Estimation of hydraulic and geometric parameters of a gravel-bed river such as dimensions of bedforms is very difficult task, although they play a fundamental role in river engineering projects. One of the methods to get essential information regarding the bedform characteristics is to find the relations between the flow parameters and bedform dimensions. We conducted this field study in the Babolroud River in northern Iran to investigate the application of double averaged method in unspecific gravel bedforms to evaluate friction factor. Using data collected from several river reaches with total length of 356 m of a gravel-bed river, the relationship between bedform geometry (height and the length of bedforms) and flow parameters including shear velocity, transport stage parameter with friction factor is investigated.
Different methods for estimating bedforms dimensions are examined to assess the ability of predicting bedform parameters (length and height) in a gravel-bed river. Using bedform parameters, the contribution of particle and form friction is estimated. Results confirm the application of the double averaged method and existing bedform parameters for unspecific bedforms. There exists a similar trend between aspect ratio and friction factor in gravel bedforms.
Professor Bedřich Hrozný (*May 6, 1879, Lysá na Labem - †December 12, 1952 Prague) is founder of Hittitology. He served for many years as Rector of Charles Univerzity in Prague and he deciphered the Hitttie cuneiform language. He is mostly known as and Old Oriental philologist, but he considered himself to be a historian. Through Hittitology, he unraveled history of a significant ancient empire. Throughout 1924 and 1925, Hrozný undertook the first Czechoslovakian archaelogical research in the Orient – in Syria and Turkey. The first excavation took place on April 4th, 1924 at the mound of Shech Sa´ad near Damascus. In northern Syria, he was also engaged in searching for new archaelogical sites – many times, he even risked his life. Further archaelogical excavations in Syria began on October 17th, 1924 at the moundof Tell Erfad situated southward from the city of Aleppo. Bedřich Hrozný was in his archaelogical works successful and he was allowed to keep and carry away from Syria a part of found artefacts. Nevertheles, he also put aside some of the archaelogical findings without the knowledge of the Syrian authorities. The findings were sent to Beirut, from where, they were trasported as a diplomatic consignment through the Italian city of Trieste to Prague. Many archaelogists from other countries did it the same way, so we shouldn´t look at Hrozný down our noses for this, as he did not do it for himself, but for the science., René Kopecký., and Obsahuje seznam literatury
An occurrence of tetra-coordinated aluminum in altered coal and low temperature coal ashes was investigated. As altered coal a sample from the Lazy mine (Upper Silesian Coal Basin) was tested, further, low-temperature ashes from different coals were prepared and measured. During preparation the selected coal samples were intensively air-oxidized; 27Al MAS NMR spectra of obtained ashes were then acquired and compared against those for initial coals. A reference wood ash and Al standards were used for identification of Al-forms. It was found that chemical shift at 4 ppm with coals corresponds to that for triaquo-hydroxo-diphenoxido-aluminum(III) complex (THDA), further, the shift at 72 ppm with altered coal and resulting ashes agrees with that for Al tetra-coordinated with oxygen. So, in the presence of coal organics the tetra-coordinated Al is formed under low temperature conditions, because during low temperature ashing the THDA complex is transformed to Al tetra-coordinated with oxygen only at 350 °C. A similar process occurred in the case of oxidation of coal substance under low temperature conditions in the nature at temperatures below 150 °C., Pavel Straka., and Obsahuje bibliografii
Prenatal exposure to methamphetamine (METH) increases nociceptive sensitivity in adult rats. As the strong analgesics have high abuse potential and drugs of abuse are known to have analgesic properties, the aim was to study analgesic effect of different psychostimulants in control and prenatally METHexposed rats. Latencies of withdrawal reflexes of hind limbs and the tail on thermal nociceptive stimuli were repeatedly measured in 15-min intervals after the application of 5 mg/kg s.c. of amphetamine (AMPH), methamphetamine (METH), cocaine (COC), 3,4-methylenedioxymethamphetamine (MDMA) or morphine (MOR). In all groups, AMPH induced on hind limbs stronger analgesia than METH and MDMA whereas COC and MOR were practically without any effect. On the tail, effect of AMPH did not differ from that of MOR. All psychostimulants increased defecation in comparison with MOR and in all groups the number of defecation boluses positively correlated with analgesia of the hind limbs. We did not confirm that prenatal exposure to METH makes adult rats more sensitive either to same drug or to other psychostimulants. The different analgesic potencies of psychostimulants and MOR at different body sites indicate the possible existence of a somatotopic organization of pain inhibition, which is controlled by different mechanisms., A. Yamamotová, R. Šlamberová., and Obsahuje seznam literatury
Dyslexie je často spojována s dalšími psychosociálními potížemi. Cílem práce je ověření těchto výsledků na české populaci, včetně odhalení vývojové trajektorie sledovaných potíží. Stať se dále zaměřuje na případné rozdíly mezi pohledem dětí (resp. adolescentů) a jejich matek. Ve studii je použit dotazník SDQ (Strengths and Difficulties Questionnaire) k měření behaviorálních, emočních a sociálních potíží, ale také prosociálního chování. Soubor tvoří děti (ze studie ELSPAC) s diagnózou dyslexie 520 / Výzkumné studie (N = 50) a kontrolní skupina dětí bez školních potíží (N = 405). Měření bylo provedeno ve třech obdobích: v 7 letech (matka); v 11 letech (matka i dítě) a v 15 letech (matka i adolescent). V 15 letech adolescenti dále vyplnili dotazník životní spokojenosti (SWLS) a škálu sebehodnocení (RSES). Provázanost dyslexie s dalšími psychosociálními problémy se však ukazuje jako nejednoznačná. Z vývojové trajektorie vyplývá, že největší potíže mají dyslektické děti v 7 letech, poté následuje značný pokles v 11 letech. V 15 letech dochází k mírnému nárůstu, který je ovšem menší než u nedyslektických adolescentů. Oproti předpokladům české děti o sobě uvádějí více projevů problematického chování, než vychází z hodnocení matkami, jsou tak k sobě mnohem kritičtější. Velmi zajímavá je shoda pohledu matek a dyslektických dětí, která se u kontrolní skupiny nevyskytuje. Adolescenti s dyslexií nevykazují nižší sebehodnocení ani celkovou životní spokojenost. Pozitivní je také to, že se od kontrolní skupiny neliší v projevech prosociálního chování., a1_Objectives. Dyslexia is often associated with other psychosocial difficulties. The aim of this work is to verify these results in the Czech population, including the detection of the developmental trajectory of the examined difficulties. Furthermore, the study focuses on potential differences between the view of children (or adolescents) themselves and their mothers. Sample and setting. In the study, the SDQ Questionnaire (Strengths and Difficulties Questionnaire) is used to measure behavioral, emotional and social difficulties, but also prosocial behavior. The sample comprises children (from the study ELSPAC) diagnosed with dyslexia (N=50) and a control group of children without school difficulties (N=405). The measurement was carried out in three periods: at 7 years (mother); at 11 years (both mother and child) and 15 years (both mother and adolescent). Furthermore, at 15 years of age, adolescents completed the Life Satisfaction Questionnaire (SWLS) and the Self- Esteem Scale (RSES)., a2_Results. The correlation of dyslexia with other psychosocial problems appears to be ambiguous. The developmental trajectory shows that greatest difficulties can be found in dyslexic children at 7 years of age; subsequently, there is a considerable decline at 11 years of age. At 15 years, there is a slight increase, which is, however, smaller than in non-dyslexic adolescents. Contrary to expectations, Czech children report about themselves more manifestations of problematic behavior than it is evident from their mothers’ assessments; therefore, they are much more critical to themselves. Interestingly, there is an agreement between the view of mothers and dyslexic children, which does not occur in the control group. Adolescents with dyslexia do not exhibit lower self-esteem or overall life satisfaction. Moreover, it is also positive that they do not differ from the control group in the manifestations of prosocial behavior. Study limitation. Sample size of dyslexic group; absence of external diagnostics., and Lucie Foltová, Šárka Portešová, Lubomír Kukla.
1_Certain monoterpenes produced by aromatic plants are known to have lethal and sublethal effects on insects. As there is a need to replace conventional pesticides (organophosphates, carbamates, pyrethroids) with biorational pesticides, we evaluated the behavioural and toxicological responses of the German cockroach, Blattella germanica, exposed to the following monoterpenes, namely (+)-a-pinene, (–)-a-pinene, limonene, menthone, linalool, menthyl acetate and geraniol. Locomotor activity and repellency were quantified using a video tracking system. To study the effect on locomotor activity, larvae were exposed to filter papers treated with concentrations of monoterpenes ranging between 1.4 and 1,400 µg/cm2. Only menthyl acetate applied at a concentration of 14 µg/cm2 or higher increased the locomotor activity of the larvae. Repellency was evaluated by exposing larvae to circles of filter paper divided in two equal zones: one zone was treated with a solution of a monoterpene in acetone (14 or 140 µg/cm2) and the other with only acetone. Larvae were repelled by all the monoterpenes tested. The two concentrations of geraniol and the highest concentration of menthyl acetate and linalool were as repellent as DEET (positive control). The fumigant effect was evaluated by exposing larvae to vapour from 100 µl of pure monoterpene in a sealed container., 2_The values of the 50% Knock-down Times (KT50), expressed in minutes, were: (+)-a-pinene: 11.8, (–)-a-pinene: 14.6, limonene: 81.0, menthone: 141.0, and linalool: 238.6. (+)-a-Pinene was as good a fumigant as dichlorvos (positive control, KT50 = 9.7 min). The least effective compounds were menthyl acetate and geraniol (both affected less than 50% of larvae after 490 min of exposure). In conclusion, (+)-a-pinene (for its fumigant effect), menthyl acetate (for its hyperactivant effect) and menthone and geraniol (for their repellent properties) could potentially be used for controlling B. germanica., Raúl A. Alzogaray ... [et al.]., and Obsahuje seznam literatury
Larvae of the endangered Scarce Large Blue butterfly, Phengaris (Maculinea) teleius, are initially endophytic, feeding upon developing seeds of Sanguisorba officinalis, but complete their development as social parasites preying on the brood of Myrmica ants. Females show very specific preferences, laying eggs exclusively in young flower heads of the food plant. In the present contribution we report the results of a detailed study of female behaviour at three sites differing in size and abundance of S. officinalis. Tracked individuals switched between feeding on nectar (nectaring), flight and oviposition. They fed exclusively on flowers of reddish, pink or violet colouration, favouring Viccia cracca and S. officinalis. However, females spent about one fifth of the time they were active ovipositing and laid about 20 eggs per hour. Oviposition visits to flower heads were highly stereotyped and followed a specific ritual. Examination of accepted, rejected and randomly sampled flower heads showed that females avoided those containing conspecific eggs and at a site where this was difficult due to a shortage of suitable flower heads, they tended to distribute their eggs evenly among the available flower heads. Our results indirectly indicate the existence of an oviposition-deterring pheromone (ODP) in P. teleius. This hypothetical marking ensures a more even distribution of eggs and possibly increases the chances of survival of caterpillars by reducing competition during both the phytophagous and myrmecophagous stages of development. There are few reports of butterflies producing ODPs and to our knowledge this is the first evidence of their presence in the family Lycaenidae., Marcin Sielezniew, Anna M. Stankiewicz-Fiedurek., and Obsahuje seznam literatury
This study describes the reproductive behaviour of silver bream, Blicca bjoerkna, in an aquarium environment with hormonal injection, constant temperature and natural photoperiod conditions. The results revealed that the reproductive behaviour of silver bream was polyandrous with courting tactics including a high level of tactile stimulation and following behaviour developed by the males, but without territorial or aggressive acts. The individual participation of males in mating acts showed a significant positive correlation with the individual participation of males in following a female. A successful spawning act included trembling movements and violent splashing while eggs and sperm were released on plants. The female mated with one to five males without an active inter- and intra-sexual selection.
Several tendencies seem to indicate that in the hinterland of Bratislava specific new residential zones are forming with a different socio-economic structure. This article analyses the hinterland of Bratislava from various perspectives of suburban development. The selection of variables covers the origin of in-migrants and their economic activity, education, and family status. Indicators of land use, housing construction, and property prices supplement these data. The data are processed based on a factorial ecology approach, which tries to discover the basic dimensions of the socio-spatial structure, and cluster analysis. Using these methods the authors identify similar clusters and categorise individual municipalities into relatively homogeneous units—suburban development types. The results lead to a number of very interesting findings. The same types of suburban municipalities are not arranged in concentric zones, which means that the factor of distance from the city does not play a prominent role. The prevailing factor is the sectorial structure, which reflects the different levels of attractiveness municipalities hold for different socio-economic groups of in-migrants. This article seeks to identify key factors that affect the formation of individual suburban zones and thus contributes to a better understanding of the processes that decisively shape the socio-spatial organisation of hinterlands in post-socialist cities today.