The effects of environmental salinity on physiological responses, growth, and survival of the Gulf corvina, C. othonopterus, were evaluated in a 6-week completely randomized design experiment. Corvina (17.2±2.3 g mean initial body weight) were subjected to salinities of 5, 15, 25, and 35 ‰ and fed a commercial feed with protein and lipid contents of 46 and 14 %, respectively. Plasma osmolality increased significantly with salinity, ranging from 335.1±5.3 mOsm/kg in fish maintained at 5 ‰, to 354.8±6.8 mOsm/kg in fish kept in seawater, while a significant inverse relationship was observed between salinity and moisture content of whole fish, ranging from 73.8±0.7 (measured at 5 ‰) to 76.9±1.0 % (measured at 35 ‰). In spite of this, growth indices (final weight, weight gain, specific growth rate, condition factor, survival) were not altered, suggesting that, like other members of the family Sciaenidae, the Gulf corvina is a strong osmoregulator. The isosmotic point for this species was estimated to correspond to a salinity of 9.8 ‰. The present study represents the first set of experimental data on salinity tolerance of C. othonopterus and confirms the euryhalinity of this species., M. Perez-Velazquez, P. Urquidez-Bejarano, M. L. González-Félix, C. Minjarez-Osorio., and Obsahuje bibliografii
The purpose of this study was to investigate the occurrence and time-course of apoptosis in soleus skeletal muscle during the first 48 hours of unloading. Fifty Charles River mice were randomly divided into five groups (n=10 each) according to the time of hindlimb suspension (HS). Mice we re suspended for 0 (Control), 6 (6HS), 12 (12HS), 24 (24HS), and 48 hours (48HS). Soleus muscle atrophy was confirmed by a significant decrease of 20 % in muscle-wet weight and of 5 % in the ratio protein concentration/muscle wet-weight observed after 48 hours of unloading. The apoptotic index, the AIF (apoptosis-inducing factor) and p53 expression presented th eir uppermost value (304 %, 241 % and 246 %, respectively) at 24HS, and were preceded by the highest activity of caspase-3 and -8 at 12HS (170 % and 218 %, respectively) and of Bax/Bcl-2 content at 6HS (160 %). There were no marked ultrastructural alterations until 24 hours of simulated weightlessness. Lysosomal autophagic activity and infiltration of phagocytic cells were observed at 24HS and 48HS and might have contributed to the degenerative changes noticed in both groups. Though not consistently supported by morphological evidences, the biochemical parameters sustain the concept that the occurrence of apoptosis parallels the soleus atrophic response in its early phase., R. Ferreira, M. J. Neuparth, R. Vittorino, H. J. Appell, F. Amado, J. A. Duarte., and Obsahuje bibliografii a bibliografické odkazy
The paper presents a contrastive Czech–Spanish study concentrating on reportative markers. Methodologically, it is based on the cognitive theories of mental spaces and grounding, with the primary focus on the Spanish counterparts of the Czech prý, and the secondary focus on the Czech counterparts of the Spanish dizque. The analysis is conducted using the parallel corpus InterCorp and presents evidentiality as a complex category, which is closely related to tense and evaluative modality. The translation respondents of prý and dizque in both languages display significant variability. The corpus data reveal that notions attributed to them are expressed in a complex way in the other language, pointing out that grammatical and lexical elements such as sequence of tenses and diminutive suffixes can convey notions similar to those conveyed by adverbial hearsay markers or verba dicendi. and Článek se zaměřuje na kontrastivní česko-španělskou analýzu reportativních částic. Metodologicky vychází z kognitivních teorií mentálních prostorů a groundingu, přičemž pozornost je zaměřena primárně na španělské protějšky českého prý, ve druhém plánu také na české protějšky španělského dizque. Analýzy vycházejí z jazykového materiálu pocházejícího z korpusu InterCorp a prezentují evidencialitu jakožto komplexní kategorii, která je blízce spjatá s kategoriemi času a evaluativní modality. Překladatelské protějšky prý a dizque vykazují v obou jazycích velkou variabilitu, přičemž data z korpusu dokazují, že významy, které v sobě tyto částice zahrnují, jsou v druhém jazyce často vyjádřeny komplexním způsobem. Časová souslednost nebo deminutivní sufixy v některých kontextech vyjadřují podobné významové odstíny, jaké přisuzujeme adverbiálním částicím označujícím externí zdroj informace nebo slovesům mluvení.
S myšlenkou vytvořit vlastní evoluci a její úspěšnou implementaci přišel Thomas Ray, biolog z Delawarské univerzity. Na počátku 90. let minulého století vytvořil systém zvaný Tierra (Země). Šlo o počítačový systém několika krátkých vzájemně si konkurujících programů. Programy se množily, v systému docházelo k mutacím a díky tomu k evoluci. V tomto systému Thomas Ray mj. pozoroval vznik parazitismu, kdy některé programy zkrátily svůj kód a k životu používaly kód programů jiných. Dalším významným systémem byla Avida, vyvinutá na Michigan State University, kde byl pozorován vznik složitých funkcí, a systém Amoeba, ve které byl pozorován vznik samoreplikujících struktur z náhodného počátečního kódu., The idea of creating an own self-evolution and its successful implementation came from Thomas Ray, a biologist at the University of Delaware, In the early 90s of the last century he created a computer system of short competing programs called Tierra (Earth) where programs reproduce and mutations occur. Thomas Ray observed the creation of parasitism, where some programs shorten their code length and the missing parts used from other programs. Another important system Avida was developed at Michigan State University, where the creation of new complex functions was observed and the system Amoeba, in which the emergence of self-replicating structures from random initial code was observed., Vladimír Scholtz., and Obsahuje seznam literatury
Příspěvek pojednává o využití výpočetní techniky ve fyzikálních vědách, speciálně o aplikaci evolučních algoritmů v problematice deterministického chaosu. V obou ukázkových studiích jsou použity jak klasické evoluční algoritmy, tak algoritmy moderní. Veškeré údaje byly získány mnohonásobně opakovanými simulacemi, jejichž výsledky jasně poukazují na robustnost a životaschopnost použitých metod. Získaná řešení a postupy k nim vedoucí uvedené v článku jsou diskutovány pouze na úrovni informativního charakteru; pro nastudování plného popisu jsou na konci příspěvku uvedeny potřebné odkazy., Ivan Zelinka, Roman Šenkeřík, Zuzana Oplatková., and Obsahuje seznam literatury
Changes in photosynthetic attributes related to genetic improvement of cotton yield were studied in seven Chinese cotton cultivars widely grown in Xinjiang during the past 30 years. Our results showed that a chlorophyll (Chl) content and net photosynthetic rate (PN) of the 1980s cultivar was the highest among all after 60 days from planting (DAP). However, after 75 DAP, the Chl content, PN, and actual photochemical efficiency of PSII of the old cultivars declined gradually, whereas those of the new cultivars remained relatively high. Compared to the old cultivars, leaves of the new cultivars endured a longer period and their senescence was slower, shoot and boll dry mass was higher, but the root to shoot ratio was lower. The lint yield of the 2000s cultivars was 14.7 and 21.4% higher than that of 1990s and 1980s cultivars, respectively. The high yield of the new cultivars was attributed to a greater number of bolls per unit of area with high lint percentage. We suggested that the improved photosynthetic capacity and the increased ability to deliver photosynthates to reproductive sites during the peak boll-setting stage to boll-opening stage were the key physiological basis in the evolution process of cotton cultivars from 1980s to 2000s for the cotton yield improvement within a short growing period., H. H. Luo, H. L. Zhang, Y. L. Zhang, W. F. Zhang., and Obsahuje bibliografii
The epizootiology, transmission dynamics, and survival strategies employed by two mosquito-parasitic microsporidia that utilize copepods as intermediate hosts are examined in relation to the biological attributes of their hosts and the environments in which they inhabit. Amblyospora connecticus Andreadis, 1988, a parasite of Ochlerotatus cantator (Coquillett) and Acanthocyclops vernalis (Fischer) is found in an unstable salt marsh environment that is subject to periodic flooding and drying. Both hosts have distinct non-overlapping generations. A. connecticus exhibits a well-defined seasonal transmission cycle that relies heavily on maternal-mediated transovarial transmission by female O. cantator during the summer, and horizontal transmission via the copepod host during the spring (copepod to mosquito) and fall (mosquito to copepod). Its survival strategies include: delayed virulence, low pathogenicity and high tissue specificity that allow for transstadial transmission of horizontally acquired infections and maximum spore production, reliance on living hosts throughout most of its life cycle with overwintering in the copepod, polymorphic development that is well synchronized with host physiology, and production and dissemination of infectious spores that are coincident with the seasonal occurrence of susceptible stages in each host. Hyalinocysta chapmani Hazard et Oldacre, 1975, a parasite of Culiseta melanura (Coquillett) and Orthocyclops modestus (Herrick) is found in a comparatively stable, subterranean habitat that is inundated with water throughout the year. Copepods are omnipresent and C. melanura has overlapping broods. H. chapmani is maintained in a continuous cycle of horizontal transmission between each host throughout the summer and fall but lacks a developmental sequence leading to transovarial transmission in the mosquito host. It relies on living hosts for most of its life cycle and overwinters in diapausing mosquito larvae. Transstadial transmission does not occur and there is no dimorphic development in the mosquito host. The spatial and temporal overlap of both mosquito and copepod hosts during the summer and fall affords abundant opportunity for continuous horizontal transmission and increases the likelihood that H. chapmani will find a target host, thus negating the need for a transovarial route. It is hypothesized that natural selection has favoured the production of meiospores in larval female mosquitoes rather than congenital transfer of infection to progeny via ovarian infection as a strategy for achieving greater transmission success. and Analysis of the molecular phylogeny data suggest that (1) transovarial transmission and the developmental sequence leading to ovarian infection have been secondarily lost in H. chapmani, as they occur in all other closely related genera, (2) the ancestral state included complex life cycles involving transovarial transmission and an intermediate host, and (3) mosquito-parasitic microsporidia are adjusting their life cycles to accommodate host ecological conditions.