bluuebunny/crossref_metadata_2025 huggingface dataset:
The Job of Representation in Congress: Public Expectations and Representative Approval
Authors: GRANT J. TOBIN , RUDOLPH THOMAS J.
Published: March 2010

Few concepts are more central to democratic theory than that of representation. Theories of representation are commonly premised on the belief that citizens' expectations of their representative are politically consequential, yet we know little about the nature of these expectations and precisely how they matter. Using individual‐level data from a recent national survey, we investigate the influence of constituents' job expectations on their approval of their representative in Congress. We find that citizens' job expectations condition the effects of members' legislative activities on their job approval.
Explaining Women's Legislative Representation in Sub‐Saharan Africa
Authors: YOON MI YUNG
Published: March 2010

This study examines the relative impacts of social, economic, cultural, and political determinants on women's legislative representation in sub‐Saharan Africa by using an ordinary least squares multiple regression model. Under study are sub‐Saharan African countries that held democratic legislative elections between January 1990 and June 30, 2001. Only the latest election in each country is included for analysis. My study finds that patriarchal culture, proportional representation systems, and gender quotas are statistically significant. This study, by focusing on sub‐Saharan Africa, fills a gap in the extant literature, which has focused on women's legislative representation in advanced industrialized democracies.
Who Wins? Party Effects in Legislative Voting
Authors: LAWRENCE ERIC D. , MALTZMAN FORREST , SMITH STEVEN S.
Published: March 2010

Political scientists have long attempted to measure and describe the modest and contingent effects of party on the behavior of members of Congress. Recent efforts have extended the debate to the more specific question of whether or not party influences are sufficiently strong to move policy outcomes away from the median position. In this article, we specify four theories of legislative behavior. One is a preference‐based, or partyless, theory of behavior. This theory posits that there are no party effects independent of preferences and that equilibrium outcomes are located at the chamber's median. The other theories rely on different conceptions of the foundations of party effects and yield distinctive predictions about the legislators who will support bills on final passage votes. After testing, our conclusion is that strong party influences can be found in final passage voting in the House: the partyless theory receives little support, but a model based on majority party agenda control works well. Legislative outcomes are routinely on the majority party's side of the chamber median.
The Effects of Term Limits on State Legislatures: A New Survey of the 50 States
Authors: CAREY JOHN M. , NIEMI RICHARD G. , POWELL LYNDA W. , MONCRIEF GARY F.
Published: March 2010

Term limits on legislators were adopted in 21 states during the early 1990s. Beginning in 1996, the limits legally barred incumbents from reelection in 11 states, and they will do so in four more by 2010. In 2002, we conducted the only survey of legislators in all 50 states aimed at assessing the impact of term limits on state legislative representation. We found that term limits have virtually no effect on the types of people elected to office—whether measured by a range of demographic characteristics or by ideological predisposition—but they do have measurable impact on certain behaviors and priorities reported by legislators in the survey, and on the balance of power among various institutional actors in the arena of state politics. We characterize the biggest impact on behavior and priorities as a “Burkean shift,” whereby term‐limited legislators become less beholden to the constituents in their geographical districts and more attentive to other concerns. The reform also increases the power of the executive branch (governors and the bureaucracy) over legislative outcomes and weakens the influence of majority party leaders and committee chairs, albeit for different reasons.
Proportional Representation and Female Parliamentarians
Authors: SALMOND ROB
Published: March 2010

This article asks, “What effect does the choice of a nation's electoral system have on the gender composition of its parliament over time?” I find that the electoral system has an important part to play, but previous work has overstated, by factors of between two and three, how much of a difference an electoral system can make. This article contributes an updated nonlinear theory of female representation, an improved dataset on women's representation across space and time, and more modern statistical techniques than previously used in research on this question.
The Impact of Party and Ideology on Roll‐Call Voting in State Legislatures
Authors: JENKINS SHANNON
Published: March 2010

To assess the relative impact of party and ideology on legislative behavior, I utilize survey‐based measures of legislator ideology to examine voting in five state legislatures. The results suggest that, although party and ideology both influence voting, the impact of party is greater. The magnitude of this impact varies, however, from chamber to chamber. The activity of parties in the electoral arena explains part of this variance, with more active parties having more influence. Thus, research on legislative behavior should focus on the context surrounding the decision‐making process in order for us to understand the influences on voting.
Term Limits, Campaign Contributions, and the Distribution of Power in State Legislatures
Authors: APOLLONIO D.E. , LA RAJA RAYMOND J.
Published: March 2010

Using campaign contributions to legislators as an indicator of member influence, we explore the impact of term limits on the distribution of power within state legislatures. Specifically, we perform a cross‐state comparison of the relative influence of party caucus leaders, committee chairs, and rank‐and‐file legislators before and after term limits. The results indicate that term limits diffuse power in state legislatures, both by decreasing average contributions to incumbents and by reducing the power of party caucus leaders relative to other members. The change in contribution levels across legislators in different chambers implies a shift in power to the upper chamber in states with term limits. Thus, the impact of term limits may be attenuated in a bicameral system.
Term Limits and Pork
Authors: HERRON MICHAEL C. , SHOTTS KENNETH W.
Published: March 2010

We describe a model of electoral selection and legislative policy choice that explores the effects of term limits on legislative spending. In the model, self‐interested voters in a collection of districts prefer representatives who deliver pork over representatives who maximize aggregate social welfare. Term limits can, in some cases, inhibit voters from selecting representatives who deliver particularistic benefits, and, in these cases, term limits reduce pork spending. On the other hand, when pork is extremely socially inefficient, representatives who want to deliver pork to their districts have incentives to refrain from doing so to reduce future pork in other districts. In this scenario, term limits actually prevent legislators from promoting future spending moderation and thus paradoxically increase pork spending.
Pulling Punches: Congressional Constraints on the Supreme Court's Constitutional Rulings, 1987–2000
Authors: HARVEY ANNA , FRIEDMAN BARRY
Published: March 2010

To date, no study has found evidence that the U.S. Supreme Court is constrained by Congress in its constitutional decisions. We addressed the selection bias inherent in previous studies with a statute‐centered, rather than a case‐centered, analysis, following all congressional laws enacted between 1987 and 2000. We uncovered considerable congressional constraint in the Court's constitutional rulings. In particular, we found that the probability that the Rehnquist Court would strike a liberal congressional law rose between 47% and 288% as a result of the 1994 congressional elections, depending on the legislative model used.
Government Growth and Professionalism in U.S. State Legislatures
Authors: MALHOTRA NEIL
Published: March 2010

This article analyzes the professionalization of American state legislatures since the 1960s and expands on previous studies by considering the strategic incentives of members. Fiorina and Noll's (1978a, 1978b) theory that reelection‐minded legislators serve as “ombudsmen to the bureaucracy” on behalf of their constituents suggests that legislatures have professionalized in response to growth in public spending in order to strengthen members' abilities to handle increased facilitation duties. I used longitudinal analysis and instrumental variables regression to test this hypothesis and disentangle causal directionality, since professional legislators may have the means and incentive to spend more than their citizen counterparts. Both methods revealed empirical support for the Fiorina and Noll hypothesis that spending increases caused legislators to become more professional.
Searching for the Electoral Connection: Parliamentary Party Switching In the Ukrainian Rada, 1998–2002
Authors: THAMES FRANK C.
Published: March 2010

Studies of legislative behavior almost universally begin with the assumption that legislators desire reelection. For scholars who study the Ukrainian Verkhovna Rada, this assumption is perhaps tenuous, given the weaknesses of political parties and the significant party switching. Yet an analysis of party switching between 1998 and 2002 using a new method that controls for selection bias demonstrates that, although turnover among parties was high, this turnover followed an electoral logic: deputies changed parties, in part, to secure reelection. Thus, the electoral connection, assumed in so much of the legislative behavior literature, existed even in the chaotic Rada.
The Policymaking Role of State Supreme Courts in Education Policy
Authors: WILHELM TEENA
Published: March 2010

In this article, I examine the relationship between courts and legislatures from a comparative perspective. Specifically, I discuss how (1) the ideological composition of the bench, (2) the propensity of court involvement in a given policy area, and (3) the presence of an advisory opinion affect the number of bill introductions and policy enactments by state legislatures. Examination of education policy in the American states reveals that ideologically distant courts limit the number of bill introductions and bill enactments in state legislatures. Alternatively, the presence of an advisory opinion increases policy introduction and enactment in state legislatures. A fundamental implication of these findings is that courts exert the greatest impact on policy during the introduction stage of the legislative process. Previous studies have not examined the introduction stage and have therefore marginalized the real impact of court influence on policy.
Bridging the Gender Gap In Bill Sponsorship
Authors: BARNELLO MICHELLE A. , BRATTON KATHLEEN A.
Published: March 2010

Under what circumstances do men sponsor issues that are traditionally regarded as salient primarily to women? By examining the sponsorship of legislation in the upper and lower chambers of 15 state legislatures in 2001, we explored the conditions under which men are likely to focus attention on policy areas involving women's issues and children's issues. We found little effect of institutional context (such as party control of the legislature or diversity within the legislature) on the sponsorship behavior of either men or women. Personal characteristics such as race, education, age, and family circumstances are associated with sponsorship by men, but not by women. Committee service is also strongly associated with sponsorship behavior, particularly for men. Differences in sponsorship are relatively marked in the sponsorship of legislation that focuses on reproduction or other health issues particularly relevant to women. We conclude that the boundaries of the set of issues traditionally defined as “women's issues” may be changing over time and that it is important to recognize that the influences on the sponsorship of women's issues can be different for men than they are for women.
Presidential Campaigning in the 2002 Congressional Elections
Authors: HERRNSON PAUL S. , MORRIS IRWIN L.
Published: March 2010

Theories involving coattails, surge and decline, presidential popularity, and the economy ascribe little importance to presidential efforts to influence congressional elections. Since such efforts do occur, we ask: What happens when a president campaigns for fellow partisans? We examined President George W. Bush's decisions to campaign for certain House candidates in 2002, and we assessed the effect of his visits on Republicans' electoral successes. Both the competitiveness of a race and the president's electoral self‐interest increased the likelihood of a visit on behalf of a candidate. Neither party loyalty nor presidential support in Congress had an effect. We conclude that presidential campaign visits significantly enhance candidates' electoral prospects.
Do Multimember Districts Lead to Free‐Riding?
Authors: SNYDER JAMES M. , UEDA MICHIKO
Published: March 2010

We studied the effects of districting on intergovernmental aid by state governments to local governments in the United States. We found that metropolitan areas receive relatively more aid when represented in the state legislature by an at‐large delegation than when divided into single‐member districts. This suggests that the free‐riding that may occur with at‐large representation is more than counterbalanced by other factors. The estimated effects are robust to the effects of other confounding factors as well as the choice of estimators.
Representation and Backlash: The Positive and Negative Influence of Descriptive Representation
Authors: HAIDER‐MARKEL DONALD P.
Published: March 2010

For this article, I built on previous studies of representation by exploring the potential positive and negative impacts of descriptive representation in the policy process. Specifically, I examined the influence of openly lesbian, gay, bisexual, and transgendered (LGBT) state legislators on the amount and types of LGBT‐related state legislation introduced from 1992 to 2002. My findings suggest that higher LGBT representation in state legislatures leads to greater substantive representation. The results also suggest, however, that descriptive representation is associated with the amount of anti‐LGBT legislation introduced. Additional analysis reveals that the net policy influence of increased LGBT representation is positive for the LGBT community.
Campaign War Chests and Challenger Quality in Senate Elections
Authors: GOODLIFFE JAY
Published: March 2010

This article presents the first comprehensive analysis of the role of war chests in U.S. Senate elections. Using data on races from 1980 to 2000, I demonstrate the effect of an incumbent senator's war chest on a campaign. War chests do not deter strong general‐election challengers and have an insubstantial or insignificant effect on primary elections, challenger spending, and other electoral variables. Also, war chests are not raised in anticipation of a tough electoral battle but are instead the result of money left over from the previous campaign.
Intended Consequences: Jurisdictional Reform and Issue Control In the U.S. House of Representatives
Authors: ADLER E. SCOTT , WILKERSON JOHN D.
Published: March 2010

The power of congressional committees rests in large part on their ability to set the legislative agenda in particular issue areas. But how do committees acquire their issue jurisdictions? Existing research points to informal committee turf wars— not collective reforms—as the roots of jurisdictional allocations (King 1994, 1997). Yet the House of Representatives has made nearly 150 formal changes to its committees' jurisdictions since 1973. We investigated the effects of one prominent instance of extensive jurisdictional changes, the Bolling‐Hansen reforms of 1975, and found that this body of reforms advanced collective goals of improved policy coordination and enhanced information sharing.
Uncertainty and the Prevalence of Committee Outliers
Authors: RICHMAN JESSE
Published: March 2010

Political scientists often suppose that the informational model of legislative organization predicts an absence of committee outliers. In fact, the model predicts that committee outliers will be more common when the floor is more uncertain than its committees. Data limitations have largely prevented testing this uncertainty‐outlier prediction, until now. For this article, I investigated whether or not the informational model correctly predicts under what scenarios outliers will be more frequent. As predicted, more uncertainty is associated with more committee outliers in U.S. state legislatures. Legislatures in which the floor is less informed than the committees are more likely to have committee outliers.
Job Approval and Senate Election Outcomes In the United States
Authors: HIGHTON BENJAMIN
Published: March 2010

A growing body of congressional scholarship investigates variation in the incumbent electoral advantage that depends on factors such as competence, political skill, and ideological extremity. This article contributes to this line of work by providing analysis of the relationship between senators' home‐state approval ratings and their electoral fortunes using newly available data from the Job Approval Ratings (JAR) collection. The findings show that senatorial job approval affects retirement, quality‐candidate emergence, campaign spending, and outcomes. The myriad indirect effects suggest that strategic political actors are central to the process by which incumbents are held accountable for the reputations they develop in their constituencies.
Invisible Politics: Institutional Incentives and Legislative Alignments in the Russian Duma, 1996–99
Authors: BAGASHKA TANYA
Published: March 2010

Previous analysis of legislative voting has focused on the behavior of nominal legislative parties, regardless of whether the country under examination was an established democracy or a newly democratized country. This approach is inadequate for countries with young party systems. To establish the extent to which legislative coalitions are party based, scholars must allow for the possibility that institutional incentives predominate over party influence. For this study, I applied a Bayesian discrete latent variable method to identify the legislative coalitions in the 1996‐99 Duma. I found that legislative alignments cut across party lines: electoral incentives and support for the president contribute to divides within parties that lack coherent platforms. Here I present a novel methodological approach to the identification of intraparty divisions and the major determinants of legislative coalitions in many legislative settings. This approach allows a comparison of the importance of party influence relative to other institutional incentives. It is especially useful for analyzing legislative voting in young party systems and where constitutional frameworks and electoral systems subject legislators to competing pressures.
Making Quotas Work: The Effect of Gender Quota Laws On the Election of Women
Authors: SCHWINDT‐BAYER LESLIE A.
Published: March 2010

Gender quota laws are intended to increase the number of women elected to legislatures, but initial evidence suggests that many laws have had little effect. I present a cross‐national, statistical test that analyzes how three key dimensions of candidate quota laws affect women's representation. My results show that quotas that require more women to be on party ballots lead to the election of more women, independent of placement mandates and enforcement mechanisms, but rules governing where female candidates are listed on the ballot and sanctions for noncompliance amplify that effect. Candidate quotas can increase women's representation, but the quotas' effectiveness depends on their design.
After Enlargement: Voting Patterns in the Sixth European Parliament
Authors: HIX SIMON , NOURY ABDUL
Published: March 2010

We examined how voting behavior in the European Parliament changed after the European Union added ten new member‐states in 2004. Using roll‐call votes, we compared voting behavior in the first half of the Sixth European Parliament (July 2004‐December 2006) with voting behavior in the previous Parliament (1999–2004). We looked at party cohesion, coalition formation, and the spatial map of voting by members of the European Parliament. We found stable levels of party cohesion and interparty coalitions that formed mainly around the left‐right dimension. Ideological distance between parties was the strongest predictor of coalition preferences. Overall, the enlargement of the European Union in 2004 did not change the way politics works inside the European Parliament. We also looked at the specific case of the controversial Services Directive and found that ideology remained the main predictor of voting behavior, although nationality also played a role.
Divided We Quarrel: The Politics of Congressional Investigations, 1947–2004
Authors: PARKER DAVID C.W. , DULL MATTHEW
Published: March 2010

Are congressional committee investigations into alleged executive‐branch wrongdoing more common during periods of divided government? We analyze original data tracking congressional committee investigations into alleged fraud, waste, and abuse by the executive branch between 1947 and 2004. Countering David Mayhew's (1991) empirical finding, we show that divided government generates more and more‐intensive congressional investigations, but this relationship is contingent on partisan and temporal factors. Our findings shed new light on the shifting dynamic between partisan institutional politics and congressional oversight.
The Calculus of Cosponsorship in the U.S. Senate
Authors: HARWARD BRIAN M. , MOFFETT KENNETH W.
Published: March 2010

We investigated why a legislator would be willing to vote “yea” on final passage of a bill but would choose not to cosponsor that bill. We tested a series of hypotheses regarding the cosponsorship decisions of individual senators, using a dataset that includes every major initiative that was introduced and received a floor vote in the Senate between 1975 and 2000. We found that senators are more likely to cosponsor bills when their preferences diverge from the Senate median but are closer to those of the bill's sponsor. Also, senators are more likely to cosponsor bills when they sponsor a higher number of bills overall, when they become more connected with colleagues, and when their constituents increase demand for legislation within particular policy areas. Senators are less likely to cosponsor bills if they received a higher percentage of the general election vote in their most recent election.
Delegation and Defensive Legislative Strategies in Brazil
Authors: GAYLORD SYLVIA
Published: March 2010

In the course of the legislative process, legislators choose how much policy discretion to delegate to the executive branch. Uncertainty about policy outcomes and bureaucratic intentions weighs heavily in such decisions. In Brazil, executive control over the budget creates uncertainty about the availability of discretionary spending, which results in comparatively high levels of delegation in the legislature's direct‐spending decisions. I demonstrate that sidelining the legislature from the budget in order to insulate government spending from political pressures diminishes the value of legislative work in Brazil and reinforces historical patterns of policymaking centered on the federal executive.
Climate Change and Health
Authors: Faiz MA , Islam Quazi Tarikul
Published: March 2010

DOI: 10.3329/jbcps.v28i1.4635Journal of Bangladesh College of Physicians and Surgeons Vol.28(1) 2010 pp.1-3
Preterm Prelabour Rupture of the Membrane & Feto-Maternal out come: an Observational Study
Authors: Akter S , Akter R , Rashid M
Published: March 2010

Objective: The aim of this study was to see the maternal and fetal outcome of preterm pre labor rupture membrane and to identify the risk factors for preterm pre labor rupture membrane. Methods and Material: This was a cross-sectional descriptive type study carried out in Dhaka Medical College Hospital, Dhaka, during April to September, 2005 (6months) in the Department of Obstetric and Gynecology. 50 pregnant women with preterm premature rupture of the membrane (gestational age 29-0 to 36-6 weeks) were included in this study. Results: The mean age of the women was 27.24±6.28years and 36% of them more than 30 years old. Sixty two percent women were multi gravid .Socio-economic condition, level of education and antenatal care of the women was low. Median gestational age of the patient was 35 weeks. Fifty six percent had previous history of PROM, preterm delivery, abortion, MR and dilatation and curettage. Sixty two percent women had history of sexual activity between 2 to 7days. Seventy two percent women had UTI, anaemia, and lower genital tract infection. Mean duration of the latent period was 18.87 ±16.17hours and time interval of rupture membrane and delivery was 27.60 ± 21.127 hours. Eighty four percent patient delivered by vaginal route and Fifty four percent delivered within 24 hours of ruptured membrane. Forty two percent newborn suffered from neonatal asphyxia, respiratory distress syndrome, neonatal jaundice and neonatal sepsis. Thirty two percent women suffered from chorioamnionitis, abruptio placent and endometritis.Conclusion: PPROM is malnutrition and poverty related disease. Antenatal care is an important tool to prevent PPROM by identifying the risk factors and its management. Steroid for fetal lung maturity, antibiotics to prevent fetal and maternal infection and induction and /or augmentation of labor will speeded delivery and reduce hospital stay and infection. Key words: Premature rupture of the membrane; maternal and neonatal outcome; risk factors. DOI: 10.3329/jbcps.v28i1.4639 J Bangladesh Coll Phys Surg 2010; 28: 17-23
Burden of Heart Failure Patients in a Tertiary Level Cardiac Hospital
Authors: Kabiruzzaman M , Malik FN , Ahmed N , Badiuzzaman M , Choudhury SR , Haque T , Rahman H , Ahmed MN , Banik D , Khan MAM , Dutta AK , Sayeed S , Khandaker RK , Malik A
Published: March 2010

Objective: Heart failure (HF) has become an increasingly frequent cause of hospital admission and carries a poor prognosis. There is a paucity of data in Indo-Asians particularly in Bangladesh on characteristics of heart failure patients. The purpose of this study was to determine the etiological factors and co-morbidity of hospitalized heart failure patients. Method: A hospital based cross sectional study was done at a tertiary cardiac hospital in Dhaka city. Hospital medical records of 14009 patients admitted between January 2005 and August 2006 were reviewed and 1970 patients with the diagnosis of HF were identified. Relevant etiological information and socio demographic data were abstracted from the hospital record files. Result: About one-seventh of total hospital admitted patient had HF. Mean age (SD) was 54.1 (15.3) years. Majority (35.79%) had ischaemic heart disease (IHD) as the principal etiological factor but this frequently coexisted with a history of hypertension (46.8%). Hypertension was considered the primary risk factor of HF in 29.14% of cases. Hypertension alone and in coexistence with other etiology was found in 48.07% (947) cases. Diabetes Mellitus (DM) co-existed with IHD in 41.4% (292) and it (32.64%) was found more prevalent in Dilated Cardiomyopathy (DCM) patient with HF. Conclusions: The mean age of hospitalized HF patients is remarkably lower than other related studies done abroad. The single most common etiology for HF is ischemic heart disease in this population. Hypertension is the most common risk factor. Measures to prevent ischaemic heart disease and control of risk factors are essential to prevent premature onset of HF. DOI: 10.3329/jbcps.v28i1.4640 J Bangladesh Coll Phys Surg 2010; 28: 24-29
Lupus Nephritis in a 2.5 Year Old Girl- An Uncommon Presentation
Authors: Rahman H , Begum A , Roy RR , Siddique R , Alam K , Haque S , Jahan S , Uddin GM , Hossain MM
Published: March 2010

Systemic lupus erythematosus (SLE) is very rare and difficult to diagnose before 5 years of age. We are reporting a case of SLE at 2.5- year who presented with recurrent episodes of fever, haematuria , proteinuria and rash . Diagnosis of SLE was confirmed by reduced serum complement level and positive anti double stranded DNA (anti ds DNA). Class IV histological type of Lupus nephritis was evaluated by renal biopsy DOI: 10.3329/jbcps.v28i1.4647 J Bangladesh Coll Phys Surg 2010; 28: 59-62
Freeze-Casting of Porous Biomaterials: Structure, Properties and Opportunities
Authors: Deville Sylvain
Published: March 2010

The freeze-casting of porous materials has received a great deal of attention during the past few years. This simple process, where a material suspension is simply frozen and then sublimated, provides materials with unique porous architectures, where the porosity is almost a direct replica of the frozen solvent crystals. This review focuses on the recent results on the process and the derived porous structures with regards to the biomaterials applications. Of particular interest is the architecture of the materials and the versatility of the process, which can be readily controlled and applied to biomaterials applications. A careful control of the starting formulation and processing conditions is required to control the integrity of the structure and resulting properties. Further in vitro and in vivo investigations are required to validate the potential of this new class of porous materials.
Production of Metabolites as Bacterial Responses to the Marine Environment
Authors: De Carvalho Carla C. C. R. , Fernandes Pedro
Published: March 2010

Bacteria in marine environments are often under extreme conditions of e.g., pressure, temperature, salinity, and depletion of micronutrients, with survival and proliferation often depending on the ability to produce biologically active compounds. Some marine bacteria produce biosurfactants, which help to transport hydrophobic low water soluble substrates by increasing their bioavailability. However, other functions related to heavy metal binding, quorum sensing and biofilm formation have been described. In the case of metal ions, bacteria developed a strategy involving the release of binding agents to increase their bioavailability. In the particular case of the Fe3+ ion, which is almost insoluble in water, bacteria secrete siderophores that form soluble complexes with the ion, allowing the cells to uptake the iron required for cell functioning. Adaptive changes in the lipid composition of marine bacteria have been observed in response to environmental variations in pressure, temperature and salinity. Some fatty acids, including docosahexaenoic and eicosapentaenoic acids, have only been reported in prokaryotes in deep-sea bacteria. Cell membrane permeability can also be adapted to extreme environmental conditions by the production of hopanoids, which are pentacyclic triterpenoids that have a function similar to cholesterol in eukaryotes. Bacteria can also produce molecules that prevent the attachment, growth and/or survival of challenging organisms in competitive environments. The production of these compounds is particularly important in surface attached strains and in those in biofilms. The wide array of compounds produced by marine bacteria as an adaptive response to demanding conditions makes them suitable candidates for screening of compounds with commercially interesting biological functions. Biosurfactants produced by marine bacteria may be helpful to increase mass transfer in different industrial processes and in the bioremediation of hydrocarbon-contaminated sites. Siderophores are necessary e.g., in the treatment of diseases with metal ion imbalance, while antifouling compounds could be used to treat man-made surfaces that are used in marine environments. New classes of antibiotics could efficiently combat bacteria resistant to the existing antibiotics. The present work aims to provide a comprehensive review of the metabolites produced by marine bacteria in order to cope with intrusive environments, and to illustrate how such metabolites can be advantageously used in several relevant areas, from bioremediation to health and pharmaceutical sectors.
Virtual Sensor for Failure Detection, Identification and Recovery in the Transition Phase of a Morphing Aircraft
Authors: Heredia Guillermo , Ollero Aníbal
Published: March 2010

The Helicopter Adaptive Aircraft (HADA) is a morphing aircraft which is able to take-off as a helicopter and, when in forward flight, unfold the wings that are hidden under the fuselage, and transfer the power from the main rotor to a propeller, thus morphing from a helicopter to an airplane. In this process, the reliable folding and unfolding of the wings is critical, since a failure may determine the ability to perform a mission, and may even be catastrophic. This paper proposes a virtual sensor based Fault Detection, Identification and Recovery (FDIR) system to increase the reliability of the HADA aircraft. The virtual sensor is able to capture the nonlinear interaction between the folding/unfolding wings aerodynamics and the HADA airframe using the navigation sensor measurements. The proposed FDIR system has been validated using a simulation model of the HADA aircraft, which includes real phenomena as sensor noise and sampling characteristics and turbulence and wind perturbations.
Effect of Silver Annealing Conditions on the Performance of Electrolytic Silver/Silver Chloride Electrodes used in Harned Cell Measurements of pH
Authors: Brewer Paul. J. , Brown Richard. J. C.
Published: March 2010

We have studied the long and short term stability of electrolytic Ag/AgCl electrodes fabricated from Ag wire that has been subjected to a range of different annealing conditions. At elevated temperatures, the presence of oxygen during the annealing process has been shown to be detrimental to the performance of electrodes produced. This phenomenon has been attributed to the dissolution of oxygen in the Ag lattice leading to structural changes in the Ag/AgCl electrode material. Electrodes prepared from Ag wire annealed in the absence of oxygen have shown no appreciable change in performance throughout the temperature range employed. This work has resulted in an improved understanding of the optimum annealing conditions required for Ag used in the preparation of electrolytic Ag/AgCl reference electrodes. This work has positive implications for the accuracy of Harned cell measurements of pH.
The canopy effect in AEM revisited: investigations using laser and radar altimetry
Authors: Beamish David , Leväniemi Hanna
Published: March 2010

This study considers a specific issue, often termed the canopy effect that relates to our ability to provide accurate conductivity models from airborne electromagnetic (AEM) data. The central issue is one of the correct determination of sensor height(s) above the ground surface (terrain clearance) to the appropriate accuracy. The present study uses the radar and laser systems installed on a fixed‐wing AEM system to further investigate the effect. The canopy effect can arise due to a variety of elevated features below and in the vicinity of, the flight line. The most obvious features are well‐defined forest and copse zones together with domestic, commercial and agricultural buildings. Such features may cause the terrain clearance to be underestimated and this has the potential to introduce resistive artefacts and incorrect interface depths into conductivity models. Correct determination of terrain clearance is also important for the accurate processing of the other geophysical data sets acquired by airborne surveys. Radar and laser altimetry offer two very different physical measurements of height above ground. Airborne radars detect the range to the nearest reflecting object. They do this over a cone of influence that may have a radius (at the ground surface) of ~55 m (assuming a survey height of 60 m). Reflections from objects that are off‐line are thus a distinct possibility. In direct contrast, a laser ranging device with low beam divergence provides a highly focused measurement. Laser accuracies (typically <2 cm) are far greater than those of radars (typically ~0.5 m). In addition, the rapid sampling of laser ranging devices (e.g., up to 2 kHz) allows both real‐time and post‐processing algorithms to be applied to estimate the maximum range recorded across appropriate time/spatial windows. In our case a 2 kHz (maximum) dual‐pulse laser when sampled at 200 Hz provides a ×50 oversampling in relation to the 4 Hz sampling of the EM components. Our studies from recent surveys indicate that the radar altimeter often provides significantly underestimated values of terrain clearance. Such estimates may be in error by up to 10 m or 15 m across dense woodland. The issues of accuracy and reliability raised by the routine application of laser altimetry to AEM surveys and conductivity models are evaluated. It is demonstrated that it is now possible to obtain reliable laser estimates of true height above ground surface across: a) most forms of canopy encountered, b) built structures of limited spatial scale and c) bodies of water.
Comparative study of local versus global methods for 1D joint inversion of direct current resistivity and time‐domain electromagnetic data
Authors: Santos Monteiro Fernando A. , El‐Kaliouby Hesham M.
Published: March 2010

Direct current resistivity and time‐domain electromagnetic (TDEM) surveys are often used in environmental, hydrological and mining evaluation. The interpretation of the data acquired with each of these geophysical methods, assuming one‐dimensional models, frequently produces ambiguous results. The joint inversion of TDEM and direct current resistivity data is considered by several authors as an efficient method to reduce the ambiguity inherent to each of these methods. This paper presents the results of a comparative study on the use of a local optimization method, iteratively reweighted least squares and global optimization methods of simulated annealing and particle swarm optimization in the joint inversion of TDEM and direct current resistivity data. The models obtained from joint inversion of synthetic data (H‐ and K‐type) and of experimental data using the three methods yield similar results. The iteratively reweighted least squares method is the fastest while the simulated annealing is the most time‐consuming. Simulated annealing and particle swarm optimization are the most efficient methods when studying equivalence problems.
Short-term selection for yearling weight in a small-experimental Iranian Afshari sheep flock
Authors: Ghafouri-Kesbi Farhad , Eskandarinasab Moradpasha , Hassanabadi Ahmad
Published: March 2010

A selection experiment was initiated in 2000 in an Afshari sheep flock at the department of animal breeding and genetics of the University of Zanjan, Iran. The aim was to evaluate the response of Afshari sheep to selection for yearling live weight. Here, we evaluate the results of this breeding program obtained between 2000 and 2005. Traits studied were birth weight (BW), weaning weight (WW), yearling weight (YW), average daily gain from birth to weaning (WWDG) and average daily gain from weaning to yearling age (YWDG). Mixed model methodology based on a multi-trait animal model was employed to estimate (co)variance components and corresponding genetic parameters. Estimates of breeding values were obtained by the best linear unbiased prediction (BLUP) method. Generation intervals on the four genetic pathways were estimated as the average age of parents at the birth of their progeny kept for reproduction. The heritability estimates were 0.34, 0.27, 0.14, 0.20 and 0.01 for BW, WW, YW, WWDG and YWDG, respectively. Estimates of genetic correlations among traits studied were positive, and ranged from low (0.07, YW/WWDG) to high (0.76, YW/YWDG). Genetic improvements over the experiment based on estimated breeding values were 0.104, 0.824, 1.247, 0.005 and ≈0.00 kg for BW, WW, YW, WWDG and YWDG, respectively. Annual genetic gain for YW was relatively high, 0.311 kg yr-1, which demonstrated the effectiveness of the implemented breeding program. Correlated responses in BW, WW, WWDG and YWDG were 0.021, 0.167, 0.001 and ≈0.00 kg yr-1, respectively. Estimates of heritabilities and observed genetic trends indicated that selective breeding can lead to significant genetic improvement in Afshari sheep. The average generation interval was estimated to be 3.35 yr. The shorter generation interval was observed on the sire side compared with the dam side (3.30 yr vs. 3.78 yr), indicating faster generation turnover for sires than for dams. Key words: Sheep, animal model, genetic trend, generation interval, heritability
Effect of dry matter intake on visceral organ mass, cellularity, and the protein expression of ATP synthase, Na+/K+-ATPase, proliferating cell nuclear antigen and ubiquitin in feedlot steers
Authors: Wang Y J , Ko M. , Holligan S. , McBride B W , Fan M Z , Swanson K C
Published: March 2010

Twenty-four steers [467 ± 7.2 kg initial body weight (BW)] predominately of Angus breeding were used to determine the effect of dry matter intake (1.25, 1.50, 1.75, and 2.00% of BW) on visceral mass, cellularity, and the protein expression of ATP synthase, Na+/K+-ATPase, proliferating cell nuclear antigen (PCNA) and ubiquitin. There were linear increases (P ≤ 0.05) in weights of total viscera, total digestive tract, liver, kidney, heart, lung, spleen, rumen, and abomasum with increasing dry matter intake (DMI). Protein concentration decreased linearly (P < 0.05) in small intestinal mucosa as DMI increased. PCNA expression increased linearly (P < 0.01) in liver as DMI increased. PCNA expression was affected quadratically (P < 0.05) in pancreas and small intestinal mucosa with an increase when DMI increased from 1.25 to 1.75% of BW, and a decrease when DMI increased from 1.75 to 2% of BW. ATP synthase, Na+/K+-ATPase, and ubiquitin expression in pancreas and ubiquitin expression in small intestinal mucosa increased linearly (P < 0.05) as DMI increased. These results indicate that increasing DMI increases the mass of visceral organs and carcass and influences expression of proteins influencing energy utilization and efficiency in pancreas, small intestine, liver, and sternomandibularis muscle.Key words: Dry matter intake, visceral organ mass, cellular energy metabolism, steer
Effect of graded levels of wheat-based dried distillers’ grains with solubles on rumen fermentation in finishing cattle
Authors: Beliveau R M , McKinnon J J
Published: March 2010

A 4 × 4 Latin square experiment using ruminally cannulated heifers (388 ± 25 kg, mean ± SD) was conducted to evaluate the effects of graded levels (0, 7, 14, 21% DM basis) of wheat-based dried distillers’ grains with solubles (DDGS) on rumen fermentation characteristics and eating behaviour of cattle fed barley-based diets. Mean rumen pH at cutoff values of pH 5.8 or less (P = 0.02) and pH 5.5 or less (P < 0.01) and pH area between 5.2 and 5.5 (P = 0.02) decreased cubically as DDGS content increased with maximum pH at 2.6% and minimum pH at 14.7% DDGS inclusion levels. A cubic effect of DDGS inclusion level (P = 0.03) was noted for time below pH 5.2 where local minima and maxima were found at 2.9 and 15.0% DDGS. Ammonia N (P < 0.01) and the acetate:propionate ratio (P = 0.01) increased, while propionate decreased (P < 0.01) linearly as DDGS content increased. It was concluded that despite the high fibre, low starch nature of wheat-based DDGS, substitution for barley did not improve the acidic rumen fermentation conditions associated with feeding barley-based finishing diets. Key words: Wheat dried distillers’ grains with solubles, rumen fermentation, feeding behaviour, sub-acute ruminal acidosis
Impact of a mixed culture of Lactobacillus casei and L. lactis on in vitro ruminal fermentation and the growth of feedlot steers fed barley-based diets
Authors: Baah J. , Wang Y. , McAllister T A
Published: March 2010

The effect of a direct-fed microbial (DFM) poduct containing a mixed culture of Lactobacillus casei and L. lactis on in vitro ruminal fermentation of barley-grain/barley-silage-based backgrounding and finishing diets and on growth performance and carcass characteristics of feedlot cattle was evaluated during backgrounding (84 d) and finishing (140 d) of 100 Hereford × Angus steers (initial body weight = 280 ± 15.5 kg). The inclusion rates of DFM in the in vitro study were 4, 8, 12 and 16 million colony forming units (CFU) of lactic acid bacteria (LAB) kg-1 DM of substrate. Total in vitro volatile fatty acids (VFA) production increased at 6 and 12 h of incubation (P < 0.01; linear response) when the backgrounding diet was supplemented with DFM. Dry matter digestibility and VFA production also increased (P < 0.05) during a 12-h fermentation of the finishing diet. Steers were randomly allocated to one of four dietary treatments that comprised feeding DFM tp provide 0 (control), 4 × 107, 8 × 107, or 12 × 107 CFU kg-1 diet DM. Average daily gain (ADG, kg) and feed efficiency (G:F; kg gain kg-1 DM consumed) of steers improved (P = 0.002 and 0.001, respectively) as a result of feeding DFM during the backgrounding period, but not during the finishing period. Saleable meat and rib eye area decreased (P = 0.038, linear; and P = 0.041, quadratic) with DFM supplementation. The results indicated that supplementing barley-grain/barley-silage-based feedlot cattle diets with 12 × 107 CFU of the mixed culture of lactobacilli used in these studies could improve ruminal fermentation, ADG and G:F in backgrounding feedlot steers. However, supplementation during the finishing period may not be warranted in terms of growth performance and carcass characteristics. Differences in the microbial ecology of the intestinal tract as a result of differences in diet composition may account for the varied response between the backgrounding and finishing periods.Key words: Beef cattle, direct-fed microbial, growth performance, Lactobacillus casei, Lactobacillus lactis, ruminal fermentation
GnRH agonist (buserelin) up regulates estrogen receptor α mRNA but not estrogen receptor β and progesterone receptor mRNA in bovine endometrium in vitro
Authors: Singh R , Pretheeban T , Rajamahendran R
Published: March 2010

The local modulatory role of gonadotropin releasing hormone (GnRH), gonadotropin releasing hormone receptor (GnRH-R) system in regulating steroid hormone receptors at the endometrial level is still not known. Estrogen and progesterone maintain uterine functions by acting through their corresponding receptors; estrogen receptors (ERα and ERβ) and progesterone receptors (PR). We recently demonstrated GnRH-R in bovine endometrium and find the co-existence of GnRH and steroid hormone receptors in endometrium as interesting. Our objective was to determine the effect of a GnRH agonist (buserelin), on the expression of ERα, ERβ, and PR messenger RNA (mRNA) in bovine endometrium. Reproductive tracts were collected from slaughtered cows at a local abattoir, and endometrial explants were treated with buserelin (0, 200, 500, 1000 ng mL-1 respectively), GnRH antagonist-antide (500 ng mL-1) and antide + buserelin (500+200 ng mL-1) for 6 h and stored at -80°C for RNA extraction. Two micrograms of total RNA was subjected to reverse transcription polymerase chain reaction, PCR products electrophoresed (2% agrose gel); visualized and statistically analyzed. The results showed that buserelin (200 ng mL-1) increased the expression of ERα in the luteal phase endometrium. In addition, the expression of endometrial ERα was greater during the follicular than luteal phase. This up regulation of ERα mRNA in luteal phase endometrium suggests that GnRH administration may influence pregnancy in bovines. Key words: GnRH, bovine, endometrium, estrogen receptors, progesterone receptors