Search

Spectral plant phenology, based on time series of vegetation indices, is a useful tool for monitoring vegetation condition and climatic changes. The chlorophyll/carotenoid index (CCI) and photochemical reflectance index (PRI) show promise for spectral phenology of coniferous plants. This study evaluates the potential of using CCI, PRI, and the normalised difference vegetation index (NDVI) as phenological metrics for Platycladus orientalis. The study found a strong correlation between the annual dynamics of the chlorophyll/carotenoid ratio (Chl/Car) and the time series of CCI (R2 = 0.89, p < 0.001) and PRI (R2 = 0.85, p < 0.001). The CCI time series was used to determine the beginning and end of the phenological vegetation period (PVP) of P. orientalis through a double logistic regression model. The PRI model had an error of approximately two weeks in predicting the beginning and end of the PVP, with a tendency to overestimate the duration of the PVP. The use of NDVI as a model is unsuitable for describing the P. orientalis 2023 PVP.

Based on the regression, factor and discriminant analysis of the depersonalized data of 1082 patients with combined pelvic injuries, prognostic logit models were developed, including such factors as age, the variant of the mechanism of pelvic injury, results of the assessment of the degree of impaired consciousness and coma on the Glasgow scale, and total quantitative scores of damage severity for each of the three commonly used scales (Yu. N. Tsibin's, VPH-P (MT), ISS). The resulting three models for each of the three scales of injury severity have almost equal prediction efficiency for the dependent variable “outcome”. The revealed regularities and the coefficient-formalized models for the predicting of the fatal outcome of pelvic injury treatment formed the base for the software implementations in the forms of tables and the calculator. During the testing, the usability as well as the satisfactory prediction accuracy were confirmed.

The development of methods to detect plant stress is not only a scientific challenge, but is also of great importance for agriculture and forestry. However, at present, stress diagnostics based on plant spectral characteristics has several limitations: (1) the high dependence of stress assessment on plant species identity; (2) the poor differentiation of different types of stress; and (3) the difficulty of detecting stress before visible symptoms appear. In this regard, the development of plant spectral metrics represents a significant area of research. Ficus elastica plants were exposed under the photosynthetic photon flux density (PPFD) from 0 to 1200 μmol photons m−2s−1. Exposure of F. elastica leaves to excess light (EL) (≥400 μmol photons m−2s−1) resulted in an increase in reflectance in the yellow-green region (522–594 nm) and a decrease in reflectance in the red region (666–682 nm) of the spectrum, accompanied by a shift of the red edge point toward the longer wavelength. These changes were revealed using the previously proposed light stress index (LSI = mean(R666:682)/mean(R522:594)). Based on the results obtained, two new vegetation indices (VIs) were proposed: LSIRed = R674/R654 and LSINorm = (R674 − R654)/(R674 + R654), indicating light stress by changes in the red region of the spectrum. The results of the study showed that LSI, LSIRed, and LSINorm have a high degree of coupling strength with maximal quantum yields of photosystem II values. The plant response to EL exposure, as assessed by the values of these three VIs, was well expressed regardless of the PPFD levels. The effect of EL at non-stressful PPFDs (50–200 μmol photons m−2s−1) was found to disappear within one hour after cessation of exposure. In contrast, the effect of the stressful PPFD (800 μmol photons m−2s−1) was found to persist for at least 80 h after cessation of exposure. The results of the study indicate the need to consider light history in spectral monitoring of vegetation. [ABSTRACT FROM AUTHOR]

The article provides an analysis of the improvement of methods for calculating of leaf spring suspensions in retrospect; features of modern calculation methods and own experience in developing of a spring suspension design for a medium-tonnage truck with a gross weight of 6 tons.

Hibiscus moscheutos L. 'Berry Awesome' is a complex hybrid of the new Proven Winners Summerific series of varieties with highly ornamental characteristics. Micropropagation of highly ornamental varieties is important for mass production of planting material for commercial purposes. The traditional methods for propagating Hibiscus varieties, such as cuttings or seed propagation, however, do not guarantee high rates of production of high-quality seedlings. To solve this problem, an attempt was made to develop protocols for micropropagation of Hibiscus moscheutos L. 'Berry Awesome' in vitro on agar and liquid medium using a bioreactor system, followed by ex vitro adaptation of the regenerants. The optimal method for sterilization of nodal explants as well as the optimal composition of the initiation medium for shoot proliferation and rooting were determined. For micropropagation on a liquid medium, a rocker-type bioreactor was used, and its advantages over micropropagation on an agar medium were demonstrated. The results showed that the best sterilization method for nodal segment explants was as follows: pretreatment by rinsing with running tap water, sterile water, and distilled water for 70 min and soaking for 5 min in a mixture of solutions of ethyl alcohol (96%), hydrogen peroxide (38%), and water in a ratio of 1:1:2. In this case, live and sterile explants accounted for 62.6%. The optimal initiation medium for axillary buds in nodal segments was the Murashige and Skoog (MS) medium supplemented with 0.1 mg L−1 N-(2-chloro-4-pyridinyl)-N'-phenylurea (CPPU), which resulted in 73.3% of axillary buds being induced. The optimal solid proliferation medium was MS medium supplemented with 0.1 mg L−1 CPPU with a proliferation coefficient of 5.8. In a liquid medium, the optimal concentration of CPPU was 0.05 mg L−1 with a proliferation coefficient of 9.2. The best medium for rooting/shoots with agar and in bioreactors was MS medium with the addition of 0.1 mg L−1 indole-3-butyric acid (IBA). The highest rooting rate was 99.0% in both types of media, and the survival rate of plantlets was 88.7% in solid media and 98.7% in the bioreactor. [ABSTRACT FROM AUTHOR]

Hyperspectral imaging techniques are widely used to remotely assess the vegetation and physiological condition of plants. Usually, such studies are carried out without taking into account the light history of the objects (for example, direct sunlight or light scattered by clouds), including light-stress conditions (photoinhibition). In addition, strong photoinhibitory lighting itself can cause stress. Until now, it is unknown how light history influences the physiologically meaningful spectral indices of reflected light. In the present work, shifts in the spectral reflectance characteristics of Ficus elastica leaves caused by 10 h exposure to photoinhibitory white LED light, 200 μmol photons m−2 s−1 (light stress), and moderate natural light, 50 μmol photons m−2 s−1 (shade) are compared to dark-adapted plants. Measurements were performed with a Cubert UHD-185 hyperspectral camera in discrete spectral bands centred on wavelengths from 450 to 950 nm with a 4 nm step. It was shown that light stress leads to an increase in reflection in the range of 522–594 nm and a decrease in reflection at 666–682 nm. The physiological causes of the observed spectral shifts are discussed. Based on empirical data, the light-stress index (LSI) = mean(R666:682)/mean(R552:594) was calculated and tested. The data obtained suggest the possibility of identifying plant light stress using spectral sensors that remotely fix passive reflection with the need to take light history into account when analysing hyperspectral data. [ABSTRACT FROM AUTHOR]

Context: Preservation of genetic diversity of species is a pressing issue; in particular, the preservation of the gene pool of many rare and endangered plants is a priority. Species of the genus Crambe (family Brassicaceae) have potential in agriculture and bioremediation. Aims: This study aims to assess the genetic diversity and DNA fingerprint of five rare species of the genus Crambe , and to develop the concept of a genetic passport for rare plants. Methods: DNA fingerprinting was conducted via the inter simple sequence repeat (ISSR) method, using six ISSR primers. Hierarchical cluster analysis of the species was performed. Key results: In total, 145 polymorphic loci were detected. The studied species formed two different clusters on genetic dendrogram analysis. The first cluster comprised two species, Crambe steveniana and C. tataria from a single subsection (Tatariae), forming a common clade. They were the most genetically close species with genetic similarity of 0.8431. The remaining three species (C. cordifolia , C. maritima , C. pinnatifida), from another subsection of Crambe , formed nodes from the general clade. Conclusions: The findings allow plants to be genetically certified using our methods and informative ISSR primers for rare plants. We were able to propose a genetic formula identifying a species and present an example of a genetic passport for rare plants. The genetic structure of C. pinnatifida was investigated for the first time. Implications: The present findings contribute to the systematics and critical investigation of rare plant species with genetic resource potential. A genetic passport could be used in the protection of copyright of agricultural varieties. We assessed the genetic diversity and DNA fingerprint of five rare species of the Brassicaceae genus Crambe , using six inter simple sequence repeat primers. The species could be clustered into two groups according to subsection of Crambe. The results demonstrate that the methods allow rare plants to be genetically certified. [ABSTRACT FROM AUTHOR]

In this work, we study long-term changes in the main directions of movement (storm tracks) of extratropical cyclones in the North Atlantic for the period 1873–2021, based on the data of the MSLP (Mean Sea Level Pressure) archives from the Climatic Research Unit and NCEP/DOE AMIP-II reanalysis. It was found that in the cold half of the year, the mean latitudes of storm tracks undergo oscillations with the periods ~80–100, ~40–45, and ~22 years, which indicates their possible association with solar cyclicity. Cyclone trajectories were found to shift northward at the minimum of the Gleissberg secular cycle (~1900–1930) and southward at its maximum (~1940–1960). The secular variations are the most pronounced in the western part of the North Atlantic, with the peak-to-peak amplitude reaching ~3–5°, and disappear at longitudes east of Greenwich. On the bidecadal timescale, cyclone tracks were found to shift noticeably to the north in even solar cycles and weakly to the south in odd ones. The most significant northward shifts (~1–2°) were detected during the descending phase and the minimum of the solar cycle (from the second to the sixth year after the solar maximum) in the eastern part of the North Atlantic (longitudes 30–10° W). The detected oscillations of cyclone trajectories may be caused by long-term changes in the intensity of the stratospheric polar vortex associated with galactic cosmic ray variations and geomagnetic activity. [ABSTRACT FROM AUTHOR]