26,971 research outputs found

    Using ultra-short pulses to determine particle size and density distributions

    Get PDF
    We analyze the time dependent response of strongly scattering media (SSM) to ultra-short pulses of light. A random walk technique is used to model the optical scattering of ultra-short pulses of light propagating through media with random shapes and various packing densities. The pulse spreading was found to be strongly dependent on the average particle size, particle size distribution, and the packing fraction. We also show that the intensity as a function of time-delay can be used to analyze the particle size distribution and packing fraction of an optically thick sample independently of the presence of absorption features. Finally, we propose an all new way to measure the shape of ultra-short pulses that have propagated through a SSM.Comment: 15 pages, 29 figures, accepted for publication in Optics Express will update with full reference when it is availabl

    Bridging the distance:Continuing psycho‐oncological care via video‐consults during the COVID‐19 pandemic

    Get PDF
    Key points: Video‐consults feel distant; patients and therapists miss the non‐verbal contact. Non‐verbal contact during face‐to‐face sessions helps clients to express what is most difficult for them. Video‐consults are a good alternative when face‐to‐face psycho‐oncological care is too burdensome for patients. Therapists preferably would continue with video consults for a mean of 28% of their time. Tips are provided to improve care through video‐consults

    Loneliness and belonging:Exploring experiences with the COVID-19 pandemic in psycho-oncology

    Get PDF
    Keypoints Patients (45.5% of n = 233) and family members (41.5% of n = 41) experience more peace, as lockdown slowed down the pace of life. Some patients described feeling part of society again as everyone is advised to stay home. Patients worry about getting infected (50.5%) and needing treatment on the intensive care unit (58%). Family members mainly worry about infecting the patient (65.9%). Patients (36.3%) and their family (41.4%) feel lonelier because of lockdown regulations

    Personalizing psychological care for chronic cancer-related fatigue:A case study on symptom dynamics

    Get PDF
    Approximately 25% of cancer patients suffer from chronic cancer-related fatigue (CCRF), which is a complex, multifactorial condition. While there are evidence-based interventions, it remains unclear what treatment works best for the individual patient. Psychological network models can offer a schematic representation of interrelations among fatigue and protective and perpetuating factors for the individual patient. We explored whether feedback based on these individual fatigue networks can help personalize psychological care for CCRF. A 34-year old woman with CCRF was referred to our mental healthcare institute for psycho-oncology. During the waitlist period, she filled out an experience sampling app for 101 days, including five daily assessments of fatigue, pain, mood, activity and fatigue coping. The interplay between items was visualized in network graphs at the moment-level and day-level, which were discussed with the patient. For example, acceptance of fatigue in the past three hours was associated with less hopelessness and less fatigue in the following moment. At the day-level, acceptance was also being associated with less fatigue, less hopelessness, a better mood, and more motivation to do things. The patient recognized these patterns and explained how unexpected waves of fatigue can make her feel hopeless. This started a dialogue on how cultivating acceptance could potentially help her handle the fatigue. The patient would discuss this with her therapist. Feedback based on individual fatigue networks can provide direct insight into how one copes with CCRF and subsequently offer directions for treatment. Further research is needed in order to implement this in clinical practice

    Verontreiniging rode aal Nederlandse binnenwateren : monitoring voor sportvisserij 2004-2008

    Get PDF
    Rode aal, ook bekend als Europese paling (Anguilla anguilla) werd gebruikt als bioindicator binnen het monitoringsprogramma 'verontreiniging in vis uit de Nederlandse binnenwateren'. In de afgelopen 5 jaar zijn 65 mengmonsters rode aal met een lengte van 30-40 cm onderzocht op de aanwezigheid van dioxines en dioxineachtige PCB's. Deze alen zijn afkomstig van 38 locaties uit de nederlandse binnenwateren. In 54% van de onderzochte alen zijn normoverschrijdende gehaltes dioxines en / of dioxine-achtige PCB's aangetoond. Aal uit de Roer, Dordsche Biesbosch, Amer, Hollands Diep en verschillende locaties in de grote rivieren is sterk vervuild. In 2007 werd specifiek gekeken naar 40 individuele schieralen gevangen in het Haringvliet. In dit stadium trekt deze relatief oude aal naar zee om zich voort te planten in de Sagossozee

    A gain-coefficient switched Alexandrite laser

    Get PDF
    We report on a gain-coefficient switched Alexandrite laser. An electro-optic modulator is used to switch between high and low gain states by making use of the polarization dependent gain of Alexandrite. In gain-coefficient switched mode, the laser produces 85 ns pulses with a pulse energy of 240 mJ at a repetition rate of 5 Hz.Comment: 8 pages, 5 figure

    Condensation phase transitions of symmetric conserved-mass aggregation model on complex networks

    Full text link
    We investigate condensation phase transitions of symmetric conserved-mass aggregation (SCA) model on random networks (RNs) and scale-free networks (SFNs) with degree distribution P(k)kγP(k) \sim k^{-\gamma}. In SCA model, masses diffuse with unite rate, and unit mass chips off from mass with rate ω\omega. The dynamics conserves total mass density ρ\rho. In the steady state, on RNs and SFNs with γ>3\gamma>3 for ω\omega \neq \infty, we numerically show that SCA model undergoes the same type condensation transitions as those on regular lattices. However the critical line ρc(ω)\rho_c (\omega) depends on network structures. On SFNs with γ3\gamma \leq 3, the fluid phase of exponential mass distribution completely disappears and no phase transitions occurs. Instead, the condensation with exponentially decaying background mass distribution always takes place for any non-zero density. For the existence of the condensed phase for γ3\gamma \leq 3 at the zero density limit, we investigate one lamb-lion problem on RNs and SFNs. We numerically show that a lamb survives indefinitely with finite survival probability on RNs and SFNs with γ>3\gamma >3, and dies out exponentially on SFNs with γ3\gamma \leq 3. The finite life time of a lamb on SFNs with γ3\gamma \leq 3 ensures the existence of the condensation at the zero density limit on SFNs with γ3\gamma \leq 3 at which direct numerical simulations are practically impossible. At ω=\omega = \infty, we numerically confirm that complete condensation takes place for any ρ>0\rho > 0 on RNs. Together with the recent study on SFNs, the complete condensation always occurs on both RNs and SFNs in zero range process with constant hopping rate.Comment: 6 pages, 6 figure

    Variation in sequence and location of the fumonisin mycotoxin niosynthetic gene cluster in Fusarium

    Get PDF
    In Fusarium, the ability to produce fumonisins is governed by a 17-gene fumonisin biosynthetic gene (FUM) cluster. Here, we examined the cluster in F. oxysporum strain O-1890 and nine other species selected to represent a wide range of the genetic diversity within the GFSC

    Superfluid-insulator transition of the Josephson junction array model with commensurate frustration

    Full text link
    We have studied the rationally frustrated Josephson-junction array model in the square lattice through Monte Carlo simulations of (2+1)(2+1)D XY-model. For frustration f=1/4f=1/4, the model at zero temperature shows a continuous superfluid-insulator transition. From the measurement of the correlation function and the superfluid stiffness, we obtain the dynamical critical exponent z=1.0z=1.0 and the correlation length critical exponent ν=0.4±0.05\nu=0.4 \pm 0.05. While the dynamical critical exponent is the same as that for cases f=0f=0, 1/2, and 1/3, the correlation length critical exponent is surprisingly quite different. When f=1/5f=1/5, we have the nature of a first-order transition.Comment: RevTex 4, to appear in PR
    corecore