2,048 research outputs found
Notes on the germination of the endangered species Sclerolaena napiformis (Chenopodiaceae)
Sclerolaena napiformis is found on fertile plains in northern Victoria and southern New South Wales and is endangered Australia-wide. Introductory work on its germination shows that seeds cannot germinate until the woody fruit has broken down. The seeds tolerate a wide range of temperatures for germination, suggesting that germination occurs regardless of season if sufficient rain falls. Seed ageing effects reduce seed viability, but some seed is still viable after two years storage. Flower buds first appear 21 weeks from germination and some fruits have matured by week 29. In the field, plants die back to their taproots in late autumn and resprout in spring. Ninety percent of tagged plants were still alive two years later. The physiological seed dormancy imposed by an intact fruit wall provides a mechanism for the development of persistent soil seed banks. Work on the ecological significance of such banks is needed. The literature on interactions between Sclerolaena fruit and seed biology and ants is briefly reviewed
Evidence for uteroplacental malperfusion in fetuses with major congenital heart defects.
AIMS: Fetuses affected by congenital heart defects (CHD) are considered to be at increased risk of fetal growth restriction and intrauterine demise. Whether these risks are a direct consequence of fetal CHD or a result of associated uteroplacental dysfunction is not evident from the data of recent studies. The aim of this study was to investigate the prevalence of uteroplacental dysfunction reflected by abnormal uterine artery Doppler indices and reduced fetal growth in CHD pregnancies. METHODS: This is a retrospective case-control study including singleton pregnancies referred for detailed fetal cardiac assessment subsequently diagnosed with or without CHD. Mid-trimester uterine artery Doppler assessment at 20-24 weeks as well as third trimester fetal biometry and arterial Doppler pulsatility indices (PI) were performed. All fetal biometry were converted into centiles and Doppler values to multiples of median (MoM) to adjust for physiological changes with gestation. RESULTS: The study included 811 pregnancies including 153 cases where the fetus was diagnosed with CHD. Mid-pregnancy uterine artery PI was significantly higher in women with fetal CHD compared to controls (0.90MoM vs 0.83MoM; p = 0.006). In the third trimester, median centiles for fetal head circumference (45.4 vs 57.07; p<0.001), abdominal circumference (51.17 vs 55.71; p = 0.014), estimated fetal weight (33.6 vs 56.7; p<0.001) and cerebroplacental ratio (CPR: 0.84MoM vs 0.95MoM; p<0.001) were significantly lower in fetuses with CHD compared to controls. The percentage of small for gestational age births <10th centile (24.0% vs 10.7%; <0.001) and low CPR <0.6MoM (11.7% vs 2.5%; p<0.001) were significantly higher in the fetal CHD cohort. CONCLUSIONS: Mid-pregnancy uterine artery resistance is increased and subsequent fetal biometry reduced in pregnancies with CHD fetuses. These findings suggest that fetal CHD are associated with uteroplacental dysfunction, secondary to impaired maternal uteroplacental perfusion resulting in relative fetal hypoxaemia and reduced fetal growth
Un insediamento di età eneolitica nella Sardegna centro-occidentale: il villaggio di cultura Monte Claro nel sito di Cuccurada, Mogoro (OR)
Nel sito archeologico di Cuccurada, in comune di Mogoro, è stato posto in luce, a partire dagli anni ’90 del secolo scorso, un vasto insediamento pluristratificato che ha restituito varie fasi di occupazione preistorica e protostorica dal Neolitico Recente (cultura di Ozieri), passando dall’Eneolitico (cultura di Monte Claro) sino alle Età del Bronzo e del Ferro, con momenti di rioccupazione più tarda di epoca romana e medievale. In questo lavoro si espone in dettaglio la fase insediativa di età eneolitica, a cui sono riferibili resti monumentali e manufatti pertinenti alla cultura di Monte Claro. Si presentano inediti dati stratigrafici, materiali ceramici e spunti di analisi sulla cultura Monte Claro in questa zona della Sardegna centro-occidentale.In the archaeological site of Cuccurada, in municipality of Mogoro, the research has revealed, since the 90s of the last century, a large pluristratified settlement. Various phases of prehistoric and protohistoric occupation have been recognized, from recent Neolithic (Ozieri culture), with evidences ofCopper Age (Monte Claro culture), up to the Bronze Age and Iron Age; the site was later reoccupied in Roman and medieval age. In this work we expose in detail the settlement phase of the Copper Age, to which monumental remains and artifacts pertinent to the Monte Claro culture are referable. We present unpublished stratigraphical data, ceramic materials and new elements ofanalysis about the cultural phase ofMonte Claro in this zone ofcentral-western Sardinia
Chiral Anomalies via Classical and Quantum Functional Methods
In the quantum path integral formulation of a field theory model an anomaly
arises when the functional measure is not invariant under a symmetry
transformation of the Lagrangian. In this paper, generalizing previous work
done on the point particle, we show that even at the classical level we can
give a path integral formulation for any field theory model. Since classical
mechanics cannot be affected by anomalies, the measure of the classical path
integral of a field theory must be invariant under the symmetry. The classical
path integral measure contains the fields of the quantum one plus some extra
auxiliary ones. So, at the classical level, there must be a sort of
"cancellation" of the quantum anomaly between the original fields and the
auxiliary ones. In this paper we prove in detail how this occurs for the chiral
anomaly.Comment: 26 pages, Latex, misprint fixed, a dedication include
Metabolic interactions between vitamin A and conjugated linoleic acid
Lipid-soluble molecules share several aspects of their physiology due to their common adaptations to a hydrophilic environment, and may interact to regulate their action in a tissue-specific manner. Dietary conjugated linoleic acid (CLA) is a fatty acid with a conjugated diene structure that is found in low concentrations in ruminant products and available as a nutritional supplement. CLA has been shown to increase tissue levels of retinol (vitamin A alcohol) and its sole specific circulating carrier protein retinol-binding protein (RBP or RBP4). However, the precise mechanism of this action has not been elucidated yet. Here, we provide a summary of the current knowledge in this specific area of research and speculate that retinol and CLA may compete for catabolic pathways modulated by the activity of PPAR- and RXR heterodimer. We also present preliminary data that may position PPAR- at the crossroads between the metabolism of lipids and vitamin
Effect of Intravitreal Brolucizumab in the Treatment of Polypoidal Choroidal Vasculopathy With Foveal Lipid Exudation.
A 71-year-old woman with a history of blurred vision in her right eye for nearly two months came to our attention. A complete ophthalmological evaluation, including best-corrected visual acuity measurement, fundus examination, spectral-domain optical coherence tomography, fluorescein angiography, and indocyanine green angiography, was performed. Multimodal imaging showed the presence of a polypoidal choroidal vasculopathy (PCV) lesion surrounded by diffuse hard exudates in the macular area. Our patient received three monthly intravitreal injections of brolucizumab during the loading phase, followed by an intravitreal injection every eight weeks for a total of 48 weeks of follow-up. The therapy appeared to be effective for improving both visual and anatomical outcomes revealing an important regression of the PCV and an almost complete reabsorption of lipid exudates. Intravitreal brolucizumab could be considered an effective treatment in the management of lipid exudation in PCV patients
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