Study on CAT activity of tomato leaf cells under salt stress based on microhyperspectral imaging and transfer learning algorithm.

Salt stress easily leads to oxidative stress and promotes the catalase (CAT) response in tomato leaves. For the changes in catalase activity in leaf subcells, there is a need for a visual in situ detection method and mechanism analysis. This paper, taking catalase in leaf subcells under salt stress as the starting point, describes the use of microscopic hyperspectral imaging technology to dynamically detect and study catalase activity from a microscopic perspective, and lay the theoretical foundation for exploring the detection limit of catalase activity under salt stress. In this study, a total of 298 microscopic images were obtained under different concentrations of salt stress (0 g/L, 1 g/L, 2 g/L, 3 g/L) in the spectral range of 400-1000 nm. With the increase in salt solution concentration and the advancement of the growth period, the CAT activity value increased. Regions of interest were extracted according to the reflectance of the samples, and the model was established by combining CAT activity. The characteristic wavelength was extracted by five methods (SPA, IVISSA, IRFJ, GAPLSR and CARS), and four models (PLSR, PCR, CNN and LSSVM) were established according to the characteristic wavelengths. The results show that the random sampling (RS) method was better for the selection samples of the correction set and prediction set. Raw wavelengths are optimized as the pretreatment method. The partial least-squares regression model based on the IRFJ method is the best, and the coefficient of correlation (Rp) and root mean square error of the prediction set (RMSEP) are 0.81 and 58.03 U/g, respectively. According to the ratio of microarea area to the area of the macroscopic tomato leaf slice, the Rp and RMSEP of the prediction model for the detection of microarea cells are 0.71 and 23.00 U/g, respectively. Finally, the optimal model was used for quantitative visualization analysis of CAT activity in tomato leaves, and the distribution of CAT activity was consistent with its color trend. The results show that it is feasible to detect the CAT activity in tomato leaves by microhyperspectral imaging combined with stoichiometry.

Oral contraceptives containing drospirenone for premenstrual syndrome.

BACKGROUND: Premenstrual syndrome (PMS) is a common problem. Premenstrual dysphoric disorder (PMDD) is a severe form of premenstrual syndrome. Combined oral contraceptives (COC), which provide both progestin and oestrogen, have been examined for their ability to relieve premenstrual symptoms. A combined oral contraceptive containing drospirenone and a low oestrogen dose has been approved for treating PMDD in women who choose combined oral contraceptives for contraception. OBJECTIVES: To evaluate the effectiveness and safety of COCs containing drospirenone in women with PMS. SEARCH METHODS: We searched the Cochrane Gynaecology and Fertility Group trial register, CENTRAL (now containing output from two trials registers and CINAHL), MEDLINE, Embase, PsycINFO, LILACS, Google Scholar, and Epistemonikos on 29 June 2022. We checked included studies' reference lists and contacted study authors and experts in the field to identify additional studies. SELECTION CRITERIA: We included randomised controlled trials (RCT) that compared COCs containing drospirenone with placebo or with another COC for treatment of women with PMS. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures recommended by Cochrane. The primary review outcomes were effects on premenstrual symptoms that were prospectively recorded, and withdrawal due to adverse events. Secondary outcomes included effects on mood, adverse events, and response rate to study medications. MAIN RESULTS: We included five RCTs (858 women analysed, most diagnosed with PMDD). The evidence was very low to moderate quality; the main limitations were serious risk of bias due to poor reporting of study methods, and serious inconsistency and imprecision. COCs containing drospirenone and ethinylestradiol (EE) versus placebo COCs containing drospirenone and EE may improve overall premenstrual symptoms (standardised mean difference (SMD) -0.41, 95% confidence interval (CI) -0.59 to -0.24; 2 RCTs, N = 514; I2 = 64%; low-quality evidence); and functional impairment due to premenstrual symptoms in terms of productivity (mean difference (MD) -0.31, 95% CI -0.55 to -0.08; 2 RCTs, N = 432; I2 = 47%; low-quality evidence), social activities (MD -0.29, 95% CI -0.54 to -0.04; 2 RCTs, N = 432; I2 = 53%; low-quality evidence), and relationships (MD -0.30, 95% CI -0.54 to -0.06; 2 RCTs, N = 432; I2 = 45%; low-quality evidence). The effects from COCs containing drospirenone may be small to moderate. COCs containing drospirenone and EE may increase withdrawal from trials due to adverse effects (odds ratio (OR) 3.41, 95% CI 2.01 to 5.78; 4 RCT, N = 776; I2 = 0%; low-quality evidence). This suggests that if you assume the risk of withdrawal due to adverse effects from placebo is 3%, the risk from drospirenone plus EE will be between 6% and 16%. We are uncertain of the effect of drospirenone plus EE on premenstrual mood symptoms, when measured by validated tools that were not developed to assess premenstrual symptoms. COCs containing drospirenone may lead to more adverse effects in total (OR 2.31, 95% CI 1.71 to 3.11; 3 RCT, N = 739; I2 = 0%; low-quality evidence). This suggests that if you assume the risk of having adverse effects from placebo is 28%, the risk from drospirenone plus EE will be between 40% and 54%. It probably leads to more breast pain, and may lead to more nausea, intermenstrual bleeding, and menstrual disorder. Its effect on nervousness, headache, asthenia, and pain is uncertain. There was no report of any rare but serious adverse effects, such as venous thromboembolism in any of the included studies. COCs containing drospirenone may improve response rate (OR 1.65, 95% CI 1.13 to 2.40; 1 RCT, N = 449; I2 not applicable; low-quality evidence). This suggests that if you assume the response rate from placebo is 36%, the risk from drospirenone plus EE will be between 39% and 58%. We did not identify any studies that compared COCs containing drospirenone with other COCs. AUTHORS' CONCLUSIONS: COCs containing drospirenone and EE may improve premenstrual symptoms that result in functional impairments in women with PMDD. The placebo also had a significant effect. COCs containing drospirenone and EE may lead to more adverse effects compared to placebo. We do not know whether it works after three cycles, helps women with less severe symptoms, or is better than other combined oral contraceptives that contain a different progestogen.

On the inter- and intra-annual variability of ecosystem evapotranspiration and water use efficiency of an oak savanna and annual grassland subjected to booms and busts in rainfall.

Whether annual evapotranspiration of native ecosystems is increasing or decreasing with time as CO2 concentrations are rising, the climate is warming and rainfall experiences booms and busts, remains an unanswered question in the field of global change biology. To answer this question, we measured evapotranspiration and carbon dioxide exchange over and under an oak savanna and over an annual grassland in the Mediterranean climate of California, USA, from 2001 through 2019 with the eddy covariance method; during this 19-year period, CO2 rose 40 ppm, air temperature increased by 1°C and annual rainfall ranged between 133 and 890 mm/year. No temporal trend in evapotranspiration or water use efficiency was observed over this time duration. Many competing positive and negative feedbacks among stomatal sensitivity to carbon dioxide concentrations, soil moisture, and vapor pressure deficit, the impact of temperature on saturation vapor pressure and access to groundwater muted the response of evapotranspiration to its changing world when integrated to the ecosystem scale and annual time steps. At the intra-annual time scale, we found that plants transmit information on soil moisture status through their influence on the vapor pressure deficit of the atmospheric boundary layer. The inter-annual variations in evaporative water use by the savanna and annual grassland were relatively decoupled from the booms and busts in rainfall. Instead, variations in length of growing season and access to groundwater explained much of this year-to-year variation in annual evapotranspiration. The access of groundwater by the oak savanna may make these ecosystems more robust in a warmer world, than was previously thought. This is a scale emergent property that needs better consideration in coupled climate-ecosystem models.

Using imaging spectroscopy to detect variation in terrestrial ecosystem productivity across a water-stressed landscape.

A central challenge to understanding how climate anomalies, such as drought and heatwaves, impact the terrestrial carbon cycle, is quantification and scaling of spatial and temporal variation in ecosystem gross primary productivity (GPP). Existing empirical and model-based satellite broadband spectra-based products have been shown to miss critical variation in GPP. Here, we evaluate the potential of high spectral resolution (10 nm) shortwave (400-2,500 nm) imagery to better detect spatial and temporal variations in GPP across a range of ecosystems, including forests, grassland-savannas, wetlands, and shrublands in a water-stressed region. Estimates of GPP from eddy covariance observations were compared against airborne hyperspectral imagery, collected across California during the 2013-2014 HyspIRI airborne preparatory campaign. Observations from 19 flux towers across 23 flight campaigns (102 total image-flux tower pairs) showed GPP to be strongly correlated to a suite of spectral wavelengths and band ratios associated with foliar physiology and chemistry. A partial least squares regression (PLSR) modeling approach was then used to predict GPP with higher validation accuracy (adjusted R2  = 0.71) and low bias (0.04) compared to existing broadband approaches (e.g., adjusted R2  = 0.68 and bias = -5.71 with the Sims et al. model). Significant wavelengths contributing to the PLSR include those previously shown to coincide with Rubisco (wavelengths 1,680, 1,740, and 2,290 nm) and Vcmax (wavelengths 1,680, 1,722, 1,732, 1,760, and 2,300 nm). These results provide strong evidence that advances in satellite spectral resolution offer significant promise for improved satellite-based monitoring of GPP variability across a diverse range of terrestrial ecosystems.

Photosynthetic responses to temperature across leaf-canopy-ecosystem scales: a 15-year study in a Californian oak-grass savanna.

Ecosystem CO2 fluxes measured with eddy-covariance techniques provide a new opportunity to retest functional responses of photosynthesis to abiotic factors at the ecosystem level, but examining the effects of one factor (e.g., temperature) on photosynthesis remains a challenge as other factors may confound under circumstances of natural experiments. In this study, we developed a data mining framework to analyze a set of ecosystem CO2 fluxes measured from three eddy-covariance towers, plus a suite of abiotic variables (e.g., temperature, solar radiation, air, and soil moisture) measured simultaneously, in a Californian oak-grass savanna from 2000 to 2015. Natural covariations of temperature and other factors caused remarkable confounding effects in two particular conditions: lower light intensity at lower temperatures and drier air and soil at higher temperatures. But such confounding effects may cancel out. At the ecosystem level, photosynthetic responses to temperature did follow a quadratic function on average. The optimum value of photosynthesis occurred within a narrow temperature range (i.e., optimum temperature, T opt): 20.6 ± 0.6, 18.5 ± 0.7, 19.2 ± 0.5, and 19.0 ± 0.6 °C for the oak canopy, understory grassland, entire savanna, and open grassland, respectively. This paradigm confirms that photosynthesis response to ambient temperature changes is a functional relationship consistent across leaf-canopy-ecosystem scales. Nevertheless, T opt can shift with variations in light intensity, air dryness, or soil moisture. These findings will pave the way to a direct determination of thermal optima and limits of ecosystem photosynthesis, which can in turn provide a rich resource for baseline thresholds and dynamic response functions required for predicting global carbon balance and geographic shifts of vegetative communities in response to climate change.

Fundamental ratios and logarithmic periodicity in human limb bones.

Fundamental mathematical relationships are widespread in biology yet there is little information on this topic with regard to human limb bone lengths and none related to human limb bone volumes. Forty-six sets of ipsilateral upper and lower limb long bones and third digit short bones were imaged by computed tomography. Maximum bone lengths were measured manually and individual bone volumes calculated from computed tomography images using a stereologic method. Length ratios of femur : tibia and humerus : ulna were remarkably similar (1.21 and 1.22, respectively) and varied little (<7%) between individuals. The volume ratio of femur : tibia was approximately half that of humerus : ulna (1.58 and 3.28, respectively; P < 0.0001). Lower limb bone volume ratios varied much more than upper limb ratios. The relationship between bone length and volume was found to be well described by power laws, with R(2) values ranging from 0.983 to 0.995. The most striking finding was a logarithmic periodicity in bone length moving from distal to proximal up the limb (upper limb λ = 0.72, lower limb λ = 0.93). These novel data suggest that human limb bone lengths and volumes follow fundamental and highly conserved mathematical relationships, which may contribute to our understanding of normal and disordered growth, stature estimation, and biomechanics.

Reappraising the surface anatomy of the pterion and its relationship to the middle meningeal artery.

Despite its clinical importance, the surface anatomy of the pterion is inconsistently reported. This study reappraises the surface marking of the pterion and its relationship to the middle meningeal artery (MMA). The position and morphology of the pterion were analyzed in the Frankfurt plane in 76 adult skulls and 50 adult cranial cone beam CT scans. Relationship to the anterior branch of the MMA was examined in the skulls. Measurement reproducibility was assessed in a 20% randomly selected sample. In the skulls, the majority of pteria were sphenoparietal (78%), followed by epipteric (16%) and frontotemporal (5%). The center of the pterion was a mean of 26 ± 4 mm behind and 11 ± 4 mm above the posterolateral margin of the frontozygomatic suture; measurements were reproducible and consistent between sides and genders. Distances from the frontozygomatic suture were slightly greater (29 and 16 mm, respectively) in cranial CTs. A one centimeter circle centered on the midpoint of the pterion overlapped the anterior branch of the MMA in 68% of skulls; the artery was a few millimeters posterior in the remainder. Mean skull thickness at the midpoint of the pterion was 4.4 mm compared to 1 mm at its thinnest point in the squamous temporal bone. In conclusion, in most adults, the pterion lies within a one centimeter diameter circle 2.6 cm behind and 1.3 cm above the posterolateral margin of the frontozygomatic suture (which is easily palpable in vivo). This region overlaps the anterior branch of the MMA in two-thirds of cases.

On the differential advantages of evergreenness and deciduousness in mediterranean oak woodlands: a flux perspective.

We assessed the differential advantages of deciduousness and evergreenness by examining 26 site-years of carbon dioxide, water vapor, and energy flux measurements from five comparable oak woodlands in France, Italy, Portugal, and California (USA). On average, the evergreen and deciduous oak woodlands assimilated and respired similar amounts of carbon while using similar amounts of water. These results suggest that evergreen and deciduous woodlands have specific, and similar, ecological costs in mediterranean climates, and that both leaf habits are able to meet these costs. What are the mechanisms behind these findings? Deciduous oaks compensated for having a shorter growing season by attaining a greater capacity to assimilate carbon for a given amount of intercepted solar radiation during the well-watered spring period; at saturating light levels, deciduous oaks gained carbon at six times the rate of evergreen oaks. Otherwise, the two leaf habits experienced similar efficiencies in carbon use (the change in carbon respired per change in carbon assimilated), water use (the change in carbon assimilation per change in water evaporated), and rainfall use (the change in evaporation per change in rainfall). Overall, leaf area index, rather than leaf habit, was the significant factor in determining the absolute magnitude of carbon gained and water lost by each evergreen and deciduous oak woodland over an annual interval; the closed canopies assimilated and respired more carbon and transpired more water than the open canopies. Both deciduous and evergreen mediterranean oaks survive in their seasonally hot/dry, wet/ cool native range by ensuring that actual evaporation is less than the supply of water. This feat is accomplished by adjusting the leaf area index to reduce total water loss at the landscape scale, by down-regulating photosynthesis, respiration, and stomatal conductance with progressive seasonal soil water deficits, and by extending their root systems to tap groundwater.