890 resultados para Recording instruments
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We present the development of a multifunctional platform equipped with an array of silicon nitride micropipettes with dimensions allowing the implementation of extra- and intracellular operations. Micropipettes with outer diameter that ranges from 6 mum down to 300 nm and with walls thicknesses of 500 down to 150 nm are presented. The generic technology developed to fabricate these micropipettes has a number of advantages, including the ability to be implemented as ion-selective electrodes for (A) intracellular and (B) extracellular recordings and as (C) local drug microdispensers.
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Methodological approaches in which data on nonverbal behavior are collected usually involve interpretive methods in which raters must identify a set of defined categories of behavior. However, present knowledge about the qualitative aspects of head movement behavior calls for recording detailed transcriptions of behavior. These records are a prerequisite for investigating the function and meaning of head movement patterns. A method for directly collecting data on head movement behavior is introduced. Using small ultrasonic transducers, which are attached to various parts of an index person's body (head and shoulders), a microcomputer defines receiver-transducers distances. Three-dimensional positions are calculated by triangulation. These data are used for further calculations concerning the angular orientation of the head and the direction, size, and speed of head movements (in rotational, lateral, and sagittal dimensions).
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What characterizes micropollution as a policy problem and which policy instruments are adequate to regulate micropollution, given the specific problem features? In this article, problem characteristics of micropollution are systematically analyzed and linked to potential policy solutions.
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Rumination und Suppression sind 2 maladaptive Emotionsregulationsstrategien, die im Zusammenhang mit pathologischem Verhalten wie übermäßigem Essen oder Trinken stehen. Ein Messinstrument, welches beide Strategien in Kurzform erfasst, fehlt bisher. Der RS-8 erfasst mit 8 Items die beiden Dimensionen Rumination und Suppression. Anhand von 2 klinischen (Patienten mit Alkoholabhängigkeit [n = 79], Patienten mit Adipositas [n = 53]) und einer nichtklinischen Stichprobe (n = 133) wurde die psychometrische Qualität der Skala überprüft. Die Ergebnisse zeigen, dass der RS-8 ein valides und reliables Messinstrument ist. Die interne Konsistenz kann als gut und die faktorielle Validität als sehr gut bewertet werden. Der RS-8 ist ein ökonomisches Screening-Instrument, welches bei klinischen und nicht-klinischen Stichproben eingesetzt werden kann.
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Intensive Family Preservation Services seek to reflect the values of focusing on client strengths and viewing clients as colleagues. To promote those values, Intensive Family Preservation Programs should include a systematic form of client self monitoring in their packages of outcome measures. This paper presents a model of idiographic self-monitoring used in time series, single system research design developed for Family Partners, a family preservation program of the School for Contemporary Education in Annandale, Virginia. The evaluation model provides a means of empowering client families to utilize their strengths and promote their status as colleague in determining their own goals, participating in the change process, and measuring their own progress.
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The reliability of millimeter and sub-millimeter wave radiometer measurements is dependent on the accuracy of the loads they employ as calibration targets. In the recent past on-board calibration loads have been developed for a variety of satellite remote sensing instruments. Unfortunately some of these have suffered from calibration inaccuracies which had poor thermal performance of the calibration target as the root cause. Stringent performance parameters of the calibration target such as low reflectivity, high temperature uniformity, low mass and low power consumption combined with low volumetric requirements remain a challenge for the space instrument developer. In this paper we present a novel multi-layer absorber concept for a calibration load which offers an excellent compromise between very good radiometric performance and temperature uniformity and the mass and volumetric constraints required by space-borne calibration targets.
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BACKGROUND: Accurate projection of implanted subdural electrode contacts in presurgical evaluation of pharmacoresistant epilepsy cases by invasive EEG is highly relevant. Linear fusion of CT and MRI images may display the contacts in the wrong position due to brain shift effects. OBJECTIVE: A retrospective study in five patients with pharmacoresistant epilepsy was performed to evaluate whether an elastic image fusion algorithm can provide a more accurate projection of the electrode contacts on the pre-implantation MRI as compared to linear fusion. METHODS: An automated elastic image fusion algorithm (AEF), a guided elastic image fusion algorithm (GEF), and a standard linear fusion algorithm (LF) were used on preoperative MRI and post-implantation CT scans. Vertical correction of virtual contact positions, total virtual contact shift, corrections of midline shift and brain shifts due to pneumencephalus were measured. RESULTS: Both AEF and GEF worked well with all 5 cases. An average midline shift of 1.7mm (SD 1.25) was corrected to 0.4mm (SD 0.8) after AEF and to 0.0mm (SD 0) after GEF. Median virtual distances between contacts and cortical surface were corrected by a significant amount, from 2.3mm after LF to 0.0mm after AEF and GEF (p<.001). Mean total relative corrections of 3.1 mm (SD 1.85) after AEF and 3.0mm (SD 1.77) after GEF were achieved. The tested version of GEF did not achieve a satisfying virtual correction of pneumencephalus. CONCLUSION: The technique provided a clear improvement in fusion of pre- and post-implantation scans, although the accuracy is difficult to evaluate.
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OBJECTIVE Fractured endodontic instruments inhibit optimal cleaning and filling of dental root canals, which may result in a less favorable prognosis for the tooth. Several techniques are available to remove fractured instruments; however, healthy tooth substance often must be destroyed in the process. This study was intended to evaluate Nd:YAG laser treatment as a method to remove fractured stainless steel instruments without destroying healthy tooth substance. METHOD AND MATERIALS Stainless steel endodontic instruments were fractured in 33 unprocessed root canals of mandibular central and lateral incisors and premolars in vitro. A brass tube charged with solder was placed at the coronal end of the fractured instrument and laser energy was used to melt the solder, connecting the fractured instrument with the brass tube. The success rates of connecting and removal of fractured instruments from the root channel were recorded for each case. RESULTS Connecting was achieved in every case in which more than 1.5 mm of the fractured instrument was tangible (22 out of 22). In cases where less than 1.5 mm was tangible, the rate for successful connection decreased to 4 out of 11 (36.4%). Fractured endodontic instruments were removed successfully in 17 out of 22 cases (77.3%) in which more than 1.5 mm was tangible. If less than 1.5 mm was tangible, the removal success rate decreased to 3 out of 11 cases (27.3%). CONCLUSION Our data support Nd:YAG laser-mediated connecting of a brass tube to a fractured endodontic instrument as a feasible and tissue conserving removal approach when more than 1.5 mm of the instrument is tangible.
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This paper introduces an area- and power-efficient approach for compressive recording of cortical signals used in an implantable system prior to transmission. Recent research on compressive sensing has shown promising results for sub-Nyquist sampling of sparse biological signals. Still, any large-scale implementation of this technique faces critical issues caused by the increased hardware intensity. The cost of implementing compressive sensing in a multichannel system in terms of area usage can be significantly higher than a conventional data acquisition system without compression. To tackle this issue, a new multichannel compressive sensing scheme which exploits the spatial sparsity of the signals recorded from the electrodes of the sensor array is proposed. The analysis shows that using this method, the power efficiency is preserved to a great extent while the area overhead is significantly reduced resulting in an improved power-area product. The proposed circuit architecture is implemented in a UMC 0.18 [Formula: see text]m CMOS technology. Extensive performance analysis and design optimization has been done resulting in a low-noise, compact and power-efficient implementation. The results of simulations and subsequent reconstructions show the possibility of recovering fourfold compressed intracranial EEG signals with an SNR as high as 21.8 dB, while consuming 10.5 [Formula: see text]W of power within an effective area of 250 [Formula: see text]m × 250 [Formula: see text]m per channel.