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Numerous outbreaks of high-pathogenicity avian influenza (HPAI) were reported during 2020–2021. In Africa, H5Nx has been detected in Benin, Burkina Faso, Nigeria, Senegal, Lesotho, Namibia and South Africa in both wild birds and poultry. Botswana reported its first outbreak of HPAI to the World Organisation for Animal Health (WOAH) in 2021. An H5N1 virus was detected in a fish eagle, doves, and chickens. Full genome sequence analysis revealed that the virus belonged to clade 2.3.4.4b and showed high identity within haemagglutinin (HA) and neuraminidase proteins (NA) for viruses identified across a geographically broad range of locations. The detection of H5N1 in Botswana has important implications for disease management, wild bird conservation, tourism, public health, economic empowerment of vulnerable communities and food security in the region.

Fisheries monitoring can be improved by studying the influence of gear selectivity, sampling design, and habitat conditions. We used boat-electrofishing data to investigate how sample unit placement (shoreline and channel transects) and sampling conditions (low and high flow years) affect detection of fishes in a highly regulated Ontario (Canada) river system. Species detection histories associated with a spatially replicated sampling design was fit to a Bayesian hierarchical site occupancy model for 14 fishes. Habitat (transect location) had a significant effect on detection probabilities (p) for all species, with shoreline sampling more likely to detect species than channel. Sampling year had a significant effect on detectability of six species. The relative influence of habitat and sampling year varied among species. Detection probabilities based on combined shoreline and channel transect data across both years ranged from 0.09 to 0.48 and were positively correlated to species abundance. High detection probabilities and precise occupancy estimates were associated with sunfish and bass abundant in shoreline habitats. Small-bodied species closely associated with the riverbed or exhibiting schooling behavior tended to be poorly detected. Power to detect future changes in species distribution is expected to differ based on habitat sampled, with greater power associated with shoreline boat-electrofishing. Detecting small to moderate changes is not likely for most species. The addition of channel transects did not improve the effectiveness of shoreline sampling. Improvements to the current design could be realized by reallocating sampling effort from channel to shoreline and testing different gear in deep (> 3 m) habitats.

Background Multiple outbreaks with highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.4b viruses, including H5N8 and H5N1, have occurred in the United Kingdom, as well as in other European countries, since late 2020. Methods This report describes the pathology among poultry species (chickens, turkeys, ducks, and pheasants) and captive birds (Black Swans, a whistling duck and peregrine falcons) naturally infected with HPAIV from 22 cases of HPAIV H5N8 and two cases of HPAIV H5N1 outbreaks investigated between October 2020 and April 2021. Results On gross examination, pancreatic necrosis was easily identified and most commonly observed in galliformes infected with both subtypes of HPAIV but rarely in anseriformes. In addition, splenic necrosis was also frequently observed in chickens and turkeys infected with HPAIV H5N8. Other less common lesions included cardiac petechiae, serosal haemorrhages and ascites in a variety of species. Conclusion Given the widespread dissemination of HPAIV infection in susceptible avian species during autumn/winter 2020-2021, these data, when evaluated along with clinical information, is a valuable first step for both veterinarians and field services to evaluate gross pathology at post-mortem to support the diagnosis of HPAIV infection.

Fishes are among the most threatened taxa in Canada with over 70 species, subspecies, and (or) designatable units presently listed for protection under the Species at Risk Act (SARA). Protecting these species requires a diverse set of strategies based on the best-available data and information. One approach identified under SARA and in Canadian federal recovery strategies for improving the status of SARA-listed fishes is species reintroduction, which involves the release of individuals into areas from which they have been extirpated with the goal of re-establishing self-sustaining populations. The success of reintroduction relies on a comprehensive understanding of species ecology and life history, with considerations around population genetics and genomics. However, SARA-listed species are some of the most poorly known species in Canada due to their rarity and relative lack of research investment prior to the enactment of SARA. As a result, SARA-listed species have the most to lose if reintroduction activities are not carefully researched, planned, and executed. Therefore, the purpose of this review is to present an accessible summary on the state of reintroduction science for SARA-listed fishes in Canada with the hope of motivating future research to support reintroduction activities. We focus our review on 14 SARA-listed freshwater or anadromous fishes identified as candidates for reintroduction in federal recovery strategies. We follow the species-specific summaries with guidance on how basic research questions in population ecology, habitat science, and threat science provide a critical foundation for addressing knowledge gaps in reintroduction science. Subsequently, we identify the importance of genetic and genomic techniques for informing future research on the reintroduction of SARA-listed species. We conclude with recommendations for active, experimental approaches for moving reintroduction efforts forward to recover Canadian fishes.

Some people share knowledge online, often without tangible compensation. Who does this, when, and why? According to costly signaling theory people use behavioral displays to provide observers with useful information about traits or states in exchange for fitness benefits. We tested whether individuals higher in general intelligence, g, provided better quality contributions to an information pool under high than low identifiability, and whether observers could infer signaler g from contribution quality. Using a putative online wiki (N = 98) we found that as individuals' scores on Ravens Progressive Matrices (RPM) increased, participants were judged to have written better quality articles, but only when identifiable and not when anonymous. Further, the effect of RPM scores on inferred intelligence was mediated by article quality, but only when signalers were identifiable. Consistent with costly signaling theory, signalers are extrinsically motivated and observers act as “naive psychometricians.” We discuss the implications for understanding online information pools and altruism.

The non-native swim bladder nematode Anguillicoloides crassus was first documented in wild American eel (Anguilla rostrata) in South Carolina in 1996, and has since spread through rivers and estuaries along the east coast of the United States and Canada. American eel in Canada are a species of conservation concern, primarily due to a severe decline in recruitment within the St. Lawrence River watershed. We report the first occurrence of A. crassus in American eel in the St. Lawrence River watershed in 2010. Prevalence of A. crassus infection remained low through 2014, but has since increased to approximately 30% over the past 3 years. Infection intensity has also increased from only a single nematode up to 2013 to an average of 6.5 nematodes per infected eel in 2018. In outmigrating silver-stage eels sampled in the St. Lawrence estuary, the first occurrence of A. crassus was noted in 2015 and prevalence has fluctuated from a low 0.2% in 2015 to a high of 3.6% in 2017. In 2018, A. crassus was first identified in an eel recruiting to the upper St. Lawrence River. A. crassus was likely inadvertently introduced to the St. Lawrence River watershed during a conservation stocking research project in which glass-stage eels from infected areas were translocated to the region to supplement natural recruitment. It is not clear at this time what harm this additional threat will pose to an already declining contingent of this panmictic species.

It is well known that upon electronic excitation various π-stacked dimers readily exhibit excimer formation, facilitated by a perfect sandwich-like arrangement between the chromophores. However, it is unclear whether such a dimer is also capable of electron transfer upon excitation, if a strong electron-donating group is covalently attached. In this work, we probe the nature of the excited state in a series of cofacially arrayed polyfluorene derivatives with electron-rich aromatic donor attached via a methylene linker. Our studies show that in all cases excimer formation is energetically favorable, and promotion of a charge-transfer state in such systems is possible but requires a free energy for electron transfer far exceeding 1 V. These findings shed light on important design principles for molecular scaffolds capable of stabilizing both excimeric and charge-transfer states upon their excitation.

Fisheries monitoring can be improved by studying the influence of gear selectivity, sampling design, and habitat conditions. We used boat-electrofishing data to investigate how sample unit placement (shoreline and channel transects) and sampling conditions (low and high flow years) affect detection of fishes in a highly regulated Ontario (Canada) river system. Species detection histories associated with a spatially replicated sampling design was fit to a Bayesian hierarchical site occupancy model for 14 fishes. Habitat (transect location) had a significant effect on detection probabilities (p) for all species, with shoreline sampling more likely to detect species than channel. Sampling year had a significant effect on detectability of six species. The relative influence of habitat and sampling year varied among species. Detection probabilities based on combined shoreline and channel transect data across both years ranged from 0.09 to 0.48 and were positively correlated to species abundance. High detection probabilities and precise occupancy estimates were associated with sunfish and bass abundant in shoreline habitats. Small-bodied species closely associated with the riverbed or exhibiting schooling behavior tended to be poorly detected. Power to detect future changes in species distribution is expected to differ based on habitat sampled, with greater power associated with shoreline boat-electrofishing. Detecting small to moderate changes is not likely for most species. The addition of channel transects did not improve the effectiveness of shoreline sampling. Improvements to the current design could be realized by reallocating sampling effort from channel to shoreline and testing different gear in deep ( 3 m) habitats.

Avian influenza virus (AIV) subtypes H5 and H7 are capable of mutating from low to high pathogenicity strains, causing high mortality in poultry with significant economic losses globally. During 2015, two outbreaks of H7N7 low pathogenicity AIV (LPAIV) in Germany, and one each in the United Kingdom (UK) and The Netherlands occurred, as well as single outbreaks of H7N7 high pathogenicity AIV (HPAIV) in Germany and the UK. Both HPAIV outbreaks were linked to precursor H7N7 LPAIV outbreaks on the same or adjacent premises. Herein, we describe the clinical, epidemiological, and virological investigations for the H7N7 UK HPAIV outbreak on a farm with layer chickens in mixed free-range and caged units. H7N7 HPAIV was identified and isolated from clinical samples, as well as H7N7 LPAIV, which could not be isolated. Using serological and molecular evidence, we postulate how the viruses spread throughout the premises, indicating potential points of incursion and possible locations for the mutation event. Serological and mortality data suggested that the LPAIV infection preceded the HPAIV infection and afforded some clinical protection against the HPAIV. These results document the identification of a LPAIV to HPAIV mutation in nature, providing insights into factors that drive its manifestation during outbreaks.

This chapter begins with a case study of Strava, a fitness app that inadvertently exposed sensitive military information even while protecting individual users' information privacy. The case study is analyzed as an example of how recent advances in algorithmic group inference technologies threaten privacy, both for individuals and for groups. It then argues that while individual privacy from big data analytics is well understood, group privacy is not. Results of an experiment to better understand group privacy are presented. Findings show that group and individual privacy are psychologically distinct and uniquely affect people's evaluations, use, and tolerance for a fictitious fitness app. The chapter concludes with a discussion of group-inference technologies ethics and offers recommendations for fitness app designers.

Gentrification is the process whereby an urban community is reinvested and redeveloped, often promoted through neoliberal urban policies. This results in an area with a higher average household income and, typically, a higher percentage of white residents. However, this phenomenon also affects the longstanding residents who face displacement due to raised taxes, increased rent, or rezoning and redevelopment. Displaced residents then move to other communities, often the suburbs with cheaper rent and taxes. Some emerging research and media stories also suggest that when residents are displaced, their new communities offer a lower quality of life with fewer community amenities. Given the rapid increase in gentrification across the United States, this likely invokes a systematic increase in the rate of adolescent mobility from their neighborhoods and schools. The study is conceptualized through the understanding that displacement by gentrification may affect adolescents in the following ways: social-emotional effects and place attachment, social relationships, community opportunities, and school opportunities. I first contextualize gentrification and displacement in Austin through GIS analysis and conversations with public servants in the schools and communities. Then, following a qualitative interview research design, I conduct responsive interviews with five adolescents who were displaced by gentrification and their parents. Findings suggest that adolescents experience gentrification-driven displacement in Austin in several ways. Some move several times as a result of their parents trying to maintain a sense of community. Other adolescents return to Austin for extracurricular activities to maintain their community despite moving. Three of the adolescents moved to mobile home communities located away from Austin, even though their parents continued to work in the city. Although there were varied school experiences, including facing bullying and problems with language education, they used their social networks and technology to overcome obstacles. This display of resilience helped to mitigate the more painful experiences related to displacement. This study contributes to the literature on gentrification and education in several ways. First, it defines the construct of “student displacement.” This is an understudied resulting effect of gentrification for adolescents. Second, it emphasizes student voice. As students are the most important members of a school community, understanding their perspectives will help make better informed policy and practice decisions. This study provides a critical perspective of a neoliberal and neocolonial logic permeating schools and communities globally. These perspectives should be used to help inform coordinated policy and practice decisions related to education and urban planning

Avian Influenza A Viruses (IAV) in different species of seals display a spectrum of pathogenicity, from subclinical infection to unusual mortality events. In this report, we describe a case of avian IAV infection in a 3-4 month old grey seal (Halichoerus grypus) pup, rescued from St Michael’s Mount, Cornwall in 2017. The pup underwent medical treatment, but died after two weeks. Post-mortem examination and histology indicated sepsis as the cause of death. IAV NP antigen was detected by immunohistochemistry in the nasal mucosa only, with no evidence of pathology. Sensitive real-time reverse transcription polymerase chain reaction assays detected trace amounts of viral RNA within the lower respiratory tract, suggesting that the infection may have been cleared naturally. IAV infection prevalence among grey seals might therefore be underestimated. In addition, the fact that the animal was rescued and entered into contact with humans raised concerns about potential zoonotic risk. Nucleotide sequencing revealed the virus to be IAV subtype H3N8. Combining a GISAID database BLAST search and time-scaled phylogenetic analyses, we inferred that the seal infection came from an unsampled, locally circulating (in Northern Europe) source viruses, likely originally derived from wild Anseriformes, which may or may not have been circulating in seals. From examining the protein alignments, we found several residue changes in the seal virus that did not occur in the bird viruses, including D701N in the PB2 segment, a rare mutation, and a hallmark of mammalian adaptation of bird viruses, which has been reported in another IAV H3N8 avian-to-seal transmission event. IAVs of H3N8 subtype have been noted for their particular ability to cross the species barrier and cause productive infections, including historical records suggesting that they may have caused the 1889 pandemic. Therefore, infections such as the one we report here may be of interest to pandemic surveillance and risk, and may help us better understand the determinants and drivers of mammalian adaptation in influenza.

Avian influenza virus (AIV) is classified as high or low pathogenicity AIV (HPAIV/LPAIV) based on intravenous pathogenicity in chickens and/or the presence or absence of multiple basic residues at the heamagglutinin (HA) cleavage site (CS). Since 2014, Europe has experienced waves of incursions of H5Nx HPAIV. Between November 2020 and March 2021, these included HPAIV H5N8, with sporadic of H5N1 and H5N5 (all clade 2.3.4.4b), detected in more than 300 "found dead" wild birds submitted through a passive surveillance programme in the United Kingdom. Currently, H5Nx HPAIV detection relies on identification of AIV RNA and H5 subtyping using real-time reverse transcription PCR (rRT-PCR) assays. The pathotype is subsequently determined by Sanger sequencing of the HA CS. Here, we report the validation and application of a rapid, more cost-effective HP H5-detection rRT-PCR assay. The HP H5 rRT-PCR assay specifically, sensitively and reproducibly detected RNA from contemporary clade 2.3.4.4b H5 HPAIVs with comparable sensitivity to the diagnostic H5-specific rRT-PCR; LPAIV H5 RNA and non-AIV RNA were not detected. On material from "found-dead" wild birds, and for statutory disease diagnosis on poultry, the HP H5 rRT-PCR results provided 100% discrimination when compared to conventional CS sequencing, significantly reducing time-to-pathotype determination and cost, enhancing the diagnostic workflow.

Machine learning and data mining threaten personal privacy, and many tools exist to help users protect their privacy (e.g., available privacy settings on Facebook, anonymization and encryption of personal data, etc.). But such technologies also pose threats to "group privacy," which is a concept scholars know relatively little about. Moreover, there are few tools to address the problem of protecting group privacy. This paper discusses an emerging class of software applications and services that pose new risks to group privacy by revealing group-level information based on individual information, such as social media postings or fitness app usage. The paper describes the results of two experiments that empirically establish the concept of group privacy and shows that it affects user perceptions of and interactions with information technology. The findings serve as a call to developers to design tools for group privacy protection.

Photoinitiated reactions in van der Waals complexes provide a means to examine reactive pathways from well-defined initial geometries. In recent work, we re-examined reactive pathways following resonant two-photon ionization (R2PI) of the chlorobenzene-ammonia (PhCl⋯NH3) dimer. The dimer cation radical reacts primarily via Cl atom loss, and additional channels corresponding to HCl and H atom loss were identified. The structure of the reactive complex was confirmed as an in-plane σ-type, and computational studies of the dimer cation radical potential energy landscape revealed two nearly isoenergetic arenium ion intermediates (or Wheland intermediates). The intermediate produced from ipso addition was not stable with respect to either Cl or HCl loss, and the relative branching observed in experiment was well reproduced by microcanonical transition state theory (TST) calculations. Here, we report experimental and computational studies of the related PhBr⋯NH3 dimer, examined for the first time. We present evidence that the dimer structure is also an in-plane σ-type. However, in contrast to the PhCl⋯NH3 system, calculations predict that the structure of the reactive intermediate corresponds to a distonic ion-radical complex, where the radical density is largely localized on the bromine atom. The calculated barrier to HBr loss is sufficiently high to render this channel nearly insignificant (less than 1% branching) in TST calculations, yet experiment shows a sizable (37%) branching into this channel. We rationalize these results in terms of a roaming Br radical mechanism for HBr formation.

Calixarenes have found widespread application as building blocks for the design and synthesis of functional materials in host-guest chemistry. The ongoing desire to develop a detailed understanding of the nature of NO bonding to multichromophoric π-stacked assemblies led us to develop an electron-rich methoxy derivative of calix[4]arene (3), which we show exists as a single conformer in solution at ambient temperature. Here, we examine the redox properties of this derivative, generate its cation radical (3+. ) using robust chemical oxidants, and determine the relative efficacy of its NO binding in comparison with model calixarenes. We find that 3/3+. is a remarkable receptor for NO+ /NO, with unprecedented binding efficacy. The availability of precise experimental structures of this calixarene derivative and its NO complex, obtained by X-ray crystallography, is critically important both for developing novel functional NO biosensors, and understanding the role of stacked aromatic donors in efficient NO binding, which may have relevance to biological NO transport.

A 12-month pilot project for notifiable avian disease (NAD) exclusion testing in chicken and turkey flocks in Great Britain (GB) offered, in partnership with industry, opportunities to carry out differential diagnosis in flocks where NAD was not suspected, and to identify undetected or undiagnosed infections. In May 2014, clinical samples received from a broiler breeder chicken premises that had been experiencing health and production problems for approximately one week tested positive by avian influenza (AI) real-time reverse transcription polymerase chain reaction (RRT-PCR). Following immediate escalation to an official, statutory investigation to rule out the presence of notifiable AI virus (AIV; H5 or H7 subtypes), a non-notifiable H4N6 low pathogenicity (LP) AIV was detected through virus isolation in embryonated specific pathogen free (SPF) fowls' eggs, neuraminidase inhibition test, cleavage site sequencing and AIV subtype H4-specific serology. Premises movement restrictions were lifted, and no further disease control measures were implemented as per the United Kingdom (UK) legislation. Phylogenetic analysis of the haemagglutinin and neuraminidase genes of the virus revealed closest relationships to viruses from Mallard ducks in Sweden during 2007 and 2009. In June 2014, clinical suspicion of NAD was reported in a flock of free-range laying chickens elsewhere in GB, due to increasing daily mortality and reduced egg production over a five-day period. An H4N6 LPAIV with an intravenous pathogenicity index of 0.50 was isolated. This virus was genetically highly similar, but not identical, to the virus detected during May 2014. Full viral genome analyses showed characteristics of a strain that had not recently transferred from wild birds, implying spread within the poultry sector had occurred. A stalk deletion in the neuraminidase gene sequence indicated an adaptation of the virus to poultry. Furthermore, there was unexpected evidence of systemic spread of the virus on post-mortem. No other cases were reported. Infection with LPAIVs often result in variable clinical presentation in poultry, making detection of disease more difficult.

The development of novel polychromophoric materials using extended polycyclic aromatic hydrocarbons as a single large chromophore holds promise for long-range charge-transfer applications in photovoltaic devices and molecular electronics. However, it is not well-understood how the interchromophoric electronic coupling varies with the chromophore size in linearly connected molecular wires. Here, we show with the aid of electrochemistry, electronic spectroscopy, density functional theory calculations, and theoretical modeling that as the number of aromatic moieties in a single chromophore increases, the interchromophoric electronic coupling decreases and may reach negligible values if the chromophore is sufficiently large. The origin of this initially surprising result becomes clear when one considers this problem with the aid of Huckel molecular orbital theory, as at the polymeric limit energies of the molecular orbitals cluster to form bands and thus the energy spacing between orbitals, and thereby the el...

There is much current interest in the design of molecular actuators, which undergo reversible, controlled motion in response to an external stimulus (light, heat, oxidation, etc.). Here we describe the design and synthesis of a series of cofacially arrayed polyfluorenes (MeFnHm) with varied end-capping groups, which undergo redox-controlled electromechanical actuation. Such cofacially arrayed polyfluorenes are a model molecular scaffold to investigate fundamental processes of charge and energy transfer across a π-stacked assembly, and we show with the aid of NMR and optical spectroscopies, X-ray crystallography and DFT calculations that in the neutral state the conformation of MeFnH1 and MeFnH2 is open rather than cofacial, with a conformational dependence that is highly influenced by the local environment. Upon (electro)chemical oxidation, these systems undergo a reversible transformation into a closed fully π-stacked conformation, driven by charge-resonance stabilization of the cationic charge. These fi...

Exciton and charge delocalization across π-stacked assemblies is of importance in biological systems and functional polymeric materials. To examine the requirements for exciton and hole stabilization, cofacial bifluorene (F2) torsionomers were designed, synthesized, and characterized: unhindered (model) Me F2, sterically hindered tBu F2, and cyclophane-like C F2, where fluorenes are locked in a perfect sandwich orientation via two methylene linkers. This set of bichromophores with varied torsional rigidity and orbital overlap shows that exciton stabilization requires a perfect sandwich-like arrangement, as seen by strong excimeric-like emission only in C F2 and Me F2. In contrast, hole delocalization is less geometrically restrictive and occurs even in sterically hindered tBu F2, as judged by 160 mV hole stabilization and a near-IR band in the spectrum of its cation radical. These findings underscore the diverse requirements for charge and energy delocalization across π-stacked assemblies.

One third of the total global land viable for agricultural production has artificial drainage systems. These drainage systems can provide important habitat for fishes and, in some cases, imperiled fish species vulnerable to impact by drainage maintenance activities. A framework to provide quantitative assessments of the effects of maintenance activities on imperiled fish species is needed. In this study, a six-step habitat-based framework was developed to predict suitable habitat for two at-risk species in an agricultural drain: the Endangered Pugnose Shiner ( Notropis anogenus) and the Special Concern Blackstripe Topminnow ( Fundulus notatus) . Using the framework, spatial models were developed to assess the effects of proposed drain maintenance on the overall amount of suitable habitat, habitat patch size, and connectivity of habitat patches. Maintenance had a significant impact on habitat connectivity, but did not significantly reduce the habitat size of isolated patches. The amount of suitable habitat available after maintenance fell below the minimum area for population viability (MAPV) for the Pugnose Shiner, but not the Blackstripe Topminnow. Future impact assessments of drain maintenance should incorporate population viability analysis, coupled with habitat patch analysis (patch size and connectivity), to quantitatively test consequences of proposed alteration to the viability of spatially structured populations.

Redside dace Clinostomus elongatus (Teleostei: Cyprinidae) is a species of conservation concern that is declining throughout its range as a result of habitat fragmentation, degradation and loss. We characterized the genetic structure and diversity of redside dace populations across the species range using mitochondrial and microsatellite data to inform conservation efforts and assess how historical and recent events have shaped genetic structure and diversity within and among populations. Phylogeographic structure among 28 redside dace populations throughout southern Ontario (Canada) and the United States was assessed by sequence analysis of the mitochondrial cytochrome b and ATPase 6 and 8 genes. Populations were also genotyped using ten microsatellite loci to examine genetic diversity within and among populations as well as contemporary spatial structuring. Mitochondrial DNA sequence data revealed three geographically distinct lineages, which were highly concordant with groupings identified by microsatellite analysis. The combined genetic data refute published glacial refugia hypotheses of a single Mississippian refugium or of two lineages associated with Mississippian and Atlantic refugia. Secondary contact between the two eastern groups was documented in the Allegheny River drainage and tributaries to Lake Ontario. With the exception of several allopatric populations within the Allegheny watershed, high genetic structuring among populations suggests their isolation, indicating that recovery efforts should be population-based.

Summary An increased electrofishing sampling effort will increase detection probabilities of riverine fishes. In this study, a repeat-sampling approach was used in small to medium-sized Ontario (Canada) rivers to estimate: (i) species-specific detection probabilities of freshwater fishes, (ii) the number of sampling events required to confidently detect species, and (iii) the power of timed-search surveys to detect future distribution (or occupancy) declines. Wadeable habitats at 36 sites were sampled with a backpack electrofisher on four separate dates during the summer low-flow period in 2013 and 2014. Forty-two species were collected, including three species of conservation concern (American eel Anguilla rostrata Lacepede, 1802, channel darter Percina copelandi Jordan, 1877, northern sunfish Lepomis peltastes Cope, 1870), and two recreationally important species (largemouth bass Micropterus salmoides Lacepede, 1802 and smallmouth bass Micropterus dolomieu Lacepede, 1802). A hierarchical Bayesian modelling approach was used to estimate detection probabilities and site occupancy for 18 species at four levels of effort: 250, 500, 750 and 1,000 s. In all cases, species detection was imperfect. Search effort had a positive effect on estimates of detection probability and site occupancy and the power to detect declines in future distribution. Detection probabilities ranged from 0.11 to 0.66 with an effort of 250 s, and 0.27 to 0.92 with an effort of 1,000 s. For 13 species, detection and power to detect changes in distribution were significantly improved by increasing sampling effort from 250 to 750 s or 1,000 s. For the channel darter and northern sunfish, three replicate sampling visits (of 750 or 1,000 s duration) are recommended for confident detection.

Environmental DNA (eDNA) detection is increasingly being used to assess the potential presence of aquatic species. Setting defensible thresholds for qPCR assays are necessary to differentiate “detection” from “non-detection”, but threshold rationales are rarely reported in eDNA studies. Detection thresholds for data inclusion and exclusion have implications for downstream data analysis; uncritical acceptance could result in false positive results (Type I error), whereas overly conservative thresholds could result in high false negative interpretation (Type II error). We assessed the use of the receiver operator characteristics (ROC) framework to identify a detection threshold for balancing sensitivity and specificity of eDNA data. The ROC framework was tested using empirical eDNA data from redside dace (Clinostomus elongatus), an endangered freshwater fish in southwestern Ontario. Based on negative controls, positive controls, and quality assurance guidelines, a minimum concentration of 1 copy reaction−1 was identified as the most appropriate threshold for this study. Although optimal thresholds will likely vary between studies and labs based on empirical data, the ROC framework provides a statistical method for establishing defensible thresholds for data acceptance or rejection as well as tradeoffs between the sensitivity and specificity of eDNA data.

Wetlands are increasingly in peril as a result of human activities. In the Laurentian Great Lakes, coastal wetlands provide essential habitats for many fishes. Consequently, efficient sampling approaches for wetland fishes are needed for effective management. We employed a repeat-sampling strategy using a seine to collect fishes from seven wetlands. The data set was used to develop guidance for optimizing wetland fish sampling. To meet richness targets, the required number of sampling sites decreases as sampling intensity increases. Half the number of sites was required when three seine hauls per site were done compared with one haul. On average, 97 one-haul sites were required to detect 90% of species, whereas only 47 three-haul sites were required. Sampling effort is predicted to be greater in areas with more species and larger wetlands. The number of individuals and sites needed to detect 90% of species increased exponentially as species richness increased, and the number of individuals needed was positively related to wetland area. The use of block nets did not improve species detection or affect the composition.

Excimer formation and charge resonance stabilization in covalently linked bichromophoric systems with flexible spacers are important processes relevant to biochemistry and functional materials. Requiring a π-stacked cofacial arrangement of a pair of aromatic molecules at a van der Waals contact, the underlying geometrical reorganization that accompanies these events continues to be debated. Here we use a variety of methods including two-color resonant two-photon ionization spectroscopy (2CR2PI), ion yield measurements, hole-burning spectroscopy (HB), and laser-induced fluorescence (LIF) excitation and emission spectroscopy to compare the gas-phase spectroscopy and dynamics of the van der Waals dimers of fluorene, 9-methylfluorene (MF), and 9,9′-dimethylfluorene (F1). The goal of this work is to probe the influence of methyl substitution on the dynamics of excimer formation and charge resonance (CR) stabilization. The fluorene dimer, (F)2, displays lifetime broadened electronic spectra and the dominance of...

Summary Lake Whitefish (Coregonus clupeaformis) species pairs exist in a small number of northern temperate lakes in North America. Sympatric populations of dwarf and normal-sized whitefish represent a continuum of morphological and genetic divergence among these lakes. In this study, we used morphological and age data to assess the status of the Lake Whitefish species pair in Como Lake, Ontario (Canada). Whitefish were collected with gill-nets from spawning shoals during the fall of 2012 and 2014 and compared with archived (circa 1989) dwarf and normal-sized specimens. Our study indicates that the two previously collected forms have been replaced by a single form with a different morphology and age structure. In comparison to archived specimens, contemporary Lake Whitefish were larger, deeper-bodied and older; with more gill rakers, lateral line scales, smaller eyes and a wider interorbital width. We hypothesize that the recent invasion of Como Lake by Spiny Waterflea (Bythotrephes longimanus) has affected whitefish growth rates and changed the ecosystem conditions that previously maintained the species pair.

Research suggests that male voice pitch is an honest dominance signal because it indexes men's physicality and because lower-pitched voices are more costly to develop and maintain. Rather than considering these signaler-dependent mechanisms, we tested a receiver-dependent mechanism hypothesized by M. Enquist's (1985) retaliation-cost model of aggressive signaling. The model predicts that, given a competitive scenario, low-pitched male voices will elicit aggression from male listeners (i.e., signal receivers) who are relatively high in threat potential. We confirmed this hypothesis in two experiments. Under a sexual but not control prime and after listening to low- but not average-pitched male voices, increases in heterosexual male participants' trait dominance predicted stronger aggressive cognitions (Experiment 1), and increases in male participants' handgrip strength predicted stronger aggressive intent (Experiment 2). These findings provide the first direct support for the retaliation-cost model in humans, extend research on the effects of male voice pitch on receiver psychology, and demonstrate an additional cost mechanism that explains why voice pitch is an honest signal of dominance in men.

Understanding the epidemiological dynamics of highly pathogenic avian influenza virus (HPAIV) in wild birds is crucial for guiding effective surveillance and control measures. The spread of H5 HPAIV has been well characterized over large geographical and temporal scales. However, information about the detailed dynamics and demographics of individual outbreaks in wild birds is rare and important epidemiological parameters remain unknown. We present data from a wild population of long-lived birds (mute swans; Cygnus olor ) that has experienced three outbreaks of related H5 HPAIVs in the past decade, specifically, H5N1 (2007), H5N8 (2016) and H5N6 (2017). Detailed demographic data were available and intense sampling was conducted before and after the outbreaks; hence the population is unusually suitable for exploring the natural epidemiology, evolution and ecology of HPAIV in wild birds. We show that key epidemiological features remain remarkably consistent across multiple outbreaks, including the timing of virus incursion and outbreak duration, and the presence of a strong age-structure in morbidity that likely arises from an equivalent age-structure in immunological responses. The predictability of these features across a series of outbreaks in a complex natural population is striking and contributes to our understanding of HPAIV in wild birds. This article is part of the theme issue ‘Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes’. This issue is linked with the subsequent theme issue ‘Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control’.

Noncovalent forces such as hydrogen bonding, halogen bonding, π-π stacking, and C-H/π and C-H/O interactions hold the key to such chemical processes as protein folding, molecular self-assembly, and drug-substrate interactions. Invaluable insight into the nature and strength of these forces continues to come from the study of isolated molecular clusters. In this work, we report on a study of the isolated anisole-methane complex, where both C-H/π and C-H/O interactions are possible, using a combination of theory and experiments that include mass-selected two-color resonant two-photon ionization spectroscopy, two-color appearance potential (2CAP) measurements, and velocity mapped ion imaging (VMI). Using 2CAP and VMI, we derive the binding energies of the complex in ground, excited, and cation radical states. The experimental values from the two methods are in excellent agreement, and they are compared with selected theoretical values calculated using density functional theory and ab initio methods. The optimized ground-state cluster geometry, which is consistent with the experimental observations, shows methane sitting above the ring, interacting with anisole via both C-H/π and C-H/O interactions, and this dual mode of interaction is reflected in a larger ground-state binding energy as compared with the prototypical benzene-methane system.

Swine influenza A virus (swIAV) causes respiratory disease and productivity loss in pigs. Swine ‘flu viruses have been known to be both zoonotic and reverse zoonotic and they contain genes of swine, avian(av) and human(hu) origin. Surveillance of swIAV subtypes is important as genotypes/phenotypes are fluid and impact with respect to epidemiology, vaccination, pig welfare, veterinary and public health. Three sub-types (H1avN1, H1N1pdm09, H1huN2) are currently found in pigs from Great Britain (GB), plus H3huN2 in Europe and their reassortants. Screening of candidate samples is carried out by RRT-PCR assays – generic detection of swIAV (M gene) followed by a specific RRT-PCR for H1N1pdm09 (HA gene), a suite of RRT-PCR assays for sub-typing (HA and NA genes) and a (differential) RRT-PCR to specifically identify reassortant swIAVs that incorporate the pandemic 2009 internal gene cassette (NP gene). Subtyping assays, conventional and/or molecular, are carried out on virus isolation-positive and –negative (RNA only) samples from clinical material (respiratory tissue and/or nasal swabs). Since 2009, the number of swIAV has expanded with the H1N1pdm09 isolates reassorting with the traditional subtypes. Many European variants arose (>25) of which some have become established – in GB including H1huN2/pdm (since 2010), and H1avN1/pdm (since 2012), and in Belgium the traditional isolates were detected plus H1pdmN1/pdm and H3huN2/pdm reassortants. PCR subtyping (2012 onwards ∼130 from GB and ∼40 from BE/NL), wholegenome sequencing and bioinformatics analysis of these isolates facilitate further diagnostic improvements and assessment of zoonotic pandemic potential (in silico and in vivo).

The anisole-ammonia 1:1 complex is a challenge for both experiment and theory. Early studies supported a non-planar structure, involving a trifecta of weak non-covalent interactions: N-H/O, N-H/π, and C-H/N. The calculated structure and binding energy of the complex proved remarkably sensitive to the level of theory employed. Here, we report the first experimental measurement of the ground state dissociation energy of the complex, and derive an excited (S1) state dissociation energy that is in excellent agreement with the cutoff observed in the experimental excitation spectrum. Results are compared with previous predictions and new calculations based on benchmarked Density Functional Theory methods.

BackgroundA diversifying pool of mammalian-adapted influenza A viruses (IAV) with largely unknown zoonotic potential is maintained in domestic swine populations worldwide. The most recent human influenza pandemic in 2009 was caused by a virus with genes originating from IAV isolated from swine. Swine influenza viruses (SIV) are widespread in European domestic pig populations and evolve dynamically. Knowledge regarding occurrence, spread and evolution of potentially zoonotic SIV in Europe is poorly understood.ObjectivesEfficient SIV surveillance programmes depend on sensitive and specific diagnostic methods which allow for cost-effective large-scale analysis.MethodsNew SIV haemagglutinin (HA) and neuraminidase (NA) subtype- and lineage-specific multiplex real-time RT-PCRs (RT-qPCR) have been developed and validated with reference virus isolates and clinical samples.ResultsA diagnostic algorithm is proposed for the combined detection in clinical samples and subtyping of SIV strains currently circulating in Europe that is based on a generic, M-gene-specific influenza A virus RT-qPCR. In a second step, positive samples are examined by tetraplex HA- and triplex NA-specific RT-qPCRs to differentiate the porcine subtypes H1, H3, N1 and N2. Within the HA subtype H1, lineages “av” (European avian-derived), “hu” (European human-derived) and “pdm” (human pandemic A/H1N1, 2009) are distinguished by RT-qPCRs, and within the NA subtype N1, lineage “pdm” is differentiated. An RT-PCR amplicon Sanger sequencing method of small fragments of the HA and NA genes is also proposed to safeguard against failure of multiplex RT-qPCR subtyping.ConclusionsThese new multiplex RT-qPCR assays provide adequate tools for sustained SIV monitoring programmes in Europe.

Exciton formation and charge separation and transport are key dynamical events in a variety of functional polymeric materials and biological systems, including DNA. Beyond the necessary cofacial approach of a pair of aromatic molecules at van der Waals contact, the extent of overlap and necessary geometrical reorganization for optimal stabilization of an excimer vs dimer cation radical remain unresolved. Here, we compare experimentally the dynamics of excimer formation (via emission) and charge stabilization (via threshold ionization) of a novel covalently linked, cofacially stacked fluorene dimer (F2) with the unlinked van der Waals dimer of fluorene, that is, (F)2. Although the measured ionization potentials are identical, the excimeric state is stabilized by up to ∼30 kJ/mol in covalently linked F2. Supported by theory, this work demonstrates for the first time experimentally that optimal stabilization of an excimer requires a perfect sandwich-like geometry with maximal overlap, whereas hole stabilization in π-stacked aggregates is less geometrically restrictive.

Understanding the mechanisms of long-range energy transfer through polychromophoric assemblies is critically important in photovoltaics and biochemical systems. Using a set of cofacially arrayed polyfluorenes (Fn), we investigate the mechanism of (singlet) exciton delocalization in π-stacked polychromophoric assemblies. Calculations reveal that effective stabilization of an excimeric state requires an ideal sandwich-like arrangement; yet surprisingly, emission spectroscopy indicates that exciton delocalization is limited to only two fluorene units for all n. Herein, we show that delocalization is determined by the interplay between the energetic gain from delocalization, which quickly saturates beyond two units in larger Fn, and an energetic penalty associated with structural reorganization, which increases linearly with n. With these insights, we propose a hopping mechanism for exciton transfer, based upon the presence of multiple excimeric tautomers of similar energy in larger polyfluorenes (n ≥ 4) together with the anticipated low thermal barrier of their interconversion.

Expectation states theory, role congruity theory, and the biosocial model, respectively, predict that perceptions of competence, agency and communality, and physical dominance explain the effects of nonverbal communication on social influence. This study contrasts these mechanisms by using voice pitch variation as a nonverbal signal in mixed-sex dyads. Thirty-seven pairs of male and female participants were recorded discussing a controversial topic under conditions where either their gender or a shared identity as college students was salient. Consistent with expectation states theory, men who varied their pitch more during discussion were perceived as more competent and influential by their female interlocutors, but only when gender was salient. In the same condition, male and female participants’ pitch variation negatively predicted their perceptions of their discussion partner’s influence, suggesting that nonverbal communication constitutes and reflects competition over status. Our findings favor expectation states theory over role congruity theory and the biosocial model.

Multiple molecular wires braided together in a single assembly, termed as molecular cable, are promising next-generation materials for effective long-range charge transport. As an example of the platform for constructing molecular cables, 1,3,5-trifluorenylcyclohexane (TFC) and its difluorenyl analogues (DFCs) were systematically investigated both experimentally (X-ray crystallography) and theoretically (DFT calculations). Although the syntheses of DFCs were successfully achieved, the synthesis of TFC, which involved a similar intramolecular Friedel-Crafts cyclization as the last step, was unsuccessful. An exhaustive study of the conformational landscape of cyclohexane ring of TFC and DFCs revealed that TFC is a moderately strained molecule (∼17 kcal/mol), and computational studies of the reaction profile show that this steric strain, present in the transition state, is responsible for the unusually high (∼5 years) reaction half-life. A successful synthesis of TFC will require that the steric strain is introduced in multiple steps, and such alternative strategies are being currently explored.