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Post-course instructor ratings are a common practice at universities in Europe, Australia, and North America. Rather than solely describing teaching practice, however, such ratings may be associated with a range of non-pedagogical factors. We explored engineering students' instructor ratings at a large United States institution, investigating relationships between overall instructor rating and some of those non-pedagogical factors, including subject area, class size, and students' course grades. Instructor ratings were more favourable in humanities courses than in science or math courses, and students gave higher ratings to instructors who taught smaller class sizes. The strongest relationship existed between overall rating and students' course grades: students who received A's rated instructors an average 0.84 points higher on a 6-point scale than students who received F's. Students who withdrew from a course provided the lowest instructor ratings. When instructor ratings are used as metrics of teaching ability in discussions related to promotion, tenure, or salary adjustments, there is an inherent inequity in the system that must be acknowledged beyond already well-documented biases, as non-pedagogical factors often outside of the instructor's control may be significantly associated with those ratings. [ABSTRACT FROM AUTHOR]

Does higher perceived neighborhood social cohesion in adolescence lead to better health and well‐being 10–12 years later? We evaluated this question using data from a large, prospective, and nationally representative sample of US adolescents (Add Health; N = 10,963), and an outcome‐wide approach. Across 38 outcomes, perceived neighborhood social cohesion was associated with some: mental health outcomes (i.e., depressive symptoms, suicidal ideation, perceived stress), psychological well‐being outcomes (i.e., happiness, optimism), social outcomes (i.e., loneliness, romantic relationship quality, satisfaction with parenting), and civic/prosocial outcomes (i.e., volunteering). However, it was not associated with health behaviors nor physical health outcomes. These results were maintained after robust control for a wide range of potential confounders. [ABSTRACT FROM AUTHOR]

On a single weekend in June 2021, seven people died of drug overdoses in Rochester, New York. On that Saturday morning, three adults were found dead on a front porch [...]

The ability to quickly develop predictions of the service lifetime of plastic pipes at different load levels allows designers to choose the best plastic material and design pipe for a specific application. Additionally, it helps material producers to rapidly design, manufacture, test, screen, and modify the base polymeric material. The aim of this study is to introduce a combined experimental and analytical framework to develop accelerated lifetime estimates for semi-crystalline plastic pipes which is sensitive to the structure, orientation, and morphology changes introduced by changing processing conditions. To accomplish this task, high density polyethylene (HDPE) is chosen as the exemplary base material and custom fixtures are developed to admit tensile and hoop burst tests on the as-manufactured HDPE pipes. A pressure-modified Eyring flow equation is employed to predict the rupture lifetime of HDPE pipes using the measured mechanical properties under uniaxial tensile and compression loading in different temperatures and strain rates. The method allows the prediction of pipe service lifetimes in excess of 50 years using experiments conducted over approximately 10 days instead of the traditional 13 months., INTRODUCTION The use of plastic pipes to carry liquids and gases has greatly expanded in recent decades because of their moderate cost, ease of handling and installation, long service life, [...]

During the solar minimum, when the Sun is at its least active, the solar wind.sup.1,2 is observed at high latitudes as a predominantly fast (more than 500 kilometres per second), highly Alfvénic rarefied stream of plasma originating from deep within coronal holes. Closer to the ecliptic plane, the solar wind is interspersed with a more variable slow wind.sup.3 of less than 500 kilometres per second. The precise origins of the slow wind streams are less certain.sup.4; theories and observations suggest that they may originate at the tips of helmet streamers.sup.5,6, from interchange reconnection near coronal hole boundaries.sup.7,8, or within coronal holes with highly diverging magnetic fields.sup.9,10. The heating mechanism required to drive the solar wind is also unresolved, although candidate mechanisms include Alfvén-wave turbulence.sup.11,12, heating by reconnection in nanoflares.sup.13, ion cyclotron wave heating.sup.14 and acceleration by thermal gradients.sup.1. At a distance of one astronomical unit, the wind is mixed and evolved, and therefore much of the diagnostic structure of these sources and processes has been lost. Here we present observations from the Parker Solar Probe.sup.15 at 36 to 54 solar radii that show evidence of slow Alfvénic solar wind emerging from a small equatorial coronal hole. The measured magnetic field exhibits patches of large, intermittent reversals that are associated with jets of plasma and enhanced Poynting flux and that are interspersed in a smoother and less turbulent flow with a near-radial magnetic field. Furthermore, plasma-wave measurements suggest the existence of electron and ion velocity-space micro-instabilities.sup.10,16 that are associated with plasma heating and thermalization processes. Our measurements suggest that there is an impulsive mechanism associated with solar-wind energization and that micro-instabilities play a part in heating, and we provide evidence that low-latitude coronal holes are a key source of the slow solar wind. Measurements from the Parker Solar Probe show that slow solar wind near the Sun's equator originates in coronal holes., Author(s): S. D. Bale [sup.1] [sup.2] [sup.3] [sup.4] , S. T. Badman [sup.1] [sup.2] , J. W. Bonnell [sup.1] , T. A. Bowen [sup.1] , D. Burgess [sup.4] , A. [...]

The prediction of a supersonic solar wind.sup.1 was first confirmed by spacecraft near Earth.sup.2,3 and later by spacecraft at heliocentric distances as small as 62 solar radii.sup.4. These missions showed that plasma accelerates as it emerges from the corona, aided by unidentified processes that transport energy outwards from the Sun before depositing it in the wind. Alfvénic fluctuations are a promising candidate for such a process because they are seen in the corona and solar wind and contain considerable energy.sup.5-7. Magnetic tension forces the corona to co-rotate with the Sun, but any residual rotation far from the Sun reported until now has been much smaller than the amplitude of waves and deflections from interacting wind streams.sup.8. Here we report observations of solar-wind plasma at heliocentric distances of about 35 solar radii.sup.9-11, well within the distance at which stream interactions become important. We find that Alfvén waves organize into structured velocity spikes with duration of up to minutes, which are associated with propagating S-like bends in the magnetic-field lines. We detect an increasing rotational component to the flow velocity of the solar wind around the Sun, peaking at 35 to 50 kilometres per second--considerably above the amplitude of the waves. These flows exceed classical velocity predictions of a few kilometres per second, challenging models of circulation in the corona and calling into question our understanding of how stars lose angular momentum and spin down as they age.sup.12-14. Data collected by the Parker Solar Probe in the solar corona are used to determine the organization of Alfvén waves, revealing an increasing flow velocity peaking at 35-50 km s.sup.-1., Author(s): J. C. Kasper [sup.1] [sup.2] , S. D. Bale [sup.3] [sup.4] [sup.5] , J. W. Belcher [sup.6] , M. Berthomier [sup.7] , A. W. Case [sup.2] , B. D. [...]

Switchbacks are sudden and large deflections in the magnetic field that Parker Solar Probe frequently observes in the inner heliosphere. Their ubiquitous occurrence has prompted numerous studies to determine their nature and origin. Our goal is to describe the boundary of these switchbacks using a series of events detected during the spacecraft's first encounter with the Sun. Using FIELDS and SWEAP data, we investigate different methods for determining the boundary normal. The observed boundaries are arc-polarized structures with a rotation that is always contained in a plane. Classical minimum variance analysis gives misleading results and overestimates the number of rotational discontinuities. We propose a robust geometric method to identify the nature of these discontinuities, which involves determining whether or not the plane that contains them also includes the origin ( B = 0). Most boundaries appear to have the same characteristics as tangential discontinuities in the context of switchbacks, with little evidence for having rotational discontinuities. We find no effect of the size of the Parker spiral deviation. Furthermore, the thickness of the boundary is within MHD scales. We conclude that most of the switchback boundaries observed by Parker Solar Probe are likely to be closed, in contrast to previous studies. Our results suggest that their erosion may be much slower than expected. [ABSTRACT FROM AUTHOR]

Female cancer patients who have undergone chemotherapy have an elevated risk of developing ovarian dysfunction and failure. Experimental approaches to treat iatrogenic infertility are evolving rapidly; however, challenges and risks remain that hinder clinical translation. Biomaterials have improved in vitro follicle maturation and in vivo transplantation in mice, but there has only been marginal success for early-stage human follicles. Here, we developed methods to obtain an ovarian-specific extracellular matrix hydrogel to facilitate follicle delivery and establish an in situ ovary (ISO), which offers a permissive environment to enhance follicle survival. We demonstrate sustainable follicle engraftment, natural pregnancy, and the birth of healthy pups after intraovarian microinjection of isolated exogenous follicles into chemotherapy-treated (CTx) mice. Our results confirm that hydrogel-based follicle microinjection could offer a minimally invasive delivery platform to enhance follicle integration for patients post-chemotherapy. [ABSTRACT FROM AUTHOR]

Standard methods for fire resistance testing require large-scale assemblies and are typically conducted on specialized furnaces at considerable cost. This research focused on developing a scaling methodology for a reduced-scale fire resistance test that reduces the size of the test article while maintaining the same thermal and structural response exhibited in the large-scale test. The developed scaling methodology incorporates uniform geometric scaling, Fourier number time scaling, and furnace boundary condition matching. The scaling laws were experimentally validated with fire exposure tests on gypsum wallboard samples at three scales (full-scale, 1/2-scale, and 1/6-scale). In the tests, samples were exposed to a full-scale equivalent of 60-min of ASTM E119 fire curve exposure on a reduced-scale horizontal furnace, and the temperature rise through the thickness profile was measured. Models were created to calculate the modified fire curves for the smaller-scale tests. Experimental results show that on the exposed surface, the 1/2-scale absolute temperature was within 1.7% of full-scale, while the 1/6-scale temperature was within 2.5%. While the time-dependent properties of burning and cracking caused visual differences in these gypsum tests, modeling and temperature measurements demonstrated that the test results were thermally similar. The good similarity of temperatures is achievable in fire exposure tests of non-combustible gypsum wallboard down to 1/6-scale. [ABSTRACT FROM AUTHOR]

Parker Solar Probe observes unexpectedly prevalent switchbacks, which are rapid magnetic field reversals that last from seconds to hours, in the inner heliosphere, posing new challenges to understanding their nature, origin, and evolution. In this work, we investigate the thermal states, electron pitch-angle distributions, and pressure signatures of both inside and outside the switchbacks, separating a switchback into spike, transition region (TR), and quiet period (QP). Based on our analysis, we find that the proton temperature anisotropies in TRs seem to show an intermediate state between spike and QP plasmas. The proton temperatures are more enhanced in the spike than in the TR and QP, but the alpha temperatures and alpha-to-proton temperature ratios show the opposite trend to the proton temperatures, implying that the preferential heating mechanisms of protons and alphas are competing in different regions of switchbacks. Moreover, our results suggest that the electron-integrated intensities are almost the same across the switchbacks, but the electron pitch-angle distributions are more isotropic inside than outside switchbacks, implying switchbacks are intact structures, but strong scattering of electrons happens inside switchbacks. In addition, the examination of pressures reveals that the total pressures are comparable through an individual switchback, confirming switchbacks are pressure-balanced structures. These characteristics could further our understanding of ion heating, electron scattering, and the structure of switchbacks. [ABSTRACT FROM AUTHOR]

Radiation in the form of solar energetic particles (SEPs) presents a severe risk to the short-term health of astronauts and the success of human exploration missions beyond Earth’s protective shielding. Modeling how shielding mitigates the dose accumulated by astronauts is an essential step toward reducing these risks. PREDICCS (Predictions of radiation from REleASE, EMMREM, and Data Incorporating the CRaTER, COSTEP, and other SEP measurements) is an online tool for the near real-time prediction of radiation exposure at Earth, the Moon, and Mars behind various levels of shielding. We compare shielded dose rates from PREDICCS with dose rates from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) onboard the Lunar Reconnaissance Orbiter (LRO) at the Moon and from the Radiation Assessment Detector (RAD) on the Mars Science Laboratory (MSL) during its cruise phase to Mars for five solar events in 2012 when Earth, MSL, and Mars were magnetically well connected. Calculations of the accumulated dose demonstrate a reasonable agreement between PREDICCS and RAD ranging from as little as 2% difference to 54%. We determine mathematical relationships between shielding levels and accumulated dose. Lastly, the gradient of accumulated dose between Earth and Mars shows that for the largest of the five solar events, lunar missions require aluminum shielding between 1.0 g cm−2 and 5.0 g cm−2 to prevent radiation exposure from exceeding the 30-day limits for lens and skin. The limits were not exceeded near Mars.

The change in the Dutch secondary school mathematics curriculum known as Realistic Mathematics Education advocated by the National Council of Teachers of Mathematics (NCTM 2000) is discussed. There are very good chances in Netherlands to finish its mathematics revolution which would be a revolution in content, teaching style and student learning.

This paper presents a novel and efficient micromechanical framework for finite element simulation of damage and failure in 3-D printed aligned discontinuous fiber-reinforced composites. The framework can predict the initiation and propagation of different types of damage in the composite under tensile loading along the fibers' axis. The micromechanical framework includes the microstructural representation of the composite with explicit fibers and matrix in addition to linear expansions at the ends. Accurate constitutive equations are utilized for fibers, matrix, and fiber/matrix interfaces in the microstructural representation. Fibers' locations and lengths are generated randomly; based on a target distribution for the fibers' aspect ratios measured experimentally; within the microstructural representation. Optimal microstructural representative dimensions for reliable investigation of the mechanical response are computed by conducting sensitivity analyses. The accuracy of the micromechanical framework is validated versus the experimental results of a 3-D printed aligned discontinuous fiber-reinforced composite as the composite of interest. It is shown that the proposed framework can simulate various aspects of the mechanical response, including the failure pattern and stress-strain behavior. Subsequently, the sensitivity of the mechanical response of the composite to a few constitutive equation-related parameters, including the strength and fracture toughness of the fiber/matrix interfaces and the matrix strength, is investigated. The correlation between the studied parameters and the composite's strength and failure pattern is also analyzed and discussed. This paper delivers valuable guidance on the mechanical response of printed aligned discontinuous fiber-reinforced composites, eventually resulting in the paradigm-shifting design, manufacturing, and analysis of such advanced composites. [ABSTRACT FROM AUTHOR]

Describes how one university's teacher education program infuses issues of inquiry, reflection, equity, and diversity, examining reasons for preparing teachers this way and arguing that school-based inquiry and reflection should be deeply imbedded in teacher preparation programs, which are linked to practical experiences. Examples of collaborative inquiry and reflection as part of the everyday lives of teachers are presented. (SM)