329 research outputs found
Collective Effects in Models for Interacting Molecular Motors and Motor-Microtubule Mixtures
Three problems in the statistical mechanics of models for an assembly of
molecular motors interacting with cytoskeletal filaments are reviewed. First, a
description of the hydrodynamical behaviour of density-density correlations in
fluctuating ratchet models for interacting molecular motors is outlined.
Numerical evidence indicates that the scaling properties of dynamical behavior
in such models belong to the KPZ universality class. Second, the generalization
of such models to include boundary injection and removal of motors is provided.
In common with known results for the asymmetric exclusion processes,
simulations indicate that such models exhibit sharp boundary driven phase
transitions in the thermodynamic limit. In the third part of this paper, recent
progress towards a continuum description of pattern formation in mixtures of
motors and microtubules is described, and a non-equilibrium ``phase-diagram''
for such systems discussed.Comment: Proc. Int. Workshop on "Common Trends in Traffic Systems", Kanpur,
India, Feb 2006; to be published in Physica
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The first antenatal appointment: An exploratory study of the experiences of women with a diagnosis of mental illness
Objective
to explore and gain insight into the expectations and experiences of women with a pre-existing diagnosis of mental illness, of their first booking appointment; to make recommendations for practice development and collaborative partnership working between healthcare professionals.
Design
a qualitative design using semi structured interviews and thematic analysis of the data. QSR NVivo 10 software is used to organise the data into themes.
Setting
the interviews took place either at the women׳s homes, or within the antenatal service with the consent of the woman and relevant practitioners.
Participants
twelve participants were selected from one antenatal clinic and one perinatal mental health service.
Findings
the themes identified within the data included the lack of information prior to the initial midwife booking appointment; the perception of too much information at the initial booking appointment and women not being clear about their mental health needs at this time; a general positivity about disclosing mental illness diagnoses; overall positive thoughts about midwives although some midwives appeared less knowledgeable about bipolar disorder, and perceptions about a lack of joined up working between antenatal and perinatal mental health services.
Key conclusions and implications for practice
it is recommended that GPs receive adequate training in order to equip them with the skills needed to discuss sensitive issues around perinatal mental illness and the impact on pregnancy and childbirth. Women require more information about their booking appointment, and it would be beneficial for their emotional and physical health needs to be assessed at each follow-up antenatal appointment. Midwives need to be facilitated to receive up-to-date knowledge of antenatal and postnatal mental illness and treatments, and the referral process to perinatal mental health services
Hydrellia lagarosiphon Deeming (Diptera: Ephydridae), a potential biological control agent for the submerged aquatic weed, Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae)
The leaf-mining fly, Hydrellia lagarosiphon Deeming (Diptera: Ephydridae), was investigated in its native range in South Africa, to determine its potential as a biological control agent for Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae), an invasive submerged macrophyte that is weedy in many parts of the world. The fly was found throughout the indigenous range of the plant in South Africa. High larval abundance was recorded at field sites with nearly all L. major shoots sampled ontaining larvae, with densities of up to 10 larvae per shoot. Adults laid batches of up to 15 eggs, usually on the abaxial sides of L. major leaves. The larvae mined internally, leaving the epidermal tissues of the upper and lower leaves intact. The larvae underwent three instars which took an average of 24 days and pupated within the leaf tissue, from which the adults emerged. Impact studies in the laboratory showed that H. lagarosiphon larval feeding significantly restricted the formation of L. major side branches. Based on its biology and damage caused to the plant, Hydrellia lagarosiphon could be considered as a useful biological control candidate for L. major in countries where the plant is invasive
Reaction Diffusion Models in One Dimension with Disorder
We study a large class of 1D reaction diffusion models with quenched disorder
using a real space renormalization group method (RSRG) which yields exact
results at large time. Particles (e.g. of several species) undergo diffusion
with random local bias (Sinai model) and react upon meeting. We obtain the
large time decay of the density of each specie, their associated universal
amplitudes, and the spatial distribution of particles. We also derive the
spectrum of exponents which characterize the convergence towards the asymptotic
states. For reactions with several asymptotic states, we analyze the dynamical
phase diagram and obtain the critical exponents at the transitions. We also
study persistence properties for single particles and for patterns. We compute
the decay exponents for the probability of no crossing of a given point by,
respectively, the single particle trajectories () or the thermally
averaged packets (). The generalized persistence exponents
associated to n crossings are also obtained. Specifying to the process or A with probabilities , we compute exactly the exponents
and characterizing the survival up to time t of a domain
without any merging or with mergings respectively, and and
characterizing the survival up to time t of a particle A without
any coalescence or with coalescences respectively.
obey hypergeometric equations and are numerically surprisingly close to pure
system exponents (though associated to a completely different diffusion
length). Additional disorder in the reaction rates, as well as some open
questions, are also discussed.Comment: 54 pages, Late
IgA and IgM protein primarily drive plasma coronaâ induced adhesion reduction of PLGA nanoparticles in human blood flow
The high abundance of immunoglobulins (Igs) in the plasma protein corona on poly(lacticâ coâ glycolic) acid (PLGA)â based vascularâ targeted carriers (VTCs) has previously been shown to reduce their adhesion to activated endothelial cells (aECs) in human blood flow. However, the relative role of individual Ig classes (e.g., IgG, IgA, and IgM) in causing adhesion reduction remains largely unknown. Here, we characterized the influence of specific Ig classes in prescribing the binding efficiency of PLGA nanoâ sized VTCs in blood flow. Specifically, we evaluated the flow adhesion to aECs of PLGA VTCs with systematic depletion of various Igs in their corona. Adhesion reduction was largely eliminated for PLGA VTCs when all Igs were removed from the corona. Furthermore, reâ addition of IgA or IgM to the Igsâ depleted corona reinstated the low adhesion of PLGA VTCs, as evidenced by â ¼40â 70% reduction relative to particles with an Igsâ deficient corona. However, reâ addition of a high concentration of IgG to the Igsâ depleted corona did not cause significant adhesion reduction. Overall, the presented results reveal that PLGA VTC adhesion reduction in blood flows is primarily driven by high adsorption of IgA and IgM in the particle corona. Preâ coating of albumin on PLGA VTCs mitigated the extent of adhesion reduction in plasma for some donors but was largely ineffective in general. Overall, this work may shed light into effective control of protein corona composition, thereby enhancing VTC functionality in vivo for eventual clinical use.The high abundance of immunoglobulins (Igs) in the plasma protein corona formed on vascularâ targeted carriers (VTCs) has previously been shown to reduce their adhesion to activated endothelial cells. Here, we report that high adsorption of IgA and IgM, and not IgG, primarily drives VTC adhesion reduction in human blood flows.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137722/1/btm210064_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137722/2/btm210064.pd
Nivolumab versus Everolimus in Advanced Renal-Cell Carcinoma
This randomised phase III trial compared standard of care Everolimus with the anti-PD1 monoclonal antibody Nivolumab in previously treated patients with locally advanced inoperable or metastatic clear cell renal cancer. 810 patients were randomised to receive either Everolimus 10 mg orally daily or 3 mg/kg of Nivolumab intravenously every two weeks. Patients were treated until unacceptable toxicity or disease progression. Patients could be treated beyond progression if the investigator believed that the patient was gaining clinical benefit. The primary endpoint was overall survival. The median survival was 25 months for Nivolumab and 19.8 months for Everolimus (p=0.002). The objective response rate was higher for Nivolumab (25 versus 5%; p=<0.001).The median progression free survivals were 4.6 & 4.4 months (p=0.11). Grade 3 & 4 treatment related toxicities were observed in 19 & 37% of patients on Nivolumab or Everolimus respectively. In patients with previously treated renal cell carcinoma Nivolumab produced superior survival and more tolerable treatment than Everolimus
History, Commemoration, and Belief: Abraham Lincoln in American Memory, 1945-2001
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91765/1/Schuman-History_Commemoration_Belief.pd
First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data
Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of
continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a
fully coherent search, based on matched filtering, which uses the position and rotational parameters
obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto-
noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch
between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have
been developed, allowing a fully coherent search for gravitational waves from known pulsars over a
fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of
11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial
outliers, further studies show no significant evidence for the presence of a gravitational wave signal.
Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of
the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for
the first time. For an additional 3 targets, the median upper limit across the search bands is below the
spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried
out so far
Expanding understanding of service exchange and value co-creation: A social construction approach
According to service-dominant logic (S-D logic), all providers are service providers, and service is the fundamental basis of exchange. Value is co-created with customers and assessed on the basis of value-in-context. However, the extensive literature on S-D logic could benefit from paying explicit attention to the fact that both service exchange and value co-creation are influenced by social forces. The aim of this study is to expand understanding of service exchange and value co-creation by complementing these central aspects of S-D logic with key concepts from social construction theories (social structures, social systems, roles, positions, interactions, and reproduction of social structures). The study develops and describes a new framework for understanding how the concepts of service exchange and value co-creation are affected by recognizing that they are embedded in social systems. The study contends that value should be understood as value-in-social-context and that value is a social construction. Value co-creation is shaped by social forces, is reproduced in social structures, and can be asymmetric for the actors involved. Service exchanges are dynamic, and actors learn and change their roles within dynamic service systems
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