bluuebunny/crossref_metadata_2025 huggingface dataset:
Associations between tissue fatty acid composition and physiological traits of performance and metabolism in the seabass (Dicentrarchus labrax)
Authors: Chatelier A. , McKenzie D. J. , Prinet A. , Galois R. , Robin J. , Zambonino J. , Claireaux G.
Published: August 2006

Seabass were fed for 4 months with diets where the lipid was provided as either canola oil (CO), palm oil (PO) or fish oil (FO), to generate diversity in their tissue fatty acid (FA) composition and investigate how this influenced major traits of exercise performance, cardiac performance and respiratory metabolism. In particular, based upon previous observations, we investigated the hypothesis that enriching the fish tissues with oleic and linoleic acids (OA, 18:1n-9 and LA, 18:2n-6, respectively) from the CO and PO diets would improve maximum exercise and cardiac performance, and increase aerobic metabolic scope. This proved to be the case; exercise respirometry on bass fitted with cardiac flow probes revealed that those fed CO and PO diets had a significantly higher critical swimming speed (Ucrit)than those fed the FO diet. The improved swimming performance in the CO and PO groups was accompanied by a higher maximum cardiac output(Q̇) and net cardiac scope, and a higher active metabolic rate (AMR) and aerobic scope (AS) than in the FO group. Analysis of tissue FA composition revealed that the fish fed the CO and PO diets had accumulated significantly higher levels of OA and LA in their heart and muscle than the fish from the FO group, which had significantly higher levels of highly unsaturated FA of the n-3 series, such as EPA and DHA(20:5n-3 and 22:6n-3, respectively). Principal components analysis revealed significant positive associations between tissue OA and LA content and Ucrit, maximum Q, the increase in Q during exercise, AMR and aerobic scope. There was a negative association between these physiological traits and tissue content of EPA. Therefore, diet composition is an environmental factor that can generate significant phenotypic diversity in major physiological traits of performance and metabolism in the seabass, with increased intake of FAs such as OA and LA leading to improved cardiorespiratory performance.
Seed husking time and maximal bite force in finches
Authors: van der Meij M. A. A. , Bout R. G.
Published: August 2006

Many studies on the efficiency of feeding in finches concentrate on husking time in relation to average seed size and bird size. Large species are capable of eating larger seeds and are able to husk large seeds faster than smaller species. It is generally assumed that husking time is related to bite force. However, there are very few studies that investigate the relationship between husking time, seed hardness and bite force directly.

In our experiments we measured the seed husking time and the maximal bite force of two taxa of seed cracking birds. Husking time is related to maximal bite force in a highly non-linear way and differs between estrildids and fringillids. Fringillids with the same bite force as estrildids take less time to crack seeds, but only when the strength of the seed coat is close to their maximal bite force. For seeds that are relatively soft the difference in husking time becomes very small. A preliminary jaw motion analysis provides evidence that this difference in husking time between estrildids and fringillids is paralleled by a difference in husking technique. This difference in technique does not affect bite force as such, but decreases the chance of failed cracking attempts.

The selective advantage of a small increase in maximal bite force may be related more to the decrease in husking time for seeds with hardness below the maximal bite force, than to the increase in range of seed hardness that the bird is able to crack.
Becoming airborne without legs: the kinematics of take-off in a flying snake,Chrysopelea paradisi
Authors: Socha John J.
Published: August 2006

Among terrestrial vertebrate gliders, take-off presents a unique problem to flying snakes (Chrysopelea). Without legs, snakes must use fundamentally different kinematics to begin their aerial trajectories. To determine the effectiveness of different modes of take-off in a gliding snake(C. paradisi), I videotaped multiple views of take-off from a horizontal branch and quantified the two- and three-dimensional coordinates of three points on the snake's body. Performance values derived from these coordinates were used to describe take-off in C. paradisi, compare modes of take-off, and make predictions about the ecological use of take-off in the wild. Four types of take-off were identified. In most observed take-offs, snakes used a vertically looped take-off (termed `anchored J-loop'and `sliding J-loop'), which represent the only true jumping in snakes. In an anchored J-loop take-off, the snake formed an anterior hanging loop and then jumped by holding the posterior body static on the branch and accelerating up and away from the branch. This was the most commonly used take-off mode. A sliding J-loop take-off was similar but occurred with the entire body in motion. Snakes using such take-offs lowered less of their body below the branch than in an anchored J-loop take-off, resulting in shorter preparation and vertical acceleration durations and producing a lower maximum vertical velocity. However, these differences did not produce significant differences after the snakes were fully airborne and had started their aerial trajectories. The non-looped take-offs (termed `dive' and `fall') were the least kinematically complex. Compared to the non-looped take-offs, looped take-offs allowed snakes to reach higher, range farther, and attain greater speeds. Futhermore, snakes that launched with looped take-offs traveled farther over the course of a full glide trajectory when starting from a 10 m high perch. Take-off in C. paradisi is qualitatively similar to that in other species of Chrysopelea and may represent a suite of behaviors that preceded the evolution of gliding flight in snakes.
`Binaural echo disparity' as a potential indicator of object orientation and cue for object recognition in echolocating nectar-feeding bats
Authors: Holderied Marc W. , von Helversen Otto
Published: August 2006

Echolocating bats emit ultrasonic calls through their mouth or their nostrils and receive echoes from objects with both their ears. Information conveyed in the echoes is the basis for their three-dimensional acoustic perception of the surroundings. The direction of an object is encoded in binaural echo differences, i.e. on the one hand in the different arrival times of its echo at the two ears, and on the other hand in spectral differences through direction-dependent frequency filtering of head and pinnae. Insufficient attention has been paid, however, to the fact that three-dimensional objects produce structured spatial echo fields, and that the position of the ear in this field determines the echo it receives. We were interested to determine whether the two ears, in addition to direction-specific echo differences, receive object-specific echo disparities that might be useful for the bat. Our measurements with an artificial bat head, which consisted of two microphones and a small ultrasound loudspeaker arranged to resemble a bat's ears and mouth, revealed that echoes at the two ears differed largely depending on the shape and orientation of the echo-giving object. Binaural echo disparities of a bat-pollinated flower did indeed carry information about the orientation and, to a lesser extent, the shape of the flower. During flower approach such object-specific binaural echo disparities even exceed the binaural differences encoding direction of echo incidence, because the echo from the flower in front undergoes the same directional filtering by the two symmetrical ears. Nectar-feeding bats could use these object-specific binaural echo disparities not only to determine the object's orientation relative to the approaching bat, facilitating flight planning, but also to improve object recognition through spatial reconstruction of details of the object creating the echo. Our results suggest that the evaluation of binaural echo disparity has a greater importance for these tasks than has previously been assumed.
Water balance of field-excavated aestivating Australian desert frogs, the cocoon-formingNeobatrachus aquiloniusand the non-cocooningNotaden nichollsi(Amphibia: Myobatrachidae)
Authors: Cartledge Victoria A. , Withers Philip C. , McMaster Kellie A. , Thompson Graham G. , Bradshaw S. Don
Published: August 2006

Burrowed aestivating frogs of the cocoon-forming species Neobatrachus aquilonius and the non-cocooning species Notaden nichollsi were excavated in the Gibson Desert of central Australia. Their hydration state(osmotic pressure of the plasma and urine) was compared to the moisture content and water potential of the surrounding soil. The non-cocooning N. nichollsi was consistently found in sand dunes. While this sand had favourable water potential properties for buried frogs, the considerable spatial and temporal variation in sand moisture meant that frogs were not always in positive water balance with respect to the surrounding soil. The cocoon-forming N. aquilonius was excavated from two distinct habitat types, a claypan in which frogs had a well-formed cocoon and a dune swale where frogs did not have a cocoon. Cocoons of excavated frogs ranged in thickness from 19.4 μm to 55.61 μm and consisted of 81-229 layers. Cocooned claypan N. aquilonius were nearing exhaustion of their bladder water reserves and had a urine osmolality approaching that of the plasma. By contrast, non-cocooned N. aquilonius from the dune swale were fully hydrated, although soil moisture levels were not as high as calculated to be necessary to maintain water balance. Both species had similar plasma arginine vasotocin (AVT) concentrations ranging from 9.4 to 164 pg ml-1, except for one cocooned N. aquilonius with a higher concentration of 394 pg ml-1. For both species, AVT showed no relationship with plasma osmolality over the lower range of plasma osmolalities but was appreciably increased at the highest osmolality recorded. This study provides the first evidence that cocoon formation following burrowing is not obligatory in species that are capable of doing so, but that cocoon formation occurs when soil water conditions are more desiccating than for non-cocooned frogs.
Selection for desiccation resistance in adultDrosophila melanogasteraffects larval development and metabolite accumulation
Authors: Gefen Eran , Marlon Anthony J. , Gibbs Allen G.
Published: August 2006

We studied larval development and acquisition of metabolic resources in Drosophila melanogaster selected for adult desiccation resistance. Desiccation-selected (D) flies had longer developmental times in comparison with control populations, resulting in significantly higher body mass. No differences were found in larval growth rates, suggesting that increased body mass results from the extended larval feeding period. Larvae from both D and control lines molted from second to third instar 81-84 h after egg laying,whereas D larvae pupated 5-6 h later than controls. This indicates that selecting adults for desiccation resistance results in longer third larval instar. Newly eclosed D flies had higher carbohydrate and water contents in comparison with control populations. No differences were found in body mass,water or metabolite contents of newly eclosed selected and control flies after larvae were prevented from further feeding from 96 h after egg laying onwards. This shows that differences in accumulated carbohydrate and water stores are a result of evolved differences in the duration of third larval instar. The contribution of third instar feeding to desiccation resistance of adult selected flies is higher than that of controls. Thus, selection for adult stress resistance has resulted in correlated changes in larval physiology.
Development of swimming behaviour in the larva of the ascidianCiona intestinalis
Authors: Zega Giuliana , Thorndyke Michael C. , Brown Euan R.
Published: August 2006

The aim of this study was to characterize the swimming behaviour of C. intestinalis larvae during the first 6 h after hatching by measuring tail muscle field potentials. This recording method allowed a quantitative description of the responses of the larva under light and dark conditions. Three different larval movements were distinguished by their specific frequencies: tail flicks, `spontaneous' swimming, and shadow response, or dark induced activity, with respective mean frequencies of about 10, 22 and 32 Hz. The shadow response develops at about 1.5 h post hatching (h.p.h.). The frequency of muscle potentials associated with this behaviour became higher than those of spontaneous swimming activity, shifting from 20 to 30 Hz, but only from about 2 h.p.h. onwards. Swimming rate was influenced positively for about 25 s after the beginning of the shadow response. Comparison of swimming activity at three different larval ages (0-2, 2-4 and 4-6 h.p.h.) showed that Ciona larvae swim for longer periods and more frequently during the first hours after hatching. Our results provide a starting point for future studies that aim to characterize the nervous control of ascidian locomotion,in wild-type or mutant larvae.
Mediterranean Forecasting System: An improved assimilation scheme for sea‐level anomaly and its validation
Authors: Dobricic S. , Pinardi N. , Adani M. , Bonazzi A. , Fratianni C. , Tonani M.
Published: August 2006

The assimilation of satellite and in situ data in the Mediterranean Forecast System (MFS) is based on an optimal interpolation scheme which uses empirical orthogonal functions (EOFs) to represent vertical modes of the background‐error correlation matrix. In this study we present a new methodology to estimate, and the calculation of, these multivariate EOFs. The new EOFs are considered time and space varying (seasonal time‐scales and subregional). They examine the vertical‐error cross‐variance between temperature, salinity, barotropic stream function and sea‐level anomaly. These EOFs are used to assimilate four years of along‐track sea‐level anomaly data. The validation of MFS analyses and forecasts using the assimilation system diagnostics and the comparison with independent observations show that, in relation to an old operational scheme which was using only one EOF, the use of several multivariate EOFs significantly improves the accuracy of analyses and forecasts in the Mediterranean. Copyright © 2005 Royal Meteorological Society
Diagnosis of observation, background and analysis‐error statistics in observation space
Authors: Desroziers G. , Berre L. , Chapnik B. , Poli P.
Published: August 2006

Most operational assimilation schemes rely on linear estimation theory. Under this assumption, it is shown how simple consistency diagnostics can be obtained for the covariances of observation, background and estimation errors in observation space. Those diagnostics are shown to be nearly cost‐free since they only combine quantities available after the analysis, i.e. observed values and their background and analysis counterparts in observation space. A first application of such diagnostics is presented on analyses provided by the French 4D‐Var assimilation. A procedure to refine background and observation‐error variances is also proposed and tested in a simple toy analysis problem. The possibility to diagnose cross‐correlations between observation errors is also investigated in this same simple framework. A spectral interpretation of the diagnosed covariances is finally presented, which allows us to highlight the role of the scale separation between background and observation errors. Copyright © 2005 Royal Meteorological Society
Issues in targeted observing
Authors: Langland Rolf H.
Published: August 2006

This paper summarizes successes and limitations of targeted observing field programmes starting from the Fronts and Atlantic Storm‐Track Experiment in 1997 through recent programmes targeting winter storms and tropical cyclones. These field programmes have produced average reductions in short‐range forecast errors of about 10 per cent over regional verification areas, and maximum forecast error reductions as large as 50 per cent in certain cases. The majority of targeting cases investigated so far involve sets of dropsondes and other observation data that provide partial coverage of target areas. The primary scientific challenges for targeting include the refinement of objective methods that can identify optimal times and locations for targeted observations, as well as identify the specific types of satellite and in situ measurements that are required for the improvement of numerical weather forecasts. The most advanced targeting procedures, at present, include: the ensemble transform Kalman Filter, Hessian singular vectors, and observation‐space targeting using the adjoint of a variational data assimilation procedure. Targeted observing remains an active research topic in numerical weather prediction, with plans for continued refinement of objective targeting procedures, and field tests of new satellite and in situ observing systems. Copyright © 2005 Royal Meteorological Society
Bias and data assimilation
Authors: Dee D. P.
Published: August 2006

All data assimilation systems are affected by biases, caused by problems with the data, by approximations in the observation operators used to simulate the data, by limitations of the assimilating model, or by the assimilation methodology itself. A clear symptom of bias in the assimilation is the presence of systematic features in the analysis increments, such as large persistent mean values or regularly recurring spatial structures. Bias can also be detected by monitoring statistics of observed‐minus‐background residuals for different instruments. Bias‐aware assimilation methods are designed to estimate and correct systematic errors jointly with the model state variables. Such methods require attribution of a bias to a particular source, and its characterization in terms of some well‐defined set of parameters. They can be formulated either in a variational or sequential estimation framework by augmenting the system state with the bias parameters. Copyright © 2005 Royal Meteorological Society
Data assimilation for marine monitoring and prediction: The MERCATOR operational assimilation systems and the MERSEA developments
Authors: Brasseur P. , Bahurel P. , Bertino L. , Birol F. , Brankart J.‐M. , Ferry N. , Losa S. , Remy E. , Schröter J. , Skachko S. , Testut C.‐E. , Tranchant B. , Van Leeuwen P. J. , Verron J.
Published: August 2006

During the past 15 years, a number of initiatives have been undertaken at national level to develop ocean forecasting systems operating at regional and/or global scales. The co‐ordination between these efforts has been organized internationally through the Global Ocean Data Assimilation Experiment (GODAE). The French MERCATOR project is one of the leading participants in GODAE. The MERCATOR systems routinely assimilate a variety of observations such as multi‐satellite altimeter data, sea‐surface temperature and in situ temperature and salinity profiles, focusing on high‐resolution scales of the ocean dynamics.

The assimilation strategy in MERCATOR is based on a hierarchy of methods of increasing sophistication including optimal interpolation, Kalman filtering and variational methods, which are progressively deployed through the Système d'Assimilation MERCATOR (SAM) series. SAM‐1 is based on a reduced‐order optimal interpolation which can be operated using ‘altimetry‐only’ or ‘multi‐data’ set‐ups; it relies on the concept of separability, assuming that the correlations can be separated into a product of horizontal and vertical contributions. The second release, SAM‐2, is being developed to include new features from the singular evolutive extended Kalman (SEEK) filter, such as three‐dimensional, multivariate error modes and adaptivity schemes. The third one, SAM‐3, considers variational methods such as the incremental four‐dimensional variational algorithm.

Most operational forecasting systems evaluated during GODAE are based on least‐squares statistical estimation assuming Gaussian errors. In the framework of the EU MERSEA (Marine EnviRonment and Security for the European Area) project, research is being conducted to prepare the next‐generation operational ocean monitoring and forecasting systems. The research effort will explore nonlinear assimilation formulations to overcome limitations of the current systems. This paper provides an overview of the developments conducted in MERSEA with the SEEK filter, the Ensemble Kalman filter and the sequential importance re‐sampling filter. Copyright © 2005 Royal Meteorological Society
The transformation of earth‐system observations into information of socio‐economic value in GEOSS
Authors: Hollingsworth Anthony , Uppala Sakari , Klinker Ernst , Burridge David , Vitart Frederic , Onvlee Jeanette , Vries J. W. De , Roo Ad De , Pfrang Christian
Published: August 2006

The Group on Earth Observations System of Systems, GEOSS, is a co‐ordinated initiative by many nations to address the needs for earth‐system information expressed by the 2002 World Summit on Sustainable Development. We discuss the role of earth‐system modelling and data assimilation in transforming earth‐system observations into the predictive and status‐assessment products required by GEOSS, across many areas of socio‐economic interest. First we review recent gains in the predictive skill of operational global earth‐system models, on time‐scales of days to several seasons. We then discuss recent work to develop from the global predictions a diverse set of end‐user applications which can meet GEOSS requirements for information of socio‐economic benefit; examples include forecasts of coastal storm surges, floods in large river basins, seasonal crop yield forecasts and seasonal lead‐time alerts for malaria epidemics. We note ongoing efforts to extend operational earth‐system modelling and assimilation capabilities to atmospheric composition, in support of improved services for air‐quality forecasts and for treaty assessment. We next sketch likely GEOSS observational requirements in the coming decades. In concluding, we reflect on the cost of earth observations relative to the modest cost of transforming the observations into information of socio‐economic value. Copyright © 2005 Royal Meteorological Society
Stochastic modelling of model errors: a simulation study
Authors: Tsyrulnikov M. D.
Published: August 2006

In the setting with known ‘truth’, the spatio‐temporal structure of forecast‐model (tendency) errors is studied. The shallow‐water model is used as the ‘truth’ and the vorticity equation as a forecast model. It is found that state‐dependent model errors (MEs) are of primary importance. The residual state‐independent (stochastic) part of MEs can be modelled with the advection‐diffusion equation driven by the white noise. The ME effective advection velocity appears to be very different from the wind and resembles the Rossby‐wave phase velocity. Three versions of increasing complexity for the advection and diffusion operators are proposed. Ensemble‐based adequacy checks of the proposed ME model are presented. Sensitivity of the ensemble forecast‐error spatial and temporal structure to various aspects of the ME model used to create the ensemble is investigated. Copyright © 2005 Royal Meteorological Society
Why does 4D‐Var beat 3D‐Var?
Authors: Lorenc Andrew C. , Rawlins F.
Published: August 2006

A set of four experiments is described which measure the expected beneficial aspects of incremental four‐dimensional variational (4D‐Var) compared to 3D‐Var data assimilation systems: allowing for the time of each observation in the full and increment fields with which it is compared, and using time‐evolved covariances. Judging each scheme by the overall accuracy of resulting numerical weather prediction forecasts compared to observations, each aspect is shown to provide benefit.

On other measures of analysis quality, such as the fit of short‐period forecasts and analyses to observations, the benefits of 4D‐Var are less clear; it is sometimes worse. Perhaps 4D‐Var is improving the analysis of growing modes, which are more important for forecasts, without improving all aspects of the analysis.

Our basic 4D‐Var was not provided with many observations distributed in time, and had very simple parametrizations. There is an expectation of enhanced benefits as these aspects are developed. Copyright © 2005 Royal Meteorological Society
The impact of ensemble filter definition on the assimilation of temperature profiles in the tropical Pacific
Authors: Leeuwenburgh O. , Evensen G. , Bertino L.
Published: August 2006

The traditional analysis scheme in the Ensemble Kalman Filter (EnKF) uses a stochastic perturbation or randomization of the measurements which ensures a correct variance in the updated ensemble. An alternative so‐called deterministic analysis algorithm is based on a square‐root formulation where the perturbation of measurements is avoided. Experiments with simple models have indicated that ensemble collapse is likely to occur when deterministic filters are applied to nonlinear problems. In this paper the properties of stochastic and deterministic ensemble analysis algorithms are evaluated in an identical‐twin experiment using an ocean general‐circulation model. In particular, the implications of the use of deterministic Ensemble Square‐Root Filters (EnSRF) for ensemble distribution are investigated. An explanation is presented for the observed collapse, and a simple solution based on randomization of the analysis ensemble anomalies is examined. A one‐year assimilation run with this improved EnSRF is found to produce Gaussian distributions, similar to the EnKF. Copyright © 2005 Royal Meteorological Society
Ionospheric nowcasting via assimilation of GPS measurements of ionospheric electron content in a global physics‐based time‐dependent model
Authors: Khattatov B. , Murphy M. , Gnedin M. , Sheffel J. , Adams J. , Cruickshank B. , Yudin V. , Fuller‐rowell T. , Retterer J.
Published: August 2006

We present the rationale for having accurate nowcast and forecast ionospheric conditions, and a brief overview of recent work on assimilation of ionospheric measurements in physics‐based models. This manuscript describes the results of a project aimed at generating accurate operational specifications of ionospheric electron content by the assimilation of Global Positioning System (GPS) ionospheric measurements in a relatively complex first‐principles forecast model. We describe: the overall design of the model, the implemented sequential data assimilation scheme, the specifics of GPS data processing, and the on‐line scheme for estimation of instrumental biases inherent in GPS measurements of ionospheric electron content. Performance of the designed ionospheric specification system is illustrated via common statistical tests, comparisons with data withheld from the assimilation process and comparisons with independent non‐GPS measurements. Web‐based access to the system results is provided athttp://fusionnumerics.com/ionosphere. Copyright © 2005 Royal Meteorological Society
The Economics of HIV/AIDS in Low-Income Countries: The Case for Prevention
Authors: Canning David
Published: August 2006

There are two approaches to reducing the burden of sickness and death associated with the human immunodeficiency virus (HIV), which leads to acquired immunodeficiency syndrome (AIDS): treatment and prevention. Despite large international aid flows for HIV/AIDS, the needs for prevention and treatment in low- and middle-income countries outstrip the resources available. Thus, it becomes necessary to set priorities. With limited resources, should the focus of efforts to combat HIV/AIDS be on prevention or treatment? I discuss the range of prevention and treatment alternatives and examine their cost effectiveness. I consider various arguments that have been raised against the use of cost-effectiveness analysis in setting public policy priorities for the response to HIV/AIDS in developing countries. I conclude that promoting AIDS treatment using antiretrovirals in resource-constrained countries comes at a huge cost in terms of avoidable deaths that could be prevented through interventions that would substantially lower the scale of the epidemic.
An Economic Evaluation of the Moneyball Hypothesis
Authors: Hakes Jahn K , Sauer Raymond D
Published: August 2006

Michael Lewis's book, Moneyball, describes how an innovative manager working for the Oakland Athletics successfully exploited an inefficiency in baseball's labor market over a prolonged period of time. We evaluate Lewis's claims by applying standard econometric procedures to data on player productivity and compensation from 1999 to 2004. These methods support Lewis's argument that certain baseball skills were valued inefficiently in the early part of this period, and that this inefficiency was profitably exploited by managers with the ability to generate and interpret statistical knowledge. Consistent with Lewis's story and economic reasoning, as knowledge of the inefficiency became increasingly dispersed across baseball teams the market corrected the original mispricing.
Retrospectives: The Coining of “Privatization” and Germany's National Socialist Party
Authors: Bel Germà
Published: August 2006

The concept of privatization attracted much attention in the late 1970s and early 1980s, as Margaret Thatcher's privatization policies were implemented in the United Kingdom. My goal here is not to comment on the merits of privatization as a policy, but rather to investigate the history of the term “privatization” in economics and to shed some light on the context in which the word was coined. Although the origin of the term is often attributed to a 1969 book by Peter Drucker, I will show that this attribution is incorrect, and that the terminology of privatization played an evolving role in German economic policy from the 1930s through the 1950s.
Markets: Continuity and Change in the International Diamond Market
Authors: Spar Debora L
Published: August 2006

The international diamond cartel, which presides over the production side of the industry, may be the most successful and longest-lasting cartel in the world. The dominant company in the industry, DeBeers, has been around since 1880 and has been controlled by a single South African family, the Oppenheimers, since 1925. Eight countries produce the bulk of the world's gem diamonds, and most of the producing entities within these countries conform to a set of rules. This conformity is the product of over a century of careful planning and negotiation, in which DeBeers has undertaken largely successful efforts to control the diamond trade and maximize its long-term prospects. The past decade has seen the end of apartheid in South Africa, the fall of communism in Russia, the opening of major mines in Canada, and the emergence of a worldwide movement against so-called “blood” or “conflict” diamonds. While, these developments have pummeled the diamond industry and forced its central players—most notably DeBeers—to change the nature of their trade, these changes have not affected the core dynamic of the global diamond market. It remains an industry dominated by a single firm and an industry in which, perhaps uniquely, all of the major players understand the extent to which their long-term livelihood depends on the fate and actions of the others.
Changes in Labor Force Participation in the United States
Authors: Juhn Chinhui , Potter Simon
Published: August 2006

The labor force participation rate in the United States increased almost continuously for two-and-a-half decades after the mid-1960s, pausing only briefly during economic downturns. The pace of growth slowed considerably during the 1990s, however, and after reaching a record high of 67.3 percent in the first quarter of 2000, participation had declined by 1.5 percentage points by 2005. This paper reviews the social and demographic trends that contributed to the movements in the labor force participation rate in the second half of the twentieth century. It also examines the manner in which developments in the 2000s reflect a break from past trends and considers implications for the future.
Unemployment Insurance: Strengthening the Relationship between Theory and Policy
Authors: Nicholson Walter , Needels Karen
Published: August 2006

Ever since the U.S. federal–state system of unemployment insurance was founded in the 1930s, it has provided partial, temporary replacement of wages to eligible workers who lose jobs “through no fault of their own” (as determined by state-level regulations). Unemployment insurance is one of the largest social insurance programs in the United States, with benefits paid totaling about $34 billion in 2004. Economic theory can help us understand the challenges this complex program is likely to face over the next few years. We begin by summarizing the salient characteristics of the unemployment insurance program and then examine the theoretical and econometric research. Much of this research revolves around the main goals of the program, which include: 1) sustaining consumption for workers and their families; 2) helping recipients to make efficient job choices during a period of financial stress; and 3) minimizing the adverse incentives that may accompany partial wage replacement. Of course, these goals can come into conflict—for example, if replacing wages for an unemployed worker also discourages that worker from aggressively searching for or accepting a new job—and our discussion will focus on these conflicts. In conclusion, we address the key policy issues that the unemployment insurance system is likely to face in upcoming years and ways policymakers may be able to use economic analysis to adjust the program so that it remains effective in addressing the needs of unemployed workers.
Needle exchange use, sexual risk behaviour, and the prevalence of HIV, hepatitis B virus, and hepatitis C virus infections among Bulgarian injection drug users
Authors: Vassilev Z P , Hagan H , Lyubenova A , Tomov N , Vasilev G , Krasteva D , Des Jarlais D C
Published: August 2006

At a time when the rates of HIV, hepatitis C virus (HCV), and hepatitis B virus (HBV) infections have risen among injection drug users (IDUs) in other countries in the region, little is known about the prevalence of these infections among Bulgarian injectors and about their sexual risk behaviours. IDUs ( n = 773) in a community-based needle exchange programme (NEP) and two major drug treatment facilities in Sofia completed a structured interview and were tested for HIV, HBV, and HCV antibodies. While HCV prevalence in the sample was 73.9%, HBV and HIV prevalence was low −6% and 0.5%, respectively. Having more than 10 sexual partners, having sex with someone with hepatitis C or another IDU, and never using a condom with another IDU were common among those who were recruited through NEP. As 40% of the IDUs reported using NEP, it appears that needle exchange provides an opportunity to reach high-risk populations and prevent sexual transmission of blood-borne pathogens.
Factors associated with HIV prevalence in a pre-partum cohort of Zambian women
Authors: St Lawrence J S , Klaskala W , Kankasa C , West J T , Mitchell C D , Wood C
Published: August 2006

An ongoing study of mother-to-child human herpes virus-8 (HHV-8) transmission in Zambian women ( n = 3160) allowed us to examine the association of medical injections with HIV serostatus while simultaneously accounting for other factors known to be correlated with HIV prevalence. Multi-method data collection included structured interviews, medical record abstraction, clinical examinations, and biological measures. Medically administered intramuscular or intravenous injections in the past five years (but not blood transfusions) were overwhelmingly correlated with HIV prevalence, exceeding the contribution of sexual behaviours in a multivariable logistic regression. Statistically significant associations with HIV also were found for some demographic variables, sexual behaviours, alcohol use, and sexually transmitted diseases (STD). The results confirmed that iatrogenic needle exposure, sexual behaviour, demographic factors, substance use, and STD history are all implicated in Zambian women's HIV+ status. However, the disproportionate association of medical injection history with HIV highlights the need to investigate further and prospectively the role of health-care injection in sub-Saharan Africa's HIV epidemic.
Cervical screening and management of cervical intraepithelial neoplasia in HIV-positive women
Authors: Danso Dennis , Lyons Fiona , Bradbeer Caroline
Published: August 2006

The high prevalence of abnormal cervical cytology in the context of immunosuppression has been recognized for many years. In response to repeated observations of cervical cancers in HIV-infected women, moderate and severe cervical dysplasia were designated as early symptomatic HIV infection (Category B) by the Centers for Disease Control and Prevention (CDC) in 1993, and invasive cervical cancer as an AIDS-defining condition (Category C). HIV-infected women, therefore, differ from the general population not only with a greater risk for more, but also potentially more severe cervical disease. In the era of highly active antiretroviral therapy, with HIV-infected women living for longer, there is a clear need to address this increased risk with appropriate management guidelines which this review attempts to provide.
Therapeutic strategies for epidemic Kaposi's sarcoma
Authors: Aldenhoven M , Barlo N P , Sanders C J G
Published: August 2006

Kaposi's sarcoma (KS) remains the most commonly diagnosed malignancy in HIV-infected patients, and is one of the AIDS-defining diagnoses. Several different therapeutic options are available, but the optimal therapy is still unclear. The incidence of KS has sharply declined since highly active antiretroviral therapy (HAART) became widely available, making HAART indispensable in the treatment of epidemic KS. HAART can be given alone or in combination with systemic and local therapy. Systemic therapy can be given in disseminated, progressive or symptomatic disease. Treatment options are interferon-α and chemotherapy including pegylated-liposomal anthracyclines and paclitaxel. For local disease, radiotherapy, intralesional chemotherapy or cryotherapy may be used. In resource-limited settings, intravenous vincristine, oral etoposide or intramuscular bleomycin may be feasible options. Other therapies, such as angiogenesis inhibitors, are under investigation in clinical trials.
Can chlamydial conjunctivitis result from direct ejaculation into the eye?
Authors: Rackstraw S , Viswalingam N D , Goh B T
Published: August 2006

The majority of cases of chlamydial conjunctivitis are thought to result from autoinoculation by the patient of infected genital secretions from themselves or their sexual partners. We noted that some patients had developed symptoms following direct ejaculation into the affected eye. We describe four cases of chlamydial conjunctivitis following ejaculation of semen directly into the eye, which have not been previously described. In only one case was chlamydia detected in the genital tract. In three cases, there was no evidence of genital chlamydial infection; the sources of the eye infection being either from infected genital material of their sexual partners transferred by hands to the eyes, or more likely from direct ejaculate inoculation. It is likely that this mode of transmission is underestimated as a history of ejaculation into the conjunctiva is not normally asked for.
Lack of awareness of HIV post-exposure prophylaxis among HIV-infected and uninfected men attending an inner London clinic
Authors: de Silva Shamela , Miller Robert F , Walsh John
Published: August 2006

An audit of HIV-infected and -uninfected men attending two clinics at an inner London treatment centre demonstrated an alarming lack of awareness of post-exposure prophylaxis following sexual exposure (PEPSE). This audit suggests that strategies for increasing awareness of PEPSE among 'at risk' men are urgently needed.
The Nuclear Power Option in the Italian Energy Policy
Authors: Nucci Maria Rosaria Di
Published: August 2006

Italy took a pioneering role in the early development of nuclear power. This source of energy should have provided the answer to the lack of domestic fossil resources. Due to the cheap oil prices, the influence of the state hydrocarbons company ENI and an influential petroleum lobby, following the nationalisation of the electricity sector in the early sixties, the nuclear option was no longer consequently pursued. Italy became heavily dependent on imported oil. Although in the period 1974–1975 an intensive nuclear power development programme was launched, the share of nuclear power remained marginal. In the aftermath of the Chernobyl disaster and following the referendum phasing out nuclear power in 1987, the national energy policy was newly defined. Our analysis will follow the customary practice to subdivide the Italian nuclear power development into three phases: the pioneering years till the mid-1960s; the period between 1966 and 1987 and the post-Chernobyl phase. We discuss the early phase at a certain length, since it is symptomatic of the way in Italy technological and industrial matters are dealt with and well illustrates the alliance games and behaviour of still existing market players. Although disputes about the alleged advantages of nuclear power are revived with certain regularity and are justified with arguments such as climate change and dependence on imported fuel, we argue that a return to nuclear power in Italy is not foreseeable. Nonetheless, the country cannot be considered a nuclear-free area. Nuclear wastes still play a disquieting role and imported electricity is generated also by nuclear power. Moreover, another tendency has set through. Due to a large liquidity provided by the mandated divestments in the framework of the liberalisation of the electricity market, the previous monopolist ENEL is heavily investing in generating capacities, including stakes in nuclear plants abroad, especially in new EU countries.
History of Nuclear Power in Brazil
Authors: Rosa Luiz Pinguelli
Published: August 2006

The 1973 energy crisis prompted the United States to suspend supplies of enriched uranium to the reactor being built in Brazil, Angra I. In 1975, the Brazil–Germany Nuclear Agreement was announced. The Programme was a failure. Today the Angra II nuclear reactor has been completed, the only reactor completed under the agreement with Germany. Brazil's last military President implemented the Parallel Nuclear Programme, which included uranium enrichment with the justification of developing the technology that had not been transferred through the Nuclear Agreement with Germany. In 1986, the existence of a deep shaft drilled by the Air Force was revealed. A Technical Report concluded that it had all the characteristics and dimensions required to test a nuclear bomb. Some years later, the Civilian Government acknowledged the existence of an underground nuclear explosion facility and symbolically sealed this shaft. The situation in Brazil has improved recently. Brazil ratified the Treaty of Tlatelolco on the denuclearisation of Latin America and established ABACC, an agency handling mutual inspections of nuclear facilities in Brazil and Argentina. Brazil also signed the Nuclear Weapons Non-Proliferation Treaty. The uranium enrichment activities are being transferred to a civilian industry. More importantly, I do not believe that the uranium enrichment project is intended to endow Brazil with the capacity to produce nuclear weapons.
Contested Technology
Authors: Arentsen Maarten J.
Published: August 2006

Despite high ambitions nuclear technology hardly developed in the Netherlands. Already from the very start, nuclear technology was contested and became subject of power games. Two reactors, one 50 MW the other 450 MW were connected to the grid and several more were planned. Social protest and aversion was mitigated by a nationwide energy debate. In 1986 Chernobyl interrupted and finally stopped the Dutch nuclear ambitions. Twenty years after Chernobyl, the debate about the nuclear option has been re-opened in reference to climate change, security of supply and resource independence.
The Current Outlook for the Nuclear Power Industry in the United States
Authors: Jurewitz John L.
Published: August 2006

Serious concerns about national energy security and the need to begin preparing for a post-petroleum world are opening a window of opportunity for a potential “nuclear renaissance” in the United States. Whether such a renaissance takes root will depend on a number of countervailing tensions. This paper briefly reviews the history of the U.S. nuclear power industry and then discusses the cross-cutting forces that will determine the future course of the industry. At the moment, the single largest impediment is the failure to resolve the long term high level waste disposal issue. Other significant impediments include local NIMBYism, fear of nuclear terrorism, and financial community skepticism. Weighing on the opposite side of the scale are several favourable factors including improved operating and safety records, consolidation of plant ownership in more expert hands, extensive authorisation of license extensions for existing plants, and streamlining of licensing procedures for new plants. Most importantly, the recently enacted Energy Policy Act of 2005 creates significant economic incentives for new construction. As a result, a number of consortia are moving towards adding new units at existing generation sites. Whether these incremental additions eventually lead to a “nuclear renaissance” will depend on how economically they are constructed as well as other factors that will become clear only as the future unfolds.
Unchanging Vision of Nuclear Energy: Nuclear Power Policy of the South Korean Government and Citizens' Challenge
Authors: Leem Sung-Jin
Published: August 2006

This article reports on the status and perspectives of South Korea's nuclear power policy, enabling a discussion regarding how much of South Korea's nuclear and energy policy has changed. Despite the phase-out or slowdown of nuclear industry in European countries, the Korean Government continues to maintain a traditional energy policy paradigm, expanding nuclear energy continuously in essence for the past several decades. The country ranks now sixth in the world for generating capacity from nuclear power, and a total of 36 nuclear units might be in operation by 2030. The entire country has been seething over the nuclear waste problem for many years. The government's long standing attempts to build the nuclear waste disposal facility have provoked violent resistance from citizens, awakening public awareness of nuclear problems. Under the pressure of environmental movements and climate convention the South Korean Government has taken a small step towards change in its energy policy. However, as long as the illusion of nuclear power is maintained, no change in Korea's energy policy can be effected.
Twenty Years after Chernobyl in Hungary
Authors: Ámon Ada
Published: August 2006

The article guides the reader through the past 20 years of Hungarian energy policy development, which is still controlled by the old nomenclature. The officials and the academic circles were and are trying to undermine and make a bagatelle out of the Chernobyl disaster. While, in April 2003 at the Paks Nuclear Power Plant the worst accident after Chernobyl in Europe happened. Even though 3.6 tonnes of fission material has been laying at the bottom of a container close to the reactor for three years, the Parliament gave a green light to life-time extension of the Hungarian nuclear plant.