2,740 research outputs found
An Improved Tax Scheme for Selfish Routing
We study the problem of routing traffic for independent selfish users in a congested network to minimize the total latency. The inefficiency of selfish routing motivates regulating the flow of the system to lower the total latency of the Nash Equilibrium by economic incentives or penalties. When applying tax to the routes, we follow the definition of [Christodoulou et al, Algorithmica, 2014] to define ePoA as the Nash total cost including tax in the taxed network over the optimal cost in the original network. We propose a simple tax scheme consisting of step functions imposed on the links. The tax scheme can be applied to routing games with parallel links, affine cost functions and single-commodity networks to lower the ePoA to at most 4/3 - epsilon, where epsilon only depends on the discrepancy between the links. We show that there exists a tax scheme in the two link case with an ePoA upperbound less than 1.192 which is almost tight. Moreover, we design another tax scheme that lowers ePoA down to 1.281 for routing games with groups of links such that links in the same group are similar to each other and groups are sufficiently different
Environmental and Energy Assessment of Biomass Residues to Biochar as Fuel: A Brief Review with Recommendations for Future Bioenergy Systems
This study explores the environmental and energy benefits of biomass residues, including crop residues and agricultural waste, for the production of renewable energy in the form of biochar as fuel, in order to offer recommendations for policy makers, by reviewing information regarding the key environmental issues associated with the implementation of the systems. The highest environmental benefits for biochar-to-fuel systems were most observed in reduction of global warming potentials (i.e., carbon abatement), particularly for those integrated with combined heat and power technology, or for those incorporating electricity offsets from biochar combustion and co-firing. But all of these practices come at the cost of hidden environmental burdens, such as elevations in eutrophication, acidification, carcinogens and ecotoxicity impacts, as a consequence from land use change, additional infrastructure requirement or additional fertilizer application connected to biochar production or post-treatment. Other notable challenges, including regional availability of biomass residues, improper management of the residues, limited economic incentives, low energy efficiency and synergies, as well as mistreating adverse impacts from indirect land use change, were discussed. This suggests the flexibility to adjust the biomass-biochar ratio to optimize desired energy yields, carbon abatement and environmental beneficial objectives. Comprehensive analysis of the trade-offs between energy yields, carbon abatement and other associated environmental impacts is therefore recommended for future studies. Future studies in this field are also advised to explore the solution and to develop methodologies capable of quantifying the impacts and other equally relevant trade-offs, to better reflect the changes in real-world trends for decision making
Differential Dopamine D1 and D3 Receptor Modulation and Expression in the Spinal Cord of Two Mouse Models of Restless Legs Syndrome
Restless Legs Syndrome (RLS) is often and successfully treated with dopamine receptor
agonists that target the inhibitory D3 receptor subtype, however there is no clinical
evidence of a D3 receptor dysfunction in RLS patients. In contrast, genome-wide
association studies in RLS patients have established that a mutation of the MEIS1 gene is
associated with an increased risk in developing RLS, but the effect of MEIS1 dysfunction
on sensorimotor function remain unknown. Mouse models for a dysfunctional D3
receptor (D3KO) and Meis1 (Meis1KO) were developed independently, and each animal
expresses some features associated with RLS in the clinic, but they have not been
compared in their responsiveness to treatment options used in the clinic. We here confirm
that D3KO and Meis1KO animals show increased locomotor activities, but that only
D3KO show an increased sensory excitability to thermal stimuli. Next we compared
the effects of dopaminergics and opioids in both animal models, and we assessed D1
and D3 dopamine receptor expression in the spinal cord, the gateway for sensorimotor
processing. We found that Meis1KO share most of the tested behavioral properties with
their wild type (WT) controls, including the modulation of the thermal pain withdrawal
reflex by morphine, L-DOPA and D3 receptor (D3R) agonists and antagonists. However,
Meis1KO and D3KO were behaviorally more similar to each other than to WT when tested
with D1 receptor (D1R) agonists and antagonists. Subsequent Western blot analyses of
D1R and D3R protein expression in the spinal cord revealed a significant increase in D1R
but not D3R expression in Meis1KO and D3KO over WT controls. As the D3R is mostly
present in the dorsal spinal cord where it has been shown to modulate sensory pathways,
while activation of the D1Rs can activate motoneurons in the ventral spinal cord, we
speculate that D3KO and Meis1KO represent two complementary animal models for
RLS, in which the mechanisms of sensory (D3R-mediated) and motor (D1R-mediated)
dysfunctions can be differentially explored
The Immunomodulatory Effect of You-Gui-Wan on Dermatogoides-pteronyssinus-Induced Asthma
The traditional Chinese medicine You-Gui-Wan (YGW) contains ten species of medicinal plants and has been used to improve health in remissive states of asthma for hundreds of years in Asia. However, little is known about the immunomodulatory mechanisms in vivo. Therefore, this study investigated the pathologic and immunologic responses to YGW in mice that had been repeatedly exposed to Dermatogoides-pteronyssinus (Der p). YGW reduced Der-p-induced airway hyperresponsiveness and total IgE in serum. It also inhibited eosinophil infiltration by downregulating the protein expression of IL-5 in serum and changed the Th2-bios in BALF by upregulating IL-12. Results of the collagen assay and histopathologic examination showed that YGW reduced airway remodeling in the lung. In addition, after YGW treatment there was a relative decrease in mRNA expression of TGF-β1, IL-13, eotaxin, RANTES, and MCP-1 in lung in the YGW group. The results of EMSA and immunohistochemistry revealed that YGW inhibited NF-κB expression in epithelial lung cells. YGW exerts its regulative effects in chronic allergic asthmatic mice via its anti-inflammatory activity and by inhibiting the progression of airway remodeling
Unusual case of spontaneous uterine rupture in a single gestational primipara
AbstractSpontaneous rupture of the primiparous uterus is a rare but catastrophic obstetrical emergency. It is usually associated with prior uterine surgery, trauma, or placental abnormality. To remind physicians to include this condition in their differential diagnosis of acute abdominal pain in pregnant patients, we describe an interesting case of spontaneous uterine rupture that clinically mimicked bowel perforation. A 27-year-old single primiparous pregnant woman presented with sudden onset of severe abdominal pain and peritoneal signs, with absence of vaginal bleeding at 26 weeks’ gestation. The usual risk factors for uterine rupture, such as advanced maternal age, scarred uterus due to mode of previous delivery, or unusual pregnancy, were not present in our patient. Based on clinical examination, abdominal sonography and magnetic resonance imaging, uterine rupture was suspected and eventually confirmed at exploratory laparotomy. No uterine pathological abnormality was noted on the microscopic examination The preterm newborn expired after surgery. Since surgical intervention is the only definitive treatment, emergency physicians should be aware of this rare complication. Emergency physicians should be aware of spontaneous uterine rupture in pregnant patients, even in the absence of risk factors
On the Influencing Factors of Dictionary App Interface Design for the Elders
AbstractEnglish learning is becoming one of the popular movements towards the Globalization. In recent years especially, more people use smartphones to learn English. However, it was found in the current market that most dictionary apps were designed for the younger generation and neglected the needs of the elderly. The issue of memory over-load turned out to be the critical problem of the usability for the elderly, due to the complex menu structures. Thus this study is meant to explore a suitable menu structure for the senior user, and provide suggestions for the relative researches.The study results are:1.Gender: There is no significant between male and female in the operating performance.2.Menu structure: the performance of the hybrid structure is superior to the linear structure.3.Display mode: There is no significant between the horizontal and vertical display modes in operating performance.4.Task Complexity: A positive ratio between task complexity and menu topological structure was revealed, the harder the task complexity, the better performance of mixed structure can be expected
Melatonin Therapy Prevents Programmed Hypertension and Nitric Oxide Deficiency in Offspring Exposed to Maternal Caloric Restriction
Nitric oxide (NO) deficiency is involved in the development of hypertension, a condition that can originate early in life. We examined whether NO deficiency contributed to programmed hypertension in offspring from mothers with calorie-restricted diets and whether melatonin therapy prevented this process. We examined 3-month-old male rat offspring from four maternal groups: untreated controls, 50% calorie-restricted (CR) rats, controls treated with melatonin (0.01% in drinking water), and CR rats treated with melatonin (CR + M). The effect of melatonin on nephrogenesis was analyzed using next-generation sequencing. The CR group developed hypertension associated with elevated plasma asymmetric dimethylarginine (ADMA, a nitric oxide synthase inhibitor), decreased L-arginine, decreased L-arginine-to-ADMA ratio (AAR), and decreased renal NO production. Maternal melatonin treatment prevented these effects. Melatonin prevented CR-induced renin and prorenin receptor expression. Renal angiotensin-converting enzyme 2 protein levels in the M and CR + M groups were also significantly increased by melatonin therapy. Maternal melatonin therapy had long-term epigenetic effects on global gene expression in the kidneys of offspring. Conclusively, we attributed these protective effects of melatonin on CR-induced programmed hypertension to the reduction of plasma ADMA, restoration of plasma AAR, increase of renal NO level, alteration of renin-angiotensin system, and epigenetic changes in numerous genes
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