Puckering Coordinates of Monocyclic Rings by Triangular Decomposition

We describe a new method of describing the pucker of an N-member monocyclic ring using N−3 parameters. To accomplish this, three ring atoms define a reference plane, and the remainder of the ring is decomposed into triangular flaps. The angle of incidence for each flap upon the reference plane is then measured. The combination of these angles is characteristic of the ring\u27s pucker. This puckering coordinate system is compared to existing reduced parameter systems to describe rings using a cyclohexane molecule. We show that this method has the same descriptive power of previous systems while offering advantages in molecular simulations

Computational methods for higher real K-theory with applications to tmf

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2006.Includes bibliographical references (p. 67-69).We begin by present a new Hopf algebra which can be used to compute the tmf homology of a space or spectrum at the prime 3. Generalizing work of Mahowald and Davis, we use this Hopf algebra to compute the tmf homology of the classifying space of the symmetric group on three elements. We also discuss the E3 Tate spectrum of tmf at the prime 3. We then build on work of Hopkins and his collaborators, first computing the Adams-Novikov zero line of the homotopy of the spectrum eo4 at 5 and then generalizing the Hopf algebra for tmf to a family of Hopf algebras, one for each spectrum eop_l at p. Using these, and using a K(p - 1)-local version, we further generalize the Davis-Mahowald result, computing the eop_1 homology of the cofiber of the transfer map [...]. We conclude by computing the initial computations needed to understand the homotopy groups of the Hopkins-Miller real K-theory spectra for heights large than p- 1 at p. The basic computations are supplemented with conjectures as to the collapse of the spectral sequences used herein to compute the homotopy.by Michael Anthony Hill.Ph.D

Effects of diamagnetic levitation on bacterial growth in liquid

Diamagnetic levitation is a technique that uses a strong, spatially-varying magnetic field to levitate diamagnetic materials, such as water and biological cells. This technique has the potential to simulate aspects of weightlessness, on the Earth. In common with all ground-based techniques to simulate weightlessness, however, there are effects introduced by diamagnetic levitation that are not present in space. Since there have been few studies that systematically investigate these differences, diamagnetic levitation is not yet being fully exploited. For the first time, we critically assess the effect of diamagnetic levitation on a bacterial culture in liquid. We used a superconducting magnet to levitate growing bacterial cultures for up to 18 hours, in a series of experiments to determine the effect of diamagnetic levitation on all phases of the bacterial growth cycle. We find that diamagnetic levitation increases the rate of population growth in a liquid culture. The speed of sedimentation of the bacterial cells to the bottom of the container is considerably reduced. Further experiments and microarray gene analysis show that the growth enhancement is due to greater oxygen availability in the magnetically levitated sample. We demonstrate that the magnetic field that levitates the cells also induces convective stirring in the liquid, an effect not present in microgravity. We present a simple theoretical model, showing how the paramagnetic force on dissolved oxygen can cause the liquid to become unstable to convection when the consumption of oxygen by the bacteria generates an oxygen concentration gradient. We propose that this convection enhances oxygen availability by transporting oxygen around the sample. Since convection is absent in space, these results are of significant importance and timeliness to researchers considering using diamagnetic levitation to explore weightless effects on living organisms and a broad range of other topics in the physical and life sciences

PCR Cloning Combined With DNA Barcoding Enables Partial Identification of Fish Species in a Mixed-Species Product

DNA barcoding is a valuable tool for regulatory identification of fish species; however, it does not perform well when multiple species are present within the same food product. Therefore, the objective of this study was to examine the use of PCR cloning to identify fish in a mixed-species product that cannot be identified with standard DNA barcoding. A total of 15 fish ball mixtures were prepared with known amounts of Nile tilapia (Oreochromis niloticus), Pacific cod (Gadus macrocephalus), and walleye pollock (Gadus chalcogrammus). Three subsamples from each fish ball underwent DNA extraction, full DNA barcoding (655 bp), and mini-barcoding (226 bp) of the cytochrome c oxidase subunit 1 (CO1) gene. Subsamples that did not pass sequencing according to regulatory standards were further analyzed with PCR cloning. All fish balls made of just one species tested positive for that species (i.e., tilapia, cod, or pollock) with both full and mini-barcoding. However, only tilapia was detected in fish balls containing multiple species when tested with standard barcoding techniques, reflecting an inaccurate representation of the fish mixture and suggesting species bias. PCR cloning allowed for identification of Pacific cod in 86% of the mixed-species fish balls tested with fullbarcode cloning and 100% of the mixed-species fish ball tested with mini-barcode cloning. However, PCR cloning did not enable the identification of walleye pollock. Standard full barcoding produced more high quality sequences compared to minibarcoding yet failed to accurately detect all species present in the tested fish mixtures. Overall, the results of this study show that PCR cloning may be an effective method to identify certain fish in mixed-species products when standard DNA barcoding fails. However, additional research is needed to overcome the species bias observed in this study

Effects of unilateral isokinetic eccentric training (and detraining) on musculoskeletal characteristics in older people

Introduction: Reductions in lower-limb strength and muscle mass are common in ageing, with a concomitant reduction in aerobic capacity also limiting exercise tolerance. However, eccentric-only exercise has a lower cardiovascular demand (Vallejo et al., 2006) and higher loading potential that may improve exercise tolerance whilst providing a high musculoskeletal adaptive stimulus. Therefore, the present study examined the impact of a 6-week seated isokinetic eccentric training programme and 8 weeks of detraining on lower-limb strength and muscle architectural characteristics in older people. Methods: Maximal eccentric lower-limb force, and vastus lateralis (VL) thickness, pennation angle and fascicle length were measured in 12 participants (age = 67.0 ± 6.3 y, mass = 80.6 ± 16.0 kg, height = 1.6 ± 0.1 m) before (on two occasions separated by 1 week to determine reliability) and after the 6-week training programme using isokinetic dynamometry and real-time ultrasonography. All measures were then re-examined 8 weeks later to quantify detraining (i.e. regression) effects. Training was performed twice-weekly on a BTE Eccentron that simulated downhill walking using an alternating unilateral leg press motion and consisted of 5 min (week 1) or 10 min (weeks 2-6) of isokinetic eccentric contractions performed at 50%MVC at a rate of 40 ‘steps’ per minute. Strength was reassessed every 2 weeks to ensure subjects’ training intensities remained at 50%MVC, with rate of perceived exertion (RPE) recorded after each training session. Results: A significant (P < 0.05) increase in lower-limb eccentric strength (58.8 ± 39.9%), VL muscle thickness (9.8 ± 5.4%), pennation angle (4.4 ± 5.7%) and fascicle length (5.4 ± 4.3%) was detected immediately after the 6-week training programme. RPE remained consistently low throughout the programme (3.3-4.1 out of 10), despite the increased duration and absolute intensity of training. Eight weeks later, lower-limb eccentric strength (50.4 ± 38.0%), VL muscle thickness (6.1 ± 5.5%) and fascicle length (5.8 ± 7.5%) remained significantly greater than pre-training levels, while pennation angle (1.0 ± 6.7%) returned to baseline. Discussion: The substantial increases in strength and muscle size achieved whilst training with low RPE have important clinical and practical implications for exercise prescription in older people, with the practical application and functional outcomes of the exercise regime well-suited to the specific physical needs and challenges of older people. Furthermore, the limited regression detected eight weeks after the completion of the training programme is indicative that eccentric strength training provides prolonged musculoskeletal functional benefits

On the Generation, Structure, and Semantics of Grammar Patterns in Source Code Identifiers

Identifier names are the atoms of program comprehension. Weak identifier names decrease developer productivity and degrade the performance of automated approaches that leverage identifier names in source code analysis; threatening many of the advantages which stand to be gained from advances in artificial intelligence and machine learning. Therefore, it is vital to support developers in naming and renaming identifiers. In this paper, we extend our prior work, which studies the primary method through which names evolve: rename refactorings. In our prior work, we contextualize rename changes by examining commit messages and other refactorings. In this extension, we further consider data type changes which co-occur with these renames, with a goal of understanding how data type changes influence the structure and semantics of renames. In the long term, the outcomes of this study will be used to support research into: (1) recommending when a rename should be applied, (2) recommending how to rename an identifier, and (3) developing a model that describes how developers mentally synergize names using domain and project knowledge. We provide insights into how our data can support rename recommendation and analysis in the future, and reflect on the significant challenges, highlighted by our study, for future research in recommending renames

Potent selective inhibitors of protein kinase C

AbstractA series of potent, selective inhibitors of protein kinase C has been derived from the structural lead provided by the microbial broth products, staurosporine and K252a. Our inhibitors block PCK in intact cells (platelets and T cells), and prevent the proliferation of mononuclear cells in response to interleukin 2 (IL2)

An introduction to Elinor Glyn : her life and legacy

This special issue of Women: A Cultural Review re-evaluates an author who was once a household name, beloved by readers of romance, and whose films were distributed widely in Europe and the Americas. Elinor Glyn (1864–1943) was a British author of romantic fiction who went to Hollywood and became famous for her movies. She was a celebrity figure of the 1920s, and wrote constantly in Hearst's press. She wrote racy stories which were turned into films—most famously, Three Weeks (1924) and It (1927). These were viewed by the judiciary as scandalous, but by others—Hollywood and the Spanish Catholic Church—as acceptably conservative. Glyn has become a peripheral figure in histories of this period, marginalized in accounts of the youth-centred ‘flapper era’. Decades on, the idea of the ‘It Girl’ continues to have great pertinence in the post-feminist discourses of the twenty-first century. The 1910s and 1920s saw the development of intermodal networks between print, sound and screen cultures. This introduction to Glyn's life and legacy reviews the cross-disciplinary debate sparked by renewed interest in Glyn by film scholars and literary and feminist historians, and offers a range of views of Glyn's cultural and historical significance and areas for future research

Changes in postural sway and gait characteristics as a consequence of anterior load carriage

INTRODUCTION: Previous research has indicated that carrying a backpack elicits an increase in postural sway during quiet standing (Heller et al. 2009) and stride-to-stride gait variability during walking (Qu and Yeo, 2011). Despite these initial enquires into the effects of carrying external loads on postural stability, little research has examined the effects of anterior load carriage. This gap in the literature is important because many daily (e.g. carrying a laundry basket) and occupational (e.g. courier delivery) activities require loads to be carried in front of the body. Within this context, to further develop the external load-postural stability database we examined the effects of increasing loads carried anteriorly on postural sway and gait parameters in healthy adults. METHODS: Twenty-nine subjects (19 males, 10 females, age = 33.8 ± 12.7 years, height = 1.73 ± 0.07 m, mass = 75.1 ± 13.7 kg) were assessed in four conditions; (1) carrying no load (CON), (2) carrying a load with no added weight (i.e. empty box), (3) carrying a load with 5% body mass, and (4) carrying a load with 10% body mass. Anteroposterior and mediolateral centre of pressure (COP) displacement (cm) and the mean COP velocity (cm·s-1) were used to characterise postural sway. Coefficient of variation of the stride length, stride time and double support time were calculated from 1 min of treadmill walking at a preferred pace for gait assessment. RESULTS: When compared to CON, anteroposterior COP displacement increased with the addition of a 5% (P < 0.001, d = 0.74) and 10% (P < 0.001, d = 1.59) load. The anteroposterior COP displacement also increased from the 5% to the 10% load (P < 0.001, d = 0.75). The addition of the 10% load increased stride time (d = 1.71) and stride length (d = 1.20) variability when compared to CON (P < 0.001). Additionally, stride length variability was significantly greater during 10% compared to 0% (P = 0.004, d = 1.08) and 5% (P = 0.001, d = 1.01) conditions. CONCLUSION: In summary, the increase in postural sway and gait variability with added weight is dependent on the magnitude of the load, where the greater the load, the greater the effect on static and dynamic stability. Changes in the mass-inertia characteristics of the body is one of several mechanisms that have been offered to explain the increased postural sway and gait variability when holding an external load. Given that increased postural sway (Johansson et al. 2017) and gait variability (Verghese et al. 2009) are indicators of increased fall-risk, it can be inferred from the present findings that carrying heavy loads in front of the body increases the likelihood of fall-related incidents