837 research outputs found

    Genetic variation and possible origins of weedy rice found in California.

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    Control of weeds in cultivated crops is a pivotal component in successful crop production allowing higher yield and higher quality. In rice-growing regions worldwide, weedy rice (Oryza sativa f. spontanea Rosh.) is a weed related to cultivated rice which infests rice fields. With populations across the globe evolving a suite of phenotypic traits characteristic of weeds and of cultivated rice, varying hypotheses exist on the origin of weedy rice. Here, we investigated the genetic diversity and possible origin of weedy rice in California using 98 simple sequence repeat (SSR) markers and an Rc gene-specific marker. By employing phylogenetic clustering analysis, we show that four to five genetically distinct biotypes of weedy rice exist in California. Analysis of population structure and genetic distance among individuals reveals diverse evolutionary origins of California weedy rice biotypes, with ancestry derived from indica, aus, and japonica cultivated rice as well as possible contributions from weedy rice from the southern United States and wild rice. Because this diverse parentage primarily consists of weedy, wild, and cultivated rice not found in California, most existing weedy rice biotypes likely originated outside California

    Decorating Metal Oxide Surfaces with Fluorescent Chlorosulfonated Corroles

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    We have prepared 2,17-bis(chlorosulfonyl)-5,10,15-tris(pentafluorophenyl)corrole (1), 2,17-bis(chlorosulfonyl)-5,10,15-tris(pentafluorophenyl)corrolatoaluminum(III) (1-Al), and 2,17-bis(chlorosulfonyl)-5,10,15-tris(pentafluorophenyl)corrolatogallium(III) (1-Ga). The metal complexes 1-Al and 1-Ga were isolated and characterized by electronic absorption and NMR spectroscopies, as well as by mass spectrometry. Relative emission quantum yields for 1, 1-Al, and 1-Ga, determined in toluene, are 0.094, 0.127, and 0.099, respectively. Reactions between 1, 1-Al, and 1-Ga and TiO2 nanoparticles (NPs) result in corrole–TiO_2 NP conjugates. The functionalized NP surfaces were investigated by solid-state Fourier transform infrared and X-ray photoelectron spectroscopies and by confocal fluorescence imaging. The fluorescence images for 1-Al–TiO_2 and 1-Ga–TiO_2 suggest a promising application of these NP conjugates as contrast agents for noninvasive optical imaging

    Dynamic classification using case-specific training cohorts outperforms static gene expression signatures in breast cancer

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    The molecular diversity of breast cancer makes it impossible to identify prognostic markers that are applicable to all breast cancers. To overcome limitations of previous multigene prognostic classifiers, we propose a new dynamic predictor: instead of using a single universal training cohort and an identical list of informative genes to predict the prognosis of new cases, a case-specific predictor is developed for each test case. Gene expression data from 3,534 breast cancers with clinical annotation including relapse-free survival is analyzed. For each test case, we select a case-specific training subset including only molecularly similar cases and a case-specific predictor is generated. This method yields different training sets and different predictors for each new patient. The model performance was assessed in leave-one-out validation and also in 325 independent cases. Prognostic discrimination was high for all cases (n = 3,534, HR = 3.68, p = 1.67 E-56). The dynamic predictor showed higher overall accuracy (0.68) than genomic surrogates for Oncotype DX (0.64), Genomic Grade Index (0.61) or MammaPrint (0.47). The dynamic predictor was also effective in triple-negative cancers (n = 427, HR = 3.08, p = 0.0093) where the above classifiers all failed. Validation in independent patients yielded similar classification power (HR = 3.57). The dynamic classifier is available online at http://www.recurrenceonline.com/?q=Re_training. In summary, we developed a new method to make personalized prognostic prediction using case-specific training cohorts. The dynamic predictors outperform static models developed from single historical training cohorts and they also predict well in triple-negative cancers

    Bacterial Spore Detection by [Tb^(3+)(macrocycle)(dipicolinate)] Luminescence

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    Dipicolinic acid (DPA) is a unique constituent of bacterial spores, a dormant form of Bacillus and Clostridium, which can be detected using DPA-triggered Tb^(3+) luminescence. [Tb(DO2A)]^+ improves the sensitivity of bacterial spore detection over Tb^(3+)(aq) owing to the exclusion of coordinated water molecules and represents the first step toward construction of a DPA receptor site with enhanced binding selectivity. The title ternary [Tb(DO2A)(DPA)]- complex was structurally characterized and features two DO2A-DPA interligand hydrogen interactions that stabilize the complex

    Home sweet home: a critical comment on Saunders and Williams

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    While accepting the need for research which focuses on the social meaning of the home, this article takes issue with some of Saunders’ and Williams’ formulations for a research programme — in particular, the emphasis given to physical and design features of the home at the expense of an understanding of more fundamental gender and generational relations within the home. It attempts to uncover the assumptions lying behind those formulations, to clarify some of the conceptual confusions, and to point out some of the serious theoretical difficulties which such formulations have to resolve. It argues that theoretical advance in this area does not have to depend upon the adoption of a Weberian perspective, but must be situated within a broader theory of the production and maintenance of ideology, and this theory must be explicitly linked with theories of power and kinship. In particular, it is emphasised that power relations within the home, associated mainly with gender and age differences, need to be investigated in greater depth if the social significance of the home is to be properly understood

    Large field of view scanning fluorescence lifetime imaging system for multimode optical imaging of small animals

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    We describe a scanning fluorescence lifetime imaging (SFLIM) system that provides a large field of view (LFOV), using a femtosecond (fs) pulsed laser, for multi-mode optical imaging of small animals. Fluorescence lifetime imaging (FLIM) can be a useful optical method to distinguish between fluorophores inside small animals. However, difficulty arises when LFOV is required in FLIM using a fs pulsed laser for the excitation of the fluorophores at low wavelengths (<500nm), primarily because the field of view of the pulsed blue excitation light generated from the second harmonic of the fs pulsed light is limited to about a centimeter in diameter due to the severe scattering and absorption of the light inside tissues. Here, we choose a scanning method in order to acquire a FLIM image with LFOV as one alternative. In the SFLIM system, we used a conventional cooled CCD camera coupled to an ultra-fast time-gated intensifier, a tunable femtosecond laser for the excitation of fluorophores, and an x-y moving stage for scanning. Images acquired through scanning were combined into a single image and then this reconstructed image was compared with images obtained by spectral imaging. The resulting SFLIM system is promising as an alternative method for the FLIM imaging of small animals, containing fluorophores exited by blue light, for LFOV applications such as whole animal imaging

    Large field of view scanning fluorescence lifetime imaging system for multimode optical imaging of small animals

    Get PDF
    We describe a scanning fluorescence lifetime imaging (SFLIM) system that provides a large field of view (LFOV), using a femtosecond (fs) pulsed laser, for multi-mode optical imaging of small animals. Fluorescence lifetime imaging (FLIM) can be a useful optical method to distinguish between fluorophores inside small animals. However, difficulty arises when LFOV is required in FLIM using a fs pulsed laser for the excitation of the fluorophores at low wavelengths (<500nm), primarily because the field of view of the pulsed blue excitation light generated from the second harmonic of the fs pulsed light is limited to about a centimeter in diameter due to the severe scattering and absorption of the light inside tissues. Here, we choose a scanning method in order to acquire a FLIM image with LFOV as one alternative. In the SFLIM system, we used a conventional cooled CCD camera coupled to an ultra-fast time-gated intensifier, a tunable femtosecond laser for the excitation of fluorophores, and an x-y moving stage for scanning. Images acquired through scanning were combined into a single image and then this reconstructed image was compared with images obtained by spectral imaging. The resulting SFLIM system is promising as an alternative method for the FLIM imaging of small animals, containing fluorophores exited by blue light, for LFOV applications such as whole animal imaging

    A Maternal Death due to an Unsafe Abortion in Rural Nepal - A Case Report

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    Background: Abortion was illegal before 2002 A.D. in Nepal and was legalized under the 11th amendment to the Country Code (Muluki Ain) in March 2002, receiving royal assent in September 2002. Nepal Government began providing comprehensive abortion care services from March 2004 after 18 months of legalization of abortion, when the government issued Safe Abortion Service Procedure. The maternal mortality ratio in Nepal is among the highest in South Asia. Unsafe abortion is defined as an induced abortion process either conducted by less skilled personnel or performed in a non-accredited facility. Though abortion has been legal in Nepal for more than 14 years now; physicians in Nepal still face problems of abortions done by less qualified personnel.Case Report: We report a fatal case of unsafe abortion in a 32 year old lady whose cause of death was ascertained as irreversible septic shock due to septic abortion.Conclusion: Prompt diagnosis and appropriate intervention might provide better outcome in these types of cases. Therefore, we stress the importance of safe abortion services provided by skilled personnel at rural areas in developing countries and of early referral in case complication arises so that the life of the patient is not endangered

    Trouble at the top: The construction of a tenant identity in the governance of social housing organizations

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    The project of citizen governance has transformed the social housing sector in England where 20,000 tenants now sit as directors on the boards of housing associations, but the entrance of social housing tenants to the boardroom has aroused opposition from the chief executives of housing companies and triggered regulatory intervention from government inspectors. This paper investigates the cause of these tensions through a theoretical framework drawn from the work of feminist philosopher Judith Butler. It interprets housing governance as an identificatory project with the power to constitute tenant directors as regulated subjects, and presents evidence to suggest that this project of identity fails to completely enclose its subject, allowing tenant directors to engage in ‘identity work’ that threatens the supposed unity of the board. The paper charts the development of antagonism and political tension in the board rooms of housing companies to present an innovative account of the construction and contestation of identities in housing governance

    Proliferation and estrogen signaling can distinguish patients at risk for early versus late relapse among estrogen receptor positive breast cancers

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    Introduction: We examined if a combination of proliferation markers and estrogen receptor (ER) activity could predict early versus late relapses in ER-positive breast cancer and inform the choice and length of adjuvant endocrine therapy. Methods: Baseline affymetrix gene-expression profiles from ER-positive patients who received no systemic therapy (n = 559), adjuvant tamoxifen for 5 years (cohort-1: n = 683, cohort-2: n = 282) and from 58 patients treated with neoadjuvant letrozole for 3 months (gene-expression available at baseline, 14 and 90 days) were analyzed. A proliferation score based on the expression of mitotic kinases (MKS) and an ER-related score (ERS) adopted from Oncotype DX® were calculated. The same analysis was performed using the Genomic Grade Index as proliferation marker and the luminal gene score from the PAM50 classifier as measure of estrogen-related genes. Median values were used to define low and high marker groups and four combinations were created. Relapses were grouped into time cohorts of 0-2.5, 0-5, 5-10 years. Results: In the overall 10 years period, the proportional hazards assumption was violated for several biomarker groups indicating time-dependent effects. In tamoxifen-treated patients Low-MKS/Low-ERS cancers had continuously increasing risk of relapse that was higher after 5 years than Low-MKS/High-ERS cancers [0 to 10 year, HR 3.36; p = 0.013]. High-MKS/High-ERS cancers had low risk of early relapse [0-2.5 years HR 0.13; p = 0.0006], but high risk of late relapse which was higher than in the High-MKS/Low-ERS group [after 5 years HR 3.86; p = 0.007]. The High-MKS/Low-ERS subset had most of the early relapses [0 to 2.5 years, HR 6.53; p < 0.0001] especially in node negative tumors and showed minimal response to neoadjuvant letrozole. These findings were qualitatively confirmed in a smaller independent cohort of tamoxifen-treated patients. Using different biomarkers provided similar results. Conclusions: Early relapses are highest in highly proliferative/low-ERS cancers, in particular in node negative tumors. Relapses occurring after 5 years of adjuvant tamoxifen are highest among the highly-proliferative/high-ERS tumors although their risk of recurrence is modest in the first 5 years on tamoxifen. These tumors could be the best candidates for extended endocrine therapy
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