622 research outputs found
Constituent Groups of Clifford Semigroups Arising from t-Closure
The t-class semigroup of an integral domain R, denoted S_t(R), is the
semigroup of fractional t-ideals modulo its subsemigroup of nonzero principal
ideals with the operation induced by ideal t-multiplication. We recently proved
that if R is a Krull-type domain, then S_t(R) is a Clifford semigroup. This
paper aims to describe the idempotents of S_t(R) and the structure of their
associated groups. We extend and recover well-known results on class semigroups
of valuation domains and Prufer domains of finite character.Comment: 13 pages. To appear in Journal of Algebr
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Perinatal aspects on the covid-19 pandemic: a practical resource for perinatal-neonatal specialists.
BackgroundLittle is known about the perinatal aspects of COVID-19.ObjectiveTo summarize available evidence and provide perinatologists/neonatologists with tools for managing their patients.MethodsAnalysis of available literature on COVID-19 using Medline and Google scholar.ResultsFrom scant data: vertical transmission from maternal infection during the third trimester probably does not occur or likely it occurs very rarely. Consequences of COVID-19 infection among women during early pregnancy remain unknown. We cannot conclude if pregnancy is a risk factor for more severe disease in women with COVID-19. Little is known about disease severity in neonates, and from very few samples, the presence of SARS-CoV-2 has not been documented in human milk. Links to websites of organizations with updated COVID-19 information are provided. Infographics summarize an approach to the pregnant woman or neonate with suspected or confirmed COVID-19.ConclusionsAs the pandemic continues, more data will be available that could lead to changes in current knowledge and recommendations
Condensed And Strongly Condensed Domains
This paper deals with the concepts of condensed and strongly condensed domains. By definition, an integral domain R is condensed (resp. strongly condensed) if each pair of ideals I and J of R, IJ = {ab/a is an element of I, b is an element of J} (resp. IJ = aJ for some a is an element of I or IJ = Ib for some b is an element of J). More precisely,we investigate the ideal theory of condensed and strongly condensed domains in Noetherian-like settings, especially Mori and strong Mori domains and the transfer of these concepts to pullbacks
Some larval morphological characteristics of Camelostrongylus mentulatus and Nematodirus spathiger
Monitoring of gastrointestinal nematode parasites in ruminants (domestic and wild) is often based on fecal examination techniques, looking for excreted eggs and larval forms using morphological keys. These, are more available in domestic ruminants, in which helminths are widely studied, than in wild ruminants. This study tried to provide certain morphological elements that will help to recognize the L3 larvae of Camelostrongylus mentulatus and Nematodirus spathiger that could parasite either domestic or wild ruminants. For that, we resorted first to the culture of L3 larvae from fecal samples taken from African antelopes, and second by the microscopic characterization of each isolated larval morphological pattern previously identified by sequencing of its internal transcribed spacer (ITS-2) regions of the ribosomal DNA. The results of different microscopic captured images showed that Camelostrongylus mentulatus larva is 16 intestinal cells that measuring approximately 820 µm length, ‎≈ 25 µm wide, and ‎≈ 47 µm for its sheath tail extension and by this be closer to Teladorsagia circumcincta characteristics. For Nematodirus spathiger, it possesses 8 gut cells and measuring about 1020 µm long, ‎≈ 25 µm wide, and‎ ≈ 143 µm for its sheath tail extension with specific tail appendages. Have done this, we were able to get some clarifications on the morphology of the studied larvae, and we believe thus that this study will contribute to the establishment of morphological identification keys especially for parasitic nematodes of wild ruminants
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