The Smell of Age: Perception and Discrimination of Body Odors of Different Ages

Our natural body odor goes through several stages of age-dependent changes in chemical composition as we grow older. Similar changes have been reported for several animal species and are thought to facilitate age discrimination of an individual based on body odors, alone. We sought to determine whether humans are able to discriminate between body odor of humans of different ages. Body odors were sampled from three distinct age groups: Young (20–30 years old), Middle-age (45–55), and Old-age (75–95) individuals. Perceptual ratings and age discrimination performance were assessed in 41 young participants. There were significant differences in ratings of both intensity and pleasantness, where body odors from the Old-age group were rated as less intense and less unpleasant than body odors originating from Young and Middle-age donors. Participants were able to discriminate between age categories, with body odor from Old-age donors mediating the effect also after removing variance explained by intensity differences. Similarly, participants were able to correctly assign age labels to body odors originating from Old-age donors but not to body odors originating from other age groups. This experiment suggests that, akin to other animals, humans are able to discriminate age based on body odor alone and that this effect is mediated mainly by body odors emitted by individuals of old age

The institutions of archaic post-modernity and their organizational and managerial consequences: The case of Portugal

The long march of modernization of the Western societies tends to be presented as following a regular sequence: societies and institutions were pre-modern, and then they were modernized, eventually becoming post-modern. Such teleology may provide an incomplete or distorted narrative of societal evolution in many parts of the world, even in the ‘post-modern heartland’ of Western Europe, with Portugal being a case in point. The concept of archaic post-modernity has been developed by a philosopher, José Gil, to show how Portuguese institutions and organizations combine elements of pre-modernity and post-modernity. The notion of an archaic post-modernity is advanced in order to provide an alternative account of the modernization process, which enriches discussion of the varieties of capitalism. Differences in historical experiences create singularities that may be considered in the analysis of culture, management and organization

Relatório de estágio em farmácia comunitária

Relatório de estágio realizado no âmbito do Mestrado Integrado em Ciências Farmacêuticas, apresentado à Faculdade de Farmácia da Universidade de Coimbr

Optimization of recombinant in protein production in an E.coli-based process with limited oxygen transfer

E. coli continues to be a popular host organism for production of recombinant proteins. To obtain a high volumetric productivity at the cultivation stage, it is important to achieve a high cell density and a high specific productivity per cell. In many fed-batch processes, the substrate feed rate eventually becomes limited by the oxygen transfer capacity of the bioreactor. While biomass can continue to increase, parameters like specific substrate uptake and specific growth rate will decrease with time. As the specific productivity of a particular protein may depend critically on the growth rate and the substrate supply, the time for induction of the recombinant production becomes a key parameter for process optimization.A probing technique enabled the development of a substrate feeding strategy that automatically avoids overflow metabolism as well as oxygen limitation due to reactor constraints. It is based on a standard dissolved oxygen sensor and does not require any strain-, product-, or media-specific knowledge. This gives a powerful tool for process development as it allows the user to experiment with different constructs and media compositions in a flexible way.The probing feeding strategy was employed when investigating the influence of induction time and media composition in a process for production of a recombinant xylanase in E. coli BL21(DE3) where oxygen transfer quickly became a limiting factor. It is shown how the specific productivity increases with increasing induction OD, that is, decreasing substrate uptake. For higher induction OD, the enzyme activity tend to decrease after 1.5-2 h, which could be correlated to a significantly higher protease activity for low specific glucose uptakes. As has been suggested previously, addition of complex media components (TSB) to the feed medium reduced the protease activity and improved the xylanase production further to approximately 10 g xylanase per liter broth. The results suggest that a "late" induction is preferred for the xylanase process (increased specific productivity and increased cell mass) and that a production phase of 2 h should be enough. If a complex medium can be used, the productivity can be improved further.In processes with limited oxygen transfer, the described approach, with the probing feeding startegy and changing the induction time, gives a simple but powerful approach for process optimization. A limited number of experiments give information that can improve the process productivity significantly, in the described example more than three-fold. The method will be further evaluated, and is currently applied to a process for production of a 50 kDa fusion protein.References1) Hellmuth, K. et al., "Effect of growth rate on stability and gene expression of recombinant plasmids during continuous and high cell density cultivation of Escherichia coli TG1", J. Biotechnol. 32:289-298,1994.2) Wong, H. et al., "Effect of post-induction feeding strategies on the production of bioadhesive protein in Escherichia coli", Biotechnol. Bioeng. 60:271-276, 1998.3) Åkesson, M. et al., "On-line detection of acetate formation in Escherichia coli cultures using dissolved oxygen responses to feed transients", Biotechnol. Bioeng. 64:590-598, 1999.4) Åkesson, M., "Probing control of glucose feeding in Escherichia coli cultures", Ph.D. thesis, ISRN LUTFD2/TFRT-1057-SE, Lund Institute of Technology, Lund, Sweden. 1999.5) Tsai, L. et al., "The effect of organic nitrogen and glucose on the production of recombinant human insulin-like growth-factor in high-cell-density Escherichia coli fermentations", J. Ind. Microbiol. 2:181-187, 1987

Levamisole : a common adulterant in cocaine street samples hindering electrochemical detection of cocaine

The present work investigates the electrochemical determination of cocaine in the presence of levamisole, one of the most common adulterants found in cocaine street samples. Levamisole misleads cocaine color tests, giving a blue color (positive test) even in the absence of cocaine. Moreover, the electrochemical detection of cocaine is also affected by the presence of levamisole, with a suppression of the oxidation signal of cocaine. When levamisole is present in the sample in ratios higher than 1:1, the cocaine signal is no longer detected, thus leading to false negative results. Mass spectrometry and nuclear magnetic resonance were used to investigate if the signal suppression is due to the formation of a complex between cocaine and levamisole in bulk solution. Strategies to eliminate this suppressing effect are further suggested in this manuscript. In a first approach, the increase of the pH of the sample solution from pH 7 to pH 12 allowed the voltammetric determination of cocaine in the presence of levamisole in a concentration range from 10 to 5000 mu M at nonmodified graphite disposable electrodes with a detection limit of 5 mu M. In a second approach, the graphite electrode was cathodically pretreated, resulting in the presence of oxidation peaks of both cocaine and levamisole, with a detection limit for cocaine of 3 mu M over the linear range of concentrations from 10 to 2500 mu M. Both these strategies have been successfully applied for the simultaneous detection of cocaine and levamisole in three street samples on unmodified graphite disposable electrodes

An ApiAP2 member regulates expression of clonally variant genes of the human malaria parasite Plasmodium falciparum

Abstract Variegated surface antigen expression is key to chronic infection and pathogenesis of the human malaria parasite Plasmodium falciparum. This protozoan parasite expresses distinct surface molecules that are encoded by clonally variant gene families such as var, rif and stevor. The molecular mechanisms governing activation of individual members remain ill-defined. To investigate the molecular events of the initial transcriptional activation process we focused on a member of the apicomplexan ApiAP2 transcription factor family predicted to bind to the 5′ upstream regions of the var gene family, AP2-exp (PF3D7_1466400). Viable AP2-exp mutant parasites rely on expressing no less than a short truncated protein including the N-terminal AP2 DNA-binding domain. RNA-seq analysis in mutant parasites revealed transcriptional changes in a subset of exported proteins encoded by clonally variant gene families. Upregulation of RIFINs and STEVORs was validated at the protein levels. In addition, morphological alterations were observed on the surface of the host cells infected by the mutants. This work points to a complex regulatory network of clonally variant gene families in which transcription of a subset of members is regulated by the same transcription factor. In addition, we highlight the importance of the non-DNA binding AP2 domain in functional gene regulation