1,352 research outputs found
Efficient channeling of fluorescence photons from single quantum dots into guided modes of optical nanofiber
We experimentally demonstrate the efficient channeling of fluorescence
photons from single q-dots on optical nanofiber into the guided modes, by
measuring the photon-count rates through the guided and radiation modes
simultaneously. We obtain the maximum channeling efficiency to be 22.0
(\pm4.8)% at fiber diameter of 350 nm for the emission wavelength of 780 nm.
The results may open new possibilities in quantum information technologies for
generating single photons into single-mode optical-fibers.Comment: 5 pages, 4 figure
Assessing research impact potential: using the transdisciplinary Outcome Spaces Framework with New Zealand’s National Science Challenges
© 2020, © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. Calls for science to have impact as well as excellence have been loud and clear from research funders, policymakers and research institutions for some time. Transdisciplinary research (TDR) is expected to deliver impact by connecting scientists with stakeholders and end users to co-produce knowledge to respond to complex issues. While New Zealand’s science system is geared to deliver excellence, its capability to also deliver impact beyond academic institutions is less clear. This paper has two interconnected aims. Firstly, it presents findings from testing innovations to the TDR Outcome Spaces Framework (OSF+) with four National Science Challenges (NSCs). We conclude that OSF+ is a useful tool for planning for multiple outcomes and assessing the potential for impact. Secondly, it presents findings of how using OSF+ to assess research impact potential revealed a range of implicit theories of change (i.e. catalyst, deficit, engagement and collaboration) across the NSCs. The findings raise important questions about the prospects for New Zealand’s science system to deliver the envisaged and needed levels of research impact when current institutional settings, expectations, recognition systems, career paths and measures of success are not yet able to adequately accommodate TDR to deliver the research impact
Atom trapping and guiding with a subwavelength-diameter optical fiber
We suggest using an evanescent wave around a thin fiber to trap atoms. We
show that the gradient force of a red-detuned evanescent-wave field in the
fundamental mode of a silica fiber can balance the centrifugal force when the
fiber diameter is about two times smaller than the wavelength of the light and
the component of the angular momentum of the atoms along the fiber axis is in
an appropriate range. As an example, the system should be realizable for Cesium
atoms at a temperature of less than 0.29 mK using a silica fiber with a radius
of 0.2 m and a 1.3-m-wavelength light with a power of about 27 mW.Comment: 5 pages, 5 figure
Early results of fissurectomy and advancement flap for resistant chronic anal fissure without hypertonia of the internal anal sphincter
The aim of this study was to assess the efficacy of fissurectomy with skin advancement flap in healing chronic anal fissures without hypertonia of the internal anal sphincter. Twenty-six consecutive patients who failed healing after well-practiced topical medical therapy were enrolled. Anorectal manometry was performed preoperative and 6 months postoperatively. All patients were treated with fissurectomy and advancement flap through healthy skin tissue. All patients healed completely within 30 days from operation. The intensity and the duration of pain postdefecation was reduced significantly with respect to the preoperative values starting from the first defecation. One patient suffered urinary retention, two patients suffered infections, and two partial breakdowns were recorded. At 6 months the maximum resting pressure values were similar to those were detected preoperatively. One month after surgery, anal incontinence was reported in seven patients, four of whom complained about it preoperatively. At 12 months, only three subjects reported incontinence. No patients needed reoperation and no recurrences were detected. The fissurectomy, in combination with advancement flap, is a safe sphincter-saving procedure for the treatment of chronic anal fissures without hypertonia of internal anal sphincter that fails medical conservative treatment
Visual rehabilitation in combined surgical procedures: bridging two eye poles for better vision
Augenzentrum Nymphenburger Höfe and Augenklinik Herzog Carl Theodor, München, GermanyDepartment of Ophthalmology, University of Heidelberg, Heidelberg, GermanyDepartment of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of KoreaCleveland Clinic Foundation, Cole Eye Institute, Cleveland, OH, USADepartment of Ophthalmology, Universidade Federal de São Paulo, São Paulo, SP, BrazilDepartment of Ophthalmology, Tan Tock Seng Hospital, SingaporeDepartment of Ophthalmology, Universidade Federal de São Paulo, São Paulo, SP, BrazilWeb of Scienc
Multiorder coherent Raman scattering of a quantum probe field
We study the multiorder coherent Raman scattering of a quantum probe field in
a far-off-resonance medium with a prepared coherence. Under the conditions of
negligible dispersion and limited bandwidth, we derive a Bessel-function
solution for the sideband field operators. We analytically and numerically
calculate various quantum statistical characteristics of the sideband fields.
We show that the multiorder coherent Raman process can replicate the
statistical properties of a single-mode quantum probe field into a broad comb
of generated Raman sidebands. We also study the mixing and modulation of photon
statistical properties in the case of two-mode input. We show that the prepared
Raman coherence and the medium length can be used as control parameters to
switch a sideband field from one type of photon statistics to another type, or
from a non-squeezed state to a squeezed state and vice versa.Comment: 12 pages, 7 figures, to be published in Phys. Rev.
Glutamate, N-acetyl aspartate and psychotic symptoms in chronic ketamine users
Rationale:
Ketamine, a non-competitive NMDA receptor antagonist, induces acute effects resembling the positive, negative and cognitive symptoms of schizophrenia. Chronic use has been suggested to lead to persistent schizophrenia-like neurobiological changes.
Objectives:
This study aims to test the hypothesis that chronic ketamine users have changes in brain neurochemistry and increased subthreshold psychotic symptoms compared to matched poly-drug users.
Methods:
Fifteen ketamine users and 13 poly-drug users were included in the study. Psychopathology was assessed using the Comprehensive Assessment of At-Risk Mental State. Creatine-scaled glutamate (Glu/Cr), glutamate + glutamine (Glu + Gln/Cr) and N-acetyl aspartate (NAA/Cr) were measured in three brain regions—anterior cingulate, left thalamus and left medial temporal cortex using proton magnetic resonance spectroscopy.
Results:
Chronic ketamine users had higher levels of subthreshold psychotic symptoms (p < 0.005, Cohen’s d = 1.48) and lower thalamic NAA/Cr (p < 0.01, d = 1.17) compared to non-users. There were no differences in medial temporal cortex or anterior cingulate NAA/Cr or in Glu/Cr or Glu + Gln/Cr in any brain region between the two groups. In chronic ketamine users, CAARMS severity of abnormal perceptions was directly correlated with anterior cingulate Glu/Cr (p < 0.05, r = 0.61—uncorrected), but NAA/Cr was not related to any measures of psychopathology.
Conclusions:
The finding of lower thalamic NAA/Cr in chronic ketamine users may be secondary to the effects of ketamine use compared to other drugs of abuse and resembles previous reports in individuals at genetic or clinical risk of schizophrenia
Evaluasi Instalasi Listrik Dan Penerangan Pada Gedung Unit Pengembangan Benih Tanaman Pangan Dan Holtikutura(UPBTPH) Kabupaten Mempawah
Gedung UPBTPH Kabupaten Mempawah merupakan Unit Pelaksana Teknis (UPT) di bidang pengembangan benih tanaman pangan dan hortikultura terpasang daya PT. PLN (Persero) sebesar 13.200 VA. Dengan adanya beberapa penambahan peralatan berupa Air Conditioning (AC), jumlah titik lampu, dan peralatan lainnya, daya tersebut tidak mencukupi lagi untuk melayani beban. Hal tersebut berindikasi sering terjadinya overload pada pembatas arus (MCB) pada waktu terjadinya penambahan beban. Berdasarkan hasil observasi dilapangan total beban pada saat ini sebesar 32.598 Watt dengan beban antar fasanya tidak seimbang, sehingga perlu dilakukan penambahan daya dan perbaikan instalasi untuk memperoleh keseimbangan beban pada setiap fasanya. Dengan upaya perbaikan instalasi pada Gedung UPBTPH Kabupaten Mempawah, diperoleh jumlah beban pada fasa R sebesar 10.850 Watt, fasa S sebesar 10.877 Watt, dan fasa T sebesar 10.871 Watt. Sedangkan kapasitas daya PT. PLN (Persero) yang diusulkan sebesar 33.000 VA, dengan pembatas arus MCB sebesar 3 x 50 A pada masing-masing fasanya. Berdasarkan hasil pengukuran, diperoleh bahwa kualitas penerangan untuk setiap ruangan pada Gedung UPBTPH Kabupaten Mempawah masih belum mencapai standar kualitas yang ditentukan SNI 03-6575-2001. Sehingga untuk memperbaiki kualitas penerangan pada ruangan-ruangan Gedung UPBTPH Kabupaten Mempawah yaitu dengan menambah titik lampu sesuai perhitungan atau mengubah lampu dengan daya lebih besar/terang
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