516 research outputs found
Food profitability and recruitment behaviour in a scent trail laying stingless bee (Scaptotrigona aff. depilis)
Innerhalb der sozialen Insekten haben viele Gruppen die faszinierende FĂ€higkeit entwickelt, Nestgenossinnen zu rekrutieren. Rekrutierung beruht auf einer Kommunikation, die angewandt wird, um Mitglieder des Nestes zu einem bestimmten Ort zu bringen, wo Arbeit von Nöten ist (Wilson 1971). Daher beinhaltet die Rekrutierungskommunikation sowohl die Aktivierung von Nestgenossinnen innerhalb des Nestes, als auch die Orientierungshilfen fĂŒr das Auffinden des Zielortes (Traniello & Robson 1995). Die stachellosen Bienen (Hymenoptera, Meliponini) sind unter den sozialen Insekten eine hoch diverse Tiergruppe (ĂŒber 400 Arten, Michener 2000). Sie eignen sich ausgezeichnet fĂŒr die Untersuchung der ebenso diversen Rekrutierungs- und Kommunikationsmechanismen. Bei stachellosen Bienen, wie bei anderen sozialen Insekten, beeinflusst die GĂŒte der Futterquelle die Rekrutierung. Bisher wurde an Arten, die keinen Duftpfad legen, gezeigt, dass zu ertragreichen Futterquellen mehr Bienen rekrutiert werden als zu weniger ertragreichen (Biesmeijer & Ermers 1999). In der vorliegenden Arbeit wurde erstmals untersucht, wie die Zuckerkonzentration des Futters die Rekrutierung einer Art (Scaptotrigona aff. depilis) beeinflusst, welche Rekruten durch das Auslegen eines Duftpfades zur Futterquelle fĂŒhrt (Schmidt & al. 2006b).How does the sugar concentration of the food source affect the recruitment of the stingless bee Scaptotrigona aff. depilis (Hymenoptera, Meliponini)? We offered sugar water of either constant, increasing, or decreasing concentrations. Simultaneously, we recorded the number of recruits and the recruitersâ running speed, jostling contacts, and vibrations inside the nest. Neither the number of recruits nor the behavioural parameters depended on the actual sugar concentration but rather on the changes experienced over time. Concentration decreases resulted in significantly decreased numbers of recruits. Concentration increases neither led to increased numbers of recruits nor to increased recruitment activity. However, most parameters of intranidal activity changed significantly only when the concentration was reduced from 40% to 20% w/w and recruitment to the food source nearly ceased. These findings support the idea of a feedback mechanism reducing the colonyâs effort to exploit food sources of decreasing profitability
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Precise Localization and Control of Catalytic Janus Micromotors Using Weak Magnetic Fields
We experimentally demonstrate the precise localization of spherical Pt-Silica Janus micromotors (diameter 5 ÎŒm) under the influence of controlled magnetic fields. First, we control the motion of the Janus micromotors in two-dimensional (2D) space. The control system achieves precise localization within an average region-of-convergence of 7 ÎŒm. Second, we show that these micromotors provide sufficient propulsion force, allowing them to overcome drag and gravitational forces and move both downwards and upwards. This propulsion is studied by moving the micromotors in three-dimensional (3D) space. The micromotors move downwards and upwards at average speeds of 19.1 ÎŒm/s and 9.8 ÎŒm/s, respectively. Moreover, our closed-loop control system achieves localization in 3D space within an average region-of-convergence of 6.3 ÎŒm in diameter. The precise motion control and localization of the Janus micromotors in 2D and 3D spaces provides broad possibilities for nanotechnology applications
Rethinking the Language Learner in the Post-method Era The Question of Identity
AbstractTaking into consideration the requirements of postmethod era which, according to Kumaravadivelu (2001), called for particular stances of language teachers towards the role of language learning theories in practice and putting the language learner within the frameworks of such theories as competition model, this paper attempts to verify and substantiate the claim that the language learner does not have a particular identity. This substantiation draws on two interrelated issues: (1) as people concerned with language education, teachers are responsible for practice which is mediated by different theories in the postmethod era, and (2) each theory allows for looking at the learner from one perspective according to which only partial understanding of the learner is within reach (only partial theoretical resource to pave the grounds for effective learning opportunities is available). Furthermore, since depending upon a particular theory there might be an understanding of the learner differnet from and sometimes even the opposite of that formed on the basis of another theory, and because in the postmethod era practice in general and moment by moment instances of practice in particular are quite likely to be subjected to opposing theories, it is concluded that the foreign language learner does not have a particular identity
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Sperm-Driven Micromotors Moving in Oviduct Fluid and Viscoelastic Media
Biohybrid micromotors propelled by motile cells are fascinating entities for autonomous biomedical operations on the microscale. Their operation under physiological conditions, including highly viscous environments, is an essential prerequisite to be translated to in vivo settings. In this work, a sperm-driven microswimmer, referred to as a spermbot, is demonstrated to operate in oviduct fluid in vitro. The viscoelastic properties of bovine oviduct fluid (BOF), one of the fluids that sperm cells encounter on their way to the oocyte, are first characterized using passive microrheology. This allows to design an artificial oviduct fluid to match the rheological properties of oviduct fluid for further experiments. Sperm motion is analyzed and it is confirmed that kinetic parameters match in real and artificial oviduct fluids, respectively. It is demonstrated that sperm cells can efficiently couple to magnetic microtubes and propel them forward in media of different viscosities and in BOF. The flagellar beat pattern of coupled as well as of free sperm cells is investigated, revealing an alteration on the regular flagellar beat, presenting an onâoff behavior caused by the additional load of the microtube. Finally, a new microcap design is proposed to improve the overall performance of the spermbot in complex biofluids. © 2020 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei
Intervenção da fisioterapia na esclerose mĂșltipla: uma revisĂŁo da literatura
Mestrado em FisioterapiaA esclerose mĂșltipla Ă© uma doença do sistema nervoso central, que afeta mais frequentemente mulheres jovens. A esclerose mĂșltipla Ă© uma doença progressiva e imprevisĂvel, resultando em alguns casos de incapacidades e limitaçÔes a nĂvel fĂsico, psicolĂłgico e social. Objetivo: RevisĂŁo da literatura na busca de evidĂȘncia da efetividade da fisioterapia na Intervenção da Esclerose MĂșltipla. MĂ©todo: As pesquisas foram feitas nas bases de dado SciELO, RCAAP, PubMed e B-ON, selecionados artigos com idioma InglĂȘs e PortuguĂȘs, publicados entre os anos de 2003 a 2013. Na SciELO foi utilizada as seguintes palavras-chave: Esclerose MĂșltipla e Fisioterapia na Esclerose MĂșltipla tendo como resultado 16 artigos. No RCAAP fisioterapia na esclerose mĂșltipla, fisioterapia e intervenção da fisioterapia na esclerose mĂșltipla tendo como resultados 12 artigos. Na B-ON intervention of physical therapy in multiple sclerose e exercise in multiple sclerosis tendo como resultado 17 artigos e na PubMed foram utilizadas as mesmas da B-ON, tendo como resultados 13. Resultados: ApĂłs a seleção dos artigos, utilizou-se os critĂ©rios de inclusĂŁo e exclusĂŁo. Tivemos como amostra final 26 artigos ou seja 32 foram excluĂdos e 26 incluĂdos. DiscussĂŁo: A intervenção da fisioterapia Ă© importante para uma administração bem-sucedida das limitaçÔes funcionais, incapacidades e melhorias sobre a qualidade de vida dos pacientes com esclerose mĂșltipla. Os pacientes devem incidir precocemente numa intervenção de neurofacilitação e nos casos de EDSS menor que 7 e estĂĄveis deverĂŁo realizar exercĂcio. O nĂșmero de sĂ©ries de exercĂcios deverĂĄ iniciar com 1-3 sĂ©ries, aumentando progressivamente para 3-4 sĂ©ries. O descanso entre as sĂ©ries de exercĂcios deverĂĄ ser de 2â4 minutos. Alguns autores aconselham a combinação de treino aerĂłbico e de força. Com 3 sessĂ”es/semana de treino de força e 1 sessĂŁo de exercĂcio aerĂłbio. ConclusĂŁo: AtravĂ©s da leitura dos resultados podemos verificar que a fisioterapia tem um papel fundamental na reabilitação e prevenção do indivĂduo com esclerose mĂșltipla.ABSTRACT - Multiple sclerosis is a disease of the central nervous system that affects more frequently young women. It is a progressive and unpredictable disease, resulting in some cases of disabilities and limitations to physical, psychological and social level. Purpose: To review the literature searching for evidence of the effectiveness of physiotherapy intervention in Multiple Sclerosis. Methodology: The research was performed in the databases SciELO, RCAAP, PubMed and B-ON, where articles in english and portuguese idioms published from 2003 to 2013 were selected. In the SciELO database were used the following keywords: multiple sclerosis and Physioterapy in multiple sclerosis, having as result 16 articles. The keywords in the RCAAP database were Physioterapy in multiple sclerosis, Physioterapy and intervention of Physioterapy in multiple sclerosis, having as result 12 articles. In B-ON databases the keywords were intervention of physical therapy in multiple sclerose and exercise in multiple sclerosis, having as result 17 articles and in the database PubMed were used the same keyword of B-ON, having as result 13 articles. Results: After selecting the items, using the criteria for inclusion and exclusion as a final sample we have come to 26, been 32 articles excluded and 26 included. Discussion: The physiotherapy intervention is important for a successful management of functional limitations, disabilities, and to improve the quality of life of patients with multiple sclerosis. Patients should be submitted to early intervention of neurofacilitation and in cases of EDSS less than 7 with stability they should perform the exercise. The number of series of exercises should start with 1-3 series, progressively increasing to 3-4 series. The resting between series of exercises should be 2-4 minutes. Some authors advise the combination of aerobic and strength training with 3 sessions / week of strength training and 1 session of aerobic exercise. Conclusion: Through the reading of the results we can see that physical therapy plays a key role in the prevention and rehabilitation of individuals with multiple sclerosis
Diagnostic challenges within the Bacillus cereus-group: finding the beast without teeth
The Bacillus cereus-group (B. cereus sensu lato) includes common, usually avirulent species, often considered contaminants of patient samples in routine microbiological diagnostics, as well as the highly virulent B. anthracis. Here we describe 16 isolates from 15 patients, identified as B. cereus-group using a MALDI-TOF MS standard database. Whole genome sequencing (WGS) analysis identified five of the isolates as B. anthracis species not carrying the typical virulence plasmids pXO1 and pXO2, four isolates as B. paranthracis, three as B. cereus sensu stricto, two as B. thuringiensis, one as B. mobilis, and one isolate represents a previously undefined species of Bacillus (B. basilensis sp. nov.). More detailed analysis using alternative MALDI-TOF MS databases, biochemical phenotyping, and diagnostic PCRs, gave further conflicting species results. These cases highlight the difficulties in identifying avirulent B. anthracis within the B. cereus-group using standard methods. WGS and alternative MALDI-TOF MS databases offer more accurate species identification, but so far are not routinely applied. We discuss the diagnostic resolution and discrepancies of various identification methods
Prognostic impact of CD4-positive T cell subsets in early breast cancer : a study based on the FinHer trial patient population
Background: The clinical importance of tumor-infiltrating cluster of differentiation 4 (CD4) T cells is incompletely understood in early breast cancer. We investigated the clinical significance of CD4, forkhead box P3 (FOXP3), and B cell attracting chemokine leukocyte chemoattractant-ligand (C-X-C motif) 13 (CXCL13) in early breast cancer. Methods: The study is based on the patient population of the randomized FinHer trial, where 1010 patients with early breast cancer were randomly allocated to adjuvant chemotherapy containing either docetaxel or vinorelbine, and human epidermal growth factor receptor 2 (HER2)-positive patients were also allocated to trastuzumab or no trastuzumab. Breast cancer CD4, FOXP3, and CXCL13 contents were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR), and their influence on distant disease-free survival (DDFS) was examined using univariable and multivariable Cox regression and Kaplan-Meier estimates in the entire cohort and in selected molecular subgroups. Interactions between variables were analyzed using Cox regression. The triple-negative breast cancer (TNBC) subset of the HE10/97 randomized trial was used for confirmation. Results: High CXCL13 was associated with favorable DDFS in univariable analysis, and independently in multivariable analysis (HR 0.44, 95% CI 0.29-0.67, P Conclusions: The results provide a high level of evidence that humoral immunity influences the survival outcomes of patients with early breast cancer, in particular of those with TNBC.Peer reviewe
Clec16a is critical for autolysosome function and Purkinje cell survival
CLEC16A is in a locus genetically linked to autoimmune diseases including multiple sclerosis, but the function of this gene in the nervous system is unknown. Here we show that two mouse strains carrying independent Clec16a mutations developed neurodegenerative disease characterized by motor impairments and loss of Purkinje cells. Neurons from Clec16a-mutant mice exhibited increased expression of the autophagy substrate p62, accumulation of abnormal intra-axonal membranous structures bearing the autophagy protein LC3, and abnormal Golgi morphology. Multiple aspects of endocytosis, lysosome and Golgi function were normal in Clec16a-deficient murine embryonic fibroblasts and HeLa cells. However, these cells displayed abnormal bulk autophagy despite unimpaired autophagosome formation. Cultured Clec16a-deficient cells exhibited a striking accumulation of LC3 and LAMP-1 positive autolysosomes containing undigested cytoplasmic contents. Therefore Clec16a, an autophagy protein that is critical for autolysosome function and clearance, is required for Purkinje cell survival
Source partitioning of H2O and CO2 fluxes based on high-frequency eddy covariance data: a comparison between study sites
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