Controlo químico de infestantes

Uma planta é considerada infestante quando nasce espontaneamente num local e momento indesejados, podendo interferir negativamente com a cultura instalada. As infestantes competem com as culturas para o espaço, a luz, água e nutrientes, podendo atrasar e prejudicar as operações de colheita, depreciar o produto final e assegurarem a reinfestação nas culturas seguintes. Dado o modo de propagação diferenciado das diversas espécies de infestantes, com as anuais a propagarem-se por semente e as perenes ou vivazes a assegurarem a sua propagação através de órgãos vegetativos (rizomas, bolbos, tubérculos, etc.), assim, também o seu controlo quer químico, quer mecânico terá que ser diferenciado, ou seja, para controlar infestantes anuais será suficiente destruir a sua parte aérea, enquanto para controlar infestantes perenes teremos que destruir os seus órgãos reprodutivos. O controlo de infestantes poderá ser químico, através da utilização de herbicidas, ou mecânico pela utilização de alfaias agrícolas, tais como a charrua de aivecas, a charrua de discos, a grade de discos, o escarificador e a fresa. Quando a técnica utilizada na instalação das culturas é a sementeira directa, o controlo das infestantes terá que ser obrigatoriamente químico, enquanto se o recurso à mobilização do solo for a técnica mais utilizada (sistema de mobilização tradicional ou sistema de mobilização reduzida), o controlo das infestantes tanto poderá ser químico como mecânico. Neste trabalho iremos abordar apenas, o controlo químico de infestantes

Hematopoietic cell transplantation in severe combined immunodeficiency : The SCETIDE 2006-2014 European cohort

Publisher Copyright: © 2021 The AuthorsBackground: Hematopoietic stem cell transplantation (HSCT) represents a curative treatment for patients with severe combined immunodeficiency (SCID), a group of monogenic immune disorders with an otherwise fatal outcome. Objective: We performed a comprehensive multicenter analysis of genotype-specific HSCT outcome, including detailed analysis of immune reconstitution (IR) and the predictive value for clinical outcome. Methods: HSCT outcome was studied in 338 patients with genetically confirmed SCID who underwent transplantation in 2006-2014 and who were registered in the SCETIDE registry. In a representative subgroup of 152 patients, data on IR and long-term clinical outcome were analyzed. Results: Two-year OS was similar with matched family and unrelated donors and better than mismatched donor HSCT (P 0.5 × 10e3/μL at +1 year were identified as independent predictors of favorable clinical and immunologic outcome. Conclusion: Recent advances in HSCT in SCID patients have resulted in improved OS and EFS in all genotypes and donor types. To achieve a favorable long-term outcome, treatment strategies should aim for optimal naive CD4 T lymphocyte regeneration.Peer reviewe

Hematopoietic stem cell transplantation for CD40 ligand deficiency : results from an EBMT/ESID-IEWP-SCETIDE-PIDTC Study

BACKGROUND: CD40 ligand (CD40L) deficiency, an X-linked primary immunodeficiency, causes recurrent sinopulmonary, Pneumocystis and Cryptosporidium species infections. Long-term survival with supportive therapy is poor. Currently, the only curative treatment is hematopoietic stem cell transplantation (HSCT). OBJECTIVE: We performed an international collaborative study to improve patients' management, aiming to individualize risk factors and determine optimal HSCT characteristics. METHODS: We retrospectively collected data on 130 patients who underwent HSCT for CD40L deficiency between 1993-2015. We analyzed outcome and variables' relevance with respect to survival and cure. RESULTS: Overall survival (OS), event-free survival (EFS), and disease-free survival (DFS) were 78.2%, 58.1%, and 72.3% 5 years after HSCT. Results were better in transplantations performed in 2000 or later and in children less than 10 years old at the time of HSCT. Pre-existing organ damage negatively influenced outcome. Sclerosing cholangitis was the most important risk factor. After 2000, superior OS was achieved with matched donors. Use of myeloablative regimens and HSCT at 2 years or less from diagnosis associated with higher OS and DFS. EFS was best with matched sibling donors, myeloablative conditioning (MAC), and bone marrow-derived stem cells. Most rejections occurred after reduced-intensity or nonmyeloablative conditioning, which associated with poor donor cell engraftment. Mortality occurred mainly early after HSCT, predominantly from infections. Among survivors who ceased immunoglobulin replacement, T-lymphocyte chimerism was 50% or greater donor in 85.2%. CONCLUSION: HSCT is curative in patients with CD40L deficiency, with improved outcome if performed before organ damage development. MAC is associated with better OS, EFS, and DFS. Prospective studies are required to compare the risks of HSCT with those of lifelong supportive therapy.status: publishe

Proactive Environmental Strategies and Their Impact on Hotel Competitiveness During Crisis: The Case of the Czech Hotel Industry

This research focuses on hotel competitiveness in the Czech Republic. It provides evidence that proactive environmental strategies implemented in hotel operations are a competitive advantage for hotels, especially during a crisis. This research determined the impact of proactive environmental strategies on hotel competitiveness in the period before and during the COVID-19 pandemic. Competitiveness was assessed based on the occupancy rate and hotel experience. Data were obtained through quantitative research, which involved 110 accommodation facilities from the Czech Republic, of which 51 were common hotels and 59 were green hotels. The research yields two groups of results. The first group is the results of testing the dependence between the type of hotel and changes in hotel competitiveness. These results did not confirm the relationship between hotel type according to implementation of proactive environmental strategies and competitiveness based neither on evaluation of hotel experience nor on the occupancy rate. According to these findings, it does not matter whether the hotel is green during a crisis. The second group of results includes concrete values of changes in occupancy in the second and third quarters of 2019 and 2020, as well as specific changes in the clientele. The decrease in occupancy in the second quarter of 2020 compared with 2019 was not as significant as expected. In the third quarter of 2020, the year-on-year change was minimal, and some accommodation facilities experienced an increase in occupancy because Czech visitors embraced domestic tourism. In this case, the absolute indicators show that green hotels had an advantage.</jats:p

Detectable Minimal Residual Disease before Haematopoietic Stem Cell Transplantation Predicts Extremely Poor Prognosis in Children with Acute Lymphoblastic Leukaemia.

Abstract The level of minimal residual disease (MRD) prior to allogeneic haematopoietic stem cell transplantation (HSCT) was shown to be an independent prognostic factor for the outcome of paediatric patients with high-risk acute lymphoblastic leukemia (ALL). Retrospective studies which used (semi-)quantitation of clone-specific immunoglobulin/T-cell receptor (Ig/TCR) rearrangements documented feasibility and practicality of such an approach. Recently, this approach was disputed by Imashuku et al (BMT 2003) due to great occurrence of the clonal evolution and generally high MRD levels prior HSCT in their cohort. In our prospective study, MRD before and after HSCT was monitored in a cohort of 36 children with ALL consecutively transplanted in our centre between VIII/2000 and VII/2004. We used a quantitative real-time PCR approach introduced and standardised by European Study Group on MRD in ALL. In 25 of 36 patients MRD level prior HSCT was assessed (9 patients lacked adequately sensitive Ig/TCR target; two lacked analysable DNA prior HSCT). Seventeen patients were MRD-negative prior HSCT (including two with MRD level below the quantitative range 10(−4)) and 8 were MRD-positive up to 9x10(−2). In the MRD-positive subgroup, 7 events (6 relapses) occurred post-transplant in striking contrast to only one relapse in MRD-negative subgroup (EFS log-rank p&lt;0.0001). MRD proved to be the only significant prognostic factor in a multivariate analysis (p&lt;0.0001). Adoptive immunotherapy including donor lymphocyte infusions in patients with adverse dynamics of MRD after HSCT had only limited and/or temporary effect. Clonal evolution did not present a problem precluding MRD monitoring in any of patients suffering a post-transplant relapse. We show that MRD quantitation using clonal Ig/TCR rearrangements represents a feasible approach for the risk assessment in paediatric ALL patients undergoing allogeneic HSCT. However, our ability to respond to detectable MRD levels after HSCT and to avert an impending relapse is very limited. The change of the approach to MRD-positive patients prior HSCT is necessary because of very questionable benefit of HSCT in these children. Supported by grants MSM0021620813, FNM 9735 and GAUK 62/2004.</jats:p