Weak Interaction Rate Coulomb Corrections in Big Bang Nucleosynthesis

We have applied a fully relativistic Coulomb wave correction to the weak reactions in the full Kawano/Wagoner Big Bang Nucleosynthesis (BBN) code. We have also added the zero temperature radiative correction. We find that using this higher accuracy Coulomb correction results in good agreement with previous work, giving only a modest 0.04 percent increase in helium mass fraction over correction prescriptions applied previously in BBN calculations. We have calculated the effect of these corrections on other light element abundance yields in BBN and we have studied these yields as functions of electron neutrino lepton number. This has allowed insights into the role of the Coulomb correction in the setting of the neutron-to-proton ratio during the BBN epoch. We find that the lepton capture processes' contributions to this ratio are only second order in the Coulomb correction.Comment: 8 pages, 3 figure

Big Bang Nucleosynthesis with Independent Neutrino Distribution Functions

We have performed new Big Bang Nucleosynthesis calculations which employ arbitrarily-specified, time-dependent neutrino and antineutrino distribution functions for each of up to four neutrino flavors. We self-consistently couple these distributions to the thermodynamics, the expansion rate and scale factor-time/temperature relationship, as well as to all relevant weak, electromagnetic, and strong nuclear reaction processes in the early universe. With this approach, we can treat any scenario in which neutrino or antineutrino spectral distortion might arise. These scenarios might include, for example, decaying particles, active-sterile neutrino oscillations, and active-active neutrino oscillations in the presence of significant lepton numbers. Our calculations allow lepton numbers and sterile neutrinos to be constrained with observationally-determined primordial helium and deuterium abundances. We have modified a standard BBN code to perform these calculations and have made it available to the community.Comment: 9 pages, 5 figure

Optimal decision making for sperm chemotaxis in the presence of noise

For navigation, microscopic agents such as biological cells rely on noisy sensory input. In cells performing chemotaxis, such noise arises from the stochastic binding of signaling molecules at low concentrations. Using chemotaxis of sperm cells as application example, we address the classic problem of chemotaxis towards a single target. We reveal a fundamental relationship between the speed of chemotactic steering and the strength of directional fluctuations that result from the amplification of noise in the chemical input signal. This relation implies a trade-off between slow, but reliable, and fast, but less reliable, steering. By formulating the problem of optimal navigation in the presence of noise as a Markov decision process, we show that dynamic switching between reliable and fast steering substantially increases the probability to find a target, such as the egg. Intriguingly, this decision making would provide no benefit in the absence of noise. Instead, decision making is most beneficial, if chemical signals are above detection threshold, yet signal-to-noise ratios of gradient measurements are low. This situation generically arises at intermediate distances from a target, where signaling molecules emitted by the target are diluted, thus defining a `noise zone' that cells have to cross. Our work addresses the intermediate case between well-studied perfect chemotaxis at high signal-to-noise ratios close to a target, and random search strategies in the absence of navigation cues, e.g. far away from a target. Our specific results provide a rational for the surprising observation of decision making in recent experiments on sea urchin sperm chemotaxis. The general theory demonstrates how decision making enables chemotactic agents to cope with high levels of noise in gradient measurements by dynamically adjusting the persistence length of a biased persistent random walk.Comment: 9 pages, 5 figure

The acute phase protein, haptoglobin : a potential parameter in welfare assessment?

Physiological parameters are important measures in animal welfare assessment. To assess the amount of stress an animal experiences, stress hormones like cortisol are frequently used. However, measuring cortisol has major disadvantages due to its rapid reactivity and decline and many influencing factors. Other potential alternative markers are acute phase proteins, since stress is known to affect the immune system. A pilot study was conducted to investigate the response of the acute phase protein, plasma haptoglobine (HP), in pigs subjected to a stressor (food deprivation) and to examine the correlation between HP levels and average daily growth (ADG). Forty grower pigs (25.1 ± 4.4 kg, mean ± SD) (sex and former pen mates balanced), were allocated to 4 conventional pens, 2 treatment (T) and 2 control (C) groups (10 pigs per pen). After 10 days of adaptation the experiment started and ran for 3 weeks. In the 2nd week, T groups were repeatedly subjected to an 8-hour food deprivation (day 1, 3, 5 and 7 of week 2), C groups had normal, unrestricted, access to food. Pigs were weighed twice a week and blood was collected once a week (every 5th day). Mean levels of plasma HP of C and T groups showed large variation between individuals (C groups, week 2: 1.84 ± 3.11 mg/ml; T groups, week 2: 1.40 ± 1.16 mg/ml). No significant differences (Kruskal-Wallis test) in HP levels or growth were found between the C and T groups or between the different weeks within the T groups. Significant negative weak to moderate correlations were found between ADG and HP levels (HP week 1 and ADG week 1: rs = -0.47, p=0.005; HP week 2 and ADG total; rs= -0.60, p=0.015; HP week 3 and ADG total: rs = -0.43, p=0.025; average HP total and ADG total: rs= -0.41, p=0.017). Large variations in HP levels between individuals were shown and no effect of treatment on HP levels or growth was found. Possibly, food deprivation had no apparent stress eliciting effect. Despite these results, interesting correlations between the level of HP and ADG were found, corroborating the inverse relationship between the acute phase response and growth. To further investigate the relation of the acute phase response and stress a successive experiment will be conducted in which we apply a stronger stressor (mixing pigs) and combine the physiological data with behavior

Does combined posterior cruciate ligament and posterolateral corner reconstruction for chronic posterior and posterolateral instability restore normal knee function?

SummaryIntroductionPosterior cruciate ligament (PCL) injuries are frequently associated with posterolateral corner (PLC) damages. These complex lesions are most often poorly tolerated clinically. Adherence to sound biomechanical principles treating these complex lesions entails obtaining a functional PCL and reconstructing sufficient posterolateral stability.HypothesisSurgical treatment of postero-posterolateral laxity (PPLL) re-establishes sufficient anatomical integrity to provide stability and satisfactory knee function.Material and methodsIn this retrospective, continuous, single-operator study, 21 patients were operated for chronic PPLL with combined reconstruction of the PCL and PLC and were reviewed with a minimum 1 year follow-up. The clinical and subjective outcomes were evaluated using the IKDC score. Surgical correction of posterior laxity was quantified clinically and radiologically on dynamic posterior drawer images (posterior Telos™ stress test and hamstrings contraction lateral view).ResultsThe mean subjective IKDC score was 62.8 at the last follow-up versus a preoperative score of 54.5 (NS). Preoperatively, all were classified in groups C and D. Postoperatively, 13 patients out of 21 were classified in groups A and B according to the overall clinical IKDC score. The radiological gain in laxity was 51% on the hamstring contraction films and 67% on the posterior Telos™ images (p<0.05).DiscussionThe objective of surgical treatment is to re-establish anatomical integrity to the greatest possible extent. The clinical and radiological laxity results are disappointing in terms of the objectives but are in agreement with the literature. The subjective evaluation demonstrated that this operation can provide sufficient function for standard daily activities but not sports activities.Level of evidenceLevel IV retrospective study

Enclothed Cognition: Professional Clothing Symbolism among Plus-Size Women Ages 18 to 24

This research explores how young, plus-size female consumers engage with the process of enclothed cognition. It is believed that clothing inherently carries symbolism within the garment itself, which may then be transmitted to the wearer, such as the feeling of authority felt when wearing a business suit. Traditionally, plus-size consumers are considered to be individuals ages 30-40, wearing an American size 16 or above. However, this does not cover a key area of the plus-size demographic: young plus-size consumers. This research utilizes semi-structured narrative interviews to further explore young plus-size women\u27s personal definitions of professionalism and the enclothing process. Results indicate that these women may have difficulties enclothing the garments currently offered by plus-size retailers, as they do not match personal definitions of professionalism. Retailers should aim to provide garments that encloth a larger demographic area to provide greater options to consumers

What plus-size means for plus-size women: A mixed-methods approach

Western fashion is constantly evolving and in order to obtain notoriety, brands need to positively connect with consumers. Individuals who wear plus-sizes are acutely aware of their reduced clothing choices and rely on language cues to find clothing. Unfortunately, the categorisation of plus-size consumers is fraught with discord and frustration. Fashion communication should consider consumer needs and preferences. However, the language used to classify plus-size consumers has yet to be examined. Plus-size women were recruited online to rate twelve terms associated with plus-size women’s clothing. The survey collected a total of 324 responses of age, height, weight and ratings of terms used to classify plus-size apparel, such as Women’s, Curvy. Data were analysed using descriptive statistics and analysis of variance to compare differences considering age and body mass. This study revealed 96% of the sample ranked the classification Women’s higher than Plus-Size. The study offers insights into how plus-size consumers view sizing communications. It also offers a useful ranking of terms that fashion companies can adopt to ensure they are communicating in language that the intended consumer prefers. This study contributes to research on social identity of clothing size, plus-size consumer experiences, and further validates the multidimensional challenges faced by plus-size consumers

High-level feature detection from video in TRECVid: a 5-year retrospective of achievements

Successful and effective content-based access to digital video requires fast, accurate and scalable methods to determine the video content automatically. A variety of contemporary approaches to this rely on text taken from speech within the video, or on matching one video frame against others using low-level characteristics like colour, texture, or shapes, or on determining and matching objects appearing within the video. Possibly the most important technique, however, is one which determines the presence or absence of a high-level or semantic feature, within a video clip or shot. By utilizing dozens, hundreds or even thousands of such semantic features we can support many kinds of content-based video navigation. Critically however, this depends on being able to determine whether each feature is or is not present in a video clip. The last 5 years have seen much progress in the development of techniques to determine the presence of semantic features within video. This progress can be tracked in the annual TRECVid benchmarking activity where dozens of research groups measure the effectiveness of their techniques on common data and using an open, metrics-based approach. In this chapter we summarise the work done on the TRECVid high-level feature task, showing the progress made year-on-year. This provides a fairly comprehensive statement on where the state-of-the-art is regarding this important task, not just for one research group or for one approach, but across the spectrum. We then use this past and on-going work as a basis for highlighting the trends that are emerging in this area, and the questions which remain to be addressed before we can achieve large-scale, fast and reliable high-level feature detection on video

Evaluating the Impact of Broadband Access and Internet Use in a Small Underserved Rural Community

Having adequate access to the internet at home enhances quality-of-life for households and facilitates economic and social opportunities. Despite increased investment in response to the COVID-19 pandemic, millions of households in the rural United States still lack adequate access to high-speed internet. In this study, we evaluate a wireless broadband network deployed in Turney, a small, underserved rural community in northwest Missouri. In addition to collecting survey data before and after this internet intervention, we collected pre-treatment and post-treatment survey data from comparison communities to serve as a control group. Due to technical constraints, some of Turney\u27s interested participants could not connect to the network, creating an additional comparison group. These comparisons suggest two primary findings, (1) changes in using the internet for employment, education, and health could not be directly attributed to the internet intervention, and (2) the internet intervention was associated with benefits stemming from the ability to use multiple devices at once. This study has implications for the design of future broadband evaluation studies, particularly those examining underserved rather than unserved communities. Recommendations for identifying appropriate outcome variables, executing recruitment strategies, and selecting the timing of surveys are made