Assessing the Effects of Cold Storage Regimes of North American Bombus Queens: Long Live the Humble Queen

Bumble bees (Bombus) provide critical pollination services for wild plants and crops. They are generalist pollinators, and do not depend on one singular floral type. Native bumble bees are adapted to pollinating many native plants, such as blueberries, squash, and tomatoes. A critical component of bumble bee pollination in the greenhouse tomato industry is the domestication of commercially bred colonies. However, the domestication of Bombus is pretty early in its development, and not all aspects of the bumble bee life cycle is fully understood. This thesis addresses one of the major obstacles in domestication, which is successful mimicking of the overwintering phase of the lifecycle in captivity. Traditionally, captive Bombus queens are stored in constant low temperatures for a period of twelve weeks to mimic hibernation. However, there is a high mortality associated with this cold storage period, and we are unable to replicate wild overwintering durations in captive settings. To address the high mortality, we used three North American bumble bee species, stored queens in different cold storage regimes and assessed survivability. Here, we present results that there were other components to consider outside of thermal regimes such as initial weight, bumble bee colony age, and queen’s geographic origins. We found survivorship varied between wild queens (B. vosnesenskii and B. huntii) and commercial queens (B. impatiens). We saw with wild queens survival response was lower in a temperature cycling regime (FTR) compared to static thermal treatments (Control). However, in commercial B. impatiens, we saw the opposite outcome in survival, where survival response was higher in FTR. The variation in survival outcome may be reflective of their geographic differences. Results also suggested that high initial weight prior to cold storage determined survival and was linked to post hibernation lipids, which serves as an energy reserve. Despite the fact, lipids and weight are important to surviving captive cold storage, colony age influenced overwintering fitness. We have evidence that a queen’s initial weight prior to entering captive overwintering, survival, and colony’s age were inter-related. This study highlights that we should take a more comprehensive approach and take into account that overwintering treatments alone are not the silver bullet to addressing premature deaths in cold storage. Standardizing methods for Bombus cold storage will require careful consideration of the interplay between physiological variations, individual queen characteristics, and limitations among Bombus that emerge from seasonal colony aging

Effect of cerium salt-activated ceria on the UV degradation resistance of waterborne epoxy coatings

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Security for Multi-hop Communication of Two-tier Wireless Networks with Different Trust Degrees

Many effective strategies for enhancing network performance have been put forth for wireless communications' physical-layer security. Up until now, wireless communications security and privacy have been optimized based on a set assumption on the reliability or network tiers of certain wireless nodes. Eavesdroppers, unreliable relays, and trustworthy cooperative nodes are just a few examples of the various sorts of nodes that are frequently categorized. When working or sharing information for one another, wireless nodes in various networks may not always have perfect trust in one another. Modern wireless networks' security and privacy may be enhanced in large part by optimizing the network based on trust levels. To determine the path with the shortest total transmission time between the source and the destination while still ensuring that the private messages are not routed through the untrusted network tier, we put forth a novel approach. To examine the effects of the transmit SNR, node density, and the percentage of the illegitimate nodes on various network performance components, simulation results are provided

Static and Dynamic Analysis of Piezoelectric Laminated Composite Beams and Plates

In this chapter, the mechanical behavior analysis of piezoelectric laminated composite beams and plates is influenced subjected to static, dynamic, and aerodynamic loads. Algorithm for dynamic, stability problem analysis and vibration control of laminated composite beams and plates with piezoelectric layers is presented. In addition, numerical calculations, considering the effect of factors on static, dynamic, and stability response of piezoelectric laminated composite beams and plates are also clearly presented. The content of this chapter can equip readers with the knowledge used to calculate the static, dynamic, and vibration control of composite beams, panels made of piezoelectric layers applied in the field different techniques

An innovative approach to study the impact of different blends of learning on learning performance in higher education

This study investigates the differential impact of blended learning (BL), face-to-face (F2F) and eLearning (EL) on learning performance (LP), also considering the effect of particular variables (self-efficacy (SE), intrinsic motivation(IM) and flexibility). Students were randomly allocated to one of the four experimental conditions (n F2F= 22, n BL1= 22, n EL= 23, n BL2= 23). Analysis of covariance (ANCOVA) was applied to study the differential impact of teaching approaches. The results reflect a significant difference in LP after studying in a particular higher education setup [F(3,86) = 9.44, p<. 001], R-2= 22.1. Learning performance was superior in both blended learning conditions. Though the different teaching setups resulted in small significant differences in mediating variables, these did not interact significantly with the research conditions. Based on the present findings, blended learning instruction could be put forward as a promising alley to enhance students' performance

Antibiotic characteristics of clinical isolates of multi-drug resistant Stenotrophomonas maltophilia strains in the military hospital Vietnam

Stenotrophomonas maltophilia (S. maltophilia) is its best known species because it is a globally emerging, multidrug-resistant (MDR), opportunistic pathogen. The aim of the study was to identify species in this collection, defined as genetically cohesive sequence clusters, and to determine the extent of their genetic, ecological and phenotypic differentiation. This framework was used to analyze 50 specimens for cultures were collected from patients in the military hospital in Hanoi, Vietnam, between 2015 and 2017. Three of the 30 MDR S. maltophilia isolates identified by Vitek technology in hospital were confirmed using 16S rRNA gene sequencing. The alignment sequences were analyzed in RAxML version 8.2.10 to estimate the best maximum likelihood phylogenetic tree, with 1,000 bootstrap replicates, estimated GTRGAMMA model and the rapid bootstrapping algorithm. Over 70% of S. maltophilia isolates were resistant to β-lactams (such as carbapenem, penicilline, monobactam, amoxicillin, cephem, and β-lactam); Aminoglycosides (such as gentamycine and tobramycin); Miscellaneous (such as fosfomycin and chloramphenicol). In particularly, all of this strain isolates were resistant to β-lactams and Aminoglycosides high annual increasing/ frequency from 2015 to 2017 year. Three resistant strains with most antibiotics (S. maltophilia 17-87M, 17-95M and 17-90N) were randomly selected to test the association between genotype and phenotypic resistance. The results were shown a significantly different in antibiotic genes expression among three strains and a few difference in phenotypic resistance. These data in light of current models of bacterial speciation, which fit these data well, are stressing the implications of species delimitation in ecological, evolutionary and clinical research

DOES DEMOGRAPHICS MATTER IN LIFELONG LEARNING? A RESEARCH CONTEXT OF VIETNAM

Objective: Lifelong learning (LLL) has lately attracted significant attention from the society in general, universities and corporations in particular. For the case of Vietnam, the Government has pledged to create a Lifelong Learning Society. A number of initiatives have been launched to help achieve this goal, including the Southeast Asian Ministers of Education Organization Centre for Lifelong Learning (SEAMEO CELLL) and "Book Day", a day dedicated to encouraging reading and raising awareness of its importance in the development of knowledge and skills. Lifelong learning (LLL) programs are also being adopted at libraries, museums, cultural centers, and clubs in Vietnam. In addition to the effort done by the Vietnamese government, a number of non-governmental, non-profit organizations and educational institutions have started to take action to encourage literacy and lifelong learning. It can be said that education and educational reforms are always the top concern of each country. This study is to investigate about lifelong learning of community with 4 aspects: (1) Learning Competencies; (2) Learning Contexts; (3) Learning Contents and (4) Learning Goals as well as examining the differences in the opinion about lifelong learning between categorical variables. The second purpose of the study is to examine the relationship between an individual's perspective on lifelong learning and their actual learning capacity, as well as learning motive. Methods: The paper deploys primary data collecting from 270 people in different sectors and different occupations. Standard statistical techniques such as mean analysis, OLS multivariable analysis are used to find the answer for proposed hypotheses. Results: Using a sample of 270 respondents varying in age, gender, and employment status, the authors found that there are differences on the attitudes towards lifelong learning, the motivations and skills needed for this “journey”. Conclusion: From the findings, researchers proposed recommendations to promoting and fostering lifelong learning of community with the case of Vietnam

Effect of Polypyrrole on the Electrical, Dielectric and Mechanical Properties of Waterborne Epoxy Coatings

In this context, conducting composite based on waterborne epoxy system and polypyrrole (PPy) was investigated. The polypyrrole was synthesized by chemical oxidation polymerization. Its morphology and chemical structure were confirmed by using field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR). Then, PPy was well-dispersed in the epoxy coating and had a good compatibility with the matrix. The effects of PPy on dielectric, electrical and mechanical properties of epoxy/PPy composites was examined. The dielectric constant and electrical conductivity of the coatings increased with addition of PPy fillers. Over to 15 wt. % of PPy loading, the volume resistivity of samples slightly decreased from 6.7 × 1010 to 1.5 × 1010 Ω cm. In contrast, the presence of PPy diminished both impact and abrasion resistance of the epoxy/PPy composites, down to 160 kg cm and 10.2 L/mil, respectively, but they stayed acceptable for the coatings. The results reveal that the epoxy containing polypyrrole is suitable for various electrical and dielectric applications