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1.
J Anim Ecol ; 93(6): 663-675, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38494654

ABSTRACT

Mathematical models highlighted the importance of pathogen-mediated invasion, with the replacement of red squirrels by squirrelpox virus (SQPV) carrying grey squirrels in the UK, a well-known example. In this study, we combine new epidemiological models, with a range of infection characteristics, with recent longitudinal field and experimental studies on the SQPV dynamics in red and grey squirrel populations to better infer the mechanistic basis of the disease interaction. A key finding is that a model with either partial immunity or waning immunity and reinfection, where individuals become seropositive on the second exposure to infection, that up to now has been shown in experimental data only, can capture the key aspects of the field study observations. By fitting to SQPV epidemic observations in isolated red squirrel populations, we can infer that SQPV transmission between red squirrels is significantly (4×) higher than the transmission between grey squirrels and as a result our model shows that disease-mediated replacement of red squirrels by greys is considerably more rapid than replacement in the absence of SQPV. Our findings recover the key results of the previous model studies, which highlights the value of simple strategic models that are appropriate when there are limited data, but also emphasise the likely complexity of immune interactions in wildlife disease and how models can help infer disease processes from field data.


Subject(s)
Poxviridae Infections , Sciuridae , Animals , Sciuridae/virology , Sciuridae/immunology , Sciuridae/physiology , United Kingdom/epidemiology , Poxviridae Infections/veterinary , Poxviridae Infections/transmission , Poxviridae Infections/virology , Poxviridae Infections/immunology , Poxviridae Infections/epidemiology , Rodent Diseases/virology , Rodent Diseases/transmission , Rodent Diseases/immunology , Rodent Diseases/epidemiology , Models, Biological , Poxviridae/physiology , Poxviridae/immunology , Introduced Species
2.
Sci Adv ; 6(41)2020 Oct.
Article in English | MEDLINE | ID: mdl-33033037

ABSTRACT

Thermal inertia and surface roughness are proxies for the physical characteristics of planetary surfaces. Global maps of these two properties distinguish the boulder population on near-Earth asteroid (NEA) (101955) Bennu into two types that differ in strength, and both have lower thermal inertia than expected for boulders and meteorites. Neither has strongly temperature-dependent thermal properties. The weaker boulder type probably would not survive atmospheric entry and thus may not be represented in the meteorite collection. The maps also show a high-thermal inertia band at Bennu's equator, which might be explained by processes such as compaction or strength sorting during mass movement, but these explanations are not wholly consistent with other data. Our findings imply that other C-complex NEAs likely have boulders similar to those on Bennu rather than finer-particulate regoliths. A tentative correlation between albedo and thermal inertia of C-complex NEAs may be due to relative abundances of boulder types.

3.
Science ; 370(6517)2020 11 06.
Article in English | MEDLINE | ID: mdl-33033157

ABSTRACT

Visible-wavelength color and reflectance provide information about the geologic history of planetary surfaces. Here we present multispectral images (0.44 to 0.89 micrometers) of near-Earth asteroid (101955) Bennu. The surface has variable colors overlain on a moderately blue global terrain. Two primary boulder types are distinguishable by their reflectance and texture. Space weathering of Bennu surface materials does not simply progress from red to blue (or vice versa). Instead, freshly exposed, redder surfaces initially brighten in the near-ultraviolet region (i.e., become bluer at shorter wavelengths), then brighten in the visible to near-infrared region, leading to Bennu's moderately blue average color. Craters indicate that the time scale of these color changes is ~105 years. We attribute the reflectance and color variation to a combination of primordial heterogeneity and varying exposure ages.

4.
Nat Astron ; 3(4): 332-340, 2019.
Article in English | MEDLINE | ID: mdl-31360777

ABSTRACT

Early spectral data from the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission reveal evidence for abundant hydrated minerals on the surface of near-Earth asteroid (101955) Bennu in the form of a near-infrared absorption near 2.7 µm and thermal infrared spectral features that are most similar to those of aqueously altered CM carbonaceous chondrites. We observe these spectral features across the surface of Bennu, and there is no evidence of substantial rotational variability at the spatial scales of tens to hundreds of meters observed to date. In the visible and near-infrared (0.4 to 2.4 µm) Bennu's spectrum appears featureless and with a blue (negative) slope, confirming previous ground-based observations. Bennu may represent a class of objects that could have brought volatiles and organic chemistry to Earth.

5.
Nat Commun ; 10(1): 1291, 2019 03 19.
Article in English | MEDLINE | ID: mdl-30890725

ABSTRACT

During its approach to asteroid (101955) Bennu, NASA's Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) spacecraft surveyed Bennu's immediate environment, photometric properties, and rotation state. Discovery of a dusty environment, a natural satellite, or unexpected asteroid characteristics would have had consequences for the mission's safety and observation strategy. Here we show that spacecraft observations during this period were highly sensitive to satellites (sub-meter scale) but reveal none, although later navigational images indicate that further investigation is needed. We constrain average dust production in September 2018 from Bennu's surface to an upper limit of 150 g s-1 averaged over 34 min. Bennu's disk-integrated photometric phase function validates measurements from the pre-encounter astronomical campaign. We demonstrate that Bennu's rotation rate is accelerating continuously at 3.63 ± 0.52 × 10-6 degrees day-2, likely due to the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect, with evolutionary implications.

6.
Nature ; 568(7750): 55-60, 2019 04.
Article in English | MEDLINE | ID: mdl-30890786

ABSTRACT

NASA'S Origins, Spectral Interpretation, Resource Identification and Security-Regolith Explorer (OSIRIS-REx) spacecraft recently arrived at the near-Earth asteroid (101955) Bennu, a primitive body that represents the objects that may have brought prebiotic molecules and volatiles such as water to Earth1. Bennu is a low-albedo B-type asteroid2 that has been linked to organic-rich hydrated carbonaceous chondrites3. Such meteorites are altered by ejection from their parent body and contaminated by atmospheric entry and terrestrial microbes. Therefore, the primary mission objective is to return a sample of Bennu to Earth that is pristine-that is, not affected by these processes4. The OSIRIS-REx spacecraft carries a sophisticated suite of instruments to characterize Bennu's global properties, support the selection of a sampling site and document that site at a sub-centimetre scale5-11. Here we consider early OSIRIS-REx observations of Bennu to understand how the asteroid's properties compare to pre-encounter expectations and to assess the prospects for sample return. The bulk composition of Bennu appears to be hydrated and volatile-rich, as expected. However, in contrast to pre-encounter modelling of Bennu's thermal inertia12 and radar polarization ratios13-which indicated a generally smooth surface covered by centimetre-scale particles-resolved imaging reveals an unexpected surficial diversity. The albedo, texture, particle size and roughness are beyond the spacecraft design specifications. On the basis of our pre-encounter knowledge, we developed a sampling strategy to target 50-metre-diameter patches of loose regolith with grain sizes smaller than two centimetres4. We observe only a small number of apparently hazard-free regions, of the order of 5 to 20 metres in extent, the sampling of which poses a substantial challenge to mission success.


Subject(s)
Extraterrestrial Environment/chemistry , Minor Planets , Space Flight , Exobiology , Origin of Life , Space Flight/instrumentation , Surface Properties
7.
Contemp Clin Trials ; 62: 159-167, 2017 11.
Article in English | MEDLINE | ID: mdl-28887069

ABSTRACT

BACKGROUND: Chronic Obstructive Pulmonary Disease (COPD) is a leading cause of hospitalizations. Interventional studies focusing on the hospital-to-home transition for COPD patients are few. In the BREATHE (Better Respiratory Education and Treatment Help Empower) study, we developed and tested a patient and family-centered transitional care program that helps prepare hospitalized COPD patients and their family caregivers to manage COPD at home. METHODS: In the study's initial phase, we co-developed the BREATHE transitional care program with COPD patients, family-caregivers, and stakeholders. The program offers tailored services to address individual patients' needs and priorities at the hospital and for 3months post discharge. We tested the program in a single-blinded RCT with 240 COPD patients who were randomized to receive the program or 'usual care'. Program participants were offered the opportunity to invite a family caregiver, if available, to enroll with them into the study. The primary outcomes were the combined number of COPD-related hospitalizations and Emergency Department (ED) visits per participant at 6months post discharge, and the change in health-related quality of life over the 6months study period. Other measures include 'all cause' hospitalizations and ED visits; patient activation; self-efficacy; and, self-care behaviors. DISCUSSION: Unlike 1month transitional care programs that focus on patients' post-acute care needs, the BREATHE program helps hospitalized COPD patients manage the post discharge period as well as prepare them for long term self-management of COPD. If proven effective, this program may offer a timely solution for hospitals in their attempts to reduce COPD rehospitalizations.


Subject(s)
Emergency Service, Hospital/statistics & numerical data , Hospitalization/statistics & numerical data , Patient-Centered Care/organization & administration , Transitional Care/organization & administration , Age Factors , Aged , Community Health Services/organization & administration , Family , Female , Humans , Male , Middle Aged , Patient Care Team/organization & administration , Patient Education as Topic/organization & administration , Pilot Projects , Pulmonary Disease, Chronic Obstructive/therapy , Quality of Life , Research Design , Self Care , Self Efficacy , Sex Factors , Single-Blind Method , Socioeconomic Factors
8.
Matern Child Health J ; 21(7): 1457-1468, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28102504

ABSTRACT

Objective To measure stigma associated with four types of postpartum depression therapies and to estimate the association between stigma and the acceptance of these therapies for black and white postpartum mothers. Methods Using data from two postpartum depression randomized trials, this study included 481 black and white women who gave birth in a large urban hospital and answered a series of questions at 6-months postpartum. Survey items included socio demographic and clinical factors, attitudes about postpartum depression therapies and stigma. The associations between race, stigma, and treatment acceptability were examined using bivariate and multivariate analyses. Results Black postpartum mothers were less likely than whites to accept prescription medication (64 vs. 81%, p = 0.0001) and mental health counseling (87 vs. 93%, p = 0.001) and more likely to accept spiritual counseling (70 vs. 52%, p = 0.0002). Women who endorsed stigma about receipt of postpartum depression therapies versus those who did not were less likely to accept prescription medication, mental health and spiritual counseling for postpartum depression. Overall black mothers were less likely to report stigma associated with postpartum depression therapies. In adjusted models, black women versus white women remained less likely to accept prescription medication for postpartum depression (OR = 0.42, 95% CI 0.24-0.72) and stigma did not explain this difference. Conclusions Although treatment stigma is associated with lower postpartum depression treatment acceptance, stigma does not explain the lower levels of postpartum depression treatment acceptance among black women. More research is needed to understand treatment barriers for postpartum depression, especially among black women.


Subject(s)
Black or African American/psychology , Depression, Postpartum/therapy , Mental Health Services/statistics & numerical data , Mothers/psychology , Patient Acceptance of Health Care/ethnology , Social Stigma , White People/psychology , Adolescent , Adult , Counseling , Depression/psychology , Depression, Postpartum/ethnology , Depression, Postpartum/psychology , Female , Humans , Mental Health , Postpartum Period , Randomized Controlled Trials as Topic
9.
BMC Bioinformatics ; 15: 376, 2014 Nov 25.
Article in English | MEDLINE | ID: mdl-25420746

ABSTRACT

BACKGROUND: Label-free quantitation of mass spectrometric data is one of the simplest and least expensive methods for differential expression profiling of proteins and metabolites. The need for high accuracy and performance computational label-free quantitation methods is still high in the biomarker and drug discovery research field. However, recent most advanced types of LC-MS generate huge amounts of analytical data with high scan speed, high accuracy and resolution, which is often impossible to interpret manually. Moreover, there are still issues to be improved for recent label-free methods, such as how to reduce false positive/negatives of the candidate peaks, how to expand scalability and how to enhance and automate data processing. AB3D (A simple label-free quantitation algorithm for Biomarker Discovery in Diagnostics and Drug discovery using LC-MS) has addressed these issues and has the capability to perform label-free quantitation using MS1 for proteomics study. RESULTS: We developed an algorithm called AB3D, a label free peak detection and quantitative algorithm using MS1 spectral data. To test our algorithm, practical applications of AB3D for LC-MS data sets were evaluated using 3 datasets. Comparisons were then carried out between widely used software tools such as MZmine 2, MSight, SuperHirn, OpenMS and our algorithm AB3D, using the same LC-MS datasets. All quantitative results were confirmed manually, and we found that AB3D could properly identify and quantify known peptides with fewer false positives and false negatives compared to four other existing software tools using either the standard peptide mixture or the real complex biological samples of Bartonella quintana (strain JK31). Moreover, AB3D showed the best reliability by comparing the variability between two technical replicates using a complex peptide mixture of HeLa and BSA samples. For performance, the AB3D algorithm is about 1.2 - 15 times faster than the four other existing software tools. CONCLUSIONS: AB3D is a simple and fast algorithm for label-free quantitation using MS1 mass spectrometry data for large scale LC-MS data analysis with higher true positive and reasonable false positive rates. Furthermore, AB3D demonstrated the best reproducibility and is about 1.2- 15 times faster than those of existing 4 software tools.


Subject(s)
Algorithms , Chromatography, Liquid/methods , Databases, Protein , Mass Spectrometry/methods , Peptide Fragments/analysis , Proteins/analysis , Proteome/analysis , Software , Animals , Cattle , HeLa Cells , Humans , Proteomics/methods , Serum Albumin, Bovine/analysis
10.
J Strength Cond Res ; 2014 Aug 21.
Article in English | MEDLINE | ID: mdl-25148468

ABSTRACT

The Certified Strength and Conditioning Specialist (CSCS) credential is intended to demonstrate expertise in strength and conditioning principles and implementation of this knowledge into training for performance enhancement. There is a lack of evidence regarding the value of the CSCS in physical therapist (PT) practice. The purpose of this study was to discern perceived benefits of the CSCS in physical therapists. Methodology for this descriptive study included administration of a cross-sectional, online survey to physical therapists holding the CSCS credential. The survey was administered online over 5 months and consisted of 14 multiple choice and Likert scale questions. Results indicated that 136 participants completed the survey with a 32.1% response rate. Exactly 53.7% of respondents reported their primary motivation for attaining the CSCS was "To further increase my knowledge base." A majority agreed that the CSCS led to new opportunities in their practice (66.7%), more respect from other therapists (79.3%), and better care provided for patients (77.9%). However, the majority of participants disagreed that the CSCS led to more respect from physicians (66.7%) or an increase in salary (56.7%). Most importantly, 94.1% reported that they would still attain the CSCS credential if they went back in time. The conclusions from this study indicate that there are perceived benefits in PT's who hold the CSCS credential. The findings from this study may positively affect the decisional balance in PT's who are considering acquiring the CSCS credential in the future, though results should be interpreted cautiously due to the relatively low response rate.

11.
J Proteome Res ; 13(8): 3846-3853, 2014 Aug 01.
Article in English | MEDLINE | ID: mdl-24965016

ABSTRACT

We have developed Mass++, a plug-in style visualization and analysis tool for mass spectrometry. Its plug-in style enables users to customize it and to develop original functions. Mass++ has several kinds of plug-ins, including rich viewers and analysis methods for proteomics and metabolomics. Plug-ins for supporting vendors' raw data are currently available; hence, Mass++ can read several data formats. Mass++ is both a desktop tool and a software development platform. Original functions can be developed without editing the Mass++ source code. Here, we present this tool's capability to rapidly analyze MS data and develop functions by providing examples of label-free quantitation and implementing plug-ins or scripts. Mass++ is freely available at http://www.first-ms3d.jp/english/ .

12.
Am J Law Med ; 39(1): 62-133, 2013.
Article in English | MEDLINE | ID: mdl-23678788

ABSTRACT

Even though most American retirees benefit from Medicare coverage, a mounting body of research predicts that many will face large and increasing out-of-pocket expenditures for healthcare costs in retirement and that many already struggle to finance these costs. It is unclear, however, whether the general population understands the likely magnitude of these out-of-pocket expenditures well enough to plan for them effectively. This study is the first comprehensive examination of Americans' expectations regarding their out-of-pocket spending on healthcare in retirement. We surveyed over 1700 near retirees and retirees to assess their expectations regarding their own spending and then compared their responses to experts' estimates. Our main findings are twofold. First, overall expectations of out-of-pocket spending are mixed. While a significant proportion of respondents estimated out-of-pocket costs in retirement at or above expert estimates of what the typical retiree will spend, a disproportionate number estimated their future spending substantially below what experts view as likely. Estimates by members of some demographic subgroups, including women and younger respondents, deviated relatively further from the experts' estimates. Second, respondents consistently misjudged spending uncertainty. In particular, respondents significantly underestimated how much individual health experience and changes in government policy can affect individual out-of-pocket spending. We discuss possible policy responses, including efforts to improve financial planning and ways to reduce unanticipated financial risk through reform of health insurance regulation.


Subject(s)
Health Care Costs , Health Expenditures , Retirement/economics , Demography , Health Care Costs/trends , Health Policy , Humans , Inflation, Economic , Insurance, Health/economics , Medicare/economics , United States
13.
J Econ Perspect ; 25(1): 91-114, 2011.
Article in English | MEDLINE | ID: mdl-24991083
14.
J Perinatol ; 30(9): 590-5, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20182436

ABSTRACT

OBJECTIVE: To assess concordance with a locally developed standard of care for premature infants with respiratory distress syndrome (RDS) for whom the standard recommends surfactant treatment within 2 h of birth, and to examine the association between clinical, demographic, and hospital characteristics with discordance from the standard. STUDY DESIGN: Retrospective cohort study of 773 infants weighing < or =1750 g born in any of the three New York City hospitals between 1999 and 2002. RESULT: 227 of the 773 infants (29%) met criteria for treatment according to the standard. Of these, 37% received surfactant by 2 h. By 4 h, 70% of infants who met the standard received surfactant. White infants were more likely to receive surfactant by 4 h (85%) than African American (61%) or Latino infants (67%). Multivariable logistic regression revealed significant odds ratios predicting discordance from the relaxed criteria (4 h) for African American race (4.10, 95% confidence interval: 1.30 to 13.00), 100 g of birth weight (odds ratio: 1.22, 95% confidence interval: 1.10 to 1.34), and hospital of birth. CONCLUSION: Many infants with RDS failed to receive surfactant replacement therapy at 2 and 4 h after birth. African Americans and those born larger were less likely to receive surfactant. If these data can be generalized, there is a large opportunity to reduce infant morbidity from RDS and to reduce racial/ethnic disparities in birth outcomes by increasing the rate and speed with which surfactant is delivered to these infants.


Subject(s)
Black or African American , Guideline Adherence , Healthcare Disparities/ethnology , Pulmonary Surfactants/therapeutic use , Respiratory Distress Syndrome, Newborn/drug therapy , Respiratory Distress Syndrome, Newborn/ethnology , Cohort Studies , Female , Humans , Infant, Newborn , Infant, Premature , Infant, Very Low Birth Weight , Male , Medical Audit , New York City , Retrospective Studies
15.
Can J Microbiol ; 55(3): 269-76, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19370070

ABSTRACT

Repetitive element-polymerase chain reaction (REP-PCR) DNA fingerprinting and library-based microbial source tracking (MST) methods were utilized to investigate the potential sources of Escherichia coli pollution in recreational waters of southeastern Lake Huron. In addition to traditional sources such as humans, agriculture, and wildlife, environmentally persistent E. coli isolates were included in the identification library as a separate library unit consisting of the E. coli strains isolated from interstitial water on the beach itself. Our results demonstrated that the dominant source of E. coli pollution of the lake was agriculture, followed by environmentally adapted E. coli strains, wildlife, and then humans. A similar ratio of contributing sources was observed in all samples collected from various locations including the river discharging to the beach in both 2005 and 2006. The high similarity between the compositions of E. coli communities collected simultaneously in the river and in the lake suggests that tributaries were the major overall sources of E. coli to the lake. Our findings also suggest that environmentally adapted strains (EAS) of E. coli should be included as one of the potential sources in future microbial source tracking efforts.


Subject(s)
Bathing Beaches , Escherichia coli/classification , Escherichia coli/isolation & purification , Fresh Water/microbiology , Polymerase Chain Reaction/methods , Repetitive Sequences, Nucleic Acid/genetics , Water Pollution/analysis , Adaptation, Physiological , Agriculture , Animals , Animals, Wild/microbiology , Bacterial Typing Techniques , Canada , Colony Count, Microbial , DNA Fingerprinting/methods , DNA, Bacterial/analysis , Environmental Monitoring , Escherichia coli/genetics , Humans
16.
Environ Pollut ; 157(4): 1210-8, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19167794

ABSTRACT

Concentrations and congener profile patterns of 2378-substituted PCDD/Fs and DLPCBs in offshore, nearshore and tributary sediments of Lakes Superior and Huron are reported, and spatial trends and source contributions assessed. PCDD/F concentrations ranged from 5 to 18,000 pg/g dw (Lake Superior) and 3 to 6100 pg/g dw (Lake Huron); DLPCBs ranged from 9 to 11,000 pg/g dw (Lake Superior) and 9 to 27,000 pg/g dw (Lake Huron). Our analysis indicated atmospheric deposition is a primary source to depositional areas of both lakes; however, greater PCDD/F and DLPCB concentrations were observed at several nearshore and tributary sites, and were attributed to corresponding land use in the watershed. Statistical analysis and pattern comparison suggested that industrial inputs mainly associated with wood treatment plants, pulp and paper mills, mining operations, and chlorine-based chemical manufacturing also contributed to contamination by PCDD/Fs and DLPCBs in certain nearshore and offshore areas of Lakes Superior and Huron.


Subject(s)
Benzofurans/analysis , Geologic Sediments/chemistry , Pesticides/analysis , Polychlorinated Biphenyls/analysis , Polychlorinated Dibenzodioxins/analogs & derivatives , Water Pollutants, Chemical/analysis , Air Pollutants/analysis , Benzofurans/chemistry , Canada , Environmental Monitoring/methods , Fresh Water , Pesticides/chemistry , Polychlorinated Biphenyls/chemistry , Polychlorinated Dibenzodioxins/analysis , Polychlorinated Dibenzodioxins/chemistry , Water Pollutants, Chemical/chemistry
17.
Shock ; 31(1): 55-63, 2009 Jan.
Article in English | MEDLINE | ID: mdl-18497707

ABSTRACT

The IL-1 receptor-associated kinase 1 (IRAK-1) and IRAK-M are key signaling molecules in cellular responses to endotoxin initiated through the Toll-like receptors (TLRs). The aim of this study was to evaluate the effect of age on the modulation of TLRs and IRAK-1 and IRAK-M in peripheral blood mononuclear cells (PBMCs) exposed in vitro to endotoxin under conditions that could induce endotoxin tolerance. Peripheral blood mononuclear cells obtained from young (4- to 6-month-old) and aged (24- to 26-month-old) Brown Norway rats were treated with high-dose LPS, with or without priming with low-dose LPS. In comparison with younger rats, the intensity of TLR-4 expression was persistently high in monocytes from aged rats after stimulation with LPS and was not decreased by priming with low-dose LPS (P < 0.05). Messenger RNA (mRNA) for TLR-4 in PBMCs from aged rats did not show any decrease after priming with low-dose LPS as seen in PBMCs from young rats at 24 h (P = 0.01) after restimulation. In PBMCs from young rats, but not aged rats, preconditioning with low-dose LPS and subsequent stimulation with high-dose LPS resulted in markedly decreased IRAK-1 protein (P = 0.02) and decreased mRNA for IRAK-1 (P < 0.05). In contrast, PBMCs from aged rats treated in this manner continued to express measurable levels of IRAK-1 protein. Preconditioning with low-dose LPS caused an increase in both IRAK-M protein and mRNA (P = 0.05) after stimulation with high-dose LPS only in cells from young rats. These phenotypic characteristics of PBMCs from aged rats can interfere with their ability to develop tolerance to endotoxin.


Subject(s)
Aging/metabolism , Gene Expression Regulation, Enzymologic/drug effects , Interleukin-1 Receptor-Associated Kinases/biosynthesis , Leukocytes, Mononuclear/enzymology , Lipopolysaccharides/pharmacology , Protein Serine-Threonine Kinases/biosynthesis , Animals , Dose-Response Relationship, Drug , Drug Tolerance , Male , Rats , Toll-Like Receptor 4/biosynthesis
18.
Theor Appl Genet ; 116(2): 179-92, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17938878

ABSTRACT

Previous locations of flowering time (FT) QTL in several Brassica species, coupled with Arabidopsis synteny, suggest that orthologues of the genes FLC, FY or CONSTANS might be the candidates. We focused on FLC, and cloned paralogous copies in Brassica oleracea, obtained their genomic DNA sequences, and confirmed their locations relative to those of known FT-QTL by genetical mapping. They varied in total length mainly due to the variable size of the first and last introns. A high level of identity was observed among Brassica FLC genes at the amino acid level but non-synonymous differences were present. Comparative analysis of the promoter and intragenic regions of BoFLC paralogues with Arabidopsis FLC revealed extensive differences in overall structure and organisation but showed high conservation within those segments known to be essential in regulating FLC expression. Four B. oleracea FLC copies (BoFLC1, BoFLC3, BoFLC4 and BoFLC5) were located to their respective linkage groups based on allelic sequence variation in lines from a doubled haploid population. All except BoFLC4 were within the confidence intervals of known FT-QTL. Sequence data indicated that relevant non-synonymous polymorphisms were present between parents A12DHd and GDDH33 for BoFLC genes. However, BoFLC alleles segregated independently of FT in backcrosses while the study provided evidence that BoFLC4 and BoFLC5 contain premature stop codons and so could not contribute to flowering time variation. Therefore, there is strong evidence against any of the 4 BoFLC being FT-QTL candidates in this population.


Subject(s)
Arabidopsis Proteins/genetics , Brassica/genetics , Brassica/physiology , Flowers/physiology , MADS Domain Proteins/genetics , Phylogeny , Polymorphism, Genetic , Quantitative Trait Loci , Amino Acid Sequence , Base Sequence , Cluster Analysis , DNA Primers/genetics , Gene Components , Gene Library , Molecular Sequence Data , Sequence Analysis, DNA , Synteny/genetics
19.
J Phycol ; 44(4): 839-54, 2008 Aug.
Article in English | MEDLINE | ID: mdl-27041601

ABSTRACT

Cladophora glomerata (L.) Kütz. is, potentially, the most widely distributed macroalga throughout the world's freshwater ecosystems. C. glomerata has been described throughout North America, Europe, the Atlantic Islands, the Caribbean Islands, Asia, Africa, Australia and New Zealand, and the Pacific Islands. Cladophora blooms were a common feature of the lower North American Great Lakes (Erie, Michigan, Ontario) from the 1950s through the early 1980s and were largely eradicated through the implementation of a multibillion-dollar phosphorus (P) abatement program. The return of widespread blooms in these lakes since the mid-1990s, however, was not associated with increases in P loading. Instead, current evidence indicates that the resurgence in blooms was directly related to ecosystem level changes in substratum availability, water clarity, and P recycling associated with the establishment of dense colonies of invasive dreissenid mussels. These results support the hypothesis that dreissenid mussel invasions may induce dramatic shifts in energy and nutrient flow from pelagic zones to the benthic zone.

20.
Appl Environ Microbiol ; 73(6): 1961-7, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17261522

ABSTRACT

Research was undertaken to characterize Escherichia coli isolates in interstitial water samples of a sandy beach on the southeastern shore of Lake Huron, Ontario, Canada. A survey of the beach area revealed the highest abundance of E. coli in interstitial water of the foreshore beach sand next to the swash zone. Higher concentrations of E. coli (up to 1.6 x 10(6) CFU/100 ml of water) were observed in the interstitial water from the sampling holes on the beach itself compared to lake water and sediment. Repetitive extragenic palindromic PCR (REP-PCR) was used to characterize the genetic diversity of E. coli isolates from interstitial water samples on the beach. E. coli isolates from the same sampling location frequently exhibited the same REP-PCR pattern or were highly similar to each other. In contrast, E. coli isolates from different sampling locations represented populations distinct from each other. This study has identified a unique ecological niche within the foreshore area of the beach where E. coli may survive and possibly multiply outside of host organisms. The results are of interest as increasing concentrations of E. coli in recreational waters are often considered to be an indication of recent fecal pollution.


Subject(s)
Escherichia coli/classification , Escherichia coli/genetics , Fresh Water/microbiology , Soil Microbiology , Water Microbiology , Bacterial Typing Techniques , Canada , Cluster Analysis , Colony Count, Microbial , DNA Fingerprinting , DNA, Bacterial/genetics , DNA, Intergenic/genetics , Escherichia coli/isolation & purification , Genetic Variation , Genotype , Geologic Sediments/microbiology , Polymerase Chain Reaction , Repetitive Sequences, Nucleic Acid/genetics
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