426 research outputs found
Open Innovation in a Dynamic Cournot Duopoly
We analyze an Open Innovation process in a Cournot duopoly using a differential game approach where knowledge spillovers are endogenously determined via the R&D process. The game produces multiple steady states, allowing for an asymmetric solution where a firm may trade off the R&D investment against information absorption from the rival.
Optical and structural properties of sol-gel derived materials embedded in porous anodic alumina
Structure composing a xerogel, doped with lanthanide ions (erbium, terbium and europium), embedded in porous anodic alumina (PAA) have been fabricated and their optical and electrical characterisitics have been studied. Erbium photoluminescence at 1.53 µm from titania xerogel/PAA was found to increase with the number of xerogel layers and erbium concnetration for the excitation wavelength 532 nm, matching the area of transparency of both titania xerogel and PAA. Visible green and red electroluminescence was observed for terbium- and europium-doped IN2O3 and SnO2 xerogels embedded in porous anodic alumina. The improvement of the electrical properties of the xerogel/PAA cell is discussed, taking into account the observed ability of conducting In2O3:Sn (ITO) nanoparticles to penetrate into the anodic alumina pores
Increasing Dominance - the Role of Advertising, Pricing and Product Design
Despite the empirical relevance of advertising strategies in concentrated markets, the economics literature is largely silent on the effect of persuasive advertising
strategies on pricing, market structure and increasing (or decreasing) dominance. In a simple model of persuasive advertising and pricing with differentiated goods,
we analyze the interdependencies between ex-ante asymmetries in consumer appeal, advertising and prices. Products with larger initial appeal to consumers will
be advertised more heavily but priced at a higher level - that is, advertising and price discounts are strategic substitutes for products with asymmetric initial appeal.
We find that the escalating effect of advertising dominates the moderating effect of pricing so that post-competition market shares are more asymmetric than pre-competition differences in consumer appeal. We further find that collusive advertising (but competitive pricing) generates the same market outcomes, and that network effects lead to even more extreme market outcomes, both directly and via
the effect on advertising
Expansive reed populations-alien invasion or disturbed wetlands?
The tall-statured grasses in the genus Phragmites are dominant vegetation in wetlands worldwide and thus play a vital role in ecosystem functioning. As a result, Phragmites spp. are some of the most widely studied plants; particularly in areas where changes to their abundances have occurred, most notably in Europe and North America. In southern Africa a pattern of reed expansion has occurred in recent decades that has shown a similar trend to cryptic invasions reported in North America. This study used molecular techniques to explore the phylogeography of P. australis and P. mauritianus in the region to investigate whether the expansion is due to an alien invasion or local factors such as wetland disturbance. Three haplotypes were found and all haplotypes are presently considered African haplotypes (haplotype K for P. australis and haplotype V and AP for P. mauritianus). Both Phragmites spp. were found to have high genetic diversity. Microsatellite and grass-waxy analysis also found evidence of hybridization between the two species. No evidence was found for a recent cryptic invasion of non-native haplotypes in southern Africa. The expansion of P. australis and P. mauritianus is therefore most likely a result of anthropogenic activity. Identifying and mitigating the human-mediated factors that may be contributing to reed growth, such as eutrophication and sedimentation, should be the focus of future management protocols
Feeding dehydrated alfalfa increases polyunsaturated fatty acids concentration in Marchigiana beef muscle
Beef meat is a low fat food (<5% fat). However, the fatty acid composition of beef is relatively saturated (approximately 45-50%). The polyunsaturated/saturated fatty acids (P/S) ratio in beef is approximately 0.1, the ideal being about 0.4 (Department of Health, 1994). This can cause critical comments to beef meat related to human health
A retrospective study evaluating the impact of scattering radiation from imaging procedures on oocyte quality during ovarian stimulation for fertility preservation in young breast cancer patients
Purpose: Ovarian stimulation for oocyte and embryo cryopreservation is the standard of care for fertility preservation in young breast cancer patients before gonadotoxic chemotherapy. The procedure should be started as soon as possible to avoid delay of treatment; thus, it is often performed concomitantly with tumor staging assessments. However, questions remain regarding the potential negative impact on oocyte quality that may occur due to exposure to scattered ionizing radiation from imaging techniques when staging assessment is conducted at the same time as ovarian stimulation. Methods: We conducted a retrospective study on all breast cancer patients who performed ovarian stimulation for fertility preservation at our center between November 2012 and May 2020. Results: Gynecologic and oncological characteristics were similar between patients exposed (n = 14) or not (n = 60) to ionizing radiation. Exposed patients started the ovarian stimulation sooner after diagnosis than non-exposed patients (11.5 vs 28 days, respectively, P < 0.01). Cycle parameters, including the median number of oocytes collected (10.5 vs 7, P = 0.16), maturation rates (92.5% vs 85.7%, P = 0.54), and fertilization rates (62.2% vs 65.4%, P = 0.70), were similar between groups. Conclusion: This study shows that scattered ionizing radiation due to staging assessment appears to be safe without compromising follicular growth and maturation. Larger studies on fertility and obstetrical outcomes are needed to confirm these preliminary data
Ovarian toxicity of carboplatin and paclitaxel in mouse carriers of mutation in BRIP1 tumor suppressor gene
open6More than 10% of women diagnosed with breast cancer during reproductive age carry hereditary germline pathogenic variants in high-penetrance BRCA genes or in others genes involved in DNA repair mechanisms such as PALB2, BRIP or ATM. Anticancer treatments may have an additional negative impact on the ovarian reserve and subsequently on the fertility of young patients carrying such mutations. Recently, the combination of carboplatin and paclitaxel is being recommended to these BRCA-mutated patients as neoadjuvant therapy. However, the impact on the ovary is unknown. Here, we investigated their effect of on the ovarian reserve using mice carriers of BRCA1-interacting protein C-terminal helicase-1 (BRIP1) mutation that plays an important role in BRCA1-dependent DNA repair. Results revealed that the administration of carboplatin or paclitaxel did not affect the ovarian reserve although increased DNA double-strand breaks were observed with carboplatin alone. Co-administration of carboplatin and paclitaxel resulted in a significant reduction of the ovarian reserve leading to a lower IVF performance, and an activation of the PI3K-Pten pathway, irrespective of the genetic background. This study suggests that co-administration of carboplatin and paclitaxel induces cumulative ovarian damage and infertility but a heterozygote genetic predisposition for DNA damage related to BRCA1 gene function does not increase this risk.openNtemou E.; Vidal P.D.; Alexandri C.; Van den Steen G.; Lambertini M.; Demeestere I.Ntemou, E.; Vidal, P. D.; Alexandri, C.; Van den Steen, G.; Lambertini, M.; Demeestere, I
LH prevents cisplatin-induced apoptosis in oocytes and preserves female fertility in mouse
Premature ovarian failure and female infertility are frequent side effects of anticancer therapies, owing to the extreme sensitivity of the ovarian reserve oocytes to the damaging effects of irradiation and chemotherapy on DNA. We report here a robust protective effect of luteinizing hormone (LH) on the primordial follicle pool of prepubertal ovaries against the cisplatin (Cs)-induced apoptosis. In vitro LH treatment of prepubertal ovarian fragments generated anti-apoptotic signals by a subset of ovarian somatic cells expressing LH receptor (LHR) through cAMP/PKA and Akt pathways. Such signals, reducing the oocyte level of pro-apoptotic TAp63 protein and favoring the repair of the Cs-damaged DNA in the oocytes, prevented their apoptosis. Noteworthy, in vivo administration to prepubertal female mice of a single dose of LH together with Cs inhibited the depletion of the primordial follicle reserve caused by the drug and preserved their fertility in reproductive age, preventing significant alteration in the number of pregnancy and of delivered pups. In conclusion, these findings establish a novel ovoprotective role for LH and further support the very attracting prospective to use physiological 'fertoprotective' approaches for preventing premature infertility and risks linked to precocious menopause in young patients who survived cancer after chemotherapy
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