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1.
Front Artif Intell ; 6: 1129370, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36909205

RESUMEN

We show how reinforcement learning can be used in conjunction with quantile regression to develop a hedging strategy for a trader responsible for derivatives that arrive stochastically and depend on a single underlying asset. We assume that the trader makes the portfolio delta-neutral at the end of each day by taking a position in the underlying asset. We focus on how trades in options can be used to manage gamma and vega. The option trades are subject to transaction costs. We consider three different objective functions. We reach conclusions on how the optimal hedging strategy depends on the trader's objective function, the level of transaction costs, and the maturity of the options used for hedging. We also investigate the robustness of the hedging strategy to the process assumed for the underlying asset.

2.
Child Care Health Dev ; 48(1): 80-87, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34355408

RESUMEN

AIM: This study aims to evaluate a Tele-P cognitive behavioural intervention (CBT) to promote the emotional functioning (i.e. reduce anxiety, depression and social isolation) and improve the quality of life (QoL) of caregivers of children who are ventilator dependent at home. BACKGROUND: There is an urgent need for support of parents with technology-dependent children. Research shows that the parents of children whose chronic illness require assisted-technology experience significant emotional stress, potential gaps in social isolation, and social isolation leading to lower quaility of life, unhealthy family functioning, and negative psychological consequences. RESULTS: Participation in a Tele-P intervention significantly reduced caregivers' anxiety, depression and fatigue, and reduction was sustained in a 4 week follow-up period. There was no significant change in social isolation. CONCLUSION: Findings demonstrate preliminary efficacy of an innovative Tele-P intervention on outcomes of anxiety, depression and fatigue in an at-risk group of caregivers. Although the intervention did not improve self-reported social isolation, using technology in combination with established psychological support is an efficient way to better equip our mental health intervention systems to serve vulnerable populations.


Asunto(s)
Cuidadores , Calidad de Vida , Ansiedad/prevención & control , Niño , Depresión/prevención & control , Humanos , Salud Mental , Padres
3.
Integr Environ Assess Manag ; 11(2): 195-207, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25323491

RESUMEN

This paper reviews general approaches for applying activated carbon (AC) amendments as an in situ sediment treatment remedy. In situ sediment treatment involves targeted placement of amendments using installation options that fall into two general approaches: 1) directly applying a thin layer of amendments (which potentially incorporates weighting or binding materials) to surface sediment, with or without initial mixing; and 2) incorporating amendments into a premixed, blended cover material of clean sand or sediment, which is also applied to the sediment surface. Over the past decade, pilot- or full-scale field sediment treatment projects using AC-globally recognized as one of the most effective sorbents for organic contaminants-were completed or were underway at more than 25 field sites in the United States, Norway, and the Netherlands. Collectively, these field projects (along with numerous laboratory experiments) have demonstrated the efficacy of AC for in situ treatment in a range of contaminated sediment conditions. Results from experimental studies and field applications indicate that in situ sequestration and immobilization treatment of hydrophobic organic compounds using either installation approach can reduce porewater concentrations and biouptake significantly, often becoming more effective over time due to progressive mass transfer. Certain conditions, such as use in unstable sediment environments, should be taken into account to maximize AC effectiveness over long time periods. In situ treatment is generally less disruptive and less expensive than traditional sediment cleanup technologies such as dredging or isolation capping. Proper site-specific balancing of the potential benefits, risks, ecological effects, and costs of in situ treatment technologies (in this case, AC) relative to other sediment cleanup technologies is important to successful full-scale field application. Extensive experimental studies and field trials have shown that when applied correctly, in situ treatment via contaminant sequestration and immobilization using a sorbent material such as AC has progressed from an innovative sediment remediation approach to a proven, reliable technology.


Asunto(s)
Carbón Orgánico/química , Restauración y Remediación Ambiental , Sedimentos Geológicos/química , Contaminantes Químicos del Agua/química , Países Bajos , Noruega , Estados Unidos
4.
Popul Health Manag ; 16(4): 221-6, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23405876

RESUMEN

The objective of this study was to describe employees most likely to participate in a Personal Wellness Profile (PWP) and/or in a worksite Wellness Program (WP), and to identify whether an association exists between participation and trends in number of health care services and cost of services per person. A retrospective cohort study was conducted using medical claims data from the Deseret Mutual Benefit Administrators, 2004 through 2009. The PWP and WP involved more than 30% of employee contract holders. Participation in the PWP and WP were lower in the older age group and higher among women, married people, and those with an annual income of at least $40,000. Average annual cost per person during 2004-2006 was significantly positively associated with completing the PWP in 2007-2009. Those in the highest quartile for average annual cost per person in 2004-2006 were significantly less likely to participate in the WP in 2007-2009. During 2004-2009, a significantly increasing trend in average annual cost per person was similar, but at a lower level for PWP participants. The trend line also was lower for WP participants, and increased at a lower rate. The lower rate of increase in the trends for average cost per person among those in the WP indicates that the intervention is effective at slowing escalating costs. Additional years of data should be assessed, when available, to confirm this pattern.


Asunto(s)
Costos de la Atención en Salud/tendencias , Promoción de la Salud/tendencias , Tamizaje Masivo/economía , Servicios de Salud del Trabajador/organización & administración , Lugar de Trabajo , Adulto , Análisis Costo-Beneficio , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Estados Unidos
5.
Inorg Chem ; 49(19): 8684-9, 2010 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-20812678

RESUMEN

A large number of polyhalides, especially polyiodides, have been discovered and studied, but definitive studies on polybromides remain scarce. Br(3)(-) is the only monovalent polybromide with a known structure. Higher-order monovalent polybromide anions have been proposed but not structurally confirmed as discrete species. In this study tetraalkylammonium polybromides with molecular formulas R(4)NBr(2x+1) (R = ethyl; x = 1-4) were prepared by reacting tetraalkylammonium monobromide or tribromide salts with gas-phase bromine. Distinct and characteristic Raman spectra were obtained from the solid polybromides in the spectral range between 100 and 400 cm(-1). Experimental Raman spectra were compared to ab initio calculations to propose the structure of these polybromide anions. A general agreement between the experimental and theoretical results was observed. This study demonstrates that Raman spectroscopy is a sensitive technique for probing the structure of discrete monovalent polybromides.


Asunto(s)
Bromuros/química , Tetraetilamonio/química , Bromuros/síntesis química , Teoría Cuántica , Espectrometría Raman , Tetraetilamonio/síntesis química
6.
Beilstein J Org Chem ; 3: 23, 2007 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-17784956

RESUMEN

BACKGROUND: Dow AgroSciences has been investigating a new family of functionalized 2,6-dihaloaryl 1,2,4-triazole insecticides featuring specifically targeted insecticidal activities coupled with low mammalian toxicity. With broad spectrum control of both chewing and sap-feeding pests in mind, this family of compounds has been under investigation for aphid, mite, and whitefly control in food crop protection as well as ornamental applications. Two specific targets for development have been the 2,6-dihalo 1,2,4-triazoles XR-693 and XR-906, which require a supply of the halogenated 2-thiophenecarboxylic acid derivatives 1, 2, and 3 for assembly of the C-ring portion of the triazole products. RESULTS: Potential manufacturing routes to three halogenated 2-thiophenecarboxylic acid derivatives 4-bromo-3-methyl-2-thiophenecarbonyl chloride 1, 3,4,5-trichloro-2-thiophenecarbonyl chloride 2, and 3,4,5-trichloro-2-thiophenecarbonitrile 3 from commercially available thiophene raw materials have been developed and demonstrated on a laboratory scale. A one-pot bromination/debromination procedure developed for 3-methylthiophene gave 2,4-dibromo-3-methylthiophene. Carboxylic acid functionality was then introduced either by a Grignard metallation followed by carbonation with CO2, or by a palladium catalyzed carbonylation procedure under CO pressure. The vapor phase chlorination of 2-thiophenecarbonitrile with chlorine gas at 500 degrees C with an average residence time of 6 seconds gave 3,4,5-trichloro-2-thiophenenitrile 3 in a 69% distilled yield, a process that was carried out on a multi-kilogram scale in the laboratory. Finally, a route for the preparation of 3,4,5-trichloro-2-thiophenecarbonyl chloride 2 was developed from tetrachlorothiophene via either a lithiation reaction with n-butyllithium in MTBE solvent, or by a previously reported Grignard method using 1,2-dibromoethane as activator, followed by carbonation of the anion with CO2 to give the trichloro-2-thiophenecarboxylic acid, which was readily converted to the acid chloride 2 with SOCl2. CONCLUSION: The successful development of efficient synthetic routes to the halogenated thiophene building blocks 4-bromo-3-methyl-2-thiophenecarbonyl chloride 1, 3,4,5-trichloro-2-thiophenecarbonyl chloride 2, and 3,4,5-trichloro-2-thiophenecarbonitrile 3 paved the way for the development of viable commercial processes for XR-693 and XR-906, members of a new class of 2,6-dihaloaryl 1,2,4-triazole insecticides that exhibit selective activity against aphids, mites, and whiteflies coupled with low mammalian toxicity. The process development work for the experimental insecticide target molecules XR-693 and XR-906 will be the topic of a forthcoming paper.

7.
J Gen Psychol ; 97(1): 151-152, 1977 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28137200
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