The influence of a weak magnetic field in the Renormalization-Group functions of (2+1)-dimensional Dirac systems

The experimental observation of the renormalization of the Fermi velocity $v_{F}$ as a function of doping has been a landmark for confirming the importance of electronic interactions in graphene. Although the experiments were performed in the presence of a perpendicular magnetic field $B$, the measurements are well described by a renormalization-group (RG) theory that did not include it. Here we clarify this issue, for both massive and massless Dirac systems, and show that for the weak magnetic fields at which the experiments are performed, there is no change in the renormalization-group functions. Our calculations are carried out in the framework of the Pseudo-quantum electrodynamics (PQED) formalism, which accounts for dynamical interactions. We include only the linear dependence in $B$, and solve the problem using two different parametrizations, the Feynman and the Schwinger one. We confirm the results obtained earlier within the RG procedure and show that, within linear order in the magnetic field, the only contribution to the renormalization of the Fermi velocity arises due to interactions. In addition, for gapped systems, we observe a running of the mass parameter.Comment: Discussion about the fermionic mass has been added to the previous versio

Japanese automotive supplier investment directory: October 1991. Fourth edition

http://deepblue.lib.umich.edu/bitstream/2027.42/1514/2/95628.0001.001.pd

Alcohol Safety Action Project bibliography

http://deepblue.lib.umich.edu/bitstream/2027.42/731/2/35890.0001.001.pd

The Relationship Between Arterial Elasticity and Metabolic Syndrome Features

The purpose of this study was to examine the effects of metabolic syndrome (MS) features on arterial elasticity of the large and small arteries in apparently healthy adults, to examine the effect of clustered features of MS, and to determine which features are most predictive of large and small artery elasticity. The subjects for this study consisted of 126 men and women, age 45 years and older. The subjects rested supine while pulse contour analysis was measured from the radial artery by using an HDI/Pulsewave CR-2000 instrument (Hypertension Diagnostic, Inc) to assess arterial elasticity in the large and small arteries. Medical history was obtained along with body mass index, waist circumference, body surface area, and blood pressure. Large artery elasticity was lower (p=0.002) in subjects with hypertension (12.7 ∓4.3 mL/mm Hg × 10) than in those with normotension (15.0 ∓4.2 mL/mm Hg × 10; mean ∓ SD), and small artery elasticity was lower (p=0.001) as well (3.9 ∓2.3 mL/mm Hg × 100 vs 5.3 ∓2.5 mL/mm Hg × 100). Large artery elasticity was lower (p=0.02) in obese subjects (12.2 ∓4.9 mL/mm Hg × 10) than in nonobese subjects (14.2 ∓4.5 mL/mm Hg × 10), and large artery elasticity was lower (p=0.04) in subjects with abdominal obesity (12.2 ∓4.5 mL/mm Hg × 10) than in those without (14.5 ∓4.8 mL/mm Hg × 10). Large artery elasticity decreased as the number of features of MS increased (p<0.01). Multiple regression showed that body mass index and the presence of hypertension were predictors of large artery elasticity (R =0.61, R 2 =0.37, p=0.003, SEE = 3.60 mL/mm Hg × 10), and hypertension was a predictor of small artery elasticity (R =0.53, R 2 =0.28, p=0.001, SEE = 2.12 mL/mm Hg × 100). Hypertension and obesity are the features of MS that are most predictive of impairment in large and small artery elasticity in apparently healthy middle-aged and older adults. Furthermore, impairment in large artery elasticity is more evident in subjects with at least three features of MS.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

The influence of obesity on calf blood flow and vascular reactivity in older adults

OBJECTIVE: To determine whether differences in vascular reactivity existed among normal weight, overweight, and obese older men and women, and to examine the association between abdominal fat distribution and vascular reactivity. METHODS: Eighty-seven individuals who were 60 years of age or older (age = 69 ± 7 yrs; mean ± SD) were grouped into normal weight (BMI < 25; n = 30), overweight (BMI ≥ 25 and < 30; n = 28), or obese (BMI ≥ 30; n = 29) categories. Calf blood flow (BF) was assessed by venous occlusion strain-gauge plethysmography at rest and post-occlusive reactive hyperemia. RESULTS: Post-occlusive reactive hyperemia BF was lower (p = 0.038) in the obese group (5.55 ± 4.67 %/min) than in the normal weight group (8.34 ± 3.89 %/min). Additionally, change in BF from rest to post-occlusion in the obese group (1.93 ± 2.58 %/min) was lower (p = 0.001) than in the normal weight group (5.21 ± 3.59 %/min), as well as the percentage change (75 ± 98 % vs. 202 ± 190 %, p = 0.006, respectively). After adjusting for age, prevalence in hypertension and calf skinfold thickness, change in BF values remained lower (p < 0.05) in obese subjects compared to the normal weight subjects. Lastly, the absolute and percentage change in BF were significantly related to BMI (r = -0.44, p < 0.001, and r = -0.37, p < 0.001, respectively) and to waist circumference (r = -0.36, p = 0.001, and r = -0.32, p = 0.002). CONCLUSION: Obesity and abdominal adiposity impair vascular reactivity in older men and women, and these deleterious effects on vascular reactivity are independent of conventional risk factors

Estudios postcoloniales : ensayos fundamentales

278 p. : il. ; 22 cm.Libro ElectrónicoEste libro presenta una amplia panorámica de los estudios postcoloniales, un campo heterogéneo de prácticas teóricas que se ha ido constituyendo en el mundo académico anglosajón a partir de la mitad de la década de 1980. Se ofrecen aquí traducidos al castellano dos de los textos fundamentales que pueden situarse en el origen de los estudios postcoloniales —el de Gayatri Spivak, «Los Estudios de la Subalternidad. Deconstruyendo la historiografía » (1984), y el de Chandra Talpade Mohanty, «Bajo los ojos de Occidente» (1985). Las intervenciones de Ella Shohat y Stuart Hall documentan la discusión que se desarrolló, con particular intensidad a lo largo de la primera mitad de la década de 1990, sobre el «significado de lo “post” en el término postcolonial». Los artículos de Dipesh Chakrabarty, Achille Mbembe, Robert Young, Nirmal Puwar, Sandro Mezzadra y Federico Rahola dan cuenta, por último, de la evolución del debate en los últimos años a partir de distintas perspectivas teóricas y posiciones «geográficas».índice INTRODUCCIÓN. Sandro Mezzadra 15 1. Estudios de la Subalternidad. Deconstruyendo la Historiografía. Gayatri Chakravorty Spivak 33 2. Bajo los ojos de Occidente. Saber académico y discursos coloniales. Chandra Talpade Mohanty 69 3. Notas sobre lo «postcolonial» Ella Shohat 103 4. ¿Cuándo fue lo postcolonial? Pensar al límite. Stuart Hall 121 5. La historia subalterna como pensamiento político. Dipesh Chakrabarty 145 6. Al borde del mundo. Fronteras, territorialidad y soberanía en África. Achille Mbembe 167 7. Nuevo recorrido por (las) Mitologías Blancas. Robert J. C. Young 197 8. Poses y construcciones melodramáticas. Nirmal Puwar 237 9. La condición postcolonial. Unas notas sobre la cualidad del tiempo histórico en el presente global. Sandro Mezzadra y Federico Rahola 26

Stabilizing chiral spin-structures via an alternating Dzyaloshinskii-Moriya interaction

The stabilization of chiral magnetic spin-structures in thin films is often attributed to the interfacial Dzyaloshinskii-Moriya interaction (DMI). Very recently, however, it has been reported that the chirality induced by the DMI can be affected by dipolar interactions. These dipolar fields tend to form N\'eel caps, which entails the formation of a clockwise chirality at the top of the film and a counterclockwise chirality at the bottom. Here, we show that engineering an alternating DMI that changes sign across the film thickness, together with the tendency to form N\'eel caps, leads to an enhanced stability of chiral spin-structures. Micromagnetic simulations for skyrmions demonstrate that this can increase the effective DMI in a prototypical [Pt/Co/Ir] multilayer system by at least \SI{0.6}{mJ.m^{-2}}. These gains are comparable to what has been achieved using additive DMI, but more flexible as we are not limited to a select set of material combinations. We also present experimental results: by measuring equilibrium domain widths we quantify the effective DMI in [Pt/Co/Ir] multilayer systems typically used for skyrmion stabilization. Upon introducing an alternating DMI we demonstrate changes in the effective DMI that agree with our simulations. Our results provide a route towards enhancing the stability of chiral spin-structures that does not rely on enlarging the chiral interactions.Comment: Includes supplementar