997 research outputs found
Effect of Martian Suspended Dust on Albedo Measurements from the MGS-TES Data
Suspended dust on Mars influences albedo measurements by orbiting instruments, but not necessary the real surface albedo. The aim of this study is to characterize the role of suspended aerosols on albedo measurement by remote sensing instruments
New high-performance liquid chromatography-dad method for analytical determination of arbutin and hydroquinone in rat plasma
Natural substances present in herbal preparations should be carefully used because they can give toxic or therapeutic effects despite of their amount or the way of administration. The safety of products of vegetable origin must be assessed before commercialisation by monitoring the active ingredients and their metabolites. This study was therefore designed to identify and quantify arbutin and its metabolite hydroquinone, naturally present in Arctostaphylos uva-ursi (L.) Spreng plant in rat plasma, after an acute and subacute administration of aqueous arbutin solution in Wistar rats. For this purpose a reversed-phase high-performance liquid chromatography coupled with photodiode array detection was developed to assess the pharmacokinetic of arbutin and hydroquinone in plasma of female rats treated with aqueous arbutin solutions. The detection (arbutin: 0.0617 µg/ml and hydroquinone 0.0120 µg/ml) and quantification (arbutin: 0.2060 µg/ml and hydroquinone: 0.0400 µg/ml) limits were determined. At the arbutin concentration level of 10.7 µg/ml repeatability was 13.33% and its recovery 93.4±6.93%, while at the hydroquinone concentration level of 10.6 µg/ml repeatability was 11.66% and its recovery 92.9±7.75%. Furthermore the method was fully validated and the obtained data indicate that the new method provides good performances
Osteoporosis in adult with Marfan syndrome: casuality or causality?
Nearly 100 years ago, Antoine Marfan first described a recurrent systemic disorder of connective tissue characterized by overgrowth of the long bones (1). It took an additional 50 years before ocular and cardiovascular manifestations were associated with this disorder, now termed Marfan syndrome (MFS). MFS is an inherited connective tissue disorder transmitted as an autosomal dominant trait. This relatively common genetic condition affects approximately 2 to 3 per 10,000 individuals, without a particular gender, racial, geographic, or ethnic predilection (2). The disorder results from mutations in the fibrillin-1 (FBN1) gene located on chromosome 15q21.1(3). Approximately 15% of cases occur in the absence of a family history, representing new mutations; infact to date, over 550 mutations have been identified in patients with MFS and related connective tissue diseases. However, about a half of MFS cases do not possess mutations in the FBN1 gene..
Peaceful coexistence: agile developer perspectives on software architecture.
This study aims to explore the relationship between agility and architecture by surveying 72 software
developers at IBM. Results suggest that software architecture and agility are not like oil and water. In particular,
Agile developers perceived architectures as important and supportive (rather than in contrast or neutral) to agile
values. This kind of positive perception of software architectural principles and practice bodes well for future
efforts to integrate agile and architecture practices
Sound absorption performance of sustainable foam materials: Application of analytical and numerical tools for the optimization of forecasting models
Traditional models used to predict acoustic properties of poroelastic materials are usually applied to fibrous layers or polyurethane foams. However, for new materials like complex cellular foams these procedures may not be applied due to the different cell microstructure. To this aim, the sound absorbing properties of novel sustainable foam materials are investigated as a function of the nature and loading of waste powders and their effects on the microstructure and the acoustic properties. The foams are prepared from naturally occurring alginates that are in situ polymerized. The morphology and the acoustic properties of the foam-cells appear linked to the particle size distribution of the starting powder. Determination of the parameters of Johnson\u2013Champoux\u2013Allard acoustic model (tortuosity, viscous characteristic length, thermal characteristic length, porosity and flow resistivity) was performed using five different forecasting methods, including traditional analytical model for fibrous materials as well as inverse procedure. A new procedure for tortuosity computation of foam is proposed and validated. Transfer Matrix Method calculation of the absorption coefficient was performed and compared with the experimental data, in order to assess the validity of the model. Indirect method technique is demonstrated to be dependent on experimental measurement of thermal characteristic length
Artificial Intelligence in the Water–Energy–Food Model: A Holistic Approach towards Sustainable Development Goals
This study aims to analyze the role of artificial intelligence (AI) in the Water–Energy–Food (WEF) nexus under the lens of institutional, stakeholder, and innovation theories. Specifically, this study focuses on AI as the technology adopted by companies to promote Sustainable Development Goals (SDGs). A structured literature review has been conducted on 94 articles published from 1990 to 2021 in ISI Web of Science, Scopus, and Google Scholar. This study develops an in-depth review of the literature on the main articles arguing about these issues. The findings highlight the increasing relevance of AI in the water, energy, and food industries individually considered, but the study of AI as a connector between water, energy, and food to achieve SDGs is still under investigation. Research on AI for WEF nexus management has adopted mostly a technical perspective, neglecting the relevance of management tools and the business model concept. Most of the articles did not adopt a specific theoretical lens, but scholars recognize the need to adopt a multi-stakeholder approach and the important role played by AI and other digital technologies to address the WEF nexus challenge. This study proposes an integrated approach for managing the nexus through AI technologies to meet sustainable and responsible business models. The gap between research and policy making could be filled by combining scientific data and policy needs with inclusive tools that are technically viable for sustainable resource utilization
the strange case of a patient affected by acromegaly with osteoporomalacia without hypogonadism
Acromegaly is a rare disease that, in the majority of cases, is due to the presence of a benign growth hormone (GH)- producing tumor of the pituitary. Growth hormone has profound effects on linear bone growth, bone metabolism, and bone mass. In acromegaly, the skeletal effects of chronic GH excess have been mainly addressed by evaluating bone mineral density (BMD). Most data were obtained in patients with active acromegaly, and apparently high or normal BMD was observed in the absence of hypogonadism. The Autors describe a case of patient affected by acromegaly without hypogonadism with serious osteoporosis and biological signs of osteomalacia
- …