Home About us Contact
|
Home About us Contact | ||
|
|
||
Specific Character (specific + character)
Selected AbstractsThe cranial morphology of Kayentachelys, an Early Jurassic cryptodire, and the early history of turtlesACTA ZOOLOGICA, Issue 3 2010Eugene S. Gaffney Abstract Gaffney, E.S. and Jenkins, F.A., Jr. 2010. The cranial morphology of Kayentachelys, an Early Jurassic cryptodire, and the early history of turtles. , Acta Zoologica (Stockholm) 91: 335,368 The skull morphology of Kayentachelys aprixGaffney et al., 1987, a turtle from the Early Jurassic Kayenta Fm of northern Arizona, demonstrates the presence of cryptodiran synapomorphies in agreement with Gaffney et al. (1987, 1991, 2007), and contrary to the conclusions of Sterli and Joyce (2007), Joyce (2007), Sterli (2008), and Anquetin et al. (2008). Specific characters found in Kayentachelys and diagnostic of cryptodires include the processus trochlearis oticum, the curved processus pterygoideus externus with a vertical plate, and the prefrontal,vomer contact, which are confirmed as absent in the outgroups, specifically the Late Triassic Proganochelys. The Joyce (2007) analysis suffers from the reduction of the signal from skull characters, with a consequently greater reliance on shell characters, resulting in pleurodires being resolved at various positions within the cryptodires. Kayentachelys reveals what a primitive cryptodire would be expected to look like: a combination of primitive and derived characters, with the fewer derived characters providing the best test of its relationships to other turtles. Although incompletely known, the Mid-Late Jurassic Condorchelys, Heckeremys, and Eileanchelys may be early cryptodires close to Kayentachelys. We confirm the Late Triassic Proterochersis as a pleurodire, dating the pleurodire,cryptodire split as Late Triassic or earlier. [source] Electronic Control of the Rotational Barrier in ,2 -Alkyne-1-thio ComplexesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 7 2007Wolfram W. Seidel Abstract A family of thio-alkyne complexes [Tp,Mo(CO)(L)(BnSC2S)] {Bn = benzyl, Tp, = hydrotris(3,5-dimethylpyrazolyl)borate, L = carbonyl (2), 2,6-dimethylphenyl isocyanide (7), tert -butyl isocyanide (8), 4-(dimethylamino)pyridine (9)} was prepared by reductive removal of a benzyl group in the corresponding bis(benzylthio)acetylene complexes [Tp,Mo(CO)(L)(BnSC2SBn)](PF6) (1 -PF6, 4 -PF6, 5 -PF6 and 6 -PF6). All complexes were characterized by IR, 1H, 13C spectroscopy and cyclic voltammetry. X-ray diffraction studies of 5 -PF6, 8 and 9 were carried out. The alkyne ligand is bound symmetrically to molybdenum in 5 -PF6 and unsymmetrically in 8 and 9. The trend in the ,-acidity of ligand L is reflected in the spectroscopic and electrochemical data as well as in the molecular structures. Variable temperature 1H NMR investigations with 7, 8 and 9 disclosed that the barrier of the alkyne rotation at molybdenum decreases in the order of rising electron density at the metal center while the steric demand increases. Therefore, electronic control of the barrier by the specific character of the ligand L is evident.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Rett Syndrome and long-term disorder profileJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 10 2008E. Smeets Since the identification of mutations in MECP2 in females with clinical Rett syndrome, numerous efforts have been made to understand phenotype-genotype relationships. Most of these studies were conducted by examining the type and localization of these mutations in the gene in relation to clinical severity. It seemed unsatisfactory, in view of the age range and variable severity, to look only at the type and localization of the mutation in MECP2 in trying to establish a phenotype/genotype relationship. Describing each RTT individual after a long term follow up and grouping females with the same disorder history and same MECP2 mutation is therefore appropriate. Complete clinical and molecular data were obtained on 103 females. The guidelines for reporting manifestations common in Rett syndrome were used in the evaluation of clinical severity. The individuals were grouped according to similar disorder profiles on long-term follow up. In a cohort of 103 females clinically diagnosed with Rett syndrome, 91 had a detectable MECP2 mutation. 60% still sit and walk. Hand use is preserved or reduced in 44%. Speech has been lost in the majority (87%). Epilepsy was problematic in about 30%. Scoliosis, severe kyphosis or a combination of both was present in 27%, needing surgery in 13%. Description of the profile of the disorder and long-term clinical history facilitated the grouping of females with the same MECP2 mutation and a similar history. This approach will contribute more to the understanding of the ongoing pathology in Rett syndrome relative to the specific character of the involved MECP2 mutation. Some examples of these disorder profiles will be discussed. [source] Topography of Arterial Circle of the Brain in Egyptian Spiny Mouse (Acomys cahirinus, Desmarest)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2007A. Szczurkowski Summary Using stained acryl latex-injected techniques, the arterial circle of the brain in Acomys cahirinus Desmarest was studied. Results revealed an important individual variability of investigated structure. Three morphological variants were found: (1) the lack of typical arterial circle , opened in front and the back side, (2) partial opened at the back side, (3) completely closed arterial circle. This finding is opposed to many species of mammals, including rodents, and especially laboratory mouse. In our point of view, it seems to be a specific character. [source] Chiral Multidimensional Gas Chromatography (MDGC) and Chiral GC,Olfactometry with a Double-Cool-Strand Interface: Application to MalodorsCHEMISTRY & BIODIVERSITY, Issue 2 2006Frédéric Begnaud Abstract Volatile sulfur compounds such as 3-methyl-3-sulfanylhexan-1-ol (1) are largely responsible for axillary-sweat malodors. In this work, we describe the determination of the enantiomer ratio of the trace constituent 1 and the odor description of its antipodes (R)- and (S)- 1 by means of multidimensional gas chromatography (MDGC) in combination with chiral gas chromatography,olfactometry (GC-O). This technique allowed the on-line evaluation of the sensory character of both enantiomers via a sniffing port, and is based on a novel double-cool-strand interface (DCSI). First, the system's inertness was tested towards the labile compound 2-methylfuran-3-thiol (MFT; 2). Then, the DCSI was used in a new configuration to achieve olfactive characterization by means of chiral GC-O. In contrast to direct smelling after the chiral column, our technique allows, for the first time, to significantly delay the perception of the second-eluting enantiomer after the first one. This lowers the risk of sensory saturation, as the panelist can recover from the first stimulus, before evaluating the second one. To help programming the DCSI, a dedicated program was set up. The enantiomer ratio of the sweat malodor 1 was determined as (S)/(R) 3,:,1, and the dominating (S)-isomer was shown to largely impart its specific character to the overall odor of the sweat extract. [source] Fine Structure of Elytral Punctures and Diffraction Gratings in Korean Sericinae (Coleoptera, Melolonthidae)ENTOMOLOGICAL RESEARCH, Issue 2 2003Jin Ill KIM ABSTRACT The surface structures of the elytra in twenty two species belonging to the subfamily Sericinae (Coleoptera, Melolonthidae) were observed by scanning electron microscopy. For viewing specific characters, elytral punctures and diffraction gratings on interstitial surface were focused on. The elytral punctures of observed Sericid beetles have three representative forms: horseshoe, ocellus, and crease types. The diffraction gratings of the elytra show three distinctive patterns: regular and parallel, discontinued, and interconnected and curved. These patterns of elytral punctures and diffraction gratings considered to be useful for identification. [source] Pollen types of the Egyptian species of the genus Salvia (Lamiaceae)FEDDES REPERTORIUM, Issue 7-8 2009N. Hassan Pollen morphology of seven species of genus Salvia (Lamiaceae) was investigated using light and scanning electron microscopy. Pollen was studied to show all possible characteristic features like shape, size, apertures, wall stratification, etc., with special reference to the specific characters of each pollen type. Four pollen types were recognized viz. Salvia aegyptiaca pollen type, Salvia deserti pollen type, Salvia palaestina pollen type and Salvia spinosa pollen type. Description of each type, a key to the investigated taxa as well as SEM micrographs of pollen types are provided. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] PHYLOGENETIC SELECTION OF A RESOURCE: A NEW USE FOR CLADISTICSJOURNAL OF PHYCOLOGY, Issue 2000K. M. Dreckmann A phylogenetic model for the selection of commercial resources using the cladistic method is proposed. The group selected as an example was the marine agarophyte red algal genus Gracilaria Greville. We suggest the use of the cladistic principle of evolutionary transformational series in order to test the quality of agars instead of the assay-herror traditional method that consumes time and budget. If we asume that the "good quality of agar" in extant taxa is a sinapomorphic character (but not a reliable taxonomic one), then taxa included in the same monophiletic clade in which the species with "good quality of agar" are, has a high evolutionary posibility to share that character. In order to do this we have to incorporate to the set of available specific characters, those of the taxa actually used as a agar source but not present in the area under scope. A complete set of the basic cladistic data required for run the most popular program currently in use (PAUP) are provided. We applied the model to the Mexican Atlantic species and found that, using Gracilaria chilensis and G. cornea as "indicator taxa," and found Mexican populations of G. crassissima, G. caudata, G. cervicornis and Gracilariopsis lemaneiformis are candidates for a study of yield and agar properties. [source] Statistical basis for positive identification in forensic anthropologyAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2006Dawnie Wolfe Steadman Abstract Forensic scientists are often expected to present the likelihood of DNA identifications in US courts based on comparative population data, yet forensic anthropologists tend not to quantify the strength of an osteological identification. Because forensic anthropologists are trained first and foremost as physical anthropologists, they emphasize estimation problems at the expense of evidentiary problems, but this approach must be reexamined. In this paper, the statistical bases for presenting osteological and dental evidence are outlined, using a forensic case as a motivating example. A brief overview of Bayesian statistics is provided, and methods to calculate likelihood ratios for five aspects of the biological profile are demonstrated. This paper emphasizes the definition of appropriate reference samples and of the "population at large," and points out the conceptual differences between them. Several databases are introduced for both reference information and to characterize the "population at large," and new data are compiled to calculate the frequency of specific characters, such as age or fractures, within the "population at large." Despite small individual likelihood ratios for age, sex, and stature in the case example, the power of this approach is that, assuming each likelihood ratio is independent, the product rule can be applied. In this particular example, it is over three million times more likely to obtain the observed osteological and dental data if the identification is correct than if the identification is incorrect. This likelihood ratio is a convincing statistic that can support the forensic anthropologist's opinion on personal identity in court. Am J Phys Anthropol, 2006. © 2006 Wiley-Liss, Inc. [source] | |||||||||||||