bluuebunny/crossref_metadata_2025 huggingface dataset:
Seed micromorphology supports the splitting ofLimnorchisfromPlatanthera(Orchidaceae)
Authors: Gamarra Roberto , Galán Pablo , Herrera Irene , Ortúñez Emma
Published: November 2008

Seeds of several species of the generaPlatantheraandHabenariahave been studied by means of scanning electron microscopy. In the genusPlatanthera, two morphological patterns were found. One of these appears in the so‐called ‘dilatata–hyperboreacomplex’. It is proposed that this pattern is a good diagnostic character to split off this group of species into the genusLimnorchis. InHabenaria, the morphological patterns vary between the species and differs completely from those found inPlatanthera.
A Nonlinear Rubber Material Model Combining Fractional Order Viscoelasticity and Amplitude Dependent Effects
Authors: Gil-Negrete N. , Vinolas J. , Kari L.
Published: November 2008

A nonlinear rubber material model is presented, where influences of frequency and dynamic amplitude are taken into account through fractional order viscoelasticity and plasticity, respectively. The problem of simultaneously modeling elastic, viscoelastic, and friction contributions is removed by additively splitting them. Due to the fractional order representation mainly, the number of parameters of the model remains low, rendering an easy fitting of the values from tests on material samples. The proposed model is implemented in a general-purpose finite element (FE) code. Since commercial FE codes do not contain any suitable constitutive model that represents the full dynamic behavior of rubber compounds (including frequency and amplitude dependent effects), a simple approach is used based on the idea of adding stress contributions from simple constitutive models: a mesh overlay technique, whose basic idea is to create a different FE model for each material definition (fractional derivative viscoelastic and elastoplastic), all with identical meshes but with different material definition, and sharing the same nodes. Fractional-derivative viscoelasticity is implemented through user routines and the algorithm for that purpose is described, while available von Mises’ elastoplastic models are adopted to take rate-independent effects into account. Satisfactory results are obtained when comparing the model results with tests carried out in two rubber bushings at a frequency range up to 500 Hz, showing the ability of the material model to accurately describe the complex dynamic behavior of carbon-black filled rubber compounds.
Snap-Through of Shallow Elastic Arches Under End Moments
Authors: Plaut Raymond H.
Published: November 2008

Snap-through of buckled beams or shallow arches may be utilized in some MEMS devices. Such behavior can be induced by applied moments at the ends. A simply-supported uniform shallow elastic arch is analyzed. For equal end moments, the critical value is compared for arches with a sinusoidal shape, a circular shape, and a shape that maximizes the critical moment. For unequal moments, the effect of the amount of loading asymmetry on the critical value is determined for sinusoidal arches.
Spatial Distribution of Pacific Halibut (Hippoglossus stenolepis): An Application of Geostatistics to Longline Survey Data
Authors: Pelletier Dominique , Parma Ana M.
Published: November 2008

The spatial distribution of Pacific halibut (Hippoglossus stenolepis) in the Gulf of Alaska was analyzed using longline catch per unit of effort (CPUE) data collected during three grid surveys in 1984, 1985, and 1986. Geostatistical techniques were used: (i) a variographic analysis to model and estimate the spatial structure of halibut abundance and (ii) ordinary kriging to predict local abundance. Available small-scale information made it possible to model satisfactorily the spatial structure. Results show (i) a persistent large-scale east–west difference in average CPUE and (ii) spatially correlated CPUE data with an average covariance decreasing as the distance between observations increased, over a range of 0–20 nautical miles (nmi) in 1984 and 1985, and 50 nmi in 1986. The survey design had limitations in that it was too unbalanced, with stations very close together along north–south transects, and transects too far apart from each other. Consequently, prediction error was small close to the transects and large in between in a clear banded pattern. To achieve a more regular coverage of the same area, a new survey design was developed: the global variances obtained with this new design using the variogram parameters for 1985 and 1986 were 20% lower than those based on the old design.
A Preseason Simulation Model for Fisheries on Fraser River Sockeye Salmon (Oncorhynchus nerka)
Authors: Cave James D. , Gazey William J.
Published: November 2008

Using a preseason fishery simulation model that refines previous reconstruction models, we explored the effects of various fishing regimes on annual catch and escapement of the major stocks of Fraser River sockeye salmon (Oncorhynchus nerka). To obtain harvest rate parameters for the model, we analyzed historical fishery catches to develop a theory of fish movement through time and space. Harvest parameters were then calculated using run reconstruction techniques. The model uses a daily time step to move fish sequentially through the major fishing areas. Fishing scenarios may be examined in the preseason to aid in developing annual management plans. Inputs of run size, timing, and diversion rate via Johnstone Strait are used to calculate run-timing curves which are normally distributed. The proportion of sockeye migrating via the northern approach or Johnstone Strait diversion, is shown to be a major factor in the sensitivity of fishing plans to altered input parameters. Clearly stated goals and objectives for spawning escapement and allocation of catch by stock groups are essential in the modelling process. The model permits managers to examine underlying assumptions and biological, economic, and social requirements centred on the harvest of these stocks.
Zooplankton Assemblages in the Ohio River: Seasonal, Tributary, and Navigation Dam Effects
Authors: Thorp James H. , Black A. Ross , Haag Kim H. , Wehr John D.
Published: November 2008

Ohio River Zooplankton were collected monthly or quarterly for 1 yr from littoral and pelagic (main channel) areas in three navigation pools (constricted and floodplain) with four intrapool locations (lower pool and above, below, and within major tributaries). Total densities were minimal (1.64/L) when discharge and turbidities peaked (December–April) but were relatively high otherwise (21.63/L). Seasonal rises in rotifer density preceded increases in cladocerans and copepods; rotifers were nearly twice as abundant as cladocerans and copepods. Diversity (species richness) was not correlated with temperature, velocity, or turbidity. Density was positively linked with temperature and negatively correlated with river velocity and turbidity. Diversities in littoral and pelagic areas were not different, but densities were higher nearshore (mostly copepods and cladocerans); rotifers were usually more common in the main channel. Neither proximity to low-head navigation dams nor channel morphology had detectable effects on zooplankton. Although total diversity and density were similar in tributaries and the main channel, rotifers were more abundant in tributaries, and the Ohio contained more cladocerans and copepods. Densities in the Ohio were greater below than above tributaries for rotifers and cladocerans but lower for copepods, primarily because of nauplii.
Effect of Changes in Streamflow on the Microhabitat Use and Movements of Sympatric Juvenile Coho Salmon (Oncorhynchus kisutch) and Chinook Salmon (O. tshawytscha) in a Natural Stream
Authors: Shirvell C. S.
Published: November 2008

The microhabitats at positions selected by juvenile coho (Oncorhynchus kisutch) and chinook salmon (O. tshawytscha) following a change in streamflow differed from microhabitats occupied at normal streamflows. At drought streamflow (37% mean seasonal streamflow (MSF)), juvenile coho salmon selected slower, darker, and higher sites above the streambed (P < 0.05) than sites selected at normal (75% MSF) or flood (159% MSF) flows. Juvenile chinook salmon microhabitat use changed similarly with changes in streamflow, but the differences were not significant. Up to one fifth of the fish chose positions with faster water velocities than those available either 30 cm above or 30 cm lateral to them. These fish chose positions inconsistent with the hypothesis of optimal position selection based on maximizing net energy gain. On average, fish moved 6.8 m following a change in streamflow. Juvenile coho salmon generally moved upstream in response to decreasing streamflows and downstream in response to increasing streamflows. Juvenile chinook salmon tended to move offshore and downstream in response to all streamflow changes. These results show that juvenile coho and chinook salmon will move to find suitable microhabitat following a change in streamflow and that the microhabitats are not the same at all streamflows.
Regulation of glucocorticoid sensitivity in thymocytes from burn-injured mice
Authors: D'Elia Michele , Patenaude Julie , Bernier Jacques
Published: November 2008

Glucocorticoids (GC) are important steroid hormones that regulate metabolism, development, and the immune system. GC are produced continuously, and maximal levels are reached following stress-related stimuli. Previous studies have demonstrated that increased GC production following thermal injury was responsible for thymic involution. Although GC are mainly synthesized by the adrenal glands, there is increasing evidence that GC may also be produced in nonadrenal tissues. The thymus was reported to express steroidogenic enzymes and to release GC. 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is predominantly a reductase in cells and is essential for the local reactivation of GC. Here, we report that increased GC-induced apoptosis in thymocytes from burn-injured mice is related to increased glucocorticoid receptor (GR) expression and 11β-HSD1 expression in thymocytes at day 1 postburn injury. In vitro, thymocytes were able to convert 11-dehydrocorticosterone (DHC) to corticosterone (CORT), which induced their apoptosis, and this was pharmacologically inhibited by 18β-glycyrrhetinic acid, a specific 11β-HSD inhibitor. Moreover, 11β-HSD1 expression was confirmed in the 267S3 thymoma-derived cell line, and its activity was responsible for greater sensitivity of these cells to CORT-induced apoptosis. Finally, proinflammatory cytokines [tumor necrosis factor-α, interleukin (IL)-1β, and IL-6] increased thymocyte sensitivity to DHC-induced apoptosis through a mechanism involving 11β-HSD1. Overall, we have shown that burn injury induced 11β-HSD1 expression in thymocytes, which led to a greater sensitivity of these cells to CORT-induced apoptosis. Increased expression of 11β-HSD1 and GR may play a role in intrathymic T cell development and can be major determinants of GC sensitivity after a trauma.
Impaired mitochondria-dependent vasodilation in cerebral arteries of Zucker obese rats with insulin resistance
Authors: Katakam Prasad V. G. , Domoki Ferenc , Snipes James A. , Busija Anna R. , Jarajapu Yagna P. R. , Busija David W.
Published: November 2008

Mitochondria affect cerebrovascular tone by activation of mitochondrial ATP-sensitive K+ (KATP) channels and generation of reactive oxygen species (ROS). Insulin resistance accompanying obesity causes mitochondrial dysfunction, but the consequences on the cerebral circulation have not been fully identified. We evaluated the mitochondrial effects of diazoxide, a putative mitochondrial KATP channel activator, on cerebral arteries of Zucker obese (ZO) rats with insulin resistance and lean (ZL) controls. Diameter measurements showed diminished diazoxide-induced vasodilation in ZO compared with ZL rats. Maximal relaxation was 38 ± 3% in ZL vs. 21 ± 4% in ZO rats ( P < 0.05). Iberiotoxin, a Ca2+-activated K+ channel inhibitor, or manganese(III) tetrakis(4-benzoic acid)porphyrin chloride, an SOD mimetic, or endothelial denudation diminished vasodilation to diazoxide, implicating Ca2+-activated K+ channels, ROS, and endothelial factors in vasodilation. Inhibition of nitric oxide synthase (NOS) in ZL rats diminished diazoxide-induced vasodilation in intact arteries, but vasodilation was unaffected in endothelium-denuded arteries. In contrast, NOS inhibition in ZO rats enhanced vasodilation in endothelium-denuded arteries, but intact arteries were unaffected, suggesting that activity of endothelial NOS was abolished, whereas factors derived from nonendothelial NOS promoted vasoconstriction. Fluorescence microscopy showed decreased mitochondrial depolarization, ROS production, and nitric oxide generation in response to diazoxide in ZO arteries. Protein and mRNA measurements revealed increased expression of endothelial NOS and SODs in ZO arteries. Thus, cerebrovascular dilation to mitochondria-derived factors involves integration of endothelial and smooth muscle mechanisms. Furthermore, mitochondria-mediated vasodilation was diminished in ZO rats due to impaired mitochondrial KATP channel activation, diminished mitochondrial ROS generation, increased ROS scavenging, and abnormal NOS activity.
Methods for Determining Frequency- and Region-Dependent Relationships Between Estimated LFPs and BOLD Responses in Humans
Authors: Martuzzi Roberto , Murray Micah M. , Meuli Reto A. , Thiran Jean-Philippe , Maeder Philippe P. , Michel Christoph M. , Grave de Peralta Menendez Rolando , Gonzalez Andino Sara L.
Published: November 2008

The relationship between electrophysiological and functional magnetic resonance imaging (fMRI) signals remains poorly understood. To date, studies have required invasive methods and have been limited to single functional regions and thus cannot account for possible variations across brain regions. Here we present a method that uses fMRI data and singe-trial electroencephalography (EEG) analyses to assess the spatial and spectral dependencies between the blood-oxygenation-level-dependent (BOLD) responses and the noninvasively estimated local field potentials (eLFPs) over a wide range of frequencies (0–256 Hz) throughout the entire brain volume. This method was applied in a study where human subjects completed separate fMRI and EEG sessions while performing a passive visual task. Intracranial LFPs were estimated from the scalp-recorded data using the ELECTRA source model. We compared statistical images from BOLD signals with statistical images of each frequency of the eLFPs. In agreement with previous studies in animals, we found a significant correspondence between LFP and BOLD statistical images in the gamma band (44–78 Hz) within primary visual cortices. In addition, significant correspondence was observed at low frequencies (<14 Hz) and also at very high frequencies (>100 Hz). Effects within extrastriate visual areas showed a different correspondence that not only included those frequency ranges observed in primary cortices but also additional frequencies. Results therefore suggest that the relationship between electrophysiological and hemodynamic signals thus might vary both as a function of frequency and anatomical region.
Clinical Course of Virologic Breakthrough after Emergence of YMDD Mutations in HBeAg-Positive Chronic Hepatitis B
Authors: Kim Do Young , Ahn Sang Hoon , Lee Hyun Woong , Park Jun Yong , Kim Seung Up , Paik Yong Han , Lee Kwan Sik , Han Kwang-Hyub , Chon Chae Yoon
Published: November 2008

Objective: High rate of resistance to lamivudine is a major problem in treating chronic hepatitis B (CHB) patients. We investigated the course of virologic breakthrough (VB) after emergence of YMDD mutants in CHB patients receiving lamivudine. Methods: Ninety-three consecutive HBeAg-positive CHB patients treated with lamivudine (100 mg/day) who developed YMDD mutants and VB were enrolled. The clinical breakthrough (CB) was defined by elevation of alanine aminotransferase (ALT) >2 times the upper limit of normal. Results: The median age was 47 years, and genotype of hepatitis B virus (HBV) was all C. The median duration of lamivudine administration was 39 months, and median pre-lamivudine ALT and HBV DNA were 165 IU/l and 1.2 × 108 copies/ml. In all patients, CB concurred with VB or appeared some months following VB. When patients were divided into two groups according to time sequence of two breakthroughs – group 1 (VB followed by CB, n = 68) and group 2 (concurrent VB and CB, n = 25) – there was no difference in patient and virologic characteristics between the two groups. The median time from VB to CB was 8 months in group 1. Conclusion: VB might eventually progress to CB in HBeAg-positive patients harboring YMDD mutants with high pretreatment ALT and HBV DNA.
Survival and Complications of Beta-Thalassemia in Lebanon
Authors: Charafeddine K. , Isma’eel H. , Charafeddine M. , Inati A. , Koussa S. , Naja M. , Taher A.
Published: November 2008

β-Thalassemia major is a debilitating disease with a considerable incidence in Lebanon (around 2–3% carriership). The present article describes our experience to this day with 214 patients, emphasizing the survival of β-thalassemia major and development of complications among patients with different parameters. Fifteen deaths were reported. The most common cause of death was heart failure (60%). Patients with a ferritin level of 3,000 ng/ml showed better survival than those with a level >3,000 ng/ml (p < 0.006). In addition, patients with a ferritin level of 1,500 ng/ml showed less complication-free survival than those with a level >1,500 ng/ml (p < 0.024). High level of ferritin (1,500 ng/ml) is associated with increased risk of heart failure. Overall and complication-free survival were statistically different among patients classified according to birth cohort or ferritin level. The Chronic Care Center, a multidisciplinary center located in the suburbs of Beirut, led to an increase in complication-free as well as overall survival. Although patients are being diagnosed earlier and chelation therapy is being initiated at an earlier age, complications due to iron overload still persist. The introduction of new oral iron chelators and better iron overload quantitation methods will most likely modify this picture, and a follow-up study will examine their impact.
Nephrotoxicity of Cyclosporine A in the Rat
Authors: Schmid Heide , Schmitt Hans , Eissele Rolf , Neuhaus Gisela
Published: November 2008

The intranephronal distribution pattern of the activity of succinate dehydrogenase, a marker enzyme of mitochondrial inner membranes, was examined by histochemical investigation in the kidneys of 27 male Sprague-Dawley rats. The animals received cyclosporine A per os (15 30 or 50 mg/kg day) for 12 or 24 days. Six animals of the latter group remained untreated for a further 24 days. Five rats treated orally with 30 mg/kg day olive oil served as controls. The kidneys of 2 normal male Sprague-Dawley rats were examined for comparison. Cyclosporine A reversibly induced a characteristic pattern of nephron segments with various degrees of reduced succinate dehydrogenase activity: in the proximal and distal tubules of subcapsular areas of the cortical labyrinth, of the medullary rays, and of the outer stripe of the outer medulla. The remaining areas contained tubules with normal succinate dehydrogenase activity, as confirmed by microphotometrical measurement. The number of these tubules appeared to be decreased under higher doses of cyclosporine A, irrespective of the duration of treatment. The finding of heterogeneous affection of tubular mitochondrial cristae membranes reflects direct tubulotoxicity of cyclosporine A.
Ammoniagenesis in Renal Cell Culture
Authors: Gstraunthaler Gerhard , Landauer Franz , Pfaller Walter
Published: November 2008

In renal ammoniagenesis, two major pathways of glutamine metabolism have been described: (i) intracellular metabolism by phosphate-dependent glutaminase (PDG) and glutamate dehydrogenase and (ii) extracellular metabolism by phosphate-independent glutaminase. The latter has been identified as the hydrolytic activity of the apically membrane-bound γ-glutamyl transpeptidase (γ-GT). The growth properties of cultured renal epithelia enable the study of in vitro extracellular metabolic properties occurring at the apical epithelial surface in the culture dish. Therefore, confluent epithelia of the LLC-PK1 renal epithelial cell line were used to elucidate the role of extracellular (apical) hydrolysis of glutamine by γ-GT in LLC-PK1 ammonia production. To distinguish between intra- and extracellular metabolism of glutamine, confluent LLC-PK1 epithelia were incubated with either D-glutamine as substrate, which cannot be metabolized intracellularly by PDG, or with L-glutamine and hippurate to stimulate, and AT-125 (acivicin) to inhibit γ-GT activity, respectively. In addition, cellular uptake of the glutamate, extracellularly formed by γ-GT, was inhibited by D-aspartate. D-Glutamine (2 mM) did not increase ammonia formation above endogenous production levels, indicating the negligible role of extracellular hydrolysis of glutamine by γ-GT. After modulating γ-GT activity by hippurate or AT-125, almost identical ammonia production rates were found within the various experimental protocols, further confirming that extracellular metabolism of glutamine does not significantly contribute to LLC-PK1 ammoniagenesis.
Proximal Na+, Fluid and HCO-3 Reabsorption in Uninephrectomized Rats after a Saline Load
Authors: Laughlin Mac , Malnic G. , de Mello Aires M.
Published: November 2008

We studied the effect of a saline load on proximal tubular Na+, fluid and HCO-3 handling of control and uninephrectomized (UNx) rats. Glomerular filtration rate (GFR) was measured by inulin clearance, Na+ reabsorption in the proximal tubule by lithium clearance (CLi+), proximal tubule fluid reabsorption (Jv) by microperfusion with l4C inulin and proximal tubule HCO-3 reabsorption (JHCO-3) by estimating pH of perfusate and collected fluid in vitro under CO2 equilibrated oil by means of Sb microelectrodes. No significant differences were found between control and UNx animals in baseline values of urine flow, GFR, fractional water and sodium excretion and blood and urine pH and pCO2, showing that renal function was compensated 4 weeks after UNx. On the other hand, UNx rats showed a significant increase in proximal tubule Jv and JHCO-3. After extracellular fluid volume expansion (EFVE) by infusion of HCO-3 Ringer solution (0.1 ml/min) during 90-120 min, in both groups of animals hematocrit decreased by 15%, GFR remained unchanged and fractional Na+ and water excretion increased significantly. However, after EFVE Jv and JHCO-3 decreased significantly in control rats but were not modified in UNx animals. Fractional proximal Na+ reabsorption as measured by CLi+ decreased in control rats after EFVE and was not altered in UNx rats. After EFVE the fall in fractional distal Na+ reabsortion was significantly higher in control than in UNx rats. The present results provide evidence that after a saline load the impaired natriuretic response in UNx rats could be attributed to an alteration in proximal and distal tubular Na+ and HCO-3 handling. The data also showed a close correlation between proximal tubular function evaluated by CLi+ and by Jv.
Abnormal Gene Expression of Matrix Metalloproteinases and Their Inhibitor in Glomeruli from Diabetic Rats
Authors: Nakamura Tsukasa , Fukui Mitsumine , Ebihara Isao , Osada Shiori , Tomino Yasuhiko , Koide Hikaru
Published: November 2008

The steady state levels of mRNA encoding for metalloproteinase (MMP)-l -2, -3, and -9 and tissue inhibitor of metalloproteinase (TIMP)-1 were examined in glomeruli at 4,12, and 24 weeks after the injection of streptozocin (STZ) in rats. The mRNA levels for MMP-1 and MMP-3 decreased with age in STZ-induced diabetes. At 24 weeks after STZ injection, mRNA levels for MMP-1 and MMP-3 fell to 40% (p < 0.01) and 20% (p < 0.01), respectively, in the glomeruli of diabetic rats when compared with control rats. In contrast, mRNA levels for TIMP-1 increased significantly with age in the diabetic glomeruli and reached an 8-fold (p < 0.01) increase at 24 weeks after STZ injection. mRNA levels for MMP-2 were not altered in glomeruli from diabetic and control rats throughout the experimental period, whereas those for MMP-9 were not detected in glomeruli from either group of rats. Insulin treatment partially ameliorated the decrease in mRNA levels for MMP-1 and MMP-3 and the increase in those for TIMP-1 in the glomeruli of diabetic rats. These data indicate that abnormal gene regulation of MMPs and TIMP-1 in the glomeruli of diabetic rats may contribute to the progression of glomerular lesions and that hyperglycemia or insulin deficiency may be associated with abnormal MMPs and TIMP-1 gene regulation.
Multiple Pathways for ATP-lnduced Intracellular Calcium Elevation in Pheochromocytoma (PC12) Cells
Authors: Gollasch Maik , Haller Hermann
Published: November 2008

Extracellular ATP excites neurons in both the peripheral and central nervous system. To elucidate the mechanisms involved, we used spectrofluorometric analysis to study the pathways by which extracellular ATP elevates the intracellular Ca2+ concentration ([Ca2+]i) in individual, fura-2-loaded, rat pheochromocytoma PC12 cells. ATP ( > 1 µM) increased [Ca2+]i. The ATP effect on [Ca2+]i was completely abolished by a nominally Ca2+-free extracellular medium, which indicates that the ATP-induced increase in [Ca2+]i was due to an influx of extracellular Ca2+. We next applied specific blockers of voltage-dependent Ca2+ channels and used experimental protocols with depolarizing external K+-rich solutions. Our results show that ATP induces influx of extracellular Ca2+ through (a) dihydropyridine-sensitive (Ln-type) Ca2+ channels, (b) Ca2+-permeable, voltage-independent, Cd2+-insensitive cation channels, and (c) an as yet unidentified, voltage-dependent, Cd2+-sensitive Ca2+ influx system.
Stimulation of Lactate Production in Human Granulosa Cells by Metformin and Potential Involvement of Adenosine 5′ Monophosphate-Activated Protein Kinase
Authors: Richardson Malcolm C. , Ingamells Susan , Simonis Chantal D. , Cameron Iain T. , Sreekumar Rajiv , Vijendren Ananth , Sellahewa Luckni , Coakley Stephanie , Byrne Christopher D.
Published: November 2008

Context: Production of 3-carbon units (as lactate) by granulosa cells (GCs) is important in follicular and oocyte development and may be modulated by metformin.

Objective: The aim of the study was to examine the action of metformin on GC lactate production and potential mediation via AMP-activated protein kinase (AMPK).

Design: GCs were prepared from follicular aspirates. After exposure to metformin and other potential modulators of AMPK in culture, aspects of cellular function were examined.

Setting: The study was conducted in a private fertility clinic/university academic center.

Patients: Women undergoing routine in vitro fertilization participated in the study.

Interventions: All agents were added in culture.

Main Outcome Measures: Lactate output of GCs was measured. Cell extracts were prepared after culture, and phosphorylated forms of AMPK and acetyl CoA carboxylase (ACC) were assayed using Western analysis.

Results: Metformin led to a rapid increase in lactate production by GCs [minimum effective dose, 250 μm; maximum dose studied, 1 mm (1.22-fold; P < 0.01)]. This dose range of metformin was similar to that required for stimulation of phospho-AMPK in GCs [minimum effective dose, 250 μm; maximum effect, 500 μm (2.01-fold; P < 0.001)]. Increasing phospho-ACC, as a representative downstream target regulated by AMPK, was apparent over a lower range (minimum effective dose, 31 μm; maximum effect, 250 μm; P < 0.001). A level of metformin (125 μm) insufficient for the stimulation of lactate output when used alone potentiated the effects of suboptimal doses of insulin on lactate production. Adiponectin (2.5 μg/ml) had a small but significant effect on lactate output.

Conclusions: Metformin activates AMPK in GCs, stimulating lactate production and increasing phospho-ACC. Metformin also enhances the action of suboptimal insulin concentrations to stimulate lactate production.
Strong Resetting of the Mammalian Clock by Constant Light Followed by Constant Darkness
Authors: Chen Rongmin , Seo Dong-oh , Bell Elijah , von Gall Charlotte , Lee Choogon
Published: November 2008

The mammalian molecular circadian clock in the suprachiasmatic nuclei (SCN) regulates locomotor activity rhythms as well as clocks in peripheral tissues (Reppert and Weaver, 2002; Ko and Takahashi, 2006). Constant light (LL) can induce behavioral and physiological arrhythmicity by desynchronizing clock cells in the SCN (Ohta et al., 2005). We examined how the disordered clock cells resynchronize by probing the molecular clock and measuring behavior in mice transferred from LL to constant darkness (DD). The circadian locomotor activity rhythms disrupted in LL become robustly rhythmic again from the beginning of DD, and the starting phase of the rhythm in DD is specific, not random, suggesting that the desynchronized clock cells are quickly reset in an unconventional manner by the L/D transition. By measuring mPERIOD protein rhythms, we showed that the SCN and peripheral tissue clocks quickly become rhythmic again in phase with the behavioral rhythms. We propose that this resetting mechanism may be different from conventional phase shifting, which involves light induction ofPeriodgenes (Albrecht et al., 1997; Shearman et al., 1997; Shigeyoshi et al., 1997). Using our functional insights, we could shift the circadian phase of locomotor activity rhythms by 12 h using a 15 h LL treatment: essentially producing phase reversal by a single light pulse, a feat that has not been reported previously in wild-type mice and that has potential clinical utility.
New Developments in Sleep Research: Molecular Genetics, Gene Expression, and Systems Neurobiology
Authors: Kilduff Thomas S. , Lein Ed S. , de la Iglesia Horacio , Sakurai Takeshi , Fu Ying-hui , Shaw Paul
Published: November 2008

Understanding the mechanisms that underlie the control of sleep and wakefulness is a major research area in neuroscience. This mini-symposium review highlights some recent developments at the gene, molecular, cellular, and systems levels that have advanced this field. The studies discussed below use organisms ranging from flies to humans and focus on the interaction between the sleep homeostatic and circadian systems, the consequences of mutations in genes involved in the circadian clock on sleep timing, the effects of sleep deprivation on brain gene expression, the discovery of “sleep active” neurons in the cerebral cortex, the role of the hypocretin/orexin system in the maintenance of sleep and wakefulness, and the interaction between sleep and learning.
Amyloid-β Peptide (Aβ) Neurotoxicity Is Modulated by the Rate of Peptide Aggregation: Aβ Dimers and Trimers Correlate with Neurotoxicity
Authors: Hung Lin Wai , Ciccotosto Giuseppe D. , Giannakis Eleni , Tew Deborah J. , Perez Keyla , Masters Colin L. , Cappai Roberto , Wade John D. , Barnham Kevin J.
Published: November 2008

Alzheimer's disease is an age-related neurodegenerative disorder with its toxicity linked to the generation of amyloid-β peptide (Aβ). Within the Aβ sequence, there is a systemic repeat of a GxxxG motif, which theoretical studies have suggested may be involved in both peptide aggregation and membrane perturbation, processes that have been implicated in Aβ toxicity. We synthesized modified Aβ peptides, substituting glycine for leucine residues within the GxxxG repeat motif (GSL peptides). These GSL peptides undergo β-sheet and fibril formation at an increased rate compared with wild-type Aβ. The accelerated rate of amyloid fibril formation resulted in a decrease in the presence of small soluble oligomers such as dimeric and trimeric forms of Aβ in solution, as detected by mass spectrometry. This reduction in the presence of small soluble oligomers resulted in reduced binding to lipid membranes and attenuated toxicity for the GSL peptides. The potential role that dimer and trimer species binding to lipid plays in Aβ toxicity was further highlighted when it was observed that annexin V, a protein that inhibits Aβ toxicity, specifically inhibited Aβ dimers from binding to lipid membranes.
The Steady-State Level of the Nervous-System-Specific MicroRNA-124a Is Regulated by dFMR1 inDrosophila
Authors: Xu Xia-Lian , Li Yan , Wang Fay , Gao Fen-Biao
Published: November 2008

Fragile X syndrome is the most common form of inherited mental retardation caused by loss of the fragile X mental retardation protein 1 (FMRP). The detailed molecular pathways underlying the pathogenesis of this disorder remain incompletely understood. Here, we show that miR-124a, a nervous-system-specific miRNA, is associated with theDrosophilahomolog of FMRP (dFMR1)in vivo. Ectopic expression of wild-type but not mutant miR-124a precursors decreased dendritic branching of dendritic arborization sensory neurons, which was partially rescued by the loss of dFMR1 activity, suggesting that the biogenesis and/or function of miR-124a are partially dependent on dFMR1. Indeed, in contrast with the complete loss of mature miR-124a inDicer-1mutants, steady-state levels of endogenous or ectopically expressed mature miR-124a were partially reduced indfmr1mutants, whereas the level of pre-miR-124a increased. This effect could be explained in part by the reduced abundance of the Dicer-1-Ago1 complex in the absence of dFMR1. These findings suggest a modulatory role for dFMR1 to maintain proper levels of miRNAs during neuronal development.
Packet Transport for the Future InternetPaketorientierter Transport für das zukünftige Internet
Authors: Flinck Hannu , Gruber Claus G. , Hoffmann Marco , Kirstädter Andreas , Merkle Christian , Michaelis Thomas , Schupke Dominic A.
Published: November 2008

The enormous growth of bandwidth needs and the constant revenues of the carriers at the same time require the introduction of packet technologies in transport networks. The extension of Ethernet with carrier-grade features is a promising approach to provide necessary characteristics like scalability, quality of service, and operations, administration, and maintenance. Interesting technological aspects are multi-layer and multi-domain operation of these packet transport networks and their control via Generalized MPLS. A possible solution can be seen in a function split where IP stays the convergence platform for applications and services and Ethernet becomes the convergence platform for transport.
Diversifying the College Campus
Authors: Tienda Marta
Published: November 2008

One thing I know is that race-neutral alternatives to affirmative action have not diversified college campuses.
Acúmulo de massa seca e marcha de absorção de nutrientes em mudas de goiabeira 'Pedro Sato'
Authors: Augostinho Leonardo Mariano Dias , Prado Renato de Mello , Rozane Danilo Eduardo , Freitas Narimã
Published: November 2008

Objetivou-se determinar a curva de acúmulo da matéria seca de mudas e a marcha de absorção de macro e micronutrientes de goiabeira cultivar 'Pedro Sato'. O delineamento experimental foi o inteiramente casualizado, com três repetições. Foram utilizadas sete coletas de plantas de goiabeira 'Pedro Sato', em cultivo hidropônico, em casa de vegetação da Unesp, Campus de Jaboticabal. Nas coletas, avaliaram-se o crescimento das plantas e o acúmulo de nutrientes, a cada 15 dias, durante 120 dias após o transplantio. As mudas de goiabeira proporcionaram maior acúmulo de biomassa no órgão folha em relação ao caule e à raiz. Observou-se alta absorção dos nutrientes, no período de 60 a 90 dias após o transplantio, nas mudas de goiabeira. O acúmulo de nutrientes das mudas de goiabeira (planta inteira) foi de 340, 44, 380, 173, 33 e 40 mg planta-1, respectivamente para N, P, K, Ca, Mg, S, e de 743, 118, 5.114, 2.151, 566 mg planta-1, respectivamente, para B, Cu, Fe, Mn e Zn.
Desempenho de linhagens de trigo, oriundas de hibridações, em duas condições de cultivo do Estado de São Paulo e tolerância de alumínio em laboratório
Authors: Camargo Carlos Eduardo de Oliveira , Ferreira Filho Antonio Wilson Penteado , Felicio João Carlos , Gallo Paulo Boller , Lobato Mary Túlia Vargas , Biudes Gustavo Barnabé
Published: November 2008

Compararam-se 18 linhagens provenientes de cruzamentos entre genótipos de trigo comum (Triticum aestivum L.) e entre genótipos de trigo comum e de trigo duro (T. durum L.), e as cultivares-controle IAC-24 e IAC-370 em experimentos instalados em condição de sequeiro e solo ácido de Capão Bonito, e em condição de irrigação por aspersão e solo ácido com aplicação de calcário de Mococa, no período 2003-2005. Analisaram-se produção de grãos, outros componentes da produção, características agronômicas e resistência ao agente causal da ferrugem-da-folha. Estudou-se também a tolerância ao alumínio em soluções nutritivas, no laboratório. As linhagens 9 (IAC-24/Anahuac M - Tol Al) e 14 (BH-1146//AA"S"/WIN"S"/3/G.C.W1/SERI) destacaram-se quanto à produção de grãos em Mococa e a linhagem 10 (IAC-24/Anahuac M - Tol Al), tolerante à toxicidade de Al3+, em soluções nutritivas, sobressaíu-se quanto à produção de grãos, apresentando as plantas semi-anãs mais altas, em Capão Bonito. Todos os genótipos tiveram porte semi-anão e a cultivar IAC-370 e as linhagens 13 (BH-1146//AA"S"/WIN"S"/3/IAC-287), 14 e 15 F12.71/COC// CMH76.173/CMH 75 A 66/3/Desconhecido exibiram resistência ao acamamento. As linhagens 13 e 14 pela baixa incidência da ferrugem-da-folha mostraram ser boas fontes de resistência a essa doença em programas de melhoramento genético. As linhagens 17, 18, 19 e 20, oriundas do cruzamento interespecífico Maya"S"/SPRW"S"//SAP"S"/3/BUC"S"/4/IAC-225/5/IAC-1003 tiveram espigas compridas associadas aos grãos pesados, a linhagem 3 (IAC-24/Siete Cerros) destacaram-se em relação ao número de grãos por espiga e por espigueta e a linhagem 14 pelo número de espiguetas por espiga. As cultivares IAC-24 e BH-1146, e as linhagens 4, 5, 6, 7, 8 e 10, selecionadas a partir do híbrido IAC-24/Anahuac M - Tol Al sobressaíram-se em relação à tolerância, à presença de 10 mg L-1 de Al3+, em soluções nutritivas.
Temperatura mínima letal para plantas jovens de pinhão-manso
Authors: Andrade Giselly Aparecida , Caramori Paulo Henrique , Souza Fábio Suano de , Marur Celso Jamil , Ribeiro Ana Maria de Arruda
Published: November 2008

O objetivo deste trabalho foi determinar a temperatura mínima letal em plantas jovens de Pinhão-manso (Jatropha curcas L.), visando à expansão desta cultura no sul do Brasil como alternativa para produção de biodiesel. O experimento foi desenvolvido no Instituto Agronômico do Paraná (IAPAR), em Londrina (PR) a 23º23' S, 50º11' W. Em uma câmara fria, foram realizados tratamentos com temperaturas mínimas de +1 ºC, 0 ºC, -1 ºC, -2 ºC, -3 ºC, -4 ºC e -5 ºC, comparados com um controle exposto à temperatura ambiente. O delineamento estatístico foi inteiramente casualizado, com 10 repetições. As variáveis avaliadas foram: taxa fotossintética das plantas após 6 horas, 7 e 14 dias; danos foliares visuais um dia e um mês após os tratamentos, mortalidade das plantas um mês após os tratamentos e recuperação das plantas no campo. De acordo com as observações, a temperatura mínima letal para o pinhão-manso está entre -3 ºC e -4 ºC.
Efeitos gradativos do toque terapêutico na redução da ansiedade de estudantes universitários
Authors: Gomes Vanessa Miranda , Silva Maria Júlia Paes da , Araújo Eutália Aparecida Cândido
Published: November 2008

Trabalho de pesquisa quantitativo realizado com 42 discentes de uma instituição pública de ensino superior, utilizando-se a técnica do Toque Terapêutico - Método Krieger-Kunz e aplicação de um questionário validado no Brasil para avaliar a ansiedade durante três sessões. Os sujeitos foram alocados em dois grupos: experimental (1), em que receberam a terapia complementar; e controle (2), em que foram submetidos a imitação da técnica sem intenção terapêutica. O objetivo foi identificar a influência gradativa desta terapia complementar de saúde no que se refere ao estado de ansiedade dos estudantes. A análise dos dados revelou uma redução estatisticamente significativa do estado de ansiedade em ambos os grupos, com pd" 0,05.
Os reflexos da formação inicial na atuação dos professores enfermeiros
Authors: Ferreira Júnior Marcos Antonio
Published: November 2008

Com o aumento do número de escolas formadoras de profissionais de nível técnico em enfermagem, a ação docente despontou como grande campo de atuação profissional para o enfermeiro, mesmo sem ter recebido qualquer formação pedagógica inicial. Este estudo focalizou um grupo de enfermeiros-professores de uma escola de nível técnico, analisando sua formação inicial com vistas à prática pedagógica. Trata-se de um estudo com abordagem qualitativa, de natureza descritivo-explicativa, com dados coletados por questionário e as informações tratadas mediante análise de conteúdo. O que se pode concluir é que não se deve atribuir somente à formação inicial a responsabilidade de capacitação para a ação docente, uma vez que a prática profissional aliada à educação permanente em serviço são reforçadores desta ação.
Centro CIPE® do Programa de Pós-Graduação em Enfermagem da UFPB
Authors: Garcia Telma Ribeiro , Nóbrega Maria Miriam Lima da , Coler Marga Simon
Published: November 2008

A Classificação Internacional para a Prática de Enfermagem - CIPE® é um programa oficial do Conselho Internacional de Enfermagem CIE. Em 2003, o CIE começou a desenvolver e testar a idéia de criação de Centros de Pesquisa e Desenvolvimento da CIPE®, considerados elementos importantes para concentrar e disseminar novas idéias e discussões que promovam o avanço da CIPE®. Neste trabalho focalizamos o significado, possíveis formas de organização, vantagens e obrigações dos Centros de Pesquisa e Desenvolvimento da CIPE®; e descrevemos o Centro CIPE® do Programa de Pós-Graduação em Enfermagem da Universidade Federal da Paraíba, acreditado pelo CIE em julho de 2007.
Enfermagem como prática social: um exercício de reflexão
Authors: Trezza Maria Cristina A. Figueiredo , Santos Regina Maria dos , Leite Joséte Luzia
Published: November 2008

Neste trabalho propomos refletir sobre a enfermagem entendida como uma prática social. Para construir essas idéias, revisitamos esse conceito nas suas raízes filosóficas e sociais. Com o intuito de contribuir para esta reflexão, buscamos, no desenvolvimento da enfermagem, desde os seus primórdios, características que a definem como uma prática histórica e socialmente construída. Por fim propomos também um conceito de prática social e, nesta perspectiva, construímos, ao longo do texto, um outro conceito para enfermagem.
As contribuições do Serviço Especial de Saúde Pública para a formação profissional da Enfermagem no Brasil (1942-1960)
Authors: Renovato Rogério Dias , Bagnato Maria Helena Salgado
Published: November 2008

O objetivo desse estudo foi conhecer e compreender as estratégias do Serviço Especial de Saúde Pública (SESP) para expandir a formação de profissionais da Enfermagem em nível superior e técnico no Brasil, entre 1942 a 1960. Utilizamos como fontes históricas a Revista do SESP e o Boletim do SESP, incluindo os números publicados a partir de 1944. A atuação do SESP junto a processos de formação de profissionais em Enfermagem, caracterizou-se pelo uso de várias estratégias como a concessão de bolsas ou o apoio financeiro e técnico para a implantação de escolas de Enfermagem no Brasil. Assim, as ações sespianas convergiram para a ascensão de um novo ethos da Enfermagem, não apenas na zona rural, como também, a Enfermagem hospitalar.
Programa Saúde da Família e condições sensíveis à atenção primária, Bagé (RS)
Authors: Nedel Fúlvio Borges , Facchini Luiz Augusto , Martín-Mateo Miguel , Vieira Lúcia Azambuja Saraiva , Thumé Elaine
Published: November 2008

OBJETIVO: Condições sensíveis à atenção primária (CSAP) são problemas de saúde atendidos por ações do primeiro nível de atenção. A necessidade de hospitalização por essas causas deve ser evitada por uma atenção primária oportuna e efetiva. O objetivo do estudo foi estimar a probabilidade do diagnóstico de CSAP em pacientes hospitalizados pelo Sistema Único de Saúde. MÉTODOS: Estudo transversal com 1.200 pacientes internados entre setembro/2006 e janeiro/2007 em Bagé (RS). Os pacientes responderam a questionário aplicado por entrevistadoras, sendo classificados segundo o modelo de atenção utilizado previamente à hospitalização. As CSAP foram definidas em oficina promovida pelo Ministério da Saúde. Analisaram-se variáveis demográficas, socioeconômicas, de situação de saúde e relativas aos serviços de saúde utilizados. A análise multivariável foi realizada por modelo de Poisson, seguindo modelo teórico hierárquico de determinação da hospitalização segundo sexo e modelo de atenção. RESULTADOS: O total de 42,6% das internações foi por condições sensíveis à atenção primária. A probabilidade de que o diagnóstico principal de internação seja por uma dessas condições aumenta com as características: ser do sexo feminino, ter idade menor de cinco anos, ter escolaridade menor de cinco anos, ter sido hospitalizado no ano anterior à entrevista, ter consulta médica na emergência, estar internado no hospital universitário. Associaram-se à probabilidade de CSAP: (a) mulheres: faixa etária, escolaridade, tempo de funcionamento da unidade de saúde, residir em área de saúde da família, ser usuária do Programa Saúde da Família, consulta médica na emergência no mês anterior à pesquisa e hospital de internação; (b) homens: faixa etária, ter sofrido outra internação no ano anterior à entrevista e o hospital de internação. CONCLUSÕES: As condições sensíveis à atenção primária permitem identificar grupos carentes de atenção à saúde adequada. Embora o estudo não permita inferências sobre o risco de internação, as análises por sexo e modelo de atenção sugerem que o Programa Saúde da Família é mais eqüitativo que a atenção básica tradicional.
Fauna de flebotomíneos (Diptera: Psychodidae) em um foco de leishmaniose tegumentar americana na área periurbana de Manaus, Estado do Amazonas
Authors: Barbosa Maria das Graças Vale , Fé Nelson Ferreira , Marcião Alexandre Herculano Ribera , Silva Ana Paula Thome , Monteiro Wuelton Marcelo , Guerra Jorge Augusto de Oliveira
Published: November 2008

No período de agosto de 2001 a julho de 2002, usando armadilhas CDC e Disney, realizaram-se coletas de flebotomíneos, na base de árvores no peridomicílio e nas matas da Comunidade São João, área periurbana de Manaus, Amazonas. Foram capturados 4.104 espécimes, pertencentes a quatro subtribos, 13 gêneros e 49 espécies da subfamília Phlebotominae. Predominou a subtribo Psychodopygina com 3.403 (83%) espécimes, destacando-se Nyssomyia umbratilis, Nyssomyia anduzei, Trichophoromyia eurypyga, Bichromomyia olmeca nociva e Bichromomyia flaviscutellata. O registro de Nyssomyia umbratilis e Nyssomyia anduzei, incriminadas como vetoras de Leishmania (Viannia) guyanensis, e de Bichromomyia flaviscutellata e Bichromomyia olmeca nociva, de Leishmania (Leishmania) amazonensis, indicam risco de infecção para os moradores da área. A grande maioria (98,5%) dos flebotomíneos foi capturada na área de mata. Nyssomyia anduzei e Bichromomyia olmeca nociva foram coletadas no peridomicílio. A riqueza de espécies vetoras de Leishmania nessa área revela a necessidade de uma vigilância entomológica constante.