Early and late stage profiles for a new chemotaxis model with density-dependent jump probability and quorum-sensing mechanisms

In this paper, we derive a new chemotaxis model with degenerate diffusion and density-dependent chemotactic sensitivity, and we provide a more realistic description of cell migration process for its early and late stages. Different from the existing studies focusing on the case of non-degenerate diffusion, the new model with degenerate diffusion causes us some essential difficulty on the boundedness estimates and the propagation behavior of its compact support. In the presence of logistic damping, for the early stage before tumour cells spread to the whole body, we first estimate the expanding speed of tumour region as $O(t^{\beta})$ for $0<\beta<\frac{1}{2}$. Then, for the late stage of cell migration, we further prove that the asymptotic profile of the original system is just its corresponding steady state. The global convergence of the original weak solution to the steady state with exponential rate $O(e^{-ct})$ for some $c>0$ is also obtained

A Simple Algorithm for Semi-supervised Learning with Improved Generalization Error Bound

In this work, we develop a simple algorithm for semi-supervised regression. The key idea is to use the top eigenfunctions of integral operator derived from both labeled and unlabeled examples as the basis functions and learn the prediction function by a simple linear regression. We show that under appropriate assumptions about the integral operator, this approach is able to achieve an improved regression error bound better than existing bounds of supervised learning. We also verify the effectiveness of the proposed algorithm by an empirical study.Comment: Appears in Proceedings of the 29th International Conference on Machine Learning (ICML 2012

3-Mesityl-2-oxo-1-oxaspiro­[4.4]non-3-en-4-yl benzoate

In the title compound, C24H24O4, a derivative of the potent insecticide and miticide spiro­mesifen, one cyclo­pentane C atom is disordered over two positions with occupancies of 0.574 (12) and 0.426 (12), resulting in respective envelope and twisted conformations for the cyclo­pentane ring. The atom at the flap position is 0.620 (5) Å out of the mean plane formed by the other four atoms of the envelope form. The furan ring makes dihedral angles of 68.26 (3) and 69.38 (2)°, respectively, with the 2,4,6-trimethyl­phenyl and benzene rings. The dihedral angle between the two benzene rings is 62.27 (3)°

Aerosolised surfactant generated by a novel noninvasive apparatus reduced acute lung injury in rats

Abstract Introduction Exogenous surfactant has been explored as a potential therapy for acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). In the present study, a nebuliser driven by oxygen lines found in the hospital was developed to deliver aerosolised porcine pulmonary surfactant (PPS). We hypothesised that aerosolised surfactant inhaled through spontaneous breathing may effectively reduce severe lung injury. Methods Rats were intravenously injected with oleic acid (OA) to induce ALI and 30 minutes later they were divided into five groups: model (injury only), PPS aerosol (PPS-aer), saline aerosol (saline-aer), PPS instillation (PPS-inst), and saline instillation (Saline-Inst). Blood gases, lung histology, and protein and TNF-α concentrations in the bronchoalveolar lavage fluid (BALF) were examined. Results The PPS aerosol particles were less than 2.0 μm in size as determined by a laser aerosol particle counter. Treatment of animals with a PPS aerosol significantly increased the phospholipid content in the BALF, improved lung function, reduced pulmonary oedema, decreased total protein and TNF-α concentrations in BALF, ameliorated lung injury and improved animal survival. These therapeutic effects are similar to those seen in the PPS-inst group. Conclusions This new method of PPS aerosolisation combines the therapeutic effects of a surfactant with partial oxygen inhalation under spontaneous breathing. It is an effective, simple and safe method of administering an exogenous surfactant

The Drosophila Inhibitor of Apoptosis (IAP) DIAP2 Is Dispensable for Cell Survival, Required for the Innate Immune Response to Gram-negative Bacterial Infection, and Can Be Negatively Regulated by the Reaper/Hid/Grim Family of IAP-binding Apoptosis Inducers

Many inhibitor of apoptosis (IAP) family proteins inhibit apoptosis. IAPs contain N-terminal baculovirus IAP repeat domains and a C-terminal RING ubiquitin ligase domain. Drosophila IAP DIAP1 is essential for the survival of many cells, protecting them from apoptosis by inhibiting active caspases. Apoptosis initiates when proteins such as Reaper, Hid, and Grim bind a surface groove in DIAP1 baculovirus IAP repeat domains via an N-terminal IAP-binding motif. This evolutionarily conserved interaction disrupts DIAP1-caspase interactions, unleashing apoptosis-inducing caspase activity. A second Drosophila IAP, DIAP2, also binds Rpr and Hid and inhibits apoptosis in multiple contexts when overexpressed. However, due to a lack of mutants, little is known about the normal functions of DIAP2. We report the generation of diap2 null mutants. These flies are viable and show no defects in developmental or stress-induced apoptosis. Instead, DIAP2 is required for the innate immune response to Gram-negative bacterial infection. DIAP2 promotes cytoplasmic cleavage and nuclear translocation of the NF-{kappa}B homolog Relish, and this requires the DIAP2 RING domain. Increasing the genetic dose of diap2 results in an increased immune response, whereas expression of Rpr or Hid results in down-regulation of DIAP2 protein levels. Together these observations suggest that DIAP2 can regulate immune signaling in a dose-dependent manner, and this can be regulated by IBM-containing proteins. Therefore, diap2 may identify a point of convergence between apoptosis and immune signaling pathways

3-Benzyl-1-methyl­imidazolium picrate

In the title salt, C11H13N2 +·C6H2N3O7 −, the dihedral angles between the benzene ring in the cation and the imidazolium ring and the benzene ring of the picrate anion are 113.7 (2) and 116.3 (2)°, respectively. The imidazolium ring is nearly parallel to the benzene ring of the picrate anion, the dihedral angle between the planes being 2.6 (1)°. The nitro groups in the picrate anions are disordered (occupancy ratio 0.54:0.46). The crystal packing is stabilized by weak C—H⋯O inter­actions between the cation–anion pairs

3-Mesityl-2-oxo-1-oxaspiro­[4.4]non-3-en-4-yl 4-chloro­benzoate

The title compound, C24H23ClO4, is a potent insecticide and miticide. The five-membered cyclo­pentane ring displays an envelope conformation with the atom at the flap position 0.611 (2) Å out of the mean plane formed by the other four atoms. The furan ring makes dihedral angles of 71.3 (2) and 81.9 (2)°, respectively, with the 2,4,6-trimethyl­phenyl and 4-chloro­phenyl rings. The dihedral angle between the two benzene rings is 76.6 (1)°. In the crystal, mol­ecules are linked through weak inter­molecular C—H⋯O hydrogen bonds, forming chains running along the c axis

Inhibitory effect of tetramethylpyrazine combined with propranolol on murine hemangioma endothelial cells

Purpose: To study the inhibitory effect of different doses of tetramethylpyrazine (TMP) combined with the beta-blocker, propranolol (Pro) on hemangioma endothelial (EOMA) cells. Methods: EOMA cells were cultured in vitro with varying doses of TMP and Pro (5, 10, 20 and 40 uM). The effect of treatments on cell proliferation was assessed by MTT assay, while cell apoptosis was assayed by flow cytometry. The expressions of Bcl-2, Bax, p-mTOR), total-mammalian target of rapamycin (t-mTOR, p-p70S6) and total-p70 ribosomal protein S6 (t-p70S6) proteins were determined using Western blot. Results: MTT data showed that when used alone, TMP had no significant inhibitory effect on EOMA cells (p &gt; 0.05). However, when TMP was combined with propranolol, there was significant inhibition of EOMA cells, and that the inhibition is dependent on TMP dose. Flow cytometry results showed that the combination of TMP and Pro induced EOMA cell apoptosis dose-dependently (p &lt; 0.05). Moreover, TMP dose-dependently inhibited the phosphorylation of mTOR and p70S6 in EOMA cells, and enhanced Bax expression, but downregulated Bcl-2 (p &lt; 0.05). Conclusion: These results suggest that TMP enhances the inhibitory influence of Pro p-mTOR and pp-70S6 in EOMA cells in a dose-dependent manner. Thus, TMP may enhance Pro-induced inhibition of the growth of endothelial cells, and promote apoptosis through suppression of activation of PI3K/AKT signal route. These findings provide a theoretical basis for the clinical application of TMP/Pro combination for the treatment of hemangioma

Hypoglycemic and Hypolipidemic Effects of Ethanolic Extract of Mirabilis jalapa L. Root on Normal and Diabetic Mice

The present study investigated the insulin sensitivity, hypoglycemic, and hypolipidemic activities of ethanolic extract of Mirabilis jalapa L. root (EEM) in normal and diabetic mice. After induction of diabetes with streptozotocin, both normal and diabetic mice were singly or repeatedly for 28 days administrated with EEM at doses of 2, 4, 8 g/kg, respectively. Before induction of diabetes, mice were administrated with EEM at doses of 2, 4, 8 g/kg for 14 days and were injected with streptozotocin and continued on EEM administration for another 28 days. Both after and before induction of diabetes, repeated administration with 4, 8 g/kg EEM continually lowered blood glucose level, decreased serum insulin level and improved insulin sensitivity index, and lowered serum total cholesterol, triglyceride levels and triglyceride content in liver and skeletal muscle, and increased glycogen content in these tissues; but repeated administration had no influence on those indexes of normal mice. Single administration with EEM (4, 8 g/kg) showed hypoglycemic effect in oral glucose tolerance test in normal and diabetic mice. Single administration with EEM had no hypoglycemic and hypolipidemic effects on normal and diabetic mice. These results suggest that EEM possesses both potential insulin sensitivity, hypoglycemic, and hypolipidemic effects on diabetes