Acta et Commentationes Exact and Natural Sciences

The ontogenetic development of Rana dalmatina Bonaparte, 1840 species (Amphibia: Ranidae) in the context of climate change

Tudor Cozari — 2024-09-30

Globally, amphibians represent one of the main objects of study in the context of climate change, because the temperature variations recorded and in the Republic of Moldova also represent a major threat to their development and sustainability.

For this purpose, a complex ecological study was carried out regarding the embryonic and larval development strategies of the Rana dalmatina Bonaparte, 1840, species and the main particularities related to its population structure and dynamics were described. This research allowed us to evaluate the degree of ecological plasticity of natural populations of Rana dalmatina in relation to the plurality of environmental factors, which allows us to develop suitable and safe measures for monitoring and conservation of the species.

The biochemical composition of the biomass of the oat cultivar 'Sorin' grown under the conditions of the Republic of Moldova and its possible uses

Victor Țîței — 2024-09-30

We investigated the quality indices of the biomass from common oat Avena sativa, romanian cultivar 'Sorin' which was grown in the experimental plot of the ``Alexandru Ciubotaru'' National Botanical Garden (Institute),

Chisinau, Republic of Moldova. The results revealed that the dry matter of whole oat plants contained 9.5% CP with forage value 598 g/kg DDM, RFV= 89, 11.84 MJ/kg DE, 9.72 MJ/kg ME and 5.37 MJ/kg NEl; prepared oat hay contained 10.5%

CP, 574 g/kg DDM, 11.40 MJ/kg DE, 9.36 MJ/kg ME and 5.39 MJ/kg NEl. The oat haylage is characterized by pH = 3.77, 38.1 g/kg lactic acid, 5.9 g/kg acetic acid, 10.2% CP, 567-619 g/kg DDM, 11.28 MJ/kg DE, 9.26 MJ/kg ME and 5.29 MJ/kg NEl.

The biochemical methane potential of the studied substrates from Avena sativa cv. 'Sorin' reaches 329-355 l/kg VS.

New (o-phenylenediaminglyoximato)-(o-phenylenediaminglyoxime)zinc(II) chloride. Synthesis and crystal structure

Dumitru Ureche — 2024-10-02

The interaction of dichloroglyoxime and o-phenylenediamine with zinc(II) acetate dihydrate leads to the formation of a new compound of Zn(II) with o-phenylenediamineglyoxime (o-FDH₂), very little studied ligand. The X-ray study, on the basis of which the crystal structure of this compound was determined, established that this oxime ligand was obtained from the condensation of organic components and coordinates to the metal atom like most vic-dioximes – bidentate-chelate through two nitrogen atoms, forming metallic rings of five atoms. The presented mononuclear complex compound is of a molecular type, the coordination polyhedron of Zn(II) being a pyramidal-tetragonal one is formed by a neutral o-FDH₂ ligand, a monodeprotonated o-FDH^- one and a chloride anion.

Influence of fertilization and row spacing on seed yield and quality of Lathyrus sativus L.

Nelly Lili Fînaru — 2024-10-02

Pulses provide, along with other species, a rich source of nutrients needed both for human food and animal feed. These include Lathyrus sativus L, a grain legume that is less cultivated worldwide, especially in Europe, but of interest because of its ecological plasticity such as tolerance to drought, waterlogging, salinity, etc.

Diversity of avifauna in the orchards of the Republic of Moldova

Tudor Țibuleac — 2024-10-02

The study was conducted in the period 1991-2018 in 86 different types of orchards from the central part of the Republic of Moldova, in all phenological periods. The bird fauna in the orchards is well represented, with a rich diversity of 95 species from 13 orders, which represents 35% of the avifauna of the republic. The dominant species were the passerine birds that are widespread and have high density in various arboreal biotopes. There were recorded 5 protected species: Ciconia ciconia, Circus pygargus, Milvus migrans, Falco vespertinus and Dendrocopos medius. In terms of phenology, the predominance of migratory species was found, followed by sedentary ones, winter guests, occasional and passage species. Further research is needed on orchard avifauna, which provide a range of economically valuable ecosystem services.

ISSR fingerprinting of genetic diversity within and among Orobanche cumana wallr. populations from different countries

Ina Bivol — 2024-10-02

Molecular genetic diversity was analysed for 23 Orobanche cumana populations from four countries using 13 ISSR markers. Descriptive population genetic statistics and AMOVA analysis revealed a marked degree of intrapopulation differentiation. PCA and UPGMA clustering showed a clear division into two main regional groups, i.e. the first group was more closely related to the Middle East and the second group belonged to Eastern Europe. The results of this research would suggest that the Moldavian, Bulgarian, and Romanian populations, which have many molecular markers in common, may share many genetic traits that indicate their monophyletic origin.

[CaL3][Co(NCS)4] – potential agent for enhancing the productivity of Chlorella Vulgaris Beijer. microalga

Boris Nedbaliuc — 2024-10-02

The advancing of modern biotechnologies requires the development of new procedures for stimulating the biological activity of some cultures that produce substances of vital importance. Coordination compounds present an effective solution for achieving this objective. The inclusion of some biometals in the composition of the coordination compounds, as well as some organic ligands with electron-donating atoms, creates premises for the assembly of molecules that can influence biological systems. The productivity of the microalgae Chlorella vulgaris Beijer., cultivated on modified nutrient media and supplemented with a coordination compound containing calcium, was evaluated. It was found that increased concentrations of this compound have an inhibitory action on Chlorella strain. A stimulatory effect was registered when the concentrations of 10 mg/L, 5 mg/L and 1 mg/L of the tested coordination compound were administered, the biomass obtained was higher by 10.8%, 7.6% and 5.4% in relation to the control group.

The dependence of the adaptation of the cardiovascular system in adolescents on the state of some environmental factors

Diana Koshkodan — 2024-10-02

This article presents the experimental data related to the ecological factors that have an impact on the adaptation of children and adolescents. The selected ecological factors are the air and water quality in the areas surrounding the investigated educational institutions. It was established that there is a correlation between the degree of pollution of the external environment and the cardiovascular indices of adolescents. Thus, for the students from the academic institutions located in the more polluted areas, the indices of heart economy and the restoration of the frequency of heart contractions after physical effort are lower compared to those of students located in the educational institutions from the less polluted areas.

Floristic notes from Bessarabia No. 241-276

Pavel Pînzaru — 2024-10-02

The paper presents new growing stations for 36 species of rare vascular plants from the spontaneous flora of the Republic of Moldova, highlighted as the result of the new floristic investigations carried out from the spring to the summer of the current year. The species Valerianella eriocarpa Desv. was recorded for the first time in the local flora, the presence of 7 rare species, little known previously, was confirmed and they were proposed to be included in the List of protected species and in The Red Book of the Republic of Moldova, 4th edition: Carex pseudocyperus L., C. strigosa Huds., C. vesicaria L., Epipactis leptochila (Godfery) Godfery, Fraxinus coriariifolia Scheele, Linum catharticum L. Senecio macrophyllus M.Bieb., and for the species Klasea bulgarica (Acht. & Stoj.) Holub, indicated only for one station in Batîr commune, Cimișlia district, from where it disappeared, another station was registered in the same locality.

DFT analysis of intermolecular and intramolecular double proton transfer during the condensation process of 4-pyridinecarboxaldehyde with isomers of aminobenzoic acid

Ion Arsene — 2024-10-02

To understand in detail the double proton transfer in the condensation reaction of 4-pyridinecarboxaldehyde with isomers of aminobenzoic acid (in the gas phase and in solvent), the dynamic mechanism was studied using the DFT method implemented in the GAUSSIAN 09 program and the 6-31G basis set. All condensation processes described in this study proceed in two stages: the first stage involves the interaction of the reactants and the methanol-mediated proton transfer from the amine group to the aldehyde group, forming an intermediate compound; the second stage is identified by the intramolecular donation of the second proton from the (-NH) group to the hydroxyl oxygen, forming highly stable Schiff base products with the elimination of water and methanol molecules. From the perspective of activation energy, it is observed that the solvent has a positive influence on intermolecular transfer, which is not the case for intramolecular transfer. Additionally, the solvent positively contributes to the energetic stability of the final reaction products.

Physiological particularities of calves' organisms in early postnatal ontogenesis

Sergiu Balacci — 2024-10-02

This article presents a synthesis of the specialized literature regarding some aspects of the physiological state, growth, and development of calves in early postnatal ontogenesis. Calves have a distinct physiology, by comparison to adult cattle, adapted to their period of rapid development. Studying the physiology of calves during the early postnatal period is essential for ensuring their healthy growth and development, directly influencing long-term health and productivity. This critical period is marked by numerous physiological changes and adaptations, and understanding them is vital for implementing effective management and care strategies.

Diversity of small rodents (Mammalia: Rodentia) in various sectors of the municipality of Chisinau

Natalia Caraman — 2024-10-02

The small rodents in various sectors of the municipality of Chisinau are represented by 10 species. In the recreational sectors of the municipality of Chisinau, a rather rich fauna of small rodents was recorded due to the existence of various types of biotopes, including natural and wetland, which denotes the presence of stable communities of rodents, favoring in turn the existence of a series of predatory vertebrates.