CHROMOSOME-NUCLEAR MEMBRANE-CYTOPLASMIC INTERRELATIONS IN DROSOPHILA

The structural evidence for nucleocytoplasmic interrelationships observed in electron micrographs of salivary-gland cells of third instar larvae of Drosophila melanogaster has been reviewed. It has been found that the characteristic nuclear membrane outpocketings with their adjacent highly differentiated chromosomal materials occur at one stage of larval development at a time when a new cellular function is being initiated. Preliminary cytochemical studies to characterize the materials transferred from nucleus to cytoplasm indicate that deoxyribonucleic acid occurs within the blebs. Observations on chromosome and nuclear membrane structure are also presented

Potential HPAI Shocks and Welfare Implications of Market Power in the U.S. Broiler Industry

Recent outbreaks of highly pathogenic avian influenza (HPAI) in Asia, Europe, and Africa have caused severe impacts on the broiler sector through production losses, trade restrictions and negative shocks to demand. This study develops a multimarket econometric model that is the basis of simulations to assess the spread and market implications of a potential HPAI outbreak in U.S. broiler industry. It takes into account market power that might exist within the livestock and meat sectors and endogenizes the optimal production condition on the model system. The results imply that the HPAI shocks affect prices at different marketing levels unequally and change the price margins along the supply chain with the existence of market power. The change in the price margin, although statistically significant, is quite small in absolute value.animal disease, broilers, HPAI, market power, meat market price margins, Agricultural and Food Policy,

Potential HPAI Shocks and Welfare Implications of Market Power in the U.S. Broiler Industry

Recent outbreaks of highly pathogenic avian influenza (HPAI) in Asia, Europe, and Africa have caused severe impacts on the broiler sector through production losses, trade restrictions and negative shocks to demand. This study develops a multimarket econometric model that is the basis of simulations to assess the spread and market implications of a potential HPAI outbreak in U.S. broiler industry. It takes into account market power that might exist within the livestock and meat sectors and endogenizes the optimal production condition on the model system. The results imply that the HPAI shocks affect prices at different marketing levels unequally and change the price margins along the supply chain with the existence of market power. The change in the price margin, although statistically significant, is quite small in absolute value

The Nature Of The Wall Between Generative And Vegetative Nuclei In The Pollen Grain Of Tradescantia Paludosa

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141268/1/ajb206828.pd

Measuring the usability of a smartphone delivered museum guide

AbstractSmartphones are increasingly being deployed by museums and other cultural spaces to provide guides for visitors, replacing dedicated audioguides or docents. This paper describes a study investigating a scale to measure the usability of a multimedia smartphone guide for a museum, the Multimedia Guide Scale (MMGS). Two different types of museum guide were compared: a free choice tour (FC-tour) and guided tour (G-tour). Result shows that there was a significant difference in scores on the MMGS between the two tours, between the three components of the MMGS (Quality of Interaction; Learnability and Control; General Usability) and a significant interaction between the two variables (factors and the guides). The mean scores were higher for the G-tour on the General Usability component and particularly on the Quality of Interaction component, whereas for the Learnability and Control component, scores were higher for the FC-tour Guide. The implications of these findings and the use of the MMGS are discussed

Histone-protein transition in Drosophila melanogaster : I. Changes during spermatogenesis

The basic protein of the mature spermatozoa of Drosophila melanogaster is an arginine-rich histone but not a protamine, as determined by cytochemical criteria.The histone shift during spermatogenesis occurs during maturation of the sperm rather than at the spermatid stage."Maturity" of a spermatozoon should not be defined purely on morphological criteria. Adjudged cytochemically, the spermatozoa of the early pupal testis of Drosophila cannot be considered as mature; mature sperms first appear shortly before eclosion.The sperm nucleus, by the very nature of its nucleohistone complex, is assumedly devoid of any synthetic activity. This appears to be an evolutionary adaptation for insulating the genetic information during the period of its transit from one generation to the next.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32103/1/0000153.pd