Ammonium ions affect metal toxicity in chamomile plants

AbstractThe impact of ammonium presence (+NH4+) or absence (−NH4+) on cadmium (Cd) and nickel (Ni) toxicity in chamomile (Matricaria chamomilla) was studied. Elimination of ammonium elevated tissue water content, amount of soluble proteins and Fv/Fm ratio though responses differed between Cd and Ni. Antioxidative enzyme activities (ascorbate- and guaiacol-peroxidase) were also more enhanced in Cd–NH4+ than in Ni–NH4+ treatments (in comparison with respective +NH4+ counterparts). Thiols rather decreased in shoots and increased in roots in the absence of ammonium. At the level of coumarin-related metabolites, NH4+ absence typically elevated amount of herniarin glycoside precursor while “stress” coumarin derivative umbelliferone decreased, indicating an additional negative impact of ammonium presence. Subsequently, total soluble phenols and PAL activity were not enhanced by ammonium absence. Mineral nutrients were not considerably affected with the exception of Fe and K that increased preferentially in the roots in the absence of ammonium. These data clearly show that NH4+ presence is stressful alone or in the presence of metals and that ammonium is not a suitable alternative source of nitrogen

Content changes of assimilative pigments in leaves after fertilizer Mg-Titanit application

DOI: 10.15414/afz.2014.17.02.58–64Received 9. May 2014 ǀ Accepted 10. June 2014 ǀ Available online 23. June 2014The impact of the liquid fertilizer Mg-Titanit (MGT) containing titanium on the dynamics of the content changes of the total chlorophyll in the leaves of winter wheat and winter rape was studied in the field small-area trial carried out at the Haplic Chernozem. The trial involved 5 variants. 0 – control, MGT unfertilized variant; 2xTi 0,2 – spraying twice by MGT in the dose 0.2 l.ha-1; 3xTi 0,2 – spraying thrice by MGT in the dose 0.2 l.ha-1; 2xTi 0,4 – spraying twice by MGT in the dose 0.4 l.ha-1, 3xTi 0,4 –spraying thrice by MGT in the dose 0.4 l.ha-1. The fertilizer was used at two or three growth stages: wheat was fertilized at the stages BBCH 29, BBCH 32, BBCH 55 – 60; rape at the stages BBCH 50 – 52, BBCH 59, BBCH 66 – 67. The results proved that in the cultivation of winter wheat the content of the total chlorophyll was increased annually with two applied doses of Mg-Titanit if the spraying was carried out at the growth stage BBCH 32 (the second spraying). The winter rape reacted positively to Mg-Titanit spraying applied at the growth stage BBCH 50 – 52 (first spraying) by the chlorophyll formation in both years of the trial. The third spraying tended to decrease the content of total chlorophyll with both crops and both applied doses of Mg-Titanit in the most cases. In the overwhelming majority of cases the content of the total chlorophyll was higher in the plants treated with the dose of 0.2 l.ha-1 than those treated by the dose 0.4 l.ha-1. The positive impact of Mg-Titanit on the content of the total chlorophyll was carried out by the increase of the amount of both assimilative pigments (chlorophyll a and chlorophyll b).Keywords: chlorophyll, fertilizer, titanium, winter wheat, winter rap

Does apricot seeds consumption cause changes in human urine?

Natural substances, such as amygdalin, used in alternative medicine gained high popularity. Common people as well as patients with different diseases have almost unlimited access to various natural supplements. To protect human health, it is very important to study effect of these substances. Amygdalin is a cyanogenic glucoside derived from seeds of rosaceous plants, for example seeds of bitter almonds (Prunus dulcis), or apricot, cherry, apple, peach, plum, etc. It is a natural product that owns antitumor activity, it has also been used for the treatment of asthma, bronchitis, emphysema, leprosy and diabetes and produces a kind of antitussive and antiasthmatic effects. The present in vivo study was designed to reveal whether amygdalin in apricot seeds has got an effect on human urine composition, pH value and urine associated health status after six weeks of oral administration. The study group finally consisted of 34 healthy adult volunteers (21 females and 13 males). All participants were asked to consume 60 mg.kg-1 body weight of bitter apricot seeds daily (approximately 3.0 mg.kg-1 of amygdalin) during 6 weeks. During the experiment, three urine collections were carried out (first collection - at the beginning of the experiment; second collection - after 21 days; third collection - after 42 days). Quantification of urine calcium (Ca), magnesium (Mg), phosphorus (P), sodium (Na), potassium (K), chlorides (Cl-), urea and pH value after apricot seeds supplementation was performed. Statistical analysis of variance showed, that consumption of bitter apricot seeds during 42 days had a significant (p <0.01) effect on amount of calcium excreted in urine, though this decrease shifted its level from elevated mean value in control collection into normal physiological range. Significant changes were observed in urea (p <0.05) and phosphorus (p <0.01) levels in urine after apricot seed ingestion, but gender was also considered to be a source of their variation

Návrh drevostavby rodinného domu

This work contains desing of Timber House. Construction system produces in the Czech Republic under name Europeans. Part of the work is describe that system, each part of the structure and details. Work includes also completed project documentation for planning permission and statement about peripheral part of construction by the requirements for thermal protection of buildings

HOW DO TEACHERS TEACH BOTANY AT GYMNASIA? A SURVEY IN SLOVAKIA

We investigated the experiences of high school biology teachers in teaching botany. A questionnaire was chosen as a research tool, which was filled out by a total of 124 gymnasium teachers from 4 regions (capital city Bratislava 19 teachers, west SK 40 teachers, central SK 31 teachers, east SK 34 teachers). Gymnasia teachers do not have adequate equipment at their disposal (e. g. only 42.1% of quality microscopes in Bratislava and 73.5 – 77.5% in other regions), but they are relatively active (e. g. 73.5 – 87.1% of teachers use native microscopy and 64.5 – 84.2% of teachers use 3D models in teaching). They also use various plant materials, but algae, mosses and ferns are used less frequently (mainly by teachers from Bratislava). Also, most teachers do not consider students’ knowledge of plant biology to be adequate and have identified which areas of plant biology are problematic for students. In addition, even the teachers admit that their knowledge of plant anatomy and plant physiology is not adequate (29.4 – 57.5 % in individual regions). We also found positive correlations between the number of gaps in teachers’ knowledge and the number of gaps in students’ knowledge (r = 0.4892). The relationship between the number of tools available to teachers and their activity, i.e. the number of aids and equipment they use in teaching, was also found (r = 0.5063)

Let’s Ask the Other Side: Teaching Gymnasium Plant Biology from a Teacher’s Perspective

It has been repeatedly found that plant biology is less attractive for students than other biology fields. We, therefore, focused on the opposite and, through an online questionnaire, we asked biology teachers at gymnasia throughout Slovakia how they teach plant biology and where they experience problems. Almost 30% of teachers characterized technical equipment as insufficient but use some visual aids for ca. 50% of lessons. Despite the dominant use of microscopy, teachers admit that students’ biggest shortcomings are found in the anatomy of organs, photosynthesis, ontogenesis and its regulation by exogenous/endogenous factors, or when connecting knowledge about tissues with their functions. About half of the teachers rate their knowledge of plant anatomy and physiology as sufficient, but these teachers rate only about 20% of their students in the same way. Based on the negative correlation between the use of aids and the lack of student knowledge, and, at the same time, the positive correlation between the activity of teachers and better technical equipment, we conclude that the mainly neglected technical infrastructure does not allow for a better practical education (e.g., only 13.7% of gymnasia have analytical balances and only 1.6% a spectrophotometer). Furthermore, almost 90% of teachers mentioned that online education during COVID-19 pandemic negatively affected students’ knowledge. We hope that our research can contribute to changes in the Slovak educational curriculum focused on plant biology in a more scientific direction and inspire research in other countries, with the aim of exchanging knowledge regarding the species diversity of plants around the world and their importance for people and the environment

Enhancement of carbon-steel peel adhesion to rubber blend using atmospheric pressure plasma

The surface of carbon-steel plates was modified by non-equilibrium plasma of diffuse coplanar surface barrier discharge (DCSBD) in order to improve the adhesive properties to the NR (natural rubber) green rubber compound. The effect of different treatment times as well as different input power and frequency of supplied high voltage was investigated. The samples were characterized using contact angle and surface free energy measurement, measurement of adhesive properties, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Surface chemical composition was studied by energy-dispersive X-ray spectroscopy (EDX). Significant increase in wettability was observed even after 2 s of plasma exposure. The surface modification was confirmed also by peel test, where the best results were obtained for 6 s of plasma treatment. In addition the ageing effect was studied to investigate the durability of modification, which is crucial for the industrial applications