Development of an instrument to measure high school students' global awareness and attitudes: Looking through the lens of social sciences

The purpose of this study was to develop an instrument to measure high school students’ perspectives on global awareness and attitudes toward social issues. The research questions that guided this study were: (a) Can acceptable validity and reliability estimates be established for an instrument developed to measure high schools students' global awareness? (b) Can acceptable validity and reliability estimates be established for an instrument developed to measure high schools students' attitudes towards global social issues? (c) What is the relationship between high school students’ GPA, race/ethnicity, gender, socio-economic status, parents’ education, getting the news, reading and listening habits, the number of classes taken in the social sciences, whether they speak a second language, and have experienced living in or visiting other countries, and their perception of global awareness and attitudes toward global social issues. ^ An ex post facto research design was used and the data were collected using a 4-part Likert-type survey. It was administered to 14 schools in the Miami-Dade County, Florida area to 704 students. A factor analysis with an orthogonal varimax rotation was vii used to select the factors that best represented the three constructs – global education, global citizenship, and global workforce. This was done to establish construct validity. Cronbach’s alpha was used to determine the reliability of the instrument. Descriptive statistics and a hierarchical multiple regression were used for the demographics to establish their relationship, if any, to the findings. ^ Key findings of the study were that reliable and valid estimates can be developed for the instrument. The multiple regression analysis for model 1 and 2 accounted for a variance of 3% and 5% for self-perceptions of global awareness (factor 1). The regression model also accounted for a 5% and 13% variance in the two models for attitudes toward global social issues (factor 2). The demographics that were statistically significant were: ethnicity, gender, SES, parents’ education, listening to music, getting the news, speaking a second language, GPA, classes taken in the social sciences, and visiting other countries. An important finding for the study was those attending public schools (as opposed to private schools) had more positive attitudes towards global social issues (factor 2) The statistics indicated that these students had taken history, economics, and social studies – a curriculum infused with global perspectives.^

A Conference on The 200th Anniversary of the Birth of Gertrud is Gómez de Avellaneda: A Celebration of Nineteenth-Century Cuban Literature

This flyer promotes the event "A Conference on The 200th Anniversary of the Birth of Gertrud is Gómez de Avellaneda: A Celebration of Nineteenth-Century Cuban Literature" cosponsored by the Cuban Research Institute and the Department of Modern Languages at Florida International University.

Combination of 16S rRNA variable regions provides a detailed analysis of bacterial community dynamics in the lungs of cystic fibrosis patients

Chronic bronchopulmonary bacterial infections remain the most common cause of morbidity and mortality among patients with cystic fibrosis (CF). Recent community sequencing work has now shown that the bacterial community in the CF lung is polymicrobial. Identifying bacteria in the CF lung through sequencing can be costly and is not practical for many laboratories. Molecular techniques such as terminal restriction fragment length polymorphism or amplicon length heterogeneity-polymerase chain reaction (LH-PCR) can provide many laboratories with the ability to study CF bacterial communities without costly sequencing. The aim of this study was to determine if the use of LH-PCR with multiple hypervariable regions of the 16S rRNA gene could be used to identify organisms found in sputum DNA. This work also determined if LH-PCR could be used to observe the dynamics of lung infections over a period of time. Nineteen samples were analysed with the V1 and the V1_V2 region of the 16S rRNA gene. Based on the amplicon size present in the V1_V2 region, Pseudomonas aeruginosa was confirmed to be in all 19 samples obtained from the patients. The V1 region provided a higher power of discrimination between bacterial profiles of patients. Both regions were able to identify trends in the bacterial population over a period of time. LH profiles showed that the CF lung community is dynamic and that changes in the community may in part be driven by the patient's antibiotic treatment. LH-PCR is a tool that is well suited for studying bacterial communities and their dynamics.

Understanding the role of Dimethylsulfoniopropionate as a potential chemotactic cue for coral-associated bacteria

Most reef-building corals are known to engage in non-pathogenic symbiosis not only with unicellular dinoflagellates from the genus Symbiodinium, but also with other microscopic organisms such as bacteria, fungi, and viruses. The functional details of these highly complex associations remain largely unclear. The impetus of this study is to gain a better understanding of the symbiotic interaction between marine bacteria and their coral host. Studies have shown that certain bacterial orders associate with specific certain coral species, thus making the symbiotic synergy a non-random consortium. Consequently both corals and bacteria may be capable of emitting chemical cues that enable both parties to find one another and thus generate the symbiosis. The production of these cues by the symbionts may be the result of environmental stimuli such as elevated ocean temperatures, increased water acidity, and even predation. One potential chemical cue could be the compound DMSP (Dimethylsulfoniopropionate) and its sulphur derivatives. Reef-building corals are believed to be the major producers of the DMSP during times of stress. Marine bacteria utilize DMSP as a source of sulfur and carbon. As a result corals could potentially attract their bacterial consortium depending on their DMSP production. This would enable them to adapt to fluctuating environmental conditions by changing their bacterial communities to that which may aid in survival. To test the hypothesis that coral-produced DMSP plays a role in attracting symbiotic bacteria, this study utilized the advent of high-throughput sequencing paired with chemotactic assays to determine the response of coral-associated bacterial isolates towards the DMSP compound at differing concentrations. Chemotaxis assays revealed that some isolates responded positively towards the DMSP compound. This finding adds to existing evidence suggesting that coral-associated pathogens utilize chemotaxis as a host colonization and detection mechanism. Thus the symbiotic bacteria that make up the coral microbiome may also employ this process. Furthermore this study demonstrates that bacterial motility may be a strong contributing factor in the response to the chemotactic cue. Swarming motility may be better suited for bacteria that need to respond to a chemical gradient on the surface of the coral. Therefore the isolates that were able to swarm seemed to respond more strongly to the DMSP.

Phylogenetic and ontogenetic influences on the distribution of anthocyanins and betacyanins in leaves of tropical plants

We examined the anatomy of expanding, mature, and senescing leaves of tropical plants for the presence of red pigments: anthocyanins and betacyanins. We studied 463 species in total, 370 genera, belonging to 94 families. This included 21 species from five families in the Caryophyllales, where betacyanins are the basis for red color. We also included 14 species of ferns and gymnosperms in seven families and 29 species with undersurface coloration at maturity. We analyzed 399 angiosperm species (74 families) for factors (especially developmental and evolutionary) influencing anthocyanin production during expansion and senescence. During expansion, 44.9% produced anthocyanins and only 13.5% during senescence. At both stages, relatively few patterns of tissue distributions developed, primarily in the mesophyll, and very few taxa produced anthocyanins in dermal and ground tissue simultaneously. Of the 35 species producing anthocyanins both in development and senescence, most had similar cellular distributions. Anthocyanin distributions were identical in different developing leaves of three heteroblastic taxa. Phylogeny has influenced the distribution of anthocyanins in the epidermis and mesophyll of expanding leaves and the palisade parenchyma during senescence, although these influences are not strong. Betacyanins appear to have similar distributions in leaves of taxa within the Caryophyllales and, perhaps, similar functions. The presence of anthocyanins in the mesophyll of so many species is inconsistent with the hypothesis of protection against UV damage or fungal pathogens, and the differing tissue distributions indicate that the pigments may function in different ways, as in photoprotection and freeradical scavenging.

Why Leaves Turn Red in Autumn. The Role of Anthocyanins in Senescing Leaves of Red-Osier Dogwood

Why the leaves of many woody species accumulate anthocyanins prior to being shed has long puzzled biologists because it is unclear what effects anthocyanins may have on leaf function. Here, we provide evidence for red-osier dogwood (Cornus stolonifera) that anthocyanins form a pigment layer in the palisade mesophyll layer that decreases light capture by chloroplasts. Measurements of leaf absorbance demonstrated that red-senescing leaves absorbed more light of blue-green to orange wavelengths (495–644 nm) compared with yellow-senescing leaves. Using chlorophyll a fluorescence measurements, we observed that maximum photosystem II (PSII) photon yield of red-senescing leaves recovered from a high-light stress treatment, whereas yellow-senescing leaves failed to recover after 6 h of dark adaptation, which suggests photo-oxidative damage. Because no differences were observed in light response curves of effective PSII photon yield for red- and yellow-senescing leaves, differences between red- and yellow-senescing cannot be explained by differences in the capacities for photochemical and non-photochemical light energy dissipation. A role of anthocyanins as screening pigments was explored further by measuring the responses PSII photon yield to blue light, which is preferentially absorbed by anthocyanins, versus red light, which is poorly absorbed. We found that dark-adapted PSII photon yield of red-senescing leaves recovered rapidly following illumination with blue light. However, red light induced a similar, prolonged decrease in PSII photon yield in both red- and yellow-senescing leaves. We suggest that optical masking of chlorophyll by anthocyanins reduces risk of photo-oxidative damage to leaf cells as they senesce, which otherwise may lower the efficiency of nutrient retrieval from senescing autumn leaves.

Are mangroves in the tropical Atlantic ripe for invasion? Exotic mangrove trees in the forests of South Florida

Abstract Two species of mangrove trees of Indo- Pacific origin have naturalized in tropical Atlantic mangrove forests in South Florida after they were planted and nurtured in botanic gardens. Two Bruguiera gymnorrhiza trees that were planted in the intertidal zone in 1940 have given rise to a population of at least 86 trees growing interspersed with native mangrove species Rhizophora mangle, Avicennia germinans and Laguncularia racemosa along 100 m of shoreline; the population is expanding at a rate of 5.6% year-1. Molecular genetic analyses confirm very low genetic diversity, as expected from a population founded by two individuals. The maximumnumber of alleles at any locus was three, and we measured reduced heterozygosity compared to native-range populations. Lumnitzera racemosa was introduced multiple times during the 1960s and 1970s, it has spread rapidly into a forest composed of native R. mangle, A. germinans, Laguncularia racemosa and Conocarpus erectus and now occupies 60,500 m2 of mangrove forest with stem densities of 24,735 ha-1. We estimate the population growth rate of Lumnitzera racemosa to be between 17 and 23% year-1. Populations of both species of naturalized mangroves are dominated by young individuals. Given the long life and water-dispersed nature of propagules of the two exotic species, it is likely that they have spread beyond our survey area. We argue that the species-depauperate nature of tropical Atlantic mangrove forests and close taxonomic relatives in the more species-rich Indo-Pacific region result in the susceptibility of tropical Atlantic mangrove forests to invasion by Indo-Pacific mangrove species.

Unravelling the evolution of autumn colours: an interdisciplinary approach.

Leaf colour change is commonly observed in temperate deciduous forests in autumn. This is not simply a side effect of leaf senescence, and, in the past decade, several hypotheses have emerged to explain the evolution of autumn colours. Yet a lack of crosstalk between plant physiologists and evolutionary ecologists has resulted in slow progress, and so the adaptive value of this colour change remains a mystery. Here we provide an interdisciplinary summary of the current body of knowledge on autumn colours, and discuss unresolved issues and future avenues of research that might help reveal the evolutionary meaning of this spectacle of nature.

The biology of rudraksha

Rudraksha, used throughout India and Southeast Asia in religious jewellery, is the stony endocarp of a tree distributed from northern Australia to southern Nepal. This article summarizes its biology, particularly recent research on the remarkable fruit colour. The iridescent blue colour is caused by a remarkable structure an 'iridosome'. It is secreted by the epidermal cell, and is located above the plasmalemma and beneath the adaxial wall. Cellulosic layers within the iridosome constructively interfere with blue wavelengths, causing an intense colour production at 439 nm. This colour persists in senescing fruits and may enhance their dispersal. The transparency of the cuticle at longer wavelengths allows photosynthesis to occur in the fleshy green exocarp tissue, enhancing the carbon balance of the tree. More research will certainly reveal the evolution of this remarkable phenomenon, as well as the origins of the rudraksha's cultural use.

Are mangroves in the tropical Atlantic ripe for invasion? Exotic mangrove trees in the forests of South Florida

Two species of mangrove trees of Indo- Pacific origin have naturalized in tropical Atlantic mangrove forests in South Florida after they were planted and nurtured in botanic gardens. Two Bruguiera gymnorrhiza trees that were planted in the intertidal zone in 1940 have given rise to a population of at least 86 trees growing interspersed with native mangrove species Rhizophora mangle, Avicennia germinans and Laguncularia racemosa along 100 m of shoreline; the population is expanding at a rate of 5.6% year-1. Molecular genetic analyses confirm very low genetic diversity, as expected from a population founded by two individuals. The maximumnumber of alleles at any locus was three, and we measured reduced heterozygosity compared to native-range populations. Lumnitzera racemosa was introduced multiple times during the 1960s and 1970s, it has spread rapidly into a forest composed of native R. mangle, A. germinans, Laguncularia racemosa and Conocarpus erectus and now occupies 60,500 m2 of mangrove forest with stem densities of 24,735 ha-1. We estimate the population growth rate of Lumnitzera racemosa to be between 17 and 23% year-1. Populations of both species of naturalized mangroves are dominated by young individuals. Given the long life and water-dispersed nature of propagules of the two exotic species, it is likely that they have spread beyond our survey area. We argue that the species-depauperate nature of tropical Atlantic mangrove forests and close taxonomic relatives in the more species-rich Indo-Pacific region result in the susceptibility of tropical Atlantic mangrove forests to invasion by Indo-Pacific mangrove species.

Mus Musculus Neural Crest Development: Is Pax3 Regulating the Expression of Endothelin Receptor B?

The vertebrate Neural Crest (NC) is formed during early embryonic development at the neurulation stage. This group of multi potent cells gives rise to a variety of derivatives such as the skin's pigmented cells (Melanocytes), the peripheral nervous system with its associated components, and the endocrine cells of the adrenal medulla amongst others. There are several molecular mechanisms that underlie the development and migration of NC derived cells. For example, during melanocyte differentiation and migration the Endothelin Receptor B and its ligand Endothelin 3 (EdnrB/Edn3), the kit/ Steel factor and the FGF receptor I FGF pathways amongst others play important roles. Additionally, several transcription factors such as Pax3, SoxlO and Mitfalso intervene during the NC cells differentiation processes. In this work, the possible regulatory interaction of Pax3 and EdnrB was assessed by in situ hybridization methods with EdnrB, SoxlO and Dct riboprobes in Pax3 homozygous embryos. To further characterize this interaction, genetic crosses between Pax3 heterozygous mutants and EdnrB heterozygous animals were established. Coat pigmentation was used as an indicator of genetic interaction on the progeny. Experimental results indicated that Pax3 does not directly regulate the expression of EdnrB during neural crest development but interact to produce normal coat color. I propose two possible models to explain the epistatic relationship of Pax3 and EdnrB during normal melanocyte development.

Investigating an Alternative Treatment to Cystic Fibrosis: Testing the Effect of Panax ginseng C.A. Meyer extracts on Pseudomonas aeruginosa

The predominant pathogen found in the lungs of cystic fibrosis (CF) patients is Pseudomonas aeruginosa. The success of the infection is partially due to virulence factor production, which is regulated by quorum sensing (QS) signaling. Currently, antibiotics are used to treat the infection, but resistant forms of P. aeruginosa have evolved, necessitating alternative treatments. Previous animal studies showed that treatment with extracts from the Chinese herb Panax ginseng C.A. Meyer reduced bacterial load resulting in a favorable immune response. It is hypothesized that ginsenosides, the major bioactive compounds in ginseng, is responsible for this effect. This study explores the role of ginseng extracts in attenuating P. aeruginosa virulence. A sequential extraction was performed using hexane, methylene chloride, methanol, and water. High performance liquid chromatography (HPLC) analysis showed the methanol and water ginseng extracts contained the known ginsenosides Rb1, Rb2, Rc, Rd, Re, and Rg1• All extracts were tested on biomonitor strains of Agrobacterium tumefaciens,Chromobacterium violaceum, and P. aeruginosa. Antibacterial and anti-QS activity were assessed using a disc diffusion assay. This was then followed by thin layer chromatography (TLC) bioautographic assay to further separate active compounds. The hexane and dichloromethane extracts, that lacked ginsenosides, displayed antibacterial activity against C. violaceum, whereas methanol and water extracts had anti-QS activity. The results of the bioassay with the pure ginsenoside standards showed that they lack antibacterial or anti-QS activity. Our results indicate that there are bioactive compounds, other than ginsenosides, that are the cause of antibacterial effects and anti-QS in the ginseng extracts.

Testing the Efficacy of Panax ginseng Extract as a Novel Anti-Quorum Sensing Agent

Quorum sensing (QS) is the phenomenon by which microorganisms regulate gene expression in response to cell-population density. These microorganisms synthesize and secrete small molecules known as autoinducers that increase in concentration as a function of cell density. Once the cell detects the minimal threshold concentration of an autoinducer, the gene expression is altered accordingly. Although the cellular circuitry responding to QS is relatively conserved, the cellular processes regulated by QS, for example are conjugation, motility, sporulation, biofilm formation and production of virulence factors importamt for infection. Since many pathogens have developed resistance to available antibiotics, novel therapies are required to further treat these pathogens. Inhibitors of QS are potential therapeutic candidates since they would inhibit virulence without selecting for antibiotic resistant strains. Previous studies have shown that the Chinese herb Panax ginseng contains compounds that inhibit QS activity. To further characterize this activity, a highly sensitive quantitative liquid assay was developed using a Chromobacterium violaceum AHL mutant, CV026 as a biomonitor strain. After confirmation that P. ginseng aqueous extracts had anti-QS activity, the extract was fractionated on a reverse phase C18 Sep Pak column. Most anti-QS activity was present in the flow through, and compounds eluted with ten percent acetonitrile in water antibacterial activity. We thus conclude that P. ginseng has anti-QS activity and the active compound is water soluble. Compounds from P. ginseng, could be used as a lead structure to design compound with higher anti-QS activity for therapeutic treatments.

An automated method for the determination of electroreception thresholds in weakly electric fish

Weakly electric fish produce a dual function electric signal that makes them ideal models for the study of sensory computation and signal evolution. This signal, the electric organ discharge (EOD), is used for communication and navigation. In some families of gymnotiform electric fish, the EOD is a dynamic signal that increases in amplitude during social interactions. Amplitude increase could facilitate communication by increasing the likelihood of being sensed by others or by impressing prospective mates or rivals. Conversely, by increasing its signal amplitude a fish might increase its sensitivity to objects by lowering its electrolocation detection threshold. To determine how EOD modulations elicited in the social context affect electrolocation, I developed an automated and fast method for measuring electroreception thresholds using a classical conditioning paradigm. This method employs a moving shelter tube, which these fish occupy at rest during the day, paired with an electrical stimulus. A custom built and programmed robotic system presents the electrical stimulus to the fish, slides the shelter tube requiring them to follow, and records video of their movements. I trained the electric fish of the genus Sternopygus was trained to respond to a resistive stimulus on this apparatus in 2 days. The motion detection algorithm correctly identifies the responses 91% of the time, with a false positive rate of only 4%. This system allows for a large number of trials, decreasing the amount of time needed to determine behavioral electroreception thresholds. This novel method enables the evaluation the evolutionary interplay between two conflicting sensory forces, social communication and navigation.

Characterization of L-Serine Deaminase and its Potential Role in the Pathogenicity of Pseudomonas aeruginosa

All pathogens require high energetic influxes to counterattack the host immune system and without this energy bacterial infections are easily cleared. This study is an investigation into one highly bioenergetic pathway in Pseudomonas aeruginosa involving the amino acid L-serine and the enzyme L-serine deaminase (L-SD). P. aeruginosa is an opportunistic pathogen causing infections in patients with compromised immune systems as well as patients with cystic fibrosis. Recent evidence has linked L-SD directly to the pathogenicity of several organisms including but not limited to Campylobacter jejuni, Mycobacterium bovis, Streptococcus pyogenes, and Yersinia pestis. We hypothesized that P. aeruginosa L-SD is likely to be critical for its virulence. Genome sequence analysis revealed the presence of two L-SD homo logs encoded by sdaA and sdaB. We analyzed the ability of P. aeruginosa to utilize serine and the role of SdaA and SdaB in serine deamination by comparing mutant strains of sdaA (PAOsdaA) and sdaB (PAOsdaB) with their isogenic parent P. aeruginosa P AO 1. We demonstrated that P. aeruginosa is unable to use serine as a sole carbon source. However, serine utilization is enhanced in the presence of glycine and this glycine-dependent induction of L-SD activity requires the inducer serine. The amino acid leucine was shown to inhibit L-SD activity from both SdaA and SdaB and the net contribution to L-serine deamination by SdaA and SdaB was ascertained at 34% and 66 %, respectively. These results suggest that P. aeruginosa LSD is quite different from the characterized E. coli L-SD that is glycine-independent but leucine-dependent for activation. Growth mutants able to use serine as a sole carbon source were also isolated and in addition, suicide vectors were constructed which allow for selective mutation of the sdaA and sdaB genes on any P. aeruginosa strain of interest. Future studies with a double mutant will reveal the importance of these genes for pathogenicity.