Effects of hot and cold temperatures on the survival of oospores produced by United States strains ofPhytophthora infestans

1997 ◽  
Vol 74 (5) ◽  
pp. 315-323 ◽  
Author(s):  
Justin C. Fay ◽  
William E. Fry
Keyword(s):  
United States ◽  
Cold Temperatures

scholarly journals Tornadoes with Cold Core 500-mb Lows

2006 ◽  
Vol 21 (6) ◽  
pp. 1051-1062 ◽  
Author(s):  
Jonathan M. Davies
Keyword(s):  
United States ◽  
Severe Weather ◽  
Surface Heating ◽  
Vertical Shear ◽  
Cold Temperatures ◽  
Low Level ◽  
Close Proximity ◽  
Central United States ◽  
Surface Patterns ◽  
Cold Core

Abstract Tornadoes that occur in close proximity to midlevel closed lows with a core of cold temperatures aloft are not uncommon, particularly in the central United States. Although several informal studies have shown that severe weather and tornadoes can occur with these midlevel lows, little in the way of formal work has been published documenting features and ingredients of such systems, especially those that produce what are sometimes called cold core tornadoes. Of particular concern is that these tornadoes can be associated with surface and low-level moisture that appears deceptively small or marginal regarding severe weather potential, yet on occasion tornadoes of F2 or greater intensity can develop. In other cases, vertical shear may appear relatively weak at locations close to the midlevel low, suggesting little potential for tornadoes. These “atypical” characteristics can result in poor anticipation by forecasters of tornado events associated with closed 500-mb lows. This note documents some synoptic and mesoscale features commonly associated with tornado events in close proximity to cold core 500-mb lows using four tornadic cases in Kansas as examples, including photographs to show the small nature of storms associated with such systems. Recognition of surface patterns with a particular organization of boundaries and surface heating positioned near midlevel lows, along with the presence of some amount of buoyancy, can help with the operational awareness of the potential for tornadoes in many 500-mb closed low settings.

scholarly journals The Influence of Atmospheric Blocking on Extreme Winter Minimum Temperatures in North America

2016 ◽  
Vol 29 (12) ◽  
pp. 4361-4381 ◽  
Author(s):  
Kirien Whan ◽  
Francis Zwiers ◽  
Jana Sillmann
Keyword(s):  
United States ◽  
North America ◽  
Extreme Events ◽  
Climate Models ◽  
Primary Source ◽  
The United States ◽  
Climate Projections ◽  
Cold Temperatures ◽  
Climate Conditions ◽  
The Difference

Abstract Regional climate models (RCMs) are the primary source of high-resolution climate projections, and it is of crucial importance to evaluate their ability to simulate extreme events under current climate conditions. Many extreme events are influenced by circulation features that occur outside, or on the edges of, RCM domains. Thus, it is of interest to know whether such dynamically controlled aspects of extremes are well represented by RCMs. This study assesses the relationship between upstream blocking and cold temperature extremes over North America in observations, reanalysis products (ERA-Interim and NARR), and RCMs (CanRCM4, CRCM5, HIRHAM5, and RCA4). Generalized extreme value distributions were fitted to winter minimum temperature (TNn) incorporating blocking frequency (BF) as a covariate, which is shown to have a significant influence on TNn. The magnitude of blocking influence in the RCMs is consistent with observations, but the spatial extent varies. CRCM5 and HIRHAM5 reproduce the pattern of influence best compared to observations. CanRCM4 and RCA4 capture the influence of blocking in British Columbia and the northeastern United States, but the extension of influence that is seen in observations and reanalysis into the southern United States is not evident. The difference in the 20-yr return value (20RV) of TNn between high and low BF in the Pacific Ocean indicates that blocking is associated with a decrease of up to 15°C in the 20RV over the majority of the United States and in western Canada. In northern North America the difference in the 20RV is positive as blocking is associated with warmer extreme cold temperatures. The 20RVs are generally simulated well by the RCMs.

scholarly journals First Report on Establishment of Laricobius osakensis (Coleoptera: Derodontidae), a Biological Control Agent for Hemlock Woolly Adelgid, Adelges tsugae (Hemiptera: Adelgidae), in the Eastern U.S.

Forests ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 496 ◽  
Author(s):  
Ashley Toland ◽  
Carlyle Brewster ◽  
Katlin Mooneyham ◽  
Scott Salom
Keyword(s):  
United States ◽  
Biological Control ◽  
Biological Control Agent ◽  
Polar Vortex ◽  
Hemlock Woolly Adelgid ◽  
Control Agent ◽  
Adelges Tsugae ◽  
Eastern United States ◽  
Cold Temperatures ◽  
Eastern Usa

The hemlock woolly adelgid (HWA) is an invasive insect species native to Japan causing significant hemlock mortality in the eastern United States. Laricobius spp. have been targeted as biological control agents because they are adelgid specialists. Laricobius osakensis Montgomery and Shiyake is native to the same region of Japan from which the strain of HWA found in the eastern United States originated. Studies in Japan found that it is phenologically synchronous with HWA. Following approval to release L. osakensis from quarantine in 2010, approximately 32,000 were released at a total of 61 sites starting in 2012. In winter of 2014 and 2015, periods of extreme cold temperatures throughout the eastern USA, as well as the polar vortex, resulted in extensive mortality to HWA, which likely delayed the establishment of L. osakensis. The ability of the beetle to survive and establish in the eastern United States is reported here. In the first year of this study (2015–2016), limited numbers of L. osakensis were recovered, as HWA populations were still rebounding. In the second year (2016–2017), 147 L. osakensis were collected at 5 of 9 sites sampled, coinciding with rebounding HWA populations. Larval recovery was much greater than adult recovery throughout the study. HWA density was directly correlated with warmer plant hardiness zones and recovery of Laricobius beetles was significantly correlated with HWA density. Our results suggest that L. osakensis is successfully establishing at several of the sampled release sites and that the best predictor of its presence at a site is the HWA density.

scholarly journals Spring Freeze Damage to the 1996 Peach and Nectarine Crop in the Southeastern United States

1998 ◽  
Vol 8 (3) ◽  
pp. 381-386 ◽  
Author(s):  
W.R. Okie ◽  
T.G. Beckman ◽  
G.L. Reighard ◽  
W.C. Newall ◽  
C.J. Graham ◽  
...  
Keyword(s):  
United States ◽  
Prunus Persica ◽  
Southeastern United States ◽  
Frost Tolerance ◽  
Cold Temperatures ◽  
Freeze Damage ◽  
Breeding Selections

This paper describes the climatic and cropping conditions in the major peach [Prunus persica (L.) Batsch] producing areas in the southeastern United States in 1996. The peach and nectarine crop was the smallest since 1955 due to a series of unusually cold temperatures in February, March, and April. Crop set was not strictly a function of late blooming. No variety produced a full crop across the region. Many reputedly hardy peaches cropped poorly. The only peach or nectarine varieties that produced substantial crops in multiple locations were `La Premiere', `Ruston Red', and `Contender'. Cropping ability of some breeding selections shows that peach frost tolerance may be improved further.

Party Strength in the United States: Some Corrections

1975 ◽  
Vol 37 (2) ◽  
pp. 641-642 ◽  
Author(s):  
Paul T. David
Keyword(s):  
United States ◽  
The United States ◽  
Party Strength

Application of a Simple Cold Stub to the Direct Observation of Frozen Hydrated Sand

1973 ◽  
Vol 31 ◽  
pp. 212-213
Author(s):  
John M. Wehrung ◽  
Richard J. Harniman
Keyword(s):  
United States ◽  
Surface Water ◽  
Direct Observation ◽  
Controlled Study ◽  
Clay Particles ◽  
Organic Debris ◽  
Rock Formations ◽  
Water Tables ◽  
Permeable Rock ◽  
Natural Means

Water tables in aquifer regions of the southwest United States are dropping off at a rate which is greater than can be replaced by natural means. It is estimated that by 1985 wells will run dry in this region unless adequate artificial recharging can be accomplished. Recharging with surface water is limited by the plugging of permeable rock formations underground by clay particles and organic debris.A controlled study was initiated in which sand grains were used as the rock formation and water with known clay concentrations as the recharge media. The plugging mechanism was investigated by direct observation in the SEM of frozen hydrated sand samples from selected depths.

Correlative microscopy in distrubuted (client/server) computing environments: tools for catalyzing the rapid dissemination of information about the cell biology of the human prostate

1995 ◽  
Vol 53 ◽  
pp. 682-683
Author(s):  
A. Hakam ◽  
J.T. Gau ◽  
M.L. Grove ◽  
B.A. Evans ◽  
M. Shuman ◽  
...  
Keyword(s):  
United States ◽  
Cell Biology ◽  
Tissue Bank ◽  
The United States ◽  
Prostate Adenocarcinoma ◽  
Correlative Microscopy ◽  
Client Server ◽  
Critical Elements ◽  
Transplant Organ

Prostate adenocarcinoma is the most common malignant tumor of men in the United States and is the third leading cause of death in men. Despite attempts at early detection, there will be 244,000 new cases and 44,000 deaths from the disease in the United States in 1995. Therapeutic progress against this disease is hindered by an incomplete understanding of prostate epithelial cell biology, the availability of human tissues for in vitro experimentation, slow dissemination of information between prostate cancer research teams and the increasing pressure to “ stretch” research dollars at the same time staff reductions are occurring.To meet these challenges, we have used the correlative microscopy (CM) and client/server (C/S) computing to increase productivity while decreasing costs. Critical elements of our program are as follows:1) Establishing the Western Pennsylvania Genitourinary (GU) Tissue Bank which includes >100 prostates from patients with prostate adenocarcinoma as well as >20 normal prostates from transplant organ donors.

Identification of the pulmonary syndrome hantavirus by direct and colloidal gold immune Electron Microscopy

1994 ◽  
Vol 52 ◽  
pp. 274-275
Author(s):  
C. D. Humphrey ◽  
C.S. Goldsmith ◽  
L. Elliott ◽  
S.R. Zaki
Keyword(s):  
Electron Microscopy ◽  
United States ◽  
Monoclonal Antibody ◽  
Colloidal Gold ◽  
Phosphotungstic Acid ◽  
Uranyl Acetate ◽  
Hantavirus Pulmonary Syndrome ◽  
Deer Mice ◽  
Immune Electron Microscopy ◽  
Negative Stain

An outbreak of unexplained acute pulmonary syndrome with high fatality was recognized in the spring of 1993 in the southwestern United States. The cause of the illness was quickly identified serologically and genetically as a hantavirus and the disease was named hantavirus pulmonary syndrome (HPS). Recently, the virus was isolated from deer mice which had been trapped near the homes of HPS patients, and cultivated in Vero E6 cells. We identified the cultivated virus by negative-stain direct and colloidal gold immune electron microscopy (EM).Virus was extracted, clarified, and concentrated from unfixed and 0.25% glutaraldehyde fixed supernatant fluids of infected Vero E6 cells by a procedure described previously. Concentrated virus suspensions tested by direct EM were applied to glow-discharge treated formvar-carbon filmed grids, blotted, and stained with 0.5% uranyl acetate (UA) or with 2% phosphotungstic acid (PTA) pH 6.5. Virus suspensions for immune colloidal gold identification were adsorbed similarly to filmed grids but incubated for 1 hr on drops of 1:50 diluted monoclonal antibody to Prospect Hill virus nucleoprotein or with 1:50 diluted sera from HPS virus infected deer mice.

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