2,767 research outputs found
Whispering Gallery Mode Resonator Stabilized Narrow Linewidth Fiber Loop Laser
We demonstrate a narrow line, fiber loop laser using Erbium-doped fiber as
the gain material, stabilized by using a microsphere as a transmissive
frequency selective element. Stable lasing with a linewidth of 170 kHz is
observed, limited by the experimental spectral resolution. A linear increase in
output power and a red-shift of the lasing mode were also observed with
increasing pump power. Its potential application is also discussed
Sub-kHz lasing of a CaF_2 Whispering Gallery Mode Resonator Stabilized Fiber Ring Laser
We utilize a high quality calcium fluoride whispering-gallery-mode resonator
to stabilize a simple erbium doped fiber ring laser with an emission frequency
of 196 THz (wavelenght 1530 nm) to a linewidth below 650 Hz. This corresponds
to a relative stability of 3.3 x 10^(-12) over 16 \mus. In order to
characterize the linewidth we use two identical self-built lasers and a
commercial laser to determine the individual lasing linewidth via the
three-cornered hat method.Comment: 4 pages, 3 figure
Grammatical workspace sharing during language production and language comprehension: Evidence from grammatical multitasking
Grammatical encoding and grammatical decoding (in sentence production and comprehension, respectively) are often portrayed as independent modalities of grammatical performance that only share declarative resources: lexicon and grammar. The processing resources subserving these modalities are supposed to be distinct. In particular, one assumes the existence of two workspaces where grammatical structures are assembled and temporarily maintained—one for each modality. An alternative theory holds that the two modalities share many of their processing resources and postulates a single mechanism for the online assemblage and short-term storage of grammatical structures: a shared workspace. We report two experiments with a novel “grammatical multitasking” paradigm: the participants had to read (i.e., decode) and to paraphrase (encode) sentences presented in fragments, responding to each input fragment as fast as possible with a fragment of the paraphrase. The main finding was that grammatical constraints with respect to upcoming input that emanate from decoded sentence fragments are immediately replaced by grammatical expectations emanating from the structure of the corresponding paraphrase fragments. This evidences that the two modalities have direct access to, and operate upon, the same (i.e., token-identical) grammatical structures. This is possible only if the grammatical encoding and decoding processes command the same, shared grammatical workspace. Theoretical implications for important forms of grammatical multitasking—self-monitoring, turn-taking in dialogue, speech shadowing, and simultaneous translation—are explored
The Ovaherero/Nama Genocide: A Case for an Apology and Reparations
This research examines the consequences of the Ovaherero and Nama massacres occurring in modern Namibia from 1904-08 and perpetuated by Imperial Germany. Recent political advances made by, among other groups, the Association of the Ovaherero Genocide in the United States of America, toward mutual understanding with the Federal Republic of Germany necessitates a comprehensive study about the event itself, its long-term implications, and the more current vocalization toward an apology and reparations for the Ovaherero and Nama peoples. Resulting from the Extermination Orders of 1904 and 1905 as articulated by Kaiser Wilhelm II’s Imperial Germany, over 65,000 Ovaherero and 10,000 Nama peoples perished in what was the first systematic genocide of the twentieth century. This study assesses the historical circumstances surrounding these genocidal policies carried out by Imperial Germany, and seeks to place the devastating loss of life, culture, and property within its proper historical context. The question of restorative justice also receives analysis, as this research evaluates the case made by the Ovaherero and Nama peoples in their petitions for compensation. Beyond the history of the event itself and its long-term effects, the paper adopts a comparative approach by which to integrate the Ovaherero and Nama calls for reparations into an established precedent
Neutrino spin oscillations in gravitational fields
We study neutrino spin oscillations in black hole backgrounds. In the case of
a charged black hole, the maximum frequency of oscillations is a monotonically
increasing function of the charge. For a rotating black hole, the maximum
frequency decreases with increasing the angular momentum. In both cases, the
frequency of spin oscillations decreases as the distance from the black hole
grows. As a phenomenological application of our results, we study simple
bipolar neutrino system which is an interesting example of collective neutrino
oscillations. We show that the precession frequency of the flavor pendulum as a
function of the neutrino number density will be higher for a
charged/non-rotating black hole compared with a neutral/rotating black hole
respectively.Comment: Replaced with the version accepted for publication in Gravitation and
Cosmology, Springer. 10 pages. 4 figure
Polyclonal B-cell activation by a synthetic analogue of bacterial lipoprotein is functionally different from activation by bacterial lipopolysaccharide
The reactivity of 38 murine strains to a synthetic analogue of bacterial lipoprotein, tripalmitoyl-pentapeptide (TPP), was tested and compared with the reactivity to lipopolysaccharide (LPS). These strains include common laboratory mice and H-2 recombinant inbred lines, as well as some newly bred lines originating from animals recently captured in different regions of Europe. All animals analysed were reactive to TPP and polyclonally activated to proliferation and immunoglobulin synthesis. Large differences in mitogen reactivities of various H-2 recombinant inbred strains suggest that MHC or closely linked gene products influence the reactivity to the LPS and TPP mitogens. By analysing the frequencies of precursor cells reactive to TPP or LPS and the isotype patterns obtained after stimulation, we demonstrated that both mitogens activate individual B cells in different ways.Peer reviewe
Influenza vaccines: the effect of vaccine dose on antibody response in primed populations during the ongoing interpandemic period. A review of the literature.
Health authorities tend to favour an increase of the antigen dose in inactivated influenza vaccines from or = 75%) for a 10 micrograms HA dose of influenza A vaccine components. For both response and protection rates, an increase of the antigenic load from 10 to 15 micrograms HA was not associated with a meaningful increase of seroresponse: in 38 out of 39 stratification groups, the increase of response and/or protection rate varied between -9% and +8%, with a median of 1.5%. These results do not justify the expectation that a vaccine dose of 15 micrograms HA per strain would be clinically superior to a dose of 10 micrograms HA. Only in a group of immune-compromised patients on chronic intermittent haemodialysis were results in favour of a higher dose found, which may justify further evaluation in this special population
Borderline personality disorder classification based on brain network measures during emotion regulation
- …