Pengetahuan, kemahiran dan amalan guru membina item kemahiran berfikir aras tinggi (KBAT) dalam instrumen pentaksiran pembelajaran

Kajian ini dijalankan bagi mengenal pasti tahap pengetahuan, kemahiran dan amalan guru membina item kemahiran berfikir aras tinggi (KBAT) dalam instrumen pentaksiran pembelajaran. Kajian ini juga melihat perbezaan tahap pengetahuan, kemahiran dan amalan guru membina item KBAT berdasarkan kepada kumpulan guru mengajar matapelajaran tingkatan 3 dan kumpulan guru mengajar matapelajaran tingkatan 5. Sebanyak enam persoalan kajian telah dibangunkan bagi mengkaji permasalahan kajian. Rekabentuk kajian ini melibatkan analisis deskriptif dan inferensi dalam bentuk tinjauan yang melibatkan data kuantitatif dengan menggunakan borang soal selidik berskala likert lima mata sebagai instrumen kajian. Seramai 161 sampel guru daripada 3 buah sekolah di daerah Muar, Johor terpilih menjadi responden dalam kajian ini. Model Pengukuran Rasch telah digunakan bagi menentukan kesahan dan kebolehpercayaan instrumen kajian yang telah dibina sendiri. Hasil analisis kajian menunjukkan tahap pengetahuan, kemahiran dan amalan guru membina item KBAT adalah berada pada tahap tinggi. Dapatan kajian juga menunjukkan tidak terdapat perbezaan yang signifikan di antara kumpulan guru mengajar matapelajaran tingkatan 3 dan kumpulan guru mengajar matapelajaran tingkatan 5 terhadap tahap pengetahuan, kemahiran dan amalan membina item KBAT. Hasil kajian ini dapat dijadikan sebagai satu garis panduan kepada guru-guru yang mengubal item pentaksiran dan program peningkatan profesionalisme guru di sekolah. Kajian lanjutan juga boleh dilaksanakan bagi memperbaiki kekurangan dalam kajian ini

Emerging mechanisms progress of colorectal cancer liver metastasis

Colorectal cancer (CRC) is the third most common malignancy and the second most common cause of cancer-related mortality worldwide. A total of 20% of CRC patients present with distant metastasis. The hepatic portal venous system, responsible for collecting most intestinal blood, makes the liver the most common site of CRC metastasis. The formation of liver metastases from colorectal cancer is a long and complex process. It involves the maintenance of primary tumors, vasculature invasion, distant colonization, and metastasis formation. In this review, we serve on how the CRC cells acquire stemness, invade the vascular, and colonize the liver. In addition, we highlight how the resident cells of the liver and immune cells interact with CRC cells. We also discuss the current immunotherapy approaches and challenges we face, and finally, we look forward to finding new therapeutic targets based on novel sequencing technologies

Physical Characterization and Volatile Organic Compound Monitoring of Recycled Polyethylene Terephthalate under Mechanical Recycling

In this study, physical characterization and monitoring of volatile organic compounds (VOCs) were investigated on recycled polyethylene terephthalate (rPET) from a mechanical recycling process and rPET bottles made with different rPET contents, with the aim of tracing the source of rPET and assessing its safety when use as a food contact material. It was found that rPET had a similar thermal stability to that of virgin PET (vPET). rPET bottles did not show any significant changes in groups or structure and exhibit similar crystallization and melting behaviors to vPET. However, there were minor mechanical scratches in the surface micromorphology of rPET bottles, and the color of rPET bottles became darker, greener and yellower as the content of recycled material increased. The solid-state polycondensation process was found to play an important role in the removal of VOCs, as detected by headspace gas chromatography-mass spectrometry (HS-GC-MS), resulting in a very small amount of residual VOCs in rPET. Four VOCs (acetaldehyde, glycol and nonanal at levels less than 1.00 mg/kg; 2-methyl-1,3 dioxolane at levels of 1.72-5.76 mg/kg) were detected in the rPET bottles. This study shows that rPET bottles are qualified for reuse in food contact in terms of thermal properties, structure, morphology and VOC residues, although there is variability in color

The JOBS Act, underwriting costs, and voluntary disclosure

The 2012 Jumpstart Our Business Startups Act (JOBS Act) was enacted to enable emerging growth companies (EGCs) to raise capital without facing vigorous regulations. We investigate whether underwriting fees and indirect costs of initial public offerings (IPOs) change after the passage of the JOBS Act. Unlike recent studies that investigate the impact of post-IPO voluntary disclosure, we investigate the role of the pre-IPO voluntary disclosure of use-of-proceeds for EGCs. Using a sample of 492 IPOs from April 5, 2009 to April 5, 2015, we find that after the adoption of the JOBS Act, IPOs’ indirect costs increase while the underwriting commissions decrease and that the effects of the JOBS Act on IPOs’ indirect costs and underwriting commissions are weaker for firms that have a high level of voluntary disclosure of use-of-proceeds. Results suggest that the optimal level of voluntary disclosures within the mandatory framework benefit EGCs and their investors and have policy, practice, and educational implications

Design and Analysis of a Novel Floating Docking Mechanism for On-Orbit Refueling

The docking mechanism is a key component for on-orbit refueling technology. In this paper, the design and analysis of a novel floating docking mechanism for on-orbit berthing-based refueling is presented. Compared with traditional berthing and docking, the berthing here is high in success rate and low in impact, which is accomplished by stretching out a docking subassembly instead of pulling back the client spacecraft. However, the berthing also has two problems: initial deviations between two spacecraft and an additional force generated by a hard alloy refueling pipe, which both seriously affect the docking operation. Thus, the docking mechanism is designed to have alignment abilities and decrease the additional force as much as possible. Based on the principles above, we introduced spring pins and a helical refueling pipe to design a light, compact, and simple docking mechanism. To further reduce the additional force, we proposed an elliptical-helical pipe and analyzed its mechanical properties. Finally, simulations and experiments were conducted to validate the proposed mechanism. The results show that the proposed mechanism with an elliptical-helical pipe has a high tolerance for linear and angular misalignment and superior dynamic performance during docking

Utility-based matching of vehicles and hybrid requests on rider demand responsive systems

In rider demand responsive systems riders submit requests to demand transit services and the incoming requests and vehicles are matched by the system. This demand-responsive transport problem is viewed by existing research as a kind of spatial matching problem between vehicles and riders. However, existing schemes mainly focus on maximizing the number of matching pairs. It neglects other factors like the length of pickup trajectories and riders' waiting time. And the matching is not revocable, which loses the chance for further optimizations. Moreover, there is still not much work on handling and matching the appointment-based requests that play a key role in the demand-responsive transport market. In this article, we propose an algorithm called BMCF (Bipartite Minimal-Cost Flow) to solve the taxi-rider matching problem with appointment-based rider requests on a time-dependent road network. Unlike existing solutions that map the problem into the max flow problem, we transform the optimal matching to a minimal cost flow problem which aims to maximize a utility value and could be solved efficiently. Riders and vehicles are modeled as vertices in a bipartite graph, and factors like the length of pickup trajectories, riders' waiting time, etc. are abstracted as utilities and denoted as weights of the edges which are taken into account during the matching process. To the best of our knowledge, the proposed scheme is the first to efficiently integrate and process both the real-time and appointment-based requests within the same framework, and the assignments between vehicles and requests could be dynamically adjusted and revoked to maximise the overall utility. Experimental results show that the proposed algorithm can effectively increase the appointment-based matching ratio and decrease the riders' waiting time (>10.4%) and vacant vehicles' picking up time (>60.9%) compared with existing schemes, while at the cost of acceptable increase on the running time

Study on Microstructure and Mechanical Properties of Al-Mg-Si-Cu Aluminium Alloy with High Ductility

A new type of Al-Mg-Si-Cu aluminium alloy with high ductility was studied in the present work. The microstructure features and mechanical properties of this alloy were systematically characterized by scanning electron microscopy (SEM), electron back-scatter Diffraction (EBSD), high resolution transmission electron microscopy (HRTEM) and tensile and fatigue test. The percentage of sub-grain boundary under forging and aging process reaches up to 72% which can be attributed to the suppression of recrystallization by the nano-sized AlMnCrSi dispersoids. The combination of mechanical properties of the new alloy product in aged state showed that the ductility keeps in the range of 15~18%, yield strength and tensile strength are 310MPa and 380MPa respectively, fatigue strength ranges from 130MPa to 135MPa. It presents more excellent properties than commercial 6061 alloy for the nano-sized AlMnCrSi dispersoids, initial-β” precipitates and high percentage of sub-grain boundary