2,932 research outputs found
Freire re-viewed
The work of Paulo Freire is associated with themes of oppression and liberation, and his critical pedagogy is visionary in its attempts to bring about social transformation. Freire has created a theory of education that embeds these issues within social relations that center around both ideological and material domination. In this review essay, Sue Jackson explores three books: Freire’s final work Pedagogy of Indignation; Cesar Augusto Rossatto’s Engaging Paulo Freire’s Pedagogy of Possibility, which attempts to engage Freire’s pedagogy of possibility; and C.A. Bowers and Frederique Apffel-Marglin’s edited collection Re-thinking Freire, which asks readers to reconsider Freire’s work in light of globalization and environmental crises. Jackson questions the extent to which Freire’s pedagogical approaches are useful to educators as well as to “the oppressed,” and whether challenges to re-think Freire can lead to new kinds of critical pedagogies
Hemodynamics After Glucose Loading in Hispanics With and Without Family History of Type 2 Diabetes
Type 2 Diabetes (T2D) increases cardiovascular mortality 4-fold. Although ~9% of Americans are diagnosed with T2D, T2D incidence is substantially higher in Hispanics and those with a have family history of T2D. Traditionally, T2D is diagnosed via oral glucose testing which has been shown to impair microvascular function. However, the effects of glucose loading on hemodynamics and arterial elasticity between healthy Hispanics with and without a family history of T2D are unclear. PURPOSE: To determine the effects of an oral glucose challenge (OGC) and a mixed meal challenge (MMC) on hemodynamics in healthy Hispanic individuals with and without family history of T2D. METHODS: Thirty-three healthy Hispanic individuals volunteered in this study, including 10 participants with a family history (FH+, 26 ± 7 yrs) of T2D and 23 participants without FH (FH-, 24 ± 5 yrs). Hemodynamics were assessed at rest and 60 minutes after consuming either an OGC or MMC. The OGC consisted of 50g of glucose solution while the MMC consisted of 30g of protein, 5g of fat, and 35g of carbohydrate. A 2x2x2 repeated measures ANOVA was used to evaluate the effects of family history on hemodynamics across conditions and time. RESULTS: FH+ had higher (p. CONCLUSIONS: Healthy Hispanic individuals with family history of type 2 diabetes have higher central and brachial pulse pressure compared to healthy Hispanic individuals without family history of type 2 diabetes. Moreover, glucose loading and mixed meal alter hemodynamics at 60 minutes in healthy Hispanics with and without family history of type 2 diabetes similarly
Vascular Insulin Resistance May Contribute to Health Disparities in People from the Rio Grande Valley
Microvascular blood flow (MBF) increases postprandially in skeletal muscle in response to insulin to aid in myocyte glucose delivery. This MBF response is considered a measure of vascular insulin resistance and can be impaired with altered meal composition, obesity, type 2 diabetes mellitus (T2DM), and insulin resistance. Current studies indicate this MBF response to a mixed meal challenge (MMC) may identify vascular insulin resistance before typically-presenting serum biomarkers of insulin resistance, as it displays more sensitivity than when using an oral glucose challenge (OGC). However, it is unknown if healthy adults residing in the Rio Grande Valley (RGV), an area with a 3x higher prevalence of T2DM vs the national average, demonstrate impaired MBF responses similar to those seen in overt insulin resistance. PURPOSE: To determine microvascular responses in apparently healthy individuals of the RGV between OGC and MMC. METHODS: 17 healthy participants from the RGV (age 25±6 yrs, BMI 25±3 kg/m2, fat mass % 29±9%, and android fat % 31±10.4%) without hypertension, T2DM, or dyslipidemia were administered a MMC and OGC on two separate occasions. Forearm skeletal muscle MBF (measured as acoustic intensity/second (AI/s)) was recorded pre- and 1-hour postprandial via contrast-enhanced ultrasound (CEU). RESULTS: MMC pre- vs. post-prandial demonstrated a 0.59 fold reduction (1.6101 vs. 0.6548 AI/s, 95% CI [-.2871, 3.5073] and [0.887, 1.2209], respectively). OGC pre- vs. post-prandial MBF had a 0.18 fold reduction (1.6734 vs. 1.3693 AI/s, 95% CI [.3755, 2.9714] and [.4725, 2.2661], respectively). MBF in skeletal muscle demonstrated no significant difference between MMC and OGC groups (Mean square= 2.378, F(1, 48) = .320, p = 0.574). CONCLUSION: Unlike healthy Caucasians, apparently healthy residents of the RGV display impaired microvascular responses to MMC, similar to using an OGC, suggesting early vascular insulin resistance. As this population displays significant health disparities for chronic diseases such as T2DM, obesity, and Alzheimer’s, it is plausible that early vascular insulin resistance noted in this population significantly contributes to the increased incidence of these chronic diseases. Additional research is needed to identify mechanisms explaining this population\u27s etiology of impaired MBF responses and vascular insulin resistance
Cardiovascular Responses Differ Between Different Orders of Upper- and Lower-Body Resistance Exercise
Upper-body resistance exercise (RE) induces different cardiovascular responses compared to lower-body RE. However, combination of upper- and lower-body RE with different orders on cardiovascular responses are unclear. PURPOSE: To evaluate the effects of different orders of upper-and lower-body RE on cardiovascular responses in active men. METHODS: Thirteen active men (22±2 years old) participated in the study. Heart rate (HR), systolic and diastolic blood pressure (BP), cardiac output (CO), stroke volume (SV), and total peripheral resistance (TPR) were assessed at rest, 15-20 (R1), and 25-30 (R2) minutes after performing upper- and lower-body RE (UL) or lower- and upper-body RE (LU) for 3 sets of 10 repetitions at 75% 1-repetition maximum with 90-second and 2-minute rests between sets and exercises, respectively. The upper-body RE consisted of pulldown and chest press while lower-body RE consisted of knee extension and knee flexion. A repeated measures ANOVA was used to evaluate the conditions (UL, LU) across time (rest, R1, R2) on cardiovascular responses. RESULTS: There were time-by-condition interactions (p\u3c0.05) for CO and SV such that CO was significantly elevated at R1 and R2 after UL and LU compared to rest while UL had higher CO compared to LU at R1 (UL: rest: 5.68±0.99 L/min; R1: 9.09±1.44 L/min; R2: 7.65±1.87 L/min; and LU: rest: 5.55±0.78 L/min; R1: 8.14±1.65 L/min; R2: 7.23±1.76 L/min). SV was significantly increased after UL at R1 compared to rest and LU (UL: rest: 85.2±16.5 ml/beat; R1: 90.9±14.3 ml/beat; R2: 81.8±18.8 ml/beat; and LU: rest: 84.7±12.7 ml/beat; R1: 83.0±13.9 ml/beat; R2: 78.6±16.2 ml/beat). TPR was significantly (p\u3c0.001) reduced at R1 and R2 compared to rest after UL and LU with greater reduction after UL compared to LU (UL: rest: 0.96±0.27 mmHg•min/L; R1: 0.53±0.16 mmHg•min/L; R2: 0.68±0.22 mmHg•min/L; and LU: rest: 1.03±0.33 mmHg•min/L; R1: 00.67±0.26 mmHg•min/L; R2: 0.77±0.26 mmHg•min/L). HR was significantly (p\u3c0.001) increased at R1 and R2 after UL and LU compared to rest. Systolic BP was significantly (p=0.026) decreased after LU at R1 compared to rest and R2. However, there was no change for diastolic BP. CONCLUSION: These data suggest that UL significantly increases cardiac output and stroke volume than LU which means different orders of RE change cardiovascular responses
Effects of early gestation GH administration on placental and fetal development in sheep.
Ovine GH (oGH) is synthesized in placental tissue during maximal placental growth and development. Our objectives were to localize oGH mRNA in the placenta, and study the impact of exogenous GH on twin pregnancies during the normal window (35-55 days of gestational age; dGA) of placental expression. In situ hybridization localized oGH mRNA in uterine luminal epithelium but not in tissues of fetal origin. While maternal GH and IGF-I concentrations were increased (
Postprandial And Fasting Lipopolysaccharide Levels In Healthy Hispanic Residents Of Southeast Texas With Positive Family History Of Type 2 Diabetes
PURPOSE: Healthy people with a family history (FH+) of type 2 diabetes (T2D) display impaired metabolic and microvascular function prior to glucose intolerance, and are at greater risk for developing T2D. While mechanisms to explain this disparity are lacking, it is possible that intestinal permeability plays a role, as it is also linked with insulin resistance, glucose intolerance, and chronic inflammation. Lipopolysaccharides (LPS) act as an outer membrane component of gram-negative bacteria in intestines and play a role in inflammation and chronic disease when in circulation, thus serving as a surrogate measure of intestinal permeability. However, the link between FH+ health disparities and intestinal permeability has not been studied. Thus, the purpose of this study was to quantify circulating plasma LPS in healthy FH+ and FH-. METHODS: In this cross-sectional study, FH- (n=14) and FH+ (n=18) participants matched for age (24.4 ± 1.6 and 25.0 ± 2.3 respectively) and BMI (25.0 ± 1.1 and 25.0 ± 1.1 years respectively) had blood drawn while fasting, and 60-min after consuming a mixed composition meal to quantify changes in plasma LPS, and had body composition determined via iDXA. Other anthropogenic data were collected. RESULTS: Fasting LPS was lower in FH- than FH+ (p \u3c 0.5, 42.3ng/ml ± 5.3 and 48.1ng/ml ± 6.8 respectively) with postprandial LPS increasing more in FH- than FH+ (p\u3c0.05, +10.3ng/ml ± 3.1 and + 1.4ng/ml ± 3.1 respectively). No group differences (p\u3e0.5) were noted in blood pressure (115/69 and 116/69mmHG) LDL-c (4.3mmol/L and 4.4mmol/L), HDL-c (2.2mmol/L and 2.3mmol/L), body fat (29% and 28%), or android fat (30.4% and 30.7%) between FH- and FH+ groups respectively. CONCLUSION: Disparities noted for increase T2D risk in FH+ have been linked to microvascular and metabolic function, with mechanisms for these remaining elusive. However, differences in circulating LPS suggest varying intestinal permeability in these groups, which may help explain the varying risk for T2D. Further work to characterize intestinal microbiota may advance our understanding of health disparities in this and other high-risk populations
Accuracy of Fitbit Charge 2 at Estimating VO2max, Calories, and Steps on a Treadmill
Current fitness activity trackers can account for steps, calories burned, heart rate, and distance traveled. A new feature has recently been introduced on the Fitbit Charge 2, “Cardio Fitness Level,” which is comparable to a VO2max score in that it allows consumers to be aware of their aerobic fitness level. PURPOSE: To assess the accuracy of the Fitbit Charge 2 at estimating VO2 score (“Cardio Fitness Level”), calories, and steps when compared to indirect calorimetry and video analyzed steps, respectively. METHODS: Twenty-two healthy adults (Mean±SD; 24.1±4.2yrs; 16.9±9.0%fat; 15 male) completed two separate visits. On the first visit, anthropometric measurements were taken followed by a 10-minute outdoor run. Participants ran for 10 minutes at their own pace on flat terrain as recommended by Fitbit to generate a Cardio Fitness score. On the second visit, participants came fasted, at least 8 hours, and completed a standardized VO2max protocol (Arizona State protocol) using a PARVO TrueOne2400 metabolic cart. The treadmill was set at 3mph for the first 3 minutes with 0% grade. Following the first stage, the speed was raised to the participant’s pre-selected speed (between 5-8mph) with 0% grade. After stage 2 the grade increased every minute by 1.5% and speed was kept constant until fatigue was reached. Calories and step counts from the Fitbits were correlated with the metabolic cart and tally counter respectively, using 2-tailed Pearson correlations. Significance was set at pRESULTS: Participants completed the VO2max test in an average of 11:05. Eight of the 22 estimated VO2max ranges given by Fitbit included the value given by the metabolic cart. Fitbit ranges for seven participants were below the metabolic cart values and the Fitbit ranges for the remaining seven participants were above the metabolic cart values. Calories were correlated between the Fitbit and metabolic cart (r = 0.874, pCONCLUSION: VO2 scores given by the Fitbit Charge 2 did not always match values given by the metabolic cart but may serve as a rough estimate of fitness level. Fitbit Charge 2 may also be useful in tracking calories and steps in a controlled setting, but results may differ in real world conditions
A systematic review of childhood maltreatment and resting state functional connectivity
Resting-state functional connectivity (rsFC) has the potential to shed light on how childhood abuse and neglect relates to negative psychiatric outcomes. However, a comprehensive review of the impact of childhood maltreatment on the brain's resting state functional organization has not yet been undertaken. We systematically searched rsFC studies in children and youth exposed to maltreatment. Nineteen studies (total n = 3079) met our inclusion criteria. Two consistent findings were observed. Childhood maltreatment was linked to reduced connectivity between the anterior insula and dorsal anterior cingulate cortex, and with widespread heightened amygdala connectivity with key structures in the salience, default mode, and prefrontal regulatory networks. Other brain regions showing altered connectivity included the ventral anterior cingulate cortex, dorsolateral prefrontal cortex, and hippocampus. These patterns of altered functional connectivity associated with maltreatment exposure were independent of symptoms, yet comparable to those seen in individuals with overt clinical disorder. Summative findings indicate that rsFC alterations associated with maltreatment experience are related to poor cognitive and social functioning and are prognostic of future symptoms. In conclusion, maltreatment is associated with altered rsFC in emotional reactivity, regulation, learning, and salience detection brain circuits. This indicates patterns of recalibration of putative mechanisms implicated in maladaptive developmental outcomes
Extremely Metal-Poor Stars. VII. The Most Metal-Poor Dwarf, CS 22876-032
We report high-resolution, high-signal-to-noise, observations of the
extremely metal-poor double-lined spectroscopic binary CS 22876-032. The system
has a long period : P = 424.7 0.6 days. It comprises two main sequence
stars having effective temperatures 6300 K and 5600 K, with a ratio of
secondary to primary mass of 0.89 0.04. The metallicity of the system is
[Fe/H] = -3.71 0.11 0.12 (random and systematic errors) -- somewhat
higher than previous estimates. We find [Mg/Fe] = 0.50, typical of values of
less extreme halo material. [Si/Fe], [Ca/Fe], and [Ti/Fe], however, all have
significantly lower values, ~ 0.0-0.1, suggesting that the heavier elements
might have been underproduced relative to Mg in the material from which this
object formed. In the context of the hypothesis that the abundance patterns of
extremely metal-poor stars are driven by individual enrichment events and the
models of Woosley and Weaver (1995), the data for CS 22876-032 are consistent
with its having been enriched by a zero-metallicity supernova of mass 30
M. As the most metal-poor near-main-sequence-turnoff star currently
known, the primary of the system has the potential to strongly constrain the
primordial lithium abundance. We find A(Li) (= log(N(Li)/N(H)) + 12.00) = 2.03
0.07, which is consistent with the finding of Ryan et al. (1999) that for
stars of extremely low metallicity A(Li) is a function of [Fe/H].Comment: 27 pages, 9 figures, accepted for publication in The Astrophysical
Journal, Sept. 1, 2000 issu
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