bluuebunny/crossref_metadata_2025 huggingface dataset:
The structure of a glycogen phosphorylase glucopyranose spirohydantoin complex at 1.8 Å resolution and 100 K: The role of the water structure and its contribution to binding
Authors: Gregoriou Mary , Noble Martin E. M. , Watson Kimberly A. , Garman Elspeth F. , Johnson Louise N. , Krulle Thomas M. , Fuetene Carmen De La , Fleet George W.J. , Oikonomakos Nikos G.
Published: July 2010

A glucopyranose spirohydantoin (a pyranose analogue of the potent herbicide, hydantocidin) has been identified as the highest affinity glucose analogue inhibitor of glycogen phosphorylase b (GPb). In order to elucidate the structural features that contribute to the binding, the structures of GPb in the native T state conformation and in complex with glucopyranose spirohydantoin have been determined at 100 K to 2.0 Å and 1.8 Å resolution, respectively, and refined to crystallographic R values of 0.197 (Rfree 0.248) and 0.182 (Rfree 0.229), respectively. The low temperature structure of GPb is almost identical to that of the previously determined room temperature structure, apart from a decrease in overall atomic temperature factors (〈B〉 room temperature GPb = 34.9 Å2; 〈B〉 100 K GPb = 23.4 Å2). The glucopyranose spirohydantoin inhibitor (Ki = 3.0 μM) binds at the catalytic site and induces small changes in two key regions of the protein: the 280s loop (residues 281‐286) that results in a decrease in mobility of this region, and the 380s loop (residues 377‐385) that undergoes more significant shifts in order to optimize contact to the ligand. The hydantoin group, that is responsible for increasing the affinity of the glucose compound by a factor of 103, makes only one hydrogen bond to the protein, from one of its NH groups to the main chain oxygen of His377. The other polar groups of the hydantoin group form hydrogen bonds to five water molecules. These waters are involved in extensive networks of hydrogen bonds and appear to be an integral part of the protein structure. Analysis of the water structure at the catalytic site of the native enzyme, shows that five waters are displaced by ligand binding and that there is a significant decrease in mobility of the remaining waters on formation of the GPb‐hydantoin complex. The ability of the inhibitor to exploit existing waters, to displace waters and to recruit new waters appears to be important for the high affinity of the inhibitor.
Mapping of the interleukin‐10/interleukin‐10 receptor combining site
Authors: Reineke Ulrich , Sabat Robert , Volk Hans‐Dieter , Schneider‐Mergener Jens
Published: July 2010

The discontinuous interleukin‐10(IL‐10)/interleukin‐10 receptor (IL‐10R) combining site was mapped using sets of overlapping peptides derived from both binding partners bound to continuous cellulose membranes. Low affinity binding of single regions of the discontinuous contact sites on IL‐10 and IL‐10R could be identified due to (1) high peptide density on the membrane support, (2) incubation with high protein concentrations, (3) indirect immunodetection of the ligates after electrotransfer onto polyvinylene difluoride membranes, and (4) use of highly overlapping peptide scans of different length (6‐mers and 15‐mers). The single binding regions identified for each protein species are separated in the protein sequences, but form continuous areas on the surface of IL‐10 (X‐ray structure) and IL‐10R (computer model). Furthermore, four epitopes of neutralizing anti‐IL‐10 and anti‐IL‐10R antibodies were mapped and overlap with these binding regions. Soluble peptides (15‐ to 19‐mers) each spanning one of the three identified IL‐10‐derived receptor binding regions displayed no significant affinity to IL‐10R as expected, whereas a peptide (35‐mer) comprising two of these regions had considerably higher binding activity. The data are consistent with a previously published computer model of the IL‐10/IL‐10R complex. This approach should be generally applicable for the mapping of non‐linear protein‐protein contact sites.
A differential scanning calorimetric study of the thermal unfolding of apo‐ and holo‐cytochrome b562
Authors: Robinson Clifford R. , Sligar Stephen G. , Liu Yufeng , O'Brien Ronan , Sturtevant Julian M.
Published: July 2010

Cytochrome b562 is a four‐helix‐bundle protein containing a non‐covalently bound b‐type heme prosthetic group. In the absence of heme, cytochrome b562 remains highly structured under native conditions. Here we report thermodynamic data for the thermal denaturation of the holo‐ and apoproteins as determined by differential scanning calorimetry. Thermal denaturation of holocytochrome b562 is a highly reversible process, and unexpectedly does not involve dissociation of the heme prosthetic group. Thermal denaturation of the corresponding apoprotein, with the heme group chemically removed, remains a cooperative, reversible process. Apocytochrome b562 is substantially destabilized relative to the holoprotein: the t1/2 is more than ten degrees lower, and enthalpy and heat capacity changes are about one‐half of the holoprotein values. However, the energetic parameters of apocytochrome b562denaturation are within the range of observed values for small proteins.
Conformational diversity of acid‐denatured cytochrome c studied by a matrix analysis of far‐UV CD spectra
Authors: Konno Takashi
Published: July 2010

The singular value decomposition (SVD) analysis was applied to a large set of far‐ultraviolet circular dichroism (far‐UV CD) spectra (100‐400 spectra) of horse heart cytochrome c (cyt c). The spectra were collected at pH 1.7‐5.0 in (NH4)2SO4, sorbitol and 2,2,2‐trifluoroethanol (TFE) solutions. The present purpose is to develop a rigorous matrix method applied to far‐UV CD spectra to resolve in details conformational properties of proteins in the non‐native (or denatured) regions. The analysis established that three basis spectral components are contained in a data set of difference spectra (referred to the spectrum of the native state) used here. By a further matrix transformation, any observed spectrum could be decomposed into fractions of the native (N), the molten‐globule (MG), the highly denatured (D), and the alcohol‐induced helical (H) spectral forms. This method could determine fractional transition curves of each conformer as a function of solution conditions, which gave the results consistent with denaturation curves of cyt c monitored by other spectroscopic methods. The results in sorbitol solutions, for example, suggested that the preferential hydration effect of the co‐solvent stabilizes the MG conformer of cyt c. This report has found that the systematic SVD analysis of the far‐UV CD spectra is a powerful tool for the conformational analysis of the non‐native species of a protein when it is suitably supplemented with other experimental methods.
Complete localization of disulfide bonds in GM2 activator protein
Authors: Schütte Christina G. , Lemm Thorsten , Sandhoff Konrad , Glombitza Gereon J.
Published: July 2010

Lysosomal degradation of ganglioside GM2 by hexosaminidase A requires the presence of a small, non‐enzymatic cofactor, the GM2‐activator protein (GM2AP). Lack of functional protein leads to the AB variant of GM2‐gangliosidosis, a fatal lysosomal storage disease.

Although its possible mode of action and functional domains have been discussed frequently in the past, no structural information about GM2AP is available so far. Here, we determine the complete disulfide bond pattern of the protein. Two of the four disulfide bonds present in the protein were open to classical determination by enzymatic cleavage and mass spectrometry. The direct localization of the remaining two bonds was impeded by the close vicinity of cysteines 136 and 138. We determined the arrangement of these disulfide bonds by MALDI‐PSD analysis of disulfide linked peptides and by partial reduction, cyanylation and fragmentation in basic solution, as described recently (Wu F, Watson JT, 1997, Protein Sci 6:391‐398).
Simultaneous δ15N, δ13C and δ34S measurements of low‐biomass samples using a technically advanced high sensitivity elemental analyzer connected to an isotope ratio mass spectrometer
Authors: Hansen T. , Burmeister A. , Sommer U.
Published: July 2010

Conventional simultaneous CNS stable isotope abundance measurements of solid samples usually require high sample amounts, up to 1 mg carbon, to achieve exact analytical results. This rarely used application is often impaired by high C:S element ratios when organic samples are analyzed and problems such as incomplete conversion into sulphur dioxide occur during analysis. We introduce, as a technical innovation, a high sensitivity elemental analyzer coupled to a conventional isotope ratio mass spectrometer, with which CNS‐stable isotope ratios can be determined simultaneously in samples with low carbon content (<40 µg C corresponding to ∼100 µg dry weight). The system includes downsized reactors, a temperature program‐controlled gas chromatography (GC) column and a cryogenic trap to collect small amounts of sulphur dioxide. This modified application allows for highly sensitive measurements in a fully automated operation with standard deviations better than ±0.47‰ for δ15N and δ34S and ±0.12‰ for δ13C (n = 127). Samples collected from one sampling site in a Baltic fjord within a short time period were measured with the new system to get a first impression of triple stable isotope signatures. The results confirm the potential of using δ34S as a stable isotope tracer in combination with δ15N and δ13C measurements to improve discrimination of food sources in aquatic food webs. Copyright © 2009 John Wiley & Sons, Ltd.
Bioremediation of Dinitrotoluene in Aged Clay and Sandy Soils Using Pseudomonas Organisms, Spizizen Nutrient Medium and Prairie Silt Loam
Authors: Kornguth Steven , Chambliss Glenn , Gehring Kristine , Wible Lyman , Anderson Jack , Shalabi George , Unversagt Louis , Brodman Bruce W.
Published: July 2010

This article describes the utility of Spizizen medium in effecting the release of 2,4 dinitrotoluene (DNT) from plasticized propellant in aged clay soil and of added Pseudomonas organisms in enhancing the rate of degradation of DNT in clay and sandy soils. DNT is an environmental problem because of its toxicity to mammals. It is proposed that the citrate in Spizizen medium chelates metals that form the aggregates of humin in aged clay soils, thereby releasing propellant components. Lack of awareness of DNT mobilization by citrate or other polyanions may lead to a potential underestimation of the 2,4 DNT present in aged contaminated soil and a potential increased release of DNT following exposure to solvents containing citrate or other polyanions. DNT in contaminated sandy soils was rapidly degraded when Pseudomonas and Spizizen medium were added (85% degraded in 20 days). Pseudomonas isolated/Torn soils at the Badger Plant have particular utility for the in situ degradation of 2,4 DNT in clay and sandy soils because they metabolize Spizizen medium, thrive in diverse climates, and have been selected for their ability to grow in soils contaminated with DNT. Mixture of either the contaminated clay soil or the contaminated sandy soil with uncontaminated prairie silt loam (20:80 ratio) facilitated management of the treatment process. This observation is important because of the widespread distribution, and hence low cost, of this soil type in the central United States.
Accounting for Science and Uncertainty in Cleanup Levels: The Use of 1 μg/kg as the Cleanup Criterion for Dioxin in Soil
Authors: LaGoy Peter K.
Published: July 2010

At hazardous waste sites, a 1 μg/kg (ppb) cleanup level has commonly been used for dioxin in residential soil. This article outlines reasons for the continued use of this value in site remediation. Dioxin, one of the most toxic compounds known, has been a focus of scientific study for many years. However, controversy continues to surround its regulation, with some scientists arguing that new scientific results support decreasing risk estimates for dioxin and others taking the opposite view. Part of this controversy appears to involve a decreasing emphasis on cancer and an increased concern about non‐cancer and ecological impacts of dioxin. The 1 ppb soil cleanup level represents a reasonable generic value for dioxin, with higher or lower values required on a case‐by‐case basis to protect specific populations.
Remediation of the Radioactive Waste Landfill and Chemical Disposal Pits Sites at Sandia National Laboratories
Authors: Conway Rarilee , Aas Chris
Published: July 2010

Sandia National Laboratories' Environmental Restoration (ER) Project remediated the Radioactive Waste Landfill and Chemical Disposal Pits (RWL/CDPs) sites located in Albuquerque, New Mexico. The remediation was conducted in 1996 using conventional excavation, as well as hybrid remote robotic manipulation technology at a cost of approximately $3 million. Wastes generated included approximately 73 cubic meters (m3) of debris (including thermal batteries, spark gap tubes, radioactive sources, weapons components, and some classified material), 535 m3 of plutonium‐contaminated soil, and 2,294 m3 of soil contaminated with thorium, cesium, uranium, and tritium. The remediation was successful since the project goal of risk reduction was accomplished and no injuries or negative occurrences resulted. This cleanup is one example of the Department of Energy's (DOE's) accelerated approach to environmental restoration. The remediation was performed as a voluntary corrective measure to reduce schedule and budget, compared with the traditional approach following Resource Conservation and Recovery Act (RCRA) regulations.
Remediation Technologies Screening Matrix and Reference Guide: Version III
Authors: Teefy Dennis A.
Published: July 2010

The U. S. Army Environmental Center (USAEC) is leading an effort to update the Remediation Technologies Screening Matrix and Reference Guide, Third Edition under the auspices of the Federal Remediation Technologies Roundtable (FRTR). Its purpose is to create a comprehensive “Remediation Technologies Yellow Pages” for use by those responsible for environmental cleanup. The Guide is being produced as a multiagency cooperative effort published under the FRTR. Members of this effort include USAEC, the U. S. Army Corps of Engineers (USACE), the Naval Facilities Engineering Service Center (NFESC), the Air Force Center for Environmental Excellence (AFCEE), the Environmental Protection Agency (EPA), the Department of Energy (DOE), the Department of the Interior (DOI), and the Interstate Technologies Regulation Cooperative (ITRC). This article provides a comprehensive look at environmental technology information provided in the electronic user‐defined Remediation Technologies Screening Matrix and Reference Guide.
Almost all graphs with 1.44n edges are 3‐colorable
Authors: Chvátal V.
Published: July 2010

We establish a uniform asymptotic approximation of certain probabilities arising in the coupon collector's problem. Then we use this approximation to prove that almost all graphs with n vertices and 1.44 n edges contain no subgraph with minimum degree at least three, and hence are 3‐colorable.
A central limit theorem on gln(fq)
Authors: Goh William M. Y. , Schmutz Eric
Published: July 2010

magnified image.
A power law for connectedness of some random graphs at the critical point
Authors: Zhang Yu
Published: July 2010

We consider P(G is connected) when G is a graph with vertex set Z+ = {1,2, …}, and the edge between i and j is present with probability p(i, j) = min(λ h(i, j), 1) for certain functions h(i, j) homogeneous of degree ‐1. It is known that there is a critical value λc of λ such that magnified image.

We show that the probability, at the critical point λc, that n1, and n2 are connected satisfies a power law, in the sense that for n2 ≧ nt ≧ 1 magnified image for any δ > 0 and certain constants c1 and c2.
On generalized independent subsets of trees
Authors: Drmota Michael , Kirschenhofer Peter
Published: July 2010

A natural generalization of the widely discussed independent (or “internally stable”) subsets of graphs is to consider subsets of vertices where no two elements have distance less or equal to a fixed numberk(“k‐independent subsets”). In this paper we give asymptotic results on the average number of ˆ‐independent subsets for trees of sizen, where the trees are taken from a so‐called simply generated family. This covers a lot of interesting examples like binary trees, general planted plane trees, and others.
Proportional graphs
Authors: Janson Svante , Kratochvil Jan
Published: July 2010

Let S be a finite set of graphs and t a real number, 0 < t < 1. A (deterministic) graph G is (t, 5)‐proportional if for every H ∈ S, the number of induced subgraphs of G isomorphic to H equals the expected number of induced copies of H in the random graph Gn, t where n = |V(G)|. Let Sk = {all graphs on k vertices}, in particular S3 = {K3, P2, K2Kt, D3}. The notion of proportional graphs stems from the study of random graphs (Barbour, Karoński, and Ruciński, J Combinat. Th. Ser. B, 47, 125‐145, 1989; Janson and Nowicki, Prob. Th. Rel. Fields, to appear, Janson, Random Struct. Alg., 1, 15‐37, 1990) where it is shown that (t, S3)‐proportional graphs play a very special role; we thus call them simply t‐proportional. However, only a few ½‐proportional graphs on 8 vertices were known and it was an open problem whether there are any f‐proportional graphs with t ≠ ½ at all. In this paper, we show that there are infinitely many ½‐proportional graphs and that there are t‐proportional graphs with t≠. Both results are proved constructively. [We are not able to provide the latter construction for all f∈ Q∩(0,1), but the set of ts for which our construction works is dense in (0,1).] To support a conviction that the existence of (t, S3)‐proportional graphs was not quite obvious, we show that there are no (t, S4)‐proportional graphs.
Spanning maximal planar subgraphs of random graphs
Authors: Bollobás B. , Frieze A. M.
Published: July 2010

We study the threshold for the existence of a spanning maximal planar subgraph in the random graph Gn, p . We show that it is very near p = 1/n⅓ We also discuss the threshold for the existence of a spanning maximal outerplanar subgraph. This is very near p = 1/n½.
Acyclic coloring of graphs
Authors: Alon Noga , Mcdiarmid Colin , Reed Bruce
Published: July 2010

A vertex coloring of a graph G is called acyclic if no two adjacent vertices have the same color and there is no two‐colored cycle in G. The acyclic chromatic number of G, denoted by A(G), is the least number of colors in an acyclic coloring of G. We show that if G has maximum degree d, then A(G) = 0(d4/3) as d → ∞. This settles a problem of Erdös who conjectured, in 1976, that A(G) = o(d2) as d → ∞. We also show that there are graphs G with maximum degree d for which A(G) = Ω(d4/3/(log d)1/3); and that the edges of any graph with maximum degree d can be colored by 0(d) colors so that no two adjacent edges have the same color and there is no two‐colored cycle. All the proofs rely heavily on probabilistic arguments.
Quasi‐random 2‐ colorings of point sets
Authors: Beck József
Published: July 2010

Given an arbitrary set of N points on the plane, one can two‐color the points red and blue in such a way that the difference of the numbers of red and blue points in any half‐plane has absolute value less than N1/4(log N)4. This is essentially best possible.
A zero‐one law for a random subset
Authors: Dolan Peter
Published: July 2010

We consider first order sentences about two logical structures. First we consider 1,…, n with the successor relation and a random unary relation that points satisfy with probability p(n). We then replace the successor relation with less than. For both structures we characterize those p(n) for which a zero‐one law holds.
Probabilities in first—order logic of a unary function and a binary relation
Authors: Tyszkiewicz Jerzy
Published: July 2010

We settle the question of the behavior of probabilities of sentences of first—order logic about a unary function and a binary relation. We show that there are sentences of this logic without asymptotic probability. This settles the last open case in the problem of establishing the behavior of asymptotic probabilities for classes of labeled structures corresponding to natural signatures. © 1995 John Wiley & Sons, Inc.
The diameter of a random graph with bounded diameter
Authors: Grable David A.
Published: July 2010

We prove a conjecture of Tomescu from the Random Graphs '87 Problem Session. For k ≧ 2, almost every graph with diameter at least k has diameter exactly k. © 1995 John Wiley & Sons, Inc.
The general birthday problem
Authors: Holst Lars
Published: July 2010

The general birthday problem with unlike birth probabilities and the waiting time N until c people with the same birthday have been obtained is studied in this article. It is shown that N is stochastically largest when the birth probabilities are equal. By embedding in Poisson processes it is shown how the moments of N can be expressed in moments of the minimum of gamma random variables. © 1995 John Wiley & Sons, Inc.
On uncrowded hypergraphs
Authors: Duke Richard A. , Lefmann Hanno , Rödl Vojtech
Published: July 2010

In this note we will show that every k—uniform hypergraph ℋ︁ on n vertices with average degree ik‐1 containing no 2—cycles has independence number α(ℋ︁)≧ck n/t(lnt)1/(k‐1) for t ≧ t0(k). This confirms a conjecture of Spencer. © 1995 John Wiley & Sons, Inc.
Hamilton cycles in a random tournament
Authors: Janson Svante
Published: July 2010

The number of Hamilton cycles in a random tournament is asymptotically normally distributed.
Coverings of r—graphs by complete r—partite subgraphs
Authors: Erdös Paul , Rödl Vojtech
Published: July 2010

Let G be an (r + l)—uniform hypergraph of n vertices. Let f(r + 1, G) denote the minimum number of complete (r + l)—partite subgraphs necessary to cover all edges of G. We note that f(r+ 1, G) ≦ T(r, r + 1, n); the corresponding Turán number, and prove that up to a factor of 1 + o(l) this bound is best possible. © 1995 John Wiley & Sons, Inc.
Conservation partnerships and biodiversity governance: fulfilling governance functions through interaction
Authors: Visseren‐Hamakers Ingrid Jacoba , Leroy Pieter , Glasbergen Pieter
Published: July 2010

Over the last decades, new governance mechanisms such as partnerships have been increasingly accepted as instruments for sustainable development. This article contributes to an improved understanding of the contributions of partnerships, and their interactions with and consequences for intergovernmental regimes. It answers the question to what extent the roles of international intersectoral partnerships in biodiversity governance can be assessed using a positive, negative, or utilitarian qualification. To answer this question, the article develops and applies a methodology to analyze the governance functions that partnerships fulfill, and the institutional interaction (in terms of content, discourses, and rules) between the partnerships and intergovernmental regimes. Two case studies are analyzed: the Great Apes Survival Project (GRASP), and the Critical Ecosystem Partnership Fund (CEPF), which works on biodiversity hotspots. Contrary to most partnerships, these conservation partnerships do not use the market as a steering mechanism for sustainable development, but focus on enhancing international policy processes. The article concludes that the partnerships reinvent biodiversity policy and politics, which is necessary to improve the effectiveness of the biodiversity governance system, and that they complement intergovernmental regimes, albeit with varying effectiveness. Recommendations are developed for governments to strategically enhance public–private interaction. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
A multitechnique study of archaeological bronzes: part II
Authors: Lozzi Luca , Picozzi Pietro , Zema Nicola , Grazioli Cesare , Crossley Alison , Northover Peter , La Rosa Salvatore , Paparazzo Ernesto
Published: July 2010

This study is a sequel to an earlier paper (shown as Ref. 6) recently offered by us, and is concerned with two tin bronzes (denoted as samples A and B) dating from the 9th century BC. We used XPS, synchrotron radiation‐induced total electron yield X‐ray absorption spectroscopy (XAS), synchrotron radiation‐induced photoelectron microscopy (PEM), electron‐probe microanalysis (EPMA), and optical microscopy metallographic techniques to explore the elemental and microchemical properties of the two bronzes.

The combination of these analytical methods allows us to explore the surface layers and the bulk regions of the two samples, and major interest is to study their chemistry and microstructural properties. We find that the surface is the region in which the most noteworthy differences between the two bronzes occur. The oxidation extent of the copper is distinctly higher for sample B than for sample A, and XAS highlights such difference with a detail which is higher than that provided by XPS. EPMA reveals the enrichment of cobalt species and lead species in the bulk of sample B and sample A, respectively, as well as that the enrichment of the lead species is locally inhomogeneous. PEM analysis highlights the lateral inhomogeneity of lead species at the surface of sample A with a spatial resolution of ∼0.5 µm.

We discuss the results emerged from our study in the light of the diagnostic potential of each technique in terms of elemental sensitivity, chemical‐state mapping, surface sensitivity and spatial resolution, and conclude that they can be useful to appreciate the archaeological importance of the two bronzes. Copyright © 2010 John Wiley & Sons, Ltd.
The effect of incident energy on molecular depth profiling of polymers with large Ar cluster ion beams
Authors: Ninomiya Satoshi , Ichiki Kazuya , Yamada Hideaki , Nakata Yoshihiko , Seki Toshio , Aoki Takaaki , Matsuo Jiro
Published: July 2010

In this study, we evaluated the damage caused by large Ar cluster ion irradiation on polymeric materials, and demonstrated a technique for molecular depth profiling of polymer films. The surface chemical states of the polymers were analyzed with XPS. The chemical states of the polymethyl methacrylate (PMMA) sample etched with Ar monomer ion beams differed significantly from those of the unirradiated sample, but were preserved for the sample etched with Ar cluster ion beams. SIMS depth profiling of the PMMA and polystyrene (PS) films were also carried out by using large Ar cluster ion beams at incident energies between 5.5 and 13 keV, and the effects of incident energy on damage accumulation and depth resolution were investigated. The ratios of the signal intensity at zero fluence to the signal intensity at steady state decreased with increasing incident energy, whereas the depth resolution was little affected by incident energy. Copyright © 2010 John Wiley & Sons, Ltd.
The crossover of burnout and its relation to partner health
Authors: Bakker Arnold B.
Published: July 2010

Two studies among medical residents and teachers in the Netherlands and Greece tested the hypothesis that burnout may transfer from employees to their intimate partners at home and indirectly influence the partner's health. Study 1 included a general index of self‐rated health, whereas, Study 2 included a detailed measure of depression. Results show that burnout crosses over and that partner burnout is related to health (negative) and depression (positive). Moreover, both studies supported the mediating role of partner burnout in the relationship between employee burnout and partner health/depression. Additionally, results were similar when partner burnout was used as the predictor variable of medical residents' and teachers' health through their burnout. These findings are discussed in light of the recently proposed spillover–crossover model. Copyright © 2009 John Wiley & Sons, Ltd.
Does burnout predict changes in pain experiences among women living in Sweden? A longitudinal study
Authors: Grossi Giorgio , Thomtén Johanna , Fandiño‐Losada Andrés , Soares Joaquim J. F. , Sundin Örjan
Published: July 2010

The study investigated the associations between burnout—conceptualized as a syndrome of emotional exhaustion/physical fatigue and cognitive weariness—and pain parameters (overall pain, pain sites, intensity and frequency, and perceived disability) among 2,300 women living in Stockholm County. The study was a longitudinal panel survey with two assessments by means of questionnaires, 1 year apart. After adjustment for socio‐demographic and work characteristics, smoking, psychological distress, physical health and basal pain parameters, T1 levels of burnout and/or their change scores were the most important predictors of overall pain, neck/shoulder pain, back pain and disability. Pain frequency was related to increases in tension and listlessness. The results indicated that burnout contributes to the onset and maintenance of pain and to the functional impairment that it causes. Further studies are needed to evaluate the extent to which pain and burnout, may be mutually reinforcing. Copyright © 2009 John Wiley & Sons, Ltd.
Burnout predicts hospitalization for mental and cardiovascular disorders: 10‐year prospective results from industrial sector
Authors: Toppinen‐Tanner Salla , Ahola Kirsi , Koskinen Aki , Väänänen Ari
Published: July 2010

This study investigated the prospective effect of burnout as a chronic stress reaction, on cause‐specific hospital admissions over 10 years in the forest industry. The data on burnout Maslach Burnout Inventory–General Survey was collected using a questionnaire at baseline (1996) and the data on hospital admissions were taken from the Finnish Hospital Discharge Register between March 1996 and December 2005. The participants consisted of forest industry employees (24 per cent women, 62 percent manual work), with no recent history of a disorder in the same disorder category according to the hospital admission register (January 1986–February 1996) or the registers of prescribed medication (January 1994–February 1996) ( N varied from 4543 to 7521). The results showed an increased risk of future hospitalization due to mental and cardiovascular disorders related to burnout syndrome. They also showed that of the separate burnout dimensions, exhaustion and cynicism were predictive of these hospital admissions. This longitudinal follow‐up study shows that burnout predicts future mental and cardiovascular ill health. The results illustrate the importance of preventing and alleviating burnout as a means to promote employee health. Copyright © 2009 John Wiley & Sons, Ltd.
Flexible Piezoelectric ZnO–Paper Nanocomposite Strain Sensor
Authors: Gullapalli Hemtej , Vemuru Venkata S. M. , Kumar Ashavani , Botello‐Mendez Andres , Vajtai Robert , Terrones Mauricio , Nagarajaiah Satish , Ajayan Pulickel M.
Published: July 2010

The fabrication of a mechanically flexible, piezoelectric nanocomposite material for strain sensing applications is reported. Nanocomposite material consisting of zinc oxide (ZnO) nanostructures embedded in a stable matrix of paper (cellulose fibers) is prepared by a solvothermal method. The applicability of this material as a strain sensor is demonstrated by studying its real‐time current response under both static and dynamic mechanical loading. The material presented highlights a novel approach to introduce flexibility into strain sensors by embedding crystalline piezoelectric material in a flexible cellulose‐based secondary matrix.
Elastic Deformation of Carbon‐Nanotube Nanorings
Authors: Zheng Meng , Ke Changhong
Published: July 2010

A combined experimental–theoretical study of the mechanical deformation of carbon‐nanotube (CNT) nanorings is presented. The CNT ring employed is formed by folding a long and thin single‐walled‐CNT bundle. The mechanical deformations of the CNT ring when it is pushed against and pulled away from a flat substrate are experimentally characterized in situ, inside a high‐resolution scanning electron microscope through nanomanipulation. The experimental measurements clearly reveal that the CNT ring displays a purely elastic behavior during multiple repeated large‐displacement deformation processes. A theoretical model based on nonlinear elastica theory is used to quantitatively study the mechanical behavior of the CNT ring and to interpret the experimental results. This work shows for the first time that van der Waals interactions between the CNT ring and the substrate have significant effects on the ring's elastic deformation, including a bifurcation in its force–displacement profile. The results suggest that CNT nanorings can be used as ultrasensitive force sensors and flexible and stretchable structural components in novel nanoscale mechanical and electromechanical systems.
Age‐dependent differences in dopamine transporter and vesicular monoamine transporter‐2 function and their implications for methamphetamine neurotoxicity
Authors: Volz Trent J. , Farnsworth Sarah J. , Rowley Shane D. , Hanson Glen R. , Fleckenstein Annette E.
Published: July 2010

The abuse of methamphetamine (METH) is a serious public health problem because METH can cause persistent dopaminergic deficits in the brains of both animal models and humans. Surprisingly, adolescent postnatal day (PND)40 rats are resistant to these METH‐induced deficits, whereas young adult PND90 rats are not. Studies described in this report used rotating disk electrode voltammetry and western blotting techniques to investigate whether there are age‐dependent differences in monoamine transporter function in PND38–42 and PND88–92 rats that could contribute to this phenomenon. The initial velocities of dopamine (DA) transport into, METH‐induced DA efflux from, and DA transporter (DAT) immunoreactivity in striatal suspensions are greater in PND38–42 rats than in PND88–92 rats. DA transport velocities into vesicles that cofractionate with synaptosomal membranes after osmotic lysis are also greater in PND38–42 rats. However, there is no difference in vesicular monoamine transporter‐2 (VMAT‐2) immunoreactivity between the two age groups in this fraction. This suggests that younger rats have a greater capacity to sequester cytoplasmic DA into membrane‐associated vesicles due to kinetically upregulated VMAT‐2 and also have increased levels of functionally active DAT. In the presence of METH, these may provide additional routes of cellular efflux for DA that is released from vesicles into the cytoplasm and thereby prevent cytoplasmic DA concentrations in younger rats from rising to neurotoxic levels after drug administration. These findings provide novel insight into the age‐dependent physiological regulation of neuronal DA sequestration and may advance the treatment of disorders involving abnormal DA disposition including substance abuse and Parkinson's disease. Synapse 63:147–151, 2009. © 2008 Wiley‐Liss, Inc.
An immunocapture/scintillation proximity analysis of Gαq/11 activation by native serotonin (5‐HT)2Areceptors in rat cortex: Blockade by clozapine and mirtazapine
Authors: Mannoury La Cour C. , Chaput C. , Touzard M. , Millan M.J.
Published: July 2010

Though transduction mechanisms recruited by heterologously expressed 5‐HT2Areceptors have been extensively studied, their interaction with specific subtypes of G‐protein remains to be directly evaluated in cerebral tissue. Herein, as shown by an immunocapture/scintillation proximity analysis, 5‐HT, the prototypical 5‐HT2Aagonist, DOI, and Ro60,0175 all enhanced [35S]GTPγS binding to Gαq/11 in rat cortex with pEC50values of 6.22, 7.24 and 6.35, respectively. No activation of Go or Gs/olf was seen at equivalent concentrations of DOI. Stimulation of Gαq/11 by 5‐HT (30 μM) and DOI (30 μM) was abolished by the selective 5‐HT2Avs. 5‐HT2C/5‐HT2Bantagonists, ketanserin (pKBvalues of 9.11 and 8.88, respectively) and MDL100,907 (9.82 and 9.68). By contrast, 5‐HT‐induced [35S]GTPγS binding to Gαq/11 was only weakly inhibited by the preferential 5‐HT2Creceptor antagonists, RS102,221 (6.94) and SB242,084 (7.39), and the preferential 5‐HT2Breceptor antagonist, LY266,097 (6.66). The antipsychotic, clozapine, which had marked affinity for 5‐HT2Areceptors, blocked the recruitment of Gαq/11 by 5‐HT and DOI with pKBvalues of 8.54 and 8.14, respectively. Its actions were mimicked by the “atypical” antidepressant and 5‐HT2Areceptor antagonist, mirtazapine, which likewise blocked 5‐HT and DOI‐induced Gαq/11 protein activation with pKBvalues of 7.90 and 7.76, respectively. In conclusion, by use of an immunocapture/scintillation proximity strategy, this study shows that native 5‐HT2Areceptors in rat frontal cortex specifically recruit Gαq/11 and that this action is blocked by clozapine and mirtazapine. Quantification of 5‐HT2Areceptor‐mediated Gαq/11 activation in frontal cortex should prove instructive in characterizing the actions of diverse classes of psychotropic agent. Synapse 63:95–105, 2009. © 2008 Wiley‐Liss, Inc.
Activity‐induced large amplitude postsynaptic mPSPs at soma–soma synapses between Lymnaea neurons
Authors: Dunn T.W. , McCamphill P.K. , Syed N.I.
Published: July 2010

Spontaneous transmitter release has been observed at various synapses that permit analysis at a sufficient resolution as a miniature postsynaptic potential (mPSP). However, the precise mechanisms that regulate spontaneous transmitter release have not yet been fully defined. Activity and ligand‐mediated modulation of large amplitude, spontaneous events significantly enhances postsynaptic excitation in the absence of action potential activity suggesting a more complicated role for this mode of transmitter release, and thus warrants further analysis. Here, we used Lymnaea soma–soma synaptic connections to demonstrate that a transient increase in both the frequency and amplitude of spontaneous events (mPSPs) occurs following a short burst of action potentials in the presynaptic cell. These events were of presynaptic origin and the increase in mPSP amplitude could also be achieved with a stimulatory concentration of ryanodine. Ryanodine also occluded the activity‐induced increase in mPSP amplitude implicating calcium release from these channels in the production of large amplitude spontaneous transmitter release events. This suggests that presynaptic activity triggers ryanodine receptor‐mediated large amplitude minis, indicating that although these events are action potential‐independent, they are nevertheless responsive to the prior activity of the synapse. Synapse 63:117–125, 2009. ©2008 Wiley‐Liss, Inc.
Educational reform and educational crisis
Authors: Apple Michael W.
Published: July 2010

Even though the sciences may deserve an important and enhanced place in the curriculum, it is crucial that educators situate reforms in science education in the larger social context in which educational reforms are taking place. How and by whom reform is defined and carried out will have a significant impact on who benefits from the process. I argue that education in general has increasingly become dominated by economic interests that can lead not to enhancing equality but to its opposite. There are important ideological shifts that are occurring not only in what education is for, but in the content and control of curriculum and teaching. This has also been accompanied by an attempt to not only increase the influence of economic needs on schools, but to make education itself an economic product like all others. This will have a major impact on science education in particular, because both science and technology are seen as high‐status in the transformation of education into solely an economic tool.
Rethinking science education: Beyond piagetian constructivism toward a sociocultural model of teaching and learning
Authors: O'loughlin Michael
Published: July 2010

In the first part of the article I present an epistemological critique of forms of pedagogy founded on Piagetian constructivism. Despite the appeal of the notion that learners construct their understanding, I argue that constructivism is problematic because it ignores the subjectivity of the learner and the socially and historically situated nature of knowing; it denies the essentially collaborative and social nature of meaning making; and it privileges only one form of knowledge, namely, the technical rational. I then present a critique of active learning and student‐centered forms of pedagogy. I argue that in our models of teaching we rely on too many unexamined assumptions from developmental psychology and we take for granted the problematic notion that children learn by doing. My central thesis is that constructivism is flawed because of its inability to come to grips with the essential issues of culture, power, and discourse in the classroom. In the concluding section of the article I present a preliminary account of a sociocultural approach to teaching and learning that takes seriously the notion that learning is situated in contexts, that students bring their own subjectivities and cultural perspectives to bear in constructing understanding, that issues of power exist in the classroom that need to be addressed, and that education into scientific ways of knowing requires understanding modes of classroom discourse and enabling students to negotiate these modes effectively so that they may master and critique scientific ways of knowing without, in the process, sacrificing their own personally and culturally constructed ways of knowing.
Science education reform: Building on the research base
Authors: Linn Marcia C.
Published: July 2010

Those concerned with science education are united in calling for reform, yet divided in specifying the nature of this reform. Several recent conferences (Gardner et al., 1990; Linn, 1987b; Shymansky & Kyle, 1992) have focused on reform as a joint collaborative process involving experts in cognition, science education, precollege teaching, the subject matter disciplines, teacher preparation, and curriculum design. This article (a) contrasts several perspectives on science education reform by examining recommendations for introductory science courses, (b) identifies research findings that can guide reform, (c) discusses the impact of research on national precollege curriculum reform, and (d) offers a set of recommendations to guide research and practice concerned with science education reform.
Viewpoint: What we did not learn from the 60s about science curriculum reform
Authors: Yager Robert E.
Published: July 2010

An analysis of our efforts with curriculum reform in science during the 60s is offered. Failure to state the problems and to engage all those interested, involved, and affected is noted. Instead of proceeding with the same tactics and using the same rationale for new reforms, a rationale for focusing upon instructional goals and enlarging the research and development team is presented. Basically, a call for treating science curriculum reform as a science rather than an art is advocated.
Teaching evolution and natural selection: a look at textbooks and teachers
Authors: Aleixandre Maria Pilar Jiménez
Published: July 2010

As a part of a larger study on the learning of natural selection by secondary school students in Spain, data were gathered about how textbooks deal with this topic, and about the ability of teachers to explore pupils' ideas related to it. These data were contrasted with an approach seeking to develop the pupils' capacity to explain biological change using the model of natural selection. Textbooks were analyzed with respect to the following characteristics: the way key ideas in the model were handled, the attention paid to pupils' ideas, and the type of activities used in the instruction. The study involved evaluating the above factors in a sample of 17 books used in Spain, as well as the approaches that teachers used. Results show that in most cases the approach is characterized by superficial handling of key ideas, lack of attention paid to alternative ideas, and little variety in activities. Relation between this approach and the difficulties that pupils show in the use of the model are discussed herein.

Mark what Jacob did When Laban and himself were compromis'd, That all the eanlings which were streak' d and pied, Should fall as Jacob's hire, the ewes, being rank, In end of autumn turned to the rams: and when the work of generation was Between these woolly breeders in the act. The skillful shepherd peel'd me certain wands, and, in the doing of the deed of kind, He stuck them up before the fulsome ewes, Who, then conceiving, did in earning time Fall party‐colour''d lambs, and those were Jacob's.
Conceptualizing a teaching experience on the development of the idea of evolution: An epistemological approach to the education of science teachers
Authors: Zuzovsky Ruth
Published: July 2010

This article describes and discusses an epistemological approach to the education of science teachers that emphasizes similarities in knowledge and modes of acquiring it among children, scientists in their historical contexts, and student teachers. Advanced courses in science‐teacher education aim to go beyond the attainment of scientific knowledge and pedagogical content knowledge toward the building of a guiding theory of action for teaching. This theory needs to be rooted in a broad understanding of what science is about, what is regarded as scientific knowledge, and how it is generated and evolves. These questions are of an epistemological nature. At the same time, theories of action for teaching science are also connected with questions on individual ways of learning and of acquiring meaning. Such questions are often answered by both cognitive and developmental psychologists. Even here epistemological consideration are essential. Constructivist epistemology, which describes the process of constructing knowledge both in individuals and among scientists, can serve as a basis for generating such a guiding pedagogical theory of teaching. Educating science teachers in the light of radical versions of constructivism can enhance this process. This article describes in detail a course entitled “The Growth of Thinking on Evolution,” which was taught to third‐year student teachers and which illustrates the approach and discusses the rationale behind it.
Characterization of different promoters for designing a new expression vector in Saccharomyces cerevisiae
Authors: Partow Siavash , Siewers Verena , Bjørn Sara , Nielsen Jens , Maury Jérôme
Published: July 2010

The widely used pESC vector series (Stratagene, La Jolla, CA, USA) with the bidirectional GAL1/GAL10 promoter provides the possibility of simultaneously expressing two different genes from a single vector in Saccharomyces cerevisiae. This system can be induced by galactose and is repressed by glucose. Since S. cerevisiae prefers glucose as a carbon source, and since its growth rate is higher in glucose than in galactose‐containing media, we compared and evaluated seven different promoters expressed during growth on glucose (pTEF1, pADH1, pTPI1, pHXT7, pTDH3, pPGK1 and pPYK1) with two strong galactose‐induced promoters (pGAL1 and pGAL10), using lacZ as a reporter gene and measuring LacZ activity in batch and continuous cultivation. TEF1 and PGK1 promoters showed the most constant activity pattern at different glucose concentrations. Based on these results, we designed and constructed two new expression vectors which contain the two constitutive promoters, TEF1 and PGK1, in opposite orientation to each other. These new vectors retain all the features from the pESC–URA plasmid except that gene expression is mediated by constitutive promoters. Copyright © 2010 John Wiley & Sons, Ltd.