Influence of home-cage lighting conditions on shock-induced fighting

A series of experiments was conducted to assess the influence of home-cage lighting conditions on shock-induced aggression in rats. The first two experiments tested rats six times within 24 hr and demonstrated that subjects maintained on a light/dark (LD) cycle fought more than rats maintained on a 24-hr light schedule (LL). In addition, a periodic trend could be identified in the data of the LD groups but not in the data of the LL groups. The second two experiments assessed the effects of castration on this lighting effect. Castration of adults did not influence the lighting effects, but castration of weanling rats eliminated the group difference between LL and LD groups. However, the LD rats castrated at weaning did show the periodic trend characteristic of all of the LD groups tested within 24 hr. Two additional experiments assessed the effects of time of testing in between-subjects designs. Time of testing was a significant variable in the LD groups but unimportant in the LL groups. A final experiment demonstrated that the difference between the LD and LL groups does not emerge in a daily testing procedure.     

Intermale fighting affected by home-cage odors of male and female mice.

Conducted 3 experiments to test the hypothesis that male mice can produce an aggression-inhibitory or facilitory odor under varying conditions of social stimulation. In Exp I, 25 male fighter mice fought 25 castrated opponents more vigorously in soiled home cages of either single or stable groups of male mice than they did in clean cages. Fighting was also stimulated in cages briefly occupied by other pairs of fighting mice. It is concluded that the release of aggression-promoting home-cage odors by male mice is not necessarily a consequence of social instability and that they are of urinary, rather than preputial, origin. In Exp II (with 21 fresh Ss) and Exp. III (with 30 Ss from Exp I), odors deposited by either single or groups of female mice greatly reduced fighting, indicating that their urinary aggression-inhibiting pheromone is effective after deposition upon the home environment. Testosterone propionate implants abolished the females' inhibitory pheromone and did so independently of their enlarged preputial glands. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of alcohol, gender, and sensation seeking on the gambling choices of social drinkers.

The preference-reversal, or the reflection, effect occurs when the valence of the decision option influences risk preference (A. Tversky and D. Kahneman, 1981-31998-001). The present study examined 3 possible moderators of gambling choices—alcohol, gender, and sensation seeking—among 108 healthy male and female volunteers. After receiving a moderate dose of alcohol, a placebo, or a no-alcohol control beverage, participants completed a betting task in which they could risk a monetary bonus by selecting and playing out a potential gain and a potential loss. Results indicated a preference-reversal effect among high sensation seekers only. The finding that individual differences moderated gambling choices is more consistent with L. L. Lopes's (see record 1987-98851-006) security-potential/aspiration (SP/A) theory of decision making than with prospect theory. As in previous experimental studies, no significant effects were found for a moderate dose of alcohol. Using SP/A and risk homeostasis theory, the methodological and conceptual reasons for a consistent lack of an effect of alcohol on gambling choices across several studies are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dietary variety via sweetening and voluntary feed intake of lactating dairy cows

The effects of choice of diets on feed intake were studied using 12 lactating Holstein cows. A switchback design was used that had three periods and two sequential blocks. Diets were 1) a control total mixed ration (TMR), which consisted of alfalfa haylage, corn silage, and a concentrate mixture based on ground corn and soybean meal (25:25:50 on a dry matter basis) and 2) a sweetened TMR in which a brown sugar food product constituted 1.5% of the dietary dry matter. Treatments consisted of the control TMR fed on both sides of divided feed bunks, the sweetened TMR fed on both sides of divided feed bunks, or both TMR fed on alternating (daily) sides of divided feed bunks in tie stalls. Periods were 2 wk in duration, and cows averaged 67 and 53 d of lactation at the start of blocks 1 and 2, respectively. The dry matter intake, body weight, milk yield, and percentages of milk fat, protein, and solids not fat were similar when either TMR was fed alone. A choice of control TMR or sweetened TMR did not affect any of these variables. The dry matter intake, body weight, milk yield, and milk protein percentage were affected by block; however, these effects were probably caused by differences between the blocks in environment and stage of lactation. The results of this experiment might have been affected by the composition of the control TMR, its similarity to the sweetened TMR, availability of both diets simultaneously when a choice was offered, and use of a TMR instead of separate feeds or simpler mixtures.     

The antibacterial effects of tumescent liposuction fluid

Tumescent liposuction is currently one of the most commonly performed aesthetic procedures. Despite the variable use of preoperative antibiotics, infection is uncommon. Prior works suggest that the low incidence of infection may be due to lidocaine's antibacterial properties. However, these properties have only been demonstrated using concentrations of lidocaine above 0.8%, significantly higher than those used in tumescent liposuction. The purpose of this study was to determine if the commonly used tumescent fluid containing 0.1% lidocaine, 1:1000,000 epinephrine, and 0.012 mEq sodium bicarbonate possesses antibacterial activity. Using the broth microdilution method, the minimum inhibitory concentrations of Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus, and Group A beta-hemolytic Streptococcus were determined after exposure to either lidocaine, epinephrine, bicarbonate, or the combination of all three agents. To determine if there were significant growth differences not detectable by the broth microdilution method, bacterial concentrations were obtained through the use of a spectrophotometer, and significant differences from the controls were calculated by one-way analysis of variance. To determine if prolonged exposure to the tumescent mix would alter bacterial growth, a Killing Time study was also undertaken. The results indicated that the minimum inhibitory concentration of lidocaine was not less than 0.5% for any of the bacteria, whereas the lowest minimum inhibitory concentration of the combined solution was 0.25%. The lowest inhibitory concentration as determined by spectrophotometric analysis for the combined solution was 0.13% (p < 0.01). Analysis of the Killing Time data revealed no inhibition of bacterial growth over time. In conclusion, lidocaine, epinephrine, and bicarbonate do exhibit antibacterial properties at high concentrations. However, the commonly used tumescent mixture containing dilute concentrations of these agents does not significantly inhibit the growth of commonly encountered bacteria.     

Respiratory effects of a synthetic metalworking fluid and its components

A synthetic metalworking fluid, MWF "A", and its major components were evaluated using a previously developed mouse bioassay. This fluid and its components evoked sensory (S) and pulmonary (P) irritation in mice. For MWF "A" and each of its components, a concentration-response relationship was developed on the basis of respiratory frequency (fR) responses. From such relationships, the concentration capable of evoking a 50% decrease in mean fR was determined for MWF "A" and each component (RD50). RD50S or RD50P was used to distinguish decreases in fR that were due to sensory irritation (S) from those due to pulmonary irritation (P). From RD50P values, it was concluded that the fatty acid alkanolamide condensates, tolutriazole, and triazine-type biocide components were similar in potency to one another and similar in potency to MWF "A". By examining potency and fractional composition, it was concluded that the fatty acid alkanolamide condensates and the triazine-type biocide largely contributed to the irritancy of MWF "A". From RD50P values, occupational exposure limits were proposed for MWF "A" and each of its components. The current Threshold Limit Value of 10 mg/m3 established by the American Conference of Governmental Industrial Hygienists for "particulates not otherwise classified" (PNOC) would be inadequate to protect workers from the irritating properties of MWF "A" and most of its components.     

The effects of ventricular fluid osmolality on bulk flow of nascent fluid into the cerebral ventricles of cats

Transdiaphragmatic pressure (Pdi) and expiratory flow (V) were monitored during vital capacity single breath N2 washouts in 7 seated subjects. Transient increases in V were produced (1) actively, by subjects increasing mouth pressure while expiring through a constant resistance of (2) passively, by the operator transiently decreasing the resistance. Voluntary contraction of the diaphragm (increased Pdi) was achieved when abdominal muscles were tensed while maintaining V constant. In 5 subjects a transient increase in Pdi of 25-150 cm H2O consistently produced a transient increase in expired N2 concentration of 1.80 +/- 0.06% (Mean +/- 1 SE); in 1 subject N2 concentration decreased by 0.8% to 2.7% N2, and in one subject the alveolar plateau was uninfluenced by changes in Pdi. Passive increases in V up to 21/sec had no effect on FEN2 in any of the subjects. Active increase in V changed FEN2 only when associated with increases in Pdi. Qualitatively similar results were obtained during helium (He) bolus washouts. However, whereas diaphragmatic contraction, maintained throughout expiration, had no measurable influence on the N2 washout, it changed the slope of the He alveolar plateau in 6 out of 7 subjects. We conclude that in normal subjects the alveolar N2 plateau is relatively insensitive to flow variations up to 21/sec. The fluctuations in FEN2 observed when the expiratory flow is varied are due to concomittant changes in Pdi. We propose that diaphragmatic contraction changes the pattern of lung emptying by altering the vertical gradient of pleural pressure.     

The Clinton plan: what happened to the tough choices?

This paper points out four difficult choices embedded in the Clinton plan. First, universal coverage is achieved, but with regressive head-tax financing on many workers-since the cost of the employer mandate ultimately will fall on workers' wages. Perhaps such an approach can be made politically acceptable. Second, cost containment is entrusted to global spending limits, which will limit the rate of improvement in quality. Third, the offering of choice among a variety of health plans of different costs and quality, although desirable in itself, may lead to inequity. Finally, the plan's financing will make it difficult for voters to tell what trade-offs they are making, because employer mandates and budget cuts disguise choices.     

The behavioral sequela following the prevention of home-cage grid-climbing activity in C57BL/6 mice.

Several studies have demonstrated that the early postweaning phase (3-7 weeks of age) is a crucial ontogenic period for rodent neurobehavioral development. During this phase, both brain and behavior are highly sensitive to environmental variations (i.e., changes in the standard housing conditions). In the present study, male and female C57BL/6 mice were housed at weaning in cages provided with a Plexiglas lid, and thus, they were deprived of the opportunity to perform climbing activity on the cage grid--a major component of mouse behavior in standard laboratory environments. At early adulthood (7-10 weeks old), mice underwent an extensive battery of behavioral tests. The present study demonstrates for the first time the psychological, sex-specific relevance of home-cage grid-climbing activity in mice, showing that its prevention alters fear-conditioned responses in mice of both sexes and induces psychotic-like and anxious behaviors in females only. The data further highlight the importance of the early postweaning phase for the study of environmentally induced neurobehavioral plasticity and the design of animal models of psychiatric disorders on the basis of environmental manipulation in early postweaning life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Math and science motivation: A longitudinal examination of the links between choices and beliefs.

This study addresses the longitudinal associations between youths' out-of-school activities, expectancies-values, and high school course enrollment in the domains of math and science. Data were collected on 227 youth who reported on their activity participation in 5th grade, expectancies-values in 6th and 10th grade, and courses taken throughout high school. Math and science course grades at 5th and 10th grade were gathered through school record data. Results indicated youths' math and science activity participation predicted their expectancies and values, which, in turn, predicted the number of high school courses above the predictive power of grades. Although there were mean-level differences between boys and girls on some of these indicators, relations among indicators did not significantly differ by gender. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Types and choices of performance feedback.

Although research has clearly demonstrated that specific and timely feedback to individuals is beneficial to task performance, little attention has been paid to the content of the feedback on the most typical type of work tasks—tasks in which high performance along both quality and quantity dimensions is desired and in which quality and quantity are inversely related at high levels of performance. In a two-phased study, this research placed one group of 132 subjects on a task that required both quality and quantity performance. Performance feedback was then presented on either quality or quantity, or on both dimensions. In a second set of conditions the same types of feedback were made available to 90 subjects, but the subjects were now free to access or not to access the feedback. The results showed that the nature of the feedback affected performance on both dimensions and that allowing feedback choice improved overall performance. Results are discussed in terms of the benefits of feedback choices on multifaceted performance tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Debt and career choices of underrepresented minorities

We report a case of right aortic arch with mirror-image branching and coarctation of the aorta and left ductus arteriosus in a 6-year-old boy. He was referred to Chang Gung Children's Hospital with suspected left ventricular failure. Physical examination revealed hypertension and a pulse discrepancy between the upper and lower extremities. Echocardiography and magnetic resonance imaging revealed a right aortic arch, a long segmental aortic coarctation, and a patent ductus arteriosus. In addition, mirror-image branching of the brachiocephalic vessels was found. The coarctation was resected and the ductus arteriosus was ligated. The postoperative recovery was uneventful and the blood pressure returned to normal. He remained normotensive and had no symptoms of heart failure within the 2 years of follow-up.     

Relationship styles and therapeutic choices: A commentary on the preceding four articles.

Comments on the articles by J. C. Norcross, A. A. Lazarus, R. T. Dolan et al, and L. E. Beutler and A. J. Consoli (see PA, Vols 18399, 18382, 18405, and 18374, respectively) and argues that therapeutic techniques and therapeutic relationships are not and cannot be mutually exclusive: they are inherently interrelated and interdependent. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measuring the perception of choices in the nursing home

The purpose of this study was to measure the perception of choices among elders who live in a nursing home. The perception of choices, defined as a subjective appraisal of alternatives as understood by the individual, includes the freedom to make decisions, individuality of judgment, and availability of options. The instrument--Perception of Choices in a Nursing Home (PCL)--is a 10-item dichotomous scale designed for administration to frail elderly. A study with three phases involved 228 elderly in 19 different nursing homes. The results of principal component's factor analysis supported the presence of one dimension interpreted as having choices. The internal consistency reliability was a = .84, n = 99; and a = .74, n = 129. Low mental status did not affect internal consistency reliability but affected retest reliability, r = 67. The PCL correlated significantly with depression, r = .31, p = .0001, and powerlessness, .36, p = .005.