W/O微乳液对强碱体系中钒的萃取

实验制备了水/N263/异戊醇/煤油组成的反相胶束和W/O微乳液。通过该微乳液对低浓度钒酸钠水溶液进行萃取,研究了碱浓度对钒萃取的影响。同时研究了在pH=13的强碱条件下,内水相组分、N263浓度、异戊醇浓度、温度、水乳比及萃取时间对钒萃取率的影响。研究表明,随着料液碱浓度的增高,微乳液对钒的萃取率逐步降低;当料液pH=13,内水相为0.6 mol/L NaOH+0.6 mol/L NaCl、N263浓度6%、异戊醇浓度12%、温度35℃、水乳比=3、搅拌时间3 min时,浓度为1 g/L的钒的料液经微乳液一级萃取后,可降至100 mg/L,萃取率达到90%。     

Effects of intracisternal 6-hydroxydopamine treatment on acquisition and performance of rats in a double T-maze.

136 male Sprague-Dawley rats in 4 experiments were subjected to various treatments with 6-hydroxydopamine (6-OHDA) to produce decrements in brain catecholamine content either before or after learning to respond in an appetitively motivated double –T maze task. Intracisternal injections of 6-OHDA not only impaired acquisition of the required behavioral response but also decreased performance of Ss which had previously acquired the task. Although reduced food consumption found in 6-OHDA-treated Ss may contribute to the observed deficits in –T maze responding, the behavioral deficit produced by 6-OHDA injection did not seem to be due only to a simple decrease in food intake. The decrements in acquisition and performance were clearly related to amount of central catecholamine depletion produced by 6-OHDA treatment. Further analysis suggested that the behavioral deficits were more related to the reductions in dopamine than they were to the depletion of brain norepinephrine. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hope: future imagined reality. The meaning of hope as described by a group of healthy Pentecostalists

BACKGROUND: The current study investigated the fundamental nature of the cognitive processing deficit that has been demonstrated to be associated with dieting to lose weight. Previous work has characterized this deficit as being primarily one of a reduction in working-memory capacity. The present study investigated the particular components of the working-memory system affected during dieting. METHOD: A sample of female subjects was classified as either low/medium restrained eaters (N = 34), highly restrained eaters (N = 18) or current dieters (N = 19), based on their responses to a modified version of the Dutch Eating Behaviour Questionnaire (DEBQ). Each subject completed tasks that assessed the Visuo-Spatial Sketchpad (mental rotation), Phonological Loop (effect of phonological similarity on recall) and the Central Executive (Tower of London Task) components of working memory. RESULTS: Those subjects who reported themselves to be currently dieting displayed poorer recall on the Phonological Loop task and slower planning times on the Tower of London Task. Performance on both these tasks correlated significantly with a self-report measure of body shape concern. CONCLUSIONS: These results support the hypothesis that the mediating variable in this deficit is that of preoccupying cognitions concerning food and body shape.     

Memory for emotional words following unilateral temporal lobectomy

We recently reported that patients who had received unilateral temporal lobectomy, including the amygdala and hippocampus, show impaired acquisition in a fear conditioning task (LaBar, LeDoux, Spencer, & Phelps, 1995), indicating a deficit in emotional memory. In the present paper, we examined performance of these patients on two verbal, emotional memory tasks in an effort to determine the extent of this deficit. In Experiment 1, subjects were asked to recall emotional and non-emotional words. In Experiment 2, subjects were asked to recall neutral words which were embedded in emotional and non-emotional sentence contexts. Both temporal lobectomy subjects and normal controls showed enhanced recall for emotional words (Experiment 1) and enhanced recall for neutral words embedded in emotional sentence contexts (Experiment 2). These results suggest that the deficit seen in emotional memory following unilateral temporal lobectomy is not a global deficit and may be limited to specific circumstances where emotion influences memory performance. Several hypotheses concerning the discrepancy between the present studies and the fear conditioning results (LaBar et al., 1995) are discussed.     

Effects of selective forebrain noradrenaline loss on behavioral inhibition in the rat.

In Exp I, virtually total depletion of cortical and hippocampal noradrenaline (NA) by stereotaxic injection of 6-hydroxydopamine into the fibers of the dorsal noradrenergic bundle produced no impairment in acquisition learning of a runway response for food reward by 10 male Wistar rats. Extinction of this response, once learned, was markedly slower in the treated group than in 10 controls, the treated animals perseverating in rapid running to the goal box even with no food present there. Similarly, in Exp II with the same Ss, no impairment was found on acquisition of a continuously reinforced leverpressing response for food. Extinction of this response, however, was again slower in the treated group. Exp III showed that the subsequent acquisition of a successive light-dark discrimination task was also slower in the same treated Ss, with these animals perseverating in responding to the negative stimulus. Although selective forebrain NA loss does not impair the acquisition of appetitive responses, the suppression of responses in the absence of reward is impeded. A parallel is drawn with those effects found classically after surgical lesion to the hippocampus. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The ubiquitous nature of the Hebb repetition effect: Error learning mistaken for the absence of sequence learning.

Sequence learning is essential in cognition and underpins activities such as language and skill acquisition. One classical demonstration of sequence learning is that of the Hebb repetition effect, whereby serial recall improves over repetitions on a repeated list relative to random lists. When addressing the question of which mechanism underlies the effect, the traditional approach is to prevent the action of processes thought to be responsible for sequence learning: If the typical Hebb repetition effect is reduced, these processes are key to the effect, researchers claim. By reanalyzing the data of F. B. R. Parmentier, M. T. Maybery, M. Huitson, and D. M. Jones (2008)—who reported no Hebb effect for sequences of auditory–spatial stimuli—we revealed that error learning can be mistaken for the absence of sequence learning. Indeed, incorrect responses are reproduced increasingly over repetitions. Our findings suggest that the Hebb repetition effect can be associated with response learning as well as stimulus processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Kamin effect in rats: Differential retention or differential acquisition of an active-avoidance response?

Used discriminated active avoidance in an automated maze to test various interpretations of the Kamin effect. Independent groups of Charles River male rats, CDF strain (N = 63), were 1st trained on a brightness discrimination task and then tested at 1 of 3 intervals to either the same (light) or reversed (dark) stimulus. Although the typical -shaped avoidance function was observed, choice performance in both reversed and nonreversed groups showed that ability to recall the safe stimulus did not vary as a function of time since training. This finding, plus the finding that motor activity followed the same -shaped profile as avoidance performance, strongly suggests that the Kamin effect is due to shock-induced inhibition, which is incompatible with the acquisition of an active-avoidance response. (18 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of d-amphetamine and cocaine on strained ratio behavior in a repeated-acquisition task

Pigeons acquired a different four-response chain each session by responding sequentially on three keys in the presence of four colors. When the fixed-ratio requirement for food presentation was five completions of the chain, d-amphetamine and cocaine disrupted the behavior. As the dose of each drug was increased, the overall response rate decreased, the overall accuracy was impaired (i,e., percent errors increased), and there was less within-session error reduction (acquisition). In contrast, when the fixed-ratio requirement was either 20 or 50 completions of the chain, certain doses of both drugs produced large increases in the overall response rate by eliminating the extended pausing (ratio strain) that was characteristic of the control sessions. These rate-increasing effects were accompanied by error-decreasing effects, both during acquisition and after the response chain had been acquired. Taken together, the results show that the effects of d-amphetamine and cocaine on behavior in a repeated-acquisition task can be modulated by manipulating the value of the fixed-ratio schedule maintaining the behavior.     

GluR-A-deficient mice display normal acquisition of a hippocampus-dependent spatial reference memory task but are impaired during spatial reversal.

Acquisition and reversal of a spatial discrimination were assessed in an appetitive, elevated plus-maze task in 4 groups of mice: knockout mice lacking the AMPA receptor subunit GluR-A (GluR1), wild-type controls, mice with cytotoxic hippocampal lesions, and controls that had undergone sham surgery. In agreement with previous studies using tasks such as the water maze, GluR-A-/- mice were unimpaired during acquisition of the spatial discrimination task, whereas performance in the hippocampal group remained at chance levels. In contrast to their performance during acquisition, the GluR-A-/- mice displayed a mild deficit during reversal of the spatial discrimination and were profoundly impaired during discrete trial, rewarded-alternation testing on the elevated T maze. The latter result suggests a short-term. flexible spatial working memory impairment in GluR-A-/- mice, which might also underlie their mild deficit during spatial reversal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparative analysis of matrix metalloproteinases by immunocytochemistry, immunohistochemistry and zymography in human primary brain tumours

Patients with chronic fatigue syndrome (CFS) report cognitive difficulties (impaired attention, memory and reasoning). Neuropsychological tests have failed to consistently find cognitive impairments to the degree reported by CFS patients. We tested patients with CFS and sedentary controls in protocols designed to measure sensory reactivity and acquisition of the classically conditioned eyeblink response. Patients with CFS exhibited normal sensitivity and responsivity to acoustic stimuli. However, CFS patients displayed impaired acquisition of the eyeblink response using a delayed-type conditioning paradigm. Sensitivity and responsivity to the airpuff stimulus were normal. In the absence of sensory/motor abnormalities, impaired acquisition of the classically conditioned eyeblink response indicates an associative deficit. These data suggest organic brain dysfunction within a defined neural substrate in CFS patients.     

Age dissociates recency and lag recency effects in free recall.

The temporal relations among word-list items exert a powerful influence on episodic memory retrieval. Two experiments were conducted with younger and older adults in which the age-related recall deficit was examined by using a decomposition method to the serial position curve, partitioning performance into (a) the probability of first recall, illustrating the recency effect, and (b) the conditional response probability, illustrating the lag recency effect (M. W. Howard & M. J. Kahana, 1999). Although the older adults initiated recall in the same manner in both immediate and delayed free recall, temporal proximity of study items (contiguity) exerted a much weaker influence on recall transitions in older adults. This finding suggests that an associative deficit may be an important contributor to older adults' well-known impairment in free recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rates of forgetting in organic amnesia following temporal lobe, diencephalic, or frontal lobe lesions.

Forgetting rates were examined in patients with diencephalic, temporal lobe, or frontal lesions. No significant differences were found in short-term forgetting of verbal and nonverbal material; in recognition memory for pictures, words, or designs over delays between 1 min and 20 or 30 min; or on a measure of explicit cued recall for words, calculated in terms of the process dissociation procedure. Significantly faster forgetting was found in the diencephalic and the temporal lobe groups in the free recall of pictures of objects, although there was no difference between these 2 groups. It is concluded that the major deficit in amnesic patients' memory processes is in the initial acquisition of information but that there is a subtler deficit in retention over specific delays, detectable only on measures of free recall. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The influence of hunger on the learning and recall of food related words.

To test the effect of drive state on learning in humans, Ss were presented with paired associates consisting of food and nonfood words, either before or after the evening meal. It was found that the premeal group learned faster, particularly when the paired associates was a food word, and the premeal group recalled food words, but failed to recall nonfood words. The effect of drive on learning was demonstrated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

alpha-amylase inhibitor increases plasma 3-hydroxybutyric acid in food-restricted rats

The effect on energy metabolism of delayed absorption of starch by inhibition of alpha-amylase was examined by considering levels of plasma glucose and 3-hydroxybutyric acid (3-OHBA) in rats. Addition of alpha-amylase inhibitor (alpha AI) to a high starch diet delayed the plasma glucose response after feeding: peak plasma glucose levels in the control group occurred 15 min after feeding, whereas in the alpha AI group this peak did not occur until 30 min after. The total plasma glucose response was not different between the two groups. Plasma 3-OHBA levels 1 day after food restriction increased approximately five-fold in both groups. After 3 days of food restriction, the alpha AI group maintained the same level of plasma 3-OHBA as after 1 day of food restriction, while the control group showed significantly decreased levels of 3-OHBA. After 3 days of food restriction, plasma insulin levels were significantly decreased in the alpha AI group compared with the corresponding levels of the control group and with levels before the restriction. There was no significant difference in body weight between the two groups. These findings suggest that delayed hyperglycemia due to delayed absorption of starch following alpha AI loading may attenuate insulin secretion, leading to altered metabolism of 3-OHBA during the delayed response to energy deficit.     

Learning and forgetting in schizophrenia.

Recent studies of patients with schizophrenia have consistently demonstrated marked deficits on measures of initial learning. However, contradictory results have been reported concerning retention and forgetting. The present study examined the level of initial and delayed recall of stories and visual figures in a group of 76 patients with schizophrenia and 51 normal controls. Schizophrenia patients demonstrated marked impairments in initial and delayed recall as well as significantly worse percentage retention scores. However, schizophrenia patients and healthy controls individually matched on level of initial recall had nearly identical delayed recall performance. The results suggest a primary deficit in the initial acquisition of information rather than an accelerated rate of forgetting in schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comprehension of televised stories in boys with attention deficit/hyperactivity disorder and nonreferred boys.

Two studies compared comprehension of televised stories by 7- to 12-year-old boys with attention deficit/hyperactivity disorder (ADHD) and nonreferred comparison boys. Boys watched one show with toys present and one with toys absent. Visual attention was continuously recorded, and recall was tested after each show. Across studies, visual attention was high with toys absent but decreased sharply with toys present for boys with ADHD. Groups showed similar levels of cued recall of discrete units of information regardless of differences in attention. When recall tasks and television story structure required knowledge of relations among events, the reduced attention of boys with ADHD interfered with recall. Although visual attention of comparison boys also decreased to some extent with toys present, there was no such decrement in recall. Implications of the difficulties children with ADHD have in integrated story comprehension are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Balance of activities of alcohol acetyltransferase and esterase in Saccharomyces cerevisiae is important for production of isoamyl acetate

Isoamyl acetate is synthesized from isoamyl alcohol and acetyl coenzyme A by alcohol acetyltransferase (AATFase) in Saccharomyces cerevisiae and is hydrolyzed by esterases at the same time. We hypothesized that the balance of both enzyme activities was important for optimum production of isoamyl acetate in sake brewing. To test this hypothesis, we constructed yeast strains with different numbers of copies of the AATFase gene (ATF1) and the isoamyl acetate-hydrolyzing esterase gene (IAH1) and used these strains in small-scale sake brewing. Fermentation profiles as well as components of the resulting sake were largely alike; however, the amount of isoamyl acetate in the sake increased with an increasing ratio of AATFase/Iah1p esterase activity. Therefore, we conclude that the balance of these two enzyme activities is important for isoamyl acetate accumulation in sake mash.     

Some effects of alcohol on eyewitness memory.

Male volunteers (N?=?120) in small groups of 5 to 10 watched a staged theft involving live actors. Some (n?=?47) were under the influence of alcohol (average blood alcohol level of .10) at the time. Some subjects (n?=?58) were interviewed immediately after the event, and all were interviewed 1 week later. The delayed interview included the presentation of a photospread that either did or did not contain the picture of the "thief." Alcohol suppressed the amount recalled during the immediate interview and both the amount and accuracy of recall after the 1-week delay. Alcohol had no influence on the ability of witnesses to recognize the thief's picture. When the thief's picture was not present in the photospread, however, alcohol increased the rate of false identifications. An immediate interview substantially improved the amount of information Ss were able to recall 1 week later. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Informative breath: Olfactory cues sought during social foraging among old world monkeys (Mandrillus sphinx, M. Leucophaeus, and Papio anubis).

Sociality provides a unique opportunity for animals to acquire information and learn from others. Especially during foraging, where trial-and-error food selection might be fatal, conspecifics could act as valuable sources of information. During a six-year study across captive, semifree ranging, and wild Old World monkeys, I investigated whether individuals garnered olfactory-based information from their group mates that could guide their feeding decisions. Each of three study species [mandrills (Mandrillus sphinx), drills (M. leucophaeus), and olive baboons (Papio anubis)] performed a prominent muzzle-muzzle behavior, potentially enabling individuals to smell others' mouths and determine via olfaction what foods their conspecifics had chosen. This muzzle-muzzle behavior (1) was preferentially directed by na?ve, younger individuals toward more experienced, older individuals, (2) occurred specifically while recipients were chewing and hence emitting the most potent chemical cues, (3) was typically followed by the actor consuming the very same food type the recipient had been eating, (4) was elicited most often in response to experiments involving novel foods, and (5) occurred less frequently as initially novel foods became more familiar. In contrast to this evidence for information acquisition, there was little support for previous proposals suggesting that muzzle-muzzle functions as a social display. Instead, the omnivorous diets and intensely social lifestyles of mandrills, drills, and baboons, may have each favored a convergent form of information acquisition: seeking out the breath of knowledgeable conspecifics to help decide what foods are safe to eat. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of paleocerebellar lesions on DRL performance in the albino rat.

18 male albino rats with paleocerebellar lesions and 8 controls were trained to barpress for food on continuous reinforcement (CRF) and differential reinforcement of low response rates (DRL) schedules. Ss with lesions showed normal acquisition of the CRF schedule, but they exhibited a marked deficit on the DRL task. This deficit was related to overresponding that appeared to result from an inability to inhibit the response, rather than from a dysfunction in timing ability or motor capacity. The DRL deficit, however, was overcome by the introduction of a salient stimulus object (wood block) into the operant situation. Although no explicit reinforcement contingencies were placed on interaction with the stimulus object, it appeared that the wood block facilitated the development of "collateral" behaviors that served to mediate the DRL interval. Results are consistent with the suggestion that the cerebellum may contribute to the sequential organization of complex behaviors. (51 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)