779 research outputs found
Matterwave Transport Without Transit
Classically it is impossible to have transport without transit, i.e., if the
points one, two and three lie sequentially along a path then an object moving
from one to three must, at some point in time, be located at two. However, for
a quantum particle in a three-well system it is possible to transport the
particle between wells one and three such that the probability of finding it at
any time in the classically accessible state in well two is negligible. We
consider theoretically the analogous scenario for a Bose-Einstein condensate
confined within a three well system. In particular, we predict the adiabatic
transportation of an interacting Bose-Einstein condensate of 2000 Li atoms from
well one to well three without transiting the allowed intermediate region. To
an observer of this macroscopic quantum effect it would appear that, over a
timescale of the order of one second, the condensate had transported, but not
transited, a macroscopic distance of 20 microns between wells one and three.Comment: 6 pages, 4 figure
Chronic posttraumatic pseudoaneurysm of the thoracic aorta 55 Years after a blunt trauma - A case report with review of literature
Injuries of thoracic aorta due to blunt trauma carry very high mortality rates and studies estimated that less than 2% of people who sustain it remain alive if they were not diagnosed and treated appropriately. Moreover, even those lucky few live with the risk of rupture of the Pseudoaneurysm that can develop years to decades after the causative trauma culminating in the fatal internal hemorrhage. This paper reports a case of a 72-years-old Libyan male who sustained a blunt chest injury and multiple rib fractures 55 years ago that resulted in a large pseudoaneurysm of the arch of aorta
Community Based Fisheries Management: Institutional Options for Empowering Fisher Communities
This report sheds light on the diversity of approaches adopted by the various project partners, along with lessons learned during the Community Based Fisheries Management Project (CBFM-2). CBFM 2 was the second phase of an action research project designed to establish whether the sustainable management of publicly owned and private water bodies can be carried out by community groups consisting largely of poor fishers. The first phase implemented by the Department of Fisheries, with the assistance of the WorldFish Center and supported by the Ford Foundation, demonstrated that the approach was possible in a limited number of water bodies. The second phase, with assistance from the DFID-UK, involved a much greater range of water bodies (target 120, final number 116) with a range of partners -- the Department of Fisheries (DoF), the implementing NGOs, Banchte Shekha, BRAC, CARITAS, CNRS, CRED, GHARONI, Proshika, SDC, SHISUK, and the specialist NGOs, BELA for legal assistance and FemCom for media communications. A wide range of institutional arrangements have been established under the project. Many of the project documents state that there are three main fisheries management approaches; fisher-led, community-led and women-led. The definitions of the three approaches were: 1. Fisher-led Approach -- Forming groups among the fishers for using each water body and then a committee or organisation representing these groups and taking management decisions in a participatory manner; 2. Community-led Approach -- Participatory approach at the community level. Fishery managed by the community where participatory planning with different stakeholders is followed by forming a water body management committee according to the suggestions of all stakeholder categories; 3. Women-led Approach -- Ensure participatory planning involving the whole community covering all stakeholders, with groups usually formed with women (in some cases, mixed groups with men and women), and the women's group members take a lead in resource management. However these definitions fail to capture the full diversity of approaches adopted by project partners during implementation. By the end of the project, 10 different organisations had been involved in setting up community groups to manage CBFM-2 sites
Episodic excursions of low-mass protostars on the Hertzsprung-Russell diagram
Following our recent work devoted to the effect of accretion on the
pre-main-sequence evolution of low-mass stars, we perform a detailed analysis
of episodic excursions of low-mass protostars in the Hertzsprung-Russell (H-R)
diagram triggered by strong mass accretion bursts typical of FU Orionis-type
objects (FUors). These excursions reveal themselves as sharp increases in the
stellar total luminosity and/or effective temperature of the protostar and can
last from hundreds to a few thousands of years, depending on the burst strength
and characteristics of the protostar. During the excursions, low-mass
protostars occupy the same part of the H-R diagram as young intermediate-mass
protostars in the quiescent phase of accretion. Moreover, the time spent by
low-mass protostars in these regions is on average a factor of several longer
than that spent by the intermediate-mass stars in quiescence. During the
excursions, low-mass protostars pass close to the position of most known FUors
in the H-R diagram, but owing to intrinsic ambiguity the model stellar
evolutionary tracks are unreliable in determining the FUor properties. We find
that the photospheric luminosity in the outburst state may dominate the
accretion luminosity already after a few years after the onset of the outburst,
meaning that the mass accretion rates of known FUors inferred from the
bolometric luminosity may be systematically overestimated, especially in the
fading phase.Comment: 15 pages, 12 figure
Incidence of epizootic ulcerative syndrome (EUS) in freshwater fishes in the endemic area of Punjab, Pakistan
Incidence of Epizootic Ulcerative Syndrome (EUS) has been recorded for the first time
in freshwater fishes in the endemic area of Punjab, Pakistan. Survey of private fish farms,
hatchery and natural water bodies was conducted in a radius of 14 Km from around river
Ravi near Lahore (Punjab Province) Pakistan. Out Of 1628 fishes belonging to 18 genera,
517 fishes of 10 genera were found affected with EUS. The incidence of EUS in
culturable fishes was higher in Cirrhina mrigala (15.4%) moderate in Catla cat/a (13.3%)
and lower in Labeo rohita (5.0%). Exotic fish, Chinese carp Ctenoparyngodon idella and
Hypophthalmicthys molitrix were not affected with EUS. In non-culturable fishes the
incidence of EUS was highest in Channa punctatus (72.8%) moderate in by C. straitus
(65.45%) and comparatively lower Puntius ticto (43.7%). A slow growing temperature
sensitive Saprolegnia spp. was isolated from all of EUS infected fish species. Aeromonas
spp. and Pseudomonas spp. were isolated from the diseased fishes. Ectoparasites viz.
Lernaea, Argulus and Triclwdina spp. were also isolated from the skin and gills of infected
fish species. The disease was more severe in water having low alkalinity (70 mg/1),
hardness (75 mg/1) and low temperature of 10-12 °C
Broadband and robust optical waveguide devices using coherent tunnelling adiabatic passage
We numerically demonstrate an optical waveguide structure for the coherent tunnelling adiabatic passage of photons. An alternative coupling scheme is used compared to earlier work. We show that a three rib optical waveguide structure is robust to material loss in the intermediate waveguide and variations to the waveguide parameters. We also present a five rib optical waveguide structure that represents a new class of octave spanning power divider
Infrared and sub-mm observations of outbursting young stars with Herschel and Spitzer
Episodic accretion plays an important role in the evolution of young stars.
Although it has been under investigation for a long time, the origin of such
episodic accretion events is not yet understood. We investigate the dust and
gas emission of a sample of young outbursting sources in the infrared to get a
better understanding of their properties and circumstellar material, and we use
the results in a further work to model the objects. We used Herschel data, from
our PI program of 12 objects and complemented with archival observations to
obtain the spectral energy distributions (SEDs) and spectra of our targets. We
report here the main characteristics of our sample, focussing on the SED
properties and on the gas emission lines detected in the PACS and SPIRE
spectra. The SEDs of our sample show the diversity of the outbursting sources,
with several targets showing strong emission in the far-infrared from the
embedded objects. Most of our targets reside in a complex environment, which we
discuss in detail. We detected several atomic and molecular lines, in
particular rotational CO emission from several transitions from J=38-37 to
J=4-3. We constructed rotational diagrams for the CO lines, and derived in
three domains of assumed local thermodynamic equilibrium (LTE) temperatures and
column densities, ranging mainly between 0-100 K and 400-500K. We confirm
correlation in our sample between intense CO emission and the column
density of the warm domain of CO, N(warm). We notice a strong increase in
luminosity of HH 381 IRS and a weaker increase for PP 13 S, which shows the
beginning of an outburst.Comment: 23 pages, 17 figures, A&A accepte
Addressing Food Insecurity in College: Mapping a Shared Conceptual Framework for Campus Pantries in Michigan
The first known university food pantry started at Michigan State University in 1993. Since then, campus food pantries are more widespread, although little is known about them. The current study examined how college pantries best serve students and foster their success. Twentyâ eight food pantry directors and staff from across sixteen Michigan college campuses engaged in concept mapping, a technique used to examine the interrelationships among concepts understood by stakeholders. Analyses identified six concepts, examined importance of each concept as assigned by participants, and evaluated variation among institutions. Implications for findings and future research directions are discussed.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147046/1/asap12161_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147046/2/asap12161.pd
Coherent tunneling via adiabatic passage in a three-well Bose-Hubbard system
We apply the Bose-Hubbard Hamiltonian to a three-well system and show analytically that coherent transport via adiabatic passage (CTAP) of N noninteracting particles across the chain is possible.We investigate the effect of detuning the middle well to recover CTAP when onsite interparticle interactions would otherwise disrupt the transport. The case of small interactions is restated using first-order perturbation theory to develop criteria for adiabaticity that define the regime where CTAP is possible. Within this regime we investigate restricting the Hilbert space to the minimum necessary basis needed to demonstrate CTAP, which dramatically increases the number of particles that can be efficiently considered. Finally, we compare the results of the Bose-Hubbard model to a mean-field three-mode Gross-Pitaevskii analysis for the equivalent system
Pregnant Women\u27s perceptions of exposure to brominated flame retardants
Background: Recent media reports on human studies associating brominated flame retardants (BFRs) in household products in pregnancy with urogenital anomalies in boys and endocrine disruption in both sexes. We sought to explore the perceptions of pregnant women of brominated flame retardant (BFR) exposure, in light of recent media reports on the adverse health effects of BFR exposure prenatally. Methods: Pregnant women were recruited for interviews through posters and pamphlets in prenatal clinics, prenatal fairs and community centres. Interviews were audiotaped and transcribed verbatim for Charmaz-based qualitative analysis supported by NVIVO 10â˘. Results: Theoretical sufficiency was reached after analyzing the interviews of 23 pregnant women. Themes co-constructed were: I-Lack of Awareness of BFRs; II-Factors Influencing BFR Exposure; III-Responsibility; IV-Informed Choice. Almost all participants felt it was difficult to make informed choices to avoid BFRs, and wanted communication from clinicians and regulation from governments regarding decreasing BFR exposure. Conclusion: Pregnant women in Canada may be unaware of the potential risks of exposure to BFRs. Professional organizations and governments should further study risk associated with BFR exposure in pregnancy and provide educational materials for pregnant women and clinicians regarding BFR exposure
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