Aerenchyma tissue of Juncus effusus L.:a novel resource for sustainable natural cellulose foams

The demand for sustainable, low-cost, and high-performance natural cellulose foams with isotropic structures has increased greatly due to growing environmental awareness. However, the synthesis of current cellulose foams/aerogels requires substantial amounts of energy and chemicals, mainly due to the challenges posed by the poor solubility and processability of raw cellulose derived from biomass resources. Consequently, these challenges further highlight the advantages offered by the direct utilization of natural cellulose foams, considering their economic and environmental benefits. Previous studies on natural cellulose foams have predominantly focused on specific plant components such as phloem, xylem, vascular vessels, fruits, and seeds. In this study, we present an overlooked alternative: the aerenchyma tissue of aquatic or wetland plants. Specifically, we investigated on Juncus effusus L. (JE), a commonly found problematic wetland weed that is known for its high reproductive ability, causing a reduction in annual forage yield. The aerenchyma tissue of JE was discovered to possess a well-developed 3D interconnected hierarchical structure, exhibiting remarkable properties as a natural lignocellulosic foam. These properties include exceptional compressibility, hydrophobicity (water contact angle: 147°), lightweights (density: 0.017 g/cm3), and high porosity (98%). Through this study, we have introduced a novel natural cellulose foam and explored the utilization of biomass derived from wetland weed wastes.</p

UBB+1 reduces amyloid-beta cytotoxicity by activation of autophagy in yeast

UBB+1 is a mutated version of ubiquitin B peptide caused by a transcriptional frameshift due to the RNA polymerase II "slippage". The accumulation of UBB+1 has been linked to ubiquitin-proteasome system (UPS) dysfunction and neurodegeneration. Alzheimer\u27s disease (AD) is defined as a progressive neurodegeneration and aggregation of amyloid-beta peptides (A beta) is a prominent neuropathological feature of AD. In our previous study, we found that yeast cells expressing UBB+1 at lower level display an increased resistance to cellular stresses under conditions of chronological aging. In order to examine the molecular mechanisms behind, here we performed genome-wide transcriptional analyses and molecular/cellular biology assays. We found that low UBB+1 expression activated the autophagy pathway, increased vacuolar activity, and promoted transport of autophagic marker ATG8p into vacuole. Furthermore, we introduced low UBB+1 expression to our humanized yeast AD models, that constitutively express A beta 42 and A beta 40 peptide, respectively. The co-expression of UBB+1 with A beta 42 or A beta 40 peptide led to reduced intracellular A beta levels, ameliorated viability, and increased chronological life span. In an autophagy deficient background strain (atg1 Delta), intracellular A beta levels were not affected by UBB+1 expression. Our findings offer insights for reducing intracellular A beta toxicity via autophagydependent cellular pathways under low level of UBB+1 expression

BEGIN Partnership: Using Problem-Based Learning to Teach Genetics & Bioethics

A science education center at a university medical school had grant funding to develop a genetics curriculum unit, but needed a dissemination plan. A statewide science teacher organization that provided professional development training was facing decreased funding. These two groups combined their efforts, and created a unique partnership, called BEGIN (Biotechnology, Ethics and Genetics Instructional Network) that has brought together university medical and science faculty and high school biology teachers. The main goal of this partnership is to provide high school biology teachers with new instructional tools to face the challenges of teaching genetics and bioethics in a manner that is content-rich, research and standards-based, and relevant to students\u27 lives. This article describes the BEGIN partnership and summarizes the tiered approach used for designing, pilot-testing, and disseminating a new problem-based learning (PBL) curriculum module on the bioethics of DNA testing for Huntington\u27s disease. The article also provides some preliminary data on the effectiveness of this approach in transforming teacher practice

EFFECT OF ISOTHERMAL AND ISOCHRONAL AGING ON THE MICROSTRUCTURE AND PRECIPITATE EVOLUTION IN BETA-QUENCHED N36 ZIRCONIUM ALLOY

In this study, the effect of isothermal and isochronal aging is reported to investigate the precipitate evolution and recrystallization of N36 zirconium alloy after β-quenching. Two groups of samples were cut from the as-received sheet of N36 zirconium alloy and subjected to solution treatment and subsequent aging at 580, 640, and 700 °C for 40 and 600 min, respectively. Optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and electron backscattering diffraction (EBSD) were utilized to characterize the microstructure and second-phase particle (SPPs) evolution. Results show that the implemented quenching after solution treatment produces fine interlaced α-plates structure conserved inside prior β grain boundaries with 12 variant directions that follow Burger misorientation characteristics. After aging for a short time, initial α-plates conserve their shape and become softer, and SPPs spread along their boundaries. Recrystallizations are finished for specimens aged at a higher temperature or for a longer time. The recrystallized structure exhibits non-uniform grains and a random SPPs distribution. Despite the differences in morphology, some recrystallization grains retain the orientation feature from the initial α-plates. Hardness declines as temperature and time rise, and no hardness peak is seen. Roughness and wettability rise with increasing ageing temperatures

Development of a method for heat shock stress assessment in yeast based on transcription of specific genes

All living cells, including yeast cells, are challenged by different types of stresses in their environments and must cope with challenges such as heat, chemical stress, or oxidative damage. By reversibly adjusting the physiology while maintaining structural and genetic integrity, cells can achieve a competitive advantage and adapt environmental fluctuations. The yeast Saccharomyces cerevisiae has been extensively used as a model for study of stress responses due to the strong conservation of many essential cellular processes between yeast and human cells. We focused here on developing a tool to detect and quantify early responses using specific transcriptional responses. We analyzed the published transcriptional data on S.\ua0cerevisiae DBY strain responses to 10 different stresses in different time points. The principal component analysis (PCA) and the Pearson analysis were used to assess the stress response genes that are highly expressed in each individual stress condition. Except for these stress response genes, we also identified the reference genes in each stress condition, which would not be induced under stress condition and show stable transcriptional expression over time. We then tested our candidates experimentally in the CEN.PK strain. After data analysis, we identified two stress response genes (UBI4 and RRP) and two reference genes (MEX67 and SSY1) under heat shock (HS) condition. These genes were further verified by real-time PCR at mild (42\ub0C), severe (46\ub0C), to lethal temperature (50\ub0C), respectively

Different Expression Levels of Human Mutant Ubiquitin B+1 (UBB+1) Can Modify Chronological Lifespan or Stress Resistance of Saccharomyces cerevisiae

The ubiquitin-proteasome system (UPS) is the main pathway responsible for the degradation of misfolded proteins, and its dysregulation has been implicated in several neurodegenerative diseases, including Alzheimer’s disease (AD). UBB+1, a mutant variant of ubiquitin B, was found to accumulate in neurons of AD patients and it has been linked to UPS dysfunction and neuronal death. Using the yeast Saccharomyces cerevisiae as a model system, we constitutively expressed UBB+1 to evaluate its effects on proteasome function and cell death, particularly under conditions of chronological aging. We showed that the expression of UBB+1 caused inhibition of the three proteasomal proteolytic activities (caspase-like (β1), trypsin-like (β2) and chymotrypsin-like (β5) activities) in yeast. Interestingly, this inhibition did not alter cell viability of growing cells. Moreover, we showed that cells expressing UBB+1 at lower level displayed an increased capacity to degrade induced misfolded proteins. When we evaluated cells during chronological aging, UBB+1 expression at lower level, prevented cells to accumulate reactive oxygen species (ROS) and avert apoptosis, dramatically increasing yeast life span. Since proteasome inhibition by UBB+1 has previously been shown to induce chaperone expression and thus protect against stress, we evaluated our UBB+1 model under heat shock and oxidative stress. Higher expression of UBB+1 caused thermotolerance in yeast due to induction of chaperones, which occurred to a lesser extent at lower expression level of UBB+1 (where we observed the phenotype of extended life span). Altering UPS capacity by differential expression of UBB+1 protects cells against several stresses during chronological aging. This system can be valuable to study the effects of UBB+1 on misfolded proteins involved in neurodegeneration and aging

Teachers’ Perceptions of Teacher–Child Relationships, Student Behavior, and Classroom Management

Children’s relationships with their teachers are a potential resource for enhancing developmental and academic outcomes. The effects of positive or negative teacher–child relationships can be either beneficial or detrimental to students’ academic progress, behaviors, and emotions. In the current study, we utilized a qualitative research design to examine 18 pre-kindergarten to fourth-grade teachers’ perceptions of teacher–child relationships, student behavior, and classroom management. Analysis of in-depth interviews yielded five major themes: (a) beliefs in children, (b) teaching strategies, (c) acknowledging individual differences, (d) challenges, and (e) relationships. Findings of this study have the potential to inform in-service training regarding relationship-building skills and attending to children’s social-emotional development. We discuss the limitations of the study, implications for professional school counselors, and recommendations for future research

FMN reduces Amyloid-β toxicity in yeast by regulating redox status and cellular metabolism

Alzheimer\u27s disease (AD) is defined by progressive neurodegeneration, with oligomerization and aggregation of amyloid-β peptides (Aβ) playing a pivotal role in its pathogenesis. In recent years, the yeast Saccharomyces cerevisiae has been successfully used to clarify the roles of different human proteins involved in neurodegeneration. Here, we report a genome-wide synthetic genetic interaction array to identify toxicity modifiers of Aβ42, using yeast as the model organism. We find that FMN1, the gene encoding riboflavin kinase, and its metabolic product flavin mononucleotide (FMN) reduce Aβ42 toxicity. Classic experimental analyses combined with RNAseq show the effects of FMN supplementation to include reducing misfolded protein load, altering cellular metabolism, increasing NADH/(NADH + NAD+) and NADPH/(NADPH + NADP+) ratios and increasing resistance to oxidative stress. Additionally, FMN supplementation modifies Htt103QP toxicity and α-synuclein toxicity in the humanized yeast. Our findings offer insights for reducing cytotoxicity of Aβ42, and potentially other misfolded proteins, via FMN-dependent cellular pathways

Lightweight Triboelectric Nanogenerators Based on Hollow Stellate Cellulose Films Derived from Juncus effusus L. Aerenchyma

This study reports a facile delignification and natural drying process for synthesizing cellulose films using the unique surface roughness, porosity, and lightness of the hollow stellate cellulose (HSC) united aerenchyma of the wetland weed Juncus effusus L. By controlling the grafted amino/fluorine-bearing group content of various silane coupling agents, this work successfully manipulates the triboelectric polarities of HSC films after silanization. Subsequently, a layer of Ag nanowire electrodes is coated on one side of the silanized HSC friction layers, resulting in flexible, lightweight, semi-transparent HSC-based triboelectric nanogenerators (HSC-TENGs) featuring both macro-scale surface roughness and micro-nano inner pores. These all-in-one HSC-TENGs achieve the highest output voltage of 4.86 V, which is 28 times that of TENGs employing two pristine HSC films as triboelectric layers (PHSC-TENG). Finally, the HSC-TENG with the optimum output power is applied as a wearable self-powered sensor for gait analysis, demonstrating stable and sustainable performances in distinguishing different body motions such as walking, running, jumping, and calf raising. This study not only proposes a new cellulose-based TENG for future in-depth body locomotion analysis but also paves the way for converting differently structured aerenchyma from abundant problematic aquatic or wetland weeds into promising structural templates in multifunctional cellulose-based applications.</p