bluuebunny/crossref_metadata_2025 huggingface dataset:
The cardiovascular risk factor, soluble CD40 ligand (CD154), but not soluble CD40 is lowered by ultra-endurance exercise in athletes
Authors: Geertsema Liesel , Lucas Samuel J E , Cotter James D , Hock Barry , McKenzie Judy , Fernyhough Liam J
Published: August 2008

Background

Soluble CD40 ligand (sCD40L) is a powerful marker of cardiovascular risk. Exercise is known to decrease cardiovascular risk, but the impact of ultra-endurance exercise on sCD40L responses is unknown.

Objective

To examine the relationship between ultra-endurance exercise in trained athletes and levels of sCD40L and its natural ligand sCD40.

Design

Control-trial, crossover design, exercise intervention study of sCD40L and sCD40 levels.

Setting

Outdoor exercise and laboratory testing, single centre study, School of Physical Education, University of Otago, New Zealand.

Participants

Nine trained ultra-endurance athletes.

Interventions

Athletes exercised (cycled and jogged) for 17 of 24 h. Venous blood was sampled at baseline and serially throughout exercise and 24 and 48 h after exercise. The athletes completed a 24 h control trial on a separate occasion, in randomised order.

Main outcome measurements

Mean levels of sCD40L and sCD40 during exercise and rest with 95% CIs.

Results

sCD40L levels dropped steadily from baseline (median 4128 pg/ml) to a measured nadir at 24 h following exercise (median 1409 pg/ml) (p=0.01). The levels had started to rise again by 48 h after exercise. When measured as a group, sCD40L levels remained constant during a control rest period. sCD40 levels remained constant on both exercise and control days.

Conclusion

Ultra-endurance exercise lowers the levels of the cardiovascular risk marker sCD40L in athletes. These results raise the possibility that exercise-induced changes in sCD40L may provide one of the mechanisms by which exercise lowers cardiovascular risk.
Problems with Samples of Sea Lamprey (Petromyzon marinus) Ammocoetes Used in Stock Identification Studies
Authors: Jacobson L. D. , Torblaa R. L. , Morman R. H.
Published: August 2008

Allelic variation in sea lamprey (Petromyzon marinus) ammocoetes from the Lake Huron, Lake Michigan, and Lake Superior drainage basins was studied by starch gel electrophoresis. Previously untried enzyme systems were examined in sea lamprey ammocoetes. No new polymorphic enzyme systems were found. The allelic frequencies of ammocoete samples frequently failed to conform to Hardy–Weinberg equilibrium values. Allelic frequency variation observed among samples from the same drainage was larger than the variation observed among drainages. The results of this study and field observations suggest that the effective size of spawning groups that contribute progeny to samples is often small. These factors make ammocoete samples undesirable for use in stock identification studies.
Spawning Characteristics of Sympatric Populations of Steelhead Trout (Salmo gairdneri): Evidence for Partial Reproductive Isolation
Authors: Leider Steven A. , Chilcote Mark W. , Loch John J.
Published: August 2008

We differentially tagged upstream migrant adult summer and winter steelhead trout (Salmo gairdneri) of hatchery and wild origin in the Kalama River, Washington, and subsequently observed them spawning under natural conditions in a tributary. We found that summer steelhead spawned within the study stream on a spatially random basis. The steelhead spawning interval was 6 mo long, during which hatchery summer steelhead spawned first, followed by wild summer, hatchery winter, and wild winter steelhead. Significant temporal spawning differences were found between hatchery summer and wild winter fish, and between wild summer and wild winter steelhead. We developed estimates of potential reproductive overlap between spawner groups that indicated that most reproductive activity involved members of the same spawner group. Estimated genetic exchange among groups was primarily between hatchery and wild fish within races. Of all possible spawner group comparisons, the smallest potential reproductive overlap estimated was between wild summer and wild winter steelhead. We concluded that, although wild summer and wild winter steelhead were not completely reproductively isolated, a substantial degree of successful gene flow restriction occurred, thereby providing a mechanism for the maintenance of racial identity. Additionally, spatial and temporal spawner segregation was of insufficient magnitude to prevent the potential infusion of hatchery steelhead genes into the wild summer steelhead population.
Efficiency Estimates for Various Quadrat Sizes Used in Benthic Sampling
Authors: Pringle J. D.
Published: August 2008

A review of some of the marine littoral ecological literature revealed that area sampling is frequently used to assess biomass and both species densities and associations. The three most common sample unit configurations were the quadrat, circle, and rectangle; their popularity was 66.7, 19.0, and 14.3%, respectively. The percentage of researchers using areas of < 0.25, 0.25, 1.0, and > 1.0 m2 was 42.9, 23.8, 28.6, and 4.8%, respectively; their reasons for using these areas were not stated. My sampling study was designed to determine the efficiency of six sample unit sizes (0.25, 1.0, 1.56, 2.25, 2.99, and 4.0 m2) when assessing macrophyte biomass. The cost in time to harvest a fixed sample of 20 m2 varied markedly with sample unit size, as did sampling precision. The rates to harvest 1 m2 with the 2.25- and 0.25-m2 quadrats were 9.1 and 34.8 min, respectively; the respective sampling precisions (CV) were 0.176 and 0.075. The formula [Formula: see text] was used to determine sample unit number for a given precision of the estimate (CV′s = 0.075, 0.10, and 0.15). The cost in time to attain a sampling precision of 0.10 for the 0.25- and 2.25-m2 sampling units was estimated at 393.2 and 569.9 min, respectively. A large number of small sample units (0.25 m2) was more efficient than a smaller number of large sample units (4.0 m2). I recommend that sampling efficiency be determined prior to the initiation of an area sampling program.
Socioeconomic Aspects of Sea Cage Salmon Farming in the Maritimes
Authors: Ridler Neil B.
Published: August 2008

Commercial salmon farming in the Maritimes shows potential as a source of rural employment, growth, and foreign exchange. Canada lags behind most advanced countries in developing its aquaculture industry; Atlantic salmon (Salmo salar) might be one species in which Canada has a comparative advantage and in which Canada's late start might be overcome. This paper evaluates sea pen salmon culture by a number of criteria, including financial feasibility, and concludes that salmon farming can be profitable, contribute to growth, absorb labour, and earn foreign exchange. A final section explores policy options available to governments and to private sector producers.
Stress-Related Changes in Lake Whitefish (Coregonus clupeaformis) Associated with a Hydroelectric Control Structure
Authors: Barnes M. A. , Power G. , Downer R. G. H.
Published: August 2008

Lake whitefish (Coregonus clupeaformis) that accumulate below the Lobstick control structure at the Churchill Falls hydroelectric facility exhibit many stress-related symptoms. Compared with fish from the reservoir or from a natural lake they score low on the following indices: liver somatic, gonad somatic, stomach content volumes, and condition factor; they have a low rate of circuli formation on the scales and they do not reproduce; proximate composition analyses identified reduced muscle protein levels and reduced ovarian protein and lipid. The liver may be the main site of lipid storage and the liver somatic index a sensitive condition indicator in whitefish.
Recognition of conspecific odors by the western red-backed salamander, Plethodon vehiculum
Authors: Ovaska K.
Published: August 2008

Lungless salamanders of the family Plethodontidae possess an elaborate system of glands that potentially can be used in chemical communication. I used an olfactometer to examine the behavior of adult male and female western red-backed salamanders, Plethodon vehiculum, towards airborne odors of conspecific individuals. In two-choice tests, P. vehiculum of both sexes chose the side with no odor over that with the odor of a male; however, they entered the sides at random when presented with no salamander odor on one side and the odor of a nonreproductive female on the other. Therefore, P. vehiculum was able to recognize and avoided odors of conspecific males. Odors of nonreproductive females either were not recognized or carried no social significance. Males may use pheromonal markers to space themselves out for mating purposes. Contrary to predictions, males did not prefer the odor of a reproductive female over that of a nonreproductive female when simultaneously presented with the two odors, but entered the sides in a random manner.
REAL SPECTRUM OF NON-HERMITIAN HAMILTONIANS FOR HULTHÉN POTENTIAL
Authors: MEYUR SANJIB , DEBNATH S.
Published: August 2008

The non-Hermitian Hamiltonians of the type [Formula: see text] is solved for the generalized Hulthén potential in terms of Jacobi polynomials by using Nikiforov–Uvarov method. The exact bound-state energy eigenvalues and eigenfunctions are presented.
B - L CONSERVED BARYOGENESIS
Authors: GU PEI-HONG , SARKAR UTPAL
Published: August 2008

In the presence of anomaly induced sphaleron process, only a B - L asymmetry can be partially converted to the baryon asymmetry while any B + L asymmetry would be completely erased. Thus in any successful baryogenesis theories, B - L is usually violated above the electroweak scale to explain the observed matter–antimatter asymmetry of the universe. However, if any lepton asymmetry is not affected by the sphaleron processes, a B - L conserved theory can still realize the baryogenesis. We present here an SU(5) GUT realization of this scenario, which naturally accommodates small masses of Dirac neutrinos.
Personal Knowledge Management: A Study of Knowledge Behaviour of Academicians
Authors: Mittal Monika
Published: August 2008

Current theories of knowledge management postulate a cycle of knowledge creation, refinement and implementation that hinges on the transformation of tacit, or practical, into explicit, or discursive, knowledge. The modern organisation, because it is characterised by diverse local practices, and by the increasing salience of professional work, is thus a complex mosaic of situated knowledge, grounded in process. Enabling organisations to capture, share and apply the situated knowledge grounded in the process is seen as fundamental to competing in the knowledge economy. The study is focussed on the various knowledge activities of faculty members to understand the extent of impact of information systems on those activities and how those activities contribute to value creation and knowledge management. The results of this study suggest the presence of certain type of knowledge behaviours which facilitate knowledge management.
Technology strategy and managementThe puzzle of Apple
Authors: Cusumano Michael
Published: August 2008

Given Apple's unique characteristics, should it strive to be a platform or a product leader?
CTO Roundtable
Authors: Creeger Mache
Published: August 2008

Leaders in the storage industry ponder upcoming technologies and trends.
Distributed selection
Authors: Kuhn Fabian , Locher Thomas , Wattenhofer Roger
Published: August 2008

In this article, we study the problem of distributed selection from a theoretical point of view. Given a general connected graph of diameter
D
consisting of
n
nodes in which each node holds a numeric element, the goal of a
k
-selection algorithm is to determine the
k

th

smallest of these elements. We prove that distributed selection indeed requires more work than other aggregation functions such as, e.g., the computation of the average or the maximum of all elements. On the other hand, we show that the
k

th

smallest element can be computed efficiently by providing both a randomized and a deterministic
k
-selection algorithm, dispelling the misconception that solving distributed selection through in-network aggregation is infeasible.
ViewpointGlobal warming toward open educational resources
Authors: Baraniuk Richard G. , Burrus C. Sidney
Published: August 2008

Seeking to realize the potential for significantly improving and advancing the world's standard of education.
PuzzledSolutions and sources
Authors: Winkler Peter
Published: August 2008

Last month (August 2008, p. 104) Peter Winkler posed a trio of brain teasers in his "Puzzled" column. Here, he offers some solutions. How well did you do?
A new approximation algorithm for the asymmetric TSP with triangle inequality
Authors: Bläser Markus
Published: August 2008

We present a polynomial time factor 0.999 ċ log
n
approximation algorithm for the asymmetric traveling salesperson problem with triangle inequality.
TRUES
Authors: Chen Jiang-Chun , Jang Jyh-Shing Roger
Published: August 2008

Tone recognition has been a basic but important task for speech
recognition and assessment of tonal languages, such as Mandarin
Chinese. Most previously proposed approaches adopt a two-step
approach where syllables within an utterance are identified via
forced alignment first, and tone recognition using a variety of
classifiers---such as neural networks, Gaussian mixture models
(GMM), hidden Markov models (HMM), support vector machines
(SVM)---is then performed on each segmented syllable to predict its
tone. However, forced alignment does not always generate accurate
syllable boundaries, leading to unstable voiced-unvoiced detection
and deteriorating performance in tone recognition. Aiming to
alleviate this problem, we propose a robust approach called Tone
Recognition Using Extended Segments (TRUES) for HMM-based
continuous tone recognition. The proposed approach extracts an
unbroken pitch contour from a given utterance based on dynamic
programming over time-domain acoustic features of average magnitude
difference function (AMDF). The pitch contour of each syllable is
then extended for tri-tone HMM modeling, such that the influence
from inaccurate syllable boundaries is lessened. Our experimental
results demonstrate that the proposed TRUES achieves 49.13%
relative error rate reduction over that of the recently proposed
supratone modeling, which is deemed the state of the art of tone
recognition that outperforms several previously proposed
approaches. The encouraging improvement demonstrates the
effectiveness and robustness of the proposed TRUES, as well as the
corresponding pitch determination algorithm which produces unbroken
pitch contours.
Pharmacological characterization of a small molecule inhibitor of c-Jun kinase
Authors: Cho Helen , Black Shawn C. , Looper David , Shi Manli , Kelly-Sullivan Dawn , Timofeevski Sergei , Siegel Karen , Yu Xiao-Hong , McDonnell Scott R. , Chen Ping , Yie Junming , Ogilvie Kathleen M. , Fraser James , Briscoe Celia P.
Published: August 2008

c-Jun NH2-terminal kinase (JNK) plays an important role in insulin resistance; however, identification of pharmacologically potent and selective small molecule JNK inhibitors has been limited. Compound A has a cell IC50 of 102 nM and is at least 100-fold selective against related kinases and 27-fold selective against glycogen synthase kinase-3β and cyclin-dependent kinase-2. In C57BL/6 mice, compound A reduced LPS-mediated increases in both plasma cytokine levels and phosphorylated c-Jun in adipose tissue. Treatment of mice fed a high-fat diet with compound A for 3 wk resulted in a 13.1 ± 1% decrease in body weight and a 9.3 ± 1.5% decrease in body fat, compared with a 6.6 ± 2.1% increase in body weight and a 6.7 ± 2.1% increase in body fat in vehicle-treated mice. Mice pair fed to those that received compound A exhibited a body weight decrease of 7 ± 1% and a decrease in body fat of 1.6 ± 1.3%, suggesting that reductions in food intake could not account solely for the reductions in adiposity observed. Compound A dosed at 30 mg/kg for 13 days in high-fat fed mice resulted in a significant decrease in phosphorylated c-Jun in adipose tissue accompanied by a decrease in weight and reductions in glucose and triglycerides and increases in insulin sensitivity to levels comparable with those in lean control mice. The ability of compound A to reduce the insulin-stimulated phosphorylation of insulin receptor substrate-1 (IRS-1) von Ser307 and partially reverse the free fatty acid inhibition of glucose uptake in 3T3L1 adipocytes, suggests that enhancement of insulin signaling in addition to weight loss may contribute to the effects of compound A on insulin sensitization in vivo. Pharmacological inhibition of JNK using compound A may therefore offer an effective therapy for type 2 diabetes mediated at least in part via weight reduction.
Estrogen directly modulates circadian rhythms of PER2 expression in the uterus
Authors: Nakamura Takahiro J. , Sellix Michael T. , Menaker Michael , Block Gene D.
Published: August 2008

Fluctuations in circulating estrogen and progesterone levels associated with the estrous cycle alter circadian rhythms of physiology and behavior in female rodents. Endogenously applied estrogen shortens the period of the locomotor activity rhythm in rodents. We recently found that estrogen implants affect Period ( Per) gene expression in the suprachiasmatic nucleus (SCN; central clock) and uterus of rats in vivo. To explore whether estrogen directly influences the circadian clock in the SCN and/or tissues of the reproductive system, we examined the effects of 17β-estradiol (E2) on PER2::LUCIFERASE (PER2::LUC) expression in tissue explant cultures from ovariectomized PER2::LUC knockin mice. E2 applied to explanted cultures shortened the period of rhythmic PER2::LUC expression in the uterus but did not change the period of PER2::LUC expression in the SCN. Raloxifene, a selective estrogen receptor modulator and known E2 antagonist in uterine tissues, attenuated the effect of E2 on the period of the PER2::LUC rhythm in the uterus. These data indicate that estrogen directly affects the timing of the molecular clock in the uterus via an estrogen receptor-mediated response.
Metabolic cycling in control of glucose-stimulated insulin secretion
Authors: Jensen Mette V. , Joseph Jamie W. , Ronnebaum Sarah M. , Burgess Shawn C. , Sherry A. Dean , Newgard Christopher B.
Published: August 2008

Glucose-stimulated insulin secretion (GSIS) is central to normal control of metabolic fuel homeostasis, and its impairment is a key element of β-cell failure in type 2 diabetes. Glucose exerts its effects on insulin secretion via its metabolism in β-cells to generate stimulus/secretion coupling factors, including a rise in the ATP/ADP ratio, which serves to suppress ATP-sensitive K+(KATP) channels and activate voltage-gated Ca2+channels, leading to stimulation of insulin granule exocytosis. Whereas this KATPchannel-dependent mechanism of GSIS has been broadly accepted for more than 30 years, it has become increasingly apparent that it does not fully describe the effects of glucose on insulin secretion. More recent studies have demonstrated an important role for cyclic pathways of pyruvate metabolism in control of insulin secretion. Three cycles occur in islet β-cells: the pyruvate/malate, pyruvate/citrate, and pyruvate/isocitrate cycles. This review discusses recent work on the role of each of these pathways in control of insulin secretion and builds a case for the particular relevance of byproducts of the pyruvate/isocitrate cycle, NADPH and α-ketoglutarate, in control of GSIS.
Prenatally Diagnosed Ectrodactyly at 16 Weeks’ Gestation by 2- and 3-Dimensional Ultrasonography
Authors: Koo Bon Sang , Baek Su Jin , Kim Mi Ryung , Joo Won Duk , Yoo Hang Jo
Published: August 2008

Objective: Ectrodactyly is a rare malformation with various presentations. The current report describes a case of ectrodactyly detected using 2-dimensional (2D) and 3-dimensional (3D) ultrasonography at 16 weeks’ gestation. Methods and Results: The 2D ultrasonographic findings were ectrodactyly in the right hand and monodactyly in the left hand, and these results were confirmed and further clarified using 3D imaging. The postmortem X-ray findings were consistent with the ultrasonography. Conclusion: We conclude that 3D ultrasonography can assist in clarifying 2D ultrasonography findings of hand malformations during the second trimester of pregnancy.
Prenatal Course and Postnatal Management of Peripheral Bronchial Atresia: Association with Congenital Cystic Adenomatoid Malformation of the Lung
Authors: Peranteau William H. , Merchant Aziz M. , Hedrick Holly L. , Liechty Kenneth W. , Howell Lori J. , Flake Alan W. , Wilson R. Douglas , Johnson Mark P. , Bebbington Michael W. , Adzick N. Scott
Published: August 2008

Objective: Peripheral bronchial atresia (PBA), a newly identified fetal lung lesion, is often asymptomatic and managed nonoperatively. However, recent studies suggest that bronchial atresia plays a role in the etiology of microcystic maldevelopment present in congenital cystic adenomatoid malformations (CCAM) which require resection to decrease the risk of infection, pneumothorax and malignant degeneration. The purpose of this study was to evaluate the prenatal radiographic and postnatal computed tomography (CT) scan/pathology findings with attention to the pathologic diagnosis of microcystic maldevelopment in infants with the presumptive diagnosis of PBA. Methods: A retrospective review of prenatal and postnatal records of patients diagnosed with fetal lung lesions was performed. Two groups of patients were identified: (1) patients diagnosed with PBA on postnatal CT scan (n = 16), and (2) patients with the pathologically confirmed diagnosis of PBA independent of postnatal CT findings (n = 23). Results: Prenatal ultrasound diagnosis of these lesions included CCAMs, hybrid lesions, bronchopulmonary sequestrations and bronchial atresia. Eleven of the 16 patients in group 1 with the postnatal radiologic diagnosis of PBA underwent surgical resection, 6 of which were found to have microcystic changes consistent with CCAM. Evaluation of the 23 patients in group 2 with pathologically confirmed PBA identified 65% that had evidence of microcystic maldevelopment consistent with the small cyst type of CCAM. Conclusion: Radiographically diagnosed PBA as well as pathologically confirmed PBA is frequently associated with microcystic changes consistent with the small cyst type of CCAM. Thus, operative management should be considered for PBA to decrease CCAM-associated risks.
In vivo Intrauterine Sound Pressure and Temperature Measurements during Magnetic Resonance Imaging (1.5 T) in Pregnant Ewes
Authors: Ruckhäberle E. , Nekolla S.G. , Ganter C. , Schneider K.T.M. , Peter A. , Raidt A. , Kovacs L. , Brockmeier S.J. , Schwaiger M. , Oberhoffer R. , Papadopulos N.A.
Published: August 2008

Objective: To investigate the influence of several magnetic resonance imaging (MRI) sequences on amniotic fluid temperature and intrauterine sound pressure. Material and Methods: Temperature and sound pressure measurements during MRI (1.5 T) in pregnant ewes were done. Linear levels and third octave band spectra were compared. Results: No significant changes in the temperature of amniotic fluid were observed. Intrauterine summation levels reached peak levels up to 103.0 dB(A) before starting the MRI sequence and levels up to 116.0 dB(A) during a real-time sequence. Evaluating the octave band spectra, peak levels did not exceed 100.0 dB(L). Conclusions: Our delimited data revealed no harm for the fetus by an increase in amniotic fluid temperature or hazards for the fetal auditory system by different MRI sequences.
Safer Cordocentesis by New 25-Gauge Needles
Authors: Kawakami Yuichi , Matsuda Hideo , Shibasaki Tomoko , Yoshida Masashi , Furuya Kenichi
Published: August 2008

Objective: The objective of this study was to establish safer cordocentesis by using newly produced 25-gauge needles rather than the needles currently used. Methods: Human umbilical cords were preserved in experiment 1. Pinching both ends, cordocenteses were performed by filling the cord with saline inside the sphere of the pressure-equilibrated Ringer’s solution bag in an aquarium. Pressure alterations were recorded before and after the cordocenteses (n = 5 in each needle) using 22-, 23-, and 25-gauge needles. In experiment 2, human umbilical blood after delivery was preserved. Umbilical blood was drawn in syringes, and fixed in syringe infusion pumps of 150 ml/h. The blood (n = 8) was then pushed into the test tubes through 22-, 23-, and 25-gauge needles. Hemolysis and platelet activation were evaluated. As in the case of clinical data, non-stress tests (NST) subsequent to cordocenteses were compared between 23-gauge (n = 19) and 25-gauge (n = 16) needles. Results: In experiment 1, the 25-gauge cordocenteses documented a more favorable pressure curve than other needles. In experiment 2, no statistical significance was observed for plasma-free hemoglobin, total bilirubin, hemoglobin, AST, LDH, potassium, platelet count, β-thromboglobulin, and platelet factor IV. As in the case of clinical data, NSTs subsequent to cordocenteses revealed strong significance in the duration to recover variability (p = 0.0003) and the duration to recover acceleration (p = 0.0033). Conclusion: We concluded that 25-gauge needles appear superior in avoiding blood loss in the leaking phase. Although blood drawing takes time in the sampling phase, no hemolysis or platelet activation was observed. NST proved that 25-gauge cordocenteses showed favorable patterns. We propose that use of 25-gauge needles is promising under appropriate procedures in cordocentesis.
Percutaneous Fetal Sclerotherapy for Congenital Cystic Adenomatoid Malformation of the Lung
Authors: Bermúdez Carlos , Pérez-Wulff Juan , Arcadipane Mauricio , Bufalino Gesualdo , Gómez Libardo , Flores Luis , Sosa Cristian , Bornick Patricia W. , Kontopoulos Eftichia , Quintero Rubén A.
Published: August 2008

Objectives: Congenital cystic adenomatoid malformation (CCAM) is a rare lesion of the developing fetal lung consisting of increased cell proliferation in the bronchial structures with lack of differentiation of the alveoli. Pregnancies may be at an increased risk for perinatal loss with type III CCAM. The purpose of this paper is to present our experience with the management of complicated types II and III CCAM with a novel technique: percutaneous ultrasound-guided fetal sclerotherapy (FST). Methods: Three patients were referred with type II–III CCAM. Poor prognostic factors included hydrops, severe mediastinal shift, polyhydramnios and early gestational age (<26 weeks). Patients signed an informed consent. FST was performed with percutaneous injection of Ethamolin (ethanolamine oleate) or Polidocanol (aethoxysklerol) under ultrasound guidance using a 22-gauge needle. Results: Resolution of hydrops and of the mass effect was observed in all cases without any complications. All patients were delivered at term. Conclusions: Fetal sclerotherapy is a novel approach to the management of complicated type II–III CCAM. Further studies are indicated to assess the risks and benefits of this innovative technique.
Long-Term Prognosis of Steroid-Dependent Sensorineural Hearing Loss
Authors: Kanzaki Jin , Kanzaki Sho , Ogawa Kaoru
Published: August 2008

We report on the long-term follow-up of 15 patients with steroid-dependent sensorineural hearing loss (SDSNHL), which was steroid dose dependent. We classified the patients into 2 groups: group A consisted of 6 patients with systemic SDSNHL, and group B consisted of 9 patients with inner-ear-specific SDSNHL without systemic disease. Group B patients were further classified as patients with slowly or rapidly progressive hearing loss. The yearly rate of hearing deterioration was greater in group B than in group A. Thus, the long-term hearing prognosis of patients in group B was worse than those in group A. Although SDSNHL may have immune-related origins, we hypothesize that hearing deterioration may be caused by proinflammatory cytokines because many of our cases exhibited abnormal immunological laboratory values and because many of these cases responded favorably to steroid treatment.
Role of Serum- and Glucocorticoid-Inducible Kinase SGK1 in Glucocorticoid Regulation of Renal Electrolyte Excretion and Blood Pressure
Authors: Boini Krishna M. , Nammi Srinivas , Grahammer Florian , Osswald Hartmut , Kuhl Dietmar , Lang Florian
Published: August 2008

Background/Aims: The serum- and glucocorticoid-inducible kinase SGK1 was originally cloned as a glucocorticoid-regulated gene and later as a transcriptional target for mineralocorticoids. SGK1 regulates channels and transporters including the renal Na+ channel ENaC. It contributes to mineralocorticoid regulation of renal Na+ excretion and salt appetite. The present study explored the contribution of SGK1 to effects of glucocorticoids on mineral and electrolyte metabolism. Methods: SGK1-knockout mice (sgk1–/–) and their wild-type littermates (sgk1+/+) were analyzed in metabolic cages with or without treatment for 14 days with dexamethasone (3 mg/kg b.w., i.p.). Blood pressure was determined by the tail-cuff method. Results: Prior to treatment fluid intake, urinary flow rate, urinary Na+, K+, phosphate and Cl– excretion, plasma electrolyte and glucose concentrations as well as blood pressure were similar in sgk1–/– and sgk1+/+ mice. Dexamethasone did not significantly alter renal Na+, K+, Cl– and Ca2+ excretion but decreased plasma Ca2+ and phosphate concentration in sgk1+/+ mice. The effect on Ca2+ was significantly augmented and the effect on phosphate significantly blunted in sgk1–/– mice. Dexamethasone significantly increased fasting blood glucose concentrations in both genotypes. Dexamethasone increased blood pressure in sgk1+/+ mice, an effect significantly blunted in sgk1–/– mice. Conclusions: The present observations disclose SGK1-sensitive glucocorticoid effects on calcium-phosphate metabolism and blood pressure.
Specific Residues of RUNX2 Are Obligatory for Formation of BMP2-Induced RUNX2-SMAD Complex to Promote Osteoblast Differentiation
Authors: Javed Amjad , Afzal Faiza , Bae Jong-Sup , Gutierrez Soraya , Zaidi Kaleem , Pratap Jitesh , van Wijnen Andre J. , Stein Janet L. , Stein Gary S. , Lian Jane B.
Published: August 2008

BMP2 signaling and RUNX2 regulatory pathways converge for transcriptional control of bone formation in vivo. SMAD proteins are recruited to RUNX2 regulatory complexes via an overlapping nuclear matrix targeting signal/Smad interacting domain sequence (391–432) in Runx2. To establish the contribution of RUNX2-SMAD interaction to osteoblastogenesis, we characterized a number of point mutants. Only a triple mutation of amino acids 426–428 (HTY-AAA) results in loss of RUNX2 interactions with either BMP2- or TGF-β- responsive SMADs and fails to integrate the BMP2/TGF-β signal on target gene promoters. In a Runx2 null cell reconstitution assay, the HTY mutant did not activate the program of osteoblast differentiation (alkaline phosphatase, collagen type 1, osteopontin, bone sialoprotein and osteocalcin) in response to BMP2 signaling. Thus, subnuclear targeting function and formation of a RUNX2-SMAD osteogenic complex are functionally inseparable. Taken together, these studies provide direct evidence that RUNX2 is essential for execution and completion of BMP2 signaling for osteoblast differentiation.
Tiotropium Bromide Attenuates Respiratory Syncytial Virus Replication in Epithelial Cells
Authors: Iesato Ken , Tatsumi Koichiro , Saito Kengo , Ogasawara Takashi , Sakao Seiichiro , Tada Yuji , Kasahara Yasunori , Kurosu Katsushi , Tanabe Nobuhiro , Takiguchi Yuichi , Kuriyama Takayuki , Shirasawa Hiroshi
Published: August 2008

Background: Respiratory syncytial virus (RSV) infection could be related to airway inflammation as well as exacerbation of chronic obstructive pulmonary disease (COPD). Tiotropium bromide decreases the frequency of exacerbation in patients with COPD; however, the mechanisms of tiotropium bromide to reduce the chances of exacerbation have not been defined. One potential mechanism could be that tiotropium bromide protects against RSV infection in epithelial cells. Objective: To examine whether tiotropium bromide affects RSV replication in HEp-2 cells. Methods: The supernatant titer of RSV was calculated by methylcellulose plaque assay after RSV innoculation. Intracellular RSV and ICAM-1 mRNA were measured by PCR. Syncytium formation was observed by light microscopy. Intracellular RSV fusion protein and RhoA protein were detected by Western blot analysis. Furthermore, RhoA activity, ICAM-1 expression and inflammatory cytokines in cultured supernatant were measured by binding assay, immunofluorescence staining and ELISA, respectively. Results: Tiotropium bromide decreased the supernatant titer of RSV, and it inhibited syncytium formation, RhoA activation and ICAM-1 expression. Moreover, it suppressed the production of IL-6 and IL-8 after RSV infection. Conclusions:The antiviral effects of tiotropium bromide regarding RSV replication are partly due to inhibition of RhoA activity and ICAM-1 expression. Tiotropium bromide decreases RSV replication and may modulate airway inflammation by reducing the production of inflammatory cytokines.
The Derivation of Mesenchymal Stem Cells from Human Embryonic Stem Cells
Authors: Brown Shelley E. , Tong Wilbur , Krebsbach Paul H.
Published: August 2008

Human embryonic stem cells (hESCs) hold promise for tissue regeneration therapies by providing a potentially unlimited source of cells capable of undergoing differentiation into specified cell types. Several preclinical studies and a few clinical studies use human bone marrow stromal cells (hBMSCs) to treat skeletal diseases and repair damaged tissue. However, hBMSCs have limited proliferation and differentiation capacity, suggesting that an alternate cell source is desirable, and hESCs may serve this purpose. Here we describe a protocol for the reproducible derivation of mesenchymal stem cells from hESCs (hES-MSCs). The hES-MSCs have a similar immunophenotype to hBMSCs, specifically they are CD73+, STRO-1+ and CD45–, and are karyotypically stable. The derived hES-MSCs are also capable of differentiating into osteoblasts and adipocytes. When the hES-MSCs were genetically modified with the lineage-specific Col2.3-GFP lentivirus and cultured in osteogenic medium, increased GFP expression was detected over time, indicating the hES-MSCs have the capacity to differentiate down the osteogenic lineage and had progressed toward a mature osteoblast phenotype.
All Numbers Are Not Equal: An Electrophysiological Investigation of Small and Large Number Representations
Authors: Hyde Daniel C. , Spelke Elizabeth S.
Published: August 2008

Behavioral and brain imaging research indicates that human infants, humans adults, and many nonhuman animals represent large nonsymbolic numbers approximately, discriminating between sets with a ratio limit on accuracy. Some behavioral evidence, especially with human infants, suggests that these representations differ from representations of small numbers of objects. To investigate neural signatures of this distinction, event-related potentials were recorded as adult humans passively viewed the sequential presentation of dot arrays in an adaptation paradigm. In two studies, subjects viewed successive arrays of a single number of dots interspersed with test arrays presenting the same or a different number; numerical range (small numerical quantities 1–3 vs. large numerical quantities 8–24) and ratio difference varied across blocks as continuous variables were controlled. An early-evoked component (N1), observed over widespread posterior scalp locations, was modulated by absolute number with small, but not large, number arrays. In contrast, a later component (P2p), observed over the same scalp locations, was modulated by the ratio difference between arrays for large, but not small, numbers. Despite many years of experience with symbolic systems that apply equally to all numbers, adults spontaneously process small and large numbers differently. They appear to treat small-number arrays as individual objects to be tracked through space and time, and large-number arrays as cardinal values to be compared and manipulated.
Dorsal Striatal–midbrain Connectivity in Humans Predicts How Reinforcements Are Used to Guide Decisions
Authors: Kahnt Thorsten , Park Soyoung Q , Cohen Michael X , Beck Anne , Heinz Andreas , Wrase Jana
Published: August 2008

It has been suggested that the target areas of dopaminergic midbrain neurons, the dorsal (DS) and ventral striatum (VS), are differently involved in reinforcement learning especially as actor and critic. Whereas the critic learns to predict rewards, the actor maintains action values to guide future decisions. The different midbrain connections to the DS and the VS seem to play a critical role in this functional distinction. Here, subjects performed a dynamic, reward-based decision-making task during fMRI acquisition. A computational model of reinforcement learning was used to estimate the different effects of positive and negative reinforcements on future decisions for each subject individually. We found that activity in both the DS and the VS correlated with reward prediction errors. Using functional connectivity, we show that the DS and the VS are differentially connected to different midbrain regions (possibly corresponding to the substantia nigra [SN] and the ventral tegmental area [VTA], respectively). However, only functional connectivity between the DS and the putative SN predicted the impact of different reinforcement types on future behavior. These results suggest that connections between the putative SN and the DS are critical for modulating action values in the DS according to both positive and negative reinforcements to guide future decision making.
Does White Matter Matter? Spatio-temporal Dynamics of Task Switching in Aging
Authors: Gratton Gabriele , Wee Emily , Rykhlevskaia Elena I. , Leaver Echo E. , Fabiani Monica
Published: August 2008

Older adults often encounter difficulties in switching between tasks, perhaps because of age-related decreases in executive function. Executive function may largely depend on connections between brain areas—connections that may become structurally and functionally weaker in aging. Here we investigated functional and structural age-related changes in switching between a spatial and a verbal task. These tasks were chosen because they are expected to differentially use the two hemispheres. Brain measures included anatomical information about anterior corpus callosum size (CC; the major commissure linking the left and right hemisphere), and the event-related optical signal (EROS). Behavioral results indicated that older adults had greater task-switching difficulties, which, however, were largely restricted to switching to the spatial task and to individuals with smaller anterior CCs. The EROS data showed both general switching-related activity in the left middle frontal gyrus (with approximately 300-msec latency) and task-specific activity in the inferior frontal gyrus, lateralized to the left for the switch-to-verbal condition and to the right for the switch-to-spatial condition. This lateralization was most evident in younger adults. In older adults, activity in the switch-to-spatial condition was lateralized to the right hemisphere in individuals with large CC, and to the left in individuals with small CC. These data suggest that (a) task switching may involve both task-general and task-specific processes; and (b) white matter changes may underlie some of the age-related problems in switching. These effects are discussed in terms of the hypothesis that aging involves some degree of cortical disconnection, both functional and anatomical.
Hemispheric Differences in Frontal and Parietal Influences on Human Occipital Cortex: Direct Confirmation with Concurrent TMS–fMRI
Authors: Ruff Christian C. , Blankenburg Felix , Bjoertomt Otto , Bestmann Sven , Weiskopf Nikolaus , Driver Jon
Published: August 2008

We used concurrent TMS–fMRI to test directly for hemispheric differences in causal influences of the right or left fronto-parietal cortex on activity (BOLD signal) in the human occipital cortex. Clinical data and some behavioral TMS studies have been taken to suggest right-hemisphere specialization for top–down modulation of vision in humans, based on deficits such as spatial neglect or extinction in lesioned patients, or findings that TMS to right (vs. left) fronto-parietal structures can elicit stronger effects on visual performance. But prior to the recent advent of concurrent TMS and neuroimaging, it was not possible to directly examine the causal impact of one (stimulated) brain region upon others in humans. Here we stimulated the frontal or intraparietal cortex in the left or right hemisphere with TMS, inside an MR scanner, while measuring with fMRI any resulting BOLD signal changes in visual areas V1–V4 and V5/MT+. For both frontal and parietal stimulation, we found clear differences between effects of right- versus left-hemisphere TMS on activity in the visual cortex, with all differences significant in direct statistical comparisons. Frontal TMS over either hemisphere elicited similar BOLD decreases for central visual field representations in V1–V4, but only right frontal TMS led to BOLD increases for peripheral field representations in these regions. Hemispheric differences for effects of parietal TMS were even more marked: Right parietal TMS led to strong BOLD changes in V1–V4 and V5/MT+, but left parietal TMS did not. These data directly confirm that the human frontal and parietal cortex show right-hemisphere specialization for causal influences on the visual cortex.
Differential Influences of Emotion, Task, and Novelty on Brain Regions Underlying the Processing of Speech Melody
Authors: Ethofer Thomas , Kreifelts Benjamin , Wiethoff Sarah , Wolf Jonathan , Grodd Wolfgang , Vuilleumier Patrik , Wildgruber Dirk
Published: August 2008

We investigated the functional characteristics of brain regions implicated in processing of speech melody by presenting words spoken in either neutral or angry prosody during a functional magnetic resonance imaging experiment using a factorial habituation design. Subjects judged either affective prosody or word class for these vocal stimuli, which could be heard for either the first, second, or third time. Voice-sensitive temporal cortices, as well as the amygdala, insula, and mediodorsal thalami, reacted stronger to angry than to neutral prosody. These stimulus-driven effects were not influenced by the task, suggesting that these brain structures are automatically engaged during processing of emotional information in the voice and operate relatively independent of cognitive demands. By contrast, the right middle temporal gyrus and the bilateral orbito-frontal cortices (OFC) responded stronger during emotion than word classification, but were also sensitive to anger expressed by the voices, suggesting that some perceptual aspects of prosody are also encoded within these regions subserving explicit processing of vocal emotion. The bilateral OFC showed a selective modulation by emotion and repetition, with particularly pronounced responses to angry prosody during the first presentation only, indicating a critical role of the OFC in detection of vocal information that is both novel and behaviorally relevant. These results converge with previous findings obtained for angry faces and suggest a general involvement of the OFC for recognition of anger irrespective of the sensory modality. Taken together, our study reveals that different aspects of voice stimuli and perceptual demands modulate distinct areas involved in the processing of emotional prosody.
Variability of Graupel and Snow Observed in Tropical Oceanic Convection by Aircraft during TRMM KWAJEX
Authors: Sukovich Ellen M. , Kingsmill David E. , Yuter Sandra E.
Published: August 2008

Empirical characterization of graupel and snow in precipitating tropical convective clouds is important for refining satellite precipitation retrieval algorithms and cloud-resolving and radiative transfer models. Microphysics data for this analysis were collected by the University of North Dakota (UND) Citation and the National Aeronautics and Space Agency (NASA) DC-8 aircraft during the Tropical Rainfall Measuring Mission (TRMM) Kwajalein Experiment (KWAJEX) in the western tropical Pacific Ocean. An ice particle identification algorithm was applied to two-dimensional optical array probe data for the purpose of identifying ice particle ensembles dominated by graupel or snow particles. These ensembles were accumulated along 1-km flight segments at temperatures below 0°C. A third category, mixed graupel/snow, has characteristics between those of the predominately graupel and snow ensembles and can be used either in combination with the other two categories or separately. Snow particle ensembles compose 80% of UND Citation and 98% of NASA DC-8 ensemble data. For the UND Citation, graupel ensembles compose ∼5% of the total with mixed graupel/snow ensembles composing ∼15%. There were no graupel ensembles in the NASA DC-8 data, which were collected primarily at temperatures <−35°C. Particles too small to classify (<150-μm maximum dimension) compose 56% of UND Citation and 64% of NASA DC-8 particle images. Nearly all these “tiny” particles occur coincident with particles >∼150 μm. Combining data from both aircraft, snow and mixed graupel/snow ensembles were evident over the full range of subfreezing temperatures (from 0° to −65°C) sampled by the aircraft. In contrast, graupel ensembles were present primarily at temperatures >−10°C. Accurate graupel identification was further supported by all graupel ensembles observed either coincident with or within a 10-km horizontal distance of radar-identified convective precipitation structures.
Wavelet Analysis of the Convectively Coupled Equatorial Waves in the Wavenumber–Frequency Domain
Authors: Wong Martin L. M.
Published: August 2008

Wavelet analysis is performed on 31 yr (1975–2007, except 1978 and 1979) of daily outgoing longwave radiation data in the global equatorial region (15°S–15°N). Power spectra in the zonal wavenumber–frequency domain are obtained. With different scales and bandwidths than in previous Fourier-based analysis, peaks of variances that are associated with the various convectively coupled waves are found. Further, possibly because of the ability to resolve shorter waves that have limited zonal extent, significant variances are also found at tropical depression–type scales. However, waves of zonal wavenumber zero cannot be explicitly analyzed.
Tropical SST Response to Global Warming in the Twentieth Century
Authors: Zhu Xiaojie , Liu Zhengyu
Published: August 2008

The trend of sea surface temperature (SST) in the twentieth century is examined in observations and the Intergovernmental Panel on Climate Change (IPCC) twentieth-century simulations. The observed SST neither shows a clear signal of the enhanced equatorial response (EER) warming nor exhibits a clear trend of the El Niño–like warming in the last century. Similarly, the IPCC simulations show neither a clear EER warming nor an El Niño–like warming in the last century. Furthermore, the comparison of heat fluxes in model simulations of the global warming scenario and the twentieth century indicates that the aerosol cooling effect, opposite to the greenhouse gases warming effect, plays an important role in the twentieth century and explains the EER-like signal in the twentieth-century simulations. Therefore, a conclusion that the IPCC model simulations of the twentieth century are consistent with observations within the error bars as well as the future projection of the EER warming pattern in the global warming scenario are validated.