533 research outputs found
Expert Concept-Modeling Ground Truth Construction for Word Embeddings Evaluation in Concept-Focused Domains
Zwammerdam on the Rhine: the contribution of archaeozoological research to the current knowledge of Roman Nigrum Pullum
The Dutch Roman frontier is known for providing a great deal of archaeozoological research, but the real potential has not been reached yet as there are data from many excavated sites that have still not been analysed in detail or are ́buried́ as grey literature. The research project Romeinse vicus aan de Rijn aims at filling this gap through the study and publication of Roman military vici along the Dutch part of the Rhine to better understand the development and significance of these key locations. Within this frame, archaeozoological remains from various sites are being re-analysed in order to reinforce the knowledge of economic and cultural patterns, to better understand supply networks and to study how these activities shaped the surrounding environment and impacted the landscape.One of the studied sites is the Roman fort and vicus of Zwammerdam-Nigrum Pullum, located on the Rhine in the West Netherlands. Archaeozoological remains were collected during excavations in 1968–1971 and in 2003–2004, but some of the material was not studied, and a thorough synthesis was still missing. Because of this, certain aspects within this Roman settlement remain poorly analysed.With a thorough analysis of the archaeozoological remains from both excavations at Zwammerdam, integrated with contextual and chronological data, this study brings forward new archaeozoological information for this Roman settlement. The new data not only make it possible to compare animal exploitation in the vicus with that of the fort, but it also provides an opportunity to analyse these patterns throughout time both locally and regionally. While limited to a small area in the Roman Empire, the data from Zwammerdam can provide a further step for new, broader archaeozoological research towards the role of animals in the Roman culture and economy.Bioarchaeolog
The development and validation of a five-factor model of Sources of Self-Efficacy in clinical nursing education
Background: The aim of this study is to validate a newly developed nurses' self-efficacy sources inventory. We test the validity of a five-dimensional model of sources of self-efficacy, which we contrast with the traditional four-dimensional model based on Bandura’s theoretical concepts.Methods: Confirmatory factor analysis was used in the development of the newly developed self-efficacy measure. Model fit was evaluated based upon commonly recommended goodness-of-fit indices, including the χ2 of the model fit, the Root Mean Square Error of approximation (RMSEA), the Tucker-Lewis Index (TLI), the Standardized Root Mean Square Residual (SRMR), and the Bayesian Information Criterion (BIC).Results: All 22 items of the newly developed five-factor sources of self-efficacy have high factor loadings (range .40-.80). Structural equation modeling showed that a five-factor model is favoured over the four-factor model.Conclusions and implications: Results of this study show that differentiation of the vicarious experience source into a peer- and expert based source reflects better how nursing students develop self-efficacy beliefs. This has implications for clinical learning environments: a better and differentiated use of self-efficacy sources can stimulate the professional development of nursing students
Transfer of Communication Skills to the Workplace during Clinical Rounds : Impact of a Program for Residents
peer reviewe
Comparative effects of helium-oxygen and external positive end-expiratory pressure on respiratory mechanics, gas exchange, and ventilation-perfusion relationships in mechanically ventilated patients with chronic obstructive pulmonary disease
Objective: To compare the effects of He/O2 and external PEEP (PEEPe) on intrinsic PEEP (PEEPi), respiratory mechanics, gas exchange, and ventilation/perfusion (V̇A/Q̇) in mechanically ventilated COPD patients. Design and setting: Prospective, interventional study in the intensive care unit of a university hospital. Interventions: Ten intubated, sedated, paralyzed, mechanically ventilated COPD patients studied in the following conditions: (a) baseline settings made by clinician in charge, air/O2, ZEEP; (b) He/O2, ZEEP; (c) air/O2, ZEEP; (d) air/O2, PEEPe 80% of PEEPi. Measurements at each condition included V̇A/Q̇ by the multiple inert gas elimination technique (MIGET). Results: PEEPi and trapped gas volume were comparably reduced by He/O2 (4.2±4 vs. 7.7±4cmH2O and 98±82 vs. 217±124ml, respectively) and PEEPe (4.4±1.3 vs. 7.8±3.6cmH2O and 120±107 vs. 216±115ml, respectively). He/O2 reduced inspiratory and expiratory respiratory system resistance (15.5±4.4 vs. 20.7±6.9 and 19±9 vs. 28.8±15cmH2Ol−1s−1, respectively) and plateau pressure (13±4 vs. 17±6cmH2O). PEEPe increased airway pressures, including total PEEP, and elastance. PaO2/FIO2 was slightly reduced by He/O2 (225±83 vs. 245±82) without significant V̇A/Q̇ change. Conclusions: He/O2 and PEEPe comparably reduced PEEPi and trapped gas volume. However, He/O2 decreased airway resistance and intrathoracic pressures, at a small cost in arterial oxygenation. He/O2 could offer an attractive option in COPD patients with PEEPi/dynamic hyperinflatio
Mycolactone as Analgesic: Subcutaneous Bioavailability Parameters
is the bacillus responsible for Buruli ulcer, an infectious disease and the third most important mycobacterial disease worldwide, after tuberculosis and leprosy. infection is a type of panniculitis beginning mostly with a nodule or an oedema, which can progress to large ulcerative lesions. The lesions are caused by mycolactone, the polyketide toxin of . Mycolactone plays a central role for host colonization as it has immunomodulatory and analgesic effects. On one hand, mycolactone induces analgesia by targeting type-2 angiotensin II receptors (ATR), causing cellular hyperpolarization and neuron desensitization. Indeed, a single subcutaneous injection of mycolactone into the mouse footpad induces a long-lasting hypoesthesia up to 48 h. It was suggested that the long-lasting hypoesthesia may result from the persistence of a significant amount of mycolactone locally following its injection, which could be probably due to its slow elimination from tissues. To verify this hypothesis, we investigated the correlation between hypoesthesia and mycolactone bioavailability directly at the tissue level. Various quantities of mycolactone were then injected in mouse tissue and hypoesthesia was recorded with nociception assays over a period of 48 h. The hypoesthesia was maximal 6 h after the injection of 4 μg mycolactone. The basal state was reached 48 h after injection, which demonstrated the absence of nerve damage. Surprisingly, mycolactone levels decreased strongly during the first hours with a reduction of 70 and 90% after 4 and 10 h, respectively. Also, mycolactone did not diffuse in neighboring skin tissue and only poorly into the bloodstream upon direct injection. Nevertheless, the remaining amount was sufficient to induce hypoesthesia during 24 h. Our results thus demonstrate that intact mycolactone is rapidly eliminated and that very small amounts of mycolactone are sufficient to induce hypoesthesia. Taken together, our study points out that mycolactone ought to be considered as a promising analgesic
Direct measurements of the effects of salt and surfactant on interaction forces between colloidal particles at water-oil interfaces
The forces between colloidal particles at a decane-water interface, in the
presence of low concentrations of a monovalent salt (NaCl) and of the
surfactant sodium dodecylsulfate (SDS) in the aqueous subphase, have been
studied using laser tweezers. In the absence of electrolyte and surfactant,
particle interactions exhibit a long-range repulsion, yet the variation of the
interaction for different particle pairs is found to be considerable. Averaging
over several particle pairs was hence found to be necessary to obtain reliable
assessment of the effects of salt and surfactant. It has previously been
suggested that the repulsion is consistent with electrostatic interactions
between a small number of dissociated charges in the oil phase, leading to a
decay with distance to the power -4 and an absence of any effect of electrolyte
concentration. However, the present work demonstrates that increasing the
electrolyte concentration does yield, on average, a reduction of the magnitude
of the interaction force with electrolyte concentration. This implies that
charges on the water side also contribute significantly to the electrostatic
interactions. An increase in the concentration of SDS leads to a similar
decrease of the interaction force. Moreover the repulsion at fixed SDS
concentrations decreases over longer times. Finally, measurements of three-body
interactions provide insight into the anisotropic nature of the interactions.
The unique time-dependent and anisotropic interactions between particles at the
oil-water interface allow tailoring of the aggregation kinetics and structure
of the suspension structure.Comment: Submitted to Langmui
A Review of Broadband Low-Cost and High-Gain Low-Terahertz Antennas for Wireless Communications Applications
Low-terahertz (Low-THz, 100 GHz-1.0 THz) technology is expected to provide unprecedented data rates in future generations of wireless system such as the 6th generation (6G) mobile communication system. Increasing the carrier frequencies from millimeter wave to THz is a potential solution to guarantee the transmission rate and channel capacity. Due to the large transmission loss of Low-THz wave in free space, it is particularly urgent to design high-gain antennas to compensate the additional path loss, and to overcome the power limitation of Low-THz source. Recently, with the continuous updating and progress of additive manufacturing (AM) and 3D printing (3DP) technology, antennas with complicated structures can now be easily manufactured with high precision and low cost. In the first part, this paper demonstrates different approaches of recent development on wideband and high gain sub-millimeter-wave and Low-THz antennas as well as their fabrication technologies. In addition, the performances of the state-of-the-art wideband and high-gain antennas are presented. A comparison among these reported antennas is summarized and discussed. In the second part, one case study of a broadband high-gain antenna at 300 GHz is introduced, which is an all-metal model based on the Fabry-Perot cavity (FPC) theory. The proposed FPC antenna is very suitable for manufacturing using AM technology, which provides a low-cost, reliable solution for emerging THz applications
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