172 research outputs found
Deployment and Travel Medicine Knowledge, Attitudes, Practices, and Outcomes Study (KAPOS): Malaria Chemoprophylaxis Prescription Patterns in the Military Health System
The Deployment and Travel Medicine Knowledge, Attitudes, Practices, and Outcomes Study (KAPOS) examines the integrated relationship between provider and patient inputs and health outcomes associated with travel and deployments. This study describes malaria chemoprophylaxis prescribing patterns by medical providers within the U.S. Department of Defense\u27s Military Health System and its network of civilian healthcare providers during a 5-year period. Chemoprophylaxis varied by practice setting, beneficiary status, and providers\u27 travel medicine expertise. Whereas both civilian and military facilities prescribe an increasing proportion of atovaquone-proguanil, doxycycline remains the most prevalent antimalarial at military facility based practices. Civilian providers dispense higher rates of mefloquine than their military counterparts. Within military treatment facilities, travel medicine specialists vary their prescribing pattern based on service member versus beneficiary status of the patient, both in regards to primary prophylaxis, and use of presumptive anti-relapse therapy (PQ-PART). By contrast, nonspecialists appear to carry over practice patterns developed under force health protection (FHP) policy for service members, into the care of beneficiaries, particularly in high rates of prescribing doxycycline and PQ-PART compared with both military travel medicine specialists and civilian comparators. Force health protection policy plays an important role in standardizing and improving the quality of care for deployed service members, but this may not be the perfect solution outside of the deployment context. Solutions that broaden both utilization of decision support tools and travel medicine specialty care are necessary
Self Reported Incidence and Morbidity of Acute Respiratory Illness among Deployed U.S. Military in Iraq and Afghanistan
BACKGROUND: Historically, respiratory infections have had a significant impact on U.S. military missions. Deployed troops are particularly at high risk due to close living conditions, stressful work environments and increased exposure to pathogens. To date, there are limited data available on acute respiratory illness (ARI) among troops deployed in support of ongoing military operations, specifically Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF). METHODS: Using self-report data from two sources collected from troops deployed to Iraq, Afghanistan and the surrounding region, we analyzed incidence and risk factors for ARI. Military personnel on mid-deployment Rest & Recuperation (R&R) or during redeployment were eligible to participate in the voluntary self-report survey. RESULTS: Overall, 39.5% reported having at least one ARI. Of these, 18.5% sought medical care and 33.8% reported having decreased job performance. The rate of self-reported ARI was 15 episodes per 100 person-months among those taking the voluntary survey, and 24.7 episodes per 100 person-months among those taking the clinic health questionnaire. Negative binomial regression analysis found female sex, Navy branch of service and lack of flush toilets to be independently associated with increased rates of ARI. Deployment to OIF, increasing age and higher rank were also positively associated with ARI risk. CONCLUSIONS: The overall percentage of deployed military personnel reporting at least one acute respiratory illness decreased since earlier parts of OIF/OEF. However, the reported effect on job performance increased tremendously. The most important factors associated with increased respiratory infection are female sex, Navy branch of service, lack of improved latrine facilities, deployment to OIF, increasing age and higher rank
PFGE, Lior serotype, and antimicrobial resistance patterns among Campylobacter jejuni isolated from travelers and US military personnel with acute diarrhea in Thailand, 1998-2003
<p>Abstract</p> <p>Background</p> <p><it>Campylobacter jejuni </it>is a major cause of gastroenteritis worldwide. In Thailand, several strains of <it>C. jejuni </it>have been isolated and identified as major diarrheal pathogens among adult travelers. To study the epidemiology of <it>C. jejuni </it>in adult travelers and U.S. military personnel with acute diarrhea in Thailand from 1998-2003, strains of <it>C. jejuni </it>were isolated and phenotypically identified, serotyped, tested for antimicrobial susceptibility, and characterized using pulsed-field gel electrophoresis (PFGE).</p> <p>Results</p> <p>A total of 312 <it>C. jejuni </it>isolates were obtained from travelers (n = 46) and U.S. military personnel (n = 266) in Thailand who were experiencing acute diarrhea. Nalidixic acid and ciprofloxacin resistance was observed in 94.9% and 93.0% of the isolates, respectively. From 2001-2003, resistance to tetracycline (81.9%), trimethoprim-sulfamethoxazole (57.9%), ampicillin (28.9%), kanamycin (5.9%), sulfisoxazole (3.9%), neomycin (2.0%), and streptomycin (0.7%) was observed. Combined PFGE analysis showed considerable genetic diversity among the <it>C. jejuni </it>isolates; however, four PFGE clusters included isolates from the major Lior serotypes (HL: 36, HL: 11, HL: 5, and HL: 28). The PFGE analysis linked individual <it>C. jejuni </it>clones that were obtained at U.S. military exercises with specific antimicrobial resistance patterns.</p> <p>Conclusions</p> <p>In summary, most human <it>C. jejuni </it>isolates from Thailand were multi-resistant to quinolones and tetracycline. PFGE detected spatial and temporal <it>C. jejuni </it>clonality responsible for the common sources of <it>Campylobacter </it>gastroenteritis.</p
Structures of the magnetoionic media around the FR I radio galaxies 3C 31 and Hydra A
We use high-quality VLA images of the Fanaroff & Riley Class I radio galaxy
3C 31 at six frequencies in the range 1365 to 8440MHz to explore the spatial
scale and origin of the rotation measure (RM) fluctuations on the line of sight
to the radio source. We analyse the distribution of the degree of polarization
to show that the large depolarization asymmetry between the North and South
sides of the source seen in earlier work largely disappears as the resolution
is increased. We show that the depolarization seen at low resolution results
primarily from unresolved gradients in a Faraday screen in front of the
synchrotron-emitting plasma. We establish that the residual degree of
polarization in the short-wavelength limit should follow a Burn law and we fit
such a law to our data to estimate the residual depolarization at high
resolution. We show that the observed RM variations over selected areas of 3C
31 are consistent with a power spectrum of magnetic fluctuations in front of 3C
31 whose power-law slope changes significantly on the scales sampled by our
data. The power spectrum can only have the form expected for Kolmogorov
turbulence on scales <5 kpc. On larger scales we find a flatter slope. We also
compare the global variations of RM across 3C 31 with the results of
three-dimensional simulations of the magnetic-field fluctuations in the
surrounding magnetoionic medium. We show that our data are consistent with a
field distribution that favours the plane perpendicular to the jet axis -
probably because the radio source has evacuated a large cavity in the
surrounding medium. We also apply our analysis techniques to the case of Hydra
A, where the shape and the size of the cavities produced by the source in the
surrounding medium are known from X-ray data. (Abridged)Comment: 33 pages, 25 figures, accepted for publication in MNRA
The intracluster magnetic field power spectrum in A2199
We investigate the magnetic field power spectrum in the cool core galaxy
cluster A2199 by analyzing the polarized emission of the central radio source
3C338. The polarized radiation from the radio emitting plasma is modified by
the Faraday rotation as it passes through the magneto-ionic intracluster
medium. We use Very Large Array observations between 1665 and 8415 MHz to
produce detailed Faraday rotation measure and fractional polarization images of
the radio galaxy. We simulate Gaussian random three-dimensional magnetic field
models with different power-law power spectra and we assume that the field
strength decreases radially with the thermal gas density as n_e^{\eta}. By
comparing the synthetic and the observed images with a Bayesian approach, we
constrain the strength and structure of the magnetic field associated with the
intracluster medium. We find that the Faraday rotation toward 3C338 in A2199 is
consistent with a magnetic field power law power spectrum characterized by an
index n=(2.8 \pm 1.3) between a maximum and a minimum scale of fluctuation of
\Lambda_{max}=(35 \pm 28) kpc and \Lambda_{min}=(0.7 \pm 0.1) kpc,
respectively. By including in the modeling X-ray cavities coincident with the
radio galaxy lobes, we find a magnetic field strength of =(11.7 \pm 9.0)
\mu G at the cluster center. Further out, the field decreases with the radius
following the gas density to the power of \eta=(0.9 \pm 0.5).Comment: 17 pages, 12 figures, A&A accepte
Infectious complications after deployment trauma: Following wounded US military personnel into Veterans Affairs care
BACKGROUND: Infectious complications related to deployment trauma significantly contribute to the morbidity and mortality of wounded service members. The Trauma Infectious Disease Outcomes Study (TIDOS) collects data on US military personnel injured in Iraq and Afghanistan in an observational cohort study of infectious complications. Patients enrolled in TIDOS may also consent to follow-up through the Department of Veterans Affairs (VA). We present data from the first 337 TIDOS enrollees to receive VA healthcare.
METHODS: Data were collected from the Department of Defense (DoD) Trauma Registry, TIDOS infectious disease module, DoD and VA electronic medical records, and telephone interview. Cox proportional hazard analysis was performed to identify predictors of post-discharge infections related to deployment trauma.
RESULTS: Among the first 337 TIDOS enrollees who entered VA healthcare, 111 (33%) had 244 trauma-related infections during their initial trauma hospitalization (2.1 infections per 100 person-days). Following initial discharge, 127 (38%) enrollees had 239 trauma-related infections (170 during DoD follow-up and 69 during VA time). Skin and soft-tissue infections and osteomyelitis were predominant during and after the initial trauma hospitalization. In a multivariate model, a shorter time to development of a new infection following discharge was independently associated with injury severity score âĽ10 and occurrence of âĽ1 inpatient infection during initial trauma hospitalization.
CONCLUSIONS: Incident infections related to deployment trauma continue well after initial hospital discharge and into VA healthcare. Overall, 38% of enrolled patients developed a new trauma-related infection after their initial hospital discharge, with 29% occurring after the patient left military service
Chandra Temperature Map of Abell 754 and Constraints on Thermal Conduction
We use Chandra data to derive a detailed gas temperature map of the nearby,
hot, merging galaxy cluster A754. Combined with the X-ray and optical images,
the map reveals a more complex merger geometry than previously thought,
possibly involving more than two subclusters or a cool gas cloud sloshing
independently from its former host subcluster. In the cluster central region,
we detect spatial variations of the gas temperature on all linear scales, from
100 kpc (the map resolution) and up, which likely remain from a merger shock
passage. These variations are used to derive an upper limit on effective
thermal conductivity on a 100 kpc scale, which is at least an order of
magnitude lower than the Spitzer value. This constraint pertains to the bulk of
the intracluster gas, as compared to the previously reported estimates for cold
fronts (which are rather peculiar sites). If the conductivity in a tangled
magnetic field is at the recently predicted higher values (i.e., about 1/5 of
the Spitzer value), the observed suppression can be achieved, for example, if
the intracluster gas consists of magnetically isolated domains.Comment: Discussion of relevance of our conduction constraint for cooling
flows expanded. 4 pages (using the new emulateapj), color figures. Grayscale
version at http://hea-www.harvard.edu/~maxim/papers/a754/ . ApJ Letters in
pres
Multi-Attribute Tradespace Exploration for Survivability
Multi-Attribute Tradespace Exploration for Survivability is a system design and analysis methodology that incorporates survivability considerations into the tradespace exploration process (i.e., a solution-generating and decision-making framework that applies decision theory to model-based design). During the concept generation phase of tradespace exploration, the methodology applies seventeen empirically validated survivability design principles spanning susceptibility reduction, vulnerability reduction, and resilience enhancement. During subsequent concept evaluation, the methodology adds value-based survivability metrics to traditional architectural evaluation criteria of mission utility and lifecycle cost. Applied to a satellite radar mission, the methodology allowed operational survivability to be statistically evaluated across representative distributions of naturally occurring disturbances in the space environment and for survivability to be incorporated as a decision factor earlier in the design process. Constellations in the illustrative example are shown to be the most survivable, mitigating disturbances architecturally, rather than through additive features.Massachusetts Institute of Technology (Systems Engineering Advancement Research Initiative (SEAri))Massachusetts Institute of Technology. Program on Emerging Technologie
Abell 1758N from an optical point of view: new insights on a merging cluster with diffuse radio emission
We seek to explore the internal dynamics of the cluster Abell 1758N, which
has been shown to host a radio halo and two relics, and is known to be a
merging bimodal cluster. Our analysis is mainly based on new redshift data for
137 galaxies acquired at the Telescopio Nazionale Galileo, only four of which
have redshifts previously listed in the literature. We also used photometric
data from the Sloan Digital Sky Survey and from the Canada-France-Hawaii
Telescope archive. We combined galaxy velocities and positions to select 92
cluster galaxies and analyzed the internal cluster dynamics. We estimate a
cluster redshift of =0.2782 and quite a high line-of-sight (LOS) velocity
dispersion of ~ 1300 km/s. Our 2D analysis confirms the presence of a bimodal
structure along the NW-SE direction. We add several pieces of information to
the previous merging scenario: the two subclusters (here A1758N(NW) and
A1758N(SE)) cannot be separated in the velocity analyses and we deduce a small
LOS velocity difference of ~300 km/s in the cluster rest-frame. The velocity
information successfully shows that A1758N is surrounded by two small groups
and active galaxies infalling onto, or escaping from, the cluster. Removing the
two groups, we estimate ~1000 km/s and ~800 km/s for the velocity dispertions
of A1758N(NW) and A1758N(SE), respectively. We find that Abell 1758N is a very
massive cluster with a range of M=2-3 10^15 solar masses, depending on the
adopted model. As expected for clusters that host powerful, extended, diffuse
radio emissions, Abell 1758N is a major cluster merger just forming a massive
system.Comment: Accepted for publication on Astronomy & Astrophysic
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