Secondary Transition Research Articles

Low pressure‐induced secondary structure transitions of regenerated silk fibroin in its wet film studied by time‐resolved infrared spectroscopy

The secondary structure transitions of regenerated silk fibroin (RSF) under different external perturbations have been studied extensively, except for pressure. In this work, time-resolved infrared spectroscopy with the attenuated total reflectance (ATR) accessory was employed to follow the secondary structure transitions of RSF in its wet film under low pressure. It has been found that pressure alone is favorable only to the formation of β-sheet structure. Under constant pressure there is an optimum amount of D2 O in the wet film (D2 O:film = 2:1) so as to provide the optimal condition for the reorganization of the secondary structure and to have the largest formation of β-sheet structure. Under constant amount of D2 O and constant pressure, the secondary structure transitions of RSF in its wet film can be divided into three stages along with time. In the first stage, random coil, α-helix, and β-turn were quickly transformed into β-sheet. In the second stage, random coil and β-turn were relatively slowly transformed into β-sheet and α-helix, and the content of α-helix was recovered to the value prior to the application of pressure. In the third and final stage, no measurable changes can be found for each secondary structure. This study may be helpful to understand the secondary structure changes of silk fibroin in silkworm's glands under hydrostatic pressure.

Surface and Thermodynamic Characterizations and Secondary Transition of Novel Phthalocyanine Glass

The novel 4-(3-tert-butyl-4-hydroxyanisole)]phthalonitrile and its peripherally tetra substituted zinc phthalocyanine complex [2,9(10),16(17),23(24)-tetrakis(4-(3-tert-butyl-4-hydroxyanisole) phthalocyaninato]zinc(II) (ZnPc) were synthesized and characterized by elemental and spectroscopic analysis techniques. The inverse gas chromatography (IGC) method was used to obtain secondary transition, surface properties, and thermodynamic interaction parameters of the phthalocyanine glass. Phthalocyanine selectivity was investigated using the acetate and alcohol isomers by IGC method at temperatures between 313.2 and 423.2 K. The secondary transition temperature was obtained by IGC method and differential scanning calorimetry (DSC). The dispersive component of the surface free energy, γSD, of adsorbent surface was calculated in the infinite dilution region. The specific enthalpy of adsorption, ΔHAS, the specific free energy of adsorption, ΔGAS and the specific entropy of adsorption, ΔSAS of solvents on ZnPc were ...

A range of transition activities

It is really worth the effort to get your primary to secondary school transition support processes right. Jason Wing takes us through the raft of activities that help to ensure year 7 pupils hit the ground running when they join his schools

Pupils' Expectations and Experiences of PE across the Primary–secondary Transition in South Wales

This article was published in Cylchgrawn Addysg Cymru/Wales Journal of Education on 1 March 2018, available at https://doi.org/10.16922/wje.20.1.6

Cyanidin-3-rutinoside reduces insulin fibrillation and attenuates insulin fibrils-induced oxidative hemolysis of human erythrocytes

Insulin is able to form amyloid-like fibrils, a misfolding process by which insulin molecules interact with each other to form aggregates and pathological amyloid deposition. Inhibition of amyloid aggregation using natural products is proposed as a new strategy to prohibit the development of amyloid diseases. Herein, we demonstrated the inhibitory effect of cyanidin-3-rutinoside (C3R), a natural anthocyanin with multiple biological activities, against insulin amyloid fibrillation. The results showed that increased insulin concentration resulted in faster growth and higher amounts of insulin fibrils. C3R (10.6–170μM) concentration dependently decreased insulin fibril growth and increased the duration of lag time of insulin fibril formation. Moreover, C3R directly decreased the secondary structure transition from α-helix to β-sheet structure. C3R (0.31–5μM) attenuated insulin fibrils-induced oxidative hemolysis of human erythrocytes in a concentration-dependent manner. Moreover, C3R reduced insulin fibrils-induced erythrocyte membrane disruption through the inhibition of reactive oxygen species (ROS) generation. The findings also suggest that C3R reduced fibrils-induced membrane lipid peroxidation by maintaining the catalase activity and oxidized/reduced glutathione content (GSH/GSSH) in erythrocytes. These findings suggest that C3R may serve as a potential inhibitory agent against amyloid fibril formation and insulin fibrils-induced oxidative hemolysis.

A Look at the Past, Present, and Future of Rural Secondary Transition

Depending on which date is attributed to the birth of secondary transition, it can be considered anywhere from 27 to 57 years old. No matter which date is used, it has been a while since the field “took stock” of itself. Therefore, the purpose of this article is to (a) briefly summarize where the field of secondary transition has been; (b) briefly summarize where we think the field of secondary transition now stands in terms of student postschool outcomes and barriers to successful outcomes in rural communities; and (c) conclude with some thoughts on what is next, how we might get there, and what this means for secondary transition in rural areas.

Inhibition of β-Amyloid Aggregation through a Designed β-Hairpin Peptide.

Designing peptide-based drugs to target the β-sheet-rich toxic intermediates during the aggregation of amyloid-β 1-42 (Aβ1-42) has been a major challenge. In general, β-sheet breaker peptides (BSBPs) are designed to complement the enthalpic interactions with the aggregating protein, and entropic effects are usually ignored. Here, we have developed a conformationally constrained cyclic BSBP by the use of an unnatural amino acid and a disulfide bond. We show that our peptide strongly inhibits the aggregation of Aβ1-42 in a concentration-dependent manner. It stabilizes the random coil conformation of Aβ1-42 monomers and inhibits the secondary structural transition to a β-sheet-rich conformation which allows Aβ1-42 to oligomerize in an ordered assembly during its aggregation. Our cyclic peptide also rescues the toxicity of soluble aggregates of Aβ1-42 toward neuronal cells. However, it significantly loses its potency in the conformationally relaxed acyclic form. It appears that limiting the loss of conformational entropy of the BSBP ligand can play a very important role in the attainment of conformations for precise and tight binding, making them a potent inhibitor for Aβ1-42 amyloidosis.

Charge‐Induced Secondary Structure Transformation of Amyloid‐Derived Dipeptide Assemblies from β‐Sheet to α‐Helix

AbstractSecondary structures such as α‐helix and β‐sheet are the major structural motifs within the three‐dimensional geometry of proteins. Therefore, structure transitions from β‐sheet to α‐helix not only can serve as an effective strategy for the therapy of neurological diseases through the inhibition of β‐sheet aggregation but also extend the application of α‐helix fibrils in biomedicine. Herein, we present a charge‐induced secondary structure transition of amyloid‐derived dipeptide assemblies from β‐sheet to α‐helix. We unravel that the electrostatic (charge) repulsion between the C‐terminal charges of the dipeptide molecules are responsible for the conversion of the secondary structure. This finding provides a new perspective to understanding the secondary structure formation and transformation in the supramolecular organization and life activity.

Charge-Induced Secondary Structure Transformation of Amyloid-Derived Dipeptide Assemblies from β-Sheet to α-Helix.

Secondary structures such as α-helix and β-sheet are the major structural motifs within the three-dimensional geometry of proteins. Therefore, structure transitions from β-sheet to α-helix not only can serve as an effective strategy for the therapy of neurological diseases through the inhibition of β-sheet aggregation but also extend the application of α-helix fibrils in biomedicine. Herein, we present a charge-induced secondary structure transition of amyloid-derived dipeptide assemblies from β-sheet to α-helix. We unravel that the electrostatic (charge) repulsion between the C-terminal charges of the dipeptide molecules are responsible for the conversion of the secondary structure. This finding provides a new perspective to understanding the secondary structure formation and transformation in the supramolecular organization and life activity.

Identification of side chain effect as an important factor influencing the secondary relaxation of polyesters containing cyclohexylene ring

The conformational transition of cyclohexylene ring has been recognized as the secondary transition of polyesters containing this aliphatic ring structure. Previously, the stereochemistry, i.e., trans/cis ratio, has been identified as an important factor that has a significant impact on the conformational transition of the cyclohexylene ring. In this paper, we have proposed and proved the side chain effect as another important factor that plays the same role as the stereochemistry, due to the fact that the conformational transition of the ring is usually associated with the coupled motion of it with neighboring unit. Our strategy is to design and synthesize a series of polyesters with 1,4-cyclohexanedicarboxylic acid and diols with different side chains. Polyester without any side chain has the lowest secondary relaxation temperature (T β ). Incorporation of asymmetric short side chain will result in increased T β , since it will reduce the coupled motion of the neighboring unit with the cyclohexylene ring during the conformational transition process, and thus reduces the flexibility of the chain and increases steric hindrance. However, further incorporation of long side chain will result in decreased T β because of the plasticization effect. Moreover, we also found that polyesters with low T β tend to have not only better impact strength, but also good ductility and elasticity. Our study enables people to take advantage of the cyclohexylene ring structure for the design and synthesis of thermoplastic and elastomer with better performance.

Pupils’ reflections on the primary to secondary school transition with reference to modern language learning: a motivational self-system perspective

ABSTRACTPoints of transition in life are accepted as times which impact greatly on aspects of the individual’s psyche, including motivation to learn. In spite of this, pupils’ views are rarely heard in discussions of transition from primary to secondary school in general and in relation to modern languages in particular. This exploratory study investigated the motivation of young learners of foreign languages in one region of the UK at time of transitioning from primary school to secondary school. Ten to 12 year olds shared their views of the experience of transition and provided motivational insights which test the applicability of Dörnyei’s L2 ‘motivational self system’ [2005. The Psychology of the Language Learner: Individual Differences in Second Language Acquisition. Mahwah, NJ: Lawrence Erlbaum] for learners in this age group. Eighteen students were interviewed in their final year of primary school and again one year later in their first year of secondary school. Pupils identified foreign language learning as a generally a positive experience but one which could include, in the primary school, a higher level of challenge, more ‘real’ work and evidence to facilitate a feeling of making progress. This provided the background for consideration of whether these experiences contributed to focal pupils’ vision of self. The pupils’ messages resonate beyond the confines of foreign languages to other subjects and other transition experienced by young people around this age.

Using a Universal Design for Learning Checklist to Teach Secondary Transition Skills

The authors present a tool teachers can use to modify their instruction so that it is based on universal design and includes secondary transition topics and skills. This checklist includes Universal Design for Learning (UDL) checkpoints and prompts teachers to go through a set of guiding questions that focus on both UDL and secondary transition. Also included in the article are examples of how a general education teacher can use the checklist to design inclusive instruction around secondary transition topics.

Sound walk guide: A transition tool for autism spectrum disorder

Objective: The objective of this study was to design and create a ”Sound walk Guide” for children with autism spectrum disorder (ASD) transitioning between primary and secondary education. Methods: A literature review was conducted on transition tools used for children with ASD. This informed the development of a sound walk guide based on a sound walk audio tool. Results and Discussion: The literature review highlighted the sensory difficulties faced by children with autism during transition. It described some of the transition tools used in ASD from online training programs to virtual reality tools. However, there was little literature on specific tools for primary to secondary school transition. This informed the development of a user-friendly sound walk guide which was developed along with children and professionals in education and health.

Teaching for Self-Regulated Learning: Why Aim for Behavioural Compliance When We Can Inspire Learning?

This study explored teachers’ pedagogical practices for effective learning in the middle years of schooling. In the context of the primary–secondary schooling transition years in Australia, teacher interviews and classroom observations were conducted to investigate teachers’ everyday practices for planning, instruction, and classroom organisation to frame a pedagogy for self-regulated learning. Evidence-informed practices were identified and classified through the fundamentals for self-regulated learning to explain how the teachers provided opportunities aimed at enabling young adolescent students to rationalise their goals, to accept responsibility for their learning, and to develop their capabilities as resourceful learners within social learning environments. The outcome of this research is a pedagogical model for self-regulated learning. The significance of this model is that it informs teachers’ professional reflection and learning. The findings articulated four core pedagogies that explain what the teacher did to: connect the learning, facilitate the learning; diversify the learning; and socialise the learning. Through these core pedagogies the teachers provided external supports of motivation to generate students’ internal desires for learning that go beyond achieving their behavioural compliance. The model represents a self-regulatory approach to classroom behaviour management that is intended to inspire young adolescent students towards being resourceful learners.

'Reverse' Hofmeister effects on the sol-gel transition rates for an α-helical peptide-PEG bioconjugate.

We examine the dynamics of the sol-gel transition for end-functionalized linear- and 4-arm-peptides bioconjugated to poly-ethylene glycol (PEG) in aqueous environments with increasingly chaotropic (Cl- < Br- < I-) anions. A 23-amino acid peptide sequence is rationally designed to self-assemble upon folding into the ordered α-helical conformation due to the hydrophobic effect. We use Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR) to quantify the ensemble average reversible secondary structure transitions as a function of electrolyte concentration and specific ion effects along the Hofmeister series. Subsequently, microrheology is used to quantify the kinetics of the gelation process, as it relates to folding and specific ion interactions. Our key findings were non-intuitive. We observe the faster evolution of the gel transitions in systems with more chaotropic anions. For our peptides in aqueous solution, "water-structuring" ions yield faster assembly behavior with a viscoelastic exponent, n, closer to unity representing self-assemblies that are Rouse-like. In contrast, ions that are "water-breaking" resulted in smaller viscoelastic exponents where self-assembly dynamics result in a viscoelastic exponent that suggests polymer entanglements.

Screening for amyloid-β aggregation inhibitor and neuronal toxicity of eight Tunisian medicinal plants

The aggregation and deposition of misfolded β-amyloid peptide (Aβ42) is a consistent pathological hallmark of Alzheimer Disease (AD). Mounting pieces of evidence indicate that the auto-assembly of Aß42 into toxic oligomers and fibrillar aggregates is a multi-steps process that causes an increase of ROS (Reactive oxygen species) level, disruption of calcium homeostasis and altered membrane integrity leading to neuronal death. Oxidation is thought to promote Aß42 aggregation, so the use of natural dietary antioxidants that can interfere or inhibit Aß aggregation and its cytotoxicity is a promising approach. In this study, we investigate a panel of extracts from eight Tunisian medicinal plants for their ability to counteract amyloid aggregation. A screening assay was developed to identify and to rank extracts that hinder Aβ aggregation. Thus, we report that secondary metabolites extracted from Lawsonia inermis L., Punica granatum L. and Pistacia lentiscus L. hinder Aβ42 aggregation during the early secondary structure transitions to amyloid by inhibiting the conformational changes to a β sheet-rich structure, thus inhibiting its polymerization and fibrillogenisis. Cellular study allowed us to select the extract of L. inermis as the most bioactive extract; we showed that the extract of L. inermis reduces the toxicity, ROS and calcium levels induced by Aß42 aggregates. FRET analysis confirmed the ability of the extract of L. inermis to inhibit the interaction between Aβ42 aggregates and plasma membrane, thus reducing their cytotoxicity. These results suggested that methanolic extract from L. inermis could act as neuroprotective and therapeutic factors against toxic Aβ aggregates.

Transition-Focused Professional Development: An Annotated Bibliography of Essential Elements and Features of Professional Development

Transition professional development (PD) has been identified as a way to improve transition services; however, there is a dearth of literature on transition-focused PD. To learn more about the essential features of effective PD, 73 published articles were evaluated in the area of PD in both secondary transition and special education. Articles were selected that exemplified four essential elements for PD: (a) content focus, (b) active learning, (c) team-based participation, and (d) sustained planning and implementation. We identified specific features of PD that positively influenced teachers including (a) coaching and feedback, (b) collective participation among teachers, (c) consistent “manualized” content and training, and (d) active learning embedded in PD.

Steps for Implementing a State-Level Professional Development Plan for Secondary Transition

To scale up and sustain the use of evidence-based practices, it is imperative that state education agencies systematically implement professional development that represents best practice. By delivering quality professional development to local districts, it is more likely that transition personnel will implement transition programs and practices with fidelity to sustain implementation over time. To do this, it is important for state education agencies to develop a state-level stakeholder team to determine professional development needs across districts and develop a plan to systematically deliver professional development. This article describes seven steps for using data-based decision-making to develop and implement quality professional development at the local level to ensure districts across a state effectively and sustainably implement secondary transition evidence-based practices.

State of Personnel Preparation in Secondary Transition: Introduction to the Special Series

State of Personnel Preparation in Secondary Transition: Introduction to the Special Series

Status of Credentialing Structures Related to Secondary Transition: A State-Level Policy Analysis

To understand the current status of transition-related credentialing systems in driving personnel preparation, it is necessary to identify which state education and rehabilitation services agencies are currently providing certification and licensure in the area of secondary transition. The purpose of this study was to examine the current state of requirements related to secondary transition in states’ personnel credentialing systems. Results provide a snapshot of current state credentialing policies related to secondary transition and a clear view of policy changes that have occurred over the last 14 years. Limitations and implications for future research and practice are discussed.