Twinstar/cofilin is required for regulation of epithelial integrity and tissue growth in Drosophila

Ko, C,Kim, Y-G,Le, T P,Choi, K-W Macmillan Publishers Limited 2016 Oncogene Vol.35 No.39

<P>Regulation of actin assembly and depolymerization is important for the organization of epithelia. Recent studies have shown that the actin-capping proteins are required to prevent cell extrusion and inappropriate activation of Yorkie (Yki) activity in Drosophila, implicating the importance of actin regulation for epithelial integrity and Yki-dependent tissue growth. However, the role of Twinstar (Tsr), the Drosophila homolog for cofilin/actin depolymerization factor (ADF), in epithelial integrity and Hippo signaling is unknown. Here we demonstrate that reduction of Tsr by RNA interference (RNAi) or mutant clones in wing imaginal disc induces not only F-actin accumulation but also ectopic expression of Wingless (Wg) and Yki target gene expanded (ex). Knockdown of Yki in Tsr-depleted cells reduced the level of ectopic Wg expression. Reduced Tsr also led to downregulation of cell junction proteins and extrusion of affected cells from the basal part of the epithelium. Rho GTPase 1 was upregulated in Tsr-depleted tissue, supporting the Tsr function in the inhibition of cell extrusion from the epithelium. Tsr is also required for blocking cell death and c-Jun N-terminal kinase (JNK) signaling. Ectopic JNK activation induced caspase activation but did not cause cell extrusion. Further, the invasiveness of Tsr-depleted cells was not suppressed by inhibition of cell death or JNK signaling. In contrast, Yki upregulation was significantly suppressed by cell death inhibition. Taken together, our data suggest that Tsr is required for cell survival and tissue growth by regulating JNK and Yki signaling while maintaining the epithelial integrity by controlling cell junctions. This study provides an insight into potential roles of ADF/cofilin in invasive cell migration and tumor suppression in higher animals.</P>

NOTES ON SYMMETRIC SKEW n-DERIVATION IN RINGS

Koc, Emine,Rehman, Nadeem ur Korean Mathematical Society 2018 대한수학회논문집 Vol.33 No.4

Let R be a prime ring (or semiprime ring) with center Z(R), I a nonzero ideal of R, T an automorphism of $R,S:R^n{\rightarrow}R$ be a symmetric skew n-derivation associated with the automorphism T and ${\Delta}$ is the trace of S. In this paper, we shall prove that S($x_1,{\ldots},x_n$) = 0 for all $x_1,{\ldots},x_n{\in}R$ if any one of the following holds: i) ${\Delta}(x)=0$, ii) [${\Delta}(x),T(x)]=0$ for all $x{\in}I$. Moreover, we prove that if $[{\Delta}(x),T(x)]{\in}Z(R)$ for all $x{\in}I$, then R is a commutative ring.

Histological analysis of acute toxicity of 2,4-diclorophenoxy acetic acid in ovary of zebrafish

Koc, Nazan Deniz,Akbulut, Cansu The Korean Society for Integrative Biology 2012 Animal cells and systems Vol.16 No.5

Plant growth regulators are the chemicals that are found in plants and produced synthetically. In agricultural applications, plant hormones are used in minor quantities for fixing the problems. In our research, we studied the effects of 2,4 diclorophenoxyacetic acid (2,4D), which is an auxin used in agricultural applications. Auxins are the group that are used most popularly in plant growth regulators. In our study, different doses of 2,4 diclorophenoxyacetic acid are given to zebrafish, and ovarium tissues are observed histomorphologically. We generated one control and three experiment groups from the stock solution. The experiment was carried out in 20 liter capacity complete glass aquarium at $24{\pm}1^{\circ}C$ water temperature. After five days of application, fishes were dissected. Histomorphological changes of the ovarium were investigated under a light microscope. A decrease in the number of oocytes in zebrafish ovarium was observed when compared with the control group. Many deformed and underdeveloped oocytes were detected. An increase in the number of atretic oocytes was observed. It was deduced that acute doses of 2,4 diclorophenoxyacetic acid decelerates oogenesis in fishes.

ON PSEUDO 2-PRIME IDEALS AND ALMOST VALUATION DOMAINS

Koc, Suat Korean Mathematical Society 2021 대한수학회보 Vol.58 No.4

In this paper, we introduce the notion of pseudo 2-prime ideals in commutative rings. Let R be a commutative ring with a nonzero identity. A proper ideal P of R is said to be a pseudo 2-prime ideal if whenever xy ∈ P for some x, y ∈ R, then x²ⁿ ∈ Pⁿ or y²ⁿ ∈ Pⁿ for some n ∈ ℕ. Various examples and properties of pseudo 2-prime ideals are given. We also characterize pseudo 2-prime ideals of PID's and von Neumann regular rings. Finally, we use pseudo 2-prime ideals to characterize almost valuation domains (AV-domains).

NOTES ON IDEALS AND ORTHOGONAL GENERALIZED ($\sigma$, $\tau$)-DERIVATIONS

Koc, Emine The Youngnam Mathematical Society Korea 2008 East Asian mathematical journal Vol.24 No.4

In this paper, some results of [6] concerning orthogonal ($\sigma$, $\tau$)-derivations and generalized ($\sigma$, $\tau$)-derivations are generalized for a nonzero ideal of a semiprime ring.

Color stability of bulk-fill and incremental-fill resin-based composites polished with aluminum-oxide impregnated disks

Koc-Vural, Uzay,Baltacioglu, Ismail,Altinci, Pinar The Korean Academy of Conservative Dentistry 2017 Restorative Dentistry & Endodontics Vol.42 No.2

Objectives: This study aimed to evaluate the color stability of bulk-fill and nanohybrid resin-based composites polished with 3 different, multistep, aluminum-oxide impregnated finishing and polishing disks. Materials and Methods: Disk-shaped specimens (8 mm in diameter and 4 mm in thickness) were light-cured between two glass slabs using one nanohybid bulk-fill (Tetric EvoCeram, Ivoclar Vivadent), one micro-hybrid bulk-fill (Quixfil, Dentsply), and two nanohybrid incremental-fill (Filtek Ultimate, 3M ESPE; Herculite XRV Ultra, Kerr) resin-based composites, and aged by thermocycling (between $5-55^{\circ}C$, 3,000 cycles). Then, they were divided into subgroups according to the polishing procedure as SwissFlex ($Colt\grave{e}ne/Whaledent$), Optidisc (Kerr), and Praxis TDV (TDV Dental) (n = 12 per subgroup). One surface of each specimen was left unpolished. All specimens were immersed in coffee solution at $37^{\circ}C$. The color differences (${\Delta}E$) were measured after 1 and 7 days of storage using a colorimeter based on CIE Lab system. The data were analyzed by univariate ANOVA, Mann-Whitney U test, and Friedmann tests (${\alpha}=0.05$). Results: Univariate ANOVA detected significant interactions between polishing procedure and composite resin and polishing procedure and storage time (p < 0.05). Significant color changes were detected after 1 day storage in coffee solution (p < 0.05), except Quixfil/Optidisc which was color-stable after 7 days (p > 0.05). Polishing reduced the discoloration resistance of Tetric EvoCeram/SwissFlex, Tetric EvoCeram/Praxis TDV, Quixfil-SwissFlex, and all Herculite XRV Ultra groups after 7 days storage (p < 0.05). Conclusions: Discoloration resistance of bulk-fill resin-based composites can be significantly affected by the polishing procedures.

The use of liquefied petroleum gas (lpg) and natural gas in gas turbine jet engines

Koc, Ibrahim Techno-Press 2015 Advances in energy research Vol.3 No.1

This paper compares the performance of JP-8(Jet Propellant) fuel and liquefied petroleum gas (LPG) and natural gas in the F110 GE100 jet engine. The cost of natural gas usage in gas turbine engines is lower than JP-8 and LPG. LPG cost is more than JP-8. LPG volume is bigger than JP-8 in the same flight conditions. Fuel tank should be cryogenic for using natural gas in the aircraft. Cost and weight of the cryogenic tanks are bigger. Cryogenic tanks decrease the move capability of the aircraft. The use of jet propellant (JP) is the best in available application for F110 GE 100 jet engine.

ON STRONGLY QUASI PRIMARY IDEALS

Koc, Suat,Tekir, Unsal,Ulucak, Gulsen Korean Mathematical Society 2019 대한수학회보 Vol.56 No.3

In this paper, we introduce strongly quasi primary ideals which is an intermediate class of primary ideals and quasi primary ideals. Let R be a commutative ring with nonzero identity and Q a proper ideal of R. Then Q is called strongly quasi primary if $ab{\in}Q$ for $a,b{\in}R$ implies either $a^2{\in}Q$ or $b^n{\in}Q$ ($a^n{\in}Q$ or $b^2{\in}Q$) for some $n{\in}{\mathbb{N}}$. We give many properties of strongly quasi primary ideals and investigate the relations between strongly quasi primary ideals and other classical ideals such as primary, 2-prime and quasi primary ideals. Among other results, we give a characterization of divided rings in terms of strongly quasi primary ideals. Also, we construct a subgraph of ideal based zero divisor graph ${\Gamma}_I(R)$ and denote it by ${\Gamma}^*_I(R)$, where I is an ideal of R. We investigate the relations between ${\Gamma}^*_I(R)$ and ${\Gamma}_I(R)$. Further, we use strongly quasi primary ideals and ${\Gamma}^*_I(R)$ to characterize von Neumann regular rings.

Notes on ideals and orthogonal generalized (σ, τ )-derivations

Emine KOC 영남수학회 2008 East Asian mathematical journal Vol.24 No.4

In this paper, some results of [6] concerning orthogonal (σ, τ)-derivations and generalized (σ, τ)-derivations are generalized for a nonzero ideal of a semiprime ring.

Hippophae rhamnoides Prevents Oleic Acid-Induced Acute Respiratory Distress Syndrome by Releasing Acetylcholinesterase Activity and Mitigation of Angiotensin-Converting Enzyme Level

Kubra Koc 한국식품영양과학회 2024 Journal of medicinal food Vol.27 No.1

Hippophae rhamnoides exhibit a wide variety of medicinal and pharmacological effects. The present studyaims to determine the role of ethanol extract of H. rhamnoides on oleic acid (OA)-induced acute respiratory distress syndrome(ARDS) in rats. Male rats were randomly divided into the following groups: (I) Control, (II) OA, and (III) OA+H. rhamnoides. H. rhamnoides extract (500 mg/kg) was given orally for 2 weeks before OA in Group III. Levels of total antioxidant capacity,total oxidant status (TOS), myeloperoxidase (MPO), mitogen-activated protein kinase (MAPK), acetylcholinesterase (AChE),and angiotensin-converting enzyme (ACE) were quantified by enzyme-linked immunosorbent assay (ELISA). Real timequantitative polymerase chain reaction was utilized to evaluate the expression of nuclear factor kappa B (NF-jB), tumornecrosis factor-alpha (TNF-a), interleukin (IL)-6, and matrix metalloproteinase 2 (MMP2). Also, Caspase-3 immunostainingand expression were performed to evaluate apoptosis. Compared with the OA group, there was a significantly decrease in thelevels of MPO, TOS, MAPK, and ACE and in the expression of NF-jB, TNF-a, IL-6, MMP2, and Caspase-3 in the H. rhamnoides administration group. Moreover, the activity of AChE and level of TAS were substantially higher in the H. rhamnoides administration compared with the OA group. The findings in the study suggest that the protective effect of H. rhamnoides pretreatment may act through inhibition of the ACE activity, releasing AChE, regulation of inflammatorycytokine levels, and suppression of apoptotic process in ARDS.