820 research outputs found
The Effects of Cognitive Jamming on Wireless Sensor Networks used for Geolocation
The increased use of Wireless Sensor Networks (WSN) for geolocation has led to an increased reliance on this technology. Jamming, protecting jamming, and detecting jamming in a WSN are areas of study that have greatly increased in interest. This research uses simulations and data collected from hardware experiments to test the effects of jamming on a WSN. Hardware jamming was tested using a Universal Software Radio Peripheral (USRP) Version 2 to assess the effects of jamming on a cooperative network of Java Sun SPOTs. The research combines simulations and data collected from the hardware experiments to see the effects of jamming on cooperative and noncooperative geolocation
Why do we want to think humans are different?
One harmful consequence of creating categories where one group is unique and superior to others is that it justifies committing negative, often atrocious, acts on the members of the inferior group. Correcting divisive human categorizations (racial superiority, gender superiority) has bettered society. Scholars have often claimed that humans are unique and superior to nonhuman animals. These claims need to be reevaluated. Many have already been refuted. Animals have been shown to outperform humans in many tasks, including cognitive ones. Here we raise the question: Has the false sense of superiority been used to justify human cruelty to animals
Refining thoughts about human/nonhuman differences
Our commentators come from many fields and disciplines and express highly divergent views, illustrating broad interest in the question. From the breadth of comments, we have identified two recurring themes, which we focus on here. The first is a preponderance of cautionary remarks about evaluating the differences between humans and nonhuman animals. The second concerns whether considering animals as worthy of moral consideration is one of many useful tools for conservationists trying to prevent extinction, habitat destruction, and climate change
Diversity on human difference: Unanimity on human responsibility
Further commentaries on our original target article add important new points and expand our understanding of the differences between animals, particularly between non-human and human primates. But whether they affirm or deny that humans are unique, all commentators agree that our special abilities mean we should be taking responsibility for the care of nature and the plants and animals it supports. We ask: is humankind doing this
Primate Self-Medication, Passive Prevention and Active Treatment - A Brief Review
Parasites and pathogens are a source of diseases that can affect the health, behavior and reproductive fitness of an individual. The study of animal self-medication as a science is relatively new, but traditional societies have long looked to animals for clues to natureâs medicine cabinet. Evidence of self-medication is widespread throughout the animal kingdom. To date, research has classified health maintenance and self-medicative behaviors into five levels: 1) âsick behaviorsâ; 2) behavioral avoidance or reduction of the possibility fordisease transmission; 3) dietary selection of items with a preventative or health maintenance effect; 4) ingestion of a substance for the curative treatment of a disease or the symptoms thereof, and; 5) application of a substance to the body or a living space for the treatment or control of vectors or external health condition. Among the groups of animals studied to date, primates have provided the most details for level 3 and 4 behaviors, exemplified by such diverse dietary selection and behaviors as bitter pith chewing and whole leaf swallowing behaviors, used directly in response to increased levels of parasite infection.KEYWORDS: Animal self-medication, primates, medicinal plants, disease control, homeostasi
Stone handling in geladas (Theropithecus gelada): implications for spontaneous drawing-like activity as a playful behavior
Stone handling (SH) is a form of solitary object play widely documented in four species of macaques and most recently also in geladas (Theropithecus gelada). Here, we describe the SH activity of two mother-reared captive gelada males, who combined different behavioral patterns in a sequence that occasionally led to the production of colored marks on a hard surface. Two playful techniques of different complexity emerged spontaneously in the two subjects. In the etching and releasing technique, the stone or pieces of it were repeatedly scraped across either a vertical or horizontal hard surface. In the grindandfinger technique, additional patterns were recruited such as scratching the stone to produce small debris that the subjects manipulated through a thumbâindex finger precision grip. Animals selected preferentially hard surfaces when their SH sessions involved patterns that potentially released color and engaged in such patterns for longer and in a repeated way. This evidence suggests the high motivation of the two males to engage in drawing-like behavior that, as it occurs for other forms of play, can be characterized by its autotelic self-rewarding nature. Digital video images related to the article are available at http://www.momo-p.com/showdetail-e.php?movieid=momo220922tg01a and http://www.momo-p.com/showdetail-e.php?movieid=momo220923tg01a
Fundamental constraints on particle tracking with optical tweezers
A general quantum limit to the sensitivity of particle position measurements
is derived following the simple principle of the Heisenberg microscope. The
value of this limit is calculated for particles in the Rayleigh and Mie
scattering regimes, and with parameters which are relevant to optical tweezers
experiments. The minimum power required to observe the zero-point motion of a
levitating bead is also calculated, with the optimal particle diameter always
smaller than the wavelength. We show that recent optical tweezers experiments
are within two orders of magnitude of quantum limited sensitivity, suggesting
that quantum optical resources may soon play an important role in high
sensitivity tracking applications
Processing and Transmission of Information
Contains research objectives and reports on five research projects
- âŠ