Supervising Student Teachers : A Shared Responsibility

Preparing a quality future teacher is a pressing concern of teacher education institutions, school systems, and state departments of education. It is almost impossible to train effective teachers unless these educational agencies share their responsibilities in the total teacher preparation process. This is becoming a greater reality as each agency recognises its identifiable and distinct role. Student teaching is an important component of teacher preparation and is frequently taken for granted. This internship plays a significant role in the making of a teacher who has acquired confidence in short- and long-range planning, communication and classroom management. This can be done only if co-operating teachers, college faculty member and student teacher all do their respective jobs professionally, dutifully and, above all, humanely

Preservice Classroom Experiences : The Cooperating Teacher\u27s Role

There was a time when we used to have student teaching as the only classroom experience for an individual who wanted to be a teacher. Such experiences were generally arranged during the last quarter or semester of the person\u27s college: education In these situations, it was a matter of completing it whether one liked it or not. Following this pattern of teacher training we turned out many teachers for whom teaching may not have been a number one priority. Currently, practical school experiences are provided starting in the freshman year. State of Ohio 1980 guidelines require that preservice teachers complete field-based experiences equivalent in time to one full quarter prior to student teaching. Similar guidelines are either in place or being implemented in other states

Benchmarking Apache Arrow Flight -- A wire-speed protocol for data transfer, querying and microservices

Moving structured data between different big data frameworks and/or data warehouses/storage systems often cause significant overhead. Most of the time more than 80\% of the total time spent in accessing data is elapsed in serialization/de-serialization step. Columnar data formats are gaining popularity in both analytics and transactional databases. Apache Arrow, a unified columnar in-memory data format promises to provide efficient data storage, access, manipulation and transport. In addition, with the introduction of the Arrow Flight communication capabilities, which is built on top of gRPC, Arrow enables high performance data transfer over TCP networks. Arrow Flight allows parallel Arrow RecordBatch transfer over networks in a platform and language-independent way, and offers high performance, parallelism and security based on open-source standards. In this paper, we bring together some recently implemented use cases of Arrow Flight with their benchmarking results. These use cases include bulk Arrow data transfer, querying subsystems and Flight as a microservice integration into different frameworks to show the throughput and scalability results of this protocol. We show that Flight is able to achieve up to 6000 MB/s and 4800 MB/s throughput for DoGet() and DoPut() operations respectively. On Mellanox ConnectX-3 or Connect-IB interconnect nodes Flight can utilize upto 95\% of the total available bandwidth. Flight is scalable and can use upto half of the available system cores efficiently for a bidirectional communication. For query systems like Dremio, Flight is order of magnitude faster than ODBC and turbodbc protocols. Arrow Flight based implementation on Dremio performs 20x and 30x better as compared to turbodbc and ODBC connections respectively

Continuous Correction of Differential Path Length Factor in Near-Infrared Spectroscopy

In continuous-wave near-infrared spectroscopy (CW-NIRS), changes in the concentration of oxyhemoglobin and deoxyhemoglobin can be calculated by solving a set of linear equations from the modified Beer-Lambert Law. Cross-talk error in the calculated hemodynamics can arise from inaccurate knowledge of the wavelength-dependent differential path length factor (DPF). We apply the extended Kalman filter (EKF) with a dynamical systems model to calculate relative concentration changes in oxy- and deoxyhemoglobin while simultaneously estimating relative changes in DPF. Results from simulated and experimental CW-NIRS data are compared with results from a weighted least squares (WLSQ) method. The EKF method was found to effectively correct for artificially introduced errors in DPF and to reduce the cross-talk error in simulation. With experimental CW-NIRS data, the hemodynamic estimates from EKF differ significantly from the WLSQ (p\u3c0.001 ). The cross-correlations among residuals at different wavelengths were found to be significantly reduced by the EKF method compared to WLSQ in three physiologically relevant spectral bands 0.04 to 0.15 Hz, 0.15 to 0.4 Hz and 0.4 to 2.0 Hz (p\u3c0.001 ). This observed reduction in residual cross-correlation is consistent with reduced cross-talk error in the hemodynamic estimates from the proposed EKF method

A Spatially Distributed Energy Balance Snowmelt Model

This paper describes an energy balance snowmelt model developed for the prediction of rapid snowmelt rates responsible for soil erosion and water input to a distributed water balance model. The model uses a lumped representation of the snowpack with two state variables, namely, water equivalent and energy content relative to a reference state of water in the ice phase at 0 degrees Celcius. This energy content is used to determine snowpack average temperature of liquid fraction. This representation of the snowpack is used to determine snowpack average temperature of liquid fraction. This representation of the snowpack is used in a distributed version of the model with each of these state variables modeled at each point on a rectangular grid corresponding to a digital elevation model. Inputs are air temperature, precipitation, wind speed, humidity and radiation at hourly time steps. The model uses physically based calculations of radiative, sensible, latent and advective heat exchanges. An equilibrium parameterization of snow surface temperature accounts for differences between snow surface temperature and average snowpack temperature without having to introduce additional state variables. Melt outlfow is a function of the liquid fraction, using Darcy\u27s law. This allows the model to account for continued outlflow even when the energy balance is negative. A detailed description of the model is given together with results of tests of individual components and the complete model against data collected at the Central Sierra Snow Laboratory, California; Reynolds Creek Experimental Watershed, Boise Idaho; and at the Utah State University drainage research farm, Logan Utah. The testing includes comparisons against melt outflow collected in lysimeters and melt collectors, surface snow temperatures collected using infrared temperature sensors and depth and water equivalent measured using snow core samplers

Defect engineering for improved photocatalytic performance of reduced lead titanate (PbTiO3) under solar light irradiation

Lead titanate (PbTiO3) nanoparticles were prepared successfully by template free hydrothermal  method. Size, crystallinity, morphology and phase determination of the nanoparticles were made by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and field-emission scanning electron microscopy (FESEM). FESEM results had shown that all nanoparticles were in the range between 20 to 40 nm size and found in the form of agglomerates. The average crystallite size of PbTiO3 nanoparticles was calculated to be nearly 35 nm. PbTiO3 nanoparticles were reduced by hydrogenation at high temperature to make the material active for visible light. Furthermore, optical absorbance of PbTiO3 nanoparticles was determined by applying ultraviolet-visible-near infrared (UV-Vis-NIR) spectroscopy. By using Davis-Mott model, the direct optical band gap of 2.65 eV was acquired. Methyl orange (MO) was used as pollutant to check the photocatalytic activity of reduced PbTiO3 nanoparticles under solar light irradiation. Photocatalytic activity of reduced PbTiO3 nanoparticles increased 2.6 times more than that of pure PbTiO3 nanoparticles for methyl orange (MO) under solar light irradiation.               KEY WORDS: Lead titanate (PbTiO3), Photocatalytic performance, Hydrothermal growth, Solar light, Irradiation Bull. Chem. Soc. Ethiop. 2019, 33(2), 373-380.DOI: https://dx.doi.org/10.4314/bcse.v33i2.1

The use of desalinated-dried jellyfish and rice bran for controlling weeds and rice yield

To achieve higher rice production, rice-growing countries have used great amounts of synthetic chemical compounds (chemical fertilizers and pesticides) that can have adverse effects on the environment and humans. Organic products and organic farming technologies are friendlier to the environment and more conducive to sustainable agriculture but require different inputs, knowledge and skills. Weed control is one of the major challenges in organic rice cultivation. The present study proposes and tests the use of desalinated-dried jellyfish chips in the development of sustainable rice production. Vast amounts of jellyfishes have been found in the Sea of Japan (Nomura's jellyfish, Nemopilema nomurai Kishinouye) and Japan inland sea areas (Water jelly, Aurelia aurita (Linne)), and jellyfish populationc can have a negative impact on the fishery industry. In this context, the use of jellyfish in organic agriculture has attracted attention. The present study found that the application of desalinated-dried jellyfish (small pieces of jellyfish which are desalinated and dried) mixed in soil before transplanting can effectively control weeds in rice fields and has a nutrient effect because of the high nitrogen content (12-13%). Desalinated-dried jellyfish has potential as an agricultural material that replaces herbicides and chemical fertilizers. It also contributes to environment-friendly rice production. It was found that both desalinated-dried jellyfish and rice bran effectively controlled rice weeds when mixed in the soil before the transplanting.The grain yields of desalinated-dried jellyfish treatments were consistently higher than the corresponding rice bran treatments. The rice yield from the desalinated-dried jellyfish treatments were comparable to the chemical fertilizer treatment.

Cystic artery pseudo-aneurysm: a complication of xanthogranulomatous cholecystitis

A 54-year-old man presented for radiology with pain and a feeling of fullness in the upper abdomen and an epigastric mass. Ultrasound revealed a large cystic mass with internal echoes, lying posterior and inferior to left lobe of the liver. The gallbladder was thick-walled and contracted, and contained a calculus and echogenic sludge. A cystic structure that produced swirling flow signals on colour Doppler was demonstrated within the gallbladder. The CT scan showed a thickened gallbladder with adjacent inflammation and a 2-cm pseudo-aneurysm in its wall. High-density material was present in the gallbladder lumen, in the extra-hepatic bile ducts and around the gastrohepatic ligament. A thick haemorrhagic pus, from which Escherichia coli was cultured, was drained from the gastrohepatic collection. An elective coeliac angiogram demonstrated a solitary pseudo-aneurysm of the medial branch of the cystic artery. Selective catheterisation of this artery with a micro-catheter enabled complete exclusion of the pseudo-aneurysm by a single micro-coil. Histological examination of the gallbladder, which was ultimately removed at open cholecystectomy, demonstrated xanthogranulomatous cholecystitis

A spectroscopic, thermodynamic and molecular docking study of the binding mechanism of dapoxetine with calf thymus DNA

Dapoxetine is a selective serotonin reuptake inhibitor, used to treat premature ejaculation in men. Dapoxetine may interact with theDNAand hence this study investigated dapoxetine and calf thymusDNA(ctDNA) binding interaction. The interaction study of ligands to DNA is of importance in the development of molecular probes and therapeutic agents. Spectroscopic techniques including spectrofluorometry and spectrophotometry were employed to study this interaction. Fluorescence studies indicated a static quenching mechanism between dapoxetine and ctDNA. Groove binding was suggested as the mode of interaction between dapoxetine and ctDNA based onUVabsorption, circular dichroism (CD) spectroscopy, iodide quenching and molecular docking studies. The studies conducted at three different temperatures 298, 303 and 310 K indicated a strong binding interaction at higher temperatures. Thermodynamic studies conducted indicated involvement of hydrophobic interaction between ctDNA and dapoxetine and were entropy-driven. Ethidium bromide probe study suggested that dapoxetine does not bind to ctDNA in an intercalative fashion. Iodide quenching studies further proved the non-intercalative binding of ctDNA with dapoxetine. Ionic strength studies conducted ruled out the electrostatic binding mechanism between ctDNA and dapoxetine. Molecular docking analysis performed for the dapoxetine with calf thymus DNA (ctDNA) interaction and confirmed minor groove binding of dapoxetine to ctDNA. The study helped to reveal the binding interaction mechanism between dapoxetine and ctDNA