showed poorer object placement performance than young subjects. Young subjects significantly discriminated the location of objects with a 1.5-hour intertrial delay while aged subjects did not. Spine density of basal dendrites on CA1 pyramidal cells was 16% lower in the aged subjects as compared to the young subjects. No differences in spine density were found between young and aged subjects in basal dendrites of CA1 or in either dendritic field of CA3 pyramidal neurons. Thus, decreased hippocampal CA1 dendritic spine density in aged rats may contribute to poorer spatial memory as compared to young rats. The possibility that the neuroplastic changes observed in this study may pertain only to female subjects having had a specific set of life experiences is discussed. Different factors, such as reproductive status, diet, and handling may contribute to neuroplasticity of the brain during aging; however, this view requires further examination.
Parent Report of Community Psychiatric Comorbid Diagnoses in Autism Spectrum Disorders
Authors: Rosenberg Rebecca E. , Kaufmann Walter E. , Law J. Kiely , Law Paul A.
Published: August 2011

We used a national online registry to examine variation in cumulative prevalence of community diagnosis of psychiatric comorbidity in 4343 children with autism spectrum disorders (ASD). Adjusted multivariate logistic regression models compared influence of individual, family, and geographic factors on cumulative prevalence of parent-reported anxiety disorder, depression, bipolar disorder, and attention deficit/hyperactivity disorder or attention deficit disorder. Adjusted odds of community-assigned lifetime psychiatric comorbidity were significantly higher with each additional year of life, with increasing autism severity, and with Asperger syndrome and pervasive developmental disorder—not otherwise specified compared with autistic disorder. Overall, in this largest study of parent-reported community diagnoses of psychiatric comorbidity, gender, autistic regression, autism severity, and type of ASD all emerged as significant factors correlating with cumulative prevalence. These findings could suggest both underlying trends in actual comorbidity as well as variation in community interpretation and application of comorbid diagnoses in ASD.
Amniotic Membrane as a Scaffold for Melanocyte Transplantation in Patients with Stable Vitiligo
Authors: Redondo Pedro , Giménez de Azcarate Ana , Marqués Laura , García-Guzman María , Andreu Enrique , Prósper Felipe
Published: August 2011

Vitiligo is an acquired skin disease that significantly impacts the quality of life of patients. Medical treatment of vitiligo includes the use of melanocyte transplant, but the results are variable. We have treated 4 patients with either focal or generalized stable vitiligo using a graft of autologous melanocytes' culture on a denuded amniotic membrane (AM). A culture biopsy was obtained in every patient and grown in melanocytes' media for 10–14 days after which cells were transferred to a denuded AM and transplanted into the achromic lesions. Patients were followed for up to 6 months using clinical assessment of achromic lesions. Treated areas ranged between 4 cm2and 210.6 cm2. Response to treatment was excellent in all patients with 90–95% repigmentation success rate. Our results demonstrate that transplantation of autologous melanocytes cultured on AM is a new, simple, and effective treatment for stable vitiligo.
Fuzzy Stability of a Functional Equation Deriving from Quadratic and Additive Mappings
Authors: Jin Sun Sook , Lee Yang-Hi
Published: August 2011

We investigate a
fuzzy version of stability for the functional
equation f(2x + y) + f(2x − y)+2f(x) − f(x + y) − f(x − y) − 2f(2x) = 0 in the sense of Mirmostafaee and Moslehian.
Estimation of Reliability for a Two Component Survival Stress‐Strength Model
Authors: Munoli S. B. , Mutkekar Rohit R.
Published: August 2011

The reliability function for a parallel system of two identical components is derived from a stress‐strength model, where failure of one component increases the stress on the surviving component of the system. The Maximum Likelihood Estimators of parameters and their asymptotic distribution are obtained. Further the Maximum Likelihood Estimator and Bayes Estimator of reliability function are obtained using the data from a life‐testing experiment. Computation of estimators is illustrated through simulation study.
Manipulating the Propagation of Solitons with Solid-Core Photonic Bandgap Fibers
Authors: Vanvincq O. , Kudlinski A. , Bétourné A. , Mussot A. , Quiquempois Y. , Bouwmans G.
Published: August 2011

We review the dynamics of soliton self-frequency shift induced by Raman gain in special solid-core photonic bandgap fibers and its consequences in terms of supercontinuum generation. These photonic bandgap fibers have been designed to allow nonlinear experiments in the first bandgap without suffering from significant loss even when working close to the photonic bandgap edge. We studied experimentally, numerically, and analytically the extreme deceleration of the soliton self-frequency shift at the long-wavelength edge of the first transmission window. This phenomenon is interpreted as being due to a large variation of the group-velocity dispersion in this spectral range and has been obtained with no significant power loss. Then, we investigated experimentally and numerically the generation of supercontinuum in this kind of fibers, in both spectral and temporal domains. In particular, we demonstrated an efficient tailoring of the supercontinuum spectral extension as well as a strong noise reduction at its long-wavelength edge.
Evidence of a Role for Antizyme and Antizyme Inhibitor as Regulators of Human Cancer
Authors: Olsen Rachelle R. , Zetter Bruce R.
Published: August 2011

Antizyme and its endogenous antizyme inhibitor have recently emerged as prominent regulators of cell growth, transformation, centrosome duplication, and tumorigenesis. Antizyme was originally isolated as a negative modulator of the enzyme ornithine decarboxylase (ODC), an essential component of the polyamine biosynthetic pathway. Antizyme binds ODC and facilitates proteasomal ODC degradation. Antizyme also facilitates degradation of a set of cell cycle regulatory proteins, including cyclin D1, Smad1, and Aurora A kinase, as well as Mps1, a protein that regulates centrosome duplication. Antizyme has been reported to function as a tumor suppressor and to negatively regulate tumor cell proliferation and transformation. Antizyme inhibitor binds to antizyme and suppresses its known functions, leading to increased polyamine synthesis, increased cell proliferation, and increased transformation and tumorigenesis. Gene array studies show antizyme inhibitor to be amplified in cancers of the ovary, breast, and prostate. In this review, we summarize the current literature on the role of antizyme and antizyme inhibitor in cancer, discuss how the ratio of antizyme to antizyme inhibitor can influence tumor growth, and suggest strategies to target this axis for tumor prevention and treatment. Mol Cancer Res; 9(10); 1285–93. ©2011 AACR.
Genetic Association Studies: Discovery of the Genetic Basis of Renal Disease
Authors: Verduijn Marion , Jager Kitty J. , Zoccali Carmine , Dekker Friedo W.
Published: August 2011

Genetic association studies are a means to investigate the causal role of genes in diseases in order to unravel pathways involved in the etiology of disease. There are two types of genetic association studies: hypothesis-driven studies, i.e. candidate gene studies, targeting genes with a known or presumed role in pathways or diseases of interest, and non-hypothesis-driven studies, i.e. genome-wide association studies, aiming for the discovery of new genetic associations. This educational article is an introduction to genetic association studies for nephrologists and researchers in the domain of kidney disease.
Outcome of Acute Ischemic Stroke in Very Elderly Patients: Is Intravenous Thrombolysis Beneficial?
Authors: Sung Pi-Shan , Chen Chih-Hung , Hsieh Han-Chieh , Fang Chen-Wen , Hsieh Cheng-Yang , Sun Yuan-Ting , Hwang Wen-Juh
Published: August 2011

Background/Aims: Intravenous tissue plasminogen activator (tPA) treatment is recommended in acute stroke within 3 h of onset; however, the benefit of its use in the elderly remains uncertain. We assessed the safety and efficacy of tPA treatment in elderly patients. Methods: We recruited 97 elderly Chinese patients aged ≧80 years with cerebral ischemia presenting within 3 h of onset. Favorable outcomes were defined as discharge to home and modified Rankin Scale (mRS) ≤2 at discharge. Results: For moderate to severe patients (NIHSS ≧6), the baseline characteristics between the tPA (n = 30) and non-tPA (n = 41) group were not different. The proportion of patients discharged home was 56.7 and 61%, respectively (p = 0.72). For patients with baseline mRS ≤2, the frequency of discharged mRS ≤2 was not different (27.3% of the tPA group and 26.9% of the non-tPA group; p = 1.00). Symptomatic intracranial hemorrhage was 6.7 and 2.4%, respectively (p = 0.31). For minor stroke patients (NIHSS ≤5), tPA was not considered and the outcome of those discharged home and mRS ≤2 was 73 and 88%, respectively. Conclusion: Elderly patients can be treated safely with intravenous tPA, whereas our data did not support routine thrombolysis. Further randomized trials in the elderly are encouraged.
Gamma Knife Radiosurgery for Glomus Jugulare and Tympanicum
Authors: Lee Cheng-Chia , Pan David Hung-Chi , Wu Jau-Ching , Chung Wen-Yuh , Wu Hsiu-Mei , Yang Huai-Che , Liu Kang-Du , Guo Wan-Yuo , Shih Yang-Hsin
Published: August 2011

Objective: To establish the role of gamma knife radiosurgery (GKS) as a treatment strategy for glomus jugulare and tympanicum. Method: A retrospective review of 14 glomus tumors, including 11 glomus jugulare and 3 glomus tympanicum tumors, which were treated by GKS in Taipei Veterans General Hospital from 1993 to 2009, was conducted. Two of these cases had undergone prior surgery with partial tumor resection, and the other 12 cases received primary treatment with GKS after a thorough neuroimaging and cerebral angiography. The tumor volume ranged from 6.5 to 22.1 ml. The maximum dose at the tumor center ranged from 21.6 to 26.3 Gy. All 14 patients were regularly followed up by clinical and radiological evaluations. The median follow-up time was 40.3 months. Results: All 14 patients had significant tumor regression after radiosurgery. The median tumor volume reduction was 34.0% (range 3–79%). Only 1 patient had temporary tumor volume progression (24% increment 6 months post-treatment), accompanied with unilateral facial palsy (from grade III to grade IV) and hearing impairment (from grade I to grade II). The tumor volume of this patient had regressed by 12 months, but facial palsy persisted. The tumor control rate in the series was 100% (n = 14/14), and the preservation rate of cranial nerve function was 92.8% (13/14). There was no complication of lower cranial nerve damage after radiosurgery. Conclusion: GKS appeared to be a good alternative or adjuvant to microsurgical resection in patients who are not amenable to complete surgical eradication, with an excellent tumor control rate and little morbidity after long-term follow-up.
Influence of Thyroid Function on Different Kidney Function Tests
Authors: Kimmel Martin , Braun Niko , Alscher Mark Dominik
Published: August 2011

Background/Aims: The commonly used kidney function tests have limitations, especially in thyroid dysfunction. Therefore, we studied the most commonly used kidney function tests in patients with hypo- and hyperthyroidism and after reaching euthyroidism. Methods: Prospective case series in 16 patients with thyroid dysfunction. Serum creatinine, 24-hour creatinine clearance, calculated glomerular filtration rate (GFR) by Cockroft-Gault, estimated GFR (eGFR) by the Chronic Kidney Disease Epidemiology Collaboration equation, serum cystatin C, eGFR based on cystatin C, eGFR based on a combined (cystatin C and creatinine) formula and plasma neutrophil gelatinase-associated lipocalin (NGAL) were measured in hypo- and hyperthyroidism and after gaining euthyroidism. Results: When free thyroxine (fT4) normalized in hypothyroid patients, creatinine decreased and creatinine-based eGFR increased significantly. In contrast, cystatin C increased and eGFR based on cystatin C decreased significantly. There was no significant change in NGAL levels. When fT4 normalized in patients with hyperthyroidism, creatinine increased and creatinine-based eGFR decreased significantly. In contrast, cystatin C decreased and cystatin-C-based GFR increased significantly. There was no significant change in NGAL levels. Conclusions: Thyroid function has a major influence on the vast majority of kidney function tests. Cystatin C is strongly influenced by the thyroid function and should be avoided in thyroid disorders. There was no effect on the plasma NGAL levels. The recommended kidney function test is a measurement of creatinine-based eGFR.
The Mamillothalamic Tract Is a Good Landmark for the Anterior Border of the Subthalamic Nucleus on Axial MR Images
Authors: Caire François , Maubon Antoine , Moreau Jean-Jacques , Cuny Emmanuel
Published: August 2011

Background:Identification of the subthalamic nucleus (STN) on MR images is difficult, and the use of external landmarks could be of interest for STN targeting in deep brain stimulation (DBS). Objectives:Our aim was to explore the relationship between the anteroposterior coordinates of (1) the center of the mamillothalamic tract and (2) the anterior border of the STN on axial MR images. Patients and Methods:The brains of 16 healthy volunteers were imaged on a 3T MR system. Four millimeters under the anterior-posterior commissure plane, we noted the y coordinates of (1) the center of the mamillothalamic tract and (2) the anterior border of the STN. Results:The coordinates were ySTN = 14.7 ± 1.23 mm and yTmth = 14.3 ± 1.13 mm from the posterior commissure for the STN and the mamillothalamic tract, respectively. The mean difference was 0.4 mm (range 0–1 mm). Pearson’s coefficient was 0.97 (p < 0.01). Conclusion:We observed a strong correlation between the anteroposterior coordinates of the mamillothalamic tract and the anterior border of the STN (which is located between 0 and 1 mm in front of the mamillothalamic tract). The mamillothalamic tract could be a good anterior landmark for STN targeting. It could also be tested for target determination in DBS for severe obsessive-compulsive disorder.
Hypertension as a Predictive Factor for Survival Outcomes in Patients with Metastatic Renal Cell Carcinoma Treated with Sunitinib after Progression on Cytokines
Authors: Szmit Sebastian , Langiewicz Przemysław , Żłnierek Jakub , Nurzyński Paweł , Zaborowska Magdalena , Filipiak Krzysztof J. , Opolski Grzegorz , Szczylik Cezary
Published: August 2011

Background/Aims: This retrospective analysis compared progression-free survival (PFS) in 111 patients who developed or had preexisting hypertension with those who did not during treatment with second-line sunitinib. Secondary objectives included overall survival (OS) and safety. Methods: Patients with metastatic renal cell carcinoma (mRCC) received sunitinib 50 mg orally once daily in 6-week cycles according to a 4-week on/2-week off treatment schedule. Treatment was continued until disease progression, unacceptable toxicity, withdrawal of consent, or death. Resting blood pressure (BP) was monitored by clinic and home measurements. Hypertension was defined as systolic BP ≧140 and/or diastolic BP ≧90 mm Hg. Subsequent antihypertensive treatment was empirical, depending on the patient. Results:Fifty-four (48.6%) patients experienced elevated BP related to sunitinib. Of these, 10 had preexisting hypertension. Patients who developed hypertension related to sunitinib treatment experienced significantly longer PFS and OS compared to those who did not (p < 0.00001). Patients who required at least 3 antihypertensive drugs had the longest PFS (p = 0.00002) and OS (p = 0.00001). Conclusions: The development of hypertension during sunitinib treatment was a positive predictive factor associated with a significantly longer PFS and OS in patients with mRCC.
Anti-Angiotensin and Hypoglycemic Treatments Suppress Liver Metastasis of Colon Cancer Cells
Authors: Luo Yi , Ohmori Hitoshi , Shimomoto Takasumi , Fujii Kiyomu , Sasahira Tomonori , Chihara Yoshitomo , Kuniyasu Hiroki
Published: August 2011

The effect of diabetic conditions on liver metastasis was examined using CT26 mouse colon cancer cells. CT26 cells produced angiotensin (A)-I and A-II from angiotensinogen; the production was abrogated by inhibitors of renin and chymase. Renin expression and A-II production increased with an increase in the concentration of glucose in the medium. In a streptozotocin-induced BALB/c mouse diabetes model that was fed a high-calorie diet, the blood sugar level increased and was associated with an increasing size and number of CT26 liver metastases. In this diabetic mouse model, liver metastasis of CT26 cells was suppressed by anti-angiotensin treatment with a chymase inhibitor, a renin inhibitor, and an A-II receptor blocker. Moreover, concurrent hypoglycemic and anti-angiotensin treatments showed a synergistic inhibitory effect on CT26 cell liver metastasis. These results suggest that angiotensin activation ability associated with diabetic conditions enhances liver metastasis of colon cancer. Therefore, treatment with anti-angiotensin and hypoglycemic agents might be relevant for baseline management of colon cancer patients with the diabetic condition for the prevention of liver metastasis. This scheme needs to be examined in a clinical setting.
KCNJ10 Mutations Disrupt Function in Patients with EAST Syndrome
Authors: Freudenthal Bernard , Kulaveerasingam Duvaraka , Lingappa Lokesh , Shah Mehul A. , Brueton Louise , Wassmer Evangeline , Ognjanovic Milos , Dorison Nathalie , Reichold Markus , Bockenhauer Detlef , Kleta Robert , Zdebik Anselm A.
Published: August 2011

Background/Aims: Mutations in the inwardly-rectifying K+ channel KCNJ10/Kir4.1 cause an autosomal recessive disorder characterized by epilepsy, ataxia, sensorineural deafness and tubulopathy (EAST syndrome). KCNJ10 is expressed in the kidney distal convoluted tubule, cochlear stria vascularis and brain glial cells. Patients clinically diagnosed with EAST syndrome were genotyped to identify and study mutations in KCNJ10. Methods: Patient DNA was sequenced and new mutations identified. Mutant and wild-type KCNJ10 constructs were cloned and heterologously expressed in Xenopus oocytes. Whole-cell K+ currents were measured by two-electrode voltage clamping. Results: Three new mutations in KCNJ10 (p.R65C, p.F75L and p.V259fs259X) were identified, and mutation p.R297C, previously only seen in a compound heterozygous patient, was found in a homozygous state. Wild-type human KCNJ10-expressing oocytes showed strongly inwardly-rectified currents, which by comparison were significantly reduced in all the mutants (p < 0.001). Specific inhibition of KCNJ10 currents by Ba2+ demonstrated residual function in all mutant channels (p < 0.05) but V259X. Conclusion: This study confirms that EAST syndrome can be caused by many different mutations in KCNJ10 that significantly reduce K+ conductance. EAST syndrome should be considered in any patient with a renal Gitelman-like phenotype with additional neurological signs and symptoms like ataxia, epilepsy or sensorineural deafness.
Indoxyl Sulfate Induces Epithelial-to-Mesenchymal Transition in Rat Kidneys and Human Proximal Tubular Cells
Authors: Bolati Dilinaer , Shimizu Hidehisa , Higashiyama Yukihiro , Nishijima Fuyuhiko , Niwa Toshimitsu
Published: August 2011

Background/Aims: Indoxyl sulfate (IS) is a uremic toxin that accelerates the progression of chronic kidney disease (CKD). This study aimed to determine if IS induces epithelial-to-mesenchymal transition (EMT) in the kidneys of hypertensive rats and human proximal tubular cells (HK-2). Methods: EMT was evaluated by immunohistochemistry, reverse transcription-polymerase chain reaction and immunoblotting of the epithelial markers E-cadherin and zonula occludens-1 (ZO-1), and the mesenchymal marker α-smooth muscle actin (α-SMA). Rat groups consisted of (1) Dahl salt-resistant normotensive rats (DN), (2) Dahl salt-resistant normotensive IS-administered rats (DN+IS), (3) Dahl salt-sensitive hypertensive rats (DH), and (4) Dahl salt-sensitive hypertensive IS-administered rats (DH+IS). HK-2 cells were incubated with or without IS. Results: In kidneys, DH rats showed reduced expression of E-cadherin and ZO-1, and enhanced expression of α-SMA compared with DN rats. DN+IS and DH+IS rats showed reduced expression of E-cadherin and ZO-1, and enhanced expression of α-SMA compared with DN and DH rats, respectively. DH+IS and DH rats showed increased Masson’s trichrome-positive fibrosis areas compared with DH and DN, respectively. IS-treated HK-2 cells showed reduced expression of E-cadherin and ZO-1, and enhanced expression of α-SMA. Conclusion: IS induces EMT in the kidneys of hypertensive rats and in human proximal tubular cells.
Genetics in Arterial Calcification
Authors: Rutsch Frank , Nitschke Yvonne , Terkeltaub Robert
Published: August 2011

Artery calcification reflects an admixture of factors such as ectopic osteochondral differentiation with primary host pathological conditions. We review how genetic factors, as identified by human genome-wide association studies, and incomplete correlations with various mouse studies, including knockout and strain analyses, fit into “pieces of the puzzle” in intimal calcification in human atherosclerosis, and artery tunica media calcification in aging, diabetes mellitus, and chronic kidney disease. We also describe in sharp contrast how ENPP1, CD73, and ABCC6 serve as “cogs in a wheel” of arterial calcification. Specifically, each is a minor component in the function of a much larger network of factors that exert balanced effects to promote and suppress arterial calcification. For the network to normally suppress spontaneous arterial calcification, the “cogs” ENPP1, CD73, and ABCC6 must be present and in working order. Monogenic ENPP1, CD73, and ABCC6 deficiencies each drive a molecular pathophysiology of closely related but phenotypically different diseases (generalized arterial calcification of infancy (GACI), pseudoxanthoma elasticum (PXE) and arterial calcification caused by CD73 deficiency (ACDC)), in which premature onset arterial calcification is a prominent but not the sole feature.
Medical Science and the Military: The Allies' Use of Amphetamine during World War II
Authors: Rasmussen Nicolas
Published: August 2011

Although amphetamine was thoroughly tested by leading scientists for its effects in boosting or maintaining physical and mental performance in fatigued subjects, the results never provided solid grounds for approving the drug's use, and, in any case, came too late to be decisive. The grounds on which amphetamine was actually adopted by both British and American militaries had less to do with the science of fatigue than with the drug's mood-altering effects, as judged by military men. It increased confidence and aggression, and elevated “morale.”
Local Elites and Power in the Roman World: Modern Theories and Models
Authors: Slootjes Daniëlle
Published: August 2011

In recent years, modern scholars have applied various methodologies to the study of local elites in the Roman Empire. Judith Perkins in Roman Imperial Identities in the Early Christian Era examines the concept of elite, like many other classicists, through an analysis of written texts—in her case, Greek novels and political writings of the first and second centuries. Models and theories borrowed from cultural anthropology or sociology—such as Michael Mann's sociological theory of power—offer a new way to resolve difficulties of interpretation that traditional methodological tools cannot address.
The Use of a High-Resolution Standardized Precipitation Index for Drought Monitoring and Assessment
Authors: McRoberts D. Brent , Nielsen-Gammon John W.
Published: August 2011

A high-resolution drought-monitoring tool was developed to assess drought on multiple time scales using the standardized precipitation index (SPI). Daily precipitation data at 4-km resolution are obtained from the Advanced Hydrologic Prediction Service multisensor precipitation estimates (MPE) and are aggregated on several time scales. Daily station precipitation data available from the Cooperative Observer Program (COOP) provide the historical context for the MPE precipitation data. Pearson type-III distribution parameters were interpolated to the 4-km grid on the basis of a regional frequency analysis of the COOP stations and L-moment ratios of the precipitation data. The resulting high-resolution SPI data can be used as guidance for the U.S. Drought Monitor at the subcounty scale in areas where local precipitation is the primary driver of drought. The temporal flexibility and spatial resolution of the drought-monitoring tool are used to illustrate the onset, intensity, and termination of the 2008–09 Texas drought, and the tool is shown to provide better county- and subcounty-scale information than do gauge-based products.