Teaching the hidden symmetry of the Kepler problem in relativistic quantum mechanics - from Pauli to Dirac electron

Hidden symmetry in Coulomb interaction is one of the mysterious problems of modern physics. Additional conserved quantities associated with extra symmetry govern wide variety of physics problems, from planetary motion till fine and hyperfine structures of atomic spectra. In this paper we present a simple derivation of hidden symmetry operator in relativistic quantum mechanics for the Dirac equation in the Coulomb field. We established that this operator may be reduced to the one introduced by Johnson and Lippmann. It is worthwhile to notice that this operator was discussed in literature very rarely and so is not known well among physicists and was omitted even in the recent textbooks on relativistic quantum mechanics and/or quantum electrodynamics.Comment: 5 page

Penicillin allergy SHACK : Survey of hospital and community knowledge

Aim Penicillin allergy accounts for the majority of all reported adverse drug reactions in adults and children. Foregoing first-line antibiotic therapy due to penicillin allergy label is associated with an increased prevalence of infections by resistant organisms and longer hospitalisation. Clinician awareness of allergy assessment, referral indications, management of allergy and anaphylaxis is therefore vital but globally lacking. We aim to assess the knowledge of penicillin allergy, assessment and management in Western Australian health professionals. Methods An anonymous survey was distributed to pharmacists, nurses and physicians within Western Australian paediatric and adult Hospitals, Community and General Practice. Results In total, 487/611 were completed and included in the statistical analysis. Only 62% (301/487) of respondents routinely assessed for patient medication allergies. Of those who assessed allergy, 9% (28/301) of respondents met the Australian standards for allergy assessment. Only 22% (106/487) of participants correctly cited all indications for management with adrenaline in anaphylaxis to antibiotics and 67% (197/292) of physicians rarely or never referred to an allergy service. Paediatric clinicians had an increased understanding of allergy assessment and anaphylaxis management. Recent penicillin allergy education within a 5-year period led to significant improvements in allergy knowledge. Conclusion Overall, knowledge, assessment and management of penicillin allergies among practitioners in Western Australia are currently inadequate in adults and paediatric clinicians to provide safe and effective clinical care. The implementation of a targeted education program for WA health professionals is urgently required and is expected to improve clinician knowledge and aid standardised penicillin assessment (de-labelling) practices

Acute hypoglycemia impairs executive cognitive function in adults with and without type 1 diabetes

OBJECTIVE: Acute hypoglycemia impairs cognitive function in several domains. Executive cognitive function governs organization of thoughts, prioritization of tasks, and time management. This study examined the effect of acute hypoglycemia on executive function in adults with and without diabetes. RESEARCH DESIGN AND METHODS: Thirty-two adults with and without type 1 diabetes with no vascular complications or impaired awareness of hypoglycemia were studied. Two hyperinsulinemic glucose clamps were performed at least 2 weeks apart in a single-blind, counterbalanced order, maintaining blood glucose at 4.5 mmol/L (euglycemia) or 2.5 mmol/L (hypoglycemia). Executive functions were assessed with a validated test suite (Delis-Kaplan Executive Function). A general linear model (repeated-measures ANOVA) was used. Glycemic condition (euglycemia or hypoglycemia) was the within-participant factor. Between-participant factors were order of session (euglycemia-hypoglycemia or hypoglycemia-euglycemia), test battery used, and diabetes status (with or without diabetes). RESULTS: Compared with euglycemia, executive functions (with one exception) were significantly impaired during hypoglycemia; lower test scores were recorded with more time required for completion. Large Cohen d values (>0.8) suggest that hypoglycemia induces decrements in aspects of executive function with large effect sizes. In some tests, the performance of participants with diabetes was more impaired than those without diabetes. CONCLUSIONS: Executive cognitive function, which is necessary to carry out many everyday activities, is impaired during hypoglycemia in adults with and without type 1 diabetes. This important aspect of cognition has not received previous systematic study with respect to hypoglycemia. The effect size is large in terms of both accuracy and speed

HQET chromomagnetic interaction at two loops

We present the coefficient of the chromomagnetic interaction operator, the only unknown coefficient in the Heavy Quark Effective Theory (HQET) lagrangian up to the $1/m$ level, with the two-loop accuracy by matching scattering amplitudes of an on-shell heavy quark in an external field in full QCD and HQET, and obtain the two-loop anomalous dimension of this operator in HQET.Comment: 10 pages, LaTeX2e, 2 eps figures included. Revised discussion of (n_f-1)-flavour HQET include

Feasibility of a randomized controlled trial of paediatric interdisciplinary pain management using home-based telehealth

Purpose: Chronic pain is common in adolescents. Evidence-based guidelines recommend interdisciplinary treatment, but access is limited by geography. The development of hybrid programs utilizing both face-to-face and videoconference treatment may help overcome this. We developed a 7-week hybrid pediatric interdisciplinary pain program (Hybrid-PIPP) and wished to compare it to individual face-to-face sessions (Standard Care). Our objective was to test the feasibility of a protocol that used a matched pair un-blinded randomized controlled design to investigate the efficacy and cost-effectiveness of the Hybrid-PIPP compared to Standard Care. Patients and Methods: Parent–adolescent dyads were recruited from tertiary pediatric clinics and matched by disability before randomization to minimize allocation bias. The adolescents (aged 11– 17) had experienced primary pain for > 3 months. Hybrid-PIPP involved 11 hrs of group therapy and 4 individual videoconference sessions. Standard care was provided by the same clinical team, using the same treatment model and similar intensity as the Hybrid-PIPP. The intention was to recruit participants for 3 Hybrid-PIPP groups with a comparison stream. Recruitment was ceased after 2 groups due to the high participant disability requiring more intensive intervention. Results: Eighteen dyads were screened and 13 randomized (7 Hybrid-PIPP, 6 Standard Care, 2 unsuitable, 3 unallocated when the study was stopped). The study met a priori feasibility criteria for staff availability; recruitment rate; treatment completion; and data collection. Global satisfaction ratings were similar in both streams (SC median 7, range 5– 9 and Hybrid-PIPP median 8.5, range 5– 10). Challenges were identified in both streams. A future modified Hybrid-PIPP was considered acceptable if the intensity is increased to manage the high level of disability. Standard care was considered inefficient. No adverse events were reported. Conclusion: The study determined that the protocol met a priori feasibility criteria, but to be practicable in a real world, health environment requires significant modifications

Growth and survival of cuttlefish (Sepia officinalis) of different ages fed crustaceans and fish. Effects of frozen and live prey

Three feeding experiments, using live mysid shrimp, grass shrimp or fish fry as prey for 1-, 30- and 60-day-old cuttlefish were conducted to determine the efficiency of each dietary source in relation to cuttlefish size and age. Additionally, a fourth experiment using fish fry and grass shrimp, but previously frozen, was also conducted. The results showed that when 1-day-old cuttlefish were fed mysids, grass shrimp or fish for 4 weeks, mysids were the best prey, but only during the first week. From this moment until the end of the experiment, the best growth rate was when cuttlefish were fed grass shrimp. Cuttlefish fed fish fry showed the poorest growth rate throughout the experiment. Similarly, cuttlefish aged 30 or 60 days fed grass shrimp or fish fry had the best growth rates when fed grass shrimp. When cuttlefish were fed live fish, survival increased with size of cuttlefish (73.3%, 91.7% and 100% for 1, 30 and 60 days cuttlefish, respectively). In the fourth experiment, using frozen diets, overall acceptance of each diet (feeding rates) was the same for fish and shrimp. However, lower growth was obtained when cuttlefish were fed fish compared to grass shrimp. This lower growth was due to a lower food conversion (28% vs. 41%). Since cephalopod paralarvae and juvenile most likely need prey rich in polyunsaturated fatty acids (PUFA), phospholipids and cholesterol, and a moderate content in neutral lipids, we have analyzed the biochemical compositions of the different prey to evaluate the influence of this factor on growth and survival.En prensa2,04

Quantum Electrodynamics of the Helium Atom

Using singlet S states of the helium atom as an example, I describe precise calculation of energy levels in few-electron atoms. In particular, a complete set of effective operators is derived which generates O(m*alpha^6) relativistic and radiative corrections to the Schr"odinger energy. Average values of these operators can be calculated using a variational Schr"odinger wave function.Comment: 23 pages, revte

Bigger tides, less flooding: Effects of dredging on barotropic dynamics in a highly modified estuary.

Author Posting. © American Geophysical Union, 2019. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research-Oceans 124 (2019): 196-211, doi:10.1029/2018JC014313.Since the late nineteenth century, channel depths have more than doubled in parts of New York Harbor and the tidal Hudson River, wetlands have been reclaimed and navigational channels widened, and river flow has been regulated. To quantify the effects of these modifications, observations and numerical simulations using historical and modern bathymetry are used to analyze changes in the barotropic dynamics. Model results and water level records for Albany (1868 to present) and New York Harbor (1844 to present) recovered from archives show that the tidal amplitude has more than doubled near the head of tides, whereas increases in the lower estuary have been slight (<10%). Channel deepening has reduced the effective drag in the upper tidal river, shifting the system from hyposynchronous (tide decaying landward) to hypersynchronous (tide amplifying). Similarly, modeling shows that coastal storm effects propagate farther landward, with a 20% increase in amplitude for a major event. In contrast, the decrease in friction with channel deepening has lowered the tidally averaged water level during discharge events, more than compensating for increased surge amplitude. Combined with river regulation that reduced peak discharges, the overall risk of extreme water levels in the upper tidal river decreased after channel construction, reducing the water level for the 10‐year recurrence interval event by almost 3 m. Mean water level decreased sharply with channel modifications around 1930, and subsequent decadal variability has depended both on river discharge and sea level rise. Channel construction has only slightly altered tidal and storm surge amplitudes in the lower estuary.Funding for D. K. R., W. R. G., and C. K. S. was provided by NSF Coastal SEES awards OCE-1325136 and OCE-1325102. Funding for S.T. and H. Z. was provided by the U.S. Army Corps of Engineers (award W1927 N-14-2-0015), and NSF (Career Award 1455350). Data supporting this study are posted to Zenodo (https://doi.org/10.5281/zenodo.1298636).2019-06-1

Self-Interaction and Gauge Invariance

A simple unified closed form derivation of the non-linearities of the Einstein, Yang-Mills and spinless (e.g., chiral) meson systems is given. For the first two, the non-linearities are required by locality and consistency; in all cases, they are determined by the conserved currents associated with the initial (linear) gauge invariance of the first kind. Use of first-order formalism leads uniformly to a simple cubic self-interaction.Comment: Missing last reference added. 9 pages, This article, the first paper in Gen. Rel. Grav. [1 (1970) 9], is now somewhat inaccessible; the present posting is the original version, with a few subsequent references included. Updates update

Reconsidered estimates of the 10th order QED contributions to the muon anomaly

The problem of estimating the 10th order QED corrections to the muon anomalous magnetic moment is reconsidered. The incorporation of the recently improved contributions to the $\alpha^4$ and $\alpha^5$- corrections to $a_{\mu}$ within the renormalization-group inspired scheme-invariant approach leads to the estimate $a_{\mu}^{(10)}\approx 643(\alpha/pi)^5$. It is in good agreement with the estimate $a_{\mu}^{(10)}= 663(20) (\alpha/\pi)^5$, obtained by Kinoshita and Nio from the numerical calculations of 2958 10-th order diagrams, which are considered to be more important than the still uncalculated 6122 10th-order $m_{\mu}/m_e$-dependent vertex graphs, and 12672 5-loop diagrams, responsible for the mass-independent constant contribution both to $a_{\mu}$ and $a_e$. This confirms Kinoshita and Nio guess about dominance of the 10-th order diagrams calculated by them. Comparisons with other estimates of the $\alpha^5$- contributions to $a_{\mu}$, which exist in the literature, are presented.Comment: 19 pages, LaTeX, some misprints in the text and literature corrected. Results unchaged, to appear in Phys.Rev.