Pathways to enhanced lake integrity: A Framework to assess the effectiveness of local lake associations

The promise of collaborative governance is to implement policies that address uncertain and multi‐scale environmental problems while also allowing local social systems to successfully adapt. The success of such efforts is contingent on the capacity of community‐based institutions such as lake associations to effect change. These organizations encapsulate the values communities hold for lakes and their catchments and can play a central role in managing the integrity of lakes’ freshwater resources. To this end, we develop a framework to delineate the pathways lake associations can take to contribute to the management of lakes and their catchments. We suggest the cornerstones of effective engagement in collaborative governance are the goals the organization sets for itself (mission), the capital that can be mobilized by the organization (capacity) and the activities the organization undertakes (actions). We propose measurable indicators for each component and suggest how the framework can be used to assess contributions of lake associations to multi‐scale governance. Finally, we suggest how this framework can be integrated with ecological monitoring frameworks as part of a long term social‐ecological research and monitoring program.     

Engagement in digital entertainment games: A systematic review

Since their introduction over 40 years ago, digital entertainment games have become one of the most popular leisure activities globally. While digital games clearly provide highly engaging activities, the nature of this engagement is not well understood. The current study aims to advance our understanding by reporting a systematic review of recent literature addressing engagement in computer games. The papers in the review comprise a sub-sample of papers relating to engagement in digital games that was selected from a broader literature search carried out on the outcomes and impacts of playing computer games. A diverse range of studies was identified that examined varied aspects of engagement in games including subjective experiences while playing games, the physiological concomitants of these experiences, motives for playing games, game usage and time spent playing games and the impact of playing on life satisfaction. A narrative review was carried out to capture these diverse aspects of engagement and to develop a more coherent understanding of engagement in computer games.     

The Antibiotic Doxycycline Impairs Cardiac Mitochondrial and Contractile Function

Tetracycline antibiotics act by inhibiting bacterial protein translation. Given the bacterial ancestry of mitochondria, we tested the hypothesis that doxycycline—which belongs to the tetracycline class—reduces mitochondrial function, and results in cardiac contractile dysfunction in cultured H9C2 cardiomyoblasts, adult rat cardiomyocytes, in Drosophila and in mice. Ampicillin and carbenicillin were used as control antibiotics since these do not interfere with mitochondrial translation. In line with its specific inhibitory effect on mitochondrial translation, doxycycline caused a mitonuclear protein imbalance in doxycycline-treated H9C2 cells, reduced maximal mitochondrial respiration, particularly with complex I substrates, and mitochondria appeared fragmented. Flux measurements using stable isotope tracers showed a shift away from OXPHOS towards glycolysis after doxycycline exposure. Cardiac contractility measurements in adult cardiomyocytes and Drosophila melanogaster hearts showed an increased diastolic calcium concentration, and a higher arrhythmicity index. Systolic and diastolic dysfunction were observed after exposure to doxycycline. Mice treated with doxycycline showed mitochondrial complex I dysfunction, reduced OXPHOS capacity and impaired diastolic function. Doxycycline exacerbated diastolic dysfunction and reduced ejection fraction in a diabetes mouse model vulnerable for metabolic derangements. We therefore conclude that doxycycline impairs mitochondrial function and causes cardiac dysfunction.     

A field deployable, multiplexed Bragg grating sensor system used in an extensive highway bridge monitoring evaluation tests

A multiplexed optical fiber Bragg grating sensor system with a measurement bandwidth of up to 200 Hz enabling dynamic loading events, e.g., road traffic, to be observed has been designed, installed, and tested over an 18-month period on a 346-m road bridge in Norway, for design verification and structural integrity monitoring purposes. A network of 32 fiber Bragg sensors was surface bonded along with a corresponding set of resistive strain gauges for comparative tests to be made. The wavelength data were calibrated against two thermally stabilized (/spl sim/0.15 pm) reference gratings, which rejected common mode noise and provided absolute wavelength scaling. These data provides independent strain and temperature information. Long-term test results showed good linearity and repeatability of <10 /spl mu//spl epsiv/ over the test period with a precision of /spl plusmn/5 /spl mu//spl epsiv/ and a resolution of /spl plusmn/1 /spl mu//spl epsiv/. The readings from the FBG sensors were comparable to those from the foil gauge sensors to within /spl plusmn/4 /spl mu//spl epsiv/.     

Analysis of Mobile Phone Antenna Impedance Variations With User Proximity

The impedance change that occurs when the user holds a mobile phone antenna is a well-known problem. This paper analyses the contributions to this change for a dual-band PIFA. In particular, the contribution of the slot is shown and a method of reducing it is proposed and analyzed     

Interaction of n-3 long-chain polyunsaturated fatty acids with n-6 fatty acids in suckled rat pups

The addition of long-chain polyunsaturated fatty acids (LCP: C20, and C22) to infant formula may permit fatty acid accretion rates similar to breast-fed infants, and may have long-term outcome benefits, such as improved visual acuity and cognitive development. Although fish oil may provide a source of n-3 LCP, sources of n-6 LCP have been more difficult to identify. The present study evaluates the effects of n-3 and n-6 LCP derived from single-cell oils on liver, plasma, and brain fatty acid levels in a neonatal animal model. Newborn rat pups were suckled for 14 d by dams receiving diets containing n-3 LCP alone or combinations of n-3 LCP and increasing doses of linoleic acid (18∶2n−6) or arachidonic acid (20∶4n−6). Dietary groups received 2% n−3 LCP and 1, 2, or 5% of either 18∶2n−6 or 20∶4n−6. The 20∶4n−6 source also contained modest levels of 18∶2n−6. At the termination of the study, liver, plasma, and brain were obtained from the rat pups and the phospholipid fatty acid profiles determined. The results indicate complex interactions of n−3 and n−6 fatty acids. Groups receiving dietary 20∶4n−6 incorporated higher levels of n−6 LCP into tissues than did the groups receiving 18∶2n−6. The brain was relatively resistant to changes in fatty acid composition compared with the liver and plasma. As expected, tissue n−3 LCP levels were reciprocally related to n−6 levels. The present results document that single-cell LCP oils are bioavailable in a neonatal animal model. The use of 20∶4n−6 is a more effective means of supporting n−6 status than the use of 18∶2n−6. These results may have implications for the addition of LCP to infant formula.     

PTEN and Other PtdIns(3,4,5)P3 Lipid Phosphatases in Breast Cancer

The phosphoinositide 3-kinase (PI3K)/AKT signalling pathway is hyperactivated in ~70% of breast cancers. Class I PI3K generates PtdIns(3,4,5)P₃ at the plasma membrane in response to growth factor stimulation, leading to AKT activation to drive cell proliferation, survival and migration. PTEN negatively regulates PI3K/AKT signalling by dephosphorylating PtdIns(3,4,5)P₃ to form PtdIns(4,5)P₂. PtdIns(3,4,5)P₃ can also be hydrolysed by the inositol polyphosphate 5-phosphatases (5-phosphatases) to produce PtdIns(3,4)P₂. Interestingly, while PTEN is a bona fide tumour suppressor and is frequently mutated/lost in breast cancer, 5-phosphatases such as PIPP, SHIP2 and SYNJ2, have demonstrated more diverse roles in regulating mammary tumourigenesis. Reduced PIPP expression is associated with triple negative breast cancers and reduced relapse-free and overall survival. Although PIPP depletion enhances AKT phosphorylation and supports tumour growth, this also inhibits cell migration and metastasis in vivo, in a breast cancer oncogene-driven murine model. Paradoxically, SHIP2 and SYNJ2 are increased in primary breast tumours, which correlates with invasive disease and reduced survival. SHIP2 or SYNJ2 overexpression promotes breast tumourigenesis via AKT-dependent and independent mechanisms. This review will discuss how PTEN, PIPP, SHIP2 and SYNJ2 distinctly regulate multiple functional targets, and the mechanisms by which dysregulation of these distinct phosphoinositide phosphatases differentially affect breast cancer progression.     

Constraint of Feeding by Chronic Ingestion of 1,8-Cineole in the Brushtail Possum (Trichosurus vulpecula)

Eucalyptus leaf-eating marsupials such as the brushtail possum (Trichosurus vulpecula) ingest large amounts of terpenes, especially 1,8-cineole (cineole)--the major component of many eucalyptus oils. Brushtail possums were acclimated to a non-Eucalyptus diet with increasing concentrations of cineole (0.5-4.0% wet weight) added over 18 d. We measured food and cineole consumption and urinary metabolites of cineole. Food intake decreased with cineole content, indicating that it was constrained by the maximum tolerable intake of cineole that was 3.8 +/- 0.2 g kg(-1) or 5.2 +/- 0.3 g kg(-0.75) (mean +/- SE, N = 6). The pattern of metabolites was similar at all cineole intakes (56% hydroxycineolic acids, 27% cineolic acids, 13% hydroxycineoles, and 4% dihydroxycineoles). In another experiment, possums maintained on artificial diet were abruptly presented with 4% cineole for 5 d. Food intake fell by 45 +/- 6% (mean +/- SE, N = 6) and mean cineole intake was 2.9 +/- 0.3 g kg(-1). There was evidence of induction of secondary oxidative pathways, as hydroxycineoles were the major metabolites (48% total) on the first day, but rapidly dropped to 15% on subsequent days as the acid metabolites increased. These findings indicate that ingestion of cineole is not constrained by selective saturation of individual enzymes involved in its multiple pathways of oxidation, but rather the total detoxification capacity appears to limit feeding on a cineole diet.     

Properties of lysophosphatidylcholine acyltransferase from <Emphasis Type="Italic">Brassica napus</Emphasis> cultures

Acyl-CoA:lysophosphatidylcholine acyltransferase (LPCAT; EC 2.3.1.23) catalyzes the acyl-CoA-dependent acylation of lysophosphatidylcholine (LPC) to produce PC and CoA. LPCAT activity may affect the incorporation of fatty acyl moieties at the sn-2 position of PC where PUFA are formed and may indirectly influence seed TAG composition. LPCAT activity in microsomes prepared from microspore-derived cell suspension cultures of oilseed rape (Brassica napus L. cv Jet Neuf) was assayed using [1-¹⁴C]acyl-CoA as the fatty acyl donor. LPCAT activity was optimal at neutral pH and 35°C, and was inhibited by 50% at a BSA concentration of 3 mg mL⁻¹. At acyl-CoA concentrations above 20 μM, LPCAT activity was more specific for oleoyl (18∶1)-CoA than stearoyl (18∶0)- and palmitoyl (16∶0)-CoA. Lauroyl (12∶0)-CoA, however, was not an effective acyl donor. LPC species containing 12∶0, 16∶0, 18∶0, or 18∶1 as the fatty acyl moiety all served as effective acyl acceptors for LPCAT, although 12∶0-LPC was somewhat less effective as a substrate at lower concentrations. The failure of LPCAT to catalyze the incorporation of a 12∶0 moiety from acyl-CoA into PC is consistent with the tendency of acyltransferases to discriminate against incorporation of this fatty acyl moiety at the sn-2 position of TAG from the seed oil of transgenic B. napus expressing a medium-chain thioesterase.