695 research outputs found
Oncolog, Volume 37, Issue 03, July-September 1992
Retinoic acid/interferon combination shows promising response rates Cross-matching test helps find donors for patients in dire need of platelets Silicone gel-filled implants: Women should have the option to choosehttps://openworks.mdanderson.org/oncolog/1039/thumbnail.jp
The difference between night and day: The nocturnal and diurnal activity budget of gray seals (Halichoerus grypus) during the breeding season
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Responding by exclusion in temporal discrimination tasks
Responding by exclusion, one of the most robust phenomena in Experimental
Psychology, consists of choosing an undefined comparison stimulus given an undefined
sample, when the comparison stimulus is presented next to other experimentally defined
stimuli. The goal of the present study was to determine whether responding by
exclusion could be obtained using samples that varied along a single dimension. Using a
double temporal bisection task, ten university students learned to choose visual
comparisons (colored circles) based on the duration of a tone. In tests of exclusion,
sample stimuli with new durations were followed by comparison sets that included one
previously trained, defined comparison (colored circle) and one previously untrained,
undefined comparison (geometric shape). Subjects preferred the defined comparisons
following the defined samples and the undefined comparisons following the undefined
samples, the choice pattern typical of responding by exclusion. The use of samples
varying along a single dimension allows us to study the interaction between stimulus
generalization gradients and exclusion in the control of conditional responding.The first author was supported by a master's degree fellowship by the Ministry of Education (CAPES). Armando Machado was supported by grant PTDC/MHC-PCN/3540/2012 from the Portuguese Foundation for Science and Technology. Camila Domeniconi had a post-doctoral fellowship from the Foundation for Research Support in the State of Sao Paulo (FAPESP, 2009/18479-5). She is currently affiliated with the National Institute of Science and Technology on Behavior, Cognition and Teaching. Grants: FAPESP (08/57705-8) and CNPq (573972/2008-7). She has a research productivity fellowship by the National Council for Scientific and Technological Development (CNPq, 301623/2012-0)
Urban Poverty:
Summaries The article describes how and why the scale of urban poverty in much of Africa, Asia and Latin America seems to have been underestimated, its nature misunderstood (or for political reasons, misrepresented) and the best means for reducing it rarely acted upon. It suggests that the income level needed to avoid poverty in most urban areas has been underestimated, largely because too little consideration is given to the cost of essential non?food items. It also suggests that most low?income groups in urban areas face a health burden from their housing whose physical, social and economic costs have been underestimated. This is because the only housing they can afford is of poor quality, usually too small in relation to household size, lacking in basic services and often built on a dangerous site. The article also outlines different measures through which urban poverty can be reduced. These measures include not only increasing incomes and enhancing assets for low?income households, but also upholding their right to justice and legal protection and responding to their needs and priorities for adequate housing and basic services. The final section discusses the relative balance between action at national, city and community level, and the most appropriate form of intervention for any agency that seeks to support poverty reduction at a community level
Hearing Sensation Levels of Emitted Biosonar Clicks in an Echolocating Atlantic Bottlenose Dolphin
Emitted biosonar clicks and auditory evoked potential (AEP) responses triggered by the clicks were synchronously recorded during echolocation in an Atlantic bottlenose dolphin (Tursiops truncatus) trained to wear suction-cup EEG electrodes and to detect targets by echolocation. Three targets with target strengths of −34, −28, and −22 dB were used at distances of 2 to 6.5 m for each target. The AEP responses were sorted according to the corresponding emitted click source levels in 5-dB bins and averaged within each bin to extract biosonar click-related AEPs from noise. The AEP amplitudes were measured peak-to-peak and plotted as a function of click source levels for each target type, distance, and target-present or target-absent condition. Hearing sensation levels of the biosonar clicks were evaluated by comparing the functions of the biosonar click-related AEP amplitude-versus-click source level to a function of external (in free field) click-related AEP amplitude-versus-click sound pressure level. The results indicated that the dolphin's hearing sensation levels to her own biosonar clicks were equal to that of external clicks with sound pressure levels 16 to 36 dB lower than the biosonar click source levels, varying with target type, distance, and condition. These data may be assumed to indicate that the bottlenose dolphin possesses effective protection mechanisms to isolate the self-produced intense biosonar beam from the animal's ears during echolocation
Chimpanzees communicate to two different audiences during aggressive interactions
Conflict and aggressive interactions are common phenomena in group-living animals and vocal behaviour often plays an important role in determining their outcomes. In some species, vocal signals seem to provide bystanders with information about the nature of an ongoing aggressive interaction, which can be beneficial for the victims. For example, in chimpanzees and some other primates, victims adjust their screams depending on the composition of the by-standing audience, probably to solicit their support. Considerably less is known, however, about the role of other call types produced by victims of aggression. In this study, we focused on the fact that, immediately after screams, chimpanzee, Pan troglodytes schweinfurthii, victims often produce 'waa' barks, but little is known about their function. Our results showed that for screams, but not 'waa' barks, production was dependent on the audience composition with victims being more likely to scream when adult or late-adolescent males were in close proximity. We also found that after 'waa' barking, but not screaming, victims were more likely to retaliate against and less likely to reconcile with their aggressors, and that 'waa' barking was more common after victims had received support from other party members. These results suggest that, in chimpanzees, victims of aggression vocalize with a dual social strategy of attempting to recruit support from bystanders and to repel their attackers by signalling readiness to retaliate. We conclude that victim scream and 'waa' bark calls, although often produced during the same agonistic event, are directed at different audiences and fulfil different social functions, and that these calls can mediate both aggressive interactions and aggressor-victim relationships following aggression
Two-Item Sentence Comprehension by a Dog (Canis familiaris)
Syntax use by non-human animals remains a controversial issue. We present here evidence that a dog may respond to verbal requests composed of two independent terms, one referring to an object and the other to an action to be performed relative to the object. A female mongrel dog, Sofia, was initially trained to respond to action (point and fetch) and object (ball, key, stick, bottle and bear) terms which were then presented as simultaneous, combinatorial requests (e.g. ball fetch, stick point). Sofia successfully responded to object-action requests presented as single sentences, and was able to flexibly generalize her performance across different contexts. These results provide empirical evidence that dogs are able to extract the information contained in complex messages and to integrate it in directed performance, an ability which is shared with other linguistically trained animals and may represent a forerunner of syntactic functioning
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