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The Electron Loss and Fields Investigation with a Spatio-Temporal Ambiguity-Resolving option (ELFIN-STAR, or heretoforth simply: ELFIN) mission comprises two identical 3-Unit (3U) CubeSats on a polar (â¼93∘ inclination), nearly circular, low-Earth (â¼450 km altitude) orbit. Launched on September 15, 2018, ELFIN is expected to have a >2.5 year lifetime. Its primary science objective is to resolve the mechanism of storm-time relativistic electron precipitation, for which electromagnetic ion cyclotron (EMIC) waves are a prime candidate. From its ionospheric vantage point, ELFIN uses its unique pitch-angle-resolving capability to determine whether measured relativistic electron pitch-angle and energy spectra within the loss cone bear the characteristic signatures of scattering by EMIC waves or whether such scattering may be due to other processes. Pairing identical ELFIN satellites with slowly-variable along-track separation allows disambiguation of spatial and temporal evolution of the precipitation over minutes-to-tens-of-minutes timescales, faster than the orbit period of a single low-altitude satellite (Torbit â¼ 90 min). Each satellite carries an energetic particle detector for electrons (EPDE) that measures 50 keV to 5 MeV electrons with Δ E/E < 40% and a fluxgate magnetometer (FGM) on a â¼72 cm boom that measures magnetic field waves (e.g., EMIC waves) in the range from DC to 5 Hz Nyquist (nominally) with <0.3 nT/sqrt(Hz) noise at 1 Hz. The spinning satellites (Tspin â¼ 3 s) are equipped with magnetorquers (air coils) that permit spin-up or -down and reorientation maneuvers. Using those, the spin axis is placed normal to the orbit plane (nominally), allowing full pitch-angle resolution twice per spin. An energetic particle detector for ions (EPDI) measures 250 keV - 5 MeV ions, addressing secondary science. Funded initially by CalSpace and the University Nanosat Program, ELFIN was selected for flight with joint support from NSF and NASA between 2014 and 2018 and launched by the ELaNa XVIII program on a Delta II rocket (with IceSatII as the primary). Mission operations are currently funded by NASA. Working under experienced UCLA mentors, with advice from The Aerospace Corporation and NASA personnel, more than 250 undergraduates have matured the ELFIN implementation strategy; developed the instruments, satellite, and ground systems and operate the two satellites. ELFIN's already high potential for cutting-edge science return is compounded by concurrent equatorial Heliophysics missions (THEMIS, Arase, Van Allen Probes, MMS) and ground stations. ELFIN's integrated data analysis approach, rapid dissemination strategies via the SPace Environment Data Analysis System (SPEDAS), and data coordination with the Heliophysics/Geospace System Observatory (H/GSO) optimize science yield, enabling the widest community benefits. Several storm-time events have already been captured and are presented herein to demonstrate ELFIN's data analysis methods and potential. These form the basis of on-going studies to resolve the primary mission science objective. Broad energy precipitation events, precipitation bands, and microbursts, clearly seen both at dawn and dusk, extend from tens of keV to >1 MeV. This broad energy range of precipitation indicates that multiple waves are providing scattering concurrently. Many observed events show significant backscattered fluxes, which in the past were hard to resolve by equatorial spacecraft or non-pitch-angle-resolving ionospheric missions. These observations suggest that the ionosphere plays a significant role in modifying magnetospheric electron fluxes and wave-particle interactions. Routine data captures starting in February 2020 and lasting for at least another year, approximately the remainder of the mission lifetime, are expected to provide a very rich dataset to address questions even beyond the primary mission science objective.
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The original version of this Article contained an error in the abstract, referring to "multi-megawatt-per-metre" instead of "multi-megavolt-per-metre". This has now been corrected in both the PDF and HTML versions of the Article.
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The sub-luminal phase velocity of electromagnetic waves in free space is generally unobtainable, being closely linked to forbidden faster than light group velocities. The requirement of sub-luminal phase-velocity in laser-driven particle acceleration schemes imposes a limit on the total acceleration achievable in free space, and necessitates the use of dispersive structures or waveguides for extending the field-particle interaction. We demonstrate a travelling source approach that overcomes the sub-luminal propagation limits. The approach exploits ultrafast optical sources with slow group velocity propagation, and a group-to-phase front conversion through nonlinear optical interaction. The concept is demonstrated with two terahertz generation processes, nonlinear optical rectification and current-surge rectification. We report measurements of longitudinally polarised single-cycle electric fields with phase and group velocity between 0.77c and 1.75c. The ability to scale to multi-megavolt-per-metre field strengths is demonstrated. Our approach paves the way towards the realisation of cheap and compact particle accelerators with femtosecond scale control of particles.Controlled generation of terahertz radiation with subluminal phase velocities is a key issue in laser-driven particle acceleration. Here, the authors demonstrate a travelling-source approach utilizing the group-to-phase front conversion to overcome the sub-luminal propagation limit.
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The structure of a glass obtained by the melt quenching of a two-dimensional (2D) coordination network was examined. X-ray analyses disclosed a 2D-to-0D structural transformation before and after glass formation. The mechanism is unique to coordination compounds, as it is characterized by labile and flexible coordination bonds.
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Vidrio/química , Cristalografía por Rayos X , Modelos Moleculares , Conformación MolecularRESUMEN
A general description of electro-optic detection including non-collinear phase matching and finite transverse beam profiles is presented. It is shown theoretically and experimentally that non-collinear phase matching in ZnTe (and similar materials) produces an angular chirp in the χ(2)-generated optical signal. Due to this, in non-collinear THz and probe arrangements such as single-shot THz measurements or through accidental misalignment, measurement of an undistorted THz signal is critically dependent on having sufficient angular acceptance in the optical probe path. The associated spatial walk-off can also preclude the phase retardation approximation used in THz-TDS. The rate of misalignment-induced chirping in commonly used ZnTe and GaP schemes is tabulated, allowing ready analysis of a detection system.
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OBJECTIVE: This study aimed to discover if the documented decline in nutritional status in predialysis patients could be prevented by dietetic intervention. DESIGN: Longitudinal prospective interventional study. SETTING: General hospital nephrology clinic. PATIENTS: Eleven patients with progressive chronic renal failure not yet requiring dialysis, all with creatinine clearance below 25 mL/min were studied. Mean age was 63.9 +/- 14.5 years. INTERVENTION: Patients received nutritional counseling from a renal dietitian on at least 3 occasions over a period of 6 months. Following assessment, patients were advised on dietary changes according to individual need, aiming for adequate energy intake to achieve or maintain a body mass index of 20 to 25 and protein intake of 0.8 to 1.0 g/kg/d. Dietary supplements were prescribed when necessary. OUTCOME MEASURES: Changes in nutritional status were assessed by Subjective Global Assessment, anthropometric measures (weight, triceps skinfold thickness, mid arm muscle circumference, and grip strength), and biochemical markers (serum albumin, serum transferrin, and insulin-like growth factor-1). RESULTS: None of the patients showed decline in Subjective Global Assessment category, and 2 of the patients improved. All anthropometric and biochemical measures of nutritional status were stable or increased over the course of the study, and mid arm muscle circumference increased significantly (P <.05), contrasting with published data showing a decline in these measures in patients not receiving dietetic intervention. CONCLUSION: With dietetic intervention, it may be possible to maintain or improve nutritional status in this group.
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Dieta , Ingestión de Energía , Enfermedades Renales/complicaciones , Trastornos Nutricionales/prevención & control , Estado Nutricional , Antropometría , Consejo , Proteínas en la Dieta/administración & dosificación , Femenino , Tasa de Filtración Glomerular , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
The view of delusions as discrete and discontinuous phenomena is changing. Intensity of conviction in delusional belief has been used as a dependent variable in therapeutic attempts at belief modification. It has been measured using rating scales and developments of Shapiro's Personal Questionnaire (PQ) technique. The use of Mulhall's Personal Questionnaire Rapid Scaling Technique (PQRST) has not been reported in this context. The paper reports no new clinical data but describes a modified PQRST for measuring intensity of belief conviction, suitable for clients who cannot understand the PQ technique and easily administered by ward staff.
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Deluciones/diagnóstico , Encuestas y Cuestionarios , HumanosRESUMEN
This paper reviews the use of a modern psychophysical technique known as symptom validity testing. The technique employs a forced choice procedure providing an objective method for distinguishing between functional and organic aetiology in cases with sensory or memory deficit. The determination of functionality is by the objective demonstration that behaviour is controlled by stimuli in the sense modality in which the deficit is claimed. The data can be evaluated using conventional statistical techniques. The method is an advance on classical psychophysical methods as it does not depend upon the patient reporting whether he can or cannot perceive a single stimulus.
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Trastornos de la Memoria/diagnóstico , Pruebas Psicológicas , Diagnóstico Diferencial , Trastornos Fingidos/diagnóstico , Humanos , Trastornos de la Memoria/psicologíaRESUMEN
Symptom-validity testing has been used to detect feigning in patients claiming sensory and memory deficits. Such patients typically give significantly fewer correct responses on forced-choice testing than would be expected by chance. Some subjects have been able to understand the rationale and respond at the chance level. Some have evaded detection by elaborations of the technique which seek evidence of non-randomness in the sequence of correct and incorrect responses. This paper reports the stratagem used by one such subject and a further elaboration of the technique by which it was detected.
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Amnesia/diagnóstico , Trastornos Fingidos/diagnóstico , Histeria/diagnóstico , Simulación de Enfermedad/diagnóstico , Enfermedades del Sistema Nervioso/diagnóstico , Pruebas Neuropsicológicas/estadística & datos numéricos , Sensación , Amnesia/psicología , Ceguera/diagnóstico , Ceguera/psicología , Trastornos Fingidos/psicología , Humanos , Histeria/psicología , Simulación de Enfermedad/psicología , Enfermedades del Sistema Nervioso/psicología , Reconocimiento Visual de Modelos , Psicometría , Reproducibilidad de los ResultadosRESUMEN
This paper describes the treatment of a case of mutism in Saxon England. The shaping procedure employed was similar to that reported in modern behaviour modification studies. The paper quotes from a seventh century papal letter showing an understanding of the principle of shaping as applied to populations.
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Terapia Conductista/historia , Mutismo/historia , Religión y Psicología , Adolescente , Inglaterra , Historia Medieval , Humanos , MasculinoRESUMEN
Paradoxical psychotherapy succeeded in removing the compulsive element and reducing the guilt attached to transvestism in a male transvestite patient. Cross-dressing at home became acceptable to him and the temptation to cross-dress in public ended. Data suggested three independent motivational systems in this patient.
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Psicoterapia/métodos , Travestismo/terapia , Adulto , Conducta Compulsiva/terapia , Humanos , Masculino , Motivación , Travestismo/psicologíaRESUMEN
Previous reports on psychiatric morbidity in acromegaly have been unsystematic. This study examined 51 acromegalic patients for psychiatric morbidity using the General Health Questionnaire and a standard psychiatric interview, the Present State Examination. Although psychiatric morbidity was higher in the female than the male acromegalics, the study showed no increase in psychiatric morbidity in general, nor an increased incidence of depression, in comparison with general population and patient samples. No relationship was found between growth hormone levels and psychiatric morbidity. The results raise the question whether acromegalic patients show lower psychiatric morbidity than expected from patients with such an illness. The data suggest that previous reports of depression in acromegalic patients examplify the simple coincidence of a likely and an unlikely condition.
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Acromegalia/complicaciones , Trastornos Mentales/complicaciones , Femenino , Humanos , Entrevista Psicológica , Masculino , Trastornos Mentales/diagnóstico , Persona de Mediana Edad , Encuestas y CuestionariosRESUMEN
This case study describes a female monozygotic twinship in which one of the twins presented with anorexia nervosa. The case supports the suggestion from the few such discordant pairs previously reported that the affected twin tends to have been relatively disadvantaged from an early age and to be the less dominant of the pair. A review of previously reported cases suggests a concordance rate for anorexia nervosa of about 50% in female MZ twin pairs. Some methodological problems associated with the derivation of such estimates are noted.
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Anorexia Nerviosa/genética , Enfermedades en Gemelos , Adulto , Femenino , Humanos , Gemelos MonocigóticosRESUMEN
Current available measures of sexual orientation are briefly reviewed. A novel sexual orientation measure is proposed, based on experiments in operant psychology. Previous relevant studies are reviewed, and it is suggested that a deficiency is their reliance on a single response as the dependent variable. The matching law is introduced, and it is argued that this provides a potentially powerful framework within which the relative reinforcement magnitudes of sexual stimuli may be computed, using as the dependent variable the relative rates of two responses. The proposed assessment method provides a means of answering the question "What is the reinforcement magnitude of various classes of erotic stimuli for a given individual?"