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1.
Spatial variation in soil inorganic nitrogen across an arid urban ecosystem   总被引:4,自引:1,他引:3  
We explored variations in inorganic soil nitrogen (N) concentrations across metropolitan Phoenix, Arizona, and the surrounding desert using a probability-based synoptic survey. Data were examined using spatial statistics on the entire region, as well as for the desert and urban sites separately. Concentrations of both NO3-N and NH4-N were markedly higher and more heterogeneous amongst urban compared to desert soils. Regional variation in soil NO3-N concentration was best explained by latitude, land use history, population density, along with percent cover of impervious surfaces and lawn, whereas soil NH4-N concentrations were related to only latitude and population density. Within the urban area, patterns in both soil NO3-N and NH4-N were best predicted by elevation, population density and type of irrigation in the surrounding neighborhood. Spatial autocorrelation of soil NO3-N concentrations explained 49% of variation among desert sites but was absent between urban sites. We suggest that inorganic soil N concentrations are controlled by a number of ‘local’ or ‘neighborhood’ human-related drivers in the city, rather than factors related to an urban-rural gradient.  相似文献   
2.
Understanding the role of sexualization in a depressed patient gives us the opportunity to re-examine the place of sexual activity in psychopathology. The self psychological concept of the mirror transference is used to explain the therapist's activity in the case illustration.  相似文献   
3.
The spread of an emerging infectious disease is a major public health threat. Given the uncertainties associated with vector-borne diseases, in terms of vector dynamics and disease transmission, it is critical to develop statistical models that address how and when such an infectious disease could spread throughout a region such as the USA. This paper considers a spatio-temporal statistical model for how an infectious disease could be carried into the USA by migratory waterfowl vectors during their seasonal migration and, ultimately, the risk of transmission of such a disease to domestic fowl. Modeling spatio-temporal data of this type is inherently difficult given the uncertainty associated with observations, complexity of the dynamics, high dimensionality of the underlying process, and the presence of excessive zeros. In particular, the spatio-temporal dynamics of the waterfowl migration are developed by way of a two-tiered functional temporal and spatial dimension reduction procedure that captures spatial and seasonal trends, as well as regional dynamics. Furthermore, the model relates the migration to a population of poultry farms that are known to be susceptible to such diseases, and is one of the possible avenues toward transmission to domestic poultry and humans. The result is a predictive distribution of those counties containing poultry farms that are at the greatest risk of having the infectious disease infiltrate their flocks assuming that the migratory population was infected. The model naturally fits into the hierarchical Bayesian framework.  相似文献   
4.
The theory of family welfare effort is a leading macro‐sociological explanation of variation in human fertility. It holds that states which provide universally available, inexpensive, high‐quality day care, generous parental leave, and flexible work schedules lower the opportunity cost of motherhood. They thus enable women, especially those in lower socioeconomic strata, to have the number of babies they want. A considerable body of research supports this theory. However, it is based almost exclusively on analyses of Western European and North American countries. This paper examines the Israeli case because Israel's total fertility rate is anomalously high given its family welfare effort. Based on a review of the relevant literature and a reanalysis of data from various published sources, it explains the country's unusually high total fertility rate as the product of (1) religious and nationalistic sentiment that is heightened by the Jewish population's perception of a demographic threat in the form of a burgeoning Palestinian population and (2) the state's resulting support for pro‐natal policies, including the world's most extensive in vitro fertilization (IVF) system. The paper also suggests that Israel's IVF policy may not be in harmony with the interests of many women insofar as even women with an extremely low likelihood of becoming pregnant are encouraged to undergo the often lengthy, emotionally and physically painful, and risky process of IVF.  相似文献   
5.
Psychometric growth curve modeling techniques are used to describe a person’s latent ability and how that ability changes over time based on a specific measurement instrument. However, the same instrument cannot always be used over a period of time to measure that latent ability. This is often the case when measuring traits longitudinally in children. Reasons may be that over time some measurement tools that were difficult for young children become too easy as they age resulting in floor effects or ceiling effects or both. We propose a Bayesian hierarchical model for such a scenario. Within the Bayesian model we combine information from multiple instruments used at different age ranges and having different scoring schemes to examine growth in latent ability over time. The model includes between-subject variance and within-subject variance and does not require linking item specific difficulty between the measurement tools. The model’s utility is demonstrated on a study of language ability in children from ages one to ten who are hard of hearing where measurement tool specific growth and subject-specific growth are shown in addition to a group level latent growth curve comparing the hard of hearing children to children with normal hearing.KEYWORDS: Bayesian hierarchical models, psychometric modeling, language ability, growth curve modeling, longitudinal analysis  相似文献   
6.
The Family Adaptability and Cohesion Scale (FACES) IV does not provide instructions about which family members respondents should think about while answering questions. This study examined which family members respondents thought about while completing the FACES IV, and if this changed measurement invariance and population heterogeneity of the measure. Using a sample of n = 511 individuals, a latent class analysis showed three distinct classes: Nuclear Family, Family of Origin, and All of the Above. The FACES IV demonstrated measurement invariance across classes on the majority of subscales; however, population heterogeneity tests suggested that the means and variances of the subscales varied across classes. The findings suggest further examination of how the measure functions with unique family constellations is warranted.  相似文献   
7.
Temperament by parenting interactions may reflect that individuals with greater risk are more likely to experience negative outcomes in adverse contexts (diathesis‐stress) or that these individuals are more susceptible to contextual influences in a “for better or for worse” pattern (differential susceptibility). Although such interactions have been identified for a variety of child outcomes, prior research has not examined approach characteristics—excitement and approach toward pleasurable activities—in the first year of life. Therefore, this study investigated whether 6‐month maternal reported infant negative affect—a phenotypic marker of risk/susceptibility—interacted with 8‐month observed parenting behaviors (positive parenting, negative parenting) to predict 12‐month infant behavioral approach. Based on a sample of mothers and their infants (= 150), results indicated that negative parenting was inversely associated with subsequent approach for infants with high, but not low, levels of negative affect. Similar results did not occur regarding positive parenting. These findings better fit a diathesis‐stress model rather than a differential susceptibility model. Implications and limitations of these findings are discussed.  相似文献   
8.
This paper reports on the findings of a study on the role of social work field education programmes in the transmission of developmental social work knowledge in Southern and East Africa. It highlights the challenges in locating developmental social work placements and the creativity shown by social work educators in addressing these challenges and improving learning opportunities for social work students. Both academics and students were found to be committed to developmental social work, within a willing practice environment hampered by knowledge, capacity and resource constraints. Social work education was found to be playing a transformative role through the teaching of a developmental social work curriculum and the creation of collaborative developmental social work learning experiences. Social work educators trained and supported agency supervisors in developmental social work, while students served as conduits, modelling developmental social work practice. What has yet to be determined in future research is the students’ perspective of this developmental educational environment.  相似文献   
9.
Although subprime mortgage lending and unemployment were largely responsible for the wave of foreclosures during the Great Recession, additional sources of financial risk may have exacerbated the crisis. We hypothesize that many parents sending children to college were financially overextended and vulnerable to foreclosure as the economy contracted. With commuting zone panel data from 2006 to 2011, we show that increasing rates of college attendance across the income distribution in one year predict a foreclosure rate increase in subsequent years, net of fixed characteristics and changes in employment, refinance debt, house prices, and 19-year-old population size. We find similar evidence of college-related foreclosure risk using longitudinal household data from the Panel Study of Income Dynamics. Our findings uncover a previously overlooked dimension of the foreclosure crisis, and highlight mortgage insecurity as an inadvertent consequence of parental investment in higher education.  相似文献   
10.
We use duration models on a well-known historical data set of more than 15,000 families and 60,000 births in England for the period 1540–1850 to show that the sampled families adjusted the timing of their births in accordance with the economic conditions as well as their stock of dependent children. The effects were larger among the lower socioeconomic ranks. Our findings on the existence of parity-dependent as well as parity-independent birth spacing in England are consistent with the growing evidence that marital birth control was present in pre-transitional populations.  相似文献   
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