Abstract Chimerism theoretically increases the genetic het- erogeneity of coalescing organisms, which in turn may in- crease phenotypic variability in chimeras, allowing them greater tolerance to environmental changes when compared with non-coalescing individuals. In order to test this hypoth- esis, we compared abiotic stress tolerance between coalescing and non-coalescing organisms. The specific daily growth was compared using discs formed with 1, 5, and 20 Mazzaella laminarioides carpospores. These were cultivated under three different temperature (6, 12, and 25 °C) and salinity (10, 35, and 50 g L − 1 ) conditions. Growth of the disc area was mea- sured after 30 days of cultivation under controlled conditions. Sporeling survival similarly was calculated under each of these temperatures and salinities in order to record whether stress-resistant phenotypes were present. The results showed that, under stressful conditions, non-coalescing specimens experienced a significant reduction in the specific growth rate compared with those under non-stressful conditions. The re- duction in growth falls off, however, as the number of coa- lescing spores increases. The cultivation of spore populations also indicates the presence of sporelings with the capacity to survive alone in stressful situations. The results suggest that the coalescing discs exhibit higher tolerance to environmental stressors than non-coalescing discs, allowing them to survive and grow under these conditions. This can be explained by an increase in phenotypic plasticity, resulting from greater genet- ic heterogeneity due to somatic fusion of a larger number of spores.
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Taken together, AMI1 and the two YUCCA genes, YUC8 and YUC9, from Arabidopsis, are likely involved in regulating lateral root development. Publicly available microarray data point towards a differential regulation of the three candidate genes upon various abiotic stress conditions, including salt‐, drought‐, and osmotic stress. Furthermore, several types of nutrient stresses, such as nitrogen, phosphorous, sulfur, po‐ tassium, or iron deficiency or depletion have been shown to transcriptionally control target gene expression. Possibly even more importantly, the three target genes show very broad distribution in the plant kingdom, implying an im‐ portant and perhaps basic function. Currently, there are 47 identified AMI1 homologous proteins derived from 38 dif‐ ferent species, covering both mono‐ and dicot genera (Sánchez‐Parra et al. 2014). Like AMI1 homologs, YUC‐like proteins have been identified from various plant species, in‐ cluding the relevant crop plants maize, rice, and tomato. As Brassica crops, such as Brassica rapa and Brassica napus, are phylogenetically closely related with A. thaliana the identifi‐ cation and functional characterization of pendants to AMI1, YUC8, and YUC9 in the Brassica crops is not expected to be a major obstacle. Another remarkable aspect with respect to the three selected target genes is that a loss of neither of the genes causes lethality, which makes them to ideal candidates for the generation of transgenic plant lines or for the devel‐ opment of targeted breeding programs that yield in elite germplasms with improved traits.
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the retention time, intensity, and accurate mass identity matrices, carried to compare approximately 1000 molecular features per sample with each other, revealed that the overexpression of SlCDF3 results in a distinguishable alteration of the metabolome, as indicated by the clear clustering of the datasets (Fig. 4.8A). When we tried to identify the differentially abundant components causing the grouping in the PCA, we discovered that a great part of the differences were found among the group of small and polar compounds, containing for example sugars, amino acids, and small acids. As an example, the increased abundance of glutamine in the overexpressing lines compared to the WT is shown in Fig. 4.8B and C. Hence, we focused our analyses on those polar compounds and performed a targeted metabolomic profiling by gas chromatography-mass spectrometry (GC-MS) to study the relative levels of different polar compounds, including proteinogenic amino acids as well as four other amino acids, eight distinct sugars plus two sugar alcohols, and eight small acids, extracted from 12-day-old WT and 35S::SlCDF3 (L2.10 and L10.7 lines) transgenic plants, grown under non-stress conditions. As shown in Fig. 4.8 D and Supplementary Table S4.4, the comparison of GC profiles revealed a number of clear differences between control and overexpressing lines. Overexpression of SlCDF3 in Arabidopsis significantly induced the accumulation of sugars like sucrose (2.5-fold), and amino acids like GABA (2-fold), L-proline (2.2-fold) and L-glutamine (1.8-fold), and succinate (1.3-fold), while the amount of malate and gluconate decrease by up to 24 and 34.9.%, respectively, relative to the control. Consistent with the expected similar effects in both SlCDF3 overexpressing lines, most sugars appeared at comparable levels. Interestingly, these lines showed an important increase in sucrose compared to the WT. Since glucose and fructose, the two monomeric building blocks of sucrose, showed no considerable reductions, it may be concluded that SlCDF3 overexpression either causes a change in carbon partitioning favoring the production of sucrose over that of starch, or that CO 2 fixation rates are generally increased. Finally, overexpression of SlCDF3
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varied in relation to both canopy cover and shrub microsite, while soil conditions only varied in relation to canopy cover. The hypothesis that the strength of the interaction would increase with increasing seedling size was confirmed by the RNE index. The hypothesis of a shift from positive to negative interaction as the seedling size increases can be partially accepted, because we did not observe this pattern as a generalized response in both canopy types. The hypothesis of a stronger interaction under open canopy was confirmed, but the hypothesis of a positive interaction under open canopy can be ruled out for the performance estimator used. In spite of the generality of the stress-facilitation relationship (Bertness and Callaway, 1994), species differ in their physiological and ecological optima. Stress is therefore relative to the particular species (Lortie et al., 2004; Liancourt et al., 2005), and may be relative to plant-specific traits (e.g. size or life stage) and resource availability. The plant performance estimator used, the experimental approach followed, and other stress factors not considered may have had a strong influence on both the net outcome of P. pinaster seedling-shrub interactions and the effect of the target abiotic stress on such outcomes (Maestre et al., 2006).
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Knowledge of the effects of abiotic stress is based mainly on studies performed in model species and in agricultural species such as Arabidopsis thaliana (L.) Heynh. (arabidopsis), Nicotiana tabacum L. (tobacco), Oryza sativa L. (rice), Triticum aestivum L. (wheat), Zea mays L. (corn or maize), among others. However, the information about the molecular biology and physiology of forest species under conditions of stress is limited, even non-existent for a large number of species, as in the case of the forest resources of Mexico. In this regard, a small number of species has been the object of studies related to the response to abiotic stress. For example, sensitivity to hydric deficiency was assessed in Pinus engelmannii Carrière and P. lumholtzii Robinson and Fernald of northern Mexico in a range of altitudes through a dendrochronological study for the 1945-2004 period (Bickford et al., 2011). The sensitivity of growth to the drought was determined, particularly at a low altitude, and P. engelmannii turned out to be the species with the least tolerance.
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Notably, a quantitative RT-PCR analysis showed that expression of the negative cell cycle regulators WEE1 and SMR4 increases significantly after 24 h of BA treatment (Fig. 4). WEE1 codes for a kinase protein and is transcrip- tionally activated upon the cessation of DNA replication or DNA damage, inhibiting plant growth by arresting dividing cells in the G2-phase of the cell cycle (De Schut- ter et al. 2007). Moreover, it has been reported that expres- sion of the SIM gene family responds to diverse biotic and abiotic stress treatments and it was suggested that these proteins decouple the cell cycle during unfavourable envi- ronmental conditions (Peres et al. 2007). Our results suggest that boron treatment produces genotoxic damage to root cells, thus triggering a molecular response that modifies the cell cycle and inhibits root growth. Recently, it has been suggested that boron toxicity mechanism involves DNA double-strand breaks and possibly replica- tion blocks triggered by a genotoxic stress caused by BA (Sakamoto et al. 2011).
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The mechanical development of shear bands and frac- tures is a major research topic in geology and rock mechanics. There is a large amount of studies analysing the fundamental controls of the development of shear bands and fractures in homogeneous isotropic rocks (e.g. Wolf et al., 2003 and references therein). However, many rocks in nature are anisotropic and heterogeneous (Biot, 1965; Cobbold et al., 1971, Weijermars, 1992) and have a different response to normal and shear stress. It has been historically observed that the presence of a planar anisotropy (i.e. layering, cleavage, pre-existing faults, joints, etc.) can affect the onset and orientation of fractures. The exis- tence of directional heterogeneities may enhance the partition of deformation (Lister and Williams, 1983) and can produce a deviation of the local stress field with respect to the regional deformation conditions (Bradshaw and Zoback, 1988; Peacock and Sanderson, 1992). In this kind of situations inferring the regional
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Se encontró un amplio rango en los valores de prolina acumulada que va des de 1,2 veces (maíz dulce, cultivar Sorpresa) hasta tres veces el contenido normal (De- kalb 4F33)-(Fig. 2). Sobre la base de los resultados obtenidos se pueden distinguir dos grupos que incluye a Sorpresa, San Pedro II, Dekalb 2F10, Dekalb 4F34 y Contigran en el grupo de baja acumula ción y a Dekalb 4F32, Dekalb 4F31, Long White Flint, Dekalb 3F20, Abatí II, Inta, Pisingallo, Morocho y Dekalb 4F33 en el de alta acumulación. Como se ve en el gráfico no existe correlación entre la acumulación de prolina libre y el alarga miento de la raíz expresado como porcen taje del control. De todos modos es preci so tener en cuenta que^el alargamiento ce lular, si bien es un carácter importante en la resistencia al stress porque permite man tener un ritmo de crecimiento considera ble con potenciales agua bajos, no es úni ca fuente de resistencia. Será pues necesa rio estudiar la correlación entre la acumu lación de prolina y otros caracteres de re sistencia.
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El stress es una medida de cómo se “reparte” una fuerza al aplicarla sobre una superficie (figura 1.1). Un ejemplo sencillo del significado de una fuerza repartida en una superficie está dado por un hombre que camina sobre nieve blanda: cuando lo hace con zapatos se hunde, porque su peso se aplica sobre una superficie muy reducida, la suela de sus zapatos. En cambio si lo hace sobre esquíes o raquetas, el peso se distribuye sobre una mayor superficie y, por lo tanto, no se hundirá.
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A heat stress model has been developed and evaluated in order to simulate maize grain yield under heat stress conditions around silking, obtaining satisfactory performance. Thus, a heat stress reduction factor was obtained using experimental data from Argentine and validated with experimental data from Spain, being appropriate for using under climate change conditions. The model performance was improved when canopy temperature was considered as input for the heat stress function instead of air temperature. To use air temperature as input, the critical threshold must be increased from 34 °C, determined by Cicchino et al. (2010), to 39 °C as this critical threshold could be several degrees higher under irrigation conditions due to the irrigation cooling effect (Lobell et al., 2008; Kimball et al., 2015). The improvement in crop modeling for maize and olive crops has accomplished and demonstrated the need to promote experimental studies on crop physiology and phenology under forced conditions to increase the knowledge about the response of different Mediterranean crops to climate change. Furthermore, the importance of access to high quality experimental data, to calibrate and validate crop models under local and forced climate conditions has addressed. The collaboration between modellers and experimentalist has been proved to be useful. In addition, the development of specific experimental designs to feed the crop models to evaluate future climate conditions, as heat events or water deficits under different phenological phases for maize, olive or other crops, is recommended.
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for depression, which is consistent with other studies. Previous studies have shown that, due to multiple role obligations, roles overload, and role conflicts, women tend to get more stressed and hence depressed (Hibbard and Pope, 1985; Gore and Mangione, 1983). However, it is not roles per se, but the quality of these roles that determine mental health. If roles are not stressful, but are instead rather fulfilling of women’s expectations, having multiple roles could lead to a greater satisfac- tion and a better mental health (Aneshensel, 1986; Avison, 1995). In this analysis, we found that workers who report greater stress are more depressed. Howev- er, men are more likely to be severely depressed than women if exposed to high work stress (OR of 5.7 com- pared to 3.8). This suggests that it may be exposure to stress rather than gender vulnerability which could ac- count for the level of depression among the women in our study. In other words, since more women occupy roles lacking direction, control, and autonomy –char- acteristics associated with low job satisfaction and job stress (Aneshensel, 1986; Aneshensel and Pearlin, 1987; Baruch et al., 1987; Ross and Bird, 1994)– these put them at a greater risk for depression than men. These hypotheses will be tested at a later date with the longi-
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escolha destas dimensões de confronto segue a divisão central entre estratégias centradas no problema e na emoção (Folkman & Lazarus, 1985), dividindo-se também as estratégias de regulação emocional em ativas (onde a pessoa procura lidar de forma positiva com as emoções resultantes da situação de stress) e em passivas (onde a pessoa evita a situação de stress). Esta divisão é fundamental, uma vez que existem indicações da literatura que sugerem que o uso de estratégias mais passivas traduzem-se em efeitos mais negativos para a pessoa, em termos da sua saúde e bem-estar, bem como em pior ajustamento ao stress (Coyne & Racioppo, 2000). A quarta área de confronto, relaciona-se com o uso do apoio social, efetuando-se, neste caso, uma avaliação do seu uso por razões mais emocionais (i.e., procurar a compreensão e empatia de pessoas importantes) e por razões mais instrumentais (i.e., procurar o apoio de pessoas que possam ajudar a resolver a situação de stress). Uma vez mais, estes domínios emergem como fundamentais na avaliação do confronto (Carver & Scheier, 1985; Scheier & Carver, 1988). De modo a obter-se uma ideia o mais alargada possível da multiplicidade de estratégias de confronto, foram incluídas nos instrumentos duas possibilidades de gestão da situação de stress em cada dimensão avaliada, perfazendo as oito estratégias de confronto descritas acima. Convém aqui esclarecer que esta avaliação específica das oito estratégias de confronto está disponível no Questionário de Avaliação da Adaptação ao Stress mas podem também ser usadas na entrevista de Avaliação da Adaptação ao Stress, quando o investigador opta pelo seu uso qualitativo e quantitativo.
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However, not all physiological signals involve an electrical component. Pupil dilation (PD) and eyetracking (ET) provide very precise information about frame stress. When an individ- ual is under stress, PD is wider, and the eye movement is faster. The article presented in  not only considers PD and ET but also GSR, BVP, and FT. The main purpose of this approach is to recognize emotions, interest, and attention from emotion recognition. Moreover, it is possible to deduce the intention of the individual from these results, a very remarkable conclusion for future computer applications and for the sake of a better human–computer interaction (HCI) , .
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Tal como se ha dicho, la información existente acerca de los cambios en los sis temas subcelulares que se suceden a raíz de un stress hídrico, es actualmente bas tante abundante. Entre esos cambios es posible mencionar: modificaciones en la actividad de enzimas ligadas a. la trama li- poproteica o a la fracción soluble de los extractos (Vieira de Silva, 1970; Todd, 1972); alteraciones en los procesos que tienen lugar en los cloroplástidos y mito- condrias (Stocker, 1960; Brix, 1962; Nir y Poljakoff-Mayber, 1967; Pinto y Flo wers, 1970); cambios en la estructura del ADN (Chen et al., 1968); desaparición de poliribosonas y su reemplazo por dímeros o monómeros (Henckel, 1967; Hsiao, 1970); incremento del contenido de proli na (Stewart et al., 1966, Wynn Jones y Storey, 1978); disminución de la actividad de citocininas endógenas y de glicinabeta- ína, (Itai y Benzioni, 1. c.); aumento del contenido de ABA (Mittelheuser y Van Steveninck, 1969; Mizrahi et al.., 1972); cambios en la permeabilidad de las mem
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As discussed in CHAPTER 5, flow stress model for hard turned surface obtained from ball indentation tests and FEM inverse analysis was designed to consider possible changes in workpiece plastic behavior produced by hard turning [Morris, 2005]. Simulation results shown in CHAPTER 6 were observed to be in good agreement with experimental measurements of axial and tangential residual stresses; however, FEM predicted results were not close to experimental measurements obtained at the workpiece surface, especially for the axial stresses. The reason of this lack of accuracy at the workpiece surface could be due to the same combination of factors discussed in Section 6.2.1 and to the fact that Eq. (5.4) does not consider the residual stresses produced during hard turning. As suggested in [Zhuang, 2004], inclusion of X-ray measured residual stress data can lead to an improvement of the FEM simulation model. In this appendix, a procedure to consider the cutting-induced residual stresses is presented.
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Plants possess energy-associated central network responsible for the survival under stress. This net- work is more complex in plants than in animals, using primarily photosynthesis as the energy donor under optimal growth conditions, or glycolysis, the tricar- boxylic acid (TCA) cycle, and amino acid catabolism upon exposure to stress . Genes encoding most of the enzymes in chlorophyll and heme biosynthesis appeared to be grouped in the same cluster, indicat- ing that a tightly coordinated stress-induced regula- tion of these multiple genes is required for efficient reduction in the levels of chlorophyll and heme upon exposure to stress. Such a mechanism may apparently protect plants from the accumulation of toxic reactive oxygen species derived from unused tetrapyrroles. Because of the chemical properties of tetrapyrroles as singlet-oxygen generators, it is tempting to spec- ulate that plants use tetrapyrrole molecules for the singlet-oxygen generation, which may contribute to ROS-triggered defense or protective response.
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In the next stage, the part is dried in a furnace for 1 hour and is taken to fluorescence testing with penetrating liquids and powders (Fluorescent Penetrant Inspection: FPI), to show possible fissures and defects that may become visible under fluorescent light. Consequently, the purpose of this FPI operations is to find any evidence of cracks that could be present in the surface checking in detriment of the surface integrity. The following step is the shot peening operation stage. The shot peen technique is a cold deformation process that generates a uniform layer of compressive stresses in order to analyze any defect that could have the part and prevents failures due to corrosion under stress. Finally, the part is marked and packed in the last stage, and the result is a turbine blade as a finished part.
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This work evaluates the experimental warming effects on phenology and grain yield components of wheat in the Yaqui Valley, Sonora, Me´xico, using CIRNO C2008 variety from Triticum durum L., as a model during the cropping cycle of 2016–2017 (December to April). Infrared radiators were deployed to induce experimental warming by 2 C above ambient crop canopy temperature, in a temperature free-air controlled enhancement system. Temperature was controlled by infrared temperature sensors placed in eight plots which covered a circle of r = 1.5 m starting five days after germination until harvest. The warming treatment caused a reduction of phenophases occurrence starting at the stem extension phenophase. Such phenological responses generated a significant biological cycle reduction of 14 days. Despite this delay, CIRNO C2008 completed its biological cycle adequately. However, plant height under the warming treatment was reduced significantly and differences were particularly observed at the final phenophases of the vegetative cycle. Plant height correlated negatively with spikes length, spikes mass, and number of filled grains. Warming also reduced grain yield in 33%. The warming treatment caused a stress intensity (SI = 1-yield warming/yield control) of 39.4% and 33.2% in biomass and grain yield,
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Social groups were divided into three different treatments: Control, Mixed, and CORT. Control groups (n = 13) received no cortisol im- plants, whereas 50 – 75% of females within each Mixed group (n = 5) and 100% of females within each CORT group (n = 9) were implanted with cortisol pellets. Because social groups from a separate study were opportunistically used as Control groups, we had more Control groups than Mixed or CORT groups. Because surgery is a major stressor, we did not implant Control females and certain Mixed females with placebo implants because the aim of our experiment was to manipulate stress levels, not solely cortisol levels. Consequently, surgical implantation of a placebo is the proper control for cortisol increases, but lack of surgery is the proper control for stress per se. Female degus were implanted 1 – 2 days after parturition. Females were anesthetized via inhaled Iso ﬂ urane and pellets were implanted on the back of the neck, under the skin. In 2011, we used 60-day release, 35 mg hydrocortisone pellets (Innovative Research of America, Sarasota, FL, USA). In 2012, we switched to using smaller pellets that gave the same daily dose (21-day release, 10 mg hydrocortisone pellets, Innovative Research of America). We switched to these pellets because we found in 2011 that pups emerged aboveground at 3 – 4 weeks of age, and therefore mater- nal care after 3 weeks of age was unlikely to have signi ﬁ cant effects on HPA-axis development in pups. We veri ﬁ ed that cortisol implants el- evated circulating cortisol levels in female degus 2 – 4 days after implan- tation by determining baseline cortisol levels in a sub-sample of un-implanted and implanted female degus (166 ± 42 vs. 357 ± 93 ng mL −1 , respectively, mean ± sem; t (13) = 2.2, P = 0.02). Inducing
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This paper presents a numerical study on the influence of pulsed electric signals applied to the overcooling of ther- moelectric devices. To this end, an experimental setup taken from the literature and a commercial cell are simulated using a complete, specially developed research finite element code. The electro-thermal coupling is extended to in- clude the elastic field, demonstrating that the increment of cooling can produce mechanical failure. Numerical results are developed and the variation of overcooling versus pulse gain and versus duration is validated towards a new an- alytical expression and the experimental data. The issue of optimal intensity at steady-state is also newly developed. Thermal and mechanical trends are presented using constant and variable (with temperature) material properties for a single thermoelement. While some of the first trends are similar to those of published works, others are different or directly new, all closer to those of the experiments. The mechanical results have not been thoroughly studied until recently. The three-dimensional finite element mesh includes non-thermoelectric materials that are fundamental for the current study. Distribution of stresses during steady and transient states are shown inside the thermoelement, for five components and for the combined Tresca stress. Concentrations at corners of the lower side appear close to the cold face. Due to these concentrations, 27-node isoparametric, quadratic brick elements are used. It is shown that the mechanical field is an important factor in the design of pulsed thermoelectrics, since for practical applications the stress levels are close or slightly above the admissible limits.
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