Grano-Maldonado M.I.,Autonomous University of Sinaloa
Scanning | Year: 2014
This study examines the transmission strategies employed by parasites in order to colonize new hosts. Three-spined sticklebacks, Gasterosteus aculeatus L., were challenged with Gyrodactylus gasterostei Gläser, 1974 in a chamber and the colonization of new hosts was observed. Live-video recording indicates that gyrodactylid transmission possibly maximizes the chances of contact with an alternatively feeding response from dead parasitized hosts to predatory stickleback. It is proposed that host scavenge feeding may comprise an additional route for gyrodactylid transmission, although its relative importance with respect to other recognized routes remains uncertain. Although it was clearly demonstrated that G. gasterostei can reside in the mouth of its host, the study revealed that scavenging-feeding upon dead parasitized hosts did not contribute significantly to the level of infection in 3 h and parasite transmission observed on the feeding fish. A series of experimental exposures and scanning electron microscope images suggest that once ingested, the parasites can attach to the lining of the buccal cavity and then migrate to their preferred colonization site on the outer surface of the fish. In addition to the direct contact infection pathway normally associated with many. This study highlights that diagnosticians should be aware of the fact that the oral cavity may act as temporary transmission location for gyrodactylid fauna. © 2014 Wiley Periodicals, Inc.
Vazquez B G.E.,Autonomous University of Sinaloa |
Grejner-Brzezinska D.A.,Ohio State University
GPS Solutions | Year: 2013
Three permanent GPS tracking stations in the trans Antarctic mountain deformation (TAMDEF) network were used to estimate precipitable water vapor (PWV) using measurement series covering the period of 2002-2005. TAMDEF is a National Science Foundation funded joint project between The Ohio State University and the United States Geological Survey. The TAMDEF sites with the longest GPS data spans considered in this research are Franklin Island East (FIE0), the International GNSS Service site McMurdo (MCM4), and Cape Roberts (ROB1). For the experiment, PWV was extracted from the ionosphere-free double-difference carrier phase observations, processed using the adjustment of GPS ephemerides (PAGES) software. The GPS data were processed with a 30 s sampling rate, 15-degree cutoff angle, and precise GPS orbits disseminated by IGS. The time-varying part of the zenith wet delay is estimated using the Marini mapping function, while the constant part is evaluated using the corresponding Marini tropospheric model. Previous studies using TAMDEF data for PWV estimation show that the Marini mapping function performs the best among the models offered by PAGES. The data reduction to compute the zenith wet delay follows the step piecewise linear strategy, which is subsequently transformed to PWV. The resulting GPS-based PWV is compared to the radiosonde observations and to values obtained from the Antarctic mesoscale prediction system (AMPS). This comparison revealed a consistent bias of 1.7 mm between the GPS solution and the radiosonde and AMPS reference values. © 2012 Springer-Verlag.
Bojorquez E.,Autonomous University of Sinaloa |
Iervolino I.,University of Naples Federico II
Soil Dynamics and Earthquake Engineering | Year: 2011
In this paper, spectral-shape-based intensity measures (IMs) are discussed with respect to ordinary, pulse-like and narrow-band records. First, the analyses address the ability of these IMs to capture the peak and cumulative damage potentials of ground motions. Second, a new vector-valued ground motion IM based on the spectral acceleration at the first mode of the structure, Sa(T1), and a parameter proxy for the spectral shape, namely Np, is introduced. The vector 〈Sa,Np〉 is compared to other state-of-the-art IMs in terms of estimation of the seismic response of nonlinear single degree of freedom systems, reinforced concrete and steel moment resisting frames. Results show that 〈Sa,Np〉 may be especially useful to represent the ground motion potential in the case of records with peculiar spectral shape. Further, it is shown that 〈Sa,Np〉 has the properties of efficiency, sufficiency and scaling robustness. Finally, a scalar ground motion IM based on Sa(T1) and Np is also discussed, and the possibility to compute the seismic hazard analysis for it is illustrated. © 2011 Elsevier Ltd.
Catch composition of the spiny lobster Panulirus gracilis (Decapoda: Palinuridae) off the western coast of Mexico [Composición de la captura de la langosta espinosa Panulirus gracilis (Decapoda: Palinuridae) en la costa oeste de México]
Perez-Gonzalez R.,Autonomous University of Sinaloa
Latin American Journal of Aquatic Research | Year: 2011
The lobster fishery in the Gulf of California and the south-central region of the western coast of Mexico consists of small-scale artisanal activity supported by Panulirus gracilis and P. inflatus, with an annual average catch of 132 ton. The present study analyzes the landing composition of this fishery and the population structure of P. gracilis. Carapace lengths (CL) for this species ranged from 35 to 125 mm, and the most frequent sizes were between 60 and 85 mm. The size distribution was approximately normal. This implies that the fishery is composed of several size classes, with annual recruitment to the fishing areas. For the 1989-1990 and 1990-1991 fishing seasons, the mean monthly sizes of males were between 70.18 ± 11.74 and 81.11 ± 6.76 mm CL, whereas females averaged from 73.60 ± 8.95 to 80.28 ± 7.53 mm CL. Power-law relationships between carapace length (CL in mm) and total weight (TW in g) were determined, resulting in the following equations: PT = 0.0021 CL 2.7689 for males and PT = 0.0009 CL 3.0038 for females. During certain periods of the year, males dominated the catch; however, the overall annual male:female ratio was near 1:1.
Bojorquez E.,Autonomous University of Sinaloa |
Ruiz-Garcia J.,Universidad Michoacana de San Nicolas de Hidalgo
Earthquake Engineering and Structural Dynamics | Year: 2013
SUMMARY: This paper presents the main results of the evaluation of residual inter-story drift demands in typical moment-resisting steel buildings designed accordingly to the Mexican design practice when subjected to narrow-band earthquake ground motions. Analytical 2D-framed models representative of the study-case buildings were subjected to a set of 30 narrow-band earthquake ground motions recorded on stations placed in soft-soil sites of Mexico City, where most significant structural damage was found in buildings as a consequence of the 1985 Michoacan earthquake, and scaled to reach several levels of intensity to perform incremental dynamic analyses. Thus, results were statistically processed to obtain hazard curves of peak (maximum) and residual drift demands for each frame model. It is shown that the study-case frames might exhibit maximum residual inter-story drift demands in excess of 0.5%, which is perceptible for building's occupants and could cause human discomfort, for a mean annual rate of exceedance associated to peak inter-story drift demands of about 3%, which is the limiting drift to avoid collapse prescribed in the 2004 Mexico City Seismic Design Provisions. The influence of a member's post-yield stiffness ratio and material overstrength in the evaluation of maximum residual inter-story drift demands is also discussed. Finally, this study introduces response transformation factors, Tp, that allow establishing residual drift limits compatible with the same mean annual rate of exceedance of peak inter-story drift limits for future seismic design/evaluation criteria that take into account both drift demands for assessing a building's seismic performance. © 2013 John Wiley & Sons, Ltd.