36 research outputs found
Dunbar, Hobart & Whidden, South Abbington, Mass., manufacturers of brads, tacks, nails
folded once to make 4 pages; recto 1 has scene with front and side view of manufactory; company established 1810; exhibited in the Main Building P.7
Erythropoietin: still on the neuroprotection road
Acute stroke is one of the major causes of death and disabilities. Since the 1980s many clinical studies have been conducted to evaluate neuroprotective approaches to treat this important brain vascular event. However, to date the only drug approved (recombinant tissue plasminogen activator [rtPA]) represents a thrombolytic, nonneuroprotective approach. An important neuroprotective strategy is based on erythropoietin (EPO). Exogenously administered EPO exhibits neuroprotective effects in numerous animal models, through the activation of anti-apoptotic, anti-oxidant and anti-inflammatory pathways as well as through the stimulation of angiogenic and neurogenic events. The capability of EPO to cross the bloodâbrain barrier after systemic administration and its effective therapeutic window are advantages for human acute stroke therapy. However, a multicenter stroke trial where recombinant human EPO (rhEPO) was combined with rtPA had negative outcomes. The present paper reviews the EPO neuroprotective strategy and its mechanisms in ischemic stroke and in other human nervous system diseases
Nitrogen pools and fluxes in grassland soils sequestering carbon
Carbon sequestration in agricultural, forest, and grassland soils has been promoted as a means by which substantial amounts of CO2 may be removed from the atmosphere, but few studies have evaluated the associated impacts on changes in soil N or net global warming potential (GWP). The purpose of this research was to ( 1) review the literature to examine how changes in grassland management that affect soil C also impact soil N, ( 2) assess the impact of different types of grassland management on changes in soil N and rates of change, and (3) evaluate changes in N2O fluxes from differently managed grassland ecosystems to assess net impacts on GWP. Soil C and N stocks either both increased or both decreased for most studies. Soil C and N sequestration were tightly linked, resulting in little change in C: N ratios with changes in management. Within grazing treatments N2O made a minor contribution to GWP (0.1-4%), but increases in N2O fluxes offset significant portions of C sequestration gains due to fertilization (10-125%) and conversion (average = 27%). Results from this work demonstrate that even when improved management practices result in considerable rates of C and N sequestration, changes in N2O fluxes can offset a substantial portion of gains by C sequestration. Even for cases in which C sequestration rates are not entirely offset by increases in N2O fluxes, small increases in N2O fluxes can substantially reduce C sequestration benefits. Conversely, reduction of N2O fluxes in grassland soils brought about by changes in management represents an opportunity to reduce the contribution of grasslands to net greenhouse gas forcing