245 research outputs found
Experimental Testbeds for ECOSEL: A Market Framework for Private Provision of Forest Ecosystem Services
We attempt to design a market framework (which we call ECOSEL) for private provision of forest ecosystem services. ECOSEL is a non-regulatory framework that uses a voluntary public good provision mechanism (in a form of an auction) in conjunction with a multiobjective optimization algorithm to create a market for forest ecosystem services. It is expected to be attractive to the demand side of the ecosystem service market since only Pareto-efficient bundles of services are offered for auction, and it is expected to be attractive to the supply side as well by creating a source of non-timber income for forest landowners. ECOSEL is capable of flexible response to demand for other relevant dimensions of forest-related environmental amenities such as biodiversity, viewshed or recreational services. Following Roth’s (2002) advice on behavior of economists as “market engineers”, we use both experimental economics to improve the design of the ecosystem services market. Concurrently, we provide experimental evidence on the efficiency and revenue-generating properties of a multi-good subscription game of incomplete information.Environmental Economics and Policy, Marketing,
Application of time-dependent density functional theory to optical activity
As part of a general study of the time-dependent local density approximation
(TDLDA), we here report calculations of optical activity of chiral molecules.
The theory automatically satisfies sum rules and the Kramers-Kronig relation
between circular dichroism and optical rotatory power. We find that the theory
describes the measured circular dichroism of the lowest states in methyloxirane
with an accuracy of about a factor of two. In the chiral fullerene C_76 the
TDLDA provides a consistent description of the optical absorption spectrum, the
circular dichroism spectrum, and the optical rotatory power, except for an
overall shift of the theoretical spectrum.Comment: 17 pages and 13 PostScript figure
Health-related quality of life: a retrospective study on local vs. microvascular reconstruction in patients with oral cancer
BackgroundNew medicinal and surgical oncological treatment strategies not only improve overall survival rates but continually increase the importance of Health-Related Quality of Life (HRQOL). The purpose of this retrospective cross-sectional study was to analyze HRQOL of patients with oral squamous cell carcinoma after ablative surgery and to evaluate predictive factors for HRQOL outcome.MethodsThe study included 88 patients with histologically confirmed oral squamous cell carcinoma of whom 42 had undergone local reconstruction (LR) and 46 microvascular reconstruction (MVR). During follow-up, all patients completed the University of Washington Quality of Life Questionnaire (UW-QOL) containing 12 targeted questions about the head and neck. Descriptive analyses were made for the tumor site, the T-stage, and adjuvant therapies. HRQOL was compared between the LR and the MVR group with parametric tests. Further analyses were impact of the tumor site, the T-status, and the time from surgery to survey on HRQOL. Statistics also included multivariate correlations and different interaction effects.ResultsHRQOL in the LR group was very good' with 84.313.7 and good' in the MVR group with 73.316.5 points. The physical domains swallowing (p=0.00), chewing (p=0.00), speech (p=0.01), taste (p=0.01), and pain (p=0.04) were significantly worse in the MVR group. An increase in the T-status had a significant negative effect on swallowing (p=0.01), chewing (p=0.01), speech (p=0.03), recreation (p=0.05), and shoulder (p=0.01) in both groups. Regarding the tumor site and subsequent loss of HRQOL, patients with squamous cell carcinoma on the floor of the mouth had significantly worse results in the categories pain (p=0.002), speech (p=0.002), swallowing (p=0.03), activity (p=0.02), and recreation (p=0.01) than patients with tumors in the buccal mucosa. Speech (p=0.03) and pain (p=0.01) had improved 1year after surgery.Conclusion Patients with flap reconstruction because of oral squamous cell carcinoma showed very good overall HRQOL. Outcomes for microvascular reconstruction were good, even in the case of larger defects. The T-status is a predictor for HRQOL. Swallowing, chewing, speaking, taste, and pain were the most important issues in our cohort. Implementing HRQOL questionnaires for the assessment of quality of life could further increase the treatment quality of patients with oral cancer
Infraorbital cutaneous angiosarcoma: a diagnostic and therapeutic dilemma
Background
A cutaneous angiosarcoma is a rare malignant tumour of vascular endothelial cells with aggressive clinical behaviour and poor prognosis. Diagnosis is often delayed due to its variable and often benign clinical appearance.
Case presentation
This case presents a 64-year-old man with a six-month-history of a recurrent diffuse and erythematous painless swelling below the left eye. Several resections with intraoperatively negative resection margins followed, but positive margins were repeatedly detected later on permanent sections. Histopathologic examination of the specimen diagnosed a cutaneous angiosarcoma. Neither, finally achieved negative margins on permanent sections, nor a following chemotherapy could prevent the recurrence of the disease after five months and the patient's dead 21 months after the first diagnosis.
Conclusion
The case elucidates the current diagnostic and therapeutic dilemma of this entity, which shows an unfavourable clinical course in spite of multimodal therapy
Contour identical implants to bridge mandibular continuity defects - individually generated by LaserCUSING® - A feasibility study in animal cadavers
Background
Ablative tumor surgery often results in continuity defects of the mandible. When an immediate reconstruction using autologous bone grafts is not possible the bridging of the defects with a variety of bridging plates might be achieved. However, those bridging plates have the risk of plate fractures or exposure. Customized titanium implants manufactured using CAD/CAM and the LaserCUSING® technique might be an alternative.
Methods
In the present study, computed tomographies (CT) of porcine cadaver mandibles were generated and transferred into DICOM data. Following, different continuity defects were surgically created in the mandibles. Based on the DICOM data customized titanium implants were manufactured using CAD/CAM procedures and the LaserCUSING® technique. The implants were fixed to the remaining stumps with screws. Subsequently, the accuracy of the reconstructed mandibles was tested using plaster casts.
Results
The workflow from the CT to the application of the customized implants was proved to be practicable. Furthermore, a stable fixation of the customized implant to the remaining stumps could be achieved. The control of the accuracy showed no frictions or obstacles.
Conclusion
The customized titanium implant seems to be a promising approach to bridge continuity defects of the mandible whenever an immediate reconstruction with autologous bone is not possible
Encouraging female entrepreneurship in Jordan: environmental factors, obstacles and challenges
The number of female entrepreneurs and their contribution to the economy is steadily rising. Yet research suggests that female entrepreneurs face more challenges and barriers than their male counterparts. This is expected to be even more prevalent in Islamic contexts, which are characterised by conservative and patriarchal societies. In this research, 254 female business students from a private and a public university responded to a questionnaire that gauges their perceptions about potential barriers to entrepreneurship in Jordan and whether the business education they are receiving helps to prepare them for future entrepreneurial activity. Our results help to form a basis on which a deeper understanding of the phenomena can be achieved through more in depth future research. Among the main environmental factors that worry potential female entrepreneurs are the weakness of Jordanian economy, lack of finance, fear of risk, gender inequality and inability to maintain a work and private life balance. Our results also show that students are really not aware of the opportunities available to them and are unable to make a proper assessment. We call on both universities and the Jordanian government to put more emphasis on practical entrepreneurial education and encouraging women to play a much more active role within the workforce
Hepatitis B Virus Lacks Immune Activating Capacity, but Actively Inhibits Plasmacytoid Dendritic Cell Function
Chronic hepatitis B virus (HBV) infection is caused by inadequate anti-viral immunity. Activation of plasmacytoid dendritic cells (pDC) leading to IFNα production is important for effective anti-viral immunity. Hepatitis B virus (HBV) infection lacks IFNα induction in animal models and patients and chronic HBV patients display impaired IFNα production by pDC. Therefore, HBV and HBV-derived proteins were examined for their effect on human pDC in vitro. In addition, the in vitro findings were compared to the function of pDC derived from chronic HBV patients ex vivo. In contrast to other viruses, HBV did not activate pDC. Moreover, HBV and HBsAg abrogated CpG-A/TLR9-induced, but not Loxoribine/TLR7-induced, mTOR-mediated S6 phosphorylation, subsequent IRF7 phosphorylation and IFNα gene transcription. HBV/HBsAg also diminished upregulation of co-stimulatory molecules, production of TNFα, IP-10 and IL-6 and pDC-induced NK cell function, whereas TLR7-induced pDC function was hardly affected. In line, HBsAg preferentially bound to TLR9-triggered pDC demonstrating that once pDC are able to bind HBV/HBsAg, the virus exerts its immune regulatory effect. HBV not only directly interfered with pDC function, but also indirectly by interfering with monocyte-pDC interaction. Also HBeAg diminished pDC function to a certain extent, but via another unknown mechanism. Interestingly, patients with HBeAg-positive chronic hepatitis B displayed impaired CpG-induced IFNα production by pDC without significant alterations in Loxoribine-induced pDC function compared to HBeAg-negative patients and healthy controls. The lack of activation and the active inhibition of pDC by HBV may both contribute to HBV persistence. The finding that the interaction between pDC and HBV may change upon activation may aid in the identification of a scavenging receptor supporting immunosuppressive effects of HBV and also in the design of novel treatment strategies for chronic HBV
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