Did Going North Give Us Migraine? An Evolutionary Approach on Understanding Latitudinal Differences in Migraine Epidemiology

This commentary discusses a recent publication by evolutionary biologists with strong implications for migraine experts. The Authors showed that a gene polymorphism associated with migraine gave our ancestors an evolutionary advantage when colonizing northern, and thus colder, territories. They then highlight that the prevalence of migraine may differ among countries because of climatic adaptation. These results may prove useful in planning both epidemiological and physiological studies in the field of migraine

Historical and projected future range sizes of the world's mammals, birds, and amphibians.

Species' vulnerability to extinction is strongly impacted by their geographical range size. Formulating effective conservation strategies therefore requires a better understanding of how the ranges of the world's species have changed in the past, and how they will change under alternative future scenarios. Here, we use reconstructions of global land use and biomes since 1700, and 16 possible climatic and socio-economic scenarios until the year 2100, to map the habitat ranges of 16,919 mammal, bird, and amphibian species through time. We estimate that species have lost an average of 18% of their natural habitat range sizes thus far, and may lose up to 23% by 2100. Our data reveal that range losses have been increasing disproportionately in relation to the area of destroyed habitat, driven by a long-term increase of land use in tropical biodiversity hotspots. The outcomes of different future climate and land use trajectories for global habitat ranges vary drastically, providing important quantitative evidence for conservation planners and policy makers of the costs and benefits of alternative pathways for the future of global biodiversity

Can human maxillary premolar crown dimensions discriminate between males and females?

Studies showed that odontometry can be used to analyse the influence of sexual dimorphism on the size of the teeth in specific ancestries. The aim of this study was to explore the bucco-lingual dimensions expressed as a ratio of human maxillary premolar crowns in males and females from polled ancestries. ethnicities If this measurement could discriminate sex, it would have application in forensic cases, mass disasters and archaeology where the number of mingled human remains is high and the ancestry ethnicity is unknown or multiple; Moreover, methodologies applied on radiographs or biochemical analysis in the laboratory is not always possible. The sample studied consisted of unworn premolars from 51 skeletal remains, 19 females and 32 males of known sex from collections: the Hunterian Museum, Royal College of Surgeons, England and the Natural History Museum, London and 100 archived orthodontic plaster casts of young adult dental patients (50 females and 50 males) of Royal London Hospital. Digital photographs were taken parallel to the occlusal surface and intercuspal distance and maximum bucco-lingual distance were captured using ImageJ 1.47v (U. S. National Institutes of Health, Maryland, USA), and the ratio of both distances calculated. Results were compared using a t-test and showed that for both upper premolars, the overall ratio was greater in males than females; however this was not significantly different to zero. The overall ratio for first premolar (P1) was less than second premolar (P2) in males and females. These findings show that maxillary premolar, measured in this way, are not significantly different and cannot discriminate between the sexes in this sample of different ancestries

Different environmental variables predict body and brain size evolution in Homo

Increasing body and brain size constitutes a key macro-evolutionary pattern in the hominin lineage, yet the mechanisms behind these changes remain debated. Hypothesized drivers include environmental, demographic, social, dietary, and technological factors. Here we test the influence of environmental factors on the evolution of body and brain size in the genus Homo over the last one million years using a large fossil dataset combined with global paleoclimatic reconstructions and formalized hypotheses tested in a quantitative statistical framework. We identify temperature as a major predictor of body size variation within Homo, in accordance with Bergmann’s rule. In contrast, net primary productivity of environments and long-term variability in precipitation correlate with brain size but explain low amounts of the observed variation. These associations are likely due to an indirect environmental influence on cognitive abilities and extinction probabilities. Most environmental factors that we test do not correspond with body and brain size evolution, pointing towards complex scenarios which underlie the evolution of key biological characteristics in later Homo.Introduction Results - Approach of power analysis and linear regressions - Power analysis of synthetic data - Analysis of fossil data Discussion Methods - Body and brain size database - Climate reconstructions - Synthetic datasets and power analysi

Addendum: High-resolution terrestrial climate, bioclimate and vegetation for the last 120,000 years.

Funder: European Research Council Grant 647797Abstract: The variability of climate has profoundly impacted a wide range of macroecological processes in the Late Quaternary. Our understanding of these has greatly benefited from palaeoclimate simulations, however, high-quality reconstructions of ecologically relevant climatic variables have thus far been limited to a few selected time periods. Here, we present a 0.5° resolution bias-corrected dataset of global monthly temperature, precipitation, cloud cover, relative humidity and wind speed, 17 bioclimatic variables, annual net primary productivity, leaf area index and biomes, covering the last 120,000 years at a temporal resolution of 1,000–2,000 years. We combined medium-resolution HadCM3 climate simulations of the last 120,000 years with high-resolution HadAM3H simulations of the last 21,000 years, and modern-era instrumental data. This allows for the temporal variability of small-scale features whilst ensuring consistency with observed climate. Our data make it possible to perform continuous-time analyses at a high spatial resolution for a wide range of climatic and ecological applications - such as habitat and species distribution modelling, dispersal and extinction processes, biogeography and bioanthropology

Spatial and temporal hot spots of Aedes albopictus abundance inside and outside a South European metropolitan area

Aedes albopictus is a tropical invasive species which in the last decades spread worldwide, also colonizing temperate regions of Europe and US, where it has become a public health concern due to its ability to transmit exotic arboviruses, as well as severe nuisance problems due to its aggressive daytime outdoor biting behaviour. While several studies have been carried out in order to predict the potential limits of the species expansions based on eco-climatic parameters, few studies have so far focused on the specific effects of these variables in shaping its micro-geographic abundance and dynamics. The present study investigated eco-climatic factors affecting Ae. albopictus abundance and dynamics in metropolitan and sub-urban/rural sites in Rome (Italy), which was colonized in 1997 and is nowadays one of the most infested metropolitan areas in Southern Europe. To this aim, longitudinal adult monitoring was carried out along a 70 km-transect across and beyond the most urbanized and densely populated metropolitan area. Two fine scale spatiotemporal datasets (one with reference to a 20m circular buffer around sticky traps used to collect mosquitoes and the second to a 300m circular buffer within each sampling site) were exploited to analyze the effect of climatic and socio-environmental variables on Ae. albopictus abundance and dynamics along the transect. Results showed an association between highly anthropized habitats and high adult abundance both in metropolitan and sub-urban/ rural areas, with “small green islands” corresponding to hot spots of abundance in the metropolitan areas only, and a bimodal seasonal dynamics with a second peak of abundance in autumn, due to heavy rains occurring in the preceding weeks in association with permissive temperatures. The results provide useful indications to prioritize public mosquito control measures in temperate urban areas where nuisance, human-mosquito contact and risk of local arbovirus transmission are likely higher, and highlight potential public health risks also after the summer months typically associated with high mosquito densities

Climatic windows for human migration out of Africa in the past 300,000 years.

Whilst an African origin of modern humans is well established, the timings and routes of their expansions into Eurasia are the subject of heated debate, due to the scarcity of fossils and the lack of suitably old ancient DNA. Here, we use high-resolution palaeoclimate reconstructions to estimate how difficult it would have been for humans in terms of rainfall availability to leave the African continent in the past 300k years. We then combine these results with an anthropologically and ecologically motivated estimate of the minimum level of rainfall required by hunter-gatherers to survive, allowing us to reconstruct when, and along which geographic paths, expansions out of Africa would have been climatically feasible. The estimated timings and routes of potential contact with Eurasia are compatible with archaeological and genetic evidence of human expansions out of Africa, highlighting the key role of palaeoclimate variability for modern human dispersals

Minimally invasive treatment of urinary fistulas using n-butyl-2-cyanoacrylate : a valid first option

BACKGROUND: A few single case reports and only one clinical series have been published so far about the use of N-butyl-2-cyanoacrylate in the treatment of urinary fistulas persisting after conventional urinary drainage. CASE PRESENTATION: We treated five patients with a mean age of 59.2 years presenting iatrogenic urinary fistulas which persisted following conventional drainage manouvres. There were 3 calyceal fistulas following open, laparoscopic and robotic removal of renal lesions respectively, one pelvic fistula after orthotopic ileal neobladder and a bilateral dehiscence of uretero-sigmoidostomy. We used open-end catheters of different sizes adopting a retrograde endoscopic approach for cyanoacrylate injection in the renal calyces, while a descending percutaneous approach via the pelvic drain tract and bilateral nephrostomies respectively was used for the pelvic fistulas. Fluoroscopic control was always used during the occlusion procedures. The amount of adhesive injected ranged between 2 and 5 cc and in one case the procedure was repeated. With a median follow-up of 11 months we observed clinical and radiological resolution in 4 cases (80%), while a recurrent and infected calyceal fistula after laparoscopic thermal renal damage during tumor enucleoresection required nephrectomy. No significant complications were documented. CONCLUSIONS: In an attempt to spare further challenging surgery in patients that had been already operated on recently, minimally invasive occlusion of persistent urinary fistulas with N-butyl-2-cyanoacrylate represents a valid first line treatment, justified in cases when the urinary output is not excessive and there is a favorable ratio between the length and diameter of the fistulous tract