37 research outputs found
Joint detection and classification of rockfalls in a microseismic monitoring network
A rockfall (RF) is a ubiquitous geohazard that is difficult to monitor or predict and poses a significant risk for people and transportation in several hilly and mountainous environments. The seismic signal generated by RF carries abundant physical and mechanical information. Thus, signals can be used by researchers to reconstruct the event location, onset time, volume and trajectory, and develop an efficient early warning system. Therefore, the precise automatic detection and classification of RF events are important objectives for scientists, especially in seismic monitoring arrays. An algorithm called DESTRO (DEtection and STorage of ROckfalls) aimed at combining seismic event automatic detection and classification was implemented ad hoc within the MATLAB environment. In event detection, the STA/LTA (short-time-average through long-time-average) method combined with other parameters, such as the minimum duration of an RF and the minimum interval time between two continuous seismic events is used. Furthermore, nine significant features based on the frequency, amplitude, seismic waveform, duration and multiple station attributes are newly proposed to classify seismic events in a RF environment. In particular, a three-step classification method is proposed for the discrimination of five different source types: RFs, earthquakes (EQs), tremors, multispike events (MSs) and subordinate MS events. Each component (vertical, east–west and north–south) at each station within the monitoring network is analysed, and a three-step classification is performed. At a given time, the event series detected from each component are integrated and reclassified component by component and station by station into a final event-type series as an output result. By this algorithm, a case study of the seven-month-long seismic monitoring of a former quarry in Central Italy was investigated by means of four triaxial velocimeters with continuous acquisition at a sampling rate of 200 Hz. During this monitoring period, a human-induced RF simulation was performed, releasing 95 blocks (in which 90 blocks validated) of different sizes from the benches of the quarry. Consequently, 64.9 per cent of EQs within 100 km were confirmed in a one-month monitoring period, 88 blocks in the RF simulation were classified correctly as RF events and 2 blocks were classified as MSs given their small energy. Finally, an ad hoc section of the algorithm was designed specifically for RF classification combined with EQ recognition. The algorithm could be applied in slope seismic monitoring to monitor the dynamic states of rock masses, as well as in slope instability forecasting and risk evaluation in EQ-prone areas
Assessing subsoil void hazards along a road system using H/V measurements, ERTs and IPTs to support local decision makers
A multidimensional and interdisciplinary strategy for geo-hydrological risk reduction oriented towards minors
Obtenção de uma estirpe mutante ntrC- de Rhizobium sp. NGR234
Research into fetal development and medicin
Abstracts of the 26th World Congress on Ultrasound in Obstetrics and Gynecology, Rome, Italy, 24-28 September 2016
Serological and genetic complement alterations in infection-induced and complement-mediated hemolytic uremic syndrome
Background: The role of complement in the atypical form of hemolytic uremic syndrome (aHUS) has been investigated extensively in recent years. As the HUS-associated bacteria Shiga-toxin-producing Escherichia coli (STEC) can evade the complement system, we hypothesized that complement dysregulation is also important in infection-induced HUS. Methods: Serological profiles (C3, FH, FI, AP activity, C3d, C3bBbP, C3b/c, TCC, αFH) and genetic profiles (CFH, CFI, CD46, CFB, C3) of the alternative complement pathway were prospectively determined in the acute and convalescent phase of disease in children newly diagnosed with STEC-HUS or aHUS. Serological profiles were compared with those of 90 age-matched controls. Results: Thirty-seven patients were studied (26 STEC-HUS, 11 aHUS). In 39 % of them, including 28 % of STEC-HUS patients, we identified a genetic and/or acquired complement abnormality. In all patient groups, the levels of investigated alternative pathway (AP) activation markers were elevated in the acute phase and normalized in remission. The levels were significantly higher in aHUS than in STEC-HUS patients. Conclusions: In both infection-induced HUS and aHUS patients, complement is activated in the acute phase of the disease but not during remission. The C3d/C3 ratio displayed the best discrepancy between acute and convalescent phase and between STEC-HUS and aHUS and might therefore be used as a biomarker in disease diagnosis and monitoring. The presence of aberrations in the alternative complement pathway in STEC-HUS patients was remarkable, as well
Methacholine bronchial provocation measured by spirometry versus wheeze detection in preschool children
BACKGROUND: Determination of PC(20)-FEV(1) during Methacholine bronchial provocation test (MCT) is considered to be impossible in preschool children, as it requires repetitive spirometry sets. The aim of this study was to assess the feasibility of determining PC(20)-FEV(1) in preschool age children and compares the results to the wheeze detection (PCW) method. METHODS: 55 preschool children (ages 2.8–6.4 years) with recurrent respiratory symptoms were recruited. Baseline spirometry and MCT were performed according to ATS/ERS guidelines and the following parameters were determined at baseline and after each inhalation: spirometry-indices, lung auscultation at tidal breathing, oxygen saturation, respiratory and heart rate. Comparison between PCW and PC(20)-FEV(1) and clinical parameters at these end-points was done by paired Student's t-tests. RESULTS AND DISCUSSION: Thirty-six of 55 children (65.4%) successfully performed spirometry-sets up to the point of PCW. PC(20)-FEV(1) occurred at a mean concentration of 1.70+/-2.01 while PCW occurred at a mean concentration of 4.37+/-3.40 mg/ml (p < 0.05). At PCW, all spirometry-parameters were markedly reduced: FVC by 41.3+/-16.4% (mean +/-SD); FEV(1) by 44.7+/-14.5%; PEFR by 40.5+/-14.5 and FEF(25–75) by 54.7+/-14.4% (P < 0.01 for all parameters). This reduction was accompanied by de-saturation, hyperpnoea, tachycardia and a response to bronchodilators. CONCLUSION: Determination of PC(20)-FEV(1) by spirometry is feasible in many preschool children. PC(20)-FEV(1) often appears at lower provocation dose than PCW. The lower dose may shorten the test and encourage participation. Significant decrease in spirometry indices at PCW suggests that PC(20)-FEV(1) determination may be safer
Fetal megacystis: a lot more than LUTO
ABSTRACT
Objective Fetal megacystis presents a challenge in terms
of counseling and management because of its varied
etiology and evolution. The aim of this study was to
present a comprehensive overview of the underlying
etiologies and structural anomalies associated with fetal
megacystis.
Methods This was a retrospective multicenter study of
cases referred to the fetal medicine unit of one of the eight
academic hospitals in The Netherlands with a diagnosis of
fetal megacystis. For each case, data on and measurements
of fetal urinary tract and associated structural anomalies
were collected. All available postmortem examinations
and postnatal investigations were reviewed in order to
establish the final diagnosis. In the first trimester, fetal
megacystis was defined as longitudinal bladder diameter
(LBD) ≥ 7 mm, and in the second and third trimesters as
an enlarged bladder failing to empty during an extended
ultrasound examination lasting at least 40 min.
Results Of the 541 pregnancies with fetal megacystis,
it was isolated (or solely accompanied by other signs
of lower urinary tract obstruction (LUTO)) in 360
(67%) cases and associated with other abnormal
ultrasound findings in 181 (33%) cases. The most
common associated ultrasound anomaly was an increased
nuchal translucency thickness (22%), followed by single
umbilical artery (10%) and cardiac defect (10%). A
final diagnosis was established in 418 cases, including
222 (53%) cases with isolated LUTO and 60 (14%)
infants with normal micturition or minor isolated
urological anomalies. In the remaining 136 (33%) cases,
concomitant developmental or chromosomal abnormality
or genetic syndrome was diagnosed. Overall, 40
chromosomal abnormalities were diagnosed, including
trisomy 18 (n = 24), trisomy 21 (n = 5), Turner syndrome
(n = 5), trisomy 13 (n = 3) and 22q11 deletion (n = 3).
Thirty-two cases presented with anorectal malformations
involving the anus, rectum and urogenital tract. In cases
with confirmed urethral and anal atresia, megacystis
occurred early in pregnancy and the bladder appeared
severely distended (the LBD (in mm) was equal to or
greater than twice the gestational age (in weeks)). Fetal
macrosomia was detected in six cases and an overgrowth
syndrome was detected in four cases, comprising two
infants with Beckwith–Wiedemann syndrome and two
with Sotos syndrome. Megacystis-microcolon-intestinal
hypoperistalsis syndrome was diagnosed in five (1%) cases
and prenatally suspected only in one case.
Conclusions Although the main cause of fetal megacystis
is LUTO, an enlarged fetal bladder can also be present
as a concomitant finding of miscellaneous genetic syndromes, developmental disturbances and chromosomal
abnormalities. We provide an overview of the structural anomalies and congenital disorders associated with fetal
megacystis and propose a practical guide for the differential diagnosis of genetic syndromes and chromosomal
and developmental abnormalities in pregnancies presenting with fetal megacystis, focusing on the morphological
examination of the fetus
[Nosocomial infections at a pediatric age].
The overall incidence of nosocomial infections in children ranges from 2.3% to 12.6%. Even if there are great variations among data in literature, most authors agree that nosocomial infections are less frequent in children than in adults. Differences between these two populations concern anatomical sites of infection and microrganisms: in children, most frequent are gastrointestinal infections (10-35%), respiratory infections (5-30%) and bacteremia (10-23%); Gram positive bacteria account for 31-50% of infections, Gram negative for 23-35% and viruses for 22-27%. All these percentages change enormously depending on the type of department and child age. Because of increasing rates of resistance to antimicrobial agents, it is important to identify the main infectious agents and their sensibility, considering carefully when to give antibiotic therapy and what drug should be chosen
Assessing subsoil void hazards along a road system using H/V measurements, ERTs and IPTs to support local decision makers
Between 2008 and 2014, nine sinkholes occurred in northeastern Elba Island (Tuscany, Italy), an area with mostly flat terrain (called “Il Piano”) separating the municipalities of Rio nell’Elba and Rio Marina. The last sinkhole damaged the only road (SP26) between the harbour of Rio Marina and the northwestern part of the island. A bypass was immediately built, but the SP26 remains closed. Considering that sinkholes could be densely clustered in sinkhole prone areas, their detection and forecasting are key aspects of local administrative policies. In this paper, we present the results of an integrated geophysical survey aimed at (i) characterizing the geology of the area surrounding the SP26, and (ii) assessing the subsoil void hazard around the road system to support the decision to replace or restore the SP26. Therefore, for the purposes of this research, 120 single-station seismic noise measurements were taken following the horizontal-to-vertical spectral ratio (H/V) or Nakamura technique, while eight 2D electrical resistivity tomography (ERT) and 17 3D-ERT/induced polarisation measurements were also carried out in the study area. The H/V method allowed the estimation of the mean thickness of the alluvium, whereas the 2D/3D-ERTs and IPTs permitted the characterisation of the electrical behaviours of the materials and the localisation of the lenticular sand and gravel bodies within a sandy silt layer. The large amount of collected data made the zonation of the subsoil void hazards possible