14 research outputs found
Ancient Divergence Time Estimates In Eutropis Rugifera Support The Existence Of Pleistocene Barriers On The Exposed Sunda Shelf
Episodic sea level changes that repeatedly exposed and inundated the Sunda Shelf
characterize the Pleistocene. Available evidence points to a more xeric central Sunda
Shelf during periods of low sea levels, and despite the broad land connections that
persisted during this time, some organisms are assumed to have faced barriers to
dispersal between land-masses on the Sunda Shelf. Eutropis rugifera is a secretive,
forest adapted scincid lizard that ranges across the Sunda Shelf. In this study, we
sequenced one mitochondrial (ND2) and four nuclear (BRCA1, BRCA2, RAG1, and
MC1R) markers and generated a time-calibrated phylogeny in BEAST to test whether
divergence times between Sundaic populations of E. rugifera occurred during
Pleistocene sea-level changes, or if they predate the Pleistocene. We find that
E. rugifera shows pre-Pleistocene divergences between populations on different Sundaic
land-masses. The earliest divergence within E. rugifera separates the Philippine samples
from the Sundaic samples approximately 16 Ma; the Philippine populations thus cannot
be considered conspecific with Sundaic congeners. Sundaic populations diverged
approximately 6 Ma, and populations within Borneo from Sabah and Sarawak separated
approximately 4.5 Ma in the early Pliocene, followed by further cladogenesis in
Sarawak through the Pleistocene. Divergence of peninsular Malaysian populations from
the Mentawai Archipelago occurred approximately 5 Ma. Separation among island
populations from the Mentawai Archipelago likely dates to the Pliocene/Pleistocene
boundary approximately 3.5 Ma, and our samples from peninsular Malaysia appear to
coalesce in the middle Pleistocene, about 1 Ma. Coupled with the monophyly of these
populations, these divergence times suggest that despite consistent land-connections
between these regions throughout the Pleistocene E. rugifera still faced barriers to
dispersal, which may be a result of environmental shifts that accompanied the sea-level
changes
Claudicação em cavalos Crioulos atletas Lameness in athletic Criollo horses
O objetivo deste trabalho foi identificar as principais causas de claudicação em cavalos Crioulos em treinamento para a prova do Freio de Ouro e competições de rédeas. Foram avaliados os registros clínicos de 201 cavalos Crioulos, 5,6 2,1 anos de idade, submetidos a exame físico devido à presença de claudicação ou histórico de baixo rendimento atlético entre os anos de 2002 a 2009. A claudicação foi localizada nos membros torácicos e pélvicos em 47,1% (n=105) e 52,9% (n=118), respectivamente. Nos machos, houve uma predominância de claudicação nos membros pélvicos (60,0%) e nas fêmeas nos membros torácicos (57,1%). Nos membros torácicos, 17,1% (18/105) das alterações foram diagnosticadas proximais à articulação metacarpofalangeana, 14,3% (15/105) na articulação metacarpofalangeana e 68,6% (72/105) estavam localizadas distais à articulação metacarpofalangeana. Nos membros pélvicos, 78,8% (93/118) apresentaram a origem da dor na região do tarso, 17,8% (21/118) proximal ao tarso e 3,4% (4/118) distal ao tarso. As articulações interfalangeanas distais e intertarsiana distal/tarsometatarsiana são importantes fontes de dor e inflamação e estiveram mais frequentemente envolvidas em claudicações de membro torácico e pélvico, respectivamente. Os cavalos Crioulos apresentam problemas de claudicação semelhantes aos descritos em outras raças que participam de provas de rodeio.<br>This study aimed to identify the source of lameness in Criollo horses that are competing in the most important discipline for this breed in Southern Brazil and also in reining competitions. Clinical records of adult Criollo horses (n=201), 5.6 2.1 years of age, that underwent lameness examination due to history of poor performance or lameness between 2002/2009 were analyzed. Lameness was diagnosed in the front limbs in 47.1% (n=105) and in the hind limbs 52.9% of the cases (n=118). In males 60.0% of the lameness cases were located in the hind limbs. In females 57.1% of the lameness cases were located in the front limbs. In the front limbs (47.1%, n=105/201), problems proximal to the fetlock were diagnosed in 17.1% (18/105). Fetlock problems were diagnosed in 14.3% (15/105) and lesions located distal to the fetlock level were seen in 68.6% (72/105) of the lameness cases diagnosed in the front limbs. In the hind limbs, problems located proximal to the tarsus were seen in 17.8% (21/118), 78.8% (93/118) in the tarsus and 3.4% (4/118) of the cases were seen distal to the tarsus. The distal interfalangeal joint in the front limbs and the distal tarsal joints in the hind limbs were the two most important sources of lameness. Criollo horses presented similar lameness problems as described in other show horses (reining, cutting and roping). This is the first lameness study done in Criollo horses and it will help to better understand the musculoskeletal diseases affecting this breed
A Brief Review of Ultraviolet Auroral Emissions on Giant Planets
The morphologies of the ultraviolet auroral emissions on the giant gas planets, Jupiter and Saturn, have conveniently been described with combinations of a restricted number of basic components. Although this simplified view is very handy for a gross depiction of the giant planets’ aurorae, it fails to scrutinize the diversity and the dynamics of the actual features that are regularly observed with the available ultraviolet imagers and spectrographs. In the present review, the typical morphologies of Jupiter and Saturn’s aurorae are represented with an updated and more accurate set of components. The use of sketches, rather than images, makes it possible to compile all these components in a single view and to put aside ultraviolet imaging technical issues that are blurring the emission sources, thus preventing one from disentangling the different auroral signatures. The ionospheric and magnetospheric processes to which these auroral features allude can then be more easily accounted. In addition, the use of components of the same kind for both planets may help to put forward similarities and differences between Jupiter and Saturn. The case of the ice giants Uranus and Neptune is much less compelling since their weak auroral emissions are very poorly documented and one can only speculate about their origin. This review presents a current perspective that will inevitably evolve in the future, especially with upcoming observing campaigns and forthcoming missions like Juno