Evaluation of the susceptibility of Portuguese autochthonous flora to the pine wilt nematode (Bursaphelenchus xilophylus)

info:eu-repo/semantics/publishedVersio

Study of symptoms and gene expression in four Pinus species after pinewood nematode infection

Pine wilt disease, caused by the pinewood nematode Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle, is originating severe infections in pine trees. The disease is detected when external symptoms appear (e.g. needle chlorosis), but trees could remain asymptomatic for long periods and serve as a long-term host. The primary goal of this study was to assess the effect of inoculation with an avirulent isolate of B. xylophilus (C14-5) on different Pinus spp. seedlings (P. sylvestris, P. nigra, P. pinea and P. pinaster). At the same time, seedlings were also inoculated with a virulent strain, HF, in order to compare the phenotypic and genomic results of the two types of inoculations. The effect of inoculation was determined in terms of expression of various Pinus genes potentially involved in the response to the disease.The results suggest that P. pinea and P. nigra are more resistant to infection by the nematode than P. sylvestris and P. pinaster. The phenotypic and genetic differences were more marked among P. pinea and P. pinaster.info:eu-repo/semantics/acceptedVersio

Deri yara kaplamalarindaki uygulamalar için elektrik alan lif çekim ile üretilmiş Tiger 17 peptit yüklü polikaprolakton/selüloz asetat nano lifli matlar

A skin wound if not properly treated can result in a chronic wound susceptible to widespread infections, which can result in the patient's death. Currently, tissue engineering is described as an interdisciplinary field that combines principles of engineering, chemistry and biology to generate solutions that allow to repair, restore and/or improve the functions of injured tissues. In the same sense, the textile area addresses solutions based on polymeric fibers, produced from a wide range of polymers, which allow the generation of structures with a large surface area, porosity and mechanical resistance that can be used as bioactive dressings that promote a healing and efficient antimicrobial activity. This research work focused on the synthesis of Tiger 17, through microwave-assisted solid-phase synthesis methodologies, and Tiger 17 commercially obtained, respective structural characterization and evaluation of the antimicrobial capacity. Simultaneously, nanofibrous polymer matrices were produced using the electrospinning technique with the aim of immobilizing the developed biomolecule and thus creating potential vehicles for a local and sustainable antimicrobial action (controlled release). In order to verify its physical and chemical properties, advanced characterization techniques were used: proton nuclear magnetic resonance, high performance liquid chromatography, optical microscopy, scanning electron microscopy, fourier transform infrared spectroscopy–attenuated total reflectance, thermogravimetry, differential scanning calorimetry, contact angle and surface energy and determination of porosity and hydration.Düzgün tedavi edilmeyen bir cilt yarası, hastanın ölümüyle sonuçlanabilecek yaygın enfeksiyonlara duyarlı kronik bir yaraya neden olabilir. Günümüzde doku mühendisliği, hasarlı dokuların işlevlerini onarmaya, eski haline getirmeye ve/veya iyileştirmeye olanak tanıyan çözümler üretmek için mühendislik, kimya ve biyolojinin ilkelerini birleştiren disiplinler arası bir alan olarak tanımlanmaktadır. Bu kapsamda, tekstil, iyileşmeyi ve etkili antimikrobiyal aktiviteyi teşvik eden biyoaktif pansuman olarak kullanılabilecek, geniş yüzey alanlı, gözenekli ve mekanik dirençli yapıların oluşturulmasına izin veren, geniş bir polimer yelpazesinden üretilen liflere dayalı çözümler sunmaktadır. Bu araştırma çalışması, mikrodalga destekli katı faz sentez metodolojileri aracılığıyla Tiger 17'nin sentezine ve ticari olarak temin edilen Tiger 17 ile birlikte yapısal karakterizasyonunun ve antimikrobiyal kapasitenin değerlendirilmesine odaklanmıştır. Aynı zamanda, geliştirilen biyomolekülü hareketsiz hale getirmek ve böylece lokal ve sürdürülebilir bir antimikrobiyal etki (kontrollü salım) için potansiyel çözümler yaratmak amacıyla elektrik alan lif üretim tekniği kullanılarak nanolifli polimer matrisler üretildi. Yapının fiziksel ve kimyasal özelliklerini doğrulamak için, proton nükleer manyetik rezonans, yüksek performanslı sıvı kromatografisi, optik mikroskopi, taramalı elektron mikroskobu, fourier dönüşümü kızılötesi spektroskopisi-zayıflatılmış toplam yansıma, termogravimetri, diferansiyel taramalı kalorimetri, temas açısı, yüzey enerjisi, gözeneklilik ve su tutma ölçümleri gibi ileri karakterizasyon teknikleri kullanıldı

Proposta de um algoritmo de recomendação usando uma rede bayesiana no health simulator

Este artigo apresenta o projeto Health Simulator no contexto de inteligência artificial, no que se refere ao armazenamento do conhecimento especializado na área da saúde e estratégia pedagógica, que permite o auxílio ao aluno no seu processo de aprendizagem. Para tanto é apresentada a teoria de redes bayesianas, sistemas de recomendação, o projeto Health Simulator e a proposta de aplicação das técnicas utilizadas neste ambiente

Playing Darwin. Part B. 20 years of domestication in Drosophila subobscura

Adaptation to a new environment (as well as its underlying mechanisms) is one of the most important topics in Evolutionary Biology. Understanding the adaptive process of natural populations to captivity is essential not only in general evolutionary studies but also in conservation programmes. Since 1990, the Group of Experimental Evolution (CBA/FCUL) has been performing long-term, real-time evolutionary studies, with the characterization of laboratory adaptation in populations of Drosophila subobscura founded in different times and from different locations. Initially, these experiments involved phenotypic assays and more recently were expanded to studies at the molecular level (microsatellite and chromosomal polymorphisms) and with different population sizes. Throughout these two decades, a clear pattern of evolutionary convergence to long-established laboratory populations has been consistently observed in several life-history traits. However, contingencies across foundations were also found during the adaptive process. In characters with complex evolutionary trajectories, the data suggested that the comparative method lacked predictive capacity relative to real-time evolutionary trajectories (experimental evolution). Microsatellite analysis revealed general similarity in gene diversity and allele number between studied populations, as well as an unclear association between genetic variability and evolutionary potential. Nevertheless, ongoing studies in all foundations are being carried out to further test this hypothesis. A comparison between recently introduced and long-term populations (founded from the same natural location) has shown higher degree of chromosomal polymorphism in recent ones. Finally, our findings suggest higher heterogeneity between small-sized populations, as well as a slower evolutionary rate in characters close to fitness (such as fecundity and mating behaviour). This comprehensive study is aimed at better understanding the processes and patterns underlying adaptation to captivity, as well as its genetic basis

Impact of Continuous Axenic Cultivation in Leishmania infantum Virulence

Experimental infections with visceral Leishmania spp. are frequently performed referring to stationary parasite cultures that are comprised of a mixture of metacyclic and non-metacyclic parasites often with little regard to time of culture and metacyclic purification. This may lead to misleading or irreproducible experimental data. It is known that the maintenance of Leishmania spp. in vitro results in a progressive loss of virulence that can be reverted by passage in a mammalian host. In the present study, we aimed to characterize the loss of virulence in culture comparing the in vitro and in vivo infection and immunological profile of L. infantum stationary promastigotes submitted to successive periods of in vitro cultivation. To evaluate the effect of axenic in vitro culture in parasite virulence, we submitted L. infantum promastigotes to 4, 21 or 31 successive in vitro passages. Our results demonstrated a rapid and significant loss of parasite virulence when parasites are sustained in axenic culture. Strikingly, the parasite capacity to modulate macrophage activation decreased significantly with the augmentation of the number of in vitro passages. We validated these in vitro observations using an experimental murine model of infection. A significant correlation was found between higher parasite burdens and lower number of in vitro passages in infected Balb/c mice. Furthermore, we have demonstrated that the virulence deficit caused by successive in vitro passages results from an inadequate capacity to differentiate into amastigote forms. In conclusion, our data demonstrated that the use of parasites with distinct periods of axenic in vitro culture induce distinct infection rates and immunological responses and correlated this phenotype with a rapid loss of promastigote differentiation capacity. These results highlight the need for a standard operating protocol (SOP) when studying Leishmania species