How Money Helps Keep Students in College: The Relationship between Family Finances, Merit-based Aid, and Retention in Higher Education

In this paper, we leverage detailed, individual-level student data to understand the relationships between family finances, merit-based aid, and first-year student retention. With three cohorts of student data that comprise family financial status, institutional merit scholarships, and many of the other known correlates of student retention, we regress sophomore retention of first-time, full-time students on the financial variables with controls. We find that an increase in a family’s ability to contribute to educational costs improves a student’s chances of retention. Additionally, our data show that institutional financial assistance also bolsters the likelihood that students return for their sophomore year

Climate scientists’ wide prediction intervals may be more likely but are perceived to be less certain

The use of interval forecasts allows climate scientists to issue predictions with high levels of certainty even for areas fraught with uncertainty, since wide intervals are objectively more likely to capture the truth than narrow intervals. However, wide intervals are also less informative about what the outcome will be than narrow intervals, implying a lack of knowledge or subjective uncertainty in the forecaster. In six experiments, we investigate how lay people perceive the (un)certainty associated with wide and narrow interval forecasts, and find that the preference for accuracy (seeing wide intervals as “objectively” certain) vs. informativeness (seeing wide intervals as indicating “subjective” uncertainty) is influenced by contextual cues (e.g., question formulation). Most importantly, we find that people more commonly and intuitively associate wide intervals with uncertainty than with certainty. Our research thus challenges the wisdom of using wide intervals to construct statements of high certainty in climate change reports

The Regulatory Subunit of PKA-I Remains Partially Structured and Undergoes b-Aggregation upon Thermal Denaturation

Background: The regulatory subunit (R) of cAMP-dependent protein kinase (PKA) is a modular flexible protein that responds with large conformational changes to the binding of the effector cAMP. Considering its highly dynamic nature, the protein is rather stable. We studied the thermal denaturation of full-length RIa and a truncated RIa(92-381) that contains the tandem cyclic nucleotide binding (CNB) domains A and B. Methodology/Principal Findings: As revealed by circular dichroism (CD) and differential scanning calorimetry, both RIa proteins contain significant residual structure in the heat-denatured state. As evidenced by CD, the predominantly a-helical spectrum at 25uC with double negative peaks at 209 and 222 nm changes to a spectrum with a single negative peak at 212–216 nm, characteristic of b-structure. A similar aRb transition occurs at higher temperature in the presence of cAMP. Thioflavin T fluorescence and atomic force microscopy studies support the notion that the structural transition is associated with cross-b-intermolecular aggregation and formation of non-fibrillar oligomers. Conclusions/Significance: Thermal denaturation of RIa leads to partial loss of native packing with exposure of aggregationprone motifs, such as the B’ helices in the phosphate-binding cassettes of both CNB domains. The topology of the bsandwiches in these domains favors inter-molecular b-aggregation, which is suppressed in the ligand-bound states of RIa under physiological conditions. Moreover, our results reveal that the CNB domains persist as structural cores through heatdenaturation

Conformation of the substrate and pterin cofactor bound to human tryptophan hydroxylase. Important role of Phe313 in substrate specificity

ABSTRACT: Tryptophan hydroxylase (TPH) carries out the 5-hydroxylation of L-Trp, which is the ratelimiting step in the synthesis of serotonin. We have prepared and characterized a stable N-terminally truncated form of human TPH that includes the catalytic domain (∆90TPH). We have also determined the conformation and distances to the catalytic non-heme iron of both L-Trp and the tetrahydrobiopterin cofactor analogue L-erythro-7,8-dihydrobiopterin (BH 2 ) bound to ∆90TPH by using 1 H NMR spectroscopy. The bound conformers of the substrate and the pterin were then docked into the modeled three-dimensional structure of TPH. The resulting ternary TPH‚BH 2 ‚L-Trp structure is very similar to that previously determined by the same methods for the complex of phenylalanine hydroxylase (PAH) with BH 2 and L-Phe [Teigen, K., et al. (1999) J. Mol. Biol. 294, 807-823]. In the model, L-Trp binds to the enzyme through interactions with Arg257, Ser336, His272, Phe318, and Phe313, and the ring of BH 2 interacts mainly with Phe241 and Glu273. The distances between the hydroxylation sites at C5 in L-Trp and C4a in the pterin, i.e., 6.1 ( 0.4 Å, and from each of these sites to the iron, i.e., 4.1 ( 0.3 and 4.4 ( 0.3 Å, respectively, are also in agreement with the formation of a transient iron-4a-peroxytetrahydropterin in the reaction, as proposed for the other hydroxylases. The different conformation of the dihydroxypropyl chain of BH 2 in PAH and TPH seems to be related to the presence of nonconserved residues, i.e., Tyr235 and Pro238 in TPH, at the cofactor binding site. Moreover, Phe313, which seems to interact with the substrate through ring stacking, corresponds to a Trp residue in both tyrosine hydroxylase and PAH (Trp326) and appears to be an important residue for influencing the substrate specificity in this family of enzymes. We show that the W326F mutation in PAH increases the relative preference for L-Trp as the substrate, while the F313W mutation in TPH increases the preference for L-Phe, possibly by a conserved active site volume effect. Tryptophan hydroxylase (TPH) 1 is a tetrahydrobiopterinand non-heme iron-dependent enzyme that hydroxylates L-tryptophan (L-Trp) to 5-hydroxy-L-Trp using (6R)-Lerythro- These tetrameric enzymes are organized in a regulatory N-terminal domain, a catalytic domain, and a C-terminal oligomerization domain, and they exhibit extensive sequence similarity at the catalytic domains. Due to the scarcity of the enzyme in animal tissues and its instability in vitro, TPH is the least characterized enzyme of the three aromatic amino acid hydroxylases. Although significant progress has been reported recently on the structural characterization of both TH (4) and PAH (5-7), the three-dimensional (3D) structure of TPH is still not known. The difficulties encountered in the crystallization of this enzyme seem to be related to its instability and insolubility, notably when it is expressed in bacterial systems (8). However, the catalytic domain of the enzyme from different sources, including the human brain, appears to be more stable, and several groups have reported its purification and characterization (9). Recently, stable full-length TPH forms from the human pineal gland (10) and the human parasite Schistosoma mansoni (11) have been cloned, expressed, and successfully isolated. The first observable product from the pterin cofactor in the TPH reaction is a 4a-hydroxytetrahydropterin, in which the oxygen atom a

The regulatory subunit of PKA-I remains partially structured and undergoes β-aggregation upon thermal denaturation

Background: The regulatory subunit (R) of cAMP-dependent protein kinase (PKA) is a modular flexible protein that responds with large conformational changes to the binding of the effector cAMP. Considering its highly dynamic nature, the protein is rather stable. We studied the thermal denaturation of full-length RIα and a truncated RIα(92-381) that contains the tandem cyclic nucleotide binding (CNB) domains A and B. Methodology/Principal Findings: As revealed by circular dichroism (CD) and differential scanning calorimetry, both RIα proteins contain significant residual structure in the heat-denatured state. As evidenced by CD, the predominantly α-helical spectrum at 25°C with double negative peaks at 209 and 222 nm changes to a spectrum with a single negative peak at 212-216 nm, characteristic of β-structure. A similar α→β transition occurs at higher temperature in the presence of cAMP. Thioflavin T fluorescence and atomic force microscopy studies support the notion that the structural transition is associated with cross-β-intermolecular aggregation and formation of non-fibrillar oligomers. Conclusions/Significance: Thermal denaturation of RIα leads to partial loss of native packing with exposure of aggregation-prone motifs, such as the B' helices in the phosphate-binding cassettes of both CNB domains. The topology of the β-sandwiches in these domains favors inter-molecular β-aggregation, which is suppressed in the ligand-bound states of RIα under physiological conditions. Moreover, our results reveal that the CNB domains persist as structural cores through heat-denaturation. © 2011 Dao et al

Stability and error analysis for a diffuse interface approach to an advection-diffusion equation on a moving surface

In this paper we analyze a fully discrete numerical scheme for solving a parabolic PDE on a moving surface. The method is based on a diffuse interface approach that involves a level set description of the moving surface. Under suitable conditions on the spatial grid size, the time step and the interface width we obtain stability and error bounds with respect to natural norms. Furthermore, we present test calculations that confirm our analysis

OMAE2002-28536 COUPLED DYNAMIC ANALYSIS OF A MINI TLP: COMPARISON WITH MEASUREMENTS

ABSTRACT A numerical code (COUPLE) was recently developed for computing 6 Degree-Of-Freedom (DOF) motions of a moored floating structure dynamically interacting with its mooring/riser/tendon system. The computation of hydrodynamic forces on the moored structure can be conducted based on a diffraction wave theory model, e.g. WAMIT, and/or the Morison Equation based upon a slender body assumption. Wave kinematics up to the free surface, used in the Morison Equation, is computed using nonlinear deterministic Hybrid Wave Models, and is accurate up to second order in wave steepness. Experimental data from the model tests of a mini TLP was used as the basis for investigation of the numerical computation. Using COUPLE and its alternatives, coupled as well as quasi-static analyses were conducted for the mini TLP model that incorporates four risers and four tendons. Two different methods for computing hydrodynamic loads, namely, WAMIT and Morison Equation, were used, respectively. Through the comparison between the numerical results and the corresponding measurements, dynamic interactions between the riser/tendon system and the hull were examined. Findings made in this study, though based upon a mini TLP may have valuable applications to the design and simulation of a wide range of compliant deep-water structures

Medicine in words and numbers: a cross-sectional survey comparing probability assessment scales

Contains fulltext : 56355.pdf ( ) (Open Access)Background / In the complex domain of medical decision making, reasoning under uncertainty can benefit from supporting tools. Automated decision support tools often build upon mathematical models, such as Bayesian networks. These networks require probabilities which often have to be assessed by experts in the domain of application. Probability response scales can be used to support the assessment process. We compare assessments obtained with different types of response scale. Methods / General practitioners (GPs) gave assessments on and preferences for three different probability response scales: a numerical scale, a scale with only verbal labels, and a combined verbal-numerical scale we had designed ourselves. Standard analyses of variance were performed. Results / No differences in assessments over the three response scales were found. Preferences for type of scale differed: the less experienced GPs preferred the verbal scale, the most experienced preferred the numerical scale, with the groups in between having a preference for the combined verbal-numerical scale. Conclusion / We conclude that all three response scales are equally suitable for supporting probability assessment. The combined verbal-numerical scale is a good choice for aiding the process, since it offers numerical labels to those who prefer numbers and verbal labels to those who prefer words, and accommodates both more and less experienced professionals.8 p

Belief in Conspiracy Theories and Susceptibility to the Conjunction Fallacy

People who believe in the paranormal have been found to be particularly susceptible to the conjunction fallacy. The present research examines whether the same is true of people who endorse conspiracy theories. Two studies examined the association between conspiracist ideation and the number of conjunction violations made in a variety of contexts (neutral, paranormal and conspiracy). Study 1 found that participants who endorsed a range of popular conspiracy theories more strongly also made more conjunction errors than participants with weaker conspiracism, regardless of the contextual framing of the conjunction. Study 2, using an independent sample and a generic measure of conspiracist ideation, replicated the finding that conspiracy belief is associated with domain-general susceptibility to the conjunction fallacy. The findings are discussed in relation to the association between conspiracism and other anomalous beliefs, the representativeness heuristic and the tendency to infer underlying causal relationships connecting ostensibly unrelated events

Structural mechanism for tyrosine hydroxylase inhibition by dopamine and reactivation by Ser40 phosphorylation

16 pags, 7 figs . -- The online version contains supplementary movie1: https://static-content.springer.com/esm/art%3A10.1038%2Fs41467-021-27657-y/MediaObjects/41467_2021_27657_MOESM3_ESM.mp4Tyrosine hydroxylase (TH) catalyzes the rate-limiting step in the biosynthesis of dopamine (DA) and other catecholamines, and its dysfunction leads to DA deficiency and parkinsonisms. Inhibition by catecholamines and reactivation by S40 phosphorylation are key regulatory mechanisms of TH activity and conformational stability. We used Cryo-EM to determine the structures of full-length human TH without and with DA, and the structure of S40 phosphorylated TH, complemented with biophysical and biochemical characterizations and molecular dynamics simulations. TH presents a tetrameric structure with dimerized regulatory domains that are separated 15 Å from the catalytic domains. Upon DA binding, a 20-residue α-helix in the flexible N-terminal tail of the regulatory domain is fixed in the active site, blocking it, while S40-phosphorylation forces its egress. The structures reveal the molecular basis of the inhibitory and stabilizing effects of DA and its counteraction by S40-phosphorylation, key regulatory mechanisms for homeostasis of DA and TH.This research was supported by the grant PID2019-105872GB-I00/AEI/10.13039/ 501100011033 from the Spanish Ministry of Science and Innovation to J.M.V. and J.C. as well as FRIMEDBIO (261826) from the Research Council of Norway to A.M.; the Western Norway Regional Health Authorities (912246 to A.M. and 912264 to R.K.), the K.G.Peer reviewe