Secondary Transition Research Articles

The Impact of Secondary School Transition on Self-Concept and Self-Esteem

Secondary school transition takes place earlier in Portugal than in most Western countries. This study aims to analyze the impact of this transition on the self-concept and self-esteem of Portuguese students, and to identify potential differential gender impacts. The sample included 377 students (Mage=9.46; SD=.93; 52.8% boys). Self-report questionnaires were administered in 4th grade (middle and end) and 5th grade (beginning and end). Multilevel linear modeling with a repeated measures design was used to evaluate the evolution of self-perceptions during secondary school transitions. Results show significant decreases in all dimensions of self-concept and in self-esteem during this transition. Gender differences emerged with boys showing greater decreases in emotional self-concept and girls in academic self-concept. Students retained at the end of 5th grade had greater declines in all self-perceptions. The results highlight the importance of intervention to prevent the negative impact of secondary school transition on self-perceptions.

Updated level scheme of 172Yb from 171Yb(n[formula omitted], γ) reaction studied via gamma–gamma coincidence spectrometer

This paper provides the updated information on the level scheme of 172Yb nucleus studied via 171Yb(nth, γ) reaction using the gamma–gamma coincidence spectrometer at Dalat Nuclear Research Institute (Viet Nam). The latter is used because of its advantages in achieving the low Compton background as well as in identifying the correlated gamma transitions. We have detected in total the energies and intensities of 128 two-step gamma cascades corresponding to 79 primary transitions. By comparing the measured data with those extracted from the ENSDF library, 61 primary gamma transitions and corresponding energy levels together with 20 secondary gamma transitions are found to be the same as the ENSDF data. Beside that, 18 additional primary gamma transitions and corresponding energy levels plus 108 secondary ones are not found to currently exist in this library and they are therefore considered as the new data.

Sequential Order of the Secondary Structure Transitions of Proteins under External Perturbations: Regenerated Silk Fibroin under Thermal Treatment.

Whether the process of protein folding/unfolding is fully cooperative or it contains sequential elements has long been a fundamental issue in protein science. This issue seemingly became straightforward since the appearance of generalized two-dimensional (2D) correlation spectroscopy in 1990s, because 2D correlation analysis has been considered as a convenient and powerful analytical tool to determine the sequential order of events under external physical or chemical perturbations. In this work, the sequential order of the secondary structure transitions of regenerated silk fibroin under thermal treatment from 130 to 220 °C was first studied using generalized 2D correlation spectroscopy, but an apparently doubtful sequential order was obtained; β-sheet was the first one to change at low temperature, then the random coil, followed by the nonamide C═O and, finally, the α-helix. A subsequent detailed in situ infrared spectral analysis showed that the main secondary structures of silk fibroin, including α-helix, β-turn, random coil and β-sheet (high-wavenumber component), all changed with a fully cooperative manner at a relatively low temperature of 150 °C. But the low-wavenumber component of β-sheet started to change at a higher temperature of 180 °C. Besides, it has also been found that, before 200 °C, the loss of α-helix and random coil was transformed into β-turn, β-sheet, and nonamide C═O. After 200 °C, some β-turn structure was also disruptured and transformed into β-sheet and nonamide C═O.

Dynamic mineral clouds on HD 189733b

Context. As the 3D spatial properties of exoplanet atmospheres are being observed in increasing detail by current and new generations of telescopes, the modelling of the 3D scattering effects of cloud forming atmospheres with inhomogeneous opacity structures becomes increasingly important to interpret observational data. Aims. We model the scattering and emission properties of a simulated cloud forming, inhomogeneous opacity, hot Jupiter atmosphere of HD 189733b. We compare our results to available Hubble Space Telescope (HST) and Spitzer data and quantify the effects of 3D multiple scattering on observable properties of the atmosphere. We discuss potential observational properties of HD 189733b for the upcoming Transiting Exoplanet Survey Satellite (TESS) and CHaracterising ExOPlanet Satellite (CHEOPS) missions. Methods. We developed a Monte Carlo radiative transfer code and applied it to post-process output of our 3D radiative-hydrodynamic, cloud formation simulation of HD 189733b. We employed three variance reduction techniques, i.e. next event estimation, survival biasing, and composite emission biasing, to improve signal to noise of the output. For cloud particle scattering events, we constructed a log-normal area distribution from the 3D cloud formation radiative-hydrodynamic results, which is stochastically sampled in order to model the Rayleigh and Mie scattering behaviour of a mixture of grain sizes. Results. Stellar photon packets incident on the eastern dayside hemisphere show predominantly Rayleigh, single-scattering behaviour, while multiple scattering occurs on the western hemisphere. Combined scattered and thermal emitted light predictions are consistent with published HST and Spitzer secondary transit observations. Our model predictions are also consistent with geometric albedo constraints from optical wavelength ground-based polarimetry and HST B band measurements. We predict an apparent geometric albedo for HD 189733b of 0.205 and 0.229, in the TESS and CHEOPS photometric bands respectively. Conclusions. Modelling the 3D geometric scattering effects of clouds on observables of exoplanet atmospheres provides an important contribution to the attempt to determine the cloud properties of these objects. Comparisons between TESS and CHEOPS photometry may provide qualitative information on the cloud properties of nearby hot Jupiter exoplanets.

Brazilin Inhibits Prostatic Acidic Phosphatase Fibrillogenesis and Decreases its Cytotoxicity.

A 39-amino acid peptide fragment that is derived from prostatic acidic phosphatase (PAP), PAP248-286 , is secreted in large amounts in human semen and forms amyloid fibrils. These fibrils can capture HIV virions and increase the attachment of virions to target cells; as such, they are called a "semen-derived enhancer of virus infection" (SEVI). Therefore, the inhibition of the formation of PAP248-286 amyloid fibrils is of great significance. Herein, we demonstrate that brazilin effectively inhibits PAP248-286 aggregation. The inhibitory effect increases with increasing brazilin concentration. Thioflavin T fluorescence assays and TEM observations confirmed that a few fibrils formed when brazilin was present with PAP248-286 in an equimolar concentration. Circular dichroism spectroscopy indicated that brazilin inhibited the secondary structural transitions from α-helices and random coils into β-sheets. Cytotoxicity assays showed that brazilin significantly decreased the cytotoxicity of the fibrils at 0.01 mmol L-1 . Isothermal titration calorimetry revealed that hydrophobic interactions were the main driving force for the binding of brazilin to the PAP248-286 monomer (dissociation constant, 4.03 μmol L-1 ), and that the binding affinity of brazilin for the fibrils was at least three orders of magnitude lower than that for the monomer. These results indicate that brazilin holds great potential as a small-molecule agent against SEVIs.

Suppressing prompt splash with polymer additives

Splash suppression during drop impact continues to be a grand challenge. To date, only a few techniques for the complete suppression of splash exist. Reducing the ambient pressure and using complex surfaces (microstructured and/or soft) are two of the recently discovered ones which may not be very practical in many technological processes. The idea of using additives directly into the liquid used to produce the drops, to inhibit this undesirable phenomenon, is, therefore, desired. Prompt splash is a type of splashing that releases diminutive droplets at high speeds from the tip of the lamella at the spreading liquid-substrate contact line immediately after the impact (within the first 10 μm), without generating the typical thin-sheet or corona. Prompt splash remained hidden for many years until high-speed imaging allowed for its visualisation. Here, we demonstrate that by adding very low amounts of polymer (around 0.01 wt%) into normally splashing water droplets a reduction and even a complete suppression of the prompt splash is observed. In this work, a systematic experimental study of the impact of viscoelastic drops, by varying size, impact velocity, and the “degree” of viscoelasticity, is conducted. When capillary forces are insufficient to maintain the integrity of the drop, elastic forces seem to pull the attached small droplets/fingers back to the lamella preventing their ejection and, therefore, inhibiting prompt splash. However, surprisingly, larger quantities of the polymer additive lead to a secondary transition, in which another, more common, type of splash is induced: corona splash.

Salt-Induced Swelling and Volume Phase Transition of Polyelectrolyte Gels

A theoretical model of polyelectrolyte gels is presented to study continuous and discontinuous volume phase transitions induced by changing salt concentration in the external solution. Phase diagrams are constructed in terms of the polymer–solvent interaction parameters, external salt concentration, and concentration of fixed charges. Comparisons with previous experiments for an ionized acrylamide gel in mixed water–acetone solvents are made with good quantitative agreement for a monovalent salt (NaCl) but fair qualitative agreement for a divalent salt (MgCl2), using a simple set of parameters for both cases. The effective polymer–solvent interactions vary with the volume fraction of acetone in the mixed solvent, leading to either continuous or discontinuous volume transitions. The presence of divalent ions (Mg2+) in addition to monovalent ions in the external solution reduces the critical salt concentration for the discontinuous transition by several orders of magnitude. Moreover, a secondary continuous transition is predicted between two highly swollen states for the case of a divalent salt. The present model may be further extended to study volume phase transitions of polyelectrolyte gels in response to other stimuli such as temperature, pH and electrical field.

Thermomechanical and large deformation behaviors of antiplasticized epoxy resins: Effect of material formulation and network architecture

A series of amine‐hardened epoxies were prepared by systematically varying the stoichiometric ratio and the relative amounts of diepoxide and monoepoxide resin to chemically control the material composition and macromolecular architecture (chain segments flexibility; crosslink density; amounts of dangling groups). Positron Annihilation Lifetime Spectroscopy was used to investigate the free volume associated to the various epoxy formulations, while dynamic‐mechanical analysis was employed to investigate their network density and their primary and secondary mechanical relaxations. The mechanical behavior at small and large strain was studied by means of tensile and compression tests. The results pointed out that deviations from the ideal stoichiometric composition and the addition of monoepoxide resins lead to significant room temperature stiffening, together with a reduction of the crosslink density and glass transition temperature. This behavior, phenomenologically associated to antiplasticization, was interpreted according to the specific macromolecular architecture and ascribed to chain mobility hindrance, as revealed by secondary transitions, whereas no significant contribution from the free volume could be evidenced. Furthermore, it was shown that depending on the strain scale and on the corresponding deformational mechanisms, the mechanical response may be differently influenced either by the presence of dangling groups or by the network density. POLYM. ENG. SCI., 57:553–565, 2017. © 2017 Society of Plastics Engineers

UCST‐type phase transition driven by protein‐derived polypeptide employing gelatin and chitosan

Here, we describe the thermosensitive reversible phase transition behaviors of polyelectrolyte complex composed of gelatin and chitosan (G/C complex). An aqueous dispersion of the G/C complexes showed a clear upper critical solution temperature (UCST) at around 30°C. The thermosensitive phase transition behavior showed excellent reversibility and large thermal hysteresis as a usual phenomenon based on the intra‐ and inter‐molecular interaction change. A high correlation was observed between the UCST of the G/C complex and the helix‐melting temperature of gelatin by circular dichroism, which suggested that the phase transition of the G/C complex corresponded to the secondary structure (helix‐coil) transition of gelatin. Notably, the UCST of the G/C complex shifted to lower temperatures in the presence of urea, which is well known to destabilize gelatin, whereas the addition of salt led to the dissolution of the G/C complex. It is envisaged that the results of this study will have a significant impact on the fabrication of UCST‐type thermosensitive materials, which can be utilized under aqueous physiological conditions using well‐known biopolymers. This protein‐derived functional material, which responds to the secondary structure transition, could also be used for the development of novel UCST‐type thermosensitive biomaterials. Copyright © 2017 John Wiley & Sons, Ltd.

Fluid reasoning skills at the high school transition predict subsequent dropout

The purpose of this study is to examine the prospective association between fluid reasoning skills in seventh grade and subsequent high school dropout in an at-risk population, independent of a number of important confounders. Participants are 4962 students from one of 56 high schools in the French Canadian province of Quebec. Three quarters of participants were intentionally representative of all schools in disadvantaged areas of the province. The Standard Progressive Matrices was administered to assess fluid reasoning, defined as the requisite skills for critical thought and complex problem resolution in novel situations, regardless of task and setting characteristics. Leaving high school from eighth grade onward, as a developmental milestone, was officially tracked and recorded by government sources. Dropout status was assigned if registration in school was discontinued without returning or obtaining a diploma within the period spanning from fall of Grade 8 to two years beyond expected graduation. Lower fluid reasoning skills significantly predicted less perseverance toward high school completion. Specifically, after adjusting for potential confounders, every standard deviation decrease in fluid reasoning predicted 21% increases in odds of dropout (OR=1.21; 95% C1=1.06–1.37). Youth showing below average fluid reasoning skills at the secondary transition might benefit from teacher-student support and technologically-based interventions that bolster knowledge acquisition and learning-related skills. Early approaches to screening and preventive stimulation before student trajectories become clearly characterized by indiscriminate underachievement might circumvent high school dropout and are likely to be more cost-effective than letting the bio-psycho-social developmental risks associated with dropout take their course.

Structural insight into the antiprion compound inhibition mechanism of native prion folding over misfolding.

Transition of a physiological folded prion (PrPC ) into a pathogenic misfolded prion (PrPSc ) causes lethal neurodegenerative disorders and prion diseases. Antiprion compounds have been developed to prevent this conversion; however, their mechanism of action remains unclear. Recently, we reported two antiprion compounds, BMD29 and BMD35, identified by in silico and in vitro screening. In this study, we used extensive explicit-solvent molecular dynamics simulations to investigate ligand-binding inhibition by antiprion compounds in prion folding over misfolding behavior at acidic pH. The two antiprion compounds and the previously reported GN8 compound resulted in a remarkably stabilized intermediate by binding to the hotspot region of PrPC , whereas free PrPC and the inactive compound BMD01 destabilized the structure of PrPC leading to the misfolded form. The results uncovered a secondary structural transition of free PrPC and transition suppression by the antiprion compounds. One of the major misfolding processes in PrPC , alternation of hydrophobic core residues, disruption of intramolecular interactions, and the increase in residue solvent exposure were significantly inhibited by both antiprion compounds. These findings provide insights into prion misfolding and inhibition by antiprion compounds.

The Importance of Self-Advocacy Skills for Students with Disabilities in Higher Education for a Full Inclusion and a Glimpse of Ethiopian Case: A Review of Related Literature

The transition from high schools to higher education institutions can be especially difficult for students with disabilities as the impetus for securing necessary accommodations falls on students themselves rather than on parents or on the institution as it did in high schools. Students with disabilities are still facing issues in both their transition to higher education institutions and their retention to complete a degree or certificate. Educators and researchers suggest that self-advocacy skills would address the issue. A self-advocacy skill is an evidence-based predictor in secondary transition, having an impact on improved post-school outcomes in education and employment. Coming to Ethiopia, over the last few years, higher educational institutions in Ethiopia increased from 11 to 32. Universities and enrollment rate also reached to 100,000 per annum. However, the number of students with disabilities in the universities is still low. Those who joined the universities have experienced challenges of different types ranging from academic to social. Ethiopian institutions do not have any explicit policy for students with disabilities. Similarly, the available provision for students with disabilities, if any, is negligible. For example, in the university where I work in students with physical impairments are facing lack of educational materials, non-inclusive environment (inaccessibility of library, dormitory, toilet rooms, classrooms, roads, and the like) and lack of awareness by the university community. Hence, although making higher institutions to be inclusive for students with disabilities is the responsibility of higher education communities and other stakeholders, students with disabilities are also expected to play a role (by using self-advocacy skills) to get appropriate services and supports to complete their education with better academic and psycho-social achievement that enable them to be competitive in the world of job and social integration, which is the aim of this review literature.

Effect of secondary relaxation transitions on photo-induced anisotropy in glassy azobenzene-functionalized polymers

The β-relaxation transition in side-chain azobenzene-functionalized amorphous polymers can be directly found from the temperature behavior of infrared dichroism.

School and institutional effects on secondary education transitions in Mexico

This study investigates school and institutional effects on student transitions to upper secondary, higher education, and the labor market in Mexico. I focus on school and institutional effects related to school resources, level of decentralization, and type of curriculum. Under the framework of human capital and signaling theory, I propose that the decision to pursue upper secondary and higher education depends on two main factors: first are the perceived returns to education at a school of certain characteristics; and second, the institutional characteristics of the attended school, such as level of centralization and type of curriculum. Using fixed effects and logistic regression models, I find evidence that schools matter in Mexico to foster transitions from lower secondary education to upper secondary education, particularly for students in the third quintile of test scores and higher. Similarly, I find evidence of school size as an important explanatory variable for transition outcomes in upper secondary education. Also, the socioeconomic status of schools is important and institutional effects vary on each transition outcome for graduates from upper secondary education. I show that vocational education is only relevant for labor market entry when socioeconomic status is not considered.

Educational Inequality in Apartheid South Africa

In this article, I explore the utility of effectively maintained inequality theory in examining educational inequality in South Africa at the end of the apartheid era. As an obviously unequal country, South Africa provides an excellent opportunity to test the claim that even with large quantitative differences in achievement, qualitative differences will matter. Using data from the early 1990s, I find that there were extensive quantitative differences in secondary school transitions across respondents in different racial categories. The minority White population was consistently able to achieve both more and better education. At the same time, though, qualitative distinctions mattered. For the majority of the population, particularly Africans, the quality of education attained varied across parental background. These outcomes are important not only for examining the veracity of effectively maintained inequality, both in terms of racial and class differences but also because they illustrate how educational differences have served to perpetuate inequality over time in a society that no longer allows for the explicit denial of opportunity by race.

Discovery of the secondary eclipse of HAT-P-11 b

We report the detection of the secondary eclipse of HAT-P-11 b, a Neptune-sized planet orbiting an active K4 dwarf. Using all available short-cadence data of the Kepler mission, we derive refined planetary ephemeris increasing their precision by more than an order of magnitude. Our simultaneous primary and secondary transit modeling results in improved transit and orbital parameters. In particular, the precise timing of the secondary eclipse allows to pin down the orbital eccentricity to $0.26459_{-0.00048}^{+0.00069}$. The secondary eclipse depth of $6.09_{-1.11}^{+1.12}$ ppm corresponds to a $5.5\sigma$ detection and results in a geometric albedo of $0.39\pm0.07$ for HAT-P-11 b, close to Neptune's value, which may indicate further resemblances between these two bodies. Due to the substantial orbital eccentricity, the planetary equilibrium temperature is expected to change significantly with orbital position and ought to vary between $630^\circ$ K and $950^\circ$ K, depending on the details of heat redistribution in the atmosphere of HAT-P-11 b.

Transition from Secondary School to Medical School: The Role of Self-Study and Self-Regulated Learning Skills in Freshman Burnout.

The transition from secondary to higher education is a challenging and demanding period for medical students. Theability to manage study time effectively and to be a self-regulated learner is essential to cope with the exponential growth of knowledgein medical education. Thus, the purpose of our study was to measure self-regulated learning skills and self-study across secondary highereducation transition and to explore its effect on academic burnout in the first year of medical school. We collected data from 102 (43%) freshman medical students on self-regulated learning, academicachievement, and hours of self-study/week relative to last year of secondary school (at the beginning of academic year) and the firstyear of medical school (at the end of academic year). Burnout data was collected at the end of academic year. Among the 102 participants, 12% were at risk of burnout. Self-directedness at secondary school and higher education, andstrategies for learning and assessment at higher education were protective factors against academic burnout. However, secondary selfdirectednesshas an indirect effect on academic burnout mediated by self-directedness in the first year of medical school. In addition,self-study during class period was a risk factor for burnout. Our results support the premise that students experience mental health problems from an early stage at medical school.Empowering medical students to develop strategies for learning assessment and self-direction will help them manage their learningand, consequently, promote their well-being. Finally, we found that it is not academic performance that influences burnout but the timededicated to study.

Large magnetocaloric effect of HoxEr1-xNi (0 ≤ x ≤ 1) compounds

A secondary magnetic transition (spin reorientation transition) below Curie temperature in ErNi was observed via different characterization techniques. Ho-substitution for Er atoms has a great impact on the magnetic property and magnetocaloric effect. The two magnetic transitions change close to each other with 10% of Ho-substitution at the Er site. It is also found that 10% of Ho-substitution contributes up to ∼14.9% of enhancement on the maximal magnetic entropy change (ΔSM) and ∼21.9% of enhancement on the maximal adiabatic temperature change (ΔTad). The maximum value of ΔSM and ΔTad for Ho0.1Er0.9Ni compound is as high as 34 J/kg K and 8.9 K, respectively, under a field change of 0–5 T. The relationship between the maximal ΔSM and the refrigerant temperature width (δTFWHM) for HoxEr1-xNi (0 ≤ x ≤ 1) compounds is analyzed. The enhancement of MCE for Ho0.1Er0.9Ni compound is considered to be resulted from the tendency of merging of spin reorientation transition and ferromagnetic to paramagnetic transition.

Crossflow instability in a hypersonic boundary layer

The crossflow instability in a hypersonic, laminar boundary layer is investigated using point measurements inside the boundary layer for the first time. Experiments are performed on a 7° right, circular cone with an adiabatic wall condition at 5.6° angle of incidence in the low-disturbance Mach 6 Quiet Tunnel at Texas A&M University. Measurements are made with a constant-temperature hot-wire anemometer system with a frequency response up to 180 kHz. Stationary crossflow waves are observed to grow and saturate. A travelling wave coexists with the stationary wave and occurs in a frequency band centred around 35 kHz. A type-I secondary instability is also observed in a frequency band centred around 110 kHz. The behaviour of all three modes is largely consistent with their low-speed counterparts prior to saturation of the stationary wave. Afterward, the behaviour remains in partial agreement with the low-speed case. Neither type-II secondary instability nor transition to turbulence are observed in this study.

Retinol Dehydrogenase-10 Regulates Pancreas Organogenesis and Endocrine Cell Differentiation via Paracrine Retinoic Acid Signaling.

Vitamin A-derived retinoic acid (RA) signals are critical for the development of several organs, including the pancreas. However, the tissue-specific control of RA synthesis in organ and cell lineage development has only poorly been addressed in vivo. Here, we show that retinol dehydrogenase-10 (Rdh10), a key enzyme in embryonic RA production, has important functions in pancreas organogenesis and endocrine cell differentiation. Rdh10 was expressed in the developing pancreas epithelium and surrounding mesenchyme. Rdh10 null mutant mouse embryos exhibited dorsal pancreas agenesis and a hypoplastic ventral pancreas with retarded tubulogenesis and branching. Conditional disruption of Rdh10 from the endoderm caused increased mortality, reduced body weight, and lowered blood glucose levels after birth. Endodermal Rdh10 deficiency led to a smaller dorsal pancreas with a reduced density of early glucagon+ and insulin+ cells. During the secondary transition, the reduction of Neurogenin3+ endocrine progenitors in the mutant dorsal pancreas accounted for fewer α- and β-cells. Changes in the expression of α- and β-cell-specific transcription factors indicated that Rdh10 might also participate in the terminal differentiation of endocrine cells. Together, our results highlight the importance of both mesenchymal and epithelial Rdh10 for pancreogenesis and the first wave of endocrine cell differentiation. We further propose a model in which the Rdh10-expressing exocrine tissue acts as an essential source of RA signals in the second wave of endocrine cell differentiation.