The midto long-term preservation of papaya (Carica papaya L.) would allow for the safeguarding of important germplasm. In this study, soft friable callus (SFC) and hard callus (HC) were induced from the first two true leaves of 10-day-old seedlings containing a midrib derived from the germinated seed of two cultivars (‘Rainbow’ and ‘Sunrise Solo’). Following germination on a Murashige and Skoog...

This paper was presented at a Conference on Social Mobility held at the University of Chicago on November 5th, 2014, under the title “‘The Role of Income and Credit Constraints in Human Development’ Part II.” We thank Linor Kiknadze for very helpful research assistance. We thank Magne Mogstad and the participants in the conference for thoughtful comments. We also received helpful comments at a ...

Commercial hydroponics is a modern technology involving plant growth on inert media in place of the natural soil, in order to uncouple the performance of the crop from problems associated with the ground, such as soil-borne diseases, nonarable soil, poor physical properties, etc. Various non-toxic porous materials are used as plant growth substrates, including rockwool, perlite, pumice, expande...

This paper reviews the investigations with man-made fibers (MMF). Insulation woods: glasswool (GW), rockwool (RW), slagwool (SW), glass microfibers (GMF), glass filaments (GFiI), and refractory ceramic fibers (RCF) have been used in experimental animals and in in vitro cell systems. A large heterogeneous number of fibers, methods of fiber preparation, size selection, aerosolization, fiber size,...

A mathematical model describing the dissolution and disintegration of long fibers and the clearance of short fibers is developed. For short fiber clearance, the model is based on previous modeling of the retention and clearance of particles, and most model parameters are taken from that particulate model. In addition to modeling the disappearance of long fibers, the present study includes a qua...

Five bacteria (Pseudomonas fluorescens, P. fluorescens subgroup G strain 2, P. marginalis, P. putida subgroup B strain 1 and P. syringae strain 1) and three fungi (Penicillium brevicompactum, P. solitum strain 1 and Trichoderma atroviride) were evaluated to determine their promoting effect on the growth of mature healthy tomato plants grown under hydroponic conditions. P. putida and T. atroviri...

There is abundant epidemiologic evidence that asbestos fibers can cause lung fibrosis (asbestosis), bronchial cancer, and mesothelioma in humans, as well as limited evidence for such effects in workers exposed to slag and rockwool fibers. Epidemiological evidence for human disease from inhalation exposures to conventional fibrous glass is negative. While health concerns based on the morphologic...

Nitric oxide (NO) has a number of important functions in biological systems and may play a role in the toxicity of mineral fibers. We investigated whether NO might be present on the surface of mineral fibers and if crocidolite could adsorb NO from NO gas or cigarette smoke. NO was determined with a new gas chromatography-ultraviolet spectrophotometric technique after thermal desorption from the...