Communication alarm signals

Once a sensor in an alarm system detects an event, it must communicate an alarm signal. The two basic types of alarm communication systems are hardwired and wireless. Hardwired systems rely on wire that is run from the control panel to each of the detection devices and annunciators. Wireless systems transmit signals from a transmitter to a receiver through the air—primarily using radio or other waves. Hardwired... 

An exterior intrusion sensor is a detection device that is used in an outdoor environment to detect intrusions into a protected area. These devices are designed to detect an intruder and then communicate an alarm signal to an alarm system. The alarm system can respond to the intrusion in many different ways, such as by triggering an audible or visual alarm signal, or by sending an electronic signal to a central monitoring location that notifies security personnel of the intrusion. 

Each type of emergency alarm or signal must clearly inform those onsite of the actions to be taken. This requires training and testing of the alarm so personnel can recognize the alarm and take appropriate action. Some of these alarms may be automatic. For example, detection of a fire may be signaled directly by the protection or detection system rather than by an individual. This alarm signal may alert not only personnel in the immediate area, but all facility personnel and the community fire department. 

Chemically mediated interactions have important direct and indirect effects on communities from both ecological and evolutionary standpoints.22 341 Chemical defense or communication cannot be properly understood unless it is viewed through the lenses of population, community, and ecosystem processes, and this requires consideration of both the biotic and abiotic components of the natural environment.342 For example, chemically mediated foraging is affected by water flow because it relies on water-soluble cues that are carried away from prey.343 345 Similar constraints likewise modify the effectiveness of other waterborne cues, such as alarm signals, sexual pheromones, and settlement cues, in both mobile and sessile organisms.244 345 350... 

Because an exact temperature of 37 "C is essential for the accurate measurement of blood gases and pH, state-of-the-art instrumentation is fiirnished with thermal sensors embedded in the heat sink around the measuring chamber and communicating to the microprocessor. Audible or visible alarms signal deviation of temperature outside of preset tolerances (usually 37 C + 0.1 °C). Also of value is to use temperature-sensitive buffers, such as HEPES or TES, in pH quality assurance procedures. 

We dedicate this book to the memory of R. Jan F. Smith who died unexpectedly in the fall of 1998. Jan was a pioneer in the area of chemical communication, especially in the area of alarm signaling by fish. He also made basic contributions to the field of fish migration. An excellent review of Jan s ideas on alarm signals and their evolution appears as a chapter in this book. It is the last major review he wrote on this topic. Jan s enthusiastic and imaginative research resulted in many fundamental advances in our understanding of chemical communication and stimulated many students to pursue careers in our discipline. Jan will be sorely missed by friends, family, colleagues and the broader scientific community. 

The evolutionary success of the aphid appears closely linked to the development of chemical alarm signals and the cornicle. The primitive Aphidoidea that lack or have poorly developed cornicles have adopted a strategy of predator avoidance most live within protective plant galls or are soil dwellers. There is a strong correlation between presence of well-developed cornicles in aphids and their exposed habitat. One of us (L.R.N.) discovered what may represent an evolutionary primitive form of aphid alarm communication. Hamamelistes spinosus, a Hormaphidinae that lacks cornicles, releases low levels of alarm chemicals from its punctured body wall. The aphid lives within cupped birch... 

There was no community awareness of alarm signals, nor any evacuation plan. 

The preceding falls far short of conveying a true impression of the chemical skills of arthropods. Excluded from our discussion are the diverse signaling agents that mediate such vital insectan functions as food location, mate attraction, social bonding, and alarm communication. Other contributors to this colloquium address some of these topics. While... 

In contrast to systems that are set up to transmit local only alarms when the sensors are triggered, systems can also be set up to transmit signals to a central location, such as to a control room or guard post at the utility, or to a police or fire station. Most fire/smoke alarms are set up to signal both at the location of the event and at a fire station or central monitoring station. Many insurance companies require that facilities install certified systems that include alarm communication to a central station. For example, systems certified by the Underwriters Laboratory (UL) require that the alarm be reported to a central monitoring station. 

The plan must include a list of all emergency equipment at tlie facility (such as fire cxtinguisliing systems, spill control equipment, internal and external communications and alarm s> stems, and dccontmnination equipment). In addition, the plan must include for each item on the list a physical description, a brief outline of its capabilities, and its location The contingency plan must include an evacuation plan for facility pcrsoiuicl if the possibility exists that e acuation might become neeessary. The evacuation plan must describe signal(s) to be used to begin evacuation, evacuation routes, and alternate e acuation routes (in cases where priniiiry routes could be blocked by releases of hazardous wastes or fires)" ... 

Microwave radiation is emitted by dryers, ovens, and heaters normally used in the home. The high-power radars used for military purposes, communication equipment, alarm systems, and signal generators are other sources of microwave radiation. The low-power microwave radiation can cause heating and skin redness whereas high-power microwave radiation can cause inductive heating of metals and induced currents that can produce electric spark. Containers with flammable materials may catch fire if they are placed in the microwave fields. Rings, watches, metal bands, keys, and similar objects worn or carried by a person in such a field can be heated vmtil they burn the bearers. 

Olfaction, the sense of smell, is an important neural system in various animal species, including fish, for their life. Fish can detect a variety of odorants emitted from objects and dissolved in the water, such as amino acids, bile salts, nucleotides, polyamines, prostaglandins, and steroids. The fish olfactory system is extensively developed to receive and discriminate these odorant molecules, to transmit their signals to the brain, and to mediate fundamental behaviors such as food finding, alarm response, predator avoidance, social communication, reproductive activity, and spawning migration (Sorensen and Caprio 1998 Zielinski and Hara 2007). 

Since this was quite an event at the Rad Lab, we connected a fire bell in the hallway to the counters so that the alarm would go off every time an atom of element 101 disintegrated. This was a most effective way of signaling the occurrence of a nuclear event, but quieter means of communication were soon substituted, following a suggestion put forward by the fire department. 

Insects communicate by releasing pheromones—chemical substances that other insects of the same species detect with their anteimae. There are sex, alarm, and trail pheromones, and many of these are alkenes. Interfering with an insect s ability to send or receive chemical signals is an environmentally safe way to control insect populations. For example, traps with synthetic sex attractants have been used to capture such crop-destroying insects as the gypsy moth and the boll weevil. Many of the flavors and fragrances produced by certain plants also belong to the alkene family. 

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