547 research outputs found
Environmental Flow Regimes for Dysidea avara Sponges
The aim of our research is to design tank systems to culture Dysidea avara for the production of avarol. Flow information was needed to design culture tanks suitable for effective production. Water flow regimes were characterized over a 1-year period for a shallow rocky sublittoral environment in the Northwestern Mediterranean where D. avara sponges are particularly abundant. Three-dimensional Doppler current velocities at 8¿10-m depths ranged from 5 to 15 cm/s over most seasons, occasionally spiking to 30¿66 cm/s. A thermistor flow sensor was used to map flow fields in close proximity (¿2 cm) to individual sponges at 4.5-, 8.8-, and 14.3-m depths. These ¿proximal flows¿ averaged 1.6 cm/s in calm seas and 5.9 cm/s during a storm, when the highest proximal flow (32.9 cm/s) was recorded next to a sponge at the shallowest station. Proximal flows diminished exponentially with depth, averaging 2.6 cm/s¿±¿0.15 SE over the entire study. Flow visualization studies showed that oscillatory flow (0.20¿0.33 Hz) was the most common regime around individual sponges. Sponges at the 4.5-m site maintained a compact morphology with large oscula year-around despite only seasonally high flows. Sponges at 8.8 m were more erect with large oscula on tall protuberances. At the lowest-flow 14.3-m site, sponges were more branched and heavily conulated, with small oscula. The relationship between sponge morphology and ambient flow regime is discussed
Backward Evolving Quantum States
The basic concept of the two-state vector formalism, which is the time
symmetric approach to quantum mechanics, is the backward evolving quantum
state. However, due to the time asymmetry of the memory's arrow of time, the
possible ways to manipulate a backward evolving quantum state differ from those
for a standard, forward evolving quantum state. The similarities and the
differences between forward and backward evolving quantum states regarding the
no-cloning theorem, nonlocal measurements, and teleportation are discussed. The
results are relevant not only in the framework of the two-state vector
formalism, but also in the framework of retrodictive quantum theory.Comment: Contribution to the J.Phys. A special issue in honor of GianCarlo
Ghirard
Asymmetric Dark Matter and Dark Radiation
Asymmetric Dark Matter (ADM) models invoke a particle-antiparticle asymmetry,
similar to the one observed in the Baryon sector, to account for the Dark
Matter (DM) abundance. Both asymmetries are usually generated by the same
mechanism and generally related, thus predicting DM masses around 5 GeV in
order to obtain the correct density. The main challenge for successful models
is to ensure efficient annihilation of the thermally produced symmetric
component of such a light DM candidate without violating constraints from
collider or direct searches. A common way to overcome this involves a light
mediator, into which DM can efficiently annihilate and which subsequently
decays into Standard Model particles. Here we explore the scenario where the
light mediator decays instead into lighter degrees of freedom in the dark
sector that act as radiation in the early Universe. While this assumption makes
indirect DM searches challenging, it leads to signals of extra radiation at BBN
and CMB. Under certain conditions, precise measurements of the number of
relativistic species, such as those expected from the Planck satellite, can
provide information on the structure of the dark sector. We also discuss the
constraints of the interactions between DM and Dark Radiation from their
imprint in the matter power spectrum.Comment: 22 pages, 5 figures, to be published in JCAP, minor changes to match
version to be publishe
Troubling meanings of family and competing moral imperatives in the family lives of young people with a parent who is at the end of life
This article draws on a narrative study of young people with a parent who is at the end of life to examine how family lives are troubled by life-limiting parental illness. Young people struggled to reconcile the physical and emotional absence of family members with meanings of ‘family’; the extent to which young people could rely on family to ‘be there’ in these troubling circumstances was of practical, emotional and moral significance. Our discussion is situated in the context of an English end of life care policy predicated on the ideal of a good death as one that takes place at home accompanied by family members. We explore how the shift away from family as a site for nurturing children towards family as a space to care for the dying is experienced by young people, and consider how these competing moral imperatives are negotiated through relational practices of care
Phase II study of the farnesyltransferase inhibitor R115777 in advanced melanoma (CALGB 500104)
BACKGROUND: Multiple farnesylated proteins are involved in signal transduction in cancer. Farnesyltransferase inhibitors (FTIs) have been developed as a strategy to inhibit the function of these proteins. As FTIs inhibit proliferation of melanoma cell lines, we undertook a study to assess the impact of a FTI in advanced melanoma. As farnesylated proteins are also important for T cell activation, measurement of effects on T cell function was also pursued. METHODS: A 3-stage trial design was developed with a maximum of 40 patients and early stopping if there were no responders in the first 14, or fewer than 2 responders in the first 28 patients. Eligibility included performance status of 0–1, no prior chemotherapy, at most 1 prior immunotherapy, no brain metastases, and presence of at least 2 cutaneous lesions amenable to biopsy. R115777 was administered twice per day for 21 days of a 28-day cycle. Patients were evaluated every 2 cycles by RECIST. Blood and tumor were analyzed pre-treatment and during week 7. RESULTS: Fourteen patients were enrolled. Two patients had grade 3 toxicities, which included myelosuppression, nausea/vomiting, elevated BUN, and anorexia. There were no clinical responses. All patients analyzed showed potent inhibition of FT activity (85-98%) in tumor tissue; inhibition of phosphorylated ERK and Akt was also observed. T cells showed evidence of FT inhibition and diminished IFN-γ production. CONCLUSIONS: Despite potent target inhibition, R115777 showed no evidence of clinical activity in this cohort of melanoma patients. Inhibition of T cell function by FTIs has potential clinical implications. Clinicaltrials.gov number NCT0006012
A Social Identity Approach to Sport Psychology: Principles, Practice, and Prospects.
Drawing on social identity theory and self-categorization theory, we outline an approach to sport psychology that understands groups not simply as features of sporting contexts but rather as elements that can be, and often are, incorporated into a person's sense of self and, through this, become powerful determinants of their sport-related behavior. The underpinnings of this social identity approach are outlined, and four key lessons for sport that are indicative of the analytical and practical power of the approach are presented. These suggest that social identity is the basis for sports group (1) behavior, (2) formation and development, (3) support and stress appraisal, and (4) leadership. Building on recent developments within sport science, we outline an agenda for future research by identifying a range of topics to which the social identity approach could fruitfully contribute
ATscale – Establishing a Cross-Sector Partnership to Increase Access to Assistive Technology
Given existing gaps in access to Assistive Technology (AT) globally, it is important to think broadly
and identify innovative approaches to overcome them. After an initial scoping in 2018, involving
consultations and landscape analyses, ATscale, the Global Partnership for Assistive Technology was
launched at the Global Disability Summit in July 2018 with the aim of reaching 500 million more
people with life-changing AT by 2030. Applying lessons-learned from other areas of global health
and development, ATscale was established with the recognition that to influence the complex
systems for AT access, a broad set of stakeholders is needed to invest in and coordinate a multifaceted, systematic approach spanning market shaping, capacity development, and political
prioritisation.
Already, ATscale has demonstrated how a multi-sector group can come together and develop a
cohesive strategy. This strategy overview has been released and shared broadly for additional
consultation and feedback to further refine ATscale’s approach moving forward. ATscale has
captured the attention of a diverse set of stakeholders. It now has eleven organisations within the
Forming Committee and a broad community willing to inform its development. Now that it has been
established, ATscale is working to move from an initial forming phase to a more formal organisation
and to refine its operating model by late 2019 or early 2020.
While there is significant momentum towards taking new, innovative approaches to address the
gaps in access to quality, affordable AT for all, research shows that a wide range of systemic,
underlying barriers and cross-cutting factors are contributing to the challenge in matching
appropriate supply and demand for AT. While ATscale will address many of these, it is also going to
require partnership on multiple levels with a coordinated strategic approach across a variety of
stakeholders. This collective effort will enable the global community to have an impact greater than
the sum of its individual parts in improving access to affordable, appropriate AT globally
Critical decisions for older people with advanced dementia: a prospective study in long-term institutions and district home care.
Pneumonia in Nursing Home Patients With Advanced Dementia: Decisions, Intravenous Rehydration Therapy, and Discomfort
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