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Magnetic compass orientation in amphibians is mediated by a lightdependent magnetoreception mechanism (Phillips & Borland 1992. Nature 359:142) involving extraocular photoreceptors located in or near the pineal organ (Deutschlander et al. 1999. Nature 400: 324). The functional properties of this response are consistent with a photoreceptor-based magnetoreception mechanism involving a photo-induced radical pair reaction (Ritz et al. 2000. Biophysics J. 78:707). The radical pair mechanism is predicted to be sensitive to radio frequency fields, with the most effective frequencies being those that are in resonance with the hyperfine couplings of the radical pair. Here we test the prediction that a broad band RF field overlapping the range of the Zeeman and hyperfine splittings (~1-40 MHz) should cause a change in orientation if magnetoreception is based on a radical-pair mechanism. Experimental subjects were Eastern red-spotted newts Notophthalmus viridescens that were trained in an aquatic outdoor tank with an artificial shore at one end to exhibit shoreward magnetic compass orientation (earlier references). Newts were tested in an terrestrial, visually symmetrical, indoor arena. Each newt was tested only once with equal numbers tested in each of four horizontal alignments of a static earth-strength magnetic field (magnetic North at geographic North, East, South or West). Magnetic compass orientation was compared with and without the presence of a low level, broadband oscillating field (~0.1 MHz-15 MHz). Depending on the length of training in the outdoor tank, newts tested in the absence of the oscillating field exhibited highly significant unimodal or bimodal orientation relative to the trained magnetic direction (p < 0.01, Rayleigh test). In the presence of the oscillating field, both responses were abolished. To determine whether the effects of the oscillating field were specific to the light-dependent magnetic compass, control experiments were carried out in an outdoor arena in which newts were able to orient using celestial compass cues (sun position and/or polarized light patterns). Celestial compass orientation was unaffected by exposure to the oscillating field. These findings suggest that the effects of the broadband oscillating field are specific to the magnetic compass, and provide further evidence for the involvement of a radical pair mechanism.

BACKGROUND: Studies in the last decade showed high rates of poorly treated and poorly controlled asthma in the community. Extending these findings we describe the more recent situation in specialist respiratory care as the most frequent source of treatment provision using comprehensive clinical and patient assessments and exploring predictors for poor control. METHODS: This is a German cross-sectional, clinical epidemiological study in a nationally representative stratified treatment prevalence sample of N = 572 outpatients diagnosed with allergic asthma (AA; females 58.2%, aged 47.5 ± 16.3 (16-81 years). Treating physicians completed standardized clinical assessments (lung function, laboratory, clinical findings, severity, illness and treatment history, asthma control [GINA]), supplemented by patients' self-report measures (EQ5-D, AQLQ, ACT) and mental health module (CIDI-SF). RESULTS: A total of 65.4% of patients were rated (GINA) as controlled, 30.3% partially controlled, and 4.4% uncontrolled; the patient-rated ACT showed lower rates of control (19.9% controlled, 44.2% partial, 35.8% uncontrolled, kappa: 0.2). Consistent with findings of clinical measures, controlled asthma was highest among patients with pre-treatment stage I severity (83.6%) and decreased by pre-treatment severity (stage IV patients: 29.3%). Poorer control was associated with pre-treatment severity, nocturnal attacks, diminished adherence and comorbid anxiety/depression. Patients received complex multiple drug and non-drug interventions, largely consistent with guidelines. Degree of asthma control was associated with improved and even normalized quality of life findings. CONCLUSION: In this representative sample of longterm treated AA patients in specialist respiratory care we find better control rates and better adherence to guidelines as previous studies. Despite remarkable differences in clinician- vs patient-rated control ratings even the initially most severe stage IV patients (12.9% of patients) showed remarkable control rates and close to normal quality of life. Intensified treatment (e.g. omalizumab) was associated with improved control. Poorer control was associated with higher initial severity, diminished adherence, comorbid anxiety/depression and old age. Limitation: Findings apply to AA patients in respiratory specialist care sector which is likely to treat the more severely affected patients. Thus, findings cannot be generalized to the general population, other treatment settings or asthma types. [ABSTRACT FROM AUTHOR]