322 research outputs found

    Potential use of electronic noses, electronic tongues and biosensors, as multisensor systems for spoilage examination in foods

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    Development and use of reliable and precise detecting systems in the food supply chain must be taken into account to ensure the maximum level of food safety and quality for consumers. Spoilage is a challenging concern in food safety considerations as it is a threat to public health and is seriously considered in food hygiene issues accordingly. Although some procedures and detection methods are already available for the determination ofspoilage in food products, these traditional methods have some limitations and drawbacks as they are time-consuming,labour intensive and relatively expensive. Therefore, there is an urgent need for the development of rapid, reliable, precise and non-expensive systems to be used in the food supply and production chain as monitoring devices to detect metabolic alterations in foodstuff. Attention to instrumental detection systems such as electronic noses, electronic tongues and biosensors coupled with chemometric approaches has greatly increased because they have been demonstrated as a promising alternative for the purpose of detecting and monitoring food spoilage. This paper mainly focuses on the recent developments and the application of such multisensor systems in the food industry. Furthermore, the most traditionally methods for food spoilage detection are introduced in this context as well. The challenges and future trends of the potential use of the systems are also discussed. Based on the published literature, encouraging reports demonstrate that such systems are indeed the most promising candidates for the detection and monitoring of spoilage microorganisms in different foodstuff

    The Role of Learning in Smallholder Farmers’ Decision Outcomes: An Agent-Based Modelling Approach

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    Smallholder farmers’ decisions have important implications for the global food system and global environmental changes. Models have been successfully used to understand human decision-making, including that of farmers, and to explore policy interventions towards sustainability. A frequent approach has been to represent economic decisions in aggregate ways and to assume perfect information and utility maximisation. In reality, farmers have to cope with uncertainties about the dynamics of the social-ecological system (SES) that they are part of and they also act in ways that deviate from rational choice theory. As such, learning processes and adaptive behaviour represent an unexplored, but potentially rich avenue for understanding decision-making. In this paper we study the social-ecological outcomes of two such processes that have been suggested as key by sustainability scholars: learning-by-doing and social learning. We expand a pre-existing stylised agent-based model (ABM) of human decision-making within an SES to include learning-by-doing and social learning agents, and we study the impact of their learning strategies on economic, ecological and social outcomes. Our results show that learning agents are able to better match their decisions to the ecological conditions than non-learning agents. In addition, depending on the normative goals pursued, one learning strategy might be more suitable than the other. Lastly, we analyse diffusion dynamics and we find that an initial share of learning-by-doing agents of about 11% might constitute a critical mass for this behaviour to become dominant in a population. This points to research areas of policy relevance that could be explored in future studies

    Coadministration of lopinavir/ritonavir and rifampicin in HIV and tuberculosis co-infected adults in South Africa

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    In HIV-infected patients receiving rifampicin-based treatment for tuberculosis (TB), the dosage of lopinavir/ritonavir (LPV/r) is adjusted to prevent sub-therapeutic lopinavir concentrations. In this setting, South African clinicians were advised to administer super-boosted LPV/r (400 mg/400 mg) twice daily, instead of standard dosed LPV/r (400 mg/100 mg) twice daily. We sought to determine--in routine practice--the tolerability and HIV treatment outcomes associated with super-boosted LPV/r compared to unadjusted LPV/r in combination with rifampicin-based TB treatment

    Severe spinal stenosis in an adult achondroplastic dwarf: Case report

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    Achondroplasia is the most common form of human short-limbed dwarfism and is one of a spectrum of diseases caused by mutations in the FGFR3 gene. Achondroplasia is estimated to occur in 1 in 10,000–30,000 live births4,7. The disease is autosomal dominant, but 80% of patients have new mutations. It is commonly associated with several neurological conditions such as hydrocephalus, cervicomedullary compression, cervical or thoracic cord compression, and lumbar spinal compression due to bone stenosis along the neuraxis. We report a case with severe spinal stenosis at the lumbar and thoracic levels, with minimal involvement of the cervical spine with late neurological onset in an adult patient with achondroplasia. Neurological and radiological findings and surgical procedures are discussed. The patient was admitted with profound spastic lower paraparesis and urinary incontinence. In the first operation we performed lumbar decompression and the patient improved and on the fifth day she was able to take a short walk. 3 months after the first surgery we intervened on the thoracic spine with a multi-level decompression which allowed for further neurological improvement, continued in a specialized medical facility. The case stands out as the clinical picture was dominated by the lumbar stenosis (although both lumbar and thoracic stenosis were severe at the time of presentation) with a late onset and sparing of the cervical spine

    Improving the representation of smallholder farmers’ adaptive behaviour in agent-based models: Learning-by-doing and social learning

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    Computational models have been used to investigate farmers’ decision outcomes, yet classical economics assumptions prevail, while learning processes and adaptive behaviour are overlooked. This paper advances the conceptualisation, modelling and understanding of learning-by-doing and social learning, two key processes in adaptive (co-)management literature. We expand a pre-existing agent-based model (ABM) of an agricultural social-ecological system, RAGE (Dressler et al., 2018). We endow human agents with learning-by-doing and social learning capabilities, and we study the impact of their learning strategies on economic, ecological and social outcomes. Methodologically, we contribute to an under-explored area of modelling farmers’ behaviour. Results show that agents who employ learning better match their decisions to the ecological conditions than those who do not. Imitating the learning type of successful agents further improves outcomes. Different learning processes are suited to different goals. We report on conditions under which learning-by-doing becomes dominant in a population with mixed learning approaches

    Empleo de CO2 presurizado como tecnología no térmica en la conservación de zumos

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    Póster presentado en: 9ª Reunión de Expertos en Tecnologías de Fluidos Supercríticos (Flucomp), 13 a 15 de junio de 2018, Madrid. Jornada Academia-Empresa (one‐to‐one)Este trabajo se centra en la aplicación de la tecnología no térmica HPCD (High Pressure Carbon Dioxide), basada en el empleo del dióxido de carbono a alta presión, generalmente inferior a 50 MPa, para la conservación de alimentos. Se ha estudiado específicamente su aplicación en el proceso de pasteurización de zumos con pH ácido como el de naranja1, manzana2 y tomate. Para ello se han determinado las cinéticas de inactivación de diferentes enzimas como polifenoloxidasa (PPO), responsable del pardeamiento enzimático y pectinmetilesterasa (PME), que junto con poligalacturonasa (PG) juegan un papel importante en la viscosidad de los zumos. El grado de inactivación enzimática encontrado depende tanto de la fuente de la enzima, como de las condiciones de procesado, tiempo, presión y temperatura. Así, en el caso del zumo de manzana se consiguieron actividades residuales en torno a 10 % para la PPO, mientras que para la PME fueron en torno a 65 % en las mismas condiciones de procesado, 60 min, 45ºC y 20 MPa. En este caso, la estructura más compleja de la PME, con tres subunidades frente a una de la PPO, la hace más resistente al tratamiento. Otra de las variables importantes en el tratamiento mediante HPCD es la relación CO2:volumen tratado. Se realizaron estudios con diversas enzimas comerciales (PPO y PME), encontrando que relaciones superiores a 3 g CO2:mL no conllevan un mayor grado de inactivación, pudiendo así optimizar el proceso desde un punto de vista económico. Estudios de espectroscopía de fluorescencia en estas enzimas comerciales tratadas mediante HPCD correlacionaron cambios en la estructura terciaria de la enzima con la pérdida de actividad enzimática de la mismas a diferentes condiciones de presión y temperatura.MINECO y FEDER, proyecto CTQ2015-64396-R y el contrato de AEI. MINECO, contrato FPI (BES-2013-063937) de RM y JCyL y FEDER, contrato de OBR (BU055U16)

    Seroprevalence of Zika virus in wild African green monkeys and baboons

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    ABSTRACT Zika virus (ZIKV) has recently spread through the Americas and has been associated with a range of health effects, including birth defects in children born to women infected during pregnancy. Although the natural reservoir of ZIKV remains poorly defined, the virus was first identified in a captive “sentinel” macaque monkey in Africa in 1947. However, the virus has not been reported in humans or nonhuman primates (NHPs) in Africa outside Gabon in over a decade. Here, we examine ZIKV infection in 239 wild baboons and African green monkeys from South Africa, the Gambia, Tanzania, and Zambia using combinations of unbiased deep sequencing, quantitative reverse transcription-PCR (qRT-PCR), and an antibody capture assay that we optimized using serum collected from captive macaque monkeys exposed to ZIKV, dengue virus, and yellow fever virus. While we did not find evidence of active ZIKV infection in wild NHPs in Africa, we found variable ZIKV seropositivity of up to 16% in some of the NHP populations sampled. We anticipate that these results and the methodology described within will help in continued efforts to determine the prevalence, natural reservoir, and transmission dynamics of ZIKV in Africa and elsewhere. IMPORTANCE Zika virus (ZIKV) is a mosquito-borne virus originally discovered in a captive monkey living in the Zika Forest of Uganda, Africa, in 1947. Recently, an outbreak in South America has shown that ZIKV infection can cause myriad health effects, including birth defects in the children of women infected during pregnancy. Here, we sought to investigate ZIKV infection in wild African primates to better understand its emergence and spread, looking for evidence of active or prior infection. Our results suggest that up to 16% of some populations of nonhuman primate were, at some point, exposed to ZIKV. We anticipate that this study will be useful for future studies that examine the spread of infections from wild animals to humans in general and those studying ZIKV in primates in particular. Podcast: A podcast concerning this article is available

    Intradiploic epidermoid cyst of the skull: Case report

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    Authors describe a giant intradiploic epidermoid cyst of the cranial vault with massive intra- and extracranial extension and analyze the clinicopathological, imaging features and treatment of these lesions in the light of the most important published data. A 38-years old male patient with a history of chronic headache reported a painless subcutaneous swelling 4 months ago on the right frontoparietal scalp. CT and MRI evaluation revealed a large well-defined extracerebral mass in the frontoparietal scalp with destruction of both the inner and outer tables of the bone. The patient underwent a total microsurgical resection of the tumor and the cranial defect produced by the resection of the space-occupaying lesion was repaired with titanium wire mesh and methyl methacrylate cranioplasty. The histological examination has shown a cystic structure lined by squamous epithelium and containing laminated keratin material, aspects that are suggesting a epidermoid cyst. The patient post-operative course was uneventful, without any neurological deficit and was discharged after 48 hours of hospitalisation in a good medical condition. The review of the literature shows that the parietal bone location for intradiploic epidermoid tumors in rare. Complete surgical resection represent the gold standard of treatment, and no adjuvant therapy is needed. Recent advances in diagnostic imaging and treatment of these lesions are reviewed.&nbsp

    Antibiotic and Antiinflammatory Therapy Transiently Reduces Inflammation and Hypercoagulation in Acutely SIV-Infected Pigtailed Macaques

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    Increased chronic immune activation and inflammation are hallmarks of HIV/SIV infection and are highly correlated with progression to AIDS and development of non-AIDS comorbidities, such as hypercoagulability and cardiovascular disease. Intestinal dysfunction resulting in microbial translocation has been proposed as a lead cause of systemic immune activation and hypercoagulability in HIV/SIV infection. Our goal was to assess the biological and clinical impact of a therapeutic strategy designed to reduce microbial translocation through reduction of the microbial content of the intestine (Rifaximin-RFX) and of gut inflammation (Sulfasalazine-SFZ). RFX is an intraluminal antibiotic that was successfully used in patients with hepatic encephalopathy. SFZ is an antiinflammatory drug successfully used in patients with mild to moderate inflammatory bowel disease. Both these clinical conditions are associated with increased microbial translocation, similar to HIV-infected patients. Treatment was administered for 90 days to five acutely SIV-infected pigtailed macaques (PTMs) starting at the time of infection; seven untreated SIVsab-infected PTMs were used as controls. RFX+SFZ were also administered for 90 days to three chronically SIVsab-infected PTMs. RFX+SFZ administration during acute SIVsab infection of PTMs resulted in: significantly lower microbial translocation, lower systemic immune activation, lower viral replication, better preservation of mucosal CD4+ T cells and significantly lower levels of hypercoagulation biomarkers. This effect was clear during the first 40 days of treatment and was lost during the last stages of treatment. Administration of RFX+SFZ to chronically SIVsab–infected PTMs had no discernible effect on infection. Our data thus indicate that early RFX+SFZ administration transiently improves the natural history of acute and postacute SIV infection, but has no effect during chronic infection
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