67 research outputs found
Deep Neck infections of Odontogenic Origin and Their Clinical Significance. A Retrospective Study from Hradec Králové, Czech Republic
Genetic and morphological differentiation between Melica ciliata L. and M. transsilvanica Schur (Poaceae) in Europe reveals the non-presence of M. ciliata in the Polish flora
A good knowledge of species delimitation is crucial for the biodiversity protection and the conservation of wild species. We studied the efficiency of AFLP markers and morphological characters to assist species determination for Melica ciliata L. and M. transsilvanica Schur within European range of distribution, including isolated and range-limit populations of "M. ciliata" (i.e. M. cf. ciliata) from the Polish Sudetes, where it is regarded as critically endangered. AFLP markers were found to be more effective then morphological characters (more or less continuous) in distinguishing the both studied species. AMOVA revealed very low genetic diversity within populations and high differentiation among populations of M. ciliata and M. transsilvanica (FST = 0.89 and 0.95, respectively). The species-diagnostic AFLP markers of M. transsilvanica shared with "M. ciliata" from the Sudetes were detected. On the other hand, no species-diagnostic genetic markers of M. ciliata or hybrid-diagnostic markers of M. × thuringiaca were found within "M. ciliata". PCoA and NJ showed an overlapping genetic diversity of "M. ciliata" and M. transsilvanica. Hierarchical AMOVA supported the absence of a significant genotypic distinction between "M. ciliata" and M. transsilvanica. ANOVA showed that the length ratio of lower to upper glumes was the best morphological character to discriminate between M. ciliata and M. transsilvanica. Combined morphological and genetic data show that M. ciliata is not currently present in Poland as its putative Polish populations represent M. transsilvanica. A significant decrease in genetic variability that could influence viability was not observed the in Sudetian populations of M. transsilvanica. However, the population size changes significantly as a result of plant succession. Correction of the northern limit of the continuous distribution of M. ciliata L. in Central Europe is presented
Classical Morphology of Plants as an Elementary Instance of Classical Invariant Theory
It has long been known that structural chemistry shows an intriguing correspondence with Classical Invariant Theory (CIT). Under this view, an algebraic binary form of the degree n corresponds to a chemical atom with valence n and each physical molecule or ion has an invariant-theoretic counterpart. This theory was developed using the Aronhold symbolical approach and the symbolical processes of convolution/transvection in CIT was characterized as a potential “accurate morphological method”. However, CIT has not been applied to the formal morphology of living organisms. Based on the morphological interpretation of binary form, as well as the process of convolution/transvection, the First and Second Fundamental Theorems of CIT and the Nullforms of CIT, we show how CIT can be applied to the structure of plants, especially when conceptualized as a series of plant metamers (phytomers). We also show that the weight of the covariant/invariant that describes a morphological structure is a criterion of simplicity and, therefore, we argue that this allows us to formulate a parsimonious method of formal morphology. We demonstrate that the “theory of axilar bud” is the simplest treatment of the grass seedling/embryo. Our interpretations also represent Troll's bauplan of the angiosperms, the principle of variable proportions, morphological misfits, the basic types of stem segmentation, and Goethe's principle of metamorphosis in terms of CIT. Binary forms of different degrees might describe any repeated module of plant organisms. As bacteria, invertebrates, and higher vertebrates are all generally shared a metameric morphology, wider implications of the proposed symmetry between CIT and formal morphology of plants are apparent
Vyznam, uskali a dalsi perspektivy tympanometrie v ORL diagnostice
1.a. Causes of a positive pressure in the middle ear cavity in tympanometric examination We evaluate a group of 66 ears with positive middle ear pressure during tympanometric examination. A positive pressure in the middle ear may be caused by an air current during politzerization or catheterization of the auditory tube, acute tubotympanic catarrh, or by acute otitis media in the initial or regressing stage. In the majority of patients the positive middle ear pressure is not associated with conduction deafness and there is no relationship between the pressure and the hearing loss. 1.b. Effect of inhalation anaesthesia on the middle ear pressure In a group of 108 ears we confirmed, that during inhalation anaesthesia the pressure in the middle ear cavity rises. The mean pressure before operation was -80,4 daPa. Due to inhalation anaesthesia the pressure rose to +189,1 daPa. After a meantime interval after operation of 4,4 hours the pressure declined to -167,9 daPa. If before operation an exudate was present in the middle ear cavity, the inhalation mixture usually did not have an impact on the conditions in the middle ear. 2. Tympanometry in children with adenoids In a group of 384 children we confirmed a higher incidence of exudate in the middle ear in children with adenoids, as compared with controls (B curve in 40% of ears, compared with 9% in controls). Normalization of the middle ear pressure occured within two weeks after adenotomy in almost 50% children. We investigated also the relationship between the extent of adenoids and the presence of exudate in the middle ear. 3. Tympanometry in the preoperative diagnostics of congenital and acquired defects of conductive system We investigated a group of 49 ears with conductive hearing loss with the exception of otosclerosis. For tympanosclerosis is typical type B tympanometric curve, but we can find also curves A or C, especially with lower compliance. In the ears with congenital and acquired defects of conductive system we found type A curve without any stapedius reflex. The value of compliance depends on the character of ossicular chain defect. 4. Elicitability of evoked otoacoustic emissions and the middle ear pressure We evaluate elicitability of evoked otoacoustic emissions (EOAE) in the series of 100 ears with hypo- or hyperpressure in the middle ear. These results are compared to the control group of 50 healthy ears with A type curve on tympanometry. We conclude that hyper- or hypopressure in the middle ear cavity reduce TEOAE (transiently evoked OAE). Higher the pressure change is, more EOAE are reduced. 5. Tympanometric examination of the function of the auditory tube We describe the method of tympanometric examination of the ventilation function of the auditory tube. In the group of patients with traumatic rupture of the tympanic membrane a mean value of the opening pressure of 320 daPa was recorded, the active function of the auditory tube was satisfactory. In the other examined groups (otitis media secretorica, chronic otitis media, cholesteatoma, dry perforation of the tympanic membrane) obstruction of the tube predominated. In secretory catarrh there was also a higher percentage of ears with hypercompliance of the auditory tube or with a patent tube. 6. Investigation of stapedius reflex in patients with tetania We investigated latency, acoustic reflex threshold and decay test in a group of 20 ears in the patients with hypocalcemia. We compared results with a group of patients (20 ears) with normocalcemia. We confirmed elevation of acoustic reflex threshold and a longer latency of stapedius reflex in the patients with hypocalcemia. The result of decay test were normalAvailable from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi
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