From the extraction of currently fulfilled requirements to value curves: a case-study in the field of harvesting machines for shell fruits and lessons learnt in engineering design

The market for agricultural machinery is characterized by products with a high degree of maturity in the product life cycle. Consequently, current improvements in new machinery are predominantly incremental and new projects basically use solutions that are already consolidated. This makes this domain appropriate for benchmarking existing systems and envisioning new value propositions. The present paper deals primarily with the former and uses the value curves as a means to structure the comparison among different families of technical systems; in particular, harvesting machines for shell fruits from the ground surface, e.g., chestnuts, walnuts, and hazelnuts, were investigated here. The process of building value curves requires the identification of currently fulfilled requirements. Despite the attention paid by engineering design research to requirements, a structured process is lacking to extract relevant information and create value curves or other representations useful for benchmarking. The present paper approaches this problem and presents how the authors have individuated relevant knowledge for characterizing different categories of harvesting machines. Namely, after an extensive search of the scientific literature and patents, a critical review of existing machines, aimed at individuating their functioning principles, architecture, and attitude in fulfilling specific design requirements, was performed. Then, existing machines were classified in 8 main categories, and their strengths and weaknesses were identified with reference to 11 competing factors. The consequent construction of value curves enabled the identification of possible points of intervention by hypothesizing possible future evolutions of such machinery, both in a structural and in a value-based perspective. Limitations about the repeatability of the followed approach and possible repercussions on design research are discussed

Editorial for the Special Issue "Requirements in Design Processes: Open Issues, Relevance and Implications"

Requirements play a key role in the design process by affecting analysis, synthesis and evaluation activities at different levels and in different ways [...

Biochemical characterization of the POM-1 metallo-β-lactamase from Pseudomonas otitidis

The POM-1 metallo--lactamase is a subclass B3 resident enzyme produced by Pseudomonas otitidis, a pathogen causing otic infections. The enzyme was overproduced in Escherichia coli BL21(DE3), purified by chromatography, and subjected to structural and functional analysis. The purified POM-1 is a tetrameric enzyme of broad substrate specificity with higher catalytic activities with penicillins and carbapenems than with cephalosporins

Understanding transmission and control of Cystic Echinococcosis and other taeniid infections in the Falkland Islands

Cystic echinococcosis, caused by the larval form of the cestode parasite Echinococcus granulosus, has been identified as an important public health risk in the Falkland Islands since the early 1940s. This prompted the instigation of an intensive control scheme in the mid-1960s, comprised of regular dosing of domestic dogs with the anthelmintic praziquantel and education of local people about safe disposal of potentially infected offal. This scheme has remained in place to the current day and is generally considered to be a successful programme– resulting in a reduction in the prevalence of infection in sheep has reduced from >50% in the 1950s to less than 1 % now and there has not been a case of human hydatid disease for more than 20 years. However, concerns remain that hydatid cysts are still identified in a small number of sheep at slaughter (0.004% in 2017) and occurring every year subsequently suggesting transmission is still occurring. This is also supported by the observation that sheep continue to be infected at higher levels with the (non-zoonotic) cestode Taenia hydatigena, also transmitted by dogs. In 2010, all dogs on the Falkland Islands were tested by Copro-PCR, resulting in eight dogs (1.4%) testing positive. The dog population was tested again in 2012, where there were no cases but when tested in 2014 by Coproantigen testing, six (1.04%) were positive for E. granulosus coproantigens. This project used questionnaires, coproantigen and coproPCR analysis, abattoir data surveillance, DNA sequencing, environmental sample analysis and mathematical modelling to study Echinococcus granulosus and other taeniids endemic in the Falklands and investigate how their continued transmission can occur in the face of the prolonged intensive control programme. A questionnaire survey identified possible methods of disposal of offal that in a previous study, were associated with canine coproantigen positivity. The entire dog population was analysed via coproantigen techniques in 2018, and four (0.68%) dogs were coproantigen positive, though none of these were confirmed by PCR. From 2018 to 2020, five cases of CE were identified in sheep at the Sand Bay abattoir in the Falklands (0.01%), with one of the cases coming from a positive farm in 2018. There were two cases from farms with positive dogs in 2010 and one from a farm with a positive dog in 2014. To investigate environmental contamination on farms and potentially identify historical dog infections, soil samples taken from kennel sites were analysed for the presence of coproantigens, with five farms having positive results, one farm matching with a positive dog in 2018. To identify key processes fuelling the transmission of E. granulosus in the Falklands, a mechanically informed compartmental model was created, estimating the basic reproduction number (R0) for the parasite, and identifying scenarios where this estimate increased above one suggesting continued transmission could occur. Seven scenarios where lapses in control measures could result in the R0 estimate increasing above one and continued transmission of E. granulosus could occur. The results of this project show clear evidence of dogs still being involved in the transmission of taeniid parasites in the Falklands, with key areas of the eradication programme such as the inadequate disposal of offal and dogs gaining access to offal allowing the transmission cycle to be completed and transmission of E. granulosus and other taeniids to occur. Rectifying these lapses in control measures and focussing control and surveillance to a more localised control approach will help strengthen the control programme and move the Falklands closer towards the complete eradication of Cystic Echinococcosis

Determinants of antibody persistence across doses and continents after single-dose rVSV-ZEBOV vaccination for Ebola virus disease: an observational cohort study.

BACKGROUND: The recombinant vesicular stomatitis virus (rVSV) vaccine expressing the Zaire Ebola virus (ZEBOV) glycoprotein is efficacious in the weeks following single-dose injection, but duration of immunity is unknown. We aimed to assess antibody persistence at 1 and 2 years in volunteers who received single-dose rVSV-ZEBOV in three previous trials. METHODS: In this observational cohort study, we prospectively followed-up participants from the African and European phase 1 rVSV-ZEBOV trials, who were vaccinated once in 2014-15 with 300 000 (low dose) or 10-50 million (high dose) plaque-forming units (pfu) of rVSV-ZEBOV vaccine to assess ZEBOV glycoprotein (IgG) antibody persistence. The primary outcome was ZEBOV glycoprotein-specific IgG geometric mean concentrations (GMCs) measured yearly by ELISA compared with 1 month (ie, 28 days) after immunisation. We report GMCs up to 2 years (Geneva, Switzerland, including neutralising antibodies up to 6 months) and 1 year (Lambaréné, Gabon; Kilifi, Kenya) after vaccination and factors associated with higher antibody persistence beyond 6 months, according to multivariable analyses. Trials and the observational study were registered at ClinicalTrials.gov (Geneva: NCT02287480 and NCT02933931; Kilifi: NCT02296983) and the Pan-African Clinical Trials Registry (Lambaréné PACTR201411000919191). FINDINGS: Of 217 vaccinees from the original studies (102 from the Geneva study, 75 from the Lambaréné study, and 40 from the Kilifi study), 197 returned and provided samples at 1 year (95 from the Geneva study, 63 from the Lambaréné, and 39 from the Kilifi study) and 90 at 2 years (all from the Geneva study). In the Geneva group, 44 (100%) of 44 participants who had been given a high dose (ie, 10-50 million pfu) of vaccine and who were seropositive at day 28 remained seropositive at 2 years, whereas 33 (89%) of 37 who had been given the low dose (ie, 300 000 pfu) remained seropositive for 2 years (p=0·042). In participants who had received a high dose, ZEBOV glycoprotein IgG GMCs decreased significantly between their peak (at 1-3 months) and month 6 after vaccination in Geneva (p0·05). Neutralising antibodies seem to be less durable, with seropositivity dropping from 64-71% at 28 days to 27-31% at 6 months in participants from the Geneva study. INTERPRETATION: Antibody responses to single-dose rVSV-ZEBOV vaccination are sustained across dose ranges and settings, a key criterion in countries where booster vaccinations would be impractical. FUNDING: The Wellcome Trust and Innovative Medicines Initiative 2 Joint Undertaking

The epistemological trends of Social Work in the latin american context

ABSTRACT: The purpose of this article is to share some of the results of the research State of the Art of the Theoretical and Methodological Foundations of the Professional Intervention of Social Work in Latin America. It analyzes the epistemological dimension of professional intervention in Social Work by reviewing scholarly production in Argentina, Brazil, Chile and Colombia from 1998-2008. The discussion seeks to advance in the configuration of the disciplinary status of Social Work, by consolidating intervention as the foundational and structuralizing axis of the profession, emphasizing its scientific and transformative character in the realm of the social sciences.RESUMEN: El presente artículo tiene como finalidad compartir algunos de los resultados de la investigación Estado del arte sobre la fundamentación teórica y metodológica de la intervención profesional en Trabajo Social en América Latina. Se aborda la problematización de la dimensión epistemológica en la intervención profesional en Trabajo Social a partir de la revisión de esta producción en cuatro países: Argentina, Brasil, Chile y Colombia, en el periodo comprendido ente 1998-2008. La discusión que se propone, pretende avanzar en la configuración del estatuto disciplinar en Trabajo Social, a partir de la consolidación de la intervención como eje fundante y estructurante de la profesión, reivindicando su carácter científico y transformador en el concierto de las ciencias sociales