Reversed halo sign on CT as a presentation of lymphocytic interstitial pneumonia.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.A 52 year-old African American female with a past medical history of symptomatic uterine fibroids and increasing abdominal circumference underwent abdominal computed tomography (CT) as part of her workup. Because of an abnormality in the left lower lobe, CT of the chest was subsequently performed and showed a focal region of discontinuous crescentic consolidation with central ground glass opacification in the right lower lobe, suggestive of the reversed halo sign. The patient underwent percutaneous CT-guided core biopsy of the lesion, which demonstrated lymphocytic interstitial pneumonia, a benign lymphoproliferative disease characterized histologically by small lymphocytes and plasma cells. This case report describes the first histologically confirmed presentation of lymphocytic interstitial pneumonia with the reversed halo sign on CT

Potential Minimum Threshold for Pallid Sturgeon Relative Condition in the Lower Missouri River

Pallid Sturgeon (Scaphirhynchus albus) condition has declined in the lower Missouri River but the cause and the effects of this decline remain uncertain. Adult Pallid Sturgeon are becoming reproductively ready less frequently and sub-adult Pallid Sturgeon are likely delaying sexual maturation. Even more concerning, Pallid Sturgeon capture rates have declined the past two years (i.e., 2016 and 2017), despite the ongoing Pallid Sturgeon stocking program. Several Pallid Sturgeon that have been captured are visually emaciated but a minimum condition threshold has not been described. Therefore, the aim of this study is to present a potential lethal condition level for adult Pallid Sturgeon in the lower Missouri River then determine the capture frequency of Pallid Sturgeon below this assumed minimum condition threshold to test the validity of this hypothesis. Based on the mortality of an individual female adult Pallid Sturgeon held in captivity, mortality occurred when condition was 0.71. This potential minimum threshold is further supported with very few adult Pallid Sturgeon captured below this predicted minimum threshold. Using the minimum condition threshold established here to continue monitoring the Pallid Sturgeon population and the occurrence of individuals below this condition level could help managers better address factors hindering Pallid Sturgeon recovery

Population Characteristics, Development of a Predictive Population Viability Model, and Catch Dynamics for Pallid Sturgeon in the Lower Missouri River

Population characteristics and long-term population trends of pallid sturgeon Scaphirhynchus albus in the lower Missouri River are relatively unknown. As recovery efforts continue, understanding and quantifying these characteristics and trends are critical for species recovery and future management decisions. Therefore, the objectives of this study were to determine the pallid sturgeon population characteristics, predict changes to the pallid sturgeon population based on different management and life history scenarios, and examine trot line catch dynamics in the lower Missouri River. Catch rates for pallid sturgeon collected with gill nets did not significantly change while catch rates using trot lines significantly declined for wild pallid sturgeon (P=0.0001) but did not differ among years for hatchery-reared fish (P=0.0610). The proportion of reproductively ready females to non-reproductively ready females was 1:2.0, compared to the male ratio of 1:0.9. The minimum female length-at-maturity was 788 mm and 798 mm for males while the minimum age-at-maturity for known aged hatchery-reared fish was age-9 for females and age-7 for males. The mean relative fecundity was 7%. Our population viability model was most sensitive to ≥age-1 survival rates. Fluctuating female spawning frequency by one year had minimal effect on the overall population growth and age-at-maturity was less sensitive than spawning frequency. Catch per unit effort was 14.6 fish per trot line rigged with hook timers to study the catch dynamics; however, several hook timers were activated but did not capture a fish. Therefore, the corrected CPUE was 17.7 fish per line with over half of the hook timer activations occurring 4-h post-deployment. Detecting shifts in population characteristics is essential for understanding population dynamics as hatchery inputs and natural perturbations continue to change the population structure. Barring any unforeseen natural catastrophes, the pallid sturgeon population in the lower Missouri River is not in immediate danger of local extirpation; however, the population appears to be a far from viable nor self-sustaining. Advisor: Mark A. Peg

Population Characteristics, Development of a Predictive Population Viability Model, and Catch Dynamics for Pallid Sturgeon in the Lower Missouri River

Population characteristics and long-term population trends of pallid sturgeon Scaphirhynchus albus in the lower Missouri River are relatively unknown. As recovery efforts continue, understanding and quantifying these characteristics and trends are critical for species recovery and future management decisions. Therefore, the objectives of this study were to determine the pallid sturgeon population characteristics, predict changes to the pallid sturgeon population based on different management and life history scenarios, and examine trot line catch dynamics in the lower Missouri River. Catch rates for pallid sturgeon collected with gill nets did not significantly change while catch rates using trot lines significantly declined for wild pallid sturgeon (P=0.0001) but did not differ among years for hatchery-reared fish (P=0.0610). The proportion of reproductively ready females to non-reproductively ready females was 1:2.0, compared to the male ratio of 1:0.9. The minimum female length-at-maturity was 788 mm and 798 mm for males while the minimum age-at-maturity for known aged hatchery-reared fish was age-9 for females and age-7 for males. The mean relative fecundity was 7%. Our population viability model was most sensitive to ≥age-1 survival rates. Fluctuating female spawning frequency by one year had minimal effect on the overall population growth and age-at-maturity was less sensitive than spawning frequency. Catch per unit effort was 14.6 fish per trot line rigged with hook timers to study the catch dynamics; however, several hook timers were activated but did not capture a fish. Therefore, the corrected CPUE was 17.7 fish per line with over half of the hook timer activations occurring 4-h post-deployment. Detecting shifts in population characteristics is essential for understanding population dynamics as hatchery inputs and natural perturbations continue to change the population structure. Barring any unforeseen natural catastrophes, the pallid sturgeon population in the lower Missouri River is not in immediate danger of local extirpation; however, the population appears to be a far from viable nor self-sustaining. Advisor: Mark A. Peg

Mechanisms explaining transitions between tonic and phasic firing in neuronal populations as predicted by a low dimensional firing rate model

Several firing patterns experimentally observed in neural populations have been successfully correlated to animal behavior. Population bursting, hereby regarded as a period of high firing rate followed by a period of quiescence, is typically observed in groups of neurons during behavior. Biophysical membrane-potential models of single cell bursting involve at least three equations. Extending such models to study the collective behavior of neural populations involves thousands of equations and can be very expensive computationally. For this reason, low dimensional population models that capture biophysical aspects of networks are needed. \noindent The present paper uses a firing-rate model to study mechanisms that trigger and stop transitions between tonic and phasic population firing. These mechanisms are captured through a two-dimensional system, which can potentially be extended to include interactions between different areas of the nervous system with a small number of equations. The typical behavior of midbrain dopaminergic neurons in the rodent is used as an example to illustrate and interpret our results. \noindent The model presented here can be used as a building block to study interactions between networks of neurons. This theoretical approach may help contextualize and understand the factors involved in regulating burst firing in populations and how it may modulate distinct aspects of behavior.Comment: 25 pages (including references and appendices); 12 figures uploaded as separate file

The Status of Fishes in the Missouri River, Nebraska: Lake Sturgeon \u3ci\u3e(Acipenser fulvescens)\u3c/i\u3e

Lake Sturgeon (Acipenser fulvescens) occurrences in the Missouri River along Nebraska’s eastern border are historically sporadic and rare. Presently, the wild Lake Sturgeon population in this river reach may be extirpated. A Recovery Program initiated by the Missouri Department of Conservation (MDC) has stocked almost 150,000 hatchery-reared Lake Sturgeon into the lower Missouri River at several sites in Missouri. As a result, the number of Lake Sturgeon collected has increased. Since monitoring began in 2003, no Lake Sturgeon have been collected above Gavins Point Dam while 40 fish were collected downstream of Gavins Point Dam. The majority of captures occurred in the lower channelized reach downstream of the confluence of the Platte and Missouri rivers. All fish collected are assumed to be progeny of MDC’s Recovery Program as either they were hatchery marked or their size (mean fork length = 764 mm, range = 602–997 mm) correlated with the expected growth rates. At present, their rarity warrants continued listing as a state threated species

The Status of Fishes in the Missouri River, Nebraska: Lake Sturgeon \u3ci\u3e(Acipenser fulvescens)\u3c/i\u3e

Lake Sturgeon (Acipenser fulvescens) occurrences in the Missouri River along Nebraska’s eastern border are historically sporadic and rare. Presently, the wild Lake Sturgeon population in this river reach may be extirpated. A Recovery Program initiated by the Missouri Department of Conservation (MDC) has stocked almost 150,000 hatchery-reared Lake Sturgeon into the lower Missouri River at several sites in Missouri. As a result, the number of Lake Sturgeon collected has increased. Since monitoring began in 2003, no Lake Sturgeon have been collected above Gavins Point Dam while 40 fish were collected downstream of Gavins Point Dam. The majority of captures occurred in the lower channelized reach downstream of the confluence of the Platte and Missouri rivers. All fish collected are assumed to be progeny of MDC’s Recovery Program as either they were hatchery marked or their size (mean fork length = 764 mm, range = 602–997 mm) correlated with the expected growth rates. At present, their rarity warrants continued listing as a state threated species

Relationships between synoptic-scale transport and interannual variability of inorganic cations in surface snow at Summit, Greenland: 1992-1996

Version of RecordTo fully utilize the long-term chemical records retrieved from central Greenland ice cores, specific relationships between atmospheric circulation and the variability of chemical species in the records need to be better understood. This research examines associations between the variability of surface snow inorganic cation chemistry at Summit, Greenland (collected during 1992-1996 summer field seasons) and changes in air mass transport pathways and source regions, as well as variations in aerosol source strength. Transport patterns and source regions are determined through 10-day isentropic backward air mass trajectories during a 1 month (late May to late June) common season over the 5 years. Changes in the extent of exposed continental surfaces in source regions are evaluated to estimate aerosol-associated calcium and magnesium ion source strength, while forest fire activity in the circumpolar north is investigated to estimate aerosol ammonium ion source strength. During the 1995 common season, 3 times more calcium and magnesium accumulated in the snowpack than the other study years. Also, an increasing trend of ammonium concentration was noted throughout the 5 years. Anomalous transport pathways and velocities were observed during 1995, which likely contributed to the high levels of calcium and magnesium. Increased forest fire activity in North America was concurrent with increased levels of ammonium and potassium, except for 1996, when ion levels were above average and forest fire activity was below average. Because of the ubiquitous nature of soluble ions, we conclude that it is very difficult to establish a quantitative link between the ion content of snow and firn at Summit and changes in aerosol source regions and source strength.Slater, J. F., Dibb, J. E., Keim, B. D., & Kahl, J. D. w. (2001). Relationships between synoptic-scale transport and interannual variability of inorganic cations in surface snow at Summit, Greenland: 1992-1996. Journal of Geophysical Research 106(D18), 20,897-20,91