Dydaktyka z żywym organizmem w tle : jak ciekawie nauczyć i nie zabić?

The article offers recommendations for academic teachers who deal with natural sciences in under- and graduate university or college courses. Difficulties are discussed, and solutions are offered with reference to courses that require the use of a living organism, an instrument, a model or solutions that are available on the Internet. The paper proceeds by putting emphasis on frequent mistakes which lead to situations when requirements that students have to meet are not compatible with the form and content of classes. Furthermore, the idea here is to provide academic teachers with information on how to prepare a presentation that would leave a trace in students’ mind. The discussion also includes optimal ways of assessment of laboratories, tutorials and seminars. Readers are presented with literary as well Internet sources that may prove helpful in perfecting particular didactic skills which academic teachers need to learn in order to teach natural sciences courses efficiently. The article ends with a set of practical directives, a “Didactic Decalogue.

Wstęp

"Drodzy Czytelnicy, wszyscy lubimy rankingi. W naturze ludzkiej znajdzie się zawsze zakątek, w którym kryje się skłonność do porównań. Porównujemy siebie do pozostałych, będąc świadomymi, że sami również zajmujemy kolejne miejsca na listach tworzonych przez innych. Najbardziej lubimy jednak rolę jurorów. Rankingi służą często zaspokajaniu próżności. Są jednak i takie, którym przyświeca szczytny cel: jak ratunek dla zagrożonych gatunków." [...] (fragm.

The glycolytic enzymes activity in the midgut of diabrotica virgifera virgifera (Coleoptera: Chrysomelidae) adult and their seasonal changes

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) is an important pest of maize. The diet of the D. virgifera imago is rich in starch and other polysaccharides present in cereals such as maize. Therefore, knowledge about enzymes involved in digestion of such specific food of this pest seems to be important. The paper shows, for the first time, the activities of main glycolytic enzymes in the midgut of D. virgifera imago: endoglycosidases (a-amylase, cellulase, chitinase, licheninase, laminarinase); exoglycosidases (a- and b-glucosidases, a- and b-galactosidases) and disaccharidases (maltase, isomaltase, sucrase, trehalase, lactase, and cellobiase). Activities of a-amylase, a-glucosidase, and maltase were the highest among assayed endoglycosidases, exoglycosidases, and disaccharidases, respectively. This indicates that in the midgut of D. virgifera imago a-amylase, a-glucosidase and maltase are important enzymes in starch hydrolysis and products of its digestion. These results lead to conclusion that inhibition of most active glycolytic enzymes of D. virgifera imago may be another promising method for chemical control of this pest of maize

Set of stress biomarkers as a practical tool in the assessment of multistress effect using honeybees from urban and rural areas as a model organism: a pilot study

A decrease among honey bee populations (Apis mellifera) in the traditional apiaries has been observed in recent years. In light of this negative phenomenon, urban beekeeping seems to be an appropriate alternative solution for the bee population in reducing the toxic effects of a large number of pesticides that are commonly used in agricultural ecosystems. Despite the rapid development of urban beekeeping, there is little information regarding the different aspects of the defense effectiveness of bees from the urban and rural areas. The study was aimed to show whether honey bees from these two locations differ in the level of the valuable biomarkers of stress exposure helpful in establishing which bees, from urban or rural areas, are under greater environmental pressure. For this purpose, foragers from an urban rooftop apiary and a traditional rural apiary were collected. The chosen biomarkers were measured in various tissues of bees. The activity of glutathione S-transferase and acetylcholinesterase, the level of total antioxidant capacity, heat shock protein 70 (Hsp70), and defensin were selected for the analyses. In our opinion, the Hsp70 and defensin levels seemed to be important in the indication of urban multistress factors. The higher level of heat shock proteins and defensins in tissues/organs of bees from the urban apiary—in the gut (an increase, respectively, 92% and 7.3%) and fat body (an increase, respectively, 130% and 7.8%), known as targets of environmental toxins, pointed out the urban environment as highly stressful at both the individual and colony levels. In turn, high total antioxidant capacity was measured in the guts of honey bees from rural area (an increase 107%). Such a situation suggests a different mechanism of defense and specificity of rural and urban environmental stressors and also honey bees foraging activity

Elemental Distribution in Reproductive and Neural Organs of the Epilachna nylanderi (Coleoptera: Coccinellidae), a Phytophage of Nickel Hyperaccumulator Berkheya coddii (Asterales: Asteraceae) by micro-PIXE

The phenomenon of metal hyperaccumulation by plants is often explained by a pathogen or herbivore defense hypothesis. However, some insects feeding on metal hyperaccumulating plants are adapted to the high level of metals in plant tissues. Former studies on species that feed on the leaves of Berkheya coddii Roessler 1958 (Asteraceae), a nickel-hyperaccumulating plant, demonstrated several protective mechanisms involved in internal distribution, immobilization, and elimination of Ni from the midgut and Malpighian tubules. These species are mainly coleopterans, including the lady beetle, Epilachna nylanderi (Mulsant 1850) (Coleoptera: Coccinellidae), collected from the ultramafic ecosystem near Barberton in South Africa. By performing particle-induced X-ray emission microanalysis elemental microanalysis (PIXE), this study examined whether Ni may be harmful to internal body systems that decide on insect reactivity (central nervous system [CNS]), their reproduction, and the relationships between Ni and other micronutrients. Data on elemental distribution of nine selected elements in target organs of E. nylanderi were compared with the existing data for other insect species adapted to the excess of metals. Micro-PIXE maps of seven regions of the CNS showed Ni mainly in the neural connectives, while cerebral ganglia were better protected. Concentrations of other bivalent metals were lower than those of Ni. Testis, compared with other reproductive organs, showed low amounts of Ni. Zn was effectively regulated at physiological dietary levels. In insects exposed to excess dietary Zn, it was also accumulated in the reproductive organs. Comparison of E. nylanderii with other insects that ingest hyperaccumulating plants, especially chrysomelid Chrysolina clathrata (Clark) (Coleoptera: Chrysomelidae), showed lower protection of the CNS and reproductive organs

Towards understanding Cameraria ohridella (Lepidoptera: Gracillariidae) development: effects of microhabitat variability in naturally growing horse-chestnut tree canopy

Dwelling intensity of horse-chestnut miner (Cameraria ohridella) larvae in various leaves insolation and temperature was measured to determine whether this pest’s development follows a predictable pattern or depends more on local microenvironment conditions. Mines growing on leaves of mature host plants (Aesculus hippocastanum L.) in their natural conditions were photographed for two consecutive generations of the pest and in two separated vegetation periods. Apart from meteorological data obtained from the nearest station, the temperature of intact and mined parts of sun-exposed and shaded leaf blades was measured at various daytimes throughout the experiment. Obtained sets of digital data were analysed and combined to model mine area growth as a function of degree-days sum by adopting of Verhulst logistic equation. We showed the predictive potential of our model based on experimental data, and it may be useful in the scheduling of pest control measures in natural conditions. Our analyses also revealed that despite significant differences in microenvironment conditions depending on mines’ insolation, the horse-chestnut miner larvae could partially compensate for them and complete their development at similar endpoints expressed as the cumulative sum of degree-days. We conclude that computer-aided analysis of photographic documentation of leaf-miner larval growth followed by mathematical modelling offers a noninvasive, reliable, and inexpensive alternative for monitoring local leaf-miners populations