Depth perception not found in human observers for static or dynamic anti-correlated random dot stereograms

One of the greatest challenges in visual neuroscience is that of linking neural activity with perceptual experience. In the case of binocular depth perception, important insights have been achieved through comparing neural responses and the perception of depth, for carefully selected stimuli. One of the most important types of stimulus that has been used here is the anti-correlated random dot stereogram (ACRDS). In these stimuli, the contrast polarity of one half of a stereoscopic image is reversed. While neurons in cortical area V1 respond reliably to the binocular disparities in ACRDS, they do not create a sensation of depth. This discrepancy has been used to argue that depth perception must rely on neural activity elsewhere in the brain. Currently, the psychophysical results on which this argument rests are not clear-cut. While it is generally assumed that ACRDS do not support the perception of depth, some studies have reported that some people, some of the time, perceive depth in some types of these stimuli. Given the importance of these results for understanding the neural correlates of stereopsis, we studied depth perception in ACRDS using a large number of observers, in order to provide an unambiguous conclusion about the extent to which these stimuli support the perception of depth. We presented observers with random dot stereograms in which correlated dots were presented in a surrounding annulus and correlated or anti-correlated dots were presented in a central circular region. While observers could reliably report the depth of the central region for correlated stimuli, we found no evidence for depth perception in static or dynamic anti-correlated stimuli. Confidence ratings for stereoscopic perception were uniformly low for anti-correlated stimuli, but showed normal variation with disparity for correlated stimuli. These results establish that the inability of observers to perceive depth in ACRDS is a robust phenomenon

Investigating the Effect of Hand Position on Hand Force and Rotation Time When Performing a Freestyle Flip-Turn

Havriluk (2004) found that an increase in hand force will increase a swimmer’s velocity. While the effect of hand force on a swimmer’s velocity has been studied, the forces produced by the hands as well as the effect of forearm position on hand force production during a freestyle flip-turn has not been investigated. PURPOSE: To investigate the effect of forearm orientation on freestyle flip-turn performance. METHODS: A convenience sample of ten experienced swimmers (6 Female, 4 Male, 20 ± 1.15 years) was recruited to participate. Prior to data collection, participants completed an accommodation session to familiarize them with the techniques and protocol. Freestyle flip-turns were performed with both a swimming approach and a kicking only approach under two forearm position conditions: (1) pronated so that the palms faced upward and (2) supinated so that the palms faced downward. Rotation time in the turn, defined from initial downward movement of the feet prior to the turn to the instant the feet contact the wall, was measured using underwater video collected at 50 Hz during the trials using a swimming approach. Peak hand force was measured using a differential pressure transducer system (Aquanex, Inc.) during the trials using a kicking approach. A paired samples t-Test was used to compare rotation time between hand conditions. Hand force data were analyzed using a 2x2 (forearm position x hand) repeated measures ANOVA. RESULTS: The mean (sd) rotation times were 0.849 (0.075) s and 0.885 (0.094) s for the pronated condition and supinated condition, respectively. Rotation time was significantly faster under the pronated condition (p = 0.046). The mean (sd) peak force measurements were 6.76 (3.02) lbs, 5.67 (2.82) lbs, 4.82 (2.41) lbs, and 4.60 (2.51) for the left and right hand under the pronated and supinated condition, respectively. No significant main effect on hand force was found for forearm position (p = 0.146), and hand (p = 0.071). No significant interaction was found between forearm position and hand (p = 0.300). CONCLUSION: This study provides novel evidence that performing a freestyle flip-turn with the hands in the pronated position will lead to a faster rotation time and that there is no significant effect of hand position on hand force production during a freestyle flip-turn. As a majority of the participants felt more comfortable performing freestyle flip-turns with their hands in the pronated position, it is possible that additional accommodation to the novel technique is required to comfortably perform freestyle flip-turns with supinated forearms

Comparison of Hamstring and Quadriceps Muscle Activity in Men and Women Performing a Body Weight Squat

Multiple studies support the idea that women use a more quadriceps dominant activation pattern at the knee during stabilizing movements which may predispose them to a greater risk of ACL injury. A body weight squat is a common exercise used to strengthen knee musculature in attempt to minimize the risk of ACL injury. However, it is not clear whether this exercise activates the knee musculature in a manner that would not exacerbate the quadriceps dominance often observed in women. PURPOSE: To determine if women are more quadriceps dominant than men when performing a two-legged body weight squat. METHODS: Seven male and seven female Division III collegiate athletes (20.5±1.0 yrs, 176.2± 12.6 cm, and 79.7± 16.6 kg) provided informed consent and participated in this study. Surface EMG collected at 1000 Hz was used to measure the muscle activity of the vastus lateralis (VL) and the biceps femoris (BF), and normalized to the respective maximum voluntary isometric contraction (MVIC) for each muscle. Participants performed eight repetitions of a two-legged body weight squat at a cadence of 54 bpm. RMS EMG was computed across a 200 ms window and analyzed for the middle six repetitions at 15°, 45° and 60° of knee flexion during the movement. Hamstrings and quadriceps activity for the concentric phase of movement were evaluated separately, with two 2x3 (gender x joint position) mixed model ANOVAs. RESULTS: No interaction was observed between gender and joint position for either quadriceps (F(1,11) = 0.64, p = 0.54) or hamstring activity (F(1,11) = 1.24, p = .31). As knee flexion decreased, both quadriceps and hamstrings activity significantly decreased. Quadriceps activity, decreased from 41.7± 24.9%MVIC at 60° to 37.6± 21.7% at 45° to 34.2± 22.7% at 15° (F(1,11) = 5.74, p = 0.01). Likewise, hamstring activity decreased from 26.7± 28.9%MVIC at 60° to 20.6± 20.6% at 45° and to 18.2± 19.1% at 15° (F(1,11) = 3.92, p = 0.04). CONCLUSION: Gender-specific muscular imbalances do not occur during the performance of a bodyweight squat suggesting that such an exercise is appropriate as a part of strength training program designed to reduce ACL risk in women. However, knee angle is a relevant factor to consider when examining muscular characteristics of dynamic movements and injury mechanisms

Exploring how age influences sensory perception, thirst and hunger during the consumption of oral nutritional supplements using the check-all-that-apply methodology

The Check-all-that-apply (CATA) method has been widely used for the sensory characterisation of many different foods and beverages. However, this methodology has been rarely used with older adults. The aim of this study was to measure the effectiveness of the CATA methodology to investigate the differences in sensory perception of Oral Nutritional Supplements (ONS) between younger and community dwelling older adults over successive sips of a full volume of two ONS. The study also sought to measure the effects of ONS on thirst, hunger and fullness. 160 participants (eighty aged over 65 and eighty aged 18-35) evaluated two ONS over two different days. They consumed five 40 ml aliquots of ONS amounting to one serving. After each 40 ml they completed a CATA questionnaire, which recorded liking using a 9-point hedonic scale and hunger, fullness, desire, and thirst using 100 mm visual analogue scales. The results indicated significantly lower levels in hunger (p ≤ 0.01) and thirst (p ≤ 0.01) in the older cohort than the younger cohort. Significant differences in texture perception with age were also observed with the younger cohort selecting ‘Watery’ significantly more (p ≤ 0.05) than the older cohort for ONS 1 and ‘Thick’ and ‘Viscous’ significantly more (p ≤ 0.05) for ONS 2. The study showed that the CATA methodology is appropriate for use with older adults. The findings enhanced our understanding of how an older population experience ONS and drivers of ‘liking’. This information has the potential to enhance ONS adherence and ultimately improve the nutritional status of older people

Student employability enhancement through fieldwork: purposefully integrated or a beneficial side effect?

Fieldwork provides opportunities for students to develop employability-enhancing transferable skills as well as technical, discipline-specific skills and disciplinary knowledge. However, the extent to which staff purposely plan transferable skills outcomes of field courses, and, therefore, whether they are communicated to students is unknown. We investigated whether staff intentionally plan transferable skills development opportunities into fieldwork by interviewing academic staff responsible for planning and leading residential field courses at a UK university. We also conducted a thematic analysis of associated module specifications and teaching materials to understand whether transferable skills were signposted to colleagues and students. Our findings show that although most staff recognise that their field courses help students to develop transferable skills, staff awareness of skills and professional development outcomes is narrowly focused on technical skills and discipline-related careers. Furthermore, those transferable skills outcomes that staff are aware of are not fully translated into module specifications and infrequently signposted to students via teaching materials. These findings suggest that transferable skills form a hidden curriculum of fieldwork. To maximise the employability benefits of fieldwork, we recommend that all skills should be signposted to students both during field course teaching and also via the associated teaching materials

Predator-induced fear causes PTSD-like changes in the brains and behaviour of wild animals

© 2019, The Author(s). Predator-induced fear is both, one of the most common stressors employed in animal model studies of post-traumatic stress disorder (PTSD), and a major focus of research in ecology. There has been a growing discourse between these disciplines but no direct empirical linkage. We endeavoured to provide this empirical linkage by conducting experiments drawing upon the strengths of both disciplines. Exposure to a natural cue of predator danger (predator vocalizations), had enduring effects of at least 7 days duration involving both, a heightened sensitivity to predator danger (indicative of an enduring memory of fear), and elevated neuronal activation in both the amygdala and hippocampus – in wild birds (black-capped chickadees, Poecile atricapillus), exposed to natural environmental and social experiences in the 7 days following predator exposure. Our results demonstrate enduring effects on the brain and behaviour, meeting the criteria to be considered an animal model of PTSD – in a wild animal, which are of a nature and degree which can be anticipated could affect fecundity and survival in free-living wildlife. We suggest our findings support both the proposition that PTSD is not unnatural, and that long-lasting effects of predator-induced fear, with likely effects on fecundity and survival, are the norm in nature

Suspect identification based on descriptive facial attributes

We present a method for using human describable face attributes to perform face identification in criminal inves-tigations. To enable this approach, a set of 46 facial at-tributes were carefully defined with the goal of capturing all describable and persistent facial features. Using crowd sourced labor, a large corpus of face images were manually annotated with the proposed attributes. In turn, we train an automated attribute extraction algorithm to encode target repositories with the attribute information. Attribute extrac-tion is performed using localized face components to im-prove the extraction accuracy. Experiments are conducted to compare the use of attribute feature information, derived from crowd workers, to face sketch information, drawn by expert artists. In addition to removing the dependence on expert artists, the proposed method complements sketch-based face recognition by allowing investigators to imme-diately search face repositories without the time delay that is incurred due to sketch generation. 1

A pan-cetacean MHC amplicon sequencing panel developed and evaluated in combination with genome assemblies

This study was funded by a Royal Society Research Grants for Research Fellows (RGF\R1\181014) to E.C.G. E.C.G. is funded by a Royal Society University Research Fellowship (UF160081 & URF\R\221020). F.E. is supported by a University of St Andrews School of Biology Ph.D. scholarship and a Royal Society Research Fellows Enhancement Award (RGF\EA\180213 to E.C.G). E.L.C. is funded by a Rutherford Discovery Fellowship from the Royal Society of New Zealand Te Apārangi.The major histocompatibility complex (MHC) is a highly polymorphic gene family that is crucial in immunity, and its diversity can be effectively used as a fitness marker for populations. Despite this, MHC remains poorly characterised in non-model species (e.g., cetaceans: whales, dolphins and porpoises) as high gene copy number variation, especially in the fast-evolving class I region, makes analyses of genomic sequences difficult. To date, only small sections of class I and IIa genes have been used to assess functional diversity in cetacean populations. Here, we undertook a systematic characterisation of the MHC class I and IIa regions in available cetacean genomes. We extracted full-length gene sequences to design pan-cetacean primers that amplified the complete exon2 from MHC class I and IIa genes in one combined sequencing panel. We validated this panel in 19 cetacean species and described 354 alleles for both classes. Furthermore, we identified likely assembly artefacts for many MHC class I assemblies based on the presence of class I genes in the amplicon data compared to missing genes from genomes. Finally, we investigated MHC diversity using the panel in 25 humpback and 30 southern right whales, including four paternity trios for humpback whales. This revealed copy-number variable class I haplotypes in humpback whales, which is likely a common phenomenon across cetaceans. These MHC alleles will form the basis for a cetacean branch of the Immuno-Polymorphism Database (IPD-MHC), a curated resource intended to aid in the systematic compilation of MHC alleles across several species, to support conservation initiatives.Peer reviewe

An integrated approach to historical population assessment of the great whales: case of the New Zealand southern right whale

Accurate estimation of historical abundance provides an essential baseline for judging the recovery of the great whales. This is particularly challenging for whales hunted prior to twentieth century modern whaling, as population-level catch records are often incomplete. Assessments of whale recovery using pre-modern exploitation indices are therefore rare, despite the intensive, global nature of nineteenth century whaling. Right whales (Eubalaena spp.) were particularly exploited: slow swimmers with strong fidelity to sheltered calving bays, the species made predictable and easy targets. Here, we present the first integrated population-level assessment of the whaling impact and pre-exploitation abundance of a right whale, the New Zealand southern right whale (E. australis). In this assessment, we use a Bayesian population dynamics model integrating multiple data sources: nineteenth century catches, genetic constraints on bottleneck size and individual sightings histories informing abundance and trend. Different catch allocation scenarios are explored to account for uncertainty in the population's offshore distribution. From a pre-exploitation abundance of 28 800–47 100 whales, nineteenth century hunting reduced the population to approximately 30–40 mature females between 1914 and 1926. Today, it stands at less than 12% of pre-exploitation abundance. Despite the challenges of reconstructing historical catches and population boundaries, conservation efforts of historically exploited species benefit from targets for ecological restoration

SARS-CoV-2 Antibody Prevalence Among Healthcare Workers and First Responders, Florida, May-June, 2020

Background: The SARS-CoV-2 virus responsible for severe respiratory infection associated with coronavirus disease 2019 (COVID-19) was first confirmed in Florida on March 1, 2020. Responding to the pandemic, multi-agency collaborative partnerships put in place actions integrating point-of-care antibody testing at established large-scale COVID-19 testing sites where the baseline seropositivity of COVID-19 in health care workers and first responders in Florida at the start of the pandemic was established. Purpose: Determine the seropositivity of healthcare workers and first responders at five drive thru testing sites using a rapid SARS-CoV-2 antibody test in Florida from May 6 through June 3, 2020. Methods: The first drive-thru SARS-CoV-2 antibody test site was opened at Miami Hard Rock Stadium, May 6, 2020. Testing expanded to three additional sites on May 9, 2020: Jacksonville, Orlando, and Palm Beach. The fifth and final site, Miami Beach, began testing on May 21, 2020. Healthcare workers and first responder’s self-seeking SARS-CoV-2 testing were designated for antibody testing and completed a laboratory collection form on-site for the point-of-care test. All testing was performed on whole blood specimens (obtained by venipuncture) using the Cellex Inc. qSARS-CoV-2 IgG/IgM Rapid Test. Seropositivity was assessed by univariate analysis and by logistic regression including the covariates age, sex, race/ethnicity, and testing location. Results and Discussion: As of June 3, 2020, of 5,779 healthcare workers and first responders tested, 4.1% were seropositive (range 2.6–8.2%). SARS-COV-2 antibody tests had higher odds of being positive for persons testing at the Miami Hard Rock Stadium (aOR 2.24 [95% C.I. 1.48-3.39]), persons of Haitian/Creole ethnicity (aOR 3.28 [95% C.I. 1.23-8.72]), Hispanic/Latino(a) ethnicity (aOR 2.17 [95% C.I. 1.50-3.13], and Black non-Hispanic persons (aOR 1.63 [95% C.I. 1.08-2.46]). SARS-COV-2 antibody prevalence among first responders and healthcare workers in five sites in Florida varied by race and ethnicity and by testing location