Phaeochrornocytorna - a case report

A 52-year-old man presented with a 4-year history of paroxysmal attacks of anxiety, giddiness, palpitation, sweating, and severe headache. These symptoms wereassociated with sudden increases in his blood pressure; and a provisional diagnosis of phaeochromocytoma was made.Collections of urine were submitted for catecholamine assay. One collection showed a slight increase in catecholamines but the rest were normal, including a collection made after a provocation test, using histamine 0,025 mg intravenously. The histamine test did, however, cause systolic and diastolic blood pressure to rise by 20 mmHg.As he was mildly hypertensive between paroxysms, a phentolamine test was carried out, utilising 5 mg well diluted, intravenously, over 5 minutes under basal conditions. This, too, was negative. An aortogram failed to demonstrate convincingly tumour vascularisation, but there was a mild hypertensive crisis during this examination.At laparotomy, a single phaeochromocytoma was found in the right adrenal gland, and was successfully removed. Recovery was uneventful and the patient was discharged, normotensive and not requiring hypotensive therapy, though mild hypertension has developed since. No residual catecholamine activity has been detected.The preparation of the patient for surgery and the control of operative complications are described, and the salient diagnostic features of phaeochromocytoma are briefly discussed.S. Afr. Med. J. 48, 401 (1974)

Light Curve Analysis of Hipparcos Data for the Massive O-type Eclipsing Binary UW CMa

Hipparcos photometric data for the massive O-type binary UW CMa were analysed within the framework of the Roche model. Photometric solutions were obtained for five mass ratios in the $q=M_2/M_1=0.5-1.5$ range. The system is found to be in a contact configuration. Independently of $q$, the best-fitting model solutions correspond to the orbital inclination $i \sim 71^\circ$ and the temperature of the secondary component $T_2 \sim 33500\,K$, at the fixed temperature of the primary $T_1=33750 K$. Considering that the spectrum of the secondary is very weak, photometric solutions corresponding to the contact configuration favor the mass ratio $q$ smaller than unity (in which case the luminosity of the secondary is smaller than that of the primary). The absolute parameters of the system are estimated for different values of the mass ratio.Comment: 18 pages, 6 figure

Majorana solutions to the two-electron problem

A review of the known different methods and results devised to study the two-electron atom problem, appeared in the early years of quantum mechanics, is given, with particular reference to the calculations of the ground state energy of helium. This is supplemented by several, unpublished results obtained around the same years by Ettore Majorana, which results did not convey in his published papers on the argument, and thus remained unknown until now. Particularly interesting, even for current research in atomic and nuclear physics, is a general variant of the variational method, developed by Majorana in order to take directly into account, already in the trial wavefunction, the action of the full Hamiltonian operator of a given quantum system. Moreover, notable calculations specialized to the study of the two-electron problem show the introduction of the remarkable concept of an effective nuclear charge different for the two electrons (thus generalizing previous known results), and an application of the perturbative method, where the atomic number Z was treated effectively as a continuous variable, contributions to the ground state energy of an atom with given Z coming also from any other Z. Instead, contributions relevant mainly for pedagogical reasons count simple broad range estimates of the helium ionization potential, obtained by suitable choices for the wavefunction, as well as a simple alternative to Hylleraas' method, which led Majorana to first order calculations comparable in accuracy with well-known order 11 results derived, in turn, by Hylleraas.Comment: amsart, 20 pages, no figure

Assessment of agreement between invasive blood pressure measured centrally and peripherally and the influence of different haemodynamic states in anaesthetised horses

Objective To determine the agreement of invasive blood pressure measured in the facial artery, the metatarsal artery and the carotid. Additionally, to evaluate the effects of two haemodynamic conditions on agreement. Study design Prospective, randomized study. Animals Eight horses aged 7 (4 -23) years with a body weight of 493 ± 33 kg. Methods Horses were anaesthetized and positioned in dorsal recumbency. Invasive blood pressure was measured simultaneously via catheters placed in the facial, metatarsal and carotid artery. Cardiovascular function and agreement between arteries was assessed before and during administration of phenylephrine and sodium nitroprusside. These were administered until carotid mean pressure (MAPc) increased or decreased from baseline (65 ± 5 mmHg) to > 90 mmHg or < 50 mmHg, respectively. Data recorded at each sample time included systolic (SAP), mean (MAP) and diastolic (DAP) for carotid (c), facial (f) and metatarsal (m) artery as well as cardiac output (Q̇t) and systemic vascular resistance (SVR). Bland-Altman analysis was used to assess agreement between peripheral and central sites and regression analysis was used to determine influence of Q̇t and SVR. Results The largest difference was observed in SAPc and SAPm with a bias and limits of agreement (LOA) of 2 (-15 to 19) mmHg. The bias (LOA) for MAPc and MAPf was 2 (-4 to 9) mmHg and for MAPc and MAPm was 5 (-4 to 14) mmHg. The best agreement for DAP was seen between DAPc and DAPf with bias (LOA) of 1 (-3 to 5) mmHg. Regression analysis indicated marginal influence on agreement by Q̇t on MAPc and MAPf. Conclusion and clinical relevance The MAP and DAP of the carotid was generally higher compared to the peripheral arteries, which may lead to overzealous treatment of hypotension, albeit maintaining central pressures. Cardiac output and systemic vascular resistance did not largely influence the difference between sites

A performative-performance analytical approach: infusing Butlerian theory into the narrative-discursive method

Judith Butler’s theory of performativity provides gender theorists with a rich theoretical language for thinking about gender. Despite this, Butlerian theory is difficult to apply, as Butler does not provide guidance on actual analysis of language use in context. In order to address this limitation, we suggest carefully supplementing performativity with the notion of performance in a manner that allows for the inclusion of relational specificities and the mechanisms through which gender, and gender trouble, occur. To do this, we turn to current developments within discursive psychology and narrative theory. We extend the narrative-discursive method proposed by Taylor and colleagues, infusing it with Butlerian theory in order to fashion a dual analytical lens, which we call the performativity-performance approach. We provide a brief example of how the proposed analytical process may be implemented

Simultaneous interval regression for K-nearest neighbor

International audienceIn some regression problems, it may be more reasonable to predict intervals rather than precise values. We are interested in finding intervals which simultaneously for all input instances x ∈X contain a β proportion of the response values. We name this problem simultaneous interval regression. This is similar to simultaneous tolerance intervals for regression with a high confidence level γ ≈ 1 and several authors have already treated this problem for linear regression. Such intervals could be seen as a form of confidence envelop for the prediction variable given any value of predictor variables in their domain. Tolerance intervals and simultaneous tolerance intervals have not yet been treated for the K-nearest neighbor (KNN) regression method. The goal of this paper is to consider the simultaneous interval regression problem for KNN and this is done without the homoscedasticity assumption. In this scope, we propose a new interval regression method based on KNN which takes advantage of tolerance intervals in order to choose, for each instance, the value of the hyper-parameter K which will be a good trade-off between the precision and the uncertainty due to the limited sample size of the neighborhood around each instance. In the experiment part, our proposed interval construction method is compared with a more conventional interval approximation method on six benchmark regression data sets

Controlling laser spectra in a phaseonium photonic crystal using maser

We study the control of quantum resonances in photonic crystals with electromagnetically induced transparency driven by microwave field. In addition to the control laser, the intensity and phase of the maser can alter the transmission and reflection spectra in interesting ways, producing hyperfine resonances through the combined effects of multiple scattering in the superstructure.Comment: 7 pages, 4 figure

Effectiveness of interventions targeting self-regulation to improve adherence to chronic disease medications: a meta-review of meta-analyses

Adherence to chronic disease medication regimens depends in part on successful self-regulation. However, the overall benefit of interventions targeting self-regulatory mechanisms is not well-understood. Accordingly, we conducted a meta-review of meta-analyses assessing the effect of interventions targeting self-regulation on medication adherence. For this meta-review, meta-analyses appearing between January 2006 and March 2019 were eligible if they included experimental trials that assessed the effect of an intervention targeting self-regulation on adherence to chronic disease medication. A systematic literature search of multiple databases for published and unpublished literature identified 16,001 abstracts. Twelve meta-analyses met eligibility criteria and had variable quality according to AMSTAR 2 item completion (M = 50%; range: 31–66%). Overall, meta-reviews showed small to medium effect sizes for interventions that targeted self-monitoring, provided personalised feedback on adherence, or involved complete self-management. Other interventions, such as goal setting, barrier identification and problem solving, and stress management showed little evidence of improving adherence. Only a limited number of self-regulation intervention components were able to be evaluated. Additional research is needed to advance the understanding of the efficacy of adherence interventions focussed on self-regulation by expanding the scope of self-regulation elements targeted (e.g., emotion regulation)