55 research outputs found
Wireless Sensor Networks for Building Robotic Paths - A Survey of Problems and Restrictions
The conjugation of small nodes with sensing, communication and processing capabilities allows for the
creation of wireless sensor networks (WSNs). These networks can be deployed to measure a very wide
range of environmental phenomena and send data from remote locations back to users. They offer new and
exciting possibilities for applications and research. This paper presents the background of WSNs by firstly
exploring the different fields applications, with examples for each of these fields, then the challenges faced
by these networks in areas such as energy-efficiency, node localization, node deployment, limited storage
and routing. It aims at explaining each issue and giving solutions that have been proposed in the research
literature. Finally, the paper proposes a practical scenario of deploying a WSN by autonomous robot path
construction. The requirements for such a scenario and the open issues that can be tackled by it are
exposed, namely the issues of associated with measuring RSSI, the degree of autonomy of the robot and
connectivity restoration.The authors would like to acknowledge the
company Inspiring Sci, Lda for the interest and
valuable contribution to the successful development
of this work.info:eu-repo/semantics/publishedVersio
The role of salt abuse on risk for hypercalciuria
<p>Abstract</p> <p>Background</p> <p>Elevated sodium excretion in urine resulting from excessive sodium intake can lead to hypercalciuria and contribute to the formation of urinary stones. The aim of this study was to evaluate salt intake in patients with urinary lithiasis and idiopathic hypercalciuria (IH).</p> <p>Methods</p> <p>Between August 2007 and June 2008, 105 lithiasic patients were distributed into 2 groups: Group 1 (n = 55): patients with IH (urinary calcium excretion > 250 mg in women and 300 mg in men with normal serum calcium); Group 2 (n = 50): normocalciuric patients (NC). Inclusion criteria were: age over 18 years, normal renal function (creatinine clearance ≥ 60 ml/min), absent proteinuria and negative urinary culture. Pregnant women, patients with intestinal pathologies, chronic diarrhea or using corticoids were excluded. The protocol of metabolic investigation was based on non-consecutive collection of two 24-hour samples for dosages of: calcium, sodium, uric acid, citrate, oxalate, magnesium and urinary volume. Food intake was evaluated by the three-day dietary record quantitative method, and the Body Mass Index (BMI) was calculated and classified according to the World Health Organization (WHO). Sodium intake was evaluated based on 24-hour urinary sodium excretion.</p> <p>Results</p> <p>The distribution in both groups as regards mean age (42.11 ± 10.61 vs. 46.14 ± 11.52), weight (77.14 ± 16.03 vs. 75.99 ± 15.80), height (1.64 ± 0.10 vs. 1.64 <b>± plusorminus </b>0.08) and BMI (28.78 ± 5.81 vs. 28.07 ± 5.27) was homogeneous. Urinary excretion of calcium (433.33 ± 141.92 vs. 188.93 ± 53.09), sodium (280.08 ± 100.94 vs. 200.44.93 ± 65.81), uric acid (880.63 ± 281.50 vs. 646.74 ± 182.76) and magnesium (88.78 ± 37.53 vs. 64.34 ± 31.84) was significantly higher in the IH group (p < 0.05). There was no statistical difference in calcium intake between the groups, and there was significantly higher salt intake in patients with IH than in NC.</p> <p>Conclusions</p> <p>This study showed that salt intake was higher in patients with IH as compared to NC.</p
Improved X-ray detection and particle identification with avalanche photodiodes
Avalanche photodiodes are commonly used as detectors for low energy x-rays.
In this work we report on a fitting technique used to account for different
detector responses resulting from photo absorption in the various APD layers.
The use of this technique results in an improvement of the energy resolution at
8.2 keV by up to a factor of 2, and corrects the timing information by up to 25
ns to account for space dependent electron drift time. In addition, this
waveform analysis is used for particle identification, e.g. to distinguish
between x-rays and MeV electrons in our experiment.Comment: 6 pages, 6 figure
Stroke lesion in cortical neural circuits and post-stroke incidence of major depressive episode: A 4-month prospective study
How doctors generate diagnostic hypotheses: a study of radiological diagnosis with functional magnetic resonance imaging.
In medical practice, diagnostic hypotheses are often made by physicians in the first moments of contact with patients; sometimes even before they report their symptoms. We propose that generation of diagnostic hypotheses in this context is the result of cognitive processes subserved by brain mechanisms that are similar to those involved in naming objects or concepts in everyday life
Higiene, tipologia da infância e institucionalização da criança pobre no Brasil (1875-1899)
BLADDER LEIOMYOMA - CASE-REPORT AND REVIEW OF THE LITERATURE
Mesodermal tumors of the urinary tract are anusual, being leiomyoma the most frequent tumor type. We present a case of leiomyoma of the urinary bladder in a 29 year old woman and review the literature. Clinical features, diagnosis and treatment are discussed
- …