3,077 research outputs found
Mancozeb impairs the ultrastructure of mouse granulosa cells in a dose-dependent manner
Mancozeb, an ethylene bis-dithiocarbamate, is widely used as a fungicide and exerts reproductive toxicity in vivo and in vitro in mouse oocytes by altering spindle morphology and impairing the ability to fertilize. Mancozeb also induces a premalignant status in mouse granulosa cells (GCs) cultured in vitro, as indicated by decreased p53 expression and tenuous oxidative stress. However, the presence and extent of ultrastructural alterations induced by mancozeb on GCs in vitro have not yet been reported. Using an in vitro model of reproductive toxicity, comprising parietal GCs from mouse antral follicles cultured with increasing concentrations of mancozeb (0.001-1 µg/ml), we sought to ascertain the in vitro ultrastructural cell toxicity by means of transmission (TEM) and scanning (SEM) electron microscopy. The results showed a dose-dependent toxicity of mancozeb on mouse GCs. Ultrastructural data showed intercellular contact alterations, nuclear membrane irregularities, and chromatin marginalization at lower concentrations, and showed chromatin condensation, membrane blebbing, and cytoplasmic vacuolization at higher concentrations. Morphometric analysis evidenced a reduction of mitochondrial length in GCs exposed to mancozeb 0.01-1 µg/ml and a dose-dependent increase of vacuole dimension. In conclusion, mancozeb induced dose-dependent toxicity against GCs in vitro, including ultrastructural signs of cell degeneration compatible with apoptosis, likely due to the toxic breakdown product ethylenethiourea. These alterations may represent a major cause of reduced/delayed/missed oocyte maturation in cases of infertility associated with exposure to pesticides
Integrated application of in situ non destructive techniques for the evaluation of the architectural elements of monumental structures
Virtual reality implementation as a useful software tool for e-health applications
Human hand and finger movements are of obvious
importance. The possibility of recording all fingers
joints movements during everyday life is then strategic
for medical diagnosis, surgery and post traumatic
rehabilitation. A proper presentation of recorded data
can be really useful for doctors and therapists to
correctly act in the occurrence of peripheral nerve
injury, rigidities, camptodactyly (decline in permanent
deformity of the interphalangeal junction), orthoses,
tenolisi, congenital malformations, trauma, dexterity
and/or muscular and/or articulate motility evaluations,
thumb atros, syndromes, use of mentors, spasm, use of
mechanical supports etc.. According to this context we
report a virtual reality implementation on the basis of
fingers movements recorded data, suitable for fingers
joints movement analysi
Comparison of two different classifiers for mental tasks-based Brain-Computer Interface: MLP Neural Networks vs. Fuzzy Logic
This study is devoted to the classification of fourclass
mental tasks data for a Brain-Computer Interface
protocol. In such view we adopted Multi Layer
Perceptron Neural Network (MLP) and Fuzzy C-means analysis for classifying: left and right hand movement imagination, mental subtraction operation and mental recitation of a nursery rhyme.
Five subjects participated to the experiment in two sessions recorded in distinct days. Different parameters were considered for the evaluation of the performances of the two classifiers: accuracy, that is, percentage of correct classifications, training time and size of the training dataset. The results show that even if the accuracies of the two classifiers are quite similar, the MLP classifier needs a smaller training set to reach them with respect to the Fuzzy one. This leads to the preference of MLP for the classification of
mental tasks in Brain Computer Interface protocols
Detailed petrophysical and geophysical characterization of core samples from the potential caprock-reservoir system in the Sulcis Coal Basin (Southwestern Sardinia - Italy)
In this work we present a methodology suitable to identify a caprock-reservoir system for the CO2 storage in the Sulcis Coal Basin (SW Sardinia - Italy). The petrophysical and geophysical characterizations indicate that the potential carbonate reservoir ("Miliolitico" Fm. Auct.) located at the base of the Eocene stratigraphic sequence in the mining district of the Sulcis Coal Basin, southwestern Sardinia, is heterogeneous but presents suitable reservoir zones for the storage of the CO2. The GPS data analysis indicates that the study area is stable, since it is characterized by a surface crustal deformation smaller than 1 mm/y
Desarrollo del razonamiento crítico y resolutivo en la educación para el conocimiento significativo del paisaje
Luego de una investigación que analizó las formas en que los actores del proceso educativo reconocen los conceptos, los procedimientos y las actitudes más relevantes para la educación geográfica, Se detectan falencias en la incorporación de los conceptos con una visión crítica y resolutiva. La investigación “Análisis de estrategias didácticas implementadas en niveles escolares de 7º básico a 1º medio respecto del desarrollo del razonamiento crítico y resolutivo para mejorar la calidad de la educación geográfica en Chile”,1 pretende desarrollar un enfoque teórico-metodológico pertinente para el trabajo pedagógico tendiente al logro de los aprendizajes esperados en esta área de educación. Proyecta reconocer las falencias en la acción didáctica en la enseñanza del “paisaje”, para incrementar estrategias metodológicas en los profesores colaboradores del universo de estudio. AbstractThe present research stands in the job of the classroom. It explores in the teaching-learning strategies implemented by the teacher in the classroom procedures to develop superior thinking processes (critical and decisive) in students from seventh to first year of high school. Through observation guidelines, is could to recognize that the activities implemented by teachers of studied levels not get develop superior thought processes, since they lack strategies that integrate content, activities and skills to get
Emergent quantum confinement at topological insulator surfaces
Bismuth-chalchogenides are model examples of three-dimensional topological
insulators. Their ideal bulk-truncated surface hosts a single spin-helical
surface state, which is the simplest possible surface electronic structure
allowed by their non-trivial topology. They are therefore widely
regarded ideal templates to realize the predicted exotic phenomena and
applications of this topological surface state. However, real surfaces of such
compounds, even if kept in ultra-high vacuum, rapidly develop a much more
complex electronic structure whose origin and properties have proved
controversial. Here, we demonstrate that a conceptually simple model,
implementing a semiconductor-like band bending in a parameter-free
tight-binding supercell calculation, can quantitatively explain the entire
measured hierarchy of electronic states. In combination with circular dichroism
in angle-resolved photoemission (ARPES) experiments, we further uncover a rich
three-dimensional spin texture of this surface electronic system, resulting
from the non-trivial topology of the bulk band structure. Moreover, our study
reveals how the full surface-bulk connectivity in topological insulators is
modified by quantum confinement.Comment: 9 pages, including supplementary information, 4+4 figures. A high
resolution version is available at
http://www.st-andrews.ac.uk/~pdk6/pub_files/TI_quant_conf_high_res.pd
Online Multi-Coloring with Advice
We consider the problem of online graph multi-coloring with advice.
Multi-coloring is often used to model frequency allocation in cellular
networks. We give several nearly tight upper and lower bounds for the most
standard topologies of cellular networks, paths and hexagonal graphs. For the
path, negative results trivially carry over to bipartite graphs, and our
positive results are also valid for bipartite graphs. The advice given
represents information that is likely to be available, studying for instance
the data from earlier similar periods of time.Comment: IMADA-preprint-c
Oestradiol-17β plasma concentrations after intramuscular injection of oestradiol benzoate or oestradiol cypionate in llamas (Lama glama)
<p>Abstract</p> <p>Background</p> <p>Llamas (<it>Lama glama</it>) are induced ovulators and the process of ovulation depends on dominant follicular size. In addition, a close relationship between behavioural estrus and ovulation is not registered in llamas. Therefore, the exogenous control of follicular development with hormones aims to predict the optimal time to mate. Oestradiol-17β (E<sub>2</sub>) and its esters are currently used in domestic species, including camelids, in synchronization treatments. But, in llamas, there is no reports regarding the appropriate dosages to be used and most protocols have been designed by extrapolation from those recommended for other ruminants. The aim of the present study was to characterize plasma E<sub>2 </sub>concentrations in intact female llamas following a single intramuscular (i.m.) injection of two oestradiol esters: oestradiol benzoate (EB) and oestradiol cypionate (ECP).</p> <p>Methods</p> <p>Twelve non pregnant and non lactating sexually mature llamas were i.m. injected on day 0 with 2.5 mg of EB (EB group, n = 6) or ECP (ECP group, n = 6). Blood samples were collected immediately before injection, at 1, 6, 12, 24 h after treatment and then daily until day 14 post injection. Changes in hormone concentrations with time were analyzed in each group by analysis of variance (ANOVA) using a repeated measures (within-SS) design. Plasma E<sub>2 </sub>concentrations and area under the concentration-time curve (AUC) values were compared between groups by ANOVA. In all cases a Least-Significant Difference test (LSD) was used to determine differences between means. Hormonal and AUC data are expressed as mean ± S.E.M.</p> <p>Results</p> <p>Peak plasma E<sub>2 </sub>concentrations were achieved earlier and were higher in EB group than in ECP group. Thereafter, E<sub>2 </sub>returned to physiological concentrations earlier in EB group (day 5) than in ECP group (day 9). Although plasma E<sub>2 </sub>profiles differed over time among groups there were no differences between them on AUC values.</p> <p>Conclusions</p> <p>The i.m. injection of a single dose of both oestradiol esters resulted in plasma E<sub>2 </sub>concentrations exceeding physiological values for a variable period. Moreover, the plasma E<sub>2 </sub>profiles observed depended on the derivative of oestradiol administered. This basic information becomes relevant at defining treatment protocols including oestrogens in llamas.</p
Anti-asthma medication prescribing to children in the Lombardy Region of Italy: chronic versus new users
<p>Abstract</p> <p>Background</p> <p>Although anti-asthma medications are amongst those most frequently under or over prescribed it is generally accepted that prescriptions for such agents can be used as a proxy for disease prevalence. The aims of this study were to estimate prevalence and incidence of childhood asthma in a representative Italian area by analysing three years of anti-asthmatic prescriptions and hospitalizations of subjects with chronic or first time treatment, and to underline appropriateness of therapeutic choices.</p> <p>Methods</p> <p>The analysis involved prescriptions given to 6-17 year olds between 2003 and 2005 in Italy's Lombardy Region. The youths were classified as potential asthmatics, based on the different degree of drug utilization: occasional, low or high users, and grouped as 'new onset' or 'chronic' cases based on the duration of therapy dispensed. The analysis of prescriptions and hospitalization rate of these groups provided an estimate of the 2005 asthma prevalence and incidence and allowed an estimation of the level of appropriateness of treatments.</p> <p>Results</p> <p>During 2005, the estimated incidence of potential asthmatics was 0.8% and the estimated prevalence was 3.5%. When viewed retrospectively for two years, records showed that 47% of potential asthmatics received prescriptions also during 2004 and 30% also during 2003. During the three years considered, 7.5%, 2.8%, and 1.5% of high, low, and occasional users, respectively, were hospitalized for asthma. The most important inappropriateness found was the prescription of long acting beta adrenergics as first time treatment.</p> <p>Conclusions</p> <p>This study allowed a proxy of asthma incidence, prevalence, and severity. The analyses highlighted a low compliance with the guidelines, suggesting that educational interventions are needed to obtain a more rational management of childhood asthma, especially in subjects starting therapy.</p
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