Parental behaviour is unrelated to experimentally manipulated great tit brood sex ratio

Parental investment may be biased with respect to parental sex or offspring sex or there may be an interaction between parental and offspring sex. We investigated whether any of these types of bias occurred in great tits, Parus major. By sexing chicks using random amplified polymorphic DNA (RAPD) markers and subsequently moving chicks between broods, we were able to manipulate broods early in the nestling period to give all-male, mixed-sex and all-female broods. Provisioning behaviour (total feeding rate, proportion of feeding visits by the male, prey size, visit duration and proportion of visits in which a faecal sac was removed) was measured for broods aged 8-9 and 11-12 days. Nest defence behaviour was measured for 15-day-old broods. Parental weight, the occurrence of second broods and overwinter survival of the parents were also analysed. There were some differences in parental care between the parents: males made the majority of feeding visits and were more vigorous in nest defence. However, there was no evidence that parental care varied in relation to brood sex ratio or that there was an interaction in parental care between parental sex and brood sex ratio. Copyright 1998 The Association for the Study of Animal Behaviour     

Stroke and incontinence

BACKGROUND: Urinary incontinence in the acute stage of stroke is seen as a predictor of death, severe disability, and an important factor on hospital discharge destination. Therefore, it is an important measure of stroke severity that not only affects the lives of stroke survivors but also those of caregivers. SUMMARY OF REVIEW: A number of studies have linked the presence of bladder dysfunction in stroke survivors to various neurological lesions in areas thought to be primarily involved in micturition. However, neurological deficits may affect management of bladder control secondarily by apraxia or aphasia, for example, and a significant number of strokes occur in individuals already experiencing incontinence. CONCLUSIONS: Despite incontinence being such an important prognostic feature, there are many gaps in our knowledge of the relationship of stroke and incontinence, particularly fecal incontinence. There are almost no studies on the influence of achieving continence on outcome or how this might be brought about. This article reviews the literature on this important topic and highlights deficiencies in our knowledge and areas of future research.     

No-react detoxification process: a superior anticalcification method for bioprostheses

BACKGROUND: Glutaraldehyde pretreatment of bioprosthetic heart valves is the major pathogenic factor in their calcific degeneration. This comparative study investigates the merit of the No-React aldehyde detoxification process as an alternative modifier of xenograft tissues. METHODS: Glutaraldehyde- and No-React-pretreated porcine aortic valve cusps were implanted subcutaneously in 6-week-old rats (n = 20). At 3, 6, and 14 weeks, randomly selected animals were sacrificed and the explants underwent mineral and morphologic analyses. Glutaraldehyde- and No-React-treated bovine pericardium and porcine aortic valve cusp were incubated in fibroblast cell culture plates. Cell viability was observed under reversed microscope at 6, 24, 48, and 96 hours. Erythrosin B dye exclusion test was used to validate percent cell death. RESULTS: Pretreatment with No-React significantly inhibited calcification of aortic cusp subcutaneous implants throughout the 14-week period (mean tissue Ca2+ content = 1.3 +/- 0.7 micrograms/mg at 14 weeks.) Glutaraldehyde-treated cusps underwent protracted calcification (Ca2+ content = 190.6 +/- 89.5 micrograms/mg; p < 0.01). Morphologic findings correlated with mineral analyses. One-hundred percent of fibroblast cells survived in the presence of No-React-treated tissue, with a growth pattern indistinguishable from control cell culture (ie, in the presence of no tissue). The cells incubated with glutaraldehyde-treated tissue showed signs of nonviability by 6 hours, with 100% cell death by 48 hours. Dye exclusion tests validated these findings. CONCLUSIONS: The No-React detoxification process completely abolishes the cytotoxicity of the xenograft tissue and inhibits calcific degeneration.     

Influence of triethylamine on the anodic dissolution characteristics of Ni,Cu and their alloys in non-aqueous solvents containing fluoride media: voltammetric and surface morphologic study

Multisweep cyclic voltammetric (CV) responses of nickel, copper, Monel and nickel–copper alloy had been extensively studied and compared in different non-aqueous solvents, such as acetonitrile (AN), propylene carbonate (PC) and sulpholane-containing anhydrous hydrogen fluoride (AHF) medium in the absence and the presence of triethylamine (Et₃N). The quantity of dissolution and surface morphological transformation on the electrodes as a result of anodic polarisation were investigated by means of atomic absorption spectroscopy and scanning electron microscopy (SEM), respectively. The CV study indicates that Ni, Cu and their alloys are highly unstable in AN/AHF medium. Surface morphology of Ni after polarisation in this medium reveals the generation of number of pits, whereas the evolution of small crystallites of CuF₂ is noted on the polarised alloy material, as evidenced by SEM pictures. The dissolution characteristics decrease significantly in PC/AHF medium and become low in sulpholane-containing fluoride medium on the four electrodes. The relative solubility of metal fluoride film in the three solvents increases in the order: sulpholane < PC < AN. The voltammograms suggest that addition of Et₃N (0.5 M) to AN- and PC-containing AHF medium helps both in maintaining uniform dissolution and generating compact fluoride film on the electrode surface. The addition of Et₃N to AHF/sulpholane medium shows only little influence in improving the electrocatalytic oxidation process.     

Targeting of tissue plasminogen activator into the regulated secretory pathway of neuroendocrine cells

Plasma levels of tissue plasminogen activator (tPA) increase rapidly in response to specific vasoactive agents, trauma, and neural stimulation. This response has been attributed to acute release of tPA from stored pools within the vascular endothelium and from catecholamine storage vesicles of chromaffin cells. We have tested directly whether tPA can be sorted into the regulated secretory pathway using the murine pituitary-derived neuroendocrine cell line AtT-20 transfected with tPA cDNA. Clones of AtT-20 cells expressing tPA were isolated, and targeting of tPA into the regulated secretory pathway was demonstrated by (1) stimulation of tPA secretion with 8-bromo-cAMP, the secretagogue which promotes the release of dense granule contents; (2) colocalization with ACTH, an endogenous protein that is stored in dense core granules; and (3) retention of newly synthesized tPA in the cell for prolonged periods of time. Laser scanning confocal microscopy analysis of cells immunostained with antibodies to tPA and ACTH showed colocalization at the tips of the neuritic processes under the cytoplasmic membrane, a region where dense granules are known to migrate after maturation. Treatment of the cells with 5 mM 8-bromo-cAMP for 30 min resulted in a 2.41+/-0.36-fold increase in tPA secretion. Both the magnitude of the stimulatory effect and the fraction of the intracellular tPA released were the same regardless of the tPA expression level in the various clones. Pulse-chase experiments showed that a portion of newly synthesized tPA is retained in the cell for at least 4 h and is released into the culture medium in response to 8-bromo-cAMP. These studies indicate that tPA, under the appropriate conditions, can be targeted into the regulated secretory pathway and can be stored for later release by cellular stimuli.     

Role of microwave heating strategies in enhancing the progress of a first‐order endothermic reaction

A detailed analysis has been carried out by solving coupled energy and mass balance equations along with Helmholtz equation of microwave propagation to investigate the role of microwave heating strategies in enhancing the progress of a first‐order endothermic reaction in “thin,” “intermediate,” and “thick” regimes of microwave heating. It has been shown that heating strategy plays a critical role in maximizing the efficiency of microwave heated reactors, where progress of reactor can be greatly accelerated at a given input power by either configuring microwave sources at both sides of the reactor or preferentially focusing them on one side. A series of master curves have been provided showing percentage saving of reaction time in various configurations of microwave heated reactors compared to their conventional counterparts, which can be efficiently used to select appropriate heating strategy for different dimension and dielectric properties of the reacting medium. © 2012 American Institute of Chemical Engineers AIChE J, 59: 656–670, 2013     

Effects of marital status on the risk of mortality in poor and non-poor neighborhoods

PURPOSE: The purpose of this paper is to consider whether the mortality risks associated with marital status are conditioned by the socioeconomic quality of neighborhoods. METHODS: The analysis is based on the first National Health and Nutrition Examination Survey 1971-1974 (NHANES I), and the 1987 NHANES I Epidemiologic Followup Survey (NHEFS). Cox proportional hazards regressions were used to assess whether the effect of marital status on the risk of all-cause and cause-specific mortality is altered by local area poverty. Analyses are stratified by age, sex, and urbanicity. RESULTS: The interaction between neighborhood poverty and marital status is suggested for non-elderly men, particularly for cancer mortality and for men in urban areas. Interaction effects are evident among older women residing in urban areas. CONCLUSIONS: The absence of a spouse elevates the risk of mortality but this risk is moderately higher in impoverished neighborhoods, notably in urbanized areas, for non-elderly men and elderly women. Future studies with larger samples of non-married persons where marital status changes are incorporated are needed to improve our understanding of the joint mortality effects of local area poverty and marital status.     

Doppler quantification of echo-contrast injections in vivo

It is difficult to quantify myocardial perfusion using contrast echocardiography because the echogenicity of injected contrast is unknown. We propose that a measurement of Doppler amplitude from blood in a systemic artery during the passage of contrast could define the needed input function. Time-amplitude curves from pulsed Doppler cuffs on coronary and carotid arteries of 7 dogs were analyzed during aortic root and left atrial injections of Albunex. We found in individual animals that the areas under the Doppler time-amplitude curves were correlated to the amount of Albunex injected (R = 0.87-0.99), inversely correlated to cardiac output (R = 0.83), and uncorrelated to coronary flow (R = 0.18). Due to better mixing, the coronary and carotid response areas correlated better for left atrial injections (R = 0.96) than for aortic root injections (R = 0.56). We conclude that Doppler amplitude detection can be used to quantify the passage of echo-contrast agents, that the measurements comply with indicator-dilution principles, and that systemic measurements in the carotid artery could be used to predict the coronary input function for injection sites with good systemic mixing.