10,017 research outputs found

    International trends in fresh avocado and avocado oil production and seasonal variation of fatty acids in New Zealand-grown cv. Hass : a thesis presented in partial fulfilment of the requirements for the degree of Master in Applied Science in Agribusiness at Massey University

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    Intensive cultivation of avocados for commercial purposes began in California and Florida and later in Israel, South Africa and Chile. Although a range of avocado cultivars are grown, Hass is the world's most widely-grown and exported cultivar. Avocado fruit has shown good commercial perspectives and planted areas show a tendency to increase. World production of avocado has grown on average 4.3% (over 760.000 MT) between 1988 and 1998. The main producers of avocado are Mexico (34%), USA (8%), Dominican Republic (7%), Indonesia (6%) Brazil (4%) and Israel (4%), Chile (2.4%), Spain (3%) and South Africa (2%) which during 1997 contributed together to 70% of the world production. Avocado world trade has increased greatly from 57,576 tonnes in 1980 to 238,306 tonnes in 1997. In 1997, the main players in the export market were Israel, Mexico, South Africa, USA and Chile. The main importers of this fruit were in Europe: Belgium, France, The Netherlands, Sweden, Switzerland, the United Kingdom, Germany, Spain, and in America: the USA and Canada and in Asia: Japan has emerged as a strong market since 1995. Average prices paid per metric ton have decreased over the years as higher volumes of fruit are traded and new exporters enter into the business. Avocado producer countries will face major challenges because of increasing production and low prices over the short and medium term. With the exception of Mexico, Israel and the U.S. the rest of the studied country producers are fairly new in the industry, thus, they possess great potential for growing. In New Zealand avocados are mainly cultivated in the North Island specifically in the Bay of Plenty and Northland areas. The New Zealand avocado Industry is based on the Hass cultivar. Avocado trees in New Zealand continue to be widely planted and with the entrance of new growers, in the future, the orchard area will continue to increase. The avocado industry in New Zealand is export driven. New Zealand's main export markets are Australia and recently the United States. Actual Australian market dominance by New Zealand would be reduced in the following 5 years due to a constant increase in Australian domestic avocado production. Since 1996, the U.S. has become an important market of destination for New Zealand avocados. Traditional supplier of the U.S. market has been Chile and it represents New Zealand's main competitor In avocado export leader countries usually the local market is supplied with fruit that does not meet export (usually strict) quality requirements. Great increases in production and export volumes are expected, therefore, it is forecast that large volumes of low price rated avocados would exist and would force the industry to look for alternative uses for avocados. Those avocados rejected during classification for export markets mainly due to defects in cosmetic appearance might be used for avocado oil extraction. The oil industry generally considered a by- product of the fresh fruit industry. For the multiplicity of applications and high prices that it achieves, avocado oil represents an interesting industry that should be further researched. Lipids are an important part of the composition of avocado fruit for a range of reasons. They contribute significantly to the taste of the fruit, and are used indirectly as a means of defining maturity since they correlate highly with dry matter. Although there has been some work carried out in New Zealand examining lipid changes and maturity, there has been no examination of the fatty acid makeup of the lipids, how they vary between regions, and what the lipid content is later in a commercial season. Such information is important from a fruit quality, health and marketing points of view. On seven occasions between September 1998 and April 1999, fruit from two orchards located in Te Puke and the Far North were harvested and analysed for dry matter, lipid content and fatty acid composition. Dry matter assessments were carried out using the commercial method and, the lipid fraction was extracted using a modification of the Bligh and Dyer technique. Later, the fatty acid analysis of the lipids was carried out by gas chromatography. Average dry matter increased over the period of study (September to April). Dry matter for Te Puke fruit increased from 24.6% to 36.4%, while dry matter from the Far North fruit increased from 24.1% to 32.3% over the same period of time. Total lipid content increased from 17.2% to 31.3% in Te Puke and from 16.4% to 26.7% in the Far North from September to April. The results imply that fruit from Te Puke could be preferred from the point of view of oil extraction because higher yields can be obtained than from fruit from the Far North. It was found a high and positive relationship exists between total lipids and dry matter content in avocados. During the study period, fruit from Te Puke showed consistently higher lipid content (and dry matter content) than fruit from the Far North. At both sites, the beneficial monounsaturated oleic acid was the major fatty acid synthesised, however, fruit from Te Puke showed higher levels of oleic acid than fruit from the Far North. From the nutrition point of view the ratio of monounsaturated (oleic and palmitoleic acid) to saturated fatty acids (palmitic acid) and the ratio of polyunsaturated (linoleic and linolenic acid) to saturated fatty acids found for the Far North and Te Puke regions compare favourably with those of the recommended olive oil. Due to similarities in lipid composition between olive oil and avocado oil, it can be implied that the high concentration of monounsaturated fatty acids in avocado will be beneficial to lower blood lipids as olive oil does. The food industry makes use of avocado oil to prepare concentrated foods, while the cosmetics industry prepares lotions and soaps for hair and skin treatments. Lastly, prestigious laboratories are also analysing the property of the flesh and oil for medical purposes. The information compiled here confirms that avocado oil compares to olive oil and can be regarded as a high- value product from the nutritional and the commercial point of view. On current production trends in New Zealand, the likelihood of an oil-extraction plant is not remote. An oil industry in New Zealand would benefit the growers because it will absorb the surplus of avocados in the local market that otherwise would compete with their first grade fruit

    A deep dive into NGC 604 with Gemini/NIRI imaging

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    The giant HII region NGC 604 constitutes a complex and rich population to studying detail many aspects of massive star formation, such as their environments and physical conditions, the evolutionary processes involved, the initial mass function for massive stars and star-formation rates, among many others. Here, we present our first results of a near-infrared study of NGC 604 performed with NIRI images obtained with Gemini North. Based on deep JHK photometry, 164 sources showing infrared excess were detected, pointing to the places where we should look for star-formation processes currently taking place. In addition, the color-color diagram reveals a great number of objects that could be giant/supergiant stars or unresolved, small, tight clusters. A extinction map obtained based on narrow-band images is also shown.Comment: 4 pages, 4 figures. To appear in the proceedings of IAU Symposium 266, Star Clusters: Basic Galactic Building Blocks Throughout Time and Space, eds. R. de Grijs and J. Lepin

    Circular dichroism simulated spectra of chiral gold nanoclusters: A dipole approximation

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    Circular dichroism (CD) spectra of chiral bare and thiol-passivated gold nanoclusters have been calculated within the dipole approximation. The calculated CD spectra show features that allow us to distinguish between clusters with different indexes of chirality. The main factor responsible of the differences in the CD lineshapes is the distribution of interatomic distances that characterize the chiral cluster geometry. These results provide theoretical support for the quantification of chirality and its measurement, using the CD lineshapes of chiral metal nanoclusters.Comment: 3 pages + 4 figure

    Elevated Hippocampal Cholinergic Neurostimulating Peptide precursor protein (HCNP-pp) mRNA in the amygdala in major depression

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    The amygdala is innervated by the cholinergic system and is involved in major depressive disorder (MDD). Evidence suggests a hyper-activate cholinergic system in MDD. Hippocampal Cholinergic Neurostimulating Peptide (HCNP) regulates acetylcholine synthesis. The aim of the present work was to investigate expression levels of HCNP-precursor protein (HCNP-pp) mRNA and other cholinergic-related genes in the postmortem amygdala of MDD patients and matched controls (females: N=16 pairs; males: N=12 pairs), and in the mouse unpredictable chronic mild stress (UCMS) model that induced elevated anxiety-/depressive-like behaviors (females: N=6 pairs; males: N=6 pairs). Results indicate an up-regulation of HCNP-pp mRNA in the amygdala of women with MDD (p<0.0001), but not males, and of UCMS-exposed mice (males and females; p=0.037). HCNP-pp protein levels were investigated in the human female cohort, but no difference was found. There were no differences in gene expression of acetylcholinesterase (AChE), muscarinic (mAChRs) or nicotinic receptors (nAChRs) between MDD subjects and controls or UCMS and control mice, except for an up-regulation of AChE in UCMS-exposed mice (males and females; p=0.044). Exploratory analyses revealed a baseline expression difference of cholinergic signaling-related genes between women and men (p<0.0001). In conclusion, elevated amygdala HCNP-pp expression may contribute to mechanisms of MDD in women, potentially independently from regulating the cholinergic system. The differential expression of genes between women and men could also contribute to the increased vulnerability of females to develop MDD.Fil: Bassi, Sabrina Cecilia. University of Pittsburgh; Estados Unidos. Hospital Italiano. Instituto de Ciencias Básicas y Medicina Experimental; ArgentinaFil: Seney, Marianne L.. University of Pittsburgh; Estados UnidosFil: Argibay, Pablo. Hospital Italiano. Instituto de Ciencias Básicas y Medicina Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sibille, Etienne. University of Pittsburgh; Estados Unidos. University of Toronto; Canad

    Rectangular Layouts and Contact Graphs

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    Contact graphs of isothetic rectangles unify many concepts from applications including VLSI and architectural design, computational geometry, and GIS. Minimizing the area of their corresponding {\em rectangular layouts} is a key problem. We study the area-optimization problem and show that it is NP-hard to find a minimum-area rectangular layout of a given contact graph. We present O(n)-time algorithms that construct O(n2)O(n^2)-area rectangular layouts for general contact graphs and O(nlogn)O(n\log n)-area rectangular layouts for trees. (For trees, this is an O(logn)O(\log n)-approximation algorithm.) We also present an infinite family of graphs (rsp., trees) that require Ω(n2)\Omega(n^2) (rsp., Ω(nlogn)\Omega(n\log n)) area. We derive these results by presenting a new characterization of graphs that admit rectangular layouts using the related concept of {\em rectangular duals}. A corollary to our results relates the class of graphs that admit rectangular layouts to {\em rectangle of influence drawings}.Comment: 28 pages, 13 figures, 55 references, 1 appendi

    Vortex dynamics under pulsatile flow in axisymmetric constricted tubes

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    An improved understanding of how vortices develop and propagate under pulsatile flow can shed important light on the mixing and transport processes including the transition to turbulent regime occurring in such systems. For example, the characterization of pulsatile flows in obstructed artery models serves to encourage research into flow-induced phenomena associated with changes in morphology, blood viscosity, wall elasticity and flow rate. In this work, an axisymmetric rigid model was used to study the behaviour of the flow pattern with varying constriction degree (d0d_0), mean Reynolds number (Reˉ\bar{Re}) and Womersley number (α\alpha). Velocity fields were acquired experimentally using Digital Particle Image Velocimetry and generated numerically. For the acquisition of data, Reˉ\bar{Re} was varied from 385 to 2044, d0d_0 was 1.0 cm and 1.6 cm, and α\alpha was varied from 17 to 33 in the experiments and from 24 to 50 in the numerical simulations. Results for the considered Reynolds number, showed that the flow pattern consisted of two main structures: a central jet around the tube axis and a recirculation zone adjacent to the inner wall of the tube, where vortices shed. Using the vorticity fields, the trajectory of vortices was tracked and their displacement over their lifetime calculated. The analysis led to a scaling law equation for the maximum vortex displacement as a function of a dimensionless variable dependent on the system parameters Re and α\alpha

    EMDR therapy for PTSD after motor vehicle accidents: meta-analytic evidence for specific treatment

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    Motor vehicle accident (MVA) victims may suffer both acute and post-traumatic stress disorders (PTSD). With PTSD affecting social, interpersonal and occupational functioning, clinicians as well as the National Institute of Health are very interested in identifying the most effective psychological treatment to reduce PTSD. From research findings, eye movement desensitization and reprocessing (EMDR) therapy is considered as one of the effective treatment of PTSD. In this paper, we present the results of a meta-analysis of fMRI studies on PTSD after MVA through activation likelihood estimation. We found that PTSD following MVA is characterized by neural modifications in the anterior cingulate cortex (ACC), a cerebral structure involved in fear-conditioning mechanisms. Basing on previous findings in both humans and animals, which demonstrate that desensitization techniques and extinction protocols act on the limbic system, the effectiveness of EMDR and of cognitive behavioral therapies (CBT) may be related to the fact that during these therapies the ACC is stimulated by desensitization

    Exploring Cultural Differences in HCI Education

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    The discipline of human-computer interaction has become a subject taught across universities around the world, outside of the cultures where it originated. However, the intercultural implication of its assimilation into the\ud syllabus of courses offered by universities around the world remains underresearched. The purpose of this ongoing research project is to provide insights for these implications in terms of the student and teacher experience of HCI. How this subject is socially represented across the different universities studied is a key question. In order to develop intercultural awareness of these questions\ud universities from UK, Namibia, Mexico and China are collaborating in a multiple case study involving students and lecturers engaged in evaluation and design tasks. Findings will then be used to propose an international HCI curriculum more supportive of local perspectives. This paper describes the initial steps of this study and some preliminary findings from Namibia, India and Mexico about cognitive styles and cultural attitudes
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