8,910 research outputs found
International Health Regulations (2005) and the U.S. Department of Defense: building core capacities on a foundation of partnership and trust
A cornerstone of effective global health surveillance programs is the ability to build systems that identify, track and respond to public health threats in a timely manner. These functions are often difficult and require international cooperation given the rapidity with which diseases cross national borders and spread throughout the global community as a result of travel and migration by both humans and animals. As part of the U.S. Armed Forces Health Surveillance Center (AFHSC), the Department of Defenseâs (DoD) Globa Emerging Infections Surveillance and Response System (AFHSC-GEIS) has developed a global network of surveillance sites over the past decade that engages in a wide spectrum of support activities in collaboration with host country partners. Many of these activities are in direct support of International Health Regulations (IHR[2005]). The network also supports host country military forces around the world, which are equally affected by these threats and are often in a unique position to respond in areas of conflict or during complex emergencies. With IHR(2005) as the guiding framework for action, the AFHSC-GEIS network of international partners and overseas research laboratories continues to develop into a far-reaching system for identifying, analyzing and responding to emerging disease threats
Recommended from our members
Stratigraphic Studies of the Palo Duro Basin: An Update
Stratigraphic studies of the Palo Duro Basin are now in their 8th year. Although the emphasis in these studies now lies in the San Andres Formation (possible repository host rock) and the Wolfcamp Series (sub-repository aquifer), investigations of other units (fig. 1) continue to be carried out as well. This report includes work that was not available for inclusion in last year's (1983) CSR on stratigraphy (Open File Report No. OF-WTWI-1984-30). The section on pre-Pennsylvanian stratigraphy represents the final stages of study of those units. The report detailing structural controls on deposition of the San Andres is part of an ongoing effort to recognize indications of structural or tectonic controls on sedimentation throughout the stratigraphic column in the Palo Duro Basin area. Studies of the Dockum Group are revealing similar controls during the Triassic. Core studies of the Dockum are increasing our resolution of depositional settings in the area.Bureau of Economic Geolog
Expression of Inwardly Rectifying Potassium Channels by an Inducible Adenoviral Vector Reduced the Neuronal Hyperexcitability and Hyperalgesia Produced by Chronic Compression of the Spinal Ganglion
BACKGROUND: A chronic compressed dorsal root ganglion (CCD) in rat produces pain behavior and an enhanced excitability of neurons within the compressed ganglion. Kir2.1 is an inwardly rectifying potassium channel that acts to stabilize the resting potential of certain cell types. We hypothesized that an inducible expression of Kir2.1 channels in CCD neurons might suppress neuronal excitability in the dorsal root ganglion (DRG) and reduce the associated pain behavior. RESULTS: We delivered, by microinjection into the fourth lumbar (L4) DRG, an adenoviral vector containing a reporter gene encoding the enhanced green fluorescent protein (GFP) and a Kir2.1 channel (AdKir). At the same time the ganglion was compressed by implantation of a rod through the intervertebral foramen (CCD). The in vivo expression of the transferred gene was controlled by an ecdysone analog via an ecdysone-inducible promoter in the viral vector. In comparison with the effects of vehicle or a control vector containing only the GFP gene, AdKir significantly reduced the neuronal hyperexcitability after CCD. Electrophysiological recordings, in vivo, from nociceptive and non-nociceptive DRG neurons expressing the virally produced Kir2.1 channels revealed a hyperpolarized resting membrane potential, an increased rheobase, and lack of spontaneous activity. Inducing the Kir2.1 gene at the beginning of CCD surgery partially prevented the development of mechanical hyperalgesia. However, a delayed induction of the Kir2.1 gene (3 days after CCD surgery) produced no significant effect on the pain behavior. CONCLUSIONS: We found that an inducible expression of Kir2.1 channels in chronically compressed DRG neurons can effectively suppress the neuronal excitability and, if induced at the beginning of CCD injury, prevent the development of hyperalgesia. We hypothesize that a higher level of neuronal hyperexcitability in the DRG is required to initiate than to maintain the hyperalgesia and that the hyperexcitability contributing to neuropathic pain is best inhibited as soon as possible after injury
The 1995-1996 Decline of R Coronae Borealis - High Resolution Optical Spectroscopy
A set of high-resolution optical spectra of RCrB acquired before, during, and
after its 1995-1996 decline is discussed. All of the components reported from
earlier declines are seen. This novel dataset provides new information on these
components including several aspects not previously seen in declines of RCrB
and other RCBs. In the latter category is the discovery that the decline's
onset is marked by distortions of absorption lines of high-excitation lines,
and quickly followed by emission in these and in low excitation lines. This
'photospheric trigger' implies that dust causing the decline is formed close to
the star. These emission lines fade quickly. After 1995 November 2, low
excitation narrow (FWHM ~12 km s-1) emission lines remain. These appear to be a
permanent feature, slightly blue-shifted from the systemic velocity, and
unaffected by the decline except for a late and slight decrease of flux at
minimum light. The location of the warm, dense gas providing these lines is
uncertain. Absorption lines unaffected by overlying sharp emission are greatly
broadened, weakened, and red-shifted at the faintest magnitudes when scattered
light from the star is a greater contributor than direct light transmitted
through the fresh soot cloud. A few broad lines are seen at and near minimum
light with approxiamately constant flux: prominent among these are the He I
triplet series, Na I D, and [N II] lines. These lines are blue-shifted by about
30 km s(-1) relative to the systemic velocity with no change in velocity over
the several months for whicht he lines were seen. It is suggested that these
lines, especially the He I lines, arise from an accretion disk around an unseen
compact companion, which may be a low-mass white dwarf. If so, R CrB is similar
to the unusual post-AGB star 89 Her.Comment: 31 pages, 26 figure
Corn as a Grazing Crop: An Option for Extending the Grazing Season in Kentucky
Grazing is the cheapest way to feed cattle on a cost per pound of nutrient basis. However, producers with limited land resources in Kentucky have been able to use commodities or grain by-products to increase cattle numbers due to low cost and availability of these inputs. Extending the grazing season is one solution that would enable producers to reduce cost and expand production with little or no impact on the environment
Follow-Up Observations of PTFO 8-8695: A 3 MYr Old T-Tauri Star Hosting a Jupiter-mass Planetary Candidate
We present Spitzer 4.5\micron\ light curve observations, Keck NIRSPEC radial
velocity observations, and LCOGT optical light curve observations of
PTFO~8-8695, which may host a Jupiter-sized planet in a very short orbital
period (0.45 days). Previous work by \citet{vaneyken12} and \citet{barnes13}
predicts that the stellar rotation axis and the planetary orbital plane should
precess with a period of days. As a consequence, the observed
transits should change shape and depth, disappear, and reappear with the
precession. Our observations indicate the long-term presence of the transit
events ( years), and that the transits indeed do change depth, disappear
and reappear. The Spitzer observations and the NIRSPEC radial velocity
observations (with contemporaneous LCOGT optical light curve data) are
consistent with the predicted transit times and depths for the $M_\star = 0.34\
M_\odot$ precession model and demonstrate the disappearance of the transits. An
LCOGT optical light curve shows that the transits do reappear approximately 1
year later. The observed transits occur at the times predicted by a
straight-forward propagation of the transit ephemeris. The precession model
correctly predicts the depth and time of the Spitzer transit and the lack of a
transit at the time of the NIRSPEC radial velocity observations. However, the
precession model predicts the return of the transits approximately 1 month
later than observed by LCOGT. Overall, the data are suggestive that the
planetary interpretation of the observed transit events may indeed be correct,
but the precession model and data are currently insufficient to confirm firmly
the planetary status of PTFO~8-8695b.Comment: Accepted for publication in The Astrophysical Journa
Viral gene transfer of dominant-negative Kv4 construct suppresses an O2-sensitive K+ current in chemoreceptor cells
ProducciĂłn CientĂficaHypoxia initiates the neurosecretory response of the carotid body (CB) by inhibiting one or more potassium channels in the chemoreceptor cells. Oxygen-sensitive K+ channels were first described in rabbit CB chemoreceptor cells, in which a transient outward K+ current was reported to be reversibly inhibited by hypoxia. Although progress has been made to characterize this current with electrophysiological and pharmacological tools, no attempts have been made to identify which Kv channel proteins are expressed in rabbit CB chemoreceptor cells and to determine
+
with adenoviruses that enabled ecdysone-inducible expression of the dominant-negative constructs and reporter genes in poly- cistronic vectors. In voltage-clamp experiments, we found that, whereas adenoviral infections of chemoreceptor cells with Kv1.xDN did not modify the O -sensitive K+ current, infections with Kv4.xDN suppressed the transient outward current in a time-dependent manner, significantly depolarized the cells, and abolished the depolarization induced by hypoxia. Our work dem- onstrate that genes of the Shal K+ channels underlie the tran-
+
their contribution to the native O2-sensitive K
current. To probe
sient outward, O2-sensitive, K
current of rabbit CB chemore-
the molecular identity of this current, we have used dominant-
negative constructs to block the expression of functional Kv channels of the Shaker (Kv1.xDN) or the Shal (Kv4.xDN) subfam-
ceptor cells and that this current contributes to the cell
depolarization in response to low pO2.
+
ilies, because members of these two subfamilies contribute to
Key words: O2-sensitive K
current; viral gene transfer;
the transient outward K+ currents in other preparations. Delivery of the constructs into chemoreceptor cells has been achieved2018-03-2
Rossby wave dynamics of the North Pacific extra-tropical response to El Niño: importance of the basic state in coupled GCMs
The extra-tropical response to El Nino in a "low" horizontal resolution coupled climate model, typical of the Intergovernmental Panel on Climate Change fourth assessment report simulations, is shown to have serious systematic errors. A high resolution configuration of the same model has a much improved response that is similar to observations. The errors in the low resolution model are traced to an incorrect representation of the atmospheric teleconnection mechanism that controls the extra-tropical sea surface temperatures (SSTs) during El Nino. This is due to an unrealistic atmospheric mean state, which changes the propagation characteristics of Rossby waves. These erroneous upper tropospheric circulation anomalies then induce erroneous surface circulation features over the North Pacific. The associated surface wind speed and direction errors create erroneous surface flux and upwelling anomalies which finally lead to the incorrect extra-tropical SST response to El Nino in the low resolution model. This highlights the sensitivity of the climate response to a single link in a chain of complex climatic processes. The correct representation of these processes in the high resolution model indicates the importance of horizontal resolution in resolving such processes
Observations of T-Tauri Stars using HST-GHRS: I. Far Ultraviolet Emission Lines
We have analyzed GHRS data of eight CTTS and one WTTS. The GHRS data consists
of spectral ranges 40 A wide centered on 1345, 1400, 1497, 1550, and 1900 A.
These UV spectra show strong SiIV, and CIV emission, and large quantities of
sharp (~40 km/s) H2 lines. All the H2 lines belong to the Lyman band and all
the observed lines are single peaked and optically thin. The averages of all
the H2 lines centroids for each star are negative which may indicate that they
come from an outflow. We interpret the emission in H2 as being due to
fluorescence, mostly by Ly_alpha, and identify seven excitation routes within 4
A of that line. We obtain column densities (10^12 to 10^15 cm^-2) and optical
depths (~1 or less) for each exciting transition. We conclude that the
populations are far from being in thermal equilibrium. We do not observe any
lines excited from the far blue wing of Ly_alpha, which implies that the
molecular features are excited by an absorbed profile. SiIV and CIV (corrected
for H2 emission) have widths of ~200 km/s, and an array of centroids
(blueshifted lines, centered, redshifted). These characteristics are difficult
to understand in the context of current models of the accretion shock. For DR
Tau we observe transient strong blueshifted emission, perhaps the a result of
reconnection events in the magnetosphere. We also see evidence of multiple
emission regions for the hot lines. While CIV is optically thin in most stars
in our sample, SiIV is not. However, CIV is a good predictor of SiIV and H2
emission. We conclude that most of the flux in the hot lines may be due to
accretion processes, but the line profiles can have multiple and variable
components.Comment: 67 pages, 19 figures, Accepted in Ap
The Global Emerging Infection Surveillance and Response System (GEIS), a U.S. government tool for improved global biosurveillance: a review of 2009
The Armed Forces Health Surveillance Center, Global Emerging Infections Surveillance and Response System (AFHSC-GEIS) has the mission of performing surveillance for emerging infectious diseases that could affect the United States (U.S.) military. This mission is accomplished by orchestrating a global portfolio of surveillance projects, capacity-building efforts, outbreak investigations and training exercises. In 2009, this portfolio involved 39 funded partners, impacting 92 countries. This article discusses the current biosurveillance landscape, programmatic details of organization and implementation, and key contributions to force health protection and global public health in 2009
- âŠ