35 research outputs found
Photoassociative Production and Trapping of Ultracold KRb Molecules
We have produced ultracold heteronuclear KRb molecules by the process of
photoassociation in a two-species magneto-optical trap. Following decay of the
photoassociated KRb*, the molecules are detected using two-photon ionization
and time-of-flight mass spectroscopy of KRb. A portion of the metastable
triplet molecules thus formed are magnetically trapped. Photoassociative
spectra down to 91 cm below the K(4) + Rb (5) asymptote have
been obtained. We have made assignments to all eight of the attractive Hund's
case (c) KRb* potential curves in this spectral region.Comment: 4 pages, 4 figure
S06RS SGR No. 8 (System President)
A Resolution
to urge the LSU Board of Supervisors to include student representation on the search committee for the LSU System President
Beam spin asymmetry measurements of deeply virtual π0 production with CLAS12
The new experimental measurements of beam spin asymmetry were performed for the deeply virtual exclusive pi0 production in a wide kinematic region with the photon virtualities Q2 up to 6.6 GeV2 and the Bjorken scaling variable xB in the valence regime. The data were collected by the CEBAF Large Acceptance Spectrometer (CLAS12) at Jefferson Lab with longitudinally polarized 10.6 GeV electrons scattered on an unpolarized liquid-hydrogen target. Sizable asymmetry values indicate a substantial contribution from transverse virtual photon amplitudes to the polarized structure functions. The interpretation of these measurements in terms of the Generalized Parton Distributions (GPDs) demonstrates their sensitivity to the chiral-odd GPD ET, which contains information on quark transverse spin densities in unpolarized and polarized nucleons and provides access to the nucleon's transverse anomalous magnetic moment. Additionally, the data were compared to a theoretical model based on a Regge formalism that was extended to the high photon virtualities
Adapting the Dynamic Allocation of Fires and Sensors (DAFS) model for use in maritime combat analysis
The U.S. Navy employs several models of maritime combat to provide analytical rigor to force structure and weapon system procurement policies. All of the models currently used are high resolution and deterministic, providing very detailed results but without any measurement of variance or any statistical manner of evaluating risk. This thesis provides the initial groundwork for a low resolution stochastic maritime combat model that may provide an initial evaluation and shape future detailed studies. The framework for the model is a Discrete Event Simulation (DES) Model fed by Extensible Mark-up Language (XML) input and output modules. The simulation loads scenario inputs from XML files forming the baseline values of entities, the rules employed for movement and combat, and the general concept of the scenario. During simulation run, the model makes intermittent calls to an optimization package to allocate weapons based on a multi-dimensional knapsack problem simulating a networked force. Upon completion of the simulation run, the model generates an XML output that can be later read for statistical analysis and data mining. Because of the stochastic nature of the model, it provides an increased level of analytical quality to its results as well as the ability to calculate the risk involved with the force structure and units employedhttp://archive.org/details/adaptingdynamica109454228US Navy (USN) author.Approved for public release; distribution is unlimited
Prospective Study for the Detection of Vascular Injury in Adult and Pediatric Patients with Cervicothoracic Seat Belt Signs
BACKGROUND: A delayed diagnosis of injury to cervicothoracic vessels from blunt trauma may cause significant adverse sequelae. The association of a cervicothoracic seat belt sign with such an injury is unknown. METHODS: Algorithms were prospectively studied for the detection of occult vascular injury in patients with cervicothoracic seat belt signs. Patients with neck seat belt signs underwent arteriography or computed tomographic angiography (CTA). Those with thoracic seat belt signs underwent aortography/arteriography if a ruptured thoracic aorta or injury to a great vessel was suspected or a neurovascular abnormality was present. RESULTS: During a 17-month period, 797 patients were admitted to the trauma service secondary to motor vehicle crashes. One hundred thirty-one (16.4%) had cervical or thoracic seat belt signs. Four (3%) of the patients had carotid artery injuries, the presence of which was strongly associated with a Glasgow Coma Scale score \u3c 14, an Injury Severity Score \u3e 16 (p \u3c 0.0001), and the presence of a clavicle and/or first rib fracture (p \u3c 0.0037). Of the remaining patients, 17 had thoracic trauma. There were no vascular injuries in the children and only one had thoracic trauma. CONCLUSION: The algorithms are safe and accurate for the detection of cervicothoracic vascular injury in adult and pediatric patients with seat belt signs. The cervicothoracic seat belt mark and an abnormal physical examination are an effective combination in screening for cervicothoracic vascular injury
Prospective Study for the Detection of Vascular Injury in Adult and Pediatric Patients with Cervicothoracic Seat Belt Signs
BACKGROUND:
A delayed diagnosis of injury to cervicothoracic vessels from blunt trauma may cause significant adverse sequelae. The association of a cervicothoracic seat belt sign with such an injury is unknown. METHODS:
Algorithms were prospectively studied for the detection of occult vascular injury in patients with cervicothoracic seat belt signs. Patients with neck seat belt signs underwent arteriography or computed tomographic angiography (CTA). Those with thoracic seat belt signs underwent aortography/arteriography if a ruptured thoracic aorta or injury to a great vessel was suspected or a neurovascular abnormality was present. RESULTS:
During a 17-month period, 797 patients were admitted to the trauma service secondary to motor vehicle crashes. One hundred thirty-one (16.4%) had cervical or thoracic seat belt signs. Four (3%) of the patients had carotid artery injuries, the presence of which was strongly associated with a Glasgow Coma Scale score \u3c 14, an Injury Severity Score \u3e 16 (p \u3c 0.0001), and the presence of a clavicle and/or first rib fracture (p \u3c 0.0037). Of the remaining patients, 17 had thoracic trauma. There were no vascular injuries in the children and only one had thoracic trauma. CONCLUSION:
The algorithms are safe and accurate for the detection of cervicothoracic vascular injury in adult and pediatric patients with seat belt signs. The cervicothoracic seat belt mark and an abnormal physical examination are an effective combination in screening for cervicothoracic vascular injury
The photoassociative spectroscopy, photoassociative molecule formation, and trapping of ultracold
We have observed the photoassociative spectra of colliding ultracold
39K and 85Rb atoms to produce KRb* in all eight bound electronic
states correlating with the 39K (4s) + 85Rb(5 and
5 asymptotes. These electronically excited KRb* ultracold
molecules are detected after their radiative decay to the metastable triplet
(a state and (in some cases) the singlet
(X ground state. The triplet (a
ultracold molecules are detected by two-photon ionization at 602.5 nm to
form KRb+, followed by time-of-flight mass spectroscopy. We are able to
assign a majority of the spectrum to three states (2(0, 2(0,
2([see full textsee full textsee full textsee full textsee full textsee full textsee full text])) in a lower triad of states with similar C6 values correlating to
the K(4s) + Rb (5 asymptote; and to five states in an upper triad
of three states (3(0, 3(0, 3([see full textsee full textsee full textsee full textsee full textsee full textsee full text])) and a dyad of two states
(4([see full textsee full textsee full textsee full textsee full textsee full textsee full text]), 1([see full textsee full textsee full textsee full textsee full textsee full textsee full text])), with one set of similar C6 values within the upper triad
and a different set of similar C6 values within the dyad. We are also
able to make connection with the short-range spectra of Kasahara et al. [J.
Chem. Phys. 111, 8857 (1999)], identifying three of our levels as v
= 61, 62 and 63 of the 1 4([see full textsee full textsee full textsee full textsee full textsee full textsee full text]) state they observed. We
also argue that ultracold photoassociation to levels between the K(4s) + Rb
(5 and K(4s) + Rb (5 asymptotes may be weakly or
strongly predissociated and therefore difficult to observe by ionization of
a (or X molecules; we do know
from Kasahara et al. that levels of the 1 4([see full textsee full textsee full textsee full textsee full textsee full textsee full text]) and
2 5([see full textsee full textsee full textsee full textsee full textsee full textsee full text]) states in the intra-asymptote region are
predissociated. A small fraction (1/3) of the triplet (a ultracold molecules formed are trapped in the weak magnetic field
of our magneto-optical trap (MOT).
Vaginal Challenge with an SIV-Based Dual Reporter System Reveals That Infection Can Occur throughout the Upper and Lower Female Reproductive Tract
<div><p>The majority of new HIV infections occur in women as a result of heterosexual intercourse, overcoming multiple innate barriers to infection within the mucosa. However, the avenues through which infection is established, and the nature of bottlenecks to transmission, have been the source of considerable investigation and contention. Using a high dose of a single round non-replicating SIV-based vector containing a novel dual reporter system, we determined the sites of infection by the inoculum using the rhesus macaque vaginal transmission model. Here we show that the entire female reproductive tract (FRT), including the vagina, ecto- and endocervix, along with ovaries and local draining lymph nodes can contain transduced cells only 48 hours after inoculation. The distribution of infection shows that virions quickly disseminate after exposure and can access target cells throughout the FRT, with an apparent preference for infection in squamous vaginal and ectocervical mucosa. JRFL enveloped virions infect diverse CD4 expressing cell types, with T cells resident throughout the FRT representing the primary target. These findings establish a new perspective that the entire FRT is susceptible and virus can reach as far as the ovary and local draining lymph nodes. Based on these findings, it is essential that protective mechanisms for prevention of HIV acquisition must be present at protective levels throughout the entire FRT to provide complete protection.</p></div