179 research outputs found
DNA Content, Karyotype Structure Analysis and Karyotype Symmetry in Ranunculus L. (Ranunculaceae). Italian Species Belonging to Sections Flammula (Webb) Benson and Micranthus (Ovcz.) Nyarady
SUMMARYDNA microdensitometric measurements and karyotype analysis show that in spite of variable ploidy level (2x—16x) and mean chromosome size (0.37—0.83 pg), genomic structure is remarkably constant throughout both the examined Sections. Karyotype symmetry, defined numerically for each species, has been compared with that of other species of Ranunculus (Subgen. Ranunculus). Such comparison confirms that both the examined Sections include relatively advanced species as suggested by DAVIS (1960) on the grounds of macromorphic and ecological elements
Mitochondrial Ca uptake correlates with the severity of the symptoms in autosomal dominant optic atrophy.
The most frequent form of hereditary blindness, autosomal dominant optic atrophy (ADOA), is caused by the mutation of the mitochondrial protein Opa1 and the ensuing degeneration of retinal ganglion cells. Previously we found that knockdown of OPA1 enhanced mitochondrial Ca2+ uptake (Fulop et al., 2011). Therefore we studied mitochondrial Ca2+ metabolism in fibroblasts obtained from members of an ADOA family. Gene sequencing revealed heterozygosity for a splice site mutation (c. 984+1G>A) in intron 9 of the OPA1 gene. ADOA cells showed a higher rate of apoptosis than control cells and their mitochondria displayed increased fragmentation when forced to oxidative metabolism. The ophthalmological parameters critical fusion frequency and ganglion cell-inner plexiform layer thickness were inversely correlated to the evoked mitochondrial Ca2+ signals. The present data indicate that enhanced mitochondrial Ca2+ uptake is a pathogenetic factor in the progress of ADOA
Recommended from our members
Is voice a marker for autism spectrum disorder? A systematic review and meta-analysis
Individuals with Autism Spectrum Disorder (ASD) tend to show distinctive, atypical acoustic patterns of speech. These behaviours affect social interactions and social development and could represent a non-invasive marker for ASD. We systematically reviewed the literature quantifying acoustic patterns in ASD. Search terms were: (prosody OR intonation OR inflection OR intensity OR pitch OR fundamental frequency OR speech rate OR voice quality OR acoustic) AND (autis* OR Asperger). Results were filtered to include only: empirical studies quantifying acoustic features of vocal production in ASD, with a sample size > 2, and the inclusion of a neurotypical comparison group and/or correlations between acoustic measures and severity of clinical features. We identified 34 articles, including 30 univariate studies and 15 multivariate machine-learning studies. We performed metaanalyses of the univariate studies, identifying significant differences in mean pitch and pitch range between individuals with ASD and comparison participants (Cohen’s d of 0.4-0.5 and discriminatory accuracy of about 61-64%). The multivariate studies reported higher accuracies than the univariate studies (63-96%). However, the methods used and the acoustic features investigated were too diverse for performing meta-analysis. We conclude that multivariate studies of acoustic patterns are a promising but yet unsystematic avenue for establishing ASD markers. We outline three recommendations for future studies: open data, open methods, and theory-driven research
Space Weathering on 4 Vesta: Processes and Products
The bulk properties of Vesta have previously been linked directly to the howardite, eucrite, and diogenite (HED) meteorites through remote mineral characterization of its surface from Earth-based spectroscopy [e.g., 1]. A long-standing enigma has been why does Vesta s surface appear to have suffered so little alteration from the space environment, whereas materials exposed on the Moon and some S-type asteroids are significantly changed (grains develop rims containing nano-phase opaques [e.g. 2]). The Dawn spacecraft is well suited to address this issue and is half through its extended mapping phase of this remarkable proto-planet [3]. On a local scale Dawn sees evidence of recent exposures at craters, but distinctive surface materials blend into background at older craters. The presence of space weathering processes are thus evident at Vesta, but the character and form are controlled by the unique environment and geologic history of this small body
The role of the mitochondria and the endoplasmic reticulum contact sites in the development of the immune responses
Abstract Mitochondria and endoplasmic reticulum (ER) contact sites (MERCs) are dynamic modules enriched in subset of lipids and specialized proteins that determine their structure and functions. The MERCs regulate lipid transfer, autophagosome formation, mitochondrial fission, Ca2+ homeostasis and apoptosis. Since these functions are essential for cell biology, it is therefore not surprising that MERCs also play a critical role in organ physiology among which the immune system stands by its critical host defense function. This defense system must discriminate and tolerate host cells and beneficial commensal microorganisms while eliminating pathogenic ones in order to preserve normal homeostasis. To meet this goal, the immune system has two lines of defense. First, the fast acting but unspecific innate immune system relies on anatomical physical barriers and subsets of hematopoietically derived cells expressing germline-encoded receptors called pattern recognition receptors (PRR) recognizing conserved motifs on the pathogens. Second, the slower but very specific adaptive immune response is added to complement innate immunity. Adaptive immunity relies on another set of specialized cells, the lymphocytes, harboring receptors requiring somatic recombination to be expressed. Both innate and adaptive immune cells must be activated to phagocytose and process pathogens, migrate, proliferate, release soluble factors and destroy infected cells. Some of these functions are strongly dependent on lipid transfer, autophagosome formation, mitochondrial fission, and Ca2+ flux; this indicates that MERCs could regulate immunity
Perceptual Skill And Social Structure
Visual perception relies on stored information and environmental associations to arrive at a determinate representation of the world. This opens up the disturbing possibility that our visual experiences could themselves be subject to a kind of racial bias, simply in virtue of accurately encoding previously encountered environmental regularities. This possibility raises the following question: what, if anything, is wrong with beliefs grounded upon these prejudicial experiences? They are consistent with a range of epistemic norms, including evidentialist and reliabilist standards for justification. I argue that we will struggle to locate a flaw with these sorts of perceptual beliefs so long as we focus our analysis at the level of the individual and her response to information. We should instead broaden our analysis to include the social structure within which the individual is located. Doing so lets us identify a problem with the way in which unjust social structures in particular “gerrymander” the regularities an individual is exposed to, and by extension the priors their visual system draws on. I argue that in this way, social structures can cap perceptual skill
- …