4,204 research outputs found
Science Communication Portfolio
Document describes the theory and practice of verbal and written science communication strategies, and provides an example portfolio on the topic of sea level rise.Are you working on a research manuscript, grant, annual report, or project summary that requires technical language? Do you feel that your finding, if communicated properly, could be useful to people beyond your professional network? This communication-training document for scientists is designed to help you do just that â on your own time and for a variety of verbal and written communication styles. We also provide an example portfolio on the topic of sea level rise for reference.Center for Microbial Oceanography: Research and Education (NSF #0424599, Wood-Charlson); Union of Concerned Scientists (Varga
Vertical Resolved Dust Mass Concentration and Backscatter Coefficient Retrieval of Asian Dust Plume Using Quartz Raman Channel in Lidar Measurements
In this work, we present a method for estimating vertical resolved mass concentration of dust immersed in Asian dust plume using Raman scattering of quartz (silicon dioxide, silica). During the Asian dust period of March 15, 16, and 21 in 2010, Raman lidar measurements detected the presence of quartz, and successfully showed the vertical profiles of the quartz backscatter coefficient. Since the Raman backscatter coefficient was connected with the Raman backscatter differential cross section and the number density of quartz molecules, the mass concentration of quartz in the atmosphere can be estimated from the quartz backscatter coefficient. The weight percentage from 40 to 70 % for quartz in the Asian dust was estimated from references. The vertical resolved mass concentration of dust was estimated by quartz mass concentration and weight percentage. We also present a retrieval method to obtain dust backscatter coefficient from the mixed Asian dust and pollutant layer. OPAC (Optical Properties of Aerosol and Clouds) simulations were conducted to calculate dust backscatter coefficient. The retrieved dust mass concentration was used as an input parameter for the OPAC calculations. These approaches in the study will be useful for characterizing the quartz dominated in the atmospheric aerosols and estimating vertical resolved mass concentration of dust. It will be especially applicable for optically distinguishing the dust and non-dust aerosols in studies on the mixing state of Asian dust plume. Additionally, the presented method combined with satellite observations is enable qualitative and quantitative monitoring for Asian dust
Charlson Comorbidity Index: A Critical Review of Clinimetric Properties
The present critical review was conducted to evaluate the clinimetric properties of the Charlson Comorbidity Index (CCI), an assessment tool designed specifically to predict long-term mortality, with regard to its reliability, concurrent validity, sensitivity, incremental and predictive validity. The original version of the CCI has been adapted for use with different sources of data, ICD-9 and ICD-10 codes. The inter-rater reliability of the CCI was found to be excellent, with extremely high agreement between self-report and medical charts. The CCI has also been shown either to have concurrent validity with a number of other prognostic scales or to result in concordant predictions. Importantly, the clinimetric sensitivity of the CCI has been demonstrated in a variety of medical conditions, with stepwise increases in the CCI associated with stepwise increases in mortality. The CCI is also characterized by the clinimetric property of incremental validity, whereby adding the CCI to other measures increases the overall predictive accuracy. It has been shown to predict long-term mortality in different clinical populations, including medical, surgical, intensive care unit (ICU), trauma, and cancer patients. It may also predict in-hospital mortality, although in some instances, such as ICU or trauma patients, the CCI did not perform as well as other instruments designed specifically for that purpose. The CCI thus appears to be clinically useful not only to provide a valid assessment of the patientâs unique clinical situation, but also to demarcate major diagnostic and prognostic differences among subgroups of patients sharing the same medical diagnosis
Do good health and material circumstances protect older people from the increased risk of death after bereavement?
This is an open access Article. Copyright @ 2012 The AuthorsAn increased risk of death in persons who have suffered spousal bereavement has been described in many populations. The impact of modifying factors, such as chronic disease and material circumstances, is less well understood. The authors followed 171,120 couples 60 years of age or older in a United Kingdom primary care database between 2005 and 2010 for an average of 4 years. A total of 26,646 (15.5%) couples experienced bereavement, with mean follow up after bereavement of 2 years. In a model adjusted for age, sex, comorbid conditions at baseline, material deprivation based on area of residence, season, and smoking status, the hazard ratio for mortality in the first year after bereavement was 1.25 (95% confidence interval: 1.18, 1.33). Further adjustment for changes in comorbid conditions throughout follow up did not alter the hazard ratio for bereavement (hazard ratio = 1.27, 95% confidence interval: 1.19, 1.35). The association was strongest in individuals with no significant chronic comorbid conditions throughout follow up (hazard ratio = 1.50, 95% confidence interval: 1.28, 1.77) and in more affluent couples (P = 0.035). In the first year after bereavement, the association between bereavement and death is not primarily mediated through worsening or new onset of chronic disease. Good health and material circumstances do not protect individuals from increased mortality rates after bereavement.This study was funded by a grant from the Dunhill Medical Trust
Can chemical effects on cloud droplet number rival the first indirect effect?
An increase in cloud droplet number concentration resulting from an increase in ambient aerosol (and subsequent albedo increase) is typically identified as the first indirect (or âTwomeyâ) climatic effect of aerosols [Twomey, 1974]. A key question is whether chemical effects (dissolution of soluble gases and slightly soluble substances, surface tension depression by organic substances and accommodation coefficient changes) could potentially rival changes in droplet number from changes in aerosol number concentration. We assess the sensitivity of cloud droplet number concentration to such chemical factors, using a cloud parcel model. We find that numerous conditions exist, for which chemical influences on cloud droplet activation can indeed rival the Twomey effect
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Initiation of coral/algal symbioses : the role of cell surface lectin/glycan interactions in recognition and specificity
Mutualistic associations between cnidarians, such as corals, and photosynthetic
dinoflagellate algae provide the trophic and structural foundation of coral reef
ecosystems. In many cases, this intracellular mutualism is highly specific and must be
established anew for each generation of host corals. The ability to maintain partner
specificity across generations implies that cellular mechanisms play a role in interpartner
recognition. In other mutualisms where these recognition mechanisms have
been studied, lectin/glycan interactions have been shown to function in inter-partner
recognition during the onset of a stable symbiosis. However, for the majority of
symbioses, including the cnidarian/dinoflagellate mutualism, cellular recognition
mechanisms that mediate the onset of symbiosis remain largely unknown. How do
larval corals and their symbiotic algae discriminate between their preferred partner and
other hosts or microbes during the onset of symbiosis? I hypothesized that cell surface
lectin/glycan interactions act as one mechanism of recognition and specificity during
initial contact between the partners.
Chapter one reviews the biology of cnidarian/algal symbioses and discusses the
literature to date concerning molecular mechanisms of recognition and specificity
during the onset of cnidarian/algal symbioses and how the cnidarian/algal system
compares with other horizontally-transmitted mutualisms. Chapter two and three explore the role of algal cell surface glycans during the onset of
symbiosis between the Hawai'ian solitary coral Fungia scutaria and its dinoflagellate
symbiont, Symbiodinium clade C1f. To determine whether lectin/glycan interactions
function during infection, I modified the glycans on the cell surface of algal symbionts
(C1f and C31, found in nature in adult F. scutaria and Montipora capitata,
respectively), introduced the modified symbionts to F. scutaria larvae, and then
looked for changes in infection success. After cell surface modification, infection rates
of native C1f algae decreased. In contrast, cell surface modification of non-native C31
algae resulted in higher infection rates compared to unmodified, control C31 algae.
These data suggest that the algal cell surface signals to the host F. scutaria larvae
identifying it as either a native C1f symbiont or non-native C31 algae.
These chapters also investigate the variability of glycans present on the cell surface of
several closely-related clade C symbionts to determine if each algal subclade contains
a unique cell surface glycan profile. I found that cell surface glycan profiles were
different for each symbiont tested, supporting their classification into different
subclades. I hypothesize that this subclade specific glycan profile creates the cell
surface signal that identifies the symbiont to its host coral.
Chapter four describes the complex array of C-type lectins, a type of glycan receptor,
in the anemone Nematostella vectensis genome. The diversity of glycan profiles on
symbiont cell surfaces and C-type lectins in cnidarians suggests that these interactions
could relay a signal for recognition and specificity between symbiotic partners.
Chapter five concludes with a brief discussion that places my results in the context of
cnidarian innate immunity and parallels between the onset of mutualistic symbioses
and the process of infection in parasitic relationships. I close by suggesting future
experiments that continue to explore the role of cell surface lectin/glycan interaction in
recognition and specificity during the onset of cnidarian/algal symbioses
Citizen-led sampling to monitor phosphate levels in freshwater environments using a simple paper microfluidic device
Contamination of waterways is of increasing concern, with recent studies demonstrating elevated levels of antibiotics, antidepressants, household, agricultural and industrial chemicals in freshwater systems. Thus, there is a growing demand for methods to rapidly and conveniently monitor contaminants in waterways. Here we demonstrate how a combination of paper microfluidic devices and handheld mobile technology can be used by citizen scientists to carry out a sustained water monitoring campaign. We have developed a paper-based analytical device and a 3 minute sampling workflow that requires no more than a container, a test device and a smartphone app. The contaminant measured in these pilots are phosphates, detectable down to 3 mg L-1. Together these allow volunteers to successfully carry out cost-effective, high frequency, phosphate monitoring over an extended geographies and periods
Aerosol climate feedback due to decadal increases in Southern Hemisphere wind speeds
Observations indicate that the westerly jet in the Southern Hemisphere troposphere is accelerating. Using a global aerosol model we estimate that the increase in wind speed of 0.45 + /- 0.2 m s(-1) decade(-1) at 50-65 degrees S since the early 1980s caused a higher sea spray flux, resulting in an increase of cloud condensation nucleus concentrations of more than 85% in some regions, and of 22% on average between 50 and 65 degrees S. These fractional increases are similar in magnitude to the decreases over many northern hemisphere land areas due to changes in air pollution over the same period. The change in cloud drop concentrations causes an increase in cloud reflectivity and a summertime radiative forcing between at 50 and 65 degrees S comparable in magnitude but acting against that from greenhouse gas forcing over the same time period, and thus represents a substantial negative climate feedback. However, recovery of Antarctic ozone depletion in the next two decades will likely cause a fall in wind speeds, a decrease in cloud drop concentration and a correspondingly weaker cloud feedback
CRISPR-Cas defense system and potential prophages in cyanobacteria associated with the coral black band disease
Understanding how pathogens maintain their virulence is critical to developing tools to mitigate disease in animal populations. We sequenced and assembled the first draft genome of Roseofilum reptotaenium AO1, the dominant cyanobacterium underlying pathogenicity of the virulent coral black band disease (BBD), and analyzed parts of the BBD-associated Geitlerinema sp. BBD_1991 genome in silico. Both cyanobacteria are equipped with an adaptive, heritable clustered regularly interspaced short palindromic repeats (CRISPR)-Cas defense system type I-D and have potential virulence genes located within several prophage regions. The defense system helps to prevent infection by viruses and mobile genetic elements via identification of short fingerprints of the intruding DNA, which are stored as templates in the bacterial genome, in so-called CRISPRs. Analysis of CRISPR target sequences (protospacers) revealed an unusually high number of self-targeting spacers in R. reptotaenium AO1 and extraordinary long CRIPSR arrays of up to 260 spacers in Geitlerinema sp. BBD_1991. The self-targeting spacers are unlikely to be a form of autoimmunity; instead these target an incomplete lysogenic bacteriophage. Lysogenic virus induction experiments with mitomycin C and UV light did not reveal an actively replicating virus population in R. reptotaenium AO1 cultures, suggesting that phage functionality is compromised or excision could be blocked by the CRISPR-Cas system. Potential prophages were identified in three regions of R. reptotaenium AO1 and five regions of Geitlerinema sp. BBD_1991, containing putative BBD relevant virulence genes, such as an NAD-dependent epimerase/dehydratase (a homolog in terms of functionality to the third and fourth most expressed gene in BBD), lysozyme/metalloendopeptidases and other lipopolysaccharide modification genes. To date, viruses have not been considered to be a component of the BBD consortium or a contributor to the virulence of R. reptotaenium AO1 and Geitlerinema sp. BBD_(1)991. We suggest that the presence of virulence genes in potential prophage regions, and the CRISPR-Cas defense systems are evidence of an arms race between the respective cyanobacteria and their bacteriophage predators. The presence of such a defense system likely reduces the number of successful bacteriophage infections and mortality in the cyanobacteria, facilitating the progress of BBD
The stochastic resonance mechanism in the Aerosol Index dynamics
We consider Aerosol Index (AI) time-series extracted from TOMS archive for an area covering Italy . The missing of convergence in estimating the embedding dimension of the system and the inability of the Independent Component Analysis (ICA) in separating the fluctuations from deterministic component of the signals are evidences of an intrinsic link between the periodic behavior of AI and its fluctuations. We prove that these time series are well described by a stochastic dynamical model. Moreover, the principal peak in the power spectrum of these signals can be explained whereby a stochastic resonance, linking variable external factors, such as Sun-Earth radiation budget and local insolation, and fluctuations on smaller spatial and temporal scale due to internal weather and antrophic components
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