22 research outputs found
Monitoring and modeling cropping system nitrogen for a sustainable agriculture
Modern agriculture has become heavily dependent on fossil-fuel-based commercial nitrogen (N) for maintaining soil fertility and high crop yields. In the past, farmers have not had the means to monitor soils routinely for N concentrations, nor have they been able to match yield goals to those concentrations. In addition, the nutrient value of manure applied to fields often is not taken into account before commercial N fertilizer is applied. As a result, N has been over-applied on many midwestern farms, prompting concerns about the cost of commercial inputs into farming and the amount of nitrate in groundwater
Checklist of the Vascular Flora of Lyon and Sioux Counties, Iowa
The combined vascular flora of Lyon and Sioux counties, Iowa, based upon field and herbarium study, is composed of 612 species, of which 454 species (74%) occur in both counties. The Lyon County vascular flora consists of 561 species, including 13 state endangered, 9 state threatened species, and 102 non-native species. The Sioux County vascular flora consists of 506 species, including 2 state threatened species and 106 non-native species. The floras are most notable for the presence of plants with floristic affinities to the Great Plains to the west of Iowa. They also have a very high percentage (18%-20%) of their floras comprised of non-native species, reflecting the intensity of human activities on the landscape
Effect of Amino Acids on the Corrosion and Metal Release from Copper and Stainless Steel
Copper (Cu) and stainless steel 316 L are widely used for biomedical applications, such as intrauterine devices and orthopedic/dental implants. Amino acids are abundantly present in biological environments. We investigated the influence of select amino acids on the corrosion of Cu under naturally aerated and deaerated conditions using a phosphate-free buffer. Amino acids increased the corrosion of Cu under both aeration conditions at pH 7.4. Cu release was also significantly (up to 18-fold) increased in the presence of amino acids, investigated at pH 7.4 and 37 °C for 24 h under naturally aerated conditions. Speciation modelling predicted a generally increased solubility of Cu in the presence of amino acids at pH 7.4. 316 L, investigated for metal release under similar conditions for comparison, released about 1,000-fold lower amounts of metals than did Cu and remained passive with no change in surface oxide composition or thickness. However, amino acids also increased the chromium release (up to 52-fold), significantly for lysine, and the iron release for cysteine, while nickel and molybdenum release remained unaffected. This was not predicted by solution speciation modelling. The surface analysis confirmed the adsorption of amino acids on 316 L and, to a lower extent, Cu coupons
Evaluating the safety and efficacy of epi-off corneal cross-linking in patients with thin corneas due to keratectasia
Background: Corneal cross-linking (CXL) is a safe and effective procedure for slowing keratectasia progression in eyes with a corneal thickness of at least 400 µm. Limited research has evaluated the safety and efficacy of epi-off CXL in corneas thinner than 400 µm. Objective: To evaluate the safety and efficacy of CXL to slow keratectasia progression in eyes with 1 D of K max steepening. No patients required keratoplasty and there were no cases of endothelial failure in the follow-up period. Conclusion: This research supports the safety and efficacy of epi-off, iso-osmolar CXL in eyes with <400 μm baseline corneal thickness with no patients requiring penetrating or endothelial keratoplasty, a trend toward improvement in BCVA, and K max flattening. In the future, prospective studies would be helpful to confirm these findings
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Monte Carlo simulation of light propagation in adult brain: influence of tissue blood content and indocyanine green
Near-infrared spectroscopy (NIRS), applied to a human head, is a noninvasive method in neurointensive care to monitor cerebral hemodynamics and oxygenation. The method is particularly powerful when it is applied in combination with indocyanine green (ICG) as a tracer substance. In order to assess contributions to the measured optical density (OD) which are due to extracerebral circulation and disturb the clinically significant intracerebral signals, we simulated the light propagation in an anatomically representative model of the adult head derived from MRI measurements with the aid of Monte Carlo methods. Since the measured OD signal depends largely on the relative blood content in various transilluminated tissues, we weighted the calculated densities of the photon distribution under baseline conditions within the tissues with the changes and aberrations of the relative blood volumes which we expect to prevail under physiological conditions. Furthermore, the influence of the IGC dye as a tracer substance was assessed. We conclude that up to about different 70% of the measured OD signal may have its origin in the tissues of interest under optimal conditions, which is mainly due to the extrapolated high relative blood content of brain tissue along with the influence of ICG
Pharmacogenetics, the next challenge for pharmacy?
This commentary draws attention to and raises awareness of forthcoming pharmacogenetic technologies amongst the pharmacy profession. It aims to stimulate debate around the potential role that the pharmacy profession can play in the introduction of pharmacogenetic technologies into primary healthcare. This commentary discusses potential new roles for pharmacists involving pharmacogenetic technologies, giving attention to the way the profession may need to adapt to accommodate these