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Dual Pole Indicatrix Curve and Surface
Get PDFIn this paper, the vectorial moment vector of the unit Darboux vector, which consists of the motion of the Frenet vectors on any curve, is reexpressed in the form of Frenet vectors. According to the new version of this vector, the parametric equation of the ruled surface corresponding to the unit dual pole indicatrix curve is given. The integral invariants of this surface are rederived and illustrated by presenting with examples
The Impact of Teachers\u27 Integration of Technology On Mathematics Performance of African-American High School Students
Get PDFThis research study design was to investigate the impact of teachers\u27 integration of technology into mathematics classrooms on the mathematical performance of African- American high school students. Since high school mathematics teachers should now be adept at integrating technology into mathematics classrooms, there is a need to gauge their perception of its effectiveness in enhancing the mathematical performance of their African-American students.
The participants were 31 general education high school Algebra I mathematics teachers from seven high schools in a large southeastern Texas school district. The conceptual framework that triggered this investigation was the technological pedagogical content knowledge (TPACK) model which linked teachers\u27 technological knowledge (TK), content knowledge (CK), and their pedagogical knowledge (PK). Consequently, the study investigated the impact of TPACK on the STAAR Algebra I EOC exam for first-year African-American students.
Specifically, the researcher used multiple linear regression to answer the following research questions: 1. What is the impact of the teachers\u27 level of technological knowledge (TK), content knowledge (CK), and pedagogical knowledge (PK) on the mathematical performance of African-American and non-African American high school students? 2. What is the impact of the teachers\u27 level of pedagogical content knowledge (PCK), technological content knowledge (TCK), and technologically pedagogical knowledge (TPK) on the mathematical performance of African-American and non-African American high school students? 3. What is the impact of the teachers\u27 level of TPACK on the mathematical performance of African-American and non-African American high school students?
The results of this study indicated that no meaningful relationships existed for any of the three hypotheses tested for both African-American and non-African American ninth graders. This result is significant in that it is now known that a need exists to review other options for determining how to review the implementation of technology in ninth grade mathematics classrooms.
The findings resulting from this study were beneficial in providing empirical evidence that could likewise certify which combination of technological knowledge, pedagogical knowledge, and content knowledge best facilitates mathematics learning for African-American students
Effect of Feeding a Low Level of Encapsulated Fish Oil to Dairy Goats on Milk Yield, Composition, and Fatty Acid Profile
No full textContradictory results have been found in the response of dairy goats to the supplementation of fish oil in their diet to improve the n-3 polyunsaturated fatty acids (PUFA) in milk. The responses to the inclusion of fish oil in the diet of ruminants either induced milk fat depression, increased milk fat content, and/or negatively impacted milk yield. The objective of this study was to determine whether including a low dose of encapsulated fish oil in the diet of goats can modify yield, milk composition, and the fatty acid (FA) profile of milk. Ten Alpine goats were divided into two homogeneous subgroups and assigned to either the control or experimental diet. The control animals received the basal diet without supplementation of fish oil, whereas the experimental group was given the same basal diet supplemented with encapsulated fish oil (1.14 g /kg of concentrate) for 56 days. Milk samples were analyzed for chemical composition and FA profile. The inclusion of encapsulated fish oil in the goat diet did not affect the yield and composition of goat milk. The effect of diet was not significant on the FA profile of goat milk, except that 20:0 was lower (P \u3c 0.05) in the milk of goats that received fish oil. The low dose of encapsulated fish oil supplement used in this study did not impact (P \u3e 0.05) the PUFA content of goat milk or milk composition and yield; however, the atherogenicity index (AI), which is beneficial to heart health, was lower (P \u3c 0.05) in the milk of goats that received fish oil as a supplement in their diet compared to the control
Parameterizing the modified water cloud model to improve soil moisture data retrieval using vegetation models
No full textThe objective was to parameterize a modified water cloud model using crop coefficients (A and B). These crop coefficients were derived from Landsat-8 and Sentinel-2 data. Whereas coefficients C and D are of soil parameters. The water cloud model was modified using crop coefficients by minimizing the RMSE between observed VVσ0 and Sentinel-1 based simulated VVσ0. The comparison with observed and simulated VV polarized σ0 showed low RMSE (0.81 dB) and strong R2 of 0.98 for NDVI-EVI combination. However, based on other possible combinations of vegetation indices VVσ0 and simulated VVσ0 do not show a good statistical agreement. It was observed that the errors in crop coefficients (A and B) are sensitive to errors in initial vegetation/canopy descriptor parameters
EVALUATING the EFFECT of A STUDENT-CENTERED PEDAGOGICAL APPROACH on STUDENTS SKILLS and KNOWLEDGE in COMPUTER-AIDED DESIGN (CAD) COURSE
No full textThis paper presents a quasi-experimental pre and post test design to explore the effects of a student-centered pedagogical approach in Computer-Aided Design (CAD) education. In this study, students in experimental group generated CAD screencast tutorials, recorded the supporting audio, shared the videos with their peers, and provided feedback to each other s screencast. A life-long learning survey, an engineering attitude survey, and a CAD modeling exam were used as the study instruments. Students learning outcomes were evaluated by analyzing data collected over five years from 17 classrooms. Findings indicated that first generation college students or female students were more receptive to the student centered instructional approaches and they improved their life-long learning skills and engineering attitudes. We observed a strong evidence that when students designed screencast exercises, their CAD exam performance improved. This study also contributes to our knowledge on how to effectively assess engineering attitudes and life-long learning skills
Adverse Childhood Experiences Inducement Into Substance Use
No full textAmerican adolescents are at risk for substance use. The National Center on Addiction and Substance Abuse (2011) states that three-quarters of high school students have used some addictive substance at least once. Though all American adolescents are vulnerable to substance use, experiences of trauma may increase the risk of substance use and abuse. Adolescent substance use and abuse have been linked to childhood maltreatment and household dysfunction. These traumatic events during adolescence are called Adverse Childhood Experiences (ACEs). They cover a wide-ranging scope of experiences such as sexual, physical, and emotional abuse, household drug use, and parental divorce.
Criminogenic risk factors and ACEs may cause harmful and long-term effects on the health and welfare of children. As public health observation of ACEs increases, little information exists concerning the relationship between ACEs, deviance, and delinquency. Using the 2015 Texas Behavioral Risk Factor Surveillance System (BRFSS), a project that collaborated with the Centers for Disease Control and Prevention (CDC), the current study assesses the effects of ACEs on substance use. Additionally, this study examined the impact that ACEs that are considered household dysfunction effect on substance use. Findings from the study suggested that there was partial support that some of the household dysfunction ACEs could explain smoking (e-cigarettes, vape pens, and e-hookah). In contrast, household dysfunction ACEs could not explain alcohol use
Biological Pathways Associated with Wild and Domestic Animals
Get PDFBackground: Zoonotic diseases are problematic, in that, they impact both wild and domestic animals alike. Thus, there is a need to investigate the genomes of wild and domestic. Gene ontology (GO) is a major bioinformatics initiative, whereby descriptions of gene products across the database are developed and unified to describe all species. This process is performed by biocurators, who gather, annotate, and validate information on the databases, consequently affording easy access to accurate and updated data. In this study, we investigated the biocuration of two biological processes, DNA integration, which is used for DNA coding, and the tricarboxylic acid (TCA) cycle that occurs in all aerobic organisms. The objective of this study was to compare the genomes of 271 mammals, birds, reptiles and some aquatic animals to determine the number of wild versus domesticated animals, where DNA integration and the TCA cycle have annotations. We hypothesized that there would be more annotations on domesticated animals than wild animals because of easier access to domesticated animal genomes. Methods: To test this hypothesis, we first accessed the National Center of Biotechnology Information (NCBI) to retrieve the taxonomy ID for 271 species of animals found in this study. Then the European Bioinformatics Institute (EBI) database, QuickGO, was accessed to retrieve all annotations associated with the taxonomy ID of the species. Data was assembled into a wiki-database that is now publicly available online. Results and Conclusion: Data indicated that more annotations for DNA integration and the TCA cycle were 22% higher in domestic animals than in wild animals. Therefore, we propose that more biocuration needs to be done for wild animals. The number of wild animals’ sequences available are growing, but if they are not annotated, detailed investigations are not possible. If more resources are dedicated to the investigation of the genomes of wild animals, more work can be done to study the genetic factors affecting zoonotic diseases
Expression profile of Toll-like receptor 4 in rat testis and epididymis throughout postnatal development
No full textToll-like receptors (TLRs) belonging to pattern recognition receptors are involved in maintaining testicular and epididymal immune homeostasis. The purpose of the current study was to investigate TLR4 expression in rat testis and epididymis throughout postnatal development. Weak staining was detected in peritubular myoid cells and immature Sertoli cells while no staining was observed in gonocytes during prepubertal period. However, TLR4 expression began to appear in spermatocytes in pubertal period and gradually increased in spermatids. An intense staining was observed in steps 5–19 spermatids in post pubertal and mature periods. Similarly, TLR4 expression in the testes steadily increased from pubertal period to mature period. Puberty also caused a significant increase in TLR4 expression in epididymis. TLR4 expression in cauda epididymis was lower as compared to those of other epididymal segments. The majority of epididymal epithelial cells exhibited apical TLR4 expression, whereas basal cells showed intense intracytoplasmic immunoreaction. We detected an intense staining in epididymal smooth muscle cells. The expression levels of TLR4 showed dynamic changes in both spermatogenic cells, and entire testicular and epididymal tissues during postnatal development. These results suggest that TLR4 expression contributes not only to inflammation but also to the development of spermatogenic cells