A synopsis of the milliped genus Abacion Rafinesque (Callipodida: Caspiopetalidae)

1984 ◽  
Vol 62 (5) ◽  
pp. 980-988 ◽  
Author(s):  
Rowland M. Shelley

The milliped genus Abacion is summarized, and tesselatum Rafinesque, lactarium (Say), magnum (Loomis), and texense (Loomis) are recognized as valid species even though a low level of gene interchange may be occurring between tesselatum and magnum in coastal Georgia and tesselatum and lactarium in Illinois. Geographic races do not appear to be developing in any species, and all other species group names are relegated to appropriate synonymies. Abacion occurs widely in the eastern half of the United States, from the Atlantic Ocean to the central Great Plains and from the Great Lakes to southern Florida and northeastern Mexico. Species ranges overlap broadly, and instances of sympatry and syntopy are common. The species are similar anatomically, and the most reliable taxonomic characters are found on the male gonopods, particularly the configurations of the coxal processes and the distal elements of the telopodites.

2015 ◽  
Vol 28 (19) ◽  
pp. 7518-7528 ◽  
Author(s):  
Noah Knowles

Abstract Trend tests, linear regression, and canonical correlation analysis were used to quantify changes in National Weather Service Cooperative Observer (COOP) snow depth data and derived quantities, precipitation, snowfall, and temperature over the study period 1950–2010. Despite widespread warming, historical trends in snowfall and snow depth are generally mixed owing to competing influences of trends in precipitation. Trends toward later snow-cover onset in the western half of the conterminous United States and earlier onset in the eastern half and a widespread trend toward earlier final meltoff of snow cover combined to produce trends toward shorter snow seasons in the eastern half of the United States and in the west and longer snow seasons in the Great Plains and southern Rockies. The annual total number of days with snow cover exhibited a widespread decline. Monthly trend patterns show the dominant influence of temperature trends on occurrence of snow cover in the warmer snow-season months and a combination of temperature and precipitation trends in the colder months. A canonical correlation analysis indicated that most trends presented here took hold in the 1970s, consistent with the temporal pattern of global warming during the study period.


2019 ◽  
Vol 20 (5) ◽  
pp. 833-846 ◽  
Author(s):  
Jordan I. Christian ◽  
Jeffrey B. Basara ◽  
Jason A. Otkin ◽  
Eric D. Hunt ◽  
Ryann A. Wakefield ◽  
...  

Abstract With the increasing use of the term “flash drought” within the scientific community, Otkin et al. provide a general definition that identifies flash droughts based on their unusually rapid rate of intensification. This study presents an objective percentile-based methodology that builds upon that work by identifying flash droughts using standardized evaporative stress ratio (SESR) values and changes in SESR over some period of time. Four criteria are specified to identify flash droughts: two that emphasize the vegetative impacts of flash drought and two that focus on the rapid rate of intensification. The methodology was applied to the North American Regional Reanalysis (NARR) to develop a 38-yr flash drought climatology (1979–2016) across the United States. It was found that SESR derived from NARR data compared well with the satellite-based evaporative stress index for four previously identified flash drought events. Furthermore, four additional flash drought cases were compared with the U.S. Drought Monitor (USDM), and SESR rapidly declined 1–2 weeks before a response was evident with the USDM. From the climatological analysis, a hot spot of flash drought occurrence was revealed over the Great Plains, the Corn Belt, and the western Great Lakes region. Relatively few flash drought events occurred over mountainous and arid regions. Flash droughts were categorized based on their rate of intensification, and it was found that the most intense flash droughts occurred over the central Great Plains, Corn Belt, and western Great Lakes region.


2018 ◽  
Vol 57 (2) ◽  
pp. 319-331 ◽  
Author(s):  
David Changnon

AbstractHeavy 30-day snowfall amounts were evaluated to identify spatial and temporal characteristics east of the Rocky Mountains in the United States during the period 1900–2016. An extensive data assessment identified 507 stations for use in this long-term climate study. The top 30-day heavy snowfall amount and the average of the top five 30-day heavy snowfall amounts were examined. Both amounts generally increased with latitude; however, much higher amounts were found downwind of the Great Lakes, at higher elevations, or in locations impacted by topographic features (e.g., Rockies, Black Hills, and Appalachians). When compared with the 1981–2010 average winter snowfall, the top 30-day amount was found to be greater than the winter average in most areas of the eastern United States. The number of stations experiencing a top-five 30-day heavy snowfall period in a winter ranged from 1 to 128 (1959/60), with a greater overall occurrence in the second half of the 117-yr period. Six episodes had 10% or more stations experiencing one of the top five 30-day snowfall amounts, with the February–March 1960 episode impacting 124 stations, and these episodes were associated with large negative 500-hPa height anomalies. The northern Great Plains, Great Lakes, Midwest, and Northeast experienced more top-five periods in the second half of the 117-yr period, whereas most of the southern states experienced top-five periods throughout the study’s time frame. Examining extremes at periods beyond the daily event and less than the season contributes to our knowledge of climate and provides useful information to snow-sensitive sectors.


Author(s):  
Thomas M. Onuferko

The cleptoparasitic bee genus Epeolus Latreille, 1802 is for the first time reviewed for species occurring in the Caribbean, Central America and Mexico, and a single dichotomous identification key to the females and males of species present or likely to be present in these regions is presented. A total of 25 species have been confirmed as present across the region, although another 10 likely occur south of the Mexico–United States border. Three species are newly described—E. hanusiae sp. nov., E. nomadiformis sp. nov. and E. odyneroides sp. nov.—and redescriptions are provided for species occurring exclusively south of the United States of America (species occurring north of Mexico were recently revised elsewhere) except E. danieli (Genaro, 2014) comb. nov., which was recently described. One subspecies is elevated to species level (E. obscuripes Cockerell, 1917 stat. nov.). The following five names are newly synonymized under those of four valid species: Trophocleptria schraderi Michener, 1954 syn. nov. under E. boliviensis Friese, 1908, Tro. odontothorax Michener, 1954 syn. nov. under E. claripennis Friese, 1908, E. rugosus Cockerell, 1949 syn. nov. and E. xanthurus Cockerell, 1917 syn. nov. under E. luteipennis Friese, 1916, and E. schmidti Friese, 1925 syn. nov. under E. obscuripes. A diagnosis is provided for the presumably monophyletic and almost entirely Neotropical species group originally regarded as a separate genus, Trophocleptria Holmberg, 1886. Differential diagnoses accompany the descriptions / redescriptions of Neotropical species of Epeolus, and known collection records and information about their ecology are presented.


Author(s):  
Anthony DeAngelis ◽  
Francina Dominguez ◽  
Ying Fan ◽  
Alan Robock ◽  
M. Deniz Kustu ◽  
...  

Author(s):  
Sarah L. Jackson ◽  
Sahar Derakhshan ◽  
Leah Blackwood ◽  
Logan Lee ◽  
Qian Huang ◽  
...  

This paper examines the spatial and temporal trends in county-level COVID-19 cases and fatalities in the United States during the first year of the pandemic (January 2020–January 2021). Statistical and geospatial analyses highlight greater impacts in the Great Plains, Southwestern and Southern regions based on cases and fatalities per 100,000 population. Significant case and fatality spatial clusters were most prevalent between November 2020 and January 2021. Distinct urban–rural differences in COVID-19 experiences uncovered higher rural cases and fatalities per 100,000 population and fewer government mitigation actions enacted in rural counties. High levels of social vulnerability and the absence of mitigation policies were significantly associated with higher fatalities, while existing community resilience had more influential spatial explanatory power. Using differences in percentage unemployment changes between 2019 and 2020 as a proxy for pre-emergent recovery revealed urban counties were hit harder in the early months of the pandemic, corresponding with imposed government mitigation policies. This longitudinal, place-based study confirms some early urban–rural patterns initially observed in the pandemic, as well as the disparate COVID-19 experiences among socially vulnerable populations. The results are critical in identifying geographic disparities in COVID-19 exposures and outcomes and providing the evidentiary basis for targeting pandemic recovery.


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