¿qué es la crítica poscolonial?

En este texto Robert Young se ocupa de analizar brevemente la historia y el concepto de crítica postcolonial. El autor sostiene que la teoría postcolonial ha combinado la herencia teórica del pensamiento postestructuralista con perspectivas de escritores no occidentales. En el texto se analiza el trabajo de autores como Said, Bhabha y Spivak, que son considerados los ejes de la teoría postcolonial

Structural study of Cu2−x_{2-x}Se alloys produced by mechanical alloying

The crystalline structures of superionic high temperature copper selenides Cu$_{2-x}$Se ($0 \le x \le 0.25$) produced by Mechanical Alloying were investigated using X-ray diffraction (XRD) technique. The measured XRD patterns showed the presence of the peaks corresponding to the crystalline superionic high temperature $\alpha$-Cu$_2$Se phase in the as-milled sample, and its structural data were determined by means of a Rietveld refinement procedure. After a heat treatment in argon at 200$^\circ$C for 90 h, this phase transforms to the superionic high temperature $\alpha$-Cu$_{1.8}$Se phase, whose structural data where also determined through the Rietveld refinement. In this phase, a very low occupation of the trigonal 32(f) sites ($\sim 3$%) by Cu ions is found. In order to explain the evolution of the phases in the samples, two possible mechanisms are suggested: the high mobility of Cu ions in superionic phases and the intense diffusive processes in the interfacial component of samples produced by Mechanical Alloying.Comment: 2 figures, submitted to Acta Crystallographic

Medical use of long-term extended-release opioid analgesics in commercially insured adults in the United States

Objectives. We examined the proportion of patients initiating extended-release (ER) opioids who become long-term users and describe how pain-related diagnoses before initiation of opioid therapy vary between drugs and over time. Methods. Using MarketScan (2006-2015), a US national commercial insurance database, we examined painrelated diagnoses in the 182-day baseline period before initiation of ER opioid therapy to characterize indications for opioid initiation. We report the proportion who became long-term users, the median length of opioid therapy, and the proportion with cancer and other noncancer chronic pain, by active ingredient. Results. Among 1,077,566 adults initiating ER opioids, 31% became long-term users, with a median length of use of 209 days. The most common ER opioids prescribed were oxycodone (26%) and fentanyl (23%), and the most common noncancer pain diagnoses were back pain (65%) and arthritis (48%). Among all long-term users, 16% had a diagnosis of cancer. We found notable variation by drug. Eighteen percent of patients initiating drugs approved by the Food and Drug Administration >10 years ago had evidence of cancer during baseline compared with only 8% of patients who received newer drugs. Conclusions. In a national sample of adults with private insurance, back pain was the most common diagnosis preceding initiation of opioid therapy. Opioids that have been approved within the last 10 years were more frequently associated with musculoskeletal pains and less frequently associated with cancer. Amid increasing concerns regarding long-term opioid therapy, our findings provide context regarding the conditions for which long-term opioid therapy is prescribed

Model Flames in the Boussinesq Limit: The Effects of Feedback

We have studied the fully nonlinear behavior of pre-mixed flames in a gravitationally stratified medium, subject to the Boussinesq approximation. Key results include the establishment of criterion for when such flames propagate as simple planar flames; elucidation of scaling laws for the effective flame speed; and a study of the stability properties of these flames. The simplicity of some of our scalings results suggests that analytical work may further advance our understandings of buoyant flames.Comment: 11 pages, 14 figures, RevTex, gzipped tar fil

Electron self-trapping in intermediate-valent SmB6

SmB6 exhibits intermediate valence in the ground state and unusual behaviour at low temperatures. The resistivity and the Hall effect cannot be explained either by conventional sf-hybridization or by hopping transport in an impurity band. At least three different energy scales determine three temperature regimes of electron transport in this system. We consider the ground state properties, the soft valence fluctuations and the spectrum of band carriers in n-doped SmB6. The behaviour of excess conduction electrons in the presence of soft valence fluctuations and the origin of the three energy scales in the spectrum of elementary excitations is discussed. The carriers which determine the low-temperature transport in this system are self-trapped electron-polaron complexes rather than simply electrons in an impurity band. The mechanism of electron trapping is the interaction with soft valence fluctuations.Comment: 12 pages, 3 figure

Predictors of prevalent statin use among older adults identified as statin initiators based on Medicare claims data

Purpose: Few studies have evaluated the degree to which prescription drug initiators are correctly identified using claims data. We examine the prevalence and predictors of recent statin possession in statin initiators identified using claims data. Methods: Among Medicare Current Beneficiary Survey (MCBS) respondents, we used Medicare Part D claims from 2006 to 2011 to identify statin initiators using a 12-month baseline period of no prior statin claims. Using MCBS interview data, we identified those with self-reported statins obtained during the baseline period. We used log-binomial regression to estimate adjusted prevalence ratios (adjPR) and 95% confidence intervals (CI) for predictors of recent statin possession. Results: Among 766 statin initiators identified in prescription claims, 155 (20%) reported recent statin possession during baseline. Beneficiaries with no Part D claims in the past 30 days (adjPR = 1.49, 95%CI: 1.13, 1.96), those with no inpatient, outpatient or physician visits in the past 30 days (adjPR = 1.50, 95%CI: 1.11, 2.03), those with a brand name statin index claim (adjPR = 1.55, 95%CI: 1.19, 2.02), and those with an index claim in January or February (adjPR = 1.50, 95%CI: 1.00, 2.26) had an increased probability of recent statin possession. Conclusions: In a cohort of statin initiators identified using prescription claims, 20% had evidence of statin possession during the baseline period. Pharmacoepidemiologic new user studies may benefit from including sensitivity analyses within subgroups less likely to include prevalent users to assess the robustness of key findings to misidentification of the time of treatment initiation

Postsurgical Opioid Prescriptions and Risk of Long-term Use: An Observational Cohort Study Across the United States

Objective: The aim of this study was to evaluate differences in risk of longterm opioid therapy after surgery among an opioid-naive population using varying cutoffs based on days supplied (DS), total morphine milligram equivalents (MME) dispensed, and quantity of pills (QTY) dispensed. Background: In response to the US opioid crisis, opioid prescription (Rx) limits have been implemented on a state-by-state basis beginning in 2016. However, there is limited evidence informing appropriate prescribing limits, and the effect of these policies on long-term opioid therapy. Methods: Using the MarketScan claims databases, we identified all opioidnaive patients undergoing outpatient surgery between July 1, 2006 and June 30, 2015. We identified the initial postsurgical opioid prescribed, examining the DS, total MME, and QTY dispensed.We used Poisson to estimate adjusted risk differences and risk ratios of long-term opioid use comparing those receiving larger versus smaller volume of opioids. Results: We identified 5,148,485 opioid-naive surgical patients. Overall, 55.5% received an opioid for postoperative pain, with median days supply =5 and median total MME = 240. The proportion of patients receiving prescriptions above 7 DS increased from 11% in 2006 to 19% in 2015. Among those receiving postoperative opioids, 8% had long-term opioid use, and risk of long-term use was 1.16 times [95% confidence interval (CI), 1.10-1.25] higher among those receiving >7 days compared with those receiving ≤7 days. Those receiving >400 total MME (15% of patients) were at 1.17 times (95% CI, 1.10-1.25) the risk of long-term use compared with those receiving ≤400 MME. Conclusions: Between 2005 and 2015, the amounts of opioids prescribed for postoperative pain increased dramatically, and receipt of larger volume of opioids was associated with increased risk of long-term opioid therapy