bluuebunny/crossref_metadata_2025 huggingface dataset:
Wave-equation migration velocity analysis by focusing diffractions and reflections
Authors: Sava Paul C. , Biondi Biondo , Etgen John
Published: June 2005

We propose a method for estimating interval velocity using the kinematic information in defocused diffractions and reflections. We extract velocity information from defocused migrated events by analyzing their residual focusing in physical space (depth and midpoint) using prestack residual migration. The results of this residual-focusing analysis are fed to a linearized inversion procedure that produces interval velocity updates. Our inversion procedure uses a wavefield-continuation operator linking perturbations of interval velocities to perturbations of migrated images, based on the principles of wave-equation migration velocity analysis introduced in recent years. We measure the accuracy of the migration velocity using a diffraction-focusing criterion instead of the criterion of flatness of migrated common-image gathers that is commonly used in migration velocity analysis. This new criterion enables us to extract velocity information from events that would be challenging to use with conventional velocity analysis methods; thus, our method is a powerful complement to those conventional techniques. We demonstrate the effectiveness of the proposed methodology using two examples. In the first example, we estimate interval velocity above a rugose salt top interface by using only the information contained in defocused diffracted and reflected events present in zero-offset data. By comparing the results of full prestack depth migration before and after the velocity updating, we confirm that our analysis of the diffracted events improves the velocity model. In the second example, we estimate the migration velocity function for a 2D, zero-offset, ground-penetrating radar data set. Depth migration after the velocity estimation improves the continuity of reflectors while focusing the diffracted energy.
2D electrical resistivity imaging of some complex landslides in Lucanian Apennine chain, southern Italy
Authors: Lapenna Vincenzo , Lorenzo Pietro , Perrone Angela , Piscitelli Sabatino , Rizzo Enzo , Sdao Francesco
Published: June 2005

We use high-resolution electrical resistivity imaging to delineate the geometry of complex landslides in the Lucanian Apennine chain of southern Italy, to identify the discontinuity between the landslide material and bedrock, and to locate possible surfaces of reactivation. The Lucanian Apennine chain is characterized by high hydrogeological hazard and shows a complete panorama of mass movements. In this area, all typologies of landslides markedly predisposed and tightly controlled by the geostructural characteristics, are found: rotational and translational slides, rototranslational slides, earth and mudflows, as well as deep-seated gravitational slope phenomena with a predominance of rototranslational slides evolving as earthflow slides. Three test sites, characterized by complex geology and a high hydrogeologic hazard, are studied. The Giarrossa and Varco Izzo earthflow slides are located to the west and east of the town of Potenza, whereas the Latronico slide is located close to the town of Latronico. Electrical images are produced from dipole-dipole geoelectric data acquired along arrays spanning selected profiles positioned perpendicular and parallel to the landslide bodies. High-resolution electrical resistivity images are attained through the use of geologic and borehole constraints in the interpretation phase. Integration and comparison of our results with other geophysical data delineate the geometries and hydrologic characteristics of the landslide structures.
Target signal enhancement in near-surface controlled-source electromagnetic data
Authors: Benavides I. Alfonso , Everett Mark E.
Published: June 2005

Controlled-source electromagnetic-conductivity profiles and maps were obtained on the Brazos Valley, Texas, floodplain to study the fractal statistics of geologic noise and the effects of man-made conductive metal targets. Fourier transform, discrete wavelet transforms, and variogram analyses were used. Targets tend to flatten the power-law power spectrum at small wavenumbers and shift power to higher wavenumbers. Detection and localization of targets can be achieved using wavelet spectrogram techniques. Additionally, variograms from pure background conductivity maps show a power-law trend for all lags, whereas, in the presence of targets, a short power-law trend is followed by a sill corresponding to a loss in spatial correlation. A simple preprocessing step that combines responses from two perpendicular transmitter-receiver orientations enhances the localization of targets and rejects background signals in profiles and 2D apparent-conductivity maps. Finally, a field example shows how the use of wavelet filtering is able to separate target responses from the geologic background.
Magnetic interpretation using a least-squares, depth-shape curves method
Authors: Abdelrahman El-Sayed M. , Essa Khalid S.
Published: June 2005

We have developed a least-squares approach to depth determination from residual magnetic anomalies caused by simple geologic structures. By normalizing the residual magnetic anomaly using three characteristic points and their corresponding distances on the anomaly profile, the problem of determining depth from residual magnetic anomalies has been transformed into finding a solution to a nonlinear equation of the form z = f(z). Formulas have been derived for spheres, horizontal cylinders, thin dikes, and contacts. The method is applied to synthetic data with and without random noise. We have also developed a method using depth-shape curves to simultaneously define the shape and depth of a buried structure from a residual magnetic anomaly profile. The method is based on determining the depth from the normalized residual anomaly for each shape factor using the least-squares method mentioned above. The computed depths are plotted against the shape factors on a graph. The solution for the shape and depth of the buried structure is read at the common intersection of the depth-shape curves. The depth-shape curves method was successfully tested on theoretical data with and without random noise and applied to a known field example from Ontario.
Fluid-pressure discrimination in anisotropic reservoir rocks — A sensitivity study
Authors: Stovas Alexey , Landrø Martin
Published: June 2005

We investigate how seismic anisotropy influences our ability to distinguish between various production-related effects from time-lapse seismic data. Based on rock physics models and ultrasonic core measurements, we estimate variations in PP and PS reflectivity at the top reservoir interface for fluid saturation and pore pressure changes. The tested scenarios include isotropic shale, weak anisotropic shale, and highly anisotropic shale layers overlaying either an isotropic reservoir sand layer or a weak anisotropic sand layer. We find that, for transverse isotropic media with a vertical symmetry axis (TIV), the effect of weak anisotropy in the cap rock does not lead to significant errors in, for instance, the simultaneous determination of pore-pressure and fluid-saturation changes. On the other hand, changes in seismic anisotropy within the reservoir rock (caused by, for instance, increased fracturing) might be detectable from time-lapse seismic data. A new method using exact expressions for PP and PS reflectivity, including TIV anisotropy, is used to determine pressure and saturation changes over production time. This method is assumed to be more accurate than previous methods.
A brief history of seismic migration
Authors: Bednar J. Bee
Published: June 2005

In this article, I attempt to focus on the chronology of seismic imaging. I start in the mid-1920s, progress through the human “computer”-based methods of the 1940s and 1950s, discuss the emergence of digital wave-equation technology in the 1960s and early 1970s, and finally end with a review of the present. I include a bit of speculation about the future of seismic imaging, but the meat of the article is on seismic-imaging history. Based on the timing of their publications, I claim there are three key contributors to the theoretical developments of modern seismic imaging: F. Rieber, J. G. Hagedoorn, and J. F. Claerbout. None of these men were the first to consider the seismic-imaging problem, but their papers and algorithms have probably been quoted more often than anyone else's. One certainly must give credit as well to C. H. Dix and M. M. Slotnick for similar contributions. Other names that come to mind include Hans Sattlegger in Germany, A. J. Berkhout in the Netherlands, Bill Schneider at GSI in Dallas, and Robert Stolt at CONOCO in Ponca City, Oklahoma. However, without the independent computational progression predicted by Moore's law (computer speed doubles every 18 months), the spectacular subsurface images produced today would not be possible. I hope to convince the reader that in addition to the development of the vast literature on seismic-imaging theory, another, less-publicized, parallel technological progression has focused on the development of efficient machines to produce, with minimal human intervention, an increasingly more accurate image of the strata below the recording instruments. Unfortunately, with a few key exceptions, the names of many of the contributors to this aspect of seismic imaging have been lost. The digital revolution in the 1960s appears to be the culmination of this attempt at mechanization, but not until the development of truly powerful scientific computers did the more accurate and advanced theoretical developments in seismic-imaging theory become practical to apply and use in the search for diminishing supplies of hydrocarbons. In fact, one can argue that we still don't have sufficient computer power to do everything we need and want to do. But that's another story.
Lineage restriction maintains a stable organizer cell population at the zebrafish midbrain-hindbrain boundary
Authors: Langenberg Tobias , Brand Michael
Published: June 2005

The vertebrate hindbrain is subdivided into segments, termed neuromeres,that are units of gene expression, cell differentiation and behavior. A key property of such segments is that cells show a restricted ability to mix across segment borders – termed lineage restriction. In order to address segmentation in the midbrain-hindbrain boundary (mhb) region, we have analyzed single cell behavior in the living embryo by acquiring time-lapse movies of the developing mhb region in a transgenic zebrafish line. We traced the movement of hundreds of nuclei, and by matching their position with the expression of a midbrain marker, we demonstrate that midbrain and hindbrain cells arise from two distinct cell populations. Single cell labeling and analysis of the distribution of their progeny shows that lineage restriction is probably established during late gastrulation stages. Our findings suggest that segmentation as an organizing principle in early brain development can be extended to the mhb region. We argue that lineage restriction serves to constrain the position of the mhb organizer cell population.
Congenital heart disease reminiscent of partial trisomy 2p syndrome in mice transgenic for the transcription factor Lbh
Authors: Briegel Karoline J. , Baldwin H. Scott , Epstein Jonathan A. , Joyner Alexandra L.
Published: June 2005

Partial trisomy 2p syndrome includes a spectrum of congenital heart disease(CHD) that is characterized by complex malformations of the outflow and inflow tracts, defects in cardiac septation, heart position, as well as abnormal ventricular development. Lbh (limb-bud and heart) is a novel, highly conserved putative transcriptional regulatory protein, which displays a unique spatiotemporal gene expression pattern during early mouse heart development. Here we show that human LBH maps to chromosome 2p23, a genomic region related to CHD in partial trisomy 2p syndrome. Remarkably, transgenic overexpression of Lbh in mice throughout the embryonic myocardium from a cardiomyocyte-specific promoter of the cardiac ankyrin repeat protein gene(Carp/Ankrd1) models CHD reported in humans with partial trisomy 2p syndrome. The malformations in Carp-Lbh transgenic mice reflect impaired pulmonary outflow tract valvulogenesis, cardiac septation, inflow tract morphogenesis, as well as abnormalities in ventricular cardiomyocyte growth. Furthermore, we demonstrate that overexpression of Lbh in cultured mammalian cells represses the synergistic activity of key cardiac transcription factors, Nkx2.5 and Tbx5, leading to reduced activation of the common target gene, Anf (Nppa). Strikingly, reduced levels of Anf expression were also observed in embryonic day 9.5 Carp-Lbh transgenic mice. Thus, repression of Nkx2.5 and Tbx5-mediated gene expression by deregulated Lbh may account in part for the cardiac anomalies observed in these mice. Our findings implicate LBHas a candidate gene for CHD associated with partial trisomy 2p syndrome and suggest an important role of Lbh in transcriptional control during normal cardiogenesis.
SMAD pathway mediation of BDNF and TGFβ2 regulation of proliferation and differentiation of hippocampal granule neurons
Authors: Lu Jie , Wu Yan , Sousa Nuno , Almeida Osborne F. X.
Published: June 2005

Hippocampal granule cells self-renew throughout life, whereas their cerebellar counterparts become post-mitotic during early postnatal development, suggesting that locally acting, tissue-specific factors may regulate the proliferative potential of each cell type. Confirming this, we show that conditioned medium from hippocampal cells (CMHippocampus)stimulates proliferation in cerebellar cultures and, vice versa, that mitosis in hippocampal cells is inhibited by CMCerebellum. The anti-proliferative effects of CMCerebellum were accompanied by increased expression of the cyclin-dependent kinase inhibitors p21 and p27, as well as markers of neuronal maturity/differentiation. CMCerebellumwas found to contain peptide-like factors with distinct anti-proliferative/differentiating and neuroprotective activities with differing chromatographic properties. Preadsorption of CMCerebellumwith antisera against candidate cytokines showed that TGFβ2 and BDNF could account for the major part of the anti-proliferative and pro-differentiating activities, an interpretation strengthened by studies involving treatment with purified TGFβ2 and BDNF. Interference with signaling pathways downstream of TGFβ and BDNF using dominant-negative forms of their respective receptors (TGFβ2-RII and TRKB) or of dominant-negative forms of SMAD3 and co-SMAD4 negated the anti-proliferative/differentiating actions of CMCerebellum. Treatment with CMCerebellum caused nuclear translocation of SMAD2 and SMAD4, and also transactivated a TGFβ2-responsive gene. BDNF actions were shown to depend on activation of ERK1/2 and to converge on the SMAD signaling cascade, possibly after stimulation of TGFβ2 synthesis/secretion. In conclusion, our results show that the regulation of hippocampal cell fate in vitro is regulated through an interplay between the actions of BDNF and TGFβ.
Essential kinase-independent role of a Fer-like non-receptor tyrosine kinase inCaenorhabditis elegansmorphogenesis
Authors: Putzke Aaron P. , Hikita Sherry T. , Clegg Dennis O. , Rothman Joel H.
Published: June 2005

Morphogenesis requires coordination of cell surface activity and cytoskeletal architecture. During the initial stage of morphogenesis in Caenorhabditis elegans, the concerted movement of surface epithelial cells results in enclosure of the embryo by the epidermis. We report that Fer-related kinase-1 (FRK-1), an ortholog of the mammalian non-receptor tyrosine kinase Fer, is necessary for embryonic enclosure and morphogenesis in C. elegans. Expression of FRK-1 in epidermal cells is sufficient to rescue a chromosomal deficiency that removes the frk-1locus, demonstrating its autonomous requirement in the epidermis. The essential function of FRK-1 is independent of its kinase domain, suggesting a non-enzymatic role in morphogenesis. Localization of FRK-1 to the plasma membrane requires β-catenin, but not cadherin or α-catenin, and muscle-expressed β-integrin is non-autonomously required for this localization; in the absence of these components FRK-1 becomes nuclear. Mouse FerT rescues the morphogenetic defects of frk-1 mutants and expression of FRK-1 in mammalian cells results in loss of adhesion, implying a conserved function for FRK-1/FerT in cell adhesion and morphogenesis. Thus,FRK-1 performs a kinase-independent function in differentiation and morphogenesis of the C. elegans epidermis during embryogenesis.
A method for deriving displacement data during cyclical movement using an inertial sensor
Authors: Pfau Thilo , Witte Thomas H. , Wilson Alan M.
Published: June 2005

Biomechanical studies often employ optical motion capture systems for the determination of the position of an object in a room-based coordinate system. This is not ideal for many types of study in locomotion since only a few strides may be collected per `trial', and outdoor experiments are difficult with some systems. Here, we report and evaluate a novel approach that enables the user to determine linear displacements of a proprietary orientation sensor during cyclical movement. This makes experiments outside the constraints of the laboratory possible, for example to measure mechanical energy fluctuations of the centre of mass during over-ground locomotion. Commercial orientation sensors based on inertial sensing are small and lightweight and provide a theoretical framework for determining position from acceleration. In practice,the integration process is difficult to implement because of integration errors, integration constants and the necessity to determine the orientation of the measured accelerations. Here, by working within the constraints of cyclical movements, we report and evaluate a method for determining orientation and relative position using a modified version of a commercial inertial orientation sensor that combines accelerometers, gyroscopes and magnetometers, thus giving a full set of movement parameters (displacement,velocity and acceleration in three dimensions). The 35 g sensor was attached over the spine of a horse exercising on a treadmill. During canter locomotion(9.0 m s-1), the amplitudes of trunk movement in the x(craniocaudal), y (mediolateral) and z (dorsoventral)directions were 99.6, 57.9 and 140.2 mm, respectively. Comparing sensor displacement values with optical motion capture values for individual strides,the sensor had a median error (25th, 75th percentile) in the x, y and z directions of 0.1 (–9.7, +10.8), –3.8(–15.5, +13.7) and –0.1 (–6.3, +7.1) mm, respectively. High-pass filtering of the displacement data effectively separated non-cyclical from cyclical components of the movement and reduced the interquartile ranges of the errors considerably to (–3.6, 6.2),(–4.0, 3.8) and (–4.5, 5.1) for x, y and z displacement, respectively, during canter locomotion. This corresponds to (–3.2, 5.5)%, (–6.7, 6.3)% and (–3.3, 3.7)%of the range of motion.
Regional and developmental variations of blood vessel morphometry in the chick embryo chorioallantoic membrane
Authors: Reizis Arava , Hammel Ilan , Ar Amos
Published: June 2005

Avian eggs contain all the necessary materials for embryonic development except for oxygen, which diffuses in from the environment via pores in the hard, calcified eggshell to the chorioallantoic membrane (CAM), the respiratory organ, which is rich in blood vessels. An air cell is formed at the blunt pole of the egg between the two membranes of the eggshell and enlarges during incubation due to water vapor loss. In this study of the CAM of chicken eggs, we compared blood vessel numerical density[NA(v)], area fraction of blood vessels[AA(v)], CAM thickness (DCAM), total length of blood vessels (L) and surface area of the CAM attached to the eggshell (CAMre) with those under the air cell(CAMac) during incubation. We found that NA(v), AA(v), DCAM and L of the CAM increase with embryonic age and development. The NA(v), AA(v) and L under the air cell were higher in relation to the rest of the CAM at all ages tested, while the DCAM under the air cell was always lower than around the rest of the egg. Since the eggshell over the air cell has a relatively greater porosity, and the respiratory gas exchange ratio there is higher than at other areas of the egg, there is a correlation between all the above morphometric data and the eggshell porosity. This suggests optimization of embryonic gas exchange in the chicken egg. We would like to propose that, during natural incubation, an increased gas diffusion under the air cell, together with increased blood vessel numerical density, may compensate for covering of the central part of the eggshell by the incubating parent.
Laminin and the malaria parasite's journey through the mosquito midgut
Authors: Arrighi Romanico B. G. , Lycett Gareth , Mahairaki Vassiliki , Siden-Kiamos Inga , Louis Christos
Published: June 2005

During the invasion of the mosquito midgut epithelium, Plasmodiumookinetes come to rest on the basal lamina, where they transform into the sporozoite-producing oocysts. Laminin, one of the basal lamina's major components, has previously been shown to bind several surface proteins of Plasmodium ookinetes. Here, using the recently developed RNAi technique in mosquitoes, we used a specific dsRNA construct targeted against the LANB2 gene (laminin γ1) of Anopheles gambiae to reduce its mRNA levels, leading to a substantial reduction in the number of successfully developed oocysts in the mosquito midgut. Moreover, this molecular relationship is corroborated by the intimate association of developing P. berghei parasites and laminin in the gut, as observed using confocal microscopy. Our data support the notion of laminin playing a functional role in the development of the malaria parasite within the mosquito midgut.
Emperor penguins adjust swim speed according to the above-water height of ice holes through which they exit
Authors: Sato Katsufumi , Ponganis Paul J. , Habara Yoshiaki , Naito Yasuhiko
Published: June 2005

Emperor penguins leap from the water onto the sea ice. Their ability to reach above-water height depends critically on initial vertical speed of their leaping, assuming that the kinetic energy is converted to gravitational potential energy. We deliberately changed the above-water heights of ice hole exits, in order to examine whether penguins adjusted swim speed in accordance with the above-water height of the ice. Penguins were maintained in a corral on the fast ice in Antarctica, and voluntarily dived through two artificial ice holes. Data loggers were deployed on the penguins to monitor under water behavior. Nine instrumented penguins performed 386 leaps from the holes during experiments. The maximum swim speeds within 1 s before the exits through the holes correlated significantly with the above-water height of the holes. Penguins adopted higher speed to exit through the higher holes than through the lower holes. Speeds of some failed exits were lower than the theoretical minimum values to reach a given height. Penguins failed to exit onto the sea ice in a total of 37 of the trials. There was no preference to use lower holes after they failed to exit through the higher holes. Rather, swim speed was increased for subsequent attempts after failed leaps. These data demonstrated that penguins apparently recognized the above-water height of holes and adopted speeds greater than the minimal vertical speeds to reach the exit height. It is likely, especially in the case of higher holes (>40 cm), that they chose minimum speeds to exit through the holes to avoid excess energy for swimming before leaping. However, some exceptionally high speeds were recorded when they directly exited onto the ice from lower depths. In those cases,birds could increase swim speed without strokes for the final seconds before exit and they only increased the steepness of their body angles as they surfaced, which indicates that the speed required for leaps by emperor penguins were aided by buoyancy, and that penguins can sometimes exit through the ice holes without any stroking effort before leaping.
The metabolic cost of egg production is repeatable
Authors: Vézina François , Williams Tony D.
Published: June 2005

The metabolic cost of egg production in birds (passerines) has been measured as a 16–27% increase in basal or resting metabolic rate (BMR and RMR, respectively) when comparing non-breeding values with those in egg-producing individuals. However, available data to date have been obtained in free-living birds and may thus be confounded by the effect of variable ecological conditions on non-reproductive physiological machinery (organ mass or metabolic activity) which might contribute to measured variation in RMR. Here, we show that in captive, controlled conditions, the process of egg formation induces a 22% increase in RMR in female zebra finches Taeniopygia guttata. Among individuals, variation in laying RMR is independent of egg mass, clutch size or total clutch mass. Importantly, we show that individual variation in both non-breeding and laying RMR is repeatable over periods of at least 8-10 months, i.e. individual variation in RMR remained constant over time for any given physiological state. This suggests that the metabolic cost of egg formation should respond to selection. However, we also show that in males, but not females, repeatability of RMR declines over time even when birds are kept in constant controlled conditions.
Burst characteristics of daily jaw muscle activity in juvenile rabbits
Authors: van Wessel T. , Langenbach G. E. J. , Kawai N. , Brugman P. , Tanaka E. , van Eijden T. M. G. J.
Published: June 2005

Muscle activation varies with different behaviors and can be quantified by the level and duration of activity bursts. Jaw muscles undergo large anatomical changes during maturation, which are presumably associated with changes in daily muscle function. Our aim was to examine the daily burst number, burst length distribution and duty time (fraction of the day during which a muscle was active) of the jaw muscles of juvenile male rabbits(Oryctolagus cuniculus). A radio-telemetric device was implanted to record muscle activity continuously from the digastric, superficial and deep masseter, medial pterygoid and temporalis during maturation week 9-14. Daily burst characteristics and duty times were determined for activations,including both powerful and non-powerful motor behavior. All muscles showed constant burst numbers, mean burst lengths and duty times during the recording period. Including all behavior, the temporalis showed significantly larger daily burst numbers (205 000) and duty times (18.2%) than the superficial and deep masseter (90 000; 7.5%). Burst numbers and duty times were similar for the digastric (120 000; 11.1%) and medial pterygoid (115 000; 10.4%). The temporalis and deep masseter showed many short low activity bursts (0.05 s),the digastric showed many long bursts (0.09 s). For activations during powerful behaviors the superficial masseter and medial pterygoid had the largest burst numbers and duty times. Both muscles showed similar burst characteristics for all activation levels. It was concluded that activation of the jaw muscles is differently controlled during powerful and non-powerful motor behaviors and the functional organization of motor control patterns does not vary from 9 to 14 weeks of age.
Do seasonal changes in metabolic rate facilitate changes in diving behaviour?
Authors: Green J. A. , Boyd I. L. , Woakes A. J. , Green C. J. , Butler P. J.
Published: June 2005

Macaroni penguins were implanted with data loggers to record heart rate(fh), abdominal temperature (Tab) and diving depth during their pre-moult trip (summer) and winter migration. The penguins showed substantial differences in diving behaviour between the seasons. During winter, mean and maximum dive duration and dive depth were significantly greater than during summer, but the proportion of dives within the calculated aerobic dive limit (cADL) did not change.

Rates of oxygen consumption were estimated from fh. As winter progressed, the rate of oxygen consumption during dive cycles(sV̇O2DC) declined significantly and mirrored the pattern of increase in maximum duration and depth. The decline in sV̇O2DC was matched by a decline in minimum rate of oxygen consumption(sV̇O2min). When sV̇O2min was subtracted from sV̇O2DC, the net cost of diving was unchanged between summer and winter. We suggest that the increased diving capacity demonstrated during the winter was facilitated by the decrease in sV̇O2min.

Abdominal temperature declined during winter but this was not sufficient to explain the decline in sV̇O2min. A simple model of the interactions between sV̇O2min, thermal conductance and water temperature shows how a change in the distribution of fat stores and therefore a change in insulation and/or a difference in foraging location during winter could account for the observed reduction in sV̇O2min and hence sV̇O2DC.
Low temperature acclimated populations of the grain aphidSitobion avenaeretain ability to rapidly cold harden with enhanced fitness
Authors: Powell S. J. , Bale J. S.
Published: June 2005

In contrast to previous studies of rapid cold-hardening (RCH), which have investigated the responses of insects maintained under `summer conditions'(20° to 25°C), this study focuses on the ability of low-temperature acclimated insects to undergo RCH. When the grain aphid Sitobion avenae Fabricus was low-temperature acclimated by rearing for three generations at 10°C, the discriminating temperatures (temperature that results in approximately 20% survival after direct transfer from the rearing temperature to a sub-zero temperature for a period of 3 h), of first instar nymphs and adult aphids were –11.5° and –12°C,respectively. Maximum rapid cold-hardening was induced by cooling aphids at 0°C for 2 h (nymphs) or 30 min (adults), resulting in survival at the respective discriminating temperatures increasing from 26% to 96% (nymphs) and 22% to 70% (adults). Cooling from 10° to 0°C at 1°, 0.1° and 0.05°C min-1 significantly increased survival of nymphs at the discriminating temperature, but not of adults. There were no `ecological costs' associated with rapid cold-hardening at 0°C, or with exposure of rapidly cold-hardened aphids to the discriminating temperatures; fecundity and longevity, in both nymphs and adults were either similar to control aphids or significantly increased. The study demonstrates that rapid cold-hardening ability is retained in aphids that have already undergone cold-acclimation, as would be the case in overwintering aphids. Both rapid cold-hardening and subsequent exposure at previously lethal temperatures can enhance fitness in surviving individuals.
Decomposing Influence Strategies: Argument Structure and Dependence as Determinants of the Effectiveness of Influence Strategies in Gaining Channel Member Compliance
Authors: Payan Janice M. , McFarland Richard G.
Published: June 2005

Although there is considerable research examining the effects of influence strategies on relational outcomes, research has been silent on the effectiveness of influence strategies in achieving the primary objective: channel member compliance. The authors develop a theoretical model that predicts that noncoercive influence strategies (Rationality, Recommendations, Information Exchange, and Requests) with an argument structure that contains more thorough content result in relatively greater levels of compliance. The model further predicts that coercive influence strategies (Promises and Threats) result in compliance only when target dependence levels are high. The authors develop a new influence strategy, Rationality, which represents a noncoercive strategy with a full argument structure. In general, empirical findings support the theoretical model. However, in contrast to expectations, the use of Recommendations had a negative effect on compliance. Post hoc analysis revealed a significant interaction between trust and Recommendations on compliance, thus providing an explanation for this unexpected result. When trust is low, Recommendation strategies are counterproductive. The authors discuss implications of the findings and directions for further research.
Preclinical Evaluation of a Novel Water‐soluble Chlorin E6 Derivative (BLC 1010) as Photosensitizer for the Closure of the Neovessels
Authors: Pegaz B. , Debefve E. , Borle F. , Ballini J.‐P. , Wagnières G. , Spaniol S. , Albrecht V. , Scheglmann D. , Nifantiev N. E. , van den Bergh H. , Konan Y. N.
Published: June 2005

In the present study, photodynamic activity of a novel photosensitizer (PS), Chlorin e6‐2.5 N‐methyl‐d‐glucamine (BLC 1010), was evaluated using the chorioallantoic membrane (CAM) as an in vivo model. After intravenous (i.v.) injection of BLC 1010 into the CAM vasculature, the applicability of this drug for photodynamic therapy (PDT) was assessed in terms of fluorescence pharmacokinetics, i.e. leakage from the CAM vessels, and photothrombic activity. The influence of different PDT parameters including drug and light doses on the photodynamic activity of BLC 1010 has been investigated. It was found that, irrespective of drug dose, an identical continuous decrease in fluorescence contrast between the drug inside and outside the blood vessels was observed. The optimal treatment conditions leading to desired vascular damage were obtained by varying drug and light doses. Indeed, observable damage was achieved when irradiation was performed at light doses up to 5 J/cm2 1 min after i.v. injection of drug doses up to 0.5 mg/kg body weight(b.w.). However, when irradiation with light doses of more than 10 J/cm2 was performed 1 min after injection of drug doses up to 2 mg/kg body weight, this led to occlusion of large blood vessels. It has been demonstrated that it is possible to obtain the desired vascular occlusion and stasis with BLC 1010 for different combinations of drug and/or light doses.
Geographic Patterns of Disease
Authors: Elliott Paul , Best Nicola
Published: June 2005

The study of geographic variations in disease is a classic epidemiological technique in which location is used as a surrogate for the mix of lifestyle, environmental, and possibly genetic factors that may underlie variations in rates of disease across populations. This article reviews issues involved in disease mapping (the usual means of presenting descriptive geographic data on disease occurrence) and geographic correlation studies (where the aim is to explore geographic variation in disease in terms of underlying spatially varying “risk factors”). The emphasis is on small‐area applications, where a number of recent advances in methodology have been made.
Membranes, Hollow‐Fiber
Authors: Moch Irving
Published: June 2005

Hollow‐fiber membranes were invented in the 1960s. In the ensuing decades much research and development effort has transpired with the result that these fibers have become exceedingly important to industry, academia, and government in such fields as desalination of water, wastewater reclamation, medicine, agriculture, gas separation, and pervaporation. Commercial opportunities annually exceed several hundred million dollars. The hollow‐fiber membranes are usually the base technology within a significantly larger system.This article briefly discusses the history and theory of hollow‐fiber membrane technology. Methods of manufacture are reviewed together with processing techniques employed to enhance various aspects of performance. Hollow‐fiber membranes are composed of many different materials of construction. The generic compositions are cited and specific end use applications noted. Lastly, the work to date has identified many areas where future prospects for hollow‐fiber membranes are the brightest. A number of these future growth areas are discussed together with which industrial corporations are in the forefront of the new developments.
Heat Exchanger Network Design
Authors: Polley Graham , Mukherjee Rajiv
Published: June 2005

This article addresses the problem of heat‐exchanger network design. The design of such systems can no longer be done in isolation from consideration of alternative means of energy conservation, and most importantly, from consideration of how the design of the heat recovery system interacts and impinges on the design of the core of the process and the utility system.

This article gives details on the economics of heat recovery: how to determine the energy demand; how to determine approximate capital cost; how to identify economic heat recovery level. The Pinch Design Method is discussed as a means to determine these economic factors. This method is discussed in detail from the basic principles to a worked example and shortcomings of the method are described. Systematic problem decomposition is one way to overcome the shortcomings. Many software packages are available to implement Pinch technology, but the reader is urged to develop a basic understanding of the principles of the technology and use this in combination with engineering judgement. Finally a practical design application is detailed.
Lysozyme fibrillation: Deep UV Raman spectroscopic characterization of protein structural transformation
Authors: Xu Ming , Ermolenkov Vladimir V. , He Wei , Uversky Vladimir N. , Fredriksen Laura , Lednev Igor K.
Published: June 2005

Deep ultraviolet resonance Raman spectroscopy was demonstrated to be a powerful tool for structural characterization of protein at all stages of fibril formation. The evolution of the protein secondary structure as well as the local environment of phenylalanine, a natural deep ultraviolet Raman marker, was documented for the fibrillation of lysozyme. Concentration‐independent irreversible helix melting was quantitatively characterized as the first step of the fibrillation. The native lysozyme composed initially of 32% helix transforms monoexponentially to an unfolded intermediate with 6% helix with a characteristic time of 29 h. The local environment of phenylalanine residues changes concomitantly with the secondary structure transformation. The phenylalanine residues in lysozyme fibrils are accessible to solvent in contrast to those in the native protein. © 2005 Wiley Periodicals, Inc. Biopolymers 79: 58–61, 2005

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Characterization of the nonregular regions of proteins by a contortion index
Authors: De Subhajyoti , Sur Kunal , Dasgupta Swagata
Published: June 2005

Nonstructured regions in proteins that provide the link between two regular structured regions play a significant role in maintaining the scaffold of the protein. Not only do they act as connectors between two regular secondary structural elements of proteins but they also provide the necessary turn or reversal in the polypeptide chain. This incorporates flexibility in the structure. Thus an understanding of the structural aspects of the nonregular regions is necessary to have a better insight into these features. We can assume the nonregular region to be a contorted polypeptide segment tethered by regular secondary structured regions at both ends. To describe the undulating nature of the nonregular regions, we introduce a parameter called the “contortion index.” This index describes how tortuously the region is organized. Our analysis shows that the contortion index is related to other physicochemical parameters and can be used to characterize the nonregular regions of proteins. © 2005 Wiley Periodicals, Inc. Biopolymers 79: 63–73, 2005

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Tailored therapy for early Barrett's lesions
Authors: van Lanschot J J B , Bergman J J G H M
Published: June 2005

Alternatives to oesophagectomy
Ethics of palliative surgery in patients with cancer
Authors: Hofmann B , Håheim L L , Søreide J A
Published: June 2005

Background

Surgery is an important palliative method for patients with advanced malignant disease. In addition to concerns related to clinical decision making, various moral challenges are encountered in palliative surgery. Some of these relate to the patients and their illness, others to the surgeons, their attitudes, skills and knowledge base.

Method and results

Pertinent moral challenges are addressed and analysed with respect to prevailing perspectives in normative ethics. The vulnerability of patients with non-curable cancer calls for moral awareness. Demands regarding sensibility and precaution in this clinical setting represent substantial challenges with regard to the ‘duty to help’, benevolence, respect of autonomy and proper patient information. Moreover, variations in definition of palliative surgery as well as limited scientific evidence with respect to efficacy, effectiveness and efficiency pose methodological and moral problems. Therefore, a definition of palliative surgery that addresses these issues is provided.

Conclusion

Both surgical skill and much moral sensibility are required to improve palliative care in surgical oncology. This should be taken into account not only in clinical practice but also in education and research.
Guanine and Plasmid DNA binding of Mono‐ and Trinuclear fac‐[Re(CO)3]+ Complexes with Amino Acid Ligands
Authors: Zobi Fabio , Spingler Bernhard , Alberto Roger
Published: June 2005

We have synthesized and fully characterized four new complexes comprising the fac‐[Re(CO)3]+ moiety and the ligands NH3, L‐proline (Pro), or N,N‐dimethylglycine (dmGly). The reaction of [Re(H2O)3(CO)3]+ with the two amino acids gives trinuclear complexes of general formula [Re(L)(CO)3]3 (where L=amino acid). We have studied the in vitro behavior of these compounds with guanine and DNA in order to understand whether the cytotoxicity exhibited by certain rhenium complexes based on the fac‐[Re(CO)3]+ core is due to the formation of nucleobase complexes and inter‐ or intrastrand links between DNA bases. We have performed model studies with guanine and studied the structural effects induced by different rhenium(I) tricarbonyl complexes on ΦX174 plasmid DNA by electrophoretic methods. Our results show that rhenium complexes with two available coordination sites interact with plasmid DNA to form a stable adduct that is likely to involve two bases.
Synthesis and Crystal Structure of Na2LiAlD6.
Authors: Brinks H. W. , Hauback B. C. , Jensen C. M. , Zidan R.
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Crystal Structure of Strontium Ozonide Ammoniate, Sr(O3)2×9NH3.
Authors: Klein Wilhelm , Jansen Martin
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis, Structure and Magnetization Studies on (Fe1‐xCrx)2TeO6 Tellurate System.
Authors: Mudher K. D. Singh , Krishnan K. , Gopalakrishnan I. K. , Kundaliya Darshan C. , Malik S. K.
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Crystal Structure and Magnetic Properties of NdCo9‐xFexSi4 Solid Solution.
Authors: Gorelenko Yu. , Romaka L. , Fruchart D. , Stadnyk Yu. , Gignoux D. , Mudryk Ya. , Yarovets V.
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Amorphous Carbon‐Coated Tin Anode Material for Lithium Secondary Battery.
Authors: Noh Mijung , Kwon Yoojung , Lee Hyojin , Cho Jaephil , Kim Yoojin , Kim Min Gyu
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
A Solid‐State Metathesis Route to MgSiN2.
Authors: Blair Richard G. , Anderson Arthur , Kaner Richard B.
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Monophosphite Ligands Derived from Carbohydrates and H8‐BINOL: Highly Enantioselective Rh‐Catalyzed Asymmetric Hydrogenations.
Authors: Huang Hanmin , Liu Xiongcai , Chen Huilin , Zheng Zhuo
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Chiral C2‐Symmetric Ligands Containing Two Binaphthyl Units Linked by 2,2′‐Bipyridyl Bridge in Asymmetric Catalysis.
Authors: Bai Xiao‐Li , Kang Chuan‐Qing , Liu Xu‐Dong , Gao Lian‐Xun
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Bromoallenes as Allyl Dication Equivalents in the Absence of Palladium(0): Synthesis of Bicyclic Sulfamides by Tandem Cyclization of Bromoallenes.
Authors: Hamaguchi Hisao , Kosaka Shohei , Ohno Hiroaki , Tanaka Tetsuaki
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Cycloisomerization of Olefinic Carboxylic Acids Catalyzed by Trifluoromethanesulfonic Acid.
Authors: Coulombel Lydie , Dunach Elisabet
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Generation and Reaction of Ammonium Ylides in Basic Two‐Phase Systems
Authors: Kowalkowska Anna , Sucholbiak Dorota , Jonczyk Andrzej
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
The Role of Carbon Dioxide in Chemoselective Hydrogenation of Halonitroaromatics over Supported Noble Metal Catalysts in Supercritical Carbon Dioxide.
Authors: Ichikawa Shinichiro , Tada Mizuki , Iwasawa Yasuhiro , Ikariya Takao
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Novel and Direct Oxidative Cyanation Reactions of Heteroaromatic Compounds Mediated by a Hypervalent Iodine(III) Reagent.
Authors: Dohi Toshifumi , Morimoto Koji , Kiyono Yorito , Tohma Hirofumi , Kita Yasuyuki
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Highly Alkyl‐Selective Addition to Ketones with Magnesium Ate Complexes Derived from Grignard Reagents.
Authors: Hatano Manabu , Matsumura Tokihiko , Ishihara Kazuaki
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
A Facile and Practical Method for the Preparation of Thioacetates from Alkyl Halides and Sodium Thioacetate Catalyzed by PEG400.
Authors: Cao Yu‐Qing , Du Yun‐Fei , Chen Bao‐Hua , Dai Zhi
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
A Convenient Synthesis of Functionalized 1‐Aryl‐1,3‐alkadiynes.
Authors: Balova Irina A. , Sorokoumov Victor N. , Morozkina Svetlana N. , Vinogradova Olga V. , Knight David W. , Vasilevsky Sergey F.
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Sonogashira Cross‐Coupling Reactions with Heteroaryl Halides in the Presence of a Tetraphosphine—Palladium Catalyst.
Authors: Feuerstein Marie , Doucet Henri , Santelli Maurice
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Mg(0)‐Promoted Debromometalation of gem‐Difluoropropargyl Bromides.
Authors: Mae Masayuki , Hong Jiyoung A. , Hammond Gerald B. , Uneyama Kenji
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Palladium Pincer Complex Catalyzed Allylation of Tosylimines by Potassium Trifluoro(allyl)borates.
Authors: Solin Niclas , Wallner Olov A. , Szabo Kalman J.
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Reductive Fission of Azoarenes to Aminoarenes by Aluminium/Hydrazine Hydrate.
Authors: Pasha M. A. , Nanjundaswamy H. M.
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
Unexpected 1,2 syn Diastereoselectivity in the Three‐Component “Aza Sakurai—Hosomi” Reaction.
Authors: Ella‐Menye Jean‐Rene , Dobbs William , Billet Manuella , Klotz Philippe , Mann Andre
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
A Mild and Efficient Deprotection of Geminal Diacetates Catalyzed by FeCl3×6H2O in Ionic Liquid.
Authors: Niu Hongying , Zhang Xinying , Guo Haiming , Wang Jianji
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
A Simple and Effective Method for Chemoselective Esterification of Phenolic Acids.
Authors: Guo Wei , Li Junfei , Fan Ningjuan , Wu Weiwei , Zhou Peiwen , Xia Chizhong
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.
1‐Methylimidazole 3‐N‐Oxide as a New Promoter for the Morita—Baylis—Hillman Reaction.
Authors: Lin Yu‐Sheng , Liu Chih‐Wei , Tsai Thomas Y. R.
Published: June 2005

For Abstract see ChemInform Abstract in Full Text.