4,140 research outputs found
Opportunities for Producing Table Grapes in Egypt for the Export Market: A Decision Case Study
The Barakat Fruit Farm desires to increase their share of the exportable grape market in Egypt. Unfortunately, the grape cultivars currently cultivated by the farm bear fruit after the early market window to the European Union when prices are high. An analysis of the company, competition, consumer, market channel, and conditions, provides insight into possible solutions to the challenges faced by the farm management. Designed for undergraduate classroom use, this case encourages students to think outside of traditional production techniques to arrive at solutions that are viable from both crop culture and financial standpoints.Decision case, horticulture, agriculture economics, grape production, Production Economics, Teaching/Communication/Extension/Profession, Q10, Q11,
Exciton dynamics and non-linearities in 2D-hybrid organic perovskites
Due to their high potentiality for photovoltaic applications or coherent
light sources, a renewed interest in hybrid organic perovskites has emerged for
few years. When they are arranged in two dimensions, these materials can be
considered as hybrids quantum wells. One consequence of the unique structure of
2D hybrid organic perovskites is a huge exciton binding energy that can be
tailored through chemical engineering. We present experimental investigations
of the exciton nonlinearities by means of femtosecond pump-probe spectroscopy.
The exciton dynamics is fitted with a bi-exponential decay with a free exciton
life-time of ~100 ps. Moreover, an ultrafast intraband relaxation (< 150 fs) is
also reported. Finally, the transient modification of the excitonic line is
analysed through the momenta analysis and described in terms of reduction of
the oscillator strength and linewidth broadening. We show that excitonic
non-linearities in 2D hybrid organic perovskites share some behaviours of
inorganic semiconductors despite their huge exciton binding energy
Use of sonic tomography to detect and quantify wood decay in living trees.
Premise of the studyField methodology and image analysis protocols using acoustic tomography were developed and evaluated as a tool to estimate the amount of internal decay and damage of living trees, with special attention to tropical rainforest trees with irregular trunk shapes.Methods and resultsLiving trunks of a diversity of tree species in tropical rainforests in the Republic of Panama were scanned using an Argus Electronic PiCUS 3 Sonic Tomograph and evaluated for the amount and patterns of internal decay. A protocol using ImageJ analysis software was used to quantify the proportions of intact and compromised wood. The protocols provide replicable estimates of internal decay and cavities for trees of varying shapes, wood density, and bark thickness.ConclusionsSonic tomography, coupled with image analysis, provides an efficient, noninvasive approach to evaluate decay patterns and structural integrity of even irregularly shaped living trees
Maintaining Oxygenation Successfully with High Flow Nasal Cannula during Diagnostic Bronchoscopy on a Postoperative Lung Transplant Patient in the Intensive Care
Bronchoscopy is an important diagnostic and therapeutic intervention for a variety of patients displaying pulmonary pathology. The heterogeneity of the patients undergoing bronchoscopy affords a challenge for providing minimal and safe respiratory support during anesthesia. Currently, options are intubation and general anesthesia versus frequently inadequate sedation or local anaesthesia with low flow oxygen through nasal prongs or mouthpiece. The advent of high flow nasal cannula allows the clinician to have a “middle man” that allows high flow oxygen delivery as well as a degree of respiratory support, which in some cases has been noted to be between 3 and 4 cm of continuous positive airway pressure-like effect. There are minimal data analyzing the use of high flow nasal cannula during anesthesia for bronchoscopy. We present a case report of orthotropic lung transplant recipient undergoing diagnostic bronchoscopy whilst being supported with high flow nasal oxygen in the intensive care unit
The impact of acute lung injury, ECMO and transfusion on oxidative stress and plasma selenium levels in an ovine model
The purpose of this study was to determine the effects of smoke induced acute lung. injury (S-ALI), extracorporeal membrane oxygenation (ECMO) and transfusion on oxidative stress and plasma selenium levels. Forty ewes were divided into (i) healthy control (n = 4), (ii) S-ALI control (n = 7), (iii) ECMO control (n = 7), (iv) S-ALI + ECMO (n = 8) and (v) S-ALI + ECM + packed red blood cell (PRBC) transfusion (n = 14). Plasma thiobarbituric acid reactive substances (TBARS), selenium and glutathione peroxidase (GPx) activity were analysed at baseline, after smoke injury (or sham) and 0.25, 1, 2, 6, 7, 12 and 24 h after initiation of ECMO. Peak TBARS levels were similar across all groups. Plasma selenium decreased by 54% in S-ALI sheep (1.36 +/- 0.20 to 0.63 +/- 0.27 mu mol/L, p < 0.0001), and 72% in sheep with S-ALI + ECMO at 24 h (1.36 +/- 0.20 to 0.38 +/- 0.19, p < 0.0001). PRBC transfusion had no effect on TBARS, selenium levels or glutathione peroxidase activity in plasma. While ECMO independently increased TBARS in healthy sheep to levels which were similar to the S-ALI control, the addition of ECMO after S-ALI caused a negligible increase in TBARS. This suggests that the initial lung injury was the predominant feature in the TBARS response. In contrast, the addition of ECM in S-ALI sheep exacerbated reductions in plasma selenium beyond that of S-ALI or ECM alone. Clinical studies are needed to confirm the extent and duration of selenium loss associated with ECMO. Crown Copyright (C) 2015 Published by Elsevier GmbH. All rights reserved
Splitting Arabic Texts into Elementary Discourse Units
International audienceIn this article, we propose the first work that investigates the feasibility of Arabic discourse segmentation into elementary discourse units within the segmented discourse representation theory framework. We first describe our annotation scheme that defines a set of principles to guide the segmentation process. Two corpora have been annotated according to this scheme: elementary school textbooks and newspaper documents extracted from the syntactically annotated Arabic Treebank. Then, we propose a multiclass supervised learning approach that predicts nested units. Our approach uses a combination of punctuation, morphological, lexical, and shallow syntactic features. We investigate how each feature contributes to the learning process. We show that an extensive morphological analysis is crucial to achieve good results in both corpora. In addition, we show that adding chunks does not boost the performance of our system
UBVRI Light Curves of 44 Type Ia Supernovae
We present UBVRI photometry of 44 type-Ia supernovae (SN Ia) observed from
1997 to 2001 as part of a continuing monitoring campaign at the Fred Lawrence
Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics. The
data set comprises 2190 observations and is the largest homogeneously observed
and reduced sample of SN Ia to date, nearly doubling the number of
well-observed, nearby SN Ia with published multicolor CCD light curves. The
large sample of U-band photometry is a unique addition, with important
connections to SN Ia observed at high redshift. The decline rate of SN Ia
U-band light curves correlates well with the decline rate in other bands, as
does the U-B color at maximum light. However, the U-band peak magnitudes show
an increased dispersion relative to other bands even after accounting for
extinction and decline rate, amounting to an additional ~40% intrinsic scatter
compared to B-band.Comment: 84 authors, 71 pages, 51 tables, 10 figures. Accepted for publication
in the Astronomical Journal. Version with high-res figures and electronic
data at http://astron.berkeley.edu/~saurabh/cfa2snIa
- …
