Characterization of a nonlinear sound absorber at low frequencies and high sound levels

International audienceTo characterize nonlinear acoustic loads identification techniques have been developed. A specific setup of impedance tube named “Short Kundt’s Tube” (SKT) was built to reach high sound levels at low frequencies. Two approaches, developed in the frequency domain,are discussed: a linearization method giving access to the acoustic impedance and a nonlinear model which is able to characterize energy transfer to higher harmonics. Both are excitation level dependent

Comparaison de techniques d'absorptions vibro-acoustiques

National audienceThis study presents the design of a test-rig built to caracterize a vibro-acoustical absorber. This experimental system is based on the properties of a short Kundt tube allowing low frequencies studies (below the first natural frequency of the tube). A precise measure method (surdetermined two-microphones method) is proposed in order to obtain the desired acoustical parameters of the absorber. Finally, we propose an energy balance of the obtanied frequency response (excitation frequency and its harmonics).Cette étude propose la conception d'un banc d'essai servant à la caractérisation d'absorbeurs vibro-acoustiques. Ce banc est conç u sur la propriété d'un tube de Kundt court permettant le travail en basses fréquences (en-dessous de la première fréquence de résonance du tube). Une méthode de me-sure fine (méthode à deux microphones surdéterminée) est mise en place afin d'extraire les paramètres acoustiques souhaités de l'absorbeur et in fine proposer un bilan énergétique résultant et sa répartition spectrale (fréquence d'excitation et ses harmoniques)

Clinical and brain imaging findings in a child with vitamin B12 deficiency

Vitamin B12 (Vit-B12) deficiency is a rare and treatable cause of failure to thrive and delayed development in infants who are exclusively breastfed. Apart from genetic causes, it can be related to a malabsorption syndrome or when the mother follows a strict vegetarian or vegan diet, causing a low hepatic storage of Vit-B12 in the infant at birth. As the neurological symptoms are nonspecific, a brain magnetic resonance imaging (MRI) exam is usually performed to rule out primary causes of neurodevelopmental delay. Findings related to brain atrophy are usually observed. A favorable response is achieved with Vit-B12 therapy, and neurological symptoms dramatically improve within a few days after the treatment. We present the case of an infant with severe Vit-B12 deficiency, exclusively breastfed by his young vegan mother, and whose clinical symptoms together with MRI findings improved after treatment. Brain atrophy recovery after Vit-B12 therapy has been seldom documented

Birth control knowledge among freshmen of four Italian universities

Since sexual health education (SHE) is not mandatory in Italian schools, we conducted a survey on freshmen of four Italian university campuses in 2012 to investigate the respective level of sexual health knowledge (SHK) in relation to birth control, with the aim to inform public health policy makers. A convenience strategy was employed to sample 4,552 freshmen registered with various undergraduate courses at four Italian universities: Padua university (Veneto Region); university of Milan (Lombardy Region); university of Bergamo (Lombardy Region); university of Palermo (Sicily Region). We investigated the level of SHK on birth control using 6 proxy indicators: (1) the average length of a woman\u2019s period [outcome with 3 levels: wrong (base) vs. acceptable vs. correct]; (2) the most fertile interval within a woman\u2019s period (binary outcome: correct vs. wrong answer); (3) the event between the end of a period and the beginning of the next cycle (binary outcome: correct vs. wrong answer); (4) the average survival of spermatozoa in the womb (binary outcome: correct vs. wrong answer); (5) the concept of contraception (binary outcome: correct vs. wrong answer); (6) the efcacy of various contraceptives to prevent unintended pregnancies (linear score: 0\u201317). We ftted 6 separate models of multiple regression: multinomial for outcome 1; logistic for outcomes 2, 3, 4, 6; linear for outcome 6. Statistical estimates were adjusted for a number of socio-demographic factors. Results were expressed as odds ratios (OR) for the 4 multiple logistic regression models, linear coefcients (RC) for the linear regression model and relative risk ratio (RRR) for the multinomial logistic regression model. The level of signifcance of each risk estimate was set at 0.05. The level of SHK of freshmen sampled was rather low, as 60% interviewees did not know the average length of a woman\u2019s period, the average survival of spermatozoa in the womb and the concept of contraception, whilst the most fertile interval within a woman\u2019s period was known only to 55% of interviewees. The mean score of SHK on the efcacy of various contraceptive methods was only 5 (scale 0\u201317). Some categories of students were consistently and signifcantly less knowledgeable on birth control at multivariable analysis: males; students from the university of Palermo; those with vocational secondary school education and those not in a romantic relationship at the time the survey was conducted. The results of this survey clearly call for the introduction of SHE programs in Italian schools, as already done in several European countries. School SHE should start as early as possible, ideally even before secondary school. SHE should be holistic and delivered with a multiple agency coordinated approach involving the Ministry of Health, the Ministry of Education, University and Scientifc Research (MIUR), families, schools, public health departments, primary health care providers, pharmacists, media, other

Effect of Puerperal Infections on Early Neonatal Mortality: A Secondary Analysis of Six Demographic and Health Surveys

Background: Around 1.5 million annual neonatal deaths occur in the first week of life, and infections represent one of the major causes in developing countries. Neonatal sepsis is often strictly connected to infection of the maternal genital tract during labour. Methods: The association between signs suggestive of puerperal infection and early neonatal mortality (life) was performed using Demographic and Health Surveys (DHS) data of six countries, conducted between 2010 and 2013. The population attributable fraction (PAF) was generated using the estimates on early neonatal mortality of a 1990-2013 systematic analysis for the Global Burden of Disease Study. Results: Signs of puerperal infection ranged from 0.7% in the Philippines to 16.4% in Honduras. Infection was associated with a 2.1 adjusted Risk Ratio (95% CI: 1.4-3.2) of early neonatal mortality. Around five percent of all deaths in the first week of life were attributable to signs suggestive of puerperal infections and varied from 13.9% (95% CI: 1.0-26.6) in Honduras to 3.6% (95% CI: 1.0-8.5) in Indonesia. Conclusions: Targeted interventions should be addressed to contain the burden of puerperal infections on early neonatal mortality. Consideration of the PAF will help in the discussion of the benefits of antenatal and perinatal measures

Gastrointestinal pathologistsâ perspective on managing risk in the distal esophagus: convergence on a pragmatic approach

Here, we discuss recent updates and a continuing controversy in the diagnosis and management of Barrett’s esophagus, specifically the recommendation that the irregular Zâ line not be biopsied, the diminished status of ultrashortâ segment Barrett’s esophagus, the evidence basis for excluding and including the requirement of goblet cells for the diagnosis of Barrett’s esophagus, and the conclusion that histologically confirmed lowâ grade dysplasia is best managed with endoscopic ablation rather than surveillance. We reference the American Gastroenterological Association and College of Gastroenterology and the British Society of Gastroenterology guidelines throughout, with the thesis that the field is converging on the concept of applying scarce medical resources to the diagnosis, surveillance, and therapy of patients most likely to derive benefit.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146991/1/nyas13680.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146991/2/nyas13680_am.pd

A Survey on Knowledge, Prevention, and Occurrence of Sexually Transmitted Infections among Freshmen from Four Italian Universities

Background. The peak of sexually transmitted infections (STI) among adolescents/young adults suggests a low level of prevention. In order to assess whether the level of sexual health education (SHE), received by several channels, was effective at improving sexual behaviors, we conducted a survey among freshmen from four Italian universities. Methods. This observational cross-sectional study was carried out with an anonymous self-reported paper questionnaire, administered during teaching lectures to university freshmen of the northern (Padua, Bergamo, and Milan campuses) and southern (Palermo campus) parts of the country. Knowledge of STI (a linear numerical score), knowledge of STI prevention (dichotomous variable: yes vs. no) and previous STI occurrence (polytomous variable: "no"; "don't know"; "yes") were the outcomes in the statistical analysis. Results. The final number of freshmen surveyed was 4552 (97.9% response rate). The mean age of respondents was 21.4 ± 2.2 years and most of them (70.3%) were females. A total of 60% of students were in a stable romantic relationship. Only 28% respondents knew the most effective methods to prevent STI (i.e., condom and sexual abstinence), with a slightly higher prevalence of correct answers among females (31.3%) than males (25.8%). Students with history of STIs were 5.1%; they reported referring mostly to their general practitioner (GP) (38.1%) rather than discussing the problem with their partner (13.1%). At multivariable analysis, a significantly higher level of STI knowledge was observed in older students (25+ years of age), biomedical students, and those from a non-nuclear family; lower levels were found among students of the University of Palermo, and those who completed a vocational secondary school education. Those who had less knowledge about the most effective tools to prevent STIs included males, students from the University of Palermo, students registered with educational sciences, economics/political sciences, those of foreign nationality, and those whose fathers had lower educational levels. The risk of contracting a STI was significantly lower only in students not in a stable relationship (relative risk ratio, RRR = 0.67; 95% confidence interval, 95%CI = 0.48; 0.94), whereas such risk was significantly higher in students with higher STI knowledge (RRR = 1.15; 95%CI = 1.08; 1.22). Discussion and Conclusions. University freshmen investigated in this study had poor knowledge of STIs and their prevention. Unexpectedly, those with higher levels of knowledge had an increased risk of STIs. There have been no educational interventions-with good quality and long-term follow-ups-that increased the confidence that such SHE programs could have population level effects. A new high-quality study is therefore recommended to assess the effectiveness of an intervention generating behavioral changes; increasing only STI knowledge may not be sufficient

Assessment of breast symmetry in breast cancer patients undergoing therapeutic mammaplasty using the Breast Cancer Conservation Therapy cosmetic results software (BCCT.core)

Background: Therapeutic mammaplasty (TM) is a standard oncoplastic technique utilising aesthetic breast reduction principles to facilitate tumour resection and breast reshaping. Simultaneous contralateral mammaplasties are often performed to maintain symmetry. BCCT.core software, which principally assesses breast symmetry, has been previously employed for evaluating cosmetic results after standard breast conservation therapy and latterly TMs for upper pole tumours. The purpose of this study was to validate this novel tool for TMs in all breast zones. Methods: Standardised photographs of 20 consecutive patients who underwent TM were evaluated for symmetry using BCCT.core versus a plastic surgical panel completing a visual analogue scale. Results were rated as (excellent/good/fair/poor). Outcomes between the two methods were compared. Results: Twenty patients aged 37 to 63 years with a median 36G bra size had 22 TMs (18 unilateral, 2 bilateral). Indications were invasive breast cancer (87%) and ductal carcinoma in situ (DCIS) (13%). The median (range) tumour size was 22.5 mm (6–90 mm) with a resection weight of 245.8 g (16–1,079 g). Primary nipple pedicles were superomedial (63%), inferior (21%) and superolateral (16%). Five patients required a secondary glandular pedicle for volume redistribution to maintain breast shape. The BCCT.core software vs. panel symmetry assessments were 37% vs. 39% (excellent), 63% vs. 50% (good) and 0% vs. 11% (fair). Wilcoxon matched-pairs sign rank tests and Spearman rank correlations found the pairings to be statistically significant (P<0.05). Conclusions: Despite small patient numbers, BCCT.core gave comparable findings with the panel and is thus useful for objectively assessing cosmesis of TMs in all breast zones

Levantamento de Chrysodeixis includens na cultura da soja em Palmeiras de Goiás.

A Chrysodeixis includens conhecida como falsa medideira, passou de praga secundária para primária na última década, isso aconteceu pelo aumento populacional nas lavouras causando danos econômicos para os produtores. Na safra de 2013/2014 ocorreram variações de populações muito alta em relação as safras anteriores, seu controle foi incontrolado em alguns casos