713 research outputs found
HEBE, a novel positive regulator of senescence in Solanum lycopersicum
Leaf senescence and plant aging are traits of great interest for breeders. Senescing cells undergo important physiological and biochemical changes, while cellular structures such as chloroplasts are degraded with dramatic metabolic consequences for the whole plant. The possibility of prolonging the photosynthetic ability of leaves could positively impact the plant\u2019s life span with benefits for biomass production and metabolite accumulation; plants with these characteristics display a stay-green phenotype. A group of plant transcription factors known as NAC play a pivotal role in controlling senescence: here we describe the involvement of the tomato NAC transcription factor Solyc12g036480, which transcript is present in leaves and floral buds. Since its silencing delays leaf senescence and prevents plants from ageing, we renamed Solyc12g0364 H\u1e16B\u112, for the Greek goddess of youth. In this manuscript we describe how HEB downregulation negatively affects the progression of senescence, resulting in changes in transcription of senescence-promoting genes, as well as the activity of enzymes involved in chlorophyll degradation, thereby explaining the stay-green phenotype
PERFORMANCE EVALUATION OF A STRUCTURE AND MOTION STRATEGY IN ARCHITECTURE AND CULTURAL HERITAGE
A large number of strategies and implementations of Structure from Motion (SFM) have been developed; some are being included in photogrammetric software packages. However, finding specific parameters highlighting the efficiency, the accuracy and the reliability of a SFM strategy it is difficult. While most strategies will almost always succeed in any given task (i.e. the orientation of a certain image sequence), judging how good is actually the result, is somehow still an open issue. In the first part of this paper some alternatives and parameters are presented and their pro and cons discussed, with the objective to find out whether there are alternatives to the well-established method of the check points. In the second part, the results of most of the image sequences made available by the workshop organizers, processed with the SFM approach developed by the authors, are presented; results for the sequences where external information (such as ground control points or a DTM) were available are presented in more detail
Evaluation of perioperative complications using a newly described staging system for placenta accreta spectrum
Introduction: The antenatal diagnosis of placenta accreta spectrum (PAS) is in large part subjective and based on expert interpretation. The aim of this study was to externally evaluate a recently developed staging system based on specific and defined prenatal ultrasound (US) features in a cohort of women at risk of PAS undergoing specialist prenatal US, in particular relating to surgical morbidity at delivery. Materials and methods: Database study of cases with confirmed placenta previa. In all, the placenta was evaluated in a systematic fashion. PAS was subclassified in PAS0-PAS3 according to the loss of clear zone, placental lacunae, bladder wall interruption, uterovesical hypervascularity and increased vascularity in the parametrial region. Results: 43 cases were included, of whom 33 had major placenta previa. 31 cases were categorized as PAS0; 3, 4 and 5 cases as PAS1, PAS2 and PAS3, respectively. All women underwent caesarean section and hysterectomy was required in 10. The comparison of the perinatal outcomes among the PAS categories yielded greater operative time (50 (35–129) minutes for PAS0 vs 70 (48–120) for PAS1 vs 95 (60–150) for PAS2 vs 100 (87–180) for PAS3, p < 0.001) and estimated blood loss (800 (500–2500) mls for PAS0 vs 3500 (800–7500) for PAS1 vs 2850 (500–7500) for PAS2 vs 6000 (2500–11000) for PAS3, p < 0.001) for the highest PAS categories, which were also associated with a higher rate of hysterectomy (p < 0.001), blood transfusion (p = 0.002) and admission to ITU or HDU (p < 0.001) and longer postoperative admission of 3 (1–9) days for PAS0 vs 3 (2–12) for PAS1 vs 4.5 (3–6) for PAS2 vs 5 (3–22) for PAS3, p = 0.02. Conclusion: Perioperative complications are closely associated with PAS stage. This information is useful for counselling women and may be important in allocating staff and infrastructure resources at the time of delivery
New insights into structural and functional roles of indole-3-acetic acid (IAA) : Changes in DNA topology and gene expression in bacteria
Indole-3-acetic acid (IAA) is a major plant hormone that affects many cellular processes in plants, bacteria, yeast, and human cells through still unknown mechanisms. In this study, we demonstrated that the IAA-treatment of two unrelated bacteria, the Ensifer meliloti 1021 and Escherichia coli, harboring two different host range plasmids, influences the supercoiled state of the two plasmid DNAs in vivo. Results obtained from in vitro assays show that IAA interacts with DNA, leading to DNA conformational changes commonly induced by intercalating agents. We provide evidence that IAA inhibits the activity of the type IA topoisomerase, which regulates the DNA topological state in bacteria, through the relaxation of the negative supercoiled DNA. In addition, we demonstrate that the treatment of E. meliloti cells with IAA induces the expression of some genes, including the ones related to nitrogen fixation. In contrast, these genes were significantly repressed by the treatment with novobiocin, which reduces the DNA supercoiling in bacterial cells. Taking into account the overall results reported, we hypothesize that the IAA action and the DNA structure/function might be correlated and involved in the regulation of gene expression. This work points out that checking whether IAA influences the DNA topology under physiological conditions could be a useful strategy to clarify the mechanism of action of this hormone, not only in plants but also in other unrelated organisms
Non-lethal effects of N-acetylcysteine on xylella fastidiosa strain De Donno biofilm formation and detachment
This study investigated in-vitro the non-lethal eects of N-acetylcysteine (NAC) on Xylella fastidiosa subspecies pauca strain De Donno (Xf-DD) biofilm. This strain was isolated fromthe olive trees aected by the olive quick decline syndrome in southern Italy. Xf-DD was first exposed to non-lethal concentrations of NAC from 0.05 to 1000 M. Cell surface adhesion was dramatically reduced at 500 M NAC (47%), hence, this concentration was selected for investigating the eects of pre-, postand co-treatments on biofilm physiology and structural development, oxidative homeostasis, and biofilm detachment. Even though 500 MNAC reduced bacterial attachment to surfaces, compared to the control samples, it promoted Xf-DD biofilm formation by increasing: (i) biofilm biomass by up to 78% in the co-treatment, (ii) matrix polysaccharides production by up to 72% in the pre-treatment, and (iii) reactive oxygen species levels by 3.5-fold in the co-treatment. Xf-DD biofilm detachment without and with NAC was also investigated. The NAC treatment did not increase biofilm detachment, compared to the control samples. All these findings suggested that, at 500 M, NAC diversified the phenotypes in Xf-DD biofilm, promoting biofilm formation (hyper-biofilm-forming phenotype) and discouraging biofilm detachment (hyper-attachment phenotype), while increasing oxidative stress level in the biofilm
Molecular and morphological data reveal three new cryptic species of \u3cem\u3eChiasmocleis\u3c/em\u3e (Mehely 1904) (Anura, Microhylidae) endemic to the Atlantic Forest, Brazil
Three new cryptic species of Chiasmocleis from the Atlantic Forest of Brazil are described. Two of these species occur in the northeastern states of Sergipe and Bahia, whereas the third species is found in the southeastern state of SĂŁo Paulo. The new species can be distinguished from other congeneric species by the molecular data, as evidenced in the phylogeny, and by a combination of morphological characters including: size, foot webbing, dermal spines, and coloration patterns. Chiasmocleis species differ in osteological traits, therefore we also provide an osteological description of each new species and comparisons with data reported for other species in the genus
Migrantinnen und Haushaltsdienstleistungen: Zuwanderung beeinflusst das Arbeitsangebot der einheimischen Frauen
Frauen stehen immer noch h\ue4ufig in einem Spannungsfeld zwischen Familie und Beruf. Das gilt vor allem f\ufcr Westdeutschland, wo es weniger Angebote der Kinderbetreuung gibt als in den meisten anderen europ\ue4ischen L\ue4ndern. Internationale Studien zeigen, dass Einwanderung Einfluss darauf hat, wie einheimische Frauen ihre Zeit zwischen Hausarbeit und Erwerbst\ue4tigkeit aufteilen. Die Autoren untersuchen erstmals f\ufcr Deutschland, ob und wie die Zuwanderung weiblicher Migranten das Angebot an Haushaltsdienstleistungen hierzulande ver\ue4ndert und wie sich dies auf das Erwerbsverhalten der einheimischen Frauen auswirkt
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