A comprehensive comparative study on methylene blue removal from aqueous solution using biochars produced from rapeseed, whitewood, and seaweed via different thermal conversion technologies

This paper presents, for the first time, a comprehensive comparative analysis of the potential of using biochars from three distinctly different UK-sourced biomass feedstocks, produced via three different thermal processing techniques, to adsorb methylene blue dye. Biochars were made from rapeseed, whitewood, and seaweed (Laminaria Digitata), produced via hydrothermal conversion, pyrolysis, and torrefaction. Adsorption kinetic models were developed for each biochar at different temperatures, pH and initial dye concentrations. Relatively high levels of methylene blue adsorption capacity were achieved by seaweed-based biochars (∼150 mg/g), with reasonable levels for rapeseed-based biochars (∼60 mg/g), whilst adsorption levels were found to be relatively low for whitewood-based biochars (<30 mg/g). A Pseudo-second-order kinetic model provided the best fit with experimental results. The Langmuir adsorption isotherm showed a better fit for seaweed biochars, while the Freundlich adsorption isotherm was a better fit for the rapeseed-based biochars. The Langmuir adsorption isotherms showed relatively high maximum adsorption capacity (Qo) for seaweed-based biochars; ∼175 mg/g for seaweed-Torrefaction and ∼ 117 mg/g for seaweed-Pyrolysis. Negative Gibbs free energy (ΔG°) values were observed for the seaweed-Torrefaction < seaweed-Pyrolysis < 0, which indicates that the methylene blue removal could be a thermodynamically favourable process due to the spontaneous nature of the adsorption. Our investigation has shown that the removal of methylene blue from wastewater could be a potential application for seaweed-based biochars as part of a holistic whole life cycle valorisation pathway. However, it is not suitable for all types of biomasses which emphasises the need for tailoring unique valorisation pathways for different types of biomasses

An assessment on the effect of collaborative groups on students’ problem-solving strategies and abilities

This paper reports the use of tools to probe the effectiveness of using small-group interaction to improve problem solving. We find that most students&apos; problem-solving strategies and abilities can be improved by working in short-term, collaborative groups without any other intervention. This is true even for students who have stabilized on a problem-solving strategy and who have stabilized at a problem-solving ability level. Furthermore, we find that even though most students improve by a factor of about 10% in student ability, there are two exceptions: Female students who are classified as pre-formal on a test of logical thinking improve by almost 20% when paired with concrete students; however if two students at the concrete level are paired together no improvement is seen. It has been said that problem solving is the ultimate goal of education (1), and certainly this is true in any chemistry course (2). To be sure, most instructors value this skill and try to instill the ability to solve problems in their students. However, the term &quot;problem solving&quot; means different things to different audiences, from algorithmic problems to complex, open-ended problems that do not have one particular solution. A number of attempts have been made to define problem solving, including &quot;any goal-directed sequence of cognitive operations&quot; (3), and many now agree with the general definition: &quot;what you do when you don&apos;t know what to do&quot; (4). Problem solving can be closely allied to critical thinking (5), that other goal of most science courses, in that it involves the application of knowledge to unfamiliar situations. Problem solving also requires the solver to analyze the situation and make decisions about how to proceed, which critical thinking helps. A number of information processing models for problem solving have been developed (6-8) and attempts made to develop uniform theories of problem solving (9). However, many of these studies involve knowledge-lean, closed problems (2) that do not require any specific content knowledge to solve, and that have a specific path to the answer. The truth is that many types of problems exist and there is not one model that will be effective for all categories (10). For example, in teaching science we are ultimately concerned with knowledge-rich problems requiring scientific content knowledge. Studies on problem solving in chemistry have typically revolved around development of strategies derived from research on closed-ended problems, usually pinpointing areas of difficulty that students encounter in specific subject types, such as stoichiometry or equilibrium. A number of studies where students are given strategies or heuristics allowing them resolve word problems in order to produce a numerical answer by application of an algorithm Open-ended problem solving that requires students to use data to make inferences, or to use critical thinking skills, is much more difficult to incorporate into introductory (and even higher level) courses; it is even more difficult to assess, particularly when large numbers of students are involved. Traditional assessment methods, such as examinations and quizzes-including both short answer and multiple choice-give very little insight into the problem-solving process itself. If a student does not have a successful problem-solving strategy, these methods may not allow either the student or the instructor to see where the difficulty lies, or to find ways to improve. While other investigation methods such as think-aloud protocols and videotaped problem-solving sessions (14) give a more nuanced picture of the problem-solving process (15-17), these techniques are time consuming, expensive, and require specific expertise to analyze. These methods are certainly not applicable for the formative assessment of large numbers of students, and while they give a snapshot of a student&apos;s problem-solving ability at the time of observation, it is even more difficult to monitor students&apos; development of problem-solving expertise over an extended period. The upshot of all this previous research is that while we know a great deal about the problem-solving process in an abstract environment, we do not in fact have much insight into how students solve many types of scientific problems. Since we lack this information about how students approach problems and how students achieve competence, it is not easy to address the difficulties that students encounter as they develop problemsolving abilities. Indeed, while instructors value problem-solving skills highly, it is often the case that the only explicit instruction that many students are exposed to is the modeling of the skill as the instructor solves problems for students. So we have a situation where a valued skill is often not fully developed in students, even though we implicitly expect that they will become competent problem solvers by the end of the course. The most common assessments give no real insight into student strategies for problem solving, and therefore there is little feedback the instructor can give in terms of how to improve. The traditional assessments also tend to measure and reward algorithmic problem-solving skills rather than critical thinking and application of knowledge to new situations. It seems clear that if we are serious about wanting to incorporate meaningful problem solving into our courses, then we must go beyond the traditional assessments and design systems that allow us t

Rhodium(II) Proximity-Labeling Identifies a Novel Target Site on STAT3 for Inhibitors with Potent Anti-Leukemia Activity

Nearly 40 % of children with acute myeloid leukemia (AML) suffer relapse arising from chemoresistance, often involving upregulation of the oncoprotein STAT3 (signal transducer and activator of transcription 3). Herein, rhodium(II)-catalyzed, proximity-driven modification identifies the STAT3 coiled-coil domain (CCD) as a novel ligand-binding site, and we describe a new naphthalene sulfonamide inhibitor that targets the CCD, blocks STAT3 function, and halts its disease-promoting effects in vitro, in tumor growth models, and in a leukemia mouse model, validating this new therapeutic target for resistant AML

A Community-Building Framework for Collaborative Research Coordination across the Education and Biology Research Disciplines

Since 2009, the U.S. National Science Foundation Directorate for Biological Sciences has funded Research Coordination Networks (RCN) aimed at collaborative efforts to improve participation, learning, and assessment in undergraduate biology education (UBE). RCN-UBE projects focus on coordination and communication among scientists and educators who are fostering improved and innovative approaches to biology education. When faculty members collaborate with the overarching goal of advancing undergraduate biology education, there is a need to optimize collaboration between participants in order to deeply integrate the knowledge across disciplinary boundaries. In this essay we propose a novel guiding framework for bringing colleagues together to advance knowledge and its integration across disciplines, the “Five ‘C’s’ of Collaboration: Commitment, Collegiality, Communication, Consensus, and Continuity.” This guiding framework for professional network practice is informed by both relevant literature and empirical evidence from community-building experience within the RCN-UBE Advancing Competencies in Experimentation–Biology (ACE-Bio) Network. The framework is presented with practical examples to illustrate how it might be used to enhance collaboration between new and existing participants in the ACE-Bio Network as well as within other interdisciplinary networks

The role of input noise in transcriptional regulation

Even under constant external conditions, the expression levels of genes fluctuate. Much emphasis has been placed on the components of this noise that are due to randomness in transcription and translation; here we analyze the role of noise associated with the inputs to transcriptional regulation, the random arrival and binding of transcription factors to their target sites along the genome. This noise sets a fundamental physical limit to the reliability of genetic control, and has clear signatures, but we show that these are easily obscured by experimental limitations and even by conventional methods for plotting the variance vs. mean expression level. We argue that simple, global models of noise dominated by transcription and translation are inconsistent with the embedding of gene expression in a network of regulatory interactions. Analysis of recent experiments on transcriptional control in the early Drosophila embryo shows that these results are quantitatively consistent with the predicted signatures of input noise, and we discuss the experiments needed to test the importance of input noise more generally.Comment: 11 pages, 5 figures minor correction

Effects of an open-label pilot study with high-dose EPA/DHA concentrates on plasma phospholipids and behavior in children with attention deficit hyperactivity disorder

<p>Abstract</p> <p>Background</p> <p>Attention deficit hyperactivity disorder (ADHD) is the most common neurological condition in children. This pilot study evaluated the effects of high-dose eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) supplementation on the isolated plasma phospholipids and behavior in children with ADHD (primarily inattentive subtype and combined subtype).</p> <p>Methods</p> <p>Nine children were initially supplemented with 16.2 g EPA/DHA concentrates per day. The dosage was adjusted dependent on the ratio of arachidonic acid (AA) to EPA in the isolated plasma phospholipids at four weeks to reach a level normally found in the Japanese population.</p> <p>Results</p> <p>At the end of the eight-week study, supplementation resulted in significant increases in EPA and DHA, as well as a significant reduction in the AA:EPA ratio (20.78 ± 5.26 to 5.95 ± 7.35, p < 0.01). A psychiatrist (blind to supplement compliance or dosage modifications) reported significant improvements in behavior (inattention, hyperactivity, oppositional/defiant behavior, and conduct disorder). There was also a significant correlation between the reduction in the AA:EPA ratio and global severity of illness scores.</p> <p>Conclusion</p> <p>The findings of this small pilot study suggest supplementation with high-dose EPA/DHA concentrates may improve behavior in children with ADHD.</p

Another intermediate mass black hole in a starburst galaxy?: The luminous X-ray source in NGC 3628 reappears

In a 52 ks-long Chandra ACIS-S observation of the nearby starburst galaxy NGC 3628, obtained to study the starburst-driven outflow from this galaxy, we have detected a very luminous (L_X = 1.1e40 erg/s in the 0.3-8.0 keV energy band) point source located at least 20 arcsec (~970 pc) from the nucleus of the galaxy. No radio, optical or near-IR counterpart to this source has been found. This is most probably the reappearance of the strongly-variable X-ray-luminous source discovered by Dahlem et al (1995), which faded by a factor >27 between December 1991 and March 1994 (at which point it had faded below the detection limit in a ROSAT HRI observation). This source is clearly a member of an enigmatic class of X-ray sources that are considerably more luminous than conventional X-ray binaries but less luminous than AGN, and which are not found at the dynamical center of the host galaxy. The Chandra spectrum is best-fit by an absorbed power law model with a photon index of Gamma = 1.8+/-0.2, similar to that seen in Galactic BH binary candidates in their hard state. Bremsstrahlung models or multi-color disk models (the favored spectral model for objects in this class based on ASCA observations) can provide statistically acceptable fits only if the data at energies E > 5 keV is ignored. This is one of the first X-ray spectra of such an object that is unambiguously that of the source alone, free from the spectral contamination by X-ray emission from the rest of the galaxy that affects previous spectral studies of these objects using ASCA.Comment: Accepted for publication in the Ap