Simulation of the Internal Conditions During The Hot-Pressing Process

The development of a two-dimensional mathematical model to describe the internal conditions during the hot-compression of wood-based composite panels is discussed. Five primary variables were considered during the model development: air content, vapor content, bound water content, and temperature within the mat, and the extent of the cure of the adhesive system characterized by the cure index. Different heat and mass transfer processes were identified for the transport of the heat and of the moisture phases. The heat was transported by conduction and convection due to a temperature gradient, while the water phases were transported by bulk flow and diffusion due to total pressure and partial pressure gradients. The resulting differential-algebraic equation system was solved by the method of lines. The spatial derivatives of the conduction terms were discretized by central differences, while the spatial derivatives of the convection terms were discretized according to an upwind scheme. The resulting ordinary differential equations in the time variable were solved by a freely available differential-algebraic system solver (DDASSL). The mathematical model predicted temperature, moisture content, partial air and vapor pressures, total pressure, relative humidity, and extent of adhesive cure within the mat structure under a typical hot-compression process. A set of three-dimensional profiles describes the evolution of these variables with time, in the thickness and width dimensions of the mat. The model results allow a better understanding of the interacting mechanisms involved in a complex production process. The model also supports optimization of the hot-pressing parameters for improved quality of wood-based panel products, while reducing pressing time

Sensitivity Analysis of Internal Mat Environment during Hot-Pressing

The effect of several hot-pressing parameters on the internal mat environment was investigated by using a hot-pressing simulation model. The results were compared to experimental data from laboratory-produced flakeboard. The pressing parameters included initial mat moisture content, final panel density, press platen temperature, and press closing time. The variation of temperature and total gas pressure during the press cycle at six points in the vertical mid-plane of a single layer, random mat structure was predicted with the heat and mass transfer model using the different pressing conditions. Twenty-four boards were manufactured according to the same specifications, and the temperature and internal gas pressure were measured with thermocouples and gas pressure probes at the same six locations. The model consistently predicted the major trends during the hot-pressing operation.The hot-pressing simulation model used in this study was developed based on fundamental engineering principles. The material physical and transport properties were the best available values from the literature or best estimates based on engineering judgment. A sensitivity study assessed the relative importance of the different transport properties during the hot-pressing process. The sensitivity analysis of the model parameters revealed that the thermal conductivity and gas permeability of the mat have the greatest influence on model results. The assessment of these transport properties experimentally, as a function of mat structure, is highly desirable and can considerably improve future model predictions

Assessment of Aspergillus fumigatus in Guinea Pig Bronchoalveolar Lavages and Pulmonary Tissue by Culture and Realtime Polymerase Chain Reaction Studies

In this study we pursued a diagnostic target in Aspergillus fumigatus (AF) by using qualitative Realtime PCR combined with proprietary DNA primers and a hydrolysis probe specific for this fungal target. Qualitative Realtime PCR is a diagnostic tool that utilizes Realtime PCR technology and detects the presence or absence target specific DNA within a predetermined detection range. Respiratory tissue and fluids from experimentally infected guinea pigs were tested by extracting DNA from the samples which were amplified and detected using AF specific DNA primers and probe. This study included qualitative evaluations of all specimens for the presence of the DNA of AF. The findings in the tissues after AF infection were compared to the numbers of spores in aerosolized samples used to inoculate the animals. Results demonstrated that the specific probe and primer set could detect the presence or absence of AF DNA in the sample. The qualitative detection limit of the assay ranged from 6 × 104 copies to 6 copies. Since blood cultures are rarely positive for Aspergillosis, our data indicate that qualitative Realtime PCR, in combination with the appropriate DNA primers and probe can serve as an effective diagnostic tool in the early detection of fungal infections

Underperformance of African protected area networks and the case for new conservation models : insights from Zambia

Many African protected areas (PAs) are not functioning effectively. We reviewed the performance of Zambia’s PA network and provide insights into how their effectiveness might be improved. Zambia’s PAs are under-performing in ecological, economic and social terms. Reasons include: a) rapidly expanding human populations, poverty and open-access systems in Game Management Areas (GMAs) resulting in widespread bushmeat poaching and habitat encroachment; b) underfunding of the Zambia Wildlife Authority (ZAWA) resulting in inadequate law enforcement; c) reliance of ZAWA on extracting revenues from GMAs to cover operational costs which has prevented proper devolution of user-rights over wildlife to communities; d) on-going marginalization of communities from legal benefits from wildlife; e) under-development of the photo-tourism industry with the effect that earnings are limited to a fraction of the PA network; f) unfavourable terms and corruption which discourage good practice and adequate investment by hunting operators in GMAs; g) blurred responsibilities regarding anti-poaching in GMAs resulting in under-investment by all stakeholders. The combined effect of these challenges has been a major reduction in wildlife densities in most PAs and the loss of habitat in GMAs. Wildlife fares better in areas with investment from the private and/or NGO sector and where human settlement is absent. There is a need for: elevated government funding for ZAWA; greater international donor investment in protected area management; a shift in the role of ZAWA such that they focus primarily on national parks while facilitating the development of wildlife-based land uses by other stakeholders elsewhere; and new models for the functioning of GMAs based on joint-ventures between communities and the private and/or NGO sector. Such joint-ventures should provide defined communities with ownership of land, user-rights over wildlife and aim to attract long-term private/donor investment. These recommendations are relevant for many of the under-funded PAs occurring in other African countries.The Wildlife Producers Association of Zambia. CJT was funded with a Claude Leon Fellowship.http://www.plosone.orgam201

Underperformance of African protected area networks and the case for new conservation models : insights from Zambia

Many African protected areas (PAs) are not functioning effectively. We reviewed the performance of Zambia’s PA network and provide insights into how their effectiveness might be improved. Zambia’s PAs are under-performing in ecological, economic and social terms. Reasons include: a) rapidly expanding human populations, poverty and open-access systems in Game Management Areas (GMAs) resulting in widespread bushmeat poaching and habitat encroachment; b) underfunding of the Zambia Wildlife Authority (ZAWA) resulting in inadequate law enforcement; c) reliance of ZAWA on extracting revenues from GMAs to cover operational costs which has prevented proper devolution of user-rights over wildlife to communities; d) on-going marginalization of communities from legal benefits from wildlife; e) under-development of the photo-tourism industry with the effect that earnings are limited to a fraction of the PA network; f) unfavourable terms and corruption which discourage good practice and adequate investment by hunting operators in GMAs; g) blurred responsibilities regarding anti-poaching in GMAs resulting in under-investment by all stakeholders. The combined effect of these challenges has been a major reduction in wildlife densities in most PAs and the loss of habitat in GMAs. Wildlife fares better in areas with investment from the private and/or NGO sector and where human settlement is absent. There is a need for: elevated government funding for ZAWA; greater international donor investment in protected area management; a shift in the role of ZAWA such that they focus primarily on national parks while facilitating the development of wildlife-based land uses by other stakeholders elsewhere; and new models for the functioning of GMAs based on joint-ventures between communities and the private and/or NGO sector. Such joint-ventures should provide defined communities with ownership of land, user-rights over wildlife and aim to attract long-term private/donor investment. These recommendations are relevant for many of the under-funded PAs occurring in other African countries.The Wildlife Producers Association of Zambia. CJT was funded with a Claude Leon Fellowship.http://www.plosone.orgam201

For public (and recontextualized) sociology: The promises and perils of public engagement in an age of mediated communication

This article argues for the analysis of public engagement as an essentially mediated activity. Although recent studies note that academic knowledge is increasingly available for consumption by nonacademic audiences, they tell us little about how it gets recontextualized while passing through the hands of media professionals on its way toward such audiences. In Burawoy’s (2005) influential call for the rebirth of public sociology, as in the debates his work provoked, the media is treated solely as a means for the transportation of knowledge. But as this article demonstrates, the media does not simply transport knowledge; it also, and at the same time, translates that knowledge in various, rhetorically consequential ways. Focusing on the mediated trajectory of an attempt by a group of academics to connect with audiences beyond academia, their initial contribution is compared to its subsequent translation(s) across various British newspapers. A discursive analysis reveals the techniques via which a classic form of public sociology came to be recontextualized such that, remarkably, these authors were left appearing to voice nothing but their own petty prejudices. The article concludes by noting that where public engagement involves mediation, public sociology should pay more attention to the recontextualizing affordances of media discourse

Induction of Antibodies in Rhesus Macaques That Recognize a Fusion-Intermediate Conformation of HIV-1 gp41

A component to the problem of inducing broad neutralizing HIV-1 gp41 membrane proximal external region (MPER) antibodies is the need to focus the antibody response to the transiently exposed MPER pre-hairpin intermediate neutralization epitope. Here we describe a HIV-1 envelope (Env) gp140 oligomer prime followed by MPER peptide-liposomes boost strategy for eliciting serum antibody responses in rhesus macaques that bind to a gp41 fusion intermediate protein. This Env-liposome immunization strategy induced antibodies to the 2F5 neutralizing epitope 664DKW residues, and these antibodies preferentially bound to a gp41 fusion intermediate construct as well as to MPER scaffolds stabilized in the 2F5-bound conformation. However, no serum lipid binding activity was observed nor was serum neutralizing activity for HIV-1 pseudoviruses present. Nonetheless, the Env-liposome prime-boost immunization strategy induced antibodies that recognized a gp41 fusion intermediate protein and was successful in focusing the antibody response to the desired epitope

Design of the BRISC study: a multicentre controlled clinical trial to optimize the communication of breast cancer risks in genetic counselling

Background: Understanding risks is considered to be crucial for informed decision-making. Inaccurate risk perception is a common finding in women with a family history of breast cancer attending genetic counseling. As yet, it is unclear how risks should best be communicated in clinical practice. This study protocol describes the design and methods of the BRISC (Breast cancer RISk Communication) study evaluating the effect of different formats of risk communication on the counsellee's risk perception, psychological well-being and decision-making regarding preventive options for breast cancer. Methods and design: The BRISC study is designed as a pre-post-test controlled group intervention trial with repeated measurements using questionnaires. The intervention-an additional risk consultation-consists of one of 5 conditions that differ in the way counsellee's breast cancer risk is communicated: 1) lifetime risk in numerical format (natural frequencies, i.e. X out of 100), 2) lifetime risk in both numerical format and graphical format (population figures), 3) lifetime risk and age-related risk in numerical format, 4) lifetime risk and age-related risk in both numerical format and graphical format, and 5) lifetime risk in percentages. Condition 6 is the control condition in which no intervention is given (usual care). Participants are unaffected women with a family history of breast cancer attending one of three participating clinical genetic centres in the Netherlands. Discussion: The BRISC study allows for an evaluation of the effects of different formats of communicating breast cancer risks to counsellees. The results can be used to optimize risk communication in order to improve informed decision-making among women with a family history of breast cancer. They may also be useful for risk communication in other health-related services. Trial registration: Current Controlled Trials ISRCTNI4566836

Near-ultraviolet Excess in Slowly Accreting T Tauri Stars: Limits Imposed by Chromospheric Emission

Young stars surrounded by disks with very low mass accretion rates are likely in the final stages of inner disk evolution and therefore particularly interesting to study. We present ultraviolet (UV) observations of the ~5-9 Myr old stars RECX-1 and RECX-11, obtained with the Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph on the Hubble Space Telescope , as well as optical and near-infrared spectroscopic observations. The two stars have similar levels of near-UV emission, although spectroscopic evidence indicates that RECX-11 is accreting and RECX-1 is not. The line profiles of H_ and He I _10830 in RECX-11 show both broad and narrow redshifted absorption components that vary with time, revealing the complexity of the accretion flows. We show that accretion indicators commonly used to measure mass accretion rates, e.g., U -band excess luminosity or the Ca II triplet line luminosity, are unreliable for low accretors, at least in the middle K spectral range. Using RECX-1 as a template for the intrinsic level of photospheric and chromospheric emission, we determine an upper limit of 3 _ 10 –10 M _ yr –1 for RECX-11. At this low accretion rate, recent photoevaporation models predict that an inner hole should have developed in the disk. However, the spectral energy distribution of RECX-11 shows fluxes comparable to the median of Taurus in the near-infrared, indicating that substantial dust remains. Fluorescent H 2 emission lines formed in the innermost disk are observed in RECX-11, showing that gas is present in the inner disk, along with the dust.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90770/1/0004-637X_743_2_105.pd

Reviews and bibliographical notices

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