On a class of non-self-adjoint periodic boundary value problems with discrete real spectrum

In [arXiv:0801.0172] we examined a family of periodic Sturm-Liouville problems with boundary and interior singularities which are highly non-self-adjoint but have only real eigenvalues. We now establish Schatten class properties of the associated resolvent operator.Comment: 8 pages

Nitric Oxide Mediates Biofilm Formation and Symbiosis in Silicibacter sp. Strain TrichCH4B.

UnlabelledNitric oxide (NO) plays an important signaling role in all domains of life. Many bacteria contain a heme-nitric oxide/oxygen binding (H-NOX) protein that selectively binds NO. These H-NOX proteins often act as sensors that regulate histidine kinase (HK) activity, forming part of a bacterial two-component signaling system that also involves one or more response regulators. In several organisms, NO binding to the H-NOX protein governs bacterial biofilm formation; however, the source of NO exposure for these bacteria is unknown. In mammals, NO is generated by the enzyme nitric oxide synthase (NOS) and signals through binding the H-NOX domain of soluble guanylate cyclase. Recently, several bacterial NOS proteins have also been reported, but the corresponding bacteria do not also encode an H-NOX protein. Here, we report the first characterization of a bacterium that encodes both a NOS and H-NOX, thus resembling the mammalian system capable of both synthesizing and sensing NO. We characterized the NO signaling pathway of the marine alphaproteobacterium Silicibacter sp. strain TrichCH4B, determining that the NOS is activated by an algal symbiont, Trichodesmium erythraeum. NO signaling through a histidine kinase-response regulator two-component signaling pathway results in increased concentrations of cyclic diguanosine monophosphate, a key bacterial second messenger molecule that controls cellular adhesion and biofilm formation. Silicibacter sp. TrichCH4B biofilm formation, activated by T. erythraeum, may be an important mechanism for symbiosis between the two organisms, revealing that NO plays a previously unknown key role in bacterial communication and symbiosis.ImportanceBacterial nitric oxide (NO) signaling via heme-nitric oxide/oxygen binding (H-NOX) proteins regulates biofilm formation, playing an important role in protecting bacteria from oxidative stress and other environmental stresses. Biofilms are also an important part of symbiosis, allowing the organism to remain in a nutrient-rich environment. In this study, we show that in Silicibacter sp. strain TrichCH4B, NO mediates symbiosis with the alga Trichodesmium erythraeum, a major marine diazotroph. In addition, Silicibacter sp. TrichCH4B is the first characterized bacteria to harbor both the NOS and H-NOX proteins, making it uniquely capable of both synthesizing and sensing NO, analogous to mammalian NO signaling. Our study expands current understanding of the role of NO in bacterial signaling, providing a novel role for NO in bacterial communication and symbiosis

Chapter Sizing & Allocation in Labour Market: business strategies and multivariate analysis

In Labour Market, the issue of Sizing and Allocation is a discussed problem. In this study, this topic has been considered from a statistical point of view. Indeed, the choice to change the number of your team of employees in a business context needs a very accurate analysis. If for example a firm decides to launch a new product on the market, it could be necessary to recruit new resources. The proposed statistical approach aims to give some hints about the total number of employees analysing the features of the existing market and the territorial geography. From a statistical point of two techniques of multivariate analysis have been presented as exploratory tools. In the application, a Principal Component Analysis has been used to investigate the business environment after some qualitative interviews to the board of the company. In a second step, some different scenarios have been proposed to determine the exact number of new resources using a data hybridization technique including internal and external sources. Finally, the allocation of the new hired of the scenarios on the Italian territory has been achieved thanks to the construction of a territorial potential index

A ferrofluid-based sensor to measure bottom shear stresses under currents and waves

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Journal of Hydraulic Research on 2018, available online at: http://www.tandfonline.com/10.1080/00221686.2017.1397779The measurement of the near-bottom flow characteristics is crucial to correctly understand coastal processes. To overcome some of the limits of present state-of-the-art measuring instruments, we propose a novel approach to measure bottom shear stress under currents and waves based on the exploitation of magneto-rheological fluids, named ferrofluids. In particular, the deformation of a magnetically controlled ferrofluid drop O(0.01 ml) is transformed by a conditioning circuit into an output voltage which is proportional to the bottom shear stress. Calibration curves are presented for both steady-current and regular wave conditions, over fixed and weakly mobile beds, showing that the behaviour of the proposed measuring system can be assumed linear. In the range of the investigated parameters, it is shown that the working range is comprised between 0.08 N m-2 and an upper limit which is a function of the controlling magnetic field and the flow type.Peer ReviewedPostprint (author's final draft

Air Conditioning Systems from a 2nd Law Perspective

In this paper exergy analysis is used to assess the performance of the three most common air conditioning plant schemes: all-air, dual-duct and fan-coil systems. The results are presented in terms of flow diagrams to provide a clear picture of the exergy flow across the systems. The most relevant outcomes are that the air cooling and dehumidification is the process most responsible for the exergy loss and that the exergy efficiency of the overall systems is rather lo

Monitoring the survival of subscribers in a marketing mailing list

[EN] The statistical literature proposed many contributions about survival analysis in medical research, in this work this approach is proposed in a business context. The aim of this paper is to control the mortality of the users belonging to an e-mail subscribers list for a company operating in the healthcare information sector. Having available the survival times for each subscriber, the choice was oriented to survival models to evaluate the abandon of the customers. A survival analysis was conducted through a Cox model considering some risk factors of the subscriber. The selected Cox model carried to the identification of risk profiles representing different situations in terms of probability of abandon.Marletta, A. (2022). Monitoring the survival of subscribers in a marketing mailing list. En 4th International Conference on Advanced Research Methods and Analytics (CARMA 2022). Editorial Universitat Politècnica de València. 173-180. https://doi.org/10.4995/CARMA2022.2022.1508217318

Entrepreneurial Supply Chains and Strategic Collaboration: The Case of Bagòss Cheese in Bagolino, Italy

Many small towns and communities are struggling to sustain their competitiveness in the face of increasing globalization. Yet, through entrepreneurial supply chains, some communities are organizing themselves to forge local solutions to their global challenges. The essence of entrepreneurial supply chains is its ability to facilitate alignment of all participants in the chain, eliminating moral hazard and opportunism risks. It is argued that this governance system and an ability to protect the common assets from infringement by outsiders are necessary for the success of these solutions. The research uses Bagòss cheese, produced in the small Italian village of Bagolino, to illustrate the characteristics of entrepreneurial supply chains and test the effect of the identified necessary conditions for their successful implementation.entrepreneurial supply chain, Bagòss cheese, globalization, International Development, International Relations/Trade, Q10, Q17,