49 research outputs found
School nutrition guidelines: overview of the implementation and evaluation
Objective
To holistically evaluate the extent of implementation of dietary guidelines in schools and present various monitoring systems.
Design
The study comprises three methods: (i) a cross-sectional survey (process evaluation); (ii) an indicator-based evaluation (menu quality); and (iii) a 5 d weighed food record of school lunches (output evaluation).
Setting
Slovenian primary schools.
Subjects
A total 234 food-service managers from 488 schools completed a self-administrated questionnaire for process evaluation; 177 out of 194 randomly selected schools provided menus for menu quality evaluation; and 120 school lunches from twenty-four schools were measured and nutritionally analysed for output evaluation.
Results
The survey among food-service managers revealed high levels of implementation at almost all process evaluation areas of the guidelines. An even more successful implementation of these guidelines was found in relation to organization cultural issues as compared with technical issues. Differences found in some process evaluation areas were related to location, size and socio-economic characteristics of schools. Evaluation of school menu quality demonstrated that score values followed a normal distribution. Higher (better) nutrition scores were found in larger-sized schools and corresponding municipalities with higher socio-economic status. School lunches did not meet minimum recommendations for energy, carbohydrates or dietary fibre intake, nor for six vitamins and three (macro, micro and trace) elements.
Conclusions
The implementation of the guidelines was achieved differently at distinct levels. The presented multilevel evaluation suggests that different success in implementation might be attributed to different characteristics of individual schools. System changes might also be needed to support and improve implementation of the guidelines
Dependence of radon levels in Postojna Cave on outside air temperature
Postojna Cave is the largest of 21 show caves in Slovenia. The radon concentration there was measured continuously in the Great Mountain hall from July 2005 to October 2009 and ranged from about 200 Bq m<sup>&minus;3</sup> in winter to about 3 kBq m<sup>&minus;3</sup> in summer. The observed seasonal pattern of radon concentration is governed by air movement due to the difference in external and internal air densities, controlled mainly by air temperature. The cave behaves as a large chimney and in the cold period, the warmer cave air is released vertically through cracks and fissures to the colder outside atmosphere, enabling the inflow of fresh air with low radon levels. In summer the ventilation is minimal or reversed and the air flows from the higher to the lower openings of the cave. Our calculations have shown that the effect of the difference between outside and cave air temperatures on radon concentration is delayed for four days, presumably because of the distance of the measurement point from the lower entrance (ca. 2 km). A model developed for predicting radon concentration on the basis of outside air temperature has been checked and found to be successful
How Did the Spider Cross the River? Behavioral Adaptations for River-Bridging Webs in Caerostris darwini (Araneae: Araneidae)
Interspecific coevolution is well described, but we know significantly less about how multiple traits coevolve within a species, particularly between behavioral traits and biomechanical properties of animals' "extended phenotypes". In orb weaving spiders, coevolution of spider behavior with ecological and physical traits of their webs is expected. Darwin's bark spider (Caerostris darwini) bridges large water bodies, building the largest known orb webs utilizing the toughest known silk. Here, we examine C. darwini web building behaviors to establish how bridge lines are formed over water. We also test the prediction that this spider's unique web ecology and architecture coevolved with new web building behaviors.We observed C. darwini in its natural habitat and filmed web building. We observed 90 web building events, and compared web building behaviors to other species of orb web spiders.Caerostris darwini uses a unique set of behaviors, some unknown in other spiders, to construct its enormous webs. First, the spiders release unusually large amounts of bridging silk into the air, which is then carried downwind, across the water body, establishing bridge lines. Second, the spiders perform almost no web site exploration. Third, they construct the orb capture area below the initial bridge line. In contrast to all known orb-weavers, the web hub is therefore not part of the initial bridge line but is instead built de novo. Fourth, the orb contains two types of radial threads, with those in the upper half of the web doubled. These unique behaviors result in a giant, yet rather simplified web. Our results continue to build evidence for the coevolution of behavioral (web building), ecological (web microhabitat) and biomaterial (silk biomechanics) traits that combined allow C. darwini to occupy a unique niche among spiders
Mating plugs in polyandrous giants: Which sex produces them, when, how and why?
10.1371/journal.pone.0040939PLoS ONE77
Habituation of the human blink reflex: The effect of stimulus frequency and the state of arousal
Reasons for large fluctuation of radon and CO<sub>2</sub> levels in a dead-end passage of a karst cave (Postojna Cave, Slovenia)
Measurements of radon concentration were performed at three geomorphologically different locations in Postojna Cave, Slovenia. In the part of the cave open to visitors, annual average radon activity concentrations of 3255 ± 1190 Bq m−3 and 2315 ± 1019 Bq m−3 were found at the lowest point (LP) and in the Lepe jame (Beautiful Caves, BC), respectively. A much higher average of 25 020 ± 12 653 Bq m−3 was characteristic of the dead-end passage Pisani rov (Gaily Coloured Corridor, GC), in which CO2 concentration also reached very high values of 4689 ± 294 ppm in summer. Seasonal variations of radon and CO2 levels in the cave are governed by convective airflow, controlled mainly by the temperature difference between the cave and the outside atmosphere. The following additional sources of radon and CO2 were considered: (i) flux of geogas from the Earth's crust through fractured rocks (radon and CO2 source), (ii) clay sediments inside the passage (radon source) and (iii) the soil layer above the cave (radon and CO2 source)
Radon decay products and 10–1100 nm aerosol particles in Postojna Cave
At the lowest point along the tourist route in Postojna Cave, the activity concentration of radon (222Rn) decay products and the number concentration and size distribution of aerosol particles in the size range of 10–1100 nm were monitored, with the focus on the unattached fraction (fun) of radon decay products (RnDPs), a key parameter in radon dosimetry. The total number concentration of aerosols during visits in summer was lower (700 cm−3) than in winter (2800 cm−3), and was dominated by 50 nm particles (related to the attached RnDPs) in winter. This explains the higher fun values in summer (0.75) and the lower winter measurement (0.04) and, consequently, DCFD values of 43.6 and 13.1 mSv WLM−1 respectively for the calculated dose conversion factors. The difference is caused by an enhanced inflow of fresh outside air, driven in winter by the higher air temperature in the cave compared to outside, resulting in the introduction of outside aerosol particles into the cave
Phylogenetic position and composition of Zygiellinae and Caerostris, with new insight into orb-web evolution and gigantism
Gregorič, Matjaž, Agnarsson, Ingi, Blackledge, Todd A., Kuntner, Matjaž (2015): Phylogenetic position and composition of Zygiellinae and Caerostris, with new insight into orb-web evolution and gigantism. Zoological Journal of the Linnean Society 175 (2): 225-243, DOI: 10.1111/zoj.12281, URL: http://dx.doi.org/10.1111/zoj.1228
Darwin\u27s bark spider: giant prey in giant orb webs (Caerostris darwini, Araneae: Araneidae)?
Volume: 39Start Page: 287End Page: 29