Assessing risks of invasion through gamete performance: farm Atlantic salmon sperm and eggs show equivalence in function, fertility, compatibility and competitiveness to wild Atlantic salmon

Adaptations at the gamete level (a) evolve quickly, (b) appear sensitive to inbreeding and outbreeding and (c) have important influences on potential to reproduce. We apply this understanding to problems posed by escaped farm salmon and measure their potential to reproduce in the wild. Farm Atlantic salmon (Salmo salar) are a threat to biodiversity, because they escape in large numbers and can introgress, dilute or disrupt locally adapted wild gene pools. Experiments at the whole fish level have found farm reproductive potential to be significant, but inferior compared to wild adults, especially for males. Here, we assess reproductive performance at the gamete level through detailed in vitro comparisons of the form, function, fertility, compatibility and competitiveness of farm versus wild Atlantic salmon sperm and eggs, in conditions mimicking the natural gametic microenvironment, using fish raised under similar environmental conditions. Despite selective domestication and reduced genetic diversity, we find functional equivalence in all farm fish gamete traits compared with their wild ancestral strain. Our results identify a clear threat of farm salmon reproduction with wild fish and therefore encourage further consideration of using triploid farm strains with optimized traits for aquaculture and fish welfare, as triploid fish remain reproductively sterile following escape

Cryptic choice of conspecific sperm controlled by the impact of ovarian fluid on sperm swimming behavior

Despite evidence that variation in male–female reproductive compatibility exists in many fertilization systems, identifying mechanisms of cryptic female choice at the gamete level has been a challenge. Here, under risks of genetic incompatibility through hybridization, we show how salmon and trout eggs promote fertilization by conspecific sperm. Using in vitro fertilization experiments that replicate the gametic microenvironment, we find complete interfertility between both species. However, if either species’ ova were presented with equivalent numbers of both sperm types, conspecific sperm gained fertilization precedence. Surprisingly, the species’ identity of the eggs did not explain this cryptic female choice, which instead was primarily controlled by conspecific ovarian fluid, a semiviscous, protein-rich solution that bathes the eggs and is released at spawning. Video analyses revealed that ovarian fluid doubled sperm motile life span and straightened swimming trajectory, behaviors allowing chemoattraction up a concentration gradient. To confirm chemoattraction, cell migration tests through membranes containing pores that approximated to the egg micropyle showed that conspecific ovarian fluid attracted many more spermatozoa through the membrane, compared with heterospecific fluid or water. These combined findings together identify how cryptic female choice can evolve at the gamete level and promote reproductive isolation, mediated by a specific chemoattractive influence of ovarian fluid on sperm swimming behavior

Post-copulatory opportunities for sperm competition and cryptic female choice provide no offspring fitness benefits in externally fertilizing salmon

There is increasing evidence that females can somehow improve their offspring fitness by mating with multiple males, but we understand little about the exact stage(s) at which such benefits are gained. Here, we measure whether offspring fitness is influenced by mechanisms operating solely between sperm and egg. Using externally-fertilising and polyandrous Atlantic salmon (Salmo salar), we employed split-clutch and split-ejaculate in vitro fertilisation experiments to generate offspring using designs that either denied or applied opportunities for sperm competition and cryptic female choice. Following fertilisations, we measured 140 days of offspring fitness after hatch, through growth and survival in hatchery and near-natural conditions. Despite an average composite mortality of 61%, offspring fitness at every life stage was near-identical between groups fertilised under the absence versus presence of opportunities for sperm competition and cryptic female choice. Of the 21,551 and 21,771 eggs from 24 females fertilised under monandrous versus polyandrous conditions, 68% versus 67.8% survived to the 100-day juvenile stage; sub-samples showed similar hatching success (73.1% versus 74.3%), had similar survival over 40 days in near-natural streams (57.3% versus 56.2%), and grew at similar rates throughout. We therefore found no evidence that gamete-specific interactions allow offspring fitness benefits when polyandrous fertilisation conditions provide opportunities for sperm competition and cryptic female choice

The Changing Dynamics Of A Japanese Company Amid The Globalizing Business Environment: A Case Study Of Hitachi Construction Machinery Company

Japan’s mature market combined with its decreasing population has left little room for domestic market expansion. Because of this, many Japanese companies have been required to explore overseas markets in order to maintain and expand their sales revenue. While numerous Japanese companies have struggled to adapt to globalization, Hitachi Ltd., a Japanese multinational conglomerate, has become a frontrunner in its organizational transformation. A recent example is its move from the traditional, seniority and lifelong employment system to a merit-based salary system, which aims to attract talented, high-level workers overseas. Hitachi Construction Machinery (HCM), one of Hitachi’s eleven businesses, is an excellent case study of how Japanese companies are changing in response to globalization. Three research groups investigated this on-going, momentous transformation of a representative of Japan Inc., HCM, through first-hand experiences and semi-structured interviews with company representatives throughout Japan. The research included in-depth investigations of how globalization has affected HCM in three areas: language, cultural, and unification training processes; human resource management; and reaction to global environmental issues through its product lines

Therapeutic potential and ownership of commercially available consoles in children with cerebral palsy

Introduction: We conducted a survey amongst families of children with cerebral palsy (CP) to ascertain the ownership and therapeutic use and potential of commercial games consoles to improve motor function. Method: 300 families in southeast England were identified through clinical records,and were requested to complete an anonymised questionnaire. Results: A total of 61 families (20% response) returned a completed questionnaire with 41 (68%) males and 19 (32%) females with Cerebral Palsy, with a mean age of 11Y5M (SD 3Y 7M). The large majority of families, 59 (97%), owned a commercial console and the child used this for 50-300 minutes a week. Returns by severity of motor impairment were: Gross Motor Function Classification System (GMFCS) I (21%), II (31%), III (13%), IV (15%), V (18%). Consoles were used regularly for play across all GMFCS categories. Conclusion: The potential of games consoles, as home-based virtual reality therapy (VRT), in improving the motor function of children with cerebral palsy should be appropriately tested in randomised controlled trial. Wide ownership, and the relative ease with which children engage in the use of commercial-based VRT systems suggests potential as a means of augmenting therapy protocols,taking advantage of interest and participation patterns of families. What the study has added: This study shows that there is wide ownership/use of commercial games consoles amongst children with CP; and this offers great potential to test therapeutic efficacy of home-based virtual reality therapy to improve motor function in children. Key messages: Children with Cerebral Palsy frequently access and use commercial consoles during play at home. Consoles are used by children across severity of gross motor function levels. Some families had utilized the consoles for therapeutic purposes, with anecdotal improvements in motor function. Opportunity exists for using commercial consoles within home based therapy protocols and for recreational participation across all GMFCS levels

Methodological issues of using placebos in interventions based on digital technology

Background/Aims: Use of placebo is the ideal for comparison in clinical trials to reduce biases. With digital technology being used more frequently in healthcare interventions, how do we determine the placebo effect where interventions exploit technology? If placebo in medicine is traditionally defined by a lack of pharmacological agents, how might we begin to move towards controlling for effects of digital technology? Method: This paper explores the traditional placebo effect and discusses its impact in healthcare contexts with digital technology with reference to a particular trial. Different meanings of placebo in the context of evaluating technology suggest new challenges and positive consequences. Results: Methodological considerations are discussed, which enabled the development of a placebo-controlled evaluation of a digital technology in healthcare and rehabilitation. Conclusion: Digital placebo was controlled in our trial by employing technology across all groups in the absence of evidence-based practice and shows how to control for unknown and hidden effects of technology

Calcium Handling Defects and Cardiac Arrhythmia Syndromes

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Wild Felids as Hosts for Human Plague, Western United States

Plague seroprevalence was estimated in populations of pumas and bobcats in the western United States. High levels of exposure in plague-endemic regions indicate the need to consider the ecology and pathobiology of plague in nondomestic felid hosts to better understand the role of these species in disease persistence and transmission