Search results for " persistence"
showing 10 items of 57 documents
Analysis of persistence of human papillomavirus infection in men evaluated by sampling multiple genital sites.
2015
Although human papillomavirus (HPV) infection has been studied extensively in women, data on male infection are limited. The purpose of this study was to investigate persistence of HPV infection at multiple genital sites in men and to define potential associations with socio-behavioural characteristics.Penile, urethral and seminal specimens were tested by the INNO-LiPA HPV system (Innogenetics) and a PCR assay. Persistence was defined as the detection of same HPV type at ≥ 2 consecutive visits. The Kaplan-Meier method and the log-rank test were applied to estimate the likelihood of persistence.A total of 50 men (median age: 33 years) were followed for a median of 14.7 months. Altogether, 49…
Microbial dynamics in durum wheat kernels during aging
2020
In the present work the microbial dynamics in wheat kernels were evaluated over time. The main aim of this research was to study the resistance of lactic acid bacteria (LAB) and yeasts associated to unprocessed cereals used for bread making during long term conservation. To this purpose four Triticum durum Desf. genotypes including two modern varieties (Claudio and Simeto) and two Sicilian wheat landraces (Russello and Timilia) were analysed by a combined culture-independent and -dependent microbiological approach after one, two or three years from cultivation and threshing. DNA based MiSeq Illumina technology was applied to reveal the entire bacterial composition of all semolina samples. T…
Task persistence mediates the effect of children’s literacy skills on mothers’ academic help
2015
This longitudinal study aimed at examining the relationship between children's task persistence, mothers' academic help, and the development of children’s literacy skills (reading and spelling) at the beginning of primary school. The participants were 870 children, 682 mothers, and 53 class teachers. Data were collected three times – at the beginning and the end of Grade 1 and at the end of Grade 2. Better literacy skills predicted higher persistence in completing school tasks and, correspondingly, higher persistence was related to better subsequent skills. Also, lower task persistence at the end of Grade 1 corresponded to more frequent academic help from mothers in Grade 2. Moreover, child…
Genomic Data from an Ancient European Battlefield Indicates On-Going Strong Selection on a Genomic Region Associated with Lactase Persistence Over th…
2020
Lactase persistence (LP), the continued expression of lactase into adulthood, is the most strongly selected single gene trait over the last 10,000 years in multiple human populations. It has been posited that the primary allele causing LP among Eurasians, rs4988235*T (Enattah et al. 2008), only rose to appreciable frequencies during the Bronze and Iron Ages (Mathieson et al 2015; Olalde et al. 2018), long after humans started consuming milk from domesticated animals. This rapid rise has been attributed to an influx of peoples from the Pontic-Caspian steppe that began around 5,000 years ago (Allentoft et al. 2015; Furholt et al. 2016). We investigate the spatiotemporal spread of LP through a…
Survival of Enteric Viruses in the Environment and Food
2016
Enteric viruses are those human viruses that are primarily transmitted by the fecal-oral route, either by person-to-person contact or by ingestion of contaminated food or water. The importance of viral foodborne diseases is increasingly being recognized, and several international organizations have found that there is an upward trend in their incidence. Thus, in this review, state-of-the-art information regarding virus persistence in food and the environment is compiled.
Nonlinear GARCH models for highly persistent volatility
2005
In this paper we study new nonlinear GARCH models mainly designed for time series with highly persistent volatility. For such series, conventional GARCH models have often proved unsatisfactory because they tend to exaggerate volatility persistence and exhibit poor forecasting ability. Our main emphasis is on models that are similar to previously introduced smooth transition GARCH models except for the novel feature that a lagged value of conditional variance is used as the transition variable. This choice of the transition variable corresponds to the idea that high persistence in conditional variance is related to relatively infrequent changes in regime. U sing the theory of Markov chains w…
A multicentRE observational analysiS of PErsistenCe to Treatment in the new multiple sclerosis era: the RESPECT study.
2018
In this independent, multicenter, retrospective study, we investigated the short-term persistence to treatment with first-line self-injectable or oral disease-modifying treatments (DMTs) in patients with relapsing–remitting multiple sclerosis. Data of patients regularly attending 21 Italian MS Centres who started a self-injectable or an oral DMT in 2015 were collected to: (1) estimate the proportion of patients discontinuing the treatment; (3) explore reasons for discontinuation; (3) identify baseline predictors of treatment discontinuation over a follow-up period of 12 months. We analyzed data of 1832 consecutive patients (1289 women, 543 men); 374 (20.4%) of them discontinued the prescrib…
Association of the rs4988235 in the lactase gene with obesity and its modulation by dairy products in a Mediterranean population
2011
The -13910C>T polymorphism (rs4988235) upstream from the lactase (LCT) gene, strongly associated with lactase persistence (LP) in Europeans, is emerging as a new candidate for obesity. We aimed to analyze the association of this polymorphism with obesity-related variables and its modulation by dairy product intake in an elderly population. We studied 940 high-cardiovascular risk Spanish subjects (aged 67 ± 7 years). Dairy product consumption was assessed by a validated questionnaire. Anthropometric variables were directly measured, and metabolic syndrome-related variables were obtained. Prevalence of genotypes was: 38.0% CC (lactase nonpersistent (LNP)), 45.7% CT, and 16.3% TT. The CC genot…
Ebola Virus Disease Complicated by Late-Onset Encephalitis and Polyarthritis, Sierra Leone
2016
To the Editor: Ebola virus (EBOV) disease is usually an acute illness, but increasing evidence exists of persistent infections and post-Ebola syndromes. We report a case of EBOV encephalitis.
Evolution of lactase persistence: an example of human niche construction
2011
Niche construction is the process by which organisms construct important components of their local environment in ways that introduce novel selection pressures. Lactase persistence is one of the clearest examples of niche construction in humans. Lactase is the enzyme responsible for the digestion of the milk sugar lactose and its production decreases after the weaning phase in most mammals, including most humans. Some humans, however, continue to produce lactase throughout adulthood, a trait known as lactase persistence. In European populations, a single mutation (−13910*T) explains the distribution of the phenotype, whereas several mutations are associated with it in Africa and the Middle …