Reversible Transport of Interacting Brownian Ratchets

The transport of interacting Brownian particles in a periodic asymmetric (ratchet) substrate is studied numerically. In a zero-temperature regime, the system behaves as a reversible step motor, undergoing multiple sign reversals of the particle current as any of the following parameters are varied: the pinning potential parameters, the particle occupation number, and the excitation amplitude. The reversals are induced by successive changes in the symmetry of the effective ratchet potential produced by the substrate and the fraction of particles which are effectively pinned. At high temperatures and low frequencies, thermal noise assists delocalization of the pinned particles, rendering the system to recover net motion along the gentler direction of the substrate potential. The joint effect of high temperature and high frequency, on the other hand, induces an additional current inversion, this time favoring motion along the direction where the ratchet potential is steeper. The dependence of these properties on the ratchet parameters and particle density is analyzed in detail.Comment: 8 pages, 10 figure

Prediction techniques on FPGA for latency reduction on tactile internet

Tactile Internet (TI) is a new internet paradigm that enables sending touch interaction information and other stimuli, which will lead to new human-to-machine applications. However, TI applications require very low latency between devices, as the system’s latency can result from the communication channel, processing power of local devices, and the complexity of the data processing techniques, among others. Therefore, this work proposes using dedicated hardware-based reconfigurable computing to reduce the latency of prediction techniques applied to TI. Finally, we demonstrate that prediction techniques developed on field-programmable gate array (FPGA) can minimize the impacts caused by delays and loss of information. To validate our proposal, we present a comparison between software and hardware implementations and analyze synthesis results regarding hardware area occupation, throughput, and power consumption. Furthermore, comparisons with state-of-the-art works are presented, showing a significant reduction in power consumption of ≈1300× and reaching speedup rates of up to ≈52×

Enhancement of biomethane production from the anaerobic co-digestion of sewage sludge and macroalgae by continuous and intermittent addition of glycerol

Anaerobic digestion(AD) is a multifunctional bioprocess that allows nutrient recycling and reduction, production of biogas, and a sustainable bioenergy carrier. AD of macroalgae presents a promising source of bioenergy in the future. Macroalgae have high concentration of carbohydrates, making it suitable for biogas production, not competing with food crops for arable land and irrigation water. This work aimed to enhance the methane (CH4) production from the anaerobic co- digestion of a mixture of sewage sludge (SS from a wastewater treatment plant) and Ulva sp. (Ulv macroalgae), with continuous and intermittent addition of crude glycerol (cGly from vegetable oils), in a semi-continuous system. Three 5 L stirred tank reactors (R1, R2 and R3) were fed with SS and Ulv (85/15 in total solids). The reactors were operated at 37 °C, with a 4 L working volume and inoculated with anaerobic granular sludge from a brewery industry. Until day 179, the reactors were fed only with SS, while the hydraulic retention time (HRT) has been continuously decreasing from 40 d to 20 d. After reaching stabilization at HRT of 20 d, Ulv and cGly were added to feed (until day 241). R1 was the control, without cGly. In R2, cGly was continuously supplemented, 2 % (w) of the mixture of SS and Ulv. In R3, pulses of cGly were applied once a week, with same amount introduced in R2 since the last pulse. The AD of SS with an organic loading rate (g of COD of substrate per L of reactor and time) of 3.33 g L-1 d-1 achieved a CH4 production (MP, expressed in L of CH4 produced per kg of chemical oxygen demand (COD) of substrate fed L kg-1)) of 166 L kg-1 with 39 % of volatile solid (VS) reduction. The addition of Ulv (R1) decreased the MP in 20%. The continuous introduction of cGly (R2) improved significantly the MP, reaching 204 L kg-1 (51 % of VS reduction). Noteworthy, the intermittent addition of cGly (R3) showed the best results in terms of MP, 251 L kg-1 achieving 56 % of VS reduction

Materiais de construção e materiais líticos nas práticas funerárias neolíticas da serra da Boa Viagem (Centro-Oeste de Portugal). O caso do monumento megalítico do Cabeço dos Moinhos, Figueira da Foz

Este trabalho contribui para o conhecimento do Neolítico do Centro-Oeste português. O caso de estudo foi o monumento megalítico do Cabeço dos Moinhos, edificado na serra da Boa Viajem, no que é hoje a freguesia da Brenha, concelho da Figueira da Foz. Para além de ser óbvio que esta região se encontrava, durante o Neolítico, no limiar de diferentes mundos culturais, o meridional e o setentrional, a partir das matérias usadas na construção do monumento e das matérias usadas no fabrico de oferendas líticas e de objetos de adorno, teceram-se algumas considerações relacionadas com as práticas funerárias, os modos de vida e de vivenciar o mundo por parte das comunidades neolíticas que aqui ergueram estes monumentos. Em relação às oferendas líticas notou-se a ausência de traços de uso o que indicia que foram fabricadas apenas para ritos funerários. Além do simbolismo intrínseco às formas, as diferentes matérias em que foram construídos (locais, regionais e inter-regionais) indiciam a importância da interligação física e simbólica das comunidades locais com lugares próximos e remotos, o que não será alheio a um modo de vida com grande abertura ao mundo exterior e, talvez, pouco sedentarizado . O mesmo se poderá interpretar em termos arquitetónicos pois, se a construção sobre um afloramento calcário e em local culminante poderá revelar assimilação das propriedades inerentes ao local e à matéria aí existente, a reunião de matérias de diferentes proveniências na câmara/corredor implicará uma interligação física e mental entre os diferentes lugares vivenciados pelos seus construtores, ou seja, entre lugares de habitat, de subsistência e de veneração dos espíritos dos antepassados.This paper contributes to the understanding of the Neolithic burial practices in Western Central Portugal. It relies on the reviewing of Santos Rocha texts, which describes research carried out in the megalithic monument of Cabeço dos Moinhos (Brenha, Figueira da Foz), fieldwork and the study of bone remains and “offerings” that were found in the monument. Cabeço dos Moinhos tomb was built on a limestone outcrop located in a hill placed on the ridgeline of Serra da Boa Viagem. From this hill there is a wide visibility to the sandy coastal plain (to the north) and to the Baixo Mondego area (to the south). Under a mound of "yellowish soil without mixture" a polygonal chamber with corridor oriented east was built. The standing stones were made of greyish white limestone (local) and of whitish, greyish, yellowish and reddish sandstone. The last two are sourced from slopes located more than 250m south of the tomb. Santos Rocha (1949: 14) found some "skeletons lying in gravel beds" and rare burnt bones. The dead were buried together with pottery, lithic and bone objects. Some of these indicate a reutilization of the monument during the Chalcolithic. The absence of use-wear in the majority of the lithics suggests that they were produced only for the burial practices. In addition to the symbolism intrinsic to morphologies, the use of different “raw” materials suggests the importance of the reunion of their own properties at the time of the burial, setting a symbolic and physical interconnection between local communities and near and remote places. The same reasoning can be applied to the architecture of the monument: if its construction on a limestone outcrop which is a culminating spot suggests the assimilation of the properties associated to the place and to the matter that exists there, the presence of “raw” materials from different sources among the standing stones of the chamber and the corridor imply a mental and physical interconnection between different places experienced by the builders. The visualized landscape must also have been significant to the people who built and attended the Cabeço dos Moinhos megalithic monument.info:eu-repo/semantics/publishedVersio

Chitosan nanoparticles as bioactive vehicles for textile dyeing: a proof of concept

In recent years bioactive textiles have risen to the forefront of consumers perception due to their potential protection against virus, fungi and bacteria. However, traditional textile staining is an eco-damaging process that and current methods of textile functionalization are expensive, complicated and with great environmental impact. With that in mind, this work sought to show a possible solution for this problematic through the usage of a novel one step textile dyeing and functionalization method based upon nanoencapsulated textile dyes (NTDs). To do so navy blue everzol NTDs were produced with chitosan, cotton dyed, characterized through FTIR and SEM and biological potential evaluated through biocompatibility screening and antimicrobial activity against skin pathogens. The data obtained showed that NTDs effectively dyed the target textile through a coating of the cotton fibre and that NTDs formed hydrogen bonds with the cellulose fibre via electrostatic interactions of the chitosan amino groups with cotton sulphate groups. From a biocompatibility perspective NTDs dyed cotton had no deleterious effects upon a skin cell line, as it promoted cellular metabolism of HaCat cells, while traditionally died cotton reduced it by 10%. Last but not least, NTDs dyed cotton showed significant antimicrobial activity as it reduced viable counts of MRSA, MSSA and A. baumannii between 1 and 2 log of CFU while traditional dyed cotton had no antimicrobial activity. Considering these results the novel method proposed shows is a viable and ecological alternative for the development of antimicrobial textiles with potential biomedical applications.info:eu-repo/semantics/publishedVersio

A combined approach for comparative exoproteome analysis of Corynebacterium pseudotuberculosis

Background: Bacterial exported proteins represent key components of the host-pathogen interplay. Hence, we sought to implement a combined approach for characterizing the entire exoproteome of the pathogenic bacterium Corynebacterium pseudotuberculosis, the etiological agent of caseous lymphadenitis (CLA) in sheep and goats. Results: An optimized protocol of three-phase partitioning (TPP) was used to obtain the C. pseudotuberculosis exoproteins, and a newly introduced method of data-independent MS acquisition (LC-MSE) was employed for protein identification and label-free quantification. Additionally, the recently developed tool SurfG+ was used for in silico prediction of sub-cellular localization of the identified proteins. In total, 93 different extracellular proteins of C. pseudotuberculosis were identified with high confidence by this strategy; 44 proteins were commonly identified in two different strains, isolated from distinct hosts, then composing a core C. pseudotuberculosis exoproteome. Analysis with the SurfG+ tool showed that more than 75% (70/93) of the identified proteins could be predicted as containing signals for active exportation. Moreover, evidence could be found for probable non-classical export of most of the remaining proteins. Conclusions: Comparative analyses of the exoproteomes of two C. pseudotuberculosis strains, in addition to comparison with other experimentally determined corynebacterial exoproteomes, were helpful to gain novel insights into the contribution of the exported proteins in the virulence of this bacterium. The results presented here compose the most comprehensive coverage of the exoproteome of a corynebacterial species so far

Hybrid manufacturing of aluminium parts combining additive and conventional technologies—mechanical and thermal properties

Metal additive-manufacturing technologies enable the production of complex geometries. However, high manufacturing costs hinder these technologies being employed in some industries. In this sense, a hybrid strategy is presented in this paper, to achieve the best of additive and subtractive technologies, offering economic advantages. AlSi10Mg aluminium powder was deposited on AW-6082 pre-machined substrates and mechanical and thermal properties of these specimens were evaluated considering the application of a stress relief heat treatment. The results were especially good in the compressive mechanical properties and in the thermal properties: compressive properties were improved by up to 27%, and the specific heat capacity and coefficient of thermal expansion were reduced by up to 38%, compared to additively manufactured AlSi10Mg. Therefore, hybrid manufacturing can be a profitable solution (i) in thermal management applications, (ii) when compressive loads are presented, or (iii) to repair damaged parts, providing a circular economy, as presented in a case study of this paper.Portuguese Fundação para a Ciência e a Tecnologia (FCT), for financial support under the Ph.D. scholarship SFRH/BD/144590/2019 and by the European Regional Development Fund (ERDF) through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) of the Portugal 2020 Program [Project No. 47108, “SIFA”; Funding Reference: POCI-01-0247-FEDER-047108

Teste rápido de aglutinação utilizando partículas de látex para a detecção de anticorpos anti-cisticercos em amostras de líquido cefalorraquidiano (LCR)

Simple and rapid latex-based diagnostic tests have been used for detecting specific antigens or antibodies in several diseases. In this article, we present the preliminary results obtained with a latex agglutination test (LAT) for diagnosing neurocysticercosis by detection of antibodies in CSF. A total of 43 CSF samples were assayed by the LAT: 19 CSF samples from patients with neurocysticercosis and 24 CSF samples from patients with other neurologic disorders (neurosyphilis, n = 8; neurotoxoplasmosis, n = 3; viral meningitis, n = 4, chronic headache, n = 9). The LAT exhibited 89.5% sensitivity and 75% specificity. The use of LAT seems to be an additional approach for the screening of neurocysticercosis with advantage of simplicity and rapidity. Further studies could be performed using purified antigens and serum samples.Testes diagnósticos simples e rápidos baseados na aglutinação de partículas de látex têm sido utilizados para a pequisa de antígenos ou anticorpos específicos em muitas doenças. No presente trabalho, é descrito um teste de aglutinação em lâmina para a pesquisa de anticorpos contra cisticercos de Taenia solium, utilizando partículas de látex revestidas com um extrato bruto do parasita. Anticorpos anti-cisticercos foram pesquisados em 19 amostras de LCR de pacientes com neurocisticercose e em 24 amostras de LCR de pacientes com outros problemas neurológicos (neurosífilis, n = 8; neurotoxoplasmose, n = 3; meningite viral, n = 4; cefaléia crônica, n = 9). O teste de aglutinação apresentou sensibilidade e especificidade de 89,5% e 75%, respectivamente. O teste de aglutinação para cisticercose idealizado é simples, rápido e barato. Essas características tornam o teste um meio promissor de expansão e simplificação do imunodiagnósico da neurocisticercose. Estudos futuros poderiam testar a sensibilização das partículas de látex com antígenos de cisticercos purificados e a pesquisa de anticorpos em amostras de soros