The Alpine Cushion Plant Silene acaulis as Foundation Species: A Bug’s-Eye View to Facilitation and Microclimate

Alpine ecosystems are important globally with high levels of endemic and rare species. Given that they will be highly impacted by climate change, understanding biotic factors that maintain diversity is critical. Silene acaulis is a common alpine nurse plant shown to positively influence the diversity and abundance of organisms–predominantly other plant species. The hypothesis that cushion or nurse plants in general are important to multiple trophic levels has been proposed but rarely tested. Alpine arthropod diversity is also largely understudied worldwide, and the plant-arthropod interactions reported are mostly negative, that is,. herbivory. Plant and arthropod diversity and abundance were sampled on S. acaulis and at paired adjacent microsites with other non-cushion forming vegetation present on Whistler Mountain, B.C., Canada to examine the relative trophic effects of cushion plants. Plant species richness and abundance but not Simpson’s diversity index was higher on cushion microsites relative to other vegetation. Arthropod richness, abundance, and diversity were all higher on cushion microsites relative to other vegetated sites. On a microclimatic scale, S. acaulis ameliorated stressful conditions for plants and invertebrates living inside it, but the highest levels of arthropod diversity were observed on cushions with tall plant growth. Hence, alpine cushion plants can be foundation species not only for other plant species but other trophic levels, and these impacts are expressed through both direct and indirect effects associated with altered environmental conditions and localized productivity. Whilst this case study tests a limited subset of the membership of alpine animal communities, it clearly demonstrates that cushion-forming plant species are an important consideration in understanding resilience to global changes for many organisms in addition to other plants

Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Habitat partitioning and vulnerability of sharks in the Great Barrier Reef Marine Park

Sharks present a critical conservation challenge, but little is known about their spatial distribution and vulnerability, particularly in complex seascapes such as Australia's Great Barrier Reef Marine Park (GBRMP). We review (1) the distribution of shark species among the primary habitats of the GBRMP (coral reefs, inshore/shelf, pelagic and deep-water habitats) (2) the relative exploitation of each species by fisheries, and (3) how current catch rates interact with their vulnerability and trophic index. Excluding rays and chimaeras, we identify a total of 82 shark species in the GBRMP. We find that shark research in the GBRMP has yielded little quantitative information on most species. Reef sharks are largely site-fidelic, but can move large distances and some regularly use non-reef habitats. Inshore and shelf sharks use coastal habitats either exclusively or during specific times in their life cycle (e.g. as nurseries). Virtually nothing is known about the distribution and habitat use of the GBRMP's pelagic and deep-water sharks. At least 46 species (53.5 %) are caught in one or more fisheries, but stock assessments are lacking for most. At least 17 of the sharks caught are considered highly vulnerable to exploitation. We argue that users of shark resources should be responsible for demonstrating that a fishery is sustainable before exploitation is allowed to commence or continue. This fundamental change in management principle will safeguard against stock collapses that have characterised many shark fisheries

Efficacy of Gluma Desensitizer® on dentin hypersensitivity in periodontally treated patients Eficácia do Gluma Desensitizer® sobre hipersensibilidade dentinária em pacientes periodontalmente tratados

The aim of this double-blind, controlled, split-mouth designed clinical trial was to assess the effect of a single application of Gluma Desensitizer® on alleviating dentin hypersensitivity. Twelve subjects entered the study and ten completed the protocol. Each subject had two teeth treated: one with Gluma Desensitizer® according to the manufacturer's instructions and one with water. The assessment of pain was performed with the VAS (Visual Analogue Scale), after tactile (probe), thermal (cold blast of water) and thermal/evaporative (cold blast of air) stimuli at baseline, immediately after treatment, after 1 week and after 4 weeks. The mean VAS values for the test and control teeth were compared by the paired t test (alpha = 0.05). Repeated measurements ANOVA was used to compare the different experimental times. The results showed that for test teeth, at baseline, mean VAS values were 1.76 (&plusmn; 2.82), 7.10 (&plusmn; 2.10) and 4.75 (&plusmn; 2.65), and, after 4 weeks, the mean values were 1.70 (&plusmn; 2.31), 5.50 (&plusmn; 3.30) and 4.61 (&plusmn; 3.14), respectively for probe, water and air stimuli. For the control teeth, at baseline, the mean VAS values were 1.86 (&plusmn; 2.92), 6.61 (&plusmn; 2.31) and 4.08 (&plusmn; 2.91) and, after 4 weeks, 2.66 (&plusmn; 3.07), 6.32 (&plusmn; 2.94) e 4.76 (&plusmn; 3.26).There were no statistically significant differences between test and control teeth at any time. No intra-group differences were demonstrated either. It was concluded that Gluma Desensitizer® had no effect on hypersensitive teeth from periodontally treated patients for a period up to 4 weeks.<br>O objetivo deste estudo clínico duplo-cego, controlado, de boca-dividida foi avaliar o efeito de uma aplicação única do Gluma Desensitizer® no alívio da hipersensibilidade dentinária. Doze sujeitos participaram do estudo, sendo que destes dez completaram o estudo. Cada um dos participantes teve dois dentes tratados, um com o Gluma Desensitizer®, de acordo com as orientações do fabricante, e o outro com água. Para a avaliação da dor foi utilizada a EVA (Escala Visual Analógica), após os estímulos táctil (sonda), térmico (jato de água frio) e térmico/evaporativo (jato de ar frio) no início do experimento, imediatamente após o tratamento, uma e quatro semanas após. Os valores médios encontrados na EVA foram comparados pelo teste-t pareado (alfa = 0,05). Para os diferentes tempos experimentais utilizou-se ANOVA para medidas repetidas. Os resultados mostram que, no início do tratamento, os valores médios foram de 1,76 (&plusmn; 2,82), 7,10 (&plusmn; 2,10) e 4,75 (&plusmn; 2,65) para os dentes teste e, após quatro semanas, os valores médios foram de 1,70 (&plusmn; 2,31), 5,50 (&plusmn; 3,30) e 4,61 (&plusmn; 3,14) respectivamente para os estímulos sonda, água e ar. Para os dentes controle, no início do tratamento, os valores médios segundo a EVA foram de 1,86 (&plusmn; 2,92), 6,61 (&plusmn; 2,31) e 4,08 (&plusmn; 2,91) e, após 4 semanas, 2,66 (&plusmn; 3,07), 6,32 (&plusmn; 2,94) e 4,76 (&plusmn; 3,26). Não ocorreram diferenças estatisticamente significativas entre os dentes teste e controle em nenhum dos tempos experimentais. Também não ocorreram diferenças intragrupo. Concluímos que o Gluma Desensitizer® não tem efeito sobre a hipersensibilidade dentinária de pacientes periodontalmente tratados num período de até quatro semanas

Mitochondrial-Targeted Curcuminoids: A Strategy to Enhance Bioavailability and Anticancer Efficacy of Curcumin

<div><p>Although the anti-cancer effects of curcumin has been shown in various cancer cell types, in vitro, pre-clinical and clinical studies showed only a limited efficacy, even at high doses. This is presumably due to low bioavailability in both plasma and tissues, particularly due to poor intracellular accumulation. A variety of methods have been developed to achieve the selective targeting of drugs to cells and mitochondrion. We used a novel approach by conjugation of curcumin to lipophilic triphenylphosphonium (TPP) cation to facilitate delivery of curcumin to mitochondria. TPP is selectively taken up by mitochondria driven by the membrane potential by several hundred folds. In this study, three mitocurcuminoids (mitocurcuminoids-1, 2, and 3) were successfully synthesized by tagging TPP to curcumin at different positions. ESI-MS analysis showed significantly higher uptake of the mitocurcuminoids in mitochondria as compared to curcumin in MCF-7 breast cancer cells. All three mitocurcuminoids exhibited significant cytotoxicity to MCF-7, MDA-MB-231, SKNSH, DU-145, and HeLa cancer cells with minimal effect on normal mammary epithelial cells (MCF-10A). The IC₅₀ was much lower for mitocurcuminoids when compared to curcumin. The mitocurcuminoids induced significant ROS generation, a drop in ΔØm, cell-cycle arrest and apoptosis. They inhibited Akt and STAT3 phosphorylation and increased ERK phosphorylation. Mitocurcuminoids also showed upregulation of pro-apoptotic BNIP3 expression. In conclusion, the results of this study indicated that mitocurcuminoids show substantial promise for further development as a potential agent for the treatment of various cancers.</p></div