189 research outputs found

    Mapping quantitative trait Loci associated with graft (In)compatibility in apricot (Prunus armeniaca L.)

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    Graft incompatibility (GI) between the most popular Prunus rootstocks and apricot cultivars is one of the major problems for rootstock usage and improvement. Failure in producing long-leaving healthy grafts greatly affects the range of available Prunus rootstocks for apricot cultivation. Despite recent advances related to the molecular mechanisms of a graft-union formation between rootstock and scion, information on genetic control of this trait in woody plants is essentially missing because of a lack of hybrid crosses, segregating for the trait. In this study, we have employed the next-generation sequencing technology to generate the single-nucleotide polymorphism (SNP) markers and construct parental linkage maps for an apricot F1 population “Moniqui (Mo)” × “Paviot (Pa)” segregating for ability to form successful grafts with universal Prunus rootstock “Marianna 2624”. To localize genomic regions associated with this trait, we genotyped 138 individuals from the “Mo × Pa” cross and constructed medium-saturated genetic maps. The female “Mo” and male “Pa” maps were composed of 557 and 501 SNPs and organized in eight linkage groups that covered 780.2 and 690.4 cM of genetic distance, respectively. Parental maps were aligned to the Prunus persica v2.0 genome and revealed a high colinearity with the Prunus reference map. Two-year phenotypic data for characters associated with unsuccessful grafting such as necrotic line (NL), bark and wood discontinuities (BD and WD), and an overall estimate of graft (in)compatibility (GI) were collected for mapping quantitative trait loci (QTLs) on both parental maps. On the map of the graft-compatible parent “Pa”, two genomic regions on LG5 (44.9–60.8 cM) and LG8 (33.2–39.2 cM) were associated with graft (in)compatibility characters at different significance level, depending on phenotypic dataset. Of these, the LG8 QTL interval was most consistent between the years and supported by two significant and two putative QTLs. To our best knowledge, this is the first report on QTLs for graft (in)compatibility in woody plants. Results of this work will provide a valuable genomic resource for apricot breeding programs and facilitate future efforts focused on candidate genes discovery for graft (in)compatibility in apricot and other Prunus species

    Winter Herbage Mass Accumulation and Animals Grazing Days of Set Stocking or Cell Grazing Dairy x Beef Systems in Southwest England

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    Cell grazing (CG) has shown to increase the production per hectare by allowing higher stocking rates, greater grass production and higher herbage utilisation throughout the grazing season compared to set stocking (SS). Our objective was to compare the herbage growth rate during winter resting (WHGR, October/November to April) and the animals grazing days per ha (AGD-ha) of CG and SS systems grazed by dairy x beef steers. Three 1.75ha (1.5ha in 2018) plots and three 1.0ha were used for the SS and CG, respectively. Forty-two and 48 autumn born dairy x beef steer calves were split into six equal groups and randomly allocated to treatments in April 2018 and April 2020, respectively. In the second grazing seasons (2019 and 2021), the number of animals was reduced to keep stocking rates comparative to the prior year, and steers remained in the plots until finishing (October/November). Herbage mass (HM) was recorded weekly with a rising plate meter. The WHGR was estimated by subtracting the HM recorded at the end of the previous grazing season to the HM recorded at the beginning of the following season and divided by the number of days between readings. The AGD-ha was calculated by summing the days each animal grazed each area and divided by the size of the study enclosure. In three of the four years, the CG had fewer days of winter resting (157-175) than the SS (157-182), whereas the WHGR was greater in three of the four winters (average across years: 5.77 vs. 4.05 kg DM/ha per d, for CG and SS respectively). Despite the shorter winter rest, overall, the CG accumulated 37% more HM (average across years: 976 vs. 710 kg DM/ha) and had 78% more AGD-ha (1102 vs. 620 animal.d/ha) than SS. These differences do not seem to be driven by the herbage residual at the end of the grazing season but by the change in botanical composition across time

    Impact and Therapeutic Potential of PPARs in Alzheimer's Disease

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    Peroxisome proliferator activated receptors (PPARs) are well studied for their role of peripheral metabolism, but they also may be involved in the pathogenesis of various disorders of the central nervous system (CNS) including multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's and, Parkinson's disease. The observation that PPARs are able to suppress the inflammatory response in peripheral macrophages and in several models of human autoimmune diseases, lead to the idea that PPARs might be beneficial for CNS disorders possessing an inflammatory component. The neuroinflammatory response during the course of Alzheimer's disease (AD) is triggered by the deposition of the β-amyloid peptide in extracellular plaques and ongoing neurodegeneration. Non-steroidal anti-inflammatory drugs (NSAIDs) have been considered to delay the onset and reduce the risk to develop Alzheimer’s disease, while they also directly activate PPARγ. This led to the hypothesis that NSAID protection in AD may be partly mediated by PPARγ. Several lines of evidence have supported this hypothesis, using AD related transgenic cellular and animal models. Stimulation of PPARγ by synthetic agonist (thiazolidinediones) inducing anti-inflammatory, anti-amyloidogenic and insulin sensitizing effects may account for the observed effects. Several clinical trials already revealed promising results using PPARγ agonists, therefore PPARγ represents an attractive therapeutic target for the treatment of AD

    Comparing Forage Biomass Estimation Between Forager-Mounted Near Infrared Spectroscopy (NIRS) and Rising Plate-Meter (RPM) Techniques

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    Quantifying the forage mass harvested per paddock is essential for informing late-season management decisions on grazing livestock farms. This information can be used to calculate winter feed budgets and thus support decisions such as area of land to defer for autumn grazing, and head of stock to sell before winter housing. However, there are practical limitations associated with existing measurement methods, which can influence the accuracy of forage biomass estimates. The purpose of the current study was therefore to compare biomass estimation from two alternative precision farming methods — near infrared spectroscopy (NIRS) integrated within-spout of a self-propelled forage harvester, against a rising plate meter (RPM). Data were collected from the North Wyke Farm Platform (NWFP) in South- West England. RPM readings were taken within seven days preceding harvest, and Harvester measurements taken at the point of harvest. Data from two paddocks were collected during 2021 (figure 2, points a and b) and two from 2020 (points c and d). Three of the sampled paddocks (a, c and d) contained permanent pasture and one (b) contained reseeded white clover and perennial ryegrass. Paddocks c and d in figure 2 suggest a good correspondence between methods, demonstrated by proximity to the 1:1 line which passes through the origin. However, points a and b lie parallel to the 1:1 line, suggesting a systematic underestimation from the RPM. This underestimation could be linked to the tendency of grass to lodge at high yields, or due to an unquantified factor linked to the year of harvest, such as weather conditions which are known to indirectly influence RPM readings. With suitable calibration and consideration of practical limitations, forager mounted NIRS technology can provide valuable farm management data quickly, and at a relatively low cost compared to manual methods of biomass estimation

    Biophysical, Grazing-Season Management, and Animal Traits Effects on Individual Animal Performance of Cow-Calf Systems: Insights from a Long-Term Experiment in the US Western Great Plains

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    Beef grazing systems require information on management, biophysical, and individual animal influences on performance metrics. However, long-term controlled experiments are lacking to comprehensively ascertain these individual and likely interacting influences. We used a legacy data set from the USDA Agricultural Research Service where individual weight gains were determined from on and off weights of Hereford cows and calves grazing native northern mixed-grass prairie, during the June through September season, from 1975-2001 near Cheyenne, Wyoming, USA. The herd size varied from a minimum of 10 to a maximum of 48 pairs across years. Management (on and off grazing dates and stocking rate, kg BW/ha), biophysical (forage production estimated through NDVI LANDSAT time series, temperature, and precipitation variability), and individual animal (cow age, cow body weight at beginning of grazing season, and calf gender) influences were evaluated for effects on calf weight gain (WG, kg/head). Linear mixed models were used for analyses where the above mentioned were fixed factors, and year and individual cow were random ones. Calf performance was influenced by three animal traits: gender with steer WG 4 kg more than heifer, cow body weight with calf WG increased 2kg for each 100kg of cow body weight, and cow age as optimum calf WG occurred with 5-year-old cows. Management influenced calf WG through the on and off dates. Delaying the start of a grazing season decreased calf WG by 0.80 kg per delayed day. On the contrary, extending the grazing season increased calf WG by about the same amount. Biophysical effects on calf WG were not significant suggesting that the cow performance was mitigating these effects of variability. Results suggest that calf individual performance in this resilient rangeland ecosystem relies on cows’ body weight at beginning of the grazing, their age, and the timing to enter and remove animals from pastures

    Propuesta de intervención educativa para trabajar la comprensión lectora en un niño con dislexia de 6º de Educación Primaria a través del estudio de un caso

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    Leer es una habilidad que se adquiere con mucho trabajo, ya que implica la interacción de varios procesos cognitivos que van a permitir, posteriormente, la comprensión del texto. No obstante, hay personas que tienen dificultades a la hora de adquirir y consolidar el lenguaje escrito o la lectura. Uno de los trastornos del aprendizaje más estudiados y con mayor prevalencia que afecta a la adquisición de la lectoescritura es la dislexia. Así pues, el presente trabajo tiene el objetivo de investigar y describir cómo afecta la dislexia al proceso lector y, más concretamente, a la comprensión lectora. Asimismo, se presenta el planteamiento de una intervención educativa dirigida a un alumno concreto diagnosticado con dislexia, con la que se busca mejorar el procesamiento sucesivo y, así, fomentar el resto de los procesos cognitivos implicados en la lectura para mejorar su comprensión.Reading is a skill that is acquired with hard work, since it involves the integration of several cognitive processes that will allow the reading and comprehension of a text. However, there are people who have difficulties in acquiring and consolidating written language or reading. One of the most studied and most prevalent learning disorders affecting the acquisition of reading and writing is dyslexia. The aim of this paper is to investigate and describe how dyslexia affects the reading process and, more specifically, reading comprehension. It also presents the approach of an educational intervention aimed at a specific student diagnosed with dyslexia to improve his successive processing, in order to promote the rest of the cognitive processes involved in reading and improve his reading comprehension

    Historical isolation facilitates species radiation by sexual selection: Insights from Chorthippus grasshoppers

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    Theoretical and empirical studies have shown that species radiations are facilitated when a trait under divergent natural selection is also involved in sexual selection. It is yet unclear how quick and effective radiations are where assortative mating is unrelated to the ecological environment and primarily results from sexual selection. We address this question using sympatric grasshopper species of the genus Chorthippus, which have evolved strong behavioural isolation while lacking noticeable ecomorphological divergence. Mitochondrial genomes suggest that the radiation is relatively recent, dating to the mid‐Pleistocene, which leads to extensive incomplete lineage sorting throughout the mitochondrial and nuclear genomes. Nuclear data shows that hybrids are absent in sympatric localities but that all species have experienced gene flow, confirming that reproductive isolation is strong but remains incomplete. Demographic modelling is most consistent with a long period of geographic isolation, followed by secondary contact and extensive introgression. Such initial periods of geographic isolation might facilitate the association between male signaling and female preference, permitting the coexistence of sympatric species that are genetically, morphologically, and ecologically similar, but otherwise behave mostly as good biological species

    Functional genomics of abiotic environmental adaptation in lacertid lizards and other vertebrates

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    Understanding the genomic basis of adaptation to different abiotic environments is important in the context of climate change and resulting short-term environmental fluctuations. Using functional and comparative genomics approaches, we here investigated whether signatures of genomic adaptation to a set of environmental parameters are concentrated in specific subsets of genes and functions in lacertid lizards and other vertebrates. We first identify 200 genes with signatures of positive diversifying selection from transcriptomes of 24 species of lacertid lizards and demonstrate their involvement in physiological and morphological adaptations to climate. To understand how functionally similar these genes are to previously predicted candidate functions for climate adaptation and to compare them with other vertebrate species, we then performed a meta-analysis of 1,100 genes under selection obtained from -omics studies in vertebrate species adapted to different abiotic factors. We found that the vertebrate gene set formed a tightly connected interactome, which was to 23% enriched in previously predicted functions of adaptation to climate, and to a large part (18%) involved in organismal stress response. We found a much higher degree of identical genes being repeatedly selected among different animal groups (43.6%), and of functional similarity and post-translational modifications than expected by chance, and no clear functional division between genes used for ectotherm and endotherm physiological strategies. In total, 171 out of 200 genes of Lacertidae were part of this network. These results highlight an important role of a comparatively small set of genes and their functions in environmental adaptation and narrow the set of candidate pathways and markers to be used in future research on adaptation and stress response related to climate change

    Yield-scaled global warming potential of two irrigation management systems in a highly productive rice system

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    ABSTRACT Water management impacts both methane (CH4) and nitrous oxide (N2O) emissions from rice paddy fields. Although controlled irrigation is one of the most important tools for reducing CH4emission in rice production systems it can also increase N2O emissions and reduce crop yields. Over three years, CH4 and N2O emissions were measured in a rice field in Uruguay under two different irrigation management systems, using static closed chambers: conventional water management (continuous flooding after 30 days of emergence, CF30); and an alternative system (controlled deficit irrigation allowing for wetting and drying, AWDI). AWDI showed mean cumulative CH4 emission values of 98.4 kg CH4 ha−1, 55 % lower compared to CF30, while no differences in nitrous oxide emissions were observed between treatments ( p > 0.05). No yield differences between irrigation systems were observed in two of the rice seasons ( p > 0.05) while AWDI promoted yield reduction in one of the seasons ( p< 0.05). When rice yield and greenhouse gases (GHG) emissions were considered together, the AWDI irrigation system allowed for lower yield-scaled total global warming potential (GWP). Higher irrigation water productivity was achieved under AWDI in two of the three rice seasons. These findings suggest that AWDI could be an option for reducing GHG emissions and increasing irrigation water productivity. However, AWDI may compromise grain yield in certain years, reflecting the importance of the need for fine tuning of this irrigation strategy and an assessment of the overall tradeoff between relationships in order to promote its adoption by farmers
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