1,310 research outputs found
Distribution of Malocclusion Traits in the Pediatric Population of Milan: An Observational Study
No full textBackground: Epidemiological investigations define the prevalence and distribution of the various types of malocclusions, and can help to identify etiological factors and set the most correct orthodontic therapy. Aim: The goal of this study was to verify the prevalence and distribution of various types of malocclusions in the pediatric population. Methods: The study was performed on a sample of 350 patients (ages 5–9) being treated at the ASST Grande Ospedale Metropolitano Niguarda in Milan. A comparison was presented with one similar epidemiological investigation conducted 22 years earlier by the same researchers. The values of the malocclusion indices were reported from the cephalometric analyzes of the patients and were differentiated on the basis of gender and ethnicity. Results: The predominant traits of malocclusion in the general population of the analyzed sample were: skeletal class II (47.43%), hyper-divergence (40.86%), maxillary retrusion (46%), mandibular retrusion (66%), maxillary hypoplasia (50%), mandibular hypoplasia (49.14%), Wits index > 2 mm (22.57%); overjet > 4 mm (31.1%) and overbite > 4 mm (24.86%). Substantial differences were found between Italian patients and patients belonging to different ethnic groups in almost all parameters, and between the male and female genders in some of them. Patients in the 2000 study had a higher prevalence of Class II and hyper-divergence. Conclusions: This epidemiological investigation can suggest different approaches in setting the orthodontic treatment plan based on the ethnic group of the patient taken in charge and encourage more specific and large-scale analytical studies on the subject
On ultra-high energy cosmic-ray arrival directions after ten years of operation of the Pierre Auger Observatory
No full textThe Pierre Auger Observatory has gathered, in ten years of operation, an unprecedented number of extremely energetic cosmic-ray events. We present the latest results of searches for small to intermediate-scale anisotropies in the distribution of arrival directions of such events. We update the test based on the Véron-Cetty and Véron catalog, previously performed by the Pierre Auger Observatory on early data, and conclude that it does not yield a significant indication of anisotropy with the present data set. We then study the correlation of arrival directions with the position of nearby galaxies in the 2MRS catalog, of active galactic nuclei (AGNs) detected by Swift-BAT, of a sample of radio galaxies with jets and of the Centaurus A galaxy. None of the searches shows a statistically significant evidence of anisotropy. The two largest departures from isotropy found have a post-trial probability ∼1%. The first one is for cosmic rays with energy above 58 EeV that arrive within 18° of Swift-BAT AGNs closer than 130 Mpc and brighter than 1044 erg/s. The other one is for cosmic rays above the same energy threshold that arrive within 15° of the direction of Centaurus A
Holocene climatic vs man-induced environmental change in Northern Apennines: evidences from soil charcoals.
No full textMicromorphological evidences of contrasting pedogenetic processes in Alpine paleosols in the central Italian Alps
No full textLate Holocene soil evolution and treeline fluctuations in the Northern Apennines
No full textThe aim of this study is the reconstruction of Late Holocene soil evolution and environmental changes at the treeline of Northern Apennines (Italy) through field observation, pedoanthracological analysis, soil micromorphology and dendrochronology. Nine soil profiles across the present treeline (c. 1750 m) between 1700 and 2000 m were described. Physical and chemical analyses, and pedoanthracological and micromorphological observations were carried out. Tree ring analysis was also performed to outline recent disturbance events. All soils consisted of two superimposed units. The lowermost unit consisted of a well developed B horizon resulting from intense brunification process, frequently overtopped by a dark Ab horizon. The superficial unit was up to 1 m thick, consisting of colluvium deposits with poorly developed pedogenesis. Below the present treeline, charcoals were observed in the B horizon of the buried soils: Abies and Fagus dominated the anthracological assemblages. Abies charcoals were AMS dated to 790–670 cal BP. Above the treeline, a charcoal assemblage dominated by Abies and Laburnum was found in the buried B horizon. A Laburnum charcoal sample was dated to 3920–3700 cal BP. In the Ab horizon another assemblage dominated by Abies, Laburnum and Vaccinium with abundant insect remains was observed, dated to late Middle Ages. Soil data suggest a recent phase of marked slope instability. Tree ring analysis indicated that this phase occurred at least during the 18th and early 19th century. These analyses, together with previous archaeological evidence, indicate the occurrence of forests well above the present treeline in the Early-Mid Holocene. The lowering of the treeline probably started during Late Holocene, but woody vegetation (open forest or treed heathland) occurred at high altitude until recent times. The colluvial episodes and the burial of paleosols probably took place through successive events during modern times. The dominance or co-dominance of fir at the treeline lasted until historical times. The multi-proxy approach allowed previous archaeological data to be put in a wider context, to give better spatial and temporal extent to treeline fluctuations, and to achieve high resolution for the analysis of the most recent time span
Human and climate influence on slope stability in the Northern Apennines during the Mid-Late Holocene
No full textPain reduction during rapid palatal expansion due to led photobiomodulation irradiation: A randomized clinical trial
No full textObjective: The purpose of this research is to assess the analgesic efficiency of Photobiomodu-lation (PBM) in pain reduction in young patients during rapid maxillary expansion therapy. Materials and Methods: Thirty patients were included and allocated to an experimental group [Rapid Palatal Expansion (RPE) and PBM] and a control group (RPE only) at random. Inclusion criteria were skeletal age from CVS1 to CVS3, examined on the cephalometric lateral teleradiography, with cervical vertebra staging and completed eruption of upper first molar. Exclusion criteria were previous orthodontic treatment, bone disease, disability, or skeletal age from CVS4. Patients referred the pain they felt using a Numerical scale rate (NRS), ranging from 0 to 10, with specific intervals of time: 6 h, 12 h, 24 h, and from days 2 to 7. The Wilcoxon-Mann-Whitney test was used to evaluate differences in NRS reported values between the two groups. Results: The final sample included 30 patients, 14 males and 16 females, with a mean age of 7.8 ± 1.2 years. The pain that was felt at each time interval and the maximum score of pain were significantly lower in the experimental group (p < 0.05) and decreased faster in the experimental group, with a score test near to 0 after 2/3 days. Conclusions: PBM is efficient in reducing the intensity and the time of pain felt by young patients that undergo rapid maxillary expansion
Biotic disturbance in expanding subarctic forests along the eastern coast of Hudson Bay
No full textThe past and present occurrence of insect disturbance on white spruce (Picea glauca) trees was evaluated at their northern range limit on the eastern coast of Hudson Bay, and its effects on tree growth and population dynamics studied.
Three sites were sampled along an altitudinal gradient. Ring-width chronologies and stem analysis were used to evaluate tree growth. The occurrence of holes in the bark, of resin pockets and blue-stain fungi, and ring-width evidence for growth releases were used to assess the impact of bark beetle.
The white spruce population was established at these sites in the 17th century. Since their establishment, the spruce trees have developed a tree growth form, except at the uppermost site, where severe growth suppression occurred in the 19th century. Bark beetle and blue-stain fungi occurred with different timing and intensity. Their highest occurrence, associated with high mortality rates, was at the lowest site in the late 20th century. In the uppermost sites, biotic disturbance has occurred since the 18th century, associated with evidence for mechanical disturbance.
The simultaneous arrival of white spruce in the area resulted in a synchronous onset of spruce beetle activity driven by tree ageing. Unfavourable climatic conditions affected tree growth severely in the most exposed sites
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