bluuebunny/crossref_metadata_2025_split huggingface dataset:
Risk factors for serious fall related injury in elderly women living at home
Authors: Bergland A , Wyller T B 
Published: October 2004

Objectives:To study whether balance, function, and other health status indicators can predict serious fall related injury in elderly women living at home.Methods:In this prospective study, the authors took a random sample of 307 women aged 75 years and over (mean 80.8 years, response rate 74.5%), living in the community. Serious fall injuries which occurred over a period of during one year were recorded, together with baseline registrations of health, function, and tests of walking and balance.Results:In all, 155 women (50.5%) fell one or more times. One hundred and fifty six (51%) of the 308 falls resulted in a fall related injury, 74 (24%) in a serious fall related injury, and 40 falls (13%) resulted in fractures. The presence of rheumatic disorders, inability to rise from the floor, arthrosis of the hip, having had more than one fall during the one year follow up period, and an increased tendency to sway in the frontal plane when doing a calculation task were independent and significant predictors for serious fall related injury (fractures included). The independent predictors of fall induced fractures were experiencing more than one fall in the follow up period, cognitive impairment, and receiving care from professional or other.Conclusion:The study suggests that rheumatic disorders and the inability to get up from lying on the floor were the strongest independent risk factors for serious fall related injury. Experiencing more than one fall in the follow up period and cognitive impairment are the strongest independent predictors for fall induced fractures. Age was not a significant predictor of serious fall related injury. Assessment of these markers is feasible in a clinical setting and is a useful way of identifying those who are at risk of serious fall related injuries.
Risk factors for work related violence in a health care organization
Authors: Findorff M J , McGovern P M , Wall M , Gerberich S G , Alexander B 
Published: October 2004

Objective:Identify the exposure effects of job family, patient contact, and supervisor support on physical and non-physical work related violence.Design:Cross sectional study of employees in a Midwest health care organization, utilizing a specially designed mailed questionnaire and employer secondary data.Subjects:Respondents included 1751 current and former employees (42% response rate).Results:Physical and non-physical violence was experienced by 127 (7.2%) and 536 (30.6%) of the respondents, respectively. Multivariate analyses of physical violence identified increased odds for patient care assistants (odds ratio (OR) 2.5, 95% confidence interval (CI) 1. 1 to 6.1) and decreased odds for clerical workers (OR 0.1, 95% CI 0.03 to 0.5). Adjusted for job family, increased odds of physical violence were identified for moderate (OR 5.9, 95% CI 2.1 to 16.0) and high (OR 7.8, 95% CI 2.9 to 20.8) patient contact. Similar trends were identified for non-physical violence (OR 1.4, 95% CI 1.1 to 2.0 and OR 1.7, 95% CI 1.3 to 2.3). Increased supervisor support decreased the odds of both physical (OR 0.7, 95% CI 0.6 to 0.95) and non-physical violence (OR 0.5, 95% CI 0.4 to 0.6), adjusting for job family and demographic characteristics.Conclusions:Increased odds of physical violence were identified for the job family of nurses, even when adjusted for patient contact. Increased patient contact resulted in increased physical and non-physical violence, independent of job family, while supervisor support resulted in decreased odds of physical and non-physical violence.
Quality of information on risk factors reported by ski patrols
Authors: Hagel B E , Pless I B , Goulet C , Platt R W , Robitaille Y 
Published: October 2004

Objective:To determine the reliability of reporting of information on risk factors from a standard accident report form used by ski patrols and a follow up mail questionnaire or telephone interview among injured skiers and snowboarders.Setting:19 ski areas in the Canadian province of Quebec between November 2001 and April 2002.Participants:4377 injured skiers and snowboarders seen by the ski patrol, who completed a follow up mail questionnaire or telephone interview.Main outcome measures:κ and weighted κ statistics were used to measure the chance corrected agreement for self reported ability, age, skiing time on day of injury, lessons, type of practice, use of helmet at time of injury, and hill difficulty.Results:The κ value for helmet use at the time of injury was 0.88 (95% confidence interval 0.87 to 0.90) and for other risk factors ranged from 0.45 (skiing time on day of injury) to 0.98 (age). Few differences were seen in reporting by body region of injury. Reporting consistency was lower for respondents who completed telephone interviews compared with those who completed mail questionnaires and those who responded more than four months after the injury.Conclusions:Moderate to almost perfect agreement, depending on the risk factor, exists between ski patrols’ accident report forms and follow up information. Ski patrol reports can be a reliable and readily available source of information on risk factors for skiing and snowboarding.
Urban youths’ perspectives on violence and the necessity of fighting: Table 1
Authors: Johnson S B , Frattaroli S , Wright J L , Pearson-Fields C B , Cheng T L 
Published: October 2004

Objectives:To assess youth perceptions of the causes and consequences of violence generally, the causes and consequences of fighting specifically, and to determine how best to approach fighting in the context of violence prevention activities.Methods:Thirteen structured focus group interviews with youths from three high violence urban settings: a large, urban high school, a training center for disadvantaged youths, and a school for adjudicated youths. Participants were 120 urban, predominately African-American youths and young adults ages 14–22 years (mean: 17.2 years). Seven focus groups were conducted with females, and six with males.Results:Adolescents identified the causes of violence on multiple levels including: individual, family, interpersonal, and community level factors. Most youths (89%) had been in a physical fight. Participants felt that fighting was not “right”, but identified situations in which it was necessary. Specifically, fighting was used as a problem solving tool, and could prevent escalation of violence. Youths felt that the adults in their lives, including physicians, were generally ill equipped to give advice about violence, as adults’ experiences were so removed from their own. Participants looked to experienced role models to offer problem solving and harm reduction strategies. Youths were open to receiving anticipatory guidance about violence and fighting from primary care physicians they felt comfortable with, and who showed respect for their experiences.Conclusions:Interventions that include blanket admonitions against fighting should be reassessed in light of youth perceptions that fighting plays a complex role in both inciting and preventing more serious violence.
Lost working days, productivity, and restraint use among occupants of motor vehicles that crashed in the United States
Authors: Ebel B E , Mack C , Diehr P , Rivara F P 
Published: October 2004

Background:In 2001, 6.3 million passengers were involved in motor vehicle crashes. This study aimed to determine the number of work days lost as a result of motor vehicle crashes and factors that influenced people’s return to work.Methods:This was a retrospective, population based cohort study of occupants in motor vehicles involved in crashes from the 1993–2001 Crashworthiness Data System produced by the National Highway Traffic Safety Administration. The sample population of people aged 18–65 years included two groups: occupants who survived and were working before the crash and occupants who were injured fatally and were estimated to have been working before the crash. Multivariate linear regression was used to analyze the impact of restraint use and injury type on return to work.Results:Overall, 30.1% of occupants of vehicles that crashed missed one or more days of work. A crash resulted in a mean 28.0 (95% confidence interval 15.8 to 40.1) days lost from work, including losses associated with fatalities. The 2.1 million working occupants of vehicles that crashed in 2001 lost a total of 60 million days of work, resulting in annual productivity losses of over $7.5 billion (2964 to 12 075). Unrestrained vehicle occupants accounted for $5.6 billion in lost productivity.Conclusions:Motor vehicle crashes result in large and potentially preventable productive losses that are mostly attributable to fatal injuries.
DEVELOPABLE COMPLEX ANALYTIC SUBMANIFOLDS
Authors: FISCHER GERD , WU H. 
Published: October 2004

Examples of developable submanifolds are difficult to come by. For this reason, we collect in Sec. 1 some examples. There is one due to Cayley [2] that may not be so well-known, and there is also a new one which is algebraic. A knowledge of these examples is not essential for the subsequent sections, however. The organisation of the remainder of this paper is self-explanatory from the table of contents, except to mention that Sec. 7 contains the precise statements and proofs of Theorems 4–6. This paper and Sec. 2 of the paper [8] of Griffiths and Harris treat the same topic, although the latter is mainly interested in developable submanifolds in projective space. The discerning reader would note that our outlook and emphasis are orthogonal to those of [8] and that there are more differences than similarities between these two works.
CLARIFYING CHAOS: EXAMPLES AND COUNTEREXAMPLES
Authors: BROWN RAY , CHUA LEON O. 
Published: October 2004

Over the past fifteen years there have been various attempts to define chaos. In an effort to find a universally acceptable definition we began constructing new examples of chaotic systems in the hope that the salient features of chaos could be captured. Our efforts to date have failed and the examples we have constructed seem to suggest that no such definition exists. However, these examples have proved to be valuable in spite of our inability to hone a universal definition of chaos from them. Consequently, we present this list of examples and their significance. Some interesting conclusions that we can draw from them are: It is possible to construct simple closed form solutions of chaotic one-dimensional maps; sensitive dependence on initial conditions, the most widely used definition of chaos, has many counterexamples; there are invertible chaotic dynamical systems defined by simple differential equations that do not have horseshoes; three important properties that are thought to characterize chaos, continuous power spectral density, exponentially sensitive dependence on initial conditions, and exponential loss of information (Chaitin’s concept of algorithmic complexity), are independent. Chaos seems to be tied to our notion of rates of divergence of orbits or degradation of information such as is found in systems with positive Lyapunov exponents. The reliance on rates seems to open the door to a pandora’s box of rates, both higher and lower than exponential. The intuitive notion of pseudo-randomness, a practical feature of chaos, is present in examples that do not have positive Lyapunov exponents. And in general, nonlinear polynomial rates of degradation of information are also quite “unpredictable”. We conclude that it appears that for any given definition of chaos, there may always be some “clearly” chaotic systems which do not fall under that definition, thus making chaos a cousin to Gödel’s undecidability.
ON CODING OF SERIES OF HOMOCLINIC LOOPS
Authors: ELEONSKY V. M. , KOROLEV V. G. 
Published: October 2004

Three possible general types of origin and coding of series of complicated homoclinic saddle loops in dynamical systems with two degrees-of-freedom are pointed out. As an example of a physically important application, series of complicated vector solitons in birefringent (or bimodal) fiber governed by the system of two coupled nonlinear Schrödinger equations are studied. In that system, all the three types of series are found and investigated.
SNOWFLAKE HARMONICS AND COMPUTER GRAPHICS: NUMERICAL COMPUTATION OF SPECTRA ON FRACTAL DRUMS
Authors: LAPIDUS MICHEL L. , NEUBERGER J.W. , RENKA ROBERT J. , GRIFFITH CHERYL A. 
Published: October 2004

In this work, we study the steady-states vibrations of the “Koch snowflake drum”, both numerically and by means of computer graphics. In particular, we approximate the smallest 50 eigenvalues (or “frequencies” of the drum), along with the corresponding eigenfunctions (called “snowflake harmonics”) of the Dirichlet Laplacian on the Koch snowflake domain. We describe the numerical methods used in the computations, and we display graphical representations of a selected set of the eigenfunctions (as well as of their gradients). In the case of the first harmonic, the graphical results agree with mathematically derived results (by Lapidus and Pang) concerning gradient behavior (“blow up” or “infinite stress” of the membrane) on the boundary and suggest further conjectures regarding the higher eigenfunctions. According to earlier work by the physicist Sapoval and his collaborators, this research may help better understand the formation and “stabilization” of fractal structures (e.g., coastlines, trees and blood vessels) in nature.
PERIOD-DOUBLING GEOMETRY OF THE BELOUSOV-ZHABOTINSKY REACTION DYNAMICS
Authors: WANG JICHANG , HYNNE F. , SØRENSEN P. GRAAE 
Published: October 2004

The intricate geometry of stable and unstable manifolds of a saddle cycle arising from a super-critical period-doubling bifurcation is explored experimentally for the Belousov-Zhabotinsky (BZ) reaction in a CSTR (Continuous flow Stirred Tank Reactor). We find clear experimental evidence that the stable manifold winds round the stable period-doubled orbit arising at the bifurcation. The stable manifold is probed experimentally by perturbations from the period-doubled limit cycle. The method provides a model-independent experimental test for species essential for the complexity, as well as quantitative information about the geometry of the limit cycles, the associated manifolds, and their embedding in the concentration space. The results are supported by simulations of the experiments with a four-dimensional model of the BZ reaction. Here stable manifold has several branches showing some tendency of curling. However the branches may end on the boundary of the positive orthant of the concentration space.
ORIENTATION-INDUCED PATTERN FORMATION: SWARM DYNAMICS IN A LATTICE-GAS AUTOMATON MODEL
Authors: DEUTSCH ANDREAS 
Published: October 2004

Swarming patterns might arise not just at organismic levels (bird and fishes exhibiting particularly striking examples) but even at cellular and intracellular scales whenever “collective motion” of biological or chemical entities is involved. Examples are the swarming of myxobacteria and ants, aggregation and slug pattern formation of the slime mold Dictyostelium discoideum, or intracellular network dynamics of actin filaments. Here a stochastic process — discrete in space and time — is developed, the “swarm lattice-gas automaton”. For some lattice-gas models (in physics and chemistry) it was demonstrated that the limit behavior resembles known master equations by means of expectation values of suitably chosen microscopic variables. In particular, for the Navier–Stokes equation the derivation of a continuous macroscopic description from discrete microdynamic equations was shown. The “swarm lattice-gas automaton” possesses a non-local integral-like interaction operator. Particles (cells, organisms) are assigned some orientation (and fixed absolute velocity) which might change by means of interaction with other members of the swarm within a given “region of perception”. The corresponding microdynamical equation is given and results of numerical experiments are shown. Simulations exhibit a variety of aggregation patterns which are distinguished by means of microscopic and macroscopic variables. The influence of a sensitivity parameter and particle density on pattern formation is examined systematically.
TOWARD AN UNDERSTANDING OF STOCHASTIC HOPF BIFURCATION
Authors: ARNOLD LUDWIG , SRI NAMACHCHIVAYA N. , SCHENK-HOPPÉ KLAUS R. 
Published: October 2004

In this paper, asymptotic and numerical methods are used to study the phenomenon of stochastic Hopf bifurcation. The analysis is carried out through the study of a noisy Duffing-van der Pol oscillator which exhibits a Hopf bifurcation in the absence of noise as one of the parameters is varied. In the first part of this paper, we present an introduction to the theory of random dynamical systems (in particular, their generation, their invariant measures, the multiplicative ergodic theorem, and Lyapunov exponents). We then present the two concepts of stochastic bifurcation theory: Phenomenological (based on the Fokker-Planck equation), and dynamical (based on Lyapunov exponents). The method of stochastic averaging of the nonlinear system yields a set of equations which, together with its variational equation, can be explicitly solved and hence its bifurcation behavior completely analyzed. We augment this analysis by asymptotic expansions of the Lyapunov exponents of the variational equation at zero. Finally, the stochastic normal form of the noisy Duffing-van der Pol oscillator is derived, and its bifurcation behavior is analyzed numerically. The result is that the (truncated) normal form retains the essential bifurcation characteristics of the full equation.
ANALYTICAL EXPRESSIONS FOR STABLE AND UNSTABLE MANIFOLDS IN HIGHER DEGREE OF FREEDOM HAMILTONIAN SYSTEMS
Authors: DANKOWICZ HARRY 
Published: October 2004

Perturbations of completely integrable Hamiltonian systems with three or more degrees of freedom are studied. In particular, the unperturbed systems are assumed to be separable into a product of simple oscillator-type systems and a system containing homo- or heteroclinic connections consisting of stable and unstable manifolds of saddle points. Under a perturbation, the manifolds persist but separate and may no longer intersect. In this paper we show how, with proper choices for initial conditions, one may solve the variational equations to obtain analytical expressions for orbits on the perturbed manifolds in the form of expansions in the small parameter characterizing the perturbation. The derivation also shows how the distance between the manifolds can be uniquely defined, and thus provides an alternative to the traditional higher dimensional Melnikov method. It is finally argued that the approximate knowledge of the shape and position of the perturbed manifolds could be utilized for the study of large-scale phase-space motions, such as those associated with Arnold diffusion. The theory is further illuminated in two example problems.
Trolox selectively enhances arsenic-mediated oxidative stress and apoptosis in APL and other malignant cell lines
Authors: Diaz Zuanel , Colombo Myrian , Mann Koren K. , Su Haixiang , Smith Kamilah N. , Bohle D. Scott , Schipper Hyman M. , Miller Wilson H. 
Published: October 2004

AbstractAlthough arsenic trioxide (As2O3) is an effective therapy in acute promyelocytic leukemia (APL), its use in other malignancies is limited by the toxicity of concentrations required to induce apoptosis in non-APL tumor cells. We looked for agents that would synergize with As2O3 to induce apoptosis in malignant cells, but not in normal cells. We found that trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), a widely known antioxidant, enhances As2O3-mediated apoptosis in APL, myeloma, and breast cancer cells. Treatment with As2O3 and trolox increased intracellular oxidative stress, as evidenced by heme oxygenase-1 (HO-1) protein levels, c-Jun terminal kinase (JNK) activation, and protein and lipid oxidation. The synergistic effects of trolox may be specific to As2O3, as trolox does not add to toxicity induced by other chemotherapeutic drugs. We explored the mechanism of this synergy using electron paramagnetic resonance and observed the formation of trolox radicals when trolox was combined with As2O3, but not with doxorubicin. Importantly, trolox protected nonmalignant cells from As2O3-mediated cytotoxicity. Our data provide the first evidence that trolox may extend the therapeutic spectrum of As2O3. Furthermore, the combination of As2O3 and trolox shows potential specificity for tumor cells, suggesting it may not increase the toxicity associated with As2O3 monotherapy in vivo.
A case for developing North-South partnerships for research in sickle cell disease
Authors: Weatherall David , Hofman Karen , Rodgers Griffin , Ruffin John , Hrynkow Sharon 
Published: October 2004

AbstractFor a better understanding of the pathophysiology and mechanisms of phenotypic diversity of sickle cell disease, and for the improvement of its management globally, there is a strong case for developing sustainable research partnerships between rich and poor countries.
Transplantation of 2 partially HLA-matched umbilical cord blood units to enhance engraftment in adults with hematologic malignancy
Authors: Barker Juliet N. , Weisdorf Daniel J. , DeFor Todd E. , Blazar Bruce R. , McGlave Philip B. , Miller Jeffrey S. , Verfaillie Catherine M. , Wagner John E. 
Published: October 2004

AbstractLimited umbilical cord blood (UCB) cell dose compromises the outcome of adult UCB transplantation. Therefore, to augment graft cell dose, we evaluated the safety of the combined transplantation of 2 partially human leukocyte antigen (HLA)–matched UCB units. Twenty-three patients with high-risk hematologic malignancy (median age, 24 years; range, 13-53 years) received 2 UCB units (median infused dose, 3.5 × 107 nucleated cell [NC]/kg; range, 1.1-6.3 × 107 NC/kg) after myeloablative conditioning. All evaluable patients (n = 21) engrafted at a median of 23 days (range, 15-41 days). At day 21, engraftment was derived from both donors in 24% of patients and a single donor in 76% of patients, with 1 unit predominating in all patients by day 100. Although neither nucleated or CD34+ cell doses nor HLA-match predicted which unit would predominate, the predominating unit had a significantly higher CD3+ dose (P &lt; .01). Incidences of grades II-IV and III-IV acute GVHD were 65% (95% confidence interval [CI], 42%-88%) and 13% (95% CI, 0%-26%), respectively. Disease-free survival was 57% (95% CI, 35%-79%) at 1 year, with 72% (95% CI, 49%-95%) of patients alive if they received transplants while in remission. Therefore, transplantation of 2 partially HLA-matched UCB units is safe, and may overcome the cell-dose barrier that limits the use of UCB in many adults and adolescents.