A new optical recording medium

Method has been developed for doping lithium niobiate crystals with transition metal to increase rate at which crystal can record optical data. Discovery may facilitate development of system for analog storage of TV frames, printed pages, photographs, and other visual information

Single crystals of selected titanates and tungstates

The compound preparation and crystal growth of a number of mixed titanate compositions was investigated. None of the compounds studied were found to melt congruently and therefore, crystal growth was extremely difficult. Various single crystal preparation methods always resulted in mixed phases from which 1-2 mm size crystals could be separated. It is concluded from this study that before successful single crystal growth can be accomplished, a detailed study of the phase diagrams in each of the systems of interest must be completed

MOLECULAR CHARACTERIZATION BY RT-REAL TIME PCR AND HIGH RESOLUTION MELTING ANALYSIS FOR FOOD SAFETY AND VETERINARY DIAGNOSTICS

This PhD thesis is the outcome of a range of activities and experimental results aimed to a better characterization of the risk that Escherichia coli and other microrganisms and parasites may pone to the health of animals and finally humans. One of the main activity of the present project was based on the test hypothesis that the virulence profile of E. coli strains toward bovine mammary gland can be modulated by the interaction with the host cells. These hypothesis were tested through a gene expression study of some virulence factors of six E. coli strains when co-cultured with a bovine mammary cell line, since the in vitro models represent both an essential tool to investigate the biological mechanistic of mastitis, and an efficient alternative to animal experiments. Preliminarly, a meta-analysis of existing literature studies on the available bovine mammary cell lines was performed, resulting in the selection of MAC-T as the most responsive cell line to bacteria causing mastitis. The E. coli strains used for the coculture experiments with MAC-T cells were isolated from different types of bovine mastitis (acute, chronic and undetermined) and from a VTEC food-borne strain associated to human clinical disease (O157). An upregulation of the virulence factor eae (intimin) in all but one the analyzed mastitis strains following co-culture with MAC-T cell line was detected through RT-reat time PCR, and also the adherence virulence factor ycd and the b12 gene were upregulated in some strains, overall suggesting the possibility that mastitic E. coli strains can acquire a more risky molecular profile when exposed to the bovine mammary cells. This finding may have clear implications on the risk assessment related to the E. coli strains in bovine mammary tissue and milk. In addition, with the aim to improve the current methodologies for foodborne risk analysis linked to E. coli, the project activity provided a preliminary research for the setup and validation of new protocols based on real time PCR-High Resolution Melting Analysis, a widely used technique to target sequence polymorphisms of the same gene in different species without the need to perform DNA sequencing or to use species-specific probes, to help the identification of putative verocytotoxic status in E. coli strains of O26 serogroup, and other serotypes, isolated from bovine milk. Since the applications of HRMA for the characterization of microorganisms can not be limited to food safety, but can be developed for a large number of issues linked to general veterinary diagnostics, among the objectives of this PhD project some new real-time PCR-HRMA coupled methods were also developed, providing a contribution to the advancement of the existing molecular tools for sensitive and effective species identification, or variant/mutation screening, applied to different foodborne and veterinary pathogens. Thus, new HRMA-based protocols were designed and tested for the identification of Pseudomonas spp responsible for chromatic alterations in mozzarella cheese, for the detection and differentiation of Dirofilaria repens and D. immitis in canine blood samples, for the detection of the mutation site associated to FQ resistance in Staphylococcus pseudintermedius isolated from canine diagnostic samples, and for discrimination of the two most common microsporidial parasites in honeybees, Nosema apis and N. ceranae. Overall, these new HRMA-based assays could represent additional tools for epidemiological studies, routine disease assessment and therapeutical decisions. The possibility to identify the presence of risk-predictive SNPs in E. coli isolates using these newly established HRMA-based protocols is a novel, and simpler, opportunity with respect to the current, and more complex, surveillance strategies that are based on the amplification of stx genes together with other virulence factors for the evaluation of VTEC status. In the future, a possible way forward of this research is represented, on one side, by the deeper assessment of the reciprocal modulation between E. coli mastitis-derived strains and immortalized MAC-T cells using high-throughput RNA sequencing, and on the other side by a large scale validation of the HRMA-based evaluation of risk-predictive SNPs in order to improve the current approaches. And overall, the established HRMA-based protocols when extensively validated would be highly suitable for routine veterinary diagnostics applied to field investigation, as quick and sensitive single step protocols allowing specific and sensitive detection of the targets with shorter analysis time and reduced cost, in parallel or in alternative to the classical approaches

Sample size estimation and power calculations for vaccine efficacy trials for exceedingly rare diseases

The implementation of vaccines is one of the most profound advancements in the world of public health. While the scientific process underlying vaccine development is important, determining a vaccine’s efficacy and safety profile would not be possible without vaccine efficacy trials. In terms of trial design, sample size estimation is one of the essential considerations to be made, ensuring that the trial achieves the targeted power, minimizing chances of a false-negative finding. An often considered hypothesis for such trials is testing if a new vaccine is more efficacious than a placebo or the current standard-of-care. We investigated two relevant methods, the Z-Test Normal Approximation and the Exact Conditional Test under Poisson Assumption as presented by Chan and Bohidar. While the Normal Approximation is a generally acceptable method, the Exact Conditional approach may be better suited for trials with low disease incidence. In this Thesis, we develop SAS code for estimating sample size via both methods, in addition to calculating exact power. Sample size and power calculations are performed under a range of different scenarios, stratified by high, intermediate, and low incidence of disease in the control group. Furthermore, under each scenario, simulations are utilized to evaluate the performance of the Exact Conditional approach. Both methods are generally reasonable approaches to sample size estimation and power calculations for vaccine efficacy trials. In trials of higher disease incidence, the Normal Approximation is simpler to implement, and should adequately power the trial. For scenarios of low incidence (< 0.01), the Exact Conditional approach may be more favorable, as it may provide greater power to the trial. To minimize the chance of an underpowered trial, we propose implementing a strategic inflation of sample size. Lastly, we highlight the importance of congruency between methods used for sample size estimation, trial design, and data analysis. Public Health Significance: Vaccine efficacy trials are required for vaccine licensure and distribution to the public. A robustly estimated sample size is crucial, as it ensures a trial is adequately powered, thereby improving the odds of obtaining conclusive results. The methods investigated here represent viable approaches to sample size estimation for such trials

A Human-centric AI-driven Framework for Exploring Large and Complex Datasets

Human-Centered Artificial Intelligence (HCAI) is a new frontier of research at the intersection between HCI and AI. It fosters an innovative vision of human-centred intelligent systems, which are systems that take advantage of computer features, such as powerful algorithms, big data management, advanced sensors and that are useful and usable for people, providing high levels of automation and enabling high levels of human control. This position paper presents our ongoing research aiming to extend the HCAI framework for better supporting designers in creating AI-based systems

Methods to account for measured and unmeasured confounders in influenza relative vaccine effectiveness studies:A brief review of the literature

Observational seasonal influenza relative vaccine effectiveness (rVE) studies employ a variety of statistical methods to account for confounding and biases. To better understand the range of methods employed and implications for policy, we conducted a brief literature review. Across 37 included rVE studies, 10 different types of statistical methods were identified, and only eight studies reported methods to detect residual confounding, highlighting the heterogeneous state of the literature. To improve the comparability and credibility of future rVE research, researchers should clearly explain methods and design choices and implement methods to detect and quantify residual confounding

Germinal ovarian tumors in reproductive age women: Fertility-sparing and outcome

MOGCTs (malignant ovarian germ cell tumors) are rare tumors that mainly affect patients of reproductive age. The aim of this study was to evaluate the fertility and survival outcomes in young women with MOCGTs treated with fertility-sparing surgery (FSS).From 2000 to 2018, data from 28 patients of reproductive age with a diagnosis of MOGCT at the University of Bari were collected. Most received FSS, and in patients treated conservatively, the reproductive outcome and survival were investigated. Data of patient demographics, clinical presentation, oncology marker dosage, staging, type of surgery, histological examination, survival, and reproductive outcome were collected from hospital and office charts. All informed consent was obtained from all patients. The median age was 24 (range: 9-45 years). The majority of the patients had stage IIIC. Twenty-four woman received FSS consisting of unilateral ovariectomy and omentectomy, whereas only 4 women, based on their stage (IIIC), received a radical surgery (hysterectomy with bilateral adnexectomy, lymphadenectomy, and omentectomy). Our study shows that FSS in MOGCTs can produce good results both on reproductive outcomes and on survival. Indeed, in our group, there was only 1 case of exitus as result of recurrence. Furthermore, patients after FSS maintained normal ovarian function and 5 of 5 women who tried to get pregnant succeeded spontaneously. The median follow-up was 90 months (range 3-159).Conservative surgery for MOGCTs should be considered for women of reproductive age who wish to preserve fertility