Transient engine simulation program. NERVA program

IBM 7094 transient engine simulation program for NERV

Service quality measurements for IPv6 inter-networks

Measurement-based performance evaluation of network traffic is becoming very important, especially for networks trying to provide differentiated levels of service quality to the different application flows. The non-identical response of flows to the different types of network-imposed performance degradation raises the need for ubiquitous measurement mechanisms, able to measure numerous performance properties, and being equally applicable to different applications and transports. This paper presents a new measurement mechanism, facilitated by the steady introduction of IPv6 in network nodes and hosts, which exploits native features of the protocol to provide support for performance measurements at the network (IP) layer. IPv6 Extension Headers have been used to carry the triggers involving the measurement activity and the measurement data in-line with the payload data itself, providing a high level of probability that the behaviour of the real user traffic flows is observed. End-to-end one-way delay, jitter, loss, and throughput have been measured for applications operating on top of both reliable and unreliable transports, over different-capacity IPv6 network configurations. We conclude that this technique could form the basis for future Internet measurements that can be dynamically deployed where and when required in a multi-service IP environment

Genetic Map of Bacteriophage [var phi]X174

Bacteriophage [var phi]X174 temperature-sensitive and nonsense mutations in eight cistrons were mapped by using two-, three-, and four-factor genetic crosses. The genetic map is circular with a total length of 24 × 10−4wt recombinants per progeny phage. The cistron order is D-E-F-G-H-A-B-C. High negative interference is seen, consistent with a small closed circular deoxyribonucleic acid molecule as a genome

Use of ivermectin-treated baits for management of the lone star tick, Amblyomma americanum L. (Acari:Ixodidae)

Ivermectin-treated corn was fed to deer from March to August 1994 and 1995 in a tick-infested area of Fairfield Glade, Cumberland County, Tennessee. All life stages of Amblyomma americanum L. were collected from an ivermectin-treated and a non-treated area in 1994 and 1995. In 1994, 3.4 times as many adult ticks were collected in the treated area as compared to the non-treated area. Approximately 2 times as many nymphs and 1.6 times as many larval masses were collected in the non-treated area. Adults were 1.7 times and nymphs were 1.5 times more numerous in the treated area as compared to the non-treated area in 1995. Statistical analysis revealed that ivermectin treatment had no effect on the densities of lone star ticks in the treated area in 1994 and 1995. However, there was a reduction in the numbers of all life stages collected in the treated area in 1995 compared to 1994. Also, the number of larval masses collected in the treated area in 1994 was 4 times less than what would have been expected when compared to the high numbers of females collected earlier in the season and the number of masses collected in the non-treated area. Though no significant reductions were found, ivermectin may be causing a slow reduction in free-living tick populations in the treated area. An extended study and treatment schedule could further reveal the effects of ivermectin treatment. Seasonal distributions in 1994 and 1995 are presented for the life stages of A. americanum, based on numbers of individuals collected in the non-treated area. Differences in apparent seasonal densities due to sampling method were found for nymphal and adult ticks. Significantly more nymphs were collected from the wooded areas than the grassy areas. No significant differences were found in the numbers of females and larval masses collected in the wooded and grassy areas

The Biblical Concepts of \u3cem\u3ePotentia Dei Ordinata\u3c/em\u3e and \u3cem\u3ePotentia Dei Absoluta\u3c/em\u3e in the Development of Chemistry

Medieval theologians spoke of the potentia Dei ordinata (the power of God expressed in the orderly working of nature) and the potentia Dei absoluta (the absolute power of God to intervene miraculously) (Kaiser 1997). Scientific creationists accept this understanding – we believe that God has ordained natural laws that result in a comprehensible natural world. But we recognize God is not bound by natural laws but can act miraculously, as when He spoke the world into existence. This understanding was also foundational not just for the development of science itself. It first appeared outside of the Bible in the Hexameron, a series of lectures on the six days of creation by Basil of Caesarea. Unlike most church fathers, Basil focused on what God communicated through creation itself (Bouteneff 2008). He read Genesis literally and argued for the study of nature to see God’s glory. Basil taught that the Lord had created natural laws to govern the normal operation of nature so we could see his greatness in it (Kaiser 1997). This is possibly the first extra-biblical articulation of the potentia Dei ordinata. This concept was fundamental in the establishment of the sciences, including chemistry. Chemistry has its roots in alchemy, which rested on the assumption matter was composed of Aristotle’s four elements (fire, earth, air, and water) and supernatural intervention was necessary to alter those elements for transmutation. A key figure in beginning to emphasize the potentia Dei ordinata instead was the Christian physician and alchemist Paracelsus. Paracelsus rejected the four elements of Aristotle because he did not find any mention in Genesis of God creating fire. He suggested three principles instead: sulfur, mercury, and salt (Salzeberg 1991). Furthermore, because Jesus had said the sick needed a physician, he concluded that it was unacceptable that physicians of his day were so ineffective. The Lord surely provided the information needed to treat the sick. This set him on a series of experiments that revolutionized medicine and chemistry (Kaiser 1997). Paracelsus did not make a full break from alchemy, he still believed that every organ of the body was empowered by a different spiritual force (Salzeberg 1991) but he was clearly moving the emphasis from the potentia Dei absoluta to the potentia Dei ordinata. Probably the best known of Paracelsus’ followers was Johan Van Helmont, famous in chemistry for discovering gases. While still believing that there was a separate spirit to every chemical compound, he further developed Paracelsus’s emphasis on invoking the potentia Dei ordinata to understand chemistry through experiments. Van Helmont rejected Aristotle’s 4 elements based on scripture (Genesis simply didn’t describe God creating the world from fire, earth, air, and water) but also rejected Paracelsus’s 3 principles based on experimental results (Salzeberg 1991). He wrote “I believe nature is the command of God, whereby a thing is that which it is, and doth that which it is commanded to do or act.” (Kaiser 1997). The transition from alchemy to chemistry culminated in Robert Boyle. He greatly respected Van Helmont and so expected to find spiritual forces in the movement of gases. But experiments led him to conclude it was not necessary to invoke potentia Dei absoluta to explain chemical behavior. Gas molecules behaved as they did due to natural laws God had ordained to govern them. He did not see this as detracting from God’s glory but rather emphasized His role as Creator and sustainer of an orderly world (Kaiser 1997). God was capable of intervening miraculously but generally He is glorified in creation through the potentia Dei ordinata. This was the understanding of Basil and is that of creationists today. Rather than being a modern aberration, the creationist view was foundational for the development of science, as illustrated by the history of chemistry