By hook or by crook? Morphometry, competition and cooperation in rodent sperm

Background Sperm design varies enormously across species and sperm competition is thought to be a major factor influencing this variation. However, the functional significance of many sperm traits is still poorly understood. The sperm of most murid rodents are characterised by an apical hook of the sperm head that varies markedly in extent across species. In the European woodmouse Apodemus sylvaticus (Muridae), the highly reflected apical hook of sperm is used to form sperm groups, or “trains,” which exhibited increased swimming velocity and thrusting force compared to individual sperm. Methodology/Principal Findings Here we use a comparative study of murine rodent sperm and demonstrate that the apical hook and sperm cooperation are likely to be general adaptations to sperm competition in rodents. We found that species with relatively larger testes, and therefore more intense sperm competition, have a longer, more reflected apical sperm hook. In addition, we show that sperm groups also occur in rodents other than the European woodmouse. Conclusions Our results suggest that in rodents sperm cooperation is more widespread than assumed so far and highlight the importance of diploid versus haploid selection in the evolution of sperm design and function

Classical Correlation-Length Exponent in Non-Universal Quantum Phase Transition of Diluted Heisenberg Antiferromagnet

Critical behavior of the quantum phase transition of a site-diluted Heisenberg antiferromagnet on a square lattice is investigated by means of the quantum Monte Carlo simulation with the continuous-imaginary-time loop algorithm. Although the staggered spin correlation function decays in a power law with the exponent definitely depending on the spin size $S$, the correlation-length exponent is classical, i.e., $\nu=4/3$. This implies that the length scale characterizing the non-universal quantum phase transition is nothing but the mean size of connected spin clusters.Comment: 4 pages, 3 figure

Exceptional sperm cooperation in the wood mouse

Spermatozoa from a single male will compete for fertilization of ova with spermatozoa from another male when present in the female reproductive tract at the same time. Close genetic relatedness predisposes individuals towards altruism, and as haploid germ cells of an ejaculate will have genotypic similarity of 50%, it is predicted that spermatozoa may display cooperation and altruism to gain an advantage when inter-male sperm competition is intense. We report here the probable altruistic behaviour of spermatozoa in an eutherian mammal. Spermatozoa of the common wood mouse, Apodemus sylvaticus, displayed a unique morphological transformation resulting in cooperation in distinctive aggregations or 'trains' of hundreds or thousands of cells, which significantly increased sperm progressive motility. Eventual dispersal of sperm trains was associated with most of the spermatozoa undergoing a premature acrosome reaction. Cells undergoing an acrosome reaction in aggregations remote from the egg are altruistic in that they help sperm transport to the egg but compromise their own fertilizing ability

Terrain Features and Architecture of Wolverine (Gulo gulo) Resting Burrows and Reproductive Dens on Arctic Tundra

Burrowing species rely on subterranean and subnivean sites to fulfill important life-history and behavioral processes, including predator avoidance, thermoregulation, resting, and reproduction. For these species, burrow architecture can affect the quality and success of such processes, since characteristics like tunnel width and chamber depth influence access by predators, thermal insulation, and energy spent digging. Wolverines (Gulo gulo) living in Arctic tundra environments dig burrows in snow during winter for resting sites and reproductive dens, but there are few published descriptions of such burrows. We visited 114 resting burrows and describe associated architectural characteristics and non-snow structure. Additionally, we describe characteristics of 15 reproductive den sites that we visited during winter and summer. Although many resting burrows were solely excavated in snow, most incorporated terrain structures including cliffs, talus, river shelf ice, thermokarst caves, and stream cutbanks. Burrows typically consisted of a single tunnel leading to a single chamber, though some burrows had multiple entrances, branching tunnels, or both. Tunnels in resting burrows were shorter than those in reproductive dens, and resting chambers were typically located at the deepest part of the burrow. Reproductive dens were associated with snowdrift-forming terrain features such as streambeds, cutbanks on lake edges, thermokarst caves, and boulders. Understanding such characteristics of Arctic wolverine resting and reproductive structures is critical for assessing anthropogenic impacts as snowpack undergoes climate-driven shifts.Les espèces fouisseuses dépendent de lieux enfouis sous la terre et sous la neige pour satisfaire leurs importants processus de vie et de comportement, y compris l’évitement des prédateurs, la thermorégulation, le repos et la reproduction. Pour ces espèces, l’architecture des terriers peut avoir des effets sur la qualité et la réussite des processus, car des caractéristiques comme la largeur des tunnels et la profondeur des chambres influencent l’accès aux terriers par les prédateurs, l’isolation thermique et l’énergie dépensée pour creuser. L’hiver, les carcajous (Gulo gulo) qui vivent dans les environnements de la toundra de l’Arctique creusent des terriers dans la neige afin de s’en servir comme aires de repos et comme tanières de reproduction. Cependant, peu de descriptions de tels terriers ont été publiées. Nous avons visité 114 terriers de repos, puis nous avons décrit leurs caractéristiques architecturales et les structures connexes n’étant pas recouvertes de neige. Par ailleurs, nous décrivons les caractéristiques de 15 tanières de reproduction que nous avons visitées en hiver et en été. Même si de nombreux terriers de repos ont été uniquement creusés dans la neige, la plupart des terriers incorporaient des structures topographiques, dont des falaises, des talus, de la glace de banquise, des grottes thermokarstiques et des hautes berges de cours d’eau. En général, les terriers étaient composés d’un seul tunnel menant à une seule chambre, bien que certains avaient plusieurs entrées, des galeries, ou les deux. Les tunnels des aires de repos étaient moins longs que ceux des tanières de reproduction, et les chambres de repos étaient généralement situées dans la partie la plus profonde des terriers. Les tanières de reproduction étaient installées dans des caractéristiques topographiques où s’amoncelle la neige, comme les lits de cours d’eau, les hautes berges de lacs, les grottes thermokarstiques et les rochers. Il est essentiel de comprendre les caractéristiques des structures de repos et de reproduction des carcajous de l’Arctique afin d’être en mesure d’évaluer les incidences anthropiques au moment où le manteau neigeux subit des changements liés au climat

High-throughput eDNA monitoring of fungi to track functional recovery in ecological restoration

Fungi are key functional components of ecosystems (e.g. decomposers, symbionts), but are rarely included in restoration monitoring programs. Many fungi occur belowground, making them difficult to observe directly, but are observable with environmental DNA (eDNA) methods. Although eDNA approaches have been proposed as ecological monitoring tools for microbial diversity, their application to restoration projects is very limited. We used eDNA metabarcoding of fungal ITS barcodes on soil collected across a 10-year restoration chronosequence to explore fungal responses to restoration. We observed a dramatic shift in the fungal community towards that of the natural fungal community after just 10 years of active native plant revegetation. Agaricomycetes and other Basidiomycota – involved in wood decay and ectomycorrhizal symbiosis – increased in rarefied sequence abundance in older restored sites. Ascomycota dominated the fungal community, but decreased in rarefied sequence abundance across the restoration chronosequence. Our results highlight eDNA metabarcoding as a useful restoration monitoring tool that allows quantification of changes in important fungal indicator groups linked with functional recovery and, being underground, are normally omitted in restoration monitoring.DongFeng Yan, Jacob G. Mills, Nicholas J.C. Gellie, Andrew Bissett, Andrew J. Lowe, Martin F. Bree

Evidence of Endemic Hendra Virus Infection in Flying-Foxes (Pteropus conspicillatus)—Implications for Disease Risk Management

This study investigated the seroepidemiology of Hendra virus in a spectacled flying-fox (Pteropus conspicillatus) population in northern Australia, near the location of an equine and associated human Hendra virus infection in late 2004. The pattern of infection in the population was investigated using a serial cross-sectional serological study over a 25-month period, with blood sampled from 521 individuals over six sampling sessions. Antibody titres to the virus were determined by virus neutralisation test. In contrast to the expected episodic infection pattern, we observed that seroprevalence gradually increased over the two years suggesting infection was endemic in the population over the study period. Our results suggested age, pregnancy and lactation were significant risk factors for a detectable neutralizing antibody response. Antibody titres were significantly higher in females than males, with the highest titres occurring in pregnant animals. Temporal variation in antibody titres suggests that herd immunity to the virus may wax and wane on a seasonal basis. These findings support an endemic infection pattern of henipaviruses in bat populations suggesting their infection dynamics may differ significantly from the acute, self limiting episodic pattern observed with related viruses (e.g. measles virus, phocine distemper virus, rinderpest virus) hence requiring a much smaller critical host population size to sustain the virus. These findings help inform predictive modelling of henipavirus infection in bat populations, and indicate that the life cycle of the reservoir species should be taken into account when developing risk management strategies for henipaviruses

Evidence of Endemic Hendra Virus Infection in Flying-Foxes (Pteropus conspicillatus)—Implications for Disease Risk Management

This study investigated the seroepidemiology of Hendra virus in a spectacled flying-fox (Pteropus conspicillatus) population in northern Australia, near the location of an equine and associated human Hendra virus infection in late 2004. The pattern of infection in the population was investigated using a serial cross-sectional serological study over a 25-month period, with blood sampled from 521 individuals over six sampling sessions. Antibody titres to the virus were determined by virus neutralisation test. In contrast to the expected episodic infection pattern, we observed that seroprevalence gradually increased over the two years suggesting infection was endemic in the population over the study period. Our results suggested age, pregnancy and lactation were significant risk factors for a detectable neutralizing antibody response. Antibody titres were significantly higher in females than males, with the highest titres occurring in pregnant animals. Temporal variation in antibody titres suggests that herd immunity to the virus may wax and wane on a seasonal basis. These findings support an endemic infection pattern of henipaviruses in bat populations suggesting their infection dynamics may differ significantly from the acute, self limiting episodic pattern observed with related viruses (e.g. measles virus, phocine distemper virus, rinderpest virus) hence requiring a much smaller critical host population size to sustain the virus. These findings help inform predictive modelling of henipavirus infection in bat populations, and indicate that the life cycle of the reservoir species should be taken into account when developing risk management strategies for henipaviruses

Afrikaans as Standaard Gemiddelde Europees:Wanneer ‘n lid uit sy taalarea beweeg

A recent trend in the study of Standard Average European is the extraterritorial perspective of examining the extent to which non-European languages have converged with this Sprachbund as a result of contact with one or more of its members. The present article complements this line of research in that it investigates the extent to which a European language has diverged from Standard Average European after leaving the linguistic area. The focus is on Dutch, a nuclear member of the Sprachbund, and Afrikaans, its colonial offshoot. The two languages are compared with respect to twelve of the most distinctive linguistic features of Standard Average European. Afrikaans is found to share ten of them with Dutch, including anticausative prominence and formally distinguished intensifiers and reflexives, and could therefore still be considered a core member of the Sprachbund, despite deviations in the expression of negative pronouns and the grammaticality of external possessor constructions. This relatively low degree of divergence may be attributed to the continuity from Settler Dutch to at least the variety of Afrikaans on which the standard language is based and to the important role that Dutch continued to play in the history of Afrikaans

Ecosystem restoration is integral to humanity’s recovery from COVID-19

COVID-19 has devastated global communities and economies. The pandemic has exposed socioeconomic disparities and weaknesses in health systems worldwide. Long-term health effects and economic recovery are major concerns. Ecosystem restoration—ie, the repair of ecosystems that have been degraded—relates directly to tackling the health and socioeconomic burdens of COVID-19, because stable and resilient ecosystems are fundamental determinants of health and socioeconomic stability. Here, we use COVID-19 as a case study, showing how ecosystem restoration can reduce the risk of infection and adverse sequelae and have an integral role in humanity’s recovery from COVID-19. The next decade will be crucial for humanity’s recovery from COVID-19 and for ecosystem repair. Indeed, in the absence of effective, large-scale restoration, 95% of the Earth’s land could be degraded by 2050. The UN Decade on Ecosystem Restoration (2021–30) declaration reflects the growing urgency and scale at which we should repair ecosystems. Importantly, ecosystem restoration could also help to combat the health and socioeconomic issues that are associated with COVID-19, yet it is poorly integrated into current responses to the disease. Ecosystem restoration can be a core public health intervention and assist in COVID-19 recovery if it is closely integrated with socioeconomic, health, and environmental policies.Jake M Robinson, James Aronson, Christopher B Daniels, Neva Goodwin, Craig Liddicoat, Laura Orlando, David Phillips, Jessica Stanhope, Philip Weinstein, Adam T Cross, Martin F Bree