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In this paper, we evaluate the effects of a reduction in Social Security's Old-Age and Survivors Insurance (OASI) benefits using seven different quantitative general equilibrium overlapping-generations (OLG) models. We compare the effects of an anticipated one-third reduction in OASI benefits beginning in 2031 on an economy that maintains currently schedided benefits. We find many of the models generate qualitatively similar results concerning budgetary and macroeconomic aggregates; however, the magnitude of the effects varies owing to the models' structure and calibration strategies. Keywords: Social Security, dynamic analysis JEL Codes: E62, H30, H55, I. INTRODUCTION Jaeger Nelson and Kerk Phillips In 2018, the Congressional Budget Office (CBO) projected that, if current laws did not change, Social Security's Old-Age, Survivors, and Disability Insurance (OASDI) [...]

The macroeconomic effects of tax reform are a subject of significant discussion and controversy. In 2015. the House of Representatives adopted a new 'dynamic scoring' rule requiring a point estimate within the budget window of the deficit effect due to the macroeconomic response to certain proposed tax legislation. The revenue estimates provided by the staff of the Joint Committee on Taxation (JCT) for major tax bills often play a critical role in Congressional deliberations and public discussion of those bills. The JCT has long had macroeconomic analytic capability, and in recent years, responding to Congress' interest in macrodynamic estimates for purposes of scoring legislation, outside think tank groups--notably the Tax Policy Center and the Tax Foundation--have also developed macrodynamic estimation models. The May 2017 National Tax Association (NTA) Spring Symposium brought together the JCT with the Tax Foundation and the Tax Policy Center for a panel discussion regarding their respective macrodynamic estimating approaches. This paper reports on that discussion. Below each organization provides a general description of their macrodynamic modeling methodology and answers five questions posed by the convening authors. Keywords: revenue estimation, dynamic scoring, macrodynamic estimates, tax reform JEL Codes: H20, H30, I. INTRODUCTION Alan J. Auerbach and Itai Grinberg The macroeconomic effects of tax reform are a subject of significant discussion and controversy. Although uncertain, most estimates tend to find these [...]

Tina M. Henkin and Joseph E. Peters; ASM Press and John Wiley & Sons, Washington, DC, USA, 2020; ISBN-10: 978-1-555-81975-0; Pages: 615; Price: $140.95 (Hardcover) To a molecular biologist, a [...]

I. INTRODUCTION II. BACKGROUND: THE DEAL WITH DEAL A. Enacting and Amending 18 U.S.C. § 924(c) B. Pre-Deal Application of 18 U.S.C. § 924(c) C. The Supreme Court Steps In [...]

The landfall of Hurricane Katrina marked not only one of the most significant and destructive natural disasters for the United States in recent history, but also a new benchmark in challenges faced by psychologists providing services. The authors explain their roles following the hurricane, describing not only local activities for recovery but efforts conducted in the Gulf Coast as well. Experiences and perceptions of the first author, who was deployed to the Gulf Coast on numerous occasions, are highlighted. In addition, psychological assessments were carried out with a small number of displaced Katrina survivors who were relocated to the authors' local community. The authors document many of the challenges faced by psychologists and other mental health workers during relief efforts in the Gulf Coast, concluding with a set of recommendations for future disaster-relief initiatives regarding such issues as ways in which psychologists can participate in disaster-relief efforts, challenges faced when implementing interventions, cultural competency, community preparedness, and scientific research. Keywords: trauma, disaster, Katrina, cultural competence

A new synziphosurine (Chelicerata:Xiphosura) is described from the Late Llandovery (Silurian) Konservat-Lagerstatte of Waukesha, Wisconsin, USA. Venustulus waukeshaensis n.gen, and sp. is characterized by a semicircular carapace with a slightly procurved posterior margin lacking genal spines and an opisthosoma composed of 10 freely articulating segments, divided into a preabdomen of seven segments with blunt pleurae and a postabdomen of three segments lacking pleurae. The tail spine is short and styliform. This is the earliest known unequivocal synziphosurine, extending their fossil record from the Wenlock to the Llandovery, and only the second species to be described with prosomal appendages; the presence of six pairs (a pair of chelicerae and five pairs of walking legs) contrasts with the seven in the synziphosurine Weinbergina opitzi, but is comparable to the number in modern horseshoe crabs. V. waukeshaensis n. gen. and sp. is not assigned to a family here pending a wider revision, but it bears most resemblance to the Weinberginidae.

Normal growth and morphogenesis of the cranial vault reflect a balance between cell proliferation in the sutures and osteogenesis at the margins of the cranial bones. In the clinical condition craniosynostosis, the sutures fuse prematurely as a result of precocious osteogenic differentiation and craniofacial malformation results. Mutations in several fibroblast growth factor receptor (FGFR) genes have now been identified as being responsible for the major craniosynostotic syndromes. We have used a grafting technique to manipulate the levels of endogenous FGF-2 ligand in embryonic chick cranial vaults and thereby perturb morphogenesis. Implantation of beads loaded with FGF-2 did not affect normal cranial development at physiological concentrations, although they elicited a morphogenetic response in the limb. Implantation of beads loaded with a neutralising antibody to FGF-2 generated a concentration-dependent response. When a single bead was implanted, the grafts grew to a massive size as a result of increased cell division in the tissue. With greater inactivation of FGF-2 protein (two to three beads implanted), all further bone differentiation and cell proliferation was blocked. These data further support the emerging idea that the intensity of FGF-mediated signalling determines the developmental fate of the skeletogenic cells in the cranial vault. High and low levels correlate with differentiation and proliferation, respectively. A balance between the two ensures normal cranial vault morphogenesis. This is consistent with the observation that several FGFR mutations causing craniosynostosis result in constitutive activation of the receptor. Key Words: neural crest; osteogenesis; FGF-2; cranium; suture.

Normal meals are highly viscous, and viscosity is a key factor in influencing gastric emptying of food. However, the process of meal dilution and mixing is difficult to assess with the use of conventional methods. The aim of this study was to validate an in vivo, novel, noninvasive, echo-planar magnetic resonance imaging (EPI) technique, capable of monitoring the viscosity of a model meal, and to use this to investigate the effects of viscosity on gastric emptying, meal dilution and satiety. Healthy volunteers (n = 8) ingested 500 mL of locust bean gum (0.25, 0.5, 1.0 or 1.5 g/100 g), nonnutrient, liquid meals of varying viscosities, and labeled with a nonabsorbable marker, phenol red. Meal viscosity was calibrated against the water proton transverse relaxation rate (T(sub 2)(super -1)) in vitro before ingestion, thus viscosity was measured in vivo via EPI measurements of T(sub 2)(super -1). Viscosity and dilution were also measured directly using nasogastric aspirates. Gastric volumes as measured by EPI, fullness, appetite and hunger were also assessed serially. Before ingestion, the log of initial meal viscosity was linearly related to T(sub 2)(super -1) (n = 8, r(super 2) = 0.95). Similarly, T(sub 2)(super -1) measured in vivo was also linearly related to the viscosity of the aspirates (r(super 2) = 0.88). All meals underwent rapid dilution, leading to a reduction in viscosity, which was greatest for the most viscous meal (P < 0.01). Surprisingly, despite the fact that the initial meal viscosity varied 1000-fold, there was only a small delay in gastric emptying (P for trend < 0.05). The area under the curve for satiety increased with initial meal viscosity, whereas that for hunger decreased (P < 0.05). In conclusion, the viscosity of a meal in vivo can be measured noninvasively using EPI. The stomach responds to meal ingestion by rapid intragastric dilution, causing a reduction of meal viscosity, and gastric emptying is minimally delayed. However, increased viscosity is associated with more prolonged satiety.

The relationship between the intragastric distribution, dilution, and emptying of meals and satiety was studied using noninvasive magnetic resonance imaging techniques in 12 healthy subjects with four polysaccharide test meals of varying viscosity and nutrient content as follows: 1) low-viscosity nonnutrient, 2) low-viscosity nutrient, 3) high-viscosity nonnutrient, and 4) high-viscosity nutrient. Increasing the nutrient content of the high-viscosity meal delayed gastric emptying from 46 [+ or -] 9 to 76 [+ or -] 6 min (P [is less than] 0.004), whereas increasing viscosity had a smaller effect. The volume of secretions within the stomach 60 min after ingestion was higher for the high-viscosity nutrient meal (P [is less than] 0.04). A simple model to calculate the total volume of secretion added to the test meal is presented. Color-coded dilution map images showed the heterogeneous process of progressive gastric dilution of high-viscosity meals, whereas low-viscosity meals were uniformly diluted. Fullness was found to be linearly related to total gastric volumes for the nutrient meals ([R.sup.2] = 0.98) and logarithmically related for the nonnutrient meals ([R.sup.2] = 0.96). Fullness was higher for high- compared with low-viscosity meals (P [is less than] 0.02), and with the nutrient meals this was associated with greater antral volumes (P [is less than] 0.05). stomach; polysaccharide gum; abdominal imaging; echo-planar magnetic resonance imaging

Assessment of antral grinding of a model solid meal with echoplanar imaging. Am J Physiol Gastrointest Liver Physiol 280: G844-G849, 2001.--Mathematical modeling of how physical factors alter gastric emptying is limited by lack of precise measures of the forces exerted on gastric contents. We have produced agar gel beads (diameter 1.27 cm) with a range of fracture strengths (0.15-0.90 N) and assessed their breakdown by measuring their half-residence time ([RT.sub.1/2]) using magnetic resonance imaging. Beads were ingested either with a high (HV)- or low (LV)-viscosity liquid nutrient meal. With the LV meal, [RT.sub.1/2] was similar for bead strengths ranging from 0.15 to 0.65 N but increased from 22 [+ or -] 2 min (bead strength [is less than] 0.65 N) to 65 [+ or -] 12 min for bead strengths [is greater than] 0.65 N. With the HV meal, emptying of the harder beads was accelerated. The sense of fullness after ingesting the LV meal correlated linearly (correlation coefficient = 0.99) with gastric volume and was independently increased by the harder beads, which were associated with an increased antral diameter. We conclude that the maximum force exerted by the gastric antrum is close to 0.65 N and that gastric sieving is impaired by HV meals. stomach; viscosity; gastric motility; gastric emptying; magnetic resonance imaging