1,199 research outputs found
Integrating ecology into macroevolutionary research
On 9 March, over 150 biologists gathered in London for the Centre for Ecology and Evolution spring symposium, ‘Integrating Ecology into Macroevolutionary Research’. The event brought together researchers from London-based institutions alongside others from across the UK, Europe and North America for a day of talks. The meeting highlighted methodological advances and recent analyses of exemplar datasets focusing on the exploration of the role of ecological processes in shaping macroevolutionary patterns
The past and future human impact on mammalian diversity
To understand the current biodiversity crisis, it is crucial to determine how humans have affected biodiversity in the past. However, the extent of human involvement in species extinctions from the Late Pleistocene onward remains contentious. Here, we apply Bayesian models to the fossil record to estimate how mammalian extinction rates have changed over the past 126,000 years, inferring specific times of rate increases. We specifically test the hypothesis of human-caused extinctions by using posterior predictive methods. We find that human population size is able to predict past extinctions with 96% accuracy. Predictors based on past climate, in contrast, perform no better than expected by chance, suggesting that climate had a negligible impact on global mammal extinctions. Based on current trends, we predict for the near future a rate escalation of unprecedented magnitude. Our results provide a comprehensive assessment of the human impact on past and predicted future extinctions of mammals
Deep MOS Spectroscopy of NGC 1316 Globular Clusters
The giant elliptical galaxy NGC 1316 is the brightest galaxy in the Fornax
cluster, and displays a number of morphological features that might be
interpreted as an intermediate age merger remanent (3 Gyr). Based on the
idea that globular clusters systems (GCS) constitute genuine tracers of the
formation and evolution of their host galaxies, we conducted a spectroscopic
study of approximately 40 globular clusters (GCs) candidates associated with
this interesting galaxy. We determined ages, metallicities, and
-element abundances for each GC present in the sample, through the
measurement of different Lick indices and their subsequent comparison with
simple stellar populations models (SSPs).Comment: 5 pages, 3 figure
Dynamic self-referencing approach to whispering gallery mode biosensing and its application to measurement within undiluted serum
Biosensing within complex biological samples requires a sensor that can compensate for fluctuations in the signal due to changing environmental conditions and nonspecific binding events. To achieve this, we developed a novel self-referenced biosensor consisting of two almost identically sized dye-doped polystyrene microspheres placed on adjacent holes at the tip of a microstructured optical fiber (MOF). Here self-referenced biosensing is demonstrated with the detection of Neutravidin in undiluted, immunoglobulin-deprived human serum samples. The MOF allows remote excitation and collection of the whispering gallery modes (WGMs) of the microspheres while also providing a robust and easy to manipulate dip-sensing platform. By taking advantage of surface functionalization techniques, one microsphere acts as a dynamic reference, compensating for nonspecific binding events and changes in the environment (such as refractive index and temperature), while the other microsphere is functionalized to detect a specific interaction. The almost identical size allows the two spheres to have virtually identical refractive index sensitivity and surface area, while still having discernible WGM spectra. This ensures their responses to nonspecific binding and environmental changes are almost identical, whereby any specific changes, such as binding events, can be monitored via the relative movement between the two sets of WGM peaks.Tess Reynolds, Alexandre Franc, ois, Nicolas Riesen, Michelle E. Turvey, Stephen J. Nicholls, Peter Hoffmann, and Tanya M. Monr
Sensory retraining: burden in daily life related to altered sensation after orthognathic surgery, a randomized clinical trial
OBJECTIVE: Assess the long-term effect of sensory re-training exercises, age, gender, type of surgery, and pre-surgical psychological distress on patients' perception of the interference related to altered sensation two years after orthognathic surgery. SETTING AND SAMPLE POPULATION: 186 subjects with a developmental dentofacial disharmony were enrolled in a multicenter randomized clinical trial: one center was a community based practice and the other a university-based center. METHODS AND MATERIALS: Subjects were randomly allocated to two groups: standard of care mouth opening exercises after BSSO or a progressive series of sensory retraining facial exercises in addition to the opening exercises. At 1, 3, 6, 12, and 24 months after surgery, subjects scored unusual feelings on the face, numbness, and loss of lip sensitivity from “no problem(1)” to “serious problem(7)”. A marginal proportional odds model was fit for each of the ordinal outcomes. RESULTS: Up to two years after surgery, the opening exercise only group had a higher likelihood of reporting interference in daily activities related to numbness and loss of lip sensitivity than the sensory retraining exercise group. The difference between the two groups was relatively constant. Older subjects and those with elevated psychological distress before surgery reported higher burdens related to unusual facial feelings, numbness, and loss of lip sensitivity (P<0.02). CONCLUSION: The positive effect of sensory retraining facial exercises observed after surgery is maintained over time. Clinicians should consider the patient's age and psychological well-being prior to providing pre-surgical counseling regarding the impact on daily life of persistent altered sensation following a mandibular osteotomy
Russia-UK collaboration in paleontology: past, present, and future
There is a long history of collaboration between Russia and the United Kingdom in paleontology. This began, arguably, in 1821, with the seminal work by William Fox-Strangways, who produced a geological map of the area around St Petersburg. Most famously, Roderick Murchison carried out extensive surveying and observations throughout European Russia in 1840 and 1841, and published a major monograph on geology and paleontology of European Russia in 1845. Since then, and continuing today, there have been many fruitful collaborations on Precambrian life, Paleozoic marine organisms, terrestrialization of plants and vertebrates, the Permian–Triassic mass extinction, fossil mammals, human evolution, and conservation paleobiology
Using site-directed mutagenesis to further the understanding of insulin receptor-insulin like growth factor-1 receptor heterodimer structure
Type 2 diabetes is characterised by the disruption of insulin and insulin-like growth factor (IGF) signalling. The key hubs of these signalling cascades - the Insulin receptor (IR) and Insulin-like growth factor 1 receptor (IGF1R) – are known to form functional IR-IGF1R hybrid receptors which are insulin resistant. However, the mechanisms underpinning IR-IGF1R hybrid formation are not fully understood, hindering the ability to modulate this for future therapies targeting this receptor. To pinpoint suitable sites for intervention, computational hotspot prediction was utilised to identify promising epitopes for targeting with point mutagenesis. Specific IGF1R point mutations F450A, R391A and D555A show reduced affinity of the hybrid receptor in a BRET based donor-saturation assay, confirming hybrid formation could be modulated at this interface. These data provide the basis for rational design of more effective hybrid receptor modulators, supporting the prospect of identifying a small molecule that specifically interacts with this target
Interview-based sighting histories can inform regional conservation prioritization for highly threatened cryptic species
1. The use of robust ecological data to make evidence-based management decisions is frequently prevented by limited data quantity or quality, and local ecological knowledge (LEK) is increasingly seen as an important source of information for conservation. However, there has been little assessment of LEK's usefulness for informing prioritization and management of landscapes for threatened species, or assessing comparative species status across landscapes.
2. A large-scale interview survey in the Annamite Mountains (Vietnam and Lao PDR) compiled the first systematic LEK data set for saola Pseudoryx nghetinhensis, one of the world's rarest mammals, and eight other ungulates. Saola conservation is hindered by uncertainty over continued presence across much of its proposed distribution. We analysed comparative LEK-based last-sighting data across three landscapes to determine whether regional sighting histories support previous suggestions of landscape importance for saola conservation (Hue-Quang Nam: top-priority Vietnamese landscape; Pu Mat: lower priority Vietnamese landscape; Viengthong: high-priority Lao landscape) and whether they constitute an effective spatial prioritization tool for cryptic species management.
3. Wild pig and red muntjac may be the only Annamite ungulates with stable populations; the regional status of all other species appears to be worse. Saola have declined more severely and/or are significantly rarer than most other ungulates and have been seen by relatively few respondents. Saola were also frequently considered locally rarest or declining, and never as species that had not declined.
4. In contrast to other species, there are no regional differences in saola sighting histories, with continued persistence in all landscapes challenging suggestions that regional status differs greatly. Remnant populations persist in Vietnam despite heavy hunting, but even remote landscapes in Lao may be under intense pressure.
5. Synthesis and applications. Our local ecological knowledge data suggest that intact saola populations probably no longer exist, but individuals persist in all three landscapes, making management activities to reduce hunting pressure on ungulates in each landscape a conservation priority. Analysis of last-sighting histories can constitute an important conservation tool when robust data are otherwise unavailable, and collection of last-sighting records should be incorporated more widely into field studies and management of other highly threatened, cryptic species
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