2,073 research outputs found
Land, Income, Mobility and Housing: The Case of Metro Manila
Housing developments have been hampered by exorbitantly priced land specifically in the cities. The 1991 housing survey show that Metro Manila households pay the same rate as other households from developing countries. This article reviews the Philippine urban policies and examines the expenditures of owners and renters on shelters. It also investigates the factors on residential mobility among the sample households.urban management, tariff structure, housing program, land management, rent and fee
Land, Income, Mobility and Housing: The Case of Metro Manila
Housing developments have been hampered by exorbitantly priced land specifically in the cities. The 1991 housing survey show that Metro Manila households pay the same rate as other households from developing countries. This article reviews the Philippine urban policies and examines the expenditures of owners and renters on shelters. It also investigates the factors on residential mobility among the sample households.urban management, tariff structure, housing program, land management, rent and fee
Spectral noise in quantum frequency down-conversion from the visible to the telecommunication C-band
We report a detailed study of the noise properties of a visible-to-telecom
photon frequency converter based on difference frequency generation (DFG). The
device converts 580 nm photons to 1541 nm using a strong pump laser at 930 nm,
in a periodically poled lithium niobate ridge waveguide. The converter reaches
a maximum device efficiency of 46 % (internal efficiency of 67 %) at a pump
power of 250 mW. The noise produced by the pump laser is investigated in detail
by recording the noise spectra both in the telecom and visible regimes, and
measuring the power dependence of the noise rates. The noise spectrum in the
telecom is very broadband, as expected from previous work on similar DFG
converters. However, we also observe several narrow dips in the telecom
spectrum, with corresponding peaks appearing in the 580 nm noise spectrum.
These features are explained by sum frequency generation of the telecom noise
at wavelengths given by the phase matching condition of different spatial modes
in the waveguide. The proposed noise model is in good agreement with all the
measured data, including the power-dependence of the noise rates, both in the
visible and telecom regime. These results are applicable to the class of DFG
converters where the pump laser wavelength is in between the input and target
wavelength.Comment: 10 page
Birthday at Bowfin's.
http://deepblue.lib.umich.edu/bitstream/2027.42/52760/4/1192.pd
Kin Discrimination in Dictyostelium Social Amoebae
Presentation delivered at the symposium Evidence of Taxa, Clone, and Kin Discrimination in Protists: Ecological and Evolutionary Implications, VII European Congress of Protistology, University of Seville, 5–10 September 2015, Seville Spain.
Evolved cooperation is stable only when the benefactor is compensated, either directly or through its relatives. Social amoebae cooperate by forming a mobile multicellular body in which, about 20% of participants ultimately die to form a stalk. This benefits the remaining individuals that become hardy spores at the top of the stalk, together making up the fruiting body. In studied species with stalked migration, P. violaceum, D. purpureum, and D. giganteum, sorting based on clone identity occurs in laboratory mixes, maintaining high relatedness within the fruiting bodies. D. discoideum has unstalked migration, where cell fate is not fixed until the slug forms a fruiting body. Laboratory mixes show some degree of both spatial and genotype-based sorting, yet most laboratory fruiting bodies remain chimeric. However, wild fruiting bodies are made up mostly of clonemates. A genetic mechanism for sorting is likely to be cell adhesion genes tgrB1 and tgrC1, which bind to each other. They are highly variable, as expected for a kin discrimination gene. It is a puzzle that these genes do not cause stronger discrimination between mixed wild clones, but laboratory conditions or strong sorting early in the social stage diminished by later slug fusion could be explanations
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Social context shapes individual variation in behavior, learning, and neural gene expression in a swordtail fish
The diverse challenges associated with sociality can be powerful shapers of behavior, yet how sociality affects individual variation in behavior, cognition, and its neural underpinnings is not well understood. Here, we characterized cognitive and behavioral variation as a function of social context in male and female El Abra swordtails (Xiphophorus nigrensis), a species with three genetically-influenced male mating strategies (courtship display, coercion, and mixed strategy). In males, we found that coercive males are bolder but have decreased spatial cognition abilities compared to mixed-strategy and courting males. In females, we conducted a social rearing experiment that exposed females to social treatments that varied in the presence of the type of male mating tactics (coercers only, displayers only, coercers and displayers, and mixed-strategists only). We found that females from complex environments (2 mating tactics present) developed behavioral syndromes characterized by increased boldness and decreased intrasexual aggression relative to females from simple environments (1 mating tactic present). We also found that females from simple environments developed greater spatial cognition abilities than females from simple environments, and that experience with coercion during development led to a greater ability to avoid a coercive male in adulthood. Finally, we found 416 genes were differentially expressed between learners and non-learners after a test of social cognition, as well as 950 genes that were differentially expressed between females from simple and complex rearing environments. Furthermore, we found 640 genes that showed a discordant relationship between learning score and gene expression between females from complex and simple rearing environments. Taken together, these results highlight the power of social context in shaping individual variation in behavior, cognition, and neural gene expression.Ecology, Evolution and Behavio
The distribution of Great Lakes shore plants around inland lakes.
http://deepblue.lib.umich.edu/bitstream/2027.42/52667/1/1100.pd
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