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1403. Bioluminiscence hub - odvěký a stále záhadný fenomén

Creator:
Michal Sochor and Egertová, Zuzana
Format:
print, bez média, and svazek
Type:
article, text, články, journal articles, model:article, and TEXT
Subject:
Biologické vědy, bioluminiscence, houby, mykologie, bioluminescence, mushrooms, mycology, Fungi, Mycena chlorophos, Filoboletus manipularis, 2, and 57/59
Language:
Czech
Description:
Ačkoli bylo světélkování u hub doloženo již ve starověku, intenzivnějšího vědeckého studia se tomuto jevu dostává teprve v posledních letech. Článek shrnuje naše dosavadní poznání bioluminiscence u hub z hlediska evolučního, ekologického i fyziologického. Jeho součástí jsou i fotografie dvou tropických druhů se světélkujícími plodnicemi - Mycena chlorophos a Filoboletus manipularis., Bioluminescence in fungi was first observed in the Archaic period or earlier, but it has only recently been studied scientifically. This paper sums up our knowledge on this phenomenon from evolutionary, ecological, and physiological points of view. Included are photos of two tropical species with luminescent fruiting bodies - Mycena chlorophos and Filoboletus manipularis., and Michal Sochor, Zuzana Egertová.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1404. Biomarkers of cardiometabolic risk in obese/overweight children: effect of lifestyle inetrvention

Creator:
Michal Vrablík, Milada Dobiášová, Lukáš Zlatohlávek, Zuzana Urbanová, and Richard Češka
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, obézní děti, obezita, overweight children, obesity, AIP [Log(TG/HDL-C)], ApoB/apoAI ratio, HOMA-IR (insulin resistance), cardiometabolic risk markers, intensive lifestyle intervention, obese children, 14, and 612
Language:
English
Description:
Obesity is a strong cardiometabolic (CM) risk factor in children. We tested potential CM risk in obese/overweight children and the effect of an intensive lifestyle intervention using newer CM markers: atherogenic index of plasma AIP [Log(TG/HDL-C)], apoB/apoAI ratio and a marker of insulin resistance HOMA-IR. The participants (194 girls, 115 boys, average age 13) were enrolled in an intensive, one-month, inpatient weight reduction program. The program consisted of individualised dietary changes and the exercise program comprised aerobic and resistance training. Anthropometrical and biochemical parameters in plasma and CM risk biomarkers - (AIP, apoB/apoAI ratio and HOMA-IR) were examined before and after the intervention. AIP and HOMA-IR significantly correlated with BMI while apoB/apoAI ratio did not. Only AIP and HOMA-IR showed systematic increases according to the level of obesity by BMI quartiles. Lifestyle intervention significantly improved anthropometrical and biochemical values and the biomarkers too. The response of lipid parameters to the intervention was considerably higher in boys than in girls. The children were stratified into three risk categories according to AIP, where 13.8 % of boys and 5.3 % of girls fell into high risk category. The monitored biomarkers may complement each other in the prognosis of CM risk. AIP was strongly related to obesity and to lipid and glycid metabolism, while the relationship of the apoB/apoAI ratio to obesity and glycid metabolism was not significant. The obese children benefited from the intensive lifestyle intervention which improved the anthropometrical and biochemical parameters and CM risk biomarkers., M. Vrablík, M. Dobiášová, L. Zlatohlávek, Z. Urbanová, R. Češka., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1405. Biomass partition, leaf gas exchange and water relations of alfalfa and milkvetch seedlings in response to soil drying

Creator:
Xu, B.-C., Deng, X.-P., Zhang, S.-Q., and Shan, L.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, hydraulic root signal, root shoot ratio, nonhydraulic root signal, and water stress
Language:
Multiple languages
Description:
This study compared physiological and growth responses to water stress of two legume species during the seedling stage. Potted alfalfa (Medicago sativa L. cv. Algonquin) and milkvetch (Astragalus adsurgens Pall. cv. Pengyang earlymaturing vetch) seedlings were grown under well-watered [soil water content (SWC) maintained at 14.92% daily] or water-stressed conditions (drying) for 15 days. Net photosynthetic rate (PN), transpiration rate (E) and stomatal conductance (gs) of both species decreased parabolically. When SWC decreased to 7.2% and 10.3%, gs values for alfalfa and milkvetch were significantly different from those of the respective well-watered plants (p<0.05). When SWC decreased to 6.6% for alfalfa and 6.8% for milkvetch, leaf water potentials (ψL) were significantly different from those of the well-watered plants (p<0.05). Thus the difference between the SWC thresholds for a nonhydraulic root signal (nHRS) and a hydraulic root signal (HRS) were 0.6% and 3.5% for alfalfa and milkvetch, respectively. Milkvetch had a lower gs than alfalfa for a given SWC (p<0.05). Although alfalfa seedlings had a higher dry mass (DM) and root:shoot ratio (R/S) than milkvetch in both treatments (p<0.05), we concluded that milkvetch seedlings had greater drought tolerance than alfalfa. and B.-C. Xu ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1406. Biomass partitioning and gas exchange in Dalbergia sissoo seedlings under water stress

Creator:
Singh, B. and Singh, G.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
arid areas, leaf water potential, net photosynthetic rate, soil water availability, stomatal conductance, transpiration rate, and water use efficiency
Language:
Multiple languages
Description:
Biomass, leaf water potential (Ψl), net photosynthetic rate (PN), transpiration rate (E), stomatal conductance (gs), leaf to air temperature difference (Tdiff), and instantaneous water use efficiency (WUE) were measured in the seedlings of Dalbergia sissoo Roxb. grown under irrigation of 20 (W1), 14 (W2), 10 (W3), and 8 (W4) mm. Treatments were maintained by re-irrigation when water content of the soil reached 7.4% in W1, 5.6% in W2, 4.3% in W3, and 3.2% in W4. Seedlings in a control (W5) were left without irrigation after maintaining the soil field capacity (10.7%). Seedlings of W1 had highest biomass that was one tenth in W5. Biomass allocation was highest in leaf in W2 and in root in W4 and W5 treatments. Difference between predawn leaf water potential (ΨPd) and midday (Ψmid) increased with soil water stress and with vapour pressure deficit (VPD) in April and May slowing down the recovery in plant leaf water status after transpiration loss. PN, E, and gs declined and Tdiff increased from W1 to W5. Their values were highly significant in April and May for the severely stressed seedlings of W4 and W5. PN increased from 08:00 to 10:00 and E increased until 13:00 within the day for most of the seedlings whereas gs decreased throughout the day from 08:00 to 17:00. PN and E were highest in March but their values were low in January, February, April, and May. Large variations in physiological variables to air temperature, photosynthetically active radiation, and vapour pressure deficit (VPD) indicated greater sensitivity of the species to environmental factors. WUE increased from W1 to W2 but decreased drastically at high water stress particularly during hot summer showing a kind of adaptation in D. sissoo to water stress. However, low biomass and reduced physiological functions at <50% of soil field capacity suggest that this species does not produce significant biomass at severe soil water stress or drought of a prolonged period. and B. Singh, G. Singh.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1407. Biomechanical characterization of cartilages by a novel approach of blunt impact testing

Creator:
Ferdinand Varga, Držík, M., Milan Handl, Chlpík, J., Petr Kos, Elena Filová, Michala Rampichová, Alois Nečas, Tomáš Trč, and Evžen Amler
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, tkáňové inženýrství, tissue engineering, cartilage biomechanics, impact testing, poroelastic material, impact energy dissipation, 14, and 612
Language:
English
Description:
The present article introduces a novel method of characterizing the macromechanical cartilage properties based on dynamic testing. The proposed approach of instrumented impact testing shows the possibility of more detailed investigation of the acting dynamic forces and corresponding deformations within the wide range of strain rates and loads, including the unloading part of stress-strain curves and hysteresis loops. The presented results of the unconfined compression testing of both the native joint cartilage tissues and potential substitute materials outlined the opportunity to measure the dissipation energy and thus to identify the initial mechanical deterioration symptoms and to introduce a better definition of material damage. Based on the analysis of measured specimen deformation, the intact and pathologically changed cartilage tissue can be distinguished and the differences revealed., F. Varga, M. Držík, M. Handl, J. Chlpík, P. Kos, E. Filová, M. Rampichová, A. Nečas, T. Trč, E. Amler., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1408. Biomechanical model of pregnant female for impact purposes

Creator:
Jansová, Magdalena and Hynčík, Luděk
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
human model, pregnant female, validation, and impact
Language:
English
Description:
Biomechanics has widely expanded in the last decades. The last development of computers provides new possibilities in this field. Problems can be solved faster and can be more extensive. One of these problems is the biomechanical model of human body. Its realisaton is practically impossible without using computers, because it is necessary to solve systems of thousands of equations. There are several software packages that enable human body modeling. One of them is the PAM environment [15] developed by the ESI Group International. This computational system is based on the Finite Element Method and is one of the mostly used systems for crash test simulations. Various human body models for various purposes are developed. Pregnant female model serve to optimize safety systems in cars to be more friendly to pregnant abdomen. and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1409. Biomechanical study of disk implants. Part I

Creator:
Borák, Libor, Marcián, Petr, Florian, Zdeněk, and Bartáková, Sonia
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
dental implant, osseointegration, FEM, bone, and density
Language:
English
Description:
The presented work is focused on the biomechanical study of the dental disk implant. The first part of the study deals with the strain analysis of the affected bone tissue and the dental implant loaded in the coronoapical direction by force 190 N. The study includes three types of implant anchorge, four degrees (stages) of osseointegration and nine degrees describing the quality of the cancellous bone. Two types of the disk implant were researched: single-disk and double-disk implant. Biomechanical study of the implant was focused on a stress-strain analysis of the affected bone rissue. The highest influence on the stresses in the bone tissue was primarily an implant anchorage. By the application of correlation relationships between Young modulus and the apparent density of the bone tissue - which is measurable in patients - we achieved the variable presented in this study. and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

1410. Biomechanical study of disk implants. Part II

Creator:
Marcián, Petr, Florian, Zdeněk, Borák, Libor, Krpalek, David, and Valášek, Jiří
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
disk implant, osseointegration, FEM, mandible, and density
Language:
English
Description:
The presented work follows the first part [1], which is focused on the analysis of bone tissue in terms of dependence of bone tissue 'quality' and its subsequent behaviour based on the stress around the disk implant when biting. This second part is focused on the stress-strain analysis (and tolerability) of disk implants as loaded during the masticating process. The study includes two types of disk implants (single-disk and double-disk), three types of anchorage, four degrees (stages) of osseointegration in three quality degrees of the cancellous bone. The study, as expected, has shown that the problematic area of he implants is a transition between the implant body and the disk component, where the equivalent stress in the analyzed implants reaches 700 MPa. and Obsahuje seznam literatury
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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