2,462 research outputs found
Non-autonomy of AGAMOUS function in flower development: use of a Cre/loxP method for mosaic analysis in Arabidopsis
Angiosperms use a multi-layered meristem (typically L1, L2 and L3) to produce primordia that then develop into plant organs, A number of experiments show that communication between the cell layers is important for normal development. We examined whether the function of the flower developmental control gene AGAMOUS involves communication across these layers. We developed a mosaic strategy using the Cre/loxP site-specific recombinase system, and identified the sector structure for mosaics that produced mutant flowers. The major conclusions were that (1) AGAMOUS must be active in the L2 for staminoid and carpelloid tissues, (2) that AGAMOUS must be active in the L2 and the L3 for floral meristem determinacy, and (3) that epidermal cell identity can be communicated by the L2 to the L1 layer
The Side Benefits Make It Worthwhile
Over the river and through the woods, to grandmother\u27s house we go... A readership survey can be like a visit to grandma\u27s
A lunar base reference mission for the phased implementation of bioregenerative life support system components
Previous design efforts of a cost effective and reliable regenerative life support system (RLSS) provided the foundation for the characterization of organisms or 'biological processors' in engineering terms and a methodology was developed for their integration into an engineered ecological LSS in order to minimize the mass flow imbalances between consumers and producers. These techniques for the design and the evaluation of bioregenerative LSS have now been integrated into a lunar base reference mission, emphasizing the phased implementation of components of such a BLSS. In parallel, a designers handbook was compiled from knowledge and experience gained during past design projects to aid in the design and planning of future space missions requiring advanced RLSS technologies. The lunar base reference mission addresses in particular the phased implementation and integration of BLS parts and includes the resulting infrastructure burdens and needs such as mass, power, volume, and structural requirements of the LSS. Also, operational aspects such as manpower requirements and the possible need and application of 'robotics' were addressed
The relevance of IL-1β and IL-1RN gene polymorphisms in the etiology of preterm delivery in the population of Polish women
Objectives: Preterm delivery (PTD) is one of the important challenges for perinatal medicine due to prematurity and associated complications. The mechanisms leading to the PTD occurrence are not fully clarified and it is assumed that PTD is a complex phenomenon caused by many different pathophysiological factors. Nowadays, an important role is attributed to genetic determinants of PTD, pointing to possible relevance of polymorphic variants of candidate genes to participate in the etiology of PTD. The aim of the study was to assess the relevance of +3953C > T IL-1β and 86 bp VNTR IL-1RN gene polymorphisms in the etiology of PTD in Polish women.Â
Material and methods: Study group consisted of 150 women (mean age 29.2 ± 5.6 years, mean weeks of gestational age 33.7 ± 2.8 gw.) with preterm delivery (22 + 0 – 36 + 6 gw.). To the control group 150 healthy pregnant women (mean age 29.0 ± 3.7 years, mean weeks of gestational age 39.3 ± 1.2 gw.) who delivered > 37 gw. were enrolled. All investigated polymorphisms were analyzed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP).Â
Results: The interesting observation was the notice of overrepresentation of 2/2 genotype of IL-1RN gene in the control group (8.0 vs. 3.3%, p = 0.06) and 2 allele in the control group (25.0 vs. 20.0%, p = 0.07).Â
Conclusions:Â
The +3953C > T polymorphism of IL-1β gene probably is not connected with the risk of preterm delivery.Â
The study results points to the possible modulating effect of mutated IL-1RN* 2 allele (86 bp VNTR polymorphism) of IL-1RN gene in decreased risk of preterm delivery.
A genetic and molecular model for flower development in Arabidopsis thaliana
Cells in developing organisms do not only differentiate, they differentiate in defined patterns. A striking example is the differentiation of flowers, which in most plant families consist of four types of organs: sepals, petals, stamens and carpels, each composed of characteristic cell types. In the families of flowering plants in which these organs occur, they are patterned with the sepals in the outermost whorl or whorls of the flower, with the petals next closest to the center, the stamens even closer to the center, and the carpels central. In each species of flowering plant the disposition and number (or range of numbers) of these organs is also specified, and the floral 'formula' is repeated in each of the flowers on each individual plant of the species. We do not know how cells in developing plants determine their position, and in response to this determination differentiate to the cell types appropriate for that position. While there have been a number of speculative proposals for the mechanism of organ specification in flowers (Goethe, 1790; Goebel, 1900; Heslop-Harrison, 1964; Green, 1988), recent genetic evidence is inconsistent with all of them, at least in the forms in which they were originally presented (Bowman et al. 1989; Meyerowitz et al. 1989). We describe here a preliminary model, based on experiments with Arabidopsis thaliana. The model is by and large consistent with existing evidence, and has predicted the results of a number of genetic and molecular experiments that have been recently performed
Non-invasive home telemonitoring in patients with decompensated heart failure: a systematic review and meta-analysis
cited By 0We planned this systematic review and meta-analysis to study an estimate of the effect of non-invasive home telemonitoring (TM) in the treatment of patients with recently decompensated heart failure (HF). A systematic literature search was conducted in the Medline, Cinahl, and Scopus databases to look for randomized controlled studies comparing TM with standard care in the treatment of patients with recently decompensated HF. The main outcomes of interest were all-cause hospitalizations and mortality. Eleven original articles met our eligibility criteria. The pooled estimate of the relative risk of all-cause hospitalization in the TM group compared with standard care was 0.95 (95% CI 0.84-1.08, P = 0.43) and the relative risk of all-cause death was 0.83 (95% CI 0.63-1.09, P = 0.17). There was significant clinical heterogeneity among primary studies. HF medication could be directly altered in three study interventions, and two of these had a statistically significant effect on all-cause hospitalizations. The pooled effect estimate of TM interventions on all-cause hospitalizations and all-cause death in patients with recently decompensated heart failure was neutral.Peer reviewe
- …