On certain surfaces in the Euclidean space E3{\mathbb{E}}^3

In the present paper we classify all surfaces in \E^3 with a canonical principal direction. Examples of these type of surfaces are constructed. We prove that the only minimal surface with a canonical principal direction in the Euclidean space ${\mathbb{E}}^3$ is the catenoid.Comment: 13 Latex page

What is the best method to calculate the solar wind propagation delay?

We present a statistical study of propagation times of solar wind discontinuities between Advanced Composition Explorer (ACE) spacecraft orbiting the L1 libration point and the Cluster quartet of spacecraft near the Earth's magnetopause. The propagation times for almost 200 events are compared with the predicted times from four different models. The simplest model assumes a constant convective motion of solar wind disturbances along the Sun-Earth line, whereas more sophisticated models take the orientation of the discontinuity as well as the real positions of the solar wind monitor and target into account. The results show that taking orientation and real position of the solar wind monitor and target into account gives a more precise time delay estimation in most cases. In particular, we show that recent modifications to the minimum variance technique can improve the estimation of propagation times of solar wind discontinuities

Upper bounds on the first eigenvalue for a diffusion operator via Bakry-\'{E}mery Ricci curvature II

Let $L=\Delta-\nabla\varphi\cdot\nabla$ be a symmetric diffusion operator with an invariant measure $d\mu=e^{-\varphi}dx$ on a complete Riemannian manifold. In this paper we prove Li-Yau gradient estimates for weighted elliptic equations on the complete manifold with $|\nabla \varphi|\leq\theta$ and $\infty$-dimensional Bakry-\'{E}mery Ricci curvature bounded below by some negative constant. Based on this, we give an upper bound on the first eigenvalue of the diffusion operator $L$ on this kind manifold, and thereby generalize a Cheng's result on the Laplacian case (Math. Z., 143 (1975) 289-297).Comment: Final version. The original proof of Theorem 2.1 using Li-Yau gradient estimate method has been moved to the appendix. The new proof is simple and direc

Immediate and short-term effects of short- and long-duration isometric contractions in patellar tendinopathy

Objectives: Isometric muscle contractions are used in the management of patellar tendinopathy to manage pain and improve function. Little is known about whether long- or short-duration contractions are optimal to improve pain. This study examined the immediate and short-term (4 weeks) effects of long- and short-duration isometric contraction on patellar tendon pain, and tendon adaptation. Design: Repeated measures within groups. Setting: Clinical primary care. Patients: Participants (n = 16, males) with patellar tendinopathy. Intervention: Short-duration (24 sets of 10 seconds) or long-duration (6 sets of 40 seconds) isometric knee extension loading (85% maximal voluntary contraction), for 4 weeks. Main Outcome Measure: Immediate change in pain with single-leg decline squat (SLDS) and hop, as well as change in pain and tendon adaptation [within-session anterior–posterior (AP) strain] were assessed over 4 weeks. Results: Pain was significantly reduced after isometric loading on both SLDS (P < 0.01) and hop tests (P < 0.01). Pain and quadriceps function improved over the 4 weeks (P < 0.05). There was significant AP strain at each measurement occasion (P < 0.01). Although transverse strain increased across the training period from ∼14% to 22%, this was not significant (P = 0.08). Conclusions: This is the first study to show that short-duration isometric contractions are as effective as longer duration contractions for relieving patellar tendon pain when total time under tension is equalized. This finding provides clinicians with greater options in prescription of isometric loading and may be particularly useful among patients who do not tolerate longer duration contractions. The trend for tendon adaptation over the short 4-week study period warrants further investigation

The Plateau de Bure Neutron Monitor: design, operation and Monte-Carlo simulation

This paper describes the Plateau de Bure Neutron Monitor (PdBNM), an instrument providing continuous ground-level measurements of atmospheric secondary neutron flux resulting from the interaction of primary cosmic rays with the Earth's atmosphere. The detector is installed on the Plateau de Bure (Devoluy mountains, south of France, latitude North 44{\deg} 38' 02", longitude East 5{\deg} 54' 26", altitude 2555 m) as a part of the ASTEP Platform (Altitude Single-event effects Test European Platform), a permanent installation dedicated to the study of the impact of terrestrial natural radiation on microelectronics circuit reliability. The present paper reports the neutron monitor design, its operation since August 2008 and its complete numerical simulation using the Monte Carlo codes GEANT4 and MCNPX. We particularly detail the computation of the neutron monitor detection response function for neutrons, muons, protons and pions, the comparison between GEANT4 and MCNPX numerical results and the evaluation of the PdBNM counting rate a function of both the nature and flux of the incident atmospheric particles.Comment: 37 pages, 14 figures, 5 tables; numerical error in GEANT4 particle sourse corrected, section 4.4 was significantly revised. Submitted to IEEE Transactions on Nuclear Scienc

A Randomized Parallel Controlled Study of the Efficacy and Safety of Lornoxicam Versus Etoricoxib after Total Knee Arthroplasty

Objectives: The aim of the study was to compare the postoperative analgesic efficacy and safety of lornoxicam versus etoricoxib for the first 48 hours after surgery. Methods: We conducted a prospective randomized controlled study on 110 patients ASAI-II scheduled for TKA under spinal anesthesia, who received either lornoxicam 8 mg PO at the end of surgery and a further 8 mg after 12 hours (Lornoxicam Group) or etoricoxib 120 mg at the end of surgery and one placebo pill after 12 hours (Etoricoxib Group). The primary outcome measure was the cumulative dose of morphine administered during the first postoperative 24 and 48 hours. Secondary outcomes were duration of analgesia and the side effects of the treatment. Results: The groups were similar in terms of demographic data. There are no significant differences between groups regarding the morphine consumption at 24 hours (36.2 ± 12 in Lornoxicam group and 34.5 ± 14.1 in Etoricoxib group) and 48 hours postoperatively (15.6 ± 12.8 in Lornoxicam group and 18 ± 12.3 in Etoricoxib group) or between the duration of analgesia (314.5 ± 70.4 in Lornoxicam group and 320.4 ± 89.2 in Etoricoxib group). Conclusion: Postoperative use of lornoxicam for 48 hours in the dose of 8 mg PO twice a day in patients undergoing TKA has an analgetic effect comparable to etoricoxib 120 mg, fewer patients experienced adverse symptoms in the etoricoxib group, but the difference was not statistically significant

Polylactic acid (PLA)/Silver-NP/VitaminE bionanocomposite electrospun nanofibers with antibacterial and antioxidant activity

Cataloged from PDF version of article.The antibacterial property of silver nanoparticles (Ag-NPs) and the antioxidant activity of Vitamin E have been combined by incorporation of these two active components within polylactic acid (PLA) nanofibers via electrospinning (PLA/Ag-NP/VitaminE nanofibers). The morphological and structural characterizations of PLA/Ag-NP/VitaminE nanofibers were performed by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy and X-ray diffraction. The average fiber diameter was 140 ± 60 nm, and the size of the Ag-NP was 2.7 ± 1.5 nm. PLA/Ag-NP/VitaminE nanofibers inhibited growth of Escherichia coli, Listeria monocytogenes and Salmonella typhymurium up to 100 %. The amount of released Ag ions from the nanofibers immersed in aqueous solution was determined by Inductively Coupled Plasma Mass Spectrometry, and it has been observed that the release of Ag ions was kept approximately constant after 10 days of immersion. The antioxidant activity of PLA/Ag-NP/VitaminE nanofibers was evaluated according to DPPH (2,2-diphenyl-1-picrylhydrazyl) method and determined as 94 %. The results of the tests on fresh apple and apple juice indicated that the PLA/Ag/VitaminE nanofiber membrane actively reduced the polyphenol oxidase activity. The multifunctional electrospun PLA nanofibers incorporating Ag-NP and Vitamin E may be quite applicable in food packaging due to the extremely large surface area of nanofibers along with antibacterial and antioxidant activities. These materials could find application in food industry as a potential preservative packaging for fruits and juices. © 2014, Springer Science+Business Media Dordrecht

Age-related differences in foot mobility in individuals with patellofemoral pain

Background Age-related changes in midfoot mobility have the potential to influence success with foot orthoses intervention in people with patellofemoral pain (PFP). The aim of this study was to determine whether older people with PFP demonstrate less foot mobility than younger adults with PFP. Methods One hundred ninety four participants (113 (58%) women, age 32 ± 7 years, BMI 25 ± 4.9 kg/m2) with PFP (≥ 6 weeks duration) were included, with foot mobility quantified using reliable and valid methods. K-means cluster analysis classified participants into three homogenous groups based on age. After cluster formation, univariate analyses of co-variance (covariates: sex, weight) were used to compare midfoot height mobility, midfoot width mobility, and foot mobility magnitude between age groups (significance level 0.05). Results Cluster analysis revealed three distinct age groups: 18–29 years (n = 70); 30–39 years (n = 101); and 40–50 years (n = 23). There was a significant main effect for age for midfoot height mobility (p  0.05). Conclusion Individuals with PFP aged 40–50 years have less foot mobility than younger adults with PFP. These findings may have implications for evaluation and treatment of older individuals with PFP