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The article discusses a study in which fossils and inferred homology patterns were used to determine the evolutionary history of the mammalian regionalized spine.

Background: Oceanic archipelagos typically harbour extensive radiations of flowering plants and a high proportion of endemics, many of which are restricted to a single island (Single Island Endemics; SIEs). The Azores represents an anomaly as overall levels of endemism are low; there are few SIEs and few documented cases of intra-archipelago radiations. The distinctiveness of the flora was first recognized by Darwin and has been referred to as the 'Azores Diversity Enigma' (ADE). Diversity patterns in the Macaronesian endemic genus Pericallis (Asteraceae) exemplify the ADE. In this study we used morphometric, Amplified Length Polymorphisms, and bioclimatic data for herbaceous Pericallis lineages endemic to the Azores and the Canaries, to test two key hypotheses proposed to explain the ADE: i) that it is a taxonomic artefact or Linnean shortfall, ie. the under description of taxa in the Azores or the over-splitting of taxa in the Canaries and (ii) that it reflects the greater ecological homogeneity of the Azores, which results in limited opportunity for ecological diversification compared to the Canaries. Results: In both the Azores and the Canaries, morphological patterns were generally consistent with current taxonomic classifications. However, the AFLP data showed no genetic differentiation between the two currently recognized Azorean subspecies that are ecologically differentiated. Instead, genetic diversity in the Azores was structured geographically across the archipelago. In contrast, in the Canaries genetic differentiation was mostly consistent with morphology and current taxonomic treatments. Both Azorean and Canarian lineages exhibited ecological differentiation between currently recognized taxa. Conclusions: Neither a Linnean shortfall nor the perceived ecological homogeneity of the Azores fully explained the ADE-like pattern observed in Pericallis. Whilst variation in genetic data and morphological data in the Canaries were largely congruent, this was not the case in the Azores, where genetic patterns reflected inter-island geographical isolation, and morphology reflected intra-island bioclimatic variation. The combined effects of differences in (i) the extent of geographical isolation, (ii) population sizes and (iii) geographical occupancy of bioclimatic niche space, coupled with the morphological plasticity of Pericallis, may all have contributed to generating the contrasting patterns observed in the archipelagos. [ABSTRACT FROM AUTHOR]

Ecological diversification into new environments presents new mechanical challenges for locomotion. An extreme example of this is the transition from a terrestrial to an aquatic lifestyle. Here, we examine the implications of life in a neutrally buoyant environment on adaptations of the axial skeleton to evolutionary increases in body size. On land, mammals must use their thoracolumbar vertebral column for body support against gravity and thus exhibit increasing stabilization of the trunk as body size increases. Conversely, in water, the role of the axial skeleton in body support is reduced, and, in aquatic mammals, the vertebral column functions primarily in locomotion. Therefore, we hypothesize that the allometric stabilization associated with increasing body size in terrestrial mammals will be minimized in secondarily aquatic mammals. We test this by comparing the scaling exponent (slope) of vertebral measures from 57 terrestrial species (23 felids, 34 bovids) to 23 semi-aquatic species (pinnipeds), using phylogenetically corrected regressions. Terrestrial taxa meet predictions of allometric stabilization, with posterior vertebral column (lumbar region) shortening, increased vertebral height compared to width, and shorter, more disc-shaped centra. In contrast, pinniped vertebral proportions (e.g. length, width, height) scale with isometry, and in some cases, centra even become more spool-shaped with increasing size, suggesting increased flexibility. Our results demonstrate that evolution of a secondarily aquatic lifestyle has modified the mechanical constraints associated with evolutionary increases in body size, relative to terrestrial taxa. [ABSTRACT FROM AUTHOR]

Pinnipeds (seals, sea lions and walruses) are secondarily marine carnivorans that exhibit a wide range of feeding and reproductive specializations. Extant pinnipeds are split into three families: Phocidae (seals), Otariidae (sea lions) and Odobenidae (walruses). Morphometric analyses were used to examine cranial morphology in otariid and phocid pinnipeds. Phocids are more ecologically and taxonomically diverse than otariids, and this study quantitatively assessed the effects of life history, phylogeny and ecology on cranial morphology in these closely related clades of aquatic carnivorans. Fifty-three to 58 three-dimensional landmarks were gathered from 138 specimens, representing 31 of the 33 extant species of otariids and phocids. Principal components analysis was used to identify major axes of variation, and principal component scores were compared with phylogenetic distances and ecological variables to test for significant correlates of skull morphology. Results showed that phocids exhibit a much greater diversity of adult skull morphology than otariids. Shape differences within adult otariids were dominated by males of only one species, Otaria flavescens. In contrast, several species of phocids deviated markedly from the mean phocid morphology. These atypical morphologies were consistently associated with specializations of either feeding or mating strategies. Ontogenetic shape changes are greater, relative to interspecific differences, in otariids than in phocids, and shape dimorphism was observed in only one otariid and two phocid species. Unexpectedly, neither otariids nor phocids showed strong correlations between phylogenetic relationship and cranial morphology. Both clades show strong correlations between cranial shape and some life history and some environmental variables, but phocids show stronger correlations with life-history variables, perhaps reflecting the broad range of reproductive strategies observed in phocids. [ABSTRACT FROM AUTHOR]

Obesity has become pandemic. In America, as obesity has increased, the amount of sleep Americans get per night has decreased, and studies are now showing an association. Epidemiological studies on short sleep duration (SSD) and obesity have been conducted in children and adults, and show an overall positive association. Leptin and ghrelin, two hormones that control appetite, have been studied as a mechanism for SSD causing obesity. Low leptin and high ghrelin levels have been seen in sleep deprivation, the effect of which is an increase in appetite that could be linked to obesity. Decreasing media use, namely television and computers, could be one way to increase nightly sleep and potentially help people lose weight. Paediatric studies have shown an association with bedroom media use and shorter sleep duration. Adult studies are lacking in this area. Limitations in the literature include self-report in a majority of sleep studies and only a suggested causal link between SSD and obesity among all of the epidemiological studies. In conclusion, obesity is a global problem with great complexity. Encouraging people to get more sleep could be one part of the solution to help them lose weight and gain health. [ABSTRACT FROM AUTHOR]

Abstract The intrinsic properties of mammalian spinal motoneurons provide them with the capability to produce high rates of sustained firing in response to transient inputs (bistability). Even though it has been suggested that a persistent dendritic calcium current is responsible for the depolarizing drive underlying this firing property, such a current has not been demonstrated in these cells. In this study, calcium currents are recorded from functionally mature mouse spinal motoneurons using somatic whole-cell patch-clamp techniques. Under these conditions a component of the current demonstrated kinetics consistent with a current originating at a site spatially segregated from the soma. In response to step commands this component was seen as a late-onset, low amplitude persistent current whilst in response to depolarizing–repolarizing ramp commands a low voltage clockwise current hysteresis was recorded. Simulations using a neuromorphic motoneuron model could reproduce these currents only if a noninactivating calcium conductance was placed in the dendritic compartments. Pharmacological studies demonstrated that both the late-onset and hysteretic currents demonstrated sensitivity to both dihydropyridines and the L-channel activator FPL-64176. Furthermore, the α1D subunits of L-type calcium channels were immunohistochemically demonstrated on motoneuronal dendrites. It is concluded that there are dendritically located L-type channels in mammalian motoneurons capable of mediating a persistent depolarizing drive to the soma and which probably mediate the bistable behaviour of these cells. [ABSTRACT FROM AUTHOR]

The hybrid Asplenium azoricum × A. trichomanes subsp. quadrivalens is reported for the first time and described here as A. ×vogelii. Chloroplast DNA sequences are utilised to identify the maternal parent and provide further information on the relationships and possible origin of its endemic parent, A. azoricum. While definitely known only from the type gathering, collected near Terra Chã, Terceira in 1996, there is considerable potential for this hybrid to be overlooked owing to the similarity and variability of its parents. [ABSTRACT FROM AUTHOR]

Objectives: To assess the outcome and workload of a community based, nurse led comprehensive sexual health and contraceptive service for clients aged less than 25. Methods: Review of appointment diaries and clinic records of clients who attended the Brook genitourinary medicine (GUM) clinic. The workload, case mix, and achievement of national targets in the first year of the service were compared with those for the same age group of clients attending the nearby hospital based GUM clinic. A limited client satisfaction questionnaire was carried out 8 months after the clinic opened. Results: 1061/1700 (62.4%) clients (185, 17.4% male) attended booked appointments. Chlamydia trachomatis was detected in 16.1% of women and 20.5% of men at Brook (p<0.05), where 22.6% of women and 50% of men had at least one sexually transmitted infection (p<0.001). HIY testing was offered to 98.5% of clients. 60.7% of all identified contacts attended a clinic for testing and/or treatment. Client responses to a questionnaire about the service were very favourable. Only 2.3% of Brook GUM clients needed referral to a physician. Conclusions: Nurse led community based GUM services, such as the one provided at the Merseyside Brook Centre, appeal to young people and our success should encourage others to consider similar ventures. [ABSTRACT FROM AUTHOR]

Objectives: This study compared the sensitivity and specificity of culture and two nucleic acid amplification tests (NAATs): the BD Probetec ET system (PT) and the Aptima Combo 2 (AC2) in detecting Neisseria gonorrhoeae (GC) and Chlamydia trachomatis (CT) in pharyngeal and rectal specimens. Methods: Male subjects were prospectively recruited at an MSM clinic in Toronto, Canada. Pharyngeal and rectal specimens were obtained for GC and CT culture, PT and AC2. Urine was also obtained for PT. A true positive was defined as: (1) positive culture, (2) positive PT and AC2 at the same site or (3) a single positive NAAT and detection of the same organism by any method at another site. Results: 248 subjects were recruited. The prevalence of pharyngeal GC was 8.1%, rectal GC 11.7%, pharyngeal CT 2.0% and rectal CT 7.7%. The sensitivity of culture for pharyngeal GC and CT was 0%; 41.4% for rectal GC and 21.1% for rectal CT. The sensitivity of PT for pharyngeal GC, rectal GC, pharyngeal CT and rectal CT was 95.0%, 93.1%, 80.0% and 94.7%, respectively. The sensitivity of AC2 was 95.0% for pharyngeal GC and 100% at all other sites. Specificity was consistently above 98%. Conclusions: PT and AC2 detected GC and CT with superior sensitivity compared to culture. They detected 73 pharyngeal or rectal GC and CT infections compared to 16 by culture, using a rigorous gold standard. NAATs should be the method of choice for the detection of GC and CT in extragenital sites in men who have sex with men. [ABSTRACT FROM AUTHOR]

Many life-history traits co-vary across species, even when body size differences are controlled for. This phenomenon has led to the concept of a ‘fast-slow continuum,’ which has been influential in both empirical and theoretical studies of life-history evolution. We present a comparative analysis of mammalian life histories showing that, for mammals at least, there is not a single fast-slow continuum. Rather, both across and within mammalian clades, the speed of life varies along at least two largely independent axes when body size effects are removed. One axis reflects how species balance offspring size against offspring number, while the other describes the timing of reproductive bouts. [ABSTRACT FROM AUTHOR]