Halogenated triazines and related systems

Trifluoro- and 5-chlorodifluoro-1,2,3-triazine were prepared from the vapour- phase fluorination of trichloro-1,2,3-triazine, and their reactions with several simple nucleophiles were investigated. A new reagent system for the polyfluoroalkylation of the reactive trichloro-1,2,3- and -1,3,5-triazines under very mild conditions was developed with Dr. T. Shepherd. This system was also used to fluorinate various perchloroheteroaromatics under mild conditions. The photolysis of both trifluoro- and perfluoro-4,6- bis-isopropyl-1,2,3-triazines, at liquid nitrogen temperatures, provided conclusive evidence for the direct observation of both trifluoro- and perfluoro-2,4-bisisopropyl- azetes and their respective dimers. Additionally, the transference photolysis of perfluoro-4,6-bis-isopropyl- 1,2,3-triazine provided clear evidence that the dimerisationof perfluoro-2,4-bis-isopropylazete is a thermal process. The static photolysis of trifluoro-1,2,3-triazine produced abrown polymer, which was identified as poly(trifluoroacrylonitrile). The transference photolysis of perfluoro-3,5-bisisopropylpyridazine was repeated, and the identities of two of the perfluoro- 3- isopropylazete dimers were confirmed.Some photolysis and pyrolysis reactions of both perfluoro-3,4,6-tris-isopropylpyridazine and perfluoro-4-(2' -methylpent- 2' -yl)pyridazine were also investigated. An improved synthetic route to hexachlorocinnoline wasdeveloped, but all attempts to produce fluorinated and perfluoroalkyl derivatives were unsuccessful.Studies of the negative ion mass spectra and (^13)C n.m.r. spectra of various series of halogenated and perfluoroalkyl substituted heteroaromatics were also conducted

Internet career fairs in Australian higher education

[Abstract]: Internet Career Fairs have become a feature of the Australian graduate employment recruitment market. Internet Career Fairs offer considerable benefits in terms of resources and marketing by employers. They also offer an additional form of access to employment information that is used by students to explore their graduate employment opportunities. With the advent of Web.2 technology and sophisticated platforms such as Second Life, there is far greater potential to expand the interactivity and appeal of internet Career Fairs. In context of a description of the broader use of internet technology used for the delivery of career development services in Australia and its universities, this briefly paper describes the first 3-dimensional internet Career Fair established on the Second Life platform by an Australian university Career Service

On algebra of program correctness and incorrectness

Variants of Kleene algebra have been used to provide foundations of reasoning about programs, for instance by representing HoareLogic (HL) in algebra. That work has generally emphasised program correctness, i.e., proving the absence of bugs. Recently, Incorrectness Logic (IL) has been advanced as a formalism for the dual problem: proving thepresence of bugs. IL is intended to underpin the use of logic in programtesting and static bug finding. Here, we use a Kleene algebra with diamond operators and countable joins of tests, which embeds IL, and which also is complete for reasoning about the image of the embedding. Next to embedding IL, the algebra is able to embed HL, and allows making connections between IL and HL specifications. In this sense, it unifies correctness and incorrectness reasoning in one formalis

Selection Of Independent Binary Features Using Probabilities: An Example From Veterinary Medicine

Supervised classification into c mutually exclusive classes based on n binary features is considered. The only information available is an n×c table with probabilities. Knowing that the best d features are not the d best, simulations were run for 4 feature selection methods and an application to diagnosing BSE in cattle and Scrapie in sheep is presented

Spatial constraints within the chlamydial host cell inclusion predict interrupted development and persistence

Background. The chlamydial developmental cycle involves the alternation between the metabolically inert elementary body (EB) and the replicating reticulate body (RB). The triggers that mediate the interchange between these particle types are unknown and yet this is crucial for understanding basic Chlamydia biology. Presentation of the hypothesis. We have proposed a hypothesis to explain key chlamydial developmental events whereby RBs are replicating strictly whilst in contact with the host cell membrane-derived inclusion via type three secretion (T3S) injectisomes. As the inclusion expands, the contact between each RB and the inclusion membrane decreases, eventually reaching a threshold, beyond which T3S is inactivated upon detachment and this is the signal for RB-to-EB differentiation. Testing the hypothesis. We explore this hypothesis through the development of a detailed mathematical model. The model uses knowledge and data of the biological system wherever available and simulates the chlamydial developmental cycle under the assumptions of the hypothesis in order to predict various outcomes and implications under a number of scenarios. Implications of the hypothesis. We show that the concept of in vitro persistent infection is not only consistent with the hypothesis but in fact an implication of it. We show that increasing the RB radius, and/or the maximum length of T3S needles mediating contact between RBs and the inclusion membrane, and/or the number of inclusions per infected cell, will contribute to the development of persistent infection. The RB radius is the most important determinant of whether persistent infection would ensue, and subsequently, the magnitude of the EB yield. We determine relationships between the length of the T3S needle and the RB radius within an inclusion, and between the RB radius and the number of inclusions per host cell to predict whether persistent infection or normal development would occur within a host cell. These results are all testable experimentally and could lead to significantly greater understanding of one of the most crucial steps in chlamydial development

Ultrasonic Imaging of Reproductive Events in Muskoxen

To our knowledge, this is the first detailed report of ovarian follicular dynamics in a wild species. It seems that the pattern in muskoxen, with major and minor waves and a short first cycle, is similar to that in goats. Insight of this kind is important in the design of appropriate artificial breeding systems and in this respect, the muskox may provide a useful model for the endangered takin {Budorcas taxicolor). A detailed knowledge of ovarian events may also be critical to the interpretation of the response of wild populations to environmental stress

SOCS3 is a modulator of human macrophage phagocytosis

ACKNOWLEDGMENTS This work was supported by Kidney Research UK (Grant Number RP1/2012). The authors thank the staff of the Aberdeen Microscopy and Histology Core Facility for advice and technical assistance. The authors acknowledge and are grateful to all volunteers for donating blood for macrophage and neutrophil isolation.Peer reviewedPublisher PD

Dynamics of Line-Driven Winds from Disks in Cataclysmic Variables. II. Mass Loss Rates and Velocity Laws

We analyze the dynamics of 2D stationary line-driven winds from accretion disks in cataclysmic variables (CVs), by generalizing the Castor, Abbott and Klein theory. In paper 1, we have solved the wind Euler equation, derived its two eigenvalues, and addressed the solution topology and wind geometry. Here, we focus on mass loss and velocity laws. We find that disk winds, even in luminous novalike variables, have low optical depth, even in the strongest driving lines. This suggests that thick-to-thin transitions in these lines occur. For disks with a realistic radial temperature, the mass loss is dominated by gas emanating from the inner decade in r. The total mass loss rate associated with a luminosity 10 Lsun is 10^{-12} Msun/yr, or 10^{-4} of the mass accretion rate. This is one order of magnitude below the lower limit obtained from P Cygni lines, when the ionizing flux shortwards of the Lyman edge is supressed. The difficulties with such small mass loss rates in CVs are principal, and confirm our previous work. We conjecture that this issue may be resolved by detailed nonLTE calculations of the line force within the context of CV disk winds, and/or better accounting for the disk energy distribution and wind ionization structure. We find that the wind velocity profile is well approximated by the empirical law used in kinematical modeling. The acceleration length scale is given by the footpoint radius of the wind streamline in the disk. This suggests an upper limit of 10 Rwd to the acceleration scale, which is smaller by factors of a few as compared to values derived from line fitting.Comment: 14 pages, 3 Postscript figures, also from http://www.pa.uky.edu/~shlosman/publ.html. Astrophysical Journal, submitte

Methods and apparatus for switching a transponder to an active state, and asset management systems employing same

A transponder that may be used as an RFID tag includes a passive circuit to eliminate the need for an "always on" active RF receiving element to anticipate a wake-up signal for the balance of the transponder electronics. This solution allows the entire active transponder to have all circuit elements in a sleep (standby) state, thus drastically extending battery life or other charge storage device life. Also, a wake-up solution that reduces total energy consumption of an active transponder system by allowing all non-addressed transponders to remain in a sleep (standby) state, thereby reducing total system or collection energy. Also, the transponder and wake-up solution are employed in an asset tracking system