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2. Evaluation of cold stress of young industrial chicory (Cichorium intybus L.) plants by chlorophyll a fluorescence imaging. I.. Light induction curve

Creator:
Devacht, S., Lootens, P., Baert, J., Van Waes, J., Van Bockstaele, E., and Roldán-Ruiz, I.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, chilling, low temperature, nonphotochemical quenching, photochemical quenching, photoinhibition, and screening
Language:
Multiple languages
Description:
Industrial chicory, Cichorium intybus L., is cultivated for the production of inulin. Most varieties of industrial chicory exhibit rather poor early growth, which limits further yield improvements in their European cultivation area. The poor early growth could be due to suboptimum adaptation of the gene pool to growth at low temperatures, sometimes in combination with high light intensities, which is typical of early-spring mornings. We have used chlorophyll (Chl) a fluorescence to evaluate the response of young plants of the cultivar 'Hera' to low temperatures and high light intensities. Plants were grown at three temperatures: 16°C (reference), 8°C (intermediate), and 4°C (cold stress). Light-response measurements were carried out at different light intensities in combination with different measurement temperatures. Parameters that quantify the photosystem II (PSII) operating efficiency (including PSII maximum efficiency and PSII efficiency factor) and nonphotochemical quenching (NPQ) are important to evaluate the stress in terms of severity, the photosynthetics processes affected, and acclimation to lower growth temperatures. The results clearly demonstrate that in young industrial chicory plants the photosynthetic system adapts to lower growth temperatures. However, to fully understand the plant response to the stresses studied and to evaluate the long-term effect of the stress applied on the growth dynamics, the subsequent dark relaxation dynamics should also be investigated. and S. Devacht ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

3. Existují rasy?: nový pohled na fyzickou rozmanitost lidstva

Creator:
Salzmann, Zdeněk
Format:
print
Type:
model:internalpart and TEXT
Language:
Czech
Description:
The traditional terms „race“ and „racial group (type)“, referring to a division of humankind possessing a combination of physical traits that characterize it as a distinet human type, are no longer usable. Even in the past, the concept of race was far from unambiguous: Darwin gave examples of' classifications of' humans that ranged from two to sixty-three different varieties. The modern view of the concept of race recognizes that mass migrations as well as mixed marriages have occurred so frequently during the last several centuries that the so-called races are for the most part no longer definably distinet. Two approaches are now used to discuss human physical variety. One is clinal: a cline is a gradient of morphological or physiological change in a group of related organisms, usually along a line of geographical or environmental transition. For example, if one maps the distribution (presence or absence) of epicanthus or of the degree of skin pigmentation in the world's populations, one realizes that physical traits are not covariant. The second approach is to recognize that a breeding population has a noticeable frequency of' certain genes in comparison or contrast with other populations.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6. Sand fly saliva: effects on host immune response and Leishmania transmission

Creator:
Rohoušová, Iva and Volf, Petr
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Phlebotomus, Lutzomyia, sand fly saliva, leishmaniasis, and host immune response
Language:
English
Description:
The feeding success of sand flies (Diptera: Phlebotominae) is linked to the vast array of pharmacological substances in their saliva, which interferes with the host haemostasis and immune response. Modification of feeding site plays also an important role in Leishmania transmission. In naive hosts, co-inoculation of saliva and Leishmania parasites increases the chance of successful transmission. Disease exacerbation seems to be associated with enhanced production of type 2 cytokines and selective inhibition of some macrophage functions including the production of NO and H2O2. On the other hand, hosts repeatedly exposed to sand fly bites develop anti-saliva immune response that results in a protection against Leishmania infection. This led to a new interesting approach to anti-Leishmania vaccine - using salivary components to block parasite transmission. The review is therefore focused on the interactions that run between immunomodulatory molecules in sand fly saliva and host immune response, with the impact on Leishmania infection development. Recent studies revealed that saliva-based vaccine for leishmaniasis might be effective and feasible, however, several questions still require to be solved. The knowledge based on experimental mouse model cannot be fully extrapolated to dogs or humans and due to differences in salivary antigens between sand fly species the protective effect is species-specific. On the other hand, the specificity of salivary antigens enables the use of anti-saliva antibodies for monitoring the exposure of hosts to sand fly bites and might be used as a marker of risks for Leishmania transmission in endemic areas.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public