738 research outputs found
Non-adiabatic generation of a pure spin current in a 1D quantum ring with spin-orbit interaction
We demonstrate the theoretical possibility of obtaining a pure spin current
in a 1D ring with spin-orbit interaction by irradiation with a non-adiabatic,
two-component terahertz laser pulse, whose spatial asymmetry is reflected by an
internal dephasing angle . The stationary solutions of the equation of
motion for the density operator are obtained for a spin-orbit coupling linear
in the electron momentum (Rashba) and used to calculate the time-dependent
charge and spin currents. We find that there are critical values of at
which the charge current disappears, while the spin current reaches a maximum
or a minimum value.Comment: 8 pages, 5 figure
Spatial Evidence for Transition Radiation in a Solar Radio Burst
Microturbulence, i.e. enhanced fluctuations of plasma density, electric and
magnetic fields, is of great interest in astrophysical plasmas, but occurs on
spatial scales far too small to resolve by remote sensing, e.g., at ~ 1-100 cm
in the solar corona. This paper reports spatially resolved observations that
offer strong support for the presence in solar flares of a suspected radio
emission mechanism, resonant transition radiation, which is tightly coupled to
the level of microturbulence and provides direct diagnostics of the existence
and level of fluctuations on decimeter spatial scales. Although the level of
the microturbulence derived from the radio data is not particularly high,
/n^2 ~ 10^{-5}$, it is large enough to affect the charged particle
diffusion and give rise to effective stochastic acceleration. This finding has
exceptionally broad astrophysical implications since modern sophisticated
numerical models predict generation of much stronger turbulence in relativistic
objects, e.g., in gamma-ray burst sources.Comment: 13 pages, 4 figures, ApJL accepte
Evaluating the Economic Impact of Palliative and End-of-Life Care Interventions on Intensive Care Unit Utilization and Costs from the Hospital and Healthcare System Perspective.
Purpose of report: Understanding the impact of palliative care interventions on intensive care unit (ICU) costs and utilization is critical for demonstrating the value of palliative care. Performing these economic assessments, however, can be challenging. The purpose of this special report is to highlight and discuss important considerations when assessing ICU utilization and costs from the hospital perspective, with the goal of providing recommendations on methods to consider for future analyses.
FINDINGS: ICU length of stay (LOS) and associated costs of care are common and important outcome measures, but must be analyzed properly to yield valid conclusions. There is significant variation in costs by day of stay in the ICU with only modest differences between an ICU day at the end of a stay and the first day on the acute care floor; this variation must be appropriately accounted for analytically. Furthermore, reporting direct variable costs, in addition to total ICU costs, is needed to understand short-term and long-term impact of a reduction in LOS. Importantly, incentives for the hospital to realize savings vary depending on reimbursement policies.
SUMMARY: ICU utilization and costs are common outcomes in studies evaluating palliative care interventions. Accurate estimation and interpretation are key to understanding the economic implications of palliative care interventions
Extracting Weak Phase Information from B -> V_1 V_2 Decays
We describe a new method for extracting weak, CP-violating phase information,
with no hadronic uncertainties, from an angular analysis of B -> V_1 V_2
decays, where V_1 and V_2 are vector mesons. The quantity can be cleanly obtained from the study of decays such as B_d^0(t) ->
D^{*\pm} \rho^\mp, D^{*\pm} a_1^{\mp}, D^{*0} K^{*0}, etc. Similarly, one can
use B_s^0(t) -> D_s^{*\pm} K^{*\mp} to extract . There are no
penguin contributions to these decays. It is possible that will be the second function of CP phases, after , to be
measured at B-factories.Comment: 4 pages, RevTeX, no figure
Pengabdian Masyarakat: Pemanfaatan Nasi Bekas sebagai Pupuk dan Pestisida Tanaman Rumah di PKK Perumahan Jurang Mangu Indah, Bintaro
Nasi bekas dan sisa makanan berbahan dasar karbohidrat lainnya merupakan jenis sampah organik yang dapat didaur ulang, tetapi biasanya hanya langsung dibuang atau diberikan ke unggas. Berdasarkan penelitian yang telah dilakukan bahan-bahan tersebut dapat dijadikan produk pupuk dan pestisida melalui fermentasi kapang yang disebut kapangisida. Kegiatan pengabdian masyarakat (abdimas) ini bertujuan untuk memperkenalkan pembuatan Kapangisida tersebut. Sasaran kegiatan ini adalah kelompok masyarakat dalam hal ini Pemberdayaan dan Kesejahteraan Keluarga (PKK) yang menaruh perhatian pada perawatan tanaman rumah yaitu PKK Perumahan Jurang Mangu Indah Bintaro. Hasil survei menunjukkan masyarakat di Perumahan tersebut belum melakukan daur ulang nasi bekas menjadi kapangisida. Oleh karena itu, produk ini merupakan produk baru di masyarakat. Kelompok PKK ini juga bersedia untuk melakukan duplikasi proses pembuatan produk yang bermanfaat bagi tanaman
Fibered Confocal Microscopy of Bladder Tumors: An ex Vivo Study
Background and Purpose: The inadequacy of white-light cystoscopy to detect flat bladder tumors is well recognized. Great interest exists in developing other imaging technologies to augment or supplant conventional cystoscopy. Fibered confocal microscopy offers the promise of providing in vivo histopathologic information to help distinguish malignant from benign bladder lesions. We report the initial use of this technology to visualize tumors in the human bladder. Materials and Methods: We performed ex vivo fibered confocal imaging of fresh radical cystectomy specimens using the Mauna Kea Technologies Cellvizio system. The findings were compared with results from standard histopathology. Results: The bladders of four patients were imaged using the fibered confocal microscope. Normal and neoplastic urothelium manifested differences in cellular and vascular density. Conclusion: This study demonstrates the feasibility of using fibered confocal microscopy to detect histologic differences between normal and neoplastic urothelium, and establishes a foundation for the use of fiber-based confocal microscopy in clinical studies.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78112/1/end.2008.0524.pd
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