1,016 research outputs found
Interactive effects of endogenous and exogenous nutrition on larval development for crown-cf-thorns starfish
Outbreaks of crown-of-thorns starfish are often attributed to step-changes in larval survivorship following anomalous increases in nutrients and food availability. However, larval growth and development is also influenced by the nutritional condition of spawning females, such that maternal provisioning may offset limitations imposed by limited access to exogenous sources of nutrients during the formative stages of larval development. This study examined the individual, additive, and interactive effects of endogenous (maternal diet: Acropora, Porites, mixed, and starved) and exogenous (larval diet: high concentration at 104 cells·mL−1, low concentration at 103 algal cells·mL−1, and starved) nutrition on the survival, growth, morphology, and development of larvae of the crown-of-thorns starfish. Female starfish on Acropora and mixed diet produced bigger oocytes compared to Porites-fed and starved treatments. Using oocyte size as a proxy for maternal provisioning, endogenous reserves in the oocyte had a strong influence on initial larval survival and development. This suggests that maternal reserves can delay the onset of obligate exogenous food acquisition and allow larvae to endure prolonged periods of poor environmental nutritive conditions or starvation. The influence of exogenous nutrition became more prominent in later stages, whereby none of the starved larvae reached the mid-to-late brachiolaria stage 16 days after the onset of the ability to feed. There was no significant difference in the survival, development, and competency of larvae between high and low food treatments. Under low algal food conditions, larvae compensate by increasing the length of ciliated feeding bands in relation to the maximum length and width, which improve food capture and feeding efficiency. However, the effects of endogenous nutrition persisted in the later developmental stages, as larvae from starved females were unable to develop larger feeding structures in response to food-limiting conditions. Phenotypic plasticity influenced by endogenous provisions and in response to exogenous food availability may be an important strategy in boosting the reproductive success of crown-of-thorns starfish, leading to population outbreaks
Global well-posedness of the KP-I initial-value problem in the energy space
We prove that the KP-I initial value problem is globally well-posed in the
natural energy space of the equation
Titanium sapphire : A decade of diode-laser pumping
For many years, Ti:sapphire was the prototypical example of a solid-state laser material that could not be diode pumped. The rationale for this assessment follows from the laser properties of Ti:sapphire, which combine to demand high brightness pumping in the blue-green region (see fig. 1 [1]). The development of efficient Gallium Nitride (GaN) based laser diodes eroded this logic [2], and improvements in the spatial brightness of GaN diode lasers subsequently enabled the first demonstration of a directly diode-laser pumped Ti:sapphire laser in 2009 [3], This presentation will outline the physics that makes diode-pumping difficult, and the developments that mean, it is, nonetheless, possible. Interestingly, diode-pumping of CW and modelocked Ti:sapphire lasers was achieved not by a radical redesign of the laser, but by careful optimisation of existing approaches that enabled the rapidly improving brightness of GaN diode lasers to be exploited [3-5]
Double beta decay experiments
The present status of double beta decay experiments are reviewed. The results
of the most sensitive experiments, NEMO-3 and CUORICINO, are discussed.
Proposals for future double beta decay experiments are considered. In these
experiments sensitivity for the effective neutrino mass will be on the level of
(0.1-0.01) eV.Comment: 20 pages, 7 fugures; talk at 12-th Lomonosov Conference on Elementary
Particle Physics (Moscow, August 25-31, 2005
Consumers’ intentions towards sustainability: A Spanish fast-fashion perspective
This paper examines consumer intentions towards sustainable fashion in the Spanish fashion industry. It explores consumer knowledge, attitudes, and behavioral response to sustainable fashion. The research was conducted using a mixed-method strategy. The quantitative questionnaire examines consumer attitudes towards sustainable fashion, underpinned by the Theory of Planned Behavior. This was supported by a qualitative enquiry using semi-structured interviews to explore consumer knowledge of and attitudes towards sustainable fashion in Spain. Consumer familiarity with sustainable fashion was found to be high and broad in definition scope. Social aspects of sustainability were predominant tangents. A disjuncture between company’s sustainable communication and consumer perception was apparent as well as attitudes and actual purchase intentions towards sustainable fashion. Opportunities to foster further sustainable fashion business practices and communication were identified. The findings highlight that fashion retailers should clearly communicate the meaning of sustainability and their proactive response to sustainability. The development of effective communication strategies that clearly highlights retailer’s compliance with and efforts to becoming more sustainable is a prerequisite arising from the study. This study contributes to burgeoning research on sustainable fashion within mainstream marketing and management literature. By contextualizing it to the Spanish market, it provides a novel counter-point consumer perspective on attitudes and intentions towards sustainable fashion
Entanglement in the quantum Ising model
We study the asymptotic scaling of the entanglement of a block of spins for
the ground state of the one-dimensional quantum Ising model with transverse
field. When the field is sufficiently strong, the entanglement grows at most
logarithmically in the number of spins. The proof utilises a transformation to
a model of classical probability called the continuum random-cluster model, and
is based on a property of the latter model termed ratio weak-mixing. Our proof
applies equally to a large class of disordered interactions
Global well-posedness for the KP-I equation on the background of a non localized solution
We prove that the Cauchy problem for the KP-I equation is globally well-posed
for initial data which are localized perturbations (of arbitrary size) of a
non-localized (i.e. not decaying in all directions) traveling wave solution
(e.g. the KdV line solitary wave or the Zaitsev solitary waves which are
localized in and periodic or conversely)
Shear-induced dynamics of polymeric globules at adsorbing homogeneous and inhomogeneous surfaces
Melanomas prevent endothelial cell death under restrictive culture conditions by signaling through AKT and p38 MAPK/ ERK-1/2 cascades
Although melanoma progression and staging is clinically well characterized, a large variation is observed in pathogenesis, progression, and therapeutic responses. Clearly, intrinsic characteristics of melanoma cells contribute to this variety. An important factor, in both progression of the disease and response to therapy, is the tumor-associated vasculature. We postulate that melanoma cells communicate with endothelial cells (ECs) in order to establish a functional and supportive blood supply. We investigated the angiogenic potential of human melanoma cell lines by monitoring the survival of ECs upon exposure to melanoma conditioned medium (CM), under restrictive conditions. We observed long-term (up to 72 h) EC survival under hypoxic conditions upon treatment with all melanoma CMs. No such survival effect was observed with the CM of melanocytes. The CM of pancreatic and breast tumor cell lines did not show a long-term survival effect, suggesting that the survival factor is specific to melanoma cells. Furthermore, all size fractions (up to < 1 kDa) of the melanoma CM induced long-term survival of ECs. The survival effect observed by the < 1 kDa fraction excludes known pro-angiogenic factors. Heat inactivation and enzymatic digestion of the CM did not inactivate the survival factor. Global gene expression and pathway analysis suggest that this effect is mediated in part via the AKT and p38 MAPK/ ERK-1/2 signaling axis. Taken together, these data indicate the production of (a) survival factor/s (< 1 kDa) by melanoma cell lines, which enables long-term survival of ECs and promotes melanoma-induc
Inward and outward migration of massive planets: moving towards a stalling radius
Stars and planetary system
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