bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Apparatus for Measuring Oxygen Diffusion and Water Retention in Soils
Authors: MacKay PL , Yanful EK , Kerry Rowe R , Badv K
Published: February 2009

A new apparatus developed for measuring the diffusion of oxygen, or any gas, through a soil sample is described. The apparatus uses nitrogen pressure to change a soil sample's degree of saturation and can therefore minimize the effects of structural changes due to remixing and packing. As a consequence, some innovative methods are employed to simulate oxygen concentration versus time data obtained with the apparatus. A one-dimensional semianalytic diffusion model is used to back-calculate diffusion coefficients based on laboratory data. Results for a local silt and a sand are presented to illustrate the utility of the apparatus. The apparatus is shown to perform well and provide gas diffusion coefficients similar to those reported by other researchers. The major advantage of the apparatus over other published methods lies in the fact that both the soil-water characteristic curve and oxygen diffusion coefficient at any degree of saturation can be obtained on the same soil sample in a single suite of tests. These two parameters are required for several geotechnical and geoenvironmental engineering designs involving unsaturated soils, such as the use of soil covers for mitigating acid drainage in sulfide-bearing mine waste.
Centrifuge Testing of Fixed-Head Laterally Loaded Battered and Plumb Pile Groups in Sand
Authors: McVay MC , Shang T-I , Casper R
Published: February 2009

Centrifuge tests were conducted on driven in-flight fixed-head plumb and battered 3 × 3 pile groups at three-diameter (3D) and five-diameter (5D) spacings. The piles simulated 430-mm-diameter by 13-m-long pipe piles founded in medium loose (Dr = 33%) and medium dense (Dr = 55%) sands. The battered groups were in an A frame arrangement, i.e., each pile in a given row battered the same. Results of the tests showed that fixed-head plumb groups have a 30 to 55% higher lateral resistance than free-headed piles depending on soil density and pile spacing. For the battered 3D-spaced group, the lateral resistance was greater by 20 to 50% than the fixed-head plumb response in the medium dense sand; however, in the medium loose sand, the battered and plumb fixed-head group response was very similar. The latter is attributed to the limited axial tension capacity of the piles in the medium loose sand (Dr = 33%). Increasing the dead load on a battered group to 45% of its axial capacity resulted in a 30% increase in the group's lateral resistance. The lateral resistance of the 5D-spaced battered groups were in all cases greater than their 3D counterparts.
Laboratory Testing Apparatus for Slopes Stabilized by Anchored Geosynthetics
Authors: Ghiassian H , Hryciw RD , Gray DH
Published: February 2009

A laboratory testing apparatus is described for examining slopes subjected to seepage and stabilized by anchored geosynthetics (AGS). The AGS technique can increase the stability of cohesionless slopes such as coastal dunes against surficial erosion and shallow mass failure caused by wave action and seepage forces. In the AGS, a geosynthetic fabric is placed on the face of the slope and tensioned via anchorage to the ground. The required tension is achieved through frictional or pullout resistance of earth anchors that are fastened to the fabric and driven into the underlying soil mass. In the laboratory testing apparatus, however, AGS tensioning is provided by thin wires connected to rigid steel tubes that exert line loads on the fabric. The wires in turn are connected to dead weights “beneath” the slope that simulate anchor loads. The prototype slopes are failed by uniformly decreasing anchor loads while maintaining the seepage gradient and orientation constant. Very good agreement was observed between experimental results and theoretical predictions of the failure mode and the average AGS loads at failure.
Low Strain Measurements Using Random Noise Excitation
Authors: Cascante G , Santamarina C
Published: February 2009

Low-strain wave propagation velocity and attenuation are effective measures of state in particulate media. The standard resonant column test procedure is modified to facilitate the study of wave propagation at low strains. The system uses band-limited random noise excitation in combination with signal averaging to control the signal-to-noise ratio. This procedure is efficiently implemented by replacing typical peripheral devices with a signal analyzer and computer control. The methodology permits testing at very low strains (γ ≈ 10−8). The effect of non-linear system response on computed transfer functions is addressed. Other results include the analytical treatment of coupling between torsional and transverse modes, the evaluation of local low-strain shear parameters from solid specimens tested in torsion, and the use of multi-mode testing for the evaluation of field parameters.
Deafness in TRβ Mutants Is Caused by Malformation of the Tectorial Membrane
Authors: Winter Harald , Rüttiger Lukas , Müller Marcus , Kuhn Stephanie , Brandt Niels , Zimmermann Ulrike , Hirt Bernhard , Bress Andreas , Sausbier Matthias , Conscience Aude , Flamant Frederic , Tian Yong , Zuo Jian , Pfister Markus , Ruth Peter , Löwenheim Hubert , Samarut Jacques , Engel Jutta , Knipper Marlies
Published: February 2009

Thyroid hormone receptor β (TRβ) dysfunction leads to deafness in humans and mice. Deafness in TRβ−/−mutant mice has been attributed to TRβ-mediated control of voltage- and Ca2+-activated K+(BK) channel expression in inner hair cells (IHCs). However, normal hearing in young constitutive BKα−/−mutants contradicts this hypothesis. Here, we show that mice with hair cell-specific deletion of TRβ after postnatal day 11 (P11) have a delay in BKα expression but normal hearing, indicating that the origin of hearing loss in TRβ−/−mutant mice manifested before P11. Analyzing the phenotype of IHCs in constitutive TRβ−/−mice, we found normal Ca2+current amplitudes, exocytosis, and shape of compound action potential waveforms. In contrast, reduced distortion product otoacoustic emissions and cochlear microphonics associated with an abnormal structure of the tectorial membrane and enhanced tectorin levels suggest that disturbed mechanical performance is the primary cause of deafness resulting from TRβ deficiency.
Effects of Remote Stimulation on the Modulated Activity of Cat Retinal Ganglion Cells
Authors: Passaglia Christopher L. , Freeman Daniel K. , Troy John B.
Published: February 2009

The output of retinal ganglion cells depends on local and global aspects of the visual scene. The local receptive field is well studied and classically consists of a linear excitatory center and a linear antagonistic surround. The global receptive field contains pools of nonlinear subunits that are distributed widely across the retina. The subunit pools mediate in uncertain ways various nonlinear behaviors of ganglion cells, like temporal-frequency doubling, saccadic suppression, and contrast adaptation. To clarify mechanisms of subunit function, we systematically examined the effect of remote grating patterns on the spike activity of cat X- and Y-type ganglion cellsin vivo. We present evidence for two distinct subunit types based on spatiotemporal relationships between response nonlinearities elicited by remote drifting and contrast-reversing gratings. One subunit type is excitatory and activated by gratings of ∼0.1 cycles per degree, while the other is inhibitory and activated by gratings of ∼1 cycle per degree. The two subunit pools contribute to a global gain control mechanism that differentially modulates ganglion cell response dynamics, particularly for ON-center cells, where excitatory and inhibitory subunit stimulation respectively makes responses to antipreferred and preferred contrast steps more transient. We show that the excitatory subunits also have a profound influence on spatial tuning, turning cells from lowpass into bandpass filters. Based on difference-of-Gaussians model fits to tuning curves, we attribute the increased bandpass selectivity to changes in center-surround strength and relative phase and not center-surround size. A conceptual model of the extraclassical receptive field that could explain many observed phenomena is discussed.
Sensory Attributes of Complex Tasting Divalent Salts Are Mediated by TRPM5 and TRPV1 Channels
Authors: Riera Céline E. , Vogel Horst , Simon Sidney A. , Damak Sami , le Coutre Johannes
Published: February 2009

Complex tasting divalent salts (CTDS) are present in our daily diet, contributing to multiple poorly understood taste sensations. CTDS evoking metallic, bitter, salty, and astringent sensations include the divalent salts of iron, zinc, copper, and magnesium. To identify pathways involved with the complex perception of the above salts, taste preference tests (two bottles, brief access) were performed in wild-type (WT) mice and in mice lacking (1) the T1R3 receptor, (2) TRPV1, the capsaicin receptor, or (3) the TRPM5 channel, the latter being necessary for the perception of sweet, bitter, and umami tasting stimuli. At low concentrations, FeSO4and ZnSO4were perceived as pleasant stimuli by WT mice, and this effect was fully reversed in TRPM5 knock-out mice. In contrast, MgSO4and CuSO4were aversive to WT mice, but for MgSO4the aversion was abolished in TRPM5 knock-out animals, and for CuSO4, aversion decreased in both TRPV1- and TRPM5-deficient animals. Behavioral tests revealed that the T1R3 subunit of the sweet and umami receptors is implicated in the hedonically positive perception of FeSO4and ZnSO4. For high concentrations of CTDS, the omission of TRPV1 reduced aversion. Imaging studies on heterologously expressed TRPM5 and TRPV1 channels are consistent with the behavioral experiments. Together, these results rationalize the complexity of metallic taste by showing that at low concentrations, compounds such as FeSO4and ZnSO4stimulate the gustatory system through the hedonically positive T1R3–TRPM5 pathway, and at higher concentrations, their aversion is mediated, in part, by the activation of TRPV1.
The Origin of Adaptation in the Auditory Pathway of Locusts Is Specific to Cell Type and Function
Authors: Hildebrandt K. Jannis , Benda Jan , Hennig R. Matthias
Published: February 2009

We investigated the origin of spike frequency adaptation within a layered sensory network: the auditory pathway of locusts. Spike frequency adaptation as observed in an individual neuron may arise because of intrinsic or presynaptic adaptation mechanisms. To separate the contribution of different mechanisms, we recorded from the same cell during acoustic and intracellular current stimulation. We studied three identified neuron types that are representative for each network layer and participate in processing auditory patterns and localizing sound sources. By comparing current and acoustic stimulation, three distinct patterns of the distribution of adaptation mechanisms within the sensory network emerged: (1) balanced influence of both intrinsic and presynaptic adaptation mechanisms in an interneuron that summates over several receptor afferents (TN1), (2) predominantly inhibiting input as the source for spike frequency adaptation in a cell that transmits both pattern representation and directional information (BSN1), (3) primarily intrinsic, spike-triggered adaptation currents within an interneuron coding exclusively for direction (AN2). The time courses of spike frequency adaptation differed significantly between the cells types. Using the adaptation time constants, we were able to predict signal transmission properties for the different cells. We conclude that the adaptation mechanisms differ greatly among interneurons within this sensory pathway and are a function of their role in information processing.
At Immature Mossy-Fiber–CA3 Synapses, Correlated Presynaptic and Postsynaptic Activity Persistently Enhances GABA Release and Network Excitability via BDNF and cAMP-Dependent PKA
Authors: Sivakumaran Sudhir , Mohajerani Majid H. , Cherubini Enrico
Published: February 2009

In the adult rat hippocampus, the axons of granule cells in the dentate gyrus, the mossy fibers (MF), form excitatory glutamatergic synapses with CA3 principal cells. In neonates, MF release into their targets mainly GABA, which at this developmental stage is depolarizing. Here we tested the hypothesis that, at immature MF–CA3 synapses, correlated presynaptic [single fiber-evoked GABAA-mediated postsynaptic potentials (GPSPs)] and postsynaptic activity (back propagating action potentials) may exert a critical control on synaptic efficacy. This form of plasticity, called spike-timing-dependent plasticity (STDP), is a Hebbian type form of learning extensively studied at the level of glutamatergic synapses. Depending on the relative timing, pairing postsynaptic spiking and single MF-GPSPs induced bidirectional changes in synaptic efficacy. In case of positive pairing, spike-timing-dependent-long-term potentiation (STD-LTP) was associated with a persistent increase in GPSP slope and in the probability of cell firing. The transduction pathway involved a rise of calcium in the postsynaptic cell and the combined activity of cAMP-dependent PKA (protein kinase A) and brain-derived neurotrophic factor (BDNF). Retrograde signaling via BDNF and presynaptic TrkB receptors led to a persistent increase in GABA release. In “presynaptically” silent neurons, the enhanced probability of GABA release induced by the pairing protocol, unsilenced these synapses. Shifting EGABAfrom the depolarizing to the hyperpolarizing direction with bumetanide failed to modify synaptic strength. Thus, STD-LTP of GPSPs provides a reliable way to convey information from granule cells to the CA3 associative network at a time when glutamatergic synapses are still poorly developed.
Morphine Increases Brain Levels of Ferritin Heavy Chain Leading to Inhibition of CXCR4-Mediated Survival Signaling in Neurons
Authors: Sengupta Rajarshi , Burbassi Silvia , Shimizu Saori , Cappello Silvia , Vallee Richard B. , Rubin Joshua B. , Meucci Olimpia
Published: February 2009

This study focuses on the effect of μ-opioid receptor agonists on CXCR4 signaling in neurons and the mechanisms involved in regulation of neuronal CXCR4 by opiates. The data show that CXCR4 is negatively modulated by long-term morphine treatments bothin vitroandin vivo; CXCR4 inhibition is caused by direct stimulation of μ-opioid receptors in neurons, leading to alterations of ligand-induced CXCR4 phosphorylation and upregulation of protein ferritin heavy chain (FHC), a negative intracellular regulator of CXCR4. Reduced coupling of CXCR4 to G-proteins was found in the brain of morphine-treated rats, primarily cortex and hippocampus. CXCR4-induced Gαi/Gβγ activities were suppressed after 24 h treatment of cortical neurons with morphine or the selective μ-opioid agonist DAMGO (d-Ala2-N-Me-Phe4-glycol5-enkephalin), as shown by analysis of downstream targets of CXCR4 (i.e., cAMP, Akt, and ERK1/2). These agonists also prevented CXCL12-induced phosphorylation of CXCR4, indicating a deficit of CXCR4 activation in these conditions. Indeed, morphine (or DAMGO) inhibited prosurvival signaling in neurons. These effects are not attributable to a reduction in CXCR4 expression or surface levels but rather to upregulation of FHC by opioids. The crucial role of FHC in inhibition of neuronal CXCR4 was confirmed byin vitroandin vivoRNA interference studies. Overall, these findings suggest that opiates interfere with normal CXCR4 function in the brain. By this mechanism, opiates could reduce the neuroprotective functions of CXCR4 and exacerbate neuropathology in opiate abusers who are affected by neuroinflammatory/infectious disorders, including neuroAIDS.
Finding Farms: Comparing Indicators of Farming Dependence and Agricultural Importance in the United States
Authors: Jackson‐Smith Douglas B. , Jensen Eric
Published: February 2009

Abstract  Many scholars have commented on the changing significance of farming for understanding the dynamics of social and economic change in contemporary rural America. Quantitative analyses of relationships between farming, local socioeconomic conditions, demographic trends, and policy have often relied on an indicator of “farm‐dependent” (FD) counties developed by the USDA Economic Research Service. In this article, we argue that measures of economic dependency imperfectly identify the places in the United States where farming is significant, and can paint an incomplete picture of the contemporary geographic distribution and structure of agriculture in the United States. We propose an alternative categorical indicator—agricultural importance (AI)—that provides a better direct measure of the relative size and intensity of farming across diverse U.S. counties. We compare the characteristics of FD and AI counties along a set of dimensions and discuss the strengths and weaknesses of each typology.
A Sociological Look at Biofuels: Ethanol in the Early Decades of the Twentieth Century and Lessons for Today
Authors: Carolan Michael S.
Published: February 2009

Abstract  This article develops a broad sociological understanding of why biofuels lost out to leaded gasoline as the fuel par excellence of the twentieth century, while drawing comparisons with biofuels today. It begins by briefly discussing the fuel‐scape in the United States in the late nineteenth and early twentieth centuries, examining the farm chemurgic movement, New Deal agricultural policies, mechanization trends within agriculture, and, finally, the invention of leaded gasoline. The second half of the article applies insights from that historical analysis to the biofuel craze currently under way. By employing a political‐economy interpretation of the socioeconomic context combined with a path‐dependency‐informed analysis of the technological trajectories, the article reveals the social forces that structured the trends and outcomes in biofuel innovations across the two eras.
The effect of different stressors on the QT interval and the T wave
Authors: Andrássy Gábor
Published: February 2009

Prolonged QT interval is associated with the generation of life-threatening arrhythmias and sudden death. However, neither the relation between QT duration and heart rate, nor the association between mental stress and QT time has been clarified. Aim: The relationship between QT duration and smoking, cardiovascular reactivity, and mental stress as well as newer methods of QT correction were studied. Methods: In six laboratory experiments 166 volunteers were studied. Smoking, treadmill exercise, mental arithmetic and videogame were applied as stressors. Besides fixed formulae, study and subject-specific QT correction methods were also used. Results: 1. Bazett formula is not appropriate to compare QT durations. 2. Acute smoking has no effect on QT time. 3. QT changes are related to cardiovascular reactivity. 4. Mental stress may induce QT prolongation. 5. Bifid T waves often develop during mental and isometric stress. Conclusions: New methods for QT correction are more reliable than preformed formulae. QT prolongation and bifid T waves may be the links between mental stress and life threatening arrhythmias.
Relationships among Swimming Ability, Current Velocity Association, and Morphology for Freshwater Lotic Fishes
Authors: Leavy Tracy R. , Bonner Timothy H.
Published: February 2009

We determined swimming ability for 37 warmwater stream fishes in Texas and Louisiana and assessed relationships among swimming ability, habitat selection, and fish morphology. Mean absolute speeds (cm/s) were 17.8–81.9 cm/s for Cyprinidae, 50.9 cm/s for Characidae, 70.0 cm/s for Ictaluridae, 33.0 cm/s for Cichlidae, 40.0 cm/s for Percidae, 30.7–43.4 cm/s for Cyprinodontidae, 30.2 cm/s for Atherinidae, 15.7–18.6 cm/s for Poeciliidae, and 23.4–40.5 cm/s for Centrarchidae. Absolute swimming speeds were correlated (P < 0.01) to reported habitat descriptions (i.e., sloughs, lakes, streams, and rivers) of fishes. Absolute swimming speeds also were good predictors of spatial (i.e., runs, pools, and riffles) distributions of fishes from Independence Creek, Texas (P = 0.03), and Banita Creek, Texas (P = 0.06). Multivariate ordination of nine morphological attributes identified the linear combination of relative body depth, dorsal fin length, and caudal span width as an adequate predictor (P < 0.01) of swimming speed; however, several exceptions were noted. Understanding interactions between current velocity and swimming ability in fishes is critical to species conservation and to maintaining instream flow requirements for fishes.
A Simulation Study of the Effects of Spatially Complex Population Structure for Gulf of Maine Atlantic Cod
Authors: Reich Danielle Ameen , DeAlteris Joseph Thomas
Published: February 2009

There is growing evidence that numerous fish stocks consist of several smaller, reproductively isolated units that vary in their ability to produce new recruits each year because of a mismatch with environmental conditions. It has been suggested that spawning aggregations exist for the Gulf of Maine stock of Atlantic cod Gadus morhua and that approximately one-half of the historic aggregations are locally depleted. We developed a spatially explicit, age-based projection model to investigate the effects of complex population structure and spatially variable recruitment on Gulf of Maine Atlantic cod. The results of this study demonstrate that there are significant disparities in the estimates of spawning stock biomass, annual yield, and annual recruitment when a stock with a complex population structure is treated as a single stock. In addition, treating a stock with a complex population structure as a single stock can mask a steady decline in the values of these variables as the spawning aggregations gradually become depleted. To achieve rebuilding of the simulated Gulf of Maine Atlantic cod stock within 10 years, we determined that F = 0 would be required. Because continued bycatch mortality in other fisheries would prevent this even with the closure of the Gulf of Maine cod fishery, it may not be possible to rebuild this particular stock in a short time frame. When fishing mortality is removed, the stock only rebuilds to one-half of the initial carrying capacity because about 50% of the reproductive capacity of the stock has been lost. Without recolonization, the simulated stock has lost its biological capacity to return to the original unfished condition. Based on the simulations in this study, the behavior of the Gulf of Maine Atlantic cod stock is more consistent with that of a stock with a complex population structure than with that of a truly single stock. In light of this, the management measures for this stock and other stocks with the potential for complex population structure should be carefully evaluated. Managing such stocks as single units may be inappropriate and lead to both inadequate protection of the resource and reduced fishery yields.
Variable Responses of Channel Catfish Populations to Stocking Rate: Density-Dependent and Lake Productivity Effects
Authors: Michaletz Paul H.
Published: February 2009

Put–grow–take fisheries for channel catfish Ictalurus punctatus are popular in many small impoundments but are costly because fingerling (>175 mm total length [TL]) stockings are usually necessary to maintain these fisheries. Stocking the appropriate number of fish is important for making efficient use of these hatchery products and for creating desirable fisheries. The effect of stocking rate on channel catfish populations was evaluated by examining 60 small impoundments that had been assigned to one of three annual stocking rates (12, 37, or 74 fingerlings/ha). As channel catfish stocking rate increased, catch per unit effort (CPUE, number of fish per 3-d tandem hoop-net series) and total annual mortality increased, while proportional size distribution (PSD, formerly proportional stock density), PSD for fish 508 mm or longer, relative weight, and annual growth increments decreased; these results suggest that density-dependent processes were important. However, 10-fold differences in CPUE and threefold differences in size structure indices and growth increments were common among lakes stocked at the same rate. Further analysis revealed that CPUE and lake productivity (indexed by chlorophyll-a concentration) were important variables in explaining differences in size structure, condition, and growth among populations. Because of the highly variable response, appropriate stocking rates need to be determined for each lake. I propose comparing growth increments of individuals within a lake to a statewide standard to determine the relative growth rate for the lake. Stocking rates should be reduced for channel catfish populations that are growing slowly but could be increased for fast-growing populations.
Sonic hedgehog and pancreatic-duodenal homeobox 1 expression distinguish between duodenal and pancreatic gastrinomas
Authors: Fendrich Volker , Ramerth Ricarda , Waldmann Jens , Maschuw Katja , Langer Peter , Bartsch Detlef K , Slater Emily P , Ramaswamy Annette , Rothmund Matthias
Published: February 2009

Some 80–90% of gastrinomas are located in the gastrinoma triangle, which includes the duodenum, the pancreatic head, and the hepatoduodenal ligament. The natural history of the tumors depends on their origin. Duodenal gastrinomas are much less aggressive than pancreatic primaries and infrequently develop liver metastases. The reason therefore is unclear. The transcription factor pancreatic-duodenal homeobox 1 (Pdx1) is important in differentiation and development of the pancreas and duodenum. In embryonic development, Sonic hedgehog (Shh) expression establishes a sharp molecular boundary, which allows for the proper patterning of the duodenal and pancreatic epithelium. Pancreatic polypeptide (PP) is expressed in pancreatic islets and is known to be expressed in pancreatic endocrine tumors. This study aims to clarify the expression pattern of Pdx1, Shh, and PP in duodenal and pancreatic gastrinomas. Tissue from 15 patients with duodenal and from 11 patients with pancreatic gastrinomas that underwent surgery between 1987 and 2007 at our institution because of a gastrinoma were evaluated by immunohistochemistry (IHC). Furthermore, tissue from lymph node metastases from two patients with a so far undetected primary gastrinoma was analyzed. IHC revealed strong Pdx1 expression in pancreatic gastrinomas, but not in duodenal gastrinomas. By contrast, there was no Shh expression detectable in pancreatic gastrinomas, but found in all duodenal gastrinomas. This pattern was also true for associated metastases. Shh expression combined with absence of Pdx1 expression in lymph node metastases from patients with an unknown location of the primary suggests a so far undetected duodenal gastrinoma. We show for the first time that only pancreatic, but not duodenal gastrinomas express Pdx1. Moreover, only duodenal gastrinomas express Shh, suggesting a different genetic background of these two tumors. Whereas the expression of Pdx1 in pancreatic gastrinomas might suggest their endocrine origin from islets, duodenal gastrinomas develop from a Pdx1 negative cell cluster. The expression pattern of Pdx1, Shh, and PP in resected metastases can help to locate an otherwise undetected primary gastrinoma.
Expression of excision repair cross complementing group 1 and prognosis in adrenocortical carcinoma patients treated with platinum-based chemotherapy
Authors: Ronchi Cristina L , Sbiera Silviu , Kraus Luitgard , Wortmann Sebastian , Johanssen Sarah , Adam Patrick , Willenberg Holger S , Hahner Stefanie , Allolio Bruno , Fassnacht Martin
Published: February 2009

Therapeutic progress in adrenocortical carcinoma (ACC) is severely hampered by its low incidence. Platinum-based chemotherapies are the most effective cytotoxic treatment regimens in ACC but response rates remain <50%. In other tumor entities, expression of excision repair cross complementing group 1 (ERCC1) predicts resistance to platinum compounds. Therefore, we correlated ERCC1 protein expression and clinical outcome. We have retrolectively established adrenal tissue microarrays and analyzed prospectively samples from 163 ACCs, 15 benign adrenal adenomas, and 8 normal adrenal glands by immunohistochemistry for ERCC1 protein expression. Detailed clinical data were available by the German ACC Registry. ERCC1 protein was highly expressed in all normal adrenal glands, 14 benign tumors (93%) and in 75 ACCs (47%). In ACC, no differences in baseline parameters were found between patients with and without ERCC1 expression. Detection of ERCC1 was not correlated with survival in patients who never received platinum-based chemotherapy. In platinum-treated patients (n=45), objective response to platinum compounds was observed in 3/21 patients (14.3%) with high ERCC1 expression and in 7/24 patients (29.2%) with low ERCC1 expression (P=0.23). ERCC1 expression was strongly correlated with overall survival after platinum treatment (median: eight months in patients with high ERCC1 versus 24 months in low ERCC1 expression, hazard ratio (HR) 2.95 (95% confidence interval (CI) 1.4–6.2), P=0.004). Multivariate analysis confirmed that high ERCC1 expression was a predictive factor for poor prognosis in platinum treated patients (HR 2.2, 95% CI 1.0–4.5, P=0.038). Our findings suggest that ERCC1 expression is the first factor for predicting survival in ACC patients treated with platinum-based chemotherapy.
Prognostic factors influencing survival from metastatic (stage IV) gastroenteropancreatic well-differentiated endocrine carcinoma
Authors: Durante Cosimo , Boukheris Houda , Dromain Clarisse , Duvillard Pierre , Leboulleux Sophie , Elias Dominique , de Baere Thierry , Malka David , Lumbroso Jean , Guigay Joël , Schlumberger Martin , Ducreux Michel , Baudin Eric
Published: February 2009

Survival of metastatic gastroenteropancreatic well-differentiated endocrine carcinoma (GEP WDEC) is not well characterized. We evaluated the long-term outcome and prognostic factors for survival in 118 patients with distant metastases from GEP WDEC. Inclusion criteria were 1) pathological review by a single pathologist according to the present WHO criteria, 2) absence of previous therapy apart from surgery, 3) complete morphological evaluation within 3 months including somatostatin receptor scintigraphy, and 4) follow-up at Gustave-Roussy Institute until death or study's end. Clinical, biological marker, and pathological parameters were analyzed in univariate and multivariate statistical models. Survival after the first complete imaging work-up of the metastatic disease was determined using Kaplan–Meier method. Overall, survival for 5 years after the diagnosis of metastatic disease was 54%. In multivariate analysis, age (hazard ratio (HR): 1.05, 95% confidence interval (CI): 1.01–1.08, P=0.01), the number of liver metastases (HR: 3.4, 95% CI: 1.4–8.3, P=0.01), tumor slope (HR: 1.1, 95% CI: 1.0–1.1, P=0.001), and initial surgery (HR: 0.3, 95% CI: 0.1–0.8, P=0.01) were predictive of survival. Five-year survival was 100%, 91% (95% CI, 51–98%), 62% (95% CI, 37–83%), and 9% (95% CI, 6–32%) when patients had 0, 1, 2, 3 or more poor prognostic features respectively. This study enables the stratification of metastatic GEP WDEC patients into distinct risk groups. These risk categories can be used to tailor therapeutic approaches and also to design and interpret clinical trials.
Communication towers, lights, and birds: successful methods of reducing the frequency of avian collisions
Authors: Gehring Joelle , Kerlinger Paul , Manville Albert M.
Published: February 2009

Estimates suggest that each year millions of birds, predominantly Neotropical migrating songbirds, collide with communication towers. To determine the relative collision risks that different nighttime Federal Aviation Administration (FAA) communication tower obstruction lighting systems pose to night‐migrating birds, we compared fatalities at towers with different systems: white strobe lights only; red strobe‐like lights only; red, flashing, incandescent lights only; and red, strobe‐like lights combined with non‐flashing, steady‐burning, red lights. Avian fatality data used to compare these tower light systems were collected simultaneously in Michigan on 20 consecutive days during early morning hours during peak songbird migration at 24 towers in May and September 2005 (total = 40 days). Twenty‐one towers were 116–146 m above ground level (AGL), and three were ≥305 m AGL. During the two 20‐day sample periods, we found a mean of 3.7 birds under 116–146 m AGL towers equipped with only red or white flashing obstruction lights, whereas towers with non‐flashing/steady‐burning lights in addition to the flashing lights were responsible for 13.0 fatalities per season. Kruskal‐Wallis test, ANOVA, Student's t test, and multiple comparisons procedures determined that towers lit at night with only flashing lights were involved in significantly fewer avian fatalities than towers lit with systems that included the FAA “status quo” lighting system (i.e., a combination of red, flashing lights and red, non‐flashing lights). There were no significant differences in fatality rates among towers lit with red strobes, white strobes, and red, incandescent, flashing lights. Results from related studies at the same towers in May and September 2004 and September 2003 provide ancillary support for these findings. Our results suggest that avian fatalities can be reduced, perhaps by 50–71%, at guyed communication towers by removing non‐flashing/steady‐burning red lights. Our lighting change proposal can be accomplished at minimal cost on existing towers, and such changes on new or existing towers greatly reduce the cost of tower operation. Removing non‐flashing lights from towers is one of the most effective and economically feasible means of achieving a significant reduction in avian fatalities at existing communication towers.
Riparian forest buffers mitigate the effects of deforestation on fish assemblages in tropical headwater streams
Authors: Lorion Christopher M. , Kennedy Brian P.
Published: February 2009

Riparian forest buffers may play a critical role in moderating the impacts of deforestation on tropical stream ecosystems, but very few studies have examined the ecological effects of riparian buffers in the tropics. To test the hypothesis that riparian forest buffers can reduce the impacts of deforestation on tropical stream biota, we sampled fish assemblages in lowland headwater streams in southeastern Costa Rica representing three different treatments: (1) forested reference stream reaches, (2) stream reaches adjacent to pasture with a riparian forest buffer averaging at least 15 m in width on each bank, and (3) stream reaches adjacent to pasture without a riparian forest buffer. Land cover upstream from the study reaches was dominated by forest at all of the sites, allowing us to isolate the reach‐scale effects of the three study treatments. Fish density was significantly higher in pasture reaches than in forest and forest buffer reaches, mostly due to an increase in herbivore‐detritivores, but fish biomass did not differ among reach types. Fish species richness was also higher in pasture reaches than in forested reference reaches, while forest buffer reaches were intermediate. Overall, the taxonomic and trophic structure of fish assemblages in forest and forest buffer reaches was very similar, while assemblages in pasture reaches were quite distinct. These patterns were persistent across three sampling periods during our 15‐month study. Differences in stream ecosystem conditions between pasture reaches and forested sites, including higher stream temperatures, reduced fruit and seed inputs, and a trend toward increased periphyton abundance, appeared to favor fish species normally found in larger streams and facilitate a native invasion process. Forest buffer reaches, in contrast, had stream temperatures and allochthonous inputs more similar to forested streams. Our results illustrate the importance of riparian areas to stream ecosystem integrity in the tropics and provide support for Costa Rican legislation protecting riparian forests.
Management applicability of the intermediate disturbance hypothesis across Mongolian rangeland ecosystems
Authors: Sasaki Takehiro , Okubo Satoru , Okayasu Tomoo , Jamsran Undarmaa , Ohkuro Toshiya , Takeuchi Kazuhiko
Published: February 2009

The current growing body of evidence for diversity–disturbance relationships suggests that the peaked pattern predicted by the intermediate disturbance hypothesis (IDH) may not be the rule. Even if ecologists could quantify the diversity–disturbance relationship consistent with the IDH, the applicability of the IDH to land management has rarely been addressed. We examined two hypotheses related to the generality and management applicability of the IDH to Mongolian rangeland ecosystems: that the diversity–disturbance relationship varies as a function of landscape condition and that some intermediate scales of grazing can play an important role in terms of sustainable rangeland management through a grazing gradient approach. We quantified the landscape condition of each ecological site using an ordination technique and determined two types of landscape conditions: relatively benign and harsh environmental conditions. At the ecological sites characterized by relatively benign environmental conditions, diversity–disturbance relationships were generally consistent with the IDH, and maximum diversity was observed at some intermediate distance from the source of the grazing gradient. In contrast, the IDH was not supported at most (but not all) sites characterized by relatively harsh environmental conditions. The intermediate levels of grazing were generally located below the ecological threshold representing the points or zones at which disturbance should be limited to prevent drastic changes in ecological conditions, suggesting that there is little “conundrum” with regard to intermediate disturbance in the studied systems in terms of land management. We suggest that the landscape condition is one of the primary factors that cause inconsistencies in diversity–disturbance relationships. The ecological threshold can extend its utility in rangeland management because it also has the compatibility with the maintenance of species diversity. This study thus suggests that some intermediate scales of grazing and ecological thresholds are mutually supportive tools for sustainable management of Mongolian rangelands.
Dangers of predicting bird species distributions in response to land‐cover changes
Authors: Vallecillo Sara , Brotons Lluís , Thuiller Wilfried
Published: February 2009

Land‐cover changes from the last decades are leading to important declines in habitat quality, giving rise to changes in bird species distribution all over the world. However, land‐cover changes result from a variety of different processes, and it is not clear how effective species distribution models are in capturing species responses to these changes. In this study, we evaluated our ability to predict the effects of land‐cover changes on shifts in species distributions at large spatial and temporal scales using Mediterranean landscapes and early‐successional, open‐habitat birds as study models. Based on presence–absence data from the second Catalan Breeding Bird Atlas (1999–2002), we applied six different species distribution modeling techniques for 10 bird species using climate, topographic, and land‐cover data as predictor variables. Then we back‐projected the models on land‐cover conditions from 1980 to evaluate the projections with field observation data from the first Catalan Breeding Bird Atlas (1975–1983). Finally, we assessed if, in addition to changes in habitat suitability resulting from land‐cover shifts, descriptors of fire impact contributed to further explain species distribution dynamics: colonization and local extinction.

We developed accurate model projections of current and past global patterns of species distribution, but our ability to predict species distribution dynamics was reduced. Colonization dynamics were generally more strongly related to fire descriptors than to changes in overall habitat suitability derived from land‐cover changes. Our results warn of the dangers of projecting species distribution models onto future conditions if processes behind species distribution dynamics are not explicitly included. Consideration of ecologically meaningful processes for species (i.e., fire disturbance) when modeling species' distribution might contribute to a better explanation of species' colonization dynamics.
Glycemic Variability Correlates Strongly With Postprandialβ-Cell Dysfunction in a Segment of Type 2 Diabetic Patients Using Oral Hypoglycemic Agents
Authors: Kohnert Klaus-Dieter , Augstein Petra , Zander Eckhard , Heinke Peter , Peterson Karolina , Freyse Ernst-Joachim , Hovorka Roman , Salzsieder Eckhard
Published: February 2009

OBJECTIVE

Glucose fluctuations trigger activation of oxidative stress, a main mechanism leading to secondary diabetes complications. We evaluated the relationship between glycemic variability and β-cell dysfunction.

RESEARCH DESIGN AND METHODS

We conducted a cross-sectional study in 59 patients with type 2 diabetes (aged 64.2 ± 8.6 years, A1C 6.5 ± 1.0%, and BMI 29.8 ± 3.8 kg/m2[mean ± SD]) using either oral hypoglycemic agents (OHAs) (n = 34) or diet alone (nonusers). As a measure of glycemic variability, the mean amplitude of glycemic excursions (MAGE) was computed from continuous glucose monitoring data recorded over 3 consecutive days. The relationships between MAGE, β-cell function, and clinical parameters were assessed by including postprandial β-cell function (PBCF) and basal β-cell function (BBCF) obtained by a model-based method from plasma C-peptide and plasma glucose during a mixed-meal test as well as homeostasis model assessment of insulin sensitivity, clinical factors, carbohydrate intake, and type of OHA.

RESULTS

MAGE was nonlinearly correlated with PBCF (r = 0.54, P < 0.001) and with BBCF (r = 0.31, P = 0.025) in OHA users but failed to correlate with these parameters in nonusers (PBCF P = 0.21 and BBCF P = 0.07). The stepwise multiple regression analysis demonstrated that PBCF and OHA combination treatment were independent contributors to MAGE (R2 = 0.50, P < 0.010), whereas insulin sensitivity, carbohydrate intake, and nonglycemic parameters failed to contribute.

CONCLUSIONS

PBCF appears to be an important target to reduce glucose fluctuations in OHA-treated type 2 diabetes.
Impact of Carbohydrate Counting on Glycemic Control in Children With Type 1 Diabetes
Authors: Mehta Sanjeev N. , Quinn Nicolle , Volkening Lisa K. , Laffel Lori M.B.
Published: February 2009

OBJECTIVE

To study the association between parent carbohydrate counting knowledge and glycemic control in youth with type 1 diabetes.

RESEARCH DESIGN AND METHODS

We assessed 67 youth ages 4–12 years with type 1 diabetes (duration ≥1 year). Parents estimated carbohydrate content of children's meals in diet recalls. Ratios of parent estimates to computer analysis defined carbohydrate counting knowledge; the mean and SD of these ratios defined accuracy and precision, respectively. A1C defined glycemic control.

RESULTS

Greater accuracy and precision were associated with lower A1C in bivariate analyses (P < 0.05). In a multivariate analysis (R2= 0.25, P = 0.007) adjusting for child age, sex, and type 1 diabetes duration, precision (P = 0.02) and more frequent blood glucose monitoring (P = 0.04), but not accuracy (P = 0.9), were associated with lower A1C. A1C was 0.8% lower (95% CI −0.1 to −1.4) among youth whose parents demonstrated precision.

CONCLUSIONS

Precision with carbohydrate counting and increased blood glucose monitoring were associated with lower A1C in children with type 1 diabetes.
Twenty-first Century Memory Regimes in Germany and Poland: An Analysis of Elite Discourses and Public Opinion
Authors: Langenbacher Eric
Published: February 2009

One of the most important developments in the incipient Berlin Republic's memory regime has been the return of the memory of German suffering from the end and aftermath of World War II. Elite discourses about the bombing of German cities, the mass rape of German women by members of the Red Army, and, above all, the expulsion of Germans from then-Eastern Germany and elsewhere in Central and Eastern Europe have gained massive visibility in the last decade. Although many voices have lauded these developments as liberating, many others within Germany and especially in Poland—from where the vast majority of Germans were expelled—have reacted with fear. Yet, do these elite voices resonate with mass publics? Have these arguments had demonstrable effects on public opinion? This paper delves into these questions by looking at survey results from both countries. It finds that there has been a disjuncture between the criticisms of elites and average citizens, but that the barrage of elite criticisms leveled at German expellees and their initiatives now may be affecting mass attitudes in all cases.
De-coding the Gendered Order of Memory in 'Hitlers Frauen'
Authors: Lenz Claudia , Heinsohn Kirsten
Published: February 2009

Building on the assumption that cultural representations of the past contribute to the establishment and regulation of gendered power relations, this article investigates the representations of female participation in the Nazi regime in the German television series Hitlers Frauen. Stuart Hall's concept of decoding is used for a critical media analysis, asking how men and women are positioned as historical agents or passive objects in the series. In fact, the series plays on the gendered symbols and representations associated with the Third Reich. It reproduces traditional ideas regarding the (non)relation between femininity and politics and evokes a sexualized imaginary where women are seduced by a powerful, charismatic leader. Women are represented as dependent-materially, physically, and emotionally. In this way, the television series contributes to the continuation of traditional gender regimes. Even when the series apparently reacts to ongoing debates about women's role within the Nazi system, it disappoints those who hoped to learn about the reasons, interests, and possibilities of women between 1933 and 1945.
Measurement of In Vitro Cytochrome P450 2B6 Activity
Authors: Walsky Robert L. , Obach R. Scott
Published: February 2009

Cytochrome P450 2B6 (CYP2B6) is responsible for the metabolism of a number of therapeutically relevant drugs and environmental chemicals. While not as frequently involved in xenobiotic metabolism as other more commonly studied P450 enzymes such as CYP3A, CYP2D6, or CYP2C9, its importance is becoming increasingly realized. Bupropion hydroxylase activity is an excellent indicator of in vitro CYP2B6 activity, and the metabolite formed is easily measured by HPLC/MS/MS. This assay allows the use of very low concentrations of human liver microsomes or recombinant enzyme, and it represents a selective, sensitive approach to assessing in vitro CYP2B6 activity, with minimal sample preparation.Curr. Protoc. Toxicol. 39:4.27.1‐4.27.11. © 2009 by John Wiley & Sons, Inc.