1,223 research outputs found
The credit supply channel of monetary policy: evidence from a FAVAR model with sign restrictions
We test whether the credit channel of the monetary policy was present in the United States' economy from January 2001 to April 2016. To this end, we use a factor-augmented vector autoregression, and we impose sensible theoretical sign restrictions in our structural identification scheme. We use the expected substitution effect between bank commercial loans and commercial papers to identify the credit supply channel. We found that the credit channel appears to have operated in the US economy during the sample period. However, when we split the sample, we found that the credit channel did not operate after the subprime crisis (close to the Zero Lower Bound of the interest rate). This result is robust to changing the sign restriction horizons. It supports current views in the literature regarding the ineffectiveness of the credit channel as a means to foster real economic activity during crises episodes
Gonyaulax taylorii, a new yessotoxins-producer dinoflagellate species from Chilean waters
In summer 2009, during a survey in Bahía Mejillones, a dense bloom of a dinoflagellate from the genus
Gonyaulax was detected, as well as the presence of yessotoxin. Phytoplankton samples were analyzed in
detail by light and scanning electron microscopy (SEM), revealing the presence of Gonyaulax taylorii.
Morphological examination showed that the cells in the bloom fit in Gonyaulax jollifei Murray et Whitting
sensu Dodge, subsequently classified as Gonyaulax taylorii by Carbonell-Moore. In this context, some
inconsistencies have been found in regard to the holotype; the plate 1”’ appears as two plates, 1000 and 2000,
showing a suture that does not exist in Dodge’s figure of G. jollifei, from where the holotype was drawn, nor
within the samples collected. Therefore, this plate has been originally described erroneously as two plates
named 1”’ and 2”’ instead of only one named 1000. After this correction, this species has five instead of six
postcingular plates. For this reason, the description of this species must be emended. Phytoplankton net
samples were found to containyessotoxin and homoyessotoxin, with concentrations below 1 pg cell!1. The
present study identifies, therefore, the dinoflagellate G. taylorii as a new source of yessotoxins.Versión del editor3,083
Age, growth and mortality of Caulolatilus princeps (Pisces: Malacanthidae) from the southern Gulf of California
The morphometric relationships, age, and growth of the Ocean Whitefish (Caulolatilus princeps, Jenyns 1842) were studied from a sample of 1783 specimens (1196 individuals for ageing), taken around the Bay of La Paz, in the southern Gulf of California from February 1986 to May 1987. The standard length ranged from 152 to 505 mm, and the eviscerated weight from 150 to 2660 g. The standard length-eviscerated weight relationships were estimated as: W = 0.00029 x L2.922, W = 0.00024 x L2.960, W = 0.00021 x L2.979 for males, females and the sexes combined, respectively. Twenty one age classes, ranging from 1 to 21 years were defined by whole burned otolith readings. Mean standard length, and standard length by otoliths edge-at-age data for the first 16 age groups were used to estimate the growth parameters of the von Bertalanffy equation: L? = 476.7 mm, K = 0.093, to = -3.904, for males; L? = 474.8 mm, K = 0.101, to = -3.339, for females; L? = 460.9 mm, K = 0.113, to = -2.765, for the sexes combined. The asymptotic weights were: 1847.6, 2006.8 and 1972.1 g, for males, females, and the sexes combined, respectively. Total (Z year-1) and natural (M year-1) mortalities were estimated as, respectively: 0.45 and 0.15 for males, 0.42 and 0.15 for females, and 0.41 and 0.17 year-1 for the sexes combined. The exploitation ratios (E) were: 0.67 for males, 0.63 for females, and 0.60 for the sexes combined, indicating that the fishing pressure on this population is higher than the recommended ratio of 0.5
Early and Late Reoperation Rates With Various MIS Techniques for Adult Spinal Deformity Correction.
Study designA multicenter retrospective review of an adult spinal deformity database.ObjectiveWe aimed to characterize reoperation rates and etiologies of adult spinal deformity surgery with circumferential minimally invasive surgery (cMIS) and hybrid (HYB) techniques.MethodsInclusion criteria were age ≥18 years, and one of the following: coronal Cobb >20°, sagittal vertical axis >5 cm, pelvic tilt >20°, and pelvic incidence-lumbar lordosis >10°. Patients with either cMIS or HYB surgery, ≥3 spinal levels treated with 2-year minimum follow-up were included.ResultsA total of 133 patients met inclusion for this study (65 HYB and 68 cMIS). Junctional failure (13.8%) was the most common reason for reoperation in the HYB group, while fixation failure was the most common reason in the cMIS group (14.7%). There was a higher incidence of proximal junctional failure (PJF) than distal junctional failure (DJF) within HYB (12.3% vs 3.1%), but no significant differences in PJF or DJF rates when compared to cMIS. Early (<30 days) reoperations were less common (cMIS = 1.5%; HYB = 6.1%) than late (>30 days) reoperations (cMIS = 26.5%; HYB = 27.7%), but early reoperations were more common in the HYB group after propensity matching, largely due to infection rates (10.8% vs 0%, P = .04).ConclusionsAdult spinal deformity correction with cMIS and HYB techniques result in overall reoperation rates of 27.9% and 33.8%, respectively, at minimum 2-year follow-up. Junctional failures are more common after HYB approaches, while pseudarthrosis/fixation failures happen more often with cMIS techniques. Early reoperations were less common than later returns to the operating room in both groups, but cMIS demonstrated less risk of infection and early reoperation when compared with the HYB group
Early surgical intervention among patients with acute central cord syndrome is not associated with higher mortality and morbidity
Background: Conflicting reports exist regarding mortality and morbidity of early surgical decompression in the setting of acute central cord syndrome (ACS) in multisystem trauma despite evidence of improved neurological outcomes. Consequently, optimal decompression timing in ACS in multisystem trauma patients remains controversial. This study aims to determine the association between early surgery for acute traumatic central cord and all-cause mortality among multisystem trauma patients in the National Trauma Data Bank (NTDB) using propensity score matching.
Methods: We used the NTDB (years 2011-2014) to perform a retrospective cohort study, which included patients \u3e18 years, with ACS (identified using ICD-9 coding). Collected patient data included demographics, surgery timing (≤24 hours, \u3e24 hours), injury mechanism, Charlson comorbidity index (CCI), injury severity score (ISS), serious adverse events (SAE). Logistic regression and propensity matching were used to investigate the relationship between surgery timing and subsequent inpatient mortality.
Results: We identified 2,379 traumatic ACS patients. This group was 79.3% male with an average age of 56.3±15.2. They had an average ISS of 19.5±9.0 and mortality rate of 3.0% (n=72). A total of 731 (30.7%) patients underwent surgery for ACS within 24 hours. Univariate analysis did not show a significantly higher mortality rate in the early versus late surgery groups (3.8%
Conclusions: Early surgical intervention does not appear to be associated with increased mortality among ACS patients unlike previously suggested. We theorize that survival noted within the NTDB is confounded by factors including existing comorbidities and multisystem trauma, rather than surgical timing. Delaying definitive surgical care may predispose patients to worsened greater neurological morbidity
The ecology of peace : preparing Colombia for new political and planetary climates
ABSTRACT: Colombia, one of the world’s most species-rich nations, is currently undergoing a profound social transition: the end of a decadeslong conflict with the Revolutionary Armed Forces of Colombia, known as FARC. The peace agreement process will likely transform the country’s physical and socioeconomic landscapes at a time when humans are altering Earth’s atmosphere and climate in unprecedented ways. We discuss ways in which these transformative events will act in combination to shape the ecological and environmental future of Colombia. We also highlight the risks of creating perverse development incentives in these critical times, along with the potential benefits – for the country and the world – if Colombia can navigate through the peace process in a way that protects its own environment and ecosystems
Phylogenetic relationships of cone snails endemic to Cabo Verde based on mitochondrial genomes
Background: Due to their great species and ecological diversity as well as their capacity to produce hundreds of different toxins, cone snails are of interest to evolutionary biologists, pharmacologists and amateur naturalists alike. Taxonomic identification of cone snails still relies mostly on the shape, color, and banding patterns of the shell. However, these phenotypic traits are prone to homoplasy. Therefore, the consistent use of genetic data for species delimitation and phylogenetic inference in this apparently hyperdiverse group is largely wanting. Here, we reconstruct the phylogeny of the cones endemic to Cabo Verde archipelago, a well-known radiation of the group, using mitochondrial (mt) genomes. Results: The reconstructed phylogeny grouped the analyzed species into two main clades, one including Kalloconus from West Africa sister to Trovaoconus from Cabo Verde and the other with a paraphyletic Lautoconus due to the sister group relationship of Africonus from Cabo Verde and Lautoconus ventricosus from Mediterranean Sea and neighboring Atlantic Ocean to the exclusion of Lautoconus endemic to Senegal (plus Lautoconus guanche from Mauritania, Morocco, and Canary Islands). Within Trovaoconus, up to three main lineages could be distinguished. The clade of Africonus included four main lineages (named I to IV), each further subdivided into two monophyletic groups. The reconstructed phylogeny allowed inferring the evolution of the radula in the studied lineages as well as biogeographic patterns. The number of cone species endemic to Cabo Verde was revised under the light of sequence divergence data and the inferred phylogenetic relationships. Conclusions: The sequence divergence between continental members of the genus Kalloconus and island endemics ascribed to the genus Trovaoconus is low, prompting for synonymization of the latter. The genus Lautoconus is paraphyletic. Lautoconus ventricosus is the closest living sister group of genus Africonus. Diversification of Africonus was in allopatry due to the direct development nature of their larvae and mainly triggered by eustatic sea level changes during the Miocene-Pliocene. Our study confirms the diversity of cone endemic to Cabo Verde but significantly reduces the number of valid species. Applying a sequence divergence threshold, the number of valid species within the sampled Africonus is reduced to half.Spanish Ministry of Science and Innovation [CGL2013-45211-C2-2-P, CGL2016-75255-C2-1-P, BES-2011-051469, BES-2014-069575, Doctorado Nacional-567]info:eu-repo/semantics/publishedVersio
Evolutionary relationships of West Nile virus detected in mosquitoes from a migratory bird zone of Colombian Caribbean
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