164 research outputs found
Crossing boundaries: documentation of a teacher training course on design, robotics and coding
This article reports on the results of a teacher training course in which 41 teachers, working together with three university researchers, experienced a different way to engage in meaningful teaching and learning activities in design, coding and robotics. The course was run in an Italian school during the lock-down period of the Covid-19 pandemics. The training path had the objective to make the participants work differently, acting both as researchers and as teachers in training. The research reported in this article examined if and how an online teacher training course could act as a third space between school and academic cultures to achieve a negotiation of pedagogical practices.
Findings from the study, collected through pre-post questionnaires and open-ended discussions, highlight an improvement in knowledge related to coding and robotics. Moreover, during the course, teachers experienced a new approach to space-time dimensions, first-hand experimentation and a collaborative approach, leading to greater perceived confidence in their skills and competences
Exposure to polychlorinated biphenyls and hexachlorobenzene, semen quality and testicular cancer risk
PURPOSE: We carried out a case-control study to investigate the possible role of occupational and environmental exposure to endocrine disruptors in the onset of testicular cancer (TC).
METHODS: We evaluated 125 TC patients and 103 controls. Seminal fluid examination and organochlorine analysis were performed in all subjects. Cases and controls were also interviewed using a structured questionnaire to collect demographic information, residence, andrological medical history and dietary information.
RESULTS: We found that a higher level of reproductive tract birth defects was associated with a higher risk of TC. With regard to diet, cases reported a higher consumption of milk and dairy products than controls. Overall, there was a statistically significant increase in TC risk in cases with detectable values of total polychlorinated organic compounds against controls (14.4 vs. 1.0 %; p < 0.001). TC patients with detectable levels of organochlorines had lower mean semen parameters than those with undetectable levels, although this difference was not statistically significant.
CONCLUSION: The International Agency for Research on Cancer recently included dioxin-like polychlorinated biphenyls (PCBs) in Group 1 of known human carcinogens. Our study confirmed and identified various risk factors for testicular cancer: cryptorchidism, consumption of milk and dairy products, parents' occupation and serum concentration of hexachlorobenzene and PCBs and, for the first time, we showed the correlation between semen quality and the serum concentration of these pollutants
Androgen receptor polymorphisms and testicular cancer risk
Testicular cancer (TC) is currently the most common malignant solid tumour in Caucasian males aged 15-39 years. Epidemiological evidence suggests that its onset may be due to an imbalance in the action of steroidal sex hormones and their receptors. A faulty androgen receptor signalling pathway can, in fact, cause various male reproductive disorders. The androgen receptor (AR) gene has two polymorphic segments consisting of CAG and GGC repeats. The length of CAG repeats has been shown to affect the regulation of AR activity. In our study, we used fragment analysis to evaluate the AR gene repeats of 302 TC patients and 322 controls, to establish if there is any association between repeat number and TC. This study of the largest Italian caseload investigated to date highlighted three particularly significant aspects. First, a CAG repeat number of ≥25 may be considered a risk factor for the onset of TC, given its greater frequency in patients in comparison with controls. This difference became significant for the non-seminoma group. Second, men with CAG repeats below 21 or above 24 were found to have a, respectively, 50 and 76% higher risk of TC than those with CAG 21-24, suggesting that these too can be considered a risk factor for TC. Finally, stage II patients were more likely to have a CAG repeat number 24 than stage I patients. © 2014 American Society of Andrology and European Academy of Andrology
Fully kinetic large scale simulations of the collisionless Magnetorotational instability
We present two-dimensional particle-in-cell (PIC) simulations of the fully
kinetic collisionless magnetorotational instability (MRI) in weakly magnetized
(high ) pair plasma. The central result of this numerical analysis is
the emergence of a self-induced turbulent regime in the saturation state of the
collisionless MRI, which can only be captured for large enough simulation
domains. One of the underlying mechanisms for the development of this turbulent
state is the drift-kink instability (DKI) of the current sheets resulting from
the nonlinear evolution of the channel modes. The onset of the DKI can only be
observed for simulation domain sizes exceeding several linear MRI wavelengths.
The DKI, together with ensuing magnetic reconnection, activate the turbulent
motion of the plasma in the late stage of the nonlinear evolution of the MRI.
At steady state, the magnetic energy has an MHD-like spectrum with a slope of
for ). We also
examine the role of the collisionless MRI and associated magnetic reconnection
in the development of pressure anisotropy. We study the stability of the system
due to this pressure anisotropy, observing the development of mirror
instability during the early-stage of the MRI. We further discuss the
importance of magnetic reconnection for particle acceleration during the
turbulence regime. In particular, consistent with reconnection studies, we show
that at late times the kinetic energy presents a characteristic slope of
in the high-energy region.Comment: 13 pages, 9 figures, accepted to Astrophysical Journa
A CTNNA3 compound heterozygous deletion implicates a role for \u3b1T-catenin in susceptibility to autism spectrum disorder.
Autism spectrum disorder (ASD) is a highly heritable, neurodevelopmental condition showing extreme genetic heterogeneity. While it is well established that rare genetic variation, both de novo and inherited, plays an important role in ASD risk, recent studies also support a rare recessive contribution.
METHODS:
We identified a compound heterozygous deletion intersecting the CTNNA3 gene, encoding \u3b1T-catenin, in a proband with ASD and moderate intellectual disability. The deletion breakpoints were mapped at base-pair resolution, and segregation analysis was performed. We compared the frequency of CTNNA3 exonic deletions in 2,147 ASD cases from the Autism Genome Project (AGP) study versus the frequency in 6,639 controls. Western blot analysis was performed to get a quantitative characterisation of Ctnna3 expression during early brain development in mouse.
RESULTS:
The CTNNA3 compound heterozygous deletion includes a coding exon, leading to a putative frameshift and premature stop codon. Segregation analysis in the family showed that the unaffected sister is heterozygote for the deletion, having only inherited the paternal deletion. While the frequency of CTNNA3 exonic deletions is not significantly different between ASD cases and controls, no homozygous or compound heterozygous exonic deletions were found in a sample of over 6,000 controls. Expression analysis of Ctnna3 in the mouse cortex and hippocampus (P0-P90) provided support for its role in the early stage of brain development.
CONCLUSION:
The finding of a rare compound heterozygous CTNNA3 exonic deletion segregating with ASD, the absence of CTNNA3 homozygous exonic deletions in controls and the high expression of Ctnna3 in both brain areas analysed implicate CTNNA3 in ASD susceptibility
The intellectual disability protein RAB39B selectively regulates GluA2 trafficking to determine synaptic AMPAR composition
RAB39B is a member of the RAB family of small GTPases that controls intracellular vesicular trafficking in a compartment-specific manner. Mutations in the RAB39B gene cause intellectual disability comorbid with autism spectrum disorder and epilepsy, but the impact of RAB39B loss of function on synaptic activity is largely unexplained. Here we show that protein interacting with C-kinase 1 (PICK1) is a downstream effector of GTP-bound RAB39B and that RAB39B-PICK1 controls trafficking from the endoplasmic reticulum to the Golgi and, hence, surface expression of GluA2, a subunit of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs). The role of AMPARs in synaptic transmission varies depending on the combination of subunits (GluA1, GluA2 and GluA3) they incorporate. RAB39B downregulation in mouse hippocampal neurons skews AMPAR composition towards non GluA2-containing Ca(2+)-permeable forms and thereby alters synaptic activity, specifically in hippocampal neurons. We posit that the resulting alteration in synaptic function underlies cognitive dysfunction in RAB39B-related disorders
ZYZ-168 alleviates cardiac fibrosis after myocardial infarction through inhibition of ERK1/2-dependent ROCK1 activation
Selective treatments for myocardial infarction (MI) induced cardiac fibrosis are lacking. In this study, we focus on the therapeutic potential of a synthetic cardio-protective agent named ZYZ-168 towards MI-induced cardiac fibrosis and try to reveal the underlying mechanism. ZYZ-168 was administered to rats with coronary artery ligation over a period of six weeks. Ecocardiography and Masson staining showed that ZYZ-168 substantially improved cardiac function and reduced interstitial fibrosis. The expression of α–smooth muscle actin (α-SMA) and Collagen I were reduced as was the activity of matrix metalloproteinase 9 (MMP-9). These were related with decreased phosphorylation of ERK1/2 and expression of Rho-associated coiled-coil containing protein kinase 1 (ROCK1). In cardiac fibroblasts stimulated with TGF-β1, phenotypic switches of cardiac fibroblasts to myofibroblasts were observed. Inhibition of ERK1/2 phosphorylation or knockdown of ROCK1 expectedly reduced TGF-β1 induced fibrotic responses. ZYZ-168 appeared to inhibit the fibrotic responses in a concentration dependent manner, in part via a decrease in ROCK 1 expression through inhibition of the phosphorylation status of ERK1/2. For inhibition of ERK1/2 phosphorylation with a specific inhibitor reduced the activation of ROCK1. Considering its anti-apoptosis activity in MI, ZYZ-168 may be a potential drug candidate for treatment of MI-induced cardiac fibrosis
Into the Un(Known). Unveiling Science's intrinsic Art
Entrerete in un mondo nuovo e quasi astratto, apparentemente innaturale. Sarete circondati da suoni e immagini familiari e allo stesso tempo distanti dalla vostra quotidianità. Gli eventi in cui vi troverete immersi sono comuni nella vita di tutti i giorni, anche se non li riconoscete perché “silenziati”. Sono, infatti, fenomeni che acquistano importanza su scale molto grandi, cosmiche potremmo dire, e in condizioni fisiche incompatibili con la vita umana.
A raccontarvi questo meraviglioso mondo sarà la “voce” familiare della luce, la radiazione elettromagnetica prodotta dalle varie sorgenti astrofisiche sparse nell’Universo, il principale canale di comunicazione a disposizione degli astronomi per indagare i più reconditi segreti del Cosmo. La luce, esploratrice instancabile, ci racconta gli scenari in cui è stata generata: esplosioni di Supernovae, materia che cade in un buco nero, brillamenti solari, e molto altro. Fenomeni lontani e misteriosi che sfuggono alla nostra esperienza diretta, ma che da anni sono al centro delle ricerche scientifiche più avanzate.
Preparatevi ad entrare nell'ignoto, lasciate che la luce vi mostri l'invisibile
Cystatin A, a Potential Common Link for Mutant Myocilin Causative Glaucoma
Myocilin (MYOC) is a 504 aa secreted glycoprotein induced by stress factors in the trabecular meshwork tissue of the eye, where it was discovered. Mutations in MYOC are linked to glaucoma. The glaucoma phenotype of each of the different MYOC mutation varies, but all of them cause elevated intraocular pressure (IOP). In cells, forty percent of wild-type MYOC is cleaved by calpain II, a cysteine protease. This proteolytic process is inhibited by MYOC mutants. In this study, we investigated the molecular mechanisms by which MYOC mutants cause glaucoma. We constructed adenoviral vectors with variants Q368X, R342K, D380N, K423E, and overexpressed them in human trabecular meshwork cells. We analyzed expression profiles with Affymetrix U133Plus2 GeneChips using wild-type and null viruses as controls. Analysis of trabecular meshwork relevant mechanisms showed that the unfolded protein response (UPR) was the most affected. Search for individual candidate genes revealed that genes that have been historically connected to trabecular meshwork physiology and pathology were altered by the MYOC mutants. Some of those had known MYOC associations (MMP1, PDIA4, CALR, SFPR1) while others did not (EDN1, MGP, IGF1, TAC1). Some, were top-changed in only one mutant (LOXL1, CYP1B1, FBN1), others followed a mutant group pattern. Some of the genes were new (RAB39B, STC1, CXCL12, CSTA). In particular, one selected gene, the cysteine protease inhibitor cystatin A (CSTA), was commonly induced by all mutants and not by the wild-type. Subsequent functional analysis of the selected gene showed that CSTA was able to reduce wild-type MYOC cleavage in primary trabecular meshwork cells while an inactive mutated CSTA was not. These findings provide a new molecular understanding of the mechanisms of MYOC-causative glaucoma and reveal CSTA, a serum biomarker for cancer, as a potential biomarker and drug for the treatment of MYOC-induced glaucoma
X-exome sequencing of 405 unresolved families identifies seven novel intellectual disability genes
X-linked intellectual disability (XLID) is a clinically and genetically heterogeneous disorder. During the past two decades in excess of 100 X-chromosome ID genes have been identified. Yet, a large number of families mapping to the X-chromosome remained unresolved suggesting that more XLID genes or loci are yet to be identified. Here, we have investigated 405 unresolved families with XLID. We employed massively parallel sequencing of all X-chromosome exons in the index males. The majority of these males were previously tested negative for copy number variations and for mutations in a subset of known XLID genes by Sanger sequencing. In total, 745 X-chromosomal genes were screened. After stringent filtering, a total of 1297 non-recurrent exonic variants remained for prioritization. Co-segregation analysis of potential clinically relevant changes revealed that 80 families (20%) carried pathogenic variants in established XLID genes. In 19 families, we detected likely causative protein truncating and missense variants in 7 novel and validated XLID genes (CLCN4, CNKSR2, FRMPD4, KLHL15, LAS1L, RLIM and USP27X) and potentially deleterious variants in 2 novel candidate XLID genes (CDK16 and TAF1). We show that the CLCN4 and CNKSR2 variants impair protein functions as indicated by electrophysiological studies and altered differentiation of cultured primary neurons from Clcn4−/− mice or after mRNA knock-down. The newly identified and candidate XLID proteins belong to pathways and networks with established roles in cognitive function and intellectual disability in particular. We suggest that systematic sequencing of all X-chromosomal genes in a cohort of patients with genetic evidence for X-chromosome locus involvement may resolve up to 58% of Fragile X-negative cases
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