Papers by Humberto González
Determinations of CO2 efflux, soil temperature and soil water content were monitored between July... more Determinations of CO2 efflux, soil temperature and soil water content were monitored between July 3, 2001 and January 29, 2002. At each sampling date, two daily measurements (at 08:00 and 14:00 h local time, named as morning and afternoon, respectively) were carried out. A dynamic closed chamber with a portable system EGM employing a infrared gas analyzer (IRGA) and a soil chamber (SRC-1) was used to assess soil CO2 efflux throughout the experimental period in vertisols under different land uses in northeastern Mexico: Pasture (Dichanthium annulatum), Leucaena leucocephala in an alley cropping system, a native and undisturbed shrubland plot, Eucalyptus microtheca plantation, and a Sorghum bicolor field. During the studied period, average morning soil respiration rates for all land uses ranged from 0.7 to 8.4 µmol CO2 m -2 s -1 (in Oct. and y Aug., respectively), while afternoon soil respiration rates ranged from 0.6 to 14.4 µmol CO2 m -2 s -1 throughout the experiment. Average morni...
Biotecnología Aplicada, 2013
Streptococcus pneumoniae causes annually 826 000 deaths in children under fi ve years. The seroty... more Streptococcus pneumoniae causes annually 826 000 deaths in children under fi ve years. The serotype 6B, one of higher incidence, is targeted by the Cuban research and development project to develop a conjugate vaccine. There is limited data on how modifi cations caused by conjugation affect the physicochemical and antigenic characteristics of polysaccharides, particularly for serotype 6B capsular polysaccharide (PS6B), despite being the least immunogenic among S. pneumoniae polysaccharides. In this work, a conjugation procedure was established for PS6B comprising: fragmentation by acid hydrolysis, activation by periodate oxidation, and conjugation to tetanus toxoid (TT) by reduc- tive amination to increase its immunogenicity. Reaction conditions were set to obtain the polysaccharide in three molecular size ranges (1-10, 10-30, 30-100 kDa) and levels of oxidation. PS6B fragmentation below 10 kDa and oxidation above 24 % of the repetitive units implied the loss of antigenicity. Polysa...
Amérique latine histoire et mémoire, 2001
En este articulo analizo las implicaciones que ha tenido el desarrollo de la produccion intensiva... more En este articulo analizo las implicaciones que ha tenido el desarrollo de la produccion intensiva de frutas y hortalizas en Mexico para el mercado mundial sobre la degradacion ambiental y el deterioro de la salud de los trabajadores y de los habitantes de las areas de cultivo. Mi tesis es que para entender en su complejidad la insustentabilidad de esta agricultura es necesario analizarla en la totalidad de las relaciones que establecen los actores sociales que participan en la produccion, la ...
Mineria Y Geologia, 1995
En la bahia de Levisa, costa nororiental de Cuba, se encuentra enclavada una fabrica procesadora ... more En la bahia de Levisa, costa nororiental de Cuba, se encuentra enclavada una fabrica procesadora de Ni. El arrastre de rios que drenan al area, el vertimiento de residuales industriales liquidos y solidos sin tratar y las emisiones a la atmosfera, son factores que han contribuido a la degradacion del ecosistema marino. Para evaluar la contaminacion por metales pesados se realizo un muestreo de 21 sedimentos superficiales y un testigo, distribuidos por toda la bahia. A la fraccion menor de 63U de las muestras, se les realizo digestion con HNO /HQ y mediante espectrofotometria de absorcion atomica, se determinaron los contenidos de Co, Fe, Ni, Mn, Cu, Pb y Zn. Los clasicos indicadores de contaminacion, Cu, Pb, y Zn, presentaron bajos contenidos y variabilidad en su distribucion espacial, mientras que Ni, Co, Fe y Mn, componentes mayoritarios de las lateritas, exhibieron diferencias de hasta dos ordenes de magnitud entre los valores extremos, con los maximos en las desembocaduras del rio Levisa y el arroyo Manati, provocados por el arrastre fluvial, pero especialmente en la ensenada de Arroyo Blanco, donde son depositadas las colas residuales. La muestra testigo solo mostro un Incremento de niquel en las capas superiores y permitio corroborar la elevada contaminacion que la actividad minera industrial ha causado al ecosistema, con niveles comparables solo a los de la bahia de Moa.
Journal of Anthropological Research, 2002
Proceedings of the 13th ACM international conference on Hybrid systems: computation and control, 2010
This document is an appendix to the paper "A Descent Algorithm for the Optimal Control of Constra... more This document is an appendix to the paper "A Descent Algorithm for the Optimal Control of Constrained Nonlinear Switched Dynamical Systems"[3], presented at the 13th International Conference on Hybrid Systems: Computation and Control (HSCC'10), and contains the proofs of all the propositions and theorems in Section 4 of that paper. The reader is advised to read this document after covering the first three sections of the original paper, as the notation and the problem formulation are not covered in this appendix. The numbering of the equations, propositions, and theorems is consistent with the numbering used in the original paper. A Algorithm Analysis A.1 Continuity of the Cost and Constraints We must first check that the cost function, equation (12), under Assumptions 1 and 2 is continuous. We prove the continuity of the cost function by taking a sequence, (ξ j) ∞ j=1 converging to limit ξ, in our optimization space, and proving that the corresponding sequence of trajectories (x j (t)) ∞ j=1 converge to trajectory x(t) corresponding to ξ. This result proves the sequential continuity of our cost function, which implies continuity since X is a metric space. Throughout this subsection we simplify the notation used for the functions µ, κ, π, and µ f. Given ξ j = (σ j , s j , u j) ∈ X , we define µ j (i) = µ(i; s j), κ j (i) = κ(i; s j), π j (i) = π(i; s j), and µ f,j = µ f (s j). As usual, when the choice of s ∈ S is clear in context we use our standard notation. Proposition 1. Let (ξ j := (σ j , s j , u j)) ∞ j=1 be a convergent sequence in our optimization space, X , and let ξ := (σ, s, u) be its limit. Let (x j (t)) ∞ j=1 be the corresponding trajectories (defined using Equation 11) associated with each ξ j , with common initial condition x 0. The sequence (x j (t)) ∞ j=1 converges pointwise to the trajectory x(t) associated with ξ, for all t in [0, ∞) with initial condition x 0 .
Forest Science and Practice, 2013
ABSTRACT Thorn scrub vegetation in Mexico is distributed over 50 million ha, where native tree sp... more ABSTRACT Thorn scrub vegetation in Mexico is distributed over 50 million ha, where native tree species are the source of forage, timber, fi rewood and charcoal. Research describing wood durability of species from this vegetation type has not been fully determined, nor classifi ed according to international standards. Thus, the aim of this study was to determine and classify the natural durability of ten woody species. Their natural durability was determined according to the European Pre-Norm 807, the loss of dynamic modulus of elasticity (MOEdyn) (MPa) was determined and wood mass loss (g) after being exposed to Trametes versicolor and Coniophora puteana fungi. Wood durability was classifi ed according to the European Norm 350-1. Highly signifi cant differences (p < 0.001) were found between the durability of woody species. The more durable species with lower MOEdyn lost were Condalia hookeri (57.5% ± 0.6%), Havardia pallens (58.2% ± 0.4%) and Acacia schaffneri (58.9% ± 6.3%). Species with lower mass loss after exposed to Coniophora puteana were Ebenopsis ebano (6.3% ± 1.9%), Condalia hookeri (8.6% ± 2.3%) and Cordia boissieri (11.8% ± 2.3%). E. ebano (7.1% ± 2.4%), Condalia hookeri (8.2% ± 2.5%) and Cordia boissieri (11.5% ± 3.1%) showed the lower mass lost after exposed to T. versicolor. According to European Norm 350-1, three woody species were classifi ed as very durable and durable species. Received 28 Novermber 2012; accepted 15 January 2013 Author for correspondence (Artemio CARRILLO) E-mail: [email protected] Natural durability of wood of ten native species from northeastern Mexico Artemio CARRILLO1,, Rahim FOROUGHBACHK2, Verónica BUSTAMANTE1, Christian WEHENKEL3, Humberto GONZÁLEZ1 1 Universidad Autónoma de Nuevo León (UANL), Facultad de Ciencias Forestales, Carr. Nal. No. 85, Km 145. 66700, 041. Linares, Nuevo León, México 2 Universidad Autónoma de Nuevo León (UANL), Facultad de Ciencias Biológicas, San Nicolás de los Garza, Nuevo León, 66451, México 3 Instituto de Silvicultura e Industria de la Madera, Universidad Juárez del Estado de Durango, Km 5.5 Carretera Mazatlán, 34120 Durango, México Introduction The northeastern region of Mexico shows extreme weather conditions with temperatures ranging from –12°C (winter) to 40°C (summer). A mean annual precipitation of 600 mm and a wide variety of soil types are found. Known as “matorral” or thorn scrub vegetation, the native vegetation is a subtropical, semi-arid scrubland (Rzedowski, 2006). This vegetation type covers about 50 million hectares which represents approximately 40% of
Journal of Control Theory and Applications, 2008
A new control scheme for induction motors is proposed in the present paper, applying the intercon... more A new control scheme for induction motors is proposed in the present paper, applying the interconnection and damping assignment-passivity based control (IDA-PBC) method. The scheme is based exclusively on passivity based control, without restricting the input frequency as it is done in field oriented control (FOC). A port-controlled Hamiltonian (PCH) model of the induction motor is deduced to make the interconnection and damping of energy explicit on the scheme. The proposed controller is validated under computational simulations and experimental tests using an inverter prototype.
Journal of Plankton Research, 1989
... We thank Dr Farooq Azam for introducing us to the techniques for measuring bacterial biomass ... more ... We thank Dr Farooq Azam for introducing us to the techniques for measuring bacterial biomass and production during the International Course, 'Advanced Topics in Biological Oceanography', held at BIOTECMAR under the sponsor-ship and support of UNESCO/ROSTALAC ...
Journal of Chemical Information and Computer Sciences, 2003
The numerous possibilities of using graph theoretic descriptors in QSPR/QSAR are analyzed, and so... more The numerous possibilities of using graph theoretic descriptors in QSPR/QSAR are analyzed, and some misunderstandings on the role of this theoretical approach in chemistry are clarified. Principal component analysis is used to obtain a property space for several physicochemical properties of aromatic compounds. It is proved that most of the QSPR applications of the graph-theoretic structure descriptors are concentrated to the description of properties in a very limited region of this property space. Here, we show that graphtheoretic approaches are also applicable to the modeling of physicochemical properties that are far away from this region traditionally studied. The molecular dipole moments of benzene derivatives, mono-, ortho-, meta-, and para-susbtituted, are modeled by using the Topological Sub-Structural Molecular Design (TOPS-MODE) approach. The TOPS-MODE approach used permits to calculate group dipole moments that are given for several substituents. The differences between these group dipoles and those obtained by simple difference between experimental values are analyzed. Some difficulties arising from this traditional way of deriving substituent constants are identified and analyzed.
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, 1996
Lcvisa Bay. on the northcast CO;ISI ol' Cuba. is :I semi-cnclosccl watcrbody with an arca of' 40 ... more Lcvisa Bay. on the northcast CO;ISI ol' Cuba. is :I semi-cnclosccl watcrbody with an arca of' 40 km'. A nickel-processing plant using a carbonate-ammoniacal leaching process is situated in the south of the bay. This plant has bcrn in opcrntion since I943 and utilizes li~tsritcs:~s raw material. The latcritcs originate from dil'fcrent mines in the ncarhy mountains. In Levisa. different types of WXICS arc gcncratcd by the industry. They include solid tailings which were deposital in ;I coastal :Ircu l'or fifteen years. At present, these tailings arc dumped iin a cONal area of limitcd water circulation in the southern zone of the Arroyo Blanco inlet of Levisa Bay (Fig. I). A dam was recently erectcd in order to prokct the bay (Fig. I, dashed line). Carey (19X I) overviewed the major potential environmental impacts of nickel-prcxcessing industries. Atmospheric emissions may be an important source of havy metals to the marine cnvironmcnt (Astorga and Moner, 19X8). The open-cut mcthods uscd to cxcavatc the latcritic deposits themselves also increases the load ol' minerals dis-075-h7J1/Ys/s(r).so (0 1YY3 Iilxcvicr Scicncc H.V. All right3 rcwrvcd .~.~/~/1t37S-67-1~~OJt1tOO5-I-'J I 0 factory wast l c;f" A mangrove 5 Surface sediment 23 core sediment chqcd into the bay by the lxvisa and Mannti Kivcrs (Fig. I). which Ilow throu@ the active mine ;mxs south of Lcvisa Bay. A study supported by the United Ndons Environment Program (UNEP) wits untlcrtnkcn with the ain1 of;tsscssiii~cnviroriincnt;ll inlpacts in the h;~y. Its finill goill will lx IO compkto ;I hcitvy IIWI:I~S Illilss-hitlatlcc for the hity CCOS~SIC~~. This paper prcscnts the early results from the study. 2. Malerids and methods The methotlology used throughout the research has bctx &scribed ~Ixwhcre (Gonziilcz. 1980). In May IYX!, 2 I surl';Ice sediment samples and one sediment core wc'rc collcctcd with ;I Van Veen dredge illld il gravity corer, rcspcctivcly, in ;I network covering the xxi (Fig. I). The tirst 15 cm of the sediment core were section4 into 3 cm intervals. The rcniaining pxt W;LS sub-sampled into 5 cm sections to obtain IX subsamplos. Nine stations. representative oC zones with expcctcd dit'l'ercnt pollution Iw&. were also sampled in November I YY?, and April 1993. All samples were lyophilized and the liaction < 63 pm ~9s separatrd by nylon sieves. Singk samples of this tknction were digested with HNOI/HCI (McKown et al., IY7X). Thu resulting solutions were analyzed by flame atomic absorption spectromctry with deuterium background correction. The metals dctcrmind were chosen for two reasons: Cu. Pb and Zn art' considered to be ubiquitous indicrttors ol' human activities because they originate from both. urban and industrid sources (Forstncr and Wittmunn, 1070; Yim and Funs, IYXI; Sdomons and Forstncr. IYXJ; Castaing et al.. 1086: Baisch et al.. IYHH;
Vaccimonitor, 2008
The work aimed at purifying lipopolysaccharides (LPS) of Neisseria meningitidis from a collateral... more The work aimed at purifying lipopolysaccharides (LPS) of Neisseria meningitidis from a collateral fraction of the antimeningococcal BC vaccine, VAMENGOC-BC ®. production process, the supernatant obtained from the ultra centrifugation stage during the proteins extraction process of the meningococcus outer membrane. The purification was carried out by precipitation 80% ethanol, protein extraction with 90% phenol from 65-70 ºC and fractional ultra centrifugation at 105.000 g. Three lots of LPS were obtained, in total 1.069 g, with a content of proteins, nucleic acids and sialic acid in respect to the LPS of 0.5%, 0.3% and 2.2% (m/m) respectively. The assessment by chromatography showed a high molecular integrity. with constant valves of reproducible distribution (Kd 0.36-0.38) and a possible sialic acid association to the LPS. Homogeneity was observed in the electrophoretic profile of the three lots and a high endotoxic activity. The purified LPS was mainly identified as the inmunotype L3,7,9. The purification procedure used allows making use of a collateral fraction of the vaccine production process, it is scalable, it does not include chromatographic methods and makes easy the obtainment of large quantity of LPS of Neisseria meningitidis, wihich it is non available on the market, with high purity and high endotoxic activity.
Chemistry and Ecology, 1989
... MATANZAS BAY, CUBA HUMBERTO GONZALEZ Unidad de Proteccion Ambiental, Instituto de Investigaci... more ... MATANZAS BAY, CUBA HUMBERTO GONZALEZ Unidad de Proteccion Ambiental, Instituto de Investigaciones del Trunsporte, Apartado 17029, Ciudad Habana 17, Cuba ... 1987; Larsen ei af., 1983; White and Tittlebaum, 1984; Wilson et al., 1986; Windom et al. , 1986). ...
Bulletin of Environmental Contamination and Toxicology, 1990
… sobre Preparación y …, 2002
... Autor: Salinas, César; Moreno del Cruz, Iris; González, Humberto. Título: Optimización y ampl... more ... Autor: Salinas, César; Moreno del Cruz, Iris; González, Humberto. Título: Optimización y ampliación del vertedero de El Molle en la comuna de Valparaíso. Fonte: In: ILPES. Preparación y evaluación de proyectos de desarrollo local. Santiago de Chile, CEPAL/ILPES, 2002. ...
tropentag.de, 2008
1, 2University of Nuevo León, Department of Food Sciences. PO Box 142, Sucursal F, San Nicolás de... more 1, 2University of Nuevo León, Department of Food Sciences. PO Box 142, Sucursal F, San Nicolás de los Garza, Nuevo León, 66450, Mexico. *Correspondance autor: Email: [email protected]. 3University Juarez of the State of Durango, Medicine Veterinary ...
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Papers by Humberto González