Incorporating prior knowledge improves detection of differences in bacterial growth rate

BACKGROUND: Robust statistical detection of differences in the bacterial growth rate can be challenging, particularly when dealing with small differences or noisy data. The Bayesian approach provides a consistent framework for inferring model parameters and comparing hypotheses. The method captures the full uncertainty of parameter values, whilst making effective use of prior knowledge about a given system to improve estimation. RESULTS: We demonstrated the application of Bayesian analysis to bacterial growth curve comparison. Following extensive testing of the method, the analysis was applied to the large dataset of bacterial responses which are freely available at the web-resource, ComBase. Detection was found to be improved by using prior knowledge from clusters of previously analysed experimental results at similar environmental conditions. A comparison was also made to a more traditional statistical testing method, the F-test, and Bayesian analysis was found to perform more conclusively and to be capable of attributing significance to more subtle differences in growth rate. CONCLUSIONS: We have demonstrated that by making use of existing experimental knowledge, it is possible to significantly improve detection of differences in bacterial growth rate

Differences between Resource Bounded Degree Structures

We exhibit a structural difference between the truth-table degrees of the sets which are truth-table above 0 # and the PTIME-Turing degrees of all sets

Distribution of SRPK1 in human brain

Extensive alternative splicing is observed in the mammalian nervous system providing for protein diversity and specificity to accomplish the complex neuronal functions. Mechanisms underlying neuron specific splicing are not yet well understood. Among the factors regulating splicing of major importance are serine/arginine protein kinases (SRPKs) that phosphorylate SR splicing factors. SRPK1 is known to be expressed in the mammalian central nervous system. The present immunohistochemical study reveals a region- and neuron-specific localization of SRPK1 in human brain. The potential involvement of the kinase in the regulation of alternative splicing of various neuronal proteins is discussed. © 2011 Elsevier B.V

The Sacks Density Theorem and S_2-Bounding

The Sacks Density Theorem (Sacks 1964) states that the Turing degrees of the recursively enumerable sets are dense. We show that the Density Theorem holds in every model of P \Gamma +B \Sigma 2 . The proof has two components: a lemma that in any model of P \Gamma +B \Sigma 2 , if B is recursively enumerable and incomplete then I \Sigma 1 holds relative to B and an adaptation of Shore's (1976) blocking technique in ff-recursion theory to models of arithmetic. 1 Introduction Proofs using the priority method are the trademark of recursion theory. In this paper, we continue the line of inquiry in which we use subsystems of first order arithmetic to calibrate priority methods and the theorems in whose proofs they appear. In the hierarchy of Groszek and Slaman (unpublished), we classify priority constructions according to the syntactic complexity of the outcomes in its most complicated families of strategies. In a \Pi 1 -priority construction the strategies have outcomes that are descri..

Prechiasmatic sulcus and optic strut: an anatomic study in dry skulls

Background: Although safe surgical access to the cavernous sinus is related to understanding the anatomical and ethnic variants of the prechiasmatic sulcus and the optic strut, there remains a paucity of studies of the morphology and the bony relationships in the region. The present study provides a systematic morphological and morphometric analysis of the sulcal region and the optic strut anatomy and their relations in a Greek population. Methods: The interoptic distance, length of planum sphenoidale, sulcal length and sulcal angle was determined in 96 Greek adult dry skulls. The prechiasmatic sulci and optic struts were morphologically classified and association of sulcal region measures according to type of prechiasmatic sulcus and optic strut were examined. Results: Mean interoptic distance was 1.69 ± 0.25 cm; sulcal length, 0.72 ± 0.18 cm; length of planum sphenoidale, 1.86 ± 0.32 cm; sulcal angle, 24.05 ± 17.17°. The sulcal angle was significantly smaller in female skulls compared to males (14.82 ± 12.43 vs 28.29 ± 15.24; p < 0.05). Type I (narrow, steep) prechiasmatic sulci were the most commonly observed (35.8%), followed by Type IV (wide, flat) (32.1%), Type II (narrow, flat) (18.5%) and, finally, Type III (wide, steep) sulci (13.6%). The optic strut was presulcal in 8.3% of specimens, sulcal in 31%, postsulcal in 41.7% and asymmetric in 19%. Conclusions: The present study augments the current knowledge of the morphology of key anatomical landmarks, prechiasmatic sulcus and the optic strut, for cavernous sinus surgery and indicates population and gender differences. We report significant anatomical variations in the prechiasmatic sulcus, optic strut and surrounding structures. In addition to providing a better understanding of the anatomical landmarks, necessary for the safe navigation in transcranial and endoscopic procedures, the present results also suggest that surgeons must consider population differences in determining the anatomical landmarks and navigation points in the sellar region. © 2017, Springer-Verlag Wien

Modulation of central glucocorticoid receptors in short- and long-term experimental hyperthyroidism

Hyperthyroidism is associated with a significant increase in circulating glucocorticoid levels and hyperactivity of the hypothalamic–pituitary–adrenal (HPA) axis. The aim of this study was to examine whether the HPA axis hyperactivity observed in hyperthyroidism may be explained by a disturbed feedback inhibition of endogenous glucocorticoids through two specific intracellular receptors in the brain: the high affinity mineralocorticoid receptor (MR) and the lower affinity glucocorticoid receptor (GR). Cytosolic receptor binding and gene expression was assessed in rats with short (7 days) and long standing (60 days) eu- and hyperthyroidism. Glucocorticoid receptor number and binding affinity (Kd) in the hippocampus were measured using [3H2]-dexamethasone radioreceptor assay. In situ hybridization was employed to examine the effects of hyperthyroidism on the GR and MR mRNA levels in the hippocampus and the pituitary. Both short- and long-term hyperthyroid rats showed pronounced reduction in the concentration of cytosolic GR in the hippocampus, without changes in binding affinity or changes in GR expression. In contrast, GR mRNA in the pituitary increased after 7 days and decreased after 60 days of thyroxin treatment. MR mRNA was moderately affected. Hyperthyroidism is associated with significant decreases in hippocampal GR levels supporting the hypothesis that hyperactivity of the HPA axis observed in experimentally induced hyperthyroidism may be attributed, at least in part, to decreased negative feedback at the level of the hippocampus. These findings further support the notion that a central locus is principally responsible for the hyperactivity of the HPA axis observed in hyperthyroidism. © 2015, Springer Science+Business Media New York

Incidence and morphometry of caroticoclinoid foramina in Greek dry human skulls

Background: Ossification of the caroticoclinoid ligament (CCL) and formation of a caroticoclinoid foramen (CCF) may impose significant risk to neurosurgeons by impeding mobilization of the cavernous segment of the internal carotid artery. Although safe surgical access to the clinoidal space is related to understanding the CCF anatomical and ethnic variants, there remains a paucity of studies of the morphology and bony relationships. The current study provides a systematic morphological and morphometric analysis of the CCF, the ossification of the CCL extending between the anterior and middle clinoid processes, and their relations in a Greek population. Materials and methods: The incidence of unilateral and bilateral CCF, types (complete, incomplete, and contact) of ossified CCLs, and foramina diameter according to side and gender were determined in 76 Greek adult dry skulls. Findings were correlated with the morphology of optic strut (OS) (presulcal, sulcal, postsulcal, and asymmetric). Results: A CCF was detected in 74% of the specimens. The majority of skulls (51.4%) had bilateral CCF, whereas 22.3% of the skulls had unilateral foramina. Incomplete CCF were observed in 69.3%, complete in 19.8%, and contact type in 10.9%. The mean CCF diameter was 0.55 ± 0.07 cm on the left and 0.54 ± 0.08 cm on the right side. Side symmetry existed, although there were no significant differences according to gender. The CCF were more prominent in skulls with a sulcal type of OS. Conclusions: The results of the present study augment the current knowledge on the morphology of key anatomical landmarks, CCF, and CCL ossification in the sellar area, indicating population differences. A significant side asymmetry in caroticoclinoid osseous bridging and foramina is highlighted. These findings are necessary for a safe surgical access to the clinoidal area. © 2018, Springer-Verlag GmbH Austria, part of Springer Nature