bluuebunny/crossref_metadata_2025 huggingface dataset:
Developing Mathematical Models of Neurobehavioral Performance for the “Real World”
Authors: Dean Dennis A. , Fletcher Adam , Hursh Steven R. , Klerman Elizabeth B.
Published: May 2007

Work-related operations requiring extended wake durations, night, or rotating shifts negatively affect worker neurobehavioral performance and health. These types of work schedules are required in many industries, including the military, transportation, and health care. These industries are increasingly using or considering the use of mathematical models of neurobehavioral performance as a means to predict the neurobehavioral deficits due to these operational demands, to develop interventions that decrease these deficits, and to provide additional information to augment existing decision-making processes. Recent advances in mathematical modeling have allowed its application to real-world problems. Developing application-specific expertise is necessary to successfully apply mathematical models, in part because development of new algorithms and methods linking the models to the applications may be required. During a symposium, “Modeling Human Neurobehavioral Performance II: Towards Operational Readiness,” at the 2006 SIAM-SMB Conference on the Life Sciences, examples of the process of applying mathematical models, including model construction, model validation, or developing model-based interventions, were presented. The specific applications considered included refining a mathematical model of sleep/wake patterns of airline flight crew, validating a mathematical model using railroad operations data, and adapting a mathematical model to develop appropriate countermeasure recommendations based on known constraints. As mathematical models and their associated analytical methods continue to transition into operational settings, such additional development will be required. However, major progress has been made in using mathematical model outputs to inform those individuals making schedule decisions for their workers.
Beyond Intuitive Modeling: Combining Biophysical Models with Innovative Experiments to Move the Circadian Clock Field Forward
Authors: Forger Daniel , Gonze Didier , Virshup David , Welsh David K.
Published: May 2007

Two major approaches have been used to model circadian clocks. Qualitative modeling, used prior to the recent wealth of detailed molecular knowledge, makes general predictions but cannot provide detailed mechanistic insights. The more recent biophysical approach, on the other hand, incorporates the biochemical events that drive the clock and can make detailed and testable molecular predictions. These predictions are being tested using new experimental techniques that measure reaction kinetics and the behavior of individual cells. A joint modeling and experimental approach has recently been used to understand how mutations affecting phosphorylation can lead to a short circadian period in tau mutant hamsters and in humans with familial advanced sleep phase syndrome (FASPS). Another recent study has revealed novel single-cell phenotypes of clock gene mutations, demanding revision of current biophysical models yet validating certain model predictions that were previously overlooked. A new paradigm for clock research is emerging in which modeling inspires new experimental efforts, experimental data inspire new modeling efforts, and joint modeling/experimental studies lead to a deeper understanding of mammalian circadian rhythms.
One More Piece to Make Us Puzzle
Authors: Bali Valentina A. , Davis Belinda C.
Published: May 2007

This article examines how the presence and usage of the initiative process impact the electoral chances of state legislators. Using individual-level data on state legislators across the states from 1970 to 1989, the authors find that the presence and frequency of use of the initiative do not hurt legislators' electoral chances. In fact, under certain institutional settings, the initiative process can have a small beneficial impact on legislator's reelection fortunes. In addition, the initiative can insulate legislators' electoral chances from national economic conditions. The authors argue these findings are compatible with the notion of state legislators adapting to the initiative process.
A Woman's Work Is Never Done? Fund-Raising Perception and Effort among Female State Legislative Candidates
Authors: Jenkins Shannon
Published: May 2007

The lack of female politicians has been attributed to a lack of female candidates for office. However, the reason why there are so few female candidates is not clear. The author examines whether differences in fund-raising perceptions and effort between female and male state legislative candidates contribute to the lack of female candidates. The results indicate that women do tend to be more concerned about fund-raising, as is evidenced by greater effort devoted to this campaign function as compared to their male counterparts. Women use more techniques and rely on more sources to secure funds for their campaigns. This suggests that part of the reason women are reluctant to run for office may be due to the fact that they will have to devote more effort to a task candidates generally find distasteful.
The Power of Decree
Authors: Rottinghaus Brandon , Maier Jason
Published: May 2007

Recent scholarship on unilateral presidential actions has recast our understanding of modern presidential policy making. However, our knowledge on this issue remains incomplete. In this article, the authors expand the literature on the unilateral presidency by exploring presidential proclamations from 1977 to 2005 (Presidents Carter to Bush) and identifying the importance of these tools as a policy-making instrument in expanding presidential power. By carefully examining the use of presidential proclamations, the authors discover that a majority of presidential proclamations involve presidential authority under congressionally delegated powers of international trade (and presidents most often use this authority to propose new trade arrangements or modify existing trade agreements), and they use this power in coordination with (but largely independent of) Congress. Presidents also use proclamations on the issue of national parks and federal lands exclusively to initiate new federal arrangements to establish new national parks or protections for federal lands, often against the will of Congress.
Talk Leads to Recruitment
Authors: Klofstad Casey A.
Published: May 2007

There is a positive relationship between how much we talk about politics and current events and how much we participate in civic activities. However, analytical biases make it difficult to accurately estimate the causal influence of talk on individual behavior. Moreover, existing data sources do not include information on the mechanisms that might explain how individuals translate talk into action. These problems are addressed with new data that were collected through a natural experiment. The results show that civic discussions promote civic participation largely because during such discussions we are recruited to become involved.
What Goes Around, Comes Around
Authors: Bejarano Christina , Segura Gary
Published: May 2007

The authors contrast the 2002 Senate and 2003 gubernatorial runoffs in Louisiana, noting that the margin and the breadth of victory were greater for a gubernatorial candidate who enjoyed less political resources than her copartisan. The authors argue that the GOP's southern strategy has constrained its ability to diversify its coalition and contributed to the defeat of its nonwhite candidate for governor. Using aggregate parish level data and individual survey responses, the authors demonstrate that the customary polarization of whites in favor of Republican nominees was undermined in the 2003 election. The authors offer some thoughts on the implications of the findings.
The Third Face of Social Capital
Authors: Claibourn Michele P. , Martin Paul S.
Published: May 2007

This article examines whether political accountability—the heart of a functioning democracy—is enhanced by citizen participation in voluntary associations. The authors contend that involvement in associations offers an easy avenue for acquiring political information, thereby aiding citizens in evaluating the president on the basis of the policies produced by the president. General Social Survey data from ten years, paired with presidential policy liberalism scores, are used to test the key hypothesis. The authors find support for the idea that membership in voluntary associations facilitates a more sophisticated policy accountability among citizens.
The Policy Opportunities in Presidential Honeymoons
Authors: Beckmann Matthew N. , Godfrey Joseph
Published: May 2007

This article investigates the policy opportunities in presidential honeymoons. Specifically, after reviewing a standard (pivotal politics) model of lawmaking where presidents' election results are treated as exogenous, we develop a (honeymoon politics) model in which a president's election results are treated as endogenous—that is, where legislators' positions factor in the president's electoral results among their constituents. Applying both models to every newly elected president and corresponding Senate since 1932, comparative statics show that presidents' policy-making prospects always improve in “honeymoon” settings, though this effect varies depending on lawmakers' preference distribution, presidents' electoral coalition, and the threshold required to invoke cloture.
A New Look at the Republican Advantage in Nonpartisan Elections
Authors: Schaffner Brian F. , Streb Matthew J. , Wright Gerald C.
Published: May 2007

Conventional wisdom has long held that Republicans are advantaged when partisan labels are removed from the ballot. However, in this article, the authors argue that the advantage gained from nonpartisan elections favors the minority party because the low-cost partisan cue is hidden from voters who otherwise would be inclined to support majority party candidates. The authors test this hypothesis using aggregate-level data from state legislative races in nonpartisan Nebraska and partisan Kansas, mayoral races in nonpartisan Phoenix and partisan Tucson, and California statewide races including the nonpartisan contest for superintendent of public instruction. Findings indicate that nonpartisan elections have partisan consequences but that the effect is in favor of the minority party rather than the Republican Party.
Black-Brown Coalitions in Local School Board Elections
Authors: Rocha Rene R.
Published: May 2007

As the racial composition of the United States becomes increasingly diverse, scholars have begun to examine whether interminority, or rainbow, coalitions are feasible. The power thesis suggests that lower levels of social distance between Anglos and Latinos will make the formation of Anglo-Latino coalitions more likely than black-Latino coalitions. This hypothesis is reexamined using fifteen hundred school board election results. The findings offer little evidence for the formation of Anglo-Latino coalitions. There are, however, indications that Anglo-black coalitions form when an area becomes populated by Latino noncitizens, possibly due to the increased social distance this causes between Latinos and other racial/ethnic communities.
Latino Attitudes toward Various Areas of Public Policy
Authors: Branton Regina
Published: May 2007

The growth of the Latino population and the increasing political importance of this group leads to questions about the potential political importance of this group. As such, it is important to gain a better understanding of political attitudes among Latinos. This study focuses on the relationship between Latino acculturation and attitudes toward immigration-and non-immigration-related public policies. The results indicate that Latino attitudes toward immigration related issues as well as other more general policy items vary as a function of one's level of acculturation.
Lose, Win, or Draw? A Reexamination of Direct Democracy and Minority Rights
Authors: Haider-Markel Donald P. , Querze Alana , Lindaman Kara
Published: May 2007

Researchers continue to disagree over how minority rights fare in direct democracy elections. The authors enter this debate by reviewing previous research and outlining more systematic criteria for assessing minority rights in the context of direct democracy. In applying these criteria, an analysis of direct democracy contests involving gay and lesbian civil rights suggests that minorities are more likely to lose in these contests. The authors suggest that the conclusions of previous researchers may have been premature and that their criteria should be applied to other minority groups.
A Specialized Domestic Violence Court in South Carolina
Authors: Gover Angela R. , Brank Eve M. , MacDonald John M.
Published: May 2007

The current research details interviews with 50 victims and 50 defendants who participated in a specialized criminal domestic violence court in Lexington County, South Carolina. These victims and defendants indicated satisfaction with their court experiences, thought the process allowed them to voice their views, felt they were treated with respect, and were generally satisfied with the outcome of their cases. Court observations and interviews with court personnel confirmed that this court has successfully incorporated victims and defendants into the decision-making process while also providing a fair system to address the issue of violence against women.
Night Terrors
Authors: Lowe Pam , Humphreys Cathy , Williams Simon J.
Published: May 2007

The management of sleep is embedded within the social context of individuals' lives. This article is based on an exploratory study using focus groups of the sleep problems encountered by 17 women survivors of domestic violence. It argues that fear becomes the organizing framework for the management of sleep and illustrates how this takes place both while living with the perpetrators of violence and after the women have been rehoused. It argues that sleep deprivation is a method used by the perpetrators to exert control over women and that this has long-term implications for women's physical and mental health.
The Impact of Bullying and Sexual Harassment on Middle and High School Girls
Authors: Gruber James E. , Fineran Susan
Published: May 2007

The impact of bullying and sexual harassment on six health outcomes among middle school girls were compared to these outcomes among high school girls. High school girls experienced more bullying and sexual harassment and poorer health outcomes than their middle school counterparts, but the impact of these experiences was less among high school students. Differences in outcomes may be the result of better support systems and coping mechanisms among high school girls and/or challenging developmental changes during middle school. Sexual orientation, race, and disability had some notable relationships to bullying and sexual harassment experiences as well as health outcomes.
Experiences With Intimate Partner Violence Among Latina Women
Authors: Hazen Andrea L. , Soriano Fernando I.
Published: May 2007

This study examined experiences with intimate partner violence in 292 Latina women classified as U.S. born, immigrant, or migrant-seasonal workers. High lifetime rates of violence were found, with 33.9% reporting physical violence, 20.9% reporting sexual coercion, and 82.5% reporting psychological aggression. Rates of violence in the preceding year were also high, with 18.5% experiencing physical violence, 14.4% experiencing sexual coercion, and 72.6% experiencing psychological aggression. Participants' marital status and partners' substance use were associated with victimization. The present findings suggest the need for screening for intimate partner violence and associated risk factors in settings that serve Latina women.
Leading on Top of the World: Lessons from Into Thin Air
Authors: Keller David
Published: May 2007

The problem and the solution. In May 1996, a rogue blizzard blindsided several teams of mountain climbers attempting to scale Mount Everest. Nine climbers died in the frigid conditions after enduring wind chill temperatures in excess of 100 degrees below zero (Fahrenheit). In 1997, author Jon Krakauer chronicled his own firsthand account of the Everest disaster in his best-selling book Into Thin Air. Using Krakauer's account as a backdrop, this article examines several of the leadership theories and concepts demonstrated in the failed climb. Specifically, this article explores the skills approach, situational leadership theory, and team leadership concepts, as well as the influence of power bases and trust on decision making. Finally, teaching strategies are discussed that the reader may find useful when using this work to develop leadership competencies in others.
Leadership in Desperate Times: An Analysis of Endurance: Shackleton's Incredible Voyage through the Lens of Leadership Theory
Authors: Browning Blair W.
Published: May 2007

The problem and the solution. Ernest Shackleton led a crew on the Endurance that would attempt to be the first group of individuals to cross the Antarctic continent overland. Only one day's sail away from the land, the Endurance became “iced in” and eventually sank, leaving the men with limited supplies. Shackleton's new goal quickly became getting every man home alive. Alfred Lansing's account of this amazing story, Endurance: Shackleton's Incredible Voyage, shows actual photographs and utilizes vivid accounts from different crew members' journals. Shackleton's leadership is viewed as nothing short of spectacular during this journey, and this article highlights three leadership approaches/ theories he displayed in this remarkable story: the skills and the style approaches and the contingency theory. Finally, this article offers various exercises and teaching tools that may aid instructors as they use this story in the classroom.
Relational Leadership: An Analysis of The Divine Secrets of the Ya-Ya Sisterhood
Authors: Mathis Robin Smith
Published: May 2007

The problem and the solution. The Divine Secrets of the Ya-Ya Sisterhood by Rebecca Wells describes the remarkable leadership and guidance that women provided their families and friends long before they were leaders in organizations.According to Popper and Mayseless (2003), parents, like transformational leaders, build trust with their children. Parents help guide their children to be autonomous, empowering them to believe and trust in themselves. Thus, parents take on the role of leaders; their characteristics and behaviors illustrate a wide variety of leadership theories, such as leader-member exchange and transformational leadership. Set in 20th-century Louisiana, Wells's (1999) The Divine Secrets of the Ya-Ya Sisterhood presents an explanation of the relentless support, trust, respect, loyalty, charisma, inspiration, stimulation, and consideration that make women leaders in their personal and professional spheres.
Year of Wonders: The Wonder of Leadership
Authors: Whitener J. Kori
Published: May 2007

Year of Wonders by Geraldine Brooks paints a disturbing, realistic picture of life in a small village in England in the year 1666 during the outbreak of bubonic plague. The tale of the life of the villagers and how they cope with the plague provides a backdrop for the emergence of unlikely leaders, testing of the traditional leaders within the society and revealing the weaknesses that have the potential to emerge in any leader.This is an examination of the characters within the novel and how their leadership characteristics and skills emerge and are tested. A variety of leadership theories and concepts can be seen in the leaders within the novel, including trait and process leadership; assigned and emergent leadership; the concept of power in society; path-goal theory; and transformational leadership. In this article, several characters in the novel are identified as leaders. Each of these identified characters is examined in terms of leadership theory and concepts.
The Magic of Leadership: An Exploration of Harr y Potter and the Goblet of Fire
Authors: Rosser Manda H.
Published: May 2007

The problem and the solution. One of the most popular movie series for all ages is Harry Potter, based on the books by J. K. Rowling.The fourth movie in the series, Harry Potter and the Goblet of Fire, offers lessons in decision making, risk, power, and ethics. In addition to a general discussion of the use of movies and leadership development, this article explores the use of a very popular movie in teaching leadership theory. Champoux (1999) states, “Film scenes can offer a visual portrayal of abstract theories and concepts.” Movies capture the leadership moments, allowing learners to better understand the lessons being taught. In addition to a general discussion of the use of movies and leadership development, this article explores the use of a very popular movie in teaching leadership theory.
Lost: A Sur vival Guide to Leadership Theory
Authors: Sudbrack Billie , Trombley Sarah
Published: May 2007

The problem and the solution. Perhaps some of the most revealing aspects about leadership can be evidenced through the examination of leaders facing extreme challenges. J. J. Abram's television program, Lost, provides a compelling backdrop for the study of leadership during such times of trial. Each week millions of viewers tune in to watch the struggles of the passengers of the doomed Oceanic Air Flight 815. Confronted with the constant struggle for survival in the context of bizarre occurrences, the passengers begin to demonstrate and reveal their leadership qualities and skills.This article analyzes five different leadership theories (trait, skills, path-goal, leader-member exchange, and team) using eight different characters from the television series to demonstrate leadership theory in practice. The article concludes with different teaching activities for facilitators to use when teaching various leadership theories and practices.
Pop Goes the Program: Using Popular Culture Artifacts to Educate Leaders
Authors: Callahan Jamie L. , Rosser Manda H.
Published: May 2007

The problem and the solution. Creating leaders requires both leadership education and leadership development activities.This article describes an innovative leadership education program that uses the popular culture artifacts described in this issue as a foundation for creating leaders. This program provides a flexibility that makes it applicable to delivery in either educational institutions or organizations.
Covert Association
Authors: Marshall W.L.
Published: May 2007

This article describes the application of a procedure derived from Cautela's covert sensitization, which expands the behavioral chain leading to the terminal behavior and dispenses with the need for the consequences to be repeatedly experienced as aversive. Covert association was applied to a child molester who abused boys. Results indicate that treatment produced a significant reduction in urges and fantasies relating to boys and reduced sexual responding to boys. Other features of the intervention produced an increased comfort by the client concerning his adult homosexual orientation and more effective social functioning. The covert association procedure is recommended for wider use.
Evaluation of Family-Implemented Behavioral Skills Training for Teaching Social Skills to a Child With Asperger's Disorder
Authors: Stewart Kelise K. , Carr James E. , LeBlanc Linda A.
Published: May 2007

Social deficits are a hallmark feature of Asperger's disorder. However, social skill training is often complicated because clinician trainers usually do not have the opportunity to observe social behavior in naturally occurring contexts. One way to overcome this limitation is to teach family members to become effective change agents for social behavior. A mother and a sibling of a child with Asperger's disorder were trained to use behavioral skills training (BST) procedures to teach him social skills at home. The authors collected direct observation data of (a) family member performance while learning BST, (b) family member performance while teaching the client a target social skill, and (c) client performance during BST intervention of the target skill. These data indicated that family members acquired proficient performance of BST and taught the client with a high degree of treatment integrity. An AB design was used to demonstrate that the child's frequency of the target social skill increased following BST intervention.
Integrating Jungian and Self-Psychological Perspectives Within Cognitive-Behavior Therapy for a Young Man With a Fixed Religious Delusion
Authors: Silverstein Steven M.
Published: May 2007

Although cognitive-behavior therapy (CBT) can be effective in reducing delusional thinking in schizophrenia, many patients are considered poor candidates, typically because of a lack of distress from the delusion and resistance or low motivation to challenge its validity. Recent developments in CBT for schizophrenia, however, stress the need to move from a sole focus on challenging beliefs toward a person-based model in which recognition of the vulnerability of the self guides treatment and the content of therapy is perceived as personally meaningful by the patient. This article demonstrates how the Jungian technique of archetypal amplification was modified and used within the structure of CBT treatment of a young man with schizophrenia with a religious delusion who refused to engage in standard CBT. His case demonstrates that schizophrenia patients who initially refuse to question the validity of their delusional beliefs can nevertheless be successfully engaged in CBT when the focus promotes alternative understandings of the self and preserves self-esteem.
Complexity and Comorbidity in a Case of Early-Onset Bipolar Disorder
Authors: Knowles Rebecca J.
Published: May 2007

A reproducible characteristic of early-onset bipolar disorder (BPD) is its atypicality when compared to the adult form. Research and practice consistently confirms early-onset BPD to be chronic rather than acute and continuous rather than episodic, with mixed manic states rather than biphasic and multifarious patterns of comorbidity. Research into successful psychotropic treatments for early-onset BPD is on-going and diverse. Similarly, psychosocial interventions are in the prototype phase. This school-based case study follows an 18-month course of treatment for a 16-year-old female with early-onset BPD comorbid with attentiondeficit/hyperactivity disorder (ADHD), obsessive-compulsive disorder, and situationally predisposed panic attacks. The first 6 months of treatment involved no medications. During this time, intensive psychosocial and cognitive-behavioral interventions including affect-regulation training, behavior modification, self-monitoring, contingency management, educational accommodations, emergency classroom protocols, and intensive psychotherapy were successfully implemented. In the second phase of treatment, after numerous unsuccessful psychotropic trials, the client's mood was stabilized with gabapentin (Neurontin), with methylphenidate (Ritalin) being added to treat her ADHD with astounding results.
Use of portable ultrasonography as a nondestructive method for estimating reproductive effort in lizards
Authors: Gilman Casey A. , Wolf Blair O.
Published: May 2007

Obtaining population-level life history data such as egg and clutch size in reptiles has most often required that individuals be sacrificed. This prevents a reexamination of individuals over intra-annual and inter-annual time scales,limiting insight into the effects of varying environmental conditions on reproductive output. Here, we test the use of a laptop-sized portable ultrasound imaging system as a nondestructive means for quantifying reproductive investment in five species of lizards with a range of body sizes,forms and life histories. Ultrasound scans produced egg counts that were accurate for clutch sizes of two to seven eggs, and provided good estimates(within 5.5±1.69 eggs, mean ± s.e.m., relative error 21%) for clutch sizes of between 18 and 41 eggs. Egg measurements using virtual calipers produced average egg volumes that deviated from actual volumes by 0.09±0.01 cm3 (relative error 25.9%), and estimated clutch volumes that differed from actual volumes by 1.03±0.26 cm3(relative error 29.5%). We also monitored development in five lizard species and found that changes in follicle and egg size and degree of embryonic development can be measured over periods of just a few days.
Low speed maneuvering flight of the rose-breasted cockatoo (Eolophus roseicapillus). I. Kinematic and neuromuscular control of turning
Authors: Hedrick T. L. , Biewener A. A.
Published: May 2007

Maneuvering flight has long been recognized as an important component of the natural behavior of many bird species, but has been the subject of little experimental work. Here we examine the kinematics and neuromuscular control of turning flight in the rose-breasted cockatoo Eolophus roseicapillus(N=6), testing predictions of maneuvering flight and control based on aerodynamic theory and prior kinematic and neuromuscular studies. Six cockatoos were trained to navigate between two perches placed in an L-shaped flight corridor, making a 90° turn midway through each flight. Flights were recorded with three synchronized high-speed video cameras placed outside the corridor, allowing a three-dimensional reconstruction of wing and body kinematics through the turn. We simultaneously collected electromyography recordings from bilateral implants in the pectoralis, supracoracoideus, biceps brachii and extensor metacarpi radialis muscles. The cockatoos maneuvered using flapping, banked turns with an average turn radius of 0.92 m. The mean rate of change in heading during a complete wingbeat varied through the turn and was significantly correlated to roll angle at mid-downstroke. Changes in roll angle were found to include both within-wingbeat and among-wingbeat components that bear no direct relationship to one another. Within-wingbeat changes in roll were dominated by the inertial effects while among-wingbeat changes in roll were likely the result of both inertial and aerodynamic effects.
Low speed maneuvering flight of the rose-breasted cockatoo (Eolophus roseicapillus). II. Inertial and aerodynamic reorientation
Authors: Hedrick T. L. , Usherwood J. R. , Biewener A. A.
Published: May 2007

The reconfigurable, flapping wings of birds allow for both inertial and aerodynamic modes of reorientation. We found evidence that both these modes play important roles in the low speed turning flight of the rose-breasted cockatoo Eolophus roseicapillus. Using three-dimensional kinematics recorded from six cockatoos making a 90° turn in a flight corridor, we developed predictions of inertial and aerodynamic reorientation from estimates of wing moments of inertia and flapping arcs, and a blade-element aerodynamic model. The blade-element model successfully predicted weight support(predicted was 88±17% of observed, N=6) and centripetal force(predicted was 79±29% of observed, N=6) for the maneuvering cockatoos and provided a reasonable estimate of mechanical power. The estimated torque from the model was a significant predictor of roll acceleration (r2=0.55, P<0.00001), but greatly overestimated roll magnitude when applied with no roll damping. Non-dimensional roll damping coefficients of approximately –1.5,2–6 times greater than those typical of airplane flight dynamics(approximately –0.45), were required to bring our estimates of reorientation due to aerodynamic torque back into conjunction with the measured changes in orientation. Our estimates of inertial reorientation were statistically significant predictors of the measured reorientation within wingbeats (r2 from 0.2 to 0.37, P<0.0005). Components of both our inertial reorientation and aerodynamic torque estimates correlated, significantly, with asymmetries in the activation profile of four flight muscles: the pectoralis, supracoracoideus, biceps brachii and extensor metacarpi radialis (r2 from 0.27 to 0.45, P<0.005). Thus, avian flight maneuvers rely on production of asymmetries throughout the flight apparatus rather than in a specific set of control or turning muscles.
Molecular and cellular studies in evolutionary physiology of natural vertebrate populations: influences of individual variation and genetic components on sampling and measurements
Authors: Nikinmaa Mikko , Waser Wolfgang
Published: May 2007

Studies combining ecological, genetic and physiological approaches are needed in evolutionary biology. Although the combination of approaches has been emphasized, such studies have been rare with regard to molecular and cellular studies on natural vertebrate populations. The major reasons for this are that the generation time of vertebrates is long and it is difficult to find a molecular or cell physiological measurement that is both relevant for the fitness of the population and can be repeated an adequate number of times to enable estimations of individual variability. The paucity of suitable physiological parameters is partly due to the fact that most physiological studies have not been directed towards understanding the behaviour of populations but towards understanding the basic mechanisms of the function of individuals. Also, physiological measurements that appear most relevant from the point of view of evolutionary studies are often integrative functions,composed of the function of many genes. When dissecting the integrative functions into components, it is often observed that the same integrative response can be achieved via different routes, i.e. changes in the responses of different genes. To enable cellular and molecular physiological studies to be increasingly combined with ecological and genetic studies, it is important that such studies include and report individual variability and that the sample size is increased. In addition, more sophisticated statistical methods should be used than is traditionally done, and when the function of most genes in the integrative response are not known, techniques such as QTL mapping should be used. Hitherto in vertebrates, the methodology has mainly been used in production biology (e.g. meat or milk production). With regard to combining genomic and physiological studies, one must bear in mind that the massive datasets associated with genomic studies need to be further enlarged to enable estimates of individual variation. It is also important to remember that microarray and proteomic data give the levels of mRNA and proteins,respectively. Since the function of the protein can be regulated independently of its transcription or its level in the cell, direct physiological measurements are also needed if estimations of protein activity in the individuals of a population are wanted.
Responses to hypoxia and recovery: repayment of oxygen debt is not associated with compensatory protein synthesis in the Amazonian cichlid,Astronotus ocellatus
Authors: Lewis J. M. , Costa I. , Val A. L. , Almeida-Val V. M. F. , Gamperl A. K. , Driedzic W. R.
Published: May 2007

Oxygen consumption, as an indicator of routine metabolic rate (RoMR), and tissue-specific changes in protein synthesis, as measured by 3H-labelled phenylalanine incorporation rates, were determined in Astronotus ocellatus to investigate the cellular mechanisms behind hypoxia-induced metabolic depression and recovery. RoMR was significantly depressed, by approximately 50%, when dissolved oxygen levels reached 10%saturation (0.67±0.01 mg l–1 at 28±1°C). This depression in RoMR was accompanied by a 50–60% decrease in liver,heart and gill protein synthesis, but only a 30% decrease in brain protein synthesis. During recovery from hypoxia, an overshoot in RoMR to 270% of the normoxic rate was observed, indicating the accumulation of an oxygen debt during hypoxia. This conclusion was consistent with significant increase in plasma lactate levels during the hypoxic exposure, and the fact that lactate levels rapidly returned to pre-hypoxic levels. In contrast, a hyperactivation of protein synthesis did not occur, suggesting the overshoot in oxygen consumption during recovery is attributed to an increase in cellular processes other than protein synthesis.
Validation of vertical ground reaction forces on individual limbs calculated from kinematics of horse locomotion
Authors: Bobbert Maarten F. , Álvarez Constanza B. Gómez , van Weeren P. René , Roepstorff Lars , Weishaupt Michael A.
Published: May 2007

The purpose of this study was to determine whether individual limb forces could be calculated accurately from kinematics of trotting and walking horses. We collected kinematic data and measured vertical ground reaction forces on the individual limbs of seven Warmblood dressage horses, trotting at 3.4 m s–1 and walking at 1.6 m s–1 on a treadmill. First, using a segmental model, we calculated from kinematics the total ground reaction force vector and its moment arm relative to each of the hoofs. Second, for phases in which the body was supported by only two limbs, we calculated the individual reaction forces on these limbs. Third, we assumed that the distal limbs operated as linear springs, and determined their force–length relationships using calculated individual limb forces at trot. Finally, we calculated individual limb force–time histories from distal limb lengths. A good correspondence was obtained between calculated and measured individual limb forces. At trot, the average peak vertical reaction force on the forelimb was calculated to be 11.5±0.9 N kg–1 and measured to be 11.7±0.9 N kg–1, and for the hindlimb these values were 9.8±0.7 N kg–1 and 10.0±0.6 N kg–1,respectively. At walk, the average peak vertical reaction force on the forelimb was calculated to be 6.9±0.5 N kg–1 and measured to be 7.1±0.3 N kg–1, and for the hindlimb these values were 4.8±0.5 N kg–1 and 4.7±0.3 N kg–1, respectively. It was concluded that the proposed method of calculating individual limb reaction forces is sufficiently accurate to detect changes in loading reported in the literature for mild to moderate lameness at trot.
Phosphatidylcholine profile-mediated group recognition in catfish
Authors: Matsumura Koichi , Matsunaga Shigeki , Fusetani Nobuhiro
Published: May 2007

Animal groups are integrated by emission of discrete signals from members,so-called social signals, which have evolved for each species. Among communication signals, chemical signals play an important role for recognition of group membership. The catfish Plotosus lineatus forms a dense school immediately after hatching, and school recognition is under the control of chemical signals emitted by the school members. The key substance(s)governing this recognition are deduced to be a mixture of phosphatidylcholines(PC). To substantiate this hypothesis that a mixture of PC molecular species functions as recognition of school-specific odor, we examined the ability of P. lineatus to discriminate between familiar and unfamiliar PCs. P. lineatus responded only to PCs from a familiar school, and not to those from unfamiliar schools. PC molecular species were then analyzed by quantitative high performance liquid chromatography, which resulted in not only a complex mixture of PC molecular species, but also school-specific PC profiles. Furthermore, multivariate analysis of the quantified PC peaks revealed the presence of various PC profiles. Finally, we showed that the modification of PC profiles disrupts the recognition of school odor in P. lineatus. Therefore, we conclude that the recognition of school odor in P. lineatus is governed by school-specific PC profiles.
Wet Chemical Preparation of Well-dispersed Colloidal Cerium Oxide Nanocrystals
Authors: Liu Yulan , He Shengtai , Uehara Masato , Maeda Hideaki
Published: May 2007

In this study, a simple one-step wet chemical method was presented to prepare colloidal cerium oxide, CeO2, nanocrystals. By a direct decomposition of cerium(IV) ammonium nitrate in a solution of 1-octadecene and oleylamine at 180 °C, well-dispersed CeO2 nanoparticle colloid, with an average size of about 4.5 nm, was obtained.
Preparation of Nearly Monodispersed Polystyrene Particles Formed by Polymerization in a Surfactant-free Emulsion with Silica Particles
Authors: Kawano Shintaro , Nishi Sayaka , Sakata Masayo , Kunitake Masashi
Published: May 2007

When the polymerization of styrene with a lipophilic initiator was conducted in an O/W emulsion, which was stabilized by unmodified monodispersed silica particles, it was found that near monodisperse polystyrene particles with different sub-micrometer size were formed in the emulsion. After the polymerization, the solution of silica and polystyrene mixed particles was obviously more stable than the silica-dispersed solution.
Spin Crossover Iron(II) Complexes of (2-Methylimidazol-4-yl)methylideneamino-2-ethylpyridine: 2:1 [Fe(HLMe)2](PF6)2 and 3:1 [Fe(HLMe)3](PF6)2
Authors: Arata Shinobu , Hamamatsu Takefumi , Sato Tetsuya , Iihoshi Tomotaka , Matsumoto Naohide , Iijima Seiichiro
Published: May 2007

(2-Methylimidazol-4-yl)methylideneamino-2-ethylpyridine (HLMe) functions as either bidentate or tridentate ligand to FeII ion to produce the 2:1 complex [Fe(HLMe)2](PF6)2 (1) and the 3:1 complex [Fe(HLMe)3](PF6)2 (2). Both complexes showed spin crossover (SCO) behaviors; 1 exhibited a gradual SCO between HS and (HS + LS)/2 and 2 showed an one-step abrupt SCO between HS and LS.
Boron-modified Chlorine-free K+–FeOx/SBA-15 as Highly Effective Catalyst for Propylene Epoxidation by Nitrous Oxide
Authors: Yang Sufen , Zhang Qinghong , Wang Ye
Published: May 2007

Modification of chlorine-free alkali metal ion (K+, Rb+, or Cs+)-containing FeOx/SBA-15 catalysts with boron enhanced their catalytic performances in propylene epoxidation by nitrous oxide. A B–K+–FeOx/SBA-15 catalyst (K/Fe = 2.5, B/Fe = 0.5) showed the best propylene oxide (PO) formation activity, providing PO selectivities of 79 and 55% at propylene conversions of 4.8 and 13% at 350 and 400 °C, respectively.
Higher Polyhedral Silsesquioxane (POSS) Cage by Amine-catalyzed Condensation of Silanols and Related Siloxanes
Authors: Kawakami Yoshiteru , Yamaguchi Kazuo , Yokozawa Tsutomu , Serizawa Takanori , Hasegawa Minoru , Kabe Yoshio
Published: May 2007

Amine-catalyzed condensation of silanols (1a and 1b) and related siloxanes (1c–1f) provided polyhedral oligomeric silsesquioxane (POSS) (2a, 2e, 3f, 4a, 4f, and 5f) in moderate yields. Although phenyl, o-methylphenyl (o-MePh) and vinyl (Vi) substituted silanols (1a and 1b) and siloxanes (1c–1f) gave a separable mixture of cage compounds, amine catalyst showed the selectivity of higher cage formation.
Calcium signalling in the regulation of PGC-1α, PDK4 and HKII mRNA expression
Authors: Kusuhara Keiko , Madsen Klavs , Jensen Lotte , Hellsten Ylva , Pilegaard Henriette
Published: May 2007

The role of calcium signalling and specific intracellular calcium signalling pathways in regulating skeletal muscle tissue peroxisome proliferator-activated receptor γ co-activator (PGC)-1α, hexokinase (HK)II and pyruvate dehydrogenase kinase (PDK)4 mRNA was examined. Cultured primary rat skeletal muscle cells were incubated for 6 h in caffeine or ionomycin. Because PGC-1α mRNA clearly showed greater induction with ionomycin, the latter was chosen for the main experiments, whereby cells were incubated for 6 h with either ionomycin alone or in combination with either cyclosporin A or KN-62. The PGC-1α mRNA level was increased (p<0.05) approximately six-fold and HKII mRNA content approximately two-fold by ionomycin relative to the corresponding controls, whereas the PDK4 mRNA content remained unaffected. Cyclosporin A abolished (p<0.05) and KN-62 reduced (p<0.1) the ionomycin-induced increase in PGC-1α mRNA. Electrical stimulation ofin vitroincubated rat EDL muscle increased (p<0.05) PGC-1α mRNA by 2.2-fold after 4 h of recovery relative to a resting control, and this increase was absent when muscles were incubated with KN-62 or cyclosporin A. The present data strongly suggest that calcium signalling is involved in regulating the PGC-1α and HKII genes, but not PDK4. Both calcineurin and CaMK signalling seem to be involved in the calcium- and contraction-mediated PGC-1α up-regulation in skeletal muscle.
Inhibition of cathepsin L-like proteases by cathepsin V propeptide
Authors: Burden Roberta E. , Snoddy Philip , Jefferies Caroline A. , Walker Brian , Scott Christopher J.
Published: May 2007

The N-terminal propeptide domains of several cathepsin L-like cysteine proteases have been shown to possess potent inhibitory activity. Here we report the first kinetic characterisation of the inhibition properties of the cathepsin V propeptide (CatV PP). Using a facile recombinant approach we demonstrate expression, purification and evaluation of the CatV PP. This propeptide was found to behave as a tight-binding inhibitor against CatV (K
i 10.2 nm). It also functions as an inhibitor against other members of the CatL-like subclass (CatL, 9.8 nm; CatS, 10.7 nm; and CatK, 149 nm) and had no discernible effects upon the more distantly related CatB.
Increase in kinins on post-exercise hypotension in normotensive and hypertensive volunteers
Authors: Moraes Milton R. , Bacurau Reury F.P. , Ramalho João D.S. , Reis Felipe C.G. , Casarini Dulce E. , Chagas Jair R. , Oliveira Vitor , Higa Elisa Mieko S. , Abdalla Dulcinéia S.P. , Pesquero Jorge L. , Pesquero João B. , Araujo Ronaldo C.
Published: May 2007

Post-exercise hypotension is an important event for blood pressure regulation, especially in hypertensive individuals. Although post-exercise hypotension is a well-known phenomenon, the mechanism responsible is still unclear. The kallikrein-kinin system is involved in blood pressure control, but its role in post-exercise hypotension has not yet been investigated. Thus, the purpose of this study was to investigate the involvement of the vasodilators bradykinin and des-Arg9-BK and kallikrein activity in post-exercise hypotension promoted by 35 min of cycle ergometer (CE) or circuit weight-training (CWT) bouts in normotensive and hypertensive individuals. A significant decrease in mean arterial pressure at 45 and 60 min after CE and 45 min after CWT was observed in normotensive individuals. Hypertensive values of mean arterial pressure were significantly reduced at 45 and 60 min after CE and at 60 min after CWT. Before exercise, plasma bradykinin concentrations and kallikrein activity were higher in hypertensive compared to normotensive volunteers. Kinin levels increased in the groups evaluated at the end of the training period and 60 min post-exercise. These data suggest that the kallikrein-kinin system may be involved in post-exercise hypotension in normotensive and hypertensive individuals subjected to CE and CWT bouts.
Nitric oxide modulates expression of extracellular matrix genes linked to fibrosis in kidney mesangial cells
Authors: Wani Javid , Carl Marina , Henger Anna , Nelson Peter J. , Rupprecht Harald
Published: May 2007

Mesangial cells are thought to be important mediators of glomerular inflammation and fibrosis. Studies have established a direct role for nitric oxide (NO) in the regulation of gene expression in mesangial cells. Representational difference analysis was used to investigate changes in gene expression elicited by the treatment ofS-nitroso-L-glutathione in rat mesangial cells. Seven upregulated and 11 downregulated genes were identified. Four out of 11 downregulated genes (connective tissue growth factor, thrombospondin-1, collagen type I α1 and collagen type I α2) are known to be linked to inflammation and fibrosis. Results were verified across species in mesangial cells treated with a series of NO donors using Northern blot analysis, quantitative real-time PCR and protein analysis methods. Induction of endogenous NO production by cytokine stimulation also triggered regulation of the genes. One example gene, connective tissue growth factor, was studied at the promoter level. Promoter-reporter gene studies in mesangial cells demonstrated that NO acts at the transcriptional level to suppress gene expression. Our results reveal a complex role of NO in regulating gene expression in mesangial cells and suggest an antifibrotic potential for NO.