[Nesting habitat characterization for Amazona oratrix (Psittaciformes: Psittacidae) in the Central Pacific, Mexico]. / Hábitat de anidación de Amazona oratrix (Psittaciformes: Psittacidae) en el Pacífico Central, México.

The nesting requirements of the Yellow-headed Parrot (Amazona oratrix) are poorly understood, despite their broad historical distribution, high demand for pet trade and current endangered status. Information concerning their nesting requirements is required in order to design specific restoration and conser- vation actions. To assess this, we studied their nesting ecology in the Central Pacific, Michoacan, Mexico during a ten year period. The analyzed variables ranged from local scale nest site characteristics such as nesting tree species, dimensions, geographic positions, diet and nesting forest patches structure, to large scale features such as vegetation use and climatic variables associated to the nesting tree distributions by an ecological niche model using Maxent. We also evaluated the parrot tolerance to land management regimes, and compared the Pacific nest trees with 18 nest trees recorded in an intensively managed private ranch in Tamaulipas, Gulf of Mexico. Parrots nested in tall trees with canopy level cavities in 92 nest-trees recorded from 11 tree species. The 72.8% of nesting occurred in trees of Astronium graveolens, and Enterolobium cyclocarpum which qualified as key- stone trees. The forests where the parrots nested, presented a maximum of 54 tree species, 50% of which were identified as food source; besides, these areas also had a high abundance of trees used as food supply. The lowest number of tree species and trees to forage occurred in an active cattle ranch, whereas the highest species rich- ness was observed in areas with natural recovery. The nesting cavity entrance height from above ground of the Pacific nesting trees resulted higher than those found in the Gulf of Mexico. We hypothesize that the differences may be attributed to Parrot behavioral differences adapting to differential poaching pressure and cavity avail- ability. Nesting trees were found in six vegetation types; however the parrots preferred conserved and riparian semi-deciduous forest for nesting, with fewer nests in deciduous forest, while nesting in transformed agricultural fields was avoided. The main climatic variables associated with the potential distribution of nests were: mean temperature of wettest quarter, mean diurnal temperature range, and precipitation of wettest month. Suitable cli- matic conditions for the potential presence of nesting trees were present in 61% of the region; however, most of the area consisted of tropical deciduous forests (55.8%), while semi-deciduous tropical forests covered only 17% of the region. These results indicated the importance to conserve semi-deciduous forests as breeding habitats for the Yellow-headed Parrot, and revealed the urgent need to implement conservation and restoration actions. These should include a total ban of land use change in tropical semi-deciduous forest areas, and for selective logging of all keystone tree species; besides, we recommend the establishment of wildlife sanctuaries in important nesting areas, and a series of tropical forest restoration programs in the Central Pacific coast.

Convergent and environmentally associated chromatic polymorphism in Bryconops Kner, 1858 (Ostariophysi: Characiformes: Iguanodectidae).

Bryconops Kner, 1858, includes two well defined subgenera based on morphological evidence, with each containing at least one species (B. (Bryconops) caudomaculatus and B. (Creatochanes) melanurus) with a very wide distribution, within which regional populations present color variations. To test if phenotypic variation is related to cladogenetic events, we performed tests for phylogenetic independence and determined the strength of convergence for color characters in relation to water type, as the variation between clear, black and white waters is considered to be one of the major driving forces in the evolution of Amazonian fishes. Color characters for fins above the median line of the body were generally found to be independent from phylogeny and the Wheatsheaf test strongly supports convergence of the dorsal fin color between populations of species in the same type of water, with a similar trend suggested for the color of the dorsal lobe of the caudal fin. This means that simple color characters cannot necessarily be relied upon for taxonomic revisions of the genus as local phenotypic variants may represent environmentally determined plasticity or convergent evolution. Further studies are required to determine the validity of these characters.

Using species distribution modeling to generate relative abundance information in socio-politically unstable territories: Conservation of Felidae in the central-western region of Mexico.

The distribution range and population abundance of species provide fundamental information on the species-habitat relationship required for management and conservation. Abundance inherently provides more information about the ecology of species than do occurrence data. However, information on abundance is scarce for most species, mainly at large spatial scales. The objective of this work was, therefore, to provide information regarding the population status of six wild felids inhabiting territories in Mexico that are inaccessible or politically unstable. This was done using species distribution models derived from occurrence data. We used distribution data at a continental scale for the wild felids inhabiting Mexico: jaguar (Panthera onca), bobcat (Lynx rufus), ocelot (Leopardus pardalis), cougar (Puma concolor), margay (Leopardus wiedii), and jaguarundi (Herpailurus yagouaroundi) to predict environmental suitability (estimated by both Maxent and the distance to niche centroid, DNC). Suitability was then examined by relating to a capture rate-based index, in a well-monitored area in central western Mexico in order to assess their performance as proxies of relative abundance. Our results indicate that the environmental suitability patterns predicted by both algorithms were comparable. However, the strength of the relationship between the suitability and relative abundance of local populations differed across species and between algorithms, with the bobcat and DNC, respectively, having the best fit, although the relationship was not consistent in all the models. This paper presents the potential of implementing species distribution models in order to predict the relative abundance of wild felids in Mexico and offers guidance for the proper interpretation of the relationship between suitability and population abundance. The results obtained provide a robust information base on which to outline specific conservation actions and on which to examine the potential status of endangered species inhabiting remote or politically unstable territories in which on-field monitoring programs are not feasible.

Genealogical relationship inference to identify areas of intensive poaching of the Orange-fronted Parakeet (Eupsittula canicularis).

BACKGROUND: The Orange-fronted Parakeet (Eupsittula canicularis) is the Mexican psittacine that is most captured for the illegal pet trade. However, as for most wildlife exploited by illegal trade, the genetic diversity that is extracted from species and areas of intensive poaching is unknown. In this study, we analyzed the genetic diversity of 80 E. canicularis parakeets confiscated from the illegal trade and estimated the level of extraction of genetic diversity by poaching using the mitochondrial DNA sequences of cytochrome b (Cytb). In addition, we analyzed the genealogical and haplotypic relationships of the poached parakeets and sampled wild populations in Mexico, as a strategy for identifying the places of origin of poached parakeets. RESULTS: Poached parakeets showed high haplotype diversity (Hd = 0.842) and low nucleotide diversity (Pi = 0.00182). Among 22 haplotypes identified, 18 were found exclusively in 37 individuals, while four were detected in the remaining 43 individuals and shared with the wild populations. A rarefaction and extrapolation curve revealed that 240 poached individuals can include up to 47 haplotypes and suggested that the actual haplotype richness of poached parakeets is higher than our analyses indicate. The geographic locations of the four haplotypes shared between poached and wild parakeets ranged from Michoacan to Sinaloa, Mexico. However, the rare haplotypes detected in poached parakeets were derived from a recent genetic expansion of the species that has occurred between the northwest of Michoacan and the coastal region of Colima, Jalisco and southern Nayarit, Mexico. CONCLUSIONS: Poached parakeets showed high genetic diversity, suggesting high extraction of the genetic pool of the species in central Mexico. Rarefaction and extrapolation analyses suggest that the actual haplotype richness in poached parakeets is higher than reflected by our analyses. The poached parakeets belong mainly to a very diverse genetic group of the species, and their most likely origin is between northern Michoacan and southern Nayarit, Mexico. We found no evidence that poachers included individuals from Central American international trafficking with individuals from Mexico in the sample.

Design of cassette vectors permitting cloning of all types of human TCR variable alpha and beta regions.

T cell clones are an irreplaceable asset for the study of immune responses relevant to human pathologies. Such cells, however, cannot always be maintained in long-term culture. In order to reconstitute functional human T cell receptors (TCRs) into stable and fast growing hybridoma T cells, we developed a general approach based on a versatile cassette system, which allows cloning of all types of human T cell receptor variable alpha and beta region genes fused to murine constant regions. These chimeric constructs are easily excised and transferred into expression vectors that can be used to transfect a human CD4-expressing murine T cell hybridoma recipient. The resulting transfectants are highly stable both in terms of T cell receptor-CD3 expression and IL-2 response to the specific antigenic stimulus. Using these cassette vectors, we reconstituted the original HLA-restricted antigen specificity for two human T cell clones, one recognizing an immunodominant epitope of HIV-1 gp120, and the other recognizing an immunodominant epitope of HIV-1 reverse transcriptase. We found that the reconstituted hybridomas maintain the ability of the original T cell clones to recognize the appropriate epitope in the context of the relevant MHC either as a synthetic peptide or after processing. Their unlimited growth capacity makes them particularly suited for in vitro studies.

Identical T-cell receptor beta chain rearrangements are present in T cells infiltrating the jejunal mucosa of untreated celiac patients.

The intestinal mucosal lesion in celiac disease is characterized by a predominant T-cell infiltration of both epithelium and lamina propria. However, a restricted use of T-cell receptors (TCR) in T lymphocytes infiltrating the jejunal mucosa of celiac patients has not been reported. Based on an immunohistochemical survey of jejunal biopsies from a cohort of untreated celiac patients, we demonstrated a small but significant increase of V beta 8.1/2+ T cells in the lamina propria, but not in the epithelium nor in the peripheral blood. Sequence analysis indicated the existence of a variable degree of clonality of V beta 8+ T cells in the celiac mucosa. More importantly, the recurrence of identical CDR3 regions in some patients was also observed. The altered distribution of V beta 8+ T cells and the presence of identical CDR3 regions in celiac patients, but not in controls was independently confirmed by CDR3 size analysis in a further cohort of patients. These findings suggest that disease-specific variations of the TCRBV8 repertoire are present in the small intestinal mucosa of untreated celiac patients.

Low-frequency RF hyperthermia: IV--A 27 MHz hybrid applicator for localized deep tumor heating.

A 27 MHz dual-device applicator of novel design, which is aimed to heat noninvasively with improved safety tumor masses at depth, is proposed. A substantially localized temperature gain is obtained by superimposing two delocalized low RF frequency and phase-coherent current distributions, which are launched to constructively interfere over a limited region emcompassing the tumor volume. An hybrid applicator (HA) has been developed, integrated one capacitive and one inductive heating device, and has been assessed on a 20 cm diameter cylindrical fat-muscle phantom. The interference pattern is characterized by a deep broad SAR maximum and by the disappearance of the central null SAR value typical of single inductive devices. An 80% SAR useful therapeutic volume (UTV) of a near-cylindrical shape of about 800 cm3 is obtained with a penetration of 6-8 cm for the phantom surface, with a noncritical axial length of approximately 21 cm. The UTV may be somehow controlled in size and penetration. These results are obtained with the tissue-like medium surrounding the UTV heated uniformly and safely to a temperature pedestal below the therapeutic temperature with about half RF power values to each of the heating devices.

27 MHz conformal capacitive ring (CR) applicators for uniform hyperthermic/diathermic treatment of body segments with axial fields.

A family of 27 MHz heating devices has been developed and fundamental tests carried out. The devices consist in a pair of ring-like, flexible, capacitive electrodes, conformally wrapped round the tissue to be heated, for use in hyperthermia and rehabilitation treatment. These capacitive ring (CR) applicators produce an axial E-field which can uniformly heat the central portion of a 20 cm OD cylindrical phantom simulating fat and muscle tissues. This electrode-body configuration can be used to uniformly heat most human body segments with the highest symmetry congruence, the RF currents flowing parallel to the boundaries provided by the pseudo-axial symmetry of these segments. With respect to the rigid pads used in RF capacitive heating, the CR electrodes exhibit a larger working surface area. Moreover, they may be used with an interposed dielectric layer between the electrodes and the skin, to reduce edge effects. With respect to the axially symmetric radiators of higher frequency, they are applicable to larger cross-section body segments with increased penetration and without the need of an integral water bolus. The CR devices allow free access to most of the body surface for skin temperature measurement and conditioning, and for combined treatments. Moreover, the almost uniform heating pattern may represent a useful feature for standardizing treatment. The CR electrodes can easily be matched to the RF source even if they are low impedance devices, and they give rise to low-level stray fields, which can be taken care of by a local shield. These CR devices can be considered safe and practical and suitable for regional hyperthermic and rehabilitation treatment.

[Diagnostic and therapeutic value of hysteroscopy in intrauterine synechiae]. / Validità diagnostica e terapeutica dell'isteroscopia nella patologia aderenziale intrauterina.

The paper evaluates the diagnostic and therapeutic value of hysteroscopy in a group of women suffering from intrauterine synechiae secondary to intrauterine mechanical manipulation following spontaneous abortion.

Fracture process characterization of fiber-reinforced dental composites evaluated by optical coherence tomography, SEM and optical microscopy.

This study used optical coherence tomography (OCT) compared to scanning electron microscopy (SEM) and optical microscopy (OM) to evaluate qualitatively crack propagation and final fracture in restorative composite materials - Filtek Z250 and Filtek Z350 (3M ESPE) - with fiber reinforcement after cyclic loading. Samples were made using a split mold. Initially, 3-point bending tests were performed to determine the maximum force and tension at the fracture moment using samples without fiber reinforcement. Then, mechanical cycling tests were performed using samples with glass fiber embedded internally. The failures were analyzed using the 3 methods described before. OCT permitted good characterization of internal crack propagation of the dental composites, which, however, could not be visualized by either SEM or OM. OCT was proven to be laboratory research tool that is easy to use, does not require any specific preparation of the samples, and is less expensive than SEM.

Hábitat de anidación de Amazona oratrix (Psittaciformes: Psittacidae) en el Pacífico Central, México / Nesting habitat characterization for Amazona oratrix (Psittaciformes: Psittacidae) in the Central Pacific, Mexico

The nesting requirements of the Yellow-headed Parrot (Amazona oratrix) are poorly understood, despite their broad historical distribution, high demand for pet trade and current endangered status. Information concerning their nesting requirements is required in order to design specific restoration and conservation actions. To assess this, we studied their nesting ecology in the Central Pacific, Michoacan, Mexico during a ten year period. The analyzed variables ranged from local scale nest site characteristics such as nesting tree species, dimensions, geographic positions, diet and nesting forest patches structure, to large scale features such as vegetation use and climatic variables associated to the nesting tree distributions by an ecological niche model using Maxent. We also evaluated the parrot tolerance to land management regimes, and compared the Pacific nest trees with 18 nest trees recorded in an intensively managed private ranch in Tamaulipas, Gulf of Mexico. Parrots nested in tall trees with canopy level cavities in 92 nest-trees recorded from 11 tree species. The 72.8% of nesting occurred in trees of Astronium graveolens, and Enterolobium cyclocarpum which qualified as keystone trees. The forests where the parrots nested, presented a maximum of 54 tree species, 50% of which were identified as food source; besides, these areas also had a high abundance of trees used as food supply. The lowest number of tree species and trees to forage occurred in an active cattle ranch, whereas the highest species richness was observed in areas with natural recovery. The nesting cavity entrance height from above ground of the Pacific nesting trees resulted higher than those found in the Gulf of Mexico. We hypothesize that the differences may be attributed to Parrot behavioral differences adapting to differential poaching pressure and cavity availability. Nesting trees were found in six vegetation types; however the parrots preferred conserved and riparian semi-deciduous forest for nesting, with fewer nests in deciduous forest, while nesting in transformed agricultural fields was avoided. The main climatic variables associated with the potential distribution of nests were: mean temperature of wettest quarter, mean diurnal temperature range, and precipitation of wettest month. Suitable climatic conditions for the potential presence of nesting trees were present in 61% of the region; however, most of the area consisted of tropical deciduous forests (55.8%), while semi-deciduous tropical forests covered only 17% of the region. These results indicated the importance to conserve semi-deciduous forests as breeding habitats for the Yellow-headed Parrot, and revealed the urgent need to implement conservation and restoration actions. These should include a total ban of land use change in tropical semi-deciduous forest areas, and for selective logging of all keystone tree species; besides, we recommend the establishment of wildlife sanctuaries in important nesting areas, and a series of tropical forest restoration programs in the Central Pacific coast. Rev. Biol. Trop. 62 (3): 1053-1072. Epub 2014 September 01.

Los requerimientos de anidación del loro cabeza-amarilla (Amazona oratrix) son poco conocidos a pesar de su amplia distribución histórica, la alta demanda como mascota y estar en peligro de extinción. Esta información es necesaria para diseñar acciones específicas de restauración y conservación. Durante diez años estudiamos la ecología de anidación del loro en Michoacán, México. Las variables estudiadas incluyeron en escala local las especies de árboles-nido, sus dimensiones y posición geográfica, dieta y estructura de parches de bosque; y a mayor escala el uso de la vegetación y las variables climáticas asociadas a la distribución de árboles-nido, obtenidas con un modelo de nicho ecológico utilizando Maxent. También evaluamos la tolerancia del loro al manejo de la tierra, y comparamos los árboles-nido encontrados, con 18 árboles-nido de Tamaulipas (Golfo de México), estudiados en los ochentas en un rancho privado intensamente manejado. Los loros anidaron en árboles altos en cavidades del dosel, registramos 92 árboles-nido en 11 especies de árboles, pero el 72.8% se presentó en Astronium graveolens y Enterolobium cyclocarpum que califican como árboles clave. Los bosques de anidación presentan 54 especies de árboles como máximo, y 50% sirven como alimento, también las zonas presentan alta abundancia de árboles dieta. La menor riqueza de árboles y de árboles dieta se presentó en un rancho ganadero, mientras que las áreas en regeneración natural presentaron mayor riqueza. La altura de la entrada de la cavidad en los árboles-nido del Pacífico fue mayor que en los del Golfo de México. Hipotetizamos que las diferencias se deben al comportamiento del loro, adaptado a la presión diferencial de saqueo de nidos y disponibilidad de cavidades. Los árboles-nido se encontraron en seis tipos de vegetación, pero el loro prefirió el bosque tropical subcaducifolio conservado, y ribereño, anidó menos en bosque tropical caducifolio y nunca en campos agrícolas transformados, difiriendo de lo esperado por la disponibilidad de hábitat. Las principales variables climáticas asociadas con la distribución potencial de nidos son: temperatura promedio del trimestre más lluvioso, oscilación diurna de la temperatura, y precipitación del mes más lluvioso. Las áreas de presencia potencial de árboles-nido representan el 61% de la región, sin embargo la mayor parte es bosque tropical caducifolio (55.8%), y el bosque tropical subcaducifolio sólo ocupa 17%. Los resultados indican la importancia del bosque tropical subcaducifolio conservado como hábitat de reproducción del loro cabeza-amarilla, y muestran la urgente necesidad de implementar acciones de conservación y restauración. Las acciones deben incluir la prohibición del cambio de uso del suelo del bosque tropical subcaducifolio, y de la tala selectiva de especies clave, la creación de santuarios de vida silvestre en las áreas de anidación y programas de restauración de los bosques tropicales de la costa del Pacífico central.

Fracture process characterization of fiber-reinforced dental composites evaluated by optical coherence tomography, SEM and optical microscopy

This study used optical coherence tomography (OCT) compared to scanning electron microscopy (SEM) and optical microscopy (OM) to evaluate qualitatively crack propagation and final fracture in restorative composite materials - Filtek Z250 and Filtek Z350 (3M ESPE) - with fiber reinforcement after cyclic loading. Samples were made using a split mold. Initially, 3-point bending tests were performed to determine the maximum force and tension at the fracture moment using samples without fiber reinforcement. Then, mechanical cycling tests were performed using samples with glass fiber embedded internally. The failures were analyzed using the 3 methods described before. OCT permitted good characterization of internal crack propagation of the dental composites, which, however, could not be visualized by either SEM or OM. OCT was proven to be laboratory research tool that is easy to use, does not require any specific preparation of the samples, and is less expensive than SEM.