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111.
Objective: To contrast relief efforts for the 26 December 2004 tsunami with current global HIV/AIDS relief efforts and analyse possible reasons for the disparity. Methods: Literature review and ethical analysis. Results: Just over 273,000 people died in the tsunami, resulting in relief efforts of more than US$10 bn, which is sufficient to achieve the United Nation’s long‐term recovery plan for South East Asia. In contrast, 14 times more people died from HIV/AIDS in 2004, with UNAIDS predicting a US$8 bn funding gap for HIV/AIDS in developing nations between now and 2007. This disparity raises two important ethical questions. First, what is it that motivates a more empathic response to the victims of the tsunami than to those affected by HIV/AIDS? Second, is there a morally relevant difference between the two tragedies that justifies the difference in the international response? The principle of justice requires that two cases similarly situated be treated similarly. For the difference in the international response to the tsunami and HIV/AIDS to be justified, the tragedies have to be shown to be dissimilar in some relevant respect. Are the tragedies of the tsunami disaster and the HIV/AIDS pandemic sufficiently different, in relevant respects, to justify the difference in scope of the response by the international community? Conclusion: We detected no morally relevant distinction between the tsunami and the HIV/AIDS pandemic that justifies the disparity. Therefore, we must conclude that the international response to HIV/AIDS violates the fundamental principles of justice and fairness. 相似文献
112.
Hiroshi Motomura 《Ethnic and racial studies》2015,38(8):1305-1311
Culling the Masses by Professors David Scott FitzGerald and David Cook-Martín is an impressive work that makes important scholarly contributions. It analyses the trend in the USA, Canada, Cuba, Mexico, Brazil and Argentina away from explicit racial discrimination in immigration laws. One layer of the book's argument examines how ‘vertical’ (domestic) and ‘horizontal’ (external) forces led these countries to abandon explicit racism. In another layer, the book argues that this anti-racist turn was not a product of democracy. Instead, racist immigration laws were often the product of democratic influences and institutions. The nuanced examination of external influences on national immigration laws in Culling the Masses is an invaluable contribution. However, its inconsistent definition of ‘immigration law’ across countries leaves incomplete both its assessment of racism in the present-day immigration laws, and in turn, its assessment of the relationship between democracy and racism. 相似文献
113.
Whether face adaptation confers any advantages to perceptual processing remains an open question. We investigated whether face adaptation can enhance the ability to make fine discriminations in the vicinity of the adapted face. We compared face discrimination thresholds in three adapting conditions: (i) same-face: where adapting and test faces were the same, (ii) different-face: where adapting and test faces differed, and (iii) baseline: where the adapting stimulus was a blank. Discrimination thresholds for morphed identity changes involving the adapted face (same-face) improved compared with those from both the baseline (no-adaptation) and different-face conditions. Since adapting to a face did not alter discrimination performance for other faces, this effect is selective for the facial identity that is adapted. These results indicate a form of gain control to heighten perceptual sensitivity in the vicinity of a currently viewed face, analogous to forms of adaptive gain control at lower levels of the visual system. 相似文献
114.
AMaCAID is an R program designed to analyse multilocus genotypic patterns in large samples. It allows (i) the computation of the number and frequency of the different multilocus patterns available in a molecular data set and (ii) the analysis of discriminatory power of each combination of k markers among n available. It thus enables the identification of the minimum number of markers required to distinguish all the observed genotypes and the subset of markers that maximize the number of distinct genotypes. AMaCAID can be used with any kind of molecular markers, on data sets mixing different kinds of markers, but also on qualitative characters like morphological or taxonomic traits. AMaCAID has been built primarily to select subsets of markers for identifying accessions and monitoring their genetic stability during regeneration cycles in an ex situ genebank. It can, however, also be used to screen any kind of data set that characterizes a set of individuals or species (e.g. taxonomic or phylogenetic studies) for discrimination purposes. The size of the assayed sample has no limitation, but the program only performs computations on all combinations of markers when there are less than 25 markers. For larger number of markers/characters, it is possible to ask AMaCAID to screen a large but limited number of combinations of markers. We apply AMaCAID to three data sets involving either molecular or taxonomic data and give some results on the computing time of the program with respect to the size of the data set. 相似文献
115.
Abstract. 1. This study investigates how female seed beetles, Callosobruchus maculatus , distribute their eggs on various-sized seeds when the size of seed was varied during the egg-laying period.
2. Beetles were allowed to lay eggs on one of three arrays of 64 adzuki beans ( Vigna angularis ). Each array contained four size classes of seed, ranging from small (5.0–5.5 mm diameter) to large (6.5–7.0 mm), but differed in how they were distributed within the environment. In the most heterogeneous condition (the 64-patch design), the four sizes were interspersed, while in the least heterogeneous condition (the four-patch design) they were grouped into four separate blocks. Thus, a beetle exploring the 64-patch design would frequently encounter all four seed sizes, whereas a beetle exploring the four-patch design would only rarely encounter a change in bean size.
3. Beetles experiencing greater seed size heterogeneity were more likely to lay eggs on larger seeds, whereas those in the blocked condition were more likely to oviposit on small seeds. Beetle responses to seed size heterogeneity suggest that the degree of preference for large seeds depends on a female's recent experience.
4. Female beetles exhibited size discrimination throughout their egg-laying process; however, there was a trade-off between seed size and egg discrimination (i.e. avoiding those seeds already containing developing eggs) in response to the change in fitness gained from either laying on larger seeds or lower egg-load seeds during the egg-laying process.
5. Our model provides the first evidence that evolving seed size discrimination ability is adaptive for the seed beetle with egg-discrimination ability. 相似文献
2. Beetles were allowed to lay eggs on one of three arrays of 64 adzuki beans ( Vigna angularis ). Each array contained four size classes of seed, ranging from small (5.0–5.5 mm diameter) to large (6.5–7.0 mm), but differed in how they were distributed within the environment. In the most heterogeneous condition (the 64-patch design), the four sizes were interspersed, while in the least heterogeneous condition (the four-patch design) they were grouped into four separate blocks. Thus, a beetle exploring the 64-patch design would frequently encounter all four seed sizes, whereas a beetle exploring the four-patch design would only rarely encounter a change in bean size.
3. Beetles experiencing greater seed size heterogeneity were more likely to lay eggs on larger seeds, whereas those in the blocked condition were more likely to oviposit on small seeds. Beetle responses to seed size heterogeneity suggest that the degree of preference for large seeds depends on a female's recent experience.
4. Female beetles exhibited size discrimination throughout their egg-laying process; however, there was a trade-off between seed size and egg discrimination (i.e. avoiding those seeds already containing developing eggs) in response to the change in fitness gained from either laying on larger seeds or lower egg-load seeds during the egg-laying process.
5. Our model provides the first evidence that evolving seed size discrimination ability is adaptive for the seed beetle with egg-discrimination ability. 相似文献
116.
Generalization and categorization of spectral colors in goldfish I. Experiments with one training wavelength 总被引:1,自引:1,他引:0
Manuela?Kitschmann Christa?NeumeyerEmail author 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2005,191(11):1025-1036
Goldfish have a tetrachromatic color vision with a high discrimination ability for spectral colors as well as for object colors.
We investigate the question whether goldfish organize the high number of discriminable colors in terms of color categories,
i.e. in a few larger groups of colors independent of wavelength discrimination. Twenty-four goldfish were trained with food
reward, each fish on one out of 13 wavelengths between 371 nm and 630 nm. In transfer tests two different wavelengths were
presented, one shorter and one longer than the training wavelength, and the choice behavior was determined. Choice frequencies
of ≥50% were assumed to indicate similarity to the training color. The wavelength ranges ≥50% were about 100 nm and twice
as large as the just noticeable differences measured in wavelength discrimination tests (Fig. 7). The ranges were surprisingly
about the same for all training wavelengths, provided the data were plotted on a wavelength scale weighted according to discrimination
ability (Fig. 4). Thus, with the training method chosen goldfish showed a kind of categorization which, however, depends on
training wavelength and discrimination ability. Generalization tests in which training wavelength and test wavelengths were
shown separately for 2 min each gave the same results as wavelength discrimination tests (Figs. 5 and 6) and are, therefore,
not indicative for color categories. 相似文献
117.
Timothy?H.?GoldsmithEmail author Byron?K.?Butler 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2005,191(10):933-951
Budgerigars, Melopsittacus undulatus, were trained to discriminate monochromatic lights from mixtures of two comparison lights. The addition of small amounts
of UV (365 nm) to blue or yellow lights dramatically changed the color for the birds. Hue matches showed the birds to be dichromatic
both at long wavelengths (only P565 and P508 active) and at short wavelengths (only P370 and P445 active because of screening
of P508 and P565 by cone oil droplets). In mid-spectrum (only P445 and P508 active), a hue match was achieved, but the results
were more complicated because two opponent neural processes were activated. All observed hue matches were in quantitative
agreement with calculations of relative quantum catch in the pairs of participating single cones and point to the presence
of a minimum of three opponent neural processes. For the hue matches at mid- and short wavelengths, the calculations also
predict peak values of absorbance of the cone oil droplets associated with P508 and P445. Relative intensity of the training
light affected difficult matches at long but not short wavelengths, likely due to achromatic signals from the double cones.
With suitable training, birds could make intensity discriminations at short wavelengths, where the double cones have diminished
sensitivity. 相似文献
118.
U.?LangemannEmail author M.?A.?Zokoll G.?M.?Klump 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》2005,191(10):889-901
In a behavioral experiment, we investigated how efficiently barn owls (Tyto alba) could detect changes in the spectral profile of multi-component auditory signals with stochastic envelope patterns. Signals
consisted of one or five bands of noise (bandwidth 4, 16, or 64 Hz each; center frequencies 1.02, 1.43, 2.0, 2.8, 3.92 kHz).
We determined increment thresholds for the 2 kHz component for three conditions: single-band condition (only the 2 kHz component),
all five noise bands with the envelope fluctuations of the bands being either correlated or uncorrelated. Noise bandwidth
had no significant effect on increment detection. Increment thresholds for the different conditions, however, differed significantly.
Thresholds in correlated conditions were generally the lowest of all conditions, whereas, thresholds in uncorrelated conditions
mostly resulted in the highest thresholds. This can be interpreted as evidence for comodulation masking release in barn owls.
If the increment in the 2 kHz component is balanced by decrementing the four flanking bands in amplitude, increment detection
thresholds are not affected. The data suggest that the barn owls used information from simultaneous spectral comparison across
different frequency channels to detect spectral changes in multi-component noise signals rather than sequential comparison
of overall stimulus levels. 相似文献
119.
Associations between δ13C values and leaf gas exchanges and tree-ring or needle growth, used in ecophysiological compositions, can be complex depending
on the relative timing of CO2 uptake and subsequent redistribution and allocation of carbon to needle and stem components. For palaeoenvironmental and
dendroecological studies it is often interpreted in terms of a simple model of δ13C fractionation in C3 plants. However, in spite of potential complicating factors, few studies have actually examined these relationships in mature
trees over inter- and intra-annual time-scales. Here, we present results from a 4 years study that investigated the links
between variations in leaf gas-exchange properties, growth, and dated δ13C values along the needles and across tree rings of Aleppo pine trees growing in a semi-arid region under natural conditions
or with supplemental summer irrigation. Sub-sections of tissue across annual rings and along needles, for which time of formation
was resolved from growth rate analyses, showed rapid growth and δ13C responses to changing environmental conditions. Seasonal cycles of growth and δ13C (up to ~4‰) significantly correlated (P<0.01) with photosynthetically active radiation, vapour pressure deficit, air temperature, and soil water content. The irrigation
significantly increased leaf net assimilation, stomatal conductance and needle and tree-ring growth rate, and markedly decreased
needle and tree-ring δ13C values and its sensitivity to environmental parameters. The δ13C estimates derived from gas-exchange parameters, and weighted by assimilation, compared closely with seasonal and inter-annual
δ13C values of needle- and tree-ring tissue. Higher stomatal conductances of the irrigated trees (0.22 vs. 0.08 mol m−2 s−1 on average) corresponded with ~2.0‰ lower average δ13C values, both measured and derived. Derived and measured δ13C values also indicated that needle growth, which occurs throughout the stressful summer was supported by carbon from concurrent,
low rate assimilation. For Aleppo pine under semi-arid and irrigated conditions, the δ13C of tree-ring and needle material proved, in general, to be a reasonable indicator of integrated leaf gas-exchange properties. 相似文献
120.
Daniel?M.?A.?Pessoa Eduardo?S.?Perini Lívia?S.?Carvalho Carlos?Tomaz Valdir?F.?PessoaEmail author 《International journal of primatology》2005,26(1):147-158
We assessed the color discriminations by golden-headed lion tamarins (Leontopithecus chrysomelas) via a series of tasks involving a behavioral paradigm that maximizes the naturalness of the stimuli. The stimuli were pairs of Munsell color chips used in earlier experiments with human dichromats. We tested 3 male and 3 female monkeys with stimuli of random brightness values in order to assure that discriminations were based on color rather than brightness cues. Results indicate that each male and one female presented random performances for stimuli resembling hue conditions under which tamarins forage: oranges vs. greens. Two females exhibited discriminations consistent with allelic trichromacy. Findings indicate the presence of an M/L cone opsin polymorphism, a condition of most platyrrhines that is characterized by dichromatic and/or trichromatic females and dichromatic males. Interspecific differences in allelic frequency among lion tamarins raises the possibility that habitat fragmentation is affecting heterozygous frequencies, a trend that could impact tamarin foraging efficiency. 相似文献