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991.
The ability of older adults to use a domestic appliance depends on their comprehension of the appliance's operation. This may depend on transfer of understanding from similar, more familiar technology. While this may assist their interaction with the new device, it may constrain the discovery of new functionality not represented in the familiar technology, and, thereby, constrain the discovery of advanced functionality. Older adults experience declining cognitive abilities associated with attention, perceptual encoding, and memory (cueing and recall). Designing appliances to extend cognitive abilities provides opportunity to prolong functional independence. Concepts from cognitive psychology, human factors, and gerontology are reviewed to explain age-related behavior towards technology to support innovative product development of technologies for older adults. 相似文献
992.
993.
The relationship between social insurance, which provides families protection against certain risks, and child economic security is understudied. Using the 2004 Survey of Income and Program Participation (SIPP) matched to Social Security Administration benefit records, this article investigates the economic welfare effects of the child component of the US Social Security program. We examine how the poverty rate of child beneficiaries would change, absent Social Security income, and how heavily the family incomes of these children rely on it, by family characteristics. Our findings reveal that Social Security plays an important role in mitigating economic insecurity among children deprived of a wage-earning parent through disability, death, or retirement. Family structure, earnings, and employment status are identified as key factors moderating the effect of Social Security on child recipients’ financial circumstance. 相似文献
994.
Urbanization is a pervasive and growing threat to amphibian populations globally. Although the number of studies is increasing,
many aspects of basic amphibian biology have not been investigated in urban settings. We reviewed 32 urban studies from North
America and quantified the number of species studied and their response to urbanization. We examined existing research on
breeding habitats, life-history stages, movement patterns, and habitat use relative to urbanization. We found amphibians as
a whole respond negatively to urbanization (69 reported responses were negative, 6 were positive and 35 showed no effect).
We caution, however, that many North American species still lack or are associated with conflicting information regarding
species-specific responses (e.g., 89 potential responses were unknown). Approximately 40% of all anuran and 14% of caudate
species in North America were investigated in the literature; however, the most diverse genera (e.g., Plethodon and Eurycea) were the most understudied likely due to their cryptic terrestrial lifestyles and biases in sampling protocols that assess
wetland habitats via call surveys. Research on movement and small scale habitat use was deficient. Adult, juvenile, tadpole,
and egg mass life-history stages commonly served as direct measures of species presence and abundance; however, such data
do not accurately reflect recruitment into subsequent age classes and population persistence. The lack of data on many North
American species may be contributing to poor management of urban amphibian populations and their habitats. 相似文献
995.
996.
997.
Alonso Ramírez Augustin Engman Keysa G. Rosas Omar Perez-Reyes Diana M. Martinó-Cardona 《Urban Ecosystems》2012,15(2):315-325
Improving our understanding of the impacts of urbanization on tropical island streams is critical as urbanization becomes a dominant feature in tropical areas. Although the ??urban stream syndrome?? has been successful in summarizing urban impacts on streams, the response of some island streams is different to that expected. Here we review available information on urban impacts to tropical island streams and describe unique responses to urbanization. We identified three key aspects that play particularly important or unique roles in determining tropical-island stream integrity: biotic response to water pollution, movement barriers along the stream network, and altered geomorphology that results in habitat loss. As expected, water pollution negatively impacts stream ecosystems in tropical islands and in some regions impacts can be severe, as untreated wastewaters are directly discharged into streams. While aquatic insects show the expected responses to pollution, other native fauna (e.g., shrimps and fishes) appear to be less impacted by moderate levels of pollution. Movement barriers along the stream network are especially important as much of the tropical island fauna have diadromous (either amphidromous or catadromous) life histories. Most native freshwater mollusks, shrimps, and fishes inhabiting tropical islands are diadromous and depend on unimpeded connections between freshwater and marine environments to complete their life cycles. The presence of these species in urban streams is best explained by longitudinal connectivity rather than by the degree of urban impact. Finally, in streams that remain connected to marine environments, the presence of native shrimps and fishes is strongly related to the physical habitat. Fish assemblages in channelized and severely altered stream reaches are almost completely devoid of native fauna and tend to be dominated by non-native species. In contrast, relatively diverse shrimp and fish assemblages can be found in reaches that retain their physical habitat complexity, even when they are impacted by urbanization. Our understanding of urban impacts on tropical island streams remains limited. However, the identification of key aspects can help us better understand urban impacts on streams in tropical islands, and best focus our management and research efforts to protect these unique ecosystems. 相似文献
998.
999.
In this article we highlight the effects of heterogeneous institutional contexts on transnational professional service firms, a relatively poorly studied issue. Specifically, we provide empirical analysis of how the specificities of the Italian institutional context affect the activities of English legal professional service firms in Milan. This reveals the intimate connection between a variety of capitalism, place specific workplace cultures and practices, and the institution‐related challenges transnational professional service firms and all transnational corporations (TNCs) face. We also reveal the way institutionally generated differences at the level of work practices are managed in transnational law firms through worldwide training programmes designed to ‘govern’ the practices of workers in different parts of the TNC's network. This emphasizes the importance of studying attempts to manage institutional heterogeneity at the level of workplace practices, something often missed in existing mesoscale studies of TNC governance structures. Consequently, we highlight detailed empirical archaeologies that explore the direct links between institutions and practices as an important component of future research on the effects of institutions on TNCs. 相似文献
1000.
Linguistic stress and sequential statistical cues to word boundaries interact during speech segmentation in infancy. However, little is known about how the different acoustic components of stress constrain statistical learning. The current studies were designed to investigate whether intensity and duration each function independently as cues to initial prominence (trochaic‐based hypothesis) or whether, as predicted by the Iambic‐Trochaic Law (ITL), intensity and duration have characteristic and separable effects on rhythmic grouping (ITL‐based hypothesis) in a statistical learning task. Infants were familiarized with an artificial language (Experiments 1 and 3) or a tone stream (Experiment 2) in which there was an alternation in either intensity or duration. In addition to potential acoustic cues, the familiarization sequences also contained statistical cues to word boundaries. In speech (Experiment 1) and nonspeech (Experiment 2) conditions, 9‐month‐old infants demonstrated discrimination patterns consistent with an ITL‐based hypothesis: intensity signaled initial prominence and duration signaled final prominence. The results of Experiment 3, in which 6.5‐month‐old infants were familiarized with the speech streams from Experiment 1, suggest that there is a developmental change in infants’ willingness to treat increased duration as a cue to word offsets in fluent speech. Infants’ perceptual systems interact with linguistic experience to constrain how infants learn from their auditory environment. 相似文献