External Modifications Research Articles

Design and Implementation of a Dual-Region Self-Referencing Fiber-Optic Surface Plasmon Resonance Biosensor.

The need for self-referencing is extremely important in the field of biosensing. In this manuscript, we report on the study, design, and validation of a dual-region self-referencing fiber-optic surface plasmon resonance biosensor. One region is intended to measure and monitor the binding events of the biological sample under test, while the other one is designed to be used as a reference channel to compensate for external factors, such as bulk refractive index modifications and temperature oscillations, that can negatively affect the biomolecular interaction measurement. Two different configurations for the biosensor probe are presented and investigated here, both theoretically and experimentally. First, the theoretical performance of the proposed biosensor probes, in terms of surface plasmon resonance wavelength shift, was simulated using a numerical model. Afterward, they were experimentally validated in sucrose-water solutions and showed a response to refractive index and temperature changes with sensitivities up to 2000 nm/RIU and 1.559 nm/°C, respectively. Finally, an aptamer-based bioassay and a high-resolution melting assay were successfully implemented on the two proposed configurations, demonstrating the feasibility of analyzing the binding events and measuring other external signal modifications simultaneously using the same biosensor probe.

Electrospun polymeric membranes: Potential removal of endocrine disrupting compounds using solid membrane extraction and filtration processes

AbstractThe present study aims to prepare polymeric membranes by electrospinning to apply in the removal of estrone (E1), 17β‐estradiol (E2), and 17α‐ethinylestradiol (EE2) in aqueous samples. Polymeric membranes of polyamide‐6 (PA6), polycaprolactone (PCL), polylactic acid (PLA), and poly (butylene adipate‐co‐terephthalate) (PBAT) were obtained, characterized, and tested as sorbent material in processes of solid membrane extraction (SME) and membrane filtration. The efficiencies of the membranes after washing and/or conditioning processes were compared. The characterizations showed membranes with nanometer‐diameter threads (between 250 and 1200 nm, on average). The four membranes' morphology, chemical composition, and thermal stability were like previous works. PBAT membranes were considered the most effective SME technique as a differential, with 44%–71% removal. For the membrane filtration process, the highest removal values were obtained for the PBAT membrane (82%–91%), which was also efficient in filtering a surface water sample from River Guaíba. PBAT polymeric membrane effectively removes and recovers the studied hormones, lowering production costs and allowing internal and external modifications. These aspects demonstrate that the obtained membranes offer an efficient material in extracting E1, E2, and EE2, of high simplicity, low cost, and green chemistry.

Development of a simulation method for paddy fields based on surface FTABLE of hydrological simulation program–FORTRAN

The Hydrological Simulation Program–FORTRAN (HSPF) is a widely used watershed-scale model; however, it does not comprise any functions that can be used to simulate rice paddy fields, thereby hindering its applicability in many Asian countries. To address this limitation, a paddy field simulation method was developed by considering the water detention effect and seasonal changes in the outlet height of paddy fields; this was achieved using the existing functions of HSPF. Surface FTABLE, a function of the relationship between surface water storage and outflow, was applied to represent the physical structure and inundated condition of paddy fields. Surface FTABLE was temporally changed by Special Actions, an HSPF module, to reflect the seasonal variation in drainage outlet height. By employing these methods, HSPF was applied to paddy fields for evaluating the model performance. On comparing the simulated and observed values of ponding depth and surface outflow, the model showed good performance with a coefficient of determination that ranged from 0.71 to 0.89 and an index of agreement that ranged from 0.92 to 0.97. Comparing the results of the simulation performed with or without Surface FTABLE, the simulation with Surface FTABLE exhibited a reduced surface outflow (−40.0%) due to the blocking effect of the paddy field, a decreased infiltration (−17.3%) due to the saturation of the upper soil zone, and a higher level of soil water in all subsurface layers. Based on these differences in each component, it is necessary to apply Surface FTABLE when considering the hydrological processes of paddy fields for HSPF modeling. The simulation method developed in this study only uses the existing functions of HSPF without performing any external modifications; therefore, it can be used conveniently to improve the applicability of HSPF in rice-growing regions.

Body image dissatisfaction and interoceptive sensibility significantly predict postpartum depressive symptoms

BackgroundDuring pregnancy women experience rapid and unique changes in body weight, shape and size over a relatively short time period. While research focused on the role of external bodily modifications during pregnancy, research on internal bodily variations is missing. MethodsIn a longitudinal study, we recruited healthy pregnant women and measured whether and how depressive symptoms, body image dissatisfaction and the subjective tendency to focus on one's own internal bodily sensations, i.e., interoceptive sensibility, changed during pregnancy and postpartum. Pregnant women filled online self-report questionnaires during pregnancy (i.e. second and third trimester) and after (i.e. six weeks) the delivery, including the Body Areas Satisfaction Scale, the Multidimensional Assessment of Interoceptive Awareness, and the Edinburgh Postnatal Depression Scale. ResultsWhile depressive symptoms remained stable in the peripartum, body image dissatisfaction increased in the postpartum compared to the pregnancy period, and interoceptive sensibility increased over pregnancy. Findings showed that the increase of body dissatisfaction through the peripartum and the levels of interoceptive sensibility in the early phase of pregnancy predicted depressive symptoms in the postpartum. LimitationsInteroception was evaluated as a subjective measure (i.e., interoceptive sensibility). Future studies may include objective measures of interoceptive accuracy and interoceptive awareness. ConclusionsThe current study supports the importance of body image dissatisfaction and interoceptive sensibility in the development of postpartum depressive symptoms. Future studies need to investigate if interventions aimed to increase interoceptive sensibility might be useful in preventing depressive symptoms and identify the mechanisms that can lead to these changes.

Cyclodextrin boostered-high density lipoprotein for antiatherosclerosis by regulating cholesterol efflux and efferocytosis

A promising therapy for atherosclerosis treatment was designed by targeting LXR receptor (LXR) on atherosclerotic macrophage, where LXR activation could regulate cholesterol efflux and efferocytosis. Herein, a sequential-targeting nanoplatform (HT-rHDL) was constructed to deliver LXR agonist into macrophage, which was composed of discoidal reconstituted high-density lipoprotein (d-rHDL) core for agonist encapsulation and external modifications: (i) the outermost hyaluronan, targeting injured endothelium; (ii) modified β-cyclodextrin of d-rHDL, accelerating cholesterol efflux of foam cells; (iii) conjugated apolipoprotein A-I of d-rHDL, targeting macrophage. This design underlines that the nanoplatform could increase its plaque accumulation, accomplish cholesterol efflux-remodeling-drug delivery behavior and specifically activate LXR in macrophage. After a 3-month treatment with HT-rHDL, 31.47% plaque area reduction, 56.0% lipid accumulation decrease, obvious inflammation resolution and enhanced plaque stability were observed. Furthermore, the atherosclerosis intervention was demonstrated to benefit from the upregulations of ABC transporters and Mer tyrosine kinase. Collectively, HT-rHDL provides new strategies to regress atherosclerosis.

Home modifications and disability outcomes: A longitudinal study of older adults living in England.

SummaryBackgroundThere is limited evidence on the protective effect of housing modifications on disability outcomes among older adults. We examined whether external and internal housing modifications reduce the risk of a range of disability outcomes among older adults living in England.MethodsWe analysed adults aged 60 and over from the English Longitudinal Study of Ageing, initially recruited in 2002/03. The longitudinal sample consisted of 32,126 repeated observations from 10,459 individuals across 6 waves with an average follow-up of 11·3 years. Participants were asked if their homes had external (widened doorways, ramps, automatic doors, parking and lift) and internal (rails, bathroom/kitchen modifications, chair lift) housing modifications. Mobility impairment was measured through reported difficulties in 10 activities including walking, climbing, getting up, reaching and lifting. Five disability outcomes were analysed (falls in the previous two years, pain, poor self-rated health, no social activities, and moving home within next two years) using two-way fixed effect models, controlling for key risk factors for disability.FindingsGreater mobility impairments increased the probability of falls, pain and poor self-rated health although this effect was significantly moderated by external housing modifications. Among older adults with severe mobility impairments, external housing modifications reduced the probability of falls by 3% (1%-6%), pain by 6% (4%-8%), and poor health by 4% (2%-5%). Moreover, external housing modifications reduced the probability of no social activities by 6% (5%-7%) and moving home by 4% (2%-5%) even among those without any mobility impairments. Internal housing modifications had similar, but less consistent effects on the disability outcomes.InterpretationThere was strong evidence that external housing modifications protected against a range of disability outcomes. Studies on reducing disability in ageing populations need to consider the role of housing modifications as key interventions to promote healthy ageing in place.FundingEconomic and Social Research Council ES/R008930/1 and ES/S012567/1

Halides formation dynamics in nanosecond and femtosecond laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is an analytical technique based on the measurement of the emitted radiation coming from a laser-induced plasma (LIP) created after irradiation of a sample by a short-duration laser pulse. Research on molecular presence in LIPs has increased because the use of molecular emission has proven an encouraging way to improve LIBS abilities. LIPs are dynamic plasmas with fast time and spatial evolutions, in which atoms and molecules can follow different paths in their evolution and distribution. Molecular creation mechanisms within LIPs are still a challenging issue under investigation and the prevalence of some specific mechanisms are dependent on experimental conditions (sample nature, laser parameters, surrounding atmosphere…). In this work, different time and spatially solved experiments were carried out in ns- and fs-LIBS to investigate the dynamics of alkaline-earth (Ca) halide (F) diatomic molecule formation. Experiments were carried out on powdered CaF2 samples for both ns- and fs-LIBS. The effects of a gas flow (air, He, Ar) over the plume are investigated for ns-LIBS. Nebulization-modified ns-LIBS experiments in which the alkaline-earth element is externally added to the plasma plume as an aerosol were carried out on (C2F4) n samples. The spatial separation between atomic and molecular emission distribution was found to take place with and without external modifications over the ns-LIP. Behavior in fs-LIPs was determined to differ significantly from analogous experiments with nanosecond lasers, but temporal optimization remains the optimum method for molecular detection as spatial separation was not found to provide any remarkable advantage.

Numerical Simulation Approach to Investigate the Effects of External Modifications in Reducing Aerodynamic Drag on Passenger Vehicles

This study used a numerical simulation approach to examine the effects of external modifications in reducing aerodynamic drag on passenger vehicles. During the simulation, modifications included reducing mirror size by replacing the side mirrors with cameras and covering the wheel area. The resulting changes in drag force for different combinations of modifications were compared with a conventional baseline model to determine the most aerodynamic configuration. The study found that side view cameras reduced drag forces by almost 2.6% due to their smaller frontal areas and improvement in the overall aerodynamics of the vehicle. Besides, an increase in wheel coverage decreased the drag causing up to 2.7% of drag force reduction for a wheel with an 87% coverage area. This is because of the reduction in wake formation caused by the wheel rims. Finally, using a combination of smaller cameras and wheels with larger coverage areas resulted in a maximum drag reduction of about 4.3%.

Functional Capacity of Tai Chi-Practicing Elderly People.

Research shows that ageing is modifiable or modulable, attending to external modifications and lifestyle factors: physical activity has a unique contribution to functional health and energy balance. Extensive research shows Tai Chi (TC) produced a major physical condition. To determine the impact of lifestyle on functional capacity, comparing the impact of continued long-life practice. 113 individuals (±71.53 years old): (a) PTC (n = 27); senior competitors, life-long training; (b) TC (n = 27); ±4 years; (c) Keep-Fit (KF n = 36); ±4 years; and the control group (d) sedentary individuals (SI n = 23). Five tests from the Senior Fitness Test (SFT) were used to assess the physical condition. The TC group showed significantly better results than the KF group: 30-s chair stand (23.22 ± 3.08 * rep vs. 17.17 ± 2.96 rep), chair sit-and-reach (2.19 ± 4.85 * cm vs. −1.93 ± 5.46 cm) and back scratch (1.02 ± 4.46 * cm vs. −2.43 ± 5.78 cm). The TCP group showed better results than the TC group: 30-s chair stand (27.70 ± 4.98 * rep vs. 23.22 ± 3.08 rep), 30-s arm curl (30.22 ± 4.36 * rep vs. 23.48 ± 3.42 rep), chair sit-and-reach (13.07 ± 4.00 * cm vs. 2.19 ± 4.85 cm) and back scratch (5.48 ± 3.51 * cm vs. 1.02 ± 4.46 cm). Among the different activities analysed, TC showed better results in SFT tests; in particular considering the long-life training of this martial art.

Mitigating the relative humidity effects on the simultaneous removal of VOCs and PM2.5 of a metal–organic framework coated electret filter

An electret filter media coated with highly porous metal–organic framework (MOF, i.e., MIL-125-NH2 in this work) particles, called E-MOFilter, has been developed to remove fine particulate matters (PM2.5, particulate matter less than 2.5 µm in diameter) and volatile organic compounds (VOCs, e.g., toluene) simultaneously. However, its adsorption efficiency and capacity of toluene was deteriorated at an elevated relative humidity (RH). This was due to the hydrophilic nature of MIL-125-NH2 leading to competitive adsorption between toluene and water molecules. To address this issue, five modification methods were conducted to alter MIL-125-NH2 from inherent hydrophilic into hydrophobic, which included the internal (alkylation method), external (coating with polydimethylsiloxane, PDMS), combined (alkylation plus PDMS coating), polyvinylpyrrolidone (PVP) surfactant, and N-coordination modifications. The new E-MOFilters were fabricated based on these modified MIL-125-NH2 and then systematically compared for their toluene adsorption efficiency and capacity under various RH levels (from 10, 30, 40, 50 to 60%). In addition to toluene, the PM removal efficiency and PM2.5 holding capacity by the modified E-MOFilters were also evaluated. The toluene adsorption results revealed the PDMS-coated E-MOFilter outperformed all other modifications. The PM removal ability were retained for all modified E-MOFilters indicating the charge and structure of the electret media were not altered. This study is the first to combine the MOFs with electret filter media for a low pressure drop and simultaneous removal of PM and toluene under different RHs. The effectiveness and performance towards toluene adsorption under elevated RH conditions for E-MOFilters with various modifications were comprehensively evaluated and discussed.

Exploring the forms of wetland modifications and investigating the causes in lower Atreyee river floodplain area

The current study focuses on the various kinds of external and interior hydrological and morphological modifications of wetlands in the lower Atreyee river basin of India and Bangladesh. The relevant eight diverse causes were carefully investigated adopting various approaches such as consistency scaling, change detection, landscape fragmentation, and 2D floodplain modelling. As per the results, only 274.79 km2 (2019) of wetland area is now available. A total of 650.04 km2 of wetland area has been changed to other land uses in last 30 years and 106.97 km2 of consistent wetland area has been turned into inconsistent. Reduction of the depth of water (77.09%) can be easily identified by NDWI intensity. Integrated large core wetlands have become fragmented into small patches increasing edge area ratio. Agricultural and built-up area expansions have been identified as the most important causes contributing to wetland conversion. According to the findings, 292.51 km2 of wetlands have been replaced by agricultural land, with an additional 99.44 km2 taken up by built-up area. Besides that, the construction of a dam across the Atreyee river has decreased maximum and average flow by 37% and 66.86%, respectively, which in turn has reduced overall flood frequency and the lateral flood extent of inundation areas (1627.3 km2 or 15.97%). As a result, 231.23 km2 wetland area in stress state is now left beyond the present active flood limit. Disconnection of drainage networks, groundwater-lowering, embankment of rivers, extension of infrastructure etc. are some of the other crucial causes of wetland transformation and loss. This study will undoubtedly be beneficial to decision-makers in their efforts to take a significant step towards conserving the wetland landscape, as well as to environmental preservation.

Air-Stable and Layer-Dependent Ferromagnetism in Atomically Thin van der Waals CrPS4.

Ferromagnetism in two-dimensional materials presents a promising platform for the development of ultrathin spintronic devices with advanced functionalities. Recently discovered ferromagnetic van der Waals crystals such as CrI3, readily isolated two-dimensional crystals, are highly tunable through external fields or structural modifications. However, there remains a challenge because of material instability under air exposure. Here, we report the observation of an air-stable and layer-dependent ferromagnetic (FM) van der Waals crystal, CrPS4, using magneto-optic Kerr effect microscopy. In contrast to the antiferromagnetic (AFM) bulk, the FM out-of-plane spin orientation is found in the monolayer crystal. Furthermore, alternating AFM and FM properties observed in even and odd layers suggest robust antiferromagnetic exchange interactions between layers. The observed ferromagnetism in these crystals remains resilient even after the air exposure of about a day, providing possibilities for the practical applications of van der Waals spintronics.

Diversification through gustatory courtship: an X-ray micro-computed tomography study on dwarf spiders

BackgroundSexual selection has been considered to promote diversification and speciation. Sexually dimorphic species have been used to explore the supposed effect, however, with mixed results. In dwarf spiders (Erigoninae), many species are sexually dimorphic—males possess marked prosomal modifications. These male traits vary from moderate elevations to bizarre shapes in various prosomal regions. Previous studies established that male dwarf spiders produce substances in these prosomal modifications that are taken up by the females. These substances can act as nuptial gifts, which increase the mating probability of males and the oviposition rate in females. Therefore, these dimorphic traits have evolved in the context of sexual selection. Here, we explore the evolutionary lability of this gustatory trait complex with the aim of assessing the role of this trait complex in species divergence by investigating (1) if erigonine modified prosomata are inherently linked to nuptial-gift-producing glands, (2) if the evolution of the glands evolution preceded that of the modified prosomal shapes, and by assessing (3) the occurrence of convergent/divergent evolution and cryptic differentiation.ResultsWe reconstructed the position and extent of the glandular tissue along with the muscular anatomy in the anterior part of the prosoma of 76 erigonine spiders and three outgroup species using X-ray micro-computed tomography. In all but one case, modified prosomata are associated with gustatory glands. We incorporated the location of glands and muscles into an existing matrix of somatic and genitalic morphological traits of these taxa and reanalyzed their phylogenetic relationship. Our analysis supports that the possession of glandular equipment is the ancestral state and that the manifold modifications of the prosomal shape have evolved convergently multiple times. We found differences in gland position between species with both modified and unmodified prosomata, and reported on seven cases of gland loss.ConclusionsOur findings suggest that the occurrence of gustatory glands in sexually monomorphic ancestors has set the stage for the evolution of diverse dimorphic external modifications in dwarf spiders. Differences among congeners suggest that the gland position is highly susceptible to evolutionary changes. The multiple incidences might reflect costs of glandular tissue maintenance and nuptial feeding. Our results indicate divergent evolutionary patterns of gustatory-courtship-related traits, and thus a likely facilitating effect of sexual selection on speciation.

The impact of prep class education on effective English requestive e-mails written by students in Turkey

For the past years, cross-cultural and interlanguage pragmatics have focused on native and non-native speech act descriptions, and only a small number of studies have investigated the preparatory class effect involved in speech act productions. To bridge the gap, this study aims to investigate the degree of directness and amount of lexical / phrasal internal and external modifications of requestive e-mails employed by 25 first grade students of English Language and Literature department with preparatory education and 25 first grade students of English Language and Literature department without preparatory education in their in a state university. It also aims to explore whether there is a difference between two groups according to the degree of imposition while making requests. The participants were given discourse completion tests in e-mail format including two different situations with low and high imposition levels and asked to write two requestive e-mails to their non-native professor. The e-mails were analyzed and classified based on Economidou-Kogetsidis’s (2011) framework which relies on Blum- Kulka et al. (1989) and Biesenbach-Lucas (2006, 2007). Based on the percentages and frequencies, the students with preparatory class education were compared to the students without preparatory class education, with respect to their usage of request strategies, lexical/phrasal internal modification and external modification. The results indicated that these two groups had both similarities and differences with respect to the degree of directness, the amount of internal and external modifications. Turkish ELL learners with and without prep class education employed more direct strategies in both situations. However, the group without prep class education employed more conventionally indirect strategies than the group with prep class education. None of the participants used non-conventionally indirect strategies. The group with prep class education used more internal modification than the group without prep class education. The most common internal modification was the consultative device in both groups. As for external modification, the group with prep class education utilized more supportive moves than the group without prep class education. Grounder was the most preferred supportive move by both groups. Keywords: Turkish ELL learners; requestive e-mails; academic e-mails; directness.

An epigenomic landscape of cervical intraepithelial neoplasia and cervical cancer using single-base resolution methylome and hydroxymethylome.

BackgroundCervical cancer (CC) is the second leading cause of cancer death among women worldwide. Epigenetic regulation of gene expression through DNA methylation and hydroxymethylation plays a pivotal role during tumorigenesis. In this study, to analyze the epigenomic landscape and identify potential biomarkers for CCs, we selected a series of samples from normal to cervical intra‐epithelial neoplasia (CINs) to CCs and performed an integrative analysis of whole‐genome bisulfite sequencing (WGBS‐seq), oxidative WGBS, RNA‐seq, and external histone modifications profiling data.ResultsIn the development and progression of CC, there were genome‐wide hypo‐methylation and hypo‐hydroxymethylation, accompanied by local hyper‐methylation and hyper‐hydroxymethylation. Hydroxymethylation prefers to distribute in the CpG islands and CpG shores, as displayed a trend of gradual decline from health to CIN2, while a trend of increase from CIN3 to CC. The differentially methylated and hydroxymethylated region‐associated genes both enriched in Hippo and other cancer‐related signaling pathways that drive cervical carcinogenesis. Furthermore, we identified eight novel differentially methylated/hydroxymethylated‐associated genes (DES, MAL, MTIF2, PIP5K1A, RPS6KA6, ANGEL2, MPP, and PAPSS2) significantly correlated with the overall survival of CC. In addition, no any correlation was observed between methylation or hydroxymethylation levels and somatic copy number variations in CINs and CCs.ConclusionOur current study systematically delineates the map of methylome and hydroxymethylome from CINs to CC, and some differentially methylated/hydroxymethylated‐associated genes can be used as the potential epigenetic biomarkers in CC prognosis.

Perception and Modification: A Pragmatic Study of Irai Hyougen by Japanese Learners

This research focused on describing how perceptions about the degree of imposition are manifested in requests in Japanese used by learners and how these perceptions are translated into choices of pragmatic modification. Through qualitative methods using the discourse completion test, it is known that perceptions of the degree of an imposition when requesting something are not manifested into the choice of request type used by learners. Instead, it is more visible from the variation in the choice of syntactic patterns used in request expression. The perception of the degree of imposition translated into a choice of external and internal pragmatic modifications. Although learners have varying perceptions of the degree of imposition for the same request, it does not appear that learners differentiate the choice of pragmatic modification based on the heaviness of the request’s imposition.

Análisis de las variables sociales en los actos de habla de petición en chino y en español

Basándose en un corpus literario, este estudio tiene como objetivo analizar los aspectos contrastivos de la cortesía verbal en chino y en español y comprobar si las variables sociales influyen o no sobre la reali-zación de la petición en las dos lenguas. Según los análisis, hemos conseguido los siguientes resulta-dos: 1) desde el punto de vista de las estrategias de actos principales, casi independientemente de las variables sociales, en ambas lenguas se presenta la directividad y la preferencia de uso de las estrate-gias directas en la realización de la petición; 2) en chino, a pesar de la variación de la combinación de las variables sociales, el uso de las modificaciones internas y externas es habitual; sin embargo, en español se muestra igualmente un uso reducido; 3) en comparación con el español, en chino se utilizan con más frecuencia los marcadores de apertura.

Lithuanian Refusals and Politeness

This study investigates Lithuanian refusals to comply with requests. Refusals are face-threatening speech acts. They can endanger social relationships, and therefore require mitigation by employing politeness means. The aim of the study is to find out strategies, sub-strategies, internal and external modifications of Lithuanian refusals. The research data was collected from students using an open-ended discourse completion test and consists of 1046 refusals. Summarizing the results, it can be stated that Lithuanians opt for indirect refusals. When refusing directly, the least straightforward strategy – stating the inability to comply with a request – is used, especially by women. Refusals (especially the direct ones) are often mitigated with external modifications that were again more frequent in women’s responses. Socioculturally, the most acceptable and thus polite way to refuse in Lithuanian is to apologize and provide reasons. Overall, there is a clear tendency to express positive politeness when refusing.

Tunable Stochasticity in an Artificial Spin Network.

Metamaterials present the possibility of artificially generating advanced functionalities through engineering of their internal structure. Artificial spin networks, in which a large number of nanoscale magnetic elements are coupled together, are promising metamaterial candidates that enable the control of collective magnetic behavior through tuning of the local interaction between elements. In this work, the motion of magnetic domain-walls in an artificial spin network leads to a tunable stochastic response of the metamaterial, which can be tailored through an external magnetic field and local lattice modifications. This type of tunable stochastic network produces a controllable random response exploiting intrinsic stochasticity within magnetic domain-wall motion at the nanoscale. An iconic demonstration used to illustrate the control of randomness is the Galton board. In this system, multiple balls fall into an array of pegs to generate a bell-shaped curve that can be modified via the array spacing or the tilt of the board. Ananoscale recreation of this experiment using an artificial spin network is employed to demonstrate tunable stochasticity. This type of tunable stochastic network opens new paths toward post-Von Neumann computing architectures such as Bayesian sensing or random neural networks, in which stochasticity is harnessed to efficiently perform complex computational tasks.

Kinesin-1 activity recorded in living cells with a precipitating dye

Kinesin-1 is a processive motor protein that uses ATP-derived energy to transport a variety of intracellular cargoes toward the cell periphery. The ability to visualize and monitor kinesin transport in live cells is critical to study the myriad of functions associated with cargo trafficking. Herein we report the discovery of a fluorogenic small molecule substrate (QPD-OTf) for kinesin-1 that yields a precipitating dye along its walking path on microtubules (MTs). QPD-OTf enables to monitor native kinesin-1 transport activity in cellulo without external modifications. In vitro assays show that kinesin-1 and MTs are sufficient to yield fluorescent crystals; in cells, kinesin-1 specific transport of cargo from the Golgi appears as trails of fluorescence over time. These findings are further supported by docking studies, which suggest the binding of the activity-based substrate in the nucleotide binding site of kinesin-1.