Benefits and costs to pollinating, seed-eating insects: the effect of flower size and fruit abortion on larval performance

Plant-pollinator interactions are well-known examples of mutualism, but are not free of antagonism. Antagonistic interactions and defenses or counter-defenses are expected particularly in nursery pollination. In these systems, adult insects, while pollinating, lay their eggs in flowers, and juveniles consume the seeds from one or several fruits, thereby substantially reducing plant fitness. The outcome of such interactions will depend, for the plant, on the balance between pollination versus seed predation and for the larvae on the balance between the food and shelter provided versus the costs imposed by plant defenses, e.g., through abortion of infested fruits. Here, we examine the costs and benefits to the larvae in the nursery-pollination system Silene latifolia/Hadena bicruris. Using selection lines that varied in flower size (large- vs. small-flowered plants), we investigated the effects of variation in flower and fruit size and of a potential defense, fruit abortion, on larval performance. In this system, infested fruits are significantly more likely to be aborted than non-infested fruits; however, it is unclear whether fruit abortion is effective as a defense. Larger flowers gave rise to larger fruits with more seeds, and larvae that were heavier at emergence. Fruit abortion was frequently observed (ca. 40% of the infested fruits). From aborted fruits, larvae emerged earlier and were substantially lighter than larvae emerging from non-aborted fruits. The lower mass at emergence of larvae from aborted fruits indicates that abortion is a resistance mechanism. Assuming that lower larval mass implies fewer resources invested in the frugivore, these results also suggest that abortion is likely to benefit the plant as a defense mechanism, by limiting both resources invested in attacked fruits, as well as the risk of secondary attack. This suggests that selective fruit abortion may contribute to the stability of mutualism also in this non-obligate syste

A Soft Robotic Exomusculature Glove with Integrated sEMG sensing for Hand Rehabilitation

Stroke affects around 750,000 people annually with 80% of survivors left with unilateral weakness in their extremities. Repetitive hand movement therapy is often used as a rehabilitation technique to help patients regain dexterity and strength. In order to facilitate this rehabilitation process, a soft exo-muscular robotic upper limb device was designed to aid in the movement and coordination of upper limb exercises. The device utilizes a cable system to open and close a patient’s hand and elbow. These cables run through a series of guides and pull on attachment points at the fingertips and forearms, emulating muscle tension and generating joint torque. For energy dense actuation, DC electric motors were used to drive pulleys for cable actuation. To increase user comfort and safety, mechanically compliant actuation was added by using clutches with continuously variable slip torque between motor and pulley which could act as a means of mechanical force control. For closed loop control and monitoring of patient progress, a number of sensors were added. Flex and pressure sensors in the fingers can detect patient movement as well as the force being applied to objects and force sensors in the biceps are used to measure the lift force of the users arm. The device also takes input from a custom made surface myoelectric electrode (sEMG) array that measures the myoelectric signal being produced by the user’s muscles to help aid the user in their intended movement. In practice the device will be able to provide a customized rehabilitation experience for each user based on sensor data analyzed by doctors who can adjust the therapy regiment to focus on goals and needs of a specific patient

On the importance of balancing selection in plants

This is the peer reviewed version of the following article: Delph, L. F. and Kelly, J. K. (2014), On the importance of balancing selection in plants. New Phytol, 201: 45–56. doi:10.1111/nph.12441, which has been published in final form at http://doi.org/10.1111/nph.12441. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Balancing selection refers to a variety of selective regimes that maintain advantageous genetic diversity within populations. We review the history of the ideas regarding the types of selection that maintain such polymorphism in flowering plants, notably heterozygote advantage, negative frequency-dependent selection, and spatial heterogeneity. One shared feature of these mechanisms is that whether an allele is beneficial or detrimental is conditional on its frequency in the population. We highlight examples of balancing selection on a variety of discrete traits. These include the well-referenced case of self-incompatibility and recent evidence from species with nuclear-cytoplasmic gynodioecy, both of which exhibit trans-specific polymorphism, a hallmark of balancing selection. We also discuss and give examples of how spatial heterogeneity in particular, which is often thought unlikely to allow protected polymorphism, can maintain genetic variation in plants (which are rooted in place) as a result of microhabitat selection. Lastly, we discuss limitations of the protected polymorphism concept for quantitative traits, where selection can inflate the genetic variance without maintaining specific alleles indefinitely. We conclude that while discrete-morph variation provides the most unambiguous cases of protected polymorphism, they represent only a fraction of the balancing selection at work in plants

Reaction Time and Verbal Working Memory Differences in NCAA Concussed Female Athletes

Empirical evidence suggests that female collegiate athletes participating in soccer are likely to suffer from TBI and subsequent concussion syndrome. Studies further indicate that TBI adversely affects the quality of life of athletes both on an academic level and social life. This study examined data with the intent to fill existing gaps in the current literature and focused on the experiences of NCAA female collegiate soccer athletes who have suffered TBI and neurocognitive deficit symptoms in verbal memory and reactional time. This quantitative research method relied on the theory of mind (ToM) as the theoretical basis to investigate research questions in investigating TBI\u27s relationship and an individual\u27s cognitive performance in verbal and reaction time. This quantitative study relied on a de-identified secondary dataset from the ImPACT injury database to evaluate baseline and post injury TBI evaluations, assessed injuries, and cognitive domains. The data were analyzed with descriptive statistics, paired sample t tests and independent sample t tests. There were significant differences in reaction time, but not statistically significant in verbal working memory. The implications of the study for positive change included the provision of insight into practical strategies for better management of the challenges associated with TBI to enable effect minimization of the cognitive deficits on the athlete\u27s social and academic life. The study findings will therefore facilitate the development of strategies to enhance safety in sport

Comparison of immunologic responses following intranasal and oral administration of a USDA-approved, live-attenuated Streptococcus equi vaccine

Master of ScienceDepartment of Clinical ScienceElizabeth DavisBackground: While there is a commercially-available vaccine for Streptococcus equi subsp. equi licensed for the intranasal route of administration, some equine practitioners are administering this vaccine orally despite a lack of evidence for its efficacy by this route of administration. Objectives: To compare systemic and local immune responses following intranasal or oral administration of the USDA-approved, live-attenuated Streptococcus equi subspecies equi vaccine (Pinnacle IN®, Zoetis, Florham Park, New Jersey). Study Design: Experimental, randomized clinical trial Methods: Eight healthy horses with low Streptococcus equi M protein (SeM) titers (<1:1600) were randomly assigned to an intranasal or oral two-vaccine series. SeM-specific serum immunoglobulins G (IgG) and A (IgA) and nasal secretion IgA were assessed using a commercially-available ELISA (Equine Diagnostic Solutions, LLC, Lexington, Kentucky) and a novel magnetic microsphere assay utilizing fluorescence. A general linear mixed models approach was used for statistical data analysis. Results: As expected, intranasal vaccinates showed substantial increases in both serum SeM-specific IgG and IgA levels post-vaccination (P=0.0006 and P=0.007, respectively). Oral vaccinates showed an increase in serum SeM-specific IgG post-vaccination (P=0.0150), though only one-third the magnitude of intranasal vaccinates. Oral vaccinates showed no evidence of change in SeM-specific IgA post-vaccination (P=0.15). Main Limitations: Changes in mucosal antibody responses were not identified in this study which may be related to small change in antibody response, timing of sample collection, or method of nasal secretion collection. Conclusions: Results indicate that intranasal or oral vaccine administration resulted in increased serum SeM-specific IgG, though the magnitude of response differed between routes

The dynamic stability under impulsive loading of shallow arches with elastic end restraints

A theoretical and experimental study of the buckling under impulsive load of an arch with rotational end restraints was carried out. Impulsive loading was realized experimentally by use of the spray deposited explosive silver nitrate-silver acetylide. The experimental buckling loads were compared to those obtained by a theoretical analysis. It was found that the theoretical analysis yields a quite conservative lower bound on the magnitude of load necessary for buckling. Both uniform and nonuniform loadings were considered. It was found that there exists a critical value of rotational spring constant above which dynamic buckling may not occur in the rigorous mathematical sense. An expression for this critical value was found

Sex-specific natural selection on SNPs in Silene latifolia

Selection that acts in a sex-specific manner causes the evolution of sexual dimorphism. Sex-specific phenotypic selection has been demonstrated in many taxa and can be in the same direction in the two sexes (differing only in magnitude), limited to one sex, or in opposing directions (antagonistic). Attempts to detect the signal of sex-specific selection from genomic data have confronted numerous difficulties. These challenges highlight the utility of “direct approaches,” in which fitness is predicted from individual genotype within each sex. Here, we directly measured selection on Single Nucleotide Polymorphisms (SNPs) in a natural population of the sexually dimorphic, dioecious plant, Silene latifolia. We measured flowering phenotypes, estimated fitness over one reproductive season, as well as survival to the next year, and genotyped all adults and a subset of their offspring for SNPs across the genome. We found that while phenotypic selection was congruent (fitness covaried similarly with flowering traits in both sexes), SNPs showed clear evidence for sex-specific selection. SNP-level selection was particularly strong in males and may involve an important gametic component (e.g., pollen competition). While the most significant SNPs under selection in males differed from those under selection in females, paternity selection showed a highly polygenic tradeoff with female survival. Alleles that increased male mating success tended to reduce female survival, indicating sexual antagonism at the genomic level. Perhaps most importantly, this experiment demonstrates that selection within natural populations can be strong enough to measure sex-specific fitness effects of individual loci

A three component drag probe for the measurement of ocean wave orbital velocities and turbulent water velocity fluctuations

A three component drag probe has been built, calibrated, and used to measure velocities beneath deep water ocean waves and turbulence in a tidal channel. Simple variable inductance devices which may be submerged in water were used as displacement transducers and the associated electronics provided voltage outputs which were proportional to the three components of force that were exerted on a small 5 cm diameter sphere. The force components were due to both the water drag force and the water inertial force in an accelerating flow field. Techniques are described for interpreting measurements made with the drag probe and for obtaining the three velocity components from the measured force components. From the drag probe calibration and its use in the field, it is concluded that the drag probe is a suitable instrument for the measurement of wave velocities and turbulence. Modifications are suggested to improve the performance of the drag probe. For the wave velocity measurements, the experimental results indicate that linear wave theory is adequate to describe the relations between the wave pressure and the wave velocity components. At frequencies higher than the predominant wave frequency the velocity spectra are roughly proportional to f⁻³ where f is the frequency in Hz. The wave velocity components were used to obtain an estimate of the directional energy spectrum. From the measurements in a tidal channel, it appears that the instrument is suitable to measure turbulent fluctuations with scale sizes larger than about 20 cm. If the turbulence were isotropic the velocity spectra would be proportional to f[⁻⁵/³]. Due to the influence of boundaries, the flow was not isotropic but the results appear to be consistent with other observations that turbulent velocity spectra usually show a f⁻¹ to f⁻² behavior and are quite different from wave velocity spectra