21 research outputs found

    L’imitazione come strumento per sapere e comunicare: un dialogo tra psicologia e scuola

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    The binomy between psychology and school brings to mind, almost immediately, at least three different inflections on how these two terms might be linked to each other. The first, and most immediate, is the close relationship between psychologic research and test subjects availability, offered spontaneously by the scholastic institutions. The second one, refers to the contribution that the dialogue between pedagogy and psychology can offer to the formations of teachers, of any order, and their operativity, to be applied in regards of their students. And finally a fruitful dialogue implies that the school is able to offer interrogatives, themes for analysis and support in regards to the new issues that the same school needs to face. In light of this "dialogue", in this article the authors aim to present some ideas concerning the recent mechanisms of learning that might be transmitted to teachers during their formation and inspire them during their daily pedagogic action

    Investigation on the Origin of Sperm DNA Fragmentation: Role of Apoptosis, Immaturity and Oxidative Stress

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    Sperm DNA fragmentation (sDF) represents a threat to male fertility, human reproduction and the health of the offspring. The causes of sDF are still unclear, even if apoptosis, oxidative assault and defects in chromatin maturation are hypothesized. Using multicolor flow cytometry and sperm sorting, we challenged the three hypothesized mechanisms by simultaneously evaluating sDF and signs of oxidative damage (8-hydroxy, 2′-deoxyguanosine [8-OHdG] and malondialdehyde [MDA]), apoptosis (caspase activity and cleaved poly[ADP-ribose] polymerase [cPARP]) and sperm immaturity (creatine phosphokinase [CK] and excess of residual histones). Active caspases and c-PARP were concomitant with sDF in a high percentage of spermatozoa (82.6% ± 9.1% and 53.5% ± 16.4%, respectively). Excess of residual histones was significantly higher in DNA-fragmented sperm versus sperm without DNA fragmentation (74.8% ± 17.5% and 37.3% ± 16.6%, respectively, p < 0.005), and largely concomitant with active caspases. Conversely, oxidative damage was scarcely concomitant with sDF in the total sperm population, at variance with live sperm, where 8-OHdG and MDA were clearly associated to sDF. In addition, most live cells with active caspase also showed 8-OHdG, suggesting activation of apoptotic pathways in oxidative-injured live cells. This is the first investigation on the origin of sDF directly evaluating the simultaneous presence of the signs of the hypothesized mechanisms with DNA breaks at the single cell level. The results indicate that the main pathway leading to sperm DNA breaks is a process of apoptosis, likely triggered by an impairment of chromatin maturation in the testis and by oxidative stress during the transit in the male genital tract. These findings are highly relevant for clinical studies on the effects of drugs on sDF and oxidative stress in infertile men and for the development of new therapeutic strategies

    Variation of DNA Fragmentation Levels During Density Gradient Sperm Selection for Assisted Reproduction Techniques: A Possible New Male Predictive Parameter of Pregnancy?

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    Predicting the outcome of in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) is one main goal of the present research on assisted reproduction. To understand whether density gradient centrifugation (DGC), used to select sperm, can affect sperm DNA integrity and impact pregnancy rate (PR), we prospectively evaluated sperm DNA fragmentation (sDF) by TUNEL/PI, before and after DGC. sDF was studied in a cohort of 90 infertile couples the same day of IVF/ICSI treatment. After DGC, sDF increased in 41 samples (Group A, median sDF value: 29.25% [interquartile range, IQR: 16.01–41.63] in pre- and 60.40% [IQR: 32.92–93.53] in post-DGC) and decreased in 49 (Group B, median sDF value: 18.84% [IQR: 13.70–35.47] in pre- and 8.98% [IQR: 6.24–15.58] in post-DGC). PR was 17.1% and 34.4% in Group A and B, respectively (odds ratio [OR]: 2.58, 95% confidence interval [CI]: 0.95–7.04, P = 0.056). After adjustment for female factor, female and male age and female BMI, the estimated OR increased to 3.12 (95% CI: 1.05–9.27, P = 0.041). According to the subgroup analysis for presence/absence of female factor, heterogeneity in the association between the Group A and B and PR emerged (OR: 4.22, 95% CI: 1.16–15.30 and OR: 1.53, 95% CI: 0.23–10.40, respectively, for couples without, n = 59, and with, n = 31, female factor). This study provides the first evidence that the DGC procedure produces an increase in sDF in about half of the subjects undergoing IVF/ICSI, who then show a much lower probability of pregnancy, raising concerns about the safety of this selection procedure. Evaluation of sDF before and after DGC configures as a possible new prognostic parameter of pregnancy outcome in IVF/ICSI. Alternative sperm selection strategies are recommended for those subjects who undergo the damage after DGC

    Socio-Ecological Disruptions at Critical Periods During Development Alter Stress Responses and Hippocampal Dendritic Morphology of Prairie Voles: Implications for Social Monogamy

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    Emotions are often associated with the evolution of monogamy. For example, fear of cuckoldry has been recently proposed as the driving force for human monogamy. We used prairie voles (Microtus ochrogaster) as a model of human behavior to study how stress reactivity is shaped by socio-ecological disruptions experienced as neonates and as subadults. We hypothesized that social disruptions would have a greater impact on the vole's stress levels than ecological disruptions, and that females would be more susceptible to the experience than males. At 6 days postpartum, the housing conditions were manipulated to have offspring raised by: (1) both parents under a protective cover (NoDisrupt); (2) Both parents uncovered (EcoDisrupt); (3) Mother alone covered (SocDisrupt); (4) Mother alone uncovered (SocEcoDisrupt). To experience disruptions as subadults, offspring were weaned then housed either alone (Isolate) or with a same-sex sibling (Social). As adults, each offspring was placed in an open-field arena and tested over 3 consecutive days to measure its behavior in response to an empty space (Day1), a same-sex vole in a container (Day2), and an empty container (Day3). The brain of a subgroup of subjects was processed for Golgi staining to assess the impact of disruptions on hippocampal dendritic morphology in adulthood. Males that experienced social disruption in early life displayed lower stress levels on Day2 of testing than males and females in other groups. This effect was only evident in males that did not experience social disruptions as subadults. Socio-ecological disruptions at postpartum had an unanticipated impact on the hippocampus of the voles. The apical dendrites of the CA3 neurons in male and female voles that experienced either social or ecological disruptions in early life and remained socially isolated as subadults were longer than those in undisturbed voles. Our results suggest that social disruptions experienced in early life modulate the male's stress-related behaviors and may thus influence his monogamous tendencies. Exposure to disruptions may also impact the memory circuits of the brain that monogamous animals use to make mating decisions

    Treatment with human, recombinant FSH improves sperm DNA fragmentation in idiopathic infertile men depending on the FSH receptor polymorphism p.N680S: A pharmacogenetic study

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    Study question: Does the spermDNAfragmentation index (DFI) improve depending on the FSH receptor (FSHR) genotype as assessed by the nonsynonymous polymorphisms rs6166 (p.N680S) after 3 months of recombinant FSH treatment in men with idiopathic infertility? summary answer: FSH treatment significantly improves sperm DFI only in idiopathic infertile men with the p.N680S homozygous N FSHR. what is known already: FSH, fundamental for spermatogenesis, is empirically used to treat male idiopathic infertility and several studies suggest that DFI could be a candidate predictor of response to FSH treatment, in terms of probability to conceive. Furthermore, it is known that the FSHR single nucleotide polymorphism (SNP) rs6166 (p.N680S) influences ovarian response in women and testicular volume in men. study design, size and duration: Amulticenter, longitudinal, prospective, open-label, two-arm clinical trial was performed. Subjects enrolled were idiopathic infertile men who received 150 IU recombinant human FSH s.c. every other day for 12 weeks and were followed-up for a further 12 weeks after FSH withdrawal. Patients were evaluated at baseline, at the end of treatment and at the end of follow-up. participants/materials, setting, methods: Eighty-nine men with idiopathic infertility carrier of the FSHR p.N680S homozygousNor S genotype, FSH 64 8 IU/l and DFI &gt;15%,were enrolled. A total of 66 patients had DFI analysis completed on at least two visits. DFI was evaluated in one laboratory by TUNEL/PI (propidium iodide) assay coupled to flow cytometry, resolving two different fractions of sperm, namely the 'brighter' and 'dimmer' sperm DFI fractions. main results and the roleof chance: Thirty-eightmen(57.6%)were carriers of the p.N680S homozygousNand 28 (42.4%) of the homozygous S FSHR. Sperm concentration/number was highly heterogeneous and both groups included men ranging from severe oligozoospermia to normozoospermia. Total DFI was significantly lower at the end of the study in homozygous carriers of the p.N680SNversus p.N680S S allele (P = 0.008). Total DFI decreased significantly from baseline to the end of the study (P = 0.021) only in carriers of the p.N680S homozygous N polymorphism, and this decrease involved the sperm population containing vital sperm (i.e. brighter sperm) (P = 0.008). The dimmer sperm DFI fraction, including only nonvital sperm, was significantly larger in p.N680S S homozygous patients than in homozygous N men (P = 0.018). Total DFIwas inversely related to total sperm number (P = 0.020) and progressive sperm motility (P = 0.014).Whenpatients were further stratified according to sperm concentration (normoozospermic versus oligozoospermic) or -211G&gt;T polymorphism in the FSHB gene (rs10835638) (homozygous Gversus others), the significant improvement of sperm DFI in FSHR p.N680S homozygousNmen was independent of sperm concentration and associated with the homozygous FSHB -211G&gt;T homozygous G genotype. limitations, reasons for caution: The statistical power of the study is 86.9% with alpha error 0.05. This is the first pharmacogenetic study suggesting that FSH treatment induces a significant improvement of total DFI in men carriers of the p.N680S homozygousNFSHR; however, the results need to be confirmed in larger studies using a personalized FSH dosage and treatment duration. wider implications of the findings: The evaluation of sperm DFI as a surrogate marker of sperm quality, and of the FSHR SNP rs6166 (p.N680S), might be useful to predict the response to FSH treatment in men with idiopathic infertility. study funding/competing interest(s): The study was supported by an unrestricted grant to M.S. and H.M.B. from Merck Serono that provided the drug used in the study. MS received additional grants from Merck Serono and IBSA as well as honoraria from Merck Serono. The remaining authors declare that no conflicts of interest are present. trial registration number: EudraCT number 2010-020240-35

    Improved annotation of the insect vector of citrus greening disease: Biocuration by a diverse genomics community

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    The Asian citrus psyllid (Diaphorina citri Kuwayama) is the insect vector of the bacterium Candidatus Liberibacter asiaticus (CLas), the pathogen associated with citrus Huanglongbing (HLB, citrus greening). HLB threatens citrus production worldwide. Suppression or reduction of the insect vector using chemical insecticides has been the primary method to inhibit the spread of citrus greening disease. Accurate structural and functional annotation of the Asian citrus psyllid genome, as well as a clear understanding of the interactions between the insect and CLas, are required for development of new molecular-based HLB control methods. A draft assembly of the D. citri genome has been generated and annotated with automated pipelines. However, knowledge transfer from well-curated reference genomes such as that of Drosophila melanogaster to newly sequenced ones is challenging due to the complexity and diversity of insect genomes. To identify and improve gene models as potential targets for pest control, we manually curated several gene families with a focus on genes that have key functional roles in D. citri biology and CLas interactions. This community effort produced 530 manually curated gene models across developmental, physiological, RNAi regulatory and immunity-related pathways. As previously shown in the pea aphid, RNAi machinery genes putatively involved in the microRNA pathway have been specifically duplicated. A comprehensive transcriptome enabled us to identify a number of gene families that are either missing or misassembled in the draft genome. In order to develop biocuration as a training experience, we included undergraduate and graduate students from multiple institutions, as well as experienced annotators from the insect genomics research community. The resulting gene set (OGS v1.0) combines both automatically predicted and manually curated gene models.Peer reviewedBiochemistry and Molecular BiologyEntomology and Plant Patholog

    Palaeobotanical evidence and SSR DNA analysis of archaeological apple seeds found in first century winery of Roman farm on Elba Island (Italy)

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    In the late republican Roman period (2nd-1st century BC) a Roman farm was established at San Giovanni, on the Island of Elba. About 6th century BC the area had hosted intense metallurgical activity (reduction of ion ore). In 1st century AD the farm was destroyed by fire. Since 2012, the remains of walls defining five rectangular areas have been uncovered. The first contained eight broken amphorae used to store, conserve and transport beverages. Palaeobotanical analysis of set layers of the archaeological site were performed. Palynological observations showed little pollen and major presence of fungal spores and non-pollen objects typical of moist soil, stagnant water and heavy human impact. Anthracological analysis revealed plants useful for reconstructing the palaeoecological characteristics and human attitudes of the period. In the bottom of amphorae protected by a crust of burnt soil, two sublayers of deposition and a compact layer of mud and organic material, we found about 500 well conserved apple seeds, which when compared with contemporary seeds showed morphological affinities with Malus sylvestris. Phenotypic study and genetic analysis of genomic DNA with SSR molecular markers were performed against seeds of known contemporary varieties of Malus sylvestris and Malus domestica as controls

    Archaeobotanical reconstructions of vegetation and report of mummified apple seeds found in the cellar of a first-century Roman villa on Elba Island

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    In the late Roman Republic period (2nd–1st century BC), in the area of San Giovanni on Elba Island, previously subject to intense extraction of iron ore, a rustic villa was established by Marco Valerio Messalla, a supreme Roman magistrate. The foundations of the walls were discovered and excavated by an archaeological mission. Palaeobotanical analysis of a set of stratigraphic layers was performed. Palynological slides showed remains of palynomorphic and non-pollen objects, while data combined with anthracological investigations confirmed the hypothesis that in the 1st century AD the villa was destroyed by a fire that created a compact crust under which were discovered four broken Roman amphorae containing about five hundred apple seeds. Comparisons of archaeological and fresh seeds from reference collections showed discontinuous morphology except for one group of archaeological samples. DNA was isolated from seeds that had well-preserved embryos in all groups. DNA extracts from archaeological, wild and modern domestic seeds (controls) were amplified by PCR and tested with SSR molecular markers, followed by genome analysis
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