We undertook a detailed ultrastructural investigation to gain insight into the early stages of development of the vermiform myxozoan, Buddenbrockia plumatellae Schröder, 1910 in two bryozoan hosts. Early cell complexes arise in the peritoneum after division and migration of isolated cells in the host body wall. The development of cell junctions linking the outer (mural) cells of the complex then produces a sac enclosing a mass of inner cells. Elongation to the vermiform stage (myxoworm) occurs during multiplication and reorganisation of the inner cells as a central core within the single-layered sac wall. The core cells develop into muscle and sporogonic cells separated from the mural cells by a basal lamina. Myogenesis occurs along the length of the myxoworm from cells that differentiate from the central core, and is independent of elongation. Four primary sporogonic cells maintain positions close to the basal lamina, between muscle cells, while giving rise to secondary sporogonic cells that eventually become free in the central cavity. At least some secondary sporogonic cells undergo meiosis. In view of the recent confirmation of the phylogenetic affinity of Buddenbrockia with the Cnidaria, we postulate how features observed in Buddenbrockia may be homologous with cnidarian structures. Finally we propose a new family name, Buddenbrockiidae, to replace Saccosporidae which was proposed previously in breach of the International Code of Zoological Nomenclature.
Efficient degradation of damaged D1 during the repair of PSII is carried out by a set of dedicated FtsH proteases in the thylakoid membrane. Here we investigated whether the evolution of FtsH could hold clues to the origin of oxygenic photosynthesis. A phylogenetic analysis of over 6000 FtsH protease sequences revealed that there are three major groups of FtsH proteases originating from gene duplication events in the last common ancestor of bacteria, and that the FtsH proteases involved in PSII repair form a distinct clade branching out before the divergence of FtsH proteases found in all groups of anoxygenic phototrophic bacteria. Furthermore, we showed that the phylogenetic tree of FtsH proteases in phototrophic bacteria is similar to that for Type I and Type II reaction centre proteins. We conclude that the phylogeny of FtsH proteases is consistent with an early origin of photosynthetic water oxidation chemistry., S. Shao, T. Cardona, P. J. Nixon., and Obsahuje bibliografické odkazy
Přirozená teologie se dá defi novat jako pokus o dokázání existence Boha pozorováním přírodního světa a užíváním rozumu, aniž by bylo bráno v potaz zjevení. Mnoho teologů si patrně myslí, že rané luteránství úplně popíralo možnost přirozené teologie, a opírají se v tom o názor samotného Luthera, podle nějž lidská přirozenost byla bytostně porušena hříchem a může se naučit vědět o Bohu pouze vírou. Ani Luther, ani jeho následovníci ovšem nebyli přesvědčeni, že je třeba zcela zavrhnout přirozenou teologii. Luther si je jist, že „všichni lidé přirozeně chápou a uznávají, že Bůh je nějakým druhem dobročinné božské moci.“ Přirozené vědění získávané rozumem je porušené hříchem a je pouze „zákonným“ věděním, ale toto vědění přesto odhaluje existenci Boha a vede nás k hledání spasitelského vědění, jehož může být dosaženo vírou poskytnutou Bohem., Natural theology can be defined as an attempt of proving the existence of God through the observation of the natural world and the use of reason, without appealing to divine revelation. Many theologians seem to think that early Lutheranism completely rejected the possibility of natural theology, based largely on the view of Luther himself that the human nature has been totally corrupted by sin and can only learn to know God through faith. It was, however, neither the understanding of Luther nor his successors to completely dismiss natural theology. Indeed, Luther is sure that “all men naturally understand and come to the conclusion that God is some kind of beneficent divine power.” Surely, the natural knowledge acquired by reason is distorted by sin and is only “legal” knowledge, but this knowledge still reveals the existence of God and leads us to look for the saving knowledge that can only be attained by faith bestowed by God., and Juuso Loikkanen.
This study concerns glazed objects from two major centres in Silesia: Wrocław and Opole. All the glazed items from layers dated from the late 10th to the first half of the 13th century are appraised, i.e. ceramic and stone Easter eggs, knobbed rattles, ‘stars’ and pottery. Each category of artefacts is appraised separately as they differ from each other in terms of the production technique and presumably their provenance. Therefore, the locations of the workshops that produced these items is considered. Based on the collections from Wrocław and Opole, a different frequency of individual glazed items is observed, which is related to their specific distribution and most likely the different role of both centres. A separate issue is determining the value and social function of the glazed vessels, Easter eggs and rattles. In contrast, less emphasis is placed on their symbolic function, as this issue has been widely discussed by other researchers.
Archaeological excavations at Zamárdi (Hungary) revealed one of the largest early medieval iron smelting centres in Central Europe with about a hundred ore-roasting pits, twenty bloomery furnaces, reheating furnaces and a forge. In addition, a related Avar settlement dating from the 7th to 9th centuries was also unearthed, with remains of carriage roads, about twenty houses with stone furnaces and a number of open-air furnaces. The bloomery remains fit into the series of furnaces of the 7th and 8th centuries found previously on other sites in former Pannonia. As a part of a complex research project, more than a hundred slag samples from Zamárdi were examined by XRF, ICP, XRD and SEM-EDS. Different slag types and their metallurgical roles were identified. We concluded that the nature of archaeometallurgical sites can be confidently determined by the typological examination of several kinds of slag. and Během archeologických výzkumů v Zamárdi (Maďarsko) bylo odkryto jedno z největších středověkých středisek hutnictví železa ve střední Evropě s asi sto jámami na pražení rudy, dvaceti železářskými pecemi, vyhřívacími pecemi a kovárnou. Kromě toho bylo objeveno související avarské sídliště z 7.–9. století s pozůstatky vozových cest, asi dvaceti domy s kamennými pecemi a řadou venkovních pecí. Pozůstatky železářské výroby zapadají do série nálezů pecí ze 7. a 8. století, které byly objeveny na jiných místech někdejší Panonie. V rámci komplexního výzkumného projektu bylo analyzováno více než sto struskových vzorků ze Zamárdi, a to pomocí XRF, ICP, XRD a SEM-EDS. Identifikovány byly různé druhy strusky a jejich vztah k hutnímu pochodu. Dospěli jsme k závěru, že základní rysy archeometalurgických lokalit mohou být spolehlivě stanoveny typologickou klasifikací několika druhů strusky.
The study focuses on the early medieval large glass beads from the area of Poland, i.e. specimens whose diameter equals at least 1.5 cm but usually ca. 2 cm or more. The main aim of this study is to define their function, considering precise context of discovery of particular specimens, metric data and microscopic analyses. Another important task of the study is to determine whether large beads were local products or imports, and from which region and in what social circumstances they reached the studied area. Alongside macroscopic and stylistic features, chemical composition of glass that was used for production of the beads can be conclusive in this situation. In our opinion, it is a special category of finds that appeared in this part of Europe during the time of cultural and political transformation in the 11th–13th centuries. and Předmětem studie jsou polské nálezy raně středověkých velkých skleněných korálů, tj. exemplářů, jejichž průměr činí nejméně 1,5 cm, ale obvykle kolem 2 cm či více. Hlavním cílem je přispět k objasnění jejich funkce na základě nálezového kontextu, metriky a výsledků mikroskopické analýzy. Neméně důležité jsou otázky, zda se jedná o místní produkci či o importy, jaká je jejich geografická distribuce a sociální charakteristika prostředí, ve kterém byly nalezeny. Kromě makroskopicky patrných a morfologických znaků autorky hodnotí též chemické složení korálů. Docházejí k závěru, že velké korály reprezentují samostatnou kategorii nálezů a jejich výskyt odráží kulturní a politické proměny středoevropské společnosti v 11.–13. století.
Renal sympathetic hyperactivity is critically involved in hypertension pathophysiology; renal denervation (RDN) presents a novel strategy for treatment of resistant hypertension cases. This study assessed effects of two RDN systems to detect acute intravascular, vascular and peri-vascular changes in the renal artery, and renal nerve alterations, in the sheep. The procedures using a single-point or multi-point ablation catheters, Symplicity FlexTM, Medtronic versus EnligHTNTM, St. Jude Medical were compared; the intact contralateral kidneys served as controls. Histopathological and immunohistochemical assessments were performed 48 h after RDN procedures; the kidney and suprarenal gland morphology was also evaluated. Special staining methods were applied for histologic analysis, to adequately score the injury of renal artery and adjacent renal nerves. These were more pronounced in the animals treated with the multi-point compared with the single-point catheter. However, neither RDN procedure led to complete renal nerve ablation. Forty-eight hours after the procedure no significant changes in plasma and renal tissue catecholamines were detected. The morphologic changes elicited by application of both RDN systems appeared to be dependent on individual anatomical variability of renal nerves in the sheep. Similar variability in humans may limit the therapeutic effectiveness of RDN procedures used in patients with resistant hypertension., M. Táborský, D. Richter, Z. Tonar, T. Kubíková, A. Herman, J. Peregrin, L. Červenková, Z. Husková, L. Kopkan., and Obsahuje bibliografii
This study used an experimental early rehabilitation model combining an enriched environment, multisensory (visual, acoustic and olfactory) stimulation and motor training after traumatic brain injury (via fluid-percussion model) to simulate early multisensory rehabilitation. This therapy will be used by brain injured patients to improve neural plasticity and to restore brain integration functions. Motor dysfunction was evaluated using a composite neuroscore test. Direct structural effects of traumatic brain injury were examined using Fluoro-Jade staining, which allows identification of degenerating neural cell bodies and processes. Animals in the rehabilitation model group performed significantly better when tested for neuromotor function than the animals in standard housing in the 7-day and 15-day interval after injury (7d: p=0.005; 15d: p<0.05). Statistical analysis revealed significantly lower numbers of Fluoro-Jade positive cells (degenerating neurons) in the rehabilitation model group (n=5: mean 13.4) compared to the standard housing group (n=6: mean 123.8) (p<0.005). It appears that the housing of animals in the rehabilitation model led to a clear functional increase in neuromotor functions and to reduced neural loss compared with the animal group in standard housing., M. Lippert-Grüner. M. Maegele, J. Pokorný, D. N. Angelov, O. Švestková, M. Wittner, S. Trojan., and Obsahuje bibliografii a bibliografické odkazy
In the xantha1 (xan1) mutant of sunflower (Helianthus annuus L.), the effects on organ anatomy and seedling growth did correlate to the alteration of chloroplast biogenesis. The xan1 seedlings grown under 165 µmol(photon) m-2 s-1 revealed a severely altered chloroplast ultrastructure in cotyledons and leaves. Cross-sections or clarified tissues of the xan1 cotyledons did not show evident alterations with respect to normal cotyledons suggesting that the impairment of chloroplast biogenesis has negligible consequences on embryonic leaves. By contrast, the analysis of xan1 leaves showed that the defects in chloroplast biogenesis were correlated to a drastic reduction of organ size and to a clear enhancement of the trichome growth. The differentiation of palisade and spongy parenchyma in cotyledons and leaves of the xan1 mutant was normal but both organs displayed a drastic reduction in the plastid number with respect to wild type. In addition, xan1 hypocotyls showed a reduced development of the main vascular bundles in comparison with normal seedlings and an undersized central cylinder of the primary root. The exogenous supply of sucrose was not sufficient to revert in vitro the deficit of xan1 growth and the constraints in morphogenetic processes. and M. Fambrini ... [et al.].
Different aspects of star formatlon are discussed on the basis of new submm observations. In NGC2024 slx cold (T-16K) and dense (nH“lE8-lE9cm^-3) so far unknown condensations are found and interpreted as isothermal protostars. The density and temperature structure around massive early type stars which are deeply embedded in dense regions is discussed by means of thermai
emission from dust. A star formation efficiency of 8% is derived from 90 compact HII regions. A comparison with the star formation in normal spiral galaxles and active Markarlan objects leads to a
new deflnltion of actlvity. The L/M ratlo of active sytems is by a factor of 20 higher than the corresponding value in normal splrals and galactic HII regions.