Dissolved oxygen dynamics in the Mid‐Passaic River: Late summer/early fall 1983–4 field studies

1988 ◽  
Vol 23 (6) ◽  
pp. 525-542 ◽  
Author(s):  
Christopher G. Uchrin ◽  
William K. Ahlert ◽  
Arthur P. Cryan ◽  
Janis V. Giga ◽  
Shing‐Fu Hsueh ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Late Summer ◽  
Field Studies ◽  
Passaic River ◽  
Early Fall ◽  
Oxygen Dynamics

scholarly journals Decrease in Enteroviral Meningitis - An Unexpected Benefit of COVID-19 Mitigation?

2020 ◽  
Author(s):  
Kami D Kies ◽  
Amber S Thomas ◽  
Matthew J Binnicker ◽  
Kelli L Bashynski ◽  
Robin Patel
Keyword(s):  
Cerebrospinal Fluid ◽  
Laboratory Testing ◽  
Clinical Microbiology ◽  
Late Summer ◽  
Mitigation Strategies ◽  
Clinical Microbiology Laboratory ◽  
Microbiology Laboratory ◽  
Testing Data ◽  
Early Fall ◽  
Enteroviral Meningitis

Abstract Enteroviral meningitis is seasonal, typically exhibiting a rise in prevalence in late summer/early fall. Based on clinical microbiology laboratory testing data of cerebrospinal fluid, the expected August/September/October peak in enteroviral meningitis did not occur in 2020, possibly related to COVID-19 mitigation strategies.

A study of water quality in an urban river and potential improvement using a prototype instream aerator

1989 ◽  
Vol 16 (3) ◽  
pp. 308-316 ◽  
Author(s):  
C. A. Town ◽  
D. S. Mavinic ◽  
B. Moore
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Data Base ◽  
Chlorophyll A ◽  
Late Summer ◽  
Urban River ◽  
Agricultural Activity ◽  
Fish Kills ◽  
Low Dissolved Oxygen ◽  
Oxygen Levels

Urban encroachment and intensive agricultural activity within the Serpentine–Nicomekl watershed (near Vancouver, B.C.) have caused a series of fish (salmon) kills on the Serpentine River since 1980. Low dissolved oxygen was responsible for these kills. This field project investigated some of the dynamic chemical and biological relationships within the river, as well as the use of an instream aerator as a temporary, in situ, water quality improvement measure. Weekly sampling for a 6-month period during the latter half of 1985 established a solid data base for deriving and interpreting meaningful interrelationships. A strong correlation between chlorophyll a and dissolved oxygen levels before the algae die-off supported the hypothesis that algae blooms dying in the fall could create a serious oxygen demand. Because of these environmental conditions, the river is unable to sustain healthy dissolved oxygen levels during this period. As such, a prototype, 460 m artificial aeration line was designed, installed, and monitored to evaluate its potential for alleviating low dissolved oxygen conditions and improving overall water quality during the critical fall period.The instream aerator ran continuously for over 2 months, starting in September 1985. Despite better-than-expected weather conditions (i.e., cool, wet weather) and relatively high dissolved oxygen levels during the fall of 1985, the data base appeared to support the use of this prototype aeration unit as a means of "upgrading" a stretch of an urban river subject to periodic, low dissolved oxygen levels. As a result, a 2-year follow-up study and river monitoring was initiated. In both 1986 and 1987, late summer and early fall river conditions resulted in the potential for serious salmon kills, due to higher-than-normal river temperatures and very low dissolved oxygen. In both instances, the instream aerator prevented such fish kills in a key stretch of the river. Expansion of the system to include other critical stretches of the Serpentine and other urban river systems, near Vancouver, is being considered. Key words: algae, aerator, chlorophyll a, eutrophic, fish kills, instream aeration, river improvement, urban river.

scholarly journals A biodiversity hotspot for Microgastrinae (Hymenoptera, Braconidae) in North America: annotated species checklist for Ottawa, Canada

ZooKeys ◽  
2016 ◽  
Vol 633 ◽  
pp. 1-93 ◽  
Author(s):  
Jose Fernandez-Triana ◽  
Caroline Boudreault ◽  
Joel Buffam ◽  
Ronald Maclean
Keyword(s):  
North America ◽  
General Pattern ◽  
Late Summer ◽  
The United States ◽  
Early Summer ◽  
Individual Species ◽  
Early Fall ◽  
Two Peaks ◽  
Annotated Checklist ◽  
First Time

Microgastrinae wasps (Hymenoptera, Braconidae) from the city of Ottawa and its surroundings (a 50-km radius circle, ~7,800 km2) were studied based on 1,928 specimens collected between 1894 and 2010, and housed in the Canadian National Collection of Insects. A total of 158 species from 21 genera were identified, which is by far the highest number of species ever recorded for a locality in North America. An annotated checklist of species is provided.Choerasparasitellae(Bouché, 1834) andPholetesornanus(Reinhard, 1880) are recorded for the first time in the Nearctic (previously only known from the Palearctic region),Cotesiadepressa(Viereck, 1912) is recorded for the first time in Canada (previously only known from the United States), andCotesiahemileucae(Riley, 1881) andProtapantelesphlyctaeniae(Muesebeck, 1929) are recorded for the first time in the province of Ontario. In Ottawa the most diverse genera areCotesia,Apanteles,Microplitis,Pholetesor,Microgaster, andDolichogenidea, altogether comprising 77% of the species found in the area. A total of 73 species (46%) were represented by only one or two specimens, suggesting that the inventory for Ottawa is still relatively incomplete. Seasonal distribution showed several peaks of activity, in spring, summer, and early fall. That general pattern varied for individual species, with some showing a single peak of abundance either in the summer or towards the end of the season, others species attaining two peaks, in late spring and late summer, or in early summer and early fall, and yet others attaining up to three different peaks, in spring, summer and fall. At least 72 of the Microgastrinae species from Ottawa have been previously associated with 554 species of Lepidoptera as hosts – but those historical literature records are not always reliable and in many cases are based on data from areas beyond Ottawa. Thus, our knowledge of the associations between the 158 species of microgastrine parasitoids and the caterpillars of the 2,064 species of Lepidoptera recorded from Ottawa is still very incomplete.

scholarly journals Changes in historical typhoid transmission across 16 U.S. cities, 1889-1931: Quantifying the impact of investments in water and sewer infrastructures

2019 ◽  
Author(s):  
Maile T. Phillips ◽  
Katharine A. Owers ◽  
Bryan T. Grenfell ◽  
Virginia E. Pitzer
Keyword(s):  
Late Summer ◽  
Water Source ◽  
Developed Countries ◽  
The United States ◽  
Water And Sanitation ◽  
Sewer Systems ◽  
Early Fall ◽  
Sanitation Systems ◽  
The Impact

ABSTRACTBackgroundInvestments in water and sanitation systems are believed to have led to the decline in typhoid fever in developed countries, such that most cases now occur in regions lacking adequate clean water and sanitation. Exploring seasonal and long-term patterns in historical typhoid mortality in the United States can offer deeper understanding of disease drivers.MethodsWe fit modified Time-series Susceptible-Infectious-Recovered models to city-level weekly mortality counts to estimate seasonal and long-term typhoid transmission. We examined seasonal transmission separately by city and aggregated by water source. We fit regression models to measure associations between long-term transmission and financial investments in water and sewer systems.ResultsTyphoid transmission peaked in late summer/early fall. Seasonality varied by water source, with the greatest variation occurring in cities with reservoirs. Historical $1 per capita ($25.80 in 2017) investments in construction and operation of water and sewer systems were associated with 8-53% decreases in typhoid transmission, while $1 increases in total value or debt accrued to maintain them were associated with 4-7% decreases.ConclusionOur findings aid in the understanding of typhoid transmission dynamics and potential impacts of water and sanitation improvements, and can inform cost-effectiveness analyses of interventions to reduce the typhoid burden.

Macroinfauna of Northern New England marine sand. IV. Infaunal ecology of Amphiporeia virginiana Shoemaker, 1933 (Crustacea: Amphipoda)

1979 ◽  
Vol 57 (8) ◽  
pp. 1511-1519 ◽  
Author(s):  
Richard P. Hager ◽  
Robert A. Croker
Keyword(s):  
South Carolina ◽  
New England ◽  
Late Summer ◽  
Fine Sand ◽  
High Energy ◽  
Breeding Period ◽  
Population Fluctuations ◽  
Marine Sand ◽  
Annual Population ◽  
Early Fall

Amphiporeia virginiana occurs from Nova Scotia to South Carolina where it is a dominant inhabitant of high energy sand beaches. Maximum abundance occurs on the lower foreshore in fine sand particularly during summer months. Within-habitat segregation of sexes occurs, with females more abundant at higher beach levels; ovigerous females are confined to higher levels only. Annual population fluctuations of up to 14-fold on a geometric basis are related to life history events and sedimentary changes. Breeding occurs during most of the year with peak recruitment during June and late summer to early fall, yielding summer and overwintering generations. Precopulating animals are commonly seen swimming, with two males per female occasionally evident. Females produce a mean of 6–11 eggs during the year and have one brood per breeding period. The species is a detritivore and generally inhabits the upper 2.5 cm of sand. It is most tolerant of salinities in the range of 25–35‰; mortality increases rapidly in salinities less than 20‰, and in sediments containing less than 11% water by weight exposed to temperatures simulating hot summer days.

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