An Apparent Paradox: Attenuation of Phenylephrine-mediated Calcium Mobilization and Hyperreactivity to Phenylephrine in Contralateral Carotid After Balloon Injury

Balloon catheter injury promotes hyperreactivity to phenylephrine (Phe) in the contralateral carotid. Phe-induced contraction involves calcium mobilization, a process that may be sensitive to reactive oxygen species. In this study, we investigated whether increased reactivity to Phe in the contralateral carotid is due to alterations in calcium mobilization by Phe and reactive oxygen species signaling. Concentration-response curves to Phe were obtained in control and contralateral arteries 4 days after balloon injury. Tiron did not modify E(max) to Phe in control arteries but reduced this parameter in the contralateral carotid to control levels. Moreover, immunofluorescence to dihydroethydine showed increased basal oxidative stress in the contralateral artery compared with control artery. Intracellular calcium mobilization by Phe in the contralateral artery was not different from control, but Phe-induced extracellular calcium mobilization was reduced in the contralateral artery compared with that in the control. These data were confirmed by confocal microscopy using Fluo 3-AM. Tiron and SC-236 increased Phe-induced calcium influx in the contralateral artery, which was similar to controls in the same conditions. However, catalase did not modify this response. Taken together, our results suggest that superoxide anions and prostanoids from cyclooxygenase-2 alter pathways downstream of alpha(1)-adrenoceptor activation in the contralateral carotid in response to injury. This results in reduced Phe-induced calcium influx, despite hyperreactivity to Phe.

Satisfaction with housework: Examining the paradox

This paper examines men's and women's levels of satisfaction with the domestic division of labour. In most households women continue to undertake the bulk of childcare and housework duties and consequently spend significantly greater amounts of time on domestic labour than men. Men report high levels of satisfaction with these arrangements, but surprisingly we find that almost half of our sample of women also report satisfaction with these arrangements. This finding has been reported in studies from several countries. Our paper attempts to explain this apparent paradox. Using data from a recent national survey in Australia we explore gender differences in levels of satisfaction with the domestic division of labour and examine women's levels of satisfaction with household work arrangements in relation to a number of factors such as labour force attachment, attitudes to Sender roles and husbands' participation in domestic labour. Our findings raise implications for the meaning of equity within the household.

Does the Mediterranean paradox extend to abdominal aortic aneurysm?

Background We sought to test, in men Undergoing ultrasound screening for abdominal aortic aneurysms (AAA) in Western Australia, clinical impressions that the prevalence of AAA is high in Dutch migrants and low in migrants from Mediterranean countries. Methods In a. population-based trial, men undergoing screening for AAA completed a questionnaire covering their place of birth, smoking habits and consumption of alcohol, meat, fish, salt and milk. We examined the variation by place of birth in the mean, median, 95th and 99th centiles of infrarenal aortic diameter and the prevalences of AAA defined by criteria of 30 mm, 50 mm and by the 95th and 99th centiles, in men born in Australia, of aortic diameter adjusted for height. Findings Overall, 12 203 (70.5%) of the 19 583 men took up the invitation to undergo ultrasound screening. The prevalence of AAA defined by absolute diameter was higher than average in men born in The Netherlands or Scotland (more of whom had ever smoked or smoked currently) and lower in men of Mediterranean origin (more of whom drank alcohol currently). There were no consistent relationships with simple dietary: data. Correction of aortic diameter for height eliminated the significant heterogeneity in prevalence of large AAA, although a threefold variation in prevalence of AAA exceeding the 95th centile of height-adjusted diameter in Australian men persisted. Interpretation In our cohort of men, which is subject to both 'healthy migrant' and 'survivor' effects, if it exists at all, any 'Mediterranean paradox' for AAA is more modest than that for coronary disease.

Simpson's paradox: A logically benign, empirically treacherous hydra

This article examines Simpson's paradox as applied to the theory of probabilites and percentages. The author discusses possible flaws in the paradox and compares it to the Sure Thing Principle, statistical inference, causal inference and probabilistic analyses of causation.

The paradox of commercialising public sector intellectual property

The juxtapositioning of government providing a public good through research and development investment on one hand and engaging in commercialisation of the research outcome on the other is a paradox. Using agricultural research as an example, we examine the nature of the paradox to determine if commercialisation potentially leads to a conflict in the role of public research institutions set up to fulfil public good responsibilities. We identify the reasons for the shift in policy towards commercialisation and greater exploitation of public sector intellectual property and how this has contributed to the emergence of the apparent inconsistency. We argue that the belief in working for public good is inherent and embedded in an organisation's history and its wider operating environment. We propose that the creation of public sector intellectual property and its commercialisation are influenced by the political, social and economic environment in which the public institutions operate. [ABSTRACT FROM AUTHOR]

The paradox in ageing well: stories of older women in the Australian women's weeky

This Article does not have an abstract.

Yablo's paradox and referring to infinite objects

The blame for the semantic and set-theoretic paradoxes is often placed on self-reference and circularity. Some years ago, Yablo [1985; 1993] challenged this diagnosis, by producing a paradox that's liar-like but does not seem to involve circularity. But is Yablo's paradox really non-circular? In a recent paper, Beall [2001] has suggested that there are no means available to refer to Yablo's paradox without invoking descriptions, and since Priest [1997] has shown that any such description is circular, Beall concludes that Yablo's paradox itself is circular. In this paper, we argue that Beall's conclusion is unwarranted, given that (1) descriptions are not the only way to refer to Yablo's paradox, and (ii) we have no reason to believe that because the description involves self-reference, the denotation of the description is also circular. As a result, for all that's been said so far, we have no reason to believe that Yablo's paradox is circular.

Climate paradox of the G-8: legal obligations, policy declarations and implementation gap

This article analyzes the climate policy performance of the G-8 from 1992 to 2012 based on their legal commitments (Annex-1 and Annex-B countries) under the UNFCCC (1992) and the Kyoto Protocol (1997) and their policy declarations on their GHG reduction goals until 2050. A climate paradox has emerged due to a growing implementation gap in Canada, USA and Japan, while Russia, Germany, UK, France and Italy fulfilled their GHG reduction obligation.

Which factors could explain the low birth weight paradox?

OBJECTIVE: Low birth weight children are unusual among well-off families. However, in Brazil, low birth weight rate was higher in a more developed city than in a less developed one. The study objective was to find out the reasons to explain this paradox. METHODS: A study was carried out in two municipalities, Ribeirão Preto (Southeastern Brazil) and São Luís (Northeastern Brazil), which low birth weight rates were 10.7% and 7.6% respectively. Data from two birth cohorts were analyzed: 2,839 newborns in Ribeirão Preto in 1994 and 2,439 births in São Luís in 1997-1998. Multiple logistic regression analysis was performed, adjusted for confounders. RESULTS: Low birth weight risk factors in São Luís were primiparity, maternal smoking and maternal age less than 18 years. In Ribeirão Preto, the associated variables were family income between one and three minimum wages, maternal age less than 18 and equal to or more than 35 years, maternal smoking and cesarean section. In a combined model including both cohorts, Ribeirão Preto presented a 45% higher risk of low birth weight than São Luís. When adjusted for maternal smoking habit, the excess risk for low birth weight in Ribeirão Preto compared to São Luís was reduced by 49%, but the confidence interval was marginally significant. Differences in cesarean section rates between both cities contributed to partially explain the paradox. CONCLUSIONS: Maternal smoking was the most important risk factor for explaining the difference in low birth weight between both cities. The other factors contributed little to explain the difference in low birth weight rates.

The epidemiologic paradox of low birth weight in Brazil

OBJECTIVE: To examine whether the low birth weight (LBW) paradox exists in Brazil. METHODS: LBW and cesarean section rates between 1995 and 2007 were estimated based on data from SINASC (Brazilian Live Births Database). Infant mortality rates (IMRs) were obtained using an indirect method that correct for underreporting. Schooling information was obtained from census data. Trends in LBW rate were assessed using joinpoint regression models. The correlations between LBW rate and other indicators were graphically assessed by lowess regression and tested using Spearman's rank correlation. RESULTS: In Brazil, LBW rate trends were non-linear and non-significant: the rate dropped from 7.9% in 1995 to 7.7% in 2000, then increased to 8.2% in 2003 and remained nearly steady thereafter at 8.2% in 2007. However, trends varied among Brazilian regions: there were significant increases in the North from 1999 to 2003 (2.7% per year), and in the South (1.0% per year) and Central-West regions (0.6% per year) from 1995 to 2007. For the entire period studied, higher LBW and lower IMRs were seen in more developed compared to less developed regions. In Brazilian States, in 2005, the higher the IMR rate, the lower the LBW rate (p=0.009); the lower the low schooling rate, the lower the LBW rate (p=0.007); the higher the number of neonatal intensive care beds per 1,000 live births, the higher the LBW rate (p=0.036). CONCLUSIONS: The low birth weight paradox was seen in Brazil. LBW rate is increasing in some Brazilian regions. Regional differences in LBW rate seem to be more associated to availability of perinatal care services than underlying social conditions.