Uranus evolution models with simple thermal boundary layers

The strikingly low luminosity of Uranus (Teff ~ Teq) constitutes a long-standing challenge to our understanding of Ice Giant planets. Here we present the first Uranus structure and evolution models that are constructed to agree with both the observed low luminosity and the gravity field data. Our models make use of modern ab initio equations of state at high pressures for the icy components water, methane, and ammonia. Proceeding step by step, we confirm that adiabatic models yield cooling times that are too long, even when uncertainties in the ice:rock ratio (I:R) are taken into account. We then argue that the transition between the ice/rock-rich interior and the H/He-rich outer envelope should be stably stratified. Therefore, we introduce a simple thermal boundary and adjust it to reproduce the low luminosity. Due to this thermal boundary, the deep interior of the Uranus models are up to 2--3 warmer than adiabatic models, necessitating the presence of rocks in the deep interior with a possible I:R of $1\times$ solar. Finally, we allow for an equilibrium evolution (Teff ~ Teq) that begun prior to the present day, which would therefore no longer require the current era to be a "special time" in Uranus' evolution. In this scenario, the thermal boundary leads to more rapid cooling of the outer envelope. When Teff ~ Teq is reached, a shallow, subadiabatic zone in the atmosphere begins to develop. Its depth is adjusted to meet the luminosity constraint. This work provides a simple foundation for future Ice Giant structure and evolution models, that can be improved by properly treating the heat and particle fluxes in the diffusive zones.Comment: 13 pages, Accepted to Icaru

Panel Discussion - Management of Eurasian watermilfoil in the United States using native insects: State regulatory and management issues

While researchers have evaluated the potential of native insect herbivores to manage nonindigenous aquatic plant species such as Eurasian watermilfoil ( Myriophyllum spicatum L.), the practical matters of regulatory compliance and implementation have been neglected. A panel of aquatic nuisance species program managers from three state natural resource management agencies (Minnesota, Vermont and Washington) discussed their regulatory and policy concerns. In addition, one ecological consultant attempting to market one of the native insects to manage Eurasian watermilfoil added his perspective on the special challenges of distributing a native biological control agent for management of Eurasian watermilfoil

Phase separation in hydrogen-helium mixtures at Mbar pressures

The properties of hydrogen-helium mixtures at Mbar pressures and intermediate temperatures (4000 to 10000 K) are calculated with first-principles molecular dynamics simulations. We determine the equation of state as a function of density, temperature, and composition and, using thermodynamic integration, we estimate the Gibbs free energy of mixing, thereby determining the temperature, at a given pressure, when helium becomes insoluble in dense metallic hydrogen. These results are directly relevant to models of the interior structure and evolution of Jovian planets. We find that the temperatures for the demixing of helium and hydrogen are sufficiently high to cross the planetary adiabat of Saturn at pressures around 5 Mbar; helium is partially miscible throughout a significant portion of the interior of Saturn, and to a lesser extent in Jupiter.Comment: 6 pages, 7 figures. Published in "Proceedings of the National Academy of Sciences USA

The Impact of Endothall on the Aquatic Plant Community of Kress Lake, Washington

CA dense mat-forming population of Eurasian watermilfoil ( Myriophyllum spicatum L . ) was interfering with fishing and recreation in a small western Washington lake. A low concentration (1.5 mg/L active ingredient) of the herbicide endothall formulated as Aquathol® K was used in 2000 to attempt to selectively control the Eurasian watermilfoil. Aquatic plant biomass and frequency data were collected before treatment, ten weeks after treatment and during the growing season for 3 additional years. Macrophyte data were analyzed to assess the herbicide’s impacts on Eurasian watermilfoil as well as the rest of the aquatic plant community. Results showed a significant decrease in Eurasian watermilfoil biomass and frequency 10 weeks after treatment. The Eurasian watermilfoil continued to be present, but at a significantly reduced level through the remainder of the study (3 years after treatment). Of the native plant species, large-leaf pondweed ( Potamogeton amplifolius Tucker . ) frequency and biomass was significantly reduced after treatment. Common elodea ( Elodea canadensis Rich.), muskgrass ( Chara sp. Vallaint.) and bladderwort ( Utricularia sp. L.) all increased significantly after treatment. (PDF has 6 pages.

Impact of arbuscular mycorrhizal fungi on the growth and rhizobium symbioses development in kabuli and desi chickpeas grown under drought stress conditions

Non-Peer ReviewedArbuscular mycorrhizal fungi (AMF) have induced drought tolerance in several plants and could increase chickpea yield under semiarid climates. Desi chickpea are more drought tolerant than Kabuli suggesting a weak mycorrhizal symbiosis in this chickpea type. A greenhouse experiment was conducted to assess the extent and the impact of arbuscular mycorrhizal symbiosis on the growth and yield in Kabuli and Desi chickpea cultivars under well watered and drought stress conditions and on their association with Mesorhizobium cicer. The experiment had a split-plot design with two water levels, 30% of field capacity (deficient water) and 70% of field capacity (sufficient water) randomized in main plots. Two inoculation treatments, M. cicer + AMF and M. cicer only, were applied to chickpea (Kabuli, CDC Frontier and CDC Xena; Desi, CDC Anna, and CDC Nika). The factorial combinations of inoculation and cultivar were randomized in the subplots. There were four repetitions. One set of plants was harvested at the time of symbioses development and another set was harvested at seed maturation. The data was analyzed with ANOVA. Results indicated that the Kabuli and Desi chickpea mycorrhizal symbioses are not different, as indicated by the absence of a cultivar by inoculation interaction on shoot and root growth, nodulation and nitrogen fixation. AM Fungi inoculation delayed nodule development but had no effect on grain yield. CDC Frontier had 4 times more nodules and 6 times more nitrogenase activity than CDC Anna, Nika and Xena

Foreign Direct Investments in Business Services: Transforming the Visegrád Four Region into a Knowledge-based Economy?

Foreign direct investments (FDIs) in the service sector are widely attributed an important role in bringing more skill-intensive activities into the Visegrad Four (V4). This region—comprising Poland, the Czech Republic, Hungary and Slovakia—relied heavily on FDIs in manufacturing, which was often found to generate activities with limited skill content. This contribution deconstructs the chaotic concept of “business services” by analysing the actual nature of service sector activities outsourced and offshored to the V4. Using the knowledge-based economy (KBE) as a benchmark, the paper assesses the potential of service sector outsourcing in contributing to regional competitiveness by increasing the innovative capacity. It also discusses the role of state policies towards service sector FDI (SFDI). The analysis combines data obtained from case studies undertaken in service sector outsourcing projects in V4 countries. Moreover, it draws on interviews with senior employees of investment promotion agencies and publicly available data and statistics on activities within the service sector in the region. It argues that the recent inward investments in business services in the V4 mainly utilize existing local human capital resources, and their contribution to the development of the KBE is limited to employment creation and demand for skilled labour

Diabetes Aggravates Periodontitis by Limiting Repair Through Enhanced Inflammation

Periodontitis is the most common lytic bone disease and one of the first clinical manifestations of diabetes. Diabetes increases the risk of periodontitis. The aim of the present study was to examine mechanisms by which diabetes aggravates periodontitis. Ligature-induced periodontitis was examined in Goto-Kakizaki rats with type 2 diabetes. A tumor necrosis factor (TNF)-specificinhibitor, pegsunercept, was applied to diabetic rats after the onset of periodontal disease. Interferon-γ (IFN-γ), TNF-α, interleukin-1 β (IL-1β), fibroblast growth factor-2 (FGF-2), transforming growth factor beta-1 (TGFβ-1), bone morphogenetic protein-2 (BMP-2), and BMP-6 were measured by real-time RT-PCR, and histological sections were examined for leukocyte infiltration and several parameters related to bone resorption and formation. Inflammation was prolonged in diabetic rats and was reversed by the TNF inhibitor, which reduced cytokine mRNA levels, leukocyte infiltration, and osteoclasts. In contrast, new bone and osteoid formation and osteoblast numbers were increased significantly vs. untreated diabetic animals. TNF inhibition in diabetic animals also reduced apoptosis, increased proliferation of bone-lining cells, and increased mRNA levels of FGF-2, TGFβ-1, BMP-2, and BMP-6. Thus, diabetes prolongs inflammation and osteoclastogenesis in periodontitis and through TNF limits the normal reparative process by negatively modulating factors that regulate bone. © FASEB

Pharmacokinetic Properties of Single- and Repeated-dose Sufentanil Sublingual Tablets in Healthy Volunteers

AbstractPurposeSufentanil is a μ-opioid agonist with a high therapeutic index in preclinical studies and no active metabolites, and it is highly lipophilic, thereby enabling a transmucosal route of administration. Rapid distribution from the plasma after IV sufentanil administration results in a short duration of action requiring excessive repeated dosing if used for postoperative analgesia. The sufentanil sublingual tablet system (SSTS) is a handheld, preprogrammed, patient-controlled analgesia system designed to allow patients to self-administer sufentanil 15-μg tablets under their tongue with a 20-minute lockout. The pharmacokinetic (PK) characteristics of sufentanil, administered by different routes of delivery and after single and repeated sublingual (SL) administration, were examined in 2 studies.MethodsA randomized, open-label, crossover study in healthy subjects evaluated the PK profile of sufentanil 15 μg administered by different routes: IV, SL, buccal (BU), and PO. A second open-label, crossover study in healthy subjects evaluated the PK parameters after single and repeated doses (full SSTS drug cartridge of 40 consecutive SL doses administered every 20 minutes) of a sufentanil 15-μg SL tablet. Doses were self-administered using the SSTS.FindingsIn the route of administration study (n = 25), mean Cmax values were highest with IV administration, and bioavailability values were: SL, 59%; BU, 78%; and PO, 9%. The absorption across the oral mucosa was associated with a median plasma half-time (time from Cmax to 50% of Cmax) that was 25-fold longer (2.5 hours) with SL versus IV administration (0.1 hours). In the single- and repeated-dose study (n = 38), mean AUC0–∞ was 125.5 h · pg/mL, and Cmax was 35.0 pg/mL, with a median Tmax of 0.8 hours after the administration of a single sufentanil SL tablet. With 40 consecutive doses, Cmax was 8-fold higher compared with that of a single dose, and steady state was achieved after the 13th dose. Median plasma half-time after the 40th dose was not statistically longer than that after a single dose (2.7 vs 2.2 hours, respectively), and the median Tmax was 0.3 hours after the last repeated dose.ImplicationsThese study results support the viability of the SSTS for use in patient-controlled analgesia. The wide range of mean drug concentrations achieved after repeated dosing at 20-minute intervals compared with those with a single dose suggests the flexibility of patient-controlled dosing to meet individual analgesic requirements. The prolonged plasma half-time with SL administration is expected to provide a more appropriate duration of analgesia compared with that of IV administration, and the PK properties of repeated-dose administration support a 20-minute lockout interval

Delay in diagnosis of patients with head-and-neck cancer in Canada: impact of patient and provider delay.

Background: Head-and-neck cancers (hncs) often present at an advanced stage, leading to poor outcomes. Late presentation might be attributable to patient delays (reluctance to seek treatment, for instance) or provider delays (misdiagnosis, prolonged wait time for consultation, for example). The objective of the present study was to examine the length and cause of such delays in a Canadian universal health care setting. Methods: Patients presenting for the first time to the hnc multidisciplinary team (mdt) with a biopsy-proven hnc were recruited to this study. Patients completed a survey querying initial symptom presentation, their previous medical appointments, and length of time between appointments. Clinical and demographic data were collected for all patients. Results: The average time for patients to have their first appointment at the mdt clinic was 15.1 months, consisting of 3.9 months for patients to see a health care provider (hcp) for the first time since symptom onset and 10.7 months from first hcp appointment to the mdt clinic. Patients saw an average of 3 hcps before the mdt clinic visit (range: 1-7). No significant differences in time to presentation were found based on stage at presentation or anatomic site. Conclusions: At our tertiary care cancer centre, a patient\u27s clinical pathway to being seen at the mdt clinic shows significant delays, particularly in the time from the first hcp visit to mdt referral. Possible methods to mitigate delay include education about hnc for patients and providers alike, and a more streamlined referral system