526 research outputs found
Theoretical Study of Comb-Polymers Adsorption on Solid Surfaces
We propose a theoretical investigation of the physical adsorption of neutral
comb-polymers with an adsorbing skeleton and non-adsorbing side-chains on a
flat surface. Such polymers are particularly interesting as "dynamic coating"
matrices for bio-separations, especially for DNA sequencing, capillary
electrophoresis and lab-on-chips. Separation performances are increased by
coating the inner surface of the capillaries with neutral polymers. This method
allows to screen the surface charges, thus to prevent electro-osmosis flow and
adhesion of charged macromolecules (e.g. proteins) on the capillary walls. We
identify three adsorption regimes: a "mushroom" regime, in which the coating is
formed by strongly adsorbed skeleton loops and the side-chains anchored on the
skeleton are in a swollen state, a "brush" regime, characterized by a uniform
multi-chains coating with an extended layer of non-adsorbing side-chains and a
non-adsorbed regime. By using a combination of mean field and scaling
approaches, we explicitly derive asymptotic forms for the monomer concentration
profiles, for the adsorption free energy and for the thickness of the adsorbed
layer as a function of the skeleton and side-chains sizes and of the adsorption
parameters. Moreover, we obtain the scaling laws for the transitions between
the different regimes. These predictions can be checked by performing
experiments aimed at investigating polymer adsorption, such as Neutron or X-ray
Reflectometry, Ellipsometry, Quartz Microbalance, or Surface Force Apparatus.Comment: 30 pages, 7 figures, to be published in Macromolecule
Characterizing Alpine peatlands from drones: a case study
Alpine peatlands occur in alpine, sub-alpine and mountain regions of the world and can be frequently found on the Alps as well as on the Andes, on the Tibetan Plateau, on the Australian Alps and in other regions of the world. Italian Alps host a large number of relatively small bogs and fens that can be found on gently sloping surfaces or in small valleys created by past glaciers. The high precipitation-low temperature climatic regime ensures large water availability to these ecosystems. The uniqueness and importance of peatlands in the Alpine territory is strongly linked to the countless ecosystem services that they provide, including their ability of sequestering and stocking carbon, providing habitat for flora and fauna including endangered species, supporting important biological diversity, being reservoir of high-quality freshwater during warm and dry seasons, and having the role of paleo-climate archives.
Despite their importance, the peatlands of the Alps are still poorly studied and incompletely mapped, probably because they are relatively small and difficult to access. The use of remote sensing techniques provides a possible solution, allowing extending local measurements to wider areas in a fast and cost-effective way. Our hypothesis is that the spatial distribution of different plant associations as well as the spatial variability of vegetation biomass may provide important information for mapping the spatial distribution of peat properties, thus making remote sensing an effective method for peatland studies.
In this work, we present the results obtained by using data collected by Unmanned Aerial Vehicles (UAVs) on the Val di Ciampo alpine peatland (Province of Belluno, northeast Italy) in July 2021. LiDAR data, hyperspectral data and aerial digital photos were simultaneously collected on an area of 88.000 m2. Field observations and measurements were performed in the same period, providing georeferenced ground information on vegetation and peat characteristics. Peat and vegetation samples were collected and analyzed in the lab. For each vegetation association we measured the height of plants and determined their above- and below-ground biomass based on 20 above-ground and 15 below-ground samples. As for the peat, we measured the peat thickness and determined the bulk density and the organic carbon content of 46 samples.
Our results show that some of the correlations found between the parameters that characterize different vegetation associations can be used to calibrate the data collected by UAVs and extend the results from point locations to the entire peatland. For example, we found that the aboveground biomass is significantly correlated (r = 0.81, p < 0.001) to the local average vegetation height, therefore both LiDAR data and the Digital Surface Model (DSM) extracted from the photos can be used to estimate and map the vegetation aboveground biomass. The correlation between the surface microtopography and the aboveground biomass will also be presented, as well as other correlations between vegetation patterns and peat depth and properties. The significance of combining UAVs multi-sensor data with field observations for the characterization of Alpine peatlands will be discussed
VERSO LA SCOPERTA GUIDATA: CONGIUNZIONI E AVVERBI ANAFORICI, COORDINAZIONE E GIUSTAPPOSIZIONE
Una sfida interessante nel campo della didattica è senza dubbio mettere alla prova gli apporti teorici della riflessione linguistica attraverso la sperimentazione sul campo, ovvero in classe. È quanto è stato fatto in due classi seconde di una scuola secondaria di primo grado di Vicenza e in una classe terza di una secondaria di primo grado di Padova: alle alunne e agli alunni che partecipavano alla sperimentazione sono stati sottoposti esercizi e materiale didattico per distinguere congiunzioni da avverbi anaforici e coordinazione da giustapposizione. I risultati sono stati estremamente interessanti: sono emerse la capacità di distinguere i fenomeni nonostante le grammatiche tradizionali in uso, la volontà di mettere in discussione regole acquisite e la possibilità di portare all’interno della scuola, attraverso la pratica, le innovazioni proposte dagli studi accademici.
Towards guided discovery: anaphoric conjunctions and adverbs, coordination and juxtaposition
An interesting challenge in the field of didactics is undoubtedly to test the theoretical contributions of linguistic reflection through field applications, i.e. in the classroom. This is what was done in two classes attending the second year at a secondary school in Vicenza and in a class of the third year at a secondary school in Padua: the pupils participating in the experimentation were given exercises and teaching material to distinguish conjunctions from anaphoric adverbs and coordination from juxtaposition. The results were extremely interesting, showing the ability to distinguish phenomena in spite of the traditional grammars in use, the willingness to question acquired rules and the possibility of bringing the innovations proposed by academic studies into school practice
Why donate and for what? The pseudoinefficacy bias in donating behavior
Charitable donations represent a possible indirect way to face the social challenge of poverty with people donating a certain amount of money independently of their social status and social roles. As such, scholarly authors devoted to the study of charity and donating behavior have proposed several models following different perspectives to explain the motivational factors and the individual conditions affecting donating behavior. In the present study, we aim at contributing to the selfish altruism model by suggesting the effect of pseudoinefficacy as possible cognitive bias which may be detrimental for deciding to donate. On the one hand, the selfish altruism model has gained notable attention as a possible explanation of the decision-making process underlying donating behavior. This model suggests that people offer aid to receive something in return or to gain a personal advantage. Such a personal benefit can be seen as the individual sense of being morally satisfied, namely, warm-glow. That is, those who donate may feel higher levels of social esteem, gratitude and respect from others which are aspects feeding their warm-glow. Individual would decide to donate by the possibility to gain moral satisfaction rather than acting for the common good. On the other hand, according to cognitive psychology, pseudoinefficacy may affect donating behaviors as an illusion of inefficacy that arises when individuals can only help some people but not others who yet are equally in need. In this sense, the phenomenon of pseudoinefficacy contributes to the selfish altruism model as an explanation of the individuals’ emotions that may reduce donors’ warm-glow. Ultimately, we propose a critical and interdisciplinary review of donating behaviors model and propose a research agenda for further investigations. Given the widespread of poverty as linked to the worldwide changes (i.e., novel pandemic of Sars-Cov-2), theoretical indications and reflections on donating behavior represent a pragmatic and moral concern whose relevance rests in the potential applied implications
Difficulties in the Mutation Analysis of Plasminogen Gene: A Study in Two Patients with Ligneous Conjunctivitis
The absence or very low levels of plasminogen cause a rare disabling disease called ligneous conjunctivitis, characterized by the growth of fibrin-rich pseudomembranes in the conjunctiva and on other mucosal surfaces. Several mutations have been detected in the plasminogen gene of patients affected with ligneous conjunctivitis. The human plasminogen gene, located on chromosome 6, has a marked homology with the genes belonging to the plasminogenapo(a) family, and with a number of pseudogenes and plasminogen-like genes located on chromosome 2. This work describes a series of nucleotide variations related to genes other than the plasminogen one, found during the genetic characterization of plasminogen defect in two unrelated patients with ligneous conjunctivitis. The results of automated sequences of each exon and intron-exon boundaries were compared with those of the human plasminogen gene from the NCBI gene bank. In particular, a co-amplified gene on chromosome 2 mimicking a 14 bp deletion in exon 5 of the plasminogen gene was identified by sequencing two different bands obtained from a long run of the PCR exon 5 product in NuSieve agarose gel, and by PstI restriction enzyme analysis of the same amplicons. Moreover, 21 single nucleotide exchanges due to plasminogen-like genes co-amplification were observed, namely one in exon 1, two in exon 4, three in exons 3, 5 and 16, four in exon 13, and five in exon 17. In conclusion, these data confirm the difficulty of plasminogen genetic analysis and may help researchers to better identify the true plasminogen gene mutations causing molecular defects
Neoadjuvant platinum-based chemotherapy followed by radical hysterectomy for stage Ib2-IIb adenocarcinoma of the uterine cervix – An Italian multicenter retrospective study
Understanding net-zero energy buildings: evaluation of load matching and grid interaction indicators
ABSTRACT Although several alternative definitions exist, a NetZero Energy Building (Net ZEB) can be succinctly described as a grid-connected building that generates as much energy as it uses over a year. The "net-zero" balance is attained by applying energy conservation and efficiency measures and by incorporating renewable energy systems. While based on annual balances, a complete description of a Net ZEB requires examining the system at smaller time-scales. This assessment should address: (a) the relationship between power generation and building loads and (b) the resulting interaction with the power grid. This paper presents and categorizes quantitative indicators suitable to describe both aspects of the building's performance. These indicators, named LMGI -Load Matching and Grid Interaction indicators, are easily quantifiable and could complement the output variables of existing building simulation tools. The indicators and examples presented here deal only with electric generation and loads
Efficacy and safety of ketamine for neonatal refractory status epilepticus: case report and systematic review
BackgroundEvidence-based data on treatment of neonatal status epilepticus (SE) are scarce. We aimed to collect data on the efficacy and safety of ketamine for the treatment of neonatal SE and to assess its possible role in the treatment of neonatal SE.MethodsWe described a novel case and conducted a systematic literature review on neonatal SE treated with ketamine. The search was carried out in Pubmed, Cochrane, Clinical Trial Gov, Scopus and Web of Science.ResultsSeven published cases of neonatal SE treated with ketamine were identified and analyzed together with our novel case. Seizures typically presented during the first 24 h of life (6/8). Seizures were resistant to a mean of five antiseizure medications. Ketamine, a NMDA receptor antagonist, appeared to be safe and effective in all neonates treated. Neurologic sequelae including hypotonia and spasticity were reported for 4/5 of the surviving children (5/8). 3/5 of them were seizure free at 1–17 months of life.DiscussionNeonatal brain is more susceptible to seizures due to a shift towards increased excitation because of a paradoxical excitatory effect of GABA, a greater density of NMDA receptors and higher extracellular concentrations of glutamate. Status epilepticus and neonatal encephalopathy could further enhance these mechanisms, providing a rationale for the use of ketamine in this setting.ConclusionsKetamine in the treatment of neonatal SE showed a promising efficacy and safety profile. However, further in-depth studies and clinical trials on larger populations are needed
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