292 research outputs found
The effect of the common bond and membership expansion on credit union risk
This paper examines differences in institutional risk profiles based on credit union membership type and membership expansion via “select employee groups,” or SEGs, which are now expressly allowed by the Credit Union Membership Access Act of 1998. A cross-sectional statistical model is specified that examines risk variation relative to the type of common bond and the breadth of the credit union’s membership. In findings that are consistent with earlier research, the authors document that occupationally based credit unions have a unique risk profile relative to other common bonds. This profile includes a greater exposure to concentration risk, which is hedged by holding greater proportions of capital. ; The authors also examine the subsample of Single-Bond occupational credit unions and those Multi-Bond credit unions with primarily occupational group members. They find that the presence of SEGs is negatively related to capital ratios and positively related to loan-to-share ratios relative to the Single-Bond occupational credit unions. The use of survey data documenting the number of SEGs confirms that, as more SEGs are added, credit unions tend to increase their loan-to-share ratios and decrease their capital ratios. However, the number of SEGs and the proportion of loan delinquencies are found to be positively related, suggesting that the informational advantages associated with the common bond become diluted as new groups are added. Overall, the authors conclude that there are material benefits of credit union membership diversification and that these benefits derive from expanded investment opportunities and reduced concentration risk.Credit unions ; Risk
Complementing PABITRA high-island studies by examining terrestrial plant diversity on atolls
The Pacific-Asia Biodiversity Transect (PABITRA) studies are based on a network of high-island biodiversity sites. These sites are structurally and historically complex. The majority of Pacific islands, in contrast, are low atolls with a common and simple flora and structure. As a result, atolls may serve as "controls" that may provide a way to assess impact of the upland high-island ecosystems on coastal regions of Pacific islands. Atoll studies can complement the PABITRA network because the gateway sites are near each other or separated from one another by one or more atolls. Such an addition will enhance interpretation of high-island ecosystems and their coastal zones because ecosystem surveys can be conducted quickly and accurately in atoll environments. We present results from quantitative studies of plant diversity from seven islets at Ailinginae Atoll in the northern Marshall Islands and discuss the value of this methodology as a way to enhance interpretation of the PABITRA data
The effect of the common bond and membership expansion on credit union risk
This paper examines differences in institutional risk profiles based on credit union membership type and membership expansion via "select employee groups," or SEGs, which are now expressly allowed by the Credit Union Membership Access Act of 1998. A cross-sectional statistical model is specified that examines risk variation relative to the type of common bond and the breadth of the credit union’s membership. In findings that are consistent with earlier research, the authors document that occupationally based credit unions have a unique risk profile relative to other common bonds. This profile includes a greater exposure to concentration risk, which is hedged by holding greater proportions of capital. ; The authors also examine the subsample of Single-Bond occupational credit unions and those Multi-Bond credit unions with primarily occupational group members. They find that the presence of SEGs is negatively related to capital ratios and positively related to loan-to-share ratios relative to the Single-Bond occupational credit unions. The use of survey data documenting the number of SEGs confirms that, as more SEGs are added, credit unions tend to increase their loan-to-share ratios and decrease their capital ratios. However, the number of SEGs and the proportion of loan delinquencies are found to be positively related, suggesting that the informational advantages associated with the common bond become diluted as new groups are added. Overall, the authors conclude that there are material benefits of credit union membership diversification and that these benefits derive from expanded investment opportunities and reduced concentration risk
Plant Selection for Ethnobotanical Uses on the Amalfi Coast (Southern Italy)
Background
Many ethnobotanical studies have investigated selection criteria for medicinal and non-medicinal plants. In this paper we test several statistical methods using different ethnobotanical datasets in order to 1) define to which extent the nature of the datasets can affect the interpretation of results; 2) determine if the selection for different plant uses is based on phylogeny, or other selection criteria.
Methods
We considered three different ethnobotanical datasets: two datasets of medicinal plants and a dataset of non-medicinal plants (handicraft production, domestic and agro-pastoral practices) and two floras of the Amalfi Coast. We performed residual analysis from linear regression, the binomial test and the Bayesian approach for calculating under-used and over-used plant families within ethnobotanical datasets. Percentages of agreement were calculated to compare the results of the analyses. We also analyzed the relationship between plant selection and phylogeny, chorology, life form and habitat using the chi-square test. Pearson’s residuals for each of the significant chi-square analyses were examined for investigating alternative hypotheses of plant selection criteria.
Results
The three statistical analysis methods differed within the same dataset, and between different datasets and floras, but with some similarities. In the two medicinal datasets, only Lamiaceae was identified in both floras as an over-used family by all three statistical methods. All statistical methods in one flora agreed that Malvaceae was over-used and Poaceae under-used, but this was not found to be consistent with results of the second flora in which one statistical result was non-significant. All other families had some discrepancy in significance across methods, or floras. Significant over- or under-use was observed in only a minority of cases. The chi-square analyses were significant for phylogeny, life form and habitat. Pearson’s residuals indicated a non-random selection of woody species for non-medicinal uses and an under-use of plants of temperate forests for medicinal uses.
Conclusions
Our study showed that selection criteria for plant uses (including medicinal) are not always based on phylogeny. The comparison of different statistical methods (regression, binomial and Bayesian) under different conditions led to the conclusion that the most conservative results are obtained using regression analysis
The Spectral Dimension of Arctic Outgoing Longwave Radiation and Greenhouse Efficiency Trends From 2003 to 2016
Fourteen years of spectral fluxes derived from collocated Atmospheric Infrared Sounder (AIRS) and Clouds and the Earth’s Radiant Energy System (CERES) observations are used in conjunction with AIRS retrievals to examine the trends of zonal mean spectral outgoing longwave radiation (OLR) and greenhouse efficiency (GHE) in the Arctic. AIRS retrieved profiles are fed into a radiative transfer model to generate synthetic clear‐sky spectral OLR. Trends are derived from the simulated clear‐sky spectral OLR and GHE and then compared with their counterparts derived from collocated observations. Spectral trends in different seasons are distinctively different. March and September exhibit positive trends in spectral OLR over the far‐IR dirty window and mid‐IR window region for most of the Arctic. In contrast, spectral OLR trends in July are negative over the far‐IR dirty window and can be positive or negative in the mid‐IR window depending on the latitude. Sensitivity studies reveal that surface temperature contributes much more than atmospheric temperature and humidity to the spectral OLR and GHE trends, while the contributions from the latter two are also discernible over many spectral regions (e.g., trends in the far‐IR dirty window in March). The largest increase of spectral GHE is seen north of 80°N in March across the water vapor v2 band and far‐IR. When the secular fractional change of spectral OLR is less than that of surface spectral emission, an increase of spectral GHE can be expected. Spectral trend analyses reveal more information than broadband trend analyses alone.Key PointsObserved Arctic zonal mean trends of spectral flux and greenhouse efficiency are studied for the first timeSpectral trends are seasonally dependent and reveal more information than broadband trendsChanges in surface temperature contribute the most to overall spectral trends, but changes due to air temperature and humidity trends are discerniblePeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151304/1/jgrd55648_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151304/2/jgrd55648.pd
Object Serialization and Deserialization Using XML
Interoperability of potentially heterogeneous databases has been an ongoing
research issue for a number of years in the database community. With the trend
towards globalization of data location and data access and the consequent
requirement for the coexistence of new data stores with legacy systems, the
cooperation and data interchange between data repositories has become
increasingly important. The emergence of the eXtensible Markup Language (XML)
as a database independent representation for data offers a suitable mechanism
for transporting data between repositories. This paper describes a research
activity within a group at CERN (called CMS) towards identifying and
implementing database serialization and deserialization methods that can be
used to replicate or migrate objects across the network between CERN and
worldwide centres using XML to serialize the contents of multiple objects
resident in object-oriented databases.Comment: 14 pages 7 figure
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The use of phylogeny to interpret cross-cultural patterns in plant use and guide medicinal plant discovery: an example from Pterocarpus (Leguminosae)
The study of traditional knowledge of medicinal plants has led to discoveries that have helped combat diseases and improve healthcare. However, the development of quantitative measures that can assist our quest for new medicinal plants has not greatly advanced in recent years. Phylogenetic tools have entered many scientific fields in the last two decades to provide explanatory power, but have been overlooked in ethnomedicinal studies. Several studies show that medicinal properties are not randomly distributed in plant phylogenies, suggesting that phylogeny shapes ethnobotanical use. Nevertheless, empirical studies that explicitly combine ethnobotanical and phylogenetic information are scarce.In this study, we borrowed tools from community ecology phylogenetics to quantify significance of phylogenetic signal in medicinal properties in plants and identify nodes on phylogenies with high bioscreening potential. To do this, we produced an ethnomedicinal review from extensive literature research and a multi-locus phylogenetic hypothesis for the pantropical genus Pterocarpus (Leguminosae: Papilionoideae). We demonstrate that species used to treat a certain conditions, such as malaria, are significantly phylogenetically clumped and we highlight nodes in the phylogeny that are significantly overabundant in species used to treat certain conditions. These cross-cultural patterns in ethnomedicinal usage in Pterocarpus are interpreted in the light of phylogenetic relationships.This study provides techniques that enable the application of phylogenies in bioscreening, but also sheds light on the processes that shape cross-cultural ethnomedicinal patterns. This community phylogenetic approach demonstrates that similar ethnobotanical uses can arise in parallel in different areas where related plants are available. With a vast amount of ethnomedicinal and phylogenetic information available, we predict that this field, after further refinement of the techniques, will expand into similar research areas, such as pest management or the search for bioactive plant-based compounds
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