Tomographic reconstruction of treponemal cytoplasmic filaments reveals novel bridging and anchoring components

An understanding of the involvement of bacterial cytoplasmic filaments in cell division requires the elucidation of the structural organization of those filamentous structures. Treponemal cytoplasmic filaments are composed of one protein, CfpA, and have been demonstrated to be involved in cell division. In this study, we used electron tomography to show that the filaments are part of a complex with a novel molecular organization that includes at least two distinct features decorating the filaments. One set of components appears to anchor the filaments to the cytoplasmic membrane. The other set of components appears to bridge the cytoplasmic filaments on the cytoplasmic side, and to be involved in the interfilament spacing within the cell. The filaments occupy between 3 and 18% of the inner surface of the cytoplasmic membrane. These results reveal a novel filamentous molecular organization of independent filaments linked by bridges and continuously anchored to the membrane

The impact of seismic noise produced by wind turbines on seismic borehole measurements

Seismic signals produced by wind turbines can have an adverse effect on seismological measurements up to distances of several kilometres. Based on numerical simulations of the emitted seismic wave field, we study the effectivity of seismic borehole installations as a way to reduce the incoming noise. We analyse the signal amplitude as a function of sensor depth and investigate effects of seismic velocities, damping parameters and geological layering in the subsurface. Our numerical approach is validated by real data from borehole installations affected by wind turbines. We demonstrate that a seismic borehole installation with an adequate depth can effectively reduce the impact of seismic noise from wind turbines in comparison to surface installations. Therefore, placing the seismometer at greater depth represents a potentially effective measure to improve or retain the quality of the recordings at a seismic station. However, the advantages of the borehole decrease significantly with increasing signal wavelength.</p

Predicting Delay in Goal-Directed Action: An Experience Sampling Approach Uncovering Within-Person Determinants Involved in the Onset of Academic Procrastination Behavior

Academic procrastination involves the delayed implementation of actions required to fulfill study-related tasks. These behavioral delays are thought to result from momentary failures in self-regulation (i.e., within-person processes). Most previous studies focused on the role of trait-based individual differences in students’ procrastination tendencies. Little is known about the within-person processes involved in the occurrence of procrastination behavior in real-life academic situations. The present study applied an event-based experience sampling approach to investigate whether the onset of task-specific delay behavior can be attributed to unfavorable changes in students’ momentary appraisals of tasks (value, aversiveness, effort, expectations of success), which may indicate failures in self-regulation arise between critical phases of goal-directed action. University students (N = 75) used an electronic diary over eight days to indicate their next days’ intentions to work on academic tasks and their task-specific appraisals (n = 582 academic tasks planned). For each task, a second query requested the next day determined whether students’ task-related appraisals changed and whether they implemented their intention on time or delayed working on the respective task (n = 501 completed task-specific measurements). Students’ general procrastination tendency was assessed at baseline using two established self-report questionnaires. Stepwise two-level logistic regression analyses revealed that within-person changes in task-related appraisals that reflected a devaluation of the study-related tasks increased the risk for an actual delay. The risk to delay decreased when students maintained a positive attitude toward the task. Students’ general procrastination tendency did not predict individual differences in their task-specific delay behavior. We discuss these findings in light of the growing effort to understand the within-person processes that contribute to induce procrastination behavior under real-life academic conditions and illustrate how this knowledge can benefit the design of tasks and instructions that support students’ self-regulation to their best

Surface nanoscale axial photonics: Robust fabrication of high quality factor microresonators

Recently introduced Surface Nanoscale Axial Photonics (SNAP) makes it possible to fabricate high Q-factor microresonators and other photonic microdevices by dramatically small deformation of the optical fiber surface. To become a practical and robust technology, the SNAP platform requires methods enabling reproducible modification of the optical fiber radius at nanoscale. In this Letter, we demonstrate super-accurate fabrication of high Q-factor microresonators by nanoscale modification of the optical fiber radius and refractive index using the CO2 laser and the UV excimer laser beam exposures. The achieved fabrication accuracy is better than 2 angstroms in variation of the effective fiber radius

Tomographic reconstruction of treponemal cytoplasmic filaments reveals novel bridging and anchoring components

An understanding of the involvement of bacterial cytoplasmic filaments in cell division requires the elucidation of the structural organization of those filamentous structures. Treponemal cytoplasmic filaments are composed of one protein, CfpA, and have been demonstrated to be involved in cell division. In this study, we used electron tomography to show that the filaments are part of a complex with a novel molecular organization that includes at least two distinct features decorating the filaments. One set of components appears to anchor the filaments to the cytoplasmic membrane. The other set of components appears to bridge the cytoplasmic filaments on the cytoplasmic side, and to be involved in the interfilament spacing within the cell. The filaments occupy between 3 and 18% of the inner surface of the cytoplasmic membrane. These results reveal a novel filamentous molecular organization of independent filaments linked by bridges and continuously anchored to the membrane

Influência da iluminação e da aeração sobre o crescimento de Chlorella sorokiniana em meio BG11.

Representando uns dos principais objetos de estudos atualmente, microalgas são, em geral, microrganismos fotossintetizantes altamente capazes de retirar CO2 atmosférico e gerar biomassa rica em biomoléculas de interesse industrial e comercial. No entanto, para obtenção de altos valores de rendimento e produtividade, condições ideais de crescimento são muito importantes. Diante disso, o objetivo deste trabalho foi comparar a influência de biorreatores, ou modelos utilizados para o cultivo, sobre o crescimento e o rendimento de biomassa de Chlorella sorokiniana em meio BG11 e, também, verificar os resultados que o uso de diferentes luzes pode gerar. Para tanto, foram realizados dois experimentos não simultâneos em que, primeiramente, a cepa foi cultivada em dois módulos de cultivos diferentes: módulo novo (MN), com biorreatores e sistema de aeração novos da sala de microalgas; e módulo antigo (MA), utilizando Erlenmeyers, pipeta estéril para passagem de ar e outros componentes. Em um segundo momento, com o intuito de analisar quais luzes e combinações geram maiores crescimentos e, por conseguinte, maiores biomassas secas finais, as microalgas foram cultivadas sob três condições de iluminação diferentes: luz branca (B), luz branca + luz colorida (B+C) e luz colorida (C). Para os dois módulos, temperatura, aeração e pH também foram por espectrofotometria, contagem de células, leitura de turbidez por OD manual e centrifugação e liofilização das biomassas, para saber o peso de massa seca final, foram feitas. Com isso, as análises e os testes mostraram rendimento de biomassa bem maior em MN em comparação com MA e maior crescimento dos cultivos crescidos sob luz B+C, havendo diferenças significativas em ambos os experimentos. Esses resultados permitiram demonstrar a maior eficiência dos novos módulos de cultivo de microalgas da Embrapa Agroenergia e quais luzes utilizadas geram maiores crescimentos, destacando&#8209;se também a importância de se ter condições de cultivo adequadas

YBa2Cu3O7 and Nb NanoSQUIDs for the Investigation of Magnetization Reversal of Individual Magnetic Nanoparticles

We report on the fabrication, performance and application of sensitive YBa2Cu3O7 (YBCO) and Nb nanoSQUIDs to magnetization reversal measurements of individual magnetic nanoparticles. The YBCO SQUIDs are based on grain boundary Josephson junctions and are patterned in a single layer of epitaxially grown YBCO films by Ga focused ion beam milling. The Nb SQUIDs contain sandwich-type Josephson junctions with normal conducting HfTi barriers; they are fabricated with a multilayer technology that includes patterning by e-beam lithography and a combination of milling techniques and chemical-mechanical polishing. Due to the small inductance of the SQUID loops, ultralow white flux noise at 4.2 K can be achieved, which yields spin sensitivities of down to a few Bohr magnetons per unit bandwidth for a magnetic nanoparticle placed at 10 nm distance to the SQUID loop

First results from stimulation assessment and monitoring of the 426°C geothermal well RN-15/IDDP-2 (H2020-DEEPEGS project)

The RN-15/IDDP-2 deep geothermal well of the DEEPEGS EU project on the Mid-Atlantic ridge at Reykjanes, Iceland, is a unique site for geothermal research. With a bottom hole temperature of approximately 426°C, it is one of the hottest geothermal wells ever drilled aiming for fluids at supercritical condition. Consequently, down-hole measurements are reliable to a depth of about 3.5 km, only. Pressure and temperature condition in the reservoir can be inferred using the newly developed wellbore simulator WellboreKit. Due to complete fluid loss, the well has been drilled at flow rates that reach hydraulic stimulation condition. After the drilling, the well was stimulated further by applying different concepts ranging from high flow rate hydraulic stimulation to long-term but low flow rate hydraulic stimulation to increase the reservoir performance at around 4.6 km depth. Thermo-hydro-mechanically coupled numerical modelling was performed to predict the performance response and thus, develop a well stimulation schedule. Processes related to drilling and stimulation are monitored using seismic and magnetotelluric methods to characterize and understand the processes ongoing during injection