434 research outputs found

    Tillage and manure effect on soil physical and chemical properties and on carbon and nitrogen mineralization potentials

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    The objective of this work was to study the effects of tillage and liquid manure applications on some physical and chemical properties and also on the carbon and nitrogen mineralization potential from a meadow soil. Our results indicated that tillage and manure applications had no effect on the concentration of Cu, Mn, total N and organic C in the 0 - 15 cm layer of soil after 15 years of treatment. However soil P, Ca, Mg and Zn contents increased significantly with manure applications. Soil organic matter and total N significantly decreased in the 15 – 30 cm depth. No significant change could be detected in soil structural stability in both layers. Moreover, tillage affected significantly soil soluble C and the C/N ratio. Application of 100 t ha-1 manure significantly increased soil soluble C. The results of this study suggest that tillage increased significantly the soil N mineralization rate. The potentially mineralizable nitrogen (N0) was higher in tilled than in no-tilled soil and was at its maximum in the 0 – 15 cm layer of the soil. Furthermore, a significant positive interaction was observed between tillage and manure application on N mineralized after 1.4 wk (Ne). No significant change was detected in both C mineralization rate (Cm) and potentially mineralizable C (C0). The total amounts of mineralizable carbon (Cm) and nitrogen (Nm) significantly decreased in 15 – 30 cm depth and were very closely correlated with the total amounts of C or N and mineralization rate constants (K).Key words: Carbon and nitrogen mineralization potentials, k constants, physical and chemical properties

    Contribution à la fabrication et la conservation des fruits semi-confits à base de pêche

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    Interacting with Interviewers in Voice and Text Interviews on Smartphones

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    As people increasingly adopt SMS text messaging for communicating in their daily lives, texting becomes a potentially important way to interact with survey respondents, who may expect that they can communicate with survey researchers as they communicate with others. Thus far our evidence from analyses of 642 iPhone interviews suggests that text interviewing can lead to higher quality data (less satisficing, more disclosure) than voice interviews on the same device, whether the questions are asked by an interviewer or an automated system. Respondents also report high satisfaction with text interviews, with many reporting that text is more convenient because they can continue with other activities while responding. But the interaction with an interviewer in a text interview is substantially different than in a voice interview, with much less of a sense of the interviewer’s social presence as well as quite different time pressure. In principle, this suggests there should be different potential for interviewer effects in text than in voice. In this paper we report analyses of how text interviews differed from voice interviews in our corpus, as well as how interviews with human interviewers differed from interviews with automated interviewing systems in both modes, based on transcripts and coding of multiple features of the interaction. Text interviews took more than twice as long as voice interviews, but the amount of time between turns (text messages) was large, and the total number of turns was two thirds as many as in voice interviews. As in the voice interviews, text interviews with human interviewers involved a small but significantly greater number of turns than text interviews with automated systems, not only because respondents engaged in small “talk” with human interviewers but because they requested clarification and help with the survey task more often than with the automated text interviewer. Respondents were more likely to type out full response options (as opposed to equally acceptable single character responses) with a human text interviewer. Analyses of the content and format of text interchanges compared to voice interchanges demonstrate both potential improvements in data quality and ease for respondents, but also pitfalls and challenges that a more asynchronous mode brings. The “anytime anywhere” qualities of text interviewing may reduce pressure to answer quickly, allowing respondents to answer more thoughtfully and to consult records even if they are mobile or multitasking. From a Total Survey Error perspective, the more streamlined nature of text interaction, which largely reduces the interview to its essential question-asking and -answering elements, may help reduce the potential for unintended interviewer influence

    Chapter 13: Interacting with interviewers in text and voice interviews on smartphones. Appendix 13

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    Appendix A: Example human text and voice interchange that includes clarification. Appendix B: Coding Manual Appendix A13C.1 (Data) attached belo

    Does Valproic Acid Induce Neuroendocrine Differentiation in Prostate Cancer?

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    Valproic Acid (VPA) is a histone deacetylase inhibitor that holds promise for cancer therapy. Here, we investigate whether VPA treatment induces neuroendocrine differentiation of Prostate Cancer (PCa). A tissue microarray of VPA-treated and untreated tumor xenografts and cell lines of human PCa (LNCaP, C4-2, DU145, and PC-3) were generated and were analyzed by immunohistochemical analysis (IHC) for NE markers chromogranin A (CgA), synaptophysin, and NCAM (neural cell adhesion molecule). Western blot analysis for CgA was performed to confirm the results of the TMA. IHC analysis did not reveal any induction of CgA, synaptophysin, or NCAM in any xenograft after VPA treatment in vivo. In vitro, VPA treatment induced little synaptophysin expression in C4-2 and PC-3 cells and NCAM expression in LNCaP and PC-3 cells. In the case of CgA, VPA treatment decreased its expression in vitro in a dose-dependent manner, as determined by western blot analysis. Thus our data demonstrates that VPA does not induce NE differentiation of PCa cells in the physiologically relevant in vivo setting

    Comparison of metabolic abnormalities and clinical lipodystrophy 48 weeks after switching from HAART to Trizivir versus continued HAART: the Trizal study

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    PURPOSE: To analyze the evolution of clinical lipodystrophy (LD) and metabolic abnormalities in patients continuing to receive HAART versus patients switched to Trizivir (zidovudine, lamivudine, abacavir) after 48 weeks. METHOD: Patients treated with HAART >6 months with plasma HIV-1 RNA viral load (VL) <400 copies/mL and <50 copies/mL at screening were randomly assigned to continue HAART (103 patients) or to receive Trizivir (106 patients). Clinical LD was evaluated using a standardized patient questionnaire only at baseline, weeks 4 and 8, and then every 8 weeks until Week 48. Laboratory evaluation was performed every 4 weeks. RESULTS: The proportion of patients exhibiting >or=1 LD symptom at baseline was 40% in the Trizivir arm and 50% in HAART arm (difference not significant). After 48 weeks, the prevalence was 28% and 42% respectively (p =.03), and the median number of LD symptoms per patient was 2 in the Trizivir arm and 4 in the continued HAART arm (p =.016). Median decreases in cholesterol levels over the 48-week study period were greater in the Trizivir arm than in the continued HAART arm (-0.80 vs. -0.44 mmol/L; p lt.001). Median triglyceride levels decreased in the Trizivir arm but increased in the continued HAART arm (-0.17 and +0.01 mmol/L; p =.006). Suppression of VL was maintained in most patients with no differences between the two arms. CONCLUSION: A switch from "standard" HAART to Trizivir was associated with an improvement in clinical LD and blood lipid abnormalities after 48 weeks

    Localisation of an occult thyrotropinoma with 11^{11}C-methionine PET-CT before and after somatostatin analogue therapy

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    A 75-year-old woman presented to her local endocrine service with tiredness, palpitations, and enlargement of a longstanding goitre. Unexpectedly, her thyrotropin (thyroid-stimulating hormone [TSH]) concentration was not suppressed (6·3 mU/L; reference range 0·35–5·5) despite raised concentrations of thyroid hormones (free thyroxine [T4_{4}] 89·1 pmol/L [reference range 10–19·8]; free triiodothyronine [T3_{3}] 11·7 pmol/L [3·0–6·5]). After exclusion of laboratory assay interference, a thyrotropin-releasing hormone test showed an attenuated response (TSH at 0 min was 6·1 mU/L, at 20 min was 6·8 mU/L, and at 60 min was 8·5 mU/L), raising suspicion of a thyrotropinoma (also known as TSHoma). However, pituitary MRI was normal. The patient was referred to our centre for further assessment. On repeat MRI, the pituitary gland showed mild asymmetry (right larger than left; figure A). Functional imaging with 11C-methionine (11^{11}C-Met) PET-CT revealed intense tracer uptake (denoting active peptide synthesis) on the right side of the sella (red hot spot in figure A). Treatment with a depot somatostatin analogue (SSA) led to resolution of symptoms and normalisation of thyroid function (TSH 0·6 mU/L, free T4_{4} 12·5 pmol/L, and free T3_{3} 3·8 pmol/L). Repeat 11^{11}C-Met PET-CT showed absence of the right-sided focal hot spot (figure B). 14 months into treatment, the patient had several hypoglycaemic episodes, which resolved after discontinuation of SSA. However, thyrotoxicosis recurred (TSH 4·3 mU/L, free T4_{4} 38·1 pmol/L, free T3_{3} 11·6 pmol/L), and repeat 11^{11}C-Met PET-CT revealed the reappearance of the right-sided hot spot (figure C). During pituitary surgery, a microthyrotropinoma was resected from the right side of the gland (figure D). The patient remains in clinical and biochemical remission more than 12 months after surgery and has normal pituitary function

    Gonadal sex patterns p21-induced cellular senescence in mouse and human glioblastoma

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    Males exhibit higher incidence and worse prognosis for the majority of cancers, including glioblastoma (GBM). Disparate survival may be related to sex-biased responses to treatment, including radiation. Using a mouse model of GBM, we show that female cells are more sensitive to radiation, and that senescence represents a major component of the radiation therapeutic response in both sexes. Correlation analyses revealed that the CDK inhibitor p21 and irradiation induced senescence were differentially regulated between male and female cells. Indeed, female cellular senescence was more sensitive to changes in p21 levels, a finding that was observed in wildtype and transformed murine astrocytes, as well as patient-derived GBM cell lines. Using a novel Four Core Genotypes model of GBM, we further show that sex differences in p21-induced senescence are patterned during early development by gonadal sex. These data provide a rationale for the further study of sex differences in radiation response and how senescence might be enhanced for radiation sensitization. The determination that p21 and gonadal sex are required for sex differences in radiation response will serve as a foundation for these future mechanistic studies
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