Papierchromatographische Untersuchung von Thyroxin und anderen Jodthyroninen

The Science of Nature -     

The humanitarian common logistic operating picture: a solution to the inter‐agency coordination challenge

Although significant progress has been made in developing the practice of humanitarian logistics, further improvements in efficiency and effectiveness have the potential to save lives and reduce suffering. This paper explores how the military/emergency services’ concept of a common operating picture (COP) can be adapted to the humanitarian logistics context, and analyses a practical and proven approach to addressing the key challenge of inter‐agency coordination and decision‐making. Successful adaptation could provide the mechanism through which predicted and actual demands, together with the location and status of material in transit, are captured, evaluated, and presented in real time as the basis for enhanced decision‐making between actors in the humanitarian supply network. Through the introduction of a humanitarian logistics COP and its linkages to national disaster management systems, local communities and countries affected by disasters and emergencies will be better placed to oversee and manage their response activities.     

Carbon dioxide affects charge accumulation in leaves

This work was supported by grants OKKFT (Tt) 222/1988 and 310/1988 from the National Foundation of Technical Development (Hungary). Govindjee was supported by an interdisciplinary McKnight Research Grant to the University of Illinois at Urbana, IL (USA).     

Glass buildings on river banks as “polarized light traps” for mass-swarming polarotactic caddis flies

The caddis flies Hydropsyche pellucidula emerge at dusk from the river Danube and swarm around trees and bushes on the river bank. We document here that these aquatic insects can also be attracted en masse to the vertical glass surfaces of buildings on the river bank. The individuals lured to dark, vertical glass panes land, copulate, and remain on the glass for hours. Many of them are trapped by the partly open, tiltable windows. In laboratory choice experiments, we showed that ovipositing H. pellucidula are attracted to highly and horizontally polarized light stimulating their ventral eye region and, thus, have positive polarotaxis. In the field, we documented that highly polarizing vertical black glass surfaces are significantly more attractive to both female and male H. pellucidula than weakly polarizing white ones. Using video polarimetry, we measured the reflection-polarization characteristics of vertical glass surfaces of buildings where caddis flies swarmed. We propose that after its emergence from the river, H. pellucidula is attracted to buildings by their dark silhouettes and the glass-reflected, horizontally polarized light. After sunset, this attraction may be strengthened by positive phototaxis elicited by the buildings' lights. The novelty of this visual-ecological phenomenon is that the attraction of caddis flies to vertical glass surfaces has not been expected because vertical glass panes do not resemble the horizontal surface of waters from which these insects emerge and to which they must return to oviposit.     

Ventral polarization vision in tabanids: horseflies and deerflies (Diptera: Tabanidae) are attracted to horizontally polarized light

Adult tabanid flies (horseflies and deerflies) are terrestrial and lay their eggs onto marsh plants near bodies of fresh water because the larvae develop in water or mud. To know how tabanids locate their host animals, terrestrial rendezvous sites and egg-laying places would be very useful for control measures against them, because the hematophagous females are primary/secondary vectors of some severe animal/human diseases/parasites. Thus, in choice experiments performed in the field we studied the behavior of tabanids governed by linearly polarized light. We present here evidence for positive polarotaxis, i.e., attraction to horizontally polarized light stimulating the ventral eye region, in both males and females of 27 tabanid species. The novelty of our findings is that positive polarotaxis has been described earlier only in connection with the water detection of some aquatic insects ovipositing directly into water. A further particularity of our discovery is that in the order Diptera and among blood-sucking insects the studied tabanids are the first known species possessing ventral polarization vision and definite polarization-sensitive behavior with known functions. The polarotaxis in tabanid flies makes it possible to develop new optically luring traps being more efficient than the existing ones based on the attraction of tabanids by the intensity and/or color of reflected light.     

Land use history of a floodplain area during the last 200 years in the Upper-Tisza region (Hungary)

Research into landscape history makes it possible to follow landscape changes in the past and support landscape management, conservation and restoration programs. Floodplain habitats are lost, isolated and fragmented on account of land use. Nowadays, these habitats are threatened by modifications in the natural water regime, as well as agricultural and forestry practices. Floodplains have great importance because they provide a transition between aquatic habitats and terrestrial biotopes. Our analysis of aerial photographs and topographical maps revealed that the major predicted changes in the study area are related to agricultural abandonment and afforestation. The comparison of land cover maps from 1784 to 2005 showed intensification of agriculture with land cover conversions from arable land and orchards to grasslands, marshes and woodlands. The land use types that are mostly responsible for the fragmentation of the landscape are arable land, economic plantations and orchards. We found that fragmentation was greater after 1956. This was caused by socioeconomic changes and showed that the habitats of floodplains have changed intensively during the last 200 years. Knowledge of this last 200 years of history contributes to a more careful and wiser management of the region through biodiversity protection and environmental development.     

Sorption behaviour of acetochlor,atrazine, carbendazim,diazinon, imidacloprid and isoproturon on Hungarian agricultural soil

Laboratory studies were conducted to determine the sorption behaviour of six commonly used pesticides (acetochlor, atrazine, carbendazim, diazinon, imidacloprid and isoproturon) on Hungarian brown forest soil with clay alluviation (Luvisol) using the batch equilibrium technique. The sorption isotherms could be described by the Freundlich equation in non-linear form (n < 1) for all compounds, however in case of diazinon using the extended Freundlich equation proved to be a better approach. The adsorption constant related soil organic carbon content (Koc) calculated from Freundlich equation were 314 for acetochlor, 133 for atrazine, 2805 for carbendazim, 1589 for diazinon, 210 for imidacloprid and 174 for isoproturon. The octanol-water partition coefficients (Pow), which can be a useful parameter to predict of adsorption behaviour of a chemical on soil, and dissociation coefficients of these pesticides were calculated based on the chemical structure of them using a computerized expert system. The octanol-water partition coefficients were determined experimentally from high performance liquid chromatographic parameters as well. Good agreement was observed between experimental and the computer expert system estimated data. Computer estimated log Pow values ranged 0.5 and 3.86 for the examined pesticides, with imidacloprid and diazinon being the least and most hydrophobic respectively. Experimentally determined logPow ranged between 0.92 and 3.81 with the same tendency. It can be concluded that the Freundlich adsorption constants (Kf) are slightly related to the octanol-water partition coefficients of investigated chemicals, nevertheless no close correlation could be established because of the influence of further characteristics of solutes and soil.     

Does malaoxon play a role in the geno- and cytotoxic effects of malathion on human choriocarcinoma cells?

This investigation was undertaken to elucidate whether the active metabolite of malathion, malaoxon, has any role in exerting cyto- and genotoxic effects for human choriocarcinoma (JAR) cell line which is an acceptable model for human placental cells. Gas chromatography-mass spectrometry (GC-MS) analysis were separately performed on the cell compartment and supernatant cell culture medium after subjecting the cell line to different malathion concentrations (10–400 μg/mL) and for various incubation periods (0.5 to 24 hours). GC-MS analysis showed that the sonication performed for the disruption of the cells did not cause the chemical change of malathion. The uptake of malathion by the cells was relatively fast. However, the presence of malaoxon, even in trace amounts, could not be confirmed either in samples originating from disrupted cells or in the cell culture medium. Although the hydrolysis of malaoxon occurred in the culture medium, this degradation process could not be counted as a reason for the absence of malaoxon. Since both malathion and malaoxon standard compounds could be accurately detected and distinguished by the applied liquid-liquid extraction and GC-MS methods, one can conclude that, in the case of JAR cells, the parent compound, (i.e. malathion itself) is responsible for the observed in vitro cyto- and genotoxic effects. Our results indicate that the direct toxicity of malathion contributes to the complications of pregnancy observed for environmental malathion exposure.     

Acute and sub-chronic toxicity of four cytostatic drugs in zebrafish

The acute and sub-chronic effects of four cytostatic drugs—5-fluorouracil (5-FU), cisplatin (CisPt), etoposide (ET) and imatinib mesylate (IM)—on zebrafish (Danio rerio) were investigated. Acute tests were carried out in a static system in accordance with the OECD guideline 203 for adult fish and the draft guideline for fish embryos (FET test) in order to find the LC50 values of the four cytostatic drugs. Early-life stage toxicity test on zebrafish was conducted according the OECD guideline 210 using the cytostatic drugs 5-FU and IM in a semistatic system with the objective of investigating the sub-chronic effects of the cytostatic drugs on fish. In adult fish, the cytostatic drugs 5-FU and ET did not pass the limit test, thus, are considered non-toxic. In case of cisplatin, LC50 was calculated at 64.5 mg L^?1, whereas in case of IM, LC50 was at 70.8 mg L^?1. In the FET test, LC50 of 5-FU at 72-h post fertilization (hpf) was 2441.6 mg L^?1. In case of CisPt, LC50 was 349.9 mg L^?1 at 48 hpf and it progressively decreased to 81.3 mg L^?1 at 120 hpf. In addition, CisPt caused a significant delay in the hatch of larvae. In case of ET, LC50 values were not calculable as they were higher than 300 mg L^?1 at which concentration the substance crystallized in the solution. LC50 values of IM were 48 hpf; 158.3 mg L^?1 , 72 hpf; 141.6 mg L^?1, 96 hpf; 118.0 mg L^?1, and 120 hpf; 65.9 mg L^?1. In the Early-life Stage Test with 5-FU, embryonic deformities were not detected during the tests. Regarding mortalities, the 10 mg L^?1 concentration can be considered as LOEC, as statistically significant difference in mortalities was detected in this group alone. Concerning dry body weight and standard length, 1 mg L^?1 is the LOEC. In case of IM, the highest tested concentration (10 mg L^?1) can be considered LOEC for mortalities, however, the treatment did not have an effect on the other investigated parameters (dry and wet weight, standard length). All four cytostatic drugs were characterized by low toxicity in zebrafish in acute and sub-chronic tests.