Marcapasso com sensor de contratilidade regulado pelas variações do sistema nervoso autônomo na miocardiopatia chagásica crônica

OBJETIVO: Analisar o desempenho da estimulação cardíaca artificial com marcapasso do tipo VVIR cujo sensor é regulado pelas variações do sistema nervoso autônomo em pacientes chagásicos com distúrbio no sistema de condução. MÉTODOS: Estudados 47 chagásicos, 28 do sexo masculino, com idades entre 24 e 68 anos, 36 tinham bloqueio atrioventricular (AV) total; 8, bloqueio AV de 2º grau 2; e 3 doença do nódulo sinusal, e encontravam-se, de acordo com a NYHA, em classe I (4), II (15), III (16) e IV (12). Após o implante de marcapasso do tipo VVIR os pacientes foram acompanhados durante 12 meses. A resposta de freqüência foi registrada em gravações de Holter de 24h e divididos em dois grupos de acordo com a FC em repouso - grupo 1: >65bpm e grupo 2: <=65bpm, para estudo comparativo, considerando: 1) FC em exercício no período de pós-implante; 2) PA em repouso após o implante e 3) avaliação dos grupos de eletrodos identificados como TIR-60-UP e outros eletrodos. RESULTADOS: O grupo 1 teve em exercício menor variação entre seus valores, do que o grupo 2, indicando que esse tipo de sistema de estimulação permite controlar individualmente cada paciente. Os valores de PA em repouso e em exercício não foram diferentes entre os grupos. O eletrodo do tipo TIR-60-UP, comportou-se como os demais eletrodos. CONCLUSÃO: O marcapasso do tipo VVIR cujo sensor é regulado pelas variações do SNA propicia o restabelecimento dos mecanismos fisiológicos em chagásicos, sendo que 74% deles tiveram melhora de uma ou duas classes funcionais da NYHA.

Comparing heritage speakers and late L2-learners of European Portuguese: verb movement, VP ellipsis and adverb placement

This study compares the performance of Portuguese-German heritage children and adult L2 speakers of European Portuguese whose L1 is German with respect to two aspects of grammar, adverb placement and VP-ellipsis, which depend on a core syntactic property of the language, verb movement. The results show that both groups have acquired V-to-I and adverb placement, showing no influence of a V2 grammar. Performance in the VP-ellipsis task is more complex: heritage children produce VP-ellipsis at the level of controls, as opposed to L2 speakers; however, both L2 and heritage speakers show that crosslinguistic influence may produce a preference for pronoun substitution over VP-ellipsis in a task asking for redundancy resolution. Nevertheless, given that overall results show that heritage children perform at the level of L1 children, we take our results to support approaches to heritage bilingualism which suggest the development of an intact grammar in childhood.

O sexo e a Cidade e as marcas: análise dos efeitos do product placement nos jovens portugueses

Dissertação de Mestrado em Comunicação Social

Evaluation of the determinism of the actuator sensor interface (ASI) on programmable logic controllers (PLC), personal computers (PC) and real-time operating systems (RTOS)

The purpose of this study was to evaluate the determinism of the AS-lnterface network and the 3 main families of control systems, which may use it, namely PLC, PC and RTOS. During the course of this study the PROFIBUS and Ethernet field level networks were also considered in order to ensure that they would not introduce unacceptable latencies into the overall control system. This research demonstrated that an incorrectly configured Ethernet network introduces unacceptable variable duration latencies into the control system, thus care must be exercised if the determinism of a control system is not to be compromised. This study introduces a new concept of using statistics and process capability metrics in the form of CPk values, to specify how suitable a control system is for a given control task. The PLC systems, which were tested, demonstrated extremely deterministic responses, but when a large number of iterations were introduced in the user program, the mean control system latency was much too great for an AS-I network. Thus the PLC was found to be unsuitable for an AS-I network if a large, complex user program Is required. The PC systems, which were tested were non-deterministic and had latencies of variable duration. These latencies became extremely exaggerated when a graphing ActiveX was included in the control application. These PC systems also exhibited a non-normal frequency distribution of control system latencies, and as such are unsuitable for implementation with an AS-I network. The RTOS system, which was tested, overcame the problems identified with the PLC systems and produced an extremely deterministic response, even when a large number of iterations were introduced in the user program. The RTOS system, which was tested, is capable of providing a suitable deterministic control system response, even when an extremely large, complex user program is required.

Architektur für verteilte, fehlertolerante Sensor-Aktor-Systeme

Magdeburg, Univ., Fak. für Informatik, Diss., 2011

Wideband impedance spectrum analyzer with arbitry fine frequency resolution for in situ sensor applications

Magdeburg, Univ., Fak. für Elektrotechnik und Informationstechnik, Diss., 2009

Steuerung eines zweibeinigen Schreitroboters mit einem elastischen Sensor-Aktor-System

Magdeburg, Univ., Fak. für Elektrotechnik und Informationstechnik, Diss., 2012

Studies on the mineral nutrition and fertilization of the passion fruit plant (Passiflora edulis f. flavicarpa): II - placement of fertilizer phosphorus

A localização do superfosfato (marcado com P32) no maracujá em produção foi estudada em condições de plantação comercial. Verificou-se que as aplicações em sulcos circulares ou faixas superficiais ao redor da planta tem eficiência equivalente sendo esses métodos três vezes superiores à localização do adubo em furos no solo. A pulverização foliar, por sua vez, mostrou-se 20 vezes mais eficiente que a aplicação no solo de acordo com os dois primeiros métodos.

Studies on the mineral nutrition and fertilization of the passion fruit plant (Passiflora edulis F. flavicarpa): II. placement of fertilizer phosphorus

1. Tagged superphosphate was applied to 2.5 year old passion fruit plants from a commercial plantation established in a sandy loam. 2. 100 grams of the fertilizer were distributed in the following ways: in a circular furrow 20 cm around the plant 40 cm from the stems; in a circular strip 10 cm wide, 40 cm from the stems; in six holes around the plants, 40 cm from the stems 20 cm deep, 2.5 cm in diameter. 3. 10 grams of the fertilizer in 11 of water were sprayed to the leaves. 4. Three weeks after the treatments were made, leaf samples were taken for analysis. 5. Determinations of specific activities both in the leaves and in the fertilizer used have shown that R in the plant was derived from the superphosphate in the following relative proportions (by making the first treatment equal to 100): circular furrow = 100; circular strip = 120; holes = 30; foliar spray = 230.

Apedilum griseistriatum comb. nov., placement of Chironomus (Polypedilum) griseistriatum (Diptera, Chironomidae)

The study of the type material of Chironomus (Polypedilum) griseistriatum Edwards, 1931 described from Patagonia lead us to formally transfer the species to Apedilum Townes, 1945 as a new combination, and a reared specimen allows us to describe its pupa. Based on several larvae belonging to Apedilum collected in the proximity of the localities in which the adults and pupae were found, we tentatively describe the larval stage. Subfossil larval head capsules of the same species were found in Laguna Stibnite at 46°S in Chile dated to about 2,500 years ago and in Puerto Blest, Lago Nahuel Huapi at 41°S in Argentina dated about 2,000 years ago. We discuss the habitat of the species based on both modern and subfossil material. Identification keys to male adult, pupae and fourth instar larvae are also provided.

Fair and efficient student placement with couples

We study situations of allocating positions or jobs to students or workers based on priorities. An example is the assignment of medical students to hospital residencies on the basis of one or several entrance exams. For markets without couples, e.g., for ``undergraduate student placement,'' acyclicity is a necessary and sufficient condition for the existence of a fair and efficient placement mechanism (Ergin, 2002). We show that in the presence of couples, which introduces complementarities into the students' preferences, acyclicity is still necessary, but not sufficient (Theorem 4.1). A second necessary condition (Theorem 4.2) is ``priority-togetherness'' of couples. A priority structure that satisfies both necessary conditions is called pt-acyclic. For student placement problems where all quotas are equal to one we characterize pt-acyclicity (Lemma 5.1) and show that it is a sufficient condition for the existence of a fair and efficient placement mechanism (Theorem 5.1). If in addition to pt-acyclicity we require ``reallocation-'' and ``vacancy-fairness'' for couples, the so-called dictator-bidictator placement mechanism is the unique fair and efficient placement mechanism (Theorem 5.2). Finally, for general student placement problems, we show that pt-acyclicity may not be sufficient for the existence of a fair and efficient placement mechanism (Examples 5.4, 5.5, and 5.6). We identify a sufficient condition such that the so-called sequential placement mechanism produces a fair and efficient allocation (Theorem 5.3).

Non-assisted versus neuro-navigated and XperCT-guided external ventricular catheter placement: a comparative cadaver study.

BACKGROUND AND PURPOSE: Accurate placement of an external ventricular drain (EVD) for the treatment of hydrocephalus is of paramount importance for its functionality and in order to minimize morbidity and complications. The aim of this study was to compare two different drain insertion assistance tools with the traditional free-hand anatomical landmark method, and to measure efficacy, safety and precision. METHODS: Ten cadaver heads were prepared by opening large bone windows centered on Kocher's points on both sides. Nineteen physicians, divided in two groups (trainees and board certified neurosurgeons) performed EVD insertions. The target for the ventricular drain tip was the ipsilateral foramen of Monro. Each participant inserted the external ventricular catheter in three different ways: 1) free-hand by anatomical landmarks, 2) neuronavigation-assisted (NN), and 3) XperCT-guided (XCT). The number of ventricular hits and dangerous trajectories; time to proceed; radiation exposure of patients and physicians; distance of the catheter tip to target and size of deviations projected in the orthogonal plans were measured and compared. RESULTS: Insertion using XCT increased the probability of ventricular puncture from 69.2 to 90.2 % (p = 0.02). Non-assisted placements were significantly less precise (catheter tip to target distance 14.3 ± 7.4 mm versus 9.6 ± 7.2 mm, p = 0.0003). The insertion time to proceed increased from 3.04 ± 2.06 min. to 7.3 ± 3.6 min. (p < 0.001). The X-ray exposure for XCT was 32.23 mSv, but could be reduced to 13.9 mSv if patients were initially imaged in the hybrid-operating suite. No supplementary radiation exposure is needed for NN if patients are imaged according to a navigation protocol initially. CONCLUSION: This ex vivo study demonstrates a significantly improved accuracy and safety using either NN or XCT-assisted methods. Therefore, efforts should be undertaken to implement these new technologies into daily clinical practice. However, the accuracy versus urgency of an EVD placement has to be balanced, as the image-guided insertion technique will implicate a longer preparation time due to a specific image acquisition and trajectory planning.

Bioluminescent sensor proteins for point-of-care therapeutic drug monitoring.

For many drugs, finding the balance between efficacy and toxicity requires monitoring their concentrations in the patient's blood. Quantifying drug levels at the bedside or at home would have advantages in terms of therapeutic outcome and convenience, but current techniques require the setting of a diagnostic laboratory. We have developed semisynthetic bioluminescent sensors that permit precise measurements of drug concentrations in patient samples by spotting minimal volumes on paper and recording the signal using a simple point-and-shoot camera. Our sensors have a modular design consisting of a protein-based and a synthetic part and can be engineered to selectively recognize a wide range of drugs, including immunosuppressants, antiepileptics, anticancer agents and antiarrhythmics. This low-cost point-of-care method could make therapies safer, increase the convenience of doctors and patients and make therapeutic drug monitoring available in regions with poor infrastructure.

Accuracy of a new transmittance-reflectance pulse oximetry sensor in critically ill neonates.

OBJECTIVE: To test the accuracy of a new pulse oximeter sensor based on transmittance and reflectance. This sensor makes transillumination of tissue unnecessary and allows measurements on the hand, forearm, foot, and lower limb. DESIGN: Prospective, open, nonrandomized criterion standard study. SETTING: Neonatal intensive care unit, tertiary care center. PATIENTS: Sequential sample of 54 critically ill neonates (gestational age 27 to 42 wks; postnatal age 1 to 28 days) with arterial catheters in place. MEASUREMENTS AND MAIN RESULTS: A total of 99 comparisons between pulse oximetry and arterial saturation were obtained. Comparison of femoral or umbilical arterial blood with transcutaneous measurements on the lower limb (n = 66) demonstrated an excellent correlation (r2 = .96). The mean difference was +1.44% +/- 3.51 (SD) % (range -11% to +8%). Comparison of the transcutaneous values with the radial artery saturation from the corresponding upper limb (n = 33) revealed a correlation coefficient of 0.94 with a mean error of +0.66% +/- 3.34% (range -6% to +7%). The mean difference between noninvasive and invasive measurements was least with the test sensor on the hand, intermediate on the calf and arm, and greatest on the foot. The mean error and its standard deviation were slightly larger for arterial saturation values < 90% than for values > or = 90%. CONCLUSION: Accurate pulse oximetry saturation can be acquired from the hand, forearm, foot, and calf of critically ill newborns using this new sensor.