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In response to advancing clinical practice guidelines regarding concussion management, service members, like athletes, complete a baseline assessment prior to participating in high-risk activities. While several studies have established test stability in athletes, no investigation to date has examined the stability of baseline assessment scores in military cadets. The objective of this study was to assess the test–retest reliability of a baseline concussion test battery in cadets at U.S. Service Academies.
All cadets participating in the Concussion Assessment, Research, and Education (CARE) Consortium investigation completed a standard baseline battery that included memory, balance, symptom, and neurocognitive assessments. Annual baseline testing was completed during the first 3 years of the study. A two-way mixed-model analysis of variance (intraclass correlation coefficent (ICC)3,1) and Kappa statistics were used to assess the stability of the metrics at 1-year and 2-year time intervals.
ICC values for the 1-year test interval ranged from 0.28 to 0.67 and from 0.15 to 0.57 for the 2-year interval. Kappa values ranged from 0.16 to 0.21 for the 1-year interval and from 0.29 to 0.31 for the 2-year test interval. Across all measures, the observed effects were small, ranging from 0.01 to 0.44.
This investigation noted less than optimal reliability for the most common concussion baseline assessments. While none of the assessments met or exceeded the accepted clinical threshold, the effect sizes were relatively small suggesting an overlap in performance from year-to-year. As such, baseline assessments beyond the initial evaluation in cadets are not essential but could aid concussion diagnosis.
HIV-positive individuals are at significantly increased risk of depression. In low- and middle-income countries, depression is frequently under-detected, hampered by a lack of data regarding available screening tools. The 5-item World Health Organization Well-Being Index (WHO-5) is widely used to screen for depression, yet its validity in African adults with HIV has yet to be examined.
In this cross-sectional study, we enrolled HIV-positive adults presenting to an outpatient HIV clinic in Mwanza, Tanzania. Patients were administered the Patient Health Questionnaires (PHQ)-2/9 and WHO-5 questionnaires. The rate of positive screens was calculated. Fisher's exact test and Pearson's correlation coefficients between PHQ-2/9 and WHO-5 scores were calculated.
We enrolled 72 HIV-positive adults: rates of positive depression screen were 62.5%, 77.8%, and 47.2% according to PHQ-2, PHQ-9, and WHO-5, respectively. PHQ and WHO results for depression were significantly associated (Fisher's exact test: PHQ-2 v. WHO-5, p = 0.028; PHQ-9 v. WHO-5, p = 0.002). The level of correlation between PHQ and WHO results for depression was moderate (Pearson's correlation coefficient: PHQ-2 v. WHO-5 −0.3289; PHQ-9 v. WHO-5 −0.4463).Per Mantel–Haenszel analysis, screening results were significantly more concordant among patients in the following strata: men, age >40, Sukuma ethnicity, Christian, unmarried, self-employed, at least primary school education completed, and higher than the median income level.
WHO-5 scores correlated well with those of the PHQ-9, suggesting that the WHO-5 represents a valid screening tool. The concordance of PHQ-9 and WHO-5 results was poorer in marginalized socioeconomic groups. Positive depression screens were exceedingly common among HIV-positive Tanzanian adults according to all three questionnaires.
Antarctic and Southern Ocean science is vital to understanding natural variability, the processes that govern global change and the role of humans in the Earth and climate system. The potential for new knowledge to be gained from future Antarctic science is substantial. Therefore, the international Antarctic community came together to ‘scan the horizon’ to identify the highest priority scientific questions that researchers should aspire to answer in the next two decades and beyond. Wide consultation was a fundamental principle for the development of a collective, international view of the most important future directions in Antarctic science. From the many possibilities, the horizon scan identified 80 key scientific questions through structured debate, discussion, revision and voting. Questions were clustered into seven topics: i) Antarctic atmosphere and global connections, ii) Southern Ocean and sea ice in a warming world, iii) ice sheet and sea level, iv) the dynamic Earth, v) life on the precipice, vi) near-Earth space and beyond, and vii) human presence in Antarctica. Answering the questions identified by the horizon scan will require innovative experimental designs, novel applications of technology, invention of next-generation field and laboratory approaches, and expanded observing systems and networks. Unbiased, non-contaminating procedures will be required to retrieve the requisite air, biota, sediment, rock, ice and water samples. Sustained year-round access to Antarctica and the Southern Ocean will be essential to increase winter-time measurements. Improved models are needed that represent Antarctica and the Southern Ocean in the Earth System, and provide predictions at spatial and temporal resolutions useful for decision making. A co-ordinated portfolio of cross-disciplinary science, based on new models of international collaboration, will be essential as no scientist, programme or nation can realize these aspirations alone.
This study examined high temperature survival and heat shock protein 70 (Hsp70) responses to temperature variation for two marine invertebrate species on sub-Antarctic Marion Island. The isopod Exosphaeroma gigas Leach and the amphipod Hyale hirtipalma Dana had the same tolerance to high temperature. The mean upper temperature which was lethal for 50% of the population (upper lethal temperature, ULT50) was 26.4°C for both species. However, the isopod E. gigas showed significant plasticity of ULT50, with a positive response to acclimation. In addition, the isopod had a heat shock response of Hsp70 at all acclimations, and the amount of Hsp70 protein increased significantly from basal levels upon an acute warm exposure after a cold acclimation. By contrast, the amphipod H. hirtipalma showed limited plasticity of ULT50 and no evidence for a heat shock response (failure of three different Hsp70 antibodies to bind to the extracted 70kDa proteins). Overall, these results reflect different flexibility of thermal tolerance of intertidal invertebrate species on Marion Island, with possible variation in the underlying cellular mechanisms, suggesting that warming associated with climate change may result in changes in species assemblage structure in sub-polar environments.
Strains of Escherichia coli isolated from adult females with symptomatic urinary tract infection were found to possess the following properties significantly more frequently than faecal strains: (i) high K-antigen titre; (ii) haemolysin; (iii) type 1 pili; (iv) mannose-resistant haemagglutination; (v) fermentation of dulcitol and salicin; (vi) O serotype 2, 6 and 75; (vii) H serotype 1. E. coli isolated from urine specimens containing significant numbers of antibody-coated bacteria were richer in these seven properties than strains from urines without detectable antibody-coated bacteria.
The O and H serotypes of E. coli obtained from patients with urinary tract infection in two New Zealand cities were compared with those reported in the world literature and found to be similar.
X-ray CT scans at two different energies of three articulated specimens of Spathelopsis oakvalensis n. sp., a bivalve from the Bluefield Formation of the Mauch Chunk Group (Mississippian, Chesterian) from southeastern West Virginia, permitted observation and description of poorly known internal features of the shell, resulting in a reversal of the shell orientation alleged by past authors and concomitant reassignment of this problematic genus to the palaeotaxodont family Nuculanidae Adams and Adams. Distinctive posterior and anterior gapes in Spathelopsis suggest separation of inhalant and exhalant water streams, a characteristic associated with derived but not primitive palaeotaxodonts.
We report on the discovery of a supermassive binary black-hole (SBBH) system in the radio galaxy 0402+379, with a projected separation between the two black holes of just 7.3 pc. This is the most compact SBBH pair yet imaged by more than two orders of magnitude. These results are based upon multi-frequency imaging using the Very Long Baseline Array (VLBA) which reveal two compact, variable, flat-spectrum, active nuclei within the elliptical host galaxy of 0402+379. Multi-epoch observations from the VLBA also provide constraints on the total mass and dynamics of the system. The two nuclei appear stationary while the jets emanating from the weaker of the two nuclei appear to move out and terminate in bright hot spots. The discovery of this system has implications for the number of compact binary black holes that might be sources of gravitational radiation. The VLBI Imaging and Polarimetry Survey (VIPS) currently underway should discover several more SBBHs.
Reports on Mississippian rostroconchs from the Appalachian basin are rare. Winchell (1871), Herrick (1888, 1890, 1891), Hyde (1953), and Hoare (1990, 2004) discussed taxa from Ohio. These reports concerned pre-Chesterian occurrences with the exception of the Chesterian Bransonia hydei Hoare, 1990 and Oxyprora sp. Hoare (2004) from the Maxville Limestone. Specimens of the new taxon were reported by Busanus (1974) as Conocardium spp. from the Chesterian Reynolds Limestone in northern West Virginia.
Multi-line data of ammonia (NH3) are presented for Maffei 2, IC 342, and the starburst galaxies NGC 253 and M 82. While in M 82 the NH3 emitting gas is cool, presumably arising from well shielded dense cores deeply embedded in an environment dominated by Photon Dominated Regions, the other galaxies show ‘warm’ and ‘hot’ components that may be heated by shocks, ion-slip or cosmic rays. Interferometric observations show the detailed large scale distribution of NH3 in galaxies for the first time. The first multi-line studies of ammonia at significant redshifts (z = 0.65 and 0.89) are also reported and rotational temperatures, measures of the kinetic temperature of the emitting gas, are derived for all sources.
We report new detections of three H2O megamasers and one kilomaser using the Effelsberg 100-m telescope. Isotropic luminosities are ~50, 300, 1, and 230 L⊙ for Mrk 1066, Mrk 34, NGC 3556, and Arp 299, respectively. Mrk 34 contains the most distant H2O megamaser ever detected in a Seyfert. Our targets in this survey were chosen to fit one of the following criteria: 1) to have a high probability of interaction between the radio jet and the ISM within the central few parsecs of the radio galaxy, yielding masers which arise in local molecular clouds; or 2) to have very bright IRAS sources in which massive star forming regions might yield powerful masers. The ‘jet maser’ sources can provide detailed information about the conditions in the ISM in the central 1-10 pc of AGN. The extra-galactic ‘star formation masers’ can be used to pinpoint and characterize locations of high mass star formation in nearby galaxies. In addition, these sources will help to provide a better understanding of the chemical properties of molecular clouds in extra-galactic systems.
It has been observed that a liquid jet impinging on a solid surface can produce splashing. High-speed photography has revealed that, with a turbulent jet, splashing is related to the jet surface roughness. To investigate the importance of the jet shape on splashing, perturbations of known frequency or amplitude are imposed on the surface of a smooth laminar jet.
The top picture shows the unperturbed smooth jet as it spreads radially on the solid surface. The varicose deformations imposed on the jet surface alter the flow quite dramatically (center picture). As we further increase the amplitude of the oscillations, splashing starts suddenly. The bottom picture shows the beauty and complexity of splashing.
Impacting water drops
The four photographs shown here are representative of a series which recorded the structure and evolution of the vorticity generated by a water drop impacting a free surface of water in a container. The 2.8 mm diam water drop was dyed with fluorescein and released from the tip of a hypodermic needle under specific parameters, We=26, Fr=25. The Weber number (ρU2d /γ) and Froude number (U2/gd) are based on drop diameter d, impact velocity U, and surface tension γ.
Figure 1 is photographed from the side and slightly below the free surface while Fig. 2 is shot looking directly up at the free surface via a mirror. These alternative viewing angles provide a valuable tool in visualizing the threedimensional flow structure. A “primary” vortex ring can be seen convecting away from the free surface. A convoluted secondary structure can be seen wrapped around the primary core.
The photographs displayed above show the impact, spreading, and boiling history of n-heptane droplets on a stainless steel surface. The impact velocity, Weber number, and initial droplet diameter are constant (values of 1 m/s, 43 and 1.5 mm respectively), and the view is looking down on the surface at an angle of about 30°. The photographs were taken using a spark flash method and the flash duration was 0.5 μs. The dynamic behavior illustrated in the photographs is a consequence of varying the initial surface temperature.
The effect of surface temperature on droplet shape may be seen by reading across any row; the evolution of droplet shape at various temperatures may be seen by reading down any column. An entrapped air bubble can be seen in the drop when the surface temperature is 24°C. At higher temperatures vigorous bubbling, rather like that of a droplet sizzling on a frying pan, is seen (the boiling point of n-heptane is 98°C) but the bubbles disappear as the Leidenfrost temperature of n-heptane (about 200°C) is exceeded because the droplet become levitated above a cushion of its own vapor and does not make direct contact with the surface. The droplet shape is unaffected by surface temperature in the early stage of the impact process (t≤0.8 ms) but is affected by temperature at later time (cf. t≥ 1.6 ms) because of the progressive influence of intermittent solid-liquid contact as temperature is increased.
ABSTRACT: Coal gasifiers are required to operate at very high temperatures, >1600°C, for long periods of time, > 13 months (10,000 hours) Fig.1. Under these conditions the refractory lining of choice is high chrome refractory. During operation coal contaminants form a liquid slag that run down the chamber walls which can react with the refractory walls. Albany Research Center has designed a series of experiments to understand the slag-refractory interactions, with the intent of eventually being able to reduce or minimize the problem and thereby extending the gasifier operation time before relining. To understand the slag-refractory interaction, elemental components of the slag have been allowed to react with the refractory under simulated gasifying conditions. The interactions have been characterized using X-ray diffraction, electron microscopy, elemental x-ray mapping, and quantitative microanalysis.
Eukaryotic translation initiation factor 4A (eIF4A)
has been proposed to use the energy of ATP hydrolysis to
remove RNA structure in the 5′ untranslated region
(UTR) of mRNAs, helping the 43S ribosomal complex bind
to an mRNA and scan to find the 5′-most AUG initiator
codon. We have examined the effect of changing the atomic
composition and length of single-stranded oligonucleotides
on binding to eIF4A and on stimulation of its ATPase activity
once bound. Substitution of 2′-OH groups with 2′-H
or 2′-OCH3 groups reduces ATPase stimulation
at least 100-fold, to background levels, without significantly
affecting oligonucleotide affinity. These effects suggest
that 2′-OH groups participate in an eIF4A conformational
change that occurs subsequent to oligonucleotide binding
and is required for ATPase stimulation. Replacing nonbridging
oxygen atoms in phosphodiester linkages with sulfur atoms
to make phosphorothioate linkages has no significant effect
on stimulation, while substantially increasing affinity.
Extending the length of an RNA oligonucleotide from 4 to
∼15 nt gradually increases oligonucleotide affinity
and ATPase stimulation. Consistent with this observation,
the increase in affinity and stimulation provided by phosphorothioate
linkages and 2′-OH groups is proportional to the
number of these groups present within larger oligonucleotides.
Further, changing the position of blocks of phosphorothioate
linkages or 2′-OH groups within a larger oligonucleotide
does not affect affinity and has only a small effect on
stimulation. These observations suggest that numerous interactions
between the oligonucleotide and eIF4A contribute individually
to binding and ATPase stimulation. Nevertheless, significant
stimulation is observed with as few as four RNA residues.
These properties may allow eIF4A to operate within regions
of 5′ UTRs containing only short stretches of exposed
single-stranded RNA. As stimulation increases when longer
stretches of single-stranded RNA are available, it is possible
that the accessibility of single-stranded RNA in a 5′
UTR influences translation efficiency.