bluuebunny/crossref_metadata_2025 huggingface dataset:
Reference Equations of State for the Thermodynamic Properties of Fluid Phase n-Butane and Isobutane
Authors: Bücker D. , Wagner W.
Published: June 2006

New formulations for the thermodynamic properties of fluid phase n-butane and isobutane in the form of fundamental equations explicit in the Helmholtz energy are presented. The functional form of the correlation equations for the residual parts was developed simultaneously for both substances considering data for the thermodynamic properties of ethane, propane, n-butane, and isobutane. Each contains 25 coefficients which were fitted to selected data for the thermal and caloric properties of the respective fluid both in the single-phase region and on the vapor–liquid phase boundary. This work provides information on the available experimental data for the thermodynamic properties of n- and isobutane, and presents all details of the new formulations. The new equations of state describe the pρT surfaces with uncertainties in density of 0.02% (coverage factor k=2 corresponding to a confidence level of about 95%) from the melting line up to temperatures of 340 K and pressures of 12 MPa. The available reliable data sets in other regions are represented within their experimental uncertainties. The primary data, to which the equation for n-butane was fitted, cover the fluid region from the melting line to temperatures of 575 K and pressures of 69 MPa. The equation for isobutane was fitted to primary data that cover the fluid region from the melting line to temperatures of 575 K and pressures of 35 MPa. Beyond the range described by experimental data, the equations yield reasonable extrapolation behavior up to very high temperatures and pressures. In addition to the equations of state, independent equations for the vapor pressures, the saturated-liquid and saturated-vapor densities, and the melting pressures are given. Tables of thermodynamic properties calculated from the new formulations are listed in Appendix 2. Additionally, a preliminary equation of state for propane is presented that was developed in the course of the simultaneous optimization. This equation has the same functional form as the equations of state for n- and isobutane.
IUPAC-NIST Solubility Data Series. 81. Hydrocarbons with Water and Seawater—Revised and Updated Part 12. C5–C26 Hydrocarbons with Seawater
Authors: Shaw David G. , Maczynski Andrzej , Hefter G. T. , Kleinschmidt M. , Mackay D. , Meyers P. A , Miyamoto H. , Shiu W. Y.
Published: June 2006

The mutual solubility of C5–C26 hydrocarbons with seawater is exhaustively and critically reviewed. Reports of experimental determination of solubility in 46 chemically distinct binary systems that appeared in the primary literature prior to end of 2002 are compiled. For 15 of these systems sufficient data are available to allow critical evaluation. All data are expressed as mass percent and mole fraction as well as the originally reported units.
Time-resolved optical measurements of the post-detonation combustion of aluminized explosives
Authors: Carney Joel R. , Miller J. Scott , Gump Jared C. , Pangilinan G. I.
Published: June 2006

The dynamic observation and characterization of light emission following the detonation and subsequent combustion of an aluminized explosive is described. The temporal, spatial, and spectral specificity of the light emission are achieved using a combination of optical diagnostics. Aluminum and aluminum monoxide emission peaks are monitored as a function of time and space using streak camera based spectroscopy in a number of light collection configurations. Peak areas of selected aluminum containing species are tracked as a function of time to ascertain the relative kinetics (growth and decay of emitting species) during the energetic event. At the chosen streak camera sensitivity, aluminum emission is observed for 10μs following the detonation of a confined 20g charge of PBXN-113, while aluminum monoxide emission persists longer than 20μs. A broadband optical emission gauge, shock velocity gauge, and fast digital framing camera are used as supplemental optical diagnostics. In-line, collimated detection is determined to be the optimum light collection geometry because it is independent of distance between the optics and the explosive charge. The chosen optical configuration also promotes a constant cylindrical collection volume that should facilitate future modeling efforts.
A combined explicit-implicit method for high accuracy reaction path integration
Authors: Burger Steven K. , Yang Weitao
Published: June 2006

We present the use of an optimal combined explicit-implicit method for following the reaction path to high accuracy. This is in contrast to most purely implicit reaction path integration algorithms, which are only efficient on stiff ordinary differential equations. The defining equation for the reaction path is considered to be stiff, however, we show here that the reaction path is not uniformly stiff and instead is only stiff near stationary points. The optimal algorithm developed in this work is a combination of explicit and implicit methods with a simple criterion to switch between the two. Using three different chemical reactions, we combine and compare three different integration methods: the implicit trapezoidal method [C. Gonzalez and H. Schlegel, J. Chem. Phys. 90, 2154 (1989)], an explicit stabilized third order algorithm [A. A. Medovikov, BIT 38, 372 (1998)] implemented in the code DUMKA3 and the traditional explicit fourth order Runge-Kutta method written in the code RKSUITE. The results for high accuracy show that when the implicit trapezoidal method is combined with either explicit method the number of energy and gradient calculations can potentially be reduced by almost a half compared with integrating either method alone. Finally, to explain the improvements of the combined method we expand on the concepts of stability and stiffness and relate them to the efficiency of integration methods.
Electron attachment to MoF6, ReF6, and WF6; reaction of MoF6− with ReF6 and reaction of Ar+ with MoF6
Authors: Friedman Jeffrey F. , Stevens Amy E. , Miller Thomas M. , Viggiano A. A.
Published: June 2006

Rate constants were measured for electron attachment to MoF6, ReF6, and WF6 in 133Pa of helium gas using a flowing-afterglow Langmuir-probe apparatus. The experiment is a thorny one because the molecules tend to form oxide impurities on feedline surfaces and because of thermal decomposition of MoF6 on surfaces as the gas temperature is increased. The electron attachment rate constant for MoF6 is (2.3±0.8)×10−9cm3s−1 at 297K; only MoF6− is formed in the temperature range of 297–385K. The rate constant increases with temperature up to the point where decomposition becomes apparent. Electron attachment to ReF6 occurs with a rate constant of (2.4±0.8)×10−9cm3s−1 at 297K; only ReF6− is produced. MoF6− reacts with ReF6 to form ReF6− on essentially every collision, showing definitively that the electron affinity of ReF6 is greater than that of MoF6. A rate constant of (5.0±1.3)×10−10cm3s−1 was measured for this ion-molecule reaction at 304K. The reverse reaction is not observed. The reaction of Ar+ with MoF6 was found to produce MoF5++F, with a rate constant of (1.8±0.5)×10−9cm3s−1. WF6 attaches electrons so slowly at room temperature that the attachment rate was below detection level (⩽10−12cm3s−1). By 552K, the attachment rate constant reaches a value of (2±1)×10−10cm3s−1.
Mirror test for International Thermonuclear Experimental Reactor at the JET tokamak: An overview of the program
Authors: Rubel M. J. , De Temmerman G. , Coad J. P. , Vince J. , Drake J. R. , Le Guern F. , Murari A. , Pitts R. A. , Walker C. , Contributors JET-EFDA
Published: June 2006

Metallic mirrors will be essential components of all optical spectroscopy and imaging systems for plasma diagnosis that will be used at the next-step magnetic fusion experiment, International Thermonuclear Experimental Reactor (ITER). Any change of the mirror performance, in particular, reflectivity, will influence the quality and reliability of detected signals. At the instigation of the ITER Design Team, a dedicated technical and experimental activity aiming at the assessment of mirror surface degradation as a result of exposure to the plasma has been initiated on the JET tokamak. This article provides a comprehensive overview of the mirror test program, including design details of the mirror samples and their supports, their locations within JET, and the issue of optical characterization of the mirrors both before and after exposure. The postexposure characterization is particularly challenging in JET as a consequence of an environment in which both tritium and beryllium are present.
Complex periodic potentials with a finite number of band gaps
Authors: Khare Avinash , Sukhatme Uday
Published: June 2006

We obtain several new results for the complex generalized associated Lamé potential V(x)=a(a+1)msn2(y,m)+b(b+1)msn2(y+K(m),m)+f(f+1)msn2(y+K(m)+iK′(m),m)+g(g+1)msn2(y+iK′(m),m), where y≡x−K(m)∕2−iK′(m)∕2, sn(y,m) is the Jacobi elliptic function with modulus parameter m, and there are four real parameters a,b,f,g. First, we derive two new duality relations which, when coupled with a previously obtained duality relation, permit us to relate the band edge eigenstates of the 24 potentials obtained by permutations of the parameters a,b,f,g. Second, we pose and answer the question: how many independent potentials are there with a finite number “a” of band gaps when a,b,f,g are integers and a⩾b⩾f⩾g⩾0? For these potentials, we clarify the nature of the band edge eigenfunctions. We also obtain several analytic results when at least one of the four parameters is a half-integer. As a by-product, we also obtain new solutions of Heun’s differential equation.
Design and operation of a two-stage positron accumulator
Authors: Clarke J. , van der Werf D. P. , Griffiths B. , Beddows D. C. S. , Charlton M. , Telle H. H. , Watkeys P. R.
Published: June 2006

A compact positron accumulator based upon a simple two-stage buffer gas cooling scheme is described. Its operation to produce 10–20ns wide bursts containing around 105 positrons with cycling times in the 100msto1s range is discussed. Departures of the behavior of the accumulator from that expected of such an instrument are presented. The utility of these effects in diagnosing accumulator performance is described.
Absence of reflection as a function of the coupling constant
Authors: Killip Rowan , Sims Robert
Published: June 2006

We consider solutions of the one-dimensional equation −u″+(Q+λV)u=0 where Q:R→R is locally integrable, V:R→R is integrable with supp(V)⊂[0,1], and λ∊R is a coupling constant. Given a family of solutions {uλ}λ∊R which satisfy uλ(x)=u0(x) for all x<0, we prove that the zeros of b(λ)≔W[u0,uλ], the Wronskian of u0 and uλ, form a discrete set unless V≡0. Setting Q(x)≔−E, one sees that a particular consequence of this result may be stated as: if the fixed energy scattering experiment −u″+λVu=Eu gives rise to a reflection coefficient which vanishes on a set of couplings with an accumulation point, then V≡0.
Plasma ionization by annularly bounded helicon waves
Authors: Yano Masayuki , Walker Mitchell L. R.
Published: June 2006

The general solution to the electrostatic and magnetic fields is derived with respect to the boundary conditions of a coaxial helicon plasma source. The electric field contours suggest that a simple antenna design can ionize the gas in a coaxial configuration. In addition, the power deposition as a function of excitation frequency is derived. The solution is validated by comparison with the standard cylindrical helicon plasma source. Further, a parametric study of source length, channel radius, channel width, and antenna excitation frequency are presented. This study suggests that it is possible to create a helicon plasma source with a coaxial configuration.
Variation in the sensitivity of organismal body temperature to climate change over local and geographic scales
Authors: Gilman Sarah E. , Wethey David S. , Helmuth Brian
Published: June 2006

Global climate change is expected to have broad ecological consequences for species and communities. Attempts to forecast these consequences usually assume that changes in air or water temperature will translate into equivalent changes in a species’ organismal body temperature. This simple change is unlikely because an organism’s body temperature is determined by a complex series of interactions between the organism and its environment. Using a biophysical model, validated with 5 years of field observations, we examined the relationship between environmental temperature change and body temperature of the intertidal musselMytilus californianusover 1,600 km of its geographic distribution. We found that at all locations examined simulated changes in air or water temperature always produced less than equivalent changes in the daily maximum mussel body temperature. Moreover, the magnitude of body temperature change was highly variable, both within and among locations. A simulated 1°C increase in air or water temperature raised the maximum monthly average of daily body temperature maxima by 0.07–0.92°C, depending on the geographic location, vertical position, and temperature variable. We combined these sensitivities with predicted climate change for 2100 and calculated increases in monthly average maximum body temperature of 0.97–4.12°C, depending on location and climate change scenario. Thus geographic variation in body temperature sensitivity can modulate species’ experiences of climate change and must be considered when predicting the biological consequences of climate change.
Keishibukuryogan (Gui‐Zhi‐Fu‐Ling‐Wan), a Kampo Formula, Decreases Disease Activity and Soluble Vascular Adhesion Molecule‐1 in Patients with Rheumatoid Arthritis
Authors: Nozaki Kazuya , Hikiami Hiroaki , Goto Hirozo , Nakagawa Takako , Shibahara Naotoshi , Shimada Yutaka
Published: June 2006

An increasing death rate due to cardiovascular disease in patients with rheumatoid arthritis (RA) has been reported. Keishibukuryogan (KBG) is a traditional Chinese/Japanese (Kampo) formula that has been administered to patients with blood stagnation, e.g. thrombotic disease and atherosclerosis. The objective of this study was to evaluate the efficacy of KBG on disease activity and endothelial dysfunction in RA patients. Sixteen RA patients were enrolled and administered KBG (12 g per day) for 12 weeks in addition to continuing other drugs. The disease activity of RA was assessed by modified disease activity scores for 28 joints (DAS28). Plasma levels of adhesion molecules, soluble E‐selectin (sE‐selectin), soluble intercellular adhesion molecule‐1 (sICAM‐1) and soluble vascular cell adhesion molecule‐1 (sVCAM‐1) were evaluated. C‐reactive protein (CRP), inflammatory cytokines (IL‐1β, IL‐6 and TNF‐α) and lipid peroxide (LPO) were also evaluated. Fourteen patients completed the study. The disease activity of RA, tender joint count, swollen joint count and DAS28 decreased significantly. Among adhesion molecules, only sVCAM‐1 decreased significantly. LPO also decreased significantly, whereas CRP and inflammatory cytokines remained unchanged. These results suggest that KBG has insufficient anti‐inflammatory or immunomodulating effect but does have a beneficial effect on articular symptoms and a protective effect against endothelial dysfunction in RA patients.
Contact allergy to textile dyes in southern Sweden
Authors: Ryberg K. , Isaksson M. , Gruvberger B. , Hindsén M. , Zimerson E. , Bruze M.
Published: June 2006

Contact allergy to disperse dyes in textiles is documented in prevalence studies from southern Europe. To evaluate the prevalence of allergic patch test reactions to different textile dyes in southern Sweden, and to look at the sites of dermatitis in individuals hypersensitive to textile dyes, we retrospectively investigated 3325 consecutively patch‐tested patients. They had all been patch tested with the standard test series supplemented with a textile dye mix (TDM) consisting of 8 disperse dyes, i.e. Disperse (D) Blue 35, 106 and 124, D Yellow 3, D Orange 1 and 3 and D Red 1 and 17. All but 3 of the TDM‐positive patients were additionally tested with the separate dyes included in the mix. The frequency of contact allergy to TDM was 1.5%, which is comparable with studies from southern Europe. The most common dye allergen was D Orange 1. The high prevalence of allergic reactions to D Orange 1 was unexpected, whereas test reactions to D Blue 106 and 124 were lower than expected from other studies. Compared to all tested patients, the TDM‐positive patients more often had dermatitis on their arms, face, neck and axillary folds, and women also had a higher frequency of hand dermatitis.
Is the question ‘Have you had childhood eczema?’ useful for assessing childhood atopic eczema in adult population surveys?
Authors: Stenberg Berndt , Lindberg Magnus , Meding Birgitta , Svensson Åke
Published: June 2006

Atopic eczema (AE) is a major risk factor for hand eczema. In Scandinavian population‐based studies, the occurrence of AE in childhood has often been assessed by the question ‘Have you had childhood eczema?’ In the present study, this question was validated. A questionnaire was sent to 600 cases with AE and 600 controls without eczema or allergic disease, identified in school medical records from the 1960s. The response rate was 70.5%, and the mean age of the respondents was 36.7 years. The specificity of the question was 70.7% and the sensitivity 89.9%. The sensitivity was higher and the specificity lower in a subgroup with current hand eczema compared with a group without hand eczema. The results showed that the question overestimated the prevalence of AE in childhood by a factor of 1.6. When used for risk assessment, the question provided a better estimate of the risk of current hand eczema as compared with the lifetime risk of hand eczema. In conclusion, the validated question overestimated prevalence of childhood AE and may overestimate AE as a risk factor for hand eczema in adult population surveys.
White petrolatum (Ph. Eur.) is virtually non‐sensitizing. Analysis of IVDK data on 80 000 patients tested between 1992 and 2004 and short discussion of identification and designation of allergens
Authors: Schnuch Axel , Lessmann Holger , Geier Johannes , Uter Wolfgang
Published: June 2006

Sporadic cases of contact allergy to white petrolatum, which is used as a vehicle in patch test preparations, have been reported. The quantitative relevance of the phenomenon remains yet to be elucidated. Methods: Retrospective analysis of patch test data of the Information Network of Departments of Dermatology (IVDK, http://www.ivdk.org) between 1992 and 2004. Results: Analysis of 79 365 patients patch tested with pure petrolatum yielded 27 ‘+’ (0.03%) and 2 ‘+++’ (0.003%) reactions. The majority of non‐negative reactions (0.3%) was interpreted as doubtful (235) or mild irritant (32). The negative reaction index (RI) (−0.8), and the high positivity ratio (PR) (93%) especially a lack of concordance with patch test preparations containing ≥99% petrolatum indicate that many of the ‘positive’ (+) reactions have to be considered as irritant. There were 2 ‘+++’ reactions. In 1 case, an ‘angry back reaction’ was confirmed. The other case is probably a reading or documentation error, as the majority of patch test reactions to preparations containing petrolatum remained negative in this case also. Conclusions: True allergic patch test reactions to white petrolatum are extremely rare and probably due to an individually increased susceptibility to allergens and/or irritants. This is in agreement with considering petrolatum as a non‐sensitizer.
Stress and Adaptation
Authors: Koolhaas Jaap M. , de Boer Sietse F. , Buwalda Bauke
Published: June 2006

Animal models have contributed considerably to the current understanding of mechanisms underlying the role of stress in health and disease. Despite the progress made already, much more can be made by more carefully exploiting animals' and humans' shared biology, using ecologically relevant models. This allows a fundamental analysis of factors modulating individual adaptive capacity and hence individual vulnerability to disease. This article highlights an emerging scientific approach that uses a framework of interpretation that is more biologically oriented than previous approaches, to evaluate both the adaptive and maladaptive nature of the stress response in relation to existing environmental demands.
A New Unified Treatment Approach for Emotional Disorders Based on Emotion Science
Authors: Moses Erica B. , Barlow David H.
Published: June 2006

Research on the nature of emotional disorders points toward a common set of diatheses (underlying psychological vulnerabilities) and functionally (but not superficially) similar expression of pathological emotional responding (e.g., Barlow, 2002 ). Successful drug treatments for different emotional disorders are very similar, with selective serotonin reuptake inhibitors or related compounds in wide use. Successful psychological treatments, on the other hand, are currently specifically targeted to each individual disorder. Distilling common principles among existing empirically supported psychological treatments, and giving attention to new findings on emotion regulation and dysregulation from emotion science, we propose and describe a new unified psychological treatment for emotional disorders.
Parasequence development in the Ediacaran Shuram Formation (Nafun Group, Oman): high‐resolution stratigraphic test for primary origin of negative carbon isotopic ratios
Authors: Le Guerroué Erwan , Allen Philip A. , Cozzi Andrea
Published: June 2006

Neoproterozoic carbonates are known to show exceptional variations in their carbon isotopic ratios, and in the absence of biostratigraphy and a firm geochronological framework, these variations are used as a correlation tool. However, it is controversial whether the carbon isotope record reveals a primary oceanographic signal or secondary effects such as diagenesis. The Shuram Formation of the Nafun Group of Oman allows a stratigraphic test of this problem. The Nafun Group (Huqf Supergroup, Oman) in the Huqf area of east‐central Oman consists of inner carbonate ramp facies of the Khufai Formation overlain by marine, storm‐generated, red and brown siltstones of the Shuram Formation. Towards its top, the Shuram Formation is composed of distinctive shallowing‐upward, 4–17‐m‐thick parasequences cropping out continuously over 35 km, which show recessive swaley cross‐stratified siltstones capped by ledges comprising wave‐rippled, intraclast‐rich ooidal carbonate. These storm‐dominated facies show a regional deepening in palaeobathymetry towards the south. The carbonates of the Shuram Formation are marked by an extreme depletion in 13C in bulk rock. δ13C values quickly reach a nadir of −12‰ just above the Khufai‐Shuram boundary and steadily return to positive values in the overlying mainly dolomitic Buah Formation. The Shuram excursion is thought to be ca. 50 Myr in duration and extends over 600 m of stratigraphy. Carbon isotopic values show a systematic variation in the parasequence stack, with values varying both vertically through the stratigraphy (∼2‰ per 45 m) and laterally in the progradation distance (∼1‰ over 35 km). This supports a primary, oceanographic origin for these extremely negative carbon isotopic values and independently argues strongly against diagenetic resetting.
Is the Greenland Ice Sheet in a state of collapse?
Authors: Christoffersen Poul , Hambrey Michael J.
Published: June 2006

The Greenland Ice Sheet is thinning at an accelerating pace and the ice sheet's contribution to sea‐level rise has doubled in less than a decade. New data show rapid and widespread changes in the behaviour of the ice sheet, particularly along the coastal margin. These changes coincide with a decade of sustained Arctic warming of up to 3 °C. Decay of the Greenland Ice Sheet in response to global warming will not only be governed by increased surface melting during longer and warmer summers but also by a speed‐up of coastal glaciers that drain the interior ice sheet. A precise estimate of sea‐level rise in the twenty‐first century relies on improved theoretical treatment of these glaciers in computer models.
‘Five‐parameter’ analysis of grain boundary networks by electron backscatter diffraction
Authors: RANDLE VALERIE
Published: June 2006

This paper describes state‐of‐the‐art analysis of grain boundary populations by EBSD, with particular emphasis on advanced, nonstandard analysis. Data processing based both on misorientation alone and customised additions which include the boundary planes are reviewed. Although commercial EBSD packages offer comprehensive data processing options for interfaces, it is clear that there is a wealth of more in‐depth data that can be gleaned from further analysis. In particular, determination of all five degrees of freedom of the boundary population provides an exciting opportunity to study grain boundaries by EBSD in a depth that was hitherto impossible. In this presentation we show ‘five‐parameter’ data from 50 000 boundary segments in grain boundary engineered brass. This is the first time that the distribution of boundary planes has been revealed in a grain boundary engineered material.
Automated microscopy system for mosaic acquisition and processing
Authors: CHOW S. K. , HAKOZAKI H. , PRICE D. L. , MACLEAN N. A. B. , DEERINCK T. J. , BOUWER J. C. , MARTONE M. E. , PELTIER S. T. , ELLISMAN M. H.
Published: June 2006

An automatic mosaic acquisition and processing system for a multiphoton microscope is described for imaging large expanses of biological specimens at or near the resolution limit of light microscopy. In a mosaic, a larger image is created from a series of smaller images individually acquired systematically across a specimen. Mosaics allow wide‐field views of biological specimens to be acquired without sacrificing resolution, providing detailed views of biological specimens within context. The system is composed of a fast‐scanning, multiphoton, confocal microscope fitted with a motorized, high‐precision stage and custom‐developed software programs for automatic image acquisition, image normalization, image alignment and stitching. Our current capabilities allow us to acquire data sets comprised of thousands to tens of thousands of individual images per mosaic. The large number of individual images involved in creating a single mosaic necessitated software development to automate both the mosaic acquisition and processing steps. In this report, we describe the methods and challenges involved in the routine creation of very large scale mosaics from brain tissue labelled with multiple fluorescent probes.
Comparison of I5M and 4Pi‐microscopy
Authors: BEWERSDORF J. , SCHMIDT R. , HELL S. W.
Published: June 2006

The axial (z‐) resolution of ∼100 nm provided by 4Pi and I5M fluorescence microscopy relies on the coherent addition of spherical wavefronts of two opposing high aperture angle lenses. Both microscopes feature a point‐spread function (PSF) with a sharp central spot that is accompanied by axially shifted sidelobes which leads to replication artefacts in the raw image data. In a 4Pi‐microscope the sidelobes are less pronounced than in I5M and without relevant lateral (x,y) substructure, making their posterior removal in the image reliable and fast. On the other hand, high speeds of raw data acquisition are more easily gained by I5M. Moreover, I5M features a stronger signal as compared to the commonly employed two‐photon excitation (2PE) 4Pi‐imaging mode. We investigate here the capability of both techniques to image (aqueous) specimens without artefacts. To this end, we consider the optical transfer function (OTF) of the two microscopes in conjunction with the signal‐to‐noise‐ratio (SNR) of the object to be imaged. The imaging of E. coli bacteria with an interconvertable setup enabled a direct comparison of the two imaging modes. As both systems rely on high aperture angles, water‐immersion lenses of the largest numerical aperture available (NA = 1.2) were employed. The experimental results are corroborated by simulations assuming the signal strength encountered in the experiment. The comparison of the theoretical with the experimental PSFs/OTFs showed that our setup operated close to theory in both imaging modes. Although I5M provided about 10 times brighter raw image data as compared to (2PE) 4Pi‐microscopy, the I5M data could not be entirely cleared of artefacts. In conclusion, with the current aperture angles and fluorescence signal strengths, it is not advisable to trade in the suppression of the sidelobes for a larger image signal.
Epifluorescence, confocal and total internal reflection microscopy for single‐molecule experiments: a quantitative comparison
Authors: LANG E. , BAIER J. , KÖHLER J.
Published: June 2006

Epifluorescence, confocal and total internal reflection microscopy are the most widely used techniques for optical single‐molecule experiments. Employing these methods, we recorded the emission intensity of the same single molecule as a function of the excitation rate under otherwise identical experimental conditions. Evaluation of these data provides a quantitative comparison of the signal‐to‐background ratios that can be achieved for the three microscopic techniques.
Relationship between occlusal tooth contact patterns and tightness of proximal tooth contact
Authors: OH S.‐H. , NAKANO M. , BANDO E. , KEISUKE N. , SHIGEMOTO S. , JEONG J.‐H. , KANG D.‐W.
Published: June 2006

summary  The aim of this study was to investigate the relationship between occlusal tooth contact patterns and the tightness of proximal tooth contact (TPTC) during clenching. Twenty young adult volunteers with healthy dentition participated in the study. TPTC between the left second premolar (P2) and the first molar (M1) was measured during clenching at the 50% maximum voluntary contraction level in the intercuspal position (ICP). A silicone impression material was used to make an interocclusal record at the ICP in each subject, and interocclusal records were analysed using an image‐processing system. Subjects were classified according to the presence or absence of each type (A, B or C) of occlusal contact. Statistical analysis was performed using the Mann–Whitney U‐test. The results of this study exhibited a relationship between B‐type contact and the TPTC of maxillary teeth. The experimental group with a lack of B‐type contact on maxillary P2 and/or M1 showed a statistically greater TPTC than the group with B‐type contact on both of these teeth (P < 0·01). These results suggest that occlusal tooth contact patterns have an influence on TPTC during clenching.
Phylogeography of the montane caddisfly Drusus discolor: evidence for multiple refugia and periglacial survival
Authors: PAULS STEFFEN U. , LUMBSCH H. THORSTEN , HAASE PETER
Published: June 2006

We studied the genetic population structure and phylogeography of the montane caddisfly Drusus discolor across its entire range in central and southern Europe. The species is restricted to mountain regions and exhibits an insular distribution across the major mountain ranges. Mitochondrial sequence data (COI) of 254 individuals from the entire species range is analysed to reveal population genetic structure. The data show little molecular variation within populations and regions, but distinct genetic differentiation between mountain ranges. Most populations are significantly differentiated based on FST and exact tests of population differentiation and most haplotypes are unique to a single mountain range. Phylogenetic analyses reveal deep divergence between geographically isolated lineages. Combined, these results suggest that past fragmentation is the prominent process structuring the populations across Europe. We use tests of selective neutrality and mismatch distributions, to study the demographic population history of regions with haplotype overlap. The high level of genetic differentiation between mountain ranges and estimates of demographic history provide evidence for the existence of multiple glacial refugia, including several in central Europe. The study shows that these aquatic organisms reacted differently to Pleistocene cooling than many terrestrial species. They persisted in numerous refugia over multiple glacial cycles, allowing many local endemic clades to form.
Geographic distribution of an extinct equid (Equus hydruntinus: Mammalia, Equidae) revealed by morphological and genetical analyses of fossils
Authors: ORLANDO LUDOVIC , MASHKOUR MARJAN , BURKE ARIANE , DOUADY CHRISTOPHE J. , EISENMANN VÉRA , HÄNNI CATHERINE
Published: June 2006

Equus hydruntinusinhabited Europe and the Middle East for more than 300 000 years. For a long time, palaeontological data failed to placeE. hydruntinusinto the equid phylogenetic tree, confronted with the fact that it shares primitiveEquuscharacters with both zebras and asses, and derived characters with asses and hemiones. However, the study of a recently discovered skull points to a relationship with hemiones. Extraction of DNA from ancient samples from Crimea (E. hydruntinus) and Iran (E.cf.hydruntinus) yielded 134–288 bp of the mtDNA control region and 143 bp of the cytochromebgene. This DNA analysis supports the proximity ofE. hydruntinusandEquus hemionussuggested by skull and limb bone analyses, and rejects proximity to eitherEquus burchellior the asses suggested by tooth morphology. Dental morphology may thus be of poor taxonomical value if used alone for establishing equid phylogenetic relationships. Furthermore, the small genetic distance betweenE.cf.hydruntinusof Iran and the classicalE. hydruntinusof Crimea suggests that both samples belong to the same species. Accordingly, the geographic range ofE. hydruntinus— until now believed to be restricted to Europe, Israel, and Turkey — can be extended towards East as far as Iran.
Association of canine hypothyroidism with a common major histocompatibility complex DLA class II allele
Authors: Kennedy L. J. , Quarmby S. , Happ G. M. , Barnes A. , Ramsey I. K. , Dixon R. M. , Catchpole B. , Rusbridge C. , Graham P. A. , Hillbertz N. S. , Roethel C. , Dodds W. J. , Carmichael N. G. , Ollier W. E. R.
Published: June 2006

Dogs exhibit a range of immune‐mediated conditions including a lymphocytic thyroiditis which has many similarities to Hashimoto's thyroiditis in man. We have recently reported an association in Doberman Pinschers between canine hypothyroidism and a rare DLA class II haplotype that contains the DLA‐DQA1*00101 allele. We now report a further series of 173 hypothyroid dogs in a range of breeds where a significant association with DLA‐DQA1*00101 is shown.
Rat genotype influences quantitative and qualitative aspects of xenogeneic immune response to pig blood mononuclear cells
Authors: Bridle Byram W. , Wilkie Bruce N. , Jevnikar Anthony M. , Mallard Bonnie A.
Published: June 2006

Abstract:  Background:  Xenotransplantation seeks to have cells with discordant genotypes co‐exist. The hypothesis that host genotype modulates xenogeneic immune response (IR) was tested.

Methods:  Two inbred rat strains [Dark Agouti (DA) and Lewis (LEW)] representing diverse IR phenotypes were immunized with porcine blood mononuclear cells (BMC). Delayed‐type hypersensitivity (DTH), immunoglobulin (Ig), antibody (Ab) and isotype bias of Ab response were evaluated.

Results:  DTH to pig BMC was greater in DA than in LEW rats. Natural Ab was qualitatively different between strains (IgM and IgA predominated in DA, IgM and IgG2a predominated in LEW). Twice as much IgG was elicited from DA than LEW rats and DA utilized all isotypes whereas LEW did not use IgG2a or IgG2c. IR bias was diametrically opposed; type 1 in DA but type 2 in LEW. Strains even differed in Ig profiles and dermal responses to saline injections and mitogen. The DA rats were the higher responders to pig BMC.

Conclusions:  Recipient genotype had significant and broad effects on IR to porcine BMC and may influence xenograft rejection and xenotolerance induction. Moreover, this study suggests that caution should prevail when interpreting data derived from a single inbred strain, particularly given that humans, the target species, are genetically diverse.
Early up‐regulation of CXC‐chemokine expression is associated with strong cellular immune responses to murine skin xenografts
Authors: Lee Eun Mi , Park Joon Oh , Kim Donghee , Kim Jae Young , Oh Kook‐Hwan , Park Chung‐Gyu , Oh Byung Hee , Kim Suhnggwon , Ahn Curie
Published: June 2006

Abstract:  Background:  The dynamic pattern of the cellular infiltration and mRNA expression of chemokines in rat‐to‐mouse skin xenografts were examined to gain an understanding of the possible role of chemokines in the stronger cellular immune responses to xenografts compared with the allo‐response.

Methods:  The mean survival time of the xenografts was approximately 2 days less than that of allografts (10.7 ± 0.9 days vs. 8.9 ± 0.7 days, P < 0.05). In comparison with the allografts, the xenografts were characterized by a very early infiltration of monocytes/macrophages (day 3) and a larger number of CD4+ and CD8+ cells, as well as neutrophil infiltration in the early phase (day 5), and larger number of CD8+ and CD11b+ cells, as well as macrophage infiltration, in the later phase (day 7). Xenografts showed stronger interferon (IFN)‐inducible 10‐kDa protein (IP‐10) and monokine induced by IFN (MIG) mRNA expression levels, which appeared earlier than in the allografts. In the later phase, strong expression of regulated on activation, normal T cell expressed and secreted was observed. Cytokine mRNA expression in the xenografts could be summarized by higher expression of IFN‐γ, interleukin (IL)1β, IL6, and transforming growth factor ‐β1 mRNA than in the allografts. These results suggest that the early increased CXC‐chemokine expression, such as IP‐10 and MIG, which has been known to be mainly produced by macrophages, may play a critical role in the stronger cellular xenograft rejection compared with allograft rejection. Therefore, MIG antiserum or CXCR3 antiserum was administered to the rat skin‐engrafted mice every other day until rejection.

Results:  Compared with the control normal rabbit serum‐treated mice, either the MIG antiserum‐ or CXCR3 antiserum‐treated mice showed a delayed rejection of approximately 2 days (8.3 ± 0.5 days vs. 10.6 ± 0.5 days or 10.8 ± 1.9 days, respectively, P < 0.05).

Conclusion:  Overall, these results suggest that the more aggressive rejection of xenografts compared with allografts is due to the earlier expression of CXC‐chemokines, IP‐10 and MIG, and subsequent adjuvant effects of proinflammatory cytokines.
Has the evolution of complexity in the amphibian papilla influenced anuran speciation rates?
Authors: Richards C. L.
Published: June 2006

For anurans, increasing complexity of the inner ear has been correlated with speciation rates. The evolution of a complex amphibian papilla (AP) is thought to have facilitated speciation by extending the range of frequencies over which mating calls may diverge. Although this example has been proposed to represent a key innovation, the mechanism by which the AP is thought to promote speciation makes the questionable assumption that anurans generally use the AP for detection of their mating calls. This study uses mating calls from 852 species to test this assumption. Surprisingly, the calls of most species are not detected by the AP but by a second organ, the basilar papilla (BP). This refutes the role of AP complexity in facilitating call divergence and hence, speciation. Future research into the evolution of acoustically mediated reproductive isolation should focus instead on the BP as it may play a more critical role in anuran speciation.
Rampant host switching and multiple female body colour transitions in Philotrypesis (Hymenoptera: Chalcidoidea: Agaonidae)
Authors: Jiang Z. -F. , Huang D. -W. , Chen L.-L. , Zhen W. -Q. , Fu Y. -G. , Peng Z. -Q.
Published: June 2006

Figs (Ficus, Moraceae) and their associated fig waSPS (Hymenoptera, Chalcidoidea and Agaonidae) have attracted much attention and have been used as a model system for many studies. Fig waSPS belonging to the genus Philotrypesis are very common in most figs but their taxonomy, ecology and biology are currently poorly explored. A previous study on African Philotrypesis showed that their host association is phylogenetically conserved at subsection level. We reconstructed a molecular phylogeny with extended sampling from seven sections of figs. Our study suggested that the diversification of Philotrypesis is less constrained by host figs. Host switching is rampant between figs at species level and even at section level. We also investigated the evolution of the body colour forms in female Philotrypesis. Our study first suggested that female body colour is not evolutionarily stable and that there have been multiple transitions. Possible mechanisms for multiple colour transitions are expected to be determined in the near future.
Male Drosophila melanogaster have higher mating success when adapted to their thermal environment
Authors: Dolgin E. S. , Whitlock M. C. , Agrawal A. F.
Published: June 2006

Adaptation to new environments is a well-documented phenomenon. Individuals from populations maintained in a particular environment for multiple generations tend to be better able to survive and/or reproduce in that environment than their ancestors or other individuals adapted to alternative environments. A third major component of fitness, mating success, has not been well studied in replicated populations under selection in divergent environments. In this study, we used mating trials to compare the mating success of male Drosophila melanogaster adapted for 10 years to two different temperatures, 18 and 25°C. In competition for female partners, males had significantly higher mating success at their adapted temperature compared with males adapted to a different temperature. These results are consistent with the notion that those mutations favoured by natural selection also tend to be favoured by sexual selection.
Development of tinnitus‐related neuronal hyperactivity through homeostatic plasticity after hearing loss: a computational model
Authors: Schaette Roland , Kempter Richard
Published: June 2006

Tinnitus, the perception of a sound in the absence of acoustic stimulation, is often associated with hearing loss. Animal studies indicate that hearing loss through cochlear damage can lead to behavioral signs of tinnitus that are correlated with pathologically increased spontaneous firing rates, or hyperactivity, of neurons in the auditory pathway. Mechanisms that lead to the development of this hyperactivity, however, have remained unclear. We address this question by using a computational model of auditory nerve fibers and downstream auditory neurons. The key idea is that mean firing rates of these neurons are stabilized through a homeostatic plasticity mechanism. This homeostatic compensation can give rise to hyperactivity in the model neurons if the healthy ratio between mean and spontaneous firing rate of the auditory nerve is decreased, for example through a loss of outer hair cells or damage to hair cell stereocilia. Homeostasis can also amplify non‐auditory inputs, which then contribute to hyperactivity. Our computational model predicts how appropriate additional acoustic stimulation can reverse the development of such hyperactivity, which could provide a new basis for treatment strategies.
Chronic cocaine self‐administration is associated with altered functional activity in the temporal lobes of non human primates
Authors: Beveridge Thomas J. R. , Smith Hilary R. , Daunais James B. , Nader Michael A. , Porrino Linda J.
Published: June 2006

Previous studies utilizing a nonhuman primate model have shown that cocaine self‐administration in its initial stages is accompanied by alterations in functional activity largely within the prefrontal cortex and ventral striatum. Continued cocaine exposure may considerably change this response. The purpose of the present investigation was to characterize the effects of reinforcing doses of cocaine on cerebral metabolism in a nonhuman primate model of cocaine self‐administration, following an extended history of cocaine exposure, using the quantitative 2‐[14C]deoxyglucose (2‐DG) method. Rhesus monkeys were trained to self‐administer 0.03 mg/kg/injection (n = 4) or 0.3 mg/kg/injection (n = 4) cocaine and compared to monkeys trained to respond under an identical schedule of food reinforcement (n = 6). Monkeys received 30 reinforcers per session for a total of 100 sessions. Metabolic mapping was conducted at the end of the final session. After this extended history, cocaine self‐administration dose‐dependently reduced glucose utilization throughout the striatum and prefrontal cortex similarly to the initial stages of self‐administration. However, glucose utilization was also decreased in a dose‐independent manner in large portions of the temporal lobe including the amygdala, hippocampus and surrounding neocortex. The recruitment of temporal structures indicates that the pattern of changes in functional activity has undergone significant expansion beyond limbic regions into association areas that mediate higher order cognitive and emotional processing. These data strongly contribute to converging evidence from human studies demonstrating structural and functional abnormalities in temporal and prefrontal areas of cocaine abusers, and suggest that substance abusers may undergo progressive cognitive decline with continued exposure to cocaine.
Time is a rubberband: neuronal activity in monkey motor cortex in relation to time estimation
Authors: Renoult Louis , Roux Sébastien , Riehle Alexa
Published: June 2006

Anticipation of predictable events is crucial for organizing motor performance. Using instructed delay tasks, it has been shown that even when delay duration is kept constant, reaction time fluctuates from trial to trial. As time estimation is at the core of anticipatory behavior, it is reasonable to speculate whether neuronal delay activity correlates with the subjective estimate of time. As a consequence of the scalar property of time estimation processes, the variability in time estimation increases continuously as time passes during the delay. This scalar property may then be reflected in the increasing variability in neuronal delay activity. We thus studied the influence of temporal prior information on neuronal delay activity in monkey motor cortex in two conceptually different tasks in which two equally probable delay durations were randomly presented. We hypothesized that if one considers the animal's subjective time as the time which elapses between the first (instruction) signal and movement onset, then, by suppressing this temporal variability, across‐trial variability in neuronal discharge should decrease. We thus defined a new time scale in each trial such that, after rescaling, the time between the instruction signal and movement onset was identical in all trials. Each spike was then displaced in time accordingly. As expected, the variability in the timing of neuronal peak discharges no longer increased during the trial. This suggests a direct link between the temporal profile of spiking activity and time estimation. The timing of motor cortical activity reflected the ‘elasticity’ of the animal's subjective time.