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In mammalian hearts, cardiomyocytes retain a transient capacity to proliferate and regenerate following injury before birth, whereas they lose proliferative capacity immediately after birth. It has also been known that cardiac progenitor cells including islet1-positive cells do not contribute to the cardiac repair and regeneration in mammals. In contrast, hearts of zebrafish, amphibians and reptiles maintain a regenerative ability throughout life. Here, we analyzed proliferative capacity of cardiac cells during cardiac development and post-ventricular resection using Xenopus laevis, especially focusing on islet1. Immunohistochemical examination showed that islet1-positive cells were present in a wide range of the ventricle and maintained high dividing ability after metamorphosis. Interestingly, the islet1-positive cells were preserved even at 1 year after metamorphosis, some of which showed tropomyosin expression. To assess the possibility of islet1-positive cells as a cellular resource, islet1 response to cardiac resection was analyzed, using adult hearts of 3 months after metamorphosis. Transient gene activation of islet1 in apical region was detected within 1 day after amputation. Histological analyses revealed that islet1-positive cells appeared in the vicinity of resection plane at 1 day post-amputation (dpa) and increased at 3 dpa in both tropomyosin-positive and tropomyosin-negative regions. Vascular labeling analysis by biotinylated dextran amine (BDA) indicated that the islet1-positive cells in a tropomyosin-negative region were closely associated with cardiac vessels. Moreover, dividing ability at this time point was peaked. The resected region was healed with tropomyosin-positive cardiomyocytes until 3 months post-amputation. These results suggest a role of islet1-positive cells as a cellular resource for vascularization and cardiogenesis in Xenopus laevis.

Three POU family class V gene homologues are expressed in the development of Xenopus. In contrast to the expression of Pou5f3.1 and Pou5f3.2 in organogenesis, Pou5f3.3 is expressed during oogenesis in ovary. We investigated the expression and function of Pou5f3.3 in organogenesis of Xenopus laevis. RT-PCR and immunohistochemical analysis indicated that Pou5f3.3 was expressed in a small number of adult liver cells and blood cells. Immunocytochemical investigation proved that Bmi1, a marker for hematopoietic progenitor cells, was co-expressed in Pou5f3.3-expressing small spherical cells in the peripheral blood. In anemic induction by intraperitoneal injection of phenyl hydrazine, the number of Pou5f3.3-expressing cells significantly increased within 3 days after phenyl hydrazine injection. In CRISPR/Cas mutagenesis of Pou5f3.3, Bmi1-positive hematopoietic progenitor cell count decreased in the hematopoietic dorsal-lateral plate (DLP) region, resulting in a considerable reduction in peripheral blood cells. CRISPR/Cas-induced hematopoietic deficiency was completely rescued by Pou5f3.3 supplementation, but not by Pou5f3.1 or Pou5f3.2. Transplantation experiments using the H2B-GFP transgenic line demonstrated that DLP-derived Pou5f3.3-positive and Bmi1-positive cells were translocated into the liver and bone through the bloodstream. These results suggest that Pou5f3.3 plays an essential role in the establishment and maintenance of hematopoietic progenitor cells during Xenopus development.

The purpose of this paper is to shed light on the fact that the global solvability for the quadratically perturbed wave equation with small initial data in two space dimension can be shown by using only a restricted set of vector fields associated with the space-time translation and spatial rotations. As a by-product, we establish almost best possible decay estimates related to the above vector fields, as well as the tangential derivatives to the forward light cones.

We study a kind of nonlinear wave equations with damping and potential, whose coefficients are both critical in the sense of the scaling and depend only on the spatial variables. Based on the earlier works, one may think there are two kinds of blow-up phenomenons when the exponent of the nonlinear term is small. It also means there are two kinds of law to determine the critical exponent. In this paper, we obtain a blow-up result and get the estimate of the upper bound of the lifespan in critical and sub-critical cases. All of the results support such a conjecture, although for now, the existence part is still open., Final version, to appear in Nonlinear Anal. Real World Appl. 16 pages,0 figures

We are studying possible interaction of damping coefficients in the subprincipal part of the linear 3D wave equation and their impact on the critical exponent of the corresponding nonlinear Cauchy problem with small initial data. The main new phenomena is that certain relation between these coefficients may cause very strong jump of the critical Strauss exponent in 3D to the critical 5D Strauss exponent for the wave equation without damping coefficients., 16 pages

In this paper we derive a new type of pointwise decay estimates for solutions to the Cauchy problem for the wave equation in 2D, in the sense that one can diminish the weight in the time variable for the forcing term if it is compactly supported in the spatial variables. As an application of the estimate, we also establish an improved decay estimate for the solution to the exterior problem in 2D.

We proposed a liquid immersion cooling technology with natural convection for high power server boards used in data centers with high cooling-efficiency. The cooling performance was evaluated by CFD simulation and actual experiments. As the refrigerants, several non-conductive, thermally and chemically stable fluids were applied, including silicone oil, soybean oil, and perfluorocarbon structured liquids. The CPU temperature in the refrigerant monotonically decreases with the Rayleigh numbers of the refrigerant. The smoother refrigerant is better for cooling the high power CPU. The changes in any CPU task and any slot-removal give limited cooling effects to other slots and other CPUs. These are quite useful features for stable operation of servers in data center. As a result, this proposed technology with natural convection exhibits promising potential for low energy and space-saving board cooling which demonstrates a Power Usage Efficiency (PUE) below 1.04.

In this paper we deal with the exterior problem for a system of nonlinear wave equations in two space dimensions, assuming that the initial data is small and smooth. We establish the same type of lower bound of the lifespan for the problem as that for the Cauchy problem, despite of the weak decay property of the solution in two space dimensions.

The “moth-eye” structure, which is observed on the surface of corneal lens in several insects, supports anti-reflective and self-cleaning functions due to nanoscale protrusions known as corneal nipples. Although the morphology and function of the “moth-eye” structure, are relatively well studied, the mechanism of protrusion formation from cell-secreted substances is unknown. In Drosophila melanogaster, a compound eye consists of approximately 800 facets, the surface of which is formed by the corneal lens with nanoscale protrusions. In the present study, we sought to identify genes involved in “moth-eye” structure, formation in order to elucidate the developmental mechanism of the protrusions in Drosophila. We re-examined the aberrant patterns in classical glossy-eye mutants by scanning electron microscope and classified the aberrant patterns into groups. Next, we screened genes encoding putative structural cuticular proteins and genes involved in cuticular formation using eye specific RNAi silencing methods combined with the Gal4/UAS expression system. We identified 12 of 100 candidate genes, such as cuticular proteins family genes (Cuticular protein 23B and Cuticular protein 49Ah), cuticle secretion-related genes (Syntaxin 1A and Sec61 ββ subunit), ecdysone signaling and biosynthesis-related genes (Ecdysone receptor, Blimp-1, and shroud), and genes involved in cell polarity/cell architecture (Actin 5C, shotgun, armadillo, discs large1, and coracle). Although some of the genes we identified may affect corneal protrusion formation indirectly through general patterning defects in eye formation, these initial findings have encouraged us to more systematically explore the precise mechanisms underlying the formation of nanoscale protrusions in Drosophila.

Embora aspectos econômicos sejam relevantes na decisão de se trabalhar, estes nem sempre são os únicos fatores considerados, tendo em vista que o trabalho não apenas supre necessidades de subsistência, mas também de realização e status. O objetivo deste trabalho foi identificar os aspectos associados ao significado do trabalho na vida das pessoas e caracterizar cada um dos seus componentes em função do perfil do respondente. A partir de uma amostra de 304 profissionais dos setores público e privado, foi elaborado um modelo estrutural que relaciona a centralidade do trabalho, normas sociais e objetivos e resultados advindos do trabalho, que são valorizados pelo indivíduo. Com base em testes de igualdade de média observou-se que mulheres, pessoas com pós-graduação e solteiros possuem maior centralidade; pessoas com maior contato religioso e com menos dependentes possuem maior senso de responsabilidade social. Assim, torna-se possível às organizações traçar estratégias de gestão de pessoas que aumentem o valor do trabalho, percebido pelo indivíduo.

In this paper we deal with the exterior problem for a system of nonlinear wave equations in two space dimensions under some geometric restriction on the obstacle. We prove a global existence result for the problem with small and smooth initial data, provided that the nonlinearity is taken to be cubic and satisfies the null condition.

Memantine, an uncompetitive glutamatergic N-methyl-D-aspartate (NMDA) receptor antagonist, is widely used as medication for the treatment of Alzheimer's disease (AD). It has been reported that memantine reduces amyloid-β peptide (Aβ) levels in both neuronal cultures and in brains of animal models of AD. However, the underlying mechanism of these effects is unclear. Here we examined the effect of memantine on Aβ production. Memantine was administered to 9-month-old Tg2576 mice, a transgenic mouse model of AD, at 10 or 20mg/kg/day in drinking water for 1 month. Memantine significantly reduced the amounts of both CHAPS-soluble and CHAPS-insoluble Aβ in the brains of Tg2576 mice. Memantine at 10mg/kg/day for 1 month also reduced the levels of insoluble Aβ42 in the brains of aged F344 rats. Moreover, memantine reduced Aβ and sAPPβ levels in conditioned media from rat primary cortical cultures without affecting the enzymatic activities of α-secretase, β-secretase, or γ-secretase. Notably, in a cell-surface biotinylation assay, memantine increased the amount of amyloid precursor protein (APP) at the cell surface without changing the total amount of APP. Collectively, our results indicate that chronic treatment with memantine reduces the levels of Aβ both in AD models and in aged animals, and that memantine affects the endocytosis pathway of APP, which is required for β-secretase-mediated cleavage. This leads to a reduction in Aβ production. These results suggest that memantine reduces Aβ production and plaque deposition through the regulation of intracellular trafficking of APP.

We consider an inverse problem of parameter identification for a parabolic equation. The underlying practical example is the reconstruction of the unknown drift in the extended Black–Scholes option pricing model. Using a priori information about the unknown solution (i.e. its Lipschitz constant), we provide a solution to this non-linear ill-posed problem, as well as an error estimate. Other types of a priori information may be used (for example, monotonicity and/or convexity of the unknown solution).

SummaryThe egg jelly ofDiscoglossus pictuscontains sperm motility-activating activity, the molecular basis of which has not been studied.Discoglossus pictussperm initiated motility immediately after immersion in egg-jelly extract, as well as after immersion in hyposmotic solution, which initiates sperm motility in the external fertilization of anuran amphibians. Sequential treatment of theD. pictussperm with these two solutions revealed the predominant effect of hyposmolality in initiation of motility. The motility initiation induced by jelly extract was suppressed by a monoclonal antibody (mAb) that is specific for the 34 kDa sperm motility-initiating substance (SMIS) in the egg jelly of the newt,Cynops pyrrhogaster.Immunoblotting using the anti-SMIS mAb revealed several antigenic proteins that included major ones with sizes of 18- and 34-kDa inD. pictusjelly extract. Scanning electron microscopic observation revealed that granules of jelly matrix, in which SMIS localizes and which have a critical role in the internal fertilization ofC. pyrrhogaster, were not observed near the surface of theD. pictusegg jelly. These results suggest that sperm motility-activating activity in egg jelly ofD. pictusmay be mediated by SMIS homologous proteins that act through a mechanism that is partially different from that ofC. pyrrhogaster.

Essa pesquisa teve como objetivo investigar os fatores associados ao significado do trabalho e os indicadores relevantes no ambiente empresarial de acordo com os funcionarios dos setores publico e privado. A partir de uma amostra de 304 profissionais pertencentes a estes setores, foi elaborado um modelo inicial que nao mostrou resultados estatisticos satisfatorios e foi substituido por um modelo que apresentou melhor qualidade de ajuste aos dados. o estudo revelou que, para a amostra geral e para o setor publico, o significado do trabalho se reflete, na orde, na centralidade do trabalho, objetivos e resultados valorizados e por ultimo, nas normas sociais. Ha uma inversao na segunda e terceira colocacao deste ranking quando se focaliza o setor privado. Com base neste estudo, o conhecimento das componentes do significado do trabalho na vida das pessoas pode contribuir para uma melhor gestao dos recursos humanos no contexto empresarial.

An antibody library against quail sperm plasma membrane components was established and a mAb, which strongly inhibits sperm perforations of the perivitelline membrane (PVM) was obtained from the library. The antigen molecule of the mAb showed an apparent molecular weight of 45 kDa, and was distributed both on the surface and in the acrosomal matrix of the sperm head. Periodate oxidation revealed that the epitope of the antigen includes a sugar moiety. Tandem mass spectrometry analysis of the antigen revealed that the mAb recognizes sperm acrosin. When sodium dodecyl sulfate-solubilized PVM immobilized on a polyvinylidene difluoride membrane was incubated with sperm plasma membrane lysates, the sperm acrosin was detected on the PVM immobilized on the membrane, indicating that the sperm acrosin interacts with the components of PVM. Indeed, the mAb effectively inhibited the binding of acrosome-intact sperm to the PVM. These results indicate that the 45 kDa sperm acrosin is involved in the binding of sperm to the PVM in fertilization of Japanese quail.

Ants are known to use a colony-specific blend of cuticular hydrocarbons (CHCs) as a pheromone to discriminate between nestmates and non-nestmates and the CHCs were sensed in the basiconic type of antennal sensilla (S. basiconica). To investigate the functional design of this type of antennal sensilla, we observed the ultra-structures at 2D and 3D in the Japanese carpenter ant, Camponotus japonicus, using a serial block-face scanning electron microscope (SBF-SEM), and conventional and high-voltage transmission electron microscopes. Based on the serial images of 352 cross sections of SBF-SEM, we reconstructed a 3D model of the sensillum revealing that each S. basiconica houses > 100 unbranched dendritic processes, which extend from the same number of olfactory receptor neurons (ORNs). The dendritic processes had characteristic beaded-structures and formed a twisted bundle within the sensillum. At the “beads,” the cell membranes of the processes were closely adjacent in the interdigitated profiles, suggesting functional interactions via gap junctions (GJs). Immunohistochemistry with anti-innexin (invertebrate GJ protein) antisera revealed positive labeling in the antennae of C. japonicus. Innexin 3, one of the five antennal innexin subtypes, was detected as a dotted signal within the S. basiconica as a sensory organ for nestmate recognition. These morphological results suggest that ORNs form an electrical network via GJs between dendritic processes. We were unable to functionally certify the electric connections in an olfactory sensory unit comprising such multiple ORNs; however, with the aid of simulation of a mathematical model, we examined the putative function of this novel chemosensory information network, which possibly contributes to the distinct discrimination of colony-specific blends of CHCs or other odor detection.

Motility initiation is a key event during internal fertilization of female-stored sperm, although the underlying mechanisms remain unclear. In internally fertilizing urodeles, quiescent sperm initiate motility on the surface of the egg-jelly, a thick extracellular matrix that accumulates around the egg in oviduct. By immunizing mice with egg-jelly extracts, we successfully generated an alpha34 monoclonal antibody (mAb) which neutralized sperm motility-initiating activity in the egg-jelly of the newt, Cynops pyrrhogaster, in a dose-dependent manner. The alpha34 mAb recognized an unglycosylated 34 kDa protein in the outermost of the six layers that comprise egg-jelly. Under nonreducing conditions, immunoblotting with alpha34 mAb produced many bands in addition to the 34 kDa protein, suggesting that the 34 kDa protein associates not only with the jelly matrix itself, but also with additional substances present in the matrix. Our current results are compatible with the supposed features of sperm motility-initiating substance (SMIS), indicating that the 34 kDa protein itself, or a complex consisting of the 34 kDa protein and some other molecules, is the SMIS in C. pyrrhogaster. Immunofluorescence staining further indicated that SMIS was distributed in a dot-like pattern in the outermost jelly layer and was fully covered with acrosome reaction-inducing substance (ARIS). Immunocytochemical and scanning electron microscopic examinations of the outermost jelly layer strongly suggests that the 34 kDa protein localized in granules (2 microns) and that ARIS was distributed covering the granules and in the sheet-like structure above the granules. These data suggest that the initiation of sperm motility is mediated by the acrosome reaction.

In this paper we consider the mixed problem for the wave equation exterior to a non-trapping obstacle in odd space dimensions. We derive a rate of the convergence of the solution for the mixed problem to a solution for the Cauchy problem. As a by-product, we are able to find out the radiation field of solutions to the mixed problem in terms of the scattering data., Comment: 24 pages

Xtr is present exclusively in early embryonic and germline cells. We have previously shown that loss-of-function of the Xtr in embryos causes arrest of karyokinesis progression. Since Xtr contains plural tudor domains, which are known to associate with target proteins directly, we examined Xtr-interacting proteins by immunoprecipitation with an anti-Xtr monoclonal antibody and detected a few RNA-binding proteins such as FRGY2, a component of messenger ribonucleoprotein (mRNP) particle. The coexistence of Xtr with FRGY2 by constituting an mRNP particle was further confirmed by gel filtration assay. Search of mRNAs in the immunoprecipitate with Xtr suggested that the Xtr-associated molecules included several mRNAs, of which translational products were known to play crucial roles in karyokinesis progression (RCC1, XRHAMM, and so on) and in germ cell development (XDead end). Immunohistochemical observation clearly showed the co-localization of Xtr with FRGY2 also in germ plasm, in which XDead end mRNA has been shown to be localized specifically. Taken together, we proposed the possible role of Xtr in translational activation of the maternal mRNAs repressed in mRNP particle.

To identify a molecule involved in sperm-egg plasma membrane binding at fertilization, a monoclonal antibody against a sperm-surface glycoprotein (SGP) was obtained by immunizing mice with a sperm membrane fraction of the frog, Xenopus laevis, followed by screening of the culture supernatants based on their inhibitory activity against fertilization. The fertilization of both jellied and denuded eggs was effectively inhibited by pretreatment of sperm with intact anti-SGP antibody as well as its Fab fragment, indicating that the antibody recognizes a molecule on the sperm's surface that is necessary for fertilization. On Western blots, the anti-SGP antibody recognized large molecules, with molecular masses of 65-150 kDa and minor smaller molecules with masses of 20-28 kDa in the sperm membrane vesicles. SGP was distributed over nearly the entire surface of the sperm, probably as an integral membrane protein in close association with microfilaments. More membrane vesicles containing SGP bound to the surface were found in the animal hemisphere compared with the vegetal hemisphere in unfertilized eggs, but the vesicle-binding was not observed in fertilized eggs. These results indicate that SGP mediates sperm-egg membrane binding and is responsible for the establishment of fertilization in Xenopus.

Our previous studies have shown that the acrosome reaction (AR) occurs in egg-jelly of the Japanese newt, Cynops pyrrhogaster. This is analogous to the substances of echinoderms but distinct from those of many other vertebrates derived from the egg envelope or its derivative, the zona pellucida. To identify the AR-inducing substances in newt egg jelly, a monoclonal antibody (mAb) was generated against the jelly by screening the culture supernatants to find the one that best neutralized the AR-inducing activity of the jelly substance. The mAb specifically reacted to protein bands in the jelly. These proteins, with apparent molecular weights of 122 and 90 kDa, exhibited AR-inducing activity, indicating that they are definitely AR-inducing substances. Western blotting using the mAb indicated that the 122 and 90 kDa proteins are present only in the egg jelly's outermost layer, where AR-inducing activity is known to occur. Both proteins were recognized with wheat germ agglutinin (WGA), a lectin that inhibits AR-induction in egg jelly extract. Taken together, these findings indicate that the 122 and 90 kDa proteins are the AR-inducing substances in the egg jelly of C. pyrrhogaster. The WGA recognition of the proteins was lost by N-glycosidase digestion, suggesting that N-linked carbohydrate moieties in these proteins may be responsible for the AR-inducing activity.

Alkaline hydrolysis of the ether-insoluble resin glycoside (convolvulin) fraction of the roots of Ipomoea operculata (GOMES) MART. (Convolvulaceae) afforded a glycosidic acid named operculinic acid H along with isovaleric, tiglic, and exogonic (3,6:6,9-diepoxydecanoic) acids. Operculinic acid H was characterized to be 3S,12S-dihydroxyhexadecanoic acid 12-O-beta-D-glucopyranosyl-(1--3)-O-alpha-L-rhamnopyranosyl-(1--2)-[O-beta-D-glucopyranosyl-(1--3)]-O-beta-D-glucopyranosyl-(1--2)-[O-alpha-L-rhamnopyranosyl-(1--6)]-O-beta-D-glucopyranoside on the basis of spectroscopic data and chemical evidence. The absolute configuration of exogonic acid determined from the alpha-methoxy-alpha-trifluoromethylphenylacetic acid esters of the hydrogenolysis products revealed that exogonic acid exists as a mixture (ca. 1 : 1) of two epimers, (3S,6S,9R)- and (3S,6R,9R)-diepoxydecanoic acids.

Fertilization is a programmed process that has many molecules and sequential events amenable to study. The biochemistry of fertilization has identified cellular and acellular components fundamental to the interactions between sperm and egg. Recent studies highlight the molecular details of the species-specificity of fertilization that involve protein-protein and protein-carbohydrate interactions. Although the diversity of structure and mechanism may imply rapid evolution of fertilization proteins, understanding the structure-function relationships has become important. Here, we introduce the molecules controlling the sperm AR, sperm attachment to, and penetration through, the egg investments.

Sperm binding to the vitelline envelope in dejellied Xenopus laevis eggs was effectively inhibited by inhibitors for trypsin (soybean trypsin inhibitor and p-toluenesulfonyl-L-lysine chloroethyl ketone) and aminopeptidase B (o-phenanthroline, bestatin, and arphamenine B). Likewise, synthetic 4-methylcoumaryl-7-amide (MCA) substrates (t-butoxycarbonyl-GlyArgArg-MCA, benzyloxycarbonyl-ArgArg-MCA, and Arg-MCA) inhibited binding. Consistently, when jellied eggs were inseminated in the presence of these substrates or inhibitors for proteases, fertilization was effectively blocked. The medium in which live sperm or the sperm membrane fraction were suspended exhibited hydrolyzing activities against the synthetic substrates mentioned above, and these activities were effectively inhibited by the protease inhibitors. Ultracentrifugal fractionation of the sperm suspension following induction of the acrosome reaction by a calcium ionophore, A23187, indicated that a considerable amount of the total tryptic and aminopeptidase B activity was released into the medium. On this occasion, part of the tryptic and aminopeptidase B activity was definitely estimated to be discharged in association with a vesiculated membrane, supporting the notion that the proteases involved in binding to the vitelline envelope are present on the sperm plasma membrane.

We consider the Cauchy problem for a class of systems of semilinear wave equations, which is closely connected to the weak null condition and Alinhac's condition. We show that the energy of some global solutions to these systems grows to infinity as time tends to infinity and consequently these solutions never approach any free solutions.

The acrosome reaction of Xenopus sperm is triggered by the acrosome reaction-inducing substance in Xenopus (ARISX), an oviductal pars recta-derived, sugar-rich substance decorated on the entire surface of the vitelline envelope (VE) during ovulation. Here we addressed the functional importance of the sugar moiety in ARISX. Among various lectins examined, soybean agglutinin and Dolichos biflorus agglutinin were shown to abolish the acrosome reaction-inducing activity of ARISX present in pars recta extract or on the VE, indicating the importance of the terminal α-N-acetylgalactosamine residue for the function of ARISX. Consistently, the acrosome reaction-inducing activity was not affected by proteinase K digestion, in spite of the simultaneous shift of ARISX to a smaller molecular weight. Indirect immunofluorescence microscopic examinations showed that ARISX was distributed as two types of structures on VE; thick fiber-like materials and thin filamentous materials, and that a new structure appeared on the fertilization envelope instead of the thin filamentous materials. Sperm from several amphibian species were subjected to an in vitro assay during induction of the acrosome reaction with ARISX. The resulting limited population of sperm from a non-Xenopus species underwent acrosome reaction, implying a weak species-specificity of ARISX.

RANDAM-2, a type-I transmembrane antigen constitutively expressed on the neuronal cell lineage during mouse neurogenesis, shows the highest expression level between embryonic day 8.5 (E8.5) and E10.5. As the period well overlaps with the proliferating stages of neural stem cells (NSCs), it is conceivable that NSCs are efficiently separable based on the expression level of RANDAM-2. In this paper, we show that NSCs can be efficiently enriched as RANDAM-2 high+ cells by fluorescence-activated cell sorting. Many cells in the RANDAM-2 high+ cells had the characteristics of the self-renewal capability and potential for multilineage differentiation into neural cells. In contrast, almost all of the RANDAM-2 low+/− cells exhibited not only the extremely low self-renewability but the differentiation capability restricted to neurons. These two subpopulations also differed from each other in terms of the expression level of molecules associated with neural differentiation. These findings demonstrate that RANDAM-2 can be regarded as a useful marker for enrichment of NSCs. © 2006 Elsevier Ireland Ltd. All rights reserved.

O trabalho tem sido visto não somente como forma de obter a renda, mas como atividade que proporciona realização pessoal, status social e a possibilidade de estabelecer e manter contatos interpessoais, entre outros. Essa pesquisa teve como objetivo investigar os fatores que influenciam e conferem sentido ao trabalho, tais como: - centralidade do trabalho, onde se procurou investigar o grau de importância do trabalho dentro do contexto das diversas áreas da vida das pessoas tais como família, lazer, religião e vida comunitária; - normas da sociedade tanto como fornecedora de condições como cobradora de atitudes; - objetivos e resultados valorizados, refletindo o que se busca com o trabalho. Adicionalmente, verificaram-se os diferentes significados do trabalho em função das características dos respondentes, em especial considerando os trabalhadores do setor público e de outros setores. A partir da pesquisa na literatura, foi elaborado um modelo inicial que, não se mostrando satisfatório à luz da amostra colhida, foi substituído por um outro, entre quatro analisados. O modelo escolhido foi o que melhor goodness of fit apresentou, utilizando-se modelagem de equações estruturais pelo método partial least square. Identificou-se, entre outros resultados, que o significado do trabalho se reflete, na ordem, na centralidade do trabalho, objetivos e resultados valorizados e por último, nas normas sociais. Analisando-se as diferenças entre a sub-amostra do setor público e a de outros setores, concluiu-se que os respondentes do setor público vêem o trabalho também como sentido da vida, valorizam que a tarefa seja adequada à capacidade e que tenha variedade. Os respondentes de outros setores, por sua vez, valorizam um bom ambiente físico, um bom relacionamento interpessoal, o trabalho interessante e um bom salário. Para complementar a pesquisa, foram utilizadas outras técnicas de análises, tais como regressão logística, comparação de médias e análise fatorial exploratória. Quanto à centralidade no trabalho, apresentaram maiores valores: as mulheres, os solteiros e os de maior escolaridade. Se for considerada a influência das normas sociais orientadas a deveres, apresentaram maiores valores: as mulheres, os solteiros, os religiosos, os com menos dependentes e os mais satisfeitos com a vida. Quanto ao índice de significado do trabalho, as mulheres se destacaram, apresentando maiores valores. Work has been seen not only as a means of obtaining income, but as an activity that promotes personal achievement, social status and the possibility of establishing and maintaining interpersonal contacts, among other factors. This research aimed to investigate the factors that influence and give meaning to work such as: - work centrality, which aimed to investigate the degree of the importance of work within the context of different areas of people\'s lives, such as family, leisure, religion and life in community; - social norms, both as a supplier of conditions such as a collector of attitudes; - valued objectives and results, reflecting what one aspires to by working. Additionally it sought to identify different meanings depending on the respondents´ characteristics, especially considering workers from public and other sectors. Based in the literature, an initial model was developed, which did not prove satisfactory in light of the sample. The initial model was then replaced by another, from among four models examined. The chosen model presented the best goodnessof- fit under the structural equation modeling using partial least square method. It was found, among other results, that the meaning of work reflects, by order, on the centrality of work, on valued objectives and results and finally, on social norms. Analyzing the differences between the public sector´s sub-sample and that of other sectors, it was concluded that the respondents in the public sector see work as a meaning for life, value the appropriateness of the tasks to their capacity and the variety of tasks. The respondents of other sectors, in turn, place a higher value on a proper working environment, good interpersonal relationships, the attractiveness of tasks and good remuneration. To complement the research, other techniques were used, such as logistic regression, comparison of means and exploratory factor analysis. With regard to work centrality, women have higher values than men, as do singles and those with higher education. If considering the influence of duty-oriented social norms, higher values were found for: women, singles, religious individuals, those with less dependents and those more satisfied with life. For the meaning of work, women stood out by showing higher values.

We describe the design, syntheses, and structure-activity relationships of novel zwitterionic compounds as nonthiazolidinedion-based peroxisome proliferator-activated receptor (PPAR) α/γ dual agonists. In our previous report, we obtained compound 1 showing potent PPARα/γ dual agonistic activities, together with a sufficient glucose-lowering effect in db/db mice. However, this compound possessed an issue, i.e., the 1,3,4-oxadiazole ring was not stable in acidic conditions. Thus, we carried out further optimization to improve the stability while maintaining the other favorable profile features including potent PPARα/γ dual agonistic activity. We addressed the issue by changing the oxadiazole ring to a bioisostere amide group. These amide derivatives were stable in acidic conditions and decreased plasma glucose and plasma triglyceride levels significantly without marked weight gain.

The aim of this note is to give an overview concerning the mixed problem for a system of nonlinear wave equations with small and smooth initial data. In particular, we are interested in the three and two space dimensional case.

This paper is concerned with a class of semilinear hyperbolic systems in odd space dimensions. Our main aim is to prove the existence of a small amplitude solution which is asymptotic to the free solution as t → −∞ in the energy norm, and to show it has a free profile as t → +∞. Our approach is based on the work of [11]. Namely we use a weighted L ∞ norm to get suitable a priori estimates. This can be done by restricting our attention to radially symmetric solutions. Corresponding initial value problem is also considered in an analogous framework. Besides, we give an extended result of [14] for three space dimensional case in Section 5, which is prepared independently of the other parts of the paper.

This paper is concerned with the initial value problem for semilinear systems of wave equations. First we show a global existence result for small amplitude solutions to the systems. Then we study asymptotic behavior of the global solution. We underline that ``modified'' free profiles are obtained for all global solutions to the systems even in the case where the free profile might not exist. Moreover, we prove non–existence of any free profiles for the global solution in some cases where the effect of the nonlinearity is strong enough.

This note deals with the initial value problem for a nonlinear system of wave equations. First we show the global existence of small amplitude solutions to the system. Then we study large-time behavior of the global solutions. In some cases we find different behavior of the solution from the free solution. Such a behavior is characterized as a solution to a certain inhomogeneous wave equations.

In this paper we study coupled systems of semilinear wave equations and derive sharp conditions for the small data global existence and blowup for the system. The way of the interaction in the nonlinearities plays an important role to determine the condition. We focus on the case where propagation speeds also come into play. The discrepancy of the speeds is actually essential in Theorem 3.1 for instance. Moreover, in some cases we have different conclusion for the same nonlinearity according to the order of them. To handle such cases, we modify the argument presented by F. John [12].

In the course of evolution, the vomeronasal organ (VNO) first appeared in amphibians. To understand the relationship between the VNO and the vomeronasal receptors, we isolated and analyzed the expression of the vomeronasal receptor genes of Xenopus laevis. We identified genes of the Xenopus V2R receptor family, which are predominantly expressed throughout the sensory epithelium of the VNO. The G-protein Go, which is coexpressed with V2Rs in the rodent VNO, was also extensively expressed throughout the vomeronasal sensory epithelium. These results strongly suggest that the V2Rs and Go are coexpressed in the vomeronasal receptor cells. The predominant expression of the Xenopus V2R families and the coexpression of the V2Rs and Go imply that V2Rs play important roles in the sensory transduction of Xenopus VNO. We found that these receptors were expressed not only in the VNO, but also in the posterolateral epithelial area of the principal cavity (PLPC). Electron microscopic study revealed that the epithelium of the PLPC is more like that of the VNO than that of the principal and the middle cavity. These results suggest that in adult Xenopus the V2Rs analyzed so far are predominantly expressed in the vomeronasal and vomeronasal-like epithelium. The analysis of V2R expression in Xenopus larvae demonstrates that V2Rs are predominantly expressed in the VNO even before metamorphosis. J. Comp. Neurol. 472:246–256, 2004. © 2004 Wiley-Liss, Inc.

We previously demonstrated that Xenopus sperm undergo an acrosome reaction on the vitelline envelope (VE) in response to the materials secreted from the oviductal pars recta [Dev. Biol. 243 (2002), 55]. A monoclonal antibody against the acrosome reaction-inducing substance in Xenopus (ARISX) was obtained by immunizing mice with pars recta extract (PRE). The acrosome reaction by PRE or on the VE was effectively inhibited by the intact anti-ARISX antibody as well as its Fab fragment, indicating that the antibody recognizes the epitopes localized on the acrosome reaction-inducing substance. On Western blots, the anti-ARISX antibody recognized a molecule with an apparent molecular mass of 300 kDa in PRE and in the VE, but this molecule was not detected in the coelomic envelope. The amount of ARISX in PRE was increased by the treatment of females with pregnant mare serum gonadotropin. Periodate oxidation of PRE completely abolished the acrosome reaction-inducing activity, indicating the involvement of the carbohydrate moieties of ARISX in inducing the acrosome reaction. On immunofluorescence observation, ARISX was localized in the epithelial cells in the posterior region of the pars recta and on the VE as fibrous structures.