The chemistry and physiology of sour taste--a review

ABSTRACT:  Sour taste is the key element in the flavor profile of food acidulants. Understanding the chemistry and physiology of sour taste is critical for efficient control of flavor in the formulation of acid and acidified foods. After a brief introduction to the main applications of food acidulants, several chemical parameters associated with sour taste are discussed. Special emphasis is given to hydrogen ions, protonated (undissociated) acid species, titratable acidity, anions, molar concentration, and physical and chemical properties of organic acids. This article also presents an overview of the physiology of sour taste and proposed theories for the transduction mechanisms for sour taste. The physiology of sour taste perception remains controversial and significant diversity exists among species with regard to cellular schemes used for detection of stimuli. The variety of mechanisms proposed, even within individual species, highlights the complexity of elucidating sour taste transduction. However, recent evidence suggests that at least one specific sour taste receptor protein has been identified.     

Zoning and the Nouveau Poor

The nouveau poor, women heading households, who have experienced a dramatic shift from middle income to low income status due to divorce, widowhood, or abandonment, and who own their own homes in America's suburban and small towns constitute a demographic group whose housing opportunities are limited by certain restrictive zoning practices.

Outmoded regulations, such as those with restrictive definitions of family and age-restrictive zoning regulations and covenants, deny these families the opportunity to enter into housesharing arrangements or to divide their homes into principal and accessory units. Because of these policies, nouveau poor families may find that they cannot continue to live in the communities that they had sought out as ideal places for raising their children. Although restrictive zoning regulations have generally been upheld by the courts, they have at times been successfully attacked. An understanding of the court decisions and their public policy implications will provide guidance for land use officials so they can respond to the housing needs of the nouveau poor.     

Cardiovascular reactivity during social and nonsocial stressors: Do children's personal goals and expressive skills matter?

The relationships between social competence and cardiovascular reactivity were evaluated in 180 children (ages 8-17; 52% female; 53% Caucasian). Participants performed a social task (Social Competence Interview [SCI]) and 2 nonsocial tasks while reactivity measures were obtained. Social competence was coded from SCI audiotapes. Among adolescents, higher scores on the Acceptance-Affiliation subscale were associated with increased heart rate (HR) and blood pressures and with decreased HR variability during the SCI. Among boys, greater Acceptance-Affiliation scores were associated with increased vascular reactivity during the SCI. During the nonsocial tasks, higher Self-Defensiveness and Expressiveness scores were associated with increased cardiac output and stroke volume among African American children. Personal strivings and expressive skills do matter for understanding cardiovascular responses in children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regression Model for Daily Maximum Stream Temperature

An empirical model is developed to predict daily maximum stream temperatures for the summer period. The model is created using a stepwise linear regression procedure to select significant predictors. The predictive model includes a prediction confidence interval to quantify the uncertainty. The methodology is applied to the Truckee River in California and Nevada. The stepwise procedure selects daily maximum air temperature and average daily flow as the variables to predict maximum daily stream temperature at Reno, Nev. The model is shown to work in a predictive mode by validation using three years of historical data. Using the uncertainty quantification, the amount of required additional flow to meet a target stream temperature with a desired level of confidence is determined.     

Delineation of female performance on the Rey-Osterrieth Complex Figure.

103 female college students (aged 18–24 yrs) were administered the Rey-Osterrieth Complex Figure on Copy, Immediate Recall, and 20-min Delayed Recall. Ss were grouped based on handedness, familial handedness, and academic major (mathematics/science and nonmath/science). Based on the scoring system of D. Waber and J. Holmes (see PA, Vols 72:24305 and 74:9917) the mathematics/science anomalous dominance groups obtained higher mean scores than all other subgroups, and the non-math/science familial right-handers were the low performers. The high-performing groups may have an increased ability to coordinate the use of left- and right-hemisphere processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Watershed and River Systems Management Program: Overview of Capabilities

Beginning in January 1992, the Bureau of Reclamation (Reclamation) and the US Geological Survey (USGS) formulated plans for the Watershed and River Systems Management Program—a cooperative interagency effort to develop and implement flexible and robust river basin management tools for the benefit of managers and decision makers using a data centered approach. In addition to Reclamation and the USGS, a number of other agencies and universities have made substantial contributions to the success of the program. The result has been the need driven research and development of state-of-the-art technology which benefits water managers and technical specialists in many river basins.