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

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

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

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

Solid-phase-assisted synthesis of targeting peptide-PEG-oligo(ethane amino)amides for receptor-mediated gene delivery.

In the forthcoming era of cancer gene therapy, efforts will be devoted to the development of new efficient and non-toxic gene delivery vectors. In this regard, the use of Fmoc/Boc-protected oligo(ethane amino)acids as building blocks for solid-phase-supported assembly represents a novel promising approach towards fully controlled syntheses of effective gene vectors. Here we report on the synthesis of defined polymers containing the following: (i) a plasmid DNA (pDNA) binding domain of eight succinoyl-tetraethylenpentamine (Stp) units and two terminal cysteine residues; (ii) a central polyethylene glycol (PEG) chain (with twenty-four oxyethylene units) for shielding; and (iii) specific peptides for targeting towards cancer cells. Peptides B6 and c(RGDfK), which bind transferrin receptor and αvβ3 integrin, respectively, were chosen because of the high expression of these receptors in many tumoral cells. This study shows the feasibility of designing these kinds of fully controlled vectors and their success for targeted pDNA-based gene transfer

Synthesis of Nitrogenated Heterocycles by Asymmetric Transfer Hydrogenation of N-(tert-Butylsulfinyl)haloimines

Highly optically enriched, protected, nitrogenated heterocycles with different ring sizes have been synthesized by a very efficient methodology consisting of the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)haloimines followed by treatment with a base to promote an intramolecular nucleophilic substitution process. N-Protected aziridines, pyrrolidines, piperidines, and azepanes bearing aromatic, heteroaromatic, and aliphatic substituents have been obtained in very high yields and diastereomeric ratios up to >99:1. The free heterocycles can be easily obtained by a simple and mild desulfinylation procedure. Both enantiomers of the free heterocycles can be prepared with the same good results by changing the absolute configuration of the sulfur atom of the sulfinyl group.This work was generously supported by the Spanish Ministerio de Ciencia e Innovación (MICINN; grant no. CONSOLIDER INGENIO 2010, CSD2007-00006, CTQ2007-65218 and CTQ2011-24151) and the Generalitat Valenciana (PROMETEO/2009/039 and FEDER). O.P. thanks the Spanish Ministerio de Educación for a predoctoral fellowship (grant no. AP-2008-00989)