2957 research outputs found
Sort by
Management of bacterial blight of carrots by phenolic compounds treatment
Get PDFBacterial blight is a serious disease of carrot production worldwide. Under favorable conditions, the causal organism Xanthomonas hortorum pv. carotae causes serious loss especially in seed production because of its seed-borne character. Unlike fungal diseases, the treatment of bacterial diseases is limited and methods such as hot water or sodium hypochlorite (bleach) treatment are mainly used by seed companies. Here, we compared the efficacy of hot water treatment, sodium hypochlorite treatment and treatment with three phenolic compounds-carvacrol, thymol and eugenol, to eliminate Xanthomonas growth in vitro and subsequently in vivo on seeds of Xhc low, medium and highly infested carrot seed lots. The complete elimination of Xhc from germinated plants was obtained only for Xhc low infested seed lot with 1% sodium hypochlorite and carvacrol solutions in concentrations of 0.0196%- 0.313%. The significant reduction of Xhc presence in germinated plants of Xhc medium infested seed lot was achieved with 1% sodium hypochlorite treatment and hot water treatment. However, hot water treatment resulted in a significant reduction of seed germination percentage as well. Considering the elimination of Xhc infection from germinated plants and the effect on seed germination and plant vigor, 0.0196% carvacrol solution was suggested as an alternative to 1% sodium hypochlorite treatment regarding additional costs related to the liquidation of used treated water and to hot water treatment that has been proved to be insufficient to obtain disease-free plants.O
The response of forested upland micro-watersheds to extreme precipitation in a precipitation abundant year
Get PDFWe performed a comparative paired catchment study of three headwater upland forest micro-catchments with different forest types in the precipitation-abundant year 2020. The analysis was based on baseflow separation and resulting baseflow index (BFI). The year 2020 was intentionally chosen as a way to reflect the expected effects of climate change in the region where more extreme hydroclimatic events are expected. Our team demonstrated that in case of hydroclimatic extremes, there are significant differences in the runoff response from these catchments, depending especially on the tree species composition in the forest stands. Three forest types with the predominance of European beech (Fagus sylvatica), Norway spruce (Picea abies), and mixed forest were analyzed. The observed different values of BFI were interpreted in relation to the ability of forest stands to retain water and slow runoff in extreme runoff events determined by the stormflow component as an indication of their flood control efficiency. A significantly worse flood control efficiency and an overreaction of runoff response to precipitation events were observed in the spruce catchment. This also suggests that the spruce catchment is more prone to suffer from drought since twice as much water was lost from the system during extreme hydroclimatic events as opposed to the other two with less spruce in the stands and less water is thus available for groundwater recharge.OA-hybri
Sequence and phylogenetic analysis of a novel alphaendornavirus, the first virus described from the oomycete plant pathogen Phytophthora heveae
Get PDFHere, we report the discovery and complete genome sequence of a novel virus, designated as "Phytophthora heveae alphaendornavirus 1" (PhAEV1), from a single isolate of the plant pathogenic oomycete Phytophthora heveae (kingdom Stramenipila) isolated from a tropical evergreen lowland rainforest in northern Vietnam. PhAEV1 was detected by both cellulose affinity chromatography of dsRNA and high-throughput sequencing of total RNA, and its presence and sequence were confirmed by RT-PCR and Sanger sequencing. The PhAEV1 genome, 12,820 nucleotides (nt) in length, was predicted to encode a single large polyprotein with the catalytic core domain of viral (superfamily 1) RNA helicase (HEL, amino acid [aa] positions 1,287-1,531), glycosyltransferase (GT, aa positions ca. 2,800-3,125), and RNA-directed RNA polymerase (RdRp, aa positions 3,875-4,112). PhAEV1 is the most similar to Phytophthora cactorum alphaendornavirus 3, sharing 39.4% and 39.1% nt and aa sequence identity, respectively. In addition to the first 5'-terminal AUG codon, three additional in-frame methionine codons were found in close proximity (nt 14-16, 96-98, and 176-178), suggesting potential additional translation initiation sites. Conserved RdRp motifs (A-E) similar to those detected in related endornaviruses were identified in PhAEV1, as well as in several previously described alphaendornaviruses from other Phytophthora species in which these motifs had not been identified previously. Phylogenetic analysis showed that PhAEV1 clusters with members of the genus Alphaendornavirus in the family Endornaviridae and is basal to two other alphaendornaviruses described from another oomycete, Phytophthora cactorum. PhAEV1 is the first virus reported in P. heveae.OA-hybri
Space Redevelopment of Old Landfill Located in the Zone between Urban and Protected Areas: Case Study
Get PDFLandfills are elements of the waste management system, without possibility of further reclaiming, according to the requirements of a closed-loop economy, but with the possibility of transforming the area into other functions. The research combined monitoring of plant species, suggesting the composition of vegetation cover for pro-ecological management, analysis of functional and infrastructural incorporation of the landfill in the surrounding landscape, and proposals for reclamation and social application. An assessment of geotechnical safety was also made. Modernization of the landfill suggests that the pressure placed on other untouched locations should decrease. The designed space allows reintroducing socio-ecological life into this degraded area. Taking advantage of the character of the area, including variable development and significant landscape potential on the outskirts of a large city in the vicinity of protected areas, there is the possibility of creating new spatial quality following the standards of modern architecture-urban planning. One of the innovative elements of the project is the implementation of energy from renewable sources, including landfill biogas, photovoltaic panels and heat pumps. The development design includes social expectations and adaptation of new techniques to functioning in times of increased sanitary threats. The proposed design direction may be considered as a recommended trend for the sustainable development of urban areas.O
Relative Valuation of Private Held Companies: Valuation Multiples in the Czech Brewing Industry
Get PDFThis article focuses on the topic of the relative valuation from the perspective of non-publicly traded companies and the determination of industry multiples allowing the subsequent application of this approach to specific industries. I chose the Czech brewing industry as the target industry, represented by the 50 most important entities (covering more than 99% of the industry's turnover). Due to the fact that no market value data are available for this type of company, I first used an income valuation approach - the discounted cash flow (DCF) method to assess the market value of each company in the sample. I then quantified valuation multiples of P/E, EV/EBIT, EV/EBITDA, P/S, EV/S, P/BV, and EV/IC for each company, from which I determined industry statistics. I verified their suitability for use in the relative valuation approach and compared them with the results of existing studies on the most commonly used valuation approaches in the Czech Republic. Furthermore, I compared my own calculations of industry multiples for non-publicly traded companies with available data on industry multiples of publicly-traded companies in the brewing industry across Europe. The results of the comparison show that these multiples are on average lower for non-publicly traded companies than for listed companies.OA-hybri
Urban Forest Recreation and Its Possible Role throughout the COVID-19 Pandemic
Get PDFUrban forests provide benefits in terms of the environment and society. Many people living in urban areas could profit from the recreational services provided by urban forests to alleviate the physical and psychological stresses caused by closure restrictions during the COVID-19 epidemic. However, limited research has been conducted on the role of forest recreation during the COVID-19 lockdown to support future policy decisions regarding such dramatic circumstances. The study aims to investigate the frequency of visitors in the reference Training Forest Enterprise Masaryk Forest Křtiny in Brno, Czech Republic, and to verify if the lockdown led to its intensified use, under the context of weather conditions. Data were collected using a Pyro Box Compact reader and TRAFx Infrared Trail Counter. Regression analysis was performed to determine whether individual weather factors significantly influenced the intensity of forest visitations before and during COVID-19. The number of visits in 2021 during the strict lockdown and post-lockdown periods was significantly higher during spring and autumn than in 2016 and 2017, respectively. The frequency pattern of forest users visibly changed in 2021, and the total number of visits was much higher, even though 2021 had worse weather than the reference years before the pandemic. The results show the recreational use and importance of the forest, especially during the pandemic. This work is a continuation of our previous research with regard to this area, which indicated the importance of forest recreational services for the well-being and health of city dwellers.O
Hranice karst - Analytical map
No full textSoubor map s odborným obsahem se věnuje Hranickému krasu - hydrotermálnímu krasu nacházejícímu se na výběžku karbonátových hornin devonského a paleozoického stáří u města Hranice v České republice. Cílem analytických map je vymezit citlivá místa vůči znečištění podzemních vod zvýšit retenci vody v krajině a zároveň zvýšit její odolnost vůči vlnám veder. Kombinace výše uvedených faktorů rozděluje území na zóny citlivé a na zóny odolné. Dalším krokem je vymezení míst v území, kde změnou landuse dosáhneme největšího pozitivního efektu k zvýšení odolnosti území - lokalit s nejvyšší adaptační kapacitou. Výše uvedené faktory umožňují modelování změny landuse a jednotlivých scénářů, které jsou pro vymezení míst použity. Vyhodnocení citlivosti a adaptační kapacity je převedeno na mikropovodí. Soubor výše uvedených map doplňují ma! py popisného charakteru, které charakterizuje území Hranického krasu z hlediska přírodních kulturních a percepčních charakteristik.A set of maps with scientific content focuses on the Hranice Karst, a hydrothermal karst located on a protrusion of Devonian and Paleozoic carbonate rocks near the town of Hranice in the Czech Republic. The aim of the analytical maps is to identify sensitive areas prone to groundwater contamination, increase water retention in the landscape, and simultaneously enhance its resilience to heat waves. The combination of these factors divides the territory into sensitive and resilient zones. The next step is to identify areas within the territory where land-use changes will achieve the greatest positive effect on enhancing the region's resilience - locations with the highest adaptive capacity. These factors enable the modeling of land-use changes and individual scenarios used for site identification. The evaluation of sensitivity and adaptive capacity is mapped onto micro-catchment areas. The set of maps mentioned above is complemented by descriptive maps that characterize the Hranice Karst region in terms of its natural, cultural, and perceptual characteristics.Published Versio
First observation of the beetle Sericoderus lateralis consuming Cladosporium fulvum in a greenhouse tomato: potential for biological protection or risk to the crop?
Get PDFFor the first time, the mycophagous beetle Sericoderus lateralis (Gyllenhal, 1827) was documented feeding on tomato leaf mold (Cladosporium fulvum Cooke, 1878) tissues. The phenomenon was observed during the years 2022 and 2023 in a hydroponic tomato green-house situated near the Czech-Polish border within the cadastre of Dolni Lutyne munici-pality in Czechia. Greenhouse and laboratory observations confirmed that adult and larvae feeding activity led to a reduction in tomato leaf mold lesions. In addition, there was a posi-tive correlation between tomato leaf mold disease progression and increased populations of S. lateralis in the tomato crop. Petri dish observations confirmed egg laying occurred on a diet of tomato leaf mold. Further research is warranted to discern whether S. lateralis is a potential biological control agent for tomato leaf mold or if it acts to facilitate the spread of the disease by acting as a spore vector.O
Partial asynchrony of coniferous forest carbon sources and sinks at the intra-annual time scale
Get PDFAs major terrestrial carbon sinks, forests play an important role in mitigating climate change. The relationship between the seasonal uptake of carbon and its allocation to woody biomass remains poorly understood, leaving a significant gap in our capacity to predict carbon sequestration by forests. Here, we compare the intra-annual dynamics of carbon fluxes and wood formation across the Northern hemisphere, from carbon assimilation and the formation of non-structural carbon compounds to their incorporation in woody tissues. We show temporally coupled seasonal peaks of carbon assimilation (GPP) and wood cell differentiation, while the two processes are substantially decoupled during off-peak periods. Peaks of cambial activity occur substantially earlier compared to GPP, suggesting the buffer role of non-structural carbohydrates between the processes of carbon assimilation and allocation to wood. Our findings suggest that high-resolution seasonal data of ecosystem carbon fluxes, wood formation and the associated physiological processes may reduce uncertainties in carbon source-sink relationships at different spatial scales, from stand to ecosystem levels.O
Is regulatory protection of the territory empirically detectable? Analysis of temperature and vegetation trends in the northern area of Bogota with remote sensing.
Get PDFEste trabajo presenta un análisis de las tendencias de desarrollo urbano del sector norte de Bogotá, en un área de 6930 hectáreas que incluye el Plan de Ordenamiento Zonal del Norte (POZN) y parte de la reserva natural Thomas Van der Hammen (RTVH). El plan propuesto por la Alcaldía mediante el Decreto 088 de 2017 intenta dar coherencia a un desarrollo urbano que ha ocurrido de facto y con importantes consecuencias ecológicas y sociales mientras que la RTVH intenta proteger las características ecológicas de este sector entre los cerros y el rio Bogotá. El método consistió en analizar series de tiempo de temperatura de la superficie y de vegetación mediante técnicas de teledetección e indicadores radiométricos para identificar los cambios estructurales que ha experimentado el sector en términos de sus componentes biofísicos. Los resultados del análisis ponen en evidencia que el proceso de urbanización instalado en el sector norte de Bogotá es el determinante de las tendencias del espacio biofísico observadas, más allá de las figuras de protección legal que existen que incluyen el POZN y la RTVH. En el caso de la RTVH, el marco de protección no ha sido efectivo para preservar las características ecológicas que justificaron su creación. La inclusión de evidencia empírica como la mostrada en este trabajo en la planificación del desarrollo urbano es clave para avanzar en la protección activa del medio ambiente, más allá del discurso normativo.This article analyzes the trends in urban development in an area of 6930 hectares in the northern sector of Bogotá that includes the Northern Zonal Management Plan (POZN, in Spanish) and part of the Thomas Van der Hammen Nature Reserve (RTVH, in Spanish). The plan established by the Mayor's Office through Decree 088 of 2017 seeks to manage an urban development trend that has occurred de facto, with important ecological and social consequences, while the RTVH intends to protect the ecological characteristics of this sector located between the hills and the Bogotá River. The method consisted of analyzing time series of surface temperature and vegetation using remote sensing techniques and radiometric indicators to identify the structural changes experienced by the sector in terms of its biophysical components. The results of the analysis show that the urbanization process taking place in the northern sector of Bogotá is the driver of the observed trends in the biophysical space beyond the legal protection instruments currently in force, including POZN and RTVH. In the case of RTVH, the protection framework has been insufficient to preserve the ecological characteristics that led to its creation. The inclusion of empirical evidence in urban development planning, such as that shown in this work, is key to advancing the active protection of the environment beyond the regulatory discourse.O