Wuhan Tennis Open Qualification stats & predictions

Cómo seguir las transmisiones en vivo desde España**:

Aquí tienes algunas opciones para seguir las emocionantes clasificaciones del Wuhan Open desde España:

• DAZN**: Plataforma líder para deportes vía streaming que ofrece cobertura completa del evento.1: # Using the first law of thermodynamics to evaluate the effects of photoperiod and temperature on the growth of the marine diatom Thalassiosira pseudonana 2: Author: Daniel A Purdy 3: Date: 8-10-2010 4: Link: https://doi.org/10.1186/1746-4811-6-24 5: Plant Methods: Methodology 6: ## Abstract 7: BackgroundThermodynamics has been used to understand biological processes for many years but is rarely applied to model the effects of environmental factors on photosynthesis and growth in phytoplankton. 8: ResultsThe first law of thermodynamics is used here to determine the effects of photoperiod and temperature on the growth rate of the marine diatom Thalassiosira pseudonana using existing data on photosynthesis and respiration rates at various temperatures and photoperiods. 9: ConclusionsThis method provides a simple approach for estimating how environmental factors affect growth rates in phytoplankton and other organisms that are able to fix carbon dioxide. 10: ## Background 11: The first law of thermodynamics states that energy cannot be created or destroyed but only changed from one form to another [1]. This simple law provides an important constraint on biological systems because living organisms are open systems that require energy to survive [2]. In plants and algae this energy is primarily derived from light and is used to drive photosynthesis in which carbon dioxide (CO2) is fixed into carbohydrates using water (H2O) as an electron donor with oxygen (O2) as a by-product [1]. These carbohydrates can be used as fuel for cellular processes such as respiration or can be used to build new cell material such as lipids and proteins [1]. In this way energy derived from light can be converted into chemical energy in the form of carbohydrates that are used by the organism for growth or cellular maintenance. 12: The use of thermodynamics to understand biological systems has been explored since the early days of bioenergetics [1] and has provided insight into many biological processes such as photosynthesis [2], cellular maintenance [3], and ecological energetics [4]. However these studies have generally focused on understanding basic biological processes rather than modeling how environmental factors affect biological systems at larger temporal scales such as daily or seasonal changes in growth rates due to changes in environmental conditions [5]. 13: Here I use existing data on photosynthesis and respiration rates at different temperatures and photoperiods for the marine diatom Thalassiosira pseudonana[6] to estimate how these environmental factors affect growth rates using the first law of thermodynamics as a constraint on carbon uptake and usage by the cells. 14: ## Methods 15: ### Data Sources 16: All data used in this analysis were taken from Table S1 in Ref [6] except for data at a photoperiod of zero hours that were taken from Fig S1 in Ref [6] using GetData Graph Digitizer version 2.24 http://getdata-graph-digitizer.com/. This data was collected from cultures grown at temperatures ranging from five to twenty degrees Celsius with either an eight hour or sixteen hour photoperiod. 17: ### Growth Model 18: The growth rate was estimated using the following equation: 19: where μ is the growth rate (d-1), P is the photosynthetic rate (mg C cell-1 d-1), R is the respiration rate (mg C cell-1 d-1), T is the photoperiod (hr d-1), L is light saturation constant (mg C cell-1 d-1), and L0 is initial light level (mg C cell-1 d-1). This equation assumes that photosynthetic production increases linearly with increasing light levels until it reaches saturation at L [7]. Light levels are assumed to be proportional to photoperiod assuming that cells receive light during all hours of the day when lights are on but not when they are off. 20: If we assume that all carbon produced via photosynthesis is used by cells for either cellular maintenance via respiration or building new biomass then we can write: 21: where B is biomass production (mg C cell-1 d-1). Rearranging this equation gives: 22: Since biomass production equals growth rate multiplied by cell size we can write: 23: where V is cell volume (μm3 cell-1). Substituting equation (2) into equation (5) gives: 24: ### Calculations 25: The growth rate was calculated using equation (6) for each combination of temperature and photoperiod where photosynthetic rates were measured directly at those conditions. When photosynthetic rates were not measured directly at certain combinations of temperature and photoperiod they were estimated using interpolation between data points with similar temperatures and photoperiods. 26: ## Results 27: ### Effect of Temperature 28: Figure one shows how growth rates vary with temperature for both eight hour and sixteen hour photoperiods estimated using equation (6). As expected from previous studies [8] there is an optimum temperature for growth that occurs at around fifteen degrees Celsius. 29: **Figure 1**Growth rate as a function of temperature under different photoperiods. 30: ### Effect of Photoperiod 31: Figure two shows how growth rates vary with photoperiod at different temperatures estimated using equation (6). As expected from previous studies [9] there is an optimum photoperiod for growth that occurs at around eight hours per day. 32: **Figure 2**Growth rate as a function of photoperiod at different temperatures. 33: ### Combined Effects 34: Figure three shows how both temperature and photoperiod affect growth rates estimated using equation (6). As expected from previous studies [10] there is an optimum combination of temperature and photoperiod that occurs around fifteen degrees Celsius with an eight hour photoperiod. 35: **Figure 3**Growth rate as a function of both temperature and photoperiod. 36: ## Discussion 37: The model presented here provides estimates for how environmental factors such as temperature and photoperiod affect growth rates in phytoplankton that are consistent with previous studies that have used more complex methods such as empirical models based on laboratory experiments [8–10]. This suggests that despite its simplicity this model may provide useful estimates for predicting how environmental factors affect phytoplankton growth rates even though it does not take into account other factors such as nutrient availability or grazing pressure. 38: One limitation of this model is that it assumes all carbon produced via photosynthesis is used by cells either for cellular maintenance via respiration or building new biomass which may not always be true especially if cells experience nutrient limitation or other stressors that reduce their ability to utilize available resources efficiently [11]. Another limitation is that this model does not take into account other factors such as nutrient availability or grazing pressure which can also affect phytoplankton growth rates significantly [12]. 39: Despite these limitations this model provides estimates for how environmental factors such as temperature and photoperiod affect phytoplankton growth rates that are consistent with previous studies suggesting it may provide useful predictions even though it does not take into account other important factors such as nutrient availability or grazing pressure which could potentially improve its accuracy further if included in future versions of this type of model. ** TAGS ** - ID: 1 start_line: 11 end_line: 11 information_type: scientific background brief description: Explanation of how energy from light drives photosynthesis in plants and algae. level of complexity: A factual obscurity: A formulaic complexity: N/A is a chain of reasoning: false assumptions: - Assuming basic knowledge about photosynthesis process. final_conclusion: description: Energy derived from light can be converted into chemical energy in the form of carbohydrates used by organisms. reasoning_steps: - assumption: description: Photosynthesis uses light energy to fix CO2 into carbohydrates. conclusion: description: Chemical energy stored in carbohydrates. description: Photosynthesis converts light energy into chemical energy.