bluuebunny/crossref_metadata_2025 huggingface dataset:
Programme‐related stressors among part‐time undergraduate nursing students
Authors: Nicholl Honor , Timmins Fiona
Published: March 2005

Aim.  The aim of this paper is to report a study exploring the perceived stressors identified by a group of 70 students who undertook a part‐time degree at one Irish university.

Background.  In the literature on stress, part‐time nursing students who are undertaking continuing education programmes appear to have received little attention. Stress amongst nurses is evident within the nursing literature but little information is available on the specific stressors that affect Registered Nurses who undertake further academic study. Anecdotally, students attending part‐time programmes while working full‐time report high levels of stress.

Method.  Quantitative methods were used. While many instruments exist to measure overall stress, this study aimed to explore student's perceptions of specific stressors associated with academic study. We used a questionnaire developed from the literature on the topic.

Results.  Factors related to writing assignments at degree level, fulfilling personal needs and academic demands, were perceived as major stressors by these students. Factors of little concern were financial issues and attendance on the programme. Individual items receiving highest mean scores were: trying to balance work commitments and the required study (mean 3·89, sd = 1) and the prospect of the final examination (mean 3·86, sd = 1). This study was limited by the use of convenience sampling and self‐report methods. Larger studies are required to support the findings. In addition, student stress was not observed or measured.

Conclusion.  Those involved in the delivery of nurse education programmes to part‐time students need to consider the impact of the workload on student welfare, and to prepare students for demands of the programme.
Factors influencing the decision of older people living in independent units to enter the acute care system
Authors: Cheek Julianne , Ballantyne Alison , Roder‐Allen Gerda
Published: March 2005

Aims and objectives.  This South Australian‐based study explored and described the factors influencing the decision of older people living in the community in independent living units to enter the acute care system.

Background.  Community‐based older Australians, an increasing population segment, make choices about support needed to optimize health and well‐being. This includes when to enter the acute care system. Entering this system has potential risks as well as benefits. The current South Australian Department of Human Services policies of ‘keeping older people out’ of the acute care system has implications for prevention and early intervention measures and requires an understanding of how and why older people enter the acute care system.

Method.  In‐depth interviews were conducted with older people (N = 31) and their families (N = 10), drawn from three South Australian aged care organizations providing independent living unit accommodation, and focus groups (N = 14) were conducted with stakeholders to identify factors influencing the decision of older people living in independent living units to enter the acute care system.

Findings.  Analysis of the data revealed eight facets influencing this group of older people's decision‐making with respect to entering the acute care system; they were: expectations of support in the independent living unit not being met; the presence/absence of safety nets; lack of after‐hours support; the desire to remain independent; the general practitioner as pivotal; the influence of others; perceptions of the emergency department; and having access to information.

Relevance to practice.  These facets provide insights into entry processes, links and relationships that form an interface between primary care, community care, the aged care industry and the acute system. Analysis of these insights highlight prevention and early intervention responses that can promote the health and well‐being of older people, potential ways to streamline services, as well as gaps in current services.
Involvement of older people in care, service and policy planning
Authors: Cook Glenda , Klein Barbara
Published: March 2005

In line with other helping professions nursing has moved from traditional views of technical expertise as the prime shaper of health care, to a more equal relationship with service users and patients which respects their expertise, knowledge, goals and choices. This philosophy has underpinned the movement to involve older people in care, policy and planning activities. The literature review presented in this paper highlights the growing literature on this subject with respect to older people and maps the key issues and debates for nursing.
Nutritional status and clinical outcomes of older patients in rehabilitation
Authors: Neumann S. A. , Miller M. D. , Daniels L. , Crotty M.
Published: March 2005

Background  Malnutrition is associated with poor outcomes in older adults and those admitted to rehabilitation may be particularly at risk.

Objective  To assess the nutritional status and outcomes of older adults in rehabilitation.

Subjectsandmethods  We recruited 133 adults ≥65 years from consecutive rehabilitation admissions. Nutritional status was assessed using the mini nutritional assessment, body mass index (BMI) and corrected arm muscle area (CAMA). Outcomes measured included length of stay, admission to higher level care, function and quality of life (QOL).

Results  Sixty‐two (47%) subjects were well nourished, 63 (47%) at risk of malnutrition and eight (6%) malnourished. Twenty‐two (17%) and 27 (20%) were below the desirable reference values for BMI and CAMA respectively. Subjects at risk of malnutrition/malnourished had longer length of stay (P = 0.023) and were more likely to be admitted to higher level care (P < 0.05). These subjects also had poorer function on admission (P < 0.001) and 90 days (P = 0.002) and QOL on admission (P < 0.008) and 90 days (P = 0.001). Those with low CAMA were twice as likely to be admitted to higher level care (P < 0.05) and had poorer function at 90 days (P = 0.017).

Conclusions  Over half our sample was identified as at risk of malnutrition or malnourished and this was associated with poorer clinical outcomes.
Determinants of Bilateral Trade Protection
Authors: Thede Susanna
Published: March 2005

In this paper, determinants of bilateral protection levels are empirically identified when controlling for multilateral trade regulation and importing‐country‐specific factors. Strong empirical support is provided of that three bilateral factors are influencing the bilateral protection level. Specifically, a country's protection level on goods from a trade partner is positively affected by the domestic import penetration of goods produced by the trade partner, negatively influenced by the intra‐industry traded share of these imports and positively affected by the trade partner's protection level on domestic goods. Moreover, very high explanatory values are provided in the cross‐section estimations, indicating that these determinants, policy regulations and importer‐specific factors jointly explain almost all of the variation in bilateral protection levels. The results are general in the sense that estimations are performed for a large sample of bilateral trade relations including 22 trade partners that are highly differentiated in terms of country characteristics. The overall results indicate that, to the extent that policy makers can affect bilateral protection levels under multilateral trade regulation, they act on political‐economy rather than economic goals.
On the Adequacy of Monetary Arrangements in Sub‐Saharan Africa
Authors: Bénassy‐Quéré Agnès , Coupet Maylis
Published: March 2005

We examine the economic rationale for monetary union(s) in Sub‐Saharan Africa through the use of cluster analysis on a sample of 17 countries. The variables used stem from the theory of optimum currency areas and from the fear‐of‐floating literature. It is found that the existing CFA franc zone cannot be viewed as an optimum currency area: CEMAC and UEMOA countries do not belong to the same clusters, and a ‘core’ of the UEMOA can be defined on economic grounds. The results support the inclusion of the Gambia, Ghana and Sierra Leone in an extended UEMOA arrangement, or the creation of a separate monetary union with the ‘core’ of the UEMOA and the Gambia, rather than the creation of a monetary union around Nigeria. Finally, the creation of the West African Monetary Zone (WAMZ) around Nigeria is not supported by the data.
Quality Measures in Food Trade: The Indian Experience
Authors: Sawhney Aparna
Published: March 2005

World trade in food has expanded significantly over the years and traditional tariff barriers have reduced with increasing commitments under the WTO. The industrialised countries potentially offer higher returns to food exporters from developing countries, but also pose a greater challenge in market access through stringent safety and quality standards. This paper analyses how this has impacted the Indian marine export industry, and the industry response to this challenge. The large firms are upgrading to signal quality in the OECD markets, while the small firms remain below the quality mark and are catering to other developing country markets where standards are not as stringent. Quality certification has thus become the basis of product differentiation and affected the pattern of trade. On the institutional front, a significant positive change is evident, with the Indian government taking measures to raise safety standards in the domestic food processing sector and increasing the credibility of its export certification agency abroad. There are also cooperative initiatives to improve testing facilities and promote equivalence of certification with OECD countries. The two‐pronged approach of investment in upgrading the food processing industry and promoting international partnership in certification with destination markets offers a good model to address the continuous quality challenge facing other food exporting developing countries.
Policy Networks, Elections, and State Subsidies1
Authors: Zahariadis Nikolaos
Published: March 2005

What are the effects of electoral competition on the disbursement of state subsidies in industrialized democracies? I argue that the scope of subsidies, which ranges from economy‐wide to regional and industry‐specific subsidies, is determined by the extent of political (electoral) monopoly conditioned by economic threats from foreign competition. The mechanism through which electoral competition is linked to subsidies is the policy network. I assess this argument by examining thirteen Organization for Economic Cooperation and Development (OECD) countries in the period 1990–1993. The findings offer amendments to models of policy networks and speak to the importance of domestic institutions on factor mobility and trade policy.
Border Security Technologies: Local and Regional Implications
Authors: Ackleson Jason
Published: March 2005

The Bush administration's “Smart Border” accords with Mexico and Canada present a number of important implications for North America's border communities and regions. As part of the plans, new security technologies have emerged as the preferred policy solution to the difficult problem of screening for weapons and terrorist incursions into the United States through its international boundaries while maintaining flows of goods and individuals, key drivers of globalization and hallmarks of the North American Free Trade Agreement (NAFTA) era. These new technological systems have various capabilities, ranging from prescreening cargo to identifying problematic travelers to detecting nuclear material in trucks. Deploying these systems in border communities, however, invokes a range of important economic, social, and political challenges, all of which are under examination in this work. Using a risk‐centered approach to United States border security, this article explores several technologically oriented border control systems: screening, biometrics, and information technology. The research is based on regional field research and a public policy analysis method that uses Birkland's “focusing event” framework, a model that provides insights into the postcrisis policy formation process. The article concludes by offering an initial appraisal of these policies within the context of risk, interdependent border communities, and an open democratic society.
A Prospect Theory Analysis of California's Initiatives in Implementation of its Zero Emission Vehicles (ZEV) Mandate1
Authors: Majumdar Sarmistha R.
Published: March 2005

In 1990, the state of California passed the pioneering mandate on zero emission vehicles (ZEV). This technology‐forcing regulation is aimed at improvement of air quality and protection of public health from the adverse effects of air pollutants from automobiles. Facing severe opposition from the auto industry, the mandate has been revised a number of times, most recently in 2003, whereby the requirement for ZEVs have been made to align with the pace of technology development. Review of strategies used in implementation of the mandate has revealed greater emphasis on the economic incentives for rather than on environmental merits of ZEVs. Using prospect theory as the framework for analysis, the reasons have been explored. The findings of the study help us to understand how decisions are made with respect with to deviations from a mental anchor point and through the process of evaluation of losses and gains.
Utilization‐Focused Evaluation
Authors: Briedenhann Jenny , Butts Steve
Published: March 2005

Governments, in both developed and less‐developed nations, promote rural tourism as an instrument of socioeconomic development. Tourism scholars highlight the use of evaluation as a tool in managing the development of tourism. Despite this, few evaluation studies appear to form an integral part of tourism development practice. Nevertheless, systematic evaluation is becoming a more common constituent of tourism policy and planning. However, the importance of evaluation lies not only in its technical correctness, but also in how the evaluation results are used. The emphasis on the use of evaluation findings in the utilization‐focused evaluation approach suggested by this article is congruent with this contention.
Systematic, Political, and Socioeconomic Influences on Educational Spending in the American States1
Authors: Saeki Manabu
Published: March 2005

For decades, scholars have debated the relative explanatory power of economic and political factors in determining policy outputs. In addition, I introduce a new concept, “systematic determinants,” which includes incrementalism and proportionalism. Policy spending is likely to change only marginally, or incrementally, from previous spending levels. Also, the relative sizes of policy programs in a government are likely to remain similar, or proportional.

In my study of the elementary and secondary educational spending by the state governments of the United States in 2000, I found that the systematic determinants, such as incrementalism and proportionalism, have a greater influence on the educational spending. Also, my finding shows that Democratic‐majority legislative chambers are likely to increase educational spending.
Ceramic Matrix Composites: A Challenge in Space‐Propulsion Technology Applications
Authors: Schmidt Stephan , Beyer Steffen , Immich Hans , Knabe Helmut , Meistring Rolf , Gessler Andreas
Published: March 2005

Various technology programs in Europe are concerned, besides developing reliable and rugged, low‐cost, throwaway equipment, with preparing for future reusable propulsion technologies. One of the key roles for realizing reusable engine components is the use of modern and innovative materials. One of the key technologies that concerns various engine manufacturers worldwide is the development of fiber‐reinforced ceramics—CMCs (ceramic matrix composites). The advantages for the developers are obvious–the low specific weight, the high specific strength over a large temperature range, and their great damage tolerance compared with monolithic ceramics make this material class extremely interesting as a construction material. Over the past few years, the EADS‐ST Company (formerly DASA) has, together with various partners, worked intensively on developing components for hypersonic engines and liquid rocket propulsion systems. In the year 2000, various hot‐firing tests with subscale (scale 1:5) and full‐scale nozzle extensions were conducted. In this year, a further decisive milestone was achieved in the sector of small thrusters, and long‐term tests served to demonstrate the extraordinary stability of the C/SiC material. Besides developing and testing radiation‐cooled nozzle components and small‐thruster combustion chambers, EADS‐ST worked on the preliminary development of actively cooled structures for future reusable propulsion systems. In order to get one step nearer to this objective, the development of a new fiber composite was commenced within the framework of a regionally sponsored program. The objective here is to create multidirectional (3D) textile structures combined with a cost‐effective infiltration process. Besides material and process development, the project also encompasses the development of special metal/ceramic and ceramic/ceramic joining techniques as well as studying and verifying nondestructive investigation processes for the purpose of testing components.
Evaluation of Oxide–Oxide Composites in a Novel Combustor Wall Application
Authors: Parthasarathy Triplicane A. , Zawada Larry P. , John Reji , Cinibulk Michael K. , Kerans Ronald J. , Zelina Joseph
Published: March 2005

Oxide–oxide composites were evaluated in a novel combustor design requiring higher wall temperatures than the conventional combustors. The evaluation was based on a combination of numerical modeling and experimental rig testing. The modeling included computational fluid dynamics (CFD) calculations whose results were used in a thermo‐mechanical analysis using finite element modeling (FEM). The composites tested experimentally were obtained from a commercial vendor; they were reinforced using Nextel™ 720 fibers. The rig tests showed that aluminosilicate matrix composites with higher room temperature strengths suffered cracking while the weaker alumina matrix composites performed satisfactorily. The results were consistent with numerical models that predicted residual stresses from creep during service. The models showed that in‐plane gradients and their effects were more severe than those of through‐thickness gradients and suggest that tailoring fiber architecture is important in transitioning these composites to applications.
Effects of Combustor Rig Exposure on a Porous‐Matrix Oxide Composite
Authors: Mattoni Michael A. , Yang James Y. , Levi Carlos G. , Zok Frank W. , Zawada Larry P.
Published: March 2005

The present study explores the effects of exposure in a laboratory combustor on microstructural stability and property retention of an all‐oxide fiber‐reinforced ceramic composite. The material consists of a porous mullite–alumina matrix and Nextel 720 fibers in an eight‐harness satin weave. To assess the effects of matrix strength, two matrix conditions are used, distinguished from one another by the amount of alumina added through precursor impregnation and pyrolysis (1.8% and 4.8%). In both cases, the dominant damage mode upon exposure involves interply delamination along the panel midplane. However, significant reductions in the rate and extent of cracking are obtained in the material with higher alumina content: a result of the higher delamination resistance. Mechanical tests performed on exposed specimens reveal a slight (10–20%) reduction in tensile strength along the fiber direction and a comparable increase in shear strength. These trends suggest some sintering of the matrix upon exposure. Examinations of fracture surfaces provide additional supporting evidence. Implications for long‐term performance and strategies for imparting improvement in microstructural stability and delamination resistance are discussed.
Ceramic Matrix Composites Life Cycle Testing Under Reusable Launcher Environmental Conditions
Authors: Trabandt Ulrich , Esser Burkhard , Koch Dietmar , Knoche Ralf , Tumino Giorgio
Published: March 2005

This article focuses on the thermal protection system (TPS) and hot structures based on carbon fiber‐reinforced SiC (C/SiC) material, which protects the high thermal‐loaded areas and control surfaces of a reusable launch vehicle (RLV). The goal of the test program is the evaluation of the lifetime of different types of TPS under reusability aspects for RLV application, reflecting the re‐entry environments together with the effect of impacts from low‐speed impact, rain erosion, and hail core impact. The test results of the C/SiC samples with the self‐healing oxidation protection system showed very promising results concerning reusability and lifetime.
Modeling Developable Folds on a Strip
Authors: Tang Kai , Wang Charlie C. L.
Published: March 2005

A common operation in clothing and shoe design is to design a folding pattern over a narrow strip and then superimpose it with a smooth surface; the shape of the folding pattern is controlled by the boundary curve of the strip. Previous research results studying folds focused mostly on cloth modeling or in animations, which are driven more by visual realism, but allow large elastic deformations and usually completely ignore or avoid the surface developability issue. In reality, most materials used in garment and shoe industry are inextensible and uncompressible and hence any feasible folded surface must be developable, since it eventually needs to be flattened to its two-dimensional pattern for manufacturing. Borrowing the classical boundary triangulation concept from descriptive geometry, this paper describes a computer-based method that automatically generates a specialized boundary triangulation approximation of a developable surface that interpolates a given strip. The development is achieved by geometrically simulating the folding process of the sheet as it would occur when rolled from one end of the strip to the other. Ample test examples are presented to validate the feasibility of the proposed method.
A Web-Based Interactive Virtual Environment for Mobile Phone Customization
Authors: Wang Peijun , Bja¨rnemo Robert , Motte Damien
Published: March 2005

With globalization, more and more companies are becoming multisited. Efficient and timely collaboration and communication among the development team members become critical for product success. This paper proposes a web-based virtual environment for mobile phone customization, named VMPDS (Virtual Mobile Phone Design Space). The features of this system include the combination of web technology and VR (Virtual Reality) technology, the ability to deal with and extend the product model database, adequate interaction for three-dimensional product model customization, and usefulness for the examination and evaluation of product concept design. The system is implemented by using standard open technologies to assure accessibility and platform independence.
A Linear Programming Solution for Exact Collision Detection
Authors: Akgunduz Ali , Banerjee Prashant , Mehrotra Sanjay
Published: March 2005

This paper addresses the issue of real-time collision detection between pairs of convex polyhedral objects undergoing fast rotational and translational motions. Accurate contact information between objects in virtual reality based simulations such as product design, assembly analysis, performance testing and ergonomic analysis of products are critical factors to explore when desired realism is to be achieved. For this purpose, fast, accurate and robust collision detection algorithms are required. The method described in the text models the exact collision detection problem between convex objects as a linear program. One of the strengths of the proposed methodology is its capability of addressing high speed interframe collision. In addition to the interframe collision detection, experimental data demonstrate that mathematical programming approaches offer promising results in terms of speed and robustness as well.
A Turn in the Epistemology and Hermeneutics of Twentieth Century U⋅ūl al-Fiqh
Authors: Johnston David
Published: March 2005

I argue here that an epistemological shift has taken place in twentieth century u⋅ūl al-fiqh: away from the classical/orthodox Ash'arī position in which the human mind simply discovers the divine law and extends it to new cases on the basis of consensus (ijmā') and analogical reasoning (qiyās); and toward a position in which reason is empowered to uncover the ratio legis behind the divine injunctions — a distinctly Mu'tazilī a pproach. This shift has been accompanied by a privileging of universal ethical principles (kulliyyāt), now identified as the aims of the Law (maqā⋅id al-sharī'a), over the specific injunctions of the texts (juz'iyyāt) — a hermeneutic strategy that has often favored public interest (ma⋅laha) as the chief criterion for developing fresh legal rulings in the light of new sociopolitical conditions. The main theoreticians discussed h ere are Muhammad'Abduh, Muhammad Rashīd Ridā,'Abd al-Razzāq Sanhūrī, 'Abd al-Wahhāb Khallāf, Muhammad Abū Zahra, and Muhammad Hashim Kamali.
Human Resource Dependence and Organizational Demography: A Study of Minority Employment in Private Sector Companies
Authors: Fields Dail L. , Goodman Jodi S. , Blum Terry C.
Published: March 2005

This study examines the extent to which firms’ human resource dependence explains the representation of Black employees in nonmanagement, management, and top-management jobs. Human resource dependence is a firm-level construct describing the degree to which an organization has difficulty procuring and maintaining supplies of human resources. Indicators of human resource dependence in 154 private sector firms explained the representation of Black employees in nonmanagement and management-level jobs but did not predict Black employee representation in top-management jobs. The results provide new insights into characteristics of firms that shape the demographic makeup of the workplace.
Ownership and the Internationalization of Small Firms
Authors: George Gerard , Wiklund Johan , Zahra Shaker A.
Published: March 2005

Small and medium-sized enterprises (SMEs) play an important role in international markets. This study argues that the ownership structures of SMEs influence their proclivity to take risks and expand the scale and scope of their internationalization efforts. Data from 889 Swedish SMEs reveal that internal owners (CEOs and other senior executives) tend to be risk averse and have a lower proclivity to increase scale and scope of internationalization than external owners (venture capitalists and institutional investors). The results provide interesting insights into the behavioral change of executives regarding the scale and scope of internationalization in the presence of external ownership.
Linking Leader Skills, Follower Attitudes, and Contextual Variables via an Integrated Model of Charismatic Leadership
Authors: Groves Kevin S.
Published: March 2005

A charismatic leadership model consisting of leader social and emotional skills, follower openness to organizational change, and organizational-change magnitude was tested using data from 108 leaders and 325 direct followers in 64 organizations. Leader social control and emotional expressivity skills predicted charismatic leadership whereas follower openness to change mediated the relationship between charismatic leadership and leadership effectiveness. Surprisingly, organizational-change magnitude did not moderate the relationship between charismatic leadership and leadership effectiveness. Implications for leadership theory, practice, and future research are discussed.
The Impact of Ownership Structure on Wage Intensity in Japanese Corporations
Authors: Yoshikawa Toru , Phan Phillip H. , David Parthiban
Published: March 2005

The authors studied the effect of ownership structure on human capital investments as indicated by wage intensity, defined as the ratio of expenditure on employee wages to sales, in a sample of 996 Japanese manufacturing firms during their economic recession of 1998-2002. They found that domestic shareholders, with interests beyond financial considerations, enhance wage intensity, especially when performance is low, and thereby safeguard human capital investments. Foreign shareholders with sole interest in financial returns have an opposite effect; they reduce wage intensity when firm performance is low.
The Impact of Extent of Telecommuting on Job Satisfaction: Resolving Inconsistent Findings
Authors: Golden Timothy D. , Veiga John F.
Published: March 2005

Although popular management wisdom has suggested that telecommuting enhances job satisfaction, research has found both positive and negative relationships. In this study, the authors attempt to resolve these inconsistent findings by hypothesizing a curvilinear, inverted U-shaped relationship between the extent of telecommuting and job satisfaction. Using hierarchical regression analysis on a sample of 321 professional-level employees, their findings suggest a curvilinear link between extent of telecommuting and job satisfaction, with satisfaction appearing to plateau at more extensive levels of telecommuting. In addition, task interdependence and job discretion moderated this link, suggesting that some job attributes play an important, contingent role.
The Search for Trust: Technology, Religion, and Society’s Dis-Ease
Authors: Foltz Franz , Foltz Frederick
Published: March 2005

Modern technology, and information technology in particular, has changed the nature of human interaction, which has created a certain “disease” as more and more transactions move from the familiarity of traditional community to the abstractness of modern society. This article explores two studies of trust that emerged in the past decade as a result of this “disease.” The first, rational choice, redefines trust as a risk management tool. The second, social capital, reexamines the traditional concept in light of the present situation. Our study compares both definitions with traditional Judeo-Christian conceptions of trust and measures them against the demands of the new world introduced by the Internet. We find that both definitions are lacking, offering little reason to speak of trust outside of direct human interaction. The studies reveal severe limitations when attempting to mediate trust by technology.
Hindlimb function in the alligator: integrating movements, motor patterns, ground reaction forces and bone strain of terrestrial locomotion
Authors: Reilly Stephen M. , Willey Jeffrey S. , Biknevicius Audrone R. , Blob Richard W.
Published: March 2005

Alligator hindlimbs show high torsional loads during terrestrial locomotion, in sharp contrast to the bending or axial compressive loads that predominate in animals that use parasagittal limb movements. The present study integrates new data on hindlimb muscle function with previously obtained data on hindlimb kinematics, motor patterns, ground reaction forces and bone strain in order to (1) assess mechanisms underlying limb bone torsion during non-parasagittal locomotion in alligators and (2) improve understanding of hindlimb dynamics during terrestrial locomotion. Three dynamic stance phase periods were recognized: limb-loading, support-and-propulsion, and limb-unloading phases. Shear stresses due to torsion were maximized during the limb-loading phase, during which the ground reaction force (GRF) and caudofemoralis (CFL) muscles generated opposing moments about the femur. Hindlimb retraction during the subsequent stance-and-propulsion phase involves substantial medial rotation of the femur, powered largely by coordinated action of the GRF and CFL. Several muscles that actively shorten to flex and extend limb joints during stance phase in sprawling and erect quadrupeds act in isometric or even eccentric contraction in alligators, stabilizing the knee and ankle during the support-and-propulsion phase. Motor patterns in alligators reveal the presence of local and temporal segregation of muscle functions during locomotion with muscles that lie side by side dedicated to performing different functions and only one of 16 muscles showing clear bursts of activity during both stance and swing phases. Data from alligators add to other recent discoveries that homologous muscles across quadrupeds often do not move joints the same way as is commonly assumed. Although alligators are commonly considered models for early semi-erect tetrapod locomotion, many aspects of hindlimb kinematics, muscle activity patterns, and femoral loading patterns in alligators appear to be derived in alligators rather than reflecting an ancestral semi-erect condition.
In vivomuscle functionvsspeed II. Muscle function trotting up an incline
Authors: Wickler Steven J. , Hoyt Donald F. , Biewener Andrew A. , Cogger Edward A. , De La Paz Kristin L.
Published: March 2005

Different locomotor tasks, such as moving up or down grades or changing speed, require that muscles adjust the amount of work they perform to raise or lower, accelerate or decelerate the animal's center of mass. During level trotting in the horse, the triceps had shortening strains of around 10.6%while the vastus shortened 8.1% during the stance phase. Because of the 250%increase in metabolic rate in horses trotting up a 10% incline which is,presumably, a result of the increased requirement for mechanical work, we hypothesized that muscle strain during trotting would be increased in both the triceps and the vastus over that observed when trotting on the level. Because times of contact are similar in level and incline trotting, we also hypothesized that strain rates of these muscles would be increased,accompanied by an increase in EMG activity. We examined the lateral head of the triceps and the vastus lateralis while trotting up a 10% incline(5.7°) over a range of speeds. The triceps shortened by 18% compared with 10.6% shortening on the level, and the vastus shortened by 18.5% compared with 8.1% on the level. The increased shortening velocities that were observed in both muscles probably reduced the force that any given set of activated muscle fibers could produce. If this pattern held for other limb muscles that do work to elevate the horse's center of mass on an incline, then a greater volume of muscle would have to be recruited to generate an equivalent force for body support. This was reflected in significant increases in the EMG intensity(IEMG) of both muscles.
Nitric oxide synthase in the gill of Atlantic salmon: colocalization with and inhibition of Na+,K+-ATPase
Authors: Ebbesson Lars O. E. , Tipsmark Christian K. , Holmqvist Bo , Nilsen Tom , Andersson Eva , Stefansson Sigurd O. , Madsen Steffen S.
Published: March 2005

We investigated the relationship between nitric oxide (NO) and Na+,K+-ATPase (NKA) in the gill of anadromous Atlantic salmon. Cells containing NO-producing enzymes were revealed by means of nitric oxide synthase (NOS) immunocytochemistry and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) histochemistry, which can be used as an indicator of NOS activity, i.e. NO production. Antibodies against the two constitutive NOS isoforms, neuronal and endothelial NOS, both produced immunoreactivity restricted to large cells at the base and along the secondary lamellae. NADPHd-positive cells showed a corresponding distribution. Antibodies against the inducible NOS isoform only labeled small cells located deep in the filament. Using in situ hybridization and NKA immunoreactivity, cells expressing Na+,K+-ATPaseα-subunit mRNA were found to have a similar distribution to the NOS cells. Double labeling for NOS immunoreactivity and NKA α-subunit mRNA revealed cellular colocalization of NKA α-subunit mRNA and nNOS protein in putative chloride cells at the base of the lamellae and interlamellar space. Along the lamellae, some NOS- or NKA-immunoreactive cells possessed a relatively lower expression of NKA α-subunit mRNA in smolts. A clear increase in NADPHd staining in the gill was demonstrated from parr to smolt. The regulatory role of NO on gill NKA activity was studied in vitrousing sodium nitroprusside (SNP; 1 mmol l-1) and PAPA-NONOate(NOC-15; 0.5 mmol l-1) as NO donors. Both SNP and NOC-15 inhibited gill NKA activity by 30% when compared to controls. The study shows that NO systems are abundant in the gill of Atlantic salmon, that NO may be produced preferentially by a constitutive NOS isoform, and suggests that NO influence on gill functions is mediated via intracellular, possibly both auto/paracrine,inhibition of Na+,K+-ATPase activity in chloride cells. Furthermore, the increase in NADPHd in the gill during smoltification suggests a regulatory role of NO in the attenuation of the smoltification-related increase in Na+,K+-ATPase activity prior to entering seawater.
Hypotonic shock mediation by p38 MAPK, JNK, PKC, FAK, OSR1 and SPAK in osmosensing chloride secreting cells of killifish opercular epithelium
Authors: Marshall W. S. , Ossum C. G. , Hoffmann E. K.
Published: March 2005

Hypotonic shock rapidly inhibits Cl- secretion by chloride cells, an effect that is osmotic and not produced by NaCl-depleted isosmotic solutions, yet the mechanism for the inhibition and its recovery are not known. We exposed isolated opercular epithelia, mounted in Ussing chambers, to hypotonic shock in the presence of a variety of chemicals: a general protein kinase C (PKC) inhibitor chelerythrine, Gö6976 that selectively blocks PKCα and β subtypes, H-89 that blocks PKA, SB203580 that blocks p38 mitogen-activated protein kinase (MAPK), as well as serine/threonine protein phosphatase (PP1 and 2A) inhibitor okadaic acid, and finally tamoxifen, a blocker of volume-activated anion channels (VSOAC). Chelerythrine has no effect on hypotonic inhibition but blocked the recovery, indicating PKC involvement in stimulation. Gö6976 had little effect, suggesting that PKCα and PKCβ subtypes are not involved. H-89 did not block hypotonic inhibition but decreased the recovery, indicating PKA may be involved in the recovery and overshoot (after restoration of isotonic conditions). SB203580 significantly enhanced the decrease in current by hypotonic shock, suggesting an inhibitory role of p38 MAPK in the hypotonic inhibition. Okadaic acid increased the steady state current, slowed the hypotonic inhibition but made the decrease in current larger; also the recovery and overshoot were completely blocked. Hypotonic stress rapidly and transiently increased phosphorylated p38 MAPK (pp38) MAPK (measured by western analysis) by eightfold at 5 min, then more slowly again to sevenfold at 60 min. Hypertonic shock slowly increased p38 by sevenfold at 60 min. Phosphorylated JNK kinase was increased by 40-50% by both hypotonic and hypertonic shock and was still elevated at 30 min in hypertonic medium. By immunoblot analysis it was found that the stress protein kinase (SPAK) and oxidation stress response kinase 1 (OSR1) were present in salt and freshwater acclimated fish with higher expression in freshwater. By immunocytochemistry,SPAK, OSR1 and phosphorylated focal adhesion kinase (pFAK) were colocalized with NKCC at the basolateral membrane. The protein tyrosine kinase inhibitor genistein (100 μmol l-1) inhibited Cl- secretion that was high, increased Cl- secretion that was low and reduced immunocytochemical staining for phosphorylated FAK. We present a model for rapid control of CFTR and NKCC in chloride cells that includes: (1) activation of NKCC and CFTR via cAMP/PKA, (2) activation of NKCC by PKC, myosin light chain kinase (MLCK), p38, OSR1 and SPAK, (3) deactivation of NKCC by hypotonic cell swelling, Ca2+ and an as yet unidentified protein phosphatase and (4) involvement of protein tyrosine kinase (PTK) acting on FAK to set levels of NKCC activity.
Temperature alters the respiratory surface area of crucian carpCarassius carassiusand goldfishCarassius auratus
Authors: Sollid Jørund , Weber Roy E. , Nilsson Göran E.
Published: March 2005

We have previously found that the gills of crucian carp Carassius carassius living in normoxic (aerated) water lack protruding lamellae,the primary site of O2 uptake in fish, and that exposing them to hypoxia increases the respiratory surface area of the gills ∼7.5-fold. We here examine whether this morphological change is triggered by temperature. We acclimated crucian carp to 10, 15, 20 and 25°C for 1 month, and investigated gill morphology, oxygen consumption and the critical oxygen concentration at the different temperatures. As expected, oxygen consumption increased with temperature. Also at 25°C an increase in the respiratory surface area, similar to that seen in hypoxia, occurred. This coincided with a reduced critical oxygen concentration. We also found that the rate of this transformation increased with rising temperature. Goldfish Carassius auratus, a close relative to crucian carp, previously kept at 25°C,were exposed to 15°C and 7.5°C. At 7.5°C the respiratory surface area of its gills was reduced by development of an interlamellar cell mass as found in normoxic crucian carp kept at 10-20°C. Thus, both species alter the respiratory surface area in response to temperature. Rather than being a graded change, the results suggest that the alteration of gill morphology is triggered at a given temperature. Oxygen-binding data reveal very high oxygen affinities of crucian carp haemoglobins, particularly at high pH and low temperature, which may be prerequisites for the reduced gill respiratory surface area at low temperatures. As ambient oxygen and temperature can both induce the remodelling of the gills, the response appears primarily to be an adaptation to the oxygen demand of the fish.
Honeybee flight metabolic rate: does it depend upon air temperature?
Authors: Woods William A. , Heinrich Bernd , Stevenson Robert D.
Published: March 2005

Differing conclusions have been reached as to how or whether varying heat production has a thermoregulatory function in flying honeybees Apis mellifera. We investigated the effects of air temperature on flight metabolic rate, water loss, wingbeat frequency, body segment temperatures and behavior of honeybees flying in transparent containment outdoors. For periods of voluntary, uninterrupted, self-sustaining flight, metabolic rate was independent of air temperature between 19 and 37°C. Thorax temperatures(Tth) were very stable, with a slope of thorax temperature on air temperature of 0.18. Evaporative heat loss increased from 51 mW g-1 at 25°C to 158 mW g-1 at 37°C and appeared to account for head and abdomen temperature excess falling sharply over the same air temperature range. As air temperature increased from 19 to 37°C,wingbeat frequency showed a slight but significant increase, and metabolic expenditure per wingbeat showed a corresponding slight but significant decrease. Bees spent an average of 52% of the measurement period in flight,with 19 of 78 bees sustaining uninterrupted voluntary flight for periods of>1 min. The fraction of time spent flying declined as air temperature increased. As the fraction of time spent flying decreased, the slope of metabolic rate on air temperature became more steeply negative, and was significant for bees flying less than 80% of the time. In a separate experiment, there was a significant inverse relationship of metabolic rate and air temperature for bees requiring frequent or constant agitation to remain airborne, but no dependence for bees that flew with little or no agitation;bees were less likely to require agitation during outdoor than indoor measurements. A recent hypothesis explaining differences between studies in the slope of flight metabolic rate on air temperature in terms of differences in metabolic capacity and thorax temperature is supported for honeybees in voluntary flight, but not under agitation.
Effect of microwave radiation on the biophysical properties of liposomes
Authors: Gaber Mohamed H. , Abd El Halim N. , Khalil W.A.
Published: March 2005

Steadily growing use of electromagnetic fields, especially in conjunction with wireless communication systems, has led to increasing public concern about possible health effects of electromagnetic radiation. However, besides the well‐known thermal effect of electromagnetic fields on biological tissue, there is no clear evidence of further athermal interaction mechanisms with biological systems. The present study was designed to determine the changes in bilayer permeability in egg lecithin multilamellar vesicles after exposure to 900 MHz microwave radiation for a period of 5 h. Specific absorption rate (SAR) of the radiation for the investigated liposome sample was found to be 12 ± 1 W/kg. Liposomal changes in permeability were monitored using a light scattering technique. Optical anisotropy of the liposome sample decreased dramatically upon exposure to microwave radiation, indicating structural changes in acyl chain packing. IR and NMR (1H NMR) studies, which have been employed to reveal structural alterations in microwave, exposed vesicles showed an increased damage upon exposure to microwave. The changes observed in the 1H NMR spectrum of the microwave exposed sample indicated hydrolysis of carboxylic and phosphoric esters. IR study showed conformational changes in the acyl chains of the lipids upon microwave exposure. However, both IR and 31P NMR did not show any appreciable changes in the head group part of the lipids. Bioelectromagnetics 26:194–200, 2005. © 2005 Wiley‐Liss, Inc.
Cadaveric observation of an aberrant left subclavian artery: A possible cause of thoracic outlet syndrome
Authors: Konuşkan Bahadır , Bozkurt M. Cem , Tağıl Süleyman Murat , Özçakar Levent
Published: March 2005

We report a rare anomaly of the left subclavian artery, coursing through the scalenus anterior muscle, that may cause thoracic outlet syndrome. We also discuss the anatomical basis of the possible diagnostic maneuvers for patients with thoracic outlet syndrome. Clin. Anat. 18:215–216, 2005. © 2005 Wiley‐Liss, Inc.
Electrostatic BEM for MEMS with thin beams
Authors: Bao Zhongping , Mukherjee Subrata
Published: March 2005

Micro‐electro‐mechanical (MEM) and nano‐electro‐mechanical (NEM) systems sometimes use beam‐ or plate‐shaped conductors that can be very thin—with h/L≈𝒪(10−2–10−3) (in terms of the thickness h and length L of a beam or the side of a square pate). Conventional boundary element method (BEM) analysis of the electric field in a region exterior to such thin conductors can become difficult to carry out accurately and efficiently—especially since MEMS analysis requires computation of charge densities (and then surface tractions) separately on the top and bottom surfaces of such objects. A new boundary integral equation (BIE) is derived in this work that, when used together with the standard BIE with logarithmically singular kernels, results in a powerful technique for the BEM analysis of such problems with thin beams. This new approach, in fact, works best for very thin beams. This thin beam BEM is derived and discussed in this work. Copyright © 2005 John Wiley & Sons, Ltd.