The Physical Progress of a Professional Scottish Soccer Academy Over a Ten-Year Period.

Background: Increases in high-intensity locomotor activity of match play have been recorded in elite soccer. This places an onus on academy practitioners to develop players for the future demands of the game. At an academy level, locomotor data are not available for analysis over a longitudinal period, and thus changes can only be assessed with physical attribute assessment.

A circumpolar study unveils a positive non-linear effect of temperature on arctic arthropod availability that may reduce the risk of warming-induced trophic mismatch for breeding shorebirds.

Seasonally abundant arthropods are a crucial food source for many migratory birds that breed in the Arctic. In cold environments, the growth and emergence of arthropods are particularly tied to temperature. Thus, the phenology of arthropods is anticipated to undergo a rapid change in response to a warming climate, potentially leading to a trophic mismatch between migratory insectivorous birds and their prey.

Understanding biochemistry: basic aspects of statistics for life sciences.

If the biological world is one thing it is variable. As scientists we seek to measure, quantify and explain the causes of this variation. The approach we take to this is remarkably similar whether our research is exploring global temperature, blood pressure, cancer incidence or enzyme kinetics.

Density-dependent winter survival of immatures in an irruptive raptor with pulsed breeding.

Highly mobile predators can show strong numerical responses to pulsed resources, sometimes resulting in irruptions where large numbers of young invade landscapes at a continental scale. High production of young in irruption years may have a strong influence on the population dynamics unless immature survival is reduced compared to non-irruption years. This could occur if subordinate individuals (mainly immatures) are forced into suboptimal habitats due to density-dependent effects in irruption years.

Implications of Zoonoses From Hunting and Use of Wildlife in North American Arctic and Boreal Biomes: Pandemic Potential, Monitoring, and Mitigation.

The COVID-19 pandemic has re-focused attention on mechanisms that lead to zoonotic disease spillover and spread. Commercial wildlife trade, and associated markets, are recognized mechanisms for zoonotic disease emergence, resulting in a growing global conversation around reducing human disease risks from spillover associated with hunting, trade, and consumption of wild animals. These discussions are especially relevant to people who rely on harvesting wildlife to meet nutritional, and cultural needs, including those in Arctic and boreal regions.

3D enamel profilometry reveals faster growth but similar stress severity in Neanderthal versus Homo sapiens teeth.

Early life stress disrupts growth and creates horizontal grooves on the tooth surface in humans and other mammals, yet there is no consensus for their quantitative analysis. Linear defects are considered to be nonspecific stress indicators, but evidence suggests that intermittent, severe stressors create deeper defects than chronic, low-level stressors. However, species-specific growth patterns also influence defect morphology, with faster-growing teeth having shallower defects at the population level.

Using community photography to investigate phenology: A case study of coat molt in the mountain goat () with missing data.

Participatory approaches, such as community photography, can engage the public in questions of societal and scientific interest while helping advance understanding of ecological patterns and processes. We combined data extracted from community-sourced, spatially explicit photographs with research findings from 2018 fieldwork in the Yukon, Canada, to evaluate winter coat molt patterns and phenology in mountain goats (), a cold-adapted, alpine mammal. Leveraging the community science portals iNaturalist and CitSci, in less than a year we amassed a database of almost seven hundred unique photographs spanning some 4,500 km between latitudes 37.

Faster growth corresponds with shallower linear hypoplastic defects in great ape canines.

Deeper or more 'severe' linear enamel hypoplasia (LEH) defects are hypothesized to reflect more severe stress during development, but it is not yet clear how depth is influenced by intrinsic enamel growth patterns. Recent work documented inter- and intraspecific differences in LEH defect depth in extant great apes, with mountain gorillas having shallower defects than other taxa, and females having deeper defects than males. Here, we assess the correspondence of inter- and intraspecific defect depth and intrinsic aspects of enamel growth: enamel extension rates, outer enamel striae of Retzius angles, and linear enamel thickness.

Documenting lemming population change in the Arctic: Can we detect trends?

Lemmings are a key component of tundra food webs and changes in their dynamics can affect the whole ecosystem. We present a comprehensive overview of lemming monitoring and research activities, and assess recent trends in lemming abundance across the circumpolar Arctic. Since 2000, lemmings have been monitored at 49 sites of which 38 are still active.

Can variation in standard metabolic rate explain context-dependent performance of farmed Atlantic salmon offspring?

Escaped farmed Atlantic salmon interbreed with wild Atlantic salmon, leaving offspring that often have lower success in nature than pure wild salmon. On top of this, presence of farmed salmon descendants can impair production of wild-type recruits. We hypothesize that both these effects connect with farmed salmon having acquired higher standard metabolic rates (SMR, the energetic cost of self-maintenance) during domestication.

Quantifying linear enamel hypoplasia in Virunga Mountain gorillas and other great apes.

Objective: Linear enamel hypoplasia (LEH) is a condition marked by localized reductions in enamel thickness, resulting from growth disruptions during dental development. We use quantitative criteria to characterize the depth of LEH defects and "normal" perikymata in great apes. We test the hypothesis that mountain gorillas have shallow defects compared to other taxa, which may have led to their underestimation in previous studies.

Updating histological data on crown initiation and crown completion ages in southern Africans.

Objectives: To update histological data on crown initiation and completion ages in southern Africans. To evaluate implications of these data for studies that: (a) rely on these data to time linear enamel hypoplasias (LEHs), or, (b) use these data for comparison to fossil hominins.

Materials And Methods: Initiation ages were calculated on 67 histological sections from southern Africans, with sample sizes ranging from one to 11 per tooth type.

Perikymata distribution in Homo with special reference to the Xujiayao juvenile.

Objectives: This study investigates where the Xujiayao juvenile (I(1) and C(1) ) fits into the array of perikymata distribution patterns found within the genus Homo.

Materials And Methods: In addition to the I(1) and the C(1) of the Xujiayao juvenile, this study includes samples of early Homo (H. rudolfensis and H.

The interplay between aerobic metabolism and antipredator performance: vigilance is related to recovery rate after exercise.

When attacked by a predator, fish respond with a sudden fast-start motion away from the threat. Although this anaerobically-powered swimming necessitates a recovery phase which is fueled aerobically, little is known about links between escape performance and aerobic traits such as aerobic scope (AS) or recovery time after exhaustive exercise. Slower recovery ability or a reduced AS could make some individuals less likely to engage in a fast-start response or display reduced performance.

Multidimensional approach to invasive species prevention.

Nonindigenous species (NIS) cause global biotic homogenization and extinctions, with commercial shipping being a leading vector for spread of aquatic NIS. To reduce transport of NIS by ships, regulations requiring ballast water exchange (BWE) have been implemented by numerous countries. BWE appears to effectively reduce risk for freshwater ports, but provides only moderate protection of marine ports.

Enamel extension rate patterns in modern human teeth: two approaches designed to establish an integrated comparative context for fossil primates.

Enamel extension rates (EERs), the rates at which ameloblasts differentiate, determine how fast tooth crowns grow in height. Studies of fossil primate (including hominin) enamel microstructure usually focus on species differences in enamel formation time, but they have also begun to address species-level variation in enamel extension rates. To improve our ability to compare EERs among primate species, a better understanding how EERs vary within species is necessary.

The performance advantage of a high resting metabolic rate in juvenile salmon is habitat dependent.

1. Basal levels of metabolism vary significantly among individuals in many taxa, but the effects of this on fitness are generally unknown. Resting metabolic rate (RMR) in juvenile salmon and trout is positively related to dominance status and ability to obtain a feeding territory, but it is not clear how this translates into performance in natural conditions.

Lemming winter habitat choice: a snow-fencing experiment.

The insulative value of early and deep winter snow is thought to enhance winter reproduction and survival by arctic lemmings (Lemmus and Dicrostonyx spp). This leads to the general hypothesis that landscapes with persistently low lemming population densities, or low amplitude population fluctuations, have a low proportion of the land base with deep snow. We experimentally tested a component of this hypothesis, that snow depth influences habitat choice, at three Canadian Arctic sites: Bylot Island, Nunavut; Herschel Island, Yukon; Komakuk Beach, Yukon.

Dental evidence for ontogenetic differences between modern humans and Neanderthals.

Humans have an unusual life history, with an early weaning age, long childhood, late first reproduction, short interbirth intervals, and long lifespan. In contrast, great apes wean later, reproduce earlier, and have longer intervals between births. Despite 80 y of speculation, the origins of these developmental patterns in Homo sapiens remain unknown.

Brief communication: The distribution of perikymata on Qafzeh anterior teeth.

Recent studies have suggested that Neandertals and modern humans differ in the distribution of perikymata (enamel growth increments) over their permanent anterior tooth crowns. In modern humans, perikymata become increasingly more compact toward the cervix than they do in Neandertals. Previous studies have suggested that a more homogeneous distribution of perikymata, like that of Neandertals, characterizes the anterior teeth of Homo heidelbergensis and Homo erectus as well.

Temporal nature of periradicular bands ('Striae periradicales') on mammalian tooth roots.

Periradicular bands, or fine circumferential lines on tooth roots, have received attention recently due to their prominence on hominin fossils and their potential utility for informing studies of root formation. In 1938, Komai and Miyauti [Dtsch Zahn Mund Kieferheilkd 1938;5:791-795] demonstrated that periradicular bands are related to dentine growth rather than cementum, suggesting that they were equal to accentuated lines in dentine ('dentine lamellae' or 'contour lines'). More recent indirect evidence from band spacing on primate roots suggests that they are temporally equal to other long-period lines in enamel (Retzius lines, perikymata) and dentine (Andresen lines).

Phylogeny, life history and the timing of molar crown formation in two archaic ungulates, Meniscotherium and Phenacodus (Mammalia, 'Condylarthra').

The condylarths, or archaic ungulates, are a paraphyletic mammalian group including a number of fossil taxa whose relationships are unresolved. Included are two genera from the Paleocene and Eocene of North America, Meniscotherium and Phenacodus. Some workers place both genera in the family Phenacodontidae, while others exclude the highly dentally derived Meniscotherium.