bluuebunny/crossref_metadata_2025 huggingface dataset:
Sudden intraaqueductal dislocation of a third ventricle ependymoma causing acute decompensation of hydrocephalus
Authors: Rosenstengel Christian , Baldauf Jörg , Müller Jan-Uwe , Schroeder Henry W. S.
Published: August 2011

The authors report an unusual sudden intraaqueductal dislocation of a third ventricle ependymoma causing acute loss of consciousness, and they detail its neuroendoscopic treatment. This case is unique and has never been described in the literature before.

The patient suffered from headache and recurrent nausea. Admission MR images revealed a contrast-enhancing lesion within the posterior part of the third ventricle. During the course of the day of admission, the patient suddenly became comatose. Emergency MR imaging demonstrated a deeply intraaqueductal dislocation of the pedicled tumor, with complete obstruction of the aqueduct and ventricular dilation. Immediate surgical intervention with endoscopic third ventriculostomy and complete tumor removal was performed. After surgery, the patient made a rapid recovery.

In this case, the authors presume a sudden intraaqueductal dislocation of the ependymoma caused by aspiration of the tumor as a result of the caudal CSF flow.
When only partial spinal cord detethering is possible
Authors: Ranger Adrianna , Bowden Gregory , Ryu Won Hyung A.
Published: August 2011

In most instances, initial surgery to untether a tethered spinal cord is successful. But what happens when it is not? The authors describe the case of a now 18-year-old woman with spina bifida in whom surgery for tethered cord was required on two occasions. In both instances, due to the extent of her underlying lesion and fibrous tissue, only partial detethering was possible without acutely sacrificing significant neurological function. The authors detail the patient's course and review the peer-reviewed scientific literature on outcomes in patients in whom only partial cord detethering is achieved.

In their review of all case series and clinical studies pertaining to the surgical treatment of tethered cord syndrome identified during an online search of 2184 scientific abstracts and 2 major neurosurgery textbooks, excluding the present case, the authors identified 53 confirmed or presumed cases of incomplete detethering in eight articles, incorporating 390 patients, for an overall prevalence of roughly 13.6%. Although no investigators have reported statistical comparisons of outcomes in those in whom just partial and complete detethering has been achieved, the evidence generally suggests poorer outcomes in the former. Prospective multicenter studies addressing this important issue clearly are warranted. To date, the authors believe that incomplete detethering is grossly underreported in the medical literature.
Preoperative vincristine for an inoperable choroid plexus papilloma: a case discussion and review of the literature
Authors: Addo Nii K. , Kamaly-Asl Ian D. , Josan Vivek A. , Kelsey Anna M. , Estlin Edward J.
Published: August 2011

The authors report the case of a 14-month-old boy with a large right intraventricular choroid plexus papilloma (CPP) for which the first attempt at resection resulted in life-threatening intraoperative hemorrhage. The tumor was unsuitable for embolization, and neoadjuvant ifosfamide, carboplatin, etoposide (ICE) chemotherapy had no effect on tumor size. However, chemotherapy with vincristine, although not impacting on CT perfusion parameters, resulted in a significant decrease in tumor size, enabling complete resection with manageable blood loss. The mechanism underlying the effect of vincristine in this case is uncertain, but it is a treatment strategy that warrants further evaluation for the treatment of CPPs that are not amenable to embolization.
Peritoneal Dialysis–Associated Peritonitis Rates and Outcomes in a National Cohort are not Improving in the Post-Millennium (2000 – 2007)
Authors: Brown Michaela C. , Simpson Keith , Kerssens Jan J. , Registry Robert A.
Published: August 2011

Background

Peritoneal dialysis (PD)–related peritonitis remains the leading cause of technique failure and a significant cause of morbidity among PD patients. Rates in the literature vary, reflecting differences in study design and in populations. The objective of the present study was to determine peritonitis incidence and outcomes in Scotland and to compare them with national guidelines.

Methods

All 10 adult renal units in Scotland prospectively collect data relating to peritonitis for all PD patients in Scotland. Complete audit data between 1 January 2000 and 31 December 2007 were analyzed for the study.

Results

The 1918 peritonitis episodes in 38 106 PD treatment months yielded a national rate of 1 episode every 19.9 months. The UK Renal Association standard was met every year, but is not consistently improving. The median peritonitis-free survival was 526 days (95% confidence interval: 463 to 589 days). The spectrum of causative organisms reflected those in previous reports, with a culture- negative rate of 19.4%. Nationally, the cure rate was 74.6%, the refractory rate was 22.6%, and the death rate was 2.8%. Outcome varied by organism. Recurrences represented 9.3% of episodes, and technique failure occurred in 14.9%. The peritonitis rate was higher for continuous ambulatory PD patients than for automated PD patients (1 episode every 17.6 months vs 1 episode every 22.3 months, p < 0.001, relative risk: 1.27). There were significant differences between renal units.

Conclusions

This large national PD cohort met targets for peritonitis rates every year during the 8 years covered by the present report, but showed no consistent trend for improvement. Peritonitis remains the main cause of technique failure in Scotland. Peritonitis rates varied widely between the units, which suggests that we should look to the units and countries with lower peritonitis rates to see if we can adopt successful elements of their practice before resigning ourselves to our ongoing peritonitis burden.
Peritoneal Morphology after Long-Term Peritoneal Dialysis with Biocompatible Fluid: Recent Clinical Practice in Japan
Authors: Ayuzawa Nobuhiro , Ishibashi Yoshitaka , Takazawa Yutaka , Kume Haruki , Fujita Toshiro
Published: August 2011

♦Background

Morphology changes of the peritoneal membrane after long-term peritoneal dialysis (PD) consist of denudation of peritoneal mesothelial cells, interstitial sclerosis, and hyalinizing vasculopathy. Those changes are considered to be the result of uremia and bioincompatible effects of conventional acidic lactate-buffered dialysate with glucose degradation products (GDPs). In the last decade, biocompatible dialysate with neutral pH and low GDPs has become widely used. Clinical practice has been modified in Japan, especially for anuric patients, and now includes the use of hybrid therapy. The impact on peritoneal morphology has not been well reported.

♦ Objective

The aim of the present study was to investigate the long-term effect on peritoneal morphology and function of biocompatible fluid use and current clinical practice in Japan, including hybrid dialysis therapy.

♦Methods

We evaluated peritoneal biopsy specimens from patients who had undergone PD for more than 3 years. We used the average peritoneal thickness (APT) of the submesothelial compact zone as a marker of interstitial sclerosis and the lumen/vessel diameter ratio (L/V ratio) at postcapillary venules as a marker of hyalinizing vasculopathy. Demography and other data for the patients, including dialysate-to-plasma (D/P) ratio of creatinine, were obtained at baseline and every 6 months by peritoneal equilibration test.

♦Results

Between 2002 and 2009, 110 patients started PD therapy with biocompatible dialysate at Tokyo University Hospital. Among them, 11 patients (8 men, 3 women; age: 54.2 ± 11.8 years; 1 with diabetes mellitus) were enrolled into this morphology study. The mean duration of PD in this group was 61 ± 11.3 months, and the mean time to peritoneal biopsy was 58 ± 15.1 months. The median APT was 180 μm (96 – 1424 μm), and the median L/V ratio was 0.66 (0.46 – 0.74). No obvious correlations between APT, L/V ratio, and PD duration were detected. The D/P creatinine of the 11 patients was maintained at a favorably low value, comparable with that of the other 99 patients.

♦Conclusions

Peritoneal dialysis therapy using biocompatible dialysate in conjunction with modification of clinical practice may minimize the progression of peritoneal interstitial sclerosis and hyalinizing vasculopathy, preserving favorable peritoneal function for more than 3 years.
Dietary Micronutrient Intake in Peritoneal Dialysis Patients: Relationship with Nutrition and Inflammation Status
Authors: Martín-del-Campo Fabiola , Batis–Ruvalcaba Carolina , González–Espinoza Liliana , Rojas–Campos Enrique , Ángel Juan R. , Ruiz Norma , González Juana , Pazarín Leonardo , Cueto–Manzano Alfonso M.
Published: August 2011

♦ Objective

To compare dietary intake of micronutrients by peritoneal dialysis (PD) patients according to their nutrition and inflammatory statuses.

♦ Design

This cross-sectional study evaluated 73 patients using subjective global assessment, 24-hour dietary recall, and markers of inflammation [C-reactive protein (CRP), tumor necrosis factor α, and interleukin 6].

♦Results

Half the patients had an inadequate micro-nutrient intake. Compared with dietary reference intakes, malnourished patients had lower intakes of iron (11 mg) and of vitamins C (45 mg) and B6 (0.8 mg). Malnourished and well-nourished patients both had lower intakes of sodium (366 mg, 524 mg respectively), potassium (1555 mg, 1963 mg), zinc (5 mg, 7 mg), calcium (645 mg, 710 mg), magnesium (161 mg, 172 mg), niacin (8 mg, 9 mg), folic acid (0.14 mg, 0.19 mg), and vitamin A (365 μg, 404 μg). Markers of inflammation were higher in malnourished than in well-nourished subjects. Compared with patients in lower quartiles, patients in the highest CRP quartile had lower intakes (p < 0.05) of sodium (241 mg vs 404 mg), calcium (453 mg vs 702 mg), vitamin B2 (0.88 mg vs 1.20 mg), and particularly vitamin A (207 μg vs 522 μg).

♦Conclusions

Among PD patients, half had inadequate dietary intakes of iron, zinc, calcium and vitamins A, B6, C, niacin, and folic acid. Lower micronutrient intakes were associated with malnutrition and inflammation. Patients with inflammation had lower intakes of sodium, calcium, and vitamins A and B2. Micronutrient intake must be investigated in various populations so as to tailor adequate supplementation.
Patient Perspective Workshop: Moving Towards OMERACT Guidelines for Choosing or Developing Instruments to Measure Patient-Reported Outcomes
Authors: KIRWAN JOHN R. , FRIES JAMES F. , HEWLETT SARAH E. , OSBORNE RICHARD H. , NEWMAN STANTON , CICIRIELLO SABINA , van de LAAR MART A. , DURES EMMA , MINNOCK PATRICIA , HEIBERG TURID , SANDERSON TESSA C. , FLUREY CAROLINE A. , LEONG AMY L. , MONTIE PAMELA , RICHARDS PAM
Published: August 2011

The workshop Choosing or Developing Instruments held at the Outcome Measures in Rheumatology (OMERACT) 10 meeting was designed to help participants think about the underlying methods of instrument development. Conference pre-reading material and 3 brief introductory presentations elaborated the issues, and participants broke into discussion groups before reconvening to share insights, engage in a more general discussion of the issues, and vote on recommendations. Tradeoffs between using current imperfect measures and the long and complex process of developing new instruments were considered, together with the need for rigor in patient-reported outcome (PRO) instrument development. The main considerations for PRO instrument development were listed and a research agenda for action produced. As part of the agenda for action, it is recommended that researchers and patient partners work together to tackle these issues, and that OMERACT bring forward proposals for acceptable instrument development protocols that would meet an enhanced “Truth” statement in the OMERACT Filter.
It's Good to Feel Better But It's Better To Feel Good and Even Better to Feel Good as Soon as Possible for as Long as Possible. Response Criteria and the Importance of Change at OMERACT 10: Figure 1.
Authors: STRAND VIBEKE , BOERS MAARTEN , IDZERDA LEANNE , KIRWAN JOHN R. , KVIEN TORE K. , TUGWELL PETER S. , DOUGADOS MAXIME
Published: August 2011

The OMERACT patient reported outcomes (PRO) working group evaluated the methodologies for measuring responsiveness to change at the Outcome Measures in Rheumatology (OMERACT) 10 meeting. The outcome measures used in PRO studies are often expressed as continuous data at the group level (e.g., mean change in pain on a 0–100 visual analog scale). This is difficult to interpret and cannot easily be translated to the individual level of response. When interpreting scores at the individual level, it is important to take into account the following 4 main concepts: (1) improvement; (2) status of well-being; (3) onset of action; and (4) sustainability. Information from clinical trials on how many patients showed a response, what the level of response was, and how many patients are doing well, would be extremely useful for physicians. The objective of this article is to outline how continuous data may be reported in a clinically relevant manner. We will describe 5 techniques of reporting continuous variables in clinical studies and discuss the relevance of each.
OMERACT 10 Patient Perspective Virtual Campus: Valuing Health; Measuring Outcomes in Rheumatoid Arthritis Fatigue, RA Sleep, Arthroplasty, and Systemic Sclerosis; and Clinical Significance of Changes in Health
Authors: KIRWAN JOHN R. , BOONEN ANNELIES , HARRISON MARK J. , HEWLETT SARAH E. , WELLS GEORGE A. , SINGH JASVINDER A. , FURST DANIEL E. , DWORKIN ROBERT H.
Published: August 2011

This workshop reviewed progress in a number of areas related to patient perspective outcomes that were not specifically included within other areas of the program. A substantial review of the work of the valuing health outcomes group (the “QALY” working group) with participation and feedback from the plenary audience resulted in guidance to refocus on the use of patient preferences in the elaboration of more robust outcome measures for patient-reported outcomes and life impact measures. Progress and developments in the areas of fatigue and sleep in rheumatoid arthritis, outcome measures in hip and knee arthroplasty clinical trials, and scleroderma were outlined, and the challenge of truly understanding the nature of clinically important improvement was reviewed.
Identifying Preliminary Domains to Detect and Measure Rheumatoid Arthritis Flares: Report of the OMERACT 10 RA Flare Workshop
Authors: BINGHAM CLIFTON O. , ALTEN RIEKE , BARTLETT SUSAN J. , BYKERK VIVIAN P. , BROOKS PETER M. , CHOY ERNEST , CHRISTENSEN ROBIN , FURST DANIEL E. , HEWLETT SARAH E. , LEONG AMYE , MAY JAMES E. , MONTIE PAM , POHL CHRISTOF , SANDERSON TESSA C. , STRAND VIBEKE , WOODWORTH THASIA G.
Published: August 2011

Background.

While disease flares in rheumatoid arthritis (RA) are a recognized aspect of the disease process, there is limited formative research to describe them.

Methods.

The Outcome Measures in Rheumatology Clinical Trials (OMERACT) RA Flare Definition Working Group is conducting an international research project to understand the specific characteristics and impact of episodic disease worsening, or “flare,” so that outcome measures can be developed or modified to reflect this uncommonly measured, but very real and sometimes disabling RA disease feature. Patient research partners provided critical insights into the multidimensional nature of flare. The perspectives of patients and healthcare and research professionals are being integrated to ensure that any outcome measurement to detect flares fulfills the first OMERACT criteria of Truth. Through an iterative data-driven Delphi process, a preliminary list of key domains has been identified to evaluate flare.

Results.

At OMERACT 10, consensus was achieved identifying features of flare in addition to the existing core set for RA, including fatigue, stiffness, symptom persistence, systemic features, and participation. Patient self-report of flare was identified as a component of the research agenda needed to establish criterion validity for a flare definition; this can be used in prospective studies to further evaluate the Discrimination and Feasibility components of the OMERACT filter for a flare outcome measure.

Conclusion.

Our work to date has provided better understanding of key aspects of the RA disease process as episodic, potentially disabling disease worsening even when a patient is in low disease activity. It also highlights the importance of developing ways to enhance communication between patients and clinicians and improve the ability to achieve “tight control” of disease.
Measuring the Impact of Arthritis on Worker Productivity: Perspectives, Methodologic Issues, and Contextual Factors
Authors: TANG KENNETH , ESCORPIZO REUBEN , BEATON DORCAS E. , BOMBARDIER CLAIRE , LACAILLE DIANE , ZHANG WEI , ANIS ASLAM H. , BOONEN ANNELIES , VERSTAPPEN SUZANNE M.M. , BUCHBINDER RACHELLE , OSBORNE RICHARD H. , FAUTREL BRUNO , GIGNAC MONIQUE A.M. , TUGWELL PETER S.
Published: August 2011

Leading up to the Outcome Measures in Rheumatology (OMERACT) 10 meeting, the goal of the Worker Productivity Special Interest Group (WP-SIG) was to make progress on 3 key issues that relate to the application and interpretation of worker productivity outcomes in arthritis: (1) to review existing conceptual frameworks to help consolidate our intended target and scope of measurement; (2) to examine the methodologic issues associated with our goal of combining multiple indicators of worker productivity loss (e.g., absenteeism <—> presenteeism) into a single comprehensive outcome; and (3) to examine the relevant contextual factors of work and potential implications for the interpretation of scores derived from existing outcome measures. Progress was made on all 3 issues at OMERACT 10. We identified 3 theoretical frameworks that offered unique but converging perspectives on worker productivity loss and/or work disability to provide guidance with classification, selection, and future recommendation of outcomes. Several measurement and analytic approaches to combine absenteeism and presenteeism outcomes were proposed, and the need for further validation of such approaches was also recognized. Finally, participants at the WP-SIG were engaged to brainstorm and provide preliminary endorsements to support key contextual factors of worker productivity through an anonymous “dot voting” exercise. A total of 24 specific factors were identified, with 16 receiving ≥ 1 vote among members, reflecting highly diverse views on specific factors that were considered most important. Moving forward, further progress on these issues remains a priority to help inform the best application of worker productivity outcomes in arthritis research.
Health Literacy: What Is It and Why Is It Important to Measure?
Authors: BUCHBINDER RACHELLE , BATTERHAM ROY , CICIRIELLO SABINA , NEWMAN STAN , HORGAN BEN , UEFFING ERIN , RADER TAMARA , TUGWELL PETER S. , OSBORNE RICHARD H.
Published: August 2011

This report summarizes the proceedings of the first Outcome Measures in Rheumatology Clinical Trials (OMERACT) Health Literacy Special Interest Group workshop at the OMERACT 10 conference. Health literacy refers to an individual’s capacity to seek, understand, and use health information. Discussion centered on the relevance of health literacy to the rheumatology field; whether measures of health literacy were important in the context of clinical trials and routine care; and, if so, whether disease-specific measures were required. A nominal group process involving 27 workshop participants, comprising a patient group (n = 12) and a healthcare professional and researcher group (n = 15), confirmed that health literacy encompasses a broad range of concepts and skills that existing scales do not measure. It identified the importance and relevance of patient abilities and characteristics, but also health professional factors and broader contextual factors. Sixteen themes were identified: access to information; cognitive capacity; disease; expression/communication; finances; health professionals; health system; information; literacy/numeracy; management skills; medication; patient approach; dealing with problems; psychological characteristics; social supports; and time. Each of these was divided further into subthemes of one or more of the following: knowledge, attitude, attribute, relationship, skill, action, or context. There were virtually no musculoskeletal-specific statements, suggesting that a generic health literacy tool in rheumatology is justified. The detailed concepts across themes provided new and systematic insight into what needs to be done to improve health literacy and consequently reduce health inequalities. These data will be used to derive a more comprehensive measure of health literacy.
Use of the “red gypsum” industrial waste as substitute of natural gypsum for commercial cements manufacturing
Authors: Gázquez M. J. , Bolívar J. P. , Vaca F. , García-Tenorio R. , Mena-Nieto A.
Published: August 2011

The main objective of this research has been the valorisation of a waste from the TiO2 production process (sulphate method), called red gypsum, in the production of cements. This waste is mainly formed by di-hydrate calcium sulphate and iron hydroxides. To cover this objective it has been necessary to perform the physico-chemical characterisation of the red gypsum as well as the main components in the production of cements and of the new cements generated. Moreover, for the red gypsum, has been analyzed its radioactive content because it is generated in a NORM (Naturally Occurring Radioactive Materials) industry.
Finally, the most important properties of the obtained cements with different proportions of red gypsum in their composition have been studied by comparing them with the standard ones obtained in a Portland cement. Lastly, we have demonstrated that the new cements fulfil all the quality tests imposed by the European legislation.
The Importance of Service Integration in Developing Effective Employment Services for People with Severe Mental Health Conditions
Authors: Waghorn Geoff , Stephenson Adel , Browne Deborah
Published: August 2011

Introduction:

This report examines the importance of integrating mental health services with supported employment services for people with severe mental health conditions and psychiatric disabilities. Integrated mental health and employment services are considered a key principle of evidence-based practices in supported employment for this group.

Method:

The importance of this principle was tested by examining both the service practices and the employment outcomes attained by 270 clients of a segregated employment service in Christchurch, New Zealand. Service practices were examined using an established scale to assess the fidelity of evidence-based practices in supported employment. Employment outcomes were benchmarked to a range of employment outcome variables reported in national and international studies of specialised supported employment services.

Results:

Despite only a fair overall fidelity score of 64/75, 73.7% of clients commenced competitive employment within a mean of 86 days from programme entry. The mean hours worked by those employed was 22 hours per week, and 41.5% of those who commenced employment worked for 26 weeks or more.

Conclusion:

These promising results confirm that very good implementation of evidence-based practices other than service integration practices can compensate for the disadvantages of service segregation.
Research Governance and Bureaucracy for Multisite Studies: Implications for Occupational Therapy Research
Authors: Whitehead Phillip , Drummond Avril , Fellows Karen
Published: August 2011

Obtaining research governance approvals for research involving the National Health Service (NHS) has become increasingly complex. In order to obtain the necessary approvals to interview 20 occupational therapists from a range of locations across the United Kingdom, the authors had to submit lengthy applications to all 20 sites. Before issuing their approvals, some sites raised numerous queries, whilst others did not raise any. The time taken to obtain approvals ranged from 6 to 197 days. These disparities highlight that the current research governance procedure for multisite studies is complex and subject to local interpretations. This opinion piece argues that the procedure is excessive for research that does not involve patients and involves NHS staff only. It also argues that this is an injudicious use of resources at a time of national austerity. Implications for the future of occupational therapy research in the United Kingdom are discussed.
A convergência dos aspectos de inclusão digital: experiência nos domínios de uma Universidade
Authors: Neves Barbara Coelho , Gomes Henriette Ferreira
Published: August 2011

Traz resultados de um estudo de caso, aplicado com técnicas de survey, visando analisar os aspectos da inclusão digital através dos usuários do telecentro Tabuleiro Digital da Faculdade de Educação da Universidade Federal da Bahia - FACED/UFBA. O principal objetivo destinou-se a investigar o tipo de inclusão digital, promovida por este Projeto, em conformidade com a perspectiva da literatura atual. Os objetivos específicos indicam as características do perfil dos usuários; tipos de aplicações utilizadas e a finalidade da Internet em confronto com o nível educacional e social. Desta forma, a sociedade da informação e a inclusão digital são contextualizadas; também os aspectos da inclusão do Tabuleiro são demonstrados e discutidos. Por último, com a análise, foi comprovado que o modelo de inclusão digital do Projeto é induzido (técnico).
Avaliação da acessibilidade de sites oficiais de pesquisa no Brasil por pessoas com deficiência
Authors: Ignácio Edilson Antonio , Carvalho José Oscar Fontanini de
Published: August 2011

Este artigo tem como objetivo apresentar um trabalho baseado na revisão da literatura, sobre os temas Sociedade da Informação; Interação Humano-Computador e Inclusão Digital sob a ótica da Ciência da Informação. Constitui-se da avaliação de sites oficiais de órgãos brasileiros de fomento à pesquisa, escolhidos dentre as unidades federativas mais e menos incluídas digitalmente, segundo dados do Mapa da Exclusão Digital, elaborado pela Fundação Getúlio Vargas. Buscou-se averiguar se esses sites estão cumprindo a legislação a respeito da acessibilidade para as pessoas com deficiência. O trabalho possibilitou inferir que os sites oficiais de pesquisa destinados à prestação de serviços públicos e disseminação de informação na web analisados, ainda não são efetivamente acessíveis a todos os cidadãos, de modo a realizar oprincípio da universalização da informação.
Websites de unidades de informação como ferramentas de comunicação com seus próprios públicos
Authors: Amaral Sueli Angelica do , Guimarães Tatiara Paranhos
Published: August 2011

Tem como objetivo discutir o uso de websites de unidades de informação como ferramentas de comunicação capazes de melhorar o relacionamento dessas organizações com os seus diversos públicos, levando em conta o potencial tecnológico e comunicacional da web. O estudo destaca que os gestores das unidades de informação devem se preocupar com os websites e torná-los capazes de desempenhar diversas funções, pois representam a unidade de informação na web. Ressalta que o uso do website como ferramenta de comunicação para o relacionamento com os diversos públicos pode ser analisado pelo seu desempenho da função de comunicação. Por meio dos websites, essa comunicação deve ocorrer em duas vias, tanto da unidade de informação em direção aos seus públicos, como desses públicos para a unidade de informação. São apresentados resultados obtidos em pesquisas com o uso de esquema classificatório das funções desempenhadas pelos websites de unidades de informação para verificar o  desempenho específico da função de comunicação. A maior parte dos resultados das pesquisas mostrou que o potencial da web não estava sendo explorado em sua totalidade e  evidenciou que a comunicação era realizada de forma assimétrica, pois os websites demonstraram o uso de comunicação desbalanceada.
O campo da Ciência da Informação e o patrimônio cultural: reflexões iniciais para novas discussões sobre os limites da área
Authors: Souza Willian Eduardo Righini de , Crippa Giulia
Published: August 2011

Utilizando-se da noção de campo apresentada por Pierre Bourdieu, pretende-se refletir sobre a inserção de pesquisas sobre patrimônio cultural no universo da Ciência da Informação. Para isto, torna-se necessário conhecer o que é produzido sobre o tema nas publicações consideradas da CI, saber quem são os agentes que falam do patrimônio cultural, refletir sobre a visibilidade e prestígio destes agentes e a inclusão do assunto nas instituições e principais eventos da CI.
Produção científica dos pesquisadores brasileiros que depositaram patentes na área da Biotecnologia, no período de 2001 a 2005: colaboração interinstitucional e interpessoal
Authors: Moura Ana Maria Mielniczuk de , Caregnato Sônia Elisa
Published: August 2011

Analisa a produção científica dos pesquisadores que depositaram patentes na área da Biotecnologia, no período compreendido entre 2001 a 2005. A partir de um enfoque cientométrico, objetiva revelar a colaboração interinstitucional e interpessoal existente. O corpus constitui-se em 2.584 artigos coletados na WebofScience. Utilizou-se a metodologia de Análise de Redes Sociais e MDS para observar a formação de clusters entre autores e instituições. Os resultados indicam que a a maioria dos artigos possui até três instituições relacionadas no Campo C1, pois 88,7% dos casos apresentam-se desta forma. Observou-se que a produção científica está concentrada em algumas poucas instituições, lideradas pelas universidades públicas (federais e estaduais) e instituições de pesquisa de renome. Entre as universidades, as mais produtivas são a USP, UNICAMP, UNESP e UFRJ; e entre as instituições de pesquisa, tiveram destaque a FIOCRUZ, INSTITUTO BUTANTAN e EMBRAPA. Algumas instituições apresentam um padrão regional de colaboração, pois apresentam interação somente com outras instituições mais próximas geograficamente, formando clusters com motivação regional. Os autores mais produtivos não encontram-se nas primeiras posições no ranking por grau de centralidade, significando que a centralidade não está relacionada diretamente à produtividade. Observou-se que a colaboração interpessoal se fortalece após a parceria formada pelo vínculo criado na pós-graduação, pois muitas parcerias foram formadas a partir deste tipo de vínculo, apresentando produção significativa entre orientadores e orientados.
Modeling chemical and aerosol processes in the transition from closed to open cells during VOCALS-REx
Authors: Kazil J. , Wang H. , Feingold G. , Clarke A. D. , Snider J. R. , Bandy A. R.
Published: August 2011

Abstract. Chemical and aerosol processes in the transition from closed- to open-cell circulation in the remote, cloudy marine boundary layer are explored. It has previously been shown that precipitation can initiate a transition from the closed- to the open-cellular state, but that the boundary layer cannot maintain this open-cell state without a resupply of cloud condensation nuclei (CCN). Potential sources of CCN include wind-driven production of sea salt from the ocean, nucleation from the gas phase, and entrainment from the free troposphere. In order to investigate CCN sources in the marine boundary layer and their role in supplying new particles, we have coupled in detail chemical, aerosol, and cloud processes in the WRF/Chem model, and added state-of-the-art representations of sea salt emissions and aerosol nucleation. We conduct numerical simulations of the marine boundary layer in the transition from a closed- to an open-cell state. Results are compared with observations in the Southeast Pacific boundary layer during the VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx). The transition from the closed- to the open-cell state generates conditions that are conducive to nucleation by forming a cloud-scavenged, ultra-clean layer below the inversion base. Open cell updrafts loft dimethyl sulfide from the ocean surface into the ultra-clean layer, where it is oxidized during daytime to SO2 and subsequently to H2SO4. Low H2SO4 condensation sink values in the ultra-clean layer allow H2SO4 to rise to concentrations at which aerosol nucleation produces new aerosol in significant numbers. The existence of the ultra-clean layer is confirmed by observations. We find that the observed DMS flux from the ocean in the VOCALS-REx region can support a nucleation source of aerosol in open cells that exceeds sea salt emissions in terms of the number of particles produced. The freshly nucleated, nanometer-sized aerosol particles need, however, time to grow to sizes large enough to act as CCN. In contrast, mechanical production of particles from the ocean surface by near-surface winds provides a steady source of larger particles that are effective CCN at a rate exceeding a threshold for maintenance of open-cell circulation. Entrainment of aerosol from the free troposphere contributes significantly to boundary layer aerosol for the considered VOCALS-REx case, but less than sea salt aerosol emissions.
A hybrid bin scheme to solve the condensation/evaporation equation using a cubic distribution function
Authors: Dinh T. , Durran D. R.
Published: August 2011

Abstract. A computationally efficient method is proposed to replace the piecewise linear number distribution in a hybrid bin scheme with a piecewise cubic polynomial. When the linear distribution is replaced by a cubic, the errors generated in solutions to the condensation/evaporation equation are reduced by a factor of two to three. Alternatively, using the cubic distribution function allows reducing the number of bins by 20 ± 5 % when solving the condensation/evaporation problem without sacrificing accuracy.
Two methods for transmission line simulation model creation based on time domain measurements
Authors: Rinas D. , Frei S.
Published: August 2011

Abstract. The emission from transmission lines plays an important role in the electromagnetic compatibility of automotive electronic systems. In a frequency range below 200 MHz radiation from cables is often the dominant emission factor. In higher frequency ranges radiation from PCBs and their housing becomes more relevant. Main sources for this emission are the conducting traces. The established field measurement methods according CISPR 25 for evaluation of emissions suffer from the need to use large anechoic chambers. Furthermore measurement data can not be used for simulation model creation in order to compute the overall fields radiated from a car. In this paper a method to determine the far-fields and a simulation model of radiating transmission lines, esp. cable bundles and conducting traces on planar structures, is proposed. The method measures the electromagnetic near-field above the test object. Measurements are done in time domain in order to get phase information and to reduce measurement time. On the basis of near-field data equivalent source identification can be done. Considering correlations between sources along each conductive structure in model creation process, the model accuracy increases and computational costs can be reduced.
Channel equalization using watermark as a training sequence
Authors: Samee M. K. , Götze J.
Published: August 2011

Abstract. In this paper blind equalization algorithms based on digital watermarking are presented. Training sequence is sent along with the data in the form of watermark. Robust CDMA based watermarking algorithm is used to watermark the data. Watermark, which is spread over the data, does not consume extra bandwidth. So with the help of extracted watermark channel can be equalized just by using simple mean square algorithm. Two algorithms for equalization are proposed in this paper. In algorithm I the receiver does not require to know training sequence in advance. Using algorithm II, the sender does not require to send training sequence either, and data can still be equalized using simple LMS algorithm at low computational complexity.
Benefits of on-wafer calibration standards fabricated in membrane technology
Authors: Rohland M. , Arz U. , Büttgenbach S.
Published: August 2011

Abstract. In this work we compare on-wafer calibration standards fabricated in membrane technology with standards built in conventional thin-film technology. We perform this comparison by investigating the propagation of uncertainties in the geometry and material properties to the broadband electrical properties of the standards. For coplanar waveguides used as line standards the analysis based on Monte Carlo simulations demonstrates an up to tenfold reduction in uncertainty depending on the electromagnetic waveguide property we look at.
Iterative least squares method for global positioning system
Authors: He Y. , Bilgic A.
Published: August 2011

Abstract. The efficient implementation of positioning algorithms is investigated for Global Positioning System (GPS). In order to do the positioning, the pseudoranges between the receiver and the satellites are required. The most commonly used algorithm for position computation from pseudoranges is non-linear Least Squares (LS) method. Linearization is done to convert the non-linear system of equations into an iterative procedure, which requires the solution of a linear system of equations in each iteration, i.e. linear LS method is applied iteratively. CORDIC-based approximate rotations are used while computing the QR decomposition for solving the LS problem in each iteration. By choosing accuracy of the approximation, e.g. with a chosen number of optimal CORDIC angles per rotation, the LS computation can be simplified. The accuracy of the positioning results is compared for various numbers of required iterations and various approximation accuracies using real GPS data. The results show that very coarse approximations are sufficient for reasonable positioning accuracy. Therefore, the presented method reduces the computational complexity significantly and is highly suited for hardware implementation.
Pushing energy savings in adiabatic logic by carbon-nanotube field effect transistors
Authors: Teichmann P. , Friederich C. , Schmitt-Landsiedel D.
Published: August 2011

Abstract. For the first time carbon nanotube (CNT) transistor based adiabatic logic (AL) was analyzed in this work and compared to CNT based static CMOS (CCNT). Static CCNT inverters are used as a reference and compared to inverters in the AL families Efficient Charge Recovery Logic (ECRL) and Positive Feedback Adiabatic Logic (PFAL) in terms of energy dissipation. Energy savings by adiabatic logic in dependence of operating frequency, supply voltage and number of nanotubes per transistor are reviewed. It is shown that CNT based AL circuits provide high energy saving factors even for high frequencies compared to CNT based static CMOS circuits.
Eigenmode analysis of the electromagnetic field scattered by an elliptic cone
Authors: Kijowski M. , Klinkenbusch L.
Published: August 2011

Abstract. The vector spherical-multipole analysis is applied to determine the scattering of a plane electromagnetic wave by a perfectly electrically conducting (PEC) semi-infinite elliptic cone. From the eigenfunction expansion of the total field in the space outside the elliptic cone, the scattered far field is obtained as a multipole expansion of the free-space type by a single integration over the induced surface currents. As for the evaluation of the free-space-type expansion it is necessary to apply suitable series transformation techniques, a sufficient number of eigenfunctions has to be considered. The eigenvalues of the underlying two-parametric eigenvalue problem with two coupled Lamé equations belong to the Dirichlet- or the Neumann condition and can be arranged as so-called eigenvalue curves. It has been observed that the eigenvalues are in two different domains: In the first one Dirichlet- and Neumann eigenvalues are either nearly coinciding, while in the second one they are strictly separated. The eigenfunctions of the first (coinciding) type look very similar to free-space modes and do not contribute to the scattered field. This observation allows to significantly improve the determination of diffraction coefficients.
Proposal for scalable models in EMC simulation
Authors: Leibinger Á , Hajdu Á
Published: August 2011

Abstract. In this paper a method "Component Series Modeling" (CoSeMod) is presented. This allows fast and easy implementation of scalable model generations for passive component series based on measurement data or specification provided by manufacturer. These can be used in circuit models for fast EMC analysis and optimization, especially in frequency ranges where conducted emission and susceptibility dominate. EMC tasks require high precision equivalent circuit models of components. Models generated with CoSeMod provide in many cases as high a quality as original (static) models do. One feature of scalability is that new netlisting is not needed after component changes. The process of model creation is based on similarities of the components of the same model series (packaging, manufacturing process, material etcetera). Required equations of the relationship between nominal and parasitic values are calculated by nonlinear regression. Model generation for unknown components of a known series is possible with interpolation. Implementation is possible with relatively simple actions made in circuit simulator Saber. An EMC application example of the implemented model is also shown in this paper.
Challenges for Wireless Mesh Networks to provide reliable carrier-grade services
Authors: von Hugo D. , Bayer N.
Published: August 2011

Abstract. Provision of mobile and wireless services today within a competitive environment and driven by a huge amount of steadily emerging new services and applications is both challenge and chance for radio network operators. Deployment and operation of an infrastructure for mobile and wireless broadband connectivity generally requires planning effort and large investments. A promising approach to reduce expenses for radio access networking is offered by Wireless Mesh Networks (WMNs). Here traditional dedicated backhaul connections to each access point are replaced by wireless multi-hop links between neighbouring access nodes and few gateways to the backbone employing standard radio technology. Such a solution provides at the same time high flexibility in both deployment and the amount of offered capacity and shall reduce overall expenses. On the other hand currently available mesh solutions do not provide carrier grade service quality and reliability and often fail to cope with high traffic load. EU project CARMEN (CARrier grade MEsh Networks) was initiated to incorporate different heterogeneous technologies and new protocols to allow for reliable transmission over "best effort" radio channels, to support a reliable mobility and network management, self-configuration and dynamic resource usage, and thus to offer a permanent or temporary broadband access at high cost efficiency. The contribution provides an overview on preliminary project results with focus on main technical challenges from a research and implementation point of view. Especially impact of mesh topology on the overall system performance in terms of throughput and connection reliability and aspects of a dedicated hybrid mobility management solution will be discussed.
Advanced parametrical modelling of 24 GHz radar sensor IC packaging components
Authors: Kazemzadeh R. , John W. , Wellmann J. , Bala U. B. , Thiede A.
Published: August 2011

Abstract. This paper deals with the development of an advanced parametrical modelling concept for packaging components of a 24 GHz radar sensor IC used in automotive driver assistance systems. For fast and efficient design of packages for system-in-package modules (SiP), a simplified model for the description of parasitic electromagnetic effects within the package is desirable, as 3-D field computation becomes inefficient due to the high density of conductive elements of the various signal paths in the package. By using lumped element models for the characterization of the conductive components, a fast indication of the design's signal-quality can be gained, but so far does not offer enough flexibility to cover the whole range of geometric arrangements of signal paths in a contemporary package. This work pursues to meet the challenge of developing a flexible and fast package modelling concept by defining parametric lumped-element models for all basic signal path components, e.g. bond wires, vias, strip lines, bumps and balls.
Minimizing interference in automotive radar using digital beamforming
Authors: Fischer C. , Goppelt M. , Blöcher H.-L. , Dickmann J.
Published: August 2011

Abstract. Millimetre wave radar is an essential part of automotive safety functions. A high interference tolerance, especially with other radar sensors, is vital. This paper gives an overview of the motivation, the boundary conditions and related activities in the MOSARIM project funded by the European Union and concerned with interference mitigation in automotive radars. Current and planned activities considering Digital Beamforming (DBF) as a method for interference mitigation are presented.
Performance analysis of a low cost wireless indoor positioning system with distributed antennas
Authors: Ott A. T. , Shalaby M. , Siart U. , Kaliyaperumal E. , Eibert T. F. , Engelbrecht J. , Collmann R.
Published: August 2011

Abstract. In this paper an approach for indoor localization based on already installed communication transceiver infrastructure is presented. Only marginal additional hardware is required to implement the localization functionality. The idea is to use a power level detection evaluation of the received signals in communication receivers to localize participants. In the planned configuration the power transmitted from mobile terminals is received by a leaky wave cable. Its length and coupling properties are dimensioned according to the dynamic range of two access points connected to the two cable heads. In order to adapt the problem to circuit-based analysis techniques the leaky wave cable is represented by a distributed antenna system. Thereby the considered design consists of a cascade of coupling structures with broadband Vivaldi antennas connected to the coupling ports. An experimental system has been built and also tested using an automated frequency domain measurement setup. Measurement results relating the system bandwidth to positioning accuracy show good agreement with theoretical investigations.
Timescales for the development of methanogenesis and free gas layers in recently-deposited sediments of Arkona Basin (Baltic Sea)
Authors: Mogollón J. M. , Dale A. W. , Fossing H. , Regnier P.
Published: August 2011

Abstract. Arkona Basin (southwestern Baltic Sea) is a seasonally-hypoxic basin characterized by the presence of free methane gas in its youngest organic-rich muddy stratum. Through the use of reactive transport models, this study tracks the development of the methane geochemistry in Arkona Basin as this muddy sediment becomes deposited during the last 8 kyr. Four cores are modeled each pertaining to a unique geochemical scenario according to their respective contemporary geochemical profiles. Ultimately the thickness of the muddy sediment and the flux of particulate organic carbon are crucial in determining the advent of both methanogenesis and free methane gas, the timescales over which methanogenesis takes over as a dominant reaction pathway for organic matter degradation, and the timescales required for free methane gas to form.