Cosmic voids in coupled dark energy cosmologies: the impact of halo bias

In this work we analyse the properties of cosmic voids in standard and coupled dark energy cosmologies. Using large numerical simulations, we investigate the effects produced by the dark energy coupling on three statistics: the filling factor, the size distribution and the stacked profiles of cosmic voids. We find that the bias of the tracers of the density field used to identify the voids strongly influences the properties of the void catalogues, and, consequently, the possibility of using the identified voids as a probe to distinguish coupled dark energy models from the standard $\Lambda$CDM cosmology. In fact, on one hand coupled dark energy models are characterised by an excess of large voids in the cold dark matter distribution as compared to the reference standard cosmology, due to their higher normalisation of linear perturbations at low redshifts. Specifically, these models present an excess of large voids with $R_{eff}>20, 15, 12$ Mpc h^{-1}, at $z=0, 0.55, 1$, respectively. On the other hand, we do not find any significant difference in the properties of the void detected in the distribution of collapsed dark matter halos. These results imply that the tracer bias has a significant impact on the possibility of using cosmic void catalogues to probe cosmology.Comment: 11 pages, 8 figures and 2 tables. Submitted to MNRA

Integrating literacy into the math classroom : a staff development for innovative educators

With the collaboration and advice of several mentors and practicing teachers, I found using strategies proven to help students during literacy instruction also had the same effect during mathematics instruction. I took various instructional activities, focused around using reading and writing skills in math, and was able to effectively instruct this group of students. This experience piqued my interest in the connection between literacy and mathematics. As a result, I decided to continue my research into how to effectively integrate these two core subject areas, investigating the efficacy of combining mathematics with literacy instruction

Il monitoraggio della portata cardiaca in terapia intensiva: confronto tra tecniche .

Il monitoraggio emodinamico oggi gioca un ruolo importante nella gestione del paziente ricoverato in terapia intensiva. Consiste nella rilevazione seriata dei diversi parametri emodinamici, dati che, opportunamente elaborati, consentono un' approfondita analisi della funzione cardiocircolatoria, finalizzata ad un esatto programma diagnostico e terapeutico. In Terapia Intensiva la valutazione dello stato emodinamico può essere utile per valutare lo stato della volemia e la sua relazione con la funzione cardiaca; la qualità dell’ attivita’ contrattile del cuore e della performance circolatoria; la bontà della perfusione d’organo, in particolare per gli organi "nobili" (cuore, cervello, reni) e per lo splancnico. Nel monitoraggio emodinamico abbiamo preso in considerazione la misurazione della portata cardiaca (CO) che è stata a lungo considerata essenziale per la valutazione e l'orientamento delle decisioni terapeutiche nei pazienti critici, fornendo una indicazione indiretta del trasporto sistemico di ossigeno e della perfusione tissutale globale. Tra le metodiche invasive la termodiluizione intermittente con caterere polmonare (PAC), è ampiamente considerata il metodo standard di riferimento. Tuttavia metodiche meno-invasive si stanno affacciando alla ribalta. Scopo del nostro studio è il confronto tra due metodiche differenti per la valutazione della Portata Cardiaca in terapia intensiva l’ecocardiografia transtoracica che la metodica del PCM (Pulse Contour method ) PRAM (Pressure Recording Analyting Method). A tal fine si è cercato di individuare l’accuratezza della metodica PRAM rispetto all’ecocardiografia trans toracica nel monitoraggio del Cardiac Output. Sono stati osservati 10 pazienti ricoverati presso l’U. O. IV Anestesia e Rianimazione Universitaria dell’Azienda Ospedaliera Pisana, sottoposti a monitoraggio post operatorio dopo chirurgia bariatrica. All’ingresso in reparto tutti i pazienti sono stati sottoposti a monitoraggio mediante PRAM e sottoposti , dopo consenso informato ,ad ecocardografia trans toracica. Di questi pazienti è stato studiato lo Stroke Volume e il Cardiac output. I parametri analizzati ottenuti con le due tecniche sono quindi stati posti a confronto. L’analisi statistica, che ha utilizzato il metodo Bland-Altman eseguita sui risultati ottenuti circa la misurazione del CO e dello SV ha dimostrato che le due metodiche forniscono risultati congruenti. L'ecografia si dimostra una tecnica diagnostica piuttosto versatile, ben tollerata, non invasiva, di rapida esecuzione e dai costi contenuti, tuttavia presenta delle limitazioni di attendibilità imputabili alle caratteristiche del soggetto che deve sottoporsi all'esame nonché alle capacita’ dell'operatore. Inoltre la metodica non consente una valutazione continua. La metodica PRAM si dimostra scarsamente invasiva in quanto richiede solamente l’introduzione di un catetere arterioso, non necessita di calibrazione, è facile da utilizzare, non è operatore-dipendente. Quindi fornisce informazioni utili per la comprensione dello stato emodinamico del paziente in terapia intensiva consentendo un’analisi rapida e continua. I risultati ottenuti nel nostro studio, sebbene necessitino di ulteriori conferme su un numero maggiore di pazienti, dimostrano in modo chiaro come PRAM possa essere uno strumento utile nel monitoraggio continuo della portata cardiaca

The Use Of Tai Chi With Conventional Therapy Practices For An Individual Presenting With Hemiparesis Post-Stroke: A Case Report

https://dune.une.edu/pt_studcrposter/1169/thumbnail.jp

Подготовка до экспериментальных исследований возможности использования изменений температуры лица, записанных с помощью тепловизионной камеры для детекции лжи

Publikacja recenzowana / Peer-reviewed publicatio

Cosmic voids detection without density measurements

Cosmic voids are effective cosmological probes to discriminate among competing world models. Their identification is generally based on density or geometry criteria that, because of their very nature, are prone to shot noise. We propose two void finders that are based on dynamical criterion to select voids in Lagrangian coordinates and minimise the impact of sparse sampling. The first approach exploits the Zel'dovich approximation to trace back in time the orbits of galaxies located in voids and their surroundings, the second uses the observed galaxy-galaxy correlation function to relax the objects' spatial distribution to homogeneity and isotropy. In both cases voids are defined as regions of the negative velocity divergence, that can be regarded as sinks of the back-in-time streamlines of the mass tracers. To assess the performance of our methods we used a dark matter halo mock catalogue CoDECS, and compared the results with those obtained with the ZOBOV void finder. We find that the void divergence profiles are less scattered than the density ones and, therefore, their stacking constitutes a more accurate cosmological probe. The significance of the divergence signal in the central part of voids obtained from both our finders is 60% higher than for overdensity profiles in the ZOBOV case. The ellipticity of the stacked void measured in the divergence field is closer to unity, as expected, than what is found when using halo positions. Therefore our void finders are complementary to the existing methods, that should contribute to improve the accuracy of void-based cosmological tests.Comment: 12 pages, 18 figures, accepted for publication in MNRA

The bias of cosmic voids in the presence of massive neutrinos

Cosmic voids offer an extraordinary opportunity to study the effects of massive neutrinos on cosmological scales. Because they are freely streaming, neutrinos can penetrate the interior of voids more easily than cold dark matter or baryons, which makes their relative contribution to the mass budget in voids much higher than elsewhere in the Universe. In simulations it has recently been shown how various characteristics of voids in the matter distribution are affected by neutrinos, such as their abundance, density profiles, dynamics, and clustering properties. However, the tracers used to identify voids in observations (e.g., galaxies or halos) are affected by neutrinos as well, and isolating the unique neutrino signatures inherent to voids becomes more difficult. In this paper we make use of the DEMNUni suite of simulations to investigate the clustering bias of voids in Fourier space as a function of their core density and compensation. We find a clear dependence on the sum of neutrino masses that remains significant even for void statistics extracted from halos. In particular, we observe that the amplitude of the linear void bias increases with neutrino mass for voids defined in dark matter, whereas this trend gets reversed and slightly attenuated when measuring the relative void-halo bias using voids identified in the halo distribution. Finally, we argue how the original behaviour can be restored when considering observations of the total matter distribution (e.g. via weak lensing), and comment on scale-dependent effects in the void bias that may provide additional information on neutrinos in the future.Comment: 23 pages, 18 figure

Interactive Effects Of Elevated Carbon Dioxide And Ozone On An Insect Transmitted Plant Virus

Disease epidemics can profoundly shape the ecosystems of which they are a part, affecting productivity, nutrient cycling, community composition, and species interactions. Recent changes to global ecosystems can modify the effects of disease on organisms or ecosystems, but the nature and extent of these modifications are thus far little understood, particularly for plant viruses. Among the important drivers of complex changes in ecosystems are changing levels of atmospheric gases including the greenhouse gas carbon dioxide and the oxidizing agent ozone. I used open top chambers in the field to examine the effects of rising carbon dioxide and ozone levels on the spread and severity of barley yellow dwarf virus (BYDV), an economically and environmentally important pathogen of plants in the grass tribe. I examined the effects on viral fitness and viral spread in monocultures of the epidemiologically important host Avena fatua and in mixtures of A. fatua and Setaria lutescens, a poor host of the pathogen. In monocultures of A. fatua, within-host viral fitness declined with ozone concentrations, but addition of carbon dioxide to ozone restored within-host viral fitness to ambient levels. Despite reduced virus concentration in ozonated plants, transmission of the virus did not significantly decrease with gas treatment, suggesting that no abatement of BYDV epidemics is likely under future atmospheric conditions. Ozone also reduced host vegetative and reproductive biomass in monocultures. While adding carbon dioxide to the ozone restored vegetative biomass to ambient levels, it did not compensate for losses in reproduction. If this pattern extended to crop species, yield of major grain crops such as wheat, oats, and barley could be severely reduced. In mixtures of Avena and Setaria, within-host viral fitness and transmission iii rates in both Avena and Setaria were enhanced. In addition, when Avena and Setaria were grown in competition, carbon dioxide reduced the benefits to Avena of growing in mixtures across infection treatments. Although presence in mixtures significantly suppressed growth in Setaria, CO2 increased reproductive output in infected plants. These results highlight the potential importance of disease in plant competition under changing global atmospheres. Overall, these studies demonstrate the complex interactions between atmospheric conditions and community context that are likely to regulate both disease establishment and plant health under future atmospheric conditions. i