A selective de-heparinizer filter made of new cross-linked polymers of a poly-amido-amine structure

Riassunto Dae polimeri reticolati di nuova sintesi, contenenti gruppi amminici terziari, sono in grado di assorbire selettivamente eparina dal sangue. Essi non sono emolitici e non interferiscono con i fattori della coagulazione.

---

---

Acknowledgment. This work was supported by the Programma Speciale Technologie Biomediche of the Italian National Council of Researches.     

Paper electrophoresis separation of the soluble proteins of rat muscle sarcosomes

Riassunto Viene descritta la presenza, nel succo dei sarcosomi del muscolo di ratto, di 4 componenti proteici separabili mediante elettroforesi su carta. I 4 componenti sono rappresentati nella misura di rispettivamente 26.1, 18.4, 33.2 e 22.3 per 100 delle proteine totali.     

Voluntarism and Citizenship: A Response to Lena Dominelli

This article responds to Dominelli’s contribution by mapping three lines of discussion. The first relates to the issue of how to understand voluntary work with regard to the realization of citizenship. The authors argue that this understanding depends on the way citizenship is conceived. Whereas a rights-based conception of citizenship focuses on issues of equal access to voluntary work, a duty-oriented notion of citizenship tends to see voluntarism as embedded in an educational strategy, alongside professionalized social work. The authors plead for an alternative understanding of voluntary work and social work as joined partners in practices of ‘learning democracy’. The second line of discussion revolves around the relation between social and political dimensions of citizenship. With Dominelli, the authors point out how the obscuring of the political dimension risks to nurture societal discourses that put pressure on the welfare state. The third point relates to the difficulties in positioning voluntary work with regard to professional social work. One of these difficulties is the tendency to over-romanticize voluntary work as warm, informal, generous, while giving an exclusively technical reading of social work professionalization.     

In front of a mirror: visual displays may not be aggressive signals in nocturnal tree frogs

Some evidence indicates that in anuran amphibians, visual signalling can be important during social interactions such as territorial disputes among males, especially in diurnal species. The correct identification of a signal is not a trivial matter. A visual signal provides a visual cue during a social interaction, and to be effective it must elicit an immediate response in the receiver. We tested the hypothesis that visual displays in an agonistic context constitute aggressive signals, in three nocturnal species of Hylidae. We predicted that the production of visual displays would increase in the presence of a conspecific intruder male. Males of Hypsiboas raniceps, Dendropsophus nanus and Lysapsus limellum were submitted to two treatments: (1) Self Image, a reflection in a mirror, simulating the presence of an intruder; and (2) Control, a black rectangle covering the mirror. We observed three visual displays: vocal-sac display (inflate the vocal sac and maintain it inflated for some time), limb lifting (rapid up-and-down movements of one or more limbs), and toe/finger trembling (rapid up-and-down movements of one or more toes and/or fingers). This last display was observed only in H. raniceps males. Contrary to our hypothesis, the emission rates of all visual displays of the focal animals did not differ between treatments; and the behavioural response did not differ among species. Therefore, we suggest that these behaviours could not be used directly for communication in agonistic contexts, and may represent displacement activities (involuntary responses). Alternatively, an aggressive bimodal stimulus may be necessary to trigger a behavioural response by using visual signals during territory defence in these three species.     

Cuticular hydrocarbon profiles as a chemotaxonomic tool for three blowfly species (Diptera: Calliphoridae) of forensic interest

Cuticular hydrocarbons (CHs) contain complex mixtures of components that cover the surface of all insects to restrict water loss, and in many species function in chemical communication. The complex mixtures have been used as a chemotaxonomic tool since the 1970s. The majority of CH components can be identified by gas chromatography-mass spectrometry (GC-MS), allowing hydrocarbon profiles to be used as chemotaxonomic characters, which can differentiate insect species, including cryptic species. The present study used GC-MS for the identification of CHs of males and females of three species of calliphorids: Cochliomyia macellaria (Fabricius), Hemilucilia segmentaria (Fabricius) and Lucilia cuprina (Wiedmann), A comparison of the chromatographic profiles from the three species allows them to be readily separated. Hydrocarbons identified from the three species contain 23 to 37 carbons and include n-alkanes, methyl-branched alkanes and alkenes. The most abundant compound for both sexes of C. macellaria was n-heptacosane, while for H. segmentaria it was 2-methyltriacontane; for L. cuprina, however, the most abundant compound was hentriacontene for females and nonacosene for males. The results obtained in this study are important for the establishment of a database to be used in chemotaxonomy of sanitarily and forensically important insects.     

Sphingosine 1-phosphate increases glucose uptake through trans-activation of insulin receptor

Sphingosine 1-phosphate (S1P) is a bioactive lipid that acts through a family of G-protein-coupled receptors. Herein, we report evidence of a novel redox-based cross-talk between S1P and insulin signaling pathways. In skeletal muscle cells S1P, through engagement of its S1P₂ receptor, is found to produce a transient burst of reactive oxygen species through a calcium-dependent activation of the small GTPase Rac1. S1P-induced redox-signaling is sensed by protein tyrosine phosphatase-1B, the main negative regulator of insulin receptor phosphorylation, which undergoes oxidation and enzymatic inhibition. This redox-based inhibition of the phosphatase provokes a ligand-independent trans-phosphorylation of insulin receptor and a strong increase in glucose uptake. Our results propose a new role of S1P, recognizing the lipid as an insulin-mimetic cue and pointing at reactive oxygen species as critical regulators of the cross-talk between S1P and insulin pathways. Any possible implication of S1P-directed insulin signaling in diabetes and insulin resistance remains to be established.     

Genetic diversity of rhizobial populations recovered from three Lotus species cultivated in the infra-arid Tunisian soils

gments from each strain based on the UPGMA algorithm from the combined patterns showed that Lotus isolates are very diverse and that they were affiliated to Sinorhizobium,Rhizobium,and Mesorhizobium genera.