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Industrialization Process in the Border Area of The U.S. and Mexico (미국-멕시코 국경지대의 산업화 과정)

  • 김학훈
    • Journal of the Economic Geographical Society of Korea
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    • v.1 no.1
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    • pp.81-112
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    • 1998
  • This study reviews the industrialization process of the United States-Mexico Borderlands and the economic relations between the U.S. and Mexico and examines their impact on the borderlands. Main factor in the industrialization of the borderlands was the U.S. investment on the maquiladora program of Mexico since 1965. It contributed to the increase in employment and population of borderlands and the development of service industries. Low wage level of Mexico induced not only standardized labor-intensive industries but also the high-tech automated industries because they still use a lot of labor in manufacturing and assembly process, while the functions of management. R & D, and distribution remained in the U.S. This is a typical case of international division of labor and satellite industrial district. The rules of origin in NAFTA, however forced branch Plants of multinational companies to form the local linkages between firms.

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Comparison of Mathematical Models Applied to F1 Dairy Sheep Lactations in Organic Farm and Environmental Factors Affecting Lactation Curve Parameter

  • Angeles-Hernandez, J.C.;Albarran-Portillo, B.;Gomez Gonzalez, A.V.;Pescador Salas, N.;Gonzalez-Ronquillo, M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.8
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    • pp.1119-1126
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    • 2013
  • The objective of this study was to compare the goodness of fit of four lactation curve models: Wood's Gamma model (WD), Wilmink (WL), and Pollott's multiplicative two (POL2) and three parameters (POL3) and to determine the environmental factors affecting the complete lactation curve of F1 dairy sheep under organic management. A total of 5,382 weekly milk yields records from 150 ewes, under organic management were used. Residual mean square (RMS), determination coefficients ($R^2$), and correlation (r) analysis were used as an indicator of goodness of fit for each model. WL model best fitted the lactation curves as indicated by the lower RMS values (0.019), followed by WD (0.023), POL2 (0.025) and POL3 (0.029). The four models provided total milk yield (TMY) estimations that were highly correlated (0.93 to 0.97) with observed TMY (89.9 kg). The four models under estimated peak yield (PY), whereas POL2 and POL3 gave nearer peak time lactation estimations. Ewes lambing in autumn had higher TMY and showed a typical curve shape. Higher TMY were recorded in second and third lambing. Season of lambing, number of lambing and type of lambing had a great influenced over TMY shaping the complete lactation curve of F1 dairy sheep. In general terms WL model showed the best fit to the F1 dairy sheep lactation curve under organic management.

Differences on specified and actual concrete strength for buildings on seismic zones

  • De-Leon-Escobedo, David;Delgado-Hernandez, David Joaquin;Arteaga-Arcos, Juan Carlos;Flores-Gomora, Jhonnatan
    • Earthquakes and Structures
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    • v.12 no.3
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    • pp.349-357
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    • 2017
  • The design of reinforced concrete structures strongly depends on the value of the compression concrete strength used for the structural components. Given the uncertainties involved on the materials quality provided by concrete manufacturers, in the construction stage, these components may be either over or under-reinforced respect to the nominal condition. If the structure is under reinforced, and the deficit on safety level is not as large to require the structure demolition, someone should assume the consequences, and pay for the under standard condition by means of a penalty. If the structure is over reinforced, and other failure modes are not induced, the builder may receive a bonus, as a consequence of the higher, although unrequested, building resistance. The change on the building safety level is even more critical when the structure is under a seismic environment. In this research, a reliability-based criteria, including the consideration of expected losses, is proposed for bonification/penalization, when there are moderated differences between the supplied and specified reinforced concrete strength for the buildings. The formulation is applied to two hypothetical, with regular structural type, 3 and 10 levels reinforced concrete buildings, located on the soft soil zone of Mexico City. They were designed under the current Mexican code regulations, and their responses for typical spectral pseudoaccelerations, combined with their respective occurrence probabilities, are used to calculate the building failure probability. The results are aimed at providing objective basis to start a negotiation towards a satisfactory agreement between the involved parts. The main contribution resides on the explicit consideration of potential losses, including the building and contents losses and the business interruption due to the reconstruction period.

In Vitro Cultivation of Cymatocarpus solearis(Brachycoeliidae) Metacercariae to Obtain the Adult Stage without the Marine Turtle Definitive Host

  • Grano-Maldonado, Mayra;Alvarez-Cadena, Jose
    • The Korean Journal of Parasitology
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    • v.48 no.1
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    • pp.49-55
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    • 2010
  • In vitro cultivation of trematodes would assist studies on the basic biology of the parasites and their hosts. This is the first study to use the yolk of unfertilized chicken eggs as a simple and successful method of ovocultivation and the first time to obtain the adult-stage of the trematode Cymatocarpus solearis Braun, 1899 (Digenea: Brachycoeliidae). Chicken eggs were inoculated with metacercariae from the muscle of the spiny lobster, Panulirus argus (Latreille, 1804). The metacercariae were excysted and incubated for 576 hr (24 days) at $38^{\circ}C$ to obtain the adult stage. Eggs in utero were normal in shape and light brown color. The metacercariae developed into mature parasites that have been identified as the adultstage found in marine turtles. The adult lobsters collected in Quintana Roo State, Mexico, showed the prevalence of 49.4% and the mean intensity of 26.0 per host (n=87). A statistical study was performed to determine that no parasitic preference was detected for male versus female parasitized lobsters. Morphometric measurements of the adult-stage of C. solearis obtained in our study have been deposited in the National Helminths Collection of the Institute of Biology of the National Autonomous University of Mexico. This study is significant because it is the first time that a digenean of the family Brachycoeliidae has been demonstrated to develop in vitro from metacercariae into adults capable of producing eggs using the yolk of unfertilized chicken eggs. Secondly, this technique allows to obtain the adult stage of C. solearis without the presence of its marine turtle host, allows us to describe the mature parasites, and thus contribute to our understanding of the biology of C. solearis.

Brucella melitensis omp31 Mutant Is Attenuated and Confers Protection Against Virulent Brucella melitensis Challenge in BALB/c Mice

  • Verdiguel-Fernandez, L;Oropeza-Navarro, R;Ortiz, Adolfo;Robles-Pesina, MG;Ramirez-Lezama, J;Castaneda-Ramirez, A;Verdugo-Rodriguez, A
    • Journal of Microbiology and Biotechnology
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    • v.30 no.4
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    • pp.497-504
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    • 2020
  • For control of brucellosis in small ruminants, attenuated B. melitensis Rev1 is used but it can be virulent for animals and human. Based on these aspects, it is essential to identify potential immunogens to avoid these problems in prevention of brucellosis. The majority of OMPs in the Omp25/31 family have been studied because these proteins are relevant in maintaining the integrity of the outer membrane but their implication in the virulence of the different species of this genus is not clearly described. Therefore, in this work we studied the role of Omp31 on virulence by determining the residual virulence and detecting lesions in spleen and testis of mice inoculated with the B. melitensis LVM31 mutant strain. In addition, we evaluated the conferred protection in mice immunized with the mutant strain against the challenge with the B. melitensis Bm133 virulent strain. Our results showed that the mutation of omp31 caused a decrease in splenic colonization without generating apparent lesions or histopathological changes apparent in both organs in comparison with the control strains and that the mutant strain conferred similar protection as the B. melitensis Rev1 vaccine strain against the challenge with B. melitensis Bm133 virulent strain. These results allow us to conclude that Omp31 plays an important role on the virulence of B. melitensis in the murine model, and due to the attenuation shown by the strain, it could be considered a vaccine candidate for the prevention of goat brucellosis.

RESEARCH ON SHAPE MEMORY ALLOYS IN MEXICO

  • Jara, David Rios
    • Proceedings of the Materials Research Society of Korea Conference
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    • pp.1-1
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    • 1992
  • Shape Memory Alloys have attracted the interest of a great number of researchers in the world, and Mexico is not the exception. Research in this field started ten years ago, and is actually an active line covering the classical Cu-based and Ti-Ni alloys, but also the new Fe-based alloys. Although more basic studies have been performed at the present time, interest for applied research and technological goals is increasing. In this work we present a series of studies carried on these Shape Memory Alloys by the groups in Mexico, and explain what the interest of our groups are in the next future in this are of the Materials Science. Interdisciplinary work has been necessary in the characterization of the different alloys, and multiple techniques have been used, like Mossbauer spectroscopy, thermoelectric power, electron microscopy, ultrasound techniques, neutron and x-ray diffraction, calorimetry, among others. Collaboration With other groups in Europe and in the United States have become highly useful and productive, and some examples of such activities are also reported.

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Intestinal parasitic infections in the residents of an emigration camp in Tijiuana, Mexico (멕시코 티후아나 이민촌 거주자의 장내 기생충 감염 상태)

  • Sun HUH;Curie AHN;Jong-Yil CHAI
    • The Korean Journal of Parasitology
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    • v.33 no.1
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    • pp.65-68
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    • 1995
  • We examined stool specimens of the residents in the emigi·ation camp in Tijuana, Mexico for helminth eggs or protozoan cysts with formalin-ethyl acetate concentration method in February and July 1992. Out of 92 examined samples, number of positive was 49 (53.3%). While number of cumulative positive was 66 (71.7%). Cysts of Entnmoeba coli (29.3%) Giardio lomblia (9.8%), Entamoebo histolytica (7.6%), and eggs of Tqenic app. (6.5) were most frequently observed. Filtered water supply and chemotherapy were required in this camp.

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First Record of Scytosiphon gracilis Kogame (Scytosiphonaceae,Phaeophyceae) for the Pacific coast of Mexico

  • Raul , Aguilar-Rosas;Luis E. , Aguilar-Rosas;Cho, Ga-Youn;Boo, Sung-Min
    • ALGAE
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    • v.21 no.1
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    • pp.11-13
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    • 2006
  • In this work we report the occurrence of Scytosiphon gracilis Kogame (Scytosiphonaceae, Phaeophyceae) on the Pacific coast of Mexico. This is the first report of S. gracilis outside its previously known distribution in the western North Pacific (Korea and Japan). The identification was based on a morphological revision and a comparison of the plastid-encoded RuBisCO spacer sequences determined for Korean and Mexican algal material. Thalli were collected from the intertidal zone of Saldamando Beach, Baja California, in January 2003. The vegetative structure, as well as habitat and geographic distribution of the species are described. Reproductive structures were not found in our specimens. The poor presence/absence of S. gracilis in previous floristic studies of the area could be due to its small size and low frequency.

Dry Coated Particle for Plasma Spraying

  • Briones-Rodriguez, C.;Mayagoitia-Barragan, V.;Cuenca-Alvarez, R
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • pp.156-157
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    • 2006
  • The preparation of composite powders for plasma spraying by an in-house designed mechanofusion process is investigated. Results show that dry particle coating depends on the chemical and mechanical properties of powders. In metal/oxide and metal/oxide/carbide powder mixtures, fine ceramic particles coat the surface of the metallic coarser particles. A nearly rounded shape of the final composite particles is induced by the mechanical energy input with no formation of new phases. However with the carbide/metal powdered system, only an intimate mixture of components is achieved. It is suggested that the coating mechanism is governed by agglomeration and rolling phenomena.

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Highly Economic and High Quality Zinc-flake Manufacturing by High Kinetic Processing

  • Ren, H.;Benz, H.U.;Chimal V., O.;Corral G., M.S.;Zhang, Y.;Jaramillo V., D.;Zoz, H.
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • pp.975-976
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    • 2006
  • The present paper is a parameter study of zinc flake production using a Simoloyer CM01 horizontal high energy rotary ball mill. The manufactured flakes have a dimension in thickness (t) < $1{\mu}m$ and diameters (d) 5-100 ${\mu}m$, consequently a ratio d/t up to 200. The flake geometry is mainly controlled by the variation of process parameters such as rotary speed of the rotor, ratio of powder/ball charge, load ratio of the system, process temperature, operating model and the quantity of process control agent (PCA). The Zn flakes were characterized by SEM, tap densitometry, laser diffraction and water coverage measurement.

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