352 research outputs found
Undergraduates with Employer-Sponsored Aid: Comparing Group Differences
Tuition assistance offered by employers is an understudied area of financial aid research. The purpose of this study is to compare the demographic, socioeconomic, academic and financial aid characteristics of college students who receive employer-sponsored financial aid with students who receive traditional financial aid (institutional, state, or federal) and those that receive no aid at public 4-year universities. Using the 2007-08 data from the undergraduate National Postsecondary Student Aid Study (NPSAS:08), we find that there are statistically significant differences between students who receive employer-sponsored aid and those who do not. Students receiving employer aid are older, are more likely to be married, have more children, and are more likely be a business or management major. Students receiving employer aid have higher earnings from work than students receiving traditional financial aid and students receiving no aid and higher total household income than students receiving traditional aid. In addition, the parents of students receiving employer aid are more likely to have only a high school diploma with no further education. Students receiving employer aid are also more likely to take out loans to finance their education than students with no aid but less likely than students with traditional aid
Characterizing the Temporal and Spatial Distribution of the Cannonball Jellyfish (\u3ci\u3eStomolophus meleagris\u3c/i\u3e) in the South Atlantic Bight
The cannonball jellyfish, Stomolophus meleagris, is commercially harvested throughout its range in the tropical and sub-tropical Americas, including in the South Atlantic Bight, where an estimated 4,000 tons (less than 2.4% of the estimated stock in South Carolina during the spring) are harvested annually. Like many Scyphozoan jellyfish, cannonball jellies have high interannual variability and little is known about the environmental drivers of their distribution and phenology. To better understand the ecology of this targeted species, we used fisheries-independent abundance data of cannonball jellyfish from 2001 to 2019 collected by the Southeast Area Monitoring and Assessment Program (SEAMAP) throughout the coastal zone of the South Atlantic Bight. Average biomass is highest in the spring off the coast of Georgia and lower South Carolina (south of Charleston), and the largest jellyfish occur during the spring months. The lowest biomass occurs in the summer months when smaller jellyfish occur. This could indicate that adult cannonball jellyfish occur offshore in the spring, move inshore toward estuarine habitats to release larvae, then juvenile cannonballs move out of the estuaries as they mature throughout the summer and fall, and finally the surviving adults are detected offshore again the next spring. The seasonal and spatial variability described does not appear to be connected to temperature, salinity, chlorophyll-a concentration, or river discharge, but is perhaps influenced by distance from estuarine habitats and wind direction. Interannual variability in biomass is evident in the cannonball jellyfish of the South Atlantic Bight, but no long-term trends or strong correlations with the aforementioned environmental parameters were detected. Further analyses remain necessary in order to pin-point the drivers behind the variability seen in the cannonball jellyfish of the South Atlantic Bight
Towards a method for rigorous development of generic requirements patterns
We present work in progress on a method for the engineering, validation and verification of generic requirements using domain engineering and formal methods. The need to develop a generic requirement set for subsequent system instantiation is complicated by the addition of the high levels of verification demanded by safety-critical domains such as avionics. Our chosen application domain is the failure detection and management function for engine control systems: here generic requirements drive a software product line of target systems. A pilot formal specification and design exercise is undertaken on a small (twosensor) system element. This exercise has a number of aims: to support the domain analysis, to gain a view of appropriate design abstractions, for a B novice to gain experience in the B method and tools, and to evaluate the usability and utility of that method.We also present a prototype method for the production and verification of a generic requirement set in our UML-based formal notation, UML-B, and tooling developed in support. The formal verification both of the structural generic requirement set, and of a particular application, is achieved via translation to the formal specification language, B, using our U2B and ProB tools
An alu-based phylogeny of gibbons (hylobatidae)
Gibbons (Hylobatidae) are small, arboreal apes indigenous to Southeast Asia that diverged from other apes ∼15-18 Ma. Extant lineages radiated rapidly 6-10 Ma and are organized into four genera (Hylobates, Hoolock, Symphalangus, and Nomascus) consisting of 12-19 species. The use of short interspersed elements (SINEs) as phylogenetic markers has seen recent popularity due to several desirable characteristics: the ancestral state of a locus is known to be the absence of an element, rare potentially homoplasious events are relatively easy to resolve, and samples can be quickly and inexpensively genotyped. During radiation of primates, one particular family of SINEs, the Alu family, has proliferated in primate genomes. Nomascus leucogenys (northern white-cheeked gibbon) sequences were analyzed for repetitive content with RepeatMasker using a custom library. The sequences containing Alu elements identified as members of a gibbon-specific subfamily were then compared with orthologous positions in other primate genomes. A primate phylogenetic panel consisting of 18 primate species, including 13 gibbon species representing all four extant genera, was assayed for all loci, and a total of 125 gibbon-specific Alu insertions were identified. The resulting amplification patterns were used to generate a phylogenetic tree. We demonstrate significant support for Symphalangus as the most basal lineage within the family. Our findings also place Nomascus as a derived lineage, sister to Hoolock, with the Nomascus-Hoolock clade sister to Hylobates. Further, our analysis groups N. leucogenys and Nomascus siki as sister taxa to the exclusion of the other Nomascus species assayed. This study represents the first use of SINEs to determine the genus level phylogenetic relationships within the family Hylobatidae. These relationships have been resolved with robust support at most internal nodes, demonstrating the utility of SINE-based phylogenetic analysis. We postulate that hybridization and rapid radiation may have contributed to the complex and contradictory findings of the previous studies. Our findings will aid in the conservation of these threatened primates and inform future studies of the biogeographical history and distribution of modern gibbon species. © 2012 The Author
A new conceptual framework for revenge firesetting
Revenge has frequently been acknowledged to account for a relatively large proportion of motives in deliberate firesetting. However, very little is actually known about the aetiology of revenge firesetting. Theoretical approaches to revenge-seeking behaviour are discussed. A brief review of how revenge is accounted for in existing theoretical explanations of deliberate firesetting and the known characteristics of revenge firesetters are provided. On this basis, the authors suggest, as a motive, revenge firesetting has to date been misconceptualised. A new conceptual framework is thus proposed, paying particular attention to the contextual, affective, cognitive, volitional and behavioural factors which may influence and generate a single episode of revenge firesetting. Treatment implications and suggestions for future research are also provided
Vertical consolidation and financial sustainability: evidence from English local government
Proponents of the vertical consolidation of lower-tier units into a smaller number of single-tier local governments suggest that it improves the financial sustainability of governments by generating economies of scale and scope. However, critics suggest that such structural change is beset with disruptive and unanticipated costs that outweigh any potential efficiency savings. I investigate the validity of these contrasting arguments by analysing the expenditure and fiscal health of English county councils before and after the consolidation of the lower-tier units within several counties that took place in 2009. Levels of financial sustainability are modelled using a difference-in-difference estimator for the years 2003–2012. The results suggest that in the short run the consolidated governments have been able to realize administrative economies, but their fiscal health has weakened. These findings appear to be robust to the possibility of selection effects. Theoretical and practical implications are discussed
Biosynthesis of long-chain polyunsaturated fatty acids in marine fish: Characterization of an Elovl4-like elongase from cobia Rachycentron canadum and activation of the pathway during early life stages
Marine fish, unlike freshwater species, have been generally considered to have a limited ability to biosynthesize long-chain polyunsaturated fatty acids (LC-PUFA) from C18 precursors due to apparent limited enzymatic activities involved in the pathway. Although LC-PUFA play important physiological roles throughout the entire life cycle, requirements for early life stages are especially high and provision of preformed LC-PUFA in egg lipids appears critical to support the formation of developing tissues where these compounds accumulate. No studies, however, have been conducted to explore the capability of marine fish embryos (here referring to life stages from zygote to the oesophagus opening) for de novo synthesis of the LC-PUFA required for normal growth and development. The present study aimed to investigate the activation of the LC-PUFA biosynthetic pathway during embryogenesis of the marine teleost cobia (Rachycentron canadum). First, a fatty acyl elongase with sequence similarity to mammalian elongase of very long-chain fatty acids 4 (Elovl4) was isolated, and its biochemical function characterized showing that it catalyzed the production of very long-chain fatty acids (VLC-FA) including both saturated and polyunsaturated fatty acids with chain lenghts ≥ 24 carbons. Notably, cobia Elovl4 was able to elongate 22:5n-3 to 24:5n-3 and thus could play a key role in the biosynthesis of docosahexaenoic acid (22:6n-3), a critical fatty acid in neural tissues. Subsequently, the fatty acid dynamics of embryos at different developmental stages and the temporal expression patterns of target genes including elovl4, and the formerly characterized elovl5 elongase and ∆6 fatty acyl desaturase, were analyzed in order to elucidate the overall activation of the LC-PUFA biosynthetic pathway in cobia embryos. Our results indicated that expression of the LC-PUFA biosynthetic pathway in cobia embryos is initiated at 12-18 hours post-fertilization
Methylomic analysis of monozygotic twins discordant for autism spectrum disorder and related behavioural traits
Autism spectrum disorder (ASD) defines a group of common, complex neurodevelopmental disorders. Although the aetiology of ASD has a strong genetic component, there is considerable monozygotic (MZ) twin discordance indicating a role for non-genetic factors. Because MZ twins share an identical DNA sequence, disease-discordant MZ twin pairs provide an ideal model for examining the contribution of environmentally driven epigenetic factors in disease. We performed a genome-wide analysis of DNA methylation in a sample of 50 MZ twin pairs (100 individuals) sampled from a representative population cohort that included twins discordant and concordant for ASD, ASD-associated traits and no autistic phenotype. Within-twin and between-group analyses identified numerous differentially methylated regions associated with ASD. In addition, we report significant correlations between DNA methylation and quantitatively measured autistic trait scores across our sample cohort. This study represents the first systematic epigenomic analyses of MZ twins discordant for ASD and implicates a role for altered DNA methylation in autism
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