Browsing by Author

  • Publication
    Aging at high altitudes and the risk of chronic mountain sickness
    ( 1993)
    LEON VELARDE SERVETTO, FABIOLA MARIA
    ;
    Arregui A.
    ;
    MONGE SALGADO, EDUARDO AUGUSTO
    ;
    RUIZ SESSAREGO, DAVID EUGENIO SERGIO
    Clinical records of healthy high altitude (HA) (4300 m [14 100 ft]; n=2875) and sea level (SL) (n=2899) miners were examined for vital capacities (VC), body weights (W), heights (H), and hemoglobin (Hb) concentrations in different age groups. In the HA population, excessive erythrocytosis (EE) was defined as Hb ≥ 21.3 g dl−1; i.e., the mean Hb in the 20–29 age group plus 2 sd. This level of Hb is one of the parameters above which clinical chronic mountain sickness (CMS) becomes apparent. We found a smooth increasing prevalence of EE with age: 6.8% at age 20–29 to 33.7% at age 60–69. Height corrected VC (VC/H) decreases 3.0% between ages 20–29 and 60–69 years in SL miners and 26.5% in HA for the same age interval. In the latter, the pronounced decrease in VC/H is seen both in miners with EE (30.6%) and in those with physiological erythrocytosis (PE, 22.4%). SL miners have significantly higher W/H ratios than do HA ones. This index steadily increases with age at SL. At HA, however, miners with EE and PE show a drop in their weights after ages 40–49 years. In addition, EE miners have higher W/H ratios than do PE ones between ages 40–59 years. We suggest that increasing Hb and diminishing VC with age at HA do not represent the so-called physiological adaptation. On the contrary, these may be risk factors for the development of CMS with age among HA Andean populations. © 1993, Wilderness Medical Society. All rights reserved.
    Scopus© Citations 44
  • Publication
    Changes in whole blood oxygen affinity and eggshell permeability in high altitude chickens translocated to sea level
    (Elsevier Inc., 1997)
    LEON VELARDE SERVETTO, FABIOLA MARIA
    ;
    MEJÍA ACOSTA, NELLY DELFINA
    ;
    PALACIOS CURAY, MARCO ANTONIO
    ;
    MONGE SALGADO, EDUARDO AUGUSTO
    High altitude (HA; n = 5) chickens (Gallus gallus) with a high oxygen hemoglobin (Hb) affinity were transported from their birthplace (Puno, Peru 4,000 m) down to sea level (Lima, Peru). The in vivo whole blood oxygen affinity (P50) and the eggshell permeability (P) were studied after several months living at sea level and in the first (F1) and second (F2) generations born at sea level. Our approach was to analyze changes in Hb affinity and eggshell permeability, considered as indicators of HA adaptation in birds. Our results show an increase of the P50 values (a decrease in Hb affinity) towards sea-level values. The results in P indicate that this variable increases towards sea level values in the F2 generation. We conclude that in the Andean chicken, a relative 'newcomer' to high altitude (no more than 500 years), neither the Hb affinity for oxygen nor the eggshell permeability are invariable indicators of HA adaptation, in contrast with other native high altitude mammals and birds.
    Scopus© Citations 7
  • Publication
    Non-polynomial Zig-Zag and ESL shear deformation theory to study advanced composites
    (Chinese Journal of Aeronautics, 2019)
    MANTARI LAUREANO, JOSE LUIS
    ;
    RAMOS TAIPE, CAYO LEONIDAS
    ;
    MONGE SALGADO, EDUARDO AUGUSTO
    The mechanical behavior of advanced composites can be modeled mathematically through unknown variables and Shear Strain Thickness Functions (SSTFs). Such SSTFs can be of polynomial or non-polynomial nature and some parameters of non-polynomial SSTFs can be optimized to get optimal results. In this paper, these parameters are called “r” and “s” and they are the argument of the trigonometric SSTFs introduced within the Carrera Unified Formulation (CUF). The Equivalent Single Layer (ESL) governing equations are obtained by employing the Principle of Virtual Displacement (PVD) and are solved using Navier method solution. Furthermore, trigonometric expansion with Murakami theory was implemented in order to reproduce the Zig-Zag effects which are important for multilayer structures. Several combinations of optimization parameters are evaluated and selected by different criteria of average error. Results of the present unified trigonometrical theory with CUF bases confirm that it is possible to improve the stress and displacement results through the thickness distribution of models with reduced unknown variables. Since the idea is to find a theory with reduced numbers of unknowns, the present method appears to be an appropriate technique to select a simple model. However these optimization parameters depend on the plate geometry and the order of expansion or unknown variables. So, the topic deserves further research. © 2019
    Scopus© Citations 1