Once the finite element model was calibrated to field conditions, engineering analysis was followed to address any optimized parameter that could possibly change over time or that could be unreliable with heavy loads or further damage. TheLoadRating Factor was determined by a formula based on a certain element capacity, the applied live and dead loads (and their corresponding factors), and a considered impact effect. It is known that a load-rating factor greater than 1.0 indicates a member capacity exceeds the applied loads with the desired factors of safety (AASHTO, 2002). A rating factor less than 1.0 indicates a structural member is deficient such that a specific vehicle or load cannot cross the bridge with the desired factor of safety. A number near 0.0 indicates thestructure cannot carry its own dead weight and maintain the desired safety factor. The lowest component rating-factor generally controls theloadratingofthe entire structure. As mentioned before, therating equation specified by the AASHTO - Manual for the Condition Evaluation of Bridges was applied (1).
This work assesses the structural integrity of a pier located intheGulfofMexico through a live- load testing analysis of a corrodedstructure that withstands heavy loads. Procedures included instrumentation for load application of four different loads (50, 60, 350, and 700 Ton) to examine its structural performance, then calibrate the resultant finite-element models ofthestructure, and finally estimate theloadrating factors using AASHTO methodology. Results showed that corrosion damages did not appear to represent an extreme structural menace; however, it was found that several piers’ structural elements are currently overloaded and need to be externally reinforced. This paper outlines the testing procedures, describing both the followed analysis and the data management criteria.
This original work assesses the structural integrity of a pier located intheGulfofMexico through a live-load testing analysis of a corrodedstructure that withstands heavy loads. Procedures included instrumentation for load application of four different loads (50, 60, 350, and 700 Ton) to examine its structural performance, then calibrate the resultant finite-element models ofthestructure, and finally estimate theloadrating factors using AASHTO methodology. Results showed that corrosion damages did not appear to represent an extreme structural menace; however, it was found that several piers’ structural elements are currently overloaded and need to be externally reinforced. This paper outlines the testing procedures, describing both the followed analysis and the data management criteria.
Despite a recent revision ofthe dinoﬂagellates ofthe order Dinophysiales on Mexican coasts and a checklist of dinoﬂagellates from the Mexican Paciﬁc, many records still need to be conﬁrmed, for there are very few reliable illustrations and/or descrip- tions. In this paper, species composition and distribution of dinoﬂagellates belonging to the Dinophysiales, the product ofthe analysis of net phytoplankton material collected from coasts ofthe tropical Mexican Paciﬁc (Jalisco to Chiapas) are presented. The material has been studied using light microscopy, although a few species were also studied by scanning electron microscopy (SEM). Forty-one species from ﬁve genera were identiﬁed, with two new records annotated for the Mexican Paciﬁc: Amphisolenia thrinax and Metaphalacroma skogsbergii, and two new species ofthe genus Amphisolenia, Amphisolenia fusiformis sp. nov. and Amphisolenia michoacana sp. nov. Illustrations, dimensions and distribution data are provided for each species, and descriptions ofthe new species are also given. Amphisolenia palmata, A. rectangulata, A. truncata, Dinophysis apicata, D. hindmarchii, Histioneis biremis, H. crateriformis, H. pulchra, Ornithocercus cristatus, O. heteroporoides and O. orbiculatus are illustrated for the ﬁrst time inthe waters ofthe Mexican Paciﬁc. The number of species found in this study is relatively low. The species Dinophysis norvegica and D. sacculus, reported in previous papers, do not seem to occur in Mexican waters, as their distribution is rather limited to the Mediterranean Sea and the North Atlantic, respectively. Finally, the identity of certain species of Dinophysis and the nature ofthe new species described here are discussed.
Phytoplankton communities of coastal lagoons are complex, as a high diver- sity of freshwater and marine organisms can co-occur in these environments. As a consequence, confusion about the identification of microalgae may arise. Within dinoflagellates, some genera are distinctively freshwater or marine organisms, but others can be found in both environments (Dodge, 1985; Popovský & Pfiester, 1990). The genus Peridinium Ehrenberg was split by Gran in 1902 into the genera Peri- dinium and Protoperidinium Bergh, thus providing a broad separation between the freshwater (Peridinium) and the marine species (Protoperidinium) (Balech, 1974). Thus, the genus Peridinium is commonly regarded to occur only in freshwater envi- ronments, but the subdivision into two genera was based on the number of cingular plates (Peridinium bears more than five plates) and, so far, the only species of this genus that is known to occur in marine and brackish environments is Peridinium quinquecorne. in addition, P. aciculiferum Lemmermann has been recorded in ma- rine environments in Europe (Popovský & Pfiester, 1990), and in estuarine environ- ments intheGulfofMexico (Steidinger et al., 2009). As this species is characteristic of freshwater environments (Hansen & Flaim, 2007), its occurrence in marine envi- ronments might be the result of river transportation.
In fisheries ecology, the study of condi- tion is a standard practice and assumes that a heavier fish of a given length is in better con- dition (Bolger and Connolly 1989). Condition has been most effectively used to compare monospecific populations living under similar or apparently different environmental condi- tions, in determining the timing and duration of gonad maturation, and as an indication of changing gross nutritional balance during chronic alterations in feeding activity or food supply (Bolger and Connolly 1989).
Faunal and environmental analysis: matrices of species abundance (catch /trawl) with respect to depth and season were root-root transformed; however, when proportions were used, the arc-sine ofthe square root was taken instead (Bireley 1984). The cluster analysis was carried out by means ofthe cordal distance index (0rlóci 1978b), and the resulting matrix was grouped using ofthe flexible method with B=-0.25 (Sneath and Sokal 1974, Swartz et al. 1986). For the community ordination, principal components analysis was used. The environmental variations were evaluated by kriging technique with a linear variogram model, because the data points were evenly dis- persed inthe area (Axis et al. 2001). In order to know the relationship between the abundance and the recorded parameters, a non-parametric analysis, the Spearman’s correlation was car- ried out. The diet data ofthe most important fish species in one year were analyzed using the similarity coefficient (Horn 1966). The sampled fish were injected with formol at 40 % inthe stomach in order to stop any digestive process, subsequently, the stomach contents were dissected and analyzed. The composition of each trophic group was evaluated as the percent ofthe total area ofthe stomach con- tent; the comparative weight value and the fre- quency of each food item were used to define the trophic spectra (Overstreet and Heard 1982). Values obtained are an average for each species; Fig. 8 shows the size and number of analyzed specimens. The Horn’s similarity index gives a relative value of trophic overlap (Rice 1988). The analysis was carried out both with and without considering detritus as a com- ponent ofthe food consumed.
(Hendrickx and Wicksten 1987, Wicksten and Hendrickx 1992). Except for the slippery prineeps, which typi cally occurs on sandy bottom elose to shore, lobsters and mud-shrimps (Thalassinidea) are scarce. Anomura (20 species in total) ineludes a small series of sized hermit crabs species which feature an unbroken distribution pattern from inside the Bay towards the adja cent shelf. crabs are known to be mostIy intertidal, sometimes extending their habitat to the shallow subtidal where rocky bot tom and associated fauna and flora (e.g. sponges and coralina) serve as refuges for many species of Petrolisthes, Paehyeheles or Megalobraehiunl. Exelusively subtidal porce lain occurring intheGulfof California inelude the genera Orthochela. Eueeramus, Poreellana, Minyoeerus, Ulloaia and Polyonix, all of them represented at least with one species inthe Bay of Mazatlán. The largest group of species is,
The acid deposition effects on several types of potentially sensitive receptors along the coast oftheGulfofMexico have become a topic of research, in- cluding receptors such as lakes, rivers, forests, soils, and materials from monuments of cultural heritage. It includes those found inthe Mayan Zone, the archae- ological zone of El Tajín and the San Juan de Ulúa fortress, all of which were built out of limestone, a material especially susceptible to deterioration by acid rain (Schifter et al., 2005; Bravo et al., 2006; Benítez et al., 2014).
The earthquake of 23 May 2007, offshore the city of Tuxpan, was not as well recorded by the worldwide network of seismic stations as the 2009 event. In this case, there were not many clearly recorded long- period P waves. The signals recorded at six teleseismic stations were used inthe inversion algorithm. As described before, the inversion was conducted at different trial depths. The maximum variance reduction was obtained at a depth of approximately 7 km (Figure 2). At this depth, the fit between the synthetic seismograms generated using the resulting focal mechanism match the observed waveforms (Figure 4). The resulting source mechanism for the 2007 earthquake is different from those determined further south for the 1959, 1967 and 2009 events. The 2007 earthquake is much shallower than the events further south and shows strike-slip faulting with the axes of maximum compression oriented northeast-southwest. Furthermore, this earthquake lies offshore and not along the coastline as the other earthquakes farther south.
Based on the results inthe present study, the pattern of genetic divergence and the lack of gene flow suggest that the Bottlenose Dolphin population inhabiting the inner estuary oftheGulfof Guayaquil is an isolated population with a unique genealogical and adaptive legacy. Therefore, management and conservation strategies need to be developed for the conservation of this population soon, before current activities cause irreversible damage. Such strategies have to be different to those applied to other populations of Tursiops truncatus due to the particular genetic diversity. Besides the low genetic diversity, another aspect of major concern is the high level of inbreeding, which makes this population more vulnerable to environmental stochasticity. This population must be considered as an Evolutionary Significant Unit (ESU) and its conservation status should be reevaluated. Although the sample size is small, our findings provide information on the molecular baseline for management; therefore, actions should not be delayed.
Currently, other investigations use the Lerner index employing different approaches. The work by Huang, Chiang and Wao (2016) proposes a simultaneous stochastic frontier model based on copulas, the model is comprised by a frontier of costs and two price product frontiers. Their results suggest that banks can direct their production to the bank with the greatest potential measure ofthe Lerner index to obtain greater profit. Phan, Daly and Akhter (2016) study the relation between banking competition, banking concentration and the efficiency ofthe banking sector in six Asian countries using two types ofthe Lerner index. They find that banking competition has a positive effect on efficiency while competition has a negative effect. By investigating the influence of change costs in banking for the three biggest banks ofthe Eurozone, Egarius and Weill (2016) study if the change costs have an impact on the market power measured by the Lerner index. It is concluded that there is a positive relation between the change costs and the market power. To evaluate the effect of competition on the creation of liquidity by the banks, Horvart, Seidler and Weill (2016) conduct an estimation using a dynamic data panel with GMM on a database of banks inthe Czech Republic inthe 2002-2010 period. They find that a greater competition measured by the Lerner index reduces the creation of liquidity.
The bioreactor was operated during more than 60 days with 2 L of each solution, at a recirculation rate of 3.0 L/h. The nutrient solution was renewed once a week, with the pH adjusted to 7.5, although a gradual acidification was observed. The inlet formaldehyde concentrations were 0.8 ± 0.3, 0.9 ± 0.2 and 0.8 ± 0.2 g/m 3 , when using solutions A, B and C, respectively. The results show that the average performance ofthe reactor was similar with the three solutions (Table 2). A small decrease inthe removal efficiency was observed when replacing solution A by solution B, though this difference is not really significant. The pH ofthe medium was 5.5 ± 1.1 when feeding solution A, containing ammonium, while with solution B, containing nitrate, it was 6.0 ± 0.4. A maximum formaldehyde elimination capacity of 101 g/m 3 h was obtained in this experiment, when feeding solution A.
This piece of research focuses on the lexical influence of English on a Spanish Internet forum. Some previous publications have dealt with the presence of English in various fields of Spaniards’ daily life. For instance, Rodríguez González (2012), Campos (2015) and Rodríguez Medina (2016a) examined the use of Anglicisms in areas such as sports; López-Zurita (2005) showed the importance of Anglicisms in economics. Advertising and TV commercials were also investigated by Rodríguez Díaz (2011) and García-Morales, González-Cruz, Luján-García and Rodríguez-Medina (2016); the fields of eroticism and sexuality were studied by Rodríguez-González, 2011, who includes many Anglicisms in his dictionary, and Crespo-Fernández and Luján- García (2013; 2017); other studies dealt with the employment of Anglicisms in toy leaflets aimed at young children in Spain (Luján-García, 2011) or teenagers in Las Palmas de Gran Canaria (González Cruz, Rodríguez-Medina and Déniz, 2009).
Fuschsman et al., 2007). The Ni/Al and V/Al ratios pres- ent similar variations along the core and in agreement with those observed for N1. The Pb/Al ratio inthe top (5 to 6 cm) show high values that may be a result of an unusual Pb supply originated from either the Grijalva River, the atmospheric supplies, or the oil-industry re- lated activities (Varela, 2007). Furthermore, a correla- tion analyses of normalized data for total metals, namely Fe/Al with Mn/Al, Ni/Al with V/Al, and Ni/Al with V/Al were found to be statistically significant (p < 0.05; n = 24; Table 1). These results further confirm an influence of sediments originated from oil wells. Addi- tional cluster and principal components analyses for normalized data of total metals reveal four conglomer- ates formed by the Fe/Al, Mn/Al, Ni/Al and V/Al ratios, while those presenting no statistical significance were found to be the Pb/Al and Ba/Al ratios (Balsam et al., 2007), (S4, Supplementary Information Section).
Toxins ofthe sulfocarbamoyl group, main- ly C1 and C2, predominate during adaptation and maximal growth, and thereafter toxins ofthe carbamoyl group dominate. Therefore it is plausible to infer that inthe sampled bloom, G. catenatum population was in decay. This possibility is supported by the absence or low densities of dinoflagellates observed a week afterwards. It is important to note that natural toxicity and toxin composition is the result ofthe cell response to specific physical and chemical conditions from the sampled area (Cembella 1998, Montoya et al. 2010). There- fore in a direct comparison with other studies it is only valuable to look for a general pattern of local or regional populations, if any. Studies made in natural conditions of Mexican waters of G. catenatum present important variations inthe toxin profile with no clear patterns (Gárate-Lizárraga et al. 2004a, 2004b, 2006, Hernández-Sandoval et al. 2009) indicating a clear necessity for further field investigation for this species.
Seagrasses, in general terms, appear to be relatively tolerant to many anthropogenic chemicals. Several species have been shown to be less sensitive to chemicals than other species of marine flora, corals and macroinvertebrates. In addition, some seagrasses bioaccumulate chemicals at lower concentrations (Lewis & Devereux 2009). Damage to seagrass communi- ties from oil exposure includes acute mortality resulting from physical impacts and chemical toxicity; indirect mortality as the result of light loss, death of food sources, or the destruction or removal of habitat; destruction of sensitive juve- nile fishes and invertebrates; and accumulation of potentially carcinogenic or mutagenic sub- stances inthe food chain (Zieman et al. 1984). Fauna and flora associated with seagrasses are also affected by oil. Infauna, nearly completely killed by oil exposure, gradually returned to abundances above prespill levels. However, only species with high reproductive potential or planktonic stages recovered quickly. The effects of oil on tropical fish have not been extensively studied (Peters et al. 1997).
Abstract: Fishing mortality ofthe brown shrimp (Penaeus aztecus) was estimated off Tamaulipas (northwest GulfofMexico). Monthly age structure and fishing effort data for the 1974-1980 period, and cohort analysis by the virtual population analysis (VPA) technique were used. Catchability estimates indieate higher values for the first matnrity age (six months old), fishing mortality inereases with age, with an asymptotic tendeney after 8-9 rnoths
We evaluated the mycorrhizal status of Jacaratia mexicana A. DC. and the presence of arbuscular mycorrhizal fungi (AMF) in three patches of dry deciduous forests located on the slope oftheGulfofMexico. There were no mycorrhizal structures in any ofthe materials collected in field, and therefore the susceptibility of this specie to AMF was determined. The study revealed the presence of arbuscles and vesicles 15 days after inoculation. Six morphospecies were identified: Glomus intraradices, G. constrictum, G. sinuosum, Glomus sp. 1, Glomus sp. 2. and Entrophospora infrequens. The only related morphospecies in sampled sites were G. intraradices and G. sinuosum, and they were also fairly abundant in Veracruz (8, 870 and 5), Campeche (958 and 448) and Yucatán (3,708 and 16). All of them have not been reported associated with J. mexicana in our country before.