Biology Methods and Protocols最新文献

Evolution stands as a foundational pillar within modern biology, shaping our understanding of life. Studies related to evolution, for example constructing phylogenetic trees, are often carried out using DNA or protein sequences. These data, readily accessible from public databases, represent a treasure trove of resources that can be harnessed to create engaging activities with the public. At the heart of our project lies a collection of "stories" about evolution, each rooted in genuine scientific publications that furnish both biological context and supporting evidence. These narratives serve as the focal point of our LightOfEvolution.org website. Each story is accompanied by a dedicated "Your Turn to Play" section. Within this section, we furnish user-friendly activities and step-by-step guidelines, equipping visitors with the means to replicate analyses showcased in the highlighted publications. For example, the website OhMyGenes.org, relying on authentic scientific data, provides the capability to compute the proportion of shared genes across different species. Here, visitors can address the captivating question: "How many genes do we share with a banana?" To extend the educational reach, we have developed a series of modular activities, also related to the stories. These activities have been thoughtfully designed to be adaptable for face-to-face workshops held in classrooms or presented during public events. We aim to create stories and activities that resonate with participants, offering a tangible and enjoyable experience. By providing opportunities that reflect real-world scientific practices, we seek to offer participants valuable insights into the current workings of scientists "in the light of evolution."

Successful induction of antibodies in model organisms like mice depends strongly on antigen design and delivery. New antigen designs for immunization are helpful for developing future therapeutic monoclonal antibodies (mAbs). One of the gold standards to induce antibodies in mice is to express and purify the antigen for vaccination. This is especially time-consuming when mAbs are needed rapidly. We closed this gap and used the display technology tetraspanin anchor to develop a reliable immunization technique without the need to purify the antigen. This technique is able to speed up the immunization step enormously and we have demonstrated that we were able to induce antibodies against different proteins with a focus on the receptor-binding domain of SARS-CoV-2 and the extracellular loop of canine cluster of differentiation 20 displayed on the surface of human cells.

COVID-19 affects a variety of organs and systems of the body including the central nervous system. Recent research has shown that COVID-19 survivors often experience neurological and psychiatric complications that can last for months after infection. We conducted a large Internet study using online tests to analyze the effects of SARS-CoV-2 infection, COVID-19 severity, and vaccination on health, intelligence, memory, and information processing precision and speed in a cohort of 4445 subjects. We found that both SARS-CoV-2 infection and COVID-19 severity were associated with negative impacts on patients' health. Furthermore, we observed a negative association between COVID-19 severity and cognitive performance. Younger participants had a higher likelihood of SARS-CoV-2 contraction, while the elderly had a higher likelihood of severe COVID-19 and vaccination. The association between age and COVID-19 severity was primarily mediated by older participants' impaired long-term health. Vaccination was positively associated with intelligence and the precision of information processing. However, the positive association between vaccination and intelligence was likely mediated by achieved education, which was itself strongly associated with the likelihood of being vaccinated.

Many individuals experience persistent symptoms such as deteriorated physical and mental health, increased fatigue, and reduced cognitive performance months after recovering from coronavirus disease 2019 (COVID-19). There is limited data on the long-term trajectory and prevalence of these symptoms, especially in milder cases. Our study aimed to assess the persistent effects of COVID-19 on physical and mental health, fatigue, and cognitive performance in a cohort of 214 students, averaging 21.8 years of age. Of these, 148 had contracted COVID-19 but were not hospitalized, with the time since infection ranging from 1 to 39 months. We utilized a comprehensive panel of cognitive tests to measure intelligence, memory, and psychomotor skills, and a detailed anamnestic questionnaire to evaluate physical and mental health. While contracting COVID-19 did not significantly impact overall health and performance, it was associated with increased reports of fatigue. However, the reported severity of the disease had a pronounced negative influence on physical health, mental well-being, fatigue, and reaction time. Trends of improvement in physical and mental health, as well as error rate, were observed within the first 2 years post-infection. However, fatigue and reaction time showed a trend of deterioration. Beyond the 2-year mark, physical health and error rate continued to improve, while mental health began to deteriorate. Fatigue and reaction time continued to decline. Overall, our findings suggest that some effects of contracting COVID-19 can persist or even deteriorate over time, even in younger individuals who had mild cases that did not require hospitalization.

Chitosan is a biopolymer obtained from chitin, one of the most abundant biopolymers in nature. Numerous applications of chitosan are well known in the biomedical, environmental, and industrial fields, and the potential applications are considerable. This work reports a new spectrophotometric method to determine chitosan concentration accurately. The method is based on the deamination of chitosan by nitrite in acidic conditions, followed by a carbohydrate determination by the anthrone reagent.

Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) followed by the 2^-ΔΔCt method is the most common way to measure transcript levels for relative gene expression assays. The quality of an RT-qPCR assay is dependent upon the identification and validation of reference genes to normalize gene expression data. The so-called housekeeping genes are commonly used as internal reference genes because they are assumed to be ubiquitously expressed at stable levels. Commonly, researchers do not validate their reference genes but rely on historical reference genes or previously validated genes from an unrelated experiment. Using previously validated reference genes to assess gene expression changes occurring during malting resulted in extensive variability. Therefore, a new method was tested and validated to circumvent the use of internal reference genes. Total mouse RNA was chosen as the external reference RNA and a suite of primer sets to putatively stable mouse genes was created to identify stably expressed genes for use as an external reference gene. cDNA was created by co-amplifying total mouse RNA, as an RNA spike-in, and barley RNA. When using the external reference genes to normalize malting gene expression data, standard deviations were significantly reduced and significant differences in transcript abundance were observed, whereas when using the internal reference genes, standard deviations were larger with no significant differences seen. Furthermore, external reference genes were more accurate at assessing expression levels in malting and developing grains, whereas the internal reference genes overestimated abundance in developing grains and underestimated abundance in malting grains.

Foldscopes are ultra-low-cost paper microscopes invented by Manu Prakash and Jim Cybulski at Stanford University. They are about as light as a pencil and waterproof, all whilst offering similar optic quality to traditional microscopes. Foldscopes do not require electricity or glass slides to be used, which increases the possibilities of their use in education and outreach activities with children or people with disabilities. In 2019, thanks to a material grant of 100 foldscopes from One World Science and additional purchased foldscopes, I designed and implemented a science workshop called Exploradores del Microcosmos, or Explorers of Microcosmos in English. The aim of the workshop was to help make microscopy more accessible, in particular at underfunded schools, and stimulate active learning about ecosystems and evolution in the participants. Within this article, I describe the workshop and relay my personal insights and reflections on its execution across multiple schools and groups in Mexico.