Teacher Leadership for Flexibility in Grading: an Exploration and Analysis of Grading Practices in One Urban High School

Grades are perhaps the most widely used and universally accepted representation of a student\u27s academic achievement. More importantly, they can be a vehicle to higher education, specialty programs, and access to highly competitive scholarship dollars. Given the wide disparity of grading practices from teacher to teacher and from district to district, the potential impact it could have on final grades for students, and the ever-increasing importance of grades in post-secondary pursuits, it is essential that this is further studied to discover to what extent the variability of teacher grading practices impact student grade point average (GPA). The focus of the study was around the question of what makes a grade a grade? This study examined the grading practices of one urban high school to determine that impact they had on students\u27 final HSGPA. A survey was given to all teaching staff asking teachers to self-score their current grading practices. The results of the survey created individual teacher scores as well as departmental averages. These scores were analyzed along with trend data of student HSGPAs and ACT scores for the past give years. Outlier students were identified and the full student transcripts were evaluated to determine if the teacher grading practices had an impact on the incongruency of the student\u27s GPA compared to ACT score. This study will help to determine whether current high school grading practices are solid indicators of students\u27 content mastery, or if they are artificially inflated (or deflated) by other factors. Results of the study were inconclusive in determining that teacher grading contributed to an inflated GPA, therefore, causing the incongruency. The study did expose a wide variance in grading practices within departments and more so schoolwide. However, the study did point to the need for further research on the purpose of grading the impact of entire schools or individual departments aligning with best practices

A Survey of Phonics in Primary Grades

The purpose of this study was to determine the adequacy of phonics in our reading programs by analyzing and comparing the phonics programs of eleven of the most widely used basal readers

The Right to Jury Trial in Complex Civil Litigation

This Comment examines the growing trend to strike jury demands in complex commercial litigation. The first section reviews the historical background of the seventh amendment right to jury trial. The second section examines Ross v. Bernhard, the leading Supreme Court precedent on the right. The writer next explores the five recent lower court cases dealing with a motion to strike jury demand. Finally the writer critically evaluates the new trend and demonstrates that Ross has been misinterpreted

A multiscale mechanobiological model of bone remodelling predicts site-specific bone loss in the femur during osteoporosis and mechanical disuse

We propose a multiscale mechanobiological model of bone remodelling to investigate the site-specific evolution of bone volume fraction across the midshaft of a femur. The model includes hormonal regulation and biochemical coupling of bone cell populations, the influence of the microstructure on bone turnover rate, and mechanical adaptation of the tissue. Both microscopic and tissue-scale stress/strain states of the tissue are calculated from macroscopic loads by a combination of beam theory and micromechanical homogenisation. This model is applied to simulate the spatio-temporal evolution of a human midshaft femur scan subjected to two deregulating circumstances: (i) osteoporosis and (ii) mechanical disuse. Both simulated deregulations led to endocortical bone loss, cortical wall thinning and expansion of the medullary cavity, in accordance with experimental findings. Our model suggests that these observations are attributable to a large extent to the influence of the microstructure on bone turnover rate. Mechanical adaptation is found to help preserve intracortical bone matrix near the periosteum. Moreover, it leads to non-uniform cortical wall thickness due to the asymmetry of macroscopic loads introduced by the bending moment. The effect of mechanical adaptation near the endosteum can be greatly affected by whether the mechanical stimulus includes stress concentration effects or not.Comment: 25 pages, 10 figure

Endocortical bone loss in osteoporosis: The role of bone surface availability

Age-related bone loss and postmenopausal osteoporosis are disorders of bone remodelling, in which less bone is reformed than resorbed. Yet, this dysregulation of bone remodelling does not occur equally in all bone regions. Loss of bone is more pronounced near and at the endocortex, leading to cortical wall thinning and medullary cavity expansion, a process sometimes referred to as "trabecularisation" or "cancellisation". Cortical wall thinning is of primary concern in osteoporosis due to the strong deterioration of bone mechanical properties that it is associated with. In this paper, we examine the possibility that the non-uniformity of microscopic bone surface availability could explain the non-uniformity of bone loss in osteoporosis. We use a computational model of bone remodelling in which microscopic bone surface availability influences bone turnover rate and simulate the evolution of the bone volume fraction profile across the midshaft of a long bone. We find that bone loss is accelerated near the endocortical wall where the specific surface is highest. Over time, this leads to a substantial reduction of cortical wall thickness from the endosteum. The associated expansion of the medullary cavity can be made to match experimentally observed cross-sectional data from the Melbourne Femur Collection. Finally, we calculate the redistribution of the mechanical stresses in this evolving bone structure and show that mechanical load becomes critically transferred to the periosteal cortical bone.Comment: 13 pages, 3 figures. V2: minor stylistic improvements in text/figures; more accurately referenced subsection "Internal mechanical stress distribution"; some improved remarks in the Discussion sectio

A Systems Approach to Understanding Bone Cell Interactions in Health and Disease

Bone is an important organ performing three essential physiological functions: mechanical support, mineral homeostasis (such as calcium and phosphate) and support of haematopoiesis. In fact, bone diseases in the elderly are associated with high morbidity and increased mortality. Osteoporosis and related skeletal complications are amongst the most important diseases impacting both the quality of life of our aging population and contributing costs to our health care system

Spatio-temporal structure of cell distribution in cortical Bone Multicellular Units: a mathematical model

Bone remodelling maintains the functionality of skeletal tissue by locally coordinating bone-resorbing cells (osteoclasts) and bone-forming cells (osteoblasts) in the form of Bone Multicellular Units (BMUs). Understanding the emergence of such structured units out of the complex network of biochemical interactions between bone cells is essential to extend our fundamental knowledge of normal bone physiology and its disorders. To this end, we propose a spatio-temporal continuum model that integrates some of the most important interaction pathways currently known to exist between cells of the osteoblastic and osteoclastic lineage. This mathematical model allows us to test the significance and completeness of these pathways based on their ability to reproduce the spatio-temporal dynamics of individual BMUs. We show that under suitable conditions, the experimentally-observed structured cell distribution of cortical BMUs is retrieved. The proposed model admits travelling-wave-like solutions for the cell densities with tightly organised profiles, corresponding to the progression of a single remodelling BMU. The shapes of these spatial profiles within the travelling structure can be linked to the intrinsic parameters of the model such as differentiation and apoptosis rates for bone cells. In addition to the cell distribution, the spatial distribution of regulatory factors can also be calculated. This provides new insights on how different regulatory factors exert their action on bone cells leading to cellular spatial and temporal segregation, and functional coordination.Comment: 14 pages, 5 figures; v2: Completed model description after Eq. (16), clarified discussion/description after Eq. (23), between Eqs. (29)-(31), and in 2nd bullet point in conclusion

Nanoscale Imaging of Phase Transitions with Scanning Force Microscopy

Nanoscale imaging of materials through phase transitions can provide valuable insight into the local nature of the transition and the emergence of order. The scanning force microscope used in the studies presented here is an ideal instrument to investigate phase transitions with nanoscale spatial resolution. We study phase transitions in two different systems by operating in different modes: contact mode, in which we measure the local electronic properties of the sample; and non-contact mode, in which we probe the sample by monitoring the interaction between the sample and cantilever. We increased the versatility of this microscope by developing a method to control the quality factor Q of a conducting cantilever via capacitive coupling to the local environment. We show that Q may be reversibly tuned over a range of a factor of 260. We describe the underlying physics with a point-mass oscillator model. Tuning Q can enhance force-gradient sensitivity or scan speed, which we demonstrate with topographic scans of a $(VO_2)$ acquired in high vacuum. Scanning in contact mode with a conductive cantilever, we study local electronic properties of a vanadium dioxide $(VO_2)$ thin film through an insulator to metal transition. At each point in the scan, we sweep the voltage applied to the sample, obtaining current versus voltage sweeps with nanoscale resolution while inducing the insulator to metal transition. In some $(VO_2)$ grains, we see two electronic transitions, consistent with a locally stable intermediate insulating phase. We find large insulating state resistances and transition voltages at grain boundaries, underscoring the importance of Joule heating in triggering the transition in this type of measurement. Finally, we evaluate the conduction mechanism in the insulating regime, allowing the local determination of permittivity and temperature. We scan in non-contact mode with a magnetic tip to investigate the spin reorientation transition in single-crystal $Nd_2Fe_{14}B$. This ferromagnetic system undergoes the spin reorientation transition near 135 K. We achieve nanoscale magnetic resolution at both room temperature and at a variety of temperatures around the phase transition. We demonstrate the ability to resolve the magnetic domain structure and monitor its evolution through the phase transition.Physic

Editorial: Bone integrity in patients with osteoporosis: Evaluation of fracture risk and influence of pharmacological treatments and mechanical aspects

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Bone orthotropic remodeling as a thermodynamically-driven evolution

International audienceIn this contribution we present and discuss a model of bone remodeling set up in the framework of the theory of generalized continuum mechanics and first introduced by DiCarlo et al.[1]. Bone is described as an orthotropic body experiencing remodeling as a rotation of its microstruc-ture. Thus, the complete kinematic description of a material point is provided by its position in space and a rotation tensor describing the orientation of its microstructure. Material motion is driven by energetic considerations , namely by the application of the Clausius-Duhem inequality to the microstructured material. Within this framework of orthotropic re-modeling, some key features of the remodeling equilibrium configurations are deduced in the case of homogeneous strain or stress loading conditions. First, it is shown that remodeling equilibrium configurations correspond to energy extrema. Second, stability of the remodeling equilibrium configurations is assessed in terms of the local convexity of the strain and complementary energy functionals hence recovering some classical energy theorems. Eventually, it is shown that the remodeling equilibrium configurations are not only highly dependent on the loading conditions, but also on the material properties