Linear systems with adiabatic fluctuations

We consider a dynamical system subjected to weak but adiabatically slow fluctuations of external origin. Based on the ``adiabatic following'' approximation we carry out an expansion in \alpha/|\mu|, where \alpha is the strength of fluctuations and 1/|\mu| refers to the time scale of evolution of the unperturbed system to obtain a linear differential equation for the average solution. The theory is applied to the problems of a damped harmonic oscillator and diffusion in a turbulent fluid. The result is the realization of `renormalized' diffusion constant or damping constant for the respective problems. The applicability of the method has been critically analyzed.Comment: Plain Latex, no figure, 21 page

Theory of Adiabatic fluctuations : third-order noise

We consider the response of a dynamical system driven by external adiabatic fluctuations. Based on the `adiabatic following approximation' we have made a systematic separation of time-scales to carry out an expansion in $\alpha |\mu|^{-1}$, where $\alpha$ is the strength of fluctuations and $|\mu|$ is the damping rate. We show that probability distribution functions obey the differential equations of motion which contain third order terms (beyond the usual Fokker-Planck terms) leading to non-Gaussian noise. The problem of adiabatic fluctuations in velocity space which is the counterpart of Brownian motion for fast fluctuations, has been solved exactly. The characteristic function and the associated probability distribution function are shown to be of stable form. The linear dissipation leads to a steady state which is stable and the variances and higher moments are shown to be finite.Comment: Plain Latex, no figures, 28 pages; to appear in J. Phys.

The impact of mindfulness‐based interventions on doctors’ well‐being and performance: A systematic review

Objectives: The well-being of doctors is at risk, as evidenced by high burnout rates amongst doctors around the world. Alarmingly, burned-out doctors are more likely to exhibit low levels of professionalism and provide suboptimal patient care. Research suggests that burnout and the well-being of doctors can be improved by mindfulness-based interventions (MBIs). Furthermore, MBIs may improve doctors’ performance (eg in empathy). However, there are no published systematic reviews that clarify the effects of MBIs on doctor well-being or performance to inform future research and professional development programmes. We therefore systematically reviewed and narratively synthesised findings on the impacts of MBIs on doctors’ well-being and performance. Methods: We searched PubMed and PsycINFO from inception to 9 May 2018 and independently reviewed studies investigating the effects of MBIs on doctor well-being or performance. We systematically extracted data and assessed study quality according to the Medical Education Research Study Quality Instrument (MERSQI), and narratively reported study findings. Results: We retrieved a total of 934 articles, of which 24 studies met our criteria; these included randomised, (un)controlled o

ANALISIS BIAYA PENDAPATAN BERDASARKAN SKALA PADA USAHA PENGGEMUKAN SAPI POTONG DI KECAMATAN AMARASI KABUPATEN KUPANG

Fattening cattle have a significant economic opportunities and able to contribute a relatively high income. A study of fattening with different business scale has been implemented in Districtof Amarasi where data collection was conducted over 2 months ie January to February 2016. The aim of this study was to determine the cost structure of fattening cattle in the Amarasi District - Regency of Kupang on two different business scale and to determine the cash income of fattening cattle on a different scale enterprises . The method used is a survey method in which data collection is done through observation and interviews. Sampling was done using multi stages sampling. The determination of Sselected village was done purposively as many as three villages from eight villages intheDistrict of Amarasi. Determination of the respondents in each selected  village was  done in the quota of 20 people where each scale consists of 10 people. So, it was obtained 60 respondents representatively. Data were analyzed using analysis of input output and followed by test of difference of cash income between the scales. The results showed that the total costs on a  scale I is Rp 11,789,915/year and on a scale II is Rp 18,254,845/year. The total cash earnings of farmers during the years is as follow: on scale I is Rp 10,901,750/year and on scale II is Rp 10,881,017/year. No differences in cash income on two different business scale (P> 0.05). ABSTRAK Usaha penggemukan ternak sapi memiliki peluang ekonomi yang cukup baik dan mampu memberikan sumbangan pendapatan yang relatif tinggi. Suatu studi tentang usaha penggemukan dengan Skala usaha yang berbeda telah dilaksanakan di Kecamatan Amarasi dimana pengumpulan data dilaksanakan selama 2 bulan yaitu januari sampai dengan Februari 2016. Tujuan penelitian ini adalah untuk mengetahui struktur biaya usaha penggemukan ternak sapi potong di Kecamatan Amarasi pada dua Skala usaha yang berbeda dan untuk mengetahui  pendapatan tunai dari usaha penggemukan ternak sapi potong pada Skala usaha yang berbeda. Metode penelitian yang digunakan adalah metode survei dimana pengumpulan data dilakukan melalui observasi dan wawancara. Pengambilan contoh dilakukan secara bertahap. Penentuan desa contoh dilakukan secara purposive sebanyak 3 desa dari 8 desa yang ada di Kecamatan Amarasi.  Penentuan responden pada tiap desa contoh dilakukan secara kuota sebanyak 20 orang dimana tiap Skala terdiri atas 10 orang sehingga diperoleh 60 responden representative. Data kemudian dianalisis menggunakan analisis input output dan dilanjutkan dengan uji beda rata-rata. Hasil penelitian menunjukkan bahwa total biaya pada Skala 1 sebesar Rp 11.789.915/tahun dan pada Skala 2 sebesar Rp 18.254.845/tahun. Total pendapatan tunai petani peternak selama satu tahun usaha pada Skala I Rp 10.901.750 per tahun dan pada Skala II Rp 10.881.017/tahun. Tidak ada perbedaan pendapatan tunai pada dua Skala usaha uang berbeda tersebut (P>0.05)

Bremsstrahlung in Alpha-Decay

We present the first fully quantum mechanical calculation of photon radiation accompanying charged particle decay from a barrier resonance. The soft-photon limit agrees with the classical results, but differences appear at next-to-leading-order. Under the conditions of alpha-decay of heavy nuclei, the main contribution to the photon emission stems from Coulomb acceleration and may be computed analytically. We find only a small contribution from the tunneling wave function under the barrier.Comment: 12 pages, 2 Postscript figure

Decoherence and thermalization dynamics of a quantum oscillator

We introduce the quantitative measures characterizing the rates of decoherence and thermalization of quantum systems. We study the time evolution of these measures in the case of a quantum harmonic oscillator whose relaxation is described in the framework of the standard master equation, for various initial states (coherent, `cat', squeezed and number). We establish the conditions under which the true decoherence measure can be approximated by the linear entropy $1-{Tr}\hat\rho^2$. We show that at low temperatures and for highly excited initial states the decoherence process consists of three distinct stages with quite different time scales. In particular, the `cat' states preserve 50% of the initial coherence for a long time interval which increases logarithmically with increase of the initial energy.Comment: 24 pages, LaTex, 8 ps figures, accepted for publication in J. Opt.

Coherent radiation from neutral molecules moving above a grating

We predict and study the quantum-electrodynamical effect of parametric self-induced excitation of a molecule moving above the dielectric or conducting medium with periodic grating. In this case the radiation reaction force modulates the molecular transition frequency which results in a parametric instability of dipole oscillations even from the level of quantum or thermal fluctuations. The present mechanism of instability of electrically neutral molecules is different from that of the well-known Smith-Purcell and transition radiation in which a moving charge and its oscillating image create an oscillating dipole. We show that parametrically excited molecular bunches can produce an easily detectable coherent radiation flux of up to a microwatt.Comment: 4 page

Reflection of light from a disordered medium backed by a phase-conjugating mirror

This is a theoretical study of the interplay of optical phase-conjugation and multiple scattering. We calculate the intensity of light reflected by a phase-conjugating mirror when it is placed behind a disordered medium. We compare the results of a fully phase-coherent theory with those from the theory of radiative transfer. Both methods are equivalent if the dwell time \tau_{dwell} of a photon in the disordered medium is much larger than the inverse of the frequency shift 2\Delta\omega acquired at the phase-conjugating mirror. When \tau_{dwell} \Delta\omega < 1, in contrast, phase coherence drastically affects the reflected intensity. In particular, a minimum in the dependence of the reflectance on the disorder strength disappears when \Delta\omega is reduced below 1/\tau_{dwell}. The analogies and differences with Andreev reflection of electrons at the interface between a normal metal and a superconductor are discussed.Comment: 27 pages RevTeX with 11 figures included with psfi

Steady state of atoms in a resonant field with elliptical polarization

We present a complete set of analytical and invariant expressions for the steady-state density matrix of atoms in a resonant radiation field with arbitrary intensity and polarization. The field drives the closed dipole transition with arbitrary values of the angular momenta $J_{g}$ and $J_{e}$ of the ground and excited state. The steady-state density matrix is expressed in terms of spherical harmonics of a complex direction given by the field polarization vector. The generalization to the case of broad-band radiation is given. We indicate various applications of these results.Comment: revtex, 26 pages, including 3 eps figures; PRA accepted for publication;v2 three typos are fixe