A GRADIENT-LIKE NONAUTONOMOUS EVOLUTION PROCESS

In this paper we consider a dissipative damped wave equation with nonautonomous damping of the form u(tt) + beta(t)u(t) - Delta u + f(u) (1) in a bounded smooth domain Omega subset of R(n) with Dirichlet boundary conditions, where f is a dissipative smooth nonlinearity and the damping beta : R -> (0, infinity) is a suitable function. We prove, if (1) has finitely many equilibria, that all global bounded solutions of (1) are backwards and forwards asymptotic to equilibria. Thus, we give a class of examples of nonautonomous evolution processes for which the structure of the pullback attractors is well understood. That complements the results of [Carvalho & Langa, 2009] on characterization of attractors, where it was shown that a small nonautonomous perturbation of an autonomous gradient-like evolution process is also gradient-like. Note that the evolution process associated to (1) is not a small nonautonomous perturbation of any autonomous gradient-like evolution processes. Moreover, we are also able to prove that the pullback attractor for (1) is also a forwards attractor and that the rate of attraction is exponential.

Increased Viability of Odontoblast-Like Cells Subjected to Low-Level Laser Irradiation

Studies have shown that the increase of cell metabolism depends on the low level laser therapy (LLLT) parameters used to irradiate the cells. However, the optimal laser dose to up-regulate pulp cell activity remains unknown. Consequently, the aim of this study was to evaluate the metabolic response of odontoblast-like cells (MDPC-23) exposed to different LLLT doses. Cells at 20000 cells/cm(2) were seeded in 24-well plates using plain culture medium (DMEM) and were incubated in a humidified incubator with 5% CO(2) at 37 degrees C. After 24 h, the culture medium was replaced by fresh DMEM supplemented with 5% (stress by nutritional deficit) or 10% fetal bovine serum (FBS). The cells were exposed to different laser doses from a near infrared diode laser prototype designed to provide a uniform irradiation of the wells. The experimental groups were: G1: 1.5 J/cm(2) + 5% FBS; G2: 1.5 J/cm(2) + 10% FBS; G3: 5 J/cm(2) + 5% FBS; G4: 5 J/cm(2) + 10% FBS; G5: 19 J/cm(2) + 5% FBS; G6: 19 J/cm(2) + 10% FBS. LLLT was performed in 3 consecutive irradiation cycles with a 24-hour interval. Non-irradiated cells cultured in DMEM supplemented with either 5 or 10% FBS served as control groups. The analysis of the metabolic response was performed by the MTT assay 3 h after the last irradiation. G1 presented an increase in SDH enzyme activity and differed significantly (Mann-Whitney test, p < 0.05) from the other groups. Analysis by scanning electron microscopy showed normal cell morphology in all groups. Under the tested conditions, LLLT stimulated the metabolic activity of MDPC-23 cultured in DMEM supplemented with 5% FBS and exposed to a laser dose of 1.5 J/cm(2). These findings are relevant for further studies on the action of near infrared lasers on cells with odontoblast phenotype.

Ric-8B interacts with G alpha olf and G gamma 13 and co-localizes with G alpha olf, G beta 1 and G gamma 13 in the cilia of olfactory sensory neurons

Olfactory sensory neurons are able to detect odorants with high sensitivity and specificity. We have demonstrated that Ric-8B, a guanine nucleotide exchange factor (GEF), interacts with G alpha olf and enhances odorant receptor signaling. Here we show that Ric-8B also interacts with G gamma 13, a divergent member of the G gamma subunit family which has been implicated in taste signal transduction, and is abundantly expressed in the cilia of olfactory sensory neurons. We show that G beta 1 is the predominant GP subunit expressed in the olfactory sensory neurons. Ric-8B and G beta 1, like G alpha olf and G gamma 13, are enriched in the cilia of olfactory sensory neurons. We also show that Ric-8B interacts with G alpha olf in a nucleotide dependent manner, consistent with the role as a GEF. Our results constitute the first example of a GEF protein that interacts with two different olfactory G protein subunits and further implicate Ric-8B as a regulator of odorant signal transduction. (C) 2008 Elsevier Inc. All rights reserved.

(1)H NMR spectroscopy as a tool to determine accurate photoisomerization quantum yields of stilbene-like ligands coordinated to rhenium(I) polypyridyl complexes

In this work, the use of proton nuclear magnetic resonance, (1)H NMR, was fully described as a powerful tool to follow a photoreaction and to determine accurate quantum yields, so called true quantum yields (Phi(true)), when a reactant and photoproduct absorption overlap. For this, Phi(true) for the trans-cis photoisomerization process were determined for rhenium(I) polypyridyl complexes, fac-[Re(CO)(3)(NN)(trans-L)](+) (NN = 1,10-phenanthroline, phen, or 4,7-diphenyl-1,10-phenanthroline, ph(2)phen, and L = 1,2-bis(4-pyridyl) ethylene, bpe, or 4-styrylpyridine, stpy). The true values determined at 365 nm irradiation (e. g. Phi(NMR) = 0.80 for fac-[Re(CO)(3)(phen)(trans-bpe)](+)) were much higher than those determined by absorption spectral changes (Phi(UV-Vis) = 0.39 for fac-[Re(CO)(3)(phen)(trans-bpe)](+)). Phi(NMR) are more accurate in these cases due to the distinct proton signals of trans and cis-isomers, which allow the actual determination of each component concentration under given irradiation time. Nevertheless when the photoproduct or reactant contribution at the probe wavelength is negligible, one can determine Phi(true) by regular absorption spectral changes. For instance, Phi(313) nm for free ligand photoisomerization determined both by absorption and (1)H NMR variation are equal within the experimental error (bpe: Phi(UV-Vis) = 0.27, Phi(NMR) = 0.26; stpy: Phi(UV-Vis) = 0.49, Phi(NMR) = 0.49). Moreover, (1)H NMR data combined with electronic spectra allowed molar absorptivity determination of difficult to isolate cis-complexes. (C) 2009 Elsevier B. V. All rights reserved.

Immunolocalisation of sodium/proton exchanger-like proteins in the gills of elasmobranchs

Na⁺/H⁺ exchangers are integral membrane proteins that exchange Na⁺ and H⁺ across cell membranes. The Na⁺/H⁺ exchangers 2 and 3 are epithelial isoforms in mammals and contribute to acid–base homeostasis. The gills of fishes, including elasmobranchs, are also associated with acid/base balance, and are probably the primary acid/base regulatory organ. This study examines the presence of Na⁺/H⁺ exchangers 2 and 3 using immunohistochemistry and immunoblotting in the gills of four species of elasmobranchs, the banjo ray (Trygonorrhina fasciata), southern eagle ray (Myliobatis australis), the gummy shark (Mustelus antarcticus) and the Australian angel shark (Squatina australis) using heterologous antibodies. Na⁺/H⁺ exchanger 2-like immunoreactivity was observed in the gills of the banjo ray, eagle ray and angel shark. In the banjo and eagle rays, this Na⁺/H⁺ exchanger-like immunoreactivity co-localised with immunoreactivity to Na⁺/K⁺-ATPase, a marker for the mitochondrial-rich cells of fishes. Na⁺/H⁺ exchanger 3-like immunoreactivity was only observed in the gills of the angel and gummy sharks, some Na⁺/H⁺ exchanger 3-like cells also showed Na⁺/K⁺-ATPase immunoreactivity. However, immunoblotting of banjo and eagle ray gill membranes demonstrated Na⁺/H⁺ exchanger 3-like immunoreactivity, which was not consistent with the immunohistochemical results. These data demonstrate the presence of epithelial Na⁺/H⁺ exchangers 2 and 3 in the gills of elasmobranchs and a link with acid/base regulation is suggested.

Fibroblast growth factor-2 over-rides insulin-like growth factor-I induced proliferation and cell survival in human neuroblastoma cells

The insulin-like growth factor (IGF) system is a key regulator of cell growth, survival and differentiation, and these functions are co-modulated by other growth factors including fibroblast growth factor-2 (FGF-2). To investigate IGF/FGF interactions in neuronal cells, we employed neuroblastoma cells (SK-N-MC). In serum free conditions proliferation of the SK-N-MC cells was promoted by IGF-I (25 ng/ml), but blunted by FGF-2 (50 ng/ml). IGF-I-induced proliferation was abolished in the presence of FGF-2 even when IGF-I was used at 100 ng/ml. In addition to our previously described FGF-2 induced proteolytic cleavage of IGFBP-2, we found that FGF-2 increased IGFBP-6 levels in conditioned medium (CM) without affecting IGFBP-6 mRNA abundance. Modulation of IGFBP-2 and -6 levels were not significant mechanisms involved in the blockade of IGF-I action since the potent IGF-I analogues [QAYL]IGF-I and des(1-3)IGF-I (minimal IGFBP affinity) were unable to overcome FGF-2 inhibition of cell proliferation. FGF-2 treated cells showed morphological differentiation expressing the TUJ1 neuronal marker while cells treated with IGF-I alone showed no morphological change. When IGF-I was combined with FGF-2, however, cell morphology was indistinguishable from that seen with FGF-2 alone. FGF-2 inhibited proliferation and enhanced differentiation was also associated with a 70% increase in cell death. Although IGF-I alone was potently anti-apoptotic (60% decreased), IGF-I was unable to prevent apoptosis when administrated in combination with FGF-2. Gene-array analysis confirmed FGF-2 activation of the intrinsic and extrinsic apoptotic pathways and blockade of IGF anti-apoptotic signaling. FGF-2, directly and indirectly, overcomes the proliferative and anti-apoptotic activity of IGF-I by complex mechanisms, including enhancement of differentiation and apoptotic pathways, and inhibition of IGF-I induced anti-apoptotic signalling. Modulation of IGF binding protein abundance by FGF-2 does not play a significant role in inhibition of IGF-I induced mitogenesis.

The development of a network for community based obesity prevention : the CO-OPS collaboration

Background: Community-based interventions are a promising approach and an important component of a comprehensive response to obesity. In this paper we describe the Collaboration of COmmunity-based Obesity Prevention Sites (CO-OPS Collaboration) in Australia as an example of a collaborative network to enhance the quality and quantity of obesity prevention action at the community level. The core aims of the CO-OPS Collaboration are to: identify and analyse the lessons learned from a range of community-based initiatives aimed at tackling obesity, and; to identify the elements that make community-based obesity prevention initiatives successful and share the knowledge gained with other communities.
Methods: Key activities of the collaboration to date have included the development of a set of Best Practice Principles and knowledge translation and exchange activities to promote the application (or use) of evidence, evaluation and analysis in practice.
Results: The establishment of the CO-OPS Collaboration is a significant step toward strengthening action in this area, by bringing together research, practice and policy expertise to promote best practice, high quality evaluation and knowledge translation and exchange. Future development of the network should include facilitation of further
evidence generation and translation drawing from process, impact and outcome evaluation of existing communitybased interventions.
Conclusions: The lessons presented in this paper may help other networks like CO-OPS as they emerge around the globe. It is important that networks integrate with each other and share the experience of creating these networks.

Distributional overlap rather than habitat differentiation characterizes co-occurrence of bivalves in intertidal soft sediment systems

Diverse species assemblages are often associated with a diversity of habitat structures. Sedimentary systems seem to be no exception, as within sedimentary systems benthic species diversity within a sample point appears to correlate with sediment grain size complexity. However, it remains to be shown whether total benthic species diversity relates to a system’s sediment heterogeneity across multiple systems. In the present paper we examined whether bivalve diversity is associated with: (1) sediment heterogeneity across systems and (2) sediment grain size complexity within systems, at 9 temperate and tropical tidal flat systems. Although bivalve life-history strategies, like post-settlement habitat selection, might suggest that sediment heterogeneity should be important for bivalve species, bivalve diversity and sediment heterogeneity were not associated across systems. Interestingly, the association between total benthic diversity and sediment heterogeneity was also not significant, suggesting that changing species composition across systems does not account for the lack of a correlation between bivalve diversity and sediment heterogeneity. Instead of habitat differentiation, bivalve diversity within a sample point was highest in ‘complex’ fine-grained sediments and bivalve distributions showed a large degree of distributional overlap in all systems. The results of this study at both smaller and larger spatial scales suggest that coexistence between bivalve species in diverse tidal flats is not associated with increased sediment heterogeneity.

Toll like receptors play a role in general immunity, eye infection and inflammation : TLRs for nanodelivery

Dendritic cells [DCs] are potent antigen presenting cells [APC], which plays a vital role in immune system by detecting and capturing pathogens in the body. DCs perform a pivotal role in induction of T cell response. Regulation of immune response can be achieved by specific antigen [Ag] delivery to DCs. A delivery system that can efficiently target and present Ags to DCs for the purpose of anti-tumour activity is currently a topic of significant research interest. DCs are receiving attention due to their key role in anti cancer host response and due to their adjuvanic property in tumour vaccines. Role of toll like receptors [TLR] in innate immune system and their part in eventual stimulation of adaptive immunity is exploited to develop vaccines. TLR agonists in conjugation with vaccines are shown to increase therapeutic efficacy in some cases. TLRs also play a vital role in protecting the cornea from invading pathogens. Due to adverse effects in the treatment of ocular inflammations, cancer and in viral infections, an alternate approach such as the use of TLRs will solve the inquisitive question regarding side effects. The intended delivery is attained by the use of nanoparticles which in turn leads to prolonged half-life in the body. Co-delivery of Ags, TLRs and immunomodulators using nanoparticles has been demonstrated to elicit potent cellular immune responses and are currently under development of clinically applicable immunisations and vaccines.

Brief report: children with ADHA without co-morbid autism do not have impaired motor proficiency on the Movement Assessment Battery for Children

Motor proficiency was investigated in a sample of children with Attention Deficit Hyperactivity Disorder-Combined type (ADHD-CT) without autism. Accounting for the influence of co-morbid autistic symptoms in ADHD motor studies is vital given that motor impairment has been linked to social–communication symptoms in children who have co-morbid ADHD and autistic-like symptoms. Two groups of children aged between 7–14 years were recruited; children with ADHD-CT (n = 16; mean age 10 years, 7 months [SD = 1 year, 10 months]) and a typically developing (n = 16; mean age 10 years, 6 months [SD = 2 years, 6 months]) group. Motor proficiency was measured using the Movement Assessment Battery for Children-2nd Edition, ADHD symptoms were measured using the Conner’s Parent Rating Scale. Children with ADHD-CT who had been screened for co-morbid autism did not display motor difficulties on the MABC-2. Higher levels of inattention, but not hyperactivity or impulsivity were associated with poorer motor performance. These findings provide indirect evidence that the motor problems that children with ADHD experience may be related to co-occurring social responsiveness impairments.

Contested Meme-ing: Co-opt or Co-operate

This artwork details the designs for an interactive installation that address cooperation and competition for control over meaning of a text in a a game-like situation.

Nervous control of circulation--the role of gasotransmitters, NO, CO, and H2S.

The origins and actions of gaseous signaling molecules, nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H(2)S) in the mammalian cardiovascular system have received considerable attention and it is evident that these three "gasotransmitters" perform a variety of homeostatic functions. The origins, actions and disposition of these gasotransmitters in the piscine vasculature are far from resolved. In most fish examined to date, NO or NO donors are generally in vitro and in vivo vasodilators acting via soluble guanylyl cyclase, although there is evidence for NO-mediated vasoconstriction. Injection of sodium nitroprusside into trout causes hypotension that is attributed to a reduction in systemic resistance. Unlike mammals, NO does not appear to have an endothelial origin in fish blood vessels as an endothelial NO synthase has not identified. However, neural NO synthase is prevalent in perivascular nerves and is the most likely source of NO for cardiovascular control in fish. CO is a vasodilator in lamprey and trout vessels, and it, like NO, appears to exert its action, at least in part, via guanylyl cyclase and potassium channel activation. Inhibition of CO production increases resting tone in trout vessels suggestive of tonic CO activity, but little else is known about the origin or control of CO in the fish vasculature. H(2)S is synthesized by fish vessels and its constrictory, dilatory, or even multi-phasic actions, are both species- and vessel-specific. A small component of H(2)S-mediated basal activity may be endothelial in origin, but to a large extent H(2)S affects vascular smooth muscle directly and the mechanisms are unclear. H(2)S injected into the dorsal aorta of unanesthetized trout often produces oscillations in arterial blood pressure suggestive of H(2)S activity in the central nervous system as well as peripheral vasculature. Collectively, these studies hint at significant involvement of the gasotransmitters in piscine cardiovascular function and hopefully provide a variety of avenues for future research.

Functionalism, co-operation, good faith, and the making of the "daily-preventive justice" in contract law theory and practice. A contribution to a rational understanding of good faith and to its future reseasonable developments. Evaluations from

The thoughts and observations contained in this paper were first presented in a preliminary form at the Staff Seminar that I gave at the University of Cape Town (UCT) - Department of Private Law, on Tuesday May 8 2012. The organizers generously offered me a free choice of subject. Such an offer always poses a problem to imaginative people like myself. I finally chose as my subject the role of good faith in contract law theory and practice and then entitled the Seminar “Good Faith & Contracts - Brothers in Arms”. The aim of the talk was to briefly describe what I see behind the doctrine of good faith (and, more broadly, behind the general course of the parties’ behavior before and after the conclusion of an agreement), to then explain the need of its protection and future reasonable developments by challenging the limitations of both traditional and current legal approaches to contract law theory and practice. By adopting a comparative modus investigandi, it emerged that especially in the area of contract law a new law-finding process is emerging in the European continent and it is leading to re-conceive the meta-national legislative interventions by challenging the limits of Hobbes’s Leviathan. As asserted, we ought to not take this process for granted because although there are many forms of social organization, contract is the most pervasive and the law of contract still is the most important vehicle to support and supplement private arrangements. However, the point of departure for theorizing about private law is based on experience. Consequently, despite the growing emphasis on the convergence of national legal systems in Europe, conducting research on private law theory and practice requires that imagination and creativity be matched with prudence. Proficiency has to be aligned with what we have learned from history.

Morphological and molecular investigations of the holocephalan elephant fish nephron: the existence of a countercurrent-like configuration and two separate diluting segments in the distal tubule

In marine cartilaginous fish, reabsorption of filtered urea by the kidney is essential for retaining a large amount of urea in their body. However, the mechanism for urea reabsorption is poorly understood due to the complexity of the kidney. To address this problem, we focused on elephant fish (Callorhinchus milii) for which a genome database is available, and conducted molecular mapping of membrane transporters along the different segments of the nephron. Basically, the nephron architecture of elephant fish was similar to that described for elasmobranch nephrons, but some unique features were observed. The late distal tubule (LDT), which corresponded to the fourth loop of the nephron, ran straight near the renal corpuscle, while it was convoluted around the tip of the loop. The ascending and descending limbs of the straight portion were closely apposed to each other and were arranged in a countercurrent fashion. The convoluted portion of LDT was tightly packed and enveloped by the larger convolution of the second loop that originated from the same renal corpuscle. In situ hybridization analysis demonstrated that co-localization of Na(+),K(+),2Cl(-) cotransporter 2 and Na(+)/K(+)-ATPase α1 subunit was observed in the early distal tubule and the posterior part of LDT, indicating the existence of two separate diluting segments. The diluting segments most likely facilitate NaCl absorption and thereby water reabsorption to elevate urea concentration in the filtrate, and subsequently contribute to efficient urea reabsorption in the final segment of the nephron, the collecting tubule, where urea transporter-1 was intensely localized.