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21.
PD Dr. D. Wieczorek 《Medizinische Genetik》2009,21(2):224-230
Clarification of the cause of mental retardation, which has a prevalence of 2–3%, is a common reason for genetic consultation. On the basis of the cardinal sign of microcephaly, which also has a prevalence of 2–3%, an overview on different conditions with developmental delay/mental retardation is given according to the mode of inheritance. The current version of the Winter–Baraitser Dysmorphology Database lists 558 conditions with the combination of microcephaly and developmental delay/mental retardation. This makes clear that the following overview gives only a limited look at the comprehensive field of clinical genetics/dysmorphology. 相似文献
22.
Renate Radek PD Dr. 《当今生物学》2009,39(4):242-248
Three new, membrane‐bounded organelles were detected in the last decade. Acidocalcisomes which occur in pro‐ and eukaryotes are acidic and store calcium, and further also phosphate, oxygen, magnesium, zink, sodium, potassium, and iron. Furthermore, they are engaged in osmoregulation, pH‐ and Ca2+‐homeostasis. Mitosomes are strongly reduced mitochondria of different parasitic protists, which were previously grouped as primarily mitochondria‐free organisms. Apicoplasts are the strongly reduced plastids of the parasitic apicomplexans (formerly sporozoa). They are a target for the development of new drugs, e.g. against the cause of malaria, Plasmodium. 相似文献
23.
Florian Hahne Nolwenn LeMeur Ryan R Brinkman Byron Ellis Perry Haaland Deepayan Sarkar Josef Spidlen Errol Strain Robert Gentleman 《BMC bioinformatics》2009,10(1):106-8
Background
Recent advances in automation technologies have enabled the use of flow cytometry for high throughput screening, generating large complex data sets often in clinical trials or drug discovery settings. However, data management and data analysis methods have not advanced sufficiently far from the initial small-scale studies to support modeling in the presence of multiple covariates. 相似文献24.
25.
Christine Haaland 《Journal of Insect Conservation》2017,21(5-6):917-927
Urbanisation is a rapidly ongoing process worldwide with profound consequences for wildlife in urban and peri-urban areas. Species are affected by habitat loss, habitat alternation and degradation, fragmentation and increased human population and activity. Habitat loss can occur due to construction of housing and infrastructure in peri-urban areas and within urban areas due to compaction. Undeveloped areas can also be changed from ruderal land, wilderness areas or leftover green space to more formal and more intensively used urban green space. This study investigated a butterfly species, the scarce copper (Lycaena virgaureae L.), in an urbanising and expanding settlement in a rural location in southern Sweden. The scarce copper is still relatively common in Sweden, but has experienced severe decline in certain areas and in other parts of Europe. Patch occupancy and abundance of the species were investigated in 44 patches ranging from urban and peri-urban to rural locations. Habitats investigated were parks, urban grasslands managed for biodiversity by the local authority, unmanaged abandoned arable sites, road verges, meadows and pastures. In total, 624 sightings of scarce coppers were recorded. The highest abundances were observed in larger unmanaged patches and in meadows in peri-urban areas, while pastures had low abundances. In urban parks, no coppers were found. The smaller sites managed for biodiversity by the local authority within the settlement were often occupied by the scarce copper, although abundances were low (mean number of individuals 3?±?1.2). In patches which were cut, copper numbers dropped in almost all cases to zero after cutting. Patch occupancy was affected by habitat characteristics such vegetation height, tree succession, abundance of Rumex acetosella (sheep’s sorrel), as well as landscape features such as length of forest edge. Factors identified as influencing abundance were the same, but additionally also flower abundance. The current high abundances of the scarce copper in the area will not be ensured in the longer term when all building plans are implemented and no other measures are taken. Recommendations are made on management and planning to preserve the species in the study area. 相似文献
26.
Dipl. Geol. Volker Thiel Dr. Martina Merz-Preiß Prof. Dr. Joachim Reitner PD Dr. Walter Michaelis 《Facies》1997,36(1):163-172
Summary Biomarker investigations are applied to the free lipid fractions of a naturally grown freshwater microbial mat, constructed
by calcifying cyanobacteria (Scytonema sp. andSchizothrix sp.). The absolute and relative concentrations of hydrocarbons, free alcohols and carboxylic acids are studied and their
probable biological precursors are discussed. A significant signal of cyanobacterial lipids is recognized by the strong predominance
ofn-heptadecane (C17),n-heptadecene, two monomethyl-heptadecanes, and the pentacyclic triterpenoid diploptene. Their occurrences parallel the lipid
distributions found in pure cultured cyanobacteria and in recent cyanobacterial mats grown in particular environments (hypersaline,
lagoonal, hot spring). The observed compound signature appears to be a suitable reference for environments, where cyanobacteria
are directly associated with theloci of carbonate precipitation and thus, rock formation. In the studied material, a significant contribution of organic matter
from other sources, especially higher plants is characterized by the occurrence of several specific marker compounds, namely
lup-20(29)-ene-3-ol, high molecular weightn-alkanes and carboxylic acids. Although these components comprise a notably high portion of the sample’s lipid inventory,
they are shown to be distinguished easily from the signal left by the predominant mat building organisms. 相似文献
27.
PD Dr. med. Hanspeter Rohr Ute Seitter Jürgen Schmalbeck 《Cell and tissue research》1968,85(3):376-397
Zusammenfassung Einer weiblichen Maus wurde 3 Tage post partum 750 C 3H-Leucin i. p. injiziert. Zu verschiedenen Zeiten nach der Leucinapplikation wurden dem leicht narkotisierten Tier Gewebeteile der Milchdrüse entnommen und zu elektronenmikroskopischen Autoradiogrammen verarbeitet. An Hand der dabei gewonnenen Ergebnisse wurde versucht, den zeitlichen Ablauf der Milcheiweißbildung rechnerisch zu erfassen. 5 und 15 min nach der 3H-Leucinapplikation kann die Aktivität über dem rauhen endoplasmatischen Retikulum, nach 30 min über dem Golgi-Feld, und nach 240 min zur Hauptsache über den Lumina der Ausführungsgänge beobachtet werden. Die Halbwertszeit von markierten Proteinen im Ergastoplasma errechnete sich zu etwa 22 min, diejenige im Golgi-Feld zu etwa 3 Std.Die Voraussetzungen und derzeitigen Grenzen einer quantitativen elektronenmikroskopischen Autoradiographie werden diskutiert. Wegen der vielen möglichen Fehlerquellen wird die Berechnung der Kinetik der Milcheiweißbildung lediglich als Modell gewertet.
Ausgeführt mit Unterstützung durch die Deutsche Forschungsgemeinschaft.
Wesentliche Teile der Arbeit werden Von Ute Seitter der Medizinischen Fakultät der Universität Freiburg i. Br. als Inaugural-Dissertation vorgelegt. 相似文献
Summary A female mouse, 3 days post partum, was injected with 3H-leucine. After various intervals parts of the mammary gland were processed for electronmicroscopic autoradiograms, the results of which were mathematically evaluated in order to understand the temporal course of milk protein formation. After 5 and 15 minutes the leucine-activity is located mainly in the rough endoplasmic reticulum, after 30 minutes in the Golgi field and after 240 minutes in the lumina of the mammary ducts. The half-live time of labelled proteins in the rough endoplasmic reticulum is about 22 minutes, in the Golgi field about 3 hours.The preconditions and limitations of quantitative electronmicroscopic autoradiography are discussed. Because of the many possible sources of error, the calculations of the kinetics of protein synthesis and secretion in the mammary gland are merely regarded as a model.
Ausgeführt mit Unterstützung durch die Deutsche Forschungsgemeinschaft.
Wesentliche Teile der Arbeit werden Von Ute Seitter der Medizinischen Fakultät der Universität Freiburg i. Br. als Inaugural-Dissertation vorgelegt. 相似文献
28.
Ryan W. Davis Dulce C. Arango Howland D. T. Jones Mark H. Van Benthem David M. Haaland Susan M. Brozik Michael B. Sinclair 《Journal of peptide science》2009,15(8):511-522
Using the unique quantitative capabilities of hyperspectral confocal microscopy combined with multivariate curve resolution, a comparative approach was employed to gain a deeper understanding of the different types of interactions of antimicrobial peptides (AMPs) with biological membranes and cellular compartments. This approach allowed direct comparison of the dynamics and local effects of buforin II, magainin II, and arenicin with nanoporous silica bead supported bilayers and living E. coli. Correlating between experiments and comparing these responses have yielded several important discoveries for pursuing the underlying biophysics of bacteriocidal specificity and the connection between structure and function in various cellular environments. First, a novel fluorescence method for direct comparison of a model and living system is demonstrated by utilizing the membrane partitioning and environmental sensitivity of propidium iodide. Second, measurements are presented comparing the temporal dynamics and local equilibrium concentrations of the different antimicrobial agents in the membrane and internal matrix of the described systems. Finally, we discuss how the data lead to a deeper understanding of the roles of membrane penetration and permeabilization in the action of these AMPs. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
29.
Transport and turnover of dissolved organic carbon (DOC) is important in the C cycle of organic soils. The concentration of
DOC in soil water is buffered by adsorption to the soil matrix, and has been hypothesized to depend on the pool size of adsorbed
DOC. We have studied the effect of frequent artificial excessive leaching events on concentration and flux of DOC in shallow,
organic rich mountain soils. Assuming a constant Kd value for DOC adsorption to the soil matrix, we used these data to assess the change in the pool of adsorbed (or potential)
DOC in the soil. The study involved manipulation of precipitation amount and frequency in summer and autumn in small, heathland
catchments at Storgama, southern Norway. The shallow soils (16–34 cm deep on average) limit the possibility for changes in
water flow paths during events. The mini-catchments range in size from 75 to 98 m2. Our data show that after leaching of about 1.2 g DOC m−2 the DOC concentration in runoff declines by approximately 50%. From this we conclude that the pool size of adsorbed potential
DOC in the shallow soils at any time is of the order 2–3 g m−2. Frequent episodes suggest that the replenishment rate, which depends on the decomposition rate of soil organic matter, is
fast and the potential DOC pool could be fully restored probably within days during summer, but with some more time required
in autumn, due to lower temperatures. Both pool size of potential DOC and replenishment rate are seasonally dependent. The
pool of potential DOC, and thus the DOC concentration in discharge, is at their maximum in the growing season. However, under
non-leaching conditions, the concentration of DOC in soil water and thus the pool size of potential DOC seems to level off,
possibly due to conversion of DOC to less reversibly bound forms, or to further decomposition to CO2. 相似文献
30.
Colin PD Birch Ambrose C Chikukwa Kieran Hyder Victor J Del Rio Vilas 《BMC veterinary research》2009,5(1):1-14