Analysis of the Influence of the Length Scales in a Boundary-Layer Model

AbstractWe consider the Janjic (NCEP Office Note 437:61, 2001) boundary-layer model, which is one of the most widely used in numerical weather prediction models. This boundary-layer model is based on a number of length scales that are, in turn, obtained from a master length multiplied by constants. We analyze the simulation results obtained using different sets of constants with respect to measurements using sonic anemometers, and interpret these results in terms of the turbulence processes in the atmosphere and of the role played by the different length scales. The simulations are run on a virtual machine on the Chameleon cloud for low-wind-speed, unstable, and stable conditions

A LAGRANGIAN PARTICLE MODEL WITH CHEMICAL REACTIONS: APPLICATION IN REAL ATMOSPHERE

In this work a lagrangian particle model able to account for simple chemical reactions between NO and O3 (Alessandrini et al., 2007) has been improved in order to consider the photolysis of NO2. A system of chemical equations is numerically solved on an eulerian grid, while the particles trajectories are moved in a lagrangian frame. The NOx emissions of a power plant in real atmosphere, situated in a complex topography environment, have been considered as a test case. The meteorological model RAMS has been applied to build the wind field together with the interface code MIRS to compute turbulence parameters, requested for the dispersion simulations. The plume transitions over an air quality station, allowing for a comparison between the measured and computed concentrations of all the reaction’s compounds (NO, NO2 and O3), have been simulated by the lagrangian particle model. The simulated episodes refer to the diurnal time, when the ultraviolet radiation activates the NO2 photolysis making necessary the model complete set of chemical equations. In order to reduce computational cost and improve the accuracy of the background O3 concentration representation, the concept of concentration deficit carried by the particles is proposed and tested. This new method does not need to release a big amount of particles filling the whole domain, but only the inside plume particles should be accounted for. Comparisons between NO/NO2’s concentrations ratio are presented in term of scatter plots and statistical indexes analysis. The satisfactory results suggest that the model can be used in practical applications in real atmosphere also for regulatory purposes when the NO2 concentration limits are imposed by the legislation

Nonlocal Treatment of the Buoyancy-Shear-Driven Boundary Layer

Abstract A successful description of a convective boundary layer requires that the model employed takes into account the nonlocal nature of turbulent convection. In this paper new third-order moments (TOMs) are presented and tested. Numerical solutions are obtained using mean flow components and second-order moments as input. The problem of the turbulent damping of the TOMs is considered. The terms in the dynamic equations responsible for the unphysical growth of the TOMs are parameterized, taking into account their dependence on the integral length scale vertical profile. The calculated profiles are presented and tested against large-eddy simulation data and aircraft measurements. In both cases the results compare favorably

SoxNeuro orchestrates central nervous system specification and differentiation in Drosophila and is only partially redundant with Dichaete.

BACKGROUND: Sox proteins encompass an evolutionarily conserved family of transcription factors with critical roles in animal development and stem cell biology. In common with vertebrates, the Drosophila group B proteins SoxNeuro and Dichaete are involved in central nervous system development, where they play both similar and unique roles in gene regulation. Sox genes show extensive functional redundancy across metazoans, but the molecular basis underpinning functional compensation mechanisms at the genomic level are currently unknown. RESULTS: Using a combination of genome-wide binding analysis and gene expression profiling, we show that SoxNeuro directs embryonic neural development from the early specification of neuroblasts through to the terminal differentiation of neurons and glia. To address the issue of functional redundancy and compensation at a genomic level, we compare SoxNeuro and Dichaete binding, identifying common and independent binding events in wild-type conditions, as well as instances of compensation and loss of binding in mutant backgrounds. CONCLUSIONS: We find that early aspects of group B Sox functions in the central nervous system, such as stem cell maintenance and dorsoventral patterning, are highly conserved. However, in contrast to vertebrates, we find that Drosophila group B1 proteins also play prominent roles during later aspects of neural morphogenesis. Our analysis of the functional relationship between SoxNeuro and Dichaete uncovers evidence for redundant and independent functions for each protein, along with unexpected examples of compensation and interdependency, thus providing new insights into the general issue of transcription factor functional redundancy

Ecological Relevance of Hemolymph Total Protein Concentration in Seven Unrelated Crustacean Species from Different Habitats Measured Predictively by a Density-Salinity Refractometer

In recent years, blood metabolites have been investigated as a tool for monitoring physiological condition in wild or cultured crustaceans exposed to different environmental conditions. Blood protein levels fluctuate with changes in environmental and physiological conditions and play fundamental roles in the physiology of crustaceans from O2 transport to reproduction up to stress responses. Proteins are major contributors to hemolymph density, and the present study correlates the easy and low cost measure of hemolymph density by a density-salinity refractometer with the total protein concentration, measured with a colorimetric method. Moreover, the study evaluates the accuracy of the relationship and provides a conversion factor from hemolymph density to protein in seven species of crustaceans, representative of taxa far apart in the phylogenetic tree and characterized by different life habits. Measuring serum-protein concentration by using a refractometer can provide a non-destructive field method to assess crustacean populations/species protein-related modifications of physiological state without need of costly laboratory facilities and procedures

I FABBISOGNI DEI TERRITORI, L’AGENDA ONU 2030 E L’OFFERTA FORMATIVA UNIVERSITARIA

La diffusione del Covid19 ha indubbiamente generato un’amplificazione delle preoccupazioni destate dalle emergenze climatiche e ambientali. Ne è emersa una geografia che, mentre in una prospettiva globale presenta caratteri di omogeneità, a scala locale e regionale rivela dinamiche e velocità diversificate: e questo sia con riferimento ai risvolti negativi prodotti dalla crisi e dalla pandemia, sia in relazione alle politiche adottate a livello europeo ed internazionale in ottica sostenibile. Sono mutati i fabbisogni dei territori e al contempo le relazioni tra gli attori economici e sociali che ne determinano le traiettorie evolutive. Pur nella condivisione di macro obiettivi dettati dall’Agenda ONU 2030, e rimarcati dalla strategia europea correlata al Green Deal, si registrano in Italia criticità numerose e tali per cui il rilancio degli investimenti e l’attenzione per le politiche ambientali devono andare di pari passo verso un’economia green e circolare. Da più parti viene invocato un intervento sinergico di Governo, Istituzioni e Parti Sociali per investire su settori strategici, fra cui ricerca e formazione, generando nuove competenze “verdi”, orientate alla tutela dell’ambiente e alla sostenibilità secondo un approccio interdisciplinare. In questa cornice, il lavoro si propone di presentare strategie e azioni con cui l’Università del Piemonte Orientale sta affrontando le tematiche dell’ambiente e della sostenibilità, evidenziando in particolare come la progettazione di due nuovi corsi di laurea consenta di condensare e fertilizzare spinte endogene ed esogene, includendo metodi e percorsi geografici innovativi. Questa visione integrata favorisce il consolidamento dei processi di migrazione alla sostenibilità su vari piani, dalla società civile al contesto industriale, dagli istituti scolastici al no profit e terzo settore, in modo da avviare un processo di accompagnamento alla sostenibilità tour court dell’intera società in modo armonico e sinergico

I sistemi agrovoltaici tra cambiamento climatico e nuove sfide per l’imprenditore agricolo contemporaneo

The rising demand for food and solar power generation will lead to increase more competition in land use that is a nonreplicable commodity. This can lead to potential economic and social conflicts with an alarming reduction of land destined for agricultural production. Considering the mitigation and adaptation actions that climate change requires, a solution to these critical issues could be to produce food and energy within an agrivoltaic system. In Italy, agrivoltaic is implemented thanks to the PNRR measures and, thus, the agricultural enterprise has an opportunity for innovation that appears significant

Emergenza climatica e ambientale: lezioni dalla pandemia

Gli autori ragionano sul legame fra lockdown e inquinamento urbano e, sulla base dei dati relativi a Milano e Torino, mostrano che durante questo blocco prolungato si \ue8 rilevata una moderata riduzione di uno solo degli inquinanti pi\uf9 pericolosi per la nostra salute. Da ci\uf2 gli autori deducono che per affrontare emergenze globali, come le pandemie, l\u2019inquinamento e i cambiamenti climatici, sono necessarie misure programmatiche da attuare con coraggio per tempi lunghi

The role of Dichaete in transcriptional regulation during Drosophila embryonic development.

BACKGROUND: Group B Sox domain transcription factors play conserved roles in the specification and development of the nervous system in higher metazoans. However, we know comparatively little about how these transcription factors regulate gene expression, and the analysis of Sox gene function in vertebrates is confounded by functional compensation between three closely related family members. In Drosophila, only two group B Sox genes, Dichaete and SoxN, have been shown to function during embryonic CNS development, providing a simpler system for understanding the functions of this important class of regulators. RESULTS: Using a combination of transcriptional profiling and genome-wide binding analysis we conservatively identify over 1000 high confidence direct Dichaete target genes in the Drosophila genome. We show that Dichaete plays key roles in CNS development, regulating aspects of the temporal transcription factor sequence that confer neuroblast identity. Dichaete also shows a complex interaction with Prospero in the pathway controlling the switch from stem cell self-renewal to neural differentiation. Dichaete potentially regulates many more genes in the Drosophila genome and was found to be associated with over 2000 mapped regulatory elements. CONCLUSIONS: Our analysis suggests that Dichaete acts as a transcriptional hub, controlling multiple regulatory pathways during CNS development. These include a set of core CNS expressed genes that are also bound by the related Sox2 gene during mammalian CNS development. Furthermore, we identify Dichaete as one of the transcription factors involved in the neural stem cell transcriptional network, with evidence supporting the view that Dichaete is involved in controlling the temporal series of divisions regulating neuroblast identity.This work was supported by a Medical Research Council scholarship