Search results for "CALL"
showing 10 items of 2320 documents
Sea urchin HSF activity in vitro and in transgenic embryos.
1997
Evidence is provided for the presence at the physiological temperature of 20 degrees C of a heat shock transcriptor factor, HSF, in the nuclei of P.lividus embryos. This HSF is able to specifically bind in vitro the heat shock element, HSE, of the promoter of the hsp70 gene i.v., as suggested by DNA-protein binding reactions and DNAse I protection assays. Upon heat-shock, at the temperature of 31 degrees C, its ability to bind the HSE units becomes much higher. The HSF activated by heat-shock drives in vivo the transcription of the beta-galactosidase reporter gene in transgenic sea urchin gastrulae. An ATF-like transcription factor, widely described in other organisms but not at all in sea …
Early asymmetric cues triggering the dorsal/ventral gene regulatory network of the sea urchin embryo
2014
Dorsal/ventral (DV) patterning of the sea urchin embryo relies on a ventrally-localized organizer expressing Nodal, a pivotal regulator of the DV gene regulatory network. However, the inceptive mechanisms imposing the symmetry-breaking are incompletely understood. In Paracentrotus lividus, the Hbox12 homeodomain-containing repressor is expressed by prospective dorsal cells, spatially facing and preceding the onset of nodal transcription. We report that Hbox12 misexpression provokes DV abnormalities, attenuating nodal and nodal-dependent transcription. Reciprocally, impairing hbox12 function disrupts DV polarity by allowing ectopic expression of nodal. Clonal loss-of-function, inflicted by b…
Inhibitory activities of short linear motifs underlie Hox interactome specificity in vivo
2015
Hox proteins are well-established developmental regulators that coordinate cell fate and morphogenesis throughout embryogenesis. In contrast, our knowledge of their specific molecular modes of action is limited to the interaction with few cofactors. Here, we show that Hox proteins are able to interact with a wide range of transcription factors in the live Drosophila embryo. In this context, specificity relies on a versatile usage of conserved short linear motifs (SLiMs), which, surprisingly, often restrains the interaction potential of Hox proteins. This novel buffering activity of SLiMs was observed in different tissues and found in Hox proteins from cnidarian to mouse species. Although th…
Identification of the essential protein domains for Mib2 function during the development of the Drosophila larval musculature and adult flight muscles
2016
The proper differentiation and maintenance of myofibers is fundamental to a functional musculature. Disruption of numerous mostly structural factors leads to perturbations of these processes. Among the limited number of known regulatory factors for these processes is Mind bomb2 (Mib2), a muscle-associated E3 ubiquitin ligase, which was previously established to be required for maintaining the integrity of larval muscles. In this study, we have examined the mechanistic aspects of Mib2 function by performing a detailed functional dissection of the Mib2 protein. We show that the ankyrin repeats, in its entirety, and the hitherto uncharacterized Mib-specific domains (MIB), are important for the…
Modeling transpiration and leaf temperature of urban trees – A case study evaluating the microclimate model ENVI-met against measurement data
2018
Abstract Increasing vegetation cover in cities is a key approach to mitigating urban heat excess. However, both the effect of vegetation on microclimate and the plants’ vitality need to be assessed to support and quantify the effects of such strategies. One way to assess the interactions between vegetation and the urban environment is through microclimate models that can simulate the effects of vegetation onto the urban microclimate as well as effects of urban environments onto vegetation. To provide reliable estimates microclimate models need to be parameterized based on empirically obtained data. In this paper we compare modeled transpiration rates and leaf temperatures of a leading micro…
Group analytic therapy for eating disorders: preliminary results in a single-group study.
2008
Objectives There is a lack of empirical data on the effectiveness and process of group-analytic therapy in eating disorders. This single-group study aimed to explore the effectiveness of such treatment for anorexic and bulimic individuals. Method Eight patients (three anorexic and five bulimic women) entered group-analytic treatment, meeting weekly for 2 years. Eating behaviours, overall psychological distress and group process variables were regularly assessed using quantitative and qualitative measures, with comparisons made at the beginning and end of the therapy. Results Treatment was discontinued in two cases. When outcome was classified on the basis of reliable change and clinical sig…
Comparison of three adhesive systems in class II composite restorations in endodontically treated teeth : influence of Er:YAG laser conditioning and …
2018
Background Dental surface conditioning by Er:YAG laser is currently being investigated, as not all of the mechanisms and effects of this technique have been clearly studied. Thus, the aim of the present study was to assess the cervical microleakage of Class II resin composite restorations in endodontically treated teeth following either the respective conventional conditioning or additional Er:YAG laser conditioning, in association with varied adhesives. Material and methods Standardized mesial-occlusal-distal cavities (two gingival walls positioned in dentin and enamel, respectively) were created in 60 extracted human premolar teeth. Following the completion of the endodontic therapy, the …
Trafficking of the human transferrin receptor in plant cells: effects of tyrphostin A23 and brefeldin A.
2006
Plant cells possess much of the molecular machinery necessary for receptor-mediated endocytosis (RME), but this process still awaits detailed characterization. In order to identify a reliable and well-characterized marker to investigate RME in plant cells, we have expressed the human transferrin receptor (hTfR) in Arabidopsis protoplasts. We have found that hTfR is mainly found in endosomal (Ara7- and FM4-64-positive) compartments, but also at the plasma membrane, where it mediates binding and internalization of its natural ligand transferrin (Tfn). Cell surface expression of hTfR increases upon treatment with tyrphostin A23, which inhibits the interaction between the YTRF endocytosis signa…
PERFORMANCE ASSESSMENT IN SCIENCE NATIONAL LEVEL DIAGNOSTIC TESTS
2018
National Centre of Education of the Republic of Latvia in 2016 lunched national project of the renewal of the curriculum for education funded by the European Social Fund. One of the key priorities of successful implementation of the new education curriculum is transforming national level assessment system.Assessment system measuring student performance must meet different requirements from the traditional measurement instrument assessing content knowledge.Analysing 2017 national level science assessment diagnostic tests of 15-16 years old students, it is impossible to discriminate student different level of performance. Student, demonstrating singly stored pieces of knowledge, integrating p…
The Sequential Switching Shunt Maximum Power Regulator and its Application in the Electric Propulsion System of a Spacecraft
2007
This paper describes a baseline solution of a Power Conditioning and Distribution Unit (PCDU) for Electrical Propulsion (EP) systems. The solution adopted uses two high efficiency, low-mass power regulators; a solar array regulator (SAR) based on the classical Sequential Switching Shunt Regulator with Maximum Power Point Tracking (MPPT) capability followed by a step-up converter to achieve the desired regulated bus voltage. This paper focuses on the first part of the PCDU, the Sequential Switching Shunt Maximum Power Regulator (S3MPR). This electrical architecture has been adapted and recently proposed for the Electric Propulsion power system of the European and Japanese Mercury Mission (Be…