bluuebunny/crossref_metadata_2025 huggingface dataset:
Teaching Statistics and Econometrics to Undergraduates
Authors: Becker William E , Greene William H
Published: June 2010

Traditionally econometrics and economics statistics have been taught in the theory and proof, chalk and talk mode commonly found in the teaching of mathematics. We advance the use of computer technology in the teaching of quantitative methods to get students actively engaged in the learning process. We also assert that the essential tasks for those who teach these courses are to identify important issues that lend themselves to quantitative analyses and then to help students develop an understanding of the appropriate key concepts for those analyses.
Mismeasured Variables in Econometric Analysis: Problems from the Right and Problems from the Left
Authors: Hausman Jerry
Published: June 2010

The effect of mismeasured variables in the most straightforward regression analysis with a single regressor variable leads to a least squares estimate that is downward biased in magnitude toward zero. I begin by reviewing classical issues involving mismeasured variables. I then consider three recent developments for mismeasurement econometric models. The first issue involves difficulties in using instrumental variables. A second involves the consistent estimators that have recently been developed for mismeasured nonlinear regression models. Finally, I return to mismeasured left hand side variables, where I will focus on issues in binary choice models and duration models.
A Critique of the Hypothesis, and a Defense of the Question, as a Framework for Experimentation
Authors: Glass David J
Published: June 2010

Scientists are often steered by common convention, funding agencies, and journal guidelines into a hypothesis-driven experimental framework, despite Isaac Newton’s dictum that hypotheses have no place in experimental science. Some may think that Newton’s cautionary note, which was in keeping with an experimental approach espoused by Francis Bacon, is inapplicable to current experimental method since, in accord with the philosopher Karl Popper, modern-day hypotheses are framed to serve as instruments of falsification, as opposed to verification. But Popper’s “critical rationalist” framework too is problematic. It has been accused of being: inconsistent on philosophical grounds; unworkable for modern “large science,” such as systems biology; inconsistent with the actual goals of experimental science, which is verification and not falsification; and harmful to the process of discovery as a practical matter. A criticism of the hypothesis as a framework for experimentation is offered. Presented is an alternative framework—the query/model approach—which many scientists may discover is the framework they are actually using, despite being required to give lip service to the hypothesis.
Life history and morphological studies ofPunctaria tenuissima(Chordariaceae, Phaeophyceae), a new record for the Azores
Authors: Parente Manuela I. , Fletcher Robert L. , Neto Ana I. , Tittley Ian , Sousa Ana F. , Draisma Stefano , Gabriel Daniela
Published: June 2010

Punctaria tenuissima(Chordariaceae, Phaeophyceae) is reported for the first time from the Azores. Erect thalli were collected on the Island of São Miguel; they were up to 3 cm long, flattened and often twisted. The plurilocular sporangia were formed from surface cells that were quadrate or rectangular in surface view. Unilocular sporangia were not observed in the field. In culture, the plurispores ofP. tenuissimadeveloped intoHecatonema-like, tufted, prostrate thalli that formed plurilocular sporangia. The plurispores of the prostrate thalli cultured at 15°C with a long day (LD) photoperiod developed into new prostrate thalli, which in turn formed plurilocular sporangia. This cycle was repeated 5 times, resulting in several generations of reproductive prostrate thalli. When these cultures were cooled to 10°C with a short day (SD) photoperiod, new erect thalli developed from the prostrate thalli resembling the thalli collected in the field. These erect blades produced unilocular and plurilocular sporangia on the same or on different thalli. The plurispores and unispores produced by the erect thalli at 10°C under SD conditions once again developed into new prostrate thalli. This is the first report of unilocular sporangia formed in cultures ofP. tenuissima. Sexual reproduction was not observed. The culture conditions, particularly temperature and daylength, appeared to influence the formation of erect blades. ThePunctaria-like thalli were produced in 10°C/SD conditions, whilst theHecatonema-like thalli were produced under 10°–15°C/LD and SD conditions. These results are similar to those reported forP. tenuissimafrom other locations and suggest the occurrence of both direct and heteromorphic life histories in the Azorean algae.
The Local Scripts from Nature to Culture
Authors: Luraghi Nino
Published: June 2010

The emergence of local alphabets in archaic Greece, different from one another in the shapes of only few letters, is usually seen as accidental. Observing the use of local alphabets outside their area of origin especially, this article argues that they were consciously created so as to be recognizable from one another and closely associated with perceived ethnic boundaries within the Greek world. The use of the local alphabets should be observed in conjunction with the use of dialects, which appear to have functioned in a similar way.
Distribution of adiponectin multimeric forms in Chinese women with polycystic ovary syndrome and their relation to insulin resistance
Authors: Tao Tao , Wickham Edmond P , Fan WuQiang , Yang Jiejin , Liu Wei
Published: June 2010

Objective

Adiponectin, an abundant adipokine with insulin-sensitizing properties, exists in different multimeric forms, including low-molecular weight, medium-molecular weight, and high-molecular weight (HMW) species. Alterations in the distribution of adiponectin multimers and the relationship between adiponectin multimers and insulin resistance (IR) in women with polycystic ovary syndrome (PCOS) remain unclear. The objective of this study was to compare adiponectin multimerization status and estimate insulin sensitivity in Chinese women with PCOS compared with age- and body mass index (BMI)-matched controls.

Methods

Cross-sectional study involving 64 Chinese women with PCOS and 59 normal women. Circulating total adiponectin and its multimeric forms were determined by ELISA, and IR was estimated using the homeostasis model assessment IR index (HOMA-IR).

Results

After controlling for BMI status, levels of both total and HMW adiponectin were significantly lower in women with PCOS compared with normal women (P<0.05). Furthermore, HMW adiponectin provided a stronger contribution to models predicting IR than total adiponectin. Lastly, decreased HMW adiponectin was associated with increased HOMA-IR in both normal and PCOS women, and this association was independent of both overall adiposity and visceral adiposity.

Conclusion

Levels of both total and HMW adiponectin were decreased in Chinese women with PCOS compared with normal control women, and the differences in HMW adiponectin persisted after controlling for BMI. Furthermore, HMW adiponectin is a stronger predictor of IR than total adiponectin in both women with PCOS and normal women.
A Comparison of Cooling Methods Used in Therapeutic Hypothermia for Perinatal Asphyxia
Authors: Hoque Nicholas , Chakkarapani Ela , Liu Xun , Thoresen Marianne
Published: June 2010

OBJECTIVE:

The objective of this study was to compare cooling methods during therapeutic hypothermia (TH) for moderate or severe perinatal asphyxia with regard to temperature and hemodynamic stability.

METHODS:

A total of 73 newborns received TH in our center between 1999 and 2009 by 4 methods: (1) selective head cooling with mild systemic hypothermia by using cap (SHC; n = 20); (2) whole-body cooling with mattress manually controlled (WBCmc; n = 23); (3) whole-body cooling with body wrap servo-controlled (WBCsc; n = 28); and (4) whole-body cooling with water-filled gloves (n = 2). Target rectal temperatures (Trec) were 34.5 ± 0.5°C (SHC) and 33.5 ± 0.5°C (WBC). Trec, mean arterial blood pressure, and heart rate were collected from retrospective chart review.

RESULTS:

Groups had similar baseline characteristics and condition at birth. Trec was within target temperature ±0.5°C for 97% of the time in infants with WBCsc, 81% in infants with WBCmc, 76% in infants with SHC, and 74% in infants who were cooled with gloves. Mean overshoot was 0.3°C for WBCsc, 1.3°C for WBCmc, and 0.8°C for SHC groups. There was no difference in mean arterial blood pressure or mean heart between groups during the maintenance of cooling. In infants who were rewarmed at similar speed, there was greater variation in Trec in the SHC compared with the WBCsc group.

CONCLUSIONS:

Manually controlled cooling systems are associated with greater variability in Trec compared with servo-controlled systems. A manual mattress often causes initial overcooling. It is unknown whether large variation in temperature adversely affects the neuroprotection of TH.
Prevalence and correlates of physical activity among adolescents from Southern Brazil
Authors: Dumith Samuel C , Domingues Marlos R , Gigante Denise P , Hallal Pedro C , Menezes Ana M B , Kohl Harold W
Published: June 2010

OBJECTIVE: To estimate the prevalence and identify correlates of physical activity among adolescents. METHODS: Cross-sectional study nested within a cohort of 4,325 subjects from the city of Pelotas, Southern Brazil, aged 14-15 years in 2008. Physical activity was analyzed using three different approaches: (1) prevalence of any leisure-time physical activity; (2) prevalence of any active commuting to school; and (3) prevalence of engaging in at least 300 minutes per week of both (1) and (2) combined. Independent variables included sociodemographic, behavioral, social, and biological characteristics, and number of different leisure-time physical activites practiced. Statistical analyses were carried out using Poisson regression. RESULTS: The proportion of adolescents involved in any type of leisure-time physical activity was 75.6%, while 73.4% displayed some form of active commuting to school. Prevalence of total physical activity score (> 300 min/week) was 48.2%, being greater among boys (62.6%) than among girls (34.5%). Furthermore, prevalence increased along with the number of physical activity modalities practiced (p<0.001). Factors associated with greater physical activity (leisure + commuting) at the recommended levels were: nonwhite skin color, having failed at school, and playing videogames. Lower socioeconomic status, more time spent on the computer, and parental physical activity were associated with the outcome only among girls. CONCLUSIONS: Less than half the adolescents reached recommended levels of physical activity, and this proportion tended to decrease among subjects with higher socioeconomic level. Associated factors were different for leisure-time and commuting. Engaging in a wide variety of physical activities should be encouraged already during childhood.
Risk factors for osteoporotic fractures and low bone density in pre and postmenopausal women
Authors: Pinheiro Marcelo M , Reis Neto Edgard T dos , Machado Flávia S , Omura Felipe , Yang Jeane H K , Szejnfeld Jacob , Szejnfeld Vera L
Published: June 2010

OBJECTIVE: To estimate the prevalence and analyze risk factors associated to osteoporosis and low-trauma fracture in women. METHODS: Cross-sectional study including a total of 4,332 women older than 40 attending primary care services in the Greater São Paulo, Southeastern Brazil, between 2004 and 2007. Anthropometrical and gynecological data and information about lifestyle habits, previous fracture, medical history, food intake and physical activity were obtained through individual quantitative interviews. Low-trauma fracture was defined as that resulting from a fall from standing height or less in individuals 50 years or older. Multiple logistic regression models were designed having osteoporotic fracture and bone mineral density (BMD) as the dependent variables and all other parameters as the independent ones. The significance level was set at p<0.05. RESULTS: The prevalence of osteoporosis and osteoporotic fractures was 33% and 11.5%, respectively. The main risk factors associated with low bone mass were age (OR=1.07; 95% CI: 1.06;1.08), time since menopause (OR=2.16; 95% CI: 1.49;3.14), previous fracture (OR=2.62; 95% CI: 2.08;3.29) and current smoking (OR=1.45; 95% CI: 1.13;1.85). BMI (OR=0.88; 95% CI: 0.86;0.89), regular physical activity (OR=0.78; 95% CI: 0.65;0.94) and hormone replacement therapy (OR=0.43; 95% CI: 0.33;0.56) had a protective effect on bone mass. Risk factors significantly associated with osteoporotic fractures were age (OR=1.05; 95% CI: 1.04;1.06), time since menopause (OR=4.12; 95% CI: 1.79;9.48), familial history of hip fracture (OR=3.59; 95% CI: 2.88;4.47) and low BMD (OR=2.28; 95% CI: 1.85;2.82). CONCLUSIONS: Advanced age, menopause, low-trauma fracture and current smoking are major risk factors associated with low BMD and osteoporotic fracture. The clinical use of these parameters to identify women at higher risk for fractures might be a reasonable strategy to improve the management of osteoporosis.
The integration of learning object repositories and learning management systems
Authors: Fertalj Kresimir , Bozic-Hoic Natasa , Jerkovic Hrvoje
Published: June 2010

The systems aimed for manipulating large number of courses and students are called Learning Management Systems (LMS). A LMS can have excellent performance implemented through advanced Web technologies but it is often accompanied by a poor or rarely used repository of institution?s educational content. It has still remained. Still remains a problem how to allow users of a LMS to easily modify and integrate the content from federated e-learning repositories into their courses. This article presents an analysis of present repository frameworks and projects. FEDORA (Flexible Extensible Digital Repository Object Architecture) framework is explained as an alternative repository solution. A pilot application has been developed to demonstrate the interaction between a LMS and its repository.
Prompt system redesign: Shifting to open source technology to satisfy user requirements
Authors: Svetel Igor , Djurovic Aleksandar , Grabulov Vencislav
Published: June 2010

The paper describes a redesign project undertaken in a short period to adapt a software system to user needs. Additional goals of the project included a shift to Open Source software and the selection of technology to enable sustainable system development. The paper chronologically describes all phases of the project and provides reasons for all decisions taken during the development process. The paper concludes with a discussion of the merits of the redesign methodology.
A case study on availability of sensor data in agent cooperation
Authors: Johansson Christian , Wernstedt Fredrik , Davidsson Paul
Published: June 2010

Multi-agent cooperation can in several cases be used in order to mitigate problems relating to task sharing within physical processes. In this paper we apply agent based solutions to a class of problems defined by their property of being predictable from a macroscopic perspective while being highly stochastic when viewed at a microscopic level. These characteristic properties can be found in several industrial processes and applications, e.g. within the energy market where the production and distribution of electricity follow this pattern. Another defining problem characteristic is that the supply is usually limited as well as consisting of several layers of differentiating production costs. We evaluate and compare the performance of the agent system in three different scenarios, and for each such scenario it is shown to what degree the optimization system is dependent on the level of availability of sensor data.
Cost of cooperation for scheduling meetings
Authors: Grubshtein Alon , Meisels Amnon
Published: June 2010

Scheduling meetings among agents can be represented as a game - the Meetings Scheduling Game (MSG). In its simplest form, the two-person MSG is shown to have a price of anarchy (PoA) which is bounded by 0.5. The PoA bound provides a measure on the efficiency of the worst Nash Equilibrium in social (or global) terms. The approach taken by the present paper introduces the Cost of Cooperation (CoC) for games. The CoC is defined with respect to different global objective functions and provides a measure on the efficiency of a solution for each participant (personal). Applying an ?egalitarian? objective, that maximizes the minimal gain among all participating agents, on our simple example results in a CoC which is non positive for all agents. This makes the MSG a cooperation game. The concepts are defined and examples are given within the context of the MSG. Although not all games are cooperation games, a game may be revised by adding a mediator (or with a slight change of its mechanism) so that it behaves as a cooperation game. Rational participants can cooperate (by taking part in a distributed optimization protocol) and receive a payoff which will be at least as high as the worst gain expected by a game theoretic equilibrium point.
TEAMLOG in action: A case study in teamwork
Authors: Dunin-Kęplicz Barbara , Verbrugge Rineke , Slizak Michał
Published: June 2010

This article presents a case study of a theoretical multi-agent system designed to clean up ecological disasters. It focuses on the interactions within a heterogeneous team of agents, outlines their goals and plans, and establishes the necessary distribution of information and commitment throughout the team, including its sub-teams. These aspects of teamwork are presented in the TEAMLOG formalism [20], based on multimodal logic, in which collective informational and motivational attitudes are first-class citizens. Complex team attitudes are justified to be necessary in the course of teamwork. The article shows how to make a bridge between theoretical foundations of TEAMLOG and an application and illustrates how to tune TEAMLOG to the case study by establishing sufficient, but still minimal levels for the team attitudes.
Winter Tires: Operating Conditions, Tire Characteristics and Vehicle Driving Behavior
Authors: Dörrie Helge , Schröder Carsten , Wies Burkhard
Published: June 2010

The modern development process of winter tires not only requires intense subjective and objective evaluation of the tire properties on the vehicle, but also requires knowledge about the influence of relevant tire characteristics on vehicle driving behavior. It is important to understand the influences of ambient conditions, such as temperature, track surface (asphalt vs corundum) and tire inflation pressure on tire behavior. Tire characteristic results of a parametric study, using a fully climate-controlled interior drum test stand will be presented. The effect on tire characteristics and the resulting vehicle behavior will be discussed using vehicle dynamics simulation. Furthermore the consequences for an optimal design of modern high performance winter tires will be presented.
The Impact of Tire Measurement Data on Tire Modeling and Vehicle Dynamics Analysis
Authors: Hüsemann Thomas , Wöhrmann Mark
Published: June 2010

Computer aided engineering tools play an important role in today’s vehicle development process. Today, overall vehicle dynamics analysis and chassis component fatigue resistance investigations can be carried out without the need for existing prototype hardware versions of the corresponding vehicle.

An accurate tire model is a key element in precise modeling of the vehicle and its components. All forces acting on the vehicle (except for aerodynamic forces) are transferred via the tires. Therefore, the tire and its modeled characteristics have a major influence on the results of vehicle dynamics analysis.

At present, many tire simulation models are available for application in vehicle dynamics analysis. To obtain the best possible performance from these models, a number of different tire measurements are required to support the tire model parameter identification process.

This paper presents a review of different tire simulation models and their required tire measurements. Depending on the test rigs used and the measurement procedures applied, the tire measurement results may be somewhat different. What is the impact of these differences on the tire modeling performance and the vehicle dynamics analysis output? This paper gives an answer.
A Dynamic Tire Model for ABS Maneuver Simulations
Authors: Braghin Francesco , Sabbioni Edoardo
Published: June 2010

Due to the dimensions of the tire-road contact area, transients in a tire last approximately 0.1 s. Thus, in the case of abrupt maneuvers such as ABS braking, the use of a steady-state tire model to predict the vehicle’s behavior would lead to significant errors.

Available dynamic tire models, such as Pacejka’s MF-Tire model, are based on steady-state formulations and the transient behavior of the tire is included by introducing a first order differential equation of relevant quantities such as the slip angle and the slippage. In these differential equations the most significant parameter used to describe the transient behavior is the so-called relaxation length, i.e., the distance traveled by the tire to settle to a new steady-state condition once perturbated. Usually this parameter is assumed to be constant.
Self-Evaluation as a Tool in Developing Environmental Responsibility
Authors: Pace Paul
Published: June 2010

Self-Evaluation as a Tool in Developing Environmental Responsibility

The purpose of the paper is to share the findings of an action research project aimed at exploring the impact of transformative pedagogies on pre-service teachers following an environmental education programme (EEP), offered by the University of Malta. Assessment and evaluation practices of environmental education (EE) and education for sustainable education (ESD) programmes tend to cater just for knowledge content and skills, usually failing to target the development of attitudes and values that promote sustainable lifestyles. The EEP was specifically designed to target the development of pro-environmental values by actively involving students in their learning mainly and providing opportunities for reflection and self-evaluation. The paper analyses qualitative research data obtained from evaluation questionnaires about every study unit in the programme; reflective questionnaires drawing upon the students' reflective journals; a focus group interview and in depth one-to-one interviews with individual students. The paper provides students' evaluations about the course design and effectiveness that should provide insights for course developers and evaluators seeking to develop EE/ESD programmes that address individual needs through learner centred pedagogies.
Teachers' Perceptions on What Inclusion Needs
Authors: Bērziņa Ženija
Published: June 2010

Teachers' Perceptions on What Inclusion Needs

A decade has passed since the equal right of all children to quality education regardless of their mental or physical abilities was declared by the Education Law (Izglītības likums, 1998). During that interlude, the Latvian educational system went through a period of tremendous change from total segregation of children with special needs in special schools to so-called "correction" classes in general schools, then to the special classes in general schools and finally to inclusion of special needs children in regular classrooms. Thus, the idea of inclusive education has been developed and implemented in various forms, which causes people to have a different understanding of what inclusive education means and impedes children with special needs from learning together with their peers in general classrooms. This article reflects on the findings of a qualitative study that was designed and conducted to investigate different perceptions of pre-school and primary school teachers on the preconditions for inclusive education.
The Ebb and Flow of Social Network Ties Between District Leaders Under High-Stakes Accountability
Authors: Daly Alan J. , Finnigan Kara S.
Published: June 2010

Recent scholarship suggests the importance of school district offices in supporting reform. These studies provide strategies for building relations between central offices and sites in order to improve change efforts. However, what is frequently overlooked is that organizational reform efforts are socially constructed. Therefore, examining the underlying reform-related social networks may provide insight into how relational structures support or constrain efforts at reform. This longitudinal case study draws upon social network analysis and interviews to examine the reform-related knowledge, advice, and innovation network structures of central office and site leaders in a district facing sanction for underperformance and engaging a districtwide reform. Findings indicate that over time, the networks increased the number of superficial interactions, and more frequent exchanges remained unchanged, resulting in a centralized network structure.
Treatment of endometrial polyps: a systematic review
Authors: LIENG MARIT , ISTRE OLAV , QVIGSTAD ERIK
Published: June 2010

Background. Transcervical resection of endometrial polyps is usually performed in order to exclude atypic and/or malignant endometrial changes, to relieve abnormal uterine bleeding or to improve infertility. Objective. To systematically explore the rationale of transcervical polyp resection. Search strategy. Electronic searches of MEDLINE, EMBASE and The Cochrane Library. Selection criteria. Studies reporting the prevalence of premalignant and/or malignant tissue changes within endometrial polyps, as well as outcomes of endometrial polyp removal in terms of symptom relief and improved fertility were included. Main results. 46 studies met the criteria for inclusion (malignancy: 20 studies including 9,266 women, symptom relief: 15 studies including 1,034 women, infertility: 11 studies including 935 women). Most studies were uncontrolled retrospective case series. Only two randomized controlled trials were identified. The prevalence of premalignant and malignant tissue changes within endometrial polyps varied in the included studies, 0.2–23.8% and 0–12.9%, respectively. Postmenopausal symptomatic women appeared to have the highest risk of premalignant and malignant tissue changes. The effect of polypectomy on periodic blood loss appeared to be questionable, but all studies measuring the effect of polypectomy by general terms such as improved/not improved reported a favorable outcome (75–100% success rate). Polypectomy appears to have a favorable outcome in infertile women. Conclusions. The evidence which substantiates the removal of endometrial polyps is limited, and future research evaluating the outcome of this common procedure is required. Based on the available evidence, however, we provide recommendations for treatment of women with endometrial polyps.
18F-fluoroethylcholine uptake in arterial vessel walls and cardio vascular risk factors
Authors: Rominger A. , Saam T. , Wolpers S. , Nikolaou K. , Cumming P. , Reiser M. F. , Bartenstein P. , Hacker M. , Förster S.
Published: June 2010

Aim: Fluorine-labelled choline derivatives were recently suggested as agents for visualizing vulnerable atherosclerotic plaques. We therefore aimed to evaluate the association between18F-fluoroethylcholine (FEC) uptake in the wall of large arteries, where calcification was also measured, with the presence of cardiovascular risk factors and occurrence of prior cardiovascular events. Patients, methods: Detailed clinical information, including common cardiovascular risk factors, was obtained retrospectively in 60 prostate cancer patients examined with whole-body FEC PETCT. In each patient, we calculated the mean blood pool-corrected SUV, as well as the mean target-to-background ratio (TBR), in addition to the sum of calcified plaques (CPsum) from six major vessels: ascending and descending aorta, aortic arch, abdominal aorta, and both iliac arteries. Results: As reported previously, the CPsum correlated significantly with cardiovascular risk factors, in contrast to mean SUV or TBR scores, which did not show any significance with the presence of cardiovascular risk factors. There was no correlation between CPsum, mean TBR or SUV, nor was there any significant association of CPsum, mean TBR or SUV with the prior occurrence of cardio- or cerebrovascular events. Conclusion: Contrary to a recent report, we found in our rather large cohort of elderly prostate cancer patients no significant association between FEC uptake in large vessels and atherosclerotic plaque burden, or the presence of cardiovascular risk factors. In line with prior reports on structural changes in vessels, increased calcified atherosclerotic plaque burden was strongly associated with the occurrence of common cardiovascular risk factors.
Synthesis and crystallographic analysis of meso-2,3-difluoro-1,4-butanediol and meso-1,4-dibenzyloxy-2,3-difluorobutane
Authors: Linclau Bruno , Leung Leo , Nonnenmacher Jean , Tizzard Graham
Published: June 2010

A large-scale synthesis of meso-2,3-difluoro-1,4-butanediol in 5 steps from (Z)-but-2-enediol is described. Crystallographic analysis of the diol and the corresponding benzyl ether reveals an anti conformation of the vicinal difluoride moiety. Monosilylation of the diol is high-yielding but all attempts to achieve chain extension through addition of alkyl Grignard and acetylide nucleophiles failed.
A Platform of Constructivist Learning in Practice: Computer Literacy Integrated into Elementary School
Authors: Garcia Ivan , Pacheco Carla , Garcia Gabriel
Published: June 2010

In Mexico, the conventional teaching approach, when applied specifically to elementary school, seems to fall short of attaining the overall quality objective. The main consequence of this problem is when teachers are not sure that their students really understand the dynamic nature of concepts and mechanism since an early age, particularly in elementary school. This paper presents a pedagogical/technological platform, based on constructivism ideas, as a means of making the learning process in elementary school more efficient and interesting. The constructivist platform presented here uses graphical simulators developed for Web 2.0 as a support tool, creating a teaching and learning environment in which practical experiments can be undertaken as each topic is introduced and explained.
Technical Appliance in E-Learning: Student's Perception on the Usage of Online Learning
Authors: Mohd Johari Siti Sarah , Ismail Issham , Mohammed Idrus Rozhan
Published: June 2010

The purpose of this study is to gain insights into studentâ??s perception on the usage of technical appliances on online learning. The study took place in the Universiti Sains Malaysia (USM) based on the sample of 1084 student s with the experiences of using E-learning Portal as one of the distance education academic programme. The students were surveyed on the participation needs based on respondentâ??s personal background, such as age, gender, ethnic groups, education streams and year-of-study. Results of the study showed even though most of the students felt uncertain about the technical appliances in E-learning Portal, the study illustrates the true nature of the studentâ??s perceptions with respect to the functionality and effectiveness of technical appliance in E-learning Portal. This research is essential to elucidate the functions of technical appliances in facilitating the process of learning through the portal.
Challenges of Utilizing E-Learning Systems in Public Universities in Jordan
Authors: Al-Shboul Muhannad Anwar , Alsmadi Izzat
Published: June 2010

This research paper lists and discusses major challenges and barriers that may face faculty members at the public universities in Jordan in employing e-Learning systems authoring tools in their instructions. It also proposes several suggestions for the administrators in public universities in Jordan for what they could do to improve the utilization of e-Learning authoring tools at their campuses. E-Learning systems authoring tools allow instructors to easily create and deliver their e-contents and e-lectures. Furthermore, online course materials which uploaded by using such authoring tools could be viewed by any popular web browser system.
ICT and Lifelong Learning: Hong Kong's Experience for Elderly Learners
Authors: Lam Sanches , Chung Winnie
Published: June 2010

Learning plays a key role in ageing societies as it can help to address many of the related challenges and opportunities. Opportunities to learn should be given to senior citizens through appropriate local lifelong learning programmes. There is a need to improve research and development on learning tools and approaches designed to meet the different needs of older people. ICT has an important role to play in developing learning opportunities for older people both as a topic in its own right and as a means of learning in the so called knowledge society. This paper reports on a Hong Kong case survey understanding the role of ICT in lifelong learning for elderly and its impact of learning activity. The survey results suggest numbers of areas should be taken into consideration for older people as both learners and mentors.
Metadata and Knowledge Management driven Web-based Learning Information System towards Web/e-Learning 3.0
Authors: Rego Hugo , Moreira Tiago , Morales Erla , Garcia Francisco José
Published: June 2010

AHKME e-learning system main aim is to provide a modular and extensible system with adaptive and knowledge management abilities for students and teachers. This system is based on the IMS specifications representing information through metadata, granting semantics to all contents in it, giving them meaning. Metadata is used to satisfy requirements like reusability, interoperability and multipurpose. The system provides authoring tools to define learning methods with adaptive characteristics, and tools to create courses allowing users with different roles, promoting several types of collaborative and group learning. It is also endowed with tools to retrieve, import and evaluate learning objects based on metadata, where students can use quality educational contents fitting their characteristics, and teachers have the possibility of using quality educational contents to structure their courses. The metadata management and evaluation play an important role in order to get the best results in the teaching/learning process.
An Automated Feedback System Based on Adaptive Testing: Extending the Model
Authors: Barker Trevor
Published: June 2010

Abstractâ??The results of the recent national students survey (NSS) revealed that a major problem in HE today is that of student feedback. Research carried out by members of the project team in the past has led to the development of an automated student feedback system for use with objective formative testing. This software relies on an â??intelligentâ?? engine to determine the most appropriate individual feedback, based on test performance, relating not only to answers, but also to Bloomâ??s cognitive levels. The system also recommends additional materials and challenges, for each individual learner. Detailed evaluation with more than 500 students and 100 university staff have shown that the system is highly valued by learners and seen by staff as an important addition to the methods available. The software has been used on two modules so far over a two year period
E-Learning Adoption Inside Jordanian Organizations from Change Management Perspective
Authors: Harfoushi Osama , Obiedat Ruba , Khasawneh Sahar
Published: June 2010

The objective of this research is to build a complete e-Learning adoption model which can be used to increase the acceptance of e-learning inside Jordanian organizations. This objective is achieved through the analysis of the e-learning adoption process in two different Jordanian case studies.
Mechanisms of IL-12 Synthesis by Human Dendritic Cells Treated with the Chemical Sensitizer NiSO4
Authors: Antonios Diane , Rousseau Philippe , Larangé Alexandre , Kerdine-Römer Saadia , Pallardy Marc
Published: June 2010

Allergic contact dermatitis, caused by metallic ions, is a T cell-mediated inflammatory skin disease. IL-12 is a 70-kDa heterodimeric protein composed of IL-12p40 and IL-12p35, playing a major role in the generation of allergen-specific T cell responses. Dendritic cells (DCs) are APCs involved in the induction of primary immune responses, as they possess the ability to stimulate naive T cells. In this study, we address the question whether the sensitizer nickel sulfate (NiSO4) itself or in synergy with other signals can induce the secretion of IL-12p70 in human monocyte-derived DCs (Mo-DCs). We found that IL-12p40 was produced by Mo-DC in response to NiSO4 stimulation. Addition of IFN-γ concomitantly to NiSO4 leads to IL-12p70 synthesis. NiSO4 treatment leads to the activation of MAPK, NF-κB pathways, and IFN regulatory factor 1 (IRF-1). We investigated the role of these signaling pathways in IL-12 production using known pharmacological inhibitors of MAPK and NF-κB pathways and RNA interference-mediated silencing of IRF-1. Our results showed that p38 MAPK, NF-κB, and IRF-1 were involved in IL-12p40 production induced by NiSO4. Moreover, IRF-1 silencing nearly totally abrogated IL-12p40 and IL-12p70 production provoked by NiSO4 and IFN-γ. In response to NiSO4, we observed that STAT-1 was phosphorylated on both serine and tyrosine residues and participated to NiSO4-induced IRF-1 activation. N-acetylcysteine abolished STAT-1 phosphorylation, suggesting that STAT-1 activation may be dependent on NiSO4-induced alteration of the redox status of the cell. These results indicate that p38 MAPK, NF-κB, and IRF-1 are activated by NiSO4 in Mo-DC and cooperate for IL-12 production.
TLR4-Mediated Sensing of Campylobacter jejuni by Dendritic Cells Is Determined by Sialylation
Authors: Kuijf Mark L. , Samsom Janneke N. , van Rijs Wouter , Bax Marieke , Huizinga Ruth , Heikema Astrid P. , van Doorn Pieter A. , van Belkum Alex , van Kooyk Yvette , Burgers Peter C. , Luider Theo M. , Endtz Hubert P. , Nieuwenhuis Edward E. S. , Jacobs Bart C.
Published: June 2010

In Guillain-Barré syndrome (GBS), ganglioside mimicry of Campylobacter jejuni lipo-oligosaccharide (LOS) drives the production of cross-reactive Abs to peripheral nerve gangliosides. We determined whether sialic acid residues in C. jejuni LOS modulate dendritic cell (DC) activation and subsequent B cell proliferation as a possible mechanism for the aberrant humoral immune response in GBS. Highly purified sialylated LOS of C. jejuni isolates from three GBS patients induced human DC maturation and secretion of inflammatory cytokines that were inhibited by anti-TLR4 neutralizing Abs. The extent of TLR4 signaling and DC activation was greater with LOS of the wild type isolates than with nonsialylated LOS of the corresponding sialyltransferase gene knockout (cst-II mutant) strains, indicating that sialylation boosts the DC response to C. jejuni LOS. Supernatants of LOS-activated DCs induced B cell proliferation after cross-linking of surface Igs in the absence of T cells. Lower B cell proliferation indices were found with DC supernatants after DC stimulation with cst-II mutant or neuraminidase desialylated LOS. This study showed that sialylation of C. jejuni LOS enhances human DC activation and subsequent B cell proliferation, which may contribute to the development of cross-reactive anti-ganglioside Abs found in GBS patients following C. jejuni infection.
Chronic Rejection Triggers the Development of an Aggressive Intragraft Immune Response through Recapitulation of Lymphoid Organogenesis
Authors: Thaunat Olivier , Patey Natacha , Caligiuri Giuseppina , Gautreau Chantal , Mamani-Matsuda Maria , Mekki Yahia , Dieu-Nosjean Marie-Caroline , Eberl Gérard , Ecochard René , Michel Jean-Baptiste , Graff-Dubois Stéphanie , Nicoletti Antonino
Published: June 2010

The unwarranted persistence of the immunoinflammatory process turns this critical component of the body’s natural defenses into a destructive mechanism, which is involved in a wide range of diseases, including chronic rejection. Performing a comprehensive analysis of human kidney grafts explanted because of terminal chronic rejection, we observed that the inflammatory infiltrate becomes organized into an ectopic lymphoid tissue, which harbors the maturation of a local humoral immune response. Interestingly, intragraft humoral immune response appeared uncoupled from the systemic response because the repertoires of locally produced and circulating alloantibodies only minimally overlapped. The organization of the immune effectors within adult human inflamed tissues recapitulates the biological program recently identified in murine embryos during the ontogeny of secondary lymphoid organs. When this recapitulation was incomplete, intragraft B cell maturation was impeded, limiting the aggressiveness of the local humoral response. Identification of the molecular checkpoints critical for completion of the lymphoid neogenesis program should help develop innovative therapeutic strategies to fight chronic inflammation.
Knowledge, Attitudes, and Practices about Malaria and Its Control in Rural Northwest Tanzania
Authors: Mazigo Humphrey D. , Obasy Emmanuel , Mauka Wilhellmus , Manyiri Paulina , Zinga Maria , Kweka Eliningaya J. , Mnyone Ladslaus L. , Heukelbach Jorg
Published: June 2010

Background. We assessed community knowledge, attitudes, and practices on malaria as well as acceptability to indoor residual spraying.Material and Methods. A cross-sectional survey was done in a community in Geita district (northwest Tanzania). Household heads (n=366) were interviewedResults. Knowledge on malaria transmission, prevention, and treatment was reasonable; 56% of respondents associated the disease with mosquito bites, with a significant difference between education level and knowledge on transmission (P<.001). Knowledge of mosquito breeding areas was also associated with education (illiterate: 22%; literate: 59% (P<.001). Bed nets were used by 236 (64.5%), and usage was significantly associated with education level (P<.01). The level of bed net ownership was 77.3%. Most respondents (86.3%) agreed with indoor residual spraying of insecticides. Health facilities were the first option for malaria treatment by 47.3%. Artemether-lumefantrine was the most common antimalarial therapy used.Conclusions. Despite reasonable knowledge on malaria and its preventive measures, there is a need to improve availability of information through proper community channels. Special attention should be given to illiterate community members. High acceptance of indoor residual spraying and high level of bed net ownership should be taken as an advantage to improve malaria control.
Trends in hospitalization for fall-related injury among older adults in the United States, 1988-2005.
Authors: Orces Carlos H.
Published: June 2010

The aim of the present study was to analyze trends in hospitalizations for fall-related injury among older adults in the United States from 1988 to 2005. The National Hospital Discharge Survey (NHDS) was used to generate injury hospitalization estimates based on the recommendations of the State and Territorial Injury Prevention Directors Association. Hospital- ization rates were standardized to the year 2000 U.S. population to account for changes in the age distribution of the population over time. Joinpoint regression analysis was used to calculate annual percentage changes in hospitalization rates and to identify points where a statistically significant change occurred over time. Hospitalization rates increased across all age groups (all p for trend <0.001). After age-adjustment, hospitalization rates among women increased by 5.9% (95% CI, 3.7 to 8.2) per year from 304.2 in 1988 to 729.9 per 100,000 persons in 2005. Similarly, age-adjusted rates among men increased at an annual rate of 5.8% (95% CI, 3.5 to 8.2) from 162.7 in 1988 to 377.4 per 100,000 persons in 2005. However, joinpoint regression analysis identified a change in the slope around 1997 and 1998 in men and women, respectively. Thereafter, hospitalization rates in men leveled off at an annual rate of 0.5% (95% CI, -3.6 to 4.7) from 1997 to 2005. In women, there was a non-significant trend toward decreasing rates by -1.3% (95% CI, -4.6 to 2.2) per year between 1998 and 2005. Hospitalization rates for fall-related injury clearly increased among older adults in the United States during the study period. The aging of the population is likely to increase the number of hospitalizations for severe fall-related injuries.
Immune Dysregulation in Myelodysplastic Syndrome
Authors: Sugimori Chiharu , List Alan F. , Epling-Burnette Pearlie K.
Published: June 2010

Myelodysplastic syndrome (MDS) represents one of the most challenging health-related problems in the elderly. Characterized by dysplastic morphology in the bone marrow in association with ineffective hematopoiesis, pathophysiological causes of this disease are diverse including genetic abnormalities within myeloid progenitors, altered epigenetics, and changes in the bone marrow microenvironment. The concept that T-cell mediated autoimmunity contributes to bone marrow failure has been widely accepted due to hematologic improvement after immunosuppressive therapy (IST) in a subset of patients. Currently, IST for MDS primarily involves anti-thymocyte globulin (ATG)-based regimens in which responsiveness is strongly associated with younger (under 60 years) age at disease onset. In such cases, progressive cytopenia may occur as a consequence of expanded self-reactive CD8+ cytotoxic T lymphocytes (CTLs) that suppress hematopoietic progenitors. Although most hematologists agree that IST can offer durable hematologic remission in younger patients with MDS, an international clinical study and a better understanding of the molecular mechanisms contributing to the expansion of self-reactive CTLs is crucial. In this review, data accumulated in the US, Europe, and Asia will be summarized to provide insight and direction for a multi-center international trial.
Intramedullary spinal melanocytoma
Authors: Eskandari Ramin , Schmidt Meic H
Published: June 2010

Meningeal melanocytoma is a benign lesion arising from leptomeningeal melanocytes that at times can mimic its malignant counterpart, melanoma. Lesions of the spine usually occur in extramedullary locations and present with spinal cord compression symptoms. Because most reported spinal cases occur in the thoracic region, these symptoms usually include lower extremity weakness or numbness. The authors present a case of primary intramedullary spinal meningeal melanocytoma presenting with bilateral lower extremity symptoms in which the patient had no known supratentorial primary lesions. Gross total surgical resection allowed for full recovery, but early recurrence of tumor was detected on close follow-up monitoring, allowing for elective local radiation without loss of neurological function. Case reports of such tumors discuss different treatment strategies, but just as important is the close follow-up monitoring in these patients even after gross total surgical resection, since these tumors can recur.