X-ray microtomography of hydrochloric acid propagation in carbonate rocks.

Acid treatments are used in the oil and gas industry, to increase the permeability of the carbonate reservoirs by creating preferential channels, called wormholes. Channels formation is strongly influenced by acid type and injection rate. The aim of this study is to evaluate some characteristics of the microporous system of carbonate rocks, before and after acidizing. For that purpose X-ray high-resolution microtomography was used. The results show that this technique can be used as a reliable method to analyze microstructural characteristics of the wormholes.

Internal artificial vagina (IAV) to assess breeding behavior of young Bos taurus and Bos indicus bulls.

Bull breeding soundness evaluation (BBSE) usually neglects the libido and mating ability evaluation. The internal artificial vagina (IAV) permits semen sampling, as well as mating ability evaluation. Few studies have been performed using IAV with young bulls and there are none with Bos indicus bulls. The present study evaluated sexual behavior, mating ability and semen quality in young Bos taurus (Devon) and B. indicus (Nellore) bulls using the IAV device. In the first experiment, 52 Devon bulls, 18-25 months old were observed, and the behavior and mating ability recorded over a 10-min period within a restrained mount-cow with an IAV inserted. In the second experiment, 20 Nellore bulls, 20-30 months old were evaluated over a 20 min period. Of the 52 Devon bulls, 45 (86.5%) had semen recovered with the IAV, 31 (69.0%) were considered satisfactory. Nellore bulls exhibited a different sexual behavior, with 10 bulls not showing any interest in the females. Four bulls demonstrated sexual interest only once, e.g., sniffing, two showed interest on more than one occasion, and four had more than two mounts or mounting attempts. None out of the Nellore bulls was collected with IAV. The IAV was an effective and welfare-promoting animal technology for the evaluation of semen quality and mating ability of B. taurus bulls. However, the IAV was not adequate for young Nellore bulls, probably due to their quiescent sexual behavior and delayed sexual maturity. Further studies are needed to evaluate the performance of the IAV for older Nellore bulls.

Relationships among morphology, clinging performance and habitat use in Liolaemini lizards.

The central tenet of ecomorphological theory holds that different ecological requirements lead to different organismal designs (morphology). Here, we studied the relationships between performance (interlocking grasping) and forelimb morphological traits in species of lizards that exploit different structural habitats in a phylogenetic context. The performance (measured by the maximum force of clinging to substrate) was measured on different substrate types. After phylogenetically informed analyses, we found that arboreal and saxicolous species showed stronger resistance to mechanical traction in all substrates when compared to generalists and sand dweller lizards. These species showed a positive relationship between forelimb dimensions (humerus length and length of claw of toe 5) and maximum force exerted, on the contrary, hand width, claw height (CH) of digits III and IV and claw length of toe 4 showed a negative relationship. In addition, we observed a partial positive correlation between CH and maximal cling force on rough surfaces, but not on smooth surfaces.

The interplay between claw morphology and microhabitat use in neotropical iguanian lizards.

Traditionally, it has been suggested that variation in locomotor mode should be correlated with variation in the anatomy of the structures responsible for locomotion. Indeed, organisms can expand their ecological niche by using specialized traits of the locomotor system including hooks, claws, adhesive pads, etc. Despite the fact that claws are the most common biological mechanism of clinging in vertebrates, little is known about their function or evolutionary relationship to habitat use. The present study focuses on claw morphology in 57 species of iguanian lizards occupying different microhabitats. Qualitative differences in claw shape were explored by means of digital photographs, and quantitative measurements of the length, height and curvature of the claws of both fingers and toes were taken and correlated to information on microhabitat use obtained from the literature. Our analyses showed a strong phylogenetic component that obscured relationships between morphology and ecology. Our results also show differences in claw morphology between species that appear to be related to microhabitat use (climbing versus terrestrial species), with the best ecological descriptors being claw length and height. Performance measures and biomechanical analyses of claw function may consequently be better suited to explain the evolution of claw shape in relation to habitat use in this group.

The importance of phylogenetic scale in tests of Bergmann's and Rapoport's rules: lessons from a clade of South American lizards.

We tested for the occurrence of Bergmann's rule, the pattern of increasing body size with latitude, and Rapoport's rule, the positive relationship between geographical range size and latitude, in 34 lineages of Liolaemus lizards that occupy arid regions of the Andean foothills. We tested the climatic-variability hypothesis (CVH) by examining the relationship between thermal tolerance breadth and distribution. Each of these analyses was performed varying the level of phylogenetic inclusiveness. Bergmann's rule and the CVH were supported, but Rapoport's rule was not. More variance in the data for Bergmann's rule and the CVH was explained using species belonging to the L. boulengeri series rather than all species, and inclusion of multiple outgroups tended to obscure these macroecological patterns. Evidence for Bergmann's rule and the predicted patterns from the CVH remained after application of phylogenetic comparative methods, indicating a greater role of ecological processes rather than phylogeny in shaping the current species distributions of these lizards.

The relationship between morphology, escape behaviour and microhabitat occupation in the lizard clade Liolaemus (Iguanidae: Tropidurinae: Liolaemini).

Phenotypic differences among species are known to have functional consequences that in turn allow species to use different habitats. However, the role of behaviour in this ecomorphological paradigm is not well defined. We investigated the relationship between morphology, ecology and escape behaviour among 25 species of the lizard clade Liolaemus in a phylogenetic framework. We demonstrate that the relationship between morphology and characteristics of habitat structure shows little or no association, consistent with a previous study on this group. However, a significant relationship was found between morphology and escape behaviour with the distance a lizard moved from a potential predator correlated with body width, axilla-groin length, and pelvis width. A significant relationship between escape behaviour and habitat structure occupation was found; lizards that occupied tree trunks and open ground ran longer distances from predators and were found greater distances from shelter. Behavioural strategies used by these lizards in open habitats appear to have made unnecessary the evolution of limb morphology that has occurred in other lizards from other clades that are found in open settings. Understanding differences in patterns of ecomorphological relationships among clades is an important component for studying adaptive diversification.

Prenatal care needs, availability, accessibility, use, and satisfaction: a comparison of military women within and outside the continental United States.

This article presents the results of a survey distributed to military women within and outside the continental United States (CONUS and OCONUS) who had received prenatal care and delivered at one of six Army, Navy, or Air Force military facilities. This comparative descriptive study was undertaken to determine from the mothers' perspective (1) their needs, availability, accessibility, use, satisfaction, and preferences for prenatal care services, and (2) if prenatal care and birth outcomes were significantly different for CONUS versus OCONUS women. Both groups reported a high degree of satisfaction with services, clinics/offices, and health care staff. Significant group differences were reported in transportation, length of travel time, and cost of traveling, with the CONUS group reporting greater problems with each. For both groups, quality and consistency of health care were the two most important factors in their preference of provider. More than 20% of the mothers reported receiving no information on some of the common concerns of pregnancy. There were no significant group differences with regard to infant birth weight or length of hospital stay.