Quantum Entanglement in the Two Impurity Kondo Model

In order to quantify quantum entanglement in two impurity Kondo systems, we calculate the concurrence, negativity, and von Neumann entropy. The entanglement of the two Kondo impurities is shown to be determined by two competing many-body effects, the Kondo effect and the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, $I$. Due to the spin-rotational invariance of the ground state, the concurrence and negativity are uniquely determined by the spin-spin correlation between the impurities. It is found that there exists a critical minimum value of the antiferromagnetic correlation between the impurity spins which is necessary for entanglement of the two impurity spins. The critical value is discussed in relation with the unstable fixed point in the two impurity Kondo problem. Specifically, at the fixed point there is no entanglement between the impurity spins. Entanglement will only be created (and quantum information processing (QIP) be possible) if the RKKY interaction exchange energy, $I$, is at least several times larger than the Kondo temperature, $T_K$. Quantitative criteria for QIP are given in terms of the impurity spin-spin correlation.Comment: 7 pages, 3 figures, 1 tabl

Springs of Florida

bulletin which documented the major and important springs in the state (Ferguson et al., 1947). This publication was revised in 1977, with many previously undocumented springs and many new water-quality analyses being added (Rosenau et al., 1977). The Florida Geological Survey's report on first magnitude springs (Scott et al., 2002) was the initial step in once again updating and revising the Springs of Florida bulletin. The new bulletin includes the spring descriptions and water-quality analyses from Scott et al. (2002). Nearly 300 springs were described in 1977. As of 2004, more than 700 springs have been recognized in the state and more are reported each year. To date, 33 first magnitude springs (with a flow greater than 100 cubic feet per second or approximately 64.6 million gallons of water per day) have been recognized in Florida, more than any other state or country (Rosenau et al., 1977). Our springs are a unique and invaluable natural resource. A comprehensive understanding of the spring systems will provide the basis for their protection and wise use. (Document pdf contains 677 pages

Redox-dependent conformational switching of diphenylacetylenes

Herein we describe the design and synthesis of a redox-dependent single-molecule switch. Appending a ferrocene unit to a diphenylacetylene scaffold gives a redox-sensitive handle, which undergoes reversible one-electron oxidation, as demonstrated by cyclic voltammetry analysis. 1H-NMR spectroscopy of the partially oxidized switch and control compounds suggests that oxidation to the ferrocenium cation induces a change in hydrogen bonding interactions that results in a conformational switch

Do Patient-Reported Outcomes Have a Role in the Management of Patients with Cystic Fibrosis?

Background: Health-related quality of life (HRQoL) is a rapidly growing area of expertise and the most commonly used patient-reported outcome (PRO). The impact of cystic fibrosis (CF) on HRQoL is liable to be great, making CF patients ideal candidates for the application of HRQoL instruments. The aims of this study were to assess the affect of CF on HRQoL, to ascertain the reliability and validity of the United Kingdom Sickness Impact Profile (UKSIP) and the Cystic Fibrosis Quality of Life Questionnaire (CFQoL) in the adult CF population, and to examine their role in the management of patients. Methods: Seventy participants were recruited from the All Wales Adult Cystic Fibrosis Centre at Llandough Hospital, UK. There were two stages to the study: self-report of the UKSIP and CFQoL; and completion of the same two questionnaires 7–10 days later. Results: The areas of HRQoL most impaired by CF were employment and concerns regarding the future. The UKSIP and CFQoL showed high internal consistency (rα = 0.89–0.93) and test–retest reliability (rs = 0.57–0.94, p < 0.005) in the CF population. Validity was variable with the UKSIP showing discrimination across socio-demographic factors, whilst the CFQoL showed increased sensitivity to clinical variables. Many parameters influenced patient-reported HRQoL, with the greatest correlations seen with the Borg score (p < 0.005). The use of a HRQoL instrument in CF annual reviews is recommended to provide holistic patient care. The results of this study underpin the value of HRQoL as a patient-reported outcome measure in the management of adult CF

THE BALL ORIENTATIONS USED BY PLACE KICKERS AT THE 2019 RUGBY WORLD CUP AND THEIR ASSOCIATIONS WITH KICK SUCCESS

The outcomes of place kicks can have a large impact on Rugby Union match results. This study investigated the ball orientations used in place kicking and their potential implications for success. All 416 place kicks from the 2019 Rugby World Cup were grouped into one of three ball orientation categories, and predicted odds of success were calculated for each category using a binomial logistic regression which accounted for situational factors known to affect performance outcome. Kicks taken using a slanted orientation (n = 152) had the greatest odds of success (90.0%) when taken from the mean tournament distance (29.7 m), compared to a near vertical (n = 116) orientation (84.4%), and near horizontal (n = 148) orientation (86.8%). A further investigation into the impact characteristics associated with each ball orientation is required to better understand the relative merits of each

A magnetic map leads juvenile European eels to the Gulf Stream

Migration allows animals to track the environmental conditions that maximize growth, survival, and reproduction [ 1–3 ]. Improved understanding of the mechanisms underlying migrations allows for improved management of species and ecosystems [ 1–4 ]. For centuries, the catadromous European eel (Anguilla anguilla) has provided one of Europe’s most important fisheries and has sparked considerable scientific inquiry, most recently owing to the dramatic collapse of juvenile recruitment [ 5 ]. Larval eels are transported by ocean currents associated with the Gulf Stream System from Sargasso Sea breeding grounds to coastal and freshwater habitats from North Africa to Scandinavia [ 6, 7 ]. After a decade or more, maturing adults migrate back to the Sargasso Sea, spawn, and die [ 8 ]. However, the migratory mechanisms that bring juvenile eels to Europe and return adults to the Sargasso Sea remain equivocal [ 9, 10 ]. Here, we used a “magnetic displacement” experiment [ 11, 12 ] to show that the orientation of juvenile eels varies in response to subtle differences in magnetic field intensity and inclination angle along their marine migration route. Simulations using an ocean circulation model revealed that even weakly swimming in the experimentally observed directions at the locations corresponding to the magnetic displacements would increase entrainment of juvenile eels into the Gulf Stream System. These findings provide new insight into the migration ecology and recruitment dynamics of eels and suggest that an adaptive magnetic map, tuned to large-scale features of ocean circulation, facilitates the vast oceanic migrations of the Anguilla genu

Let’s Take A Walk: Exploring the Impact of an Inclusive Walking Program on the Physical and Mental Health of Adults with Intellectual Disability

Background: People with intellectual disabilities experience health disparities and poorer health outcomes than people without disabilities. Increased physical activity has been found to reduce the impact of chronic health conditions among people with intellectual disabilities. Method: The current study explored the impact of an inclusive walking program on the physical and mental health of adults with intellectual disabilities. Let’s Take A Walk paired adults with intellectual disabilities, hereafter referred to as Community Walkers (n = 27), with college students to walk around a college campus twice a week for 45 minutes across 10 weeks. Data on mental health outcomes, specifically depression and anxiety, were collected from 24 Community Walkers across four-time points (pre-, mid-, post-, and 3-months following intervention), and data on physical health outcomes were collected across two-time points (pre- and post-intervention). Results: Community Walkers reported significant decreases in both depression and anxiety from pre to post-implementation. Particularly promising was clinically significant decreases in anxiety symptoms over the 10-week program. No differences were noted on Community Walkers’ measures of physical health. Conclusion: Inclusive walking programs are a valuable and promising mechanism for building social connections and inclusion and improving mental health for adults with intellectual disabilities

Letter from Frances B. Hatcher, as well as letters of recommendation from Luther M. Defoe, A. Ross Hill, J. C. Jones, and Sam Frank Taylor

Letter concerning a position in the mathematics department at Utah Agricultural College, as well as recommendations

Selective vulnerability of inhibitory networks in multiple sclerosis.

In multiple sclerosis (MS), a chronic demyelinating disease of the central nervous system, neurodegeneration is detected early in the disease course and is associated with the long-term disability of patients. Neurodegeneration is linked to both inflammation and demyelination, but its exact cause remains unknown. This gap in knowledge contributes to the current lack of treatments for the neurodegenerative phase of MS. Here we ask if neurodegeneration in MS affects specific neuronal components and if it is the result of demyelination. Neuropathological examination of secondary progressive MS motor cortices revealed a selective vulnerability of inhibitory interneurons in MS. The generation of a rodent model of focal subpial cortical demyelination reproduces this selective neurodegeneration providing a new preclinical model for the study of neuroprotective treatments

The three-dimensionally articulated oral apparatus of a Devonian heterostracan sheds light on feeding in Palaeozoic jawless fishes

Attempts to explain the origin and diversification of vertebrates have commonly invoked the evolution of feeding ecology, contrasting the passive suspension feeding of invertebrate chordates and larval lampreys with active predation in living jawed vertebrates. Of the extinct jawless vertebrates that phylogenetically intercalate these living groups, the feeding apparatus is well-preserved only in the early diverging stem-gnathostome heterostracans. However, its anatomy remains poorly understood. Here, we use X-ray microtomography to characterize the feeding apparatus of the pteraspid heterostracan Rhinopteraspis dunensis (Roemer, 1855). The apparatus is composed of 13 plates arranged approximately bilaterally, most of which articulate from the postoral plate. Our reconstruction shows that the oral plates were capable of rotating around the transverse axis, but likely with limited movement. It also suggests the nasohypophyseal organs opened internally, into the pharynx. The functional morphology of the apparatus in Rhinopteraspis precludes all proposed interpretations of feeding except for suspension/deposit feeding and we interpret the apparatus as having served primarily to moderate the oral gape. This is consistent with evidence that at least some early jawless gnathostomes were suspension feeders and runs contrary to macroecological scenarios that envisage early vertebrate evolution as characterized by a directional trend towards increasingly active food acquisition