Slopping resulting from gas injection in a peircesmith converter: The period of the standing wave

The periods of the transverse standing waves occurring in the Peirce-Smith converter geometry as a function of bath depth were solved using linear wave theory by formulating an integral equation of the second kind. The eigenvalues of the integral equation gave the wave periods which were calculated to four-figure accuracy. The eigenvalues were approximated using Chebyshev polynomials for the first four wave modes. They include the complete range of eigenvalues for the first two symmetric standing waves, which has not been reported in the literature. The asymptotic eigenvalues for the transverse standing waves are given. Experimental results from a water model agreed with the theoretical predictions over a wide range of bath depths. The first symmetric standing wave was enhanced by the presence of the longitudinal standing wave, which showed that the three-dimensional geometry of the model was important in the modeling of the Peirce-Smith converter. Data from a Peirce-Smith copper converter were in reasonable agreement with the theory. An analysis of the standing wave frequency showed that the presence of standing waves could be minimized by a change in the geometry.     

In disperse solution, "osmotic stress" is a restricted case of preferential interactions

In the practice of "osmotic stress," the effect of excluded cosolvents on a biochemical equilibrium is interpreted as the number of water molecules participating in the reaction. This action is attributed to lowering of solvent water activity by the cosolvent. This concept of osmotic stress in disperse solution is erroneous: (i) A cosolvent cannot be both excluded and inert, i.e., noninteracting, because exclusion requires a positive free energy change; (ii) a decrease in water activity alone by addition of solute cannot affect an equilibrium when the reacting surface is in contact with the solvent; and (iii) osmotic stress in disperse solution is a restricted case of preferential interactions; the reaction is driven by the free energy of cosolvent exclusion, and the derived number of water molecules is solely a measure of the mutual perturbations of the chemical potentials of the cosolvent and the protein.     

Deficits in discrimination and maze learning resulting from maternal histidinemia in rats.

Plasma histidine levels in female albino rats during pregnancy were elevated in 2 different ways: (a) Histidine deaminase was inactivated by periodic injection of nitromethane. (b) Rats were maintained on a high-histidine diet. Postnatal maze performance indicated that high-histidine levels impaired later learning ability. The deficit appeared to be cumulative; however, a ceiling was reached beyond which further increases in histidine levels did not result in additional learning impairment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Monotonous and wave-form changes in the myelogram of rats over a 24-hour period

Circadian changes of the mean value of each component of rat myelogram and of the proliferative pool of bone marrow cells were obtained. These changes were imposed on a monotonous decrease in the case of subpopulations of granulocytes or on a monotonous increase in the case of subpopulations of the erythroid cells and lymphocytes (from 12.00 to 09.00 next day). This process was not influenced by the elimination of the lymphocytes from the individual myelograms. These myelogram changes appeared to be due to the circadian mature cell production rhythm and flows of the lymphocytes and of mature granulocytes between the bone marrow and the peripheral blood. These changes also suggest the antiphase monotonous correction of the erythrocytic and granulocytic precursors production during several days.     

Hormone-stimulated lipolysis in isolated fat cells from "young" and "old" rats

The biphasic nature of the lipolytic dose-response curve of epinephrine in fat cells from "young" rats (40-45 days) was confirmed. The first phase (Lipolysis I) occurred at concentrations of from 10(-7) m to 3 x 10(-6) m. The second phase (Lipolysis II) occurred at concentrations of from 10(-5) m to 3 x 10(-4) m. Insulin (0.1 mU/ml) abolished Lipolysis I and slightly augmented Lipolysis II. Higher concentrations of insulin (1.0 mU/ml) augmented Lipolysis II even further. These results may help to explain some of the conflicting reports in the literature concerning the effects of insulin on lipolysis. The dose-response curve of epinephrine using fat cells from "old" rats (14-16 months) was monophasic. Based on results with propranolol, K(+)-free media, and insulin, it was concluded that the lipolytic response in tissue from older animals corresponds to Lipolysis II in tissue from younger rats. The lipolytic response to ACTH was greatly reduced in the cells from the older rats, but the response to theophylline was unaltered.     

Effect of devocalization of the male on mating behavior in rats.

Three experiments investigated the effects of devocalization of male rats on the copulatory behavior of 33 male and 9 female Long-Evans rats. No differences in any measure of masculine copulatory performance were found between vocalizing and muted males; however, estrous females mated with vocalizing males exhibited more frequent darting behavior than females mated with muted males. Females paired with vocalizing males in a tether apparatus exhibited more patterns of proceptive behavior per unit of time than did females paired with devocalized males, although the temporal distribution of this behavior, with respect to mounts by males, was unchanged. Conversely, patterns of receptive behavior were unaffected by devocalization of the male. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reduced serotonergic immunoreactive fibers in the forebrain of alcohol-preferring rats

Our previous study indicated that 5-hydroxytryptamine (5-HT) immunoreactive fiber densities were decreased in specific areas of the brain in alcohol-preferring rats (P) when compared with alcohol-nonpreferring rats (NP). The results of our current study show that there are quantitative and qualitative differences in 5-HT innervation in other selected regions of the forebrains of P rats. The 5-HT fiber density in the brains of young adult P and NP rats was measured by immunocytochemistry and quantitative image analysis. A routine error of two-dimensional quantitation of nerve fiber was addressed and an adjustment was made. The amount of 5-HT fibers was significantly lower in CA4 and fasciola cinereum of the dorsal hippocampus, caudate-putamen, and hypothalamus of the P as compared with NP rats (unpaired Student's t tests). In examining the fiber types, we found that, in the frontal cortical and hippocampal regions, where normally fine 5-HT fibers with small varicosities and thick 5-HT fibers with large varicosities coexist, fewer fine 5-HT fibers were seen in P rats as compared with NP rats. The fine fibers are known to be vulnerable to abusive drugs. These observations indicate that (a) there are quantitative differences in 5-HT innervation or that the 5-HT in some 5-HT fibers is reduced to a level undetectable by immunocytochemistry, and (b) the fine 5-HT fibers are specifically reduced to a greater degree in the selected brain regions of P rats when compared with that of NP rats. The involvement of the 5-HT system in the alcohol abuse is discussed.     

Reduced growth hormone responses to amphetamine in "endogenous" depressive patients: studies in normal, "reactive" and "endogenous" depressive, schizophrenic, and chronic alcoholic subjects

Several pharmacological stimulation tests of the pituitary-hypothalamic system have been used to investigate psychiatric disorders. This study introduces amphetamine sulfate as a stimulus for human growth hormone (HGH) release in various psychiatric patients. Peak HGH release after a single intravenous administration of amphetamine sulfate, 0.1 mg/kg, was significantly lower in nine "endogenous" depressives (P = .01) and significantly higher in seven "reactive" depressives (P less than .05) as compared to normal subjects, whereas peak HGH release in eight schizophrenics and six chronic alcoholics did not differ significantly from that in normal subjects.     

Reduced effects of L-carnitine on glucose and fatty acid metabolism in myocytes isolated from diabetic rats

Depressed glucose utilization and over-reliance of muscle tissues on fat represents a major metabolic disturbance in diabetes. This study was designed to investigate the relationship between fatty acid oxidation and glucose utilization in diabetic hearts and to examine the role of L-Carnitine on the utilization of these substrates in diabetes. 14CO2 release from [1-14C]pyruvate (an index of PDH activity), [2-14C]pyruvate and [6-14C]glucose (an index of acetyl-CoA flux through the Krebs cycle), [U-14C]glucose (an index of both PDH and acetyl-CoA flux through the Krebs cycle), and [1-14C]palmitate oxidation were studied in cardiac myocystes isolated from normal and streptozotocin-injected rats. Palmitate oxidation was increased twofold in diabetic myocytes compared to normal cells (5.4 +/- 1.45 vs 2.35 +/- 0.055 nmol/mg protein/30 min, p > 0.05). L-Carnitine (5 mM) significantly increased palmitate oxidation (60-70%) in normal cells but had no effect on diabetic cells. The activity of PDH and acetyl-CoA flux through the Krebs cycle was severely depressed in diabetes (58.14 +/- 20.27 and 8.63 +/- 0.62 in diabetes vs 128.75 +/- 11.47 and 24.84 +/- 7.81 nmol/mg protein/30 min in controls, p > 0.05, respectively). The efflux of acetylcarnitine, a by-product of PDH activity was also much lower in diabetic cells than in normal cells but had no effect in diabetes. L-Carnitine also had no effect on 14CO2 release from [U-14C]glucose but significantly decreased that from [6-14C]glucose, which reflects oxidative metabolism suggesting that L-Carnitine decreases oxidative glucose utilization. Thus, these data suggest that the overreliance on fat in diabetes may be in part secondary to a reduction of carbohydrate-generated acetyl-CoA through the Krebs cycle.     

Effect of restricted daylength during the growing period on semen quality and fertility of turkey toms

Two trials were conducted in which three daylength and light intensity treatments were applied to 144 growing turkey toms from 8 to 28 weeks of age. Treatments were (1) six hours of artificial light, (2) natural light and daylength, and (3) simulated natural daylength. At 28 weeks of age all toms were placed on 14 hours of daily light. Individual tom semen quality was evaluated every two weeks for six months, and on alternate weeks, eight hens were inseminated with semen pooled by treatment replicate to obtain fertility (May to December). Seasonal decline in semen production, sperm concentration, semen volume, and fertility was observed for toms on natural daylength after three months of production. Toms on six hours of light and those on simulated natural light maintained high levels of production and quality for the entire six month period. Semen production expressed as the average number of toms producing semen, sperm concentration, and fertily were significantly lower (P less than .01), and semen volume was significantly lower (P less than .05) for toms on natural light after six months. It was concluded that natural light was less desirable than controlled light for "off season" growing of toms.     

Reduced hexose transport by enterocytes associated with rapid, noninjurious rejection of Trichinella spiralis from immune rats

Rats immunized against Trichinella spiralis rejected larvae from a challenge infection within minutes. Infectivity of these once-rejected larvae for nonimmune rats following intestine-to-intestine transfer, infectivity for nonimmune mice following oral inoculation, and normal development in these mice indicated that the parasite did not sustain immediate or long term damage as a result of the host's immune response. Associated with rapid worm rejection was a change in host intestinal function - altered absorption. Uptake of a hexose, 14C-beta-methyl-D-glucoside, was studied in intestinal segments isolated from rats before and 30 min after primary and secondary infections. Larvae were administered intraintestinally. Absorption was measured using a tissue accumulation method, under conditions of substrate saturation (30 mMolar) and over a 5-min period. 3H-mannitol was used as a marker to measure extracellular water, hence, extracellular sugar. Following challenge infection of previously infected (immunized) hosts, there was a significant reduction (22%; P less than 0.05) in hexose absorption as compared to the uptake rate before challenge. In contrast, cellular uptake before and 30 min after primary infection was similar. These findings are presented in support of the hypothesis that the failure of T. spiralis larvae to infect immune hosts is the result, not of direct worm damage, but of functional changes in gut epithelium, the habitat of the parasite.     

Centromeric instability of chromosome 1 resulting in multibranched chromosomes, telomeric fusions, and "jumping translocations" of 1q in a human immunodeficiency virus-related non-Hodgkin's lymphoma

BACKGROUND: Acquired immunodeficiency syndrome-related non-Hodgkin's lymphomas are associated with the B-cell chromosomal translocation t(8;14)(q24; q32). The most common secondary chromosome aberrations in these patients involve 1q and are believed to be associated with tumor progression. A mechanism for the origin of these 1q aberrations has not been demonstrated. To their knowledge, the authors report the first human immunodeficiency virus (HIV)-positive patient to have centromeric decondensation and multibranched chromosome aberrations of chromosomes 1 and 16 resulting in telomeric associations and "jumping translocations" of 1q. METHODS: Tumor cells from peritoneal fluid of an HIV-positive patient were cultured for 24, 48, and 72 hours and analyzed by both conventional G-banding and fluorescence in situ hybridization. RESULTS: G-band analysis showed a stemline with t(8;14)(q24;q32), but also showed the progression from centromeric decondensation to multibranched chromosome configurations of chromosomes 1 and 16. The interchange and duplications of chromosome arms resulted in the gain of extra copies of 1q material on a number of different chromosomes, but also the loss of 16q in at least one sideline and the formation of micronuclei. Fluorescence in situ hybridization analysis demonstrated that micronuclei predominantly involved chromosome 1 and, to a lesser extent, chromosome 16. CONCLUSIONS: The cytogenetic findings in this unique case suggest that immunodeficiency may be a factor involved in centromeric instability, multibranching, and the progression to the subsequent formation of telomeric fusions and multiple unbalanced translocations of 1q (jumping translocations). The striking similarity of the centromeric instability in this patient to those with ICF syndrome (variable immunodeficiency, centromeric heterochromatin instability, and facial anomalies) suggests hypomethylation as the etiologic mechanism for the chromosome instability.     

Dissociation of behavioral changes in rats resulting from lesions of the habenula versus fasciculus retroflexus and their possible anatomical substrates

Lesions in either the habenula or its primary efferent pathway, the fasciculus retroflexus (FR), impaired avoidance responding. However, lesions of only the FR provided a persistent elevation of locomotor activity. Immunocytochemical study of the interpeduncular nucleus (IPN) through injection of retrograde tracers into the IPN and the overlying ventral tegmental area indicated that habenular lesions spared both rostral habenula and forebrain projections to the caudal midbrain, but these projections were axotomized by FR lesions. Rostral sparing of the habenula resulted in normal peptidergic staining in the IPN, and normal cholinergic innervation was absent. Performance of individual rats in behavioral tests was consistent with variations in anatomical sparing. Such considerations may account for previous discrepancies in functional effects of habenular lesions.     

Geographic variation in the calls of wild chimpanzees: a reassessment

Male chimpanzees produce a species-typical call, the pant hoot, to communicate to conspecifics over long-distances. Calls given by males from the well-known Gombe and Mahale populations typically consist of four different phases: an introduction, build-up, climax, and let-down. Recent observations suggest that chimpanzees living in the Kibale National Park, Uganda, consistently give calls that lack a build-up and are thus qualitatively distinguishable acoustically from those made by other East African conspecifics. We analyzed additional recordings from Mahale and Kibale to re-examine geographic variation in chimpanzee calls. Results indicate that males from both sites produce pant hoots containing all four parts of the call. Calls made by chimpanzees from the two populations, however, differ in quantitative acoustic measures. Specifically, males at Kibale initiate their calls with significantly longer elements and build-up over briefer periods at slower rates than individuals from Mahale. Kibale males also deliver acoustically less variable calls than chimpanzees at Mahale. Although climax elements do not differ between populations in any single acoustic feature, discriminant function analysis reveals that acoustic variables can be used in combination to assign calls to the correct population at rates higher than that expected by chance. Ecological factors related to differences in habitat acoustics, the sound environment of the local biota, and body size are likely to account for these observed macrogeographic variations in chimpanzee calls.     

Effects of 17 beta estradiol on the metabolism of labelled arachidonic acid in uteri isolated from intact and ovariectomized rats. Influence of a restricted diet

Of the 69 patients with clinical stage C prostate cancer under 75 years old and with good performance status between 1986 and 1995, 29 underwent radical prostatectomy combined with endocrine therapy, 21 underwent radiation therapy combined with endocrine therapy and remaining 19 patients were treated by endocrine therapy alone. The median followup was 44 months (range 4 to 122). Radical prostatectomy resulted in progression-free rates of 79% and 61% at 5 and 10 years, respectively. Progression-free rates were lower in patients with lymph node metastasis or positive surgical margins. In patients with clinical stage T3a-c and well or moderately differentiated tumor, radical prostatectomy resulted in a progression-free rate of 100% at 5 years. However, in patients with clinical stage T4a or poorly differentiated tumor, radiation therapy resulted in a better progression-free rate than radical prostatectomy. These findings suggest that patients with clinical stage T3a-c and well or moderately differentiated tumor will benefit from radical prostatectomy combined with endocrine therapy and that radiation therapy well be effective for advanced diseases.     

"Looking back, what period of your life brought you the most satisfaction"

Common myths hold that old persons are fixated on childhood memories, that they believe that youth is the best part of life, and that old age contains few satisfactions. Berkeley Older Generation Study members, when asked on two occasions during old age (M ages = 69.8 and 82.7) to name the periods of their lives that brought them the most and the least satisfaction, dispelled these myths. The thirties and forties were popular choices for periods of great satisfaction, but childhood and adolescence were quite unpopular for these old persons. "Right now" was named more often than any other life period as most satisfactory. Men and women did not differ in life periods nominated, but they did differ in the reasons given for their choices. Each period provided its own pattern of satisfactions and disappointments, and strong individual differences were apparent.