New evidence on Allyn Young's style and influence as a teacher

This paper publishes the hitherto unpublished correspondence between Allyn Abbott Young's biographer Charles Blitch and 17 of Young's former students or associates. Together with related biographical and archival material, the paper shows the way in which this adds to our knowledge of Young's considerable influence as a teacher upon some of the twentieth century's greatest economists. The correspondents are as follows: James W Angell, Colin Clark, Arthur H Cole, Lauchlin Currie, Melvin G de Chazeau, Eleanor Lansing Dulles, Howard S Ellis, Frank W Fetter, Earl J Hamilton, Seymour S Harris, Richard S Howey, Nicholas Kaldor, Melvin M Knight, Bertil Ohlin, Geoffrey Shepherd, Overton H Taylor, and Gilbert Walker

Superpulsed low-level laser therapy protects skeletal muscle of mdx mice against damage, inflammation and morphological changes delaying dystrophy progression.

Aim: To evaluate the effects of preventive treatment with low-level laser therapy (LLLT) on progression of dystrophy in mdx mice. Methods: Ten animals were randomly divided into 2 experimental groups treated with superpulsed LLLT (904 nm, 15 mW, 700 Hz, 1 J) or placebo-LLLT at one point overlying the tibialis anterior muscle (bilaterally) 5 times per week for 14 weeks (from 6th to 20th week of age). Morphological changes, creatine kinase (CK) activity and mRNA gene expression were assessed in animals at 20th week of age. Results: Animals treated with LLLT showed very few morphological changes in skeletal muscle, with less atrophy and fibrosis than animals treated with placebo-LLLT. CK was significantly lower (p = 0.0203) in animals treated with LLLT (864.70 U.l−1, SEM 226.10) than placebo (1708.00 U.l−1, SEM 184.60). mRNA gene expression of inflammatory markers was significantly decreased by treatment with LLLT (p<0.05): TNF-α (placebo-control = 0.51 µg/µl [SEM 0.12], - LLLT = 0.048 µg/µl [SEM 0.01]), IL-1β (placebo-control = 2.292 µg/µl [SEM 0.74], - LLLT = 0.12 µg/µl [SEM 0.03]), IL-6 (placebo-control = 3.946 µg/µl [SEM 0.98], - LLLT = 0.854 µg/µl [SEM 0.33]), IL-10 (placebo-control = 1.116 µg/µl [SEM 0.22], - LLLT = 0.352 µg/µl [SEM 0.15]), and COX-2 (placebo-control = 4.984 µg/µl [SEM 1.18], LLLT = 1.470 µg/µl [SEM 0.73]). Conclusion: Irradiation of superpulsed LLLT on successive days five times per week for 14 weeks decreased morphological changes, skeletal muscle damage and inflammation in mdx mice. This indicates that LLLT has potential to decrease progression of Duchenne muscular dystrophy

Decadal changes of the Western Arabian sea ecosystem

Historical data from oceanographic expeditions and remotely sensed data on outgoing longwave radiation, temperature, wind speed and ocean color in the western Arabian Sea (1950–2010) were used to investigate decadal trends in the physical and biochemical properties of the upper 300 m. 72 % of the 29,043 vertical profiles retrieved originated from USA and UK expeditions. Increasing outgoing longwave radiation, surface air temperatures and sea surface temperature were identified on decadal timescales. These were well correlated with decreasing wind speeds associated with a reduced Siberian High atmospheric anomaly. Shoaling of the oxycline and nitracline was observed as well as acidification of the upper 300 m. These physical and chemical changes were accompanied by declining chlorophyll-a concentrations, vertical macrofaunal habitat compression, declining sardine landings and an increase of fish kill incidents along the Omani coast

Sublittoral soft bottom communities and diversity of Mejillones Bay in northern Chile (Humboldt Current upwelling system)

The macrozoobenthos of Mejillones Bay (23°S; Humboldt Current) was quantitatively investigated over a 7-year period from austral summer 1995/1996 to winter 2002. About 78 van Veen grab samples taken at six stations (5, 10, 20 m depth) provided the basis for the analysis of the distribution of 60 species and 28 families of benthic invertebrates, as well as of their abundance and biomass. Mean abundance (2,119 individuals m-2) was in the same order compared to a previous investigation; mean biomass (966 g formalin wet mass m-2), however, exceeded prior estimations mainly due to the dominance of the bivalve Aulacomya ater. About 43% of the taxa inhabited the complete depth range. Mean taxonomic Shannon diversity (H', Log e) was 1.54 ± 0.58 with a maximum at 20 m (1.95 ± 0.33); evenness increased with depth. The fauna was numerically dominated by carnivorous gastropods, polychaetes and crustaceans (48%). About 15% of the species were suspensivorous, 13% sedimentivorous, 11% detritivorous, 7% omnivorous and 6% herbivorous. Cluster analyses showed a significant difference between the shallow and the deeper stations. Gammarid amphipods and the polychaete family Nephtyidae characterized the 5-mzone, the molluscs Aulacomya ater, Mitrella unifasciata and gammarids the intermediate zone, while the gastropod Nassarius gayi and the polychaete family Nereidae were most prominent at the deeper stations. The communities of the three depth zones did not appear to be limited by hypoxia during non-El Niño conditions. Therefore, no typical change in community structure occurred during El Niño 1997–1998, in contrast to what was observed for deeper faunal assemblages and hypoxic bays elsewhere in the coastal Humboldt Current system

Safety of Intravenous Thrombolytic Use in Four Emergency Departments Without Acute Stroke Teams

The objective was to evaluate safety of intravenous (IV) tissue plasminogen activator (tPA) delivered without dedicated thrombolytic stroke teams.This was a retrospective, observational study of patients treated between 1996 and 2005 at four southeastern Michigan hospital emergency departments (EDs) with a prospectively defined comparison to the National Institute of Neurological Disorders and Stroke (NINDS) tPA stroke study cohort. Main outcome measures were mortality, intracerebral hemorrhage (ICH), systemic hemorrhage, neurologic recovery, and guideline violations.A total of 273 consecutive stroke patients were treated by 95 emergency physicians (EPs) using guidelines and local neurology resources. One-year mortality was 27.8%. Unadjusted Cox model relative risk (RR) of mortality compared to the NINDS tPA treatment and placebo groups was 1.20 (95% confidence interval [CI] = 0.87 to 1.64) and 1.04 (95% CI = 0.76 to 1.41), respectively. The rate of significant ICH by computed tomography (CT) criteria was 6.6% (odds ratio [OR] = 1.03, 95% CI = 0.56 to 1.90 compared to the NINDS tPA treatment group). The proportions of symptomatic ICH by two other prespecified sets of clinical criteria were 4.8 and 7.0%. The rate of any ICH within 36 hours of treatment was 9.9% (RR = 0.94, 95% CI = 0.58 to 1.51 compared to the NINDS tPA group). The occurrence of major systemic hemorrhage (requiring transfusion) was 1.1%. Functional recovery by the modified Rankin Scale score (mRS = 0 to 2) at discharge occurred in 38% of patients with a premorbid disability mRS < 2. Guideline deviations occurred in the ED in 26% of patients and in 25% of patients following admission.In these EDs there was no evidence of increased risk with respect to mortality, ICH, systemic hemorrhage, or worsened functional outcome when tPA was administered without dedicated thrombolytic stroke teams. Additional effort is needed to improve guideline compliance.ACADEMIC EMERGENCY MEDICINE 2010; 17:1062–1071 © 2010 by the Society for Academic Emergency MedicinePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79179/1/ACEM_868_sm_DataSupplementS2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/79179/2/j.1553-2712.2010.00868.x.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/79179/3/ACEM_868_sm_DataSupplementS1.pd

Subtidal macrozoobenthos communities from northern Chile during and post El Niño 1997–1998

Despite a large amount of climatic and oceanographic information dealing with the recurring climate phenomenon El Niño (EN) and its well known impact on diversity of marine benthic communities, most published data are rather descriptive and consequently our understanding of the underlying mechanisms and processes that drive community structure during EN are still very scarce. In this study, we address two questions on the effects of EN on macrozoobenthic communities: (1) how does EN affect species diversity of the communities in northern Chile? and (2) is EN a phenomenon that restarts community assembling processes by affecting species interactions in northern Chile? To answer these questions, we compared species diversity and co-occurrence patterns of soft-bottoms macrozoobenthos communities from the continental shelf off northern Chile during (March 1998) and after (September 1998) the strong EN event 1997–1998. The methods used varied from species diversity and species co-occurrence analyses to multivariate ordination methods. Our results indicate that EN positively affects diversity of macrozoobenthos communities in the study area, increasing the species richness and diversity and decreasing the species dominance. EN represents a strong disturbance that affects species interactions that rule the species assembling processes in shallow-water, sea-bottom environments

Genetic Impact of a Severe El Niño Event on Galápagos Marine Iguanas (Amblyrhynchus cristatus)

The El Niño-Southern Oscillation (ENSO) is a major source of climatic disturbance, impacting the dynamics of ecosystems worldwide. Recent models predict that human-generated rises in green-house gas levels will cause an increase in the strength and frequency of El Niño warming events in the next several decades, highlighting the need to understand the potential biological consequences of increased ENSO activity. Studies have focused on the ecological and demographic implications of El Niño in a range of organisms, but there have been few systematic attempts to measure the impact of these processes on genetic diversity in populations. Here, we evaluate whether the 1997–1998 El Niño altered the genetic composition of Galápagos marine iguana populations from eleven islands, some of which experienced mortality rates of up to 90% as a result of El Niño warming. Specifically, we measured the temporal variation in microsatellite allele frequencies and mitochondrial DNA diversity (mtDNA) in samples collected before (1991/1993) and after (2004) the El Niño event. Based on microsatellite data, only one island (Marchena) showed signatures of a genetic bottleneck, where the harmonic mean of the effective population size (Ne) was estimated to be less than 50 individuals during the period between samplings. Substantial decreases in mtDNA variation between time points were observed in populations from just two islands (Marchena and Genovesa). Our results suggests that, for the majority of islands, a single, intense El Niño event did not reduce marine iguana populations to the point where substantial neutral genetic diversity was lost. In the case of Marchena, simultaneous changes to both nuclear and mitochondrial DNA variation may also be the result of a volcanic eruption on the island in 1991. Therefore, studies that seek to evaluate the genetic impact of El Niño must also consider the confounding or potentially synergistic effect of other environmental and biological forces shaping populations

Trends in thrombolytic use for ischemic stroke in the United States

BACKGROUND: Although recombinant tissue plasminogen activator (tPA) improves outcomes from ischemic stroke, prior studies have found low rates of administration. Recent guidelines and regulatory agencies have advocated for increased tPA administration in appropriate patients, but it is unclear how many patients actually receive tPA. OBJECTIVE: To determine whether national rates of tPA use for ischemic stroke have increased over time. METHODS: We identified all patients with a primary diagnosis of ischemic stroke from years 2001 to 2006 in the National Hospital Discharge Survey (NHDS), a nationally representative sample of inpatient hospitalizations, and searched for procedure codes for intravenous thrombolytic administration. Clinical and demographic factors were obtained from the survey and multivariable logistic regression used to identify independent predictors associated with thrombolytic use. RESULTS: Among the 22,842 patients hospitalized with ischemic stroke, tPA administration rates increased from 0.87% in 2001 to 2.40% in 2006 ( P < 0.001 for trend). Older patients were less likely to receive tPA (adjusted odds ratio [OR] and 95% confidence interval [CI]; 0.4 [0.3-0.6] for patients ≥80 years vs. <60 years), as were African American patients (0.4 [0.3-0.7]). Larger hospitals were more likely to administer tPA (3.3 [2.0-5.6] in hospitals with at least 300 beds compared to those with 6-99 beds). CONCLUSIONS: Although tPA administration for ischemic stroke has increased nationally in recent years, the overall rate of use remains very low. Larger hospitals were more likely to administer tPA. Further efforts to improve appropriate administration of tPA should be encouraged, particularly as the acceptable time-window for using tPA widens. Journal of Hospital Medicine 2010. © 2010 Society of Hospital Medicine.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78061/1/689_ftp.pd