76 research outputs found
Utilidad del FEV6 y del cociente FEV1/FEV6 como factores pronósticos en la enfermedad pulmonar obstructiva crónica
Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Medicina. Fecha de lectura: 11-10-201
Ancient mitogenomics clarifies radiation of extinct Mascarene giant tortoises (Cylindraspis spp.)
The five extinct giant tortoises of the genus Cylindraspis belong to the most iconic species of the
enigmatic fauna of the Mascarene Islands that went largely extinct after the discovery of the islands.
To resolve the phylogeny and biogeography of Cylindraspis, we analysed a data set of 45 mitogenomes
that includes all lineages of extant tortoises and eight near-complete sequences of all Mascarene
species extracted from historic and subfossil material. Cylindraspis is an ancient lineage that diverged
as early as the late Eocene. Diversification of Cylindraspis commenced in the mid-Oligocene, long
before the formation of the Mascarene Islands. This rejects any notion suggesting that the group either
arrived from nearby or distant continents over the course of the last millions of years or had even
been translocated to the islands by humans. Instead, Cylindraspis likely originated on now submerged
islands of the Réunion Hotspot and utilized these to island hop to reach the Mascarenes. The final
diversification took place both before and after the arrival on the Mascarenes. With Cylindraspis a
deeply divergent clade of tortoises became extinct that evolved long before the dodo or the Rodrigues
solitaire, two other charismatic species of the lost Mascarene fauna
Body size variation in a lineage of spur-thighed tortoises (Testudo graeca whitei) contrasts with that expected from the species level
Ectotherms exhibit varying geographic size patterns shaped by environmental and evolutionary factors. This variability is noticeable within taxonomic groups. For instance, certain testudinids follow Bergmann’s rule (body size increases with latitude) and Rensch’s rule (sexual size dimorphism correlates with body size), while others do not. Here we hypothesize that body size patterns can even vary within a monophyletic lineage. To address this, we evaluated the body size patterns of the spur-thighed tortoise Testudo graeca that globally follows Bergmann’s and Rensch’s rules. We specifically investigated the influence of climate variables, latitude and elevation within the subspecies T. g. whitei throughout its natural distribution in North Africa, and in a recently expanded range in SE Spain (20 kya old). We found that males were smaller than females in both regions. The tortoises from SE Spain were smaller than those from North Africa, which showcased the smallest sizes ever reported for the species. Latitude was the main variable to explain tortoise body size. In particular, body size decreased with latitude in both regions, which contrasts with Bergmann’s rule expectations based on species-level findings. Finally, to further contradict species-level expectations, we did not find any statistical correlation between sexual size dimorphism and body size across the two studied regions. Such contradictory outcomes reveal complex geographic size patterns within T. graeca and raise conservation questions about demographic viability at smaller-sized sites.This work was supported by Projects PID2019-105682RA-I00 and TED2021-130381B-I00, funded by the Spanish Ministry of Science and Innovation (MCIN/AEI/10.13039/501100011033), the last also with the support of the European Union “NextGenerationEU”/PRTR”; and by funding from the Regional Valen cian Government (AICO/2021/145). The Miguel Hernández University provided support for several stays of MJS in the Ecology Area of the university. RCRC is supported by the European Union-Next Generation EU in the Maria Zambrano Programme (ZAMBRANO 21-26). The Dirección General de Gestión del Medio Natural of Andalusian Government (SGB/FOA/AFR), the Dirección General de Medio Natural of the Murcia Region and the Ministère de l’Agriculture, de la Pêche Maritime, du Développement Rural et des Eaux et Forêts Pêche Maritime, Département des Eaux et Forêts, decisión No. 19/2022 (DEF/DLCDPN/DPRN/CFF), authorized and facilitated sampling
Assessing DESS solution for the long-term preservation of nematodes from faecal samples
Preservation of biological samples is a relevant issue for many scientific disciplines. Although traditional preservers, such as formaldehyde or ethanol, imply major disadvantages related to health risks, DNA degradation and distortion of structures, they are widely used. Hence, the search for viable alternatives preserving morphometry and genetics seems necessary. Here we assess the suitability of DESS solution to preserve adult nematodes and their eggs in faeces. Concretely, faecal samples of terrestrial tortoises with oxyurids were used to: (i) compare the 1-month storage efficacy of eggs from different conservation protocols (faeces without preserver at -20 °C, faeces with DESS solution at room temperature, faeces with DESS solution at -20 °C and faeces with ethanol 70% at room temperature); (ii) address morphological nematode identification after 2 years of storage with DESS. We also corroborated that nematode DNA remained viable after 2 years. Overall, our results showed that DESS solution at room temperature is an advisable alternative to conserve both parasite eggs and adult nematodes for morphological identification and genetic purposes. It also offers the advantages of being low-cost, safe and suitable for fieldwork conditions and shipments without refrigeration for nematode preservation.MG was supported by a contract for postdoctoral researchers from the Generalitat Valenciana with reference APOSTD/2021/181. RCRC was supported by the European Union-Next Generation EU in the Maria Zambrano Program (ZAMBRANO 21-26). This research had the financial support of project PID2019-105682RA-I00, funded by the Spanish Ministry of Science and Innovation MCIN/AEI/10.13039/501100011033
Análisis trabajo no presencial online con Google-Drive en pequeños y grandes grupos en ITE y MSC de Arquitectura (I)
Con este trabajo se ha ensayado la herramienta Google-Drive par utilizarla en el trabajo grupal colaborativo en una asignatura de primer curso del grado de Fundamentos de la Arquitectura y en otra del Master Universitario en Profesorado de Educación Secundaria. Tras la experiencia hemos constatado el desconocimiento en el manejo de este programa por parte del alumnado e incluso del profesorado, y hemos detectado varias dificultades de gestión, y errores en el planteamiento del trabajo, que a partir de la información aportada por este experimento pretendemos subsanar. Hemos concluido el interés de este tipo de herramientas que no requieren la presencia conjunta ni simultánea de los componentes del grupo para la elaboración del trabajo, ni la entrega del documento para la supervisión por parte del profesorado. También hemos descubierto algunas posibilidades que queremos aprovechar para insistir en esta opción de trabajo colaborativo online durante el próximo curso en las asignaturas en que la hemos incorporado este año. Además, pretendemos probarla en la docencia de una nueva asignatura de segundo curso del Grado, en la que se encontrarán el próximo curso los alumnos que se han iniciado este año en la experiencia y dos de las profesoras que han participado
Population density of the spur-thighed tortoise Testudo graeca declines after fire in north-western Africa
Fire is a key ecological process in several biomes worldwide. Over recent decades, human activities (e.g. rural abandonment, monoculture plantations) and global warming are magnifying the risk of fire, with changes in fire intensity and frequency. Here, we offer the first study that examines the impact of fire on the spur-thighed tortoise Testudo graeca living in a native cork oak forest and pine plantation in north-western Africa. A total of 44 transects (22 burnt and 22 unburnt) were sampled at 8 sites affected by fires of natural cork oak forest and pine plantation with 8 surveys per site in 2015–2017 (264 hours of sampling effort). Tortoise densities were estimated with line-transect distance sampling. The detection probability of tortoises was higher in burnt (0.915) than unburnt (0.474) transects. The density of tortoises was negatively associated with elevation and declined with fire by c. 50% in both forest types. The negative response of T. graeca to fire should be considered in conservation planning of this species in north-western Africa in a future scenario of changes in fire regime.BC, SF, and XS received a grant coded (2015-1) from Instituto de Estudios Ceutíes (https://www.ieceuties.org) to cover part of the fieldwork. The work of EG and RCRC was supported by the Spanish Ministry of Economy, Industry and Competitiveness and European Regional Development Fund (Project CGL2015- 64144; MINECO/FEDER)
Low tortoise abundances in pine forest plantations in forest-shrubland transition areas
The Spanish Ministry of Science and European Regional Development Fund funded this work through Projects CGL2012-33536 and CGL2015- 64144; MINECIO/FEDER. Regional Government of the Community of Valencia supported R.R-C. by a postgraduate grant (ACIF/2010/133) and E.G. by a postdoctoral grant (APOSTD/2015/048).In the transition between Mediterranean forest and the arid subtropical shrublands of the southeastern Iberian Peninsula, humans have transformed habitat since ancient times. Understanding the role of the original mosaic landscapes in wildlife species and the effects of the current changes as pine forest plantations, performed even outside the forest ecological boundaries, are important conservation issues. We studied variation in the density of the endangered spur-thighed tortoise (Testudo graeca) in three areas that include the four most common land types within the species’ range (pine forests, natural shrubs, dryland crop fields, and abandoned crop fields). Tortoise densities were estimated using a two-stage modeling approach with line transect distance sampling. Densities in dryland crop fields, abandoned crop fields and natural shrubs were higher (>6 individuals/ha) than in pine forests (1.25 individuals/ha). We also found large variation in density in the pine forests. Recent pine plantations showed higher densities than mature pine forests where shrub and herbaceous cover was taller and thicker. We hypothesize that mature pine forest might constrain tortoise activity by acting as partial barriers to movements. This issue is relevant for management purposes given that large areas in the tortoise’s range have recently been converted to pine plantations.Publisher PDFPeer reviewe
Sperm storage reduces the strength of the mate‐finding Allee effect
Mate searching is a key component of sexual reproduction that can have important implications for population viability, especially for the mate‐finding Allee effect. Interannual sperm storage by females may be an adaptation that potentially attenuates mate limitation, but the demographic consequences of this functional trait have not been studied. Our goal is to assess the effect of female sperm storage durability on the strength of the mate‐finding Allee effect and the viability of populations subject to low population density and habitat alteration. We used an individual‐based simulation model that incorporates realistic representations of the demographic and spatial processes of our model species, the spur‐thighed tortoise (Testudo graeca). This allowed for a detailed assessment of reproductive rates, population growth rates, and extinction probabilities. We also studied the relationship between the number of reproductive males and the reproductive rates for scenarios combining different levels of sperm storage durability, initial population density, and landscape alteration. Our results showed that simulated populations parameterized with the field‐observed demographic rates collapsed for short sperm storage durability, but were viable for a durability of one year or longer. In contrast, the simulated populations with a low initial density were only viable in human‐altered landscapes for sperm storage durability of 4 years. We find that sperm storage is an effective mechanism that can reduce the strength of the mate‐finding Allee effect and contribute to the persistence of low‐density populations. Our study highlights the key role of sperm storage in the dynamics of species with limited movement ability to facilitate reproduction in patchy landscapes or during population expansion. This study represents the first quantification of the effect of sperm storage durability on population dynamics in different landscapes and population scenarios.Financial support was granted by the Spanish Ministry of Economy, Industry and Competitiveness, and by the European Regional Development Fund (Projects CGL2012-33536, CGL2015-64144; MINECO/FEDER, UE). M.V.J.F. was supported by a “Juan de la Cierva-formación” postdoctoral grant of the Spanish Ministry of Economy and Competitiveness (reference JCI-2015-23508), a José Castillejo travel fund (reference CAS17/00225) from the Spanish Ministry of Education, Culture and Sport and a postdoctoral grant funded by the Regional Valencian Government and the European Social Fund (APOSTD/2018/043). A.S.A. was supported by a Vicenç Mut contract co-funded by the Regional Government of the Balearic Islands and the European Social Fund (PD/003/2016). A.S.A and J.D.A were supported by a Ramón y Cajal contracts (RYC-2017-22796 and RYC-2017-22783 respectively) co-funded by the Spanish Ministry of Science, Innovation and Universities, the State Research Agency and the European Social Fund. E.G. was supported by the Regional Valencian Government with a postdoctoral grant (APOSTD/2015/048)
Shorter telomeres are associated with shell anomalies in a long-lived tortoise
Age-related telomere length (TL) variation is relatively well-described for mammals, birds and other model organisms. Nevertheless, it remains largely unknown in ectotherms, especially turtles and tortoises, which are extremely long-lived species with slow or negligible senescence. In this study, we described TL dynamics in wild spur-thighed tortoises (Testudo graeca), one of the chelonian species with the lowest aging rates. By combining cross-sectional (single) and longitudinal (capture–recapture) samplings, we assessed the relationship between TL and individual characteristics (sex, age, individual growth rate, body condition index, presence of shell anomalies). We did not find any association between TL and sex, individual growth rate, or body condition. However, the relationship with age remains uncertain, likely due to the complex dynamics of TL over time. Interestingly, shorter telomeres correlated significantly with shell anomalies, which are usually assumed as a fitness proxy for reptiles. Overall, our results suggest TL as a potential indicator for ontogenetic studies on tortoises, while its utility as a marker of biological age appears limited.This work was supported by Project PID2019-105682RA-I00 and TED2021-130381B-I00, funded by the Spanish Ministry of Science and Innovation (MCIN/AEI/10.13039/501100011033), the last also with the support of the European Union ‘NextGenerationEU/PRTR’. RCRC is supported by the European Union-Next Generation EU in the Maria Zambrano Programme (ZAMBRANO 21-26)
One scute ring per year in Testudo graeca? A novel method to identify ring deposition patterns in tortoises
A reliable estimation of individuals’ age is helpful to conduct demographic studies on wildlife populations. In tortoises, many studies have estimated individuals’ age by counting growth rings on their scutes, assuming one ring per year (1:1 ratio). However, the accuracy of this method is controversial. The ring deposition pattern can vary depending on species, or even populations, and should be studied comprehensively. We studied the ring deposition pattern of Testudo graeca in southeastern Iberian Peninsula, using recaptures of 156 individuals between 2004 and 2010. We used a novel approach to explore the ring deposition pattern and to test possible differences between localities and individuals. Our results revealed that most analysed individuals (57.4%) showed a 1:1 ratio, in which rings were deposited during months of activity (spring to autumn). However, we found a trend to count less rings than years, which underestimated 1 year every 3 or 4 years. No differences in the deposition patterns were found among sites, sizes or sexes because the halt in growth during hibernation equally affects all tortoises in all sites. Our results support that the assumed 1:1 ratio in the assignment of individuals’ age is too simplistic. Since ring deposition patterns are complex, the use of statistical approaches capable of handling deviations from the assumed deposition ratios can help to better depict population age structures
- …