Perspectives of nonmajor undergraduate students on the impact of group discussions in learning physiology.

A 3-year study (2017-2019) was conducted to obtain the views of nonmajor undergraduate students about discussions in learning physiology. The teaching methods used were lecture only (lecture), group discussion alone (discussion), and a combination of lecture and discussion (lecture + discussion). Students were assigned homework in a textbook, and they did not have access to textbook/notes during discussions.

Impact of combination of short lecture and group discussion on the learning of physiology by nonmajor undergraduates.

This study assessed the impact of an "active learning" strategy employed alone or in combination with traditional lectures on the learning of mammalian physiology by undergraduate students. The study investigated the impact of three teaching strategies, namely ) traditional lecture, ) group discussion alone, and ) combination of lecture and group discussion. For all strategies, students were given homework in a textbook and they completed written assignments before each session.

Factors necessary to produce basoapical polarity in human glandular epithelium formed in conventional and high-throughput three-dimensional culture: example of the breast epithelium.

Background: Basoapical polarity in epithelia is critical for proper tissue function, and control of proliferation and survival. Cell culture models that recapitulate epithelial tissue architecture are invaluable to unravel developmental and disease mechanisms. Although factors important for the establishment of basal polarity have been identified, requirements for the formation of apical polarity in three-dimensional tissue structures have not been thoroughly investigated.

Phytates reduce uptake of leucine and glutamate but not lysine and glucose from the intestinal lumen of chickens: short communication.

An investigation into the influence of phytates on the in situ absorption of amino acids (lysine, glutamate and leucine) and glucose from the intestinal lumen of 3-week-old chickens was carried out. Birds were anaesthetised and the intestines exteriorised. Uptake of 5 mM of each nutrient over a 4-min period was measured in the presence of four phytate concentrations (0, 50, 250 and 500 mM).

Phytic acid increases mucin and endogenous amino acid losses from the gastrointestinal tract of chickens.

The influence of the form of phytic acid on the regulation of mucin and endogenous losses of amino acids, nitrogen and energy in chickens was investigated. Forty-eight 10-week-old male broilers were grouped by weight into eight blocks of six cages with one bird per cage. Birds received by intubation six dextrose-based combinations of phytic acid and phytase arranged in a 3 x 2 factorial consisting of phytic acid form (no phytic acid, 1.

Quadratic form: a robust metric for quantitative comparison of flow cytometric histograms.

Comparison of fluorescence distributions is a fundamental part of the analysis of flow cytometric data. This approach is applied to detect differences between control and test sample and thus analyze a biological response. Comparison of standard test samples over time provides an estimate of instrument stability for quality control.

Three-dimensional cell culture to model epithelia in the female reproductive system.

In vitro 3-dimensional (3D) cell cultures produce valuable models that mimic 3D tissue organization and function and enhance the understanding of cell/tissue function under normal and pathological situations. Tissue function depends on the interactions between cells and the extracellular matrix; thus, effective 3D cell cultures rely on the use of appropriate extracellular matrix cues. Noticeable progress in 3D cell culture was obtained from studies with epithelial cells from organs of the female reproductive system including the mammary glands, the uterus, and the ovaries.

Precision of light intensity measurement in biological optical microscopy.

Standardization and calibration of optical microscopy systems have become an important issue owing to the increasing role of biological imaging in high-content screening technology. The proper interpretation of data from high-content screening imaging experiments requires detailed information about the capabilities of the systems, including their available dynamic range, sensitivity and noise. Currently available techniques for calibration and standardization of digital microscopes commonly used in cell biology laboratories provide an estimation of stability and measurement precision (noise) of an imaging system at a single level of signal intensity.

Compression of fluorescence microscopy images based on the signal-to-noise estimation.

Modern microscopic techniques like high-content screening (HCS), high-throughput screening, 4D imaging, and multispectral imaging may involve collection of thousands of images per experiment. Efficient image-compression techniques are indispensable to manage these vast amounts of data. This goal is frequently achieved using lossy compression algorithms such as JPEG and JPEG2000.

Loss of image quality in photobleaching during microscopic imaging of fluorescent probes bound to chromatin.

Prolonged excitation of fluorescent probes leads eventually to loss of their capacity to emit light. A decrease in the number of detected photons reduces subsequently the resolving power of a fluorescence microscope. Adverse effects of fluorescence intensity loss on the quality of microscopic images of biological specimens have been recognized, but not determined quantitatively.

Confocal fluorescence imaging of photosensitized DNA denaturation in cell nuclei.

The double-stranded helical structure of DNA is maintained in part by hydrogen bonds between strands and by stacking interactions between adjacent purine and pyrimidine bases in one strand. The transition (denaturation) from a double-stranded (ds) to a single-stranded (ss) form can be induced in isolated DNA or fixed cells by exposure to elevated temperatures, alkali or acids, aprotic or nonpolar solvents or some drugs. We report here that DNA denaturation can occur in situ in cell nuclei as a result of interaction between light and an intercalated dye, acridine orange or ethidium bromide.

Postnatal ontogeny of kinetics of porcine jejunal brush border membrane-bound alkaline phosphatase, aminopeptidase N and sucrase activities.

Our objectives were to determine postnatal changes in the maximal enzyme activity (V(max)) and enzyme affinity (K(m)) of jejunal mucosal membrane-bound alkaline phosphatase, aminopeptidase N and sucrase using a porcine model which may more closely resemble the human intestine. Jejunal brush border membrane was prepared by Mg(2+)-precipitation and differential centrifugation from pigs of suckling (8 days), weaning (28 days), post-weaning (35 days) and adult (70 days) stages. p-Nitrophenyl phosphate (0-8 mM), L-alanine-p-nitroanilide hydrochloride (0-28 mM) and sucrose (0-100 mM) were used in alkaline phosphatase, aminopeptidase N and sucrase kinetic measurements.

Basal lamina of ovarian follicle regulates an inward Cl(-) current in differentiated granulosa cells.

Patch-clamp experiments were conducted to study the effects of basal lamina (basement membrane) of preovulatory chicken ovarian follicle on membrane currents in differentiated chicken granulosa cells in a homologous system. The membrane capacitance (measure of total membrane area) was smaller in cells cultured on intact basal lamina than that of control cells. The granulosa cells expressed outward and two inward currents.

Effect of basal lamina of ovarian follicle on T- and L-type Ca(2+) currents in differentiated granulosa cells.

Patch clamp experiments were conducted to study the effects of basal lamina (basement membrane) of chicken ovarian follicle on membrane Ca(2+) currents in differentiated chicken granulosa cells in a homologous system. The whole cell patch clamp technique was used to simultaneously monitor membrane capacitance (an indirect measure of total cell surface area) and currents flowing through voltage-dependent Ca(2+) channels (using Ba(2+) as the charge carrier). Membrane capacitance was smaller in cells incubated on intact basal lamina than in control cells (incubated on tissue culture-treated plastic substratum).