271 research outputs found
Genome size evaluations in cockroaches: new entries
No full textIn this paper, we report genome size (GS) values for nine cockroaches (order Blattodea, families Blattidae, Blaberidae and Ectobiidae, ex Blattelidae,), three of which are original additions to the ten already present in the GS database: the death’s head roach (Blaberus craniifer), the Surinam cockroach (Pycnoscelus surinamensis) and the Madeira cockroach (Leucophaea maderae). Regarding the American cockroach (Periplaneta americana), the GS database contains two contrasting values (2.72 vs 3.41 pg); likely, the 2.72 pg value is the correct one as it is strikingly similar to our sperm DNA content evaluation (2.80 ± 0.11 pg). Also, we suggest halving the published GS of the Argentine cockroach Blaptica dubia and the spotted cockroach (the gray cockroach) Nauphoeta cinerea discussing (i) the occurrence of a correlation between increasing 2N chromosome number and GS within the order Blattodea; and (ii) the possible occurrence of a polyploidization phenomenon doubling a basic GS of 0.58 pg of some termite families (superfamily Blattoidea, epifamily Termitoidae)
Cytoplasmic lattices are not linked to mouse 2-cell embryos developmental arrest
No full textCytoplasmic lattices are important regulators of oocyte maturation. They store components of the protein synthesis machinery including ribosomes and, among others, they are involved in the regulation of microtubule dynamics in both mouse and human. Cytoplasmic lattices undergo dramatic reorganizations at crucial stages of oocyte maturation, where they are abundantly present in the cytoplasm of developmentally competent oocytes named SN (Surrounded Nucleolus) while they are rare in the cytoplasm of 2-cell stage-arresting NSN (Not Surrounded Nucleolus) oocytes, suggestive of a requirement of cytoplasmic lattices for development past the 2-cell stage. Here, to elucidate this requirement, 2-cell mouse embryos derived from SN and NSN oocytes were analyzed by transmission electron microscopy. Contrary to what had been proposed hitherto, cytoplasmic lattices are present in 2-cell embryos derived not only from SN, but also from NSN oocytes, irrespective of the embryo production system (intra cytoplasmic sperm injection, parthenogenesis). Hence our conclusion that cytoplasmic lattices do not count among the factor(s) responsible for the embryo arrest at this crucial stage of development
Artificial intelligence selection of viable oocytes from phase contrast images for in vitro maturation and fertilization
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Francisci Redi patricii Aretini, Opusculorum pars prior, sive, Experimenta circa generationem insectorum : accedit J. Frid. Lachmund, De ave diomedea dissertatio.
No full textIncludes indexes.Paging, v. 1: [12], 216, [20], 40, [8] p. (last 2 blank), [45] leaves of plates (19 folded); v. 2: [8], 312, [32] p., [12] leaves of plates (10 folded).Getty copy lacks M12, v. 1 (blank).Signatures, v. 1: *⁶ A-I¹² K¹⁰ L-M¹². Vol. 2: pi⁴ A-O¹² P⁴.Frontispiece of v. 1 signed by Romeyn de Hooghe and dated 1670. That of v. 2 signed by Cornelis Decker. Some in-text engravings in addition to plates. Woodcut device on both t.p.'s.Edition statement from p. [12] of 1st sequence, v. 1. Previously published Amsterdam, 1671. Esperienze intorno alla generazione degli insetti first published Florence, 1668.T.p. of v. 1 has date 1686, that of v. 2 has 1685. Title on t.p., v. 2: Francisci Redi nobilis Aretini Experimenta circa varias res naturales, speciatim illas quae ex Indiis afferuntur."Elenchus authorum, quo hoc tractatu citantur vel illustrantur"--K1r-K3v, v. 1.v. 1. Experimenta circa generationem insectorum. Accedit appendicis loco: J.F. Lachmund De ave diomedea dissertatio. -- v. 2. Experimenta circa varias res naturales, speciatim illas quae ex Indiis afferuntur -- Observationes de viperis -- Epistola de quibusdam objectionibus contra suas de viperis observationes -- Observationes circa illas guttulas & fila ex vitro, quae rupta in quaecunque sui parte, dissiliunt & comminuuntur.Mode of access: Internet.Gift inscription on front pastedown to the botanist MichelAngiolo Tilli, dated 1726. Gift inscription of William Holmes to Alexander John.(?) Smith on front free endpaper. Signature of J.S. Albrecht on both t.p.'s; that on t.p. of v. 1 lined out in favor of "Etlinger." Ownership inscription of Lisa & Leonard Baskin on back pastedown, with Baskin's initial L written before signature letter B of 1st sequence, and with his printed labels for Fort Hill and Lurley Manor on front pastedown.Bound in 1 vol. in vellum. Author & title written at head of spine. Edges red
Harnessing high altitude solar power
No full textAs an intermediate solution between Glaser's satellite solar power (SSP) and ground-based photovoltaic (PV) panels, this paper examines the collection of solar energy using a high-altitude aerostatic platform. A procedure to calculate the irradiance in the medium/high troposphere, based on experimental data, is described. The results show that here a PV system could collect about four to six times the energy collected by a typical U.K.-based ground installation, and between one-third and half of the total energy the same system would collect if supported by a geostationary satellite (SSP). The concept of the aerostat for solar power generation is then briefly described together with the equations that link its main engineering parameters/variables. A preliminary sizing of a facility stationed at 6 km altitude and its costing, based on realistic values of the input engineering parameters, is then presented
Adult stem cells - Biology and methods of analysis
No full textI do not like the use of the term adult referred to the somatic stem cells but it is now-a-days impossible to call the cells we are speaking of somatic, it sounds like an incongruous aristocratic attitude, since both laypeople and scientists know very well that we are speaking of those cells able to self renew and to maintain our body efficiently working. Nowadays we find out adult stem cells in every organ we look at and the present day efforts in this area are mainly devoted to work it out new methods to validate the true stemness nature of the cell line we are able to establish. Thus, the three parts that makes up this volume, the first dealing with the basic biology, the second with the characterization of the adult stem cells phenotype and the third with the regulation of the life span of these cells, are all targeted to the critical evaluation of the techniques we use to distinguish adult stem cell-renewal from cell survival. These techniques are mainly focused on the quantification of the replicative life span, the adult stem cell capacity to grow at clonal density, to express pluripotency-related genes ....
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