Design-Based Treatment of Unit Nonresponse by the Calibration Approach

The use of nonresponse calibration weighting is considered in a complete design-based frameworkto account for the cases in which nonresponse is a fixed characteristic of the units, just like the interest variable. Approximate expressions of design-based bias and variance of the calibration estimator are derived and some estimators of the sampling variance are proposed. The choice of auxiliary variables is discussed from theoretical and practical point of view. The results of an extensive simulation study demonstrate how the reliability of the procedure is mainly determined by the capability of selecting auxiliary variables in such a way that their relationship with the interest variable is similar for both the respondent and nonrespondent sub-populations.auxiliary variables, calibration estimator, variance estimator, simulation study.

An interprofessional, intercultural, immersive short-term study abroad program: public health and service systems in rome

The purpose of this paper is to describe a short-term study abroad program that exposes engineering and nursing undergraduate students from the United States and Italy to an intercultural and interprofessional immersion experience. Faculty from Purdue University and Sapienza Università di Roma collaborated to design a technical program that demonstrates the complementary nature of engineering and public health in the service sector, with Rome as an integral component of the program. Specifically, the intersection of topics including systems, reliability, process flow, maintenance management, and public health are covered through online lectures, in-class activities and case study discussions, field experiences, and assessments. Herein, administrative issues such as student recruitment, selection, and preparation are elucidated. Additionally, the pedagogical approach used to ensure constructive alignment among the program goals, the intended learning outcomes, and the teaching and learning activities is described. Finally, examples of learning outcomes resulting from this alignment are provided

Stakeholder Engagement in State Owned Enterprises: Is Twitter a democratic tool?

Despite SOEs have to face the current CSR reporting issues balancing a wide range of stakeholders’ claims on accountability (Grossi & Steccolini, 2014), little is still known on how this can be enhanced pursuing by social media. In filling this gap, the present study aims to explore how and to what extent SOEs engage with their stakeholders by social media. In doing this, the study identifies stakeholders’ categories the SOEs are meeting with, the mate- rial content of SOEs CSR disclosure, and the level of debate democratizatio

Persistent middle ear effusion presumably biofilm-related in a paediatric patient with common variable immunodeficiency

Bacterial biofilms play a role in upper respiratory tract diseases, including acute and chronic middle ear diseases, and are involved in chronic infections and resistance to antibiotic treatment. In particular, the nasopharynx and the surrounding tissues act as important reservoirs of resistant bacterial biofilms, which have been detected in biopsies taken from adenoid and/or middle ear mucosa of children with chronic middle ear effusion. Here we describe the management of a child with congenital immunodeficiency and a chronic middle ear effusion, resistant to traditional medical treatment and presumably due to nasopharyngeal colonization by bacterial biofilms, which has been successfully treated by means of medicated nasal douches delivering antibiotic and a biofilm-destroying compound

Interaction of a Long Alkyl Chain Protic Ionic Liquid and Water

A combined experimental/theoretical approach has been used to investigate the role of water in modifying the microscopic interactions characterizing the optical response of butyl-ammonium nitrate (BAN) water solutions. Raman spectra, dominated by the signal from the protic ionic liquid, were collected as a function of the water content, and the corresponding spatial organization of the ionic couples, as well as their local arrangement with water molecules, was studied exploiting classical molecular dynamics calculations. High quality spectroscopic data, combined with a careful analysis, revealed that water affects the vibrational spectrum BAN in solution: as the water concentration is increased, peaks assigned to stretching modes show a frequency hardening together with a shape narrowing, whereas the opposite behavior is observed for peaks assigned to bending modes. Calculation results clearly show a nanometric spatial organization of the ionic couples that is not destroyed on increasing the water content at least within an intermediate range. Our combined results show indeed that small water concentrations even increase the local order. Water molecules are located among ionic couples and are closer to the anion than the cation, as confirmed by the computation of the number of H-bonds which is greater for water-anion than for water-cation. The whole results set thus clarifies the microscopic scenario of the BAN-water interaction and underlines the main role of the extended hydrogen bond network among water molecules and nitrate anions.Comment: 27 pages, 10 figure

The effectiveness of channel control works: how multi-temporal sediment dynamics analysis could support watershed management

Sustainable and effective planning of the channel control works has become an essential tool to manage the hydro-geomorphic risk in mountain basins. However, quite often, there is a lack of information on the efficiency and effectiveness of existing structures and a priori in-depth studies analysing the interaction between sediment morphology dynamics and the possible new channel control works. Nowadays, thanks to multi-temporal (4D) High-Resolution Topography (HRT) surveys, it is possible to derive accurate 4D Digital Terrain Models (DTMs), and reliable DTMs of Difference (DoDs) that greatly simplify the analysis of geomorphological changes and enables the development of innovative approaches to monitor sediment morphology dynamics and the interaction with channel control works. This research aims at introducing and applying a methodological approach. It is based on integrating sediment morphology dynamics data over large time spans in various mountain catchments with an updated, quick, and user-friendly efficiency index for the existing channel control works. The results show how the information provided by sediment morphology dynamics coupled with an updated state of efficiency of existing interventions, could help to support the development of watershed management strategies, assess afterwards the effectiveness of existing structures, and foster a more complete decision-making chain. In the basins analysed, several real examples of the proposed methodology emphasized the usefulness of providing more complete information on the ongoing phenomena, than in the past, by exploiting field surveys and remote sensing data. The realized database could provide numerical data for prediction models of the life-cycle of channel control works or be a starting point for further analysis. Furthermore, the proposed workflow could provide increasingly up-to-date information. This would allow the constant identification of the areas most prone to hazards, support effective risk management decisions, direct maintenance works and find more appropriate solutions