Linear operators that strongly preserve regularity of fuzzy matrices

An $ntimes n$ fuzzy matrix $A$ is called {regular} if there is an $ntimes n$ fuzzy matrix $G$ such that $AGA=A$. We study the problem of characterizing those linear operators $T$ on the fuzzy matrices such that $T(X)$ is regular if and only if $X$ is. Consequently, we obtain that $T$ strongly preserves regularity of fuzzy matrices if and only if there are permutation matrices $P$ and $Q$ such that it has the form $T(X)=PXQ$ or $T(X)=PX^tQ$ for all fuzzy matrices $X$

The role of FGF signaling in guiding coordinate movement of cell groups: Guidance cue and cell adhesion regulator?

Cell migration influences cell-cell interactions to drive cell differentiation and organogenesis. To support proper development, cell migration must be regulated both temporally and spatially. Mesoderm cell migration in the Drosophila embryo serves as an excellent model system to study how cell migration is controlled and influences organogenesis. First, mesoderm spreading transforms the embryo into a multilayered form during gastrulation and, subsequently, cells originating from the caudal visceral mesoderm (CVM) migrate along the entire length of the gut. Here we review our studies, which have focused on the role of fibroblast growth factor (FGF) signaling, and compare and contrast these two different cell migration processes: mesoderm spreading and CVM migration. In both cases, FGF acts as a chemoattractant to guide cells’ directional movement but is likely not the only signal that serves this role. Furthermore, FGF likely modulates cell adhesion properties since FGF mutant phenotypes share similarities with those of cell adhesion molecules. Our working hypothesis is that levels of FGF signaling differentially influence cells’ response to result in either directional movement or changes in adhesive properties

On n

We consider the fuzzification of the notion of an n-fold positive implicative ideal. We give characterizations of an n-fold fuzzy positive implicative ideal. We establish the extension property for n-fold fuzzy positive implicative ideals, and state a characterization of PIn-Noetherian BCK-algebras. Finally we study the normalization of n-fold fuzzy positive implicative ideals

Intuitionistic fuzzy ideals of BCK-algebras

We consider the intuitionistic fuzzification of the concept of subalgebras and ideals in BCK-algebras, and investigate some of their properties. We introduce the notion of equivalence relations on the family of all intuitionistic fuzzy ideals of a BCK-algebra and investigate some related properties

Pharmacoeconomic Guidelines and Their Implementation in the Positive List System in South Korea

ABSTRACTThis article reviews the change in the reimbursement and pricing system in South Korea, which was the precursor to the eventual implementation of evidence-based decision-making. There has been pressure on Korea's National Health Insurance system to control its skyrocketing expenditures on drugs. As a result, a series of cost-containment policies have been implemented. The idea of economic evidence-based decision-making was first introduced in Korea in 2001 when the government announced cost-effectiveness as one of the criteria for reimbursement decisions. After this announcement, the Health Insurance Review and Assessment Service (HIRA) developed guidelines, which became the standard for economic evaluations.In 2006, the drug listing system for reimbursement was changed from a negative to a positive system under the drug expenditure rationalization plan. Under this new system, only drugs that are proven economically and clinically valuable can be listed, and applicants have to submit economic evaluation studies to support the cost-effectiveness of their drugs. Once new applications are submitted, HIRA reviews them, and the Drug Reimbursement Evaluation Committee (DREC) decides whether or not to recommend the submitted drugs. In its reimbursement decisions, the DREC considers not only cost-effectiveness but also the availability of therapeutic alternatives, the severity of the condition treated, and the impact on the budget, among other measures. After the introduction of the positive list system, 56% of drugs were determined to be appropriate for reimbursement by the DREC. Despite limited human resources, experience, and quality local data, Korea is continuing to make efforts to establish a system of evidence-based decision-making

On ideals of implicative semigroups

We introduce the notion of ideals in implicative semigroups, and then state the characterizations of the ideals

Intuitionistic fuzzy interior ideals of semigroups

We consider the intuitionistic fuzzification of the concept of interior ideals in a semigroup S, and investigate some properties of such ideals. For any homomorphism f from a semigroup S to a semigroup T, if B=(μB,γB) is an intuitionistic fuzzy interior ideal of T, then the preimage f−1(B)=(f−1(μB),f−1(γB)) of B under f is an intuitionistic fuzzy interior ideal of S

The CIL-1 PI 5-Phosphatase Localizes TRP Polycystins to Cilia and Activates Sperm in C. elegans

SummaryBackgroundC. elegans male sexual behaviors include chemotaxis and response to hermaphrodites, backing, turning, vulva location, spicule insertion, and sperm transfer, culminating in cross-fertilization of hermaphrodite oocytes with male sperm. The LOV-1 and PKD-2 transient receptor potential polycystin (TRPP) complex localizes to ciliated endings of C. elegans male-specific sensory neurons and mediates several aspects of male mating behavior. TRPP complex ciliary localization and sensory function are evolutionarily conserved. A genetic screen for C. elegans mutants with PKD-2 ciliary localization (Cil) defects led to the isolation of a mutation in the cil-1 gene.ResultsHere, we report that a phosphoinositide (PI) 5-phosphatase, CIL-1, regulates TRPP complex ciliary receptor localization and sperm activation. cil-1 does not regulate the localization of other ciliary proteins, including intraflagellar transport (IFT) components, sensory receptors, or other TRP channels in different cell types. Rather, cil-1 specifically controls TRPP complex trafficking in male-specific sensory neurons and does so in a cell-autonomous fashion. In these cells, cil-1 is required for normal PI(3)P distribution, indicating that a balance between PI(3,5)P2 and PI(3)P is important for TRPP localization. cil-1 mutants are infertile because of sperm activation and motility defects. In sperm, the CIL-1 5-phosphatase and a wortmannin-sensitive PI 3-kinase act antagonistically to regulate the conversion of sessile spermatids into motile spermatozoa, implicating PI(3,4,5)P3 signaling in nematode sperm activation.ConclusionOur studies identify the CIL-1 5-phosphatase as a key regulator of PI metabolism in cell types that are important in several aspects of male reproductive biology