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At least 19 recordsLinked to original sources
PubMed1979

Depth of nontarget processing in an attention task.

Two studies examined the effect of the sensory discriminability of targets from nontargets on depth of nontarget processing. Subjects shadowed target words that were binaurally presented with coincident nontarget words. Targets and nontargets were spoken in the same male voice under low sensory discriminability and in male and female voices, respectively under high sensory discriminability. Across the two studies, depth of nontarget processing was assessed in three ways: extent to which shadowing accuracy was disrupted by a semantic overlap between targets and nontargets, expenditure of capacity (reaction time to subsidiary light signals), and nontarget recall. All three possible measures of depth of nontarget processing decreased as sensory discriminability increased. The data support the assumption of multiple-loci theories of attention that nontargets can be perceptually inhibited; they contraindicate the assumption of late-selection theories that perceptual processing is automatic and irrepressible.

Attention↗
PubMed1992

Perceptual processing of adjacent and nonadjacent tactile nontargets.

Previous research has shown that subjects appear unable to restrict processing to a single finger and ignore a stimulus presented to an adjacent finger. Furthermore, the evidence suggests that, at least for moving stimuli, an adjacent nontarget is fully processed to the level of incipient response activation. The present study replicated and expanded upon these original findings. The results of Experiment 1 showed that an equally large response-competition effect occurred when the nontarget was presented to adjacent and nonadjacent fingers (on the same hand). The results of Experiment 2 showed that the effects observed in Experiment 1 (and in previous studies) were also obtained with stationary stimuli. Although small, there was some indication in the results of Experiment 2 that interference may dissipate more rapidly with distance with stationary stimuli. An additional finding was that interference effects were observed in both experiments with temporal separations between the target and nontarget of up to 100 msec. In Experiment 3, target and nontarget stimuli were presented to opposite hands. Although reduced, interference was still evident with target and nontarget stimuli presented to opposite hands. Varying the physical distance between hands did not produce any change in the amount of interference. The results suggest that the focus of attention on the skin extends nearly undiminished across the fingers of one hand and is not dependent upon the physical distance between sites of stimulation.

Adult↗
PubMed1991

Oligonucleotide site directed mutagenesis of all histidine residues within the T4 endonuclease V gene: role in enzyme-nontarget DNA binding.

In order to evaluate the contributions that histidine residues might play both in the catalytic activities of endonuclease V and in binding to nontarget DNA, the technique of oligonucleotide site directed mutagenesis was used to create mutations at each of the four histidine residues in the endonuclease V gene. Although none of the histidines were shown to be absolutely required for the pyrimidine dimer specific DNA glycosylase activity or the apurinic lyase activity, conservative amino acid changes at His16 produced enzymes with little or no catalytic activity. In addition, the evaluation of conservative and radical amino acid substitutions at positions 34, 56, and 107 is consistent with the interpretation that each of these histidines may be involved in nontarget DNA binding. The data supporting this conclusion are that histidine changes to lysine at positions 34 and 107 enhance the nontarget DNA binding activity of the mutant enzymes while neutralization of charge at His56 reduces nontarget DNA binding.

Base Sequence↗
PubMed1992

Safety of Edhazardia aedis (Microspora: Amblyosporidae) for nontarget aquatic organisms.

The susceptibility of common nontarget aquatic organisms to the microsporidium Edhazardia aedis was investigated in the laboratory. Eight predacious species along with 9 scavengers and filter feeders were tested. The nontarget organisms were not susceptible to infection by E. aedis and there was no appreciable mortality. To measure the relative safety of E. aedis to nontarget organisms, a simple mathematical expression was employed where risk is defined as the product of the probability of exposure and the result of exposure (infection) expressed as P(e)P(i). In these laboratory tests, the probability of exposure was fixed at 1 (maximum challenge) and the probability of infection was determined to be 0. Therefore, the risk associated with release of E. aedis into the environment is considered to be negligible under these conditions. The true risk for nontarget organisms to E. aedis can only be determined by careful evaluation of controlled field studies in the natural habitat of the target host.

Aedes↗
PubMed1979

Effect of estrogen on ovalbumin gene expression in differentiated nontarget tissues.

By use of cloned DNA fragments as probes, low levels of ovalbumin RNA sequences (structural and intervening sequences) were detected in nuclear RNA extracts of nontarget tissues, such as liver, spleen, brain, and heart of chicks. The expression of the ovalbumin gene sequences was hormone dependent. In estrogen-stimulated chicks, a low level of ovalbumin RNA sequences, ranging from 0.2 to 0.7 molecule per cell, was present in nontarget tissues while less than 0.01 molecule per cell could be found in the same tissues of unstimulated chicks. A significant amount of the ovalbumin mRNA sequences was also found in polysomes of liver and brain. The ovalbumin mRNA sequences could be translated into proteins which were only localized in a few cells among the entire population of liver cells as determined by an immunocytochemical assay. These results suggest that there are some cells in liver, spleen, heart, and brain which can respond to hormone stimulation and produce ovalbumin mRNA and its translational product.

Animals↗
PubMed1975

Mirex residues in nontarget organisms after application of experimental baits for fire ant control, southwest Georgia--1971-72.

Mirex, the only compound approved for control of the red imported fire ant (Solenopsis invicta) and the black imported fire ant (Solenopsis richteri), is normally applied at a rate of 1.40 kg/ha. (1.25 lb/acre). Influenced by recent studies showing that low levels of mirex are toxic to certain nontarget organisms, particularly estuarine species, authors report here on a monitoring study of mirex in three large treatment areas of southwest Georgia. Four formulations of bait were applied aerially in 1971-72. Low-level residues were observed in small terrestrial vertebrates and invertebrates and in fresh-water inhabitants. Levels detected were about the same for all baits. Maximum residues were detected 1-3 months after treatment and gradually declined to low levels of 0.02-1.16 ppm 1 year after treatment.

Amphibians↗
PubMed1992

Impact of the black fly (Diptera: Simuliidae) control agent Bacillus thuringiensis var. israelensis on chironomids (Diptera: Chironomidae) and other nontarget insects: results of ten field trials.

Except for moderate mortality among filter-feeding chironomids, Rheotanytarsus spp., the results of 10 field trials with Bacillus thuringiensis var. israelensis (B.t.i.) indicated a wide margin of safety to the chironomid community and other stream nontarget insects. Mayflies, caddisflies and 2 other types of chironomids, i.e., tube-dwelling (Chironominae) and surface-dwelling, caseless larvae (mix of Chironominae, Diamesinae, Orthocladiinae, Tanypodinae), did not appear to be affected. The susceptibility of filter-feeding chironomids was considerably less than black flies; for example, 4 months of data collected during an operational black fly control program indicated a mean (+/- 95% CI) mortality among Rheotanytarsus larvae of 23 (15-32)% vs. 98 (97-99)% among black flies. Although clearly demonstrating the potential of adverse impact on filter-feeding chironomids in operational black fly programs, these trials also confirmed the narrow impact of B.t.i. on the overall stream insect community.

Animals↗
PubMed1991

Fate of Bacillus sphaericus 2362 spores following ingestion by nontarget invertebrates.

Elimination of Bacillus sphaericus spores ingested by midge larvae, snails, and oysters was most rapid among midge larvae. Spores remained in oysters up to 21 days and in snails up to 49 days. Viable spores were recovered in snail and oyster feces for these same periods. There was no indication of actively growing B. sphaericus in the animals. Passage through oyster gut detoxified the B. sphaericus mosquito larval toxin, but there was a 33% retention of toxicity following snail gut passage. Midge larvae reared to adults in spore-containing water carried spores in/on the adult body. This suggests that these animals could carry the bacteria to sites beyond the application area.

Animals↗
PubMed1991

Impact of insecticides on nontarget microarthropod fauna in agricultural soil.

Ecologically important soil microarthropods were used to evaluate the direct and residual toxicities of some insecticides under field and laboratory conditions. The density of total microarthropods and major groups, namely Acarina and Collembola, suffered a statistically significant and persistent decline in the aldrin 30 EC (0.25%)- and endosulfan 35 EC (0.33%)-treated soil of wheat fields. But dimethoate 30 EC (0.125%) and phosphamidon 85 EC (0.03%) applied in mustard fields produced only a temporary decline. Laboratory studies showed that all the above insecticides and monocrotophos 36 EC (0.2%), methyl parathion 50 EC (0.05%), chlordane 20 EC (0.125%), and carbaryl 50 WP (0.625%) had a direct knockdown effect on Cyphoderus sp. but another collembolan species, Xenylla sp., appeared to be somewhat resistant. Only endosulfan was toxic to a common soil Acarina species, Lancetoppia sp. Among four soil media, toxicity was maximum in pure sand, followed by sandy loam, clay, and organic soil. The residual toxicity of phosphamidon, dimethoate, methyl parathion, and endosulfan was more prolonged for Cyphoderus sp. than for Xenylla sp. Only the larval stage of Lancetoppia sp. was susceptible to the residual effect of endosulfan. LD50 and bioassay studies showed that Cyphoderus sp. can be employed as a potential biomonitor of insecticide pollution in soil.

Animals↗
PubMed1992

Performance of an aquatic multispecies system in evaluating the effects of a model microbial pest control agent on nontarget organisms.

A recirculating multispecies test system was developed in conjunction with a study of the fate and persistence of a model microbial pest control agent on non-target marine and freshwater organisms. The basic unit of the system was a 113-I glass aquarium with vertical biological filters in the center of the aquarium, such that two compartments were formed. This allowed the sequestration of predator and prey species within the same system. Organisms from six phyletic groups were subjected to a genetically altered strain of Pseudomonas putida for 15-29 d in either artificial seawater or fresh water. The system was able to maintain the animals for these periods with a minimum of maintenance. Additionally, the system design lent itself to disinfection, dismantling, and rebuilding between experiments with a minimum of labor, and has potential for longer-term studies.

Animals↗
PubMed1991

Ribozyme-mediated cleavage of an HIV-1 gag RNA: the effects of nontargeted sequences and secondary structure on ribozyme cleavage activity.

Catalytic antisense RNAs, or ribozymes, have great potential as inhibitors of gene expression and as antiviral therapeutic agents. The major advantage of ribozymes versus standard antisense RNAs is their catalytic capability, enabling these RNAs to cleave multiple substrates. We have been investigating the antiviral activity of ribozymes targeted to the HIV-1 genome. The successful use of these antisense agents in an intracellular milieu requires stabilization of the ribozymes by flanking, non-base-pairing sequences, or some modification of the sugar-phosphate backbone. We describe a systematic investigation of the effects of flanking, non-base-pairing sequences on the catalytic activity of an anti-HIV-1 gag ribozyme embedded in radically different transcripts. Amazingly, these complex ribozyme-containing transcripts maintain substantial catalytic activity. Finally, we describe a bacterial gene fusion system that has potential for the large scale production of catalytically active ribozymes.

Base Sequence↗
PubMed1991

Influence of the nontarget mollusc Marisa cornuarietis on the hourly cercarial production of Schistosoma mansoni from Biomphalaria glabrata.

A comparative study of hourly cercarial productivities of Schistosoma mansoni from infected Biomphalaria glabrata was carried out in the presence of either healthy B. glabrata (control) or healthy Marisa cornuarietis (experimental). The results showed that, with M. cornuarietis, almost all the hourly cercarial productivities increased by a factor varying from 1.3 to 2.5 without modification of the shedding period.

Animals↗
PubMedDate not supplied

Cholera toxin as a mucosal adjuvant: III. Antibody responses to nontarget dietary antigens are not increased.

The effect of cholera toxin, a potent mucosal adjuvant, upon the murine immune response to both soybean meal, a regular dietary antigen, and ovalbumin, a simulated dietary antigen, was examined. Mice were orally immunized with a target antigen, Sendai virus, with and without cholera toxin as a mucosal adjuvant. Both serum and intestinal IgA and IgG anti-Sendai virus antibody responses were significantly increased when cholera toxin was used. For soybean meal, the major protein source in laboratory animal chows, however, no increases in serum antibody titers were found in animals which received oral cholera toxin plus virus. In addition, in mice orally immunized with ovalbumin plus cholera toxin (and virus), both serum and intestinal IgA and IgG antibody titers against ovalbumin were increased. Oral pre-immunization with ovalbumin prior to oral ovalbumin plus cholera toxin, however, resulted in no increase in either serum or intestinal anti-ovalbumin antibody responses. Thus, the use of cholera toxin as an oral adjuvant does not increase antibody responses against dietary antigens if there has been pre-exposure to the dietary antigen.

Adjuvants, Immunologic↗
PubMed1977

Mirex residues in nontarget organisms after application of 10-5 bait for fire ant control, northeast Florida--1972-74.

The 10-5 bait formulation of mirex insecticide was applied to a 20,000-acre area of northeast Florida. For 24 months after application, samples of a wide variety of fauna were collected and analyzed for mirex content. Insects accumulated mirex to the greatest extent in the first 6 months after application; most residues had decreased greatly by 12 months. Other invertebrates showed low mirex levels during the first 9 months after application and none after 12 months. Fish possessed low levels of insecticides for 9 months; amphibians showed mirex residues for 12 months after application. In general, reptiles had low levels throughout the 24-month period and mammals had higher levels, particularly in fat tissues. Birds consistently had low to moderate mirex levels. After a single application of 10-5 mirex bait, only relatively low levels of insecticide were detected in exposed fauna. After 24-months, mirex was found infrequently and at low levels.

Animals↗