The top 500 mathematics pins: Analysis of elementary mathematics activities on Pinterest

A 2017 study found that 87% of elementary teachers reported consulting Pinterest when planning mathematical lessons (Hertel & Wessman-Enzinger, 2017). When searching for resources on Pinterest, preservice teachers identified looking at the number of pins to determine their quality (Sawyer & Meyers, 2018). This leaves teacher educators wondering, what is the quality of materials that preservice and inservice teachers are finding on Pinterest? We conducted a document analysis on the top 500 elementary mathematics pins found on Pinterest to determine what kinds of elementary mathematics materials are available, what mathematics topics are represented, the level of cognitive demand of the elementary mathematics activities, and how the image found on the activities relates to the level of cognitive demand. We found that less than two percent of activities are the highest level of cognitive demand and decorative images are correlated with lower level elementary mathematics activities. With this information, teacher educators could help prepare teachers to decide which resources they should use and what they should look for to increase the level of cognitive demand of elementary mathematics activities they implement in their classroom

Models and Strategies for Variants of the Job Shop Scheduling Problem

Recently, a variety of constraint programming and Boolean satisfiability approaches to scheduling problems have been introduced. They have in common the use of relatively simple propagation mechanisms and an adaptive way to focus on the most constrained part of the problem. In some cases, these methods compare favorably to more classical constraint programming methods relying on propagation algorithms for global unary or cumulative resource constraints and dedicated search heuristics. In particular, we described an approach that combines restarting, with a generic adaptive heuristic and solution guided branching on a simple model based on a decomposition of disjunctive constraints. In this paper, we introduce an adaptation of this technique for an important subclass of job shop scheduling problems (JSPs), where the objective function involves minimization of earliness/tardiness costs. We further show that our technique can be improved by adding domain specific information for one variant of the JSP (involving time lag constraints). In particular we introduce a dedicated greedy heuristic, and an improved model for the case where the maximal time lag is 0 (also referred to as no-wait JSPs).Comment: Principles and Practice of Constraint Programming - CP 2011, Perugia : Italy (2011

Mass Activated Droplet Sorting (MADS) Enables Highâ Throughput Screening of Enzymatic Reactions at Nanoliter Scale

Microfluidic droplet sorting enables the highâ throughput screening and selection of waterâ inâ oil microreactors at speeds and volumes unparalleled by traditional wellâ plate approaches. Most such systems sort using fluorescent reporters on modified substrates or reactions that are rarely industrially relevant. We describe a microfluidic system for highâ throughput sorting of nanoliter droplets based on direct detection using electrospray ionization mass spectrometry (ESIâ MS). Droplets are split, one portion is analyzed by ESIâ MS, and the second portion is sorted based on the MS result. Throughput of 0.7â samplesâ sâ 1 is achieved with 98â % accuracy using a selfâ correcting and adaptive sorting algorithm. We use the system to screen â 15â 000â samples in 6â h and demonstrate its utility by sorting 25â nL droplets containing transaminase expressed in vitro. Labelâ free ESIâ MS droplet screening expands the toolbox for droplet detection and recovery, improving the applicability of droplet sorting to protein engineering, drug discovery, and diagnostic workflows.A microfluidic system for sorting nanoliter droplets based on mass spectrometry is presented. Fully automated, labelâ free sorting at 0.7â samplesâ sâ 1 is achieved with 98â % accuracy. In vitro transcription and translation (ivTT) of a transaminase enzyme in ca.â 25â nL samples is demonstrated and samples are sorted on the basis of enzyme activity.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154315/1/anie201913203.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154315/2/anie201913203-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154315/3/anie201913203_am.pd

Mass Activated Droplet Sorting (MADS) Enables Highâ Throughput Screening of Enzymatic Reactions at Nanoliter Scale

Microfluidic droplet sorting enables the highâ throughput screening and selection of waterâ inâ oil microreactors at speeds and volumes unparalleled by traditional wellâ plate approaches. Most such systems sort using fluorescent reporters on modified substrates or reactions that are rarely industrially relevant. We describe a microfluidic system for highâ throughput sorting of nanoliter droplets based on direct detection using electrospray ionization mass spectrometry (ESIâ MS). Droplets are split, one portion is analyzed by ESIâ MS, and the second portion is sorted based on the MS result. Throughput of 0.7â samplesâ sâ 1 is achieved with 98â % accuracy using a selfâ correcting and adaptive sorting algorithm. We use the system to screen â 15â 000â samples in 6â h and demonstrate its utility by sorting 25â nL droplets containing transaminase expressed in vitro. Labelâ free ESIâ MS droplet screening expands the toolbox for droplet detection and recovery, improving the applicability of droplet sorting to protein engineering, drug discovery, and diagnostic workflows.Ein Mikrofluidiksystem zur Sortierung von Nanolitertröpfchen basierend auf Massenspektrometrie erreicht eine vollautomatische markierungsfreie Sortierung bei 0.7 Probenâ sâ 1 mit 98â % Genauigkeit. Die Inâ vitroâ Transkription und â Translation (ivTT) eines Transaminaseâ Enzyms in Proben von etwa 25â nL wird demonstriert, und die Proben werden nach ihrer Enzymaktivität sortiert.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154446/1/ange201913203-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154446/2/ange201913203.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154446/3/ange201913203_am.pd

TAPCHA: An Invisible CAPTCHA Scheme

TAPCHA is a universal CAPTCHA scheme designed for touch-enabled smart devices such as smartphones, tablets and smartwatches. The main difference between TAPCHA and other CAPTCHA schemes is that TAPCHA retains its security by making the CAPTCHA test ‘invisible’ for the bot. It then utilises context effects to maintain the readability of the instruction for human users which eventually guarantees the usability of the scheme. Two reference designs, namely TAPCHA SHAPE & SHADE and TAPCHA MULTI are developed to demonstrate the use of this scheme

Active behaviour during early development shapes glucocorticoid reactivity

TGlucocorticoids are the final effectors of the stress axis, with numerous targets in the central nervous system and the periphery. They are essential for adaptation, yet currently it is unclear how early life events program the glucocorticoid response to stress. Here we provide evidence that involuntary swimming at early developmental stages can reconfigure the cortisol response to homotypic and heterotypic stress in larval zebrafish (Danio rerio), also reducing startle reactivity and increasing spontaneous activity as well as energy efficiency during active behaviour. Collectively, these data identify a role of the genetically malleable zebrafish for linking early life stress with glucocorticoid function in later life

Behavioural Thermoregulatory Tactics in Lacustrine Brook Charr, Salvelinus fontinalis

The need to vary body temperature to optimize physiological processes can lead to thermoregulatory behaviours, particularly in ectotherms. Despite some evidence of within-population phenotypic variation in thermal behaviour, the occurrence of alternative tactics of this behaviour is rarely explicitly considered when studying natural populations. The main objective of this study was to determine whether different thermal tactics exist among individuals of the same population. We studied the behavioural thermoregulation of 33 adult brook charr in a stratified lake using thermo-sensitive radio transmitters that measured hourly individual temperature over one month. The observed behavioural thermoregulatory patterns were consistent between years and suggest the existence of four tactics: two “warm” tactics with both crepuscular and finer periodicities, with or without a diel periodicity, and two “cool” tactics, with or without a diel periodicity. Telemetry data support the above findings by showing that the different tactics are associated with different patterns of diel horizontal movements. Taken together, our results show a clear spatio-temporal segregation of individuals displaying different tactics, suggesting a reduction of niche overlap. To our knowledge, this is the first study showing the presence of behavioural thermoregulatory tactics in a vertebrate

Spatial Patterns in Herbivory on a Coral Reef Are Influenced by Structural Complexity but Not by Algal Traits

Background: Patterns of herbivory can alter the spatial structure of ecosystems, with important consequences for ecosystem functions and biodiversity. While the factors that drive spatial patterns in herbivory in terrestrial systems are well established, comparatively less is known about what influences the distribution of herbivory in coral reefs. Methodology and Principal Findings: We quantified spatial patterns of macroalgal consumption in a cross-section of Ningaloo Reef (Western Australia). We used a combination of descriptive and experimental approaches to assess the influence of multiple macroalgal traits and structural complexity in establishing the observed spatial patterns in macroalgal herbivory, and to identify potential feedback mechanisms between herbivory and macroalgal nutritional quality. Spatial patterns in macroalgal consumption were best explained by differences in structural complexity among habitats. The biomass of herbivorous fish, and rates of herbivory were always greater in the structurally-complex coral-dominated outer reef and reef flat habitats, which were also characterised by high biomass of herbivorous fish, low cover and biomass of macroalgae and the presence of unpalatable algae species. Macroalgal consumption decreased to undetectable levels within 75 m of structurally-complex reef habitat, and algae were most abundant in the structurally-simple lagoon habitats, which were also characterised by the presence of the most palatable algae species. In contrast to terrestrial ecosystems, herbivory patterns were not influenced by the distribution, productivity or nutritional quality of resources (macroalgae), and we found no evidence of a positive feedback between macroalgal consumption and the nitrogen content of algae. Significance: This study highlights the importance of seascape-scale patterns in structural complexity in determining spatial patterns of macroalgal consumption by fish. Given the importance of herbivory in maintaining the ability of coral reefs to reorganise and retain ecosystem functions following disturbance, structural complexity emerges as a critical feature that is essential for the healthy functioning of these ecosystems

Current strategies for treatment of intervertebral disc degeneration: substitution and regeneration possibilities

Background: Intervertebral disc degeneration has an annual worldwide socioeconomic impact masked as low back pain of over 70 billion euros. This disease has a high prevalence over the working age class, which raises the socioeconomic impact over the years. Acute physical trauma or prolonged intervertebral disc mistreatment triggers a biochemical negative tendency of catabolic-anabolic balance that progress to a chronic degeneration disease. Current biomedical treatments are not only ineffective in the long-run, but can also cause degeneration to spread to adjacent intervertebral discs. Regenerative strategies are desperately needed in the clinics, such as: minimal invasive nucleus pulposus or annulus fibrosus treatments, total disc replacement, and cartilaginous endplates decalcification. Main Body: Herein, it is reviewed the state-of-the-art of intervertebral disc regeneration strategies from the perspective of cells, scaffolds, or constructs, including both popular and unique tissue engineering approaches. The premises for cell type and origin selection or even absence of cells is being explored. Choice of several raw materials and scaffold fabrication methods are evaluated. Extensive studies have been developed for fully regeneration of the annulus fibrosus and nucleus pulposus, together or separately, with a long set of different rationales already reported. Recent works show promising biomaterials and processing methods applied to intervertebral disc substitutive or regenerative strategies. Facing the abundance of studies presented in the literature aiming intervertebral disc regeneration it is interesting to observe how cartilaginous endplates have been extensively neglected, being this a major source of nutrients and water supply for the whole disc. Conclusion: Severalinnovative avenues for tackling intervertebral disc degeneration are being reported â from acellular to cellular approaches, but the cartilaginous endplates regeneration strategies remain unaddressed. Interestingly, patient-specific approaches show great promise in respecting patient anatomy and thus allow quicker translation to the clinics in the near future.The authors would like to acknowledge the support provided by the Portuguese Foundation for Science and Technology (FCT) through the project EPIDisc (UTAP-EXPL/BBBECT/0050/2014), funded in the Framework of the “International Collaboratory for Emerging Technologies, CoLab”, UT Austin|Portugal Program. The FCT distinctions attributed to J. Miguel Oliveira (IF/00423/2012 and IF/01285/ 2015) and J. Silva-Correia (IF/00115/2015) under the Investigator FCT program are also greatly acknowledged.info:eu-repo/semantics/publishedVersio