87 research outputs found
Myiasis in domestic cats: A global review
Myiasis is an infestation caused by larvae of Diptera in humans and other vertebrates. In domestic cats, Felis silvestris catus L. (Carnivora: Felidae), four dipteran families have been reported as agents of obligatory and facultative myiasis: Oestridae, Calliphoridae, Sarcophagidae and Muscidae. Among agents of obligatory myiasis, the most frequent genus is Cuterebra Clark (Oestridae) and the most frequent species is Cochliomyia hominivorax (Coquerel) (Calliphoridae). Among the agents of facultative myiasis, the most frequent species is Lucilia sericata (Meigen) (Calliphoridae). A survey of myiasis in cats reported in literature shows that the cases are distributed worldwide and linked to the geographical range of the dipteran species. Factors favouring the occurrence of myiasis in cats are prowling in infested areas, poor hygiene conditions due to diseases and/or neglect, and wounds inflicted during territorial or reproductive competition. The aim of the review is to provide an extended survey of literature on myiasis in cats, as general information and possible development of guidelines for veterinarians, entomologists and other researchers interested in the field
Genetic improvement of n-butanol tolerance in Escherichia coli by heterologous overexpression of groESL operon from Clostridium acetobutylicum
Synthesis of CdS and CdSe nanocrystallites using a novel single-molecule precursors approach
The synthesis of CdS and CdSe nanocrystallites using the thermolysis of several dithioor
diselenocarbamato complexes of cadmium in trioctylphosphine oxide (TOPO) is reported.
The nanodispersed materials obtained show quantum size effects in their optical spectra
and exhibit near band-edge luminescence. The influence of experimental parameters on
the properties of the nanocrystallites is discussed. HRTEM images of these materials show
well-defined, crystalline nanosized particles. Standard size fractionation procedures can
be performed in order to narrow the size dispersion of the samples. The TOPO-capped CdS
and CdSe nanocrystallites and simple organic bridging ligands, such as 2,2¢-bipyrimidine,
are used as the starting materials for the preparation of novel nanocomposites. The optical
properties shown by these new nanocomposites are compared with those of the starting
nanodispersed materials
Toward Predicting Success and Failure in CS2: A Mixed-Method Analysis
Factors driving success and failure in CS1 are the subject of much study but
less so for CS2. This paper investigates the transition from CS1 to CS2 in
search of leading indicators of success in CS2. Both CS1 and CS2 at the
University of North Carolina Wilmington (UNCW) are taught in Python with annual
enrollments of 300 and 150 respectively. In this paper, we report on the
following research questions: 1) Are CS1 grades indicators of CS2 grades? 2)
Does a quantitative relationship exist between CS2 course grade and a modified
version of the SCS1 concept inventory? 3) What are the most challenging aspects
of CS2, and how well does CS1 prepare students for CS2 from the student's
perspective? We provide a quantitative analysis of 2300 CS1 and CS2 course
grades from 2013--2019. In Spring 2019, we administered a modified version of
the SCS1 concept inventory to 44 students in the first week of CS2. Further, 69
students completed an exit questionnaire at the conclusion of CS2 to gain
qualitative student feedback on their challenges in CS2 and on how well CS1
prepared them for CS2. We find that 56% of students' grades were lower in CS2
than CS1, 18% improved their grades, and 26% earned the same grade. Of the
changes, 62% were within one grade point. We find a statistically significant
correlation between the modified SCS1 score and CS2 grade points. Students
identify linked lists and class/object concepts among the most challenging.
Student feedback on CS2 challenges and the adequacy of their CS1 preparations
identify possible avenues for improving the CS1-CS2 transition.Comment: The definitive Version of Record was published in 2020 ACM Southeast
Conference (ACMSE 2020), April 2-4, 2020, Tampa, FL, USA. 8 page
Analysis of Clostridium beijerinckii NCIMB 8052's transcriptional response to ferulic acid and its application to enhance the strain tolerance
Background: Plant-based cellulose presents the best source of renewable sugars for biofuel production. However, the lignin associated with plant cellulose presents a hurdle as hydrolysis of this component leads to the production of inhibitory compounds, such as ferulic acid. Results: The impacts of ferulic acid, a phenolic compound commonly found in lignin hydrolysates, on the growth, solvent production, and transcriptional responses of Clostridium beijerinckii NCIMB 8052 were determined. Addition of ferulic acid to growing cultures resulted in a decrease in the growth and solvent production by 30% and 25%, respectively, when compared to the control cultures. To better understand the toxicity of this compound, microarray analyses were performed using samples taken from these cultures at three different growth states. Several gene ontology terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were identified showing significant change at each status, including ATP-binding cassette (ABC) transporters, two component system, and oxidoreductase activity. Moreover, genes related with efflux systems and heat shock proteins were also strongly up-regulated. Among these, expression of the groESL operon was induced by more than fourfold and was consequently selected to improve C. beijerinckii tolerance to ferulic acid. Real-time quantitative PCR (RT-qPCR) analysis confirmed that C. beijerinckii harboring the plasmid, pSAAT-ptb_Gro, had a two-to fivefold increased groESL operon expression during growth of these cultures. Moreover, this strain was more tolerant to ferulic acid as the growth of this recombinant strain and its bioconversion of glucose into solvents were both improved. Conclusions: Using transcriptomics, we identified numerous genes that are differentially expressed when C. beijerinckii cultures were exposed to ferulic acid for varying amounts of time. The operon expressing groESL was consistently up-regulated, suggesting that this gene cluster may contribute to strain tolerance. This was confirmed as recombinant cultures showed both an enhanced growth and solvent yield in the presence of 0.5 g/L ferulic acidopen00
Genome-wide Escherichia coli stress response and improved tolerance towards industrially relevant chemicals
Speciation of uranium in a South Texas lignite: additional evidence for a mixed mode of occurrence
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