Cohomological aspects on complex and symplectic manifolds

We discuss how quantitative cohomological informations could provide qualitative properties on complex and symplectic manifolds. In particular we focus on the Bott-Chern and the Aeppli cohomology groups in both cases, since they represent useful tools in studying non K\"ahler geometry. We give an overview on the comparisons among the dimensions of the cohomology groups that can be defined and we show how we reach the $\partial\overline\partial$-lemma in complex geometry and the Hard-Lefschetz condition in symplectic geometry. For more details we refer to [6] and [29].Comment: The present paper is a proceeding written on the occasion of the "INdAM Meeting Complex and Symplectic Geometry" held in Cortona. It is going to be published on the "Springer INdAM Series

Variational Problems in Conformal Geometry

We study the Euler–Lagrange equation for several natural functionals defined on a conformal class of almost Hermitian metrics, whose expression involves the Lee form θ of the metric. We show that the Gauduchon metrics are the unique extremal metrics of the functional corresponding to the norm of the codifferential of the Lee form. We prove that on compact complex surfaces, in every conformal class there exists a unique metric, up to multiplication by a constant, which is extremal for the functional given by the L2-norm of d Jθ, where J denotes the complex structure. These extremal metrics are not the Gauduchon metrics in general, hence we extend their definition to any dimension and show that they give unique representatives, up to constant multiples, of any conformal class of almost Hermitian metrics

Eficiencia de riego en el área de riego del Rio Dulce

The Río Dulce Irrigation System is located in the province of Santiago del Estero, Argentina. The system water use efficiency was calculated as 36%. This figure can be ascribed to: 1- inadequate on-farm irrigation management; 2- poor maintenance of canal network. Application of very high depths provokes the water table to rise, resulting in a secondary salinization process. Present paper deals with on-farm irrigation performance. Its main objectives are: 1- to study on-farm irrigation performance; 2- to evaluate on-farm irrigation performance indicators. Data were arranged in two groups. Application efficiency was calculated as 40% for both Group 1 and Group 2. However, causes and consequences are different for each group, depending on irrigation practices. Application efficiency was preferred more than storage efficiency as an indicator of adequacy, while standard deviation is not recommended here as a good indicator of uniformity. Others uniformity indicators (coefficient of variation, Christiansen¿s coefficient and distribution uniformity) had a similar behaviour, being all of them appropriate to evaluate uniformity. It is stressed that no single indicator is able to describe on-farm irrigation performance by itself, but a reasonable number of them can provide valuable information for decision making

A comparison between asymmetric rolling and accumulative roll bonding as means to refine the grain structure of an Al-Mg-Si alloy

The possibility of refining the grain structureof a commercial Al-Mg-Si alloy wasevaluated using asymmetric rolling (ASR) andaccumulative roll bonding (ARB) in the severeplastic deformation (SPD) regime. Bars ofannealed alloy having a thickness of 10 mmwere asymmetrically rolled down to athickness of 0.23 mm with a laboratoryrolling mill featuring the possibility ofindependently modifying the rotational speedof its two rolls. The effect of the rollingtemperature was investigated by tests in therange 150-250°C. A parallel campaign wasalso conducted to investigate the effects ofwarm accumulative roll bonding of the samealloy and in the same temperature range.These tests were carried out on annealedsamples of 1 mm thickness. The experimentalcharacterization (both mechanical andm i c ro s t ructural) demonstrated thatasymmetric rolling and accumulative rollbonding can readily promote the achievementof ultrafine grained structures in Al-Mg-Sialloys

Analisi del comportamento a creep della superlega Nimonic 263

Il comportamento a creep della superlega Nimonic 263 è stato studiato a carico e temperatura costantenell’intervallo 750-30MPa/600-950°C. I risultati sperimentali hanno mostrato che la forma della curva dicreep dipende fortemente dalle sollecitazioni applicate. Nelle prove eseguite a sollecitazioni superiori al caricodi snervamento, le curve di creep consistono essenzialmente nel solo stadio primario/decelerante, mentre persollecitazioni inferiori, ed in particolare ai più bassi carichi ed elevate temperature qui studiati, lo stadioprimario diventa molto piccolo e breve, ed altri stadi di deformazione dominano le curve di creep.In questo lavoro si dimostra che un’unica e semplice equazione costitutiva, basata sulla moltiplicazione eannichilazione delle dislocazioni mobili, è in grado di descrivere e interpolare correttamente le curve di creepin tutto l’intervallo di sollecitazioni/temperature esplorat

Sviluppo di microstrutture in campioni di argento sottoposti a deformazione plastica severa

Il lavoro presenta i risultati di indagini svolte su campioni di Ag commercialmente puro sottoposti adeformazione plastica severa mediante tecnica ECAP e attraverso laminazione asimmetrica a freddo. È statastudiata l’evoluzione della microstruttura e delle proprietà meccaniche al variare della deformazione impartita,rispettivamente mediante tecniche SEM / TEM e attraverso misure di durezza e prove di trazione. L’argentoè stato scelto come materiale rappresentativo dei metalli a struttura FCC con bassa energia dei difetti diimpilamento e quindi elevata possibilità di deformazione assistita da geminati. In letteratura esistono limitateinformazioni sull’evoluzione della struttura ultrafine di questi metalli nel regime di deformazione plasticasevera. I dati vengono discussi considerando l’evoluzione della struttura derivante dalle specifiche tecniche dideformazione e le proprietà raggiunte

Analisi microchimica mediante SPEM di una superlega di Nichel dopo prove di creep

Lo scopo di questo lavoro è mostrare le potenzialità delle analisi micro-chimiche di superficie, in particolare laspettroscopia Scanning PhotoEmission Microscopy (SPEM) ad alta risoluzione, nello studio dei fenomeni diffusiviche hanno luogo fra le fasi g e g’ nelle superleghe di Ni a seguito del creep. Si riportano le analisi condotte su unasuperlega monocristallina, CM186LC, prima e dopo prove di creep alle temperature di 800 e 900 °C.Le misure di fotoemissione ai raggi X (XPS) ad elevata risoluzione spaziale sono state effettuate presso labeam-line ESCA-microscopy del sincrotrone Elettra di Trieste, in cui è stato utilizzato lo SPEM, che opera inmodalità sia di immagine che di spettroscopia puntuale, producendo una microsonda a raggi X di diametroinferiore a 50 nm. L’alta risoluzione permette di esaminare separatamente la composizione chimica della faserinforzante g’ e della matrice g caratterizzanti la superlega. In questo modo è possibile studiare la partizionedegli elementi di lega tra le fasi nel materiale vergine e la sua evoluzione dopo le prove di creep

Anopheles darlingi polytene chromosomes: revised maps including newly described inversions and evidence for population structure in Manaus

Salivary gland polytene chromosomes of 4th instar Anopheles darlingi Root were examined from multiple locations in the Brazilian Amazon. Minor modifications were made to existing polytene photomaps. These included changes to the breakpoint positions of several previously described paracentric inversions and descriptions of four new paracentric inversions, two on the right arm of chromosome 3 and two on the left arm of chromosome 3 that were found in multiple locations. A total of 18 inversions on the X (n = 1) chromosome, chromosome 2 (n = 7) and 3 (n = 11) were scored for 83 individuals from Manaus, Macapá and Porto Velho municipalities. The frequency of 2Ra inversion karyotypes in Manaus shows significant deficiency of heterozygotes (p < 0.0009). No significant linkage disequilibrium was found between inversions on chromosome 2 and 3. We hypothesize that at least two sympatric subpopulations exist within the An. darlingi population at Manaus based on inversion frequencies

Using the Kolb’s experiential learning cycle to explore the extent of application of one health competencies to solving global health challenges; a tracer study among AFROHUN-Uganda alumni

Background The Africa One Health University Network (AFROHUN) with support from the United States Agency for International Development (USAID), has since 2012 conducted pre and in-service One health (OH) trainings with the objective of improving global health security. These trainings aim to build competencies that, enhance a multidisciplinary approach to solving global health challenges. Despite the investment in OH trainings, there is limited documentation of the extent of acquisition and application of the OH competencies at workplaces. This tracer study explored the extent of acquisition and application of the OH competencies by the AFROHUN-Uganda alumni. Methods A cross-sectional study was conducted among a random sample of 182 AFROHUN-Uganda alumni of 2013–2018 cohorts. A blended approach of interviewer-administered and self-administered questionnaires was used. Virtual platforms such as Zoom, Microsoft teams, and Skype, and phone interviews were used to collect data when face-to-face interactions with alumni were not possible. Data were collected electronically, either through a link or with the aid of the KoboCollect mobile application, pre-installed on android enabled devices, and analysed using STATA14.0. Results The majority of respondents, 78.6% (143/182) had jobs that required application of OH knowledge and skills, 95.6% (174/182) had learned employable skills from OH activities and 89.6% (163/182) had applied such skills when searching for employment. About 21.7% (34/180) to a very high extent required OH field-specific theoretical knowledge at their workplaces, 27.4% (43/80) to a very high extent required OH field-specific practical knowledge/skills, 42.7% (67/180) to a high extent required a change in attitude and perceptions towards working with people from different disciplines, 49.0% (77/180) required collaboration and networking skills, and more than half, 51.0% (80/180) required team building skills. Conclusions The majority of OH alumni to a very high extent acquired and applied OH competences such as teamwork, effective communication, community entry and engagement, report writing and problem-solving skills. This study revealed the significant contribution of the AFROHUN Uganda OH activities towards supportive work environments, and highlights areas of improvement such as supporting the trainees to acquire people-management skills, innovation, and an entrepreneurial mind set