There is a demand for newer, more effective therapeutic antagonist for bacterial threats. More specifically, overuse of currently available antibiotics, premature dosage -termination of prescription antibiotics and a growing resistance of bacteria to currently available antibiotics warrants the design, development and establishment of new and novel antibacterial therapeutics. Unfortunately, physician-scientists no longer have an antibiotic agent for an increasing number of multiple strains of bacteria. In this study, we investigate the holistic efficacy for which the plant Meswak can antagonize the vitality of some strains of bacteria and HeLa cell growth. The conclusions drawn from the findings of this investigation suggest Meswak as a potential antagonist for the growth of some strains of gram-positive and gram-negative bacteria. Preliminary studies have also revealed that Meswak acts as an inhibitor to HeLa cell growth and migration. Future studies are necessary to define the specific mechanism of action for which Meswak acts to inhibit bacterial viability and HeLa cell growth and migration.

<p> The genus <i>Symphyotrichum</i> belongs to the family Asteraceae and consists of more than 90 species of plants. It is divided into four subgenera based on morphology and molecular data. There are both annual and perennial plants present in the genus which were earlier regarded as a part of the genus <i>Aster.</i> Most of the plants occur across North America but many species are also common across South America and Eurasia (Brouillet, Semple, Allen, Chambers &amp; Sundberg, 2006). <i>Symphyotrichum parviceps</i> is usually present in the eastern part of United States and is less common than <i>Symphyotrichum pilosum</i> (Nesom, 1995). The purpose of this study is to develop microsatellite markers for <i> S.parviceps</i> and <i>S.pilosum</i> to examine their relationship to an unknown <i>Symphyotrichum</i> species found near Steelville, MO.</p><p> Previous work done by Kabjaf (2015) indicated the unknown aster is a dodecaploid (2n=12X=96) and this chromosome number is higher than the known chromosome numbers for <i>S.pilosum</i> (n=16,20,24) and <i> S.parviceps</i> (n=16,24,32) in Missouri. Kabjaf (2015) proposed that the unknown species is a hexaploid variant of <i>S.parviceps</i> and it might either be an autopolyploid of <i>S.parviceps</i> or <i> S.pilosum</i> or an allopolyploid between <i>S.parviceps</i> and <i>S.pilosum.</i> It was hypothesized that the unknown aster is a new species altogether because of the specialized habitat it was collected from.</p><p> Internal Transcribed Sequence data could not resolve any differences among the species. Although markers have been developed for different genera of the family, Asteraceae, due to its low level of genetic conservation has restricted transferability of microsatellite markers across different genera (Whitton, Rieseberg &amp; Ungerer, 1997). Presently, there are no microsatellite markers available for these species or even the genus. Development of microsatellite markers would help resolve the relationships among the species and the unknown aster.</p>

<p>Air humidity is an environmental cue that influences many physiological responses in terrestrial organisms. In early chronobiology studies, it was thought that humidity could influence the circadian clock. However, no further studies have been performed in pursuit of this idea, nor humidity been investigated as a potential Zeitgeber, despite the fact that daily humidity fluctuation has been widely observed. Here, we report that humidity is a Zeitgeber on par with light and temperature and that it can fundamentally influence plant physiology. Using 10 years of weather records obtained from Harvard Forest and Weather Underground databases, we quantitatively characterized humidity oscillation as a natural phenomenon and found that the circadian oscillation of humidity (i.e., lower during the day and higher at night) is robust and independent of climates or seasons. Moreover, there is a 2-hour overlap of high humidity with light in the morning, suggesting a possible interplay between these two environmental cues and the circadian clock. We then tested and found that humidity can indeed entrain the circadian clock as a bona fide Zeitgeber through regulation of the plant core morning clock gene CCA1 (CIRCADIAN CLOCK ASSOCIATED 1) and the core evening clock gene TOC1 (TIMING OF CAB EXPRESSION 1). However, the core morning clock gene LHY (LATE ELONGATED HYPOCOTYL), partner of CCA1, resists the humidity-entrainment, indicating that the plant circadian clock may have two intertwined loops: one is responsive to both light and humidity via CCA1, whereas the other is responsive only to light mediated by LHY. In the absence of rhythmic light signal, humidity can entrain the clock, whereas in the presence of light in the morning, humidity synergistically reinforces the clock. At the physiological level, the humidity-entrained clock provides additional advantages to plants. It can improve energy storage, reduce the flowering time and improve seed production in a circadian-dependent manner. Additionally, we found that humidity can fundamentally shape plant-microbe interactions because it is a key signal for the initial induction of the bacterial type III secretion system and effector genes required for virulence. Thus, it is necessary for plants to mount an appropriate response to pathogen infections at night when humidity naturally rises. These findings demonstrate how terrestrial organisms could adapt to humidity oscillation, a universal environmental cue, to strategically maximize their own fitness. We propose that humidity-sensing might be an ancient determinant shaping the evolution of terrestrial organisms after their transition away from aquatic environment.</p> / Dissertation

<p> The softshell clam, <i>Mya arenaria</i>, is a commercially important bivalve species that is found in soft-bottom intertidal habitats throughout the Gulf of Maine, USA. This species is subjected to seasonal blooms of the toxic algae <i>Alexandrium</i> spp., and acts as a vector for paralytic shellfish poisoning (PSP) during harmful algal bloom (HAB) events. Some clams possess a naturally occurring genetic mutation of their voltage-gated sodium channels that grants them a resistance to the paralytic effects of saxitoxin (STX) produced by <i>Alexandrium</i> spp. The mutation allows these individuals to continue feeding during HABs, and greatly increases their tissue toxicity through bioaccumulation. This work describes the distribution of the resistant mutation in wild clam populations in the Gulf of Maine, and explores the population structure of <i>M. arenaria</i> with regard to the mutation, as well as neutral genetic markers. Analysis of neutral markers revealed no significant population structure within the Gulf of Maine, however <i> M arenaria</i> does exhibit strong localized structure at the STX-resistant mutation locus. This structure is sustained by differential selective pressure exerted by <i>Alexandrium</i> spp. blooms, despite freely occurring gene flow among clam populations. In Penobscot Bay, one area where the prevalence of the resistant mutation did not match the strength of selective pressure, it is likely that the resistant allele is maintained by gene flow through larval transport from other regions, rather than by seeding of hatchery stock carrying the mutation. This work can aid PSP monitoring efforts by identifying areas where risk is greatest to humans due to high numbers of resistant clams. In addition, distinguishing areas where one genotype is clearly favored over the others may be of interest to seeding programs trying to ensure that their stock is well-suited for the location to which they will be transplanted. </p>

<p> Large scale genomic and transcriptomic analyses are illuminating the complex genetic nature of psychiatric disorders such as schizophrenia. Newly identified associations between genetic variations and disease risk must be functionally validated, in order to understand the underlying cellular and molecular mechanism contributing to disease. A scalable, robust platform for modeling the effects that such myriad perturbations might have on neural systems is necessary. Here, we combine human induced pluripotent stem cells, cerebral organoid differentiations, and a catalytically inactivated endonuclease dCas9 fused to the KRAB transcriptional repressor. We further demonstrate the feasibility of, and important considerations associated with, developing such a platform, by applying it to study the effects of perturbing <i>FURIN,</i> a gene with an expression quantitative trait locus significantly associated with schizophrenia. Our data demonstrate the utility and scalability of this system for manipulating disease-associated gene expression in order to query cellular phenotypic effect.</p><p>

Most evidence to date clearly indicates that CB4 virus can affect the pancreas of both man and mice during acute infection. Yet, conflicting evidence exists relative to the consequence of the infection in both man and mice. The study described here attempted to provide definitive evidence on the relative role of the virus isolate (i.e. heterogenous virion populations vs. purified clones) in induction of prolonged diabetes-like disease in mice.

Clinical and experimental data suggest that humans and some animals are protected from acute myocardial infarction by estrogen. There has been much speculation of the exact role which estrogen plays in the circulation. The mechanism of this hormonally related protection is unclear. In the present study the chronic effects of estradiol benzoate on coronary blood flow in adult female rats were studied. Female control rats, castrates and castrates receiving estrogen for a period of 16 weeks were used. In vivo tracer microsphere studies of myocardial blood flow allowed the quantification of the effects of estrogen on coronary circulation. Results of this work demonstrated that levels of estrogen significantly influence blood flow in ventricular myocardium.

Thirty upland deciduous stands were sampled from the mid-coastal Plain to the mid-Piedmont in New Kent, Hanover, and Louisa Counties. Density data for herb and shrub species were collected and soil samples were collected in each stand. A cluster analysis of the vegetation data was performed using Euclidean Distance and "furthest-neighbor" clustering. Four clusters of stands were identified. A cluster of six stands with Euonymus americanus as the dominant species was strongly related to the Coastal Plain, but the other clusters were not physiographically associated. Other important species in the analysis were Vaccinium vacillans, Gaylussacia baccata, and Mitchella repens. The soil nutrients most strongly correlated with the dominant species were calcium and magnesium. Euonymus americanus and associated species were positively correlated with these nutrients and the ericaceous shrubs were negatively correlated.

In this study the distribution and effects of bacterial endotoxin were examined. Adult male BALB/c and adult male DUB/ICR mice were used in all experiments. Endotoxic activity of a number of strains from three genera of bacteria, Pseudomonas, Bacteroides, and Listeria, was detected using vincristine-treated mice as sensitized indicators for endotoxin and resistance to purified endotoxin induced by pretreatment with selected bacteria. Also, the effect of bacterial endotoxin and endotoxin-like substances on the course of primary amebic meningoencephalitis in mice, caused by Naegleria fowleri, was assessed.

The symbiotic association between the aquatic water fern Azolla and its symbiont, Anabaena azollae Straus. has been extensively studied in the past ten years. The cyanobacteria has received much of the attention due to its ability to fix atmospheric nitrogen while the fern free of the cyanobiont has been somewhat neglected. The purpose of this research was to determine the nutritional requirements of the cyanobacteria free (CBF) ferns and study the morphology of the leaves and branches of these CBF ferns. Azolla filiculoides and Azolla pinnata were freed of the cyanobiont using the surface sterilization technique adopted from Duckett, et al. (1975) and the antibiotic treatments of Peters and Mayne(1974a). The size of leaf seven, both length and width, along with leaf spacing and branch spacing along the stem, in CBF ferns were compared to that in the intact ferns. Growth studies on medium containing three levels of the nutrients nitrogen, phosphorus and potassium were conducted. The CBF ferns were found to have shorter leaves with no difference in width. The leaf spacing and branch spacing in the CBF ferns were more compact than the intact association. This is the first reported quantitative data to show a definite difference in the morphology of the CBF ferns. The nutrient studies showed an interaction effect between nitrogen and phosphorus in the A. pinnata CBF ferns while the A. filiculoides CBF ferns showed a nitrogen, phosphorus, potassium interaction. The A. pinnata CBF ferns grew best on a medium containing twice the concentration of phosphorus, one times the concentration of nitrogen and three times the concentration of potassium found in our I+ medium. The A. filiculoides CBF ferns grew best on concentrations of twice phosphorus, half nitrogen and three times potassium found in our I+ medium. The results of this research shows the importance of phosphorus to the growth of the CBF ferns. This has been demonstrated in the intact fern association by Subudhi and Watanabe (1981). The results of the morphological studies indicate that either the cyanobiont, by its presence or through secretion of some substance affects the intact ferns growth and that this change can not be completely removed by the addition of specific nutrients to the medium.