598 research outputs found
Evidences of zooplankton vertical migration in stocked and never-stocked alpine lakes in Gran Paradiso National Park (Italy)
Abstract
Zooplankton vertical migration was described in four high altitude lakes in Gran Paradiso National Park (Northern Italy) during 2008 summertime. The authors succeeded in describing the vertical distribution of 6 species: diel vertical migrations were observed in the case of adult crustacean species (Cyclops gr. abyssorum, Arctodiaptomus alpinus and Daphnia gr. longispina), whereas the remaining rotifer species (Keratella quadrata, Polyarthra gr. dolichoptera and Synchaeta gr. stylata-pectinata) and naupliar stages of copepods did not undergo migrations. Migratory behavior of Daphnia gr. longispina and Cyclops gr. abyssorum was influenced by the size of individuals, especially larger individuals use to migrate deeper during the day compared to the smaller conspecific. This study provides new evidences of zooplankton vertical migration in never-stocked lakes and highlights the need to consider the zooplankton migration as result of multiple causal factors
Social media adoption in workplace by teams for knowledge work: Benefits, Barriers and Enabling Factors
Nowadays, business companies cannot be seen merely as a physical place where employees execute their daily functions. The progress and the development of technologies has made possible the continuous interconnection and interaction among co-workers, allowing to carry on own activities also if are not physically present. It became a key factor for companies or teams geographically separated which need to unit their efforts to achieve a shared goal. The aim of many companies and workers it is, indeed, to use these new technologies not merely to communicate with remote team members, but rather to take advantage of their tools in order to improve knowledge work in workplace day by day. Although there is a general agreement about the development in the future of these platforms, many companies and workers have still not understood completely the potential benefits. Thus, the aim of this work is to find and define a number of benefits from the organizational and collaborative point of view regarding the implementation of a social media platform within companies. Moreover, in order to make aware the subjects interested, here it is proposed also a number of challenges during their usage, that they will be faced during the implementation and the exploitation of the system. Finally, considering the bounds between knowledge sharing and enterprise social media platforms, with the willingness of people as common factors of both, will be analysed also this relationship in order to find the enabling factors for knowledge sharing which can make easier the social media adoption in teamwork and organizations
A new class of variable capacitance generators based on the dielectric fluid transducer
This paper introduces the novel concept of dielectric fluid transducer (DFT), which is an electrostatic variable capacitance transducer made by compliant electrodes, solid dielectrics and a dielectric fluid with variable volume and/or shape. The DFT can be employed in actuator mode and generator mode. In this work, DFTs are studied as electromechanical generators able to convert oscillating mechanical energy into direct current electricity. Beside illustrating the working principle of dielectric fluid generators (DFGs), we introduce different architectural implementations and provide considerations on limitations and best practices for their design. Additionally, the proposed concept is demonstrated in a preliminary experimental test campaign conducted on a first DFG prototype. During experimental tests a maximum energy per cycle of and maximum power of has been converted, with a conversion efficiency up to 30%. These figures correspond to converted energy densities of with respect to the displaced dielectric fluid and with respect to the mass of the solid dielectric. This promising performance can be largely improved through the optimization of device topology and dimensions, as well as by the adoption of more performing conductive and dielectric materials
Multivariate Analysis Applications in X-ray Diffraction
: Multivariate analysis (MA) is becoming a fundamental tool for processing in an efficient
way the large amount of data collected in X-ray diffraction experiments. Multi-wedge data
collections can increase the data quality in case of tiny protein crystals; in situ or operando setups
allow investigating changes on powder samples occurring during repeated fast measurements;
pump and probe experiments at X-ray free-electron laser (XFEL) sources supply structural
characterization of fast photo-excitation processes. In all these cases, MA can facilitate the extraction
of relevant information hidden in data, disclosing the possibility of automatic data processing even
in absence of a priori structural knowledge. MA methods recently used in the field of X-ray
diffraction are here reviewed and described, giving hints about theoretical background and possible
applications. The use of MA in the framework of the modulated enhanced diffraction technique is
described in detail
Ultrascan solution modeler: integrated hydrodynamic parameter and small angle scattering computation and fitting tools
This is a preprint of a paper in the proceedings of the XSEDE12 conference, held July 16-19, 2012 in Chicago, IL. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.UltraScan Solution Modeler (US-SOMO) processes atomic and lower-resolution bead model representations of biological and other macromolecules to compute various hydrodynamic parameters, such as the sedimentation and diffusion coefficients, relaxation times and intrinsic viscosity, and small angle scattering curves, that contribute to our understanding of molecular structure in solution. Knowledge of biological macromolecules' structure aids researchers in understanding their function as a path to disease prevention and therapeutics for conditions such as cancer, thrombosis, Alzheimer's disease and others. US-SOMO provides a convergence of experimental, computational, and modeling techniques, in which detailed molecular structure and properties are determined from data obtained in a range of experimental techniques that, by themselves, give incomplete information. Our goal in this work is to develop the infrastructure and user interfaces that will enable a wide range of scientists to carry out complicated experimental data analysis techniques on XSEDE. Our user community predominantly consists of biophysics and structural biology researchers. A recent search on PubMed reports 9,205 papers in the decade referencing the techniques we support. We believe our software will provide these researchers a convenient and unique framework to refine structures, thus advancing their research.
The computed hydrodynamic parameters and scattering curves are screened against experimental data, effectively pruning potential structures into equivalence classes. Experimental methods may include analytical ultracentrifugation, dynamic light scattering, small angle X-ray and neutron scattering, NMR, fluorescence spectroscopy, and others. One source of macromolecular models is X-ray crystallography. However, the conformation in solution may not match that observed in the crystal form. Using computational techniques, an initial fixed model can be expanded into a search space utilizing high temperature molecular dynamic approaches or stochastic methods such as Brownian dynamics. The number of structures produced can vary greatly, ranging from hundreds to tens of thousands or more. This introduces a number of cyberinfrastructure challenges. Computing hydrodynamic parameters and small angle scattering curves can be computationally intensive for each structure, and therefore cluster compute resources are essential for timely results. Input and output data sizes can vary greatly from less than 1 MB to 2 GB or more. Although the parallelization is trivial, along with data size variability there is a large range of compute sizes, ranging from one to potentially thousands of cores with compute time of minutes to hours.
In addition to the distributed computing infrastructure challenges, an important concern was how to allow a user to conveniently submit, monitor and retrieve results from within the C++/Qt GUI application while maintaining a method for authentication, approval and registered publication usage throttling. Middleware supporting these design goals has been integrated into the application with assistance from the Open Gateway Computing Environments (OGCE) collaboration team. The approach was tested on various XSEDE clusters and local compute resources. This paper reviews current US-SOMO functionality and implementation with a focus on the newly deployed cluster integration.This work was supported by NIH grant K25GM090154 to EB, NSF grant OCI-1032742 to MP, NSF grant TG-MCB070040N to BD, and NIH grant RR-022200 to B
Corrigendum to ‘Biomolecular and clinical practice in malignant pleural mesothelioma and lung cancer: what thoracic surgeons should know'
Biomolecular and clinical practice in malignant pleural mesothelioma and lung cancer: what thoracic surgeons should knowâ€
Today, molecular-profile-directed therapy is a guiding principle of modern thoracic oncology. The knowledge of new biomolecular technology applied to the diagnosis, prognosis, and treatment of lung cancer and mesothelioma should be part of the 21st century thoracic surgeons' professional competence. The European Society of Thoracic Surgeons (ESTS) Biology Club aims at providing a comprehensive insight into the basic biology of the diseases we are treating. During the 2013 ESTS Annual Meeting, different experts of the field presented the current knowledge about diagnostic and prognostic biomarkers in malignant pleural mesothelioma including new perspectives as well as the role and potential application of microRNA and genomic sequencing for lung cancer, which are summarized in the present articl
Single-Dose Intra-Articular Administration of a Hybrid Cooperative Complex of Sodium Hyaluronate and Sodium Chondroitin in the Treatment of Symptomatic Hip Osteoarthritis: A Single-Arm, Open-Label, Pilot Study
INTRODUCTION: Intra-articular (i.a.) hyaluronic acid is an accepted conservative therapy for knee osteoarthritis (OA). This study evaluated the safety and efficacy of a single i.a. injection of an innovative formulation of sodium hyaluronate 2.4% plus sodium chondroitin non-sulphated 1.6% of biotechnological origin (HA-SC) for the treatment of patients with radiographically confirmed symptomatic hip OA and moderate-to-severe pain.METHODS: In this prospective, multicenter, open-label, pilot study, HA-SC was administered using a standard ultrasound-guided procedure. Adverse events, global/local evaluation of tolerability, and use of rescue analgesics were recorded. Efficacy endpoints included visual analogue scale (VAS) measurement of hip pain, changes in Lequesne's algofunctional Index, and assessment of global status.RESULTS: Treatment was well tolerated; adverse device events of moderate-to-severe intensity, most commonly, injection site pain/localized arthralgia occurred in 20.8% of subjects. Global evaluation of tolerability was rated as excellent or good (75.0%), fair (16.7%), and poor (8.3%) by subjects and 77.1, 14.6, and 8.3%, respectively, by investigators. There was a rapid and significant decrease in hip pain after a single injection; VAS pain score decreased from a mean of 67.5mm at baseline to 29.3mm by day 7, with the effects sustained during 6months of follow-up (P<0.0001). There were significant improvements in Lequesne's Index for hip OA total scores at all time points during follow-up (P<0.0001). The majority of subjects reported 'Very much improved' or 'Slightly improved' global improvement at any time point. Use of rescue paracetamol was generally low.CONCLUSIONS: A single i.a. injection of an innovative HA-SC formulation was well tolerated, safe, and effective in the treatment of symptomatic hip OA
Do I Need to Operate on That in the Middle of the Night? Development of a Nomogram for the Diagnosis of Severe Acute Cholecystitis
Background Some authors have proposed different predictive factors of severe acute cholecystitis, but generally, the
results of risk analyses are expressed as odds ratios, which makes it difficult to apply in the clinical practice of the
acute care surgeon. The severe form of acute cholecystitis should include both gangrenous and phlegmonous
cholecystitis, due to their severe clinical course, and cholecystectomy should not be delayed. The aim of this study
was to create a nomogram to obtain a graphical tool to compute the probability of having a severe acute
cholecystitis.
Methods This is a retrospective study on 393 patients who underwent emergency cholecystectomy between January
2010 and December 2015 at the Acute Care Surgery Service of the S. Anna University Hospital of Ferrara, Italy.
Patients were classified as having a non-severe acute cholecystitis or a severe acute cholecystitis (i.e., gangrenous
and phlegmonous) based on the final pathology report. The baseline characteristics, pre-operative signs, and abdominal
ultrasound (US) findings were assessed with a stepwise multivariate logistic regression analysis to predict the
risk of severe acute cholecystitis, and a nomogram was created.
Results Age as a continuous variable, WBC count ≥ 12.4 × 103/μl, CRP ≥9.9 mg/dl, and presence of US thickening
of the gallbladder wall were significantly associated with severe acute cholecystitis at final pathology report. A
significant interaction between the effect of age and CRP was found. Four risk classes were identified based on the
nomogram total points.
Conclusions Patients with a nomogram total point ≥ 74 should be considered at high risk of severe acute cholecystitis (at 74 total
point, sensitivity = 78.5%; specificity = 78.2%; accuracy = 78.3%) and this finding could be useful for surgical planning once
confirmed in a prospective study comparing the risk score stratification and clinical outcomes
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