Network Traffic Processing with PFQ

This paper presents Packet Family Queue (PFQ), a high-performance framework for packet processing designed to flexibly handle network applications parallelism and making traffic processing safe and easy. PFQ is an open-source module for the Linux kernel that combines software-accelerated packet I/O to in-kernel early stage packet processing and fine-grained distribution to network applications and physical devices. PFQ does not require any modification to network device drivers and exposes programming interfaces to multi-threaded applications natively designed to run on top of it, as well as to legacy monitoring tools using the pcap library. The results show that the flexibility and the backward compatibility provided by PFQ do not impact its processing performance that, in fact, reaches line rate figures in the cases of pure speed tests and real practical monitoring use cases on 10+ Gb/s links

Enif-lang: A specialized language for programming network functions on commodity hardware

The maturity level reached by today’s commodity platforms makes even low-cost PCs viable alternatives to dedicated hardware to implement real network functions without sacrificing performance. Indeed, the availability of multi-core processing packages and multi-queue network interfaces that can be managed by accelerated I/O frameworks, provides off-the-shelf servers with the necessary power capability for running a broad variety of network applications with near hardware-class performance. At the same time, the introduction of the Software Defined Networks (SDN) and the Network Functions Virtualization (NFV) paradigms call for new programming abstractions and tools to allow this new class of network devices to be flexibly configured and functionally repurposed from the network control plane. The paper presents the ongoing work towards Enif-Lang (Enhanced Network processIng Functional Language), a functional language for programming network functions over generic middleboxes running the Linux operating system. The language addresses concurrent programming by design and is targeted at developing simple stand-alone applications as well as pre-processing stages of packet elaborations. Enif-Lang is implemented as a Domain Specific Language embedded in the Haskell language and inherits the main principles of its ancestor, including the strong typedness and the concept of function compositions. Complex network functions are implemented by composing a set of elementary operations (primitives) by means of a compact yet expressive language grammar. Throughout the paper, the description of the design principles and features of Enif-Lang are accompanied by examples and use cases. In addition, a preliminary performance assessment is carried out to prove the effectiveness of the language for developing practical applications with the performance level required by 5G systems and the Tactile Internet

Gold/Iron Carbonyl Clusters for Tailored Au/FeOx Supported Catalysts

A novel preparation method was developed for the preparation of gold/iron oxide supported catalysts using the bimetallic carbonyl cluster salts [NEt4]4[Au4Fe4(CO)16] and [NEt4][AuFe4(CO)16] as precursors of highly dispersed nanoparticles over different supports. A series of catalysts with different metal loadings were prepared and tested in the complete oxidation of dichlorobenzene, toluene, methanol and in the preferential oxidation of CO in the presence of H2 (PROX) as model reactions. The characterization by BET, XRD, TEM, H2-TPR, ICP-AES and XPS point out the way the nature of the precursors and the thermal treatment conditions affected the dispersion of the active phase and their catalytic activity in the studied reactions

Packet Fan-Out Extension for the pcap Library

The large availability of multi-gigabit network cards for commodity PCs requires network applications to potentially cope with high volumes of traffic. However, computation intensive operations may not catch up with high traffic rates and need to be run in parallel over multiple processing cores. As of today, the vast majority of network applications - e.g., monitoring and IDS systems - are still based on the pcap library interface which, unfortunately, does not provide the native multi-core support, even though the current underlying capture technologies do. This paper introduces a novel version of the pcap library for the Linux operating system that enables transparent application level parallelism. The new library supports fan-out operations for both multi-threaded and multi-process applications, by means of extended API as well as by a declarative grammar for configuration files, suitable for legacy applications. In addition, the library can transparently run on top of the standard Linux socket as well as on other accelerated active engines. Performance evaluation has been carried out on a multi-core architecture in pure capture tests and in more realistic use cases involving monitoring applications such as Tstat and Bro, with standard Linux socket as well as PFRING and PFQ accelerated engines

The attitudes of Italian consumers towards jellyfish as novel food

Abstract The globalization of food markets and the recent upgrade of the European regulation on novel foods open up new possibilities for the introduction of edible jellyfish in the diet of Europeans. In spite of no tradition of eating jellyfish in Italy and, more generally, in Western countries, several Mediterranean jellyfish species have biological and nutritional features with a large potential as innovative, sustainable novel food and source of bioactive compounds. To evaluate the Italians' attitude of considering jellyfish as food source, a survey has been carried out on a group of 1445 individuals. A questionnaire was designed to assess the jellyfish consumption attitude (JCA) of respondents and explore the effect of their individual traits (socio-demography, personality, behavior habits, neophobia, disgust sensitivity) on JCA. Gender, age, and travelling habits differently affected JCA. Possible culinary uses and food pairing of jellyfish were also significantly influenced by JCA. Individuals with the highest propensity to accept jellyfish as food are young people, familiar with the sea environment, with high education level or students, and frequent travelers. Food neophobia and sensitivity to disgust are confirmed as personality traits able to strongly impair the acceptability of a novel food. Finally, this work provides insights into the acceptance and rejection variables that should be taken into account when an unfamiliar new food product, such as jellyfish, is planned to be introduced in a new dietary culture and new markets

Undoped and Fe-Doped Anatase/Brookite TiO2 Mixed Phases, Obtained by a Simple Template-Free Synthesis Method: Physico-Chemical Characterization and Photocatalytic Activity towards Simazine Degradation

For the first time, Fe-doping (0.05, 1.0, and 2.5 wt.% Fe) was performed on a high-surface-area anatase/brookite TiO2 by adopting a simple template-free sol-gel synthesis followed by calcination at a mild temperature. The powders’ textural and surface properties were characterized by following a multi-technique approach. XRD analysis showed that the anatase/brookite ratio slightly varied in the Fe-doped TiO2 (from 76.9/23.1 to 79.3/22.7); Fe doping noticeably affected the cell volume of the brookite phase, which decreased, likely due to Fe3+ ions occupying interstitial positions, and retarded the crystallite growth. N2 sorption at −196 °C showed the occurrence of samples with disordered interparticle mesopores, with an increase in the specific surface area from 236 m2 g−1 (undoped TiO2) to 263 m2 g−1 (2.5 wt.% Fe). Diffuse Reflectance UV-Vis spectroscopy showed a progressive decrease in the bandgap energy from 3.10 eV (undoped TiO2) to 2.85 eV (2.5 wt.% Fe). XPS analysis showed the presence of some surface Fe species only at 2.5 wt.% Fe, and accordingly, the ζ-potential measurements showed small changes in the pH at the isoelectric point. The photocatalytic degradation of simazine (a persistent water contaminant) both under UV and simulated solar light was performed as a probe reaction. Under UV light, Fe-doping improved simazine degradation in the sample at 0.05 wt.% Fe, capable of degrading ca. 77% simazine. Interestingly, the undoped TiO2 was also active both under UV and 1 SUN. This is likely due to the occurrence of anatase/brookite heterojunctions, which help stabilize the photogenerated electrons/holes

Skin dendritic cells increase in number during early response to wounding

Among the cells that may participate to wound response and wound healing, coordinate with other cell types, dendritic cells have been little studied until now and the least so in humans. This issue has been addressed on samples of wounded and control skin taken at autopsy and analyzed by immunohistochemistry and morphometry. Langerhans cell number in the epidermis and the relative volume of MHC II+ cells in the dermis increased transiently upon wounding, with a significant peak in the first and the second half hour after wounding respectively. Dermal MHC II+ cells became part of a perivascular mononuclear cell infiltrate visible in the subpapillary dermis since between 30 and 60 after wounding and which contained also MC. Cells at the periphery of the infiltrates were also DC-SIGN+ and CD11c+, i.e. were well differentiated connective tissue dendritic cells. Mast cells underwent degranulation associated to an increase in number in the first hours after wounding. These modifications of dendritic cells and mast cells and the respective tissue course suggest that epidermal and dermal dendritic cells participate to the early response to wounding in humans, coordinately with mast cells and possibly stimulating the recruitment and activation of the cells involved in injury response at later time points