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Polymer electrolyte membrane fuel cells (PEMFCs) are being considered for heavy duty applications, and the DOE has established various performance and durability targets to enable their adoption.1. The key differences between light and heavy-duty application of fuel cells is their increased durability and operating efficiency requirements for heavy duty applications when compared to the lower cost requirement for light duty applications. While higher catalyst loadings can be utilized to increase the fuel cell performance and catalyst lifetime, membrane durability could be a significant outstanding challenge. Membranes are expected to last 25,000 hours to 30,000 hours for heavy duty applications and the Million Mile Fuel Cell Truck Consortium (M2FCT) is evaluating various membrane technologies for use in heavy duty drive cycles. Current state of the art membranes with both mechanical and chemical stabilization have already met light-duty durability requirement of 5000+ hours and have the potential to meet 25,000+ hour lifetimes. This talk will describe the various membrane related accelerated stress tests (ASTs) developed by the consortium and will present membrane durability results obtained from long-term (500 hours) fuel cell operation at elevated temperature (90 oC). Both the mechanical and chemical durability of membranes will be discussed with particular emphasis and fluoride emission rates (FERs) and lifetime predictions. Acknowledgement: This work was supported by the Hydrogen and Fuel Cell Technologies Office (HFTO), Office of Energy Efficiency and Renewable Energy, US Department of Energy (DOE) through the Million Mile Fuel Cell Truck (M2FCT) consortia, technology managers G. Kleen and D. Papageorgopoulos. References: 1.https://www.hydrogen.energy.gov/pdfs/19006_hydrogen_class8_long_haul_truck_targets.pdf

The application of fertilizers and soil quality are crucial for grape fruit quality. However, the molecular data linking different fertilizer (or soil conditioner [SC]) treatments with grape fruit quality is still lacking. In this study, we investigated three soil treatments, namely inorganic fertilizer (NPK, 343.5 kg/hm2 urea [N ≥ 46%]; 166.5 kg/hm2 P2O5 [P2O5 ≥ 64%]; 318 kg/hm2 K2O [K2O ≥ 50%]), organic fertilizer (Org, 9 t/hm2 [organic matter content ≥ 35%, N + P2O5 + K2O ≥ 13%]), and SC (SC, 3 t/hm2 [humic acid ≥ 38.5%; C, 56.1%; H, 3.7%; N, 1.5%; O, 38%; S, 0.6%]), on 4-year-old Cabernet Sauvignon grapevines. Compared with the NPK- and Org-treated groups, the SC significantly improved the levels of soluble solids, tannins, anthocyanins, and total phenols in the grape berries, which are important biochemical indicators that affect wine quality. Furthermore, we conducted RNA-seq analysis on the grapevine roots from each of the three treatments and used weighted gene co-expression network analysis to identify five hub genes that were associated with the biochemical indicators of the grape berries. Furthermore, we validated the expression levels of three hub genes (ERF, JP, and SF3B) and five selected genes related to anthocyanin biosynthesis (UFGT1, UFGT2, UFGT3, GST, and AT) by using quantitative reverse transcription-polymerase chain reaction. Compared to the NPK and Org treatment groups, the SC treatment resulted in a significant increase in the transcription levels of three hub genes as well as VvUFGT1, VvUFGT3, VvGST, and VvAT. These results suggest that the SC can improve grape fruit quality by altering gene transcription patterns in grapevine roots and further influence the biochemical indices of grape fruits, particularly anthocyanin content. This study reveals that the application of SC can serve as an important measure for enhancing vineyard SC and elevating grape quality.

As institutions of higher education continue to offer online instruction, educators and administrators of presentational speaking courses must adapt their classes for various modes of online delivery. One primary consideration for adapting a presentational speaking course to online delivery is how students will experience communication apprehension and/or public speaking anxiety in online communication contexts. The instructional communication field is rife with research about students' experiences with speech anxiety and communication apprehension. However, little work has explored how students' experiences may differ when the primary mode of course communication and course presentations is mediated through either synchronous or asynchronous modes of online communication. If these anxieties in face-to-face settings can deter students' academic and professional goals (Richmond et al., "Communication apprehension, avoidance, and effectiveness" [6th ed., Pearson, 2013]), researchers should investigate students' experiences in online courses. The current study begins to fill this gap. We analyze qualitative responses (N = 178) to an open-ended survey distributed to undergraduates in presentational speaking courses. Thematic analysis revealed the uniqueness of online communication apprehension and its similarities to face-to-face communication apprehension. Implications for administrators and instructors of presentational speaking courses are offered.

Promoting professional development of in-service language teachers is key to maintaining education quality. However, extant studies on test-based continuing professional development (CPD) for teachers do not emphasise primary school contexts in China, leading to difficulties in the professional development of this teacher group. Therefore, this paper reports the influences of CPD, based on the Teaching Knowledge Test (TKT) programme for in-service primary school English teachers in China, particularly concerning dynamic changes in their professional beliefs and self-efficacy due to participation in the programme. In this study, 42 English teachers were recruited from 15 primary schools to participate in the CPD programme. Through focus groups and teachers' journals, the findings showed that the teachers experienced complex transformations in their professional beliefs and self-efficacy, and revealed some influential factors of the change. This paper provides suggestions to optimise CPD programmes and facilitate long-term professional development for teachers.

Objective: Mental illness is a growing public concern, particularly for persons in higher education. This research aims to distinguish mental health and stigma experiences between three academic communities: undergraduate students, graduate students, and faculty members. Methods: The researchers conducted semi-structured interviews with nineteen individuals who self-identified as a member of one or more of these groups. Findings and discussion: Participants reported experiencing a variety of mental health conditions (e.g., depression, anxiety, and post-traumatic stress), and described having diverse cognitive, affective, and behavioral responses to internally and externally derived stigma. The findings of this study also provide insights into the ways that academic communities observe and interpret on-campus communication about mental health, and participants offered impressions about ways to improve intervention and awareness messaging. Implications of the findings are discussed.

The effect of treatment with 5 g/L chitosan (CTS), 100 μmol/L melatonin (MT) and their combination on the storage quality and chlorophyll metabolism of fresh-cut broccoli (Brassica oleracea L. var. italica Planch.) during storage at (15 ± 1) ℃ and relative humidity (RH) of 85%–90% were investigated through sensory evaluation, physiological and biochemical characterization, and texture analysis. The results showed that separate and combined treatment with CTS and MT effectively maintained the sensory quality of fresh-cut broccoli, and the sensory scores of the samples treated with CTS, MT and their combination were 3.36, 2.83 and 5.17 times higher than that of the control group on the 7th day of storage, respectively. Compared with the control group, the combined treatment could significantly inhibit the activity of chlorophyll-degrading enzymes in broccoli (P < 0.05), thereby inhibiting chlorophyll degradation, while significantly reducing the rate of mass loss and respiratory intensity of fresh-cut broccoli (P < 0.05). Furthermore, it was found that the combined treatment increased chlorophyll content by 83.80%, reduced chlorophyllase (CLH), Mg-dechelatase (MDcase), pheophyllase (PPH) and pheophyllase a oxygenase (PAO) activities by 5.78%, 26.76%, 18.59% and 34.87%, respectively, and decreased mass loss rate and respiratory intensity by 24.82% and 45.28%, respectively on the 5th day of storage. Also, the combined treatment better maintained the texture properties of fresh-cut broccoli, such as hardness and chewiness, as well as the contents of soluble solids, soluble protein, total phenols and flavonoids. These findings suggest that combined treatment with CTS and MT can effectively delay the yellowing and maintain the quality of fresh-cut broccoli.

We performed this study in order to evaluate the control effect and mechanism of the biosurfactant rhamnolipids (RLS) on black spot disease caused by Alternaria alternata in pear fruit. The results showed that RLS treatment at a mass concentration of 20 mg/mL effectively enhanced resistance to A. alternata, and the lesion diameter was only 64.29% of that of the control group at 12 days following the treatment. Furthermore, it was shown that compared to the control group, RLS treatment significantly increased the activities of phenylalanine ammonia lyase (PAL), cinnamate acid 4-hydroxylase (C4H), 4-coumarate coenzyme A ligase (4CL), and cinnamyl alcohol dehydrogenase (CAD), as well as the contents of total phenols and flavonoids in pear fruit tissue. The activities of chitinase and β-1,3-glucanase were significantly induced. The activities of NADPH oxidase (NOX), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), and the contents of H2O2 and superoxide anion radical in the early and middle stages of storage were also increased by RLS treatment. Meanwhile, the ascorbate-glutathione (ASA-GSH) cycle was activated to maintain the dynamic balance of reactive oxygen species (ROS) production and scavenging in pear fruit tissue, and the membrane permeability and the content of malondialdehyde (MDA) were reduced. Collectively, this study suggested that post-harvest rhamnolipid treatment can enhance black spot disease resistance in pear fruit by regulating phenylpropane metabolism, ROS metabolism and pathogenesis-related proteins.