Parallel performance prediction for multigrid codes on distributed memory architectures

We propose a model for describing the parallel performance of multigrid software on distributed memory architectures. The goal of the model is to allow reliable predictions to be made as to the execution time of a given code on a large number of processors, of a given parallel system, by only benchmarking the code on small numbers of processors. This has potential applications for the scheduling of jobs in a Grid computing environment where reliable predictions as to execution times on different systems will be valuable. The model is tested for two different multigrid codes running on two different parallel architectures and the results obtained are discussed

Parallel performance prediction for numerical codes in a multi-cluster environment

We propose a model for describing and predicting the performance of parallel numerical software on distributed memory architectures within a multi-cluster environment. The goal of the model is to allow reliable predictions to be made as to the execution time of a given code on a large number of processors of a given parallel system, and on a combination of systems, by only benchmarking the code on small numbers of processors. Thishas potential applications for the scheduling of jobs in a Grid computing environment where informed decisions about which resources to use in order to maximize the performance and/or minimize the cost of a job will be valuable. The methodology is built and tested for a particular class of numerical code, based upon the multilevel solution of discretized partial differential equations, and despite its simplicity it is demonstrated to be extremely accurate and robust with respect to both the processor and communications architectures considered. Furthermore,results are also presented which demonstrate that excellent predictions may also be obtained for numerical algorithms that are more general than the pure multigrid solver used to motivate the methodology. These are based upon the use of a practical parallel engineering code that is briefly described. The potential significance of this work is illustrated via two scenarios which consider a Grid user who wishes to use the available resources either (i) to obtain a particular result as quickly as possible, or (ii) to obtain results to different levels of accuracy. Index Terms—Parallel Distributed Algorithms; Grid Computing; Cluster Computing; Performance Evaluation and Prediction; Meta-Scheduling

Effects of Commercial Natural Compounds on Postharvest Decay of Strawberry Fruit

Gray mold and Rhizopus rot, which is caused by Botrytis cinerea and Rhizopus stolonifer, respectively, are the most destructive forms of postharvest decay of the strawberry fruit. In this work, we tested the effectiveness of the control on the postharvest decay of the strawberry fruit (Fragaria x ananassa Duch cv. 'Monterey') following postharvest applications of six commercial natural compounds: chitosan-based coating compound (1% of 'ChitP', 'ChitS', 'ChitK', 'ChitO'), commercial essential oil (EOs) products based on grapefruit seed extract (0.5% of 'GraFr'), sweet orange (0.5% of 'SwOr'), a product that included eugenol, geraniol, and thymol EO, (0.4% of 'EuGeTh'), an organic compound as humic acid (0.5% w/v of 'HuAc'), and, lastly, methyl jasmonate plant growth regulator (1% v/v 'MeJA'). Strawberries were dipped in solution for 30 s and incubated at room temperature (20 +/- 0.5 degrees C) or at cold storage conditions (4 +/- 0.5 degrees C) following 4 days of shelf life at 20 degrees C. The treatments with 'ChitP', 'ChitS', and 'ChitO' provided similar to 30%-40% reduction of gray mold in cold storage conditions, while the 'MeJA', 'SwOr', and 'GraFr' with high activities of volatile substances were more effective at controlling gray mold at room temperature. 'HuAc', 'ChitK', and 'ChitO' were more effective at controlling Rhizopus rot in both cold storage (similar to 50%) and room temperature conditions

(Dis)orientamento politico e precariet\ue0 lavorativa come fattori di rischio di esclusione sociale: i giovani italiani tra crisi e prospettive. Uno studio di caso

The author investigates the \u201cyouth universe\u201d in Italy; specifically, the hard relationship between it and politics and institutions, characterized by a lack of trust and credibility. The question of the absence of work makes the Italian case unique and exemplary: young people are precarious, inadequately paid. Unemployment, the late age to the first job and atypical contracts impoverish young people of the potential wealth they could carry around: innovation, change, planning, growth and future; all that exclude them from the country\u2019s decision-making processes. Thus, housing autonomy and economic independence are postponed, hence the transition to adulthood. Deprived of the fixed points that guided previous generations, today\u2019s young people do not recognize themselves into any ideology, do not feel represented by any political force. An investigation carried out close to the elections of March 4, 2018 confirmed what has been exposed so far and noted that the consequent discontent found a possibility of expression and change in the neophyte Movimento 5 Stelle. Therefore, it is appropriate to ask ourselves what are the motivations and conditions that have led young people, disappointed and disillusioned, to move away from \u201ctraditional politics\u201d. It is urgent to promote a cultural revolution to give young Italians the role of protagonists of present, backed by tradition but making space to the new and welcoming the future. Which role does the family play as the primary agency for political education? What proposal can make pedagogy of family educational relationships

Dal bambino libero all’uomo autonomo: educare alla scelta attraverso il metodo Montessori

Freedom, autonomy and responsibility are the ends of every educational process, especially in the modern society: globalized, rapid, in transformation; society in which each one of us is called to make numerous choices. Therefore, it is urgent to educate to choose and educate to the choice, so that young people can emancipate themselves from possible conditionings. To this end, the Montessori method represents a privileged way: child is free to choose his own activity and learns “to do by himself” soon; the teacher prepares the environment and the materials that allow the student to satisfy the educational needs of each period of inner development. Then, Montessori gives importance to adolescence because it is during this period that grows the social man. Consequently, it is important to reform the secondary school in order to acquire the autonomy that each student will apply to the subsequent school grades and to all areas of life

Piccole “femmine” crescono. La donna nella pop-modernità

A partire dai pesanti condizionamenti culturali che gravavano sull’educazione dei bambini e delle bambine nella società patriarcale, fortemente ancorata alle differenze di genere, l’autore si chiede se e in quale misura persistano, oggi, tali stereotipi. A tal fine, viene analizzata, e, talvolta, smascherata, la logica subliminale sottesa alla pubblicità, ai giocattoli, ai cartoni animati: dai classici ai più recenti, e, finanche, ai libri di testo scolastici. In molti casi, emerge un vero e proprio processo di induzione e allenamento dei più piccoli ad assumere, nel futuro, i tradizionali ruoli stereotipati. Seppure non trascurabili sono i danni causati ai bambini, castrati soprattutto nell’emotività, il bilancio risulta nettamente a sfavore delle bambine. Queste, infatti, vengono avviate a una precoce iperfemminilizzazione e persuase che la seduttività sia l’unico potere di cui dispongano. In chiave pedagogica, questo fenomeno viene colto anche come conseguenza dell’assenza o carenza della figura paterna, in quanto luogo di promozione della differenza. Pertanto, l’apertura progettuale si dà in una inedita paternità tenera. La riflessione si conclude nel segno della speranza, testimoniata da alcune principesse pop-moderne che, emancipandosi, si sono salvate da sole

DAD e LEAD: nuove forme di partenariato tra sistema educativo-formativo e famiglie

In emergenza pandemica da Coronavirus, l\u2019umanit\ue0 intera \ue8 stata chiamata a raccolta affinch\ue9 ognuno assumesse l\u2019impegno di dare il proprio prezioso contributo al contenimento del contagio per tutelare la salute di tutti. Il tributo pagato da ciascuno \ue8 stato elevatissimo in termini economici, sociali e relazionali. Molti hanno pagato con la propria vita. In campo educativo, i LEAD (Legami Educativi A Distanza) e la DAD (Didattica A Distanza) hanno tentato di \u201cridurre il danno e l\u2019impatto\u201d del distanziamento sociale a carico degli alunni, rispettivamente degli asili nido e della scuola dell\u2019infanzia, i primi; della scuola primaria e secondaria, la seconda. I limiti oggettivi dettati dalla carenza e/o inadeguatezza dei mezzi, degli strumenti e dei materiali a disposizione in casa, o altrimenti reperibili, in tempo di lockdown hanno rappresentato inconfutabili criticit\ue0 per gli alunni e le loro famiglie, tanto quanto per gli insegnanti. Questi ultimi sono stati, sovente, soggetti ad accuse di pretenziosit\ue0 sproporzionata rispetto alle reali possibilit\ue0 contingenti di ciascun allievo. Le famiglie, dal canto loro, hanno dovuto confrontarsi con una \u201cprossimit\ue0\u201d abitativa, emotiva e relazionale tra i vari componenti, a cui i tempi lavorativi le avevano disabituate. Il presente contributo intende superare le accuse e le forme di reciproco ostracismo tra sistemi educativo-formativi e famiglie per sottolineare, di contro, l\u2019imprescindibilit\ue0 di forme inedite di partenariato. Solo la collaborazione tra gli agenti sociali consente di oltrepassare l\u2019isolamento e l\u2019individualismo in favore di una comunit\ue0 educante alla resilienza, al processo e al divenire, pi\uf9 che al risultato

Preharvest Chitosan and Postharvest UV Irradiation Treatments Suppress Gray Mold of Table Grapes

The effectiveness of chitosan treatment of table grapes, alone or in combination with ultraviolet-C (UV-C) radiation, to control postharvest gray mold caused by Botrytis cinerea, was determined in California, United States. The influence of these treatments on catechin and resveratrol contents and chitinase activity in grape berry skins also was assessed. Clusters of cvs. Thompson Seedless, Autumn Black, and Emperor were sprayed in the vineyard with 1% chitosan, then harvested daily for 5 days. Promptly after harvest, they were inoculated with B. cinerea. Decay incidence and disease severity were significantly reduced by chitosan, which was most effective on berries harvested 1 or 2 days after treatment. In another experiment, grape berries were sprayed in the vineyard with chitosan, harvested 2 days later, irradiated for 5 min with UV-C (0.36 J/cm2), and inoculated with B. cinerea 2 days later. Combined chitosan and UV-C treatments applied to cv. Autumn Black or selection B36-55 were synergistic in reducing gray mold incidence and severity compared with either treatment alone. Preharvest chitosan treatment increased neither concentration of catechin or resveratrol nor activity of chitinase in berry skin. Conversely, UV-C irradiation, alone or combined with chitosan treatment, induced catechin in cv. Autumn Black berries and trans-resveratrol in both cv. Autumn Black and selection B36-55