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93-579: Snowflame first appeared in the 1988 comic book New Guardians #2 in a story titled Jungle Snow . In it, he meets the New Guardians in Colombia as the leader of a drug cartel. In their first encounter he defeats the superhero team, but is later killed by them in a chemical shed explosion. In Catwoman #23, Catwoman travels to South America where she meets Snowflame, whose real name is revealed to be Stefan. Snowflame reveals that he faked his death in

186-402: A change in temperature. The numbers are exactly equal if we consider the gases as ideal . The addition of water molecules, or any other molecules, to a gas, without removal of an equal number of other molecules, will necessarily require a change in temperature, pressure, or total volume; that is, a change in at least one of these three parameters. If temperature and pressure remain constant,

279-430: A feature derived from their diet of ants, mites and termites — while species which eat a much larger variety of prey have cryptic coloration with minimal to no amount of observed toxicity. Many species of this family are threatened due to human infrastructure encroaching on their habitats. These amphibians are often called "dart frogs" due to the aboriginal South Americans ' use of their toxic secretions to poison

372-574: A few grow up to 6 cm (2.4 in) in length. They weigh 1 oz. on average. Most poison dart frogs are brightly colored, displaying aposematic patterns to warn potential predators. Their bright coloration is associated with their toxicity and levels of alkaloids. For example, frogs of the genus Dendrobates have high levels of alkaloids, whereas Colostethus species are cryptically colored and are not toxic. Poison dart frogs are an example of an aposematic organism. Their bright coloration advertises unpalatability to potential predators. Aposematism

465-441: A long enough period of time. Another possibility is genetic drift, the so-called gradual-change hypothesis, which could strengthen weak pre-existing aposematism. Sexual selection may have played a role in the diversification of skin color and pattern in poison frogs. With female preferences in play, male coloration could evolve rapidly. Sexual selection is influenced by many things. The parental investment may shed some light on

558-503: A mating conflict. It has also been observed that females who are going after the same male, after hearing their call, chase each other down and wrestle to fight for the male. After a female courts with a male, they are also very likely to exhibit aggressive behavior towards any females that approach that male. Both the males and females bout their own respective sexes for each other in a fairly similar fashion. Many species of poison dart frogs are dedicated parents. Many poison dart frogs in

651-515: A much higher growth rate and typically lived much longer lives. Reasons for this behavior could be that predation and aggression was selected for and favored for a few reasons. One reason is to eliminate predators, and the second reason is that it serves as a source of food in habitats that were low in resources. This predation could have evolved over time and led to cannibalism as another form of predatory behavior that had benefitted individuals survival fitness. However, one observation has been noted in

744-433: A much lower scale height and shorter atmospheric lifetime — weeks instead of decades. Without other greenhouse gases, Earth's blackbody temperature , below the freezing point of water, would cause water vapor to be removed from the atmosphere. Water vapor is thus a "slave" to the non-condensible greenhouse gases. Humidity is one of the fundamental abiotic factors that defines any habitat (the tundra, wetlands, and

837-419: A non-condensable phase other than air. A device used to measure humidity of air is called a psychrometer or hygrometer . A humidistat is a humidity-triggered switch, often used to control a humidifier or a dehumidifier . The humidity of an air and water vapor mixture is determined through the use of psychrometric charts if both the dry bulb temperature ( T ) and the wet bulb temperature ( T w ) of

930-525: A relatively high humidity post-rainfall. Outside the monsoon seasons, humidity is high (in comparison to countries further from the Equator), but completely sunny days abound. In cooler places such as Northern Tasmania, Australia, high humidity is experienced all year due to the ocean between mainland Australia and Tasmania. In the summer the hot dry air is absorbed by this ocean and the temperature rarely climbs above 35 °C (95 °F). Humidity affects

1023-433: A tadpole and does not cross over into their adult life. All species of poison dart frogs are Neotropical in origin. Wild-caught specimens can maintain toxicity for some time (which they obtain through a form of bioaccumulation ), so appropriate care should be taken when handling them. While scientific study on the lifespan of poison dart frogs is scant, retagging frequencies indicate it can range from one to three years in

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1116-465: A way of exhibiting one's strength or fitness, territorial disputes and fights often escalate to physical combat and aggression. Physical violence and aggression are particularly common at times of calling. If it an intruder is detected making calls in the territory of a Dendrobatidae frog, the resident frog attempts to eliminate the competition to claim the territory and the females in it for himself. The resident frog initially makes its presence known by

1209-412: Is affected by winds and by rainfall. The most humid cities on Earth are generally located closer to the equator, near coastal regions. Cities in parts of Asia and Oceania are among the most humid. Bangkok, Ho Chi Minh City , Kuala Lumpur , Hong Kong, Manila , Jakarta , Naha , Singapore, Kaohsiung and Taipei have very high humidity most or all year round because of their proximity to water bodies and

1302-434: Is almost independent of the amount of air (nitrogen, oxygen, etc.) that is present. Indeed, a vacuum has approximately the same equilibrium capacity to hold water vapor as the same volume filled with air; both are given by the equilibrium vapor pressure of water at the given temperature. There is a very small difference described under "Enhancement factor" below, which can be neglected in many calculations unless great accuracy

1395-435: Is also a key metric used to evaluate when it is appropriate to install flooring over a concrete slab. Specific humidity (or moisture content) is the ratio of the mass of water vapor to the total mass of the air parcel. Specific humidity is approximately equal to the mixing ratio , which is defined as the ratio of the mass of water vapor in an air parcel to the mass of dry air for the same parcel. As temperature decreases,

1488-487: Is also measured on a global scale using remotely placed satellites. These satellites are able to detect the concentration of water in the troposphere at altitudes between 4 and 12 km (2.5 and 7.5 mi). Satellites that can measure water vapor have sensors that are sensitive to infrared radiation . Water vapor specifically absorbs and re-radiates radiation in this spectral band. Satellite water vapor imagery plays an important role in monitoring climate conditions (like

1581-543: Is an important metric used in weather forecasts and reports, as it is an indicator of the likelihood of precipitation , dew, or fog. In hot summer weather, a rise in relative humidity increases the apparent temperature to humans (and other animals) by hindering the evaporation of perspiration from the skin. For example, according to the heat index , a relative humidity of 75% at air temperature of 80.0 °F (26.7 °C) would feel like 83.6 ± 1.3 °F (28.7 ± 0.7 °C). Relative humidity

1674-506: Is around 72 °F (22 °C) to 80 °F (27 °C) during the day and no lower than 60 °F (16 °C) to 65 °F (18 °C) at night. Some species tolerate lower temperatures better than others. Many species of poison dart frogs have recently experienced habitat loss, chytrid diseases , and collection for the pet trade. Some are listed as threatened or endangered as a result. Zoos have tried to counteract this disease by treating captive frogs with an antifungal agent that

1767-471: Is currently thought to have originated at least four times within the poison dart family according to phylogenetic trees, and dendrobatid frogs have since undergone dramatic divergences – both interspecific and intraspecific – in their aposematic coloration. This is surprising given the frequency-dependent nature of this type of defense mechanism. Adult frogs lay their eggs in moist places, including on leaves, in plants, among exposed roots, and elsewhere. Once

1860-443: Is defeated and seemingly killed after choking on a poison dart frog that Peacemaker snuck into his cocaine. Snowflame is capable of granting himself superhuman strength, speed, an immunity to pain, pyrokinesis, and the ability to give targets an instant contact high , all by inhaling cocaine . Poison dart frog Poison dart frog (also known as dart-poison frog , poison frog or formerly known as poison arrow frog )

1953-460: Is defined as the ratio of the partial pressure of water vapor ( p {\displaystyle p} ) in air to the saturation vapor pressure ( p s {\displaystyle p_{s}} ) of water at the same temperature, usually expressed as a percentage: φ = 100 % ⋅ p / p s {\displaystyle \varphi =100\%\cdot p/p_{s}} Relative humidity

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2046-627: Is expressed as either mass of water vapor per volume of moist air (in grams per cubic meter) or as mass of water vapor per mass of dry air (usually in grams per kilogram). Relative humidity , often expressed as a percentage, indicates a present state of absolute humidity relative to a maximum humidity given the same temperature. Specific humidity is the ratio of water vapor mass to total moist air parcel mass. Humidity plays an important role for surface life. For animal life dependent on perspiration (sweating) to regulate internal body temperature, high humidity impairs heat exchange efficiency by reducing

2139-499: Is flipped in that the competition is prominent among the males, among the Dendrobatidae it is the opposite as the females seem to have a great deal of competition among themselves for males. Females will even take the drastic measures and resort to the destroying of other female's eggs in order to make sure that the male they mated with is receptive and that it scares the male from mating with other females. The poison dart frog

2232-595: Is further associated with diet specialization, body mass, aerobic capacity, and chemical defense. Conspicuousness and toxicity may be inversely related, as polymorphic poison dart frogs that are less conspicuous are more toxic than the brightest and most conspicuous species. Energetic costs of producing toxins and bright color pigments lead to potential trade-offs between toxicity and bright coloration, and prey with strong secondary defenses have less to gain from costly signaling. Therefore, prey populations that are more toxic are predicted to manifest less bright signals, opposing

2325-430: Is inappropriate for computations in chemical engineering, such as drying, where temperature variations might be significant. As a result, absolute humidity in chemical engineering may refer to mass of water vapor per unit mass of dry air, also known as the humidity ratio or mass mixing ratio (see "specific humidity" below), which is better suited for heat and mass balance calculations. Mass of water per unit volume as in

2418-417: Is known for its aggressive and predatory behavior. As tadpoles , the individuals of the genus Dendrobates exhibit some unique cannibalistic tendencies, along with many other forms of predatory behavior. Dendrobates tadpoles that either consumed three or more conspecific tadpoles and/or relatively large larvae of the mosquito Trichoprosopon digitatum common in their environment led them to having

2511-408: Is limited, and thus each individual offspring receives a larger portion of care, attention, and resources. However, this creates an interesting dynamic of balance as there is a limited number of males available, and with many females competing for a limited number of males for courtship this makes it difficult to limit the number of individuals a male mates with. Whereas in many species, the competition

2604-422: Is not a valid explanation. Functional trade-offs are seen in poison frog defense mechanisms relating to toxin resistance. Poison dart frogs containing epibatidine have undergone a 3 amino acid mutation on receptors of the body, allowing the frog to be resistant to its own poison. Epibatidine-producing frogs have evolved poison resistance of body receptors independently three times. This target-site insensitivity to

2697-528: Is required. Absolute humidity is the total mass of water vapor (gas form of water) present in a given volume or mass of air. It does not take temperature into consideration. Absolute humidity in the atmosphere ranges from near zero to roughly 30 g (1.1 oz) per cubic metre when the air is saturated at 30 °C (86 °F). Absolute humidity is the mass of the water vapor ( m H 2 O ) {\displaystyle (m_{{\text{H}}_{2}{\text{O}}})} , divided by

2790-556: Is shown in State B. If the system at State A is isothermally compressed (compressed with no change in system temperature), then the relative humidity of the system increases because the partial pressure of water in the system increases with the volume reduction. This is shown in State C. Above 202.64 kPa, the RH would exceed 100% and water may begin to condense. If the pressure of State A was changed by simply adding more dry air, without changing

2883-406: Is the common name of a group of frogs in the family Dendrobatidae which are native to tropical Central and South America . These species are diurnal and often have brightly colored bodies. This bright coloration is correlated with the toxicity of the species, making them aposematic . Some species of the family Dendrobatidae exhibit extremely bright coloration along with high toxicity —

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2976-450: Is the dry-bulb temperature expressed in degrees Celsius (°C), P {\displaystyle P} is the absolute pressure expressed in millibars, and e w ∗ {\displaystyle e_{w}^{*}} is the equilibrium vapor pressure expressed in millibars. Buck has reported that the maximal relative error is less than 0.20% between −20 and +50 °C (−4 and 122 °F) when this particular form of

3069-558: Is the most abundant of all greenhouse gases . Water vapor, like a green lens that allows green light to pass through it but absorbs red light, is a "selective absorber". Like the other greenhouse gasses, water vapor is transparent to most solar energy. However, it absorbs the infrared energy emitted (radiated) upward by the Earth's surface, which is the reason that humid areas experience very little nocturnal cooling but dry desert regions cool considerably at night. This selective absorption causes

3162-437: Is the ratio of how much water vapour is in the air to how much water vapour the air could potentially contain at a given temperature. It varies with the temperature of the air: colder air can contain less vapour, and water will tend to condense out of the air more at lower temperatures. So changing the temperature of air can change the relative humidity, even when the absolute humidity remains constant. Chilling air increases

3255-468: Is typically separated into two distinct categories. The first is the primary portion of Dendrobatidae's diet which include prey that are slow-moving, large in number, and small in size. This typically consists of ants , while also including mites , small beetles , and minor litter-dwelling taxa. The second category of prey are much rarer finds and are much larger in body size, and they tend to have high palatability and mobility. These typically consist of

3348-425: Is used to cure athlete's foot in humans. Poison dart frogs suffer from parasites ranging from helminths to protozoans. Poison dart frogs suffer from chytridiomycosis, which is a deadly disease that is caused by the fungus Batrachochytrium dendrobatidis (Bd). This infection has been found in frogs from Colostethus and Dendrobates . Humid Humidity is the concentration of water vapor present in

3441-629: The Magnus–Tetens approximation , are more complicated but yield better accuracy. The Arden Buck equation is commonly encountered in the literature regarding this topic: e w ∗ = ( 1.0007 + 3.46 × 10 − 6 P ) × 6.1121 e 17.502 T / ( 240.97 + T ) , {\displaystyle e_{w}^{*}=\left(1.0007+3.46\times 10^{-6}P\right)\times 6.1121\,e^{17.502T/(240.97+T)},} where T {\displaystyle T}

3534-425: The energy budget and thereby influences temperatures in two major ways. First, water vapor in the atmosphere contains "latent" energy. During transpiration or evaporation, this latent heat is removed from surface liquid, cooling the Earth's surface. This is the biggest non-radiative cooling effect at the surface. It compensates for roughly 70% of the average net radiative warming at the surface. Second, water vapor

3627-526: The monsoon season. High temperatures combine with the high dew point to create heat index in excess of 65 °C (149 °F). Darwin experiences an extremely humid wet season from December to April. Houston, Miami, San Diego, Osaka, Shanghai, Shenzhen and Tokyo also have an extreme humid period in their summer months. During the South-west and North-east Monsoon seasons (respectively, late May to September and November to March), expect heavy rains and

3720-770: The orthopteroids , lepidopteran larvae, and spiders. The natural diet of an individual dendrobatid depends on its species and prey abundance in its location, amongst other factors. The Dendrobatidae are a family of species very well known for their territorial and aggressive behavior not only as tadpoles, but as adults too. These aggression behaviors are not only limited to males, as many female Dendrobatidae also are known to defend their own native territory very aggressively. Dendrobatidae are especially aggressive in defending regions that serve as male calling sites. Males wrestle with intruders of their territory in order to defend their calling sites as well as their vegetation. While vocalization and various behavioral displays serve as

3813-533: The Bocas del Toro populations of Oophaga pumilio . The chemical defense mechanisms of the Dendrobates family are the result of exogenous means. Essentially, this means that their ability to defend has come through the consumption of a particular diet – in this case, toxic arthropods – from which they absorb and reuse the consumed toxins. The secretion of these chemicals is released by the granular glands of

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3906-419: The Dendrobatidae family suggest that males of the species typically make their mating call in morning between the times of 6:30 am to 11:30 am. The males are usually on average one meter above the ground on limbs, trunks, and stems, or logs of trees so that their call travels further and so they can be seen by potential mates. The calls are signaled towards the stream where females are located. After

3999-464: The actual patterns are probably controlled by a single locus ). Differing coloration has historically misidentified single species as separate, and there is still controversy among taxonomists over classification . Variation in predation regimens may have influenced the evolution of polymorphism in Oophaga granulifera , while sexual selection appears to have contributed to differentiation among

4092-457: The air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation , dew , or fog to be present. Humidity depends on the temperature and pressure of the system of interest. The same amount of water vapor results in higher relative humidity in cool air than warm air. A related parameter is the dew point . The amount of water vapor needed to achieve saturation increases as

4185-414: The alkaloids sequestered by wild populations. Nonetheless, the captive-bred frogs retain the ability to accumulate alkaloids when they are once again provided an alkaloidal diet. Despite the toxins used by some poison dart frogs, some predators have developed the ability to withstand them. One is the snake Erythrolamprus epinephalus , which has developed immunity to the poison. Chemicals extracted from

4278-424: The amount of water vapor needed to reach saturation also decreases. As the temperature of a parcel of air becomes lower it will eventually reach the point of saturation without adding or losing water mass. The term relative humidity is reserved for systems of water vapor in air. The term relative saturation is used to describe the analogous property for systems consisting of a condensable phase other than water in

4371-597: The ants and mites required for diet specialization, contrary to classical aposematic theory, which assumes that toxicity from diet arises before signaling. Alternatively, diet specialization preceded higher aerobic capacity, and aposematism evolved to allow dendrobatids to gather resources without predation. Prey mobility could also explain the initial development of aposematic signaling. If prey have characteristics that make them more exposed to predators, such as when some dendrobatids shifted from nocturnal to diurnal behavior, then they have more reason to develop aposematism. After

4464-663: The atmosphere is as warm or warmer than the skin during times of high humidity, blood brought to the body surface cannot dissipate heat by conduction to the air. With so much blood going to the external surface of the body, less goes to the active muscles, the brain, and other internal organs. Physical strength declines, and fatigue occurs sooner than it would otherwise. Alertness and mental capacity also may be affected, resulting in heat stroke or hyperthermia . Domesticated plants and animals (e.g. lizards) require regular upkeep of humidity percent when grown in-home and container conditions, for optimal thriving environment. Although humidity

4557-473: The call is received, the female makes its way to the male and fertilization occurs. This observed fertilization is not accomplished through amplexus. Upon meeting, courtship is generally initiated by the female. The female strokes, climbs, and jumps on the male in tactile courtship and are by far the more active sex.  The duration of courtship in poison frogs is long and females may occasionally reject males, even after an entire day of active pursuit. In

4650-578: The chemical shed explosion in order to take over the island of Isla Nevada. He then escorts Catwoman to his home where he is auctioning off expensive and dangerous artifacts to other supervillains. In Catwoman #24, Catwoman sneaks into the jungle and meets Kisin, the island's mythical giant panther and god of death, before returning to do battle with Snowflame. She defeats him with the help of Kisin. Snowflame later returns in Peacemaker Tries Hard! #4, in which he fights against Peacemaker. He

4743-448: The chilled mirror method is effective. For process on-line measurements, the most commonly used sensors nowadays are based on capacitance measurements to measure relative humidity, frequently with internal conversions to display absolute humidity as well. These are cheap, simple, generally accurate and relatively robust. All humidity sensors face problems in measuring dust-laden gas, such as exhaust streams from clothes dryers. Humidity

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4836-435: The classical view that increased conspicuousness always evolves with increased toxicity. Skin toxicity evolved alongside bright coloration, perhaps preceding it. Toxicity may have relied on a shift in diet to alkaloid-rich arthropods, which likely occurred at least four times among the dendrobatids. Either aposematism and aerobic capacity preceded greater resource gathering, making it easier for frogs to go out and gather

4929-475: The day. About 28 structural classes of alkaloids are known in poison dart frogs. The most toxic of poison dart frog species is Phyllobates terribilis . It is believed that dart frogs do not synthesize their poisons, but sequester the chemicals from arthropod prey items, such as ants, centipedes and mites – the diet-toxicity hypothesis. Because of this, captive-bred animals do not possess significant levels of toxins as they are reared on diets that do not contain

5022-415: The desert are a few examples), and is a determinant of which animals and plants can thrive in a given environment. The human body dissipates heat through perspiration and its evaporation. Heat convection , to the surrounding air, and thermal radiation are the primary modes of heat transport from the body. Under conditions of high humidity, the rate of evaporation of sweat from the skin decreases. Also, if

5115-1245: The eggs hatch, the adult piggybacks the tadpoles , one at a time, to suitable water: either a pool, or the water gathered in the throat of bromeliads or other plants. The tadpoles remain there until they metamorphose , in some species fed by unfertilized eggs laid at regular intervals by the mother. Poison dart frogs are endemic to humid , tropical environments of Central and South America. These frogs are generally found in tropical rainforests , including in Bolivia , Costa Rica , Brazil , Colombia , Ecuador , Venezuela , Suriname , French Guiana , Peru , Panama , Guyana , Nicaragua , and Hawaii (introduced). Natural habitats include moist, lowland forests (subtropical and tropical), high-altitude shrubland (subtropical and tropical), moist montanes and rivers (subtropical and tropical), freshwater marshes, intermittent freshwater marshes, lakes and swamps. Other species can be found in seasonally wet or flooded lowland grassland, arable land, pastureland, rural gardens, plantations, moist savanna and heavily degraded former forest. Premontane forests and rocky areas have also been known to hold frogs. Dendrobatids tend to live on or close to

5208-465: The enhancement factor is normally slightly greater than unity for real systems. The enhancement factor is commonly used to correct the equilibrium vapor pressure of water vapor when empirical relationships, such as those developed by Wexler, Goff, and Gratch, are used to estimate the properties of psychrometric systems. Buck has reported that, at sea level, the vapor pressure of water in saturated moist air amounts to an increase of approximately 0.5% over

5301-443: The equation above is also defined as volumetric humidity . Because of the potential confusion, British Standard BS 1339 suggests avoiding the term "absolute humidity". Units should always be carefully checked. Many humidity charts are given in g/kg or kg/kg, but any mass units may be used. The field concerned with the study of physical and thermodynamic properties of gas–vapor mixtures is named psychrometrics . Relative humidity

5394-590: The equator and often overcast weather. Some places experience extreme humidity during their rainy seasons combined with warmth giving the feel of a lukewarm sauna, such as Kolkata , Chennai and Kochi in India, and Lahore in Pakistan. Sukkur city located on the Indus River in Pakistan has some of the highest and most uncomfortable dew points in the country, frequently exceeding 30 °C (86 °F) in

5487-474: The equilibrium vapor pressure of pure water. Climate control refers to the control of temperature and relative humidity in buildings, vehicles and other enclosed spaces for the purpose of providing for human comfort, health and safety, and of meeting environmental requirements of machines, sensitive materials (for example, historic) and technical processes. While humidity itself is a climate variable, it also affects other climate variables. Environmental humidity

5580-503: The evolution of coloration in relation to female choice. In Oophaga pumilio , the female provides care for the offspring for several weeks whereas the males provides care for a few days, implying a strong female preference. Sexual selection increases phenotypic variation drastically. In populations of O. pumilio that participated in sexual selection, the phenotypic polymorphism was evident. The lack of sexual dimorphism in some dendrobatid populations however suggests that sexual selection

5673-400: The female will typically produce eggs at an exceedingly fast rate that the males cannot possibly take full care of them which then leads to some of the males becoming unreceptive.  Dendrobatidae also exhibit the parental quality hypothesis. This is where the females mating with the males try to ensure that their male mates with as few individuals as possible so that their number of offspring

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5766-418: The formation of thunderstorms) and in the development of weather forecasts . Humidity depends on water vaporization and condensation, which, in turn, mainly depends on temperature. Therefore, when applying more pressure to a gas saturated with water, all components will initially decrease in volume approximately according to the ideal gas law . However, some of the water will condense until returning to almost

5859-560: The frog. The chemicals secreted by the Dendrobatid family of frogs are alkaloids that differ in chemical structure and toxicity. Many poison dart frogs secrete lipophilic alkaloid toxins such as allopumiliotoxin 267A , batrachotoxin , epibatidine , histrionicotoxin , and pumiliotoxin 251D through their skin. Alkaloids in the skin glands of poison dart frogs serve as a chemical defense against predation, and they are therefore able to be active alongside potential predators during

5952-448: The genera Oophaga and Ranitomeya carry their newly hatched tadpoles into the canopy; the tadpoles stick to the mucus on the backs of their parents. Once in the upper reaches of the rainforest trees, the parents deposit their young in the pools of water that accumulate in epiphytic plants, such as bromeliads . The tadpoles feed on invertebrates in their nursery, and their mother will even supplement their diet by depositing eggs into

6045-429: The general characteristic of Dendrobates tadpoles including D. arboreus , D. granuliferus , D. lehmanni , D. occultator , D. pumilio , D. speciosus , and many other Dendrobates species is that they have reduced mouth parts as young tadpoles which limits their consumption typically to unfertilized eggs only. Thus, it can be assumed that the cannibalistic tendencies of Dendrobates is limited to their lifetime as

6138-409: The generalized formula is used to estimate the equilibrium vapor pressure of water. There are various devices used to measure and regulate humidity. Calibration standards for the most accurate measurement include the gravimetric hygrometer, chilled mirror hygrometer , and electrolytic hygrometer. The gravimetric method, while the most accurate, is very cumbersome. For fast and very accurate measurement

6231-450: The greenhouse effect. It raises the surface temperature substantially above its theoretical radiative equilibrium temperature with the sun, and water vapor is the cause of more of this warming than any other greenhouse gas. Unlike most other greenhouse gases, however, water is not merely below its boiling point in all regions of the Earth, but below its freezing point at many altitudes. As a condensible greenhouse gas, it precipitates , with

6324-595: The ground, but also in trees as much as 10 m (33 ft) from the ground. Dart frogs are the focus of major phylogenetic studies, and undergo taxonomic changes frequently. The family Dendrobatidae currently contains 16 genera, with about 200 species. Some poison dart frogs species include a number of conspecific color morphs that emerged as recently as 6,000 years ago. Therefore, species such as Dendrobates tinctorius , Oophaga pumilio , and Oophaga granulifera can include color pattern morphs that can be interbred (colors are under polygenic control, while

6417-440: The ideal gas law. On the contrary the saturated volume is the volume a gas mixture would have if humidity was added to it until saturation (or 100% relative humidity). Humid air is less dense than dry air because a molecule of water ( m ≈ 18  Da ) is less massive than either a molecule of nitrogen ( m ≈ 28 ) or a molecule of oxygen ( m ≈ 32 ). About 78% of the molecules in dry air are nitrogen (N 2 ). Another 21% of

6510-434: The larger portion of parental investment falls on the shoulders of the female sex, whereas the male sex has a much smaller portion. However, it has been studied that in the family of Dendrobatidae, many of the species exhibit sex role reversal in which the females are competing for a limited number of males and the males are the choosers and their parental investment is much larger than the females. This theory also says that

6603-405: The majority of cases, the males choose the oviposition site and lead the females there. In some Dendrobatidae species, such as strawberry poison frog , visual cues under high light intensity are also used to identify individuals from the same population. Different species use different cues to identify individuals from their same population during mating and courtship. Typically in many species

6696-433: The means of vocalization and various behavioral displays as a way to exert dominance, but if this does not scare away the intruder, then the resident frog moves towards the intruder and strikes them. These encounters immediately escalate into a full on fight where both strike each other and grasp each other's limbs. Similarly, the females also often get into fights and display aggressive behaviors in disputes over territory or

6789-414: The measure of relative humidity of the air, although their presence is an indication that a body of air may be close to the dew point. Relative humidity is normally expressed as a percentage; a higher percentage means that the air–water mixture is more humid. At 100% relative humidity, the air is saturated and is at its dew point. In the absence of a foreign body on which droplets or crystals can nucleate ,

6882-456: The mixture are known. These quantities are readily estimated by using a sling psychrometer . There are several empirical formulas that can be used to estimate the equilibrium vapor pressure of water vapor as a function of temperature. The Antoine equation is among the least complex of these, having only three parameters ( A , B , and C ). Other formulas, such as the Goff–Gratch equation and

6975-444: The molecules in dry air are oxygen (O 2 ). The final 1% of dry air is a mixture of other gases. For any gas, at a given temperature and pressure, the number of molecules present in a particular volume is constant. Therefore, when some number N of water molecules (vapor) is introduced into a volume of dry air, the number of air molecules in that volume must decrease by the same number N for the pressure to remain constant without using

7068-618: The most prominent roosts from which to broadcast his mating call ; females fight over desirable nests, and even invade the nests of other females to devour competitor's eggs. The operational sex ratio in the poison dart frog family is mostly female biased. This leads to a few characteristic behaviors and traits found in organisms with an uneven sex ratio. In general, females have a choice of mate. In turn, males show brighter coloration, are territorial, and are aggressive toward other males. Females select mates based on coloration (mainly dorsal), calling perch location, and territory. Observations of

7161-425: The potent toxin epibatidine on nicotinic acetylcholine receptors provides a toxin resistance while reducing the affinity of acetylcholine binding. The diet of Dendrobatidae is what gives them the alkaloids/toxins that are found in their skin. The diet that is responsible for these characteristics consists primarily of small and leaf-litter arthropods found in its general habitat, typically ants. Their diet, however,

7254-417: The rate of moisture evaporation from skin surfaces. This effect can be calculated using a heat index table, or alternatively using a similar humidex . The notion of air "holding" water vapor or being "saturated" by it is often mentioned in connection with the concept of relative humidity. This, however, is misleading—the amount of water vapor that enters (or can enter) a given space at a given temperature

7347-491: The relative humidity can exceed 100%, in which case the air is said to be supersaturated . Introduction of some particles or a surface to a body of air above 100% relative humidity will allow condensation or ice to form on those nuclei, thereby removing some of the vapour and lowering the humidity. In a scientific notion, the relative humidity ( R H {\displaystyle RH} or φ {\displaystyle \varphi } ) of an air-water mixture

7440-440: The relative humidity, and can cause the water vapour to condense (if the relative humidity rises over 100%, the dew point ). Likewise, warming air decreases the relative humidity. Warming some air containing a fog may cause that fog to evaporate, as the droplets are prone to total evaporation due to the heat. Relative humidity only considers the invisible water vapour. Mists, clouds, fogs and aerosols of water do not count towards

7533-403: The same humidity as before, giving the resulting total volume deviating from what the ideal gas law predicted. Conversely, decreasing temperature would also make some water condense, again making the final volume deviate from predicted by the ideal gas law. Therefore, gas volume may alternatively be expressed as the dry volume, excluding the humidity content. This fraction more accurately follows

7626-502: The saturated vapor pressure of pure water: f W = e w ′ e w ∗ . {\displaystyle f_{W}={\frac {e'_{w}}{e_{w}^{*}}}.} The enhancement factor is equal to unity for ideal gas systems. However, in real systems the interaction effects between gas molecules result in a small increase of the equilibrium vapor pressure of water in air relative to equilibrium vapor pressure of pure water vapor. Therefore,

7719-406: The skin of Epipedobates tricolor may have medicinal value. Scientists use this poison to make a painkiller. One such chemical is a painkiller 200 times as potent as morphine , called epibatidine ; however, the therapeutic dose is very close to the fatal dose. A derivative, ABT-594 , developed by Abbott Laboratories , was named as Tebanicline and got as far as Phase II trials in humans, but

7812-406: The switch, the frogs had greater ecological opportunities, causing dietary specialization to arise. Thus, aposematism is not merely a signaling system, but a way for organisms to gain greater access to resources and increase their reproductive success. Dietary conservatism (long-term neophobia ) in predators could facilitate the evolution of warning coloration, if predators avoid novel morphs for

7905-463: The temperature but also on the absolute pressure of the system of interest. This dependence is demonstrated by considering the air–water system shown below. The system is closed (i.e., no matter enters or leaves the system). If the system at State A is isobarically heated (heating with no change in system pressure), then the relative humidity of the system decreases because the equilibrium vapor pressure of water increases with increasing temperature. This

7998-553: The temperature increases. As the temperature of a parcel of air decreases it will eventually reach the saturation point without adding or losing water mass. The amount of water vapor contained within a parcel of air can vary significantly. For example, a parcel of air near saturation may contain 8 g of water per cubic metre of air at 8 °C (46 °F), and 28 g of water per cubic metre of air at 30 °C (86 °F) Three primary measurements of humidity are widely employed: absolute, relative, and specific. Absolute humidity

8091-465: The tips of blowdarts . However, out of over 170 species, only four have been documented as being used for this purpose ( curare plants are more commonly used for aboriginal South American darts) all of which come from the genus Phyllobates , which is characterized by the relatively large size and high levels of toxicity of its members. Most species of poison dart frogs are small, sometimes less than 1.5 cm (0.59 in) in adult length, although

8184-416: The volume increases, and the dry air molecules that were displaced will initially move out into the additional volume, after which the mixture will eventually become uniform through diffusion. Hence the mass per unit volume of the gas—its density—decreases. Isaac Newton discovered this phenomenon and wrote about it in his book Opticks . The relative humidity of an air–water system is dependent not only on

8277-468: The volume of the air and water vapor mixture ( V net ) {\displaystyle (V_{\text{net}})} , which can be expressed as: A H = m H 2 O V net . {\displaystyle AH={\frac {m_{{\text{H}}_{2}{\text{O}}}}{V_{\text{net}}}}.} If the volume is not set, the absolute humidity varies with changes in air temperature or pressure. Because of this, it

8370-499: The volume, the relative humidity would not change. Therefore, a change in relative humidity can be explained by a change in system temperature, a change in the volume of the system, or change in both of these system properties. The enhancement factor ( f w ) {\displaystyle (f_{w})} is defined as the ratio of the saturated vapor pressure of water in moist air ( e w ′ ) {\displaystyle (e'_{w})} to

8463-517: The water. Other poison frogs lay their eggs on the forest floor, hidden beneath the leaf litter . Poison frogs fertilize their eggs externally ; the female lays a cluster of eggs and a male fertilizes them afterward, in the same manner as most fish. Poison frogs can often be observed clutching each other, similar to the manner most frogs copulate. However, these demonstrations are actually territorial wrestling matches. Both males and females frequently engage in disputes over territory. A male will fight for

8556-403: The wild. However, these frogs typically live for much longer in captivity, having been reported to live as long as 25 years. These claims also seem to be questionable, since many of the larger species take a year or more to mature, and Phyllobates species can take more than two years. In captivity, most species thrive where the humidity is kept constant at 80 to 100% and where the temperature

8649-562: Was dropped from further development due to dangerous gastrointestinal side effects. Secretions from dendrobatids are also showing promise as muscle relaxants , heart stimulants and appetite suppressants . The most poisonous of these frogs, the golden poison frog ( Phyllobates terribilis ), has enough toxin on average to kill ten to twenty men or about twenty thousand mice. Most other dendrobatids, while colorful and toxic enough to discourage predation, pose far less risk to humans or other large animals. Conspicuous coloration in these frogs

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