The two-pion production reaction
pp
→
pp
π
+
π
−
was measured with a polarized proton beam at
T
p
≈ 750 and 800MeV using the short version of the COSY-TOF spectrometer. The implementation of a ...delayed-pulse technique for Quirl and central calorimeter provided positive π
+
identification in addition to the standard particle identification, energy determination as well as time-of-flight and angle measurements. Thus all four-momenta of the emerging particles could be determined with 1–4 overconstraints. Total and differential cross-sections as well as angular distributions of the vector analyzing power have been obtained. They are compared to previous data and theoretical calculations. In contrast to predictions we find significant analyzing-power values up to
A
y
= 0.3. The data taken in the energy region of the excitation of the Roper resonance confirm that its dominant ππ decay channel is
N
*
→
N
σ.
Rationale and objective
Studies indicate that nicotine enhances some aspects of attention and executive functioning and attenuates the attentional salience of emotionally negative distractors. The ...purpose of this study was to assess whether nicotine can enhance executive control over prepotent responses in emotional contexts in nonsmokers and whether such enhancement is greater in individuals with low baseline performance (BP).
Methods
The antisaccade task (AST) measures the inhibition of the tendency to glance in the direction of the onset of a visual stimulus and thus is an index of control over prepotent responses. Ten male and 14 female nonsmokers wore nicotine and placebo patches on counterbalanced days that included emotional picture primes and targets.
Results
There were significant beneficial effects of nicotine on antisaccade reaction time (RT). These beneficial effects occurred in individuals with poor and average BP, but not in high baseline performers. In slow baseline RT individuals, nicotine reduced RTs associated with negative targets in the left visual field (VF) and reduced RTs associated with positive and neutral targets in the right VF. In contrast, in the average baseline group, nicotine reduced RTs for positive targets in both VFs and neutral targets in the left VF.
Conclusions
The results suggest that nicotine may produce its effects by enhancing executive functions and that the differential effects as a function of VF, target emotion, and group may also reflect lateralized differences in the effects of nicotine on brain reactivity to emotional stimuli.
Perspectives on Fair Housing Reina, Vincent J; Pritchett, Wendell E; Wachter, Susan M ...
2020, 2020-11-20
eBook
Title VIII of the Civil Rights Act of 1968, known as the Fair Housing Act, prohibited discrimination in the sale, rent, and financing of housing based on race, religion, and national origin. However, ...manifold historical and contemporary forces, driven by both governmental and private actors, have segregated these protected classes by denying them access to homeownership or housing options in high-performing neighborhoods. Perspectives on Fair Housing argues that meaningful government intervention continues to be required in order to achieve a housing market in which a person's background does not arbitrarily restrict access.The essays in this volume address how residential segregation did not emerge naturally from minority preference but rather how it was forced through legal, economic, social, and even violent measures. Contributors examine racial land use and zoning practices in the early 1900s in cities like Atlanta, Richmond, and Baltimore; the exclusionary effects of single-family zoning and its entanglement with racially motivated barriers to obtaining credit; and the continuing impact of mid-century "redlining" policies and practices on public and private investment levels in neighborhoods across American cities today. Perspectives on Fair Housing demonstrates that discrimination in the housing market results in unequal minority households that, in aggregate, diminish economic prosperity across the country.Amended several times to expand the protected classes to include gender, families with children, and people with disabilities, the FHA's power relies entirely on its consistent enforcement and on programs that further its goals. Perspectives on Fair Housing provides historical, sociological, economic, and legal perspectives on the critical and continuing problem of housing discrimination and offers a review of the tools that, if appropriately supported, can promote racial and economic equity in America. Contributors: Francesca Russello Ammon, Raphael Bostic, Devin Michelle Bunten, Camille Zubrinsky Charles, Nestor M. Davidson, Amy Hillier, Marc H. Morial, Eduardo M. Peñalver, Wendell E. Pritchett, Rand Quinn, Vincent J. Reina, Akira Drake Rodriguez, Justin P. Steil, Susan M. Wachter.
A strategy based on reticulating metal ions and organic carboxylate links into extended networks has been advanced to a point that allowed the design of porous structures in which pore size and ...functionality could be varied systematically. Metal-organic framework (MOF-5), a prototype of a new class of porous materials and one that is constructed from octahedral Zn-O-C clusters and benzene links, was used to demonstrate that its three-dimensional porous system can be functionalized with the organic groups -Br, -NH2, -OC3H
7, -OC5H
11, -C2H
4, and -C4H
4and that its pore size can be expanded with the long molecular struts biphenyl, tetrahydropyrene, pyrene, and terphenyl. We synthesized an isoreticular series (one that has the same framework topology) of 16 highly crystalline materials whose open space represented up to 91.1% of the crystal volume, as well as homogeneous periodic pores that can be incrementally varied from 3.8 to 28.8 angstroms. One member of this series exhibited a high capacity for methane storage (240 cubic centimeters at standard temperature and pressure per gram at 36 atmospheres and ambient temperature), and others the lowest densities (0.41 to 0.21 gram per cubic centimeter) for a crystalline material at room temperature.
In the assessment of hand and upper limb function, detecting sincerity of effort (SOE) for grip strength is of major importance to identifying feigned loss of strength. Measuring maximal grip ...strength with a dynamometer is very common, often combined with calculating the coefficient of variation (CV), a measure of the variation over the three grip strength trials. Little data is available about the relevance of these measurements in patients with median nerve impairment due to the heterogeneity of patient groups. This study examined the reliability of grip strength tests as well as the CV to detect SOE in healthy subjects. The power distribution of the individual fingers and the thenar was taken into account. To assess reliability, the measurements were performed in subjects with a median nerve block to simulate a nerve injury. The ability of 21 healthy volunteers to exert maximal grip force and to deliberately exert half-maximal force to simulate reduced SOE in a power grip was examined using the Jamar® dynamometer. The experiment was performed in a combined setting with and without median nerve block of the same subject. The force at the fingertips of digits 2–5 and at the thenar eminence was measured with a sensor glove with integrated pressure receptors. For each measurement, three trials were recorded subsequently and the mean and CV were calculated. When exerting submaximal force, the subjects reached 50–62% of maximal force, regardless of the median nerve block. The sensor glove revealed a significant reduction of force when exerting submaximal force (P1 sensor) with (P<0.032) and without median nerve block (P<0.017). An increase in CV at submaximal force was found, although it was not significant. SOE can be detected with the CV at the little finger at using a 10% cut-off (sensitivity 0.84 and 0.92 without and with median nerve block, respectively). These findings suggest low reliability of the power grip measurement with the Jamar® dynamometer, as well as that of the CV for detecting SOE. However, the combination of finger forces including the thenar area and the CV at the little finger could lead to better reliability for detecting feigned reduction of grip strength. The methods were as reliable in subjects with a median nerve block as in healthy subjects.
Dans l’évaluation de la fonction de la main du membre supérieur, il est primordial de détecter la sincérité de l’effort (SDE) lors de la force de poigne pour identifier les pertes feintes de force. La mesure de la force maximale de poigne avec un dynamomètre est très répandue, souvent combinée au calcul du coefficient de variations (CV), une mesure de la variation lors de trois essais répétés successivement de la force de poigne. Peu de données sont disponibles concernant la pertinence de ces mesures chez les patients présentant une pathologie du nerf médian, en raison de l’hétérogénéité des groupes de patients. Le présent travail a évalué la fiabilité des tests de force de poigne et le CV pour détecter la SDE chez les sujets sains. La distribution de la puissance selon les différents doigts et l'éminence thénar a été prise en compte. Les mesures ont également été réalisées chez les mêmes sujets après un bloc du nerf médian simulant un groupe de patients présentant une lésion nerveuse pour en évaluer la fiabilité. Dans cette étude, 21 volontaires sains ont été examinés quant à leur capacité à développer une force de poigne maximale et une force de poigne délibérément diminuée de sa moitié pour simuler une SDE lors d’une prise de poigne évaluée avec le dynamomètre JAMAR. L’expérimentation a été réalisée avec et sans bloc du nerf médian chez le même sujet. De plus, la force développée aux pulpes des doigts 2 à 5 et au niveau de l’éminence thénar a été mesurée à l’aide d’un gant sensitif équipé de capteurs de pression. Pour chaque mesure, trois essais ont été enregistrés successivement, la moyenne et le CV ont été calculés. Lors de la prise de force avec le dynamomètre JAMAR chez les sujets exerçant une force submaximale, les patients développaient 50 à 62 % de la force maximale, même après bloc du nerf médian. En mesurant de la force développée au niveau de l’éminence thénar par le gant sensitif, on constatait une réduction significative de la force lorsque que le sujet exerçait une force submaximale (capteur P1), avec (p<0,032) et sans bloc du nerf médian (p<0,017). On enregistrait également une augmentation du CV lors des prises à force submaximale, bien qu’elle ne soit pas significative. Il était possible de détecter la SDE et le CV au petit doigt avec un seuil de 10 % (sensibilité 0,84 et 0,92, respectivement sans et avec bloc du nerf médian). Ces expérimentations suggèrent une faible fiabilité des mesures de la force de poigne avec le dynamomètre JAMAR ainsi que celle du CV pour la détection de la SDE. Cependant, sa combinaison de la mesure des forces exercées par les doigts et l’éminence thénar et le CV au niveau du petit doigt pourrait améliorer la fiabilité lors du repérage d’une réduction feinte de force de poigne. La fiabilité de ces méthodes chez les sujets après bloc du nerf médian était comparable à celles des sujets sains.
The complexity of immunoregulation has focused attention on the CD4⁺ T "suppressor" regulatory cell (Treg), which helps maintain balance between immunity and tolerance. An immunoregulatory T-cell ...population that upon activation amplifies cellular immune responses was described in murine models more than 30 years ago; however, no study has yet identified a naturally occurring T "inducer" cell type. Here, we report that the ectoenzyme CD39/NTPDase1 (ecto-nucleoside triphosphate diphosphohydrolase 1) helps to delineate a novel population of human "inducer" CD4⁺ T cells (Tind) that significantly increases the proliferation and cytokine production of responder T cells in a dose-dependent manner. Furthermore, this unique Tind subset produces a distinct repertoire of cytokines in comparison to the other CD4⁺ T-cell subsets. We propose that this novel CD4⁺ T-cell population counterbalances the suppressive activity of suppressor Treg in peripheral blood and serves as a calibrator of immunoregulation.
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