Use of Aluminum-Foil and Oat-Straw Mulches for Controlling Aster Leafhopper, \u3ci\u3eMacrosteles Fascifrons\u3c/i\u3e (Homoptera: Cicadellidae), and Aster Yellows in Carrots.

Aluminum-foil and oat-straw mulches significantly (P \u3c 0.05) reduced aster leafhopper numbers on carrots compared to an untreated control and a malathion spray treatment during the first half of the growing season. The amount of reflected light was significantly higher in both aluminum-foil and oat-straw mulched plots compared to unmulched treatments. Mulch effectiveness decreased when the closing carrot canopy reduced surface area of reflective mulches and amount of reflected light The percentage of aster yellows-infected plants was significantly lower (P \u3c 0.05) in aluminum-foil and straw mulches and in the malathion spray plots compared to the untreated control. Results demonstrated that aluminum-foil and straw mulches gave control of aster leafhoppers and aster yellows in carrots equal to that of a conventional insecticide spray program

The Development and Use of an Enzyme Linked Immunosorbent Assay (Elisa) for the Quantitative Assessment of Predation of Nezara Viridula (L.) Within a Soybean Agroecosystem.

An enzyme linked immunosorbent assay (ELISA) for detection of either Nezara viridula (L.) egg or nymphal protein in the gut of potential predators was developed. Through the use of molecular gel filtration species specific antigens were obtained from N. viridula eggs and nymphs. The ELISA developed for eggs could detect 7.6 ng of egg protein while the nymphal ELISA could detect 122 ng of the selected nymphal protein. There were 27 species of insects and spiders representing 6 orders and 15 families, tested for both egg and nymphal predation over 2 growing seasons (1977 and 1978). There were 1886 individuals tested for egg predation and 1983 tested for nymphal predation. The most important predator species were determined by a combination of their population density and the results of the ELISA. A complex consisting of 8 species plus Coccinellidae larvae as a group accounted for 91.4% of the egg predation over the entire 1978 growing season. These species were Geocoris punctipes (Say), Orius insidiosus (Say), Cycloneda sanguinea (L.), Coleomegilla maculata lengi Timberlake, Podisus maculiventris (Say), Solenopsis invicta Buren, Reduviolus roseipennis (Reuter), and Lebia analis Dejean. Nymphal predation was not as extensive as egg predation. A combination of predators consisting of a complex of 8 species plus the Coccinellidae larvae accounted for 95.4% of the entire season\u27s predation. The predators included were Oxyopes salticus Hentz, G. punctipes, P. maculiventris, C. sanguinea, C. m. lengi, R. roseipennis, Phidippus audax (Hentz), and Neoscona arabesca (Walckenaer). No one species could be considered a key predator of either eggs of nymphs. Predation had to be viewed in the context of a complex. The complex was shown not to be static but dynamic according to the time of year and species present in the agroecosystem

Producers' Use of Crop Borders for Management of Potato Virus Y (PVY) in Seed Potatoes

Potato virus Y (PVY) is a very serious problem throughout most major seed potato producing states. Seed potato producers in Minnesota and North Dakota were surveyed in early 2005 to assess their perception of the profitability and risks associated with using crop borders to manage PVY in seed lots. Five of the 23 producers responding (a 25% response rate) said they had used crop borders in 2004. These 23 producers entered 152 seed lots into state seed certification programs. On average, producers had less than 0.1 seed lots rejected for PVY based on summer inspection. The average number of seed lots rejected in winter trials was 1.7. Of the 152 seed lots, these producers said they had entered into state seed certification programs, they reported detailed information on 108 lots. Generations 1 and 2 were the most likely generations to be protected by a crop border. Of these 108 seed lots, 104 passed summer inspection for PVY. Seventy-four percent of the 89 lots sent in for the winter test were reported to have passed. The use of crop borders was significant in explaining whether a seed lot had passed the winter test or not. Thirty-one (97%) of the 32 seed lots that were planted within a crop border passed the winter test while 31 (54%) of the 57 seed lots that were not planted with a crop border passed the winter test. No relationship was found between the choice of border crop and passing the winter test. Producers also were asked to state their agreement or disagreement with several statements regarding their knowledge and opinions on use of crop borders.Crop Production/Industries,

PROFITABILITY ANALYSIS OF SOYBEAN APHID CONTROL TREATMENTS IN THREE NORTH-CENTRAL STATES

Crop Production/Industries,

ECONOMIC ANALYSIS OF USING A BORDER TREATMENT FOR REDUCING ORGANOPHOSPHATE USE IN SEED POTATO PRODUCTION

Recent research shows initial colonization of potato fields by winged green peach aphid is concentrated at field edges. This suggests that insecticides applied only to field margins during initial colonization would largely eliminate a colonizing aphid population, conserve natural enemies in the field center, and reduce insecticide use. To better understand the costs and benefits of reducing organophosphate use, the six participating growers were interviewed to ascertain their reason for participating and their satisfaction with the border only treatment method as well as their estimated net economic benefits. Five of the farms ranked cost reduction as the most important reason for participating. The sixth farm ranked reducing virus spread as the most important reason with cost reduction as their second most important reason. The average cost savings over all 28 participating fields of using the border treatment is estimated to be $23.85 per acre for the entire field-a 93% savings. Almost all the farmers found the border treatment method to be successful at aphid control. None of the farmers observed any impact on the physical yield of seed potato. All the fields were certified during the summer except for one of Farmer F's fields that was lost because of off type. In conclusion, the border treatment method seems likely to be adopted by many farmers since the potential cost saving is large and farmers dislike Monitor. However, some farmers may resist the method due to scouting requirements and costs. Also, farmers with fields that do not meet the uniformity requirements of the border treatment will not be successful in their use of the border method.Crop Production/Industries,

Quantifying the Impact that New Capital Projects Will Have on Roadway Snow and Ice Control Operations

In recent years, many states have experienced heavy burdens on their snow and ice control budgets. Increases in winter/spring precipitation results in increased costs to state DOTs for winter roadway maintenance materials (salt, sand, chemicals, etc.), plow operator time, equipment maintenance and replacement budgets, and fuel use. As state DOTs adjust to climate conditions that include not only more precipitation, but more severe and unpredictable weather events, it will become increasingly important to integrate the cost of roadway snow and ice control (RSIC) operations into their capital-project planning processes. The overall goal of this project was to support state DOTs’ operations & maintenance efforts by developing an automated method for quantifying the expected impact that new capital projects will have on RSIC operations. The effects of a new suburban roadway were found to be the most significant, requiring 266 vehicle-minutes of travel along with almost 40 minutes of additional service time or one additional fleet truck for each mile of new roadway. The results and findings of this research have implications for short-term funding allocations for RSIC operations staff and for long-term consideration of RSIC in the highway planning and design processes. The findings of this project provide defensible data for operations staff to advocate for increases in funding to offset the increased RSIC burden when a project is completed. The calculation tool created incorporates all of the results above into a MS Excel decision support platform, providing quick estimates of the monetary impact of a variety of major highway project types

Activity-dependent changes in excitability of perirhinal cortex networks in vitro

Rat brain slices comprising the perirhinal cortex (PC) and a portion of the lateral nucleus of the amygdala (LA), in standard medium, can generate synchronous oscillatory activity that is associated with action potential discharge and reflects the activation of glutamatergic and GABAergic receptors. We report here that similar synchronous oscillatory events are recorded in the PC in response to single-shock, electrical stimuli delivered in LA. In addition, we found that the latency of these responses progressively increased when the stimulus interval was varied from 10 to 1 s; for example, the response latency during stimuli delivered at 1 Hz was more than twofold longer than that seen during stimulation at 0.1 Hz. This prolongation in latency occurred after approximately 5 stimuli, attained a steady value after 24-35 stimuli, and recovered to control values 30 s after stimulation arrest. These frequency-dependent changes in latency continued to occur during NMDA receptor antagonism but weakened following application of GABAA and/or GABAB receptor blockers. Our findings identify a new type of short-term plasticity that is mediated by GABA receptor function and may play a role in decreasing neuronal network synchronization during repeated activation. We propose that this frequency-dependent adaptive mechanism influences the excitability of limbic networks, thus potentially controlling epileptiform synchronization

Comparison of the effect of environmental temperature on rabbits and cattle, Part 2, Influence of raising environmental temperature on the physiological reactions of rabbits and cattle.

The bulletin reports on Department of Dairy Husbandry Research Project 125, Climatic Factors--P. [3].Digitized 2007 AES.Includes bibliographical references (pages 15-17)

Neuropathic Nav1.3-mediated sensitization to P2X activation is regulated by protein kinase C

<p>Abstract</p> <p>Background</p> <p>Increased neuronal excitability and spontaneous firing are hallmark characteristics of injured sensory neurons. Changes in expression of various voltage-gated Na⁺channels (VGSCs) have been observed under neuropathic conditions and there is evidence for the involvement of protein kinase C (PKC) in sensory hyperexcitability. Here we demonstrate the contribution of PKC to P2X-evoked VGSC activation in dorsal root ganglion (DRG) neurons in neuropathic conditions.</p> <p>Results</p> <p>Using the spinal nerve ligation (SNL) model of neuropathic pain and whole-cell patch clamp recordings of dissociated DRG neurons, we examined changes in excitability of sensory neurons after nerve injury and observed that P2X3 purinoceptor-mediated currents induced by α,β-meATP triggered activation of TTX-sensitive VGSCs in neuropathic nociceptors only. Treatment of neuropathic DRGs with the PKC blocker staurosporine or calphostin C decreased the α,β-meATP-induced Na⁺channels activity and reversed neuronal hypersensitivity. In current clamp mode, α,β-meATP was able to evoke action-potentials more frequently in neuropathic neurons than in controls. Pretreatment with calphostin C significantly decreased the proportion of sensitized neurons that generated action potentials in response to α,β-meATP. Recordings measuring VGSC activity in neuropathic neurons show significant change in amplitude and voltage dependence of sodium currents. In situ hybridization data indicate a dramatic increase in expression of embryonic Na_v1.3 channels in neuropathic DRG neurons. In a CHO cell line stably expressing the Na_v1.3 subunit, PKC inhibition caused both a significant shift in voltage-dependence of the channel in the depolarizing direction and a decrease in current amplitude.</p> <p>Conclusion</p> <p>Neuropathic injury causes primary sensory neurons to become hyperexcitable to ATP-evoked P2X receptor-mediated depolarization, a phenotypic switch sensitive to PKC modulation and mediated by increased activity of TTX-sensitive VGSCs. Upregulation in VGSC activity after injury is likely mediated by increased expression of the Na_v1.3 subunit, and the function of the Na_v1.3 channel is regulated by PKC.</p

Metabolic reactions during thermal stress (35 degrees to 95 degrees F.) in dairy animals acclimated at 50 degrees and 80 degrees F.

This bulletin is a report on the Department of Dairy Husbandry research project no. 125, 'Climatic Factors'--P. [4].Digitized 2007 AES.Includes bibliographical references (pages 100-114)