In the eastern United States, the practice of salvage logging is common to reclaim economic losses and/or reduce fuel loading following a natural disturbance. A current hypothesis states that two ...disturbances in rapid succession (i.e., compounded disturbance) have a cumulative severity of impact and may displace the successional trajectory further than either disturbance occurring separately. On 20 April 2011, Bankhead National Forest in Alabama was affected by an EF1 tornado with accompanying straight-line winds. Much of the damage was salvaged, however adjacent disturbance in a Wilderness Area was not harvested. A unique set of conditions allowed for comparisons of woody regeneration within a single stand, reducing uncontrolled variables to test the compounded disturbance hypothesis at a fine spatial scale. After two growing seasons, species richness, species evenness, and Shannon diversity of seedlings and saplings did not significantly differ by disturbance class. We found seedling density significantly differed between functional groups and we noted a significant interaction between functional groups and disturbance classes. In the sapling layer, density was significantly different among functional groups and among disturbance classes, but our results did not reveal a significant interaction between these factors. The wind disturbance accelerated succession in the Quercus stand toward dominance by shade-tolerant species, notably A. rubrum, and the salvage operation amplified the Quercus-to-Acer transition. However, even in wind-disturbed areas that were not salvaged, the regeneration model predicted A. rubrum to have more than twice the density of all combined Quercus species in the future stand.
BACKGROUNDThe quantitative assessment of supraspinatus tendons by conventional magnetic resonance is limited by low contrast-to-noise ratio (CNR). Magnetic resonance imaging (MRI) scanners operating ...at 7 Tesla offer high signal-to noise ratio (SNR), low CNR and high spatial resolution that are well-suited for rapidly relaxing tissues like tendons. Few studies have applied T2 and T2* mapping to musculoskeletal imaging and to the rotator cuff tendons. Our objective was to analyze the T2 and T2* relaxation times from surgically repaired supraspinatus tendons and the effect of bone channeling. METHODSOne supraspinatus tendon of 112 adult female New Zealand white rabbits was surgically detached and repaired one week later. Rabbits were randomly assigned to channeling (n=64) or control (n=48) groups and harvested at 0, 1, 2, and 4 weeks. A 7T magnet was used for signal acquisition. For T2 mapping, a sagittal multi slice 2D multi-echo spin-echo (MESE) CPMG sequence with fat saturation was applied and T2* mapping was performed using a 3D UTE sequence. Magnetic resonance images from supraspinatus tendons were analyzed by two raters. Three regions of interest were manually drawn on the first T2-weighted dataset. For T2 and T2*, different ROI masks were generated to obtain relaxation times. RESULTST2-weighted maps but not T2*-weighted maps generated reliable signals for relaxation time measurement. Torn supraspinatus tendons had lower T2 than controls at the time of repair (20.0±3.4 vs. 25.6±3.9 ms; P<0.05). T2 increased at 1, 2 and 4 postoperative weeks: 22.7±3.1, 23.3±3.9 and 24.0±5.1 ms, respectively, and values were significantly different from contralateral supraspinatus tendons (24.8±3.1; 26.8±4.3 and 26.5±3.6 ms; all P<0.05). Bone channeling did not affect T2 (P>0.05). CONCLUSIONSSupraspinatus tendons detached for 1 week had shorter T2 relaxation time compared to contralateral as measured with 7T MRI.
The goal in the management of primary open-angle glaucoma is to effectively lower IOP with the least invasive approach. ...the micro-invasive glaucoma surgeries are becoming more popular. Another ...study was performed evaluating Xen gel stent implantation in conjunction with cataract surgery (Sheybani). Lavin-Dapena C, et al. 12-month results from a minimally invasive, 45 ^m lumen ab interno gelatin stent in combination with a preoperative MMC from a multicenter study conducted in Spain.
The first ever case of Middle East Respiratory Syndrome Coronavirus (MERSCoV) was reported in September 2012. This report describes the approaches taken by CDC, in collaboration with the World Health ...Organization (WHO) and other partners, to respond to this novel virus, and outlines the agency responses prior to the first case appearing in the United States in May 2014. During this time, CDC's response integrated multiple disciplines and was divided into three distinct phases: before, during, and after the initial activation of its Emergency Operations Center. CDC's response to MERS-CoV required a large effort, deploying at least 353 staff members who worked in the areas of surveillance, laboratory capacity, infection control guidance, and travelers' health. This response built on CDC's experience with previous outbreaks of other pathogens and provided useful lessons for future emerging threats.
PDF
