Protein-polynucleotide scattering centers as a protein structure probe

When certain basic globular proteins are mixed with nucleic acids near a critical concentration ratio, large, low density scattering centers of about 10⁹ particle weight are created. Scattering from these complexes is altered when thermally inactivated proteins are substituted for enzymes in their native, globular conformation. Scattering data from heat-treated ribonuclease and lysozyme mixed with four different synthetic homopolyribonucleotides are reported. The concentration of nucleic acid necessary to produce maximum scattering from a heat-treated protein sample is shown to be a direct indication of the amount of enzyme that remains biologically active after being heated.     

Regionally-Specified Second Trimester Fetal Neural Stem Cells Reveals Differential Neurogenic Programming

Neural stem/progenitor cells (NSC) have the potential for treatment of a wide range of neurological diseases such as Parkinson Disease and multiple sclerosis. Currently, NSC have been isolated only from hippocampus and subventricular zone (SVZ) of the adult brain. It is not known whether NSC can be found in all parts of the developing mid-trimester central nervous system (CNS) when the brain undergoes massive transformation and growth. Multipotent NSC from the mid-trimester cerebra, thalamus, SVZ, hippocampus, thalamus, cerebellum, brain stem and spinal cord can be derived and propagated as clonal neurospheres with increasing frequencies with increasing gestations. These NSC can undergo multi-lineage differentiation both in vitro and in vivo, and engraft in a developmental murine model. Regionally-derived NSC are phenotypically distinct, with hippocampal NSC having a significantly higher neurogenic potential (53.6%) over other sources (range of 0%–27.5%, p<0.004). Whole genome expression analysis showed differential gene expression between these regionally-derived NSC, which involved the Notch, epidermal growth factor as well as interleukin pathways. We have shown the presence of phenotypically-distinct regionally-derived NSC from the mid-trimester CNS, which may reflect the ontological differences occurring within the CNS. Aside from informing on the role of such cells during fetal growth, they may be useful for different cellular therapy applications.     

Dietary salt intake and its relevance to ionic regulation in freshwater salmonids

Dietary sodium intake for freshwater salmonids feeding in the wild (invertebrate diet) or in captivity (pellet diet) was calculated and compared with published branchial sodium influx values. Dietary sodium intake (mmol kg⁻¹ per month) increases from winter minimum values of 5 and 30-40 to reach maximum values in summer of 175 and 240 for invertebrate and pellet diet, respectively. In summer, dietary sodium intake for fish feeding in the wild was of the same magnitude as branchial sodium influx. The implications of dietary sodium intake for sodium balance in freshwater fish are discussed.     

Overview on radiation and tissue banking in Latin America

The International Atomic Energy Agency (IAEA) played an important role in the establishment of new tissue banks and the improvement of already existing ones in Latin America. The Agency strongly supported, through regional, interregional and national technical cooperation projects, providing equipment, expert missions and training for the production and application of human tissues for transplantation. From 1999 to 2005 five regional courses were given in Buenos Aires under the modality of 1-year distance learning training courses and 1-week face to face courses. The courses were organized by the IAEA, through the National Atomic Energy Commission (CNEA) and the Faculty of Medicine of Buenos Aires University as Post Graduate Specialization Course. In 2005 the Latin American countries joined with Spain and Portugal, and created the Ibero American Network Council of Donation and Transplant (Red Consejo Iberoamericano de Donación y Trasplantes—RCIDT). The objective of this network is to cooperate among twenty-one Ibero American countries in organizational and legislative aspects, training of professionals, and ethical and social issues related to the donation and transplantation of organs, tissues and cells. The members of this Network work actively to harmonize the regulations and the control of donation and transplantation of human organs, tissues and cells. At present, in Latin America, more than 220 facilities of tissues banks are operating and tissue allografts are being produced by single and multi-tissue banks. The efforts made by the governments and professionals from the region allow the tissue banks to operate under quality systems and introduce new technologies.     

Frontiers in alley cropping: Transformative solutions for temperate agriculture

Annual row crops dominate agriculture around the world and have considerable negative environmental impacts, including significant greenhouse gas emissions. Transformative land‐use solutions are necessary to mitigate climate change and restore critical ecosystem services. Alley cropping (AC)—the integration of trees with crops—is an agroforestry practice that has been studied as a transformative, multifunctional land‐use solution. In the temperate zone, AC has strong potential for climate change mitigation through direct emissions reductions and increases in land‐use efficiency via overyielding compared to trees and crops grown separately. In addition, AC provides climate change adaptation potential and ecological benefits by buffering alley crops to weather extremes, diversifying income to hedge financial risk, increasing biodiversity, reducing soil erosion, and improving nutrient‐ and water‐use efficiency. The scope of temperate AC research and application has been largely limited to simple systems that combine one timber tree species with an annual grain. We propose two frontiers in temperate AC that expand this scope and could transform its climate‐related benefits: (i) diversification via woody polyculture and (ii) expanded use of tree crops for food and fodder. While AC is ready now for implementation on marginal lands, we discuss key considerations that could enhance the scalability of the two proposed frontiers and catalyze widespread adoption.