111 research outputs found
The Law and Economics of Subprime Lending
The collapse of the subprime mortgage market has led to calls for greater regulation to protect homeowners from unwittingly trapping themselves in high-cost loans that lead to foreclosure, bankruptcy, or other financial problems. Weighed against the losses of the widespread foreclosure crisis are the benefits of financial modernization that have accrued to many American families who have been able to become homeowners who otherwise would not have access to mortgage credit. The bust of the subprime mortgage market has resulted in high levels of foreclosures and unparalleled problems on Wall Street. However, the boom generated unprecedented levels of homeownership, especially among young, low-income, and minority borrowers, putting them on a road to economic comfort and stability. Sensible regulation of subprime lending should seek to curb abusive practices while preserving these benefits. This Article reviews the theories and evidence regarding the causes of the turmoil in the subprime market. It then turns to the question of the rising number of foreclosures in the subprime market in order to understand the causes of rising foreclosures. In particular, it examines the competing models of home foreclosures that have been developed in the economics literature-the distress model and the option model. Establishing a correct model of the causes of foreclosure in the subprime market is necessary for sensible and effective policy responses to the problem. The focus in this Article is on the consumer protection side of the equation. As this Article goes to press, the federal government has authorized a massive bailout of the banking industry, raising issues which largely lie outside the scope of this Article. New regulations and other interventions into the consumer side of the market have been modest
Early red nucleus atrophy in relapse-onset multiple sclerosis
No study has investigated red nucleus (RN) atrophy in multiple sclerosis (MS) despite cerebellum and its connections are elective sites of MS-related pathology. In this study, we explore RN atrophy in early MS phases and its association with cerebellar damage (focal lesions and atrophy) and physical disability. Thirty-seven relapse-onset MS (RMS) patients having mean age of 35.6 ± 8.5 (18–56) years and mean disease duration of 1.1 ± 1.5 (0–5) years, and 36 age- and sex-matched healthy controls (HC) were studied. Cerebellar and RN lesions and volumes were analyzed on 3 T-MRI images. RMS did not differ from HC in cerebellar lobe volumes but significantly differed in both right (107.84 ± 13.95 mm3 vs. 99.37 ± 11.53 mm3, p =.019) and left (109.71 ± 14.94 mm3 vs. 100.47 ± 15.78 mm3, p =.020) RN volumes. Cerebellar white matter lesion volume (WMLV) inversely correlated with both right and left RN volumes (r = −.333, p =.004 and r = −.298, p =.010, respectively), while no correlation was detected between RN volumes and mean cortical thickness, cerebellar gray matter lesion volume, and supratentorial WMLV (right RN: r = −.147, p =.216; left RN: r = −.153, p =.196). Right, but not left, RN volume inversely correlated with midbrain WMLV (r = −.310, p =.008), while no correlation was observed between whole brainstem WMLV and either RN volumes (right RN: r = −.164, p =.164; left RN: r = −.64, p =.588). Finally, left RN volume correlated with vermis VIIb (r =.297, p =.011) and right interposed nucleus (r =.249, p =.034) volumes. We observed RN atrophy in early RMS, likely resulting from anterograde axonal degeneration starting in cerebellar and midbrain WML. RN atrophy seems a promising marker of neurodegeneration and/or cerebellar damage in RMS
Should Research Ethics Encourage the Production of Cost-Effective Interventions?
This project considers whether and how research ethics can contribute to the provision of cost-effective medical interventions. Clinical research ethics represents an underexplored context for the promotion of cost-effectiveness. In particular, although scholars have recently argued that research on less-expensive, less-effective interventions can be ethical, there has been little or no discussion of whether ethical considerations justify curtailing research on more expensive, more effective interventions. Yet considering cost-effectiveness at the research stage can help ensure that scarce resources such as tissue samples or limited subject popula- tions are employed where they do the most good; can support parallel efforts by providers and insurers to promote cost-effectiveness; and can ensure that research has social value and benefits subjects. I discuss and rebut potential objections to the consideration of cost-effectiveness in research, including the difficulty of predicting effectiveness and cost at the research stage, concerns about limitations in cost-effectiveness analysis, and worries about overly limiting researchers’ freedom. I then consider the advantages and disadvantages of having certain participants in the research enterprise, including IRBs, advisory committees, sponsors, investigators, and subjects, consider cost-effectiveness. The project concludes by qualifiedly endorsing the consideration of cost-effectiveness at the research stage. While incorporating cost-effectiveness considerations into the ethical evaluation of human subjects research will not on its own ensure that the health care system realizes cost-effectiveness goals, doing so nonetheless represents an important part of a broader effort to control rising medical costs
Ethics-in-practice in fragile contexts: research in education for displaced persons, refugees and asylum seekers
The rising numbers of forcibly displaced peoples on the move globally, and the challenges with providing access to education, reflects the shifting and complex times that we live in. Even though there has been a proliferation in educational research in the context of forced migration, in line with the increasing number of forced migrants, there has not been a commensurate focus on unpicking the increasingly complex ethical conditions within which researchers and participants operate. To examine this issue, the article provides three narrated accounts by researchers in this field and explores the interaction of researcher and researcher-author voice to critically appraise their research experience and identify critical reflections of understanding of ethics-in-practice in fragile contexts. These narratives are framed by the CERD ethical appraisal framework which explores ethical thinking through four ethical lenses – Consequential, Ecological, Relational and Deontological. The article contributes to a deeper understanding of ethics-in-practice as a central dimension in educational research. The implications of this work show how one-size-fits-all approach to ethical appraisal is inappropriate for a socially just educational research. This work also illustrates the importance of attending to relationships and voice of the forcibly displaced, both of which are often lacking in educational research in fragile contexts
The SEC\u27s Misguided Climate Disclosure Rule Proposal
The following article adapts and consolidates two comment letters submitted last spring by a group of twenty-two professors of finance and law on the SEC’s proposed climate change disclosure rules. The professors reiterate their recommendation that the SEC withdraw its proposal as legally misguided, while outlining some of the issues that the proposal will face when challenged in court
Small RNA populations revealed by blocking rRNA fragments in Drosophila melanogaster reproductive tissues
RNA interference (RNAi) is a complex and highly conserved regulatory mechanism mediated via small RNAs (sRNAs). Recent technical advances in high throughput sequencing have enabled an increasingly detailed analysis of sRNA abundances and profiles in specific body parts and tissues. This enables investigations of the localized roles of microRNAs (miRNAs) and small interfering RNAs (siRNAs). However, variation in the proportions of non-coding RNAs in the samples being compared can hinder these analyses. Specific tissues may vary significantly in the proportions of fragments of longer non-coding RNAs (such as ribosomal RNA or transfer RNA) present, potentially reflecting tissue-specific differences in biological functions. For example, in Drosophila, some tissues contain a highly abundant 30nt rRNA fragment (the 2S rRNA) as well as abundant 5’ and 3’ terminal rRNA fragments. These can pose difficulties for the construction of sRNA libraries as they can swamp the sequencing space and obscure sRNA abundances. Here we addressed this problem and present a modified “rRNA blocking” protocol for the construction of high-definition (HD) adapter sRNA libraries, in D. melanogaster reproductive tissues. The results showed that 2S rRNAs targeted by blocking oligos were reduced from >80% to < 0.01% total reads. In addition, the use of multiple rRNA blocking oligos to bind the most abundant rRNA fragments allowed us to reveal the underlying sRNA populations at increased resolution. Side-by-side comparisons of sequencing libraries of blocked and non-blocked samples revealed that rRNA blocking did not change the miRNA populations present, but instead enhanced their abundances. We suggest that this rRNA blocking procedure offers the potential to improve the in-depth analysis of differentially expressed sRNAs within and across different tissues
The role of the universally conserved A2450–C2063 base pair in the ribosomal peptidyl transferase center
Despite the fact that all 23S rRNA nucleotides that build the ribosomal peptidyl transferase ribozyme are universally conserved, standard and atomic mutagenesis studies revealed the nucleobase identities being non-critical for catalysis. This indicates that these active site residues are highly conserved for functions distinct from catalysis. To gain insight into potential contributions, we have manipulated the nucleobases via an atomic mutagenesis approach and have utilized these chemically engineered ribosomes for in vitro translation reactions. We show that most of the active site nucleobases could be removed without significant effects on polypeptide production. Our data however highlight the functional importance of the universally conserved non-Watson-Crick base pair at position A2450–C2063. Modifications that disrupt this base pair markedly impair translation activities, while having little effects on peptide bond formation, tRNA drop-off and ribosome-dependent EF-G GTPase activity. Thus it seems that disruption of the A2450–C2063 pair inhibits a reaction following transpeptidation and EF-G action during the elongation cycle. Cumulatively our data are compatible with the hypothesis that the integrity of this A-C wobble base pair is essential for effective tRNA translocation through the peptidyl transferase center during protein synthesis
2D characterization of near-surface V P/V S: surface-wave dispersion inversion versus refraction tomography
International audienceThe joint study of pressure (P-) and shear (S-) wave velocities (Vp and Vs ), as well as their ratio (Vp /Vs), has been used for many years at large scales but remains marginal in near-surface applications. For these applications, and are generally retrieved with seismic refraction tomography combining P and SH (shear-horizontal) waves, thus requiring two separate acquisitions. Surface-wave prospecting methods are proposed here as an alternative to SH-wave tomography in order to retrieve pseudo-2D Vs sections from typical P-wave shot gathers and assess the applicability of combined P-wave refraction tomography and surface-wave dispersion analysis to estimate Vp/Vs ratio. We carried out a simultaneous P- and surface-wave survey on a well-characterized granite-micaschists contact at Ploemeur hydrological observatory (France), supplemented with an SH-wave acquisition along the same line in order to compare Vs results obtained from SH-wave refraction tomography and surface-wave profiling. Travel-time tomography was performed with P- and SH- wave first arrivals observed along the line to retrieve Vtomo p and Vtomo s models. Windowing and stacking techniques were then used to extract evenly spaced dispersion data from P-wave shot gathers along the line. Successive 1D Monte Carlo inversions of these dispersion data were performed using fixed Vp values extracted from Vtomo p the model and no lateral constraints between two adjacent 1D inversions. The resulting 1D Vsw s models were then assembled to create a pseudo-2D Vsw s section, which appears to be correctly matching the general features observed on the section. If the pseudo-section is characterized by strong velocity incertainties in the deepest layers, it provides a more detailed description of the lateral variations in the shallow layers. Theoretical dispersion curves were also computed along the line with both and models. While the dispersion curves computed from models provide results consistent with the coherent maxima observed on dispersion images, dispersion curves computed from models are generally not fitting the observed propagation modes at low frequency. Surface-wave analysis could therefore improve models both in terms of reliability and ability to describe lateral variations. Finally, we were able to compute / sections from both and models. The two sections present similar features, but the section obtained from shows a higher lateral resolution and is consistent with the features observed on electrical resistivity tomography, thus validating our approach for retrieving Vp/Vs ratio from combined P-wave tomography and surface-wave profiling
Fructan and its relationship to abiotic stress tolerance in plants
Numerous studies have been published that attempted to correlate fructan concentrations with freezing and drought tolerance. Studies investigating the effect of fructan on liposomes indicated that a direct interaction between membranes and fructan was possible. This new area of research began to move fructan and its association with stress beyond mere correlation by confirming that fructan has the capacity to stabilize membranes during drying by inserting at least part of the polysaccharide into the lipid headgroup region of the membrane. This helps prevent leakage when water is removed from the system either during freezing or drought. When plants were transformed with the ability to synthesize fructan, a concomitant increase in drought and/or freezing tolerance was confirmed. These experiments indicate that besides an indirect effect of supplying tissues with hexose sugars, fructan has a direct protective effect that can be demonstrated by both model systems and genetic transformation
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