255,281 research outputs found
Does the Mass Balance of the Reactive Tracers Resazurin and Resorufin Close at the Microbial Scale?
No full textResazurin (Raz) is a phenoxazine dye that can be reduced irreversibly to the daughter compound resorufin (Rru) by aerobic respiration. Previous hydrologic studies using the Raz-Rru reactive tracer system to quantify water-sediment interactions and metabolic activity have reported that dilution-corrected masses of Raz and Rru recovered are smaller than the mass of Raz injected. This lack of mass balance closure has been reported as a nonideality of this tracer system and, to date, it is still unclear what drives incomplete recovery. We used controlled laboratory experiments varying the initial concentrations of Raz, the duration of the experiments, and the type of microbial communities present to quantify mass balances of Raz and Rru under conditions that removed other suspected causes of incomplete recovery in field experiments, i.e., sorption to sediments and photodecay. We used the summation of Raz and Rru concentrations over time to assess mass recovery and variability and found mass recoveries in the range of 85.6–110.4%, with a maximum standard deviation of 7.5%. In three of the four experiments, no strong temporal trend in mass recovery is present. In an experiment with Bacillus subtilis bacteria, lower recovery and evidence of a temporal trend in recovery only occurred after 13 hr past the complete transformation of Raz (i.e., beyond the duration of most field experiments). These results suggest that the lack of mass recovery in field studies is likely associated with physical or chemical mechanisms rather than biological interactions with the Raz-Rru tracer system
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[Letter from Pedro J. Gonzalez to J. Crúz Navarro R.]
No full textLetter from Pedro J. Gonzalez to J. Crúz Navarro R. On the front of the page, a long title is printed above small lines of text that are positioned above a wide column of text printed and a narrower text column. The word "copy" is handwritten in the page's top right corner. The wider text column continues onto the back of the page and ends above a signature, below which are a few additional lines of text
[Letter from M. R. Gonzalez to John J. Herrera - January 18, 1949]
No full textLetter from M. R. Gonzalez of Fort Stockton, Texas to John J. Herrera, Regional LULAC Governor, dated January 18, 1949. This is a request for a hotel reservation for the Regional LULAC Convention
[Letter from Alex R. Gonzalez to John J. Herrera - August 26, 1963]
No full textLetter from Alex R. Gonzalez to John J. Herrera, dated August 26, 1963, and typed on County of Pecos letterhead. The letter refers to their recent meeting at the convention and that the requested card samples are enclosed
Gonzalez, R.
No full textCentro Asturiano membership record of R. Gonzalez; Socio Number: 91380.https://digitalcommons.usf.edu/asturiano_membership/3339/thumbnail.jp
Gonzalez, Juan R.
No full textCentro Asturiano membership record of Juan R. Gonzalez; Socio Number: 134326.https://digitalcommons.usf.edu/asturiano_membership/3389/thumbnail.jp
Rumer's transformation: A symmetry puzzle standing for half a century
No full textIn 1966, only a few months after the complete elucidation of the standard nuclear genetic code (Kay, 2000), the Russian theoretical physicist Yury Borisovich Rumer uncovered the existence of a particular symmetry (Rumer, 1966): when the keto-amino transformation (also known as Rumer's transformation) is applied to the bases of a codon then the degeneracy of the transformed codon was changed. In particular, if the amino acid associated to the starting codon has degeneracy 4, then the amino acid associated to the transformed codon has degeneracy 1, 2 or 3 (and vice versa). After half a century from this discovery and despite the universality of Rumer's symmetry, little is known about its origin and its possible biological significance. In this article we show that Rumer's symmetry could have originated in an ancestral version of the genetic code, i.e., the pre-early code, and is a natural consequence of the stereo-chemical symmetries of the ancestral synthesis machinery working around such code (Gonzalez et al., 2019). Moreover, the conservation of Rumer's symmetry through evolutionary periods suggests a connection with key biological features. In this respect, intriguing possibilities include those of error detection/correction, control over the synthesis of proteins, and frame maintenance. To a certain extent, such ideas have been explored in the framework of a mathematical model of the genetic code (the non-power model of the genetic code (Gonzalez, 2004; Gonzalez, 2008; Gonzalez et al., 2016), whose definition of dichotomic classes naturally includes Rumer's symmetry (Gonzalez, 2008; Gonzalez et al., 2006, 2008) and the theory of circular codes (Arquès and Michel, 1996; Gonzalez et al., 2011; Fimmel et al., 2015)
Figs 6-10 in The larva of Lestes alfonsoi Gonzalez & Novelo (Zygoptera: Lestidae)
No full textFigs 6-10. Lestes alfonsoi details of the larval morphology: (6) left lateral margin of abdominal segments 5-10, ventral view; — (7) male gonapophyses: (a) ventral view, (b) left lateral view; — (8) female gonapophyses: (a) left lateral view of abdominal segments 8-10 [Ce: cercus; Ep: epiproct; Dv: dorsal valvae; Lv: lateral valvae; Pp; paraproct; Vv: ventral valvae], (b) valvae, ventral view; — (9) male cercus, left lateral view; — (10) caudal appendages: (a) left paraproct, lateral view, (b) epiproct, left lateral view.Published as part of R. Novelo-Gutierrez & Gonzalez-Soriano, 2003, The larva of Lestes alfonsoi Gonzalez & Novelo (Zygoptera: Lestidae), pp. 289-294 in Odonatologica 32 (3) on page 292, DOI: 10.5281/zenodo.337330
Marriage record of Gonzalez, Narciso and Archer, Maud R.
No full textMarriage license for Narciso Gonzalez and Maud R. Archer
On the origin of the mitochondrial genetic code: Towards a unified mathematical framework for the management of genetic information
No full textThe origin of the genetic code represents one of the most challenging problems in molecular evolution. The genetic code is an important universal feature of extant organisms and indicates a common ancestry of different forms of life on earth. Known variants of the genetic code can be mainly divided in mitochondrial and nuclear classes. Here we provide a new insight on the origin of the mitochondrial genetic code: we found that its degeneracy distribution can be explained by using a mathematical approach recently developed for the description of the Euplotes nuclear variant of the genetic code. The results point to a primeval mitochondrial genetic code composed of four base codons, which we call tesserae, that, among other features, exhibit outstanding error detection capabilities. The theoretical description suggests also a formulation of a plausible biological theory about the origin of protein coding. Such theory is based on the symmetry properties of hypothetical primeval chemical adaptors between nucleic acids and amino acids (ancient tRNA’s). Our paper provides a unified mathematical framework for different hypotheses on the origin of genetic coding. Also, it contributes to revisit our present view about the evolutionary steps that led to extant genetic codes by giving a new first-principles perspective on the difficult problem of the origin of the genetic code, and consequently, on the origin of life on earth
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