Conditioning

1 Laboratory of Comparative Psychology and Behavioral Biology, Departments of Psychology and Zoology, Oklahoma State University, 215 N. Murray, Stillwater, OK 74078, USA 2 Uludag Universitesi, M. Kemalpasa MYO, M. Kemalpasa, Bursa 16500, Turkey 3 Northwestern ...

Table grapes were packed in either nonperforated polypropylene or perforated polypropylene films and stored at 1 °C for 53 d. Nonperforated polypropylene packages had the highest CO2 and lowest O2 contents, with reduced weight losses and increased berry and skin firmness. Soluble solids concentration increased in unwrapped control grapes as a consequence of the higher weight losses, whereas no significant differences were found for titratable acidity. Both films were equally effective in maintaining skin color, whereas control grapes showed a reduction of color. The highest scores in sensory analyses for crunchiness, juiciness, sourness, and quality were given to nonperforated polypropylene packages after 18 d of storage, and good visual aspect and no off-flavor were detected after 53 d of cold storage.

We use a recent result concerning the eigenvalues of a generic (non-Hermitian) complex perturbation of a bounded Hermitian sequence of matrices to prove that the asymptotic spectrum of the product of Toeplitz sequences, whose symbols have a real-valued essentially bounded product h, is described by the function h in the “Szegö way”. Then, using Mergelyan’s theorem, we extend the result

Nine formulations to be used as stick bases were manufactured using sodium stearate, propyleneglycol, and water, adding different concentrations of the following conditioning agents: octyldodecanol, PPG-5-ceteth-20, and PPG-15-stearyl ether. Free-choice-profile methodology was used to select the most adequate concentration of the agents in order to improve sensory properties. The sensory descriptors were grouped into four categories: stick aspect, sensations during application, sensations immediately after application, and sensations five minutes after application. Formulations containing 4% and 6% octyldodecanol and 2% PPG-15-stearyl ether were considered inadequate, since they showed unwanted qualities such as exudation, a slow absorption rate, high oiliness, and residue. Formulations containing 2% octyldodecanol; 2%, 4%, and 6% PPG-5-ceteth-20; and 4% and 6% PPG-15-stearyl ether presented different characteristics regarding the four categories of descriptors evaluated, all of the...

The study of marine mammals in the wild is faced with major difficulties: encounter frequency and duration are limited, individual identification is difficult, social behaviors occur mostly in murky or deep water, the ability to assign vocalizations to individuals is usually very limited, sea conditions are not always suitable for research, and the design of controlled experiments is virtually impossible. In contrast, research in captivity poses different methodological obstacles due to confined space, artificial and sometimes poor environments, forced social structure, small sample sizes, subjects that are not always good representatives of wild populations etc., all provide constant challenge to scientists. This paper reviews some of the studies on Black Sea bottlenose dolphins (Tursiopstruncatus ponticus) conducted during the 15 years since the establishment of the International Laboratory for Dolphin Behaviour Research (ILDBR) located at the semi-natural Dolphin-Reef (Eilat, Isr...

Se analizan las tendencias en la investigacion basica sobre psicologia del aprendizaje y su impacto, con base en los trabajos publicados en las principales revistas de psicologia en espanol: Revista Latinoamericana de Psicologia (RLP), Psicothema (PT), Revista Mexicana de Psicologia (RMP), y Revista Interamericana de Psicologia (RIP). Las tres primeras estan ?indexadas? por el Institute for Scientific Information (ISS), y la cuarta lo estuvo hasta hace pocos anos. Los porcentajes de articulos publicados sobre investigacion basica en aprendizaje son los siguientes: RLP (40%), PT (38.3%), RIP (15%), y RMP (6.7%). Los paises con mayor numero de investigaciones publicadas son Espana, Mexico, Argentina y Colombia. La decada mas productiva fue la mas reciente, 1990-1999. Las especies mas estudiadas han sido ratas, humanos y palomas. Los tipos de aprendizaje fueron discriminacion de estimulos, condicionamiento instrumental aversivo, condicionamiento clasico, y condicionamiento instrumental...

There is an increasing interest towards synthetic closures as an alternative to cork stoppers for sealing wine bottles. In this preliminary study, a set of testing conditions using the TA-HDI Texture Analyzer were implemented to measure selected mechanical parameters for the characterization of wine closures (natural and technical corks, co-extruded and injected synthetic closures in terms of compression force, extraction force and resilience. The results showed the presence of significant differences among the closures for the parameters tested. Injected closures were characterized by the highest weight (range = 6.8–7.2 g), whereas the corks showed wide variability (SD = 0.23–0.57 = 4.4–15.3%). The force required to pull-out the closure from the bottle ranged between 176 and 421 N and the extreme values were found on natural (196 ± 20 N) and technical cork (329 ± 39 N). The force of compression was highest for corks (1006–1046 N), whereas lowest values were found for the synthetic closures (566–639 N). The Principal Component Analysis grouped the synthetic closures according to the technology process, i.e. injected and co-extruded, whereas the corks broadened aside with a little dispersion of technical cork compared to the natural cork.

The objective of this work was to study the effect of potato starch-based films acting as oxygen barrier on the oxidative rancidity of vegetable oil, as an example of a food rich in polyunsaturated fatty acids. The effect of glycerol (Gly) content (0%, 10%, 20%, 30%), film thickness (30, 60, 100 μm) as well as environmental relative humidity (RH) (50% or 75%) were analysed. Results obtained confirmed that potato starch films delayed the rancidity in vegetable oil. Films without Gly provided the same protection as films with 10% Gly. Films with higher Gly content were not as effective oxygen barrier. It is likely that the fact that film protective capability diminished with increased RH or Gly content was due to the increasing moisture content of the films. Despite that fact, potato starch films can be considered a very efficient oxygen barrier even at RH as high as 75%.

ABSTRACT:  The effect of grape seed extract (GS; 0.01% and 0.02%), oleoresin rosemary (OR; 0.02%) and water-soluble oregano extract (WS; 0.02%) on oxidative and color stability of cooked beef and pork patties stored at 4 °C for 8 d was determined. Fresh beef or pork lean and trim were ground, mixed (30% fat), and divided into 5 portions. Antioxidants mixed with salt (2%) were added. Patties were formed, cooked to an internal temperature of 71 °C, overwrapped in PVC, and stored at 4 °C. Lipid oxidation, assessed using thiobarbituric acid reactive substances (TBARS) and sensory evaluation, instrumental and visual color, and pH were determined after 0, 2, 4, 6, and 8 d. Based on TBARS values and off-odors associated with lipid oxidation such as rancidity, wet cardboard (for beef patties), and grassy (for beef and pork patties), grape seed extract resulted in the best antioxidant activity in both meat species. It did not change instrumental color measures of redness, yellowness, or color intensity, and appeared to reduce visual green discoloration in beef patties. The higher GS concentration (0.02%) exhibited more antioxidant activity than the lower concentration (0.01%). Therefore, grape seed extract at 0.02% has the potential to reduce oxidative rancidity and improve shelf life of refrigerated cooked beef and pork patties.

Asparagus (Asparagus Officinalis L.) spears were packaged in ordinary and microperforated oriented polypropylene (OPP) films and were stored at 15C and 75% RH for up to 10 days. CO2 concentrations ranged from 15.5 to 23% at 10 days of storage. Weight loss was less than 1.2% in microperforated film packages compared with 15% in air storage under similar conditions. Ascorbic acid content was found to be adversely affected at all the O2 levels (1–6%) prevailing in microperforated film packages, but it was retained to the extent of 45–55% of its original concentration in ordinary OPP film packaged asparagus. the O2 concentrations in microperforated film packages were also associated with higher glutathione concentrations in packed asparagus spears. Results of the study indicated that to preserve ascorbic acid and glutathione simultaneously in stored asparagus through MAP under high CO2 and low O2 conditions, O2 concentration levels must be selected between 1 and 6% in such a way so as to get acceptable retention levels of ascorbic acid and glutathione.

This study was designed to assess the usefulness of skinfold (SKF) equations developed by Jackson and Pollock (JP) and by Evans (Ev) in tracking body composition changes (relative fat mass [%FM], absolute fat mass [FM], and fat-free mass [FFM]) of elite male judo athletes before a competition using a 4-compartment (4C) model as the reference method. A total of 18 male, top-level (age: 22.6 +/- 2.9 yr) athletes were evaluated at baseline (weight: 73.4 +/- 7.9 kg; %FM4C: 7.0 +/- 3.3%; FM4C: 5.1 +/- 2.6 kg; and FFM4C: 68.3 +/- 7.3 kg) and before a competition (weight: 72.7 +/- 7.5 kg; %FM4C: 6.5 +/- 3.4%; FM4C: 4.8 +/- 2.6 kg; and FFM4C: 67.9 +/- 7.1 kg). Measures of body density assessed by air displacement plethysmography, bone mineral content by dual energy X-ray absorptiometry, and total-body water by bioelectrical impedance spectroscopy were used to estimate 4C model %FM, FM, and FFM. Seven SKF site models using both JP and Ev were used to estimate %FM, FM, and FFM along with the simplified Ev3SKF site. Changes in %FM, FM, and FFM were not significantly different from the 4C model. The regression model for the SKF in question and the reference method did not differ from the line of identity in estimating changes in %FM, FM, and FFM. The limits of agreement were similar, ranging from -3.4 to 3.6 for %FM, -2.7 to 2.5 kg for FM, and -2.5 to 2.7 kg for FFM. Considering the similar performance of both 7SKF- and 3SKF-based equations compared with the criterion method, these data indicate that either the 7- or 3-site SFK models are not valid to detect %FM, FM, and FFM changes of highly trained athletes. These results highlighted the inaccuracy of anthropometric models in tracking desired changes in body composition of elite male judo athletes before a competition.