Impacts of κ-Oligocarrageenan Application on Photosynthesis, Nutrient Uptake and Bean Yield of Coffee (Coffea robusta)

κ-Oligocarrgeenan (OC) is well known as an effective and green plant growth promoter and elicitor. However, its effect on coffee plant has not been investigated so far. This study aimed to examine the impacts of OC on biophysical activity, vegetative growth and productivity of coffee plant (Coffea robusta). OC with average molecular weight (AMW) of 4.0 kDa was prepared by depolymerization of carrageenan using ascorbic acid. Field experiments were conducted by foliar spray four times per year at various OC concentrations (50, 100, 150, 200, and 250 ppm) for three years (2017-2019). The results showed that OC promoted growth of coffee plant in all tested concentrations, and an optimized concentration was found at 150 ppm which showed a significant increase compared to the control plant in total chlorophyll (24.79%), carotenoid (31.65%), uptakes of N (15.66%), P (15.81%), and K (22.25%) minerals in leaves, crop yield (19.80%) and bean size (13.10%). Therefore, OC is potentially promising to apply as a promoter to enhance yield of crops for sustainable coffee plantation.

Reaching Behind the Black Screen

Shira Passentin is a MSc student in the Department of Science Teaching at the Weizmann Institute of Science. She also is a teacher of science and technology in a middle school (junior high school) in Israel. In this article, she describes a simple biophysical activity, performed by her students at home during coronavirus disease 2019 (COVID-19) lockdowns, which explicates the meaning and importance of surface area in a biologic context.

Molecular and biophysical mechanisms behind the enhancement of lung surfactant function during controlled therapeutic hypothermia

Therapeutic hypothermia (TH) enhances pulmonary surfactant performance in vivo by molecular mechanisms still unknown. Here, the interfacial structure and the composition of lung surfactant films have been analysed in vitro under TH as well as the molecular basis of its improved performance both under physiological and inhibitory conditions. The biophysical activity of a purified porcine surfactant was tested under slow and breathing-like dynamics by constrained drop surfactometry (CDS) and in the captive bubble surfactometer (CBS) at both 33 and 37 °C. Additionally, the temperature-dependent surfactant activity was also analysed upon inhibition by plasma and subsequent restoration by further surfactant supplementation. Interfacial performance was correlated with lateral structure and lipid composition of films made of native surfactant. Lipid/protein mixtures designed as models to mimic different surfactant contexts were also studied. The capability of surfactant to drastically reduce surface tension was enhanced at 33 °C. Larger DPPC-enriched domains and lower percentages of less active lipids were detected in surfactant films exposed to TH-like conditions. Surfactant resistance to plasma inhibition was boosted and restoration therapies were more effective at 33 °C. This may explain the improved respiratory outcomes observed in cooled patients with acute respiratory distress syndrome and opens new opportunities in the treatment of acute lung injury.

Ontogenes and the genetics of intraspecific similarity

The experiments by Gregor Mendel, which formed the background for genetics, were performed with the characters of intraspecific difference (alternative characters). Mendelian protein-coding genes are responsible for these characters. Until recently, these genes were regarded as the only and main hereditary factors responsible for ontogenesis and phylogenesis. The review outlines the information about another category of biological characters (the characters of intraspecific similarity) and, correspondingly, of a special category of genes responsible for these characters (ontogenes). The study into mutations of ontogenes in drosophila experiments suggests that (1) ontogenes control the construction of cell ensembles and trigger protein-coding genes in cells; (2) the program of individual development is encoded in ontogenes and “edited” in germline cells; (3) ontogenes fulfill a regulatory function without any contacts and chemical intermediaries, which suggests a kind of biophysical activity; and (4) two categories of cells—stem cells and terminally differentiated cells—correspond to these two categories of genes. Ontogenes are active in stem cells and protein-coding genes, in terminally differentiated cells.

Effect of Chlorotriphenyl Derivatives of Sn and Pb upon Biophysical Properties of Membranes

Biophysical activity of two twin organometallic compounds Triphenyltin chloride (TPhT) and Triphenyllead chloride (TPhL) in their interreaction with model membranes, as well as with yeast cellsSaccharomyces cerevisiae, was investigated. Four measurement methods were used in the experiments: two physical methods (spin probes method and the electric method); two biological methods (minimal inhibitory concentration /MIC/ and yeast survival test). It has been found that the activity of TPhT in interaction with model membranes and yeast cells is distinctly greater than that of TPhL. The activity manifests itself by considerable increase in the fluidity of the middle part of liposome bilayer, change in the polarization direction of the transmembrane voltage of filters impregnated with lauric acid, and in complete inhibition of growth of yeast cells at the concentration of 5 .