Abstract

Common ragweed ( Ambrosia artemisiifolia ) is a highly invasive annual

plant, introduced to Europe from North America. One of the important spreading

vectors of Ambrosia is trading with contaminated sunflower achenes. We analysed

the content of ragweed achenes in the packages of sunflower achenes for outdoor

birds, which are available in Slovenian shops and markets. The ragweed achenes were

found in 29 % of the 28 analysed packages. In three packages, the mass percentage of

Ambrosia achenes per kg of animal feed exceeded the maximum content (50 mg/kg)

allowed by EU law. The analysis showed that it is not possible to infer the presence

or absence of Ambrosia achenes in a sample from the amount of impurities in the

package of sunflower achenes for bird feed.

Keywords

Ambrosia artemisiifolia , Helianthus annuus , invasive species, ragweed, Slovenia, sunflower fruits

Abstract

During foraging activities honeybees are frequently exposed to different

xenobiotics, most of them are agrochemical pesticides and beehive chemicals. Many

pesticides are applied together and synergism is likely to occur in different organisms.

The risk of synergisms is neglected and relatively few studies were performed

concerning the effects and synergy mechanism of different xenobiotic combinations

in honeybees. The understanding of synergy mechanisms between xenobiotics is

very important for the control of defined mixtures use and also for the prediction of

potential toxicity of newly developed substances in agriculture and apiculture. This

review is focused on the effects, mechanisms and molecular targets of xenobiotics in

honeybees and possible complex mechanisms of their synergisms. The main threat

for honeybees are insecticides which primary molecular targets are few neuronal

molecules therefore causing the impairment of neuronal system that have a profound

effect on honeybee behavior, cognitive functions and physiology. However, the majority

of synergistic effects observed in honeybees were ascribed to the inhibition of

detoxifying midgut enzymes P450 involved in xenobiotic metabolism since most of

studies were done with the mixtures xenobiotic/P450 inhibitor. The main inhibitors

of P450 enzymes are specific compounds used to prolong the effects of pesticides as

well as some fungicides. Some insecticides can also interact with these enzymes and

influence the xenobiotis. Although the primary mechanisms of action of individual

xenobiotics especially insecticides are well known and there are possible interactions

in honeybees at their primary target sites, this issue is underestimated and it warrants

further investigation.

Keywords

synergism, xenobiotic, A pis mellifera , mechanism, pesticide, P450

Abstract

Numerous physiological processes in organisms as diverse as bacteria

and man are regulated by a small molecular clock termed the circadian clock. It is

present in virtually all cells of the body and enables various physiological processes

to occur at specific times of the day and with a period of about 24 hours. It was not

until recent years that the role of the circadian clock has become evident for normal

physiology of humans as well as other mammals. Disruption of the normal circadian

rhythms can lead to a number of metabolic disorders characteristic of modern lifestyle

including diabetes, obesity and cancer. It is the aim of this review to give the reader a

general overview of what circadian rhythms are, how they look at the molecular level

and why they can influence various metabolic processes in the way they do.

Keywords

Biological rhythms, circadian rhythms, chronobiology, circadian clock

Abstract

Fledgling mass can have great influence on individual’s life history

and reflects the availability and quality of food in the breeding territory. Thus growth

curve is used to compare the difference in the quality between different ecological

conditions. The aim of the study was to fill the knowledge gap on nestling growth

in Great Tit in Slovenia, to determine the influence of altitude on it and to present a

tool for estimating age of nestlings and key dates in breeding phenology of Great Tit.

Great Tits young were monitored using nest-boxes at three locations between years

2010 and 2012. At two locations nest-boxes were placed on three separate altitudinal

belts. Weight growth curve was compared with the curves from other parts of Europe.

Growth curve from Slovenia differs in growth parameters from other European

populations but falls within their range. Difference in growth parameters between

separate populations probably comes from the difference in ecological conditions.

When comparing three altitudes weight parameters of hatchlings were similar at lower

and middle but different at upper altitudes indicating that weigh growth changes with

the altitude. Lower food abundance that comes with rising altitude may be offset by

lower competition through lower breeding density (hence similar growth parameters in

lower and middle altitude), but not past certain altitude. Weight parameters are useful

when comparing different populations, but wing-length is better in determining the

age of young in the nest.

Keywords

Great Tit, hatchling growth, altitude, Slovenia

Abstract

The aim of the study was to compare nest survival of Great Tit between

different regions, altitudes and years to discern which has the highest influence. Temperature

is known to be prominent for breeding parameters and it changes consistently

with altitude. Our hypothesis was that altitude has greater influence on nest survival

than the region and year. Breeding parameters were monitored with the use of nestboxes

over a three year period at three altitude belts in two regions. The main factor

influencing nesting success was modelled using daily survival rate in the program

MARK. We gathered data from 104 first nesting attempts of which 26 failed. Although

nest failure increased with altitude this was significant only for one region. There was

significant difference in nest failure between the regions but not between the years.

Modelling showed higher support in data for regions than for altitudes and years thus

rejecting the hypothesis. Some possible reasons for such results are discussed.

Keywords

Great Tit, nest survival, altitude, Slovenia

Abstract

School practice shows that a cell and the related cell division represent

many problems for students as well as teachers. Students often hold misconceptions

which form in everyday life under the influence of people with whom students live, as

well as the media. Teachers are confronted with the problem of how to most effectively

introduce this subject in class. They should enable students to understand basics of the

cell and its implications as part of scientific literacy in the contemporary world. This

survey used a test to assess the knowledge of students about cells. It included students

on three levels of education; 13 year-olds, 15 year-olds, and 21 year-olds. The results

showed that the knowledge of both younger groups was insufficient. The knowledge

of the oldest group was substantially better, but still not satisfactory. It also showed

that many students learn isolated facts and do not see the relationships between those

facts. We believe that active methods of work in the classroom which are taken from

everyday life could improve these results.

Keywords

cell, cell division, genetics, education

Abstract

The purpose of this paper is to analyze the educational outcomes of

different activities organized through summer camps concerning the conservation of

freshwater ecosystems. The six-day duration camps were organised in three different

locations across Slovenia. The camps were attended by 15 males and 27 females, aged

11 to 18 years. Educational outcomes were measured on the fifth and sixth day of each

camp, using a combination of qualitative and quantitative methods. Results showed

that participants greatly enjoyed attending the camps. The respondents reported that

they learned much about freshwater ecosystems, fauna and flora, different research

methods and handling research equipment. They also showed a high awareness and

understanding of problems related to freshwater ecosystem conservation.

Keywords

outdoor education, camp, adolescents, awareness raising, freshwater ecosystem

Abstract

A survey of Potato spindle tuber viroid was initiated in Slovenia in 2006. Until the end of 2010, 100 samples of ornamental plants were found to be infected. Analysis of 96 complete master sequences of Slovene samples revealed new genetic variants. Our sequence variants showed considerable variation in their predicted secondary structure. The variability was observed in the pathogenic, central and variable domains. In several cases even single mutations were sufficient for the change in predicted secondary structure.

Keywords

Potato spindle tuber viroid, PSTVd, pospiviroid, predicted secondary structure, sequence variants