Stability of Non-linear Filter for Deterministic Dynamics

This papers shows that nonlinear filter in the case of deterministic dynamics is stable with respect to the initial conditions under the conditions that observations are sufficiently rich, both in the context of continuous and discrete time filters. Earlier works on the stability of the nonlinear filters are in the context of stochastic dynamics and assume conditions like compact state space or time independent observation model, whereas we prove filter stability for deterministic dynamics with more general assumptions on the state space and observation process. We give several examples of systems that satisfy these assumptions. We also show that the asymptotic structure of the filtering distribution is related to the dynamical properties of the signal.Comment: 24 pages, 2 figures. In V3, few subsections are added and several typos are correcte

Epigenetic Modifications Acetylation and Deacetylation Play Important Roles in Juvenile Hormone Action

Background: Epigenetic modifications including DNA methylation and post-translational modifications of histones are known to regulate gene expression. Antagonistic activities of histone acetyltransferases (HATs) and histone deacetylases (HDACs) mediate transcriptional reprogramming during insect development as shown in Drosophila melanogaster and other insects. Juvenile hormones (JH) play vital roles in the regulation of growth, development, metamorphosis, reproduction and other physiological processes. However, our current understanding of epigenetic regulation of JH action is still limited. Hence, we studied the role of CREB binding protein (CBP, contains HAT domain) and Trichostatin A (TSA, HDAC inhibitor) on JH action. Results: Exposure of Tribolium castaneum cells (TcA cells) to JH or TSA caused an increase in expression of Kr-h1 (a known JH-response gene) and 31 or 698 other genes respectively. Knockdown of the gene coding for CBP caused a decrease in the expression of 456 genes including Kr-h1. Interestingly, the expression of several genes coding for transcription factors, nuclear receptors, P450 and fatty acid synthase family members that are known to mediate JH action were affected by CBP knockdown or TSA treatment. Conclusions: These data suggest that acetylation and deacetylation mediated by HATs and HDACs play an important role in JH action

CREB-Binding Protein Plays Key Roles in Juvenile Hormone Action in the Red Flour Beetle, \u3cem\u3eTribolium Castaneum\u3c/em\u3e

Juvenile hormones (JH) and ecdysteroids regulate many biological and metabolic processes. CREB-binding protein (CBP) is a transcriptional co-regulator with histone acetyltransferase (HAT) activity. Therefore, CBP is involved in activation of many transcription factors that regulate expression of genes associated with postembryonic development in insects. However, the function of CBP in JH action in insects is not well understood. Hence, we studied the role of CBP in JH action in the red flour beetle, Tribolium castaneum and the Tribolium cell line. CBP knockdown caused a decrease in JH induction of genes, Kr-h1, 4EBP and G13402 in T. castaneum larvae, adults and TcA cells whereas, Trichostatin A [TSA, a histone deacetylase (HDAC) inhibitor] induced the expression of these JH-response genes. Western blot analysis with specific antibodies revealed the requirement of CBP for the acetylation of H3K18 and H3K27 in both T. castaneum and TcA cells. Chromatin immunoprecipitation (Chip) assays showed the importance of CBP-mediated acetylation of H3K27 for JH induction of Kr-h1, 4EBP, and G13402 in TcA cells. These data suggest that CBP plays an important role in JH action in the model insect, T.castaneum

Subgaleal dermoid cyst of the anterior fontanelle in a child

AbstractThe congenital inclusion dermoid cyst (CDIC) of the anterior fontanel is a benign, slow-growing lesion. Subgaleal location of dermoid cyst is extremely uncommon. We report a case of 14year old female who had subgaleal dermoid cyst of the anterior fontanel where the cyst could be excised completely with good outcome. Computed tomography scan is the investigations of choice as it will show the greater details of the lesion and its relation to the underlying structures. Characteristic scalloping of the outer table of cranium on radiographs can help to differentiate intracranial extension from extracranial location of the lesion

Expression of trefoil factor 3 is decreased in colorectal cancer

In colorectal cancer (CRC), high expression of trefoil factor 3 (TFF3) is associated with tumor progression and reduced patient survival; however, bioinformatics analyses of public \u27omics\u27 databases show low TFF3 expression in CRCs as compared to normal tissues. Thus, we examined TFF3 expression in CRCs and matching normal tissues to evaluate its role in CRC progression. TFF3 gene expression was char- acterized using the bioinformatics portal UALCAN (http:// ualcan.path.uab.edu). Tissue microarrays (TMAs) of archival CRC specimens (n=96) were immunostained with anti-human TFF3 antibodies. Immunohistochemical (IHC) staining intensity was semi-quantitatively scored. For this cohort, the median follow-up was 5.4 years. Associations between clinical and pathological variables were determined using Chi-square or Fisher\u27s exact tests. Univariate disease-free survival was estimated by the Kaplan-Meier method. Omics data analyses by UALCAN showed downregulation of TFF3 expression in CRC relative to normal tissue at protein (χ2, P\u3c0.0001) levels. There was a similar decreasing trend of TFF3 expression in the pathologic stages of the CRCs (RNA, χ2, P=0.88 and protein, χ2 P\u3c0.0001). UALCAN data analysis showed that TFF3 exhibited 27% lower mRNA expression in tumors with mutant TP53 (P=0.007). Confirming the findings of omics analyses, IHC analysis of TMAs exhibited lower TFF3 expression in 95.6% (65 of 68) of the available normal-tumor matching pairs (χ2, P\u3c0.0001). There was no statistically significant association of tumor TFF3 expression with patient sex, race/ ethnicity, tumor location within the colorectum, Tumor, Node, Metastasis (TNM) stage, lymph node metastasis, or surgical margins. However, low TFF3 IHC staining in tumor tissue was associated with histological grade (P=0.026). Kaplan-Meier survival analysis showed no prognostic value of low TFF3 expression relative to those with high expression (log-rank, P=0.605). Our findings demonstrate low expression of TFF3 in CRCs. Association between low TFF3 and histopathological features suggests involvement of this molecule in progression of CRC