236 research outputs found

    Feeding the World: How Changes in Biotech Regulation Can Jump-Start the Second Green Revolution and Diversify the Agricultural Industry

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    As the Earth’s population climbs from 7.7 billion in 2019 to almost 10 billion by mid-century, farmers will need to increase food production by 70 percent. This Article analyzes the tools available to achieve this demanding goal. We assess changes in agriculture related to both the organic industry and the high-tech sector that are enabling farmers to become more efficient. Critically, biotechnology offers great promise to hasten the pace of increased agricultural efficiency through genetic engineering. While genetic modification has been controversial, we cannot exclude any viable policy option, especially one with so much promise. Yet the current regulatory environment impedes bringing to market new foods produced through biotechnology and acts as a barrier to diversity for both products and producers. Our argument is straightforward: in a world of risk versus promise, the regulation of biotechnology must be correlated with the level of risk. We advocate for a system of regulation of crops based on risk—one that is tied to the product itself, not the process that created it. The complicated, expensive, and time-consuming process currently imposed on bringing genetically engineered crops to market is divorced from the potential risks these crops actually pose. We specifically suggest adopting a single-entry point to the regulatory system, creating a registry of genetically engineered products to avoid the public perception issues that genetically modified organisms (“GMOs”) have faced to date, and shifting regulatory triggers to better associate the regulatory burden with the actual risks being put forth. Proposals by the Trump Administration in June 2019 may move regulation in the direction we have suggested, but these proposed rules present other issues. A second Green Revolution that embraces the most promising available technology can help free the future of agriculture from the control of dominant agrochemical companies and help feed the world

    Application of Morphometric Relationships to Active Flow Networks Within the Mammoth Cave Watershed

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    Numerous quantitative relationships have been formulated to describe the nature of surface-drainage networks. These parameters have been used in various studies of geomorphology and surface-water hydrology, such as flood characteristics, sediment yield, and evolution of basin morphology. Little progress has been made in applying these quantitative descriptors to karst flow systems due to the lack of sufficiently complete data and inadequate technology for processing the large, complex data sets. However, as a result of four decades of investigation, an abundance of data now exists for the Mammoth Cave Watershed providing the opportunity for broader quantitative research in the organization of a large, highly-developed, karst-drainage network. Developing Geographic Information System (GIS) technology has provided tools to 1) book-keep the karst system\u27s large, complex spatial data sets, 2) analyze and quantitatively model karst processes, and 3) visualize spatially and temporally complex data. Karst aquifers display drainage characteristics that in many ways appear similar to surface networks. The purpose of my research was to explore techniques by which quantitative methods of drainage- network analysis can be applied to the organization and flow patterns in the Turnhole Bend Groundwater Basin of the Mammoth Cave Watershed. Morphometric analysis of mapped active base-flow, stream-drainage density within the Turnhole Bend Groundwater Basin resulted in values ranging from 0.24 km/km2 to 1.13 km/km2. A nearby, climatologically similar, nonkarst surface drainage system yielded a drainage density value of 1.36 km/km2. Since the mapped cave streams necessarily represent only a fraction of the total of underground streams within the study area, the actual subsurface values are likely to be much higher. A potential upper limit on perennial drainage density for the Turnhole Bend Groundwater Basin was calculated by making the assumption that each sinkhole drains at least one first-order stream. Using Anhert and Williams\u27 (1998) average of 74 sinkholes per km2 for the Turnhole Bend Groundwater Basin, the minimum flow-length draining one km2 is 6.25-7.22 km (stated as drainage density, 6.25-7.22 km/km2). Stream ordering of cave streams and their catchments generally follow Hortonian relationships observed for surface-stream networks. Subsurface streams within the Mammoth Cave Watershed generally exhibit a converging, dendritic pattern and possess drainage basins proportionately large for their order. However, even at base-flow conditions, the Turnhole Bend drainage system continues to possess confounding characteristics. These include at least one leakage to an adjacent groundwater basin (Meiman et al., 2001), diverging streams sharing the same surface catchment (Glennon and Groves, 1997), and highly complex, three-dimensional basin boundaries (Meiman et al, 2001). In spite of the incomplete data set available for the Mammoth Cave Watershed, study of initial values suggests an orderly subsurface flow network with numerical results that allow for comparison of the karst-flow network to surface fluvial systems

    Extraction of Mobility from Quantum Transport Calculations of Type-II Superlattices

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    Type-II superlattices (T2SLs) are being investigated as an alternative to traditional bulk materials in infrared photodetectors due to predicted fundamental advantages. Subject to significant quantum effects, these materials require the use of quantum transport methodologies, such as the nonequilibrium Green’s function (NEGF) formalism to fully capture the relevant physics without uncontrolled approximations. Carrier mobility is a useful parameter that affects carrier collection in photodetectors. This work investigates the application of mobility extraction methodologies from quantum transport simulations in the case of T2SLs exemplified using an InAs/GaSb midwave structure. In a resistive region, the average velocity can be used to calculate an apparent mobility that incorporates both diffusive and ballistic effects. However, the validity of this mobility for predicting device properties is limited to cases of diffusive limited transport or when the entire device can be included in the simulation domain. Two methods that have been proposed to extract diffusive limited mobility, one based on approximating the ballistic component of transport and the other which considers the scaling of resistance with simulation size, were also studied. In particular, the resistance scaling approach is demonstrated to be the method most physically relevant to predicting macroscopic transport. We present a method for calculating the mobility from resistance scaling considerations that accounts for carrier density variation between calculations, which is particularly relevant in the case of electrons. Finally, we comment on the implications of applying the different mobility extraction methodologies to device property predictions. The conclusions of this study are not limited to T2SLs, and may be generally relevant to quantum transport mobility studies

    Healthy Incentive Scheme in the Irish Full-day-care Pre-school Setting

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    A pre-school offering a full-day-care service provides for children aged 0-5 years for more than 4 hid. Researchers have called for studies that will provide an understanding of nutrition and physical activity practices in this setting. Obesity prevention in pre-schools, through the development of healthy associations with food and health-related practices, has been advocated. While guidelines for the promotion of best nutrition and health-related practice in the early years\u27 setting exist in a number of jurisdictions, associated regulations have been noted to be poor, with the environment of the child-care facility mainly evaluated for safety. Much cross-sectional research outlines poor nutrition and physical activity practice in this setting. However, there are few published environmental and policy-level interventions targeting the child-care provider with, to our knowledge, no evidence of such interventions in Ireland. The aim of the present paper is to review international guide­ lines and recommendations relating to health promotion best practice in the pre-school setting: service and resource provision; food service and food availability; and the role and involvement of parents in pre-schools. Intervention programmes and assessment tools available to measure such practice are outlined; and insight is provided into an intervention scheme, formulated from available best practice, that was introduced into the Irish full-day­ care pre-school setting

    Letter to the Editor

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    Ethylenedioxy homologs of N-methyl-(3,4-methylenedioxyphenyl)-2-aminopropane (MDMA) and its corresponding cathinone analog methylenedioxymethcathinone: Interactions with transporters for serotonin, dopamine, and norepinephrine

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    N-Methyl-(3,4-methylenedioxyphenyl)-2-aminopropane (MDMA; 'Ecstasy'; 1) and its ÎČ-keto analog methylone (MDMC; 2) are popular drugs of abuse. Little is known about their ring-expanded ethylenedioxy homologs. Here, we prepared N-methyl-(3,4-ethylenedioxyphenyl)-2-aminopropane (EDMA; 3), both of its optical isomers, and ÎČ-keto EDMA (i.e., EDMC; 4) to examine their effects at transporters for serotonin (SERT), dopamine (DAT), and norepinephrine (NET). In general, ring-expansion of the methylenedioxy group led to a several-fold reduction in potency at all three transporters. With respect to EDMA (3), S(+)3 was 6-fold, 50-fold, and 8-fold more potent than its R(-) enantiomer at SERT, DAT, and NET, respectively. Overall, in the absence of a ÎČ-carbonyl group, the ethylenedioxy (i.e., 1,4-dioxane) substituent seems better accommodated at SERT than at DAT and NET

    Anopheles stephensi p38 MAPK signaling regulates innate immunity and bioenergetics during Plasmodium falciparum infection.

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    BackgroundFruit flies and mammals protect themselves against infection by mounting immune and metabolic responses that must be balanced against the metabolic needs of the pathogens. In this context, p38 mitogen-activated protein kinase (MAPK)-dependent signaling is critical to regulating both innate immunity and metabolism during infection. Accordingly, we asked to what extent the Asian malaria mosquito Anopheles stephensi utilizes p38 MAPK signaling during infection with the human malaria parasite Plasmodium falciparum.MethodsA. stephensi p38 MAPK (AsP38 MAPK) was identified and patterns of signaling in vitro and in vivo (midgut) were analyzed using phospho-specific antibodies and small molecule inhibitors. Functional effects of AsP38 MAPK inhibition were assessed using P. falciparum infection, quantitative real-time PCR, assays for reactive oxygen species and survivorship under oxidative stress, proteomics, and biochemical analyses.ResultsThe genome of A. stephensi encodes a single p38 MAPK that is activated in the midgut in response to parasite infection. Inhibition of AsP38 MAPK signaling significantly reduced P. falciparum sporogonic development. This phenotype was associated with AsP38 MAPK regulation of mitochondrial physiology and stress responses in the midgut epithelium, a tissue critical for parasite development. Specifically, inhibition of AsP38 MAPK resulted in reduction in mosquito protein synthesis machinery, a shift in glucose metabolism, reduced mitochondrial metabolism, enhanced production of mitochondrial reactive oxygen species, induction of an array of anti-parasite effector genes, and decreased resistance to oxidative stress-mediated damage. Hence, P. falciparum-induced activation of AsP38 MAPK in the midgut facilitates parasite infection through a combination of reduced anti-parasite immune defenses and enhanced host protein synthesis and bioenergetics to minimize the impact of infection on the host and to maximize parasite survival, and ultimately, transmission.ConclusionsThese observations suggest that, as in mammals, innate immunity and mitochondrial responses are integrated in mosquitoes and that AsP38 MAPK-dependent signaling facilitates mosquito survival during parasite infection, a fact that may attest to the relatively longer evolutionary relationship of these parasites with their invertebrate compared to their vertebrate hosts. On a practical level, improved understanding of the balances and trade-offs between resistance and metabolism could be leveraged to generate fit, resistant mosquitoes for malaria control

    Fabrication and characterization of nanotemplated carbon monolithic material

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    A novel hierarchical nanotemplated carbon monolithic rod (NTCM) was prepared using a novel facile nanotemplating approach. The NTCM was obtained using C60-fullerene modified silica gels as hard templates, which were embedded in a phenolic resin containing a metal catalyst for localized graphitization, followed by bulk carbonization, and template and catalyst removal. TEM, SEM, and BET measurements revealed that NTCM possessed an integrated open hierarchical porous structure, with a trimodal pore distribution. This porous material also possessed a high mesopore volume and narrow mesopore size distribution. During the course of carbonization, the C60 conjugated to aminated silica was partly decomposed, leading to the formation of micropores. The Raman signature of NTCM was very similar to that of multiwalled carbon nanotubes as exemplified by three major peaks as commonly observed for other carbon materials, i.e., the sp3 and sp2 carbon phases coexisted in the sample. Surface area measurements were obtained using both nitrogen adsorption/desorption isotherms (BET) and with a methylene blue binding assay, with BET results showing the NTCM material possessed an average specific surface area of 435 m2 g−1, compared to an area of 372 m2 g−1 obtained using the methylene blue assay. Electrochemical studies using NTCM modified glassy carbon or boron doped diamond (BDD) electrodes displayed quasi-reversible oxidation/reduction with ferricyanide. In addition, the BDD electrode modified with NTCM was able to detect hydrogen peroxide with a detection limit of below 300 nM, whereas the pristine BDD electrode was not responsive to this target compound

    Electroanalysis of gallic and ellagic acids at a boron-doped diamond electrode coupled with high-performance liquid chromatography

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    Electrochemistry of gallic acid (GA) and ellagic acid (EA) was investigated by cyclic voltammetry (CV) using a bare boron-doped diamond (BDD) electrode. CVs indicate that the electro-oxidation of both GA and EA are quasi-reversible processes. High-performance liquid chromatography (HPLC) coupled with a BDD electrode poised at+1.4 V offers the limit of detection (LOD, S/N=3) of 60 and 200 nM for GA and EA, respectively. The optimized method was then applied to the detection of both acids in Islay, Highland and Scotch whiskeys, with the highest concentrations found in a 14-year-old Highland whiskey
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