Quantifying the Impact of Chikungunya and Dengue on Tourism Revenues

<b>Background</b><br> Health economists have traditionally quantified the burden of vector-borne diseases (such as chikungunya and dengue) as the sum of the cost of illness and the cost of intervention programmes. The objective of this paper is to predict the order of magnitude of possible reduction in tourism revenues if a major epidemic of chikungunya or dengue were to discourage visits by international tourists, and to prove that even a conservative estimate can be comparable to or even greater than the cost of illness and intervention programmes combined, and therefore should not be ignored in the estimation of the overall burden. <b>Methods</b><br> We have chosen three Asian economies where the immediate costs of these diseases have been recently calculated: Gujarat (an economically important state of India), Malaysia, and Thailand. Only international tourists from non-endemic countries have been considered to be discouraged, and a 4% annual decline in their numbers has been assumed. Revenues from these tourists have been calculated assuming that tourists from non-endemic countries would spend, on average, the same amount as all international tourists. These assumptions are conservative and consistent with the recent experience of Mauritius and R�union islands. Non-Resident Indians (NRIs) have been considered half as likely to avoid travel to Gujarat compared to non-Indians. This paper reports inflation-adjusted expenditure figures as 2008 US$, assuming recent market exchange rates of 42.0 INR/US$, 3.22 MYR/US$, 0.68 EUR/US$, and 33.6 THB/US$. <b>Findings</b><br> A 4$ 8 million for Gujarat, US$65 million for Malaysia, and US$ 363 million for Thailand. The estimated immediate annual cost of chikungunya and dengue to these economies is US$90 million, US$ 133 million, and approximately US$127 million respectively, indicating that impact on tourism revenues should not be ignored when calculating the burden of infectious diseases. The impact on Gujarat is relatively less because its share of world tourism receipts is just 0.04$ 9.6 million loss in domestic tourism revenues to Gujarat. <b>Interpretation</b><br> This paper shows that potential loss of tourism revenues due to a severe epidemic outbreak could be substantial. In some cases, ignoring this component could seriously underestimate cost-benefit results, forestalling promising interventions that could benefit the society as a whole or leading to inadequate investment of resources in prevention and public-funded control programmes. This would be to the detriment of especially poorer sections of the society, who may not be able to afford treatment costs. At present data are insufficient for us to make more than a preliminary estimate of the magnitude of the potential loss of revenues from tourism due to a major outbreak of chikungunya or dengue.

Limb position influences component orientation in Oxford mobile bearing unicompartmental knee arthroplasty: an experimental cadaveric study

Aims The mobile bearing Oxford unicompartmental knee arthroplasty (OUKA) is recommended to be performed with the leg in the hanging leg (HL) position, and the thigh placed in a stirrup. This comparative cadaveric study assesses implant positioning and intraoperative kinematics of OUKA implanted either in the HL position or in the supine leg (SL) position. Methods A total of 16 fresh-frozen knees in eight human cadavers, without macroscopic anatomical defects, were selected. The knees from each cadaver were randomized to have the OUKA implanted in the HL or SL position. Results Tibial base plate rotation was significantly more variable in the SL group with 75% of tibiae mal-rotated. Multivariate analysis of navigation data found no difference based on all kinematic parameters across the range of motion (ROM). However, area under the curve analysis showed that knees placed in the HL position had much smaller differences between the pre- and post-surgery conditions for kinematics mean values across the entire ROM. Conclusion The sagittal tibia cut, not dependent on standard instrumentation, determines the tibial component rotation. The HL position improves accuracy of this step compared to the SL position, probably due to better visuospatial orientation of the hip and knee to the surgeon. The HL position is better for replicating native kinematics of the knee as shown by the area under the curve analysis. In the supine knee position, care must be taken during the sagittal tibia cut, while checking flexion balance and when sizing the tibial component

No difference in patient reported outcomes, laxity, and failure rate after revision ACL reconstruction with quadriceps tendon compared to hamstring tendon graft: a systematic review and meta-analysis

Purpose: The purpose of this study was to synthesize and quantitatively assess the outcomes of ACL Revision using a quadriceps tendon (QT) graft and to compare them with those of ACL Revisions performed with hamstring tendons (HT) graft. Methods: A comprehensive search based on the PRISMA protocol was performed across PubMed, Scopus, Embase, and Cochrane Library from inception until February 2022. Clinical studies reporting the outcomes of ACL Revision with QT autograft were included. Subjective and Objective IKDC, Tegner activity level, Lysholm knee score, KOOS score, VAS for pain, knee laxity (KT-1000/2000 arthrometer, Lachman test, and pivot-shift test), and graft failure were assessed. A systematic review and meta-analysis were performed and a quality assessment of the included studies was carried out with the MINORS score. Results: Seven studies met the selection criteria and were included in the systematic review for the qualitative synthesis of data. A pooled mean of all the variables was provided for the 7 studies, while 3 studies included a control group of ACL Revision with HT and were included in a meta-analysis. A total of 420 participants with a mean age of 28.9 ± 10.5&nbsp;years and a mean postoperative follow-up of 39.3 ± 16.4&nbsp;months were assessed. Of these, 277 patients underwent ACL Revision with QT and 143 patients underwent ACL Revision with HT. In the QT group, average graft failure was 9.8% compared to 17.4% in the HT group. KOOS Sport and pivot-shift test showed better postoperative outcomes in QT than HT, although it was not statistically significant (p = 0.052). Conclusion: The QT autograft was associated with an improved trend of rotatory laxity, PROMs and failure rate compared to HT autograft after revision ACL reconstruction. The QT autograft for revision ACL reconstruction is supported by the current literature. It is a viable graft that should be considered for both primary and revision ACL reconstruction. Level of evidence: Level IV

Thermal Decomposition Kinetics of Woods with an Emphasis on Torrefaction

The pyrolysis kinetics of Norwegian spruce and birch wood was studied to obtain information on the kinetics of torrefaction. Thermogravimetry (TGA) was employed with nine different heating programs, including linear, stepwise, modulated and constant reaction rate (CRR) experiments. The 18 experiments on the 2 feedstocks were evaluated simultaneously via the method of least-squares. Part of the kinetic parameters could be assumed common for both woods without a considerable worsening of the fit quality. This process results in better defined parameters and emphasizes the similarities between the woods. Three pseudo-components were assumed. Two of them were described by distributed activation energy models (DAEMs), while the decomposition of the cellulose pseudo-component was described by a self-accelerating kinetics. In another approach, the three pseudo-components were described by n-order reactions. Both approaches resulted in nearly the same fit quality, but the physical meaning of the model, based on three n-order reactions, was found to be problematic. The reliability of the models was tested by checking how well the experiments with higher heating rates can be described by the kinetic parameters obtained from the evaluation of a narrower subset of 10 experiments with slower heating. A table of data was calculated that may provide guidance about the extent of devolatilization at various temperature residence time values during wood torrefaction

Pyrolysis of medium-density fiberboard: optimized search for kinetics scheme and parameters via a genetic algorithm driven by Kissinger's method

The pyrolysis kinetics of charring materials plays an important role in understanding material combustions especially for construction materials with complex degradation chemistry. Thermogravimetric analysis (TGA) is frequently used to study the heterogeneous kinetics of solid fuels; however, there is no agreed method to determine the pyrolysis scheme and kinetic parameters for charring polymers with multiple components and competing reaction pathways. This study develops a new technique to estimate the possible numbers of species and sub-reactions in pyrolysis by analyzing the second derivatives of thermogravimetry (DDTG) curves. The pyrolysis of a medium-density fiberboard (MDF) in nitrogen is studied in detail, and the DDTG curves are used to locate the temperature of the peak mass-loss rate for each sub-reaction. Then, on the basis of the TG data under multiple heating rates, Kissinger’s method is used to quickly find the possible range of values of the kinetic parameters (<i>A</i> and <i>E</i>). These ranges are used to accelerate the optimization of the inverse problem using a genetic algorithm (GA) for the kinetic and stoichiometric parameters. The proposed method and kinetic scheme found are shown to match the experimental data and are able to predict accurately results at different heating rates better than Kissinger’s method. Moreover, the search method (K–K method) is highly efficient, faster than the regular GA search alone. Modeling results show that, as the TG data available increase, the interdependence among kinetic parameters becomes weak and the accuracy of the first-order model declines. Furthermore, conducting TG experiment under multiple heating rates is found to be crucial in obtaining good kinetic parameters

CO2 gasification of chars prepared from wood and forest residue

The CO2 gasification of chars prepared from Norway spruce and its forest residue was investigated in a thermogravimetric analyzer (TGA) at slow heating rates. The volatile content of the samples was negligible; hence the gasification reaction step could be studied alone, without the disturbance of the devolatilization reactions. Six TGA experiments were carried out for each sample with three different temperature programs in 60 and 100% CO2. Linear, modulated, and constant-reaction rate (CRR) temperature programs were employed to increase the information content available for the modeling. The temperatures at half of the mass loss were lower in the CRR experiments than in the other experiments by around 120 degrees C. A relatively simple, well-known reaction kinetic equation described the experiments. The dependence on the reacted fraction as well as the dependence on the CO2, concentration were described by power functions (n-order reactions). The evaluations were also carried out by assuming a function of the reacted fraction that can mimic the various random pore/random capillary models. These attempts, however, did not result in an improved fit quality. Nearly identical activation energy values were obtained for the chars made from wood and forest residues (221 and 218 kJ/mol, respectively). Nevertheless, the forest residue char was more reactive; the temperatures at half of the mass loss showed 20-34 degrees C differences between the two chars at 10 degrees C/min heating rates. The assumption of a common activation energy, E, and a common reaction order, v, on the CO2, concentration for the two chars had only a negligible effect on the fit quality