bluuebunny/crossref_metadata_2025 huggingface dataset:
INVESTIGATING THE VIABILITY OF SQUIRREL POPULATIONS; A MODELING APPROACH FOR THE ISLAND OF LESVOS, GREECE
Authors: MATSINOS YIANNIS G. , PAPADOPOULOU ELENI
Published: August 2010

ABSTRACT. Habitat loss and fragmentation are considered to be the most important factors responsible for population decreases in small mammal populations. Particularly important is also the effect of insularity that can act syn‐ergistically with the previous factors. Population Viability Analysis (PVA) combines the spatial component of the problem with the species population structure offering an integrated platform for testing and assessing the effects of critical parameters upon the population viability. Various management options can also be quantified and tested. In the case of Sciurus anomalous, a vulnerable squirrel species endemic in Lesvos, a series of threats and management problems were identified and assessed. A stochastic simulation model was developed and parameterized with field data for the species using the program Ramas/GIS. The results suggested that special attention has to be paid to the planning of road system networks and to stopping illegal hunting, especially when extinction risks for vulnerable populations are higher with the above threats.
THE ROLE OF JUVENILE DISPERSAL IN THE REPLACEMENT OF GOLDEN‐WINGED WARBLERS BY BLUE‐WINGED WARBLERS
Authors: KOONCE ALEXANDER E.
Published: August 2010

ABSTRACT. In this paper, we test a hypothesis that the replacement of golden‐winged warblers by blue‐winged warblers in the eastern United States is due to the fact that the latter species occupies only a fraction of the habitat of the former species. We build two models, one a simple discrete population model with a one‐year time step, and the second a landscape model that incorporates juvenile dispersal. The second model involves a numerical solution to a linked pair of diffusion equations. The first model shows that eventually the blue‐winged warbler will replace the golden‐winged warbler, but not in the observed 50 year time frame. The second model extends the range of parameter values under which the replacement happens within 50 years, but it still appears that other factors must play a significant role.
A MICROFOUNDATION OF PREDATOR‐PREY DYNAMICS
Authors: EICHNER THOMAS , PETHIG RÜDIGER
Published: August 2010

ABSTRACT. Predator‐prey relationships account for an important part of all interactions betweenspecies. In this paper we provide a microfoundation for such predator‐prey relations in afood chain. Basic entities of our analysis are representative organisms of species modeled similar to economic households. With prices as indicators of scarcity, organisms are assumed to behave as if they maximize their net biomass subject to constraints which express the organisms' risk of being preyed upon during predation. Like consumers, organisms face a ‘budget constraint’ requiring their expenditure on prey biomass not to exceed their revenue from supplying own biomass. Short‐run ecosystem equilibria are defined and derived. The net biomass acquired by the representative organism in the short term determines the positive or negative population growth. Moving short‐run equilibria constitute the dynamics of the predator‐prey relations that are characterized in numerical analysis. The population dynamics derived here turn out to differ significantly from those assumed in the standard Lotka‐Volterra model.
A STATE SPACE BIOECONOMIC MODEL OF PACIFIC HALIBUT
Authors: CRIDDLE KEITH R. , HERRMANN MARK
Published: August 2010

Abstract Evaluation of potential economic consequences of alternative management actions requires an understanding of how the biological stock will be affected by the management action and an understanding of the response of economic systems to changes in the timing, magnitude, and size distribution of harvests and changes in the location and catchability of the biological stock. We use a hybrid structural time series model to represent Pacific halibut (Hippoglossus stenolepis) stock and recruitment dynamics and a system of structural equations to represent supply and demand relationships for Pacific halibut from Alaska and British Columbia. Model simulations explore the economic effects of changes in recruitment success, growth rate, and carrying capacity, and changes in international supplies of halibut.
AN INTERNATIONAL MARINE POLLUTANT SINK IN AN ASYMMETRIC ENVIRONMENTAL TECHNOLOGY GAME
Authors: HENNLOCK MAGNUS
Published: August 2010

Abstract A differential game with N countries as players is developed for the analysis of a marine resource with open access used by the countries as a pollutant sink and for production of an ecosystem good. Consumption, investment, abatement, and environmental research sectors may differ across countries. Under the assumption that property rights are well defined within the sovereignty of each country although there is a lack of enforcement in the international area, the game is solved for the feedback Nash equilibrium, using the Isaacs–Bellman dynamic programming technique, identifying the nonlinear feedback Nash flows of consumption, investment, harvest effort, abatement, and environmental research effort in each country, which is then compared to the Pareto optimal global solution.
MEASURING PRODUCTIVITY AND ITS COMPONENTS FOR FISHERIES: THE CASE OF THE ALASKAN POLLOCK FISHERY, 1994–2003
Authors: FELTHOVEN RONALD G. , PAUL CATHERINE J. MORRISON , TORRES MARCELO
Published: August 2010

Abstract Traditional productivity measures have been much less prevalent in fisheries economics than other measures of economic and biological performance. It has been increasingly recognized, however, that modeling and measuring fisheries' production relationships is central to understanding and ultimately correcting the repercussions of externalities and poorly designed regulations. We use a transformation function production model to estimate productivity and its components for catcher–processors in the Bering Sea and Aleutian Islands pollock fishery, before and after the introduction of a cooperative system that grants exclusive harvesting privileges and allows quota exchange. We also recognize the roles of externalities from pollock harvesting by incorporating data on climate, bycatch, and fish biomass. We find that productivity has been increasing over time, that many productive contributions and interactions of climate, bycatch, and fishing strategies are statistically significant, and that regulatory changes have had both direct and indirect impacts on catch patterns and productivity.
Flexible Production in Late Industrialization: The Case of Hong Kong*
Authors: Eng Irene
Published: August 2010

Abstract: This paper examines how flexible production, as a major contributing factor to Hong Kong's economic takeoff, has been organized and transformed in the territory's industrialization process. From a three‐pronged view of flexibility that encompasses government‐firm, intrafirm, and interfirm relations, I explore how Hong Kong manufacturers tackled constraints in their regulatory environment, labor processes, and business transactions. Up to the mid‐1970s regulatory laxity, moderate trade‐off between flexible (exploitative) labor practices and productivity, and external economies involving limited mutual commitment between interdependent firms converged to form a unique edge of international competitiveness for the manufacturing sector. But changes in the socioeconomic structure subsequently weakened the conditions on which such types of flexibility were based. Manufacturers were driven to search for alternative ways of profit making, especially in the form of plant relocation to China, which represents a path‐dependent extension of the rationale of the existing flexible production system to a different social space. Four existing views on Hong Kong's economic development are examined and critiqued. Implications of major findings for the flexible specialization debate are discussed.
Remapping Los Angeles, or, Taking the Risk of Class in Postmodern Urban Theory*
Authors: Arvidson Enid
Published: August 2010

Abstract: Los Angeles is an oft‐cited example where recent political, economic, technological, and demographic changes are all seen as leading to urban restructuring, including restructuring of class relations. Shaped like an hourglass—with well‐paid white professionals and producer service workers at the top, low‐paid non‐union immigrants and consumer service workers at the bottom, and a squeezed middle—the new class structure is manifest in the city as spatial polarization, a central feature of postmodern urbanism. With this restructuring has come a decline of class‐based politics. Progressive political response ranges from a normative reassertion of class‐based politics to their abandonment in favor of “new” post‐class identities and struggles. This paper presents a middle ground between reassertion versus abandonment of class‐based politics based on a threefold rethinking of the concept of class in this literature. An alternative “mapping” is presented, using U.S. census data for Los Angeles, siting a variety of class relations (capitalist, independent, feudal, communal) as spatially ubiquitous rather than polarized across the landscape. Each of these relations is understood as one in the contradictory ensemble of class and nonclass positions people occupy, complexly conditioning their identities and struggles. The paper concludes with a discussion of class relations and struggles in two seemingly polarized urban places, Malibu and Fontana, highlighting some political implications of this alternative mapping.
The Practical Politics of Knowing: State Environmental Knowledge and Local Political Economy*
Authors: Robbins Paul
Published: August 2010

Abstract: Study of local environmental knowledge has led to a general critique of state epistemology, positing a controlling, official knowledge that crushes competing accounts of nature. Skeptical of that claim, in this paper I assess the differences between state and local knowledge empirically, using a case study of the Kumbhalgarh Wildlife Sanctuary in Rajasthan, India, to explore the way knowledge varies across class, caste, gender, and affiliation within the state forest bureaucracy. The results show that state versus local knowing is not the most meaningful division in epistemology, and that it is the daily struggle over resources in local political economy that gives rise to contending accounts of nature and environmental change. The conclusions further point to knowledge alliances between state and local actors that render certain claims powerful and so determine natural resource management policy and direct landscape change.
The Firm in Economic Geography*
Authors: Maskell Peter
Published: August 2010

Abstract: This article is concerned with the alleged absence in economic geography of a particular microtheoretical foundation that spells out precisely what makes the central actor of the subdiscipline, “the firm,” behave and perform the way it does. It especially maintains that economic geography is characterized by the lack of a clear conception and understanding of why this specific form of organizing economic activity exists and prevails in a specialized exchange economy, the factors conditioning its size and boundaries, and the endogenous mechanisms that influence its mode of external interaction. The article proposes that theories developed in neighboring fields—particularly economics—can be identified, selected, and subsequently applied within economic geography by developing a selection mechanism based on a few simple criteria.
The Temporary Staffing Industry: Growth Imperatives and Limits to Contingency*
Authors: Theodore Nik , Peck Jamie
Published: August 2010

Abstract: The temporary staffing industry (TSI) in the United States has enjoyed explosive growth since the 1970s, during which time the market for temporary labor has become increasingly complex and diverse. Rather than focus, as has typically been done, on the wider labor market effects of this sustained expansion in temporary employment, this article explores patterns and processes of industrial restructuring in the TSI itself. The analysis reveals a powerfully recursive relationship among evolving TSI business practices, the industry's strategies for building and extending the market, and urban labor market outcomes as the sector has grown through a series of qualitatively differentiated phases of development or “modes of growth.” Moreover, the distinctive character of the TSI's geographic rollout raises a new set of questions concerning, inter alia, the links between temping and labor market deregulation, the nature of local competition, the scope for and limits of value‐adding strategies, and the emerging global structure of the temp market. This idiosyncratic industry—which has been a conspicuous beneficiary of growing economic instability—has, throughout the past three decades, restructured continuously through a period of sustained but highly uneven growth. In so doing, it has proved to be remarkably inventive in extending the market for contingent labor, but has encountered a series of (possibly structural) obstacles to further expansion in its domestic market. These obstacles, in turn, have triggered an unprecedented phase of international integration in the TSI, along with a new mode of development—global growth.
Does Place Still Matter? Accounting for Income Variation Across American Indian Tribal Areas
Authors: Leichenko Robin M.
Published: August 2010

Abstract: Persistent poverty is frequently identified as a key problem on American Indian tribal lands in the United States. Yet the fact that tribal lands tend to be located in isolated, nonmetropolitan areas suggests that relatively lower levels of per capita income in tribal areas may be due largely to locational factors, such as the lack of access to markets, the absence of agglomeration economies, and an inadequate infrastructure. The study presented here explored the role of location‐specific factors and other characteristics in accounting for variation in income levels between tribal and nontribal areas and across different types of tribal areas. The results suggest that location indeed plays a significant role in accounting for variation in income across both tribal and nontribal areas, but that human capital, demographics, and structural factors also matter. In particular, college‐educated and retirement‐age shares of the population have a positive effect on income levels in all areas, while unemployment rates and shares of the population that are American Indian have a negative effect in all areas. The results further indicate that once locational, structural, and demographic factors are controlled, tribal areas do not have significantly lower levels of income than do other areas. The lower income levels found in tribal areas may thus be understood as a function of location, industrial structure, human capital, and demographics, rather than as a reflection of problems that are inherent only in tribal areas.
Trade Liberalization and the Geography of Production: Agglomeration, Concentration, and Dispersal in Indonesia's Manufacturing Industry
Authors: Sjöberg Örjan , Sjöholm Fredrik
Published: August 2010

Abstract: The effect of the liberalization of trade on the spatial concentration of economic activities is not straightforward. It has been widely argued that protectionism increases spatial concentration as firms locate close to the main domestic markets. However, it has also been argued that an expansion of international trade primarily favors existing industrial centers and therefore leads to increased regional inequalities. Against the background of ongoing debates in both mainstream economics and in geography, we examine the spatial concentration of manufacturing in Indonesia between 1980 and 1996, a period when Indonesia substantially liberalized its trade regime. The high concentration did not decrease during this period, and establishments that engaged in international trade were actually comparably concentrated. We discuss some possible explanations for the spatial concentration in Indonesia and conclude that a host of factors may affect the outcome of trade liberalizations. In particular, the spatial configuration of the national settlement system is a potentially important factor in this regard.
Regional Monopoly and Interregional and Intraregional Competition: The Parallel Trade in Coca‐Cola Between Shanghai and Hangzhou in China
Authors: Yeung Godfrey , Mok Vincent
Published: August 2010

Abstract: This article uses a “principal‐agent‐subagent” analytical framework and data that were collected from field surveys in China to (1) investigate the nature and causes of the parallel trade in Coca‐Cola between Shanghai and Hangzhou and (2) assess the geographic and theoretical implications for the regional monopolies that have been artificially created by Coca‐Cola in China. The parallel trade in Coca‐Cola is sustained by its intraregional rivalry with Pepsi‐Cola in Shanghai, where Coca‐Cola (China) (the principal) seeks to maximize its share of the Shanghai soft‐drinks market. This goal effectively supersedes the market‐division strategy of Coca‐Cola (China), since the gap in wholesale prices between the Shanghai and Hangzhou markets is higher than the transaction costs of engaging in parallel trade. The exclusive distributor of Coca‐Cola in the Shanghai market (the subagent) makes opportunistic use of a situation in which it does not have to bear the financial consequences of the major residual claimants (the principal and other agents) and has an incentive to enter the nondesignated Coca‐Cola market of Hangzhou by crossing the geographic boundary between the two regional monopolies devised by Coca‐Cola. The existence of parallel trade in Coca‐Cola promotes interregional competition between the Shanghai and Hangzhou bottlers (the agents). This article enhances an understanding of the economic geography of spatial equilibrium, disequilibrium, and quasi‐equilibrium of a transnational corporation's distribution system and its artificially created market boundary in China.
Evolution of ideal gas mixtures confined in an insulated container by two identical pistons
Authors: Amor Rumelo C. , Esguerra Jose Perico H.
Published: August 2010

We study the quasistatic adiabatic expansion of monatomic-diatomic ideal gas mixtures bounded by identical pistons and obtain closed form expressions for the temperature of the gas as a function of the time. We find that the temperature decreases as an inverse power of the time for large times, with the exponent as a function of the monatomic to diatomic gas ratio. The piston speeds increase from zero to a maximum value determined by the heat capacity of the gas and the masses of the pistons. Plots of the temperature and piston speed versus the logarithm of the time show points of inflection, which are interpreted as signaling the onset of steady state behavior. These points shift to later times as the monatomic to diatomic gas ratio is varied from purely monatomic to purely diatomic.
Do We Have the Energy for the Next Transition?
Authors: Kerr Richard A.
Published: August 2010

Past energy transitions to inherently attractive fossil fuels took half a century; moving the world to cleaner fuels could be harder and slower.
Comparison of Combined Nose-Throat Swabs with Nasopharyngeal Aspirates for Detection of Pandemic Influenza A/H1N1 2009 Virus by Real-Time Reverse Transcriptase PCR
Authors: Ortiz de la Tabla Victoria , Masiá Mar , Antequera Pedro , Martin Coral , Gazquez Gregoria , Buñuel Fernando , Gutiérrez Félix
Published: August 2010

Data assessing the diagnostic accuracies of use of different respiratory samples for the detection of the novel influenza A/H1N1 2009 virus by molecular methods are lacking. The objective of this study was to compare the sensitivity of combined nose and throat swabs (CNTS) with that of nasopharyngeal aspirates (NPA). This was a prospective study of adults and children with suspected influenza. Real-time reverse transcriptase PCR testing was used for the virological diagnosis. Of the 2,473 patients included, 264 with paired CNTS and NPA were randomly selected. Novel influenza A/H1N1 virus was identified in at least one sample for 115 (43.6%) patients, the majority of them young adults. In 109 patients (94.8%) the virus was identified in the CNTS, and in 98 (85.2%) it was identified in the NPA (
P
= 0.02). In 93 patients (80.1%), the virus was identified in both specimens. Spearman's rho correlation coefficient between the two methods was 0.82 (
P
< 0.001). There were no significant differences in accuracy between the specimens when patients were stratified according to demographic or clinical characteristics except in the case of women, in whom the sensitivity of CNTS was higher (
P
= 0.01). The combination of CNTS and NPA had a significantly higher sensitivity in identifying the virus than did each method alone (
P
= 0.02 for the comparison of the combination of both sampling methods with CNTS, and
P
< 0.001 for the comparison with NPA). We conclude that in patients with the novel influenza A/H1N1 virus, the diagnostic yield of CNTS is higher than that of NPA. The combination of both sampling methods increases the likelihood of diagnosing the virus.
Mutations in the Stalk Region of the Measles Virus Hemagglutinin Inhibit Syncytium Formation but Not Virus Entry
Authors: Ennis Matthew K. , Hu Chunling , Naik Shruthi K. , Hallak Louay K. , Peng Kah Whye , Russell Stephen J. , Dingli David
Published: August 2010

Measles virus (MV) entry requires at least 2 viral proteins, the hemagglutinin (H) and fusion (F) proteins. We describe the rescue and characterization of a measles virus with a specific mutation in the stalk region of H (I98A) that is able to bind normally to cells but infects at a lower rate than the wild type due to a reduction in fusion triggering. The mutant H protein binds to F more avidly than the parent H protein does, and the corresponding virus is more sensitive to inhibition by fusion-inhibitory peptide. We show that after binding of MV to its receptor, H-F dissociation is required for productive infection.
PB2 and Hemagglutinin Mutations Are Major Determinants of Host Range and Virulence in Mouse-Adapted Influenza A Virus
Authors: Ping Jihui , Dankar Samar K. , Forbes Nicole E. , Keleta Liya , Zhou Yan , Tyler Shaun , Brown Earl G.
Published: August 2010

Serial mouse lung passage of a human influenza A virus, A/Hong Kong/1/68 (H3N2) (HK-wt), produced a mouse-adapted variant, MA, with nine mutations that was >10
3.8
-fold more virulent. In this study, we demonstrate that MA mutations of the PB2 (D701N) and hemagglutinin (HA) (G218W in HA1 and T156N in HA2) genes were the most adaptive genetic determinants for increased growth and virulence in the mouse model. Recombinant viruses expressing each of the mutated MA genome segments on the HK-wt backbone showed significantly increased disease severity, whereas only the mouse-adapted PB2 gene increased virulence, as determined by the 50% lethal dose ([LD
50
] >10
1.4
-fold). The converse comparisons of recombinant MA viruses expressing each of the HK-wt genome segments showed the greatest decrease in virulence due to the HA gene (10
2
-fold), with lesser decreases due to the M1, NS1, NA, and PB1 genes (10
0.3
- to 10
0.8
-fold), and undetectable effects on the LD
50
for the PB2 and NP genes. The HK PB2 gene did, however, attenuate MA infection, as measured by weight loss and time to death. Replication of adaptive mutations
in vivo
and
in vitro
showed both viral gene backbone and host range effects. Minigenome transcription assays showed that PB1 and PB2 mutations increased polymerase activity and that the PB2 D701N mutation was comparable in effect to the mammalian adaptive PB2 E627K mutation. Our results demonstrate that host range and virulence are controlled by multiple genes, with major roles for mutations in PB2 and HA.
A FIVE-DIMENSIONAL TOY MODEL FOR LIGHT HADRON EXCITATIONS
Authors: AFONIN S. S.
Published: August 2010

In the usual holographic approach to QCD, the meson spectrum is generated due to a nontrivial five-dimensional background. We propose an alternative five-dimensional scenario in which the spectrum emerges due to coupling to a scalar field whose condensation is supposed to be dual to the formation of gluon condensate and mimics the scale anomaly in QCD. The spectrum of model has finite number of discrete states plus continuum and reveals a Regge-like behavior in the strong coupling regime.
PROTEIN FOLDING STAGES AND UNIVERSAL EXPONENTS
Authors: HUANG KERSON
Published: August 2010

We propose three stages in protein folding, based on physical arguements involving the interplay between the hydrophobic effect and hydrogen bonding, and computer simulations using the CSAW (conditioned self-avoiding walk) model. These stages are characterized by universal exponents ν = 3/5, 3/7, 2/5 in the power law R ~ Nν, where R is the radius of gyration and N is the number of residues. They correspond to the experimentally observed stages: unfolded, preglobule, molten globule.
A NOTE ON THE CROSSING NUMBER AND THE BRAID INDEX FOR VIRTUAL LINKS
Authors: TAKEDA YASUSHI
Published: August 2010

It is well known that any virtual link is described as the closure of a virtual braid. Therefore, we can define the virtual braid index. Ohyama proved an inequality for the crossing number and the braid index of a classical link. In this paper, we prove an analogous inequality for the (total) crossing number and the braid index of a virtual link.
AN ASSESSMENT OF STIFFENED COMPOSITE FUSELAGE PANELS BASED ON THE ROBUSTNESS PARAMETER
Authors: LEE MERRILL C. W. , MIKULIK ZOLTAN , KELLY DONALD W. , THOMSON RODNEY S.
Published: August 2010

The European Commission 6th Framework Project COCOMAT was a four-and-a-half-year project (2004 to mid-2008) aimed at exploiting the large reserve of strength in composite structures through more accurate prediction of collapse. In the experimental work packages, significant statistical variations in buckling behaviour and ultimate loading were encountered. During the experiments for the COCOMAT project, it was recognised that there was a gap in knowledge about the effect of initial defects and variations in the input variables of both the experimental and simulated panels. The effect of the defects and variations in the experimental panel resulted in some failure modes that were not predicted with the finite element modelling. This led to the development of stochastic algorithms to relate variations in boundary conditions, material properties and geometries to the variation in buckling modes and compression loads up to the first failure. This paper shows the development of a stochastic methodology to identify the impact of variation in input parameters on the response of stiffened composite panels and the development of a robust index to support the evaluation of panel designs. The stochastic analysis included the generation of metamodels that allow quantification of the impact that the inputs have on the response using two first order variables, influence and sensitivity. These variables were then used to derive the robust indices to quantify the response of two COCOMAT panels that were experimentally tested, including the response of the panels to simulated damage. The robust indices that are shown in this paper are functions of the robustness parameter which has been recommended in the final Design Guidelines for the COCOMAT project to measure the effects of scatter found in postbuckling loads.
DYNAMIC BUCKLING AND POSTBUCKLING OF A COMPOSITE SHELL
Authors: CHAMIS CHRISTOS C.
Published: August 2010

A computationally effective method for evaluating the dynamic buckling and postbuckling of thin composite shells is described. It is a judicious combination of available computer codes for finite element, composite mechanics and incremental structural analysis. The solution method is an incrementally updated Lagrangian. It is illustrated by applying it to a thin composite cylindrical shell subjected to dynamic loads. Buckling loads are evaluated to demonstrate the effectiveness of the method. A universal plot is obtained for the specific shell that can be used to approximate buckling loads for different dynamic loading rates. Results from this plot show that the faster the rate, the higher the buckling load and the shorter the time. They also show that the updated solution can be carried out in the postbuckling regime until the shell collapses completely. Comparisons with published literature indicate reasonable agreement.
REPEATED BUCKLING AND POSTBUCKLING BEHAVIOR OF LAMINATED STRINGER-STIFFENED COMPOSITE PANELS WITH AND WITHOUT DAMAGE
Authors: ABRAMOVICH HAIM , WELLER TANCHUM
Published: August 2010

Eight curved blade stringer-stiffened composite panels were tested under axial compression to obtain the "first" buckling and postbuckling behavior till collapse. Except for one panel, used as a reference panel, all of the panels had stringers without dropoff layers. Four panels contained either artificial damage or both artificial and impact-induced damage. Cyclic/repeated buckling was applied well in a relatively "deep" postbuckling region. It was demonstrated that neither repeated buckling, within the number of cycles applied in the present program, nor artificial damage and impact-induced damage, which were introduced into the panels, resulted in stiffness degradation of the panels. No premature failure of any of the tested panels was observed within their expected life cycle, i.e. exposure to a few hundred cycles deep in the postbuckling region, even in the presence of either type or a combination of the damage. All of the tested panels sustained repeated postbuckling loading till they were subjected to static loading aimed at determining their collapse loads. In spite of the present design, i.e. stiffeners with no dropoff plies aimed amongst others at providing a mechanism for initiating stiffener debonding, no skin–stringer separation was encountered till collapse of the panels. It was found that composite stringer-stiffened panels can be safely and repeatedly loaded in their deep postbuckling range with no degradation in their stiffness. Damage, due to either manufacturing or impact, which usually will result in rejection of a structural element, affected neither the load-carrying capacity nor the capability to withstand repeated loading in the relatively very deep postbuckling range within the present designed life cycle of the element. It was realized that manufacturing complexities and consequently costs can be reduced by employing a simplified design configuration where the use of a dropoff ply of the stringer base has been eliminated.
EXPLOITING SEMI-ANALYTICAL SENSITIVITIES FROM LINEAR AND NON-LINEAR FINITE ELEMENT ANALYSES FOR COMPOSITE PANEL OPTIMIZATION
Authors: BRUYNEEL M. , COLSON B. , DELSEMME J.-P. , JETTEUR P. , REMOUCHAMPS A. , GRIHON S.
Published: August 2010

This paper presents a solution procedure developed in the SAMCEF finite element code for the advanced optimal design of stiffened composite panels of an aircraft fuselage. The BOSS quattro, a task manager and optimization toolbox, is used for defining and running the optimization problem. The objective function to be minimized is the weight, and the restrictions depend on structural stability requirements, such as buckling and collapse. The design variables are the panel and stringer thicknesses of the conventional proportions (i.e. 0∘, 90∘ and ±45∘) in a homogenized laminate. Since a collapse analysis introduces geometric nonlinearities into the design process, the function evaluation can take a long time. In order to obtain a rapid optimal solution, a gradient-based method is used, and the first order derivatives need to be computed, in this case with an original semianalytical approach. The sensitivity analysis of buckling and collapse is reviewed. Numerical tests on an industrial case study demonstrate the possibility and the reliability of the approach. Solving such problems is clearly difficult and remains a challenge. Through the applications, this paper provides the opportunity to discuss convergence issues and the use of such advanced optimization techniques in the overall aircraft design process.
Visible photostability of some ruthenium and platinum phthalocyanines in water and in the presence of organic substrates
Authors: Carchesio Manuela , Tonucci Lucia , d'Alessandro Nicola , Morvillo Antonino , Boccio Piero Del , Bressan Mario
Published: August 2010

Water-soluble, metal-tetrasubstituted phthalocyanines ( -SO3H , MPcS and -COOH , MPcC) of platinum and ruthenium were synthesized and their photostability to visible light irradiation was determined. For the ruthenium phthalocyanines, the characteristic visible Q band of the phthalocyanines was almost totally suppressed after five days of irradiation. The platinum derivatives were instead more resistant to photodegradation, and the Q band did not decrease by more than 25%. The addition of carbonyl compounds to the phthalocyanine solution in water (at concentrations at least 1400-fold those of the phthalocyanines) dramatically accelerated the photobleaching of these phthalocyanine complexes. PtPcS turned from blue to green and to colorless with one day of visible-light irradiation in the presence of acetone. This effect decreased with the increase in molecular weight of the ketones (from acetone to 2-pentanone). The addition of alcohols (i.e. 1-butanol) or other organics (i.e. phenylacetic acid) did not affect the photostability of these metal-tetrasubstituted phthalocyanines. Dioxygen also had an important role, as when the solutions of phthalocyanines were carefully deaerated before irradiation, the visible spectra were preserved. The platinum phthalocyanines, as with the palladium analogs, sensitize the photoproduction of 1O2 , as shown by the formation of endoperoxide and its rearranged products in the presence of furfuryl alcohol (a singlet oxygen trapping agent).
Azo-linked corner porphyrin systems: synthesis, crystal structures and spectroscopic investigation
Authors: Bašić Bruno , McMurtrie John C. , Arnold Dennis P.
Published: August 2010

1,2-bis[10,15-di(3,5-di-tert-butyl)phenylporphyrinatonickel(II)-5-yl]diazene was synthesised via copper-catalyzed coupling of aminated nickel(II) 5,10-diarylporphyrin ("corner porphyrin") and its X-ray crystal structure was determined. Two different crystals yielded different structures, one with the free meso-positions in a trans-like orientation, and the other with a cis-like disposition. The free meso-positions of the obtained dimer have been further functionalized while the synthesis of a zinc analog has so far been unsuccessful. The X-ray crystal structure of the dinitro derivative of the dinickel(II) azoporphyrin was determined, and the structure showed a cis-like disposition of the nitro groups.
Ionic mechanisms of electrophysiological heterogeneity and conduction block in the infarct border zone
Authors: Decker Keith F. , Rudy Yoram
Published: August 2010

The increased incidence of arrhythmia in the healing phase after infarction has been linked to remodeling in the epicardial border zone (EBZ). Ionic models of normal zone (NZ) and EBZ myocytes were incorporated into one-dimensional models of propagation to gain mechanistic insights into how ion channel remodeling affects action potential (AP) duration (APD) and refractoriness, vulnerability to conduction block, and conduction safety postinfarction. We found that EBZ tissue exhibited abnormal APD restitution. The remodeled Na+ current ( INa) and L-type Ca2+ current ( ICa,L) promoted increased effective refractory period and prolonged APD at a short diastolic interval. While postrepolarization refractoriness due to remodeled EBZ INa was the primary determinant of the vulnerable window for conduction block at the NZ-to-EBZ transition in response to premature S2 stimuli, altered EBZ restitution also promoted APD dispersion and increased the vulnerable window at fast S1 pacing rates. Abnormal EBZ APD restitution and refractoriness also led to abnormal periodic conduction block patterns for a range of fast S1 pacing rates. In addition, we found that INa remodeling decreased conduction safety in the EBZ but that inward rectifier K+ current remodeling partially offset this decrease. EBZ conduction was characterized by a weakened AP upstroke and short intercellular delays, which prevented ICa,L and transient outward K+ current remodeling from playing a role in EBZ conduction in uncoupled tissue. Simulations of a skeletal muscle Na+ channel SkM1- INa injection into the EBZ suggested that this recently proposed antiarrhythmic therapy has several desirable effects, including normalization of EBZ effective refractory period and APD restitution, elimination of vulnerability to conduction block, and normalization of conduction in tissue with reduced intercellular coupling.
Level-Dependent Latency Shifts Quantified Through Binaural Processing
Authors: Siveke Ida , Leibold Christian , Kaiser Katharina , Grothe Benedikt , Wiegrebe Lutz
Published: August 2010

The mammalian binaural system compares the timing of monaural inputs with microsecond precision. This temporal precision is required for localizing sounds in azimuth. However, temporal features of the monaural inputs, in particular their latencies, highly depend on the overall sound level. In a combined psychophysical, electrophysiological, and modeling approach, we investigate how level-dependent latency shifts of the monaural responses are reflected in the perception and neural representation of interaural time differences. We exploit the sensitivity of the binaural system to the timing of high-frequency stimuli with binaurally incongruent envelopes. Using these novel stimuli, both the perceptually adjusted interaural time differences and the time differences extracted from electrophysiological recordings systematically depend on overall sound pressure level. The perceptual and electrophysiological time differences of the envelopes can be explained in an existing model of temporal integration only if a level-dependent firing threshold is added. Such an adjustment of firing threshold provides a temporally accurate neural code of the temporal structure of a stimulus and its binaural disparities independent of overall sound level.
Feasibility of Bariatric Surgery as a Strategy for Secondary Prevention in Cardiovascular Disease: A Report from the Swedish Obese Subjects Trial
Authors: Delling Lotta , Karason Kristjan , Olbers Torsten , Sjöström David , Wahlstrand Björn , Carlsson Björn , Carlsson Lena , Narbro Kristina , Karlsson Jan , Behre Carl Johan , Sjöström Lars , Stenlöf Kaj
Published: August 2010

Aims. Evaluation of bariatric surgery as secondary prevention in obese patients with ischemic heart disease (IHD).Methods. Analysis of data from 4047 subjects in the Swedish Obese Subjects (SOSs) study. Thirty-five patients with IHD are treated with bariatric surgery () or conventional treatment (). Mean follow-up is 10.8 years.Results. Bariatric surgery resulted in sustained weight loss during the study period. After 2 years, the surgery group displayed significant reductions in cardiovascular risk factors, relief from cardiorespiratory symptoms, increments in physical activity, and improved quality of life. After 10 years, recovery from hypertension, diabetes, physical inactivity, and depression was still more common in the surgery group. There were no signs of increased cardiovascular morbidity or mortality in the surgery group.Conclusion. Bariatric surgery appears to be a safe and feasible treatment to achieve long-term weight loss and improvement in cardiovascular risk factors, symptoms, and quality of life in obese subjects with IHD.
Isolated Abdominal Wall Actinomycosis Associated with an Intrauterine Contraceptive Device: A Case Report and Review of the Relevant Literature
Authors: Carkman Sinan , Ozben Volkan , Durak Haydar , Karabulut Kagan , Ipek Turgut
Published: August 2010

Isolated abdominal wall actinomycosis in the presence of an intrauterine contraceptive device (IUCD) is extremely rare and only six such cases have been reported in the literature. We report a case where clinical and radiological examinations revealed a pseudotumor within the anterior abdominal wall. After being lost to follow-up, the patient presented two years later with the enlargement of the mass. The mass including the affected anterior abdominal wall was completely excised. The diagnosis of actinomycosis was established postoperatively by histopathological examination. Further questioning concerning her gynecological history revealed long-term use of the same IUCD. Surgical excision of the actinomycotic pseudotumour and removal of the IUCD followed by antibiotic therapy resulted in the full recovery of the patient.
Targeting Eukaryotic Translation Initiation Factor 4E (eIF4E) in Cancer
Authors: Hsieh Andrew C. , Ruggero Davide
Published: August 2010

Recent advances in understanding the role of eukaryotic translation initiator factor 4E (eIF4E) in tumorigenesis and cancer progression have generated significant interest in therapeutic agents that indirectly or directly target aberrant activation of eIF4E in cancer. Here, we address the general function of eIF4E in translation initiation and cancer, present evidence supporting its role in cancer initiation and progression, and highlight emerging therapeutics that efficiently target hyperactivated eIF4E. In doing so, we also highlight the major differences between these therapeutics that may influence their mechanism of action. Clin Cancer Res; 16(20); 4914–20. ©2010 AACR.
Regional and Temporal Profiles of Calpain and Caspase-3 Activities in Postnatal Rat Brain following Repeated Propofol Administration
Authors: Milanovic Desanka , Popic Jelena , Pesic Vesna , Loncarevic-Vasiljkovic Natasa , Kanazir Selma , Jevtovic-Todorovic Vesna , Ruzdijic Sabera
Published: August 2010

Exposure of newborn rats to a variety of anesthetics has been shown to induce apoptotic neurodegeneration in the developing brain. We investigated the effect of the general anesthetic propofol on the brain of 7-day-old (P7) Wistar rats during the peak of synaptic growth. Caspase and calpain protease families most likely participate in neuronal cell death. Our objective was to examine regional and temporal patterns of caspase-3 and calpain activity following repeated propofol administration (20 mg/kg). P7 rats were exposed for 2, 4 or 6 h to propofol and killed 0, 4, 16 and 24 h after exposure. Relative caspase-3 and calpain activities were estimated by Western blot analysis of the proteolytic cleavage products of α-II-spectrin, protein kinase C and poly(ADP-ribose) polymerase 1. Caspase-3 activity and expression displayed a biphasic pattern of activation. Calpain activity changed in a region- and time-specific manner that was distinct from that observed for caspase-3. The time profile of calpain activity exhibited substrate specificity. Fluoro-Jade B staining revealed an immediate neurodegenerative response that was in direct relationship to the duration of anesthesia in the cortex and inversely related to the duration of anesthesia in the thalamus. At later post-treatment intervals, dead neurons were detected only in the thalamus 24 h following the 6-hour propofol exposure. Strong caspase-3 expression that was detected at 24 h was not followed by cell death after 2- and 4-hour exposures to propofol. These results revealed complex patterns of caspase-3 and calpain activities following prolonged propofol anesthesia and suggest that both are a manifestation of propofol neurotoxicity at a critical developmental stage.
High-Density Lipoproteins Suppress Chemokines and Chemokine Receptors In Vitro and In Vivo
Authors: Bursill Christina A. , Castro Maria L. , Beattie Douglas T. , Nakhla Shirley , van der Vorst Emiel , Heather Alison K. , Barter Philip J. , Rye Kerry-Anne
Published: August 2010

Objective—

To investigate whether high-density lipoproteins (HDLs) suppress chemokine (CCL2, CCL5, and CX
3
CL1) and chemokine receptor (CCR2 and CX
3
CR1) expression, a mechanism for the atheroprotective properties of HDLs.

Methods and Results—

Apolipoprotein (apo) E
−/−
mice were fed a high-fat diet for 12 weeks. Before being euthanized, the mice received 5 consecutive daily injections of lipid-free apoA-I, 40 mg/kg, or saline (control). The injection of apoA-I reduced CCR2 and CX
3
CR1 expression in plaques compared with controls (
P
<0.05). ApoA-I–injected mice had lower plasma CCL2 and CCL5 levels. Hepatic CCL2, CCL5, and CX
3
CL1 levels were also reduced (
P
<0.05). In vitro studies found that reconstituted HDL (rHDL) reduced monocyte CCR2 and CX
3
CR1 expression and inhibited their migration toward CCL2 and CX
3
CL1 (
P
<0.05). Preincubation with rHDL reduced CCL2, CCL5, and CX
3
CL1 expression in monocytes and human coronary artery endothelial cells. The stimulation of CX
3
CR1 with peroxisome proliferator–activated receptor γ agonist CAY10410 was suppressed by preincubation with rHDL but did not affect the peroxisome proliferator–activated receptor γ antagonist (GW9664)–mediated increase in CCR2. In monocytes and human coronary artery endothelial cells, rHDL reduced the expression of the nuclear p65 subunit, IκB kinase activity, and the phosphorylation of IκBα (
P
<0.05).

Conclusion—

Lipid-free apoA-I and rHDL reduce the expression of chemokines and chemokine receptors in vivo and in vitro via modulation of nuclear factor κB and peroxisome proliferator–activated receptor γ.
Employer Characteristics and Discharge-Related Discrimination Against People With Disabilities Under the Americans With Disabilities Act
Authors: Rumrill Philip D. , Fitzgerald Shawn M.
Published: August 2010

This article describes findings from a causal comparative study of the characteristics of employers against whom allegations of discrimination related to unlawful discharge were filed with the U.S. Equal Employment Opportunity Commission (EEOC). People with disabilities filed these allegations under Title I of the Americans with Disabilities Act (ADA) between 1992 and 2008. Employer characteristics derived from 140,581 closed discharge-related allegations were compared to and contrasted with 165,447 closed allegations aggregated from four other prevalent forms of discrimination including reasonable accommodations, hiring, disability harassment and intimidation, and terms and conditions of employment. Tests of Proportion were used to examine comparisons of employer characteristics along a variety of factors, including size of workforce, location, and industrial classification. As compared to nondischarge allegations, discharge allegations were more likely to be filed against employers (a) with 15 to 200 employees; (b) in the South U.S. Census Tract Region; and (c) in the Manufacturing, Health Care and Social Assistance, Retail, Administrative Support, Waste Management and Remediation, Finance and Insurance, Professional/Scientific/Technical, Accommodation and Food Service, Wholesale, Construction, Real Estate, and Agriculture/Forestry/Fishing/ Hunting industries. Additional research is needed to specify the mechanisms by which different employer characteristics influence patterns in allegations of discrimination pertaining to discharge, and human resource management (HRM) and human resource development (HRD) practices regarding ADA responsibilities must be developed with the aforementioned characteristics in mind.