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11442. Diel changes in adipokinetic response and walking activity of Pyrrhocoris apterus (Heteroptera) in relation to physiological status and wing dimorphism
- Creator:
- Maxová, Anna, Kodrík, Dalibor, Zemek, Rostislav , and Socha , Radomír
- Type:
- article, model:article, and TEXT
- Subject:
- Pyrrhocoris apterus, Pya-AKH, adipokinetic response, walking activity, diurnal rhythm, diapause, and wing polymorphism
- Language:
- English
- Description:
- Three experimental groups of adult females of Pyrrhocoris apterus (reproductive brachypterous, diapausing brachypterous, and macropterous with non-diapause type of reproductive arrest) were analysed for their dose dependency of adipokinetic response, sensitivity of the fat body to Pya-AKH and locomotor activity during a 24 hour cycle. The greatest adipokinetic response (lipid elevation after hormonal treatment) was observed in macropterous, lower in diapausing brachypterous and the lowest in reproductive brachypterous females. Macropterous females also exhibited the highest activity of walking, while the lowest locomotor activity was found in diapausing brachypters. Diel changes of adipokinetic response were recorded in all three experimental groups, with maximal response occurring during the day at 6-7 h after the onset of light. On the contrary, the minimal adipokinetic response was found in the night and early after the onset of light. No significant differences in diel rhythms were observed between groups exposed to various day lengths. Diel changes in locomotor activity were found only in reproductive brachypterous females and females of macropterous morph, and showed a diurnal rhythm with only one peak of activity during a 24 hour cycle. In the latter, the rhythmic pattern of walking activity was positively correlated with diel changes of adipokinetic response. This indicates an important role of Pya-AKH in dispersal strategy of macropterous females of this heteropteran.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
11443. Diel distribution, migration and abundance assessment of Toxabramis houdermeri in Baise Reservoir, China
- Creator:
- Zeng, Lei, Zhou, Lei, FU, Dong-Hua, Xu, Peng, Zeng, Shuang, Tang, Qin-Dong, and Li, Gui-Feng
- Type:
- article, model:article, and TEXT
- Subject:
- hydroacoustics, fish abundance, and water quality
- Language:
- English
- Description:
- The split-beam hydro-acoustics surveys were conducted to learn about the diel migration and distribution characters of Toxabramis houdermeri and to assess its current abundance in Baise Reservoir of China in October 2013. The study revealed the average density of T. houdermeri was 258 individuals/1000 m³, and gradually increased from downstream, through middle to upstream (203 individuals/1000 m³, 252 individuals/1000 m³ and 318 individuals/1000 m³, respectively). The study also showed that the target species always distributed in the 2-42 m water layer during the daytime, before migrating upward around dusk which led the fish density to sit in the 2-12 m water layer, to reaching a peak value of 1740 individuals/1000 m³ during the night. Finally, the fish volume density was found to positively correlate with the concentration of chlorophyll, dissolved oxygen (DO) and pH value in their studied areas. In conclusion, the result presented that T. houdermeri preferred a relatively higher average chlorophyll concentration of 3.58 ug/L DO od 6,33 mg/L, and pH of 7.96 in the upstream and upper layers of Baise Reservoir.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
11444. Dielektrika
- Creator:
- Petzelt, Jan and Glogarová, Milada
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fyzika, dějiny, physics, history, 6, and 53
- Language:
- Czech and English
- Description:
- Jan Petzelt, Milada Glogarová.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
11445. Dienogest – spolehlivý progestin s unikátní přidanou hodnotou
- Creator:
- Maule, Miloslav
- Format:
- print, text, and regular print
- Type:
- model:article, article, Text, and TEXT
- Subject:
- progestiny--farmakologie--chemie--klasifikace, antikoncepční látky orální hormonální--farmakologie, nandrolon--analogy a deriváty--farmakokinetika--chemie--terapeutické užití, fixní kombinace léků, antagonisté androgenů--farmakologie--chemie, ženské pohlaví, and lidé
- Language:
- Czech and English
- Description:
- Dienogest, progestin syntetizovaný poprvé v roce 1979 v Jeně v Německu, si zachovává stále významné postavení mezi kontraceptivy. To vyplývá z jeho významných příznivých účinků – progestagenního a antiandrogenního. Další terapeutické využití stejně jako příznivý farmakologický a metabolický profil, zajišťují dienogestu, zvláště v kombinovaných formách, další perspektivu mezi perorálními kontraceptivy., Dienogest, progestin was synthesized for the first time in Jena, Germany in 1979 and still has an important role among contraceptives. This fact is based on its marked positive effects – progestagenic and antiandrogenic. Other therapeutic application as well as favorable pharmacological and metabolic profile of agent provides that dienogest, especially in combined form, has a good perspective among oral contraceptives., and Miloslav Maule
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
11446. Diet and growth of spirlin, Alburnoides bipunctatus in the barbel zone of the Sava River
- Creator:
- Treer, Tomislav, Piria, Marina, Aničić, Ivica, Safner, Roman, and Tomljanović, Tea
- Type:
- article and TEXT
- Subject:
- cyprinid, Croatia, condition, feeding, and threat
- Language:
- English
- Description:
- No spirlin have been registered in the barbel zone of the Sava River, Croatia in the late seventies of the last century. Since then, due to improved water quality the presence of spirlin gradually increased in number (23.3%) and in biomass (4.7%). The most dominant item in the diet of spirlin were Bacillariophyceae and Chlorophyceae during every monthly investigation. The diet consisted also of invertebrates which can be considered as a secondary or an accidental prey. The size related analyse of the consumed food showed Bacillariophyceae to be preferred food by fish of all sizes. The back calculated growth in the total length could be expressed by the following formula: Lt = 12.0 (1-e -0.59 (t+0.14)). The phi-prime of spirlin from the Sava river is φ’=4.44. The length-weight relationship, covering the fish from the entire growing period, showed an isometric growth with a b-value of 3.025 (p›0.05), except of September when it was significantly allometric. That was confirmed by the non-significant relationship between condition factor and total length (r = 0.014; p > 0.05). However, CF in June, September and October (0.86 ± 0.07; 0.85 ± 0.09 and 0.87 ± 0.10, respectively) was significantly lower (p<0.05) than in May and July (1.00±0.21 and 1.00±0.12, respectively). The improved water quality during the last fifteen years enabled spirlin to migrate and enlarge its population downstream, resulting in a slightly decreased condition factor.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
11447. Diet and growth of the endemic Neretva chub, Squalius svallize from the Neretva river area, Bosnia and Herzegovina
- Creator:
- Ivanković, Predrag, Treer, Tomislav, Piria, Marina, and Knezović, Zrinka
- Type:
- article and TEXT
- Subject:
- nutrition, condition, Croatia, and Adriatic dace
- Language:
- English
- Description:
- The Neretva chub, Squalius svallize is an endemic species of the Adriatic basin of the southeastern Europe. Altogether, 60 specimens were caught by gill nets from the Neretva river area, the oldest being seven years old. The most dominant item in the diet of S. svallize during winter season were larvae of Trichoptera and Diptera. Diptera larvae were also dominant during spring and summer. In autumn period the largest amount in stomach content were Trichoptera larvae and Gastropoda. Plant material was present in stomach content but not dominant food item. The von Bertalanffy formula, counted from the back calculated growth in total length, appeared to be: Lt = 35.3 (1-e-0.15 (t+1.40)). The phiprime of Neretva chub (ln base) is Φ’=5.23. The length-weight relationship, including the fish from the entire growing period, demonstrated positive allometric growth with a b-value of 3.47. The average value for condition factor was CF = 0.98±0.14 (min = 0.76; max = 1.29).
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
11448. Diet composition and body size in insect herbivores: Why do small species prefer young leaves?
- Creator:
- Čížek, Lukáš
- Type:
- article, model:article, and TEXT
- Subject:
- Body size, constraint, diet composition, herbivory, insect, leaf toughness, Papua New Guinea, phenology, specificity, plant defence, and young leaves
- Language:
- English
- Description:
- The hypothesis that small body size is correlated with preference for young leaves was tested in a community of leaf-chewing insect herbivores feeding on Ficus wassa in a humid tropical forest in Papua New Guinea. Feeding experiments on 48 species of herbivorous insects revealed a negative correlation between body size and a preference for feeding on young leaves. While small species preferred young leaves, large species showed no preferences, or preferred young leaves only slightly. This relationship was found for the entire leaf-chewing community, as well as for many of the constituent taxa on several taxonomic levels, from orders to genera. Taxonomic position of a species played little role in determining its preferences. It is proposed that higher toughness and lower nutrient content may act as complementary defences, which prevent small insects from feeding on mature foliage. While the low nutrient content of mature leaves may affect smaller herbivores due to their relatively higher metabolic rate and lower digestion efficiency, their toughness complicates feeding mechanically and may prevent the compensatory feeding necessary to offset the low nutritive value of mature leaves.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
11449. Diet composition of black-backed jackals, Canis mesomelas in the Namib Desert
- Creator:
- Goldenberg, Martina, Goldenberg, Florian, Funk, Stephan M., Henschel, Joh, and Millesi, Eva
- Type:
- article and TEXT
- Subject:
- diet frequency composition, prey abundance, foraging strategy, and desert habitat
- Language:
- English
- Description:
- Black-backed jackals (Canis mesomelas, Schreber, 1775) survive in a wide range of environments. Their foraging strategies are highly variable in different habitats. Adaptations in foraging behaviour in relation to abundance and quality of food sources are expected to be highly pronounced in an extreme habitat like a desert. This study investigated the diet composition in black-backed jackals in the Namib Desert by analysing faecal samples collected between February 2004 and August 2005. Frequency of occurrence, relative dry mass and proportion of biomass consumed were calculated for different prey items. Insect parts, mainly of two species – the giant longhorn beetle (Acanthophorus capensis) and a locust (Anacridium moestum) – were found in 72.2% of the samples and were estimated to have contributed 22% to the biomass consumed. Mammals, predominantly rodents and ungulates, represented the highest proportion of biomass consumed (42%), although their remains were found in only one third of the samples. Based on biomass, mammals are assumed to be the jackal’s preferred prey, but, probably due to lower abundance, more diffi cult to obtain than insects. More than 50% of the samples contained plant material, mainly seeds of !NARA plants (Acanthosycios horridus) and false ebony (Euclea pseudebenus), especially during their fruiting seasons. Although the abundance of A. capensis and of A. moestum varied annually, their remains were found in scats throughout the year, indicating a certain degree of specialization on these prey species.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/
11450. Diet composition of red fox during rearing in a moor
- Creator:
- Lanszki, József
- Type:
- article and TEXT
- Subject:
- Vulpes vulpes, cubs, Microtus preference, and Hungary
- Language:
- English
- Description:
- The diet of red fox (Vulpes vulpes) cubs living in a moor in Hungary was studied by scat analysis (n = 77) during the rearing period. The main food source of foxes consisted of small mammals (preferred Microtus voles) which was supplemented with brown hare and gamebirds rarely. Cubs ate remains of carrions (domestic animals, ungulates and carnivores) and invertebrates frequently but in low quantity. The food consisted of characteristically terrestrial, occasionally aquatic and rarely arboreal prey.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/