334 research outputs found
Modeling microbial dormancy in soils
Dormancy is a very effective trait of microorganisms in soil to cope with varying environmental conditions (e.g. substrate availability or moisture) that leads to a graded, switch-like microbial response to fluctuations in environmental parameters. Microbial dormancy strategies vary from rapid to delayed response to environmental change and the activation from dormant to active state is typically faster than the transition to dormant state (Blagodatskaya, E., & Kuzyakov, Y. 2013). Dormancy is typically represented in models by explicitly considering active and dormant biomass pools or by introducing a physiological state variable that describes the active fraction of the total biomass. Existing modeling approaches mainly differ in the description of the transformation process between active and dormant states and disregard the classification into active, potentially active and dormant microbial states. The growth rate, death rates and the transition rate from active to dormant state are represented by generic functions. The question arises of gauging the sensitivity of model predictions for the temporal evolution of active and dormant bacteria not only to perturbations in constants of proportionality (parameter sensitivity), but to perturbations in uncertain or assumed expressions (functional sensitivity). Instead of postulating a particular description, the functional form of the transition function can be tested by fitting a type of free-form function as a linear combination of shape functions to the experimental dataset used in Wang et al. 2014. Depending on the form of the transition function, we observe that simple SOM turnover models show qualitatively different dynamical behavior. We aim to generalize existing modeling approaches to account for diversity in dormancy strategies and to understand which strategies for transiting between dormant and active states are favoured under which environmental conditions
Hyperthermotherapy in the Rice Emasculation Process.
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Estimating the development of landrace and improved maize cultivars as a function of air temperature.
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Angular sensitivity of blowfly photoreceptors: intracellular measurements and wave-optical predictions
The angular sensitivity of blowfly photoreceptors was measured in detail at wavelengths λ = 355, 494 and 588 nm.
The measured curves often showed numerous sidebands, indicating the importance of diffraction by the facet lens.
The shape of the angular sensitivity profile is dependent on wavelength. The main peak of the angular sensitivities at the shorter wavelengths was flattened. This phenomenon as well as the overall shape of the main peak can be quantitatively described by a wave-optical theory using realistic values for the optical parameters of the lens-photoreceptor system.
At a constant response level of 6 mV (almost dark adapted), the visual acuity of the peripheral cells R1-6 is at longer wavelengths mainly diffraction limited, while at shorter wavelengths the visual acuity is limited by the waveguide properties of the rhabdomere.
Closure of the pupil narrows the angular sensitivity profile at the shorter wavelengths. This effect can be fully described by assuming that the intracellular pupil progressively absorbs light from the higher order modes.
In light-adapted cells R1-6 the visual acuity is mainly diffraction limited at all wavelengths.
Estimativa das temperaturas cardinais e modelagem do desenvolvimento vegetativo em batata-doce
The Role of Immunological Synapse in Predicting the Efficacy of Chimeric Antigen Receptor (CAR) Immunotherapy
Chimeric Antigen Receptor (CAR) immunotherapy utilizes genetically-engineered immune cells that express a unique cell surface receptor that combines tumor antigen specificity with immune cell activation. In recent clinical trials, the adoptive transfer of CAR-modified immune cells (including CAR-T and CAR-NK cells) into patients has been remarkably successful in treating multiple refractory blood cancers. To improve safety and efficacy, and expand potential applicability to other cancer types, CARs with different target specificities and sequence modifications are being developed and tested by many laboratories. Despite the overall progress in CAR immunotherapy, conventional tools to design and evaluate the efficacy and safety of CAR immunotherapies can be inaccurate, time-consuming, costly, and labor-intensive. Furthermore, existing tools cannot always determine how responsive individual patients will be to a particular CAR immunotherapy. Recent work in our laboratory suggests that the quality of the immunological synapse (IS) can accurately predict CAR-modified cell efficacy (and toxicity) that can correlate with clinical outcomes. Here we review current efforts to develop a Synapse Predicts Efficacy (SPE) system for easy, rapid and cost-effective evaluation of CAR-modified immune cell immunotherapy. Ultimately, we hypothesize the conceptual basis and clinical application of SPE will serve as an important parameter in evaluating CAR immunotherapy and significantly advance precision cancer immunotherapy. [MediaObject not available: see fulltext.] Graphical abstract: Graphic abstract for manuscript CCAS-D-20-00136 by Liu, D., et al., 'The Role of Immunological Synapse in Predicting the Efficacy of Chimeric Antigen Receptor (CAR) Immunotherapy". The various branches of evaluating cancer immunotherapy metaphorically represented as a Rubik's cube. The development of a novel approach to predict the effectiveness of Chimeric Antigen Receptor (CAR)-modified cells by quantifying the quality of CAR IS will introduce a new parameter to the rapidly expanding field of cancer immunotherapy. Currently, no single parameter can predict the clinical outcome or efficacy of a specific type of CAR-modified cell. IS quality will serve as a quantifiable measure to evaluate CAR products and can be used in conjunction with other conventional parameters to form a composite clinical predictor. Much like a Rubik's cube has countless configurations, several methods and combinations of clinical metrics have arisen for evaluating the ability of a given immunotherapeutic strategy to treat cancer. The quality of IS depicting cancer immunotherapy is metaphorically expressed as a Rubik's cube. Each face/color represents one aspect of cancer therapy. Each grid in one face indicates one factor within that aspect of cancer therapy. For example, the green color represents the tumor microenvironment, and one out of the nine grids in the green color indicates suppressor cells (suppressors in green). Changes in one factor may completely alter the entire strategy of cancer therapy. However, the quality of IS (illuminated center red grid) makes the effectiveness of CAR immunotherapy predictable
Avaliação de linhagens elites de arroz irrigado do programa de melhoramento genético da Embrapa em ensaios de VCU no RS - safra 2011/11.
O objetivo deste trabalho foi avaliar o desempenho das linhagens geradas pelo programa de melhoramento genético da Embrapa, em diferentes regiões orizícolas do Rio Grande do Sul, visando possível lançamento de novas cultivares
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