21 research outputs found

    Effects of riparian plant diversity loss on aquatic microbial decomposers become more pronounced at longer times

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    We examined the potential long-term impacts of riparian plant diversity loss on diversity and activity of aquatic microbial decomposers. Microbial assemblages were obtained in a mixed-forest stream by immersion of mesh bags contain-ing three leaf species (alder, oak and eucalyptus), commonly found in riparian corridors of Iberian streams. Simulation of species loss was done in microcosms by including a set of all leaf species, retrieved from the stream, and non-colonized leaves of three, two or one leaf species. Leaves were renewed every month throughout six months, and microbial inoculum was ensured by a set of colonized leaves from the previous month. Microbial diversity, leaf mass loss and fungal biomass were assessed at the second and sixth months after plant species loss. Molecular diversity of fungi and bacteria, as the total number of operational taxonomic units per leaf diversity treatment, decreased with leaf diversity loss. Fungal biomass tended to decrease linearly with leaf species loss on oak and eucalyptus, suggesting more pronounced effects of leaf diver-sity on lower quality leaves. Decomposition of alder and eucalyptus leaves was affected by leaf species identity, mainly after longer times following diversity loss. Leaf decomposi-tion of alder decreased when mixed with eucalyptus, while decomposition of eucalyptus decreased in mixtures with oak. Results suggest that the effects of leaf diversity on microbial decomposers depended on leaf species number and also on which species were lost from the system, especially after longer times. This may have implications for the management of riparian forests to maintain stream ecosystem functioning.FEDER-POFC-COMPETE and the Portuguese Foundation for Science and Technology supported this study (PEst-C/ BIA/UI4050/2011, PTDC/AAC-AMB/113746/2009 and PTDC/AAC-AMB/117068/2010), S. Duarte (SFRH/BPD/47574/2008) and I. Fernandes (SFRH/BD/42215/2007)

    Defining Polyamory: A Thematic Analysis of Lay People’s Definitions

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    This study aimed to analyze laypeople’s definitions of polyamory and compare definitions presented by people who are not willing to engage in consensual non-monogamy (CNM) and those who are or are willing to be in a CNM relationship. This exploratory qualitative study used data collected from a convenience sample through a web survey, where people answered the question “What does polyamory mean?” We conducted thematic analysis to examine patterns in meaning and used demographic data to compare themes among groups. The final sample comprised 463 participants aged 18–66 years (M = 32.19, SD = 10.02), mostly heterosexual (60%). Of the total sample, 54% were in a monogamous relationship, followed by 21% not in a relationship, and 13% in a non-monogamous relationship. Analysis showed that people define polyamory mostly as a set of behaviors in a relationship, followed by the potential of multiple relationships or feelings for multiple people. Definitions also include emotional, sexual, and ethical aspects. People in CNM relationships are more likely to define polyamory as constituting a potential form of relating, focus more on interpersonal feelings and ethics, and include consent in their definitions than those unwilling to engage in CNM. People in CNM relationships also focus particularly on the non-central role of sex within these relationships, which might challenge assumptions about sexuality in these relationships in clinical and research settings

    Transglutaminases : recent achievements and new sources

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    Transglutaminases are a family of enzymes (EC 2.3.2.13), widely distributed in various organs, tissues, and body fluids, that catalyze the formation of a covalent bond between a free amine group and the Îł-carboxamide group of protein or peptide-bound glutamine. Besides forming these bonds, that exhibit high resistance to proteolytic degradation, transglutaminases also form extensively cross-linked, generally insoluble, protein biopolymers that are indispensable for the organism to create barriers and stable structures. The extremely high cost of transglutaminase of animal origin has hampered its wider application and has initiated efforts to find an enzyme of microbial origin. Since the early 1990s, many microbial transglutaminase-producing strains have been found, and production processes have been optimized. This has resulted in a rapidly increasing number of applications of transglutaminase in the food sector. However, applications of microbial transglutaminase in other sectors have also been explored, but in a much lesser extent. Our group has identified a transglutaminase in the oomycete Phytophthora cinnamomi, which is able to induct defense responses and disease-like symptoms. In this mini-review, we report the achievements in this area in order to illustrate the importance and the versatility of transglutaminases

    Accomplishing the genotype-specific serodiagnosis of single and dual <i>Trypanosoma cruzi</i> infections by flow cytometry Chagas-Flow ATE-IgG2a

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    <div><p>The methods currently available for genotype-specific diagnosis of <i>T</i>. <i>cruzi</i> infection still present relevant limitations, especially to identify mixed infection. In the present investigation, we have evaluated the performance of Chagas-Flow ATE-IgG2a test for early and late differential diagnosis of single and dual genotype-specific <i>T</i>. <i>cruzi</i> infections. Serum samples from Swiss mice at early and late stages of <i>T</i>. <i>cruzi</i> infection were assayed in parallel batches for genotype-specific diagnosis of single (TcI, TcVI or TcII) and dual (TcI+TcVI, TcVI+TcII or TcII+TcI) infections. The intrinsic reactivity to TcI, TcVI and TcII target antigens, including amastigote (AI/AVI/AII), trypomastigote-(TI/TVI/TII) and epimastigote (EI/EVI/EII), at specific reverse of serum dilutions (500 to 64,000), was employed to provide reliable decision-trees for “early” <i>vs</i> “late”, “single <i>vs</i> “dual” and “genotype-specific” serology. The results demonstrated that selective set of attributes “EII 500/EI 2,000/AII 500” were able to provide high-quality accuracy (81%) to segregate early and late stages of <i>T</i>. <i>cruzi</i> infection. The sets “TI 2,000/AI 1,000/EII 1,000” and “TI 8,000/AII 32,000” presented expressive scores to discriminate single from dual <i>T</i>. <i>cruzi</i> infections at early (85%) and late stages (84%), respectively. Moreover, the attributes “TI 4,000/TVI 500/TII 1,000”, “TI 16,000/EI 2,000/EII 2,000/AI 500/TVI 500” showed good performance for genotype-specific diagnosis at early stage of single (72%) and dual (80%) <i>T</i>. <i>cruzi</i> infections, respectively. In addition, the attributes “TI 4,000/AII 1,000/EVI 1,000”, “TI 64,000/AVI 500/AI 2,000/AII 1,000/EII 4,000” showed moderate performance for genotype-specific diagnosis at late stage of single (69%) and dual (76%) <i>T</i>. <i>cruzi</i> infections, respectively. The sets of decision-trees were assembled to construct a sequential algorithm with expressive accuracy (81%) for serological diagnosis of <i>T</i>. <i>cruzi</i> infection. These findings engender new perspectives for the application of Chagas-Flow ATE-IgG2a method for genotype-specific diagnosis in humans, with relevant contributions for epidemiological surveys as well as clinical and post-therapeutic monitoring of Chagas disease.</p></div
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