An Acyl-Linked Dimer of Daptomycin Is Strongly Inhibited by the Bacterial Cell Wall

This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publi-cation in ACS Infectious Diseases,© American Chemical Society after peer review. To access the final edited and published work see http://pubs.acs.org/doi/full/10.1021/acsinfecdis.7b00019.The lipopeptide antibiotic daptomycin is active against Gram-positive pathogens. It permeabilizes bacterial cell membranes, which involves the formation of membrane-associated oligomers. We here studied a dimer of daptomycin whose two subunits were linked through a bivalent aliphatic acyl chain. Unexpectedly, the dimer had very low activity on vegetative Staphylococcus aureus and Bacillus subtilis cells. However, activity resembled that of monomeric daptomycin on liposomes and on B. subtilis L-forms. These findings underscore the importance of the bacterial cell wall in daptomycin resistance.NSERC operating grants to M.P. (250265-2013) and S.T. (155283-2012)

A Rock Classification Schema

The need for engineering data on earth materials for use in site selection, design, construction, and maintenance of major engineering structures is generally accepted. Probably the most pressing need is for such data to use in preliminary considerations of site selection and design alternatives. Maps and(or) surveys giving the areal distribution of earth materials and their characteristics, together with topographic maps available for many areas, would permit much preliminary work on engineering structures to be done without the engineer ever having to leave his office

Hormone-Type Herbicides--Safe Use and Precautions.

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Rock Evaluation for Engineered Facilities

The need for comprehensive information on the characteristics and behavior of earth materials has been recognized for many years, perhaps for as long as significant construction has taken place in and on the surface of the earth. In recent years, however, the magnitude and complexity of engineered construction has greatly increased, resulting in a corresponding increase in the need for information on the engineering properties of soil and rock materials, Direct testing of soil and rock can be utilized to furnish necessary information. However, both field and laboratory testing can be extremely expensive, particularly where testing must include applications of stress to large masses of earth material, For this reason, significant technical and economic advantages can be realized through the development of indirect or short-cut methods for obtaining indications of the properties and characteristics of geologic materials. Some years ago the value of topographic maps, aerial photographs, pedologic descriptions, and geological surveys in characterizing soil materials was realized. To make this information useful for engineering studies, a serious effort was initiated to obtain data on the engineering properties of various soil groups and associations established on the basis of geological and pedological surveys. The correlation of performance data with information on areal distribution and location furnished by geologic and pedologic works has proven extremely valuable in the planning and construction of facilities in and on soil. In recent years, the size and importance of structures and facilities designed by engineers and architects has greatly increased. This has produced an increased interest in the rock materials underlying surficial soil layers. A clear need has arisen for a program to provide an engineering evaluation of rock materials for the purposes of location, design, construction, and maintenance of engineered facilities. However, a serious gap exists in the association of engineering characteristics with rock units identified on the basis of geological classifications, Therefore, there is a need for the development of a comprehensive evaluation program which permits utilization of existing data and which aids in the procurement of necessary information on engineering characteristics of rock

Engineering Data System for Bedrock Occurrences and Properties

The initial work plan included the development of a classification system based on index tests. An investigation of previous works in classification of rock on the basis of index tests showed that a variety of classification systems utilizing many different index tests had been developed. However, this survey showed that no generally applicable system had been developed and that little communication had been established between field investigators, facility designers, and those in charge of construction and maintenance of facilities. Therefore, the initial plan for work was modified to include the development of a comprehensive methodology for evaluation of rock. The development of such an evaluation schema was to include the establishment of an information bank to provide access to collected data by any interested individual. The first step in the development of this rock evaluation program was a survey of the categories of information that have been collected concerning geologic materials, particularly rock strata. On the basis of this investigation of existing data, a method was devised to collect, categorize, and present more extensive data on rock materials. The general schema for the evaluation program was then developed. At the present time, a research effort is continuing to test and verify the validity of the evaluation program which has been developed. A final step in this effort will be a full implementation of the rock evaluation program for project planning in Kentucky

3D Bioprinted Structures from Cells of Non-Epithelial Mesodermal and Endodermal Lineage Using a Custom Accessible 3D Bioprinting Platform

Prior work within our lab has demonstrated the ability to print both murine and human mammary organoids and tumoroids in vitro that can also be reliably transplanted into a murine host for translational studies. Peripherally, this bioprinting system has also been used for 3D printing neurons, stem cells, cancer cells, and a primary cell line rich with fibroblasts, but each of these efforts were with cells of ectodermal lineage. Thus, the system\u27s capacity for use on cells of other origins had been untested. To address this, we have now developed protocols for cells of endodermal and non-epithelial mesodermal/mesenchymal lineage. In this work, we find that we can produce reliable organoids, tumoroids, and other in vitro structures from them, thus expanding the functional range of our open 3D bioprinting platform. Therefore, we demonstrate that our system is versatile for adaptation to multiple cellular systems and can be applied to the work of labs that wish to study development and pathologies in other organ systemshttps://digitalcommons.odu.edu/gradposters2022_engineering/1001/thumbnail.jp

3D Bioprinting and Implantation of Mouse Mammary Epithelial Structures Using a Custom Accessible 3D Bioprinting Platform

Prior work has shown that our bioprinting system can reliably produce human mammary organoids and tumoroids with high precision. However, this was not previously applied to mouse models, which are also important with respect to translational research in cancer drug development. To address this, we have produced protocols for the development of in vitro structures from murine mammary epithelial and tumor cells. Additionally, we assessed the translatability of both human and murine bioprinted organoids into mouse mammary fat pads over a period of 6 weeks. Our lab found that our produced organoids are reliable, they can survive in vivo, and meaningfully integrate within host systems. Therefore, we have demonstrated that our system is adaptable to both human and murine models, as it offers a unique methodology for in vivo transplantation of human or murine organoids into mice, which can boost research efforts in cancer therapy research.https://digitalcommons.odu.edu/gradposters2022_engineering/1000/thumbnail.jp

A Neural Network Approach for Waveform Generation and Selection with Multi-Mission Radar

Nonlinear frequency modulated (NLFM) pulse compression waveforms have become a mainstream methodology for radars across multiple sectors and missions, including weather observation, target tracking, and target detection. NLFM affords the ability to generate a low-sidelobe autocorrelation function and matched filter while avoiding aggressive amplitude modulation, resulting in more power incident on the target. This capability can lead to significantly lower system design costs due to the possibility of sensitivity gains on the order of 3 dB or more compared with traditional, amplitude-modulated linear frequency modulated (LFM) waveforms. Generation of an optimal NLFM waveform, however, can be an arduous task, and may involve complex optimization and non-closed-form solutions. For a multi-mission or cognitive radar, which may utilize a wide combination of frequencies, pulse lengths, and amplitude modulations (among other factors), this could lead to an extremely large waveform table for selection. This paper takes a neural network approach to this problem by optimizing a set of over 100 waveforms spanning a wide space and using the results to interpolate the waveform possibilities to a higher resolution. A modified form of a previous NLFM method is combined with a four-hidden-layer neural network to show the integrated and peak range sidelobes of the generated waveforms across the model training space. The results are applicable to multi-mission and cognitive radars that need precise waveform specifications in rapid succession. The expected waveform generation times are addressed and quantified, and the potential applicability to multi-mission and cognitive radars is discussed

Phylogenetic Analysis Of Chloroplast Dna Restriction Site Data At Higher Taxonomic Levels: An Example From The Asteraceae

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137492/1/evo04314.pd