Calcium concentration in tree sap of five species of Minnesota trees as an indicator of sugar sand

Tree sap can be collected from a variety of species (sugar maple, birch, ironwood, box elder, red maple) in Minnesota. When the sap of sugar maple trees and others are cooked into syrup, a cloudy mixture of minerals precipitates out. This precipitate, called sugar sand, gives syrup an unpleasant taste and can clog up machinery if improperly managed. Sugar sand primarily consists primarily of calcium malate. Thus, calcium concentration can be a good indicator of how much sugar sand would precipitate out if sap is processed into syrup. In general, previous literature has shown that sugar maple sap has the highest calcium concentration, followed by box elder, red maple, and paper birch. The purpose of this study was to determine the possible variations in amount of sugar sand found in syrup produced from different species of trees by measuring the calcium concentration in the trees’ sap. In addition, we aimed to determine the pattern of change in concentration of calcium over the course of the season (from March 21 to late April). Two trees each of the five following species were tapped: (Acer saccharum), box elder (Acer negundo), red maple (Acer rubrum), paper birch (Betula papyrifera), and ironwood (Ostrya virginiana). Trees were tapped with 5/16 spiles using standard procedures and the sap collected daily. The volume was measured and calcium concentration of the sap measured using a ion-selective calcium electrode. Results will be presented

Sugar Concentration in the tree sap of five species of Minnesota trees

Tree sap can be collected from a variety of species in Minnesota, including sugar maple (Acer saccharum), box elder (Acer negundo), red maple (Acer rubrum), paper birch (Betula papyrifera), and ironwood (Ostrya virginiana). The sap of different species contain varying concentrations of sugar, important for determining the amount of sap needed to boil down into a volume of syrup. In general, previous literature has shown that sugar maples have the highest concentration of sugar, followed by red maple, birch, and box elder. The sugar concentration of ironwood is as of yet unknown. The purpose of this study was to confirm the concentration of sugar in the sap of these five tree species and record the variation in sugar concentration over the tapping season (generally from early March to late April). Two trees of each species were tapped with 5/16 spiles starting on March 21 using standard procedures and the sap collected daily. The volume was measured and the sugar concentration measured using a digital refractometer. Results will be presented

Primary accumulation in the Soviet transition

The Soviet background to the idea of primary socialist accumulation is presented. The mobilisation of labour power and of products into public sector investment from outside are shown to have been the two original forms of the concept. In Soviet primary accumulation the mobilisation of labour power was apparently more decisive than the mobilisation of products. The primary accumulation process had both intended and unintended results. Intended results included bringing most of the economy into the public sector, and industrialisation of the economy as a whole. Unintended results included substantial economic losses, and the proliferation of coercive institutions damaging to attainment of the ultimate goal - the building of a communist society

Structural properties of the meniscal roots

I Brage finner du siste tekst-versjon av artikkelen, og den kan inneholde ubetydelige forskjeller fra forlagets pdf-versjon. Forlagets pdf-versjon finner du på www.sage.com: http://dx.doi.org/10.1177/0363546514531730 / In Brage you'll find the final text version of the article, and it may contain insignificant differences from the journal's pdf version. The original publication is available at www.sage.com: http://dx.doi.org/10.1177/0363546514531730Background: Current surgical techniques for meniscal root repair reattach the most prominent, dense portion of the meniscal root and fail to incorporate recently identified peripheral, supplemental attachment fibers. The contribution of supplemental fibers to the biomechanical properties of native meniscal roots is unknown. Hypothesis/Purpose: The purpose was to quantify the ultimate failure strengths, stiffness, and attachment areas of the native posterior medial (PM), posterior lateral (PL), anterior medial (AM), and anterior lateral (AL) meniscal roots compared with the most prominent, dense meniscal root attachment after sectioning of supplemental fibers. It was hypothesized that the ultimate failure strength, stiffness, and attachment area of each native root would be significantly higher than those of the respective sectioned root. Study Design: Controlled laboratory study. Methods: Twelve matched pairs of male human cadaveric knees were used. The 4 native meniscal roots were left intact in the native group, whereas the roots in the contralateral knee (sectioned group) were dissected free of all supplemental fibers. A coordinate measuring device quantified the amount of tissue resected in the sectioned group compared with the native group. A dynamic tensile testing machine pulled each root in line with its circumferential fibers. All root attachments were preconditioned from 10 to 50 N at a rate of 0.1 Hz for 10 cycles and subsequently pulled to failure at a rate of 0.5 mm/s. Results: Supplemental fibers composed a significant percentage of the native PM, PL, and AM meniscal root attachment areas. Mean ultimate failure strengths (in newtons) of the native PM, PL, and AM roots were significantly higher than those of the sectioned state, while the ultimate failure strength of the native AL root was indistinguishable from that of the sectioned state. Conclusion: Three of the 4 meniscal root attachments (PM, PL, AM) contained supplemental fibers that accounted for a significant percentage of the native root attachment areas, and these fibers significantly contributed to the failure strengths of the native roots.Seksjon for idretssmedisinske fag / Department of Sports Medicin

Synthesis of a Benzodiazepine-derived Rhodium NHC Complex by C-H Bond Activation

The synthesis and characterization of a Rh(I)-NHC complex generated by C-H activation of 1,4-benzodiazepine heterocycle are reported. This complex constitutes a rare example of a carbene tautomer of a 1,4-benzodiazepine aldimine stabilized by transition metal coordination and demonstrates the ability of the catalytically relevant RhCl(PCy{sub 3}){sub 2} fragment to induce NHC-forming tautomerization of heterocycles possessing a single carbene-stabilizing heteroatom. Implications for the synthesis of benzodiazepines and related pharmacophores via C-H functionalization are discussed

Pooled HIV-1 Viral Load Testing Using Dried Blood Spots to Reduce the Cost of Monitoring Antiretroviral Treatment in a Resource-Limited Setting

: Rollout of routine HIV-1 viral load monitoring is hampered by high costs and logistical difficulties associated with sample collection and transport. New strategies are needed to overcome these constraints. Dried blood spots from finger pricks have been shown to be more practical than the use of plasma specimens, and pooling strategies using plasma specimens have been demonstrated to be an efficient method to reduce costs. This study found that combination of finger-prick dried blood spots and a pooling strategy is a feasible and efficient option to reduce costs, while maintaining accuracy in the context of a district hospital in Malawi