Late childbearing continues to increase in developed countries

Broad societal and cultural changes since the 1970s have provided incentives for young people to postpone parenthood. The greater access to and longer pursuit of higher education, the greater involvement of women in the labour market, and changes in family behaviour have contributed to a long-term increase in age at parenthood. The spread of effective contraception and wider access to abortion have also played a part, helping women and couples better plan the timing of births. Using data from the Human Fertility Database, we document a rise in fertility rates among women aged 40 and older in low-fertility countries of Europe, East Asia, North America, and Australia

Distribution of Methadone and Metabolites in Skeletal Tissue

In forensic toxicology, when extended time has elapsed before discovery of the body, the most commonly analyzed specimens are often degraded or not available at all due to decomposition. In this case, skeletal tissue may be the only specimen left. Nevertheless, very limited research is found on the drug disposition in bone, making toxicological interpretation very difficult. Since methadone is linked to almost 50% of drug abuse fatalities in Belgium, an easy extraction and quantification method was developed and validated to investigate the distribution pattern of methadone and its metabolites in skeletal tissue after chronic dosing. In this study, Wistar rats were administered a subcutaneous daily methadone dose of 3 mg/kg for 139 days. After dissection, single whole bones or bone parts underwent a methanolic extraction. The final extract was analyzed using LC-ESI(+)-MS-MS for methadone, EDDP and EMDP. Methadone and its metabolites were proven to be detectable and quantifiable in skeletal tissue of chronically dosed rats using a fast and easy methanol extraction. Within bone, comparison showed that bone marrow yields the highest concentration. Trabecular bone also showed to be the best type of bone tissue for sampling. Between bone comparison, proved the humerus to be the best bone type for sampling. The concentrations found in tibiae and humeri appeared to be dose dependent for methadone with a variance of &lt;9%. However, for other bones the variance in methadone concentration ranged from 24 to 32%. A possible explanation is seen in the lower vascularization of these bones. For the metabolites, no correlation was seen. This could be explained by the highly inter-individual metabolism of methadone. However, skeletal tissue concentration showed no correlation to blood for methadone nor its metabolites. Using the developed method, quantitative information about methadone after chronic administration was only found in the humeri and tibiae.</p

Attracting and retaining science students

"La présente recherche a été subventionnée par le ministère de l'Éducation, du Loisir et du Sport dans le cadre du Programme d'aide à la recherche sur l'enseignement et l'apprentissage (PAREA)"Titre de l'écran-titre (visionné le 15 mars 2010)Également disponible en format papier.Bibliogr

Induction of procalcitonin in liver transplant patients treated with anti-thymocyte globulin

INTRODUCTION: The aim of this study was to compare the early postoperative kinetics of procalcitonin (PCT) and C-reactive protein (CRP) serum levels in patients undergoing orthotopic liver transplantation (OLTx) with different immunosuppressive regimens. METHODS: PCT and CRP serum concentrations were measured in a group of 28 OLTx recipients before induction of anesthesia, at 4 and 8 hours following graft reperfusion, and daily until postoperative day 4. The same parameters were determined in 12 patients undergoing liver resection without conjunctive immunosuppressive therapy. Summary data are expressed as medians and ranges. Two-tailed nonparametric tests were performed and considered significant at p values of less than 0.05. RESULTS: The highest serum levels of PCT (median 3.0 ng/mL, minimum 1.4 ng/mL, maximum 13.9 ng/mL) were found in patients after OLTx without ATG therapy, on postoperative day 1. In patients with ATG administration, PCT levels were highly increased on postoperative day 1 (median 53.0 ng/mL, minimum 7.9 ng/mL, maximum 249.1 ng/mL). Thereafter, PCT values continuously decreased independently of further ATG administration in both groups of patients. No evidence of infection was present in either group. In 12 patients undergoing liver resection, peak serum PCT levels did not exceed 3.6 ng/mL. CRP serum levels in a group of patients with and without ATG therapy increased significantly on postoperative day 1, followed by a decrease. The highest levels of CRP were found in patients after liver resection on postoperative day 2 and decreased thereafter. CONCLUSION: ATG administration to patients with OLTx is associated with an increase in serum PCT levels, with peak values on postoperative day 1, and this was in the absence of any evidence of infection. The results of this study indicate that ATG immunosuppressive therapy is a stimulus for the synthesis of PCT

Evaluating the greenhouse gas impact from biomass gasification systems in industrial clusters – methodology and examples

Biomass gasification is identified as one of the key technologies for producing biofuels for the transport sector and can also produce many other types of products. Biomass gasification systems are large-scale industrial systems and it is important to evaluate such systems from economic, environmental and synergetic perspectives before implementation. The objective of this study is to define a methodology for evaluating the greenhouse gas (GHG) impact of different biomass gasification systems and to exemplify the methodology. The ultimate purpose of the methodology is to evaluate the GHG performance of different biomass gasification systems integrated in industrial clusters. A life cycle perspective is applied. Most biomass gasification systems are multiproduct systems, simultaneously producing biofuels, heat at different temperatures and pressures and electricity. The value, in economic terms and in terms of GHG emissions, is well defined for some products (e.g. biofuels), whereas for other products (such as heat and electricity) it is more uncertain and in some cases dependent on time and location

Developmental trajectories of metacognitive processing and executive function from childhood to older age

The modern understanding of the term metacognition encompasses two levels of processing: a lower level awareness or knowledge of one’s own thoughts and a higher level regulation or control of our thinking. Metacognition, therefore, bears conceptual similarity with executive function: both are concerned with top-down monitoring and control of cognition in the service of ongoing goal-directed behaviour. Previous studies have shown a possible executive function advantage in multilingual speakers but also a possible disadvantage in metacognitive processing. To progress theory on metacognitive processing and the relationship with executive function and linguistic experience across the lifespan, we conducted a study testing 330 healthy individuals in four age groups from 7 to 80 years old. All participants performed a metacognition task and two measures of executive function, which included the Simon task and the Tower of London task. Half the participants were multilingual speakers since birth. We built developmental trajectories of metacognitive and executive function across the lifespan. The best metacognitive efficiency was observed in mid-adulthood, whereas the best executive function processing reached its peak in young adulthood. A steep cognitive decline was observed in older age, while metacognitive efficiency was preserved. Exploratory factor analysis indicated that metacognition and executive function are served by different factors across all ages. Contrary to previous findings in the bilingual literature, a multilinguistic experience conferred neither any significant advantage nor disadvantage in both executive function and metacognitive processing across the lifespan

A Role for Adenosine Deaminase in Drosophila Larval Development

Adenosine deaminase (ADA) is an enzyme present in all organisms that catalyzes the irreversible deamination of adenosine and deoxyadenosine to inosine and deoxyinosine. Both adenosine and deoxyadenosine are biologically active purines that can have a deep impact on cellular physiology; notably, ADA deficiency in humans causes severe combined immunodeficiency. We have established a Drosophila model to study the effects of altered adenosine levels in vivo by genetic elimination of adenosine deaminase-related growth factor-A (ADGF-A), which has ADA activity and is expressed in the gut and hematopoietic organ. Here we show that the hemocytes (blood cells) are the main regulator of adenosine in the Drosophila larva, as was speculated previously for mammals. The elevated level of adenosine in the hemolymph due to lack of ADGF-A leads to apparently inconsistent phenotypic effects: precocious metamorphic changes including differentiation of macrophage-like cells and fat body disintegration on one hand, and delay of development with block of pupariation on the other. The block of pupariation appears to involve signaling through the adenosine receptor (AdoR), but fat body disintegration, which is promoted by action of the hemocytes, seems to be independent of the AdoR. The existence of such an independent mechanism has also been suggested in mammals

A role for the cerebellum in the control of verbal interference: Comparison of bilingual and monolingual adults

We evaluate brain structure sensitivity to verbal interference in a sentence interpretation task, building on previously reported evidence that those with better control of verbal interference show higher grey matter density in the posterior paravermis of the right cerebellum. We compare brain structure sensitivity to verbal interference control across two groups, English monolingual (N = 41) and multilingual (N = 46) adults. Using voxel-based morphometry, our primary goal was to identify and explore differences in regional patterns of grey matter sensitivity to performance on the sentence interpretation task, controlling for group variability in age, nonverbal reasoning and vocabulary knowledge. There was no group difference in performance but there was a significant group effect in grey matter sensitivity to task performance in our region of interest: stronger sensitivity in the paravermis in bilinguals compared to monolinguals in accuracy performance in the high (relative to low) verbal interference condition. This effect was observed when the linguistic interference was presented in an unfamiliar language (Greek) but not when presented in the familiar language (English). Our findings suggest that multilanguage acquisition mediates regional involvement within the language network, conferring enhanced functional plasticity within structures (including the paravermis) in the service of control of linguistic interference