Development of Biological E-Module Based on Contextual Teaching and Learning (CTL) Learning on Structure and Function of Plants and Animal Networks to Improve Critical Thinking Skills of Class XI MIPA SMA Students

In the field of education, the presence of technology has helped teachers a lot in carrying out learning. Future education cannot only focus on cognitive aspects. To face various problems and challenges of the times in the future, students are expected to have much better attitudes, skills, and knowledge competencies, to be more creative, innovative, and productive. The purpose of this research is to analyze the feasibility and effectiveness of the development e-module Biology based on Contextual Teaching and Learning (CTL) on the material structure and function of plant and animal tissues to improve the critical thinking skills of students in class XI MIPA SMA that are valid, practical, and effective. The results showed that the e-module Biology based on Contextual Teaching and Learning (CTL) on the structure and function of plant and animal tissues to improve critical thinking skills of students in class XI MIPA SMA has a very valid category with a validator value of 89.33%, very practical 93.33% by Biology teachers and students with a score of 87.52% and the results of the effectiveness test of the CTL - based e-module showed that it was very effective, there was a significant difference between classes that used CTL - based e-modules and classes that did not use CTL - based e-modules . So, it can be concluded that the CTL-based Biology e-module that has been developed is very valid, very practical, and very effective.

The use and control of antimicrobial substances in animal feed – EU regulations and the risks related to their presence

Animal feeds are routinely subject to contamination from diverse sources, including environmental pollution, activities of microbes, and veterinary drug residues. Contamination of feed with chemical substances such as coccidiostats or antibiotics can occur at the stage of production, transport and storage, and their presence may have a negative impact on the health of animals consuming feed contaminated with certain chemicals. This study presents the legal requirements for the production of feed, the presence of antimicrobial substances in feed, and the problem of contamination of feed with antibacterial substances as well as the possible transfer of these compounds to the animal tissues and the natural environment.

Vitamin A: A Review Article

Vitamin A has important function in the body. Vitamin A is involved in growth, an reproduction. In this paper description, function and deficiency diseases of vitamin A has been delineated here with. Vitamin A is an essential micronutrient for the normal functioning of the visual system, growth and development, immunity and reproduction. Vitamin A is a constituent of visual pigment and maintains epithelium. It protects against some epithelial cancer Vitamin A being a potent antioxidant is required for cell regulation. To combat the deficiency of vitamin A in community, awareness of their importance and their source plays a vital role. Food-based approaches have been reviewed and judged to have a promising role in integrated strategies, but many gaps in knowledge were identified; more well-designed studies on efficacy, effectiveness, cost effectiveness, and sustainability of food-based approaches are needed. The main sources of preformed vitamin A or retinol are liver, whole milk, fish oil and egg. Vitamin A is present in many animal tissues and is readily absorbed from such dietary sources in the terminal small intestine.

Virtual delivery: a panacea for the financial and ethical challenges associated with physiology laboratory classes?

There has been a gradual shift in the delivery of physiology laboratory classes over the last 30 years. For many, wet-lab demonstrations using animal tissues have been reduced or replaced with student-led investigations where students are both subjects and researchers. Despite these changes, expectations remain that physiology courses should include a practical component to encourage deeper and higher-order learning. Wet-lab tissue experiments and student-based group research formats can be expensive to run, associated with various ethical constraints, and, as discovered in these times of COVID-19, difficult to operate while adhering to physical distancing. We address the proposition that online and/or remote delivery of laboratory classes using digital technologies may provide a solution to both financial and ethical constraints of on-campus laboratory classes. Our discussions, as an international group of 10 physiologists from the United States, the United Kingdom, Canada, and Australia, revealed that although some of the financial and ethical constraints of using animal tissues and student-led investigations were addressed by the introduction of online alternatives, the construction and maintenance of online delivery modes could also be expensive and ethical issues, not previously considered, included digital equity and student data security. There was also a collective perception that if face-to-face laboratory classes were changed to an entirely virtual mode there was a risk that some intended learning outcomes would not be met. It was concluded that the “ideal” approach is likely a hybrid model whereby student attendance in face-to-face, on-campus classes is supported with interactive digital content either developed in house or obtained through third-party providers.

Von Kossa and his staining technique

One hundred and twenty years ago, the Hungarian physician Julius von Kossa developed a now classical staining method for detecting mineral deposits in animal tissues. Since then, this method has been widely adapted and combined with different counterstains, but still bears the name of its original inventor, who, if alive, would have turned 150 in 2015. As a rather inexpensive technique that does not require special instrumentation, von Kossa’s staining method became extremely popular for demonstrating mineralized tissues in vivo and in vitro. This article pays tribute to von Kossa and to his handy staining method.

Simultaneous Determination of Ciprofloxacin and Ofloxacin in Animal Tissues with the Use of Capillary Electrophoresis with Transient Pseudo-Isotachophoresis

We have developed a precise and accurate method for the determination of ciprofloxacin and ofloxacin in meat tissues. Our method utilizes capillary electrophoresis with a transient pseudo-isotachophoresis mechanism and liquid–liquid extraction during sample preparation. For our experiment, a meat tissue sample was homogenized in pH 7.00 phosphate buffer at a ratio of 1:10 (tissue mass: buffer volume; g/mL). The extraction of each sample was carried out twice for 15 min with 600 µL of a mixture of dichloromethane and acetonitrile at a 2:1 volume ratio. We then conducted the electrophoretic separation at a voltage of 16 kV and a temperature of 25 °C using a background electrolyte of 0.1 mol/L phosphate–borate (pH 8.40). We used the UV detection at 288 nm. The experimentally determined LOQs for ciprofloxacin and ofloxacin were 0.27 ppm (0.8 nmol/g tissue) and 0.11 ppm (0.3 nmol/g tissue), respectively. The calibration curves exhibited linearity over the tested concentration range of 2 to 10 nmol/g tissue for both analytes. The relative standard deviation of the determination did not exceed 15%, and the recovery was in the range of 85–115%. We used the method to analyze various meat tissues for their ciprofloxacin and ofloxacin contents.

Tumorigenesis and cell competition in Drosophila in the absence of polyhomeotic function

Cell competition is a homeostatic process that eliminates by apoptosis unfit or undesirable cells from animal tissues, including tumor cells that appear during the life of the organism. In Drosophila there is evidence that many types of oncogenic cells are eliminated by cell competition. One exception is cells mutant for polyhomeotic (ph), a member of the Polycomb family of genes; most of the isolated mutant ph clones survive and develop tumorous overgrowths in imaginal discs. To characterize the tumorigenic effect of the lack of ph, we first studied the growth of different regions of the wing disc deficient in ph activity and found that the effect is restricted to the proximal appendage. Moreover, we found that ph-deficient tissue is partially refractory to apoptosis. Second, we analyzed the behavior of clones lacking ph function and found that many suffer cell competition but are not completely eliminated. Unexpectedly, we found that nonmutant cells also undergo cell competition when surrounded by ph-deficient cells, indicating that within the same tissue cell competition may operate in opposite directions. We suggest two reasons for the incompleteness of cell competition in ph mutant cells: 1) These cells are partially refractory to apoptosis, and 2) the loss of ph function alters the identity of imaginal cells and subsequently their cell affinities. It compromises the winner/loser interaction, a prerequisite for cell competition.

213 Nutritional and Genetic Influences on Fatty Acid Composition of Beef and Lamb

There is increased competition in the protein market with the entrance of cell-based and plant-based products. Consumers issues with consumption of red meat typically center around saturated (SFA) fatty acid content and environmental impacts associated with production. Nutritional system used for finishing beef and lamb alters fatty acid composition of the meat product. Forages and grasses that are utilized in a grass-fed finishing system increases the animal’s intake of a-linolenic acid (C18:3 n-3), the main fatty acid present in plants (57%) that can be converted to eicosapentaenoic (C20:5 n-3), docosapentaenoic (C22:5 n-3) and docosahexaenoic (C22:6 n-3) acids in animal tissues. Grain-fed finishing systems increases the animal’s intake of linoleic acid (C18:2 n-6), the main fatty acid present in corn grain (57%), that can be converted to arachidonic acid (C20:4 n-6) and docosatetraenoic acid (C22:4 n-6) in animal tissues. Biohydrogenation of polyunsaturated fatty acids (PUFA) is extensive in the rumen (> 80% of dietary PUFA) and rumen protected supplements are needed to enhance PUFA content of ruminant meat products. Saturated (SFA) and monounsaturated (MUFA) fatty acids are the majority (>75% of total fatty acids) of fatty acids present in ruminant meat products. Therefore, finding approaches to attain greater desaturation of palmitic and stearic acids to their MUFA products, palmitoleic and oleic acids, would be most beneficial. The content of oleic acid and MUFA in beef is highly heritable and some breeds have high levels of MUFA. Stearoyl-CoA desaturase (SCD1) is the rate limiting enzyme in the production of MUFA. More research is needed to find ways of altering SCD1 expression in meat animal tissues to enhance MUFA and lower SFA content.