bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative investigation of InGaN quantum well laser diode structures grown on freestanding GaN and sapphire substrates
Authors: Hwang J. S. , Gokarna A. , Cho Yong-Hoon , Son J. K. , Lee S. N. , Sakong T. , Paek H. S. , Nam O. H. , Park Y. , Park S. H.
Published: July 2007

Comparative analysis of optical characteristics of In0.08Ga0.92N∕In0.03Ga0.97N multiquantum well (MQW) laser diode structures grown on freestanding GaN and on sapphire substrates is reported. Higher quantum efficiency, higher thermal activation energy, smaller Stokes-like shift, and shorter radiative lifetime are observed for InGaN MQWs on GaN substrate than those of the same MQWs on sapphire substrate. From time-resolved optical analysis, we find that not only an increase in nonradiative lifetime due to reduced dislocation density but also a decrease in radiative lifetime caused by suppressed piezoelectric field play an important role in enhancing optical properties of InGaN MQWs on GaN substrates.
Synchrotron radiation x-ray photoelectron spectroscopy study on the interface chemistry of high-k PrxAl2−xO3 (x=0–2) dielectrics on TiN for dynamic random access memory applications
Authors: Schroeder T. , Lupina G. , Sohal R. , Lippert G. , Wenger Ch. , Seifarth O. , Tallarida M. , Schmeisser D.
Published: July 2007

Engineered dielectrics combined with compatible metal electrodes are important materials science approaches to scale three-dimensional trench dynamic random access memory (DRAM) cells. Highly insulating dielectrics with high dielectric constants were engineered in this study on TiN metal electrodes by partly substituting Al in the wide band gap insulator Al2O3 by Pr cations. High quality PrAlO3 metal-insulator-metal capacitors were processed with a dielectric constant of 19, three times higher than in the case of Al2O3 reference cells. As a parasitic low dielectric constant interface layer between PrAlO3 and TiN limits the total performance gain, a systematic nondestructive synchrotron x-ray photoelectron spectroscopy study on the interface chemistry of PrxAl2−xO3 (x=0–2) dielectrics on TiN layers was applied to unveil its chemical origin. The interface layer results from the decreasing chemical reactivity of PrxAl2−xO3 dielectrics with increasing Pr content x to reduce native Ti oxide compounds present on unprotected TiN films. Accordingly, PrAlO3 based DRAM capacitors require strict control of the surface chemistry of the TiN electrode, a parameter furthermore of importance to engineer the band offsets of PrxAl2−xO3∕TiN heterojunctions.
Calculations of the temperature and alloy composition effects on the optical properties of AlxGa1−xAsySb1−y and GaxIn1−xAsySb1−y in the spectral range 0.5–6 eV
Authors: Gonzalez-Cuevas Juan A. , Refaat Tamer F. , Abedin M. Nurul , Elsayed-Ali Hani E.
Published: July 2007

A detailed analysis is presented on the temperature and alloy composition dependence of the optical properties of III-V alloys AlxGa1−xAsySb1−y and GaxIn1−xAsySb1−y in the energy range 0.5–6 eV. Expressions for the complex dielectric function are based on a semiempirical phenomenological model, which takes under consideration indirect and direct transitions below and above the fundamental absorption edge. Dielectric function and absorption coefficient calculations are in satisfactory agreement with available experimental data. Other dielectric related optical data, such as the refractive index, extinction, and reflection coefficients, can also be obtained from the model.
A stochastic model for periodic domain structuring in ferroelectric crystals
Authors: Kalkum Felix , Eggert Helge A. , Jungk Tobias , Buse Karsten
Published: July 2007

A stochastic description is applied in order to understand how ferroelectric structures can be formed. The predictions are compared with experimental data of the so-called electrical fixing: domains are patterned in photorefractive lithium niobate crystals by the combination of light-induced space-charge fields with externally applied electrical fields. In terms of our stochastic model, the probability for domain nucleation is modulated according to the sum of external and internal fields. The model describes the shape of the domain pattern as well as the effective degree of modulation.
Differential regulation of CHOP-10/GADD153 gene expression by MAPK signaling in pancreatic β-cells
Authors: Lawrence Michael C. , McGlynn Kathleen , Naziruddin Bashoo , Levy Marlon F. , Cobb Melanie H.
Published: July 2007

CHOP-10 (GADD153/DDIT-3) is a bZIP protein involved in differentiation and apoptosis. Its expression is induced in response to stresses such as nutrient deprivation, perturbation of the endoplasmic reticulum, redox imbalance, and UV exposure. Here we show that CHOP expression is induced in cultured pancreatic β-cells maintained in a basal glucose concentration of 5.5 mM and repressed by stimulatory glucose (≥11 mM). Both induction and repression of CHOP are dependent on the MAPKs ERK1 and ERK2. Two regulatory composite sites containing overlapping MafA response elements (MARE) and CAAT enhancer binding (CEB) elements regulate transcription in an ERK1/2-dependent manner. One site (MARE-CEB), from −320 to −300 bp in the promoter, represses transcription. The other site (CEB-MARE), from +2,628 to +2,641 bp in the first intron of the CHOP gene, activates it. MafA can influence transcription of both sites. The MARE-CEB is repressed by MafA, whereas the CEB-MARE site, which is homologous to the A2C1 component of the glucose-sensitive RIPE3b region of the insulin gene promoter, is activated by MafA. These results indicate that ERK1/2 have dual roles in regulating CHOP gene expression via both promoter and intronic regions, depending on environmental and metabolic stresses imposed on pancreatic β-cells.
Calmodulin‐dependent activation of calcineurin by chlorogenic acid
Authors: Tong Li , Song Yan , Jia Zhiguang , Zhang Wen , Wei Qun
Published: July 2007

Chlorogenic acid (CGA) has been proved to be an activator of calcineurin (CN) in our previous research. In this study, the activation mechanism of CN by CGA was further explored. The results showed that although the purified CN was inactive in vitro if only Ca2+/calmodulin (CaM) existed without Mn2+/Ni2+, CGA activated the inactive CN potently. It was found that CN's activity increased as the concentration of CGA increased and reached a plateau of 4‐ to 6‐fold higher activity using p‐nitrophenyl phosphate (pNPP) or phosphopeptide 32P‐RII as substrate. And the activation was CaM‐dependent. Moreover, the fluorescent emission of CN had a 17 nm red shift in the presence of 128 μM CGA, and the quenching constant was 1.21×1012 M‐1 · s‐1, which indicated that CGA bound to CN statically and changed its conformation. According to the kinetic analysis, CGA preferred to activate CN in a substrate noncompetitive manner. When Mn2+ or Ni2+ presented, CGA also activated CN with CaM‐dependency by improving CN's affinity for Mn2+ or Ni2+. In addition, the inhibition of CN by Zn2+ was partially eliminated by CGA chelation. Our findings suggested the activation of CN by CGA was in a CaM‐dependent and substrate noncompetitive manner. This might provide the basis for the further study of CN‐targeted activators.
iubmb Life, 59: 1‐6, 2007
Pga1 Is an Essential Component of Glycosylphosphatidylinositol-Mannosyltransferase II ofSaccharomyces cerevisiae
Authors: Sato Keisuke , Noda Yoichi , Yoda Koji
Published: July 2007

The Saccharomyces cerevisiae essential gene YNL158w/PGA1 encodes an endoplasmic reticulum (ER)-localized membrane protein. We constructed temperature-sensitive alleles of PGA1 by error-prone polymerase chain reaction mutagenesis to explore its biological role. Pulse-chase experiments revealed that the pga1tsmutants accumulated the ER-form precursor of Gas1 protein at the restrictive temperature. Transport of invertase and carboxypeptidase Y were not affected. Triton X-114 phase separation and [3H]inositol labeling indicated that the glycosylphosphatidylinositol (GPI)-anchoring was defective in the pga1tsmutants, suggesting that Pga1 is involved in GPI synthesis or its transfer to target proteins. We found GPI18, which was recently reported to encode GPI-mannosyltransferase II (GPI-MT II), as a high-copy suppressor of the temperature sensitivity of pga1ts. Both Gpi18 and Pga1 were detected in the ER by immunofluorescence, and they were coprecipitated from the Triton X-100–solubilized membrane. The gpi18tsand pga1tsmutants accumulated the same GPI synthetic intermediate at the restrictive temperature. From these results, we concluded that Pga1 is an additional essential component of the yeast GPI-MT II.
Estimating stock parameters from trawl cpue-at-age series using year-class curves
Authors: Cotter A. J. R. , Mesnil B. , Piet G. J.
Published: July 2007

Cotter, A. J. R., Mesnil, B., and Piet, G. J. 2007. Estimating stock parameters from trawl cpue-at-age series using year-class curves. – ICES Journal of Marine Science, 64: 234–247. A year-class curve is a plot of log cpue (catch per unit effort) over age for a single year class of a species (in contrast to the better known catch curve, fitted to multiple year classes at one time). When linear, the intercept and slope estimate the log cpue at age 0 and the average rate of total mortality, Z, respectively. Here, we suggest methodological refinements within a linear least squares framework. Candidate models may include a selectivity term, fleet-specific parameters, and polynomials in year to allow for gradual variations of Z. An iterative weighting method allows for differing precisions among the different fleets, and a forward (one-step ahead) validation procedure tests predicted cpue against observed values. Choice of the best approximating model(s) is made by ranking the biological credibility of each candidate model, then by comparing graphic plots, precision of prediction, and the Akaike Information Criterion. Two example analyses are (i) a comparison of estimated and true results for five stock simulations carried out by the US National Research Council, and (ii) modelling three beam trawl surveys for plaice (Pleuronectes platessa) in the North Sea. Results were consistent with known, age-related, offshore migrations by plaice. Year-class curves are commended as a widely applicable, statistically based, visual, and robust method.
Establishing stakeholder connections for management of the Irish orange roughy fishery
Authors: Shephard Samuel , Connolly Paul , Hareide Nils-Roar , Rogan Emer
Published: July 2007

S. Shephard, P. Connolly, N.-R. Hareide, and E. Rogan. 2007. Establishing stakeholder connections for management of the Irish orange roughy fishery. – ICES Journal of Marine Science, 64: 841–845. In 2000, an Irish fishery for orange roughy commenced in ICES Subarea VII. Landings peaked at >5000 t in 2002, but the fishery was largely closed from January 2005 because of concern about unsustainable fishing and the negative effects on deepwater sharks and coral. A multidimensional project was initiated in 2003 to investigate the fishery system and to develop a management plan. The project emphasized the establishment of productive relationships with stakeholders, particularly fishers. We describe and evaluate the process by which such linkages were developed successfully. Informal discussion with fishers produced experiential knowledge that described fishery development and fishing strategies, and informed subsequent scientific data collection. Strengthening relationships permitted access to commercial fishing trips and cooperation in research. An atmosphere developed in which management options could be debated in both wheelhouse and boardroom. Eventually, a formal research/stock assessment survey took place in which fishers, agencies, and deepwater coral ecologists cooperated.
Migrations, fishery interactions, and management units of sea bass (Dicentrarchus labrax) in Northwest Europe
Authors: Pawson M. G. , Pickett G. D. , Leballeur J. , Brown M. , Fritsch M.
Published: July 2007

Pawson, M. G., Pickett, G. D., Leballeur, J. Brown, M., and Fritsch, M. 2007. Migrations, fishery interactions, and management units of sea bass (Dicentrarchus labrax) in Northwest Europe. – ICES Journal of Marine Science, 64: 332–345. A total of 4959 sea bass was tagged between 2000 and 2005 around the coasts of England, Wales, southern Ireland, and the Channel Isles to investigate whether movement patterns documented in 1987 have changed and to estimate the level of competition for sea bass between inshore and offshore fisheries. Most (54%) of the recaptures of adult bass (fish >40 cm) tagged inshore and made between May and October were within 16 km of the release positions. From November on, an increasing proportion was recaptured at least 80 km south or southwest of tagging sites. Bass tagged on offshore spawning grounds in March and April showed reciprocal movement, 75% of recaptures between May and October being at least 80 km from the release site. These observations reaffirm the hypothesis that adult sea bass may move considerable distances to offshore winter spawning areas, but there was little evidence of the spawning migrations between the North Sea and the western Channel that were observed in the early 1980s. Just 3% of the recaptures of bass >36 cm tagged in UK inshore fisheries were reported from the offshore pairtrawl fishery, whereas half the recaptures of bass tagged in that fishery were made inshore along the UK coast. When weighted by the respective catches, this suggests that the effects of management measures implemented in the UK inshore fishery are largely restricted to that fishery. A proposal for stock units for assessment and management of NW European sea bass fisheries is presented.
Environmental stewardship as a new form of fisheries governance
Authors: Gray Tim S. , Hatchard Jenny
Published: July 2007

Gray, T. S., and Hatchard, J. 2007. Environmental stewardship as a new form of fisheries governance. – ICES Journal of Marine Science, 64: 786–792. Environmental stewardship is a form of governance that reflects the rising tide of influence on fisheries management exerted by environmental principles such as marine protected areas, the ecosystem-based approach, and the precautionary approach. First, we assess the extent to which environmental stewardship has moved beyond the level of rhetoric, whereby regulators pay lip service to such principles, and has reached such a level of power that environmental priorities hold sway over the decision-making process. In other words, we consider how far environmental stewardship has infiltrated the political system by constructing a powerful network of governance, including what is known in the international environmental politics literature as an “epistemic community”. Second, we establish the foundational conception on which this environmental stewardship rests: is it nature conservation or is it sustainable development? Elements of both conceptions are found in most of the sources of the environmental stewardship mode of fisheries governance (though in differing proportions), but there is a threat to the fishing industry if the nature conservation conception becomes dominant. The best strategy for industry is to embrace the sustainable development conception of environmental stewardship and to demonstrate that the objectives of the nature conservation conception can and must be accommodated within the overarching conception of sustainable development. Otherwise, industry could find itself increasingly marginalized in fisheries decision-making by a top-down imposition of nature conservationist environmental stewardship imperatives.
Environmental variability in the North Atlantic and Iberian waters and its influence on horse mackerel (Trachurus trachurus) and albacore (Thunnus alalunga) dynamics
Authors: Lavín Alicia , Moreno-Ventas Xabier , Ortiz de Zárate Victoria , Abaunza Pablo , Cabanas José Manuel
Published: July 2007

Lavín, A., Moreno-Ventas, X., Ortiz de Zárate, V., Abaunza, P., and Cabanas, J. M. 2007. Environmental variability in the North Atlantic and Iberian waters and its influence on horse mackerel (Trachurus trachurus) and albacore (Thunnus alalunga) dynamics. – ICES Journal of Marine Science, 64: 425–438. We explore the potential impact of climatic and oceanic variables on the dynamics of horse mackerel Trachurus trachurus (coastal distribution) and albacore Thunnus alalunga (oceanic distribution). Principal components analysis of a set of environmental parameters for the years 1966–2000 allowed us to characterize the system by three components. The first consisted mainly of sea surface temperature (SST; 18.5% of variability), the second was determined by the oceanic transport indices, potential energy anomaly (PEA), and the Gulf Stream Index (15.6%), and the third by the meridional wind component and Ekman transport (11.5%). Horse mackerel recruitment was negatively correlated mainly with the first thermal component, whereas albacore age 3 catches were negatively correlated with the second oceanic component and positively with the third wind component. Multiple linear regression confirmed that environmental conditions [SST, PEA, and the zonal (east–west) wind component] explained the availability of age 3 albacore to the surface fisheries for the period 1975–1999. In contrast, cross-validation analysis showed that environmental conditions did not consistently explain horse mackerel recruitment, probably because of the short time-series available (15 y).
Developing management procedures that are robust to uncertainty: lessons from the International Whaling Commission
Authors: Punt André E. , Donovan Greg P.
Published: July 2007

Punt, A. E. and Donovan, G. P. 2007. Developing management procedures that are robust to uncertainty: lessons from the International Whaling Commission. – ICES Journal of Marine Science, 64: 603–612. Traditionally, fisheries management advice has been based on stock assessments that considered merely the “best” set of assumptions while uncertainty arising only from observation and process error was quantified, if considered at all. Unfortunately, uncertainty attributable to lack of understanding of the true underlying system and to ineffective implementation may dominate the sources of error that must be accounted for if management is to be successful. The management procedure approach is advocated as the appropriate way to develop management advice for renewable resources. This approach, pioneered by the International Whaling Commission (IWC) Scientific Committee, takes politically agreed management objectives and incorporates all scientific aspects of management including data collection and analysis, development of robust harvest control laws or effort regulations, and monitoring. A primary feature is that uncertainty (including that arising from sources conventionally ignored) is taken into account explicitly through population simulations for a variety of scenarios. The nature of the management procedures developed for commercial and aboriginal subsistence whaling and the processes by which they have been developed is highlighted. We also identify lessons that have been learned from two decades of IWC experience and suggest how these can be applied to other fishery situations.
Application of the precautionary approach and conservation reference points to management of Atlantic seals
Authors: Hammill M. O. , Stenson G. B.
Published: July 2007

Hammill, M. O., and Stenson, G. B. 2007. Application of the precautionary approach and conservation reference points to management of Atlantic seals. – ICES Journal of Marine Science, 64: 702–706. Resource management requires a trade-off between conservation, economic, and political concerns in establishing harvest levels. The precautionary approach (PA) brings scientists, resource managers, and stakeholders together to identify clear management objectives and to agree on population benchmarks that would initiate certain management actions when those benchmarks are exceeded. A conceptual framework for applying the PA to marine mammals is outlined. For a data-rich species, precautionary and conservation reference levels are proposed. When a population falls below the precautionary reference level, increasingly risk-averse conservation measures are applied. A more conservative, risk-averse approach is required for managing data-poor species. The framework has been implemented for the management of commercial seal harvests in Atlantic Canada.
Scientific tools to support the practical implementation of ecosystem-based fisheries management
Authors: Smith A. D. M. , Fulton E. J. , Hobday A. J. , Smith D. C. , Shoulder P.
Published: July 2007

Smith, A. D. M., Fulton, E. J., Hobday, A. J., Smith, D. C., and Shoulder, P. 2007. Scientific tools to support the practical implementation of ecosystem-based fisheries management. – ICES Journal of Marine Science, 64: 633–639. Ecosystem-based fisheries management (EBFM) has emerged during the past 5 y as an alternative approach to single-species fishery management. To date, policy development has generally outstripped application and implementation. The EBFM approach has been broadly adopted at a policy level within Australia through a variety of instruments including fisheries legislation, environmental legislation, and a national policy on integrated oceans management. The speed of policy adoption has necessitated equally rapid development of scientific and management tools to support practical implementation. We discuss some of the scientific tools that have been developed to meet this need. These tools include extension of the management strategy evaluation (MSE) approach to evaluate broader ecosystem-based fishery management strategies (using the Atlantis modelling framework), development of new approaches to ecological risk assessment (ERA) for evaluating the ecological impacts of fishing, and development of a harvest strategy framework (HSF) and policy that forms the basis for a broader EBFM strategy. The practical application of these tools (MSE, ERA, and HSF) is illustrated for the southern and eastern fisheries of Australia.
TEMAS: fleet-based bio-economic simulation software to evaluate management strategies accounting for fleet behaviour
Authors: Ulrich Clara , Andersen Bo Sølgaard , Sparre Per J. , Nielsen J. Rasmus
Published: July 2007

Ulrich, C., Andersen, B. S., Sparre, P. J., and Nielsen, J. R. 2007. TEMAS: fleet-based bio-economic simulation software to evaluate management strategies accounting for fleet behaviour. – ICES Journal of Marine Science, 64: 647–651. TEMAS (technical management measures) is a fleet-based bio-economic software for evaluating management strategies accounting for technical measures and fleet behaviour. It focuses on mixed fisheries in which several fleets can choose among several fishing activities to target different stocks in one or several areas. The software combines a management strategy evaluation framework, using a forward-running operating model and a management procedure with a fleet behaviour module simulating both short-term (effort allocation) and long-term (entry/exit) fleet dynamics. The suite of models behind TEMAS can be thought of as an extension of the traditional ICES forecast model. Alternative management scenarios can be compared and evaluated for their bio-economic consequences and robustness to parameter uncertainty. The software is generic and user-friendly, and can be run at several space and time scales.
Potential benefits from improved selectivity in the northwest Mediterranean multispecies trawl fishery
Authors: Bahamon Nixon , Sardà Francesc , Suuronen Petri
Published: July 2007

Bahamon, N., Sardà, F., and Suuronen, P. 2007. Potential benefits from improved selectivity in the northwest Mediterranean multispecies trawl fishery. – ICES Journal of Marine Science, 64: 757–760. The management scheme in the northwest Mediterranean multispecies demersal fishery is based largely on technical measures such as minimum mesh and landing sizes. However, selectivity of the trawls used is poor, and large numbers of juvenile fish are caught. We assess the consequences of improved gear selectivity for European hake, Norway lobster, poor cod, and greater forkbeard by assuming that the whole fleet would switch from the current 40 mm diamond-mesh to a 40 mm square-mesh (SM40) codend. The results suggest that, immediately after implementation, the yield-per-recruit (Y/R) would be reduced by up to 20% for the three fish species but that, within five years, the Y/R of European hake would increase by > 50 %, provided fishing effort did not change markedly. For poor cod and greater forkbeard, the comparable increases would be more moderate, whereas for Norway lobster, the gains would only be small. Overall, marked long-term benefits might be obtained by changing to SM40 codends.
The fishery conservation policy of the European Union after 2002: towards long-term sustainability
Authors: Penas Ernesto
Published: July 2007

Penas, E. 2007. The fishery conservation policy of the European Union after 2002: towards long-term sustainability. – ICES Journal of Marine Science, 64: 588–595. In December 2002, changes were introduced in the Common Fisheries Policy (CFP) as part of a longer-term reform process. Although implementation of these changes is gradual, experience over the past 3 years has already provided some lessons. This paper summarizes the main elements of the reform, describes the progress in their implementation, draws some provisional conclusions, and highlights the main scientific challenges in relation to implementation of the revised CFP. The adaptation of the scientific advice to changing needs, the difficulty of changing the tradition of managing stocks through annual decisions, and the development of a fruitful dialogue among fishers, scientists, and managers are the main challenges still to be resolved to ensure effective implementation.
Institutional designs to face the dark side of total allowable catches
Authors: del Valle Ikerne , Astorkiza Kepa
Published: July 2007

del Valle, I., and Astorkiza, K. 2007. Institutional designs to face the dark side of total allowable catches. – ICES Journal of Marine Science, 64: 851–857. Setting total allowable catches (TACs) is an endogenous process in which different agents and institutions, often with conflicting interests and opportunistic behaviour, try to influence policy-makers. Far from being the benevolent social planners many would wish them to be, these policy-makers may also pursue self-interest when making final decisions. Although restricted knowledge of stock abundance and population dynamics, and weakness in enforcement, have effects, these other factors may explain why TAC management has failed to guarantee sustainable exploitation of fish resources. Rejecting the exogeneity of the TAC and taking advantage of fruitful debate on economic policy (i.e. the rules vs. discretion debate, and that surrounding the independence of central banks), two institutional developments are analysed as potential mechanisms to face up to misconceptions about TACs: long-term harvest control rules and a central bank of fish.
Inflammatory Cells Invading Muscle Fibers in Myotonic Dystrophy Type 2
Authors: Kawai Makoto , Gundogdu Betul , Kwan Justin , Mosier Dennis R
Published: July 2007

We report a case of genetically confirmed myotonic dystrophy type 2 with findings of significant inflammation in muscle. The initial presentation consisted of cramps and slowly progressive proximal muscle weakness, initially without distinguishing clinical features. Muscle biopsy showed invasion of both necrotic and nonnecrotic muscle fibers by CD4+ and CD8+ lymphocytes and upregulation of major histocompatibility complex (MHC) class I expression. Empiric immunosuppressive therapy did not provide clinical benefit. We note that several hereditary muscle disorders exhibit evidence of inflammation near necrotic fibers, believed to represent a secondary immune response. However, invasion of nonnecrotic fibers by inflammatory cells, a finding regarded as typical of primary inflammatory myopathies, has not been described in patients with myotonic dystrophy type 2. This case documents a significant inflammatory response in muscle of a patient with myotonic dystrophy type 2, which could lead to diagnostic confusion with the primary inflammatory myopathies.
Crystallographic texture of stress-affected bainite
Authors: Kundu Saurabh , Hase Kazukuni , Bhadeshia H.K.D.H
Published: July 2007

A method is presented for calculating both the macroscopic strains and the crystallographic bias which develop when a polycrystalline sample of austenitic steel is transformed into bainite or martensite under the influence of an applied stress or a system of stresses. Any texture present in the austenite prior to transformation is taken into account, as is the detailed crystallography of the transformation. Comparisons with experimental data are encouraging. A strong correlation has been observed between the proportion of the driving force for transformation that is attributed to stress and the extent of variant selection.
Bifurcation phenomena and attractive periodic solutions in the saturating inductor circuit
Authors: Bartuccelli Michele V , Deane Jonathan H.B , Gentile Guido
Published: July 2007

In this paper, we investigate bifurcation phenomena, such as those of the periodic solutions, for the ‘unperturbed’ nonlinear system

, with

and
α
>1,
β
>0, when we add the two competing terms

, with
f
(
t
) a time-periodic analytic ‘forcing’ function and
γ
>0 the dissipative parameter. The resulting differential equation

describes approximately an electronic system known as the saturating inductor circuit. For any periodic orbit of the unperturbed system, we provide conditions which give rise to the appearance of subharmonic solutions. Furthermore, we show that other bifurcation phenomena arise as there is a periodic solution with the same period as the forcing function
f
(
t
) which branches off the origin when the perturbation is switched on. We also show that such a solution, which encircles the origin, attracts the entire phase space when the dissipative parameter becomes large enough. We then compute numerically the basins of attraction of the attractive periodic solutions by choosing specific examples of the forcing function
f
(
t
), which are dictated by experience. We provide evidence showing that all the dynamics of the saturating inductor circuit is organized by the persistent subharmonic solutions and by the periodic solution around the origin.
Association of MT‐ND5 gene variation with mitochondrial respiratory control ratio and NADH dehydrogenase activity in Tibet chicken embryos
Authors: Bao H. G. , Zhao C. J. , Li J. Y. , Wu Ch.
Published: July 2007

NADH dehydrogenase (complex I) couples the oxidation of NADH for the reduction of ubiquinone with the generation of a proton gradient that can be used for the synthesis of ATP. We have found a missense mutation in the MT‐ND5 subunit of NADH dehydrogenase in the Tibet chicken breed. In the present study, the mitochondrial respiratory control ratio (RCR) and NADH dehydrogenase activity in Tibet chicken embryonic brain with different genotypes were measured. Significant differences between animals carrying mitochondria with the EF493865.1:m.1627A vs. EF493865.1:m.1627C alleles were observed for RCR and enzyme activity.
Macroinvertebrate communities of mediterranean ponds (North Iberian Plateau): importance of natural and human‐induced variability
Authors: TRIGAL CRISTINA , GARCÍA‐CRIADO FRANCISCO , ALÁEZ CAMINO‐FERNÁNDEZ
Published: July 2007

1. The effects of natural and human‐induced variability on the composition of macroinvertebrate communities of 28 ponds located in the North Iberian Plateau (Spain) were studied to determine the best predictors of community structure.

2. Constrained ordination was used to identify the main factors explaining the among‐pond variance in abundance (as catch per unit effort) of total macroinvertebrate and Chironomidae assemblages and trophic structure (functional feeding groups).

3. Variance partitioning showed that human disturbance (represented by a pond condition index, total phosphorus concentration and pesticides) was the best predictor of macroinvertebrate community structure, whereas factors, such as habitat and biotic variables were of secondary importance. Factors controlling the chironomid community were broadly similar to those acting on the whole community of macroinvertebrates. In contrast, trophic structure was mainly determined by habitat and biotic variables.

4. Our results show that macroinvertebrates may be used as effective indicators of the ecological status of Mediterranean ponds. The Chironomidae deserve special attention because they were the dominant group in the study ponds and the strongest explanatory variable for their distribution was degradation.
Antibacterial activity of silver inorganic agent YDA filler
Authors: Ohashi S. , Saku S. , Yamamoto K.
Published: July 2007

summary  YDA filler is an antibacterial agent that is currently in commercial dental use. In this study, we attempted to determine whether it exerts an antibacterial effect on human saliva bacteria, and to determine whether it can be used in dental materials. CFUs in 1 mL stimulated human saliva were examined using blood agar and mitis salivarius agar after immersion, with or without YDA filler. The antibacterial effect was compared with that of Ketac‐Silver. Dental materials containing 5% wt YDA filler were prepared for in vitro testing on S. mutans and A. viscosus. Furthermore, we examined the in vitro cytotoxicity of experimental MMA resin containing YDA filler on HeLa cells. Human saliva bacteria and mutans streptococci showed reduced viability following exposure to YDA filler after 12 h. The concentration of silver ions released by YDA filler was below 1 ppm after 12 h. Two tested strains showed reduced viability following exposure to dental materials containing YDA filler. In another experiment, MMA resin containing YDA filler did not show cytotoxicity on HeLa cells after 24‐ and 48‐h exposure. Thus, YDA filler may help in the development of antibacterial dental materials, such as composite resin, glass–ionomer or temporary cement.
Plasma pharmacokinetics of midazolam in chickens, turkeys, pheasants and bobwhite quail
Authors: CORTRIGHT K. A. , WETZLICH S. E. , CRAIGMILL A. L.
Published: July 2007

In vivoplasma pharmacokinetics of midazolam hydrochloride (5 mg/kg i.v.) were determined in commercially raised broiler chickens, turkeys, ring‐necked pheasants and bobwhite quail. Pharmacokinetic profiles of midazolam were similar for all four species, especially with regard to the area under the plasma drug concentration–time curve. Estimates of the half‐life of elimination of midazolam were 0.42, 1.45, 1.90, and 9.71 h for turkeys, chickens, bobwhite quail, and pheasant, respectively. This was similar to the major metabolite (1‐hydroxymidazolam). Elimination half‐lives for 1‐hydroxymidazolam were 1.35, 1.86, 1.97, and 13.97 h for turkey, chicken, bobwhite quail and pheasant, respectively. Elimination half‐lives for 4‐hydroxymidazolam were 0.76, 1.23, 2.85, and 13.82 h for chicken, turkey, pheasant, and bobwhite quail, respectively. In addition to traditional pharmacokinetic approaches to parameter estimation, a bootstrapping technique was employed to attempt to achieve more realistic approximations of the concentrations at later time‐points.
A terrestrial scenario for the Cretaceous‐Tertiary boundary collapse of the marine pelagic ecosystem
Authors: Rohling E.J. , Zachariasse W.J. , Brinkhuis H.
Published: July 2007

In this paper, we present an expansion of the model for marine ecosystem collapse at the Cretaceous‐Tertiary boundary presented by Brinkhuis and Zachariasse (1988). A long‐term sea‐level drop at the end of the Cretaceous culminated in a short‐term regressive pulse at K‐T time. Deep‐water production was curtailed, minimizing the vertical advection of nutrients and oxygen in the oceans. Consequently, a productivity crisis developed, which could only be survived by cosmopolitan shallow‐dwellers, and the Oxygen Minimum Zone (OMZ) expanded. No sustained Oceanic Anoxic Event followed the K‐T boundary event, since productivity had dropped to extremely low values. At K‐T time, however, the short‐term expansion of the OMZ, invoked by the combination of minimized oxygen advection and abrupt mass mortality, caused dysoxic conditions even to reach up to the shelves, as can be deduced from sedimentological, chemical and faunistic observations.
The upper crust low velocity layer; a Rayleigh (Rg) phase velocity study from SE Norway
Authors: Lokshtanov D.E. , Ruud B.O. , Husebye E.S.
Published: July 2007

A recent surge of interest in short‐period fundamental mode Rayleigh waves (Rg) propagation is motivated by their usefulness for structural mapping and estimation of attenuation (Q) properties of the uppermost crust, their importance in scattering studies and as a nuisance (false alarms) in detection seismology. We have investigated Rg phase velocity dispersion characteristics, using recordings from 16 out of 22 subarrays of the NORSAR array of aperture 100 km. The observed phase velocity in combination with a one‐layer and two‐layers model over halfspace models were inverted using a maximum likelihood scheme. In view of the smoothness and simplicity of the dispersion curves, the number of unknowns were limited to three parameters, namely shear velocities and thickness, using a Poisson's ratio of 0.25 for P‐S velocity coupling and density fixed. In the general array siting area the derived low velocity layer has an average thickness of 1.02 km, and the associated shear velocity is 2.82 km s‐1. The underlying model half space appears to be uniform, and its derived shear velocity is 3.55 km s‐1, which is typical of the upper crust. In contrast to other similar studies, no obvious correlation was found with local geology, which mainly consists of Precambrian crystalline rock sequences. Group velocities were calculated from the structural models and compared to the observational ones. The agreement between calculated and observed group velocities was reasonable.
DRIFTING CONTINENTS AND SHIFTING THEORIES: THE MODERN REVOLUTION IN GEOLOGY AND SCIENTIFIC CHANGE
Authors: Legrand H.E.
Published: July 2007

1988, $52.50, xv+313 pp. Cambridge University Press, London. ISBN 0–521–32210–3.
A NEW SERIES: CEO‐GIANTS OF THE PAST
Authors: Reymenf Richard
Published: July 2007

Constantly assailed as we are by new ideas in Geology, it can be a sobering experience to restudy the works of the pioneers of our subject. The aim of the present series is to present cameos of important thinkers, whose fundamental contributions seem to have been forgotten or glossed over in the trimmed curricula we meet at universities today. Who, today, is told of the brilliant ideas of Johannes Walther, the many genial thoughts of Alcide d'orbigny, or the innovativeness of Charles Lyell.

This new series presents vignettes of the life and times of early notables and the fact that all was not milk and honey in the pursuit of knowledge.

The first profile we shall consider is Sven Nilsson, an important figure of the last century in Scandinavian natural history, including palaeontology. Our readership is invited to contribute articles on the founders of geo‐science in their own countries. Let us learn again what Choffat, Suess, Oppel, Backlund, Brogger, Sowerby, Lapworth, Brongniart, d'orbigny, von Schlotheim, etc. contributed to our pool of knowledge.

The ‘wheel’ has been rediscovered many times in geology.

SVEN NILSSON (1787–1883)
DESTRUCTIVE EARTHQUAKES AND TSUNAMI WARNING SYSTEM
Authors: Victor Luis A. Mendes , Baptista Maria Ana Viana , Simoes José Z.
Published: July 2007

The Portuguese coast has been affected several times in the past by strong earthquakes that generated tsunamis severely damaging the city of Lisbon.

The most significant event known was the Lisbon earthquake of 1 November 1755. It is generally assumed that the location of this event was the Gorringe Bank region in the North Atlantic. This ridge, located 200 km south‐west of the Portuguese shore, was also the location of the 28 February 1969 magnitude Ms= 7.9 earthquake (Fukao, 1973), that generated a tsunami of small amplitude clearly recorded at the tidal stations of the Portuguese south and south‐west coasts.

The need to reduce the social and economic impact of an event of this type, greatly amplified by the urban concentration of coastal areas, led to the research project ‘Destructive Earthquakes and Tsunami Warning System in SW Portugal’. This project, sponsored by the European Economic Community and the public Portuguese research funding agencies, has been conducted by the Geophysical Centre of the University of Lisbon, since April 1988.

The main targets of the project are:•the installation of a pilot warning system against tsunamis, based on two ocean bottom stations, comprising a 3 component seismometer and a bottom mounted pressure sensor, linked by cable to a surface buoy. This buoy is equipped with a data acquisition and data transmission system. Seismic and water level data will be collected on an almost real‐time basis and will be transmitted to Lisbon via satellite;

•the refinement of existing geological models, in order to clarify the genesis of the bank and the seismic activity in this area;

•the installation of an adequate network of seismic monitoring stations in order to better locate off shore earthquakes (Fig. 1);

•the evaluation of seismic and tsunami risk around the Iberian Peninsula.
The Numidian Sequence between Guelma and Constantine (Eastern Tell, Algeria)*
Authors: Moretti E. , Coccioni R. , Guerrera F. , Lahondère Jean‐Claude , Loiacono Francesco , Puglisi Diego
Published: July 2007

The Numidian Sequence represents one of the main tectono‐stratigraphic units involved in the geological evolution of the Maghrebian orogen during the Upper Oligocene‐Lower Miocene. Geo‐structural aqalysis led to the reconstruction of tectonc‐stratigraphic units and recognition of two main tectonic phases (Eocene and Lower Miocene). Sedimentological analysis of the studied sections has resulted in the distinction of arenaceous and conglomeratic facies generated by debris flows or high‐density turbidity currents on a submarine slope, present within the pelitic‐arenaceous and arenaceous‐pelitic sequences which also contain slumped units in places.

Previous and new micropalaeontological data indicate Late Oligocene‐Early Burdigalian ages for the Numidian sequences of the Constantine Mountains. On the basis of petrographic study the Numidian rocks can be classified as poorly sorted quartzarenites containing siliciclastic matrix. The overall petrographic data indicate that the Continental intercalaire (Hoggar, Tassili and Fezzan) and Series Pharusienne (Hoggar and Eglab) are possible supply areas for the Numidian quartz.
Geochemical signature of the Cenomanian to Eocene rocks in Israel ‐a palaeoenvironmental indicator
Authors: Ilani Shimon , Rosenfeld Amnon , Kronfeld Joel , Flexer Akiva
Published: July 2007

Distinctive trace‐metal concentrations characterize Cenomanian to Eocene marine carbonates from Israel. The Cenomanian‐Turonian platform carbonates, including clayey formations, exhibit low average values ranging between 2 and 29 ppm for Zn, Cr, V, Ni, Cu, U and Co. The Santonian‐Campanian and Early to Middle Eocene marine chalks show higher average concentrations of these trace‐metals ranging between 3 and 56 ppm. The highest average concentrations of these metals (5–118 ppm) are found in the Maastrichtian and in the Palaeocene marine chalks and marls. The possible relationship between these metal background levels and the lithology, the biogenic productivity, the organic matter content, the iron oxide concentration, the rate of sedimentation of the studied time‐rock units as well as the palaeogeographical changes are discussed. The extent of the exposed palaeo‐landmasses due to tectonics, the intensity of weathering conditions and the detritus supply into the basin, control primarily the iron and trace‐metal content in the studied sediments.
SCIENCE & THE NAVY: THE HISTORY OF THE OFFICE OF NAVAL RESEARCH
Authors: Sapolsky H.M.
Published: July 2007

1990, xvi+142 pp., $24.95 (hbk) ISBN 0–691–07847–5 Princeton University Press, Princeton, NJ.
Anaphylaxis and toxic epidermal necrolysis or Stevens–Johnson syndrome after nonmucosal topical drug application: fact or fiction?
Authors: Sachs B. , Fischer‐Barth W. , Erdmann S. , Merk H. F. , Seebeck J.
Published: July 2007

Background:  Drug‐induced anaphylaxis and toxic epidermal necrolysis (TEN) or Stevens‐Johnson syndrome (SJS) represent severe immediate and delayed‐type adverse drug reactions (ADRs), respectively. Occurrence of such reactions after topical drug application has only rarely been reported. Hence, we compiled a large number of such cases which we systematically analyzed.

Methods:  All such cases contained in the ADR database of the competent pharmacovigilance authority in Germany and cases reported in literature were identified, evaluated and analyzed with regard to potential risk factors. Since the application of drugs to mucous membranes facilitates their entry to the systemic circulation only cases occurring after non‐mucosal topical drug application were considered.

Results:  After evaluation 28 anaphylaxis database cases and 48 anaphylaxis literature cases remained for analysis. Application to skin wounds or to skin with impaired barrier function was identified as a risk factor in 10/28 (36%) of the database cases and in 42/48 (88%) of the literature cases. In 9/28 database cases (32%), anaphylaxis was induced by drugs used for their hyperemizing effect and, in 8/28 cases (29%) by antibiotics or antiseptics. In the literature cases, anaphylaxis was induced by antibiotics or antiseptics in 35/48 cases (73%). Only one SJS database case and one TEN literature case remained after case evaluation.

Conclusion:  Anaphylaxis does occur after non‐mucosal topical drug administration. Application of drugs to skin wounds or to skin with impaired barrier function may pose a risk factor for its occurrence. TEN or SJS following non‐mucosal topical drug application seems to be extremely rare.
Influence of total IgE levels on the severity of sting reactions in Hymenoptera venom allergy
Authors: Sturm G. J. , Heinemann A. , Schuster C. , Wiednig M. , Groselj‐Strele A. , Sturm E. M. , Aberer W.
Published: July 2007

Background:  Detection of specific IgE for Hymenoptera venoms and skin tests are well established diagnostic tools for the diagnosis of insect venom hypersensitivity. The aim of our study was to analyze the effect of total IgE levels on the outcome of generalized anaphylactic reactions after a Hymenoptera sting.

Methods:  Two hundred and twenty patients allergic to bee, wasp, or European hornet venom were included in the study. Their specific and total IgE levels, serum tryptase levels, skin tests, and sting history were analyzed.

Results:  In patients with mild reactions (grade I, generalized skin symptoms) we observed higher total IgE levels (248.0 kU/l) compared to patients with moderate reactions (grade II, moderate pulmonary, cardiovascular, or gastrointestinal symptoms; 75.2 kU/l) and severe reactions (grade III, bronchoconstriction, emesis, anaphylactic shock, or loss of consciousness; 56.5 kU/l; P < 0.001). Accordingly, 25% of the patients with low levels of total IgE (<50 kU/l), but no individual with total IgE levels >250 kU/l, developed loss of consciousness (P = 0.001). Additionally, specific IgE levels were related to total IgE levels: Specific IgE levels increased from 1.6 to 7.1 kU/l in patients with low (<50 kU/l) and high (>250 kU/l) total IgE levels, respectively (P < 0.001). Specific IgE levels correlated inversely to the clinical reaction grades, however, this trend was not statistically significant (P = 0.083).

Conclusion:  Patients with Hymenoptera venom allergy and high levels (>250 kU/l) of total IgE, predominantly develop grade I and grade II reactions and appear to be protected from grade III reactions. However, this hypothesis should be confirmed by extended studies with sting challenges.