Validated method for the simultaneous determination of Δ-THC and Δ-THC-COOH in oral fluid, urine and whole blood using solid-phase extraction and liquid chromatography–mass spectrometry with electrospray ionization

A fully validated, sensitive and specific method for the extraction and quantification of Δ⁹-tetrahydrocannabinol (THC) and 11-nor-9-carboxy-Δ⁹-THC (THC-COOH) and for the detection of 11-hydroxy-Δ⁹-THC (11-OH THC) in oral fluid, urine and whole blood is presented. Solid-phase extraction and liquid chromatography–mass spectrometry (LC–MS) technique were used, with electrospray ionization. Three ions were monitored for THC and THC-COOH and two for 11-OH THC. The compounds were quantified by selected ion recording of m/z 315.31, 329.18 and 343.16 for THC, 11-OH THC and THC-COOH, respectively, and m/z 318.27 and 346.26 for the deuterated internal standards, THC-d₃ and THC-COOH-d₃, respectively. The method proved to be precise for THC and THC-COOH both in terms of intra-day and inter-day analysis, with intra-day coefficients of variation (CV) less than 6.3, 6.6 and 6.5% for THC in saliva, urine and blood, respectively, and 6.8 and 7.7% for THC-COOH in urine and blood, respectively. Day-to-day CVs were less than 3.5, 4.9 and 11.3% for THC in saliva, urine and blood, respectively, and 6.2 and 6.4% for THC-COOH in urine and blood, respectively. Limits of detection (LOD) were 2 ng/mL for THC in oral fluid and 0.5 ng/mL for THC and THC-COOH and 20 ng/mL for 11-OH THC, in urine and blood. Calibration curves showed a linear relationship for THC and THC-COOH in all samples (r² > 0.999) within the range investigated.The procedure presented here has high specificity, selectivity and sensitivity. It can be regarded as an alternative method to GC–MS for the confirmation of positive immunoassay test results, and can be used as a suitable analytical tool for the quantification of THC and THC-COOH in oral fluid, urine and/or blood samples.     

Is the Walsh Contract Really Optimal?

The purpose of this paper is to show thatthe linear penalization to inflation foundin Walsh (1995) is not the government'soptimal choice when the fixed part of thetransfer scheme is any given constant and thepayment to the central bank represents acost for the government.     

Régimen político y democracia: conflicto constitucional en el pluralismo incompleto

Two constitutional features frame Mexico’s arrival to democracy: the creation of credible electoral institutions and the preservation of rules corresponding to the authoritarian regime inherited from the decade of the ‘30s in the twentieth century. These two sets of rules clash with each other, a fact which explains the low levels of democratic governance and the low quality of legislation and public policies. The political debate over this contradiction seems to have reached the lowest point and several different alternatives have been formulated to break the deadlock; nevertheless, the necessary political agreements that may clearly define a political path have not been reached. The article describes these processes and lays out the alternatives in dispute as well as possible outcomes in the near future.     

Longitudinal Associations between Maternal Involvement,Cultural Orientations,and Prosocial Behaviors Among Recent Immigrant Latino Adolescents

Prosocial behaviors (i.e., actions that benefit others) are important markers of healthy social functioning, and understanding the factors that predict such outcomes among recent immigrant Latino adolescents is important. The current study examines the longitudinal associations between maternal involvement and prosocial behaviors via collectivism values. Data comes from a longitudinal project (Construyendo Oportunidades Para los Adolescentes Latinos) of 302 recently immigrated U.S. Latina/o adolescents (53.3% male, average age?=?14.51 years old). The current study uses data from three times points across 2 years. The results demonstrated that maternal involvement was positively associated with collectivism values. Collectivism was positively associated with changes in prosocial behaviors. There was also partial support for a reverse-causal model. Discussion focuses on the links among parenting, cultural values, and prosocial behaviors among immigrant U.S. Latina/o adolescents.     

Market Structure and R∧D Joint Ventures: The Case of Product Innovations

Departing from the received fact that research joint venture agreements are allowed on the grounds of a permissive ruling, we study what conditions are necessary for venture partners to carry on RD cooperation to the marketing stage. We treat the case of product innovations exploitable with different usages in unconnected markets. Two main results appear: firms always have incentives for a distribution of varieties, but not always agree on the distribution of products. The condition for the last result to happen gives a useful rule for antitrust authorities relating the degree of sustitutability across varieties and the relative profitability of the markets.     

Deteriorating public and private sector relations in Central America

The Central American countries are divided by profound political differences. Yet surprising similarities exist in the changing relations between the public and private sectors. Throughout the region, public and private sectors lock into a vicious circle. The inability of the state to provide order and social harmony creates disincentives for the private sector to invest or even to continue existing levels of production. The government responds by increasing its responsibilities at the expense of the private sector. In doing so it assumes risks the private sector refuses, but further alienates the private sector nonetheless.     

When Green and Amber Meet

Through the ages Scotch whisky has been the drink of kings, politicians, entertainers and those who aspire to the finer things in life.It’s traditionally drunk with a splash of water,straight up or with the debonair "on the rocks" by-line.     

Extreme versus quotidian: addressing temporal dichotomies in Philippine disaster management

Brief narratives of two recent events in Luzon island—a flashflood in Angeles City and an eruption of Mayon volcano—underscore the disparity between natural hazards as amplifiers of everyday hardship for many Filipinos and the Philippine disaster management system's orientation towards extreme‐event response. Three major factors contribute to this dichotomy. First, population dynamics combined with the lack of access to resources compels poor Filipinos to live and work in hazardous areas, discounting risk from extreme natural events to focus on daily needs. Second, the institutional setting of the country's disaster management within the military establishment makes it difficult, though not impossible, to focus and address the underlying causes of vulnerability. Third, existing modes of funding disaster expenditures are all biased towards immediate response rather than long‐term risk‐reduction. The implications of these findings to disaster management and research in the Philippines are identified. Copyright © 2008 John Wiley & Sons, Ltd.