We consider the steady Navier-Stokes equations in a 2-dimensional unbounded multiply connected domain Ω under the general outflow condition. Let T be a 2-dimensional straight channel R × (−1, 1). We suppose that Ω ∩ {x1 < 0} is bounded and that Ω ∩ {x1 > −1} = T ∩ {x1 > −1}. Let V be a Poiseuille flow in T and µ the flux of V . We look for a solution which tends to V as x1 → ∞. Assuming that the domain and the boundary data are symmetric with respect to the x1-axis, and that the axis intersects every component of the boundary, we have shown the existence of solutions if the flux is small (Morimoto-Fujita [8]). Some improvement will be reported in this note. We also show certain regularity and asymptotic properties of the solutions.
Let $L(H)$ denote the algebra of all bounded linear operators on a separable infinite dimensional complex Hilbert space $H$ into itself. Given $A\in L(H)$, we define the elementary operator $\Delta _A\colon L(H)\longrightarrow L(H)$ by $\Delta _A(X)=AXA-X$. In this paper we study the class of operators $A\in L(H)$ which have the following property: $ATA=T$ implies $AT^{\ast }A=T^{\ast }$ for all trace class operators $T\in C_1(H)$. Such operators are termed generalized quasi-adjoints. The main result is the equivalence between this character and the fact that the ultraweak closure of the range of $\Delta _A$ is closed under taking adjoints. We give a characterization and some basic results concerning generalized quasi-adjoints operators.
In the paper a new proof of Lemma 11 in the above-mentioned paper is given. Its original proof was based on Theorem 3 which has been shown to be incorrect.
In 2000, Figallo and Sanza introduced n × m-valued Lukasiewicz-Moisil algebras which are both particular cases of matrix Lukasiewicz algebras and a generalization of n-valued Lukasiewicz-Moisil algebras. Here we initiate an investigation into the class tLMn×m of tense n × m-valued Lukasiewicz-Moisil algebras (or tense LMn×m-algebras), namely n×m-valued Lukasiewicz-Moisil algebras endowed with two unary operations called tense operators. These algebras constitute a generalization of tense Lukasiewicz-Moisil algebras (or tense LMn-algebras). Our most important result is a representation theorem for tense LMn×m-algebras. Also, as a corollary of this theorem, we obtain the representation theorem given by Georgescu and Diaconescu in 2007, for tense LMn-algebras.
This paper deals with Japan and Vietnam in the latter half of the 19th century. when China as a large country abundant both in treasure, trade and industrial opportunities, found itself in the centre of Western Powers´ interests which made them more involved in the Far East. The objective of the paper is to analyze the main factors which determined the way Japan and Vietnam faced up to Western encroachment, and to explain why Vietnam became a part of French Indochina and why Japan came into power. Namely, it points out the different situations and conditions of Japan and Vietnam before their openings to the Western World, and thereby clarifies the rwo countries´ positions within international relations in the Far East. Additionally, it brings up some differences in Japan´s and Vietnam´s domestic situations in order to document their readiness to meet external challenges.
For a multivalued map ϕ: Y ⊸ (X, τ ) between topological spaces, the upper semifinite topology A(τ ) on the power set A(X) = {A ⊂ X : A ≠ ∅} is such that ϕ is upper semicontinuous if and only if it is continuous when viewed as a singlevalued map ϕ: Y → (A(X), A(τ )). In this paper, we seek a result like this from a reverse viewpoint, namely, given a set X and a topology Γ on A(X), we consider a natural topology R(Γ) on X, constructed from Γ satisfying R(Γ) = τ if Γ = A(τ ), and we give necessary and sufficient conditions to the upper semicontinuity of a multivalued map ϕ: Y ⊸ (X, R(Γ)) to be equivalent to the continuity of the singlevalued map ϕ: Y → (A(X), Γ).
Dendromonocotyle species (Monogenea: Monocotylidae) are the only monocotylids to parasitize the skin of chondrichthyan hosts. Currently 11 species are recorded from the skin of ray species in the Dasyatidae, Myliobatidae and Urolophidae. There have been increasing reports of Dendromonocotyle outbreaks on rays kept in public aquaria. This paper provides a broad review of Dendromonocotyle that should assist taxonomists and aquarists with species identification and help decisions on potential control methods for Dendromonocotyle infections. The taxonomy and host-specificity of Dendromonocotyle are discussed and a key to current species is provided. We summarise what little is known about the biology of Dendromonocotyle including egg embryonation and hatching, feeding, camouflage and reproduction. The efficacy of freshwater baths, chemical treatments and biological control measures such as the use of cleaner fish for Dendromonocotyle is also discussed. We demonstrate that effective control of Dendromonocotyle on captive rays is hampered by the lack of basic biological data on the life cycle of the parasites. A case history is provided outlining the success of a public aquarium (Underwater World, Mooloolaba, Queensland, Australia) in managing D. pipinna infections on captive Taeniura meyeni without chemical intervention simply by taking measures to reduce host stress.
A fauna of quill mites of the subfamily Picobiinae (Acari: Syringophilidae) associated with African birds is revised. Two new monotypic genera are proposed, Gunabopicobia gen. n. for Picobia zumpti Lawrence, 1959 and Lawrencipicobia gen. n. for Picobia poicephali Skoracki et Dabert, 2002. These new genera differ from other genera of the subfamily by the following features: in females of Gunabopicobia, propodonotal setae vi are situated anterior to the level of setae ve; the narrow lateral propodonotal shields bear bases of setae vi, ve, si and se; the bases of setae 1a-1a are coalesced; the genital setae and the opisthosomal lobes are absent; the leg I with full set of solenidia and apodemes I are devoid of the thorn-like protuberances in the middle part. In females of Lawrencipicobia, the bases of setae 1a-1a are not coalesced; the propodonotal shield is entire; the genital setae are present; legs I are with full set of solenidia. Additionally, two new species belonging to Picobia Haller, 1878 are described, Picobia illadopsae sp. n. parasitising Illadopsis rufipennis (Sharpe) (Passeriformes: Pellorneidae) in Kenya and Picobia phoenicuri sp. n. infecting Phoenicurus moussieri (Olphe-Galliard) in Tunisia. The following species are redescribed, Columbiphilus alectoris (Fain, Bochkov et Mironov, 2000), Lawrencipicobia poicephali (Skoracki et Dabert, 2001) comb. n. and Picobia phoeniculi (Fain, Bochkov et Mironov, 2000). The key to the genera of the Picobiinae is provided.
In the present study, we review the known zoogonid cercariae, summarise their life-cycles and first intermediate host distributions, and present a new cercaria, Cercaria capricornia XI (Digenea: Zoogonidae), which was found in one of three nassariid gastropods, Nassarius olivaceus (Bruguière), surveyed in the intertidal zone in the Capricornia region of Central Queensland, Australia. Morphological data and molecular analysis of the ITS2 rDNA region support placement of this cercaria in the family Zoogonidae but do not allow any further resolution of its identity. There are now fifteen cercariae described as belonging to the Zoogonidae; thirteen of these, including the present species, infect neogastropods as first intermediate hosts and two use vetigastropods. This study reinforces the pattern that the Nassariidae is by far the most commonly reported family for the Zoogonidae. Given its richness we predict that the Nassariidae will prove to harbour many more zoogonid species.