Salivary VIP concentrations are elevated in humans after acute stress

The purpose of this research was to evaluate two salivary neuropeptides in the context of the stress response. The research was focused first and foremost on evaluating the usefulness of salivary Neuropeptide Y (NPY) and salivary vasoactive intestinal peptide (VIP) as stress indicators. Secondly, we questioned whether these markers help us in distinguishing between physical and psychological stress. Psychological stress can be experienced in a situation such as that in anticipation of an important exam or mental task. Physical stress can be experienced usually by strenuous exercise. Salivary NPY and salivary VIP are two neuropeptides that are released as a result of sympathetic and parasympathetic activity respectively. These two biomarkers are measured extensively in the blood or plasma but they are not routinely measured in saliva (Morgan et al., 2000). These neuropeptides will be evaluated in conjunction with the following salivary indicators cortisol, dehydroepiandrosterone (DHEA) (Morgan et al., 2004) and amylase (Nater et al., 2006) of the stress response. Depending on the stressful situation or stress paradigm, we used an indicator or biomarker profile in conjunction with the use of psychological assessments in order to measure the intensity of the stress response. In other situations, the biomarker profile with the aid of psychological and physical assessment tools helped us differentiate between psychological stress and physical stress. In essence, we used a matrix approach using a combination of physiological and psychological measures to develop a stress profile that could be used to determine both the degree and the nature of the stress response experienced by subjects. In this study we evaluated NPY and VIP as salivary biomarkers using different stress paradigms. We also studied the effects of the following possible confounders on the stress response: circadian variation, water, and coffee intake. Therefore, to accomplish this salivary samples were taken and s-cortisol, s- DHEA, s-amylase, s-NPY and s-VIP were measured. Assessments (Thayer Activation-Deactivation Checklist, State-Trait Anxiety Inventory, and Borg Rating of Perceived Exertion Scale) were also administered in order to evaluate the psychological state of the subjects with respect to anxiety and their perception of physical exertion. The main findings of the study indicate that a brief intense exercise lasting minutes elicited a stress response with significant increases in s-cortisol, s-DHEA, s-amylase and s-VIP. A less rigorous exercise did not elicit a stress response with no significant increases in s-cortisol, s-DHEA ,s-amylase and s-VIP. A longer intense exercise lasting hours elicited a stress response with significant increases only in s-cortisol. In addition, s-VIP displays a circadian variation which peaks with cortisol at 0800h

Volume Integral Formulation for the Calculation of Material Independent Modes of Dielectric Scatterers

In the frame of volume integral equation methods, we introduce an alternative representation of the electromagnetic field scattered by a homogeneous object of arbitrary shape at a given frequency, in terms of a set of modes independent of its permittivity. This is accomplished by introducing an auxiliary eigenvalue problem, based on a volume integral operator. With this modal basis the expansion coefficients of the scattered field are simple rational functions of the permittivity of the scatterer. We show, by studying the electromagnetic scattering from a sphere and a cylinder of dimensions comparable to the incident wavelength, that only a moderate number of modes is needed to accurately describe the scattered far field. This method can be used to investigate resonant scattering phenomena, including plasmonic and photonic resonances, and to design the permittivity of the object to pursue a prescribed tailoring of the scattered field. Moreover, the presented modal expansion is computationally advantageous compared to direct solution of the volume integral equation when the scattered field has to be computed for many different values of the dielectric permittivity, given the size and shape of the dielectric body

Magnetoquasistatic resonances of small dielectric objects

A small dielectric object with positive permittivity may resonate when the free-space wavelength is large in comparison with the object dimensions if the permittivity is sufficiently high. We show that these resonances are described by the magnetoquasistatic approximation of the Maxwell's equations in which the normal component of the displacement current density field vanishes on the surface of the particle. They are associated to values of permittivities and frequencies for which source-free quasistatic magnetic fields exist, which are connected to the eigenvalues of a magnetostatic integral operator. We present the general physical properties of magnetoquasistatic resonances in dielectrics with arbitrary shape. They arise from the interplay between the polarization energy stored in the dielectric and the energy stored in the magnetic field. Our findings improve the understanding of resonances in high-permittivity dielectric objects and provide a powerful tool that greatly simplifies the analysis and design of high-index resonators

Synthesis of resonant modes in electromagnetics

Resonant modes determine the response of electromagnetic devices, including dielectric and plasmonic resonators. Relying on the degrees of freedom that metamaterials provide, this contribution shows how to design, at will, the resonant modes of a dielectric object placed in an unbounded space. Specifically, the proposed method returns in analytical form the spatial distribution of the dielectric susceptibility tensor for which the object exhibits resonances at prescribed frequencies and spatial distribution of the polarization. Together with the synthesis of the material, two key concepts are introduced: the controlled tunability of the resonant modes and the number of essential modes, i.e. the number of modes that uniquely characterize the spatial distribution of the dielectric susceptibility. Moreover, this approach can be applied to design the resonant modes of any system where the constitutive relationship is linear and local

Detailed peptide profiling of “Scotta”: from a dairy waste to a source of potential health-promoting compound

“Scotta” is a liquid waste deriving from Ricotta cheese production, which is wrongly considered only a dairy by-product. In this work, with the aim to elucidate the presence of valuable bioactive compounds in Buffalo’s Scotta, a peptide fraction under 3000 Da was isolated by ultra-filtration, purified by solid-phase extraction, and,subsequently, characterized in detail by liquid chromatography coupled to Orbitrap mass spectrometry. Analytical results revealed a complex profile, leading to the identification of 226 peptides, belonging to alpha, beta, and kappa caseins. A database-driven search approach was used to assess the biological effects of some of the identified peptides. A wide range of healthy properties was ascribed to the encrypted peptides, comprising antihypertensive, antimicrobial, immunomodulating, opioid, antioxidant, and antithrombotic. The peptidomic profile of Scotta was highlighted in depth for the first time, and the results revealed that this matrix should not be considered only a mere by-product, but a source of potential health-promoting peptides, which can be recovered and employed in nutraceuticals and functional foods

A PCE-based Architecture for the Management of Virtualized Infrastructures

The emerging Network Function Virtualization paradigm (NFV) is a disruptive change that creates new business opportunities for vendors and carriers. By exploiting virtualization technologies, it allows the dynamic creation of logically isolated infrastructures over abstracted physical networks. To be able to offer Virtualized Services efficiently, service providers need a new class of Management systems able to manage and orchestrate both network and IT virtualized resources. In this paper, we propose an enhanced network Control Plane, based on the standard Path Computation Element (PCE) architecture, which is able to jointly make network routing and IT server provisioning decisions and that can be used in an NFV environment

Dynamic routing and virtual machine consolidation in green clouds

In the last few years, there has been a remarkable growth in the number of data centers, which represent one of the leading sources of increased business data traffic on the Internet. An effect of the growing scale and the wide use of data centers is the dramatic increase of power consumption, with significant consequences both in terms of environmental and operational costs. Hence, energy awareness has become one of the major design constraints for Cloud infrastructures. In order to face these challenges, a new generation of energy-efficient and ecosustainable network infrastructures is needed. In this work, a novel energy-aware resource orchestration framework for distributed Cloud infrastructures is introduced, in order to manage both network and IT resources in a typical optical backbone. A high-level overview of the system architecture is provided by focusing on the definition of the different layers of the whole infrastructure, and introducing the Path Computation Element, which is the key component of the proposed architecture. The aim is to explain how both network and IT resources can be managed while, at the same time, the overall power consumption is being minimized and QoS requirements are satisfied. Finally, a green migration plan that is obtained by applying Virtual Machine relocation algorithms is discussed, in order to dynamically react to the fluctuating resource requirements of the VMs

A Load Balancing Algorithm against DDoS attacks in beyond 3G wireless networks

A Distributed Denial of Service (DDoS) attack aims at exhausting the resources of a communication system. A large amount of requests is sent to the targeted system by malicious users: the overload compromises the correct working of the structure. If the attack is successful, the system stops working. The assault does not provide the hacker with any sensitive information; so it does not appear as dangerous as it really is. Nevertheless, the denial of service is a huge security risk for Long Term Evolution (LTE) networks. In order to avoid this kind of risk, we present a mechanism that relocates the resources requested by the users, both voice and data. It is able to transfer the overload from congested eNodeBs to eNodeBs with free capacities. The mechanism is a Load Balancing Algorithm, fully integrated in the architecture of LTE networks. We simulated the attack scenario through Network Simulator 3 (ns-3). If the proposed algorithm is active, in case of a DDoS attack, communication services are always available for users

Network security for hybrid cloud

Cloud computing has enabled elastic and transparent access to distributed services, without investing in new infrastructures. In the last few years, Cloud computing has grown from being a promising business concept to one of the fast growing segments of the IT industry. Despite of all the hype surrounding the Cloud, enterprise customers are still reluctant to deploy their business in the Cloud. Security is one of the major issues which reduces the growth of Cloud computing and complications with data privacy and data protection continue to plague the market. In this paper, we propose a solution for Hybrid Cloud security, focusing on a Virtual Intrusion Detection System (V-IDS). We present a new architecture that considers the basic principles of the Cloud computing, virtualization and GMPLS Control Plane and applies them to the intrusion detection systems, in order to protect Cloud networks characterized by constantly changing of the underlying infrastructure and physical topology. Based on the defined architecture, we have implemented a prototype of Cloud based IDS that validates our thesis. The prototype is realized though the integration of two open-source technologies: OpenStack and DRAGON (Dynamic Resource Allocation via GMPLS Optical Networks)