A new class of tobacco chitinases homologous to bacterial exo-chitinases displays antifungal activity

A novel chitinase gene of tobacco was isolated and characterized by DNA sequence analysis of a genomic clone and a cDNA clone. Comparative sequence analysis of both clones showed an identity of 94%. The proteins encoded by these sequences do not correspond to any of the previously characterized plant chitinases of classes I-IV and are designated as class V chitinases. Comparison of the chitinase class V peptide sequence with sequences in the Swiss Protein databank revealed significant sequence similarity with bacterial exo-chitinases from Bacillus circulans, Serratia marcescens and Streptomyces plicatus. It was demonstrated that class V chitinase gene expression is induced after treatment of tobacco with different forms of stress, like TMV-infection, ethylene treatment, wounding or ultraviolet irradiation. Two related chitinase class V proteins of 41 and 43 kDa were purified from Samsun NN tobacco leaves inoculated with tobacco mosaic virus. The proteins were purified by Chelating Superose chromatography and gel filtration. In vitro assays demonstrated that class V chitinases have endo-chitinase activity and exhibit antifungal activity toward Trichoderma viride and Alternaria radicina. In addition, it was shown that class V chitinase acts synergistically with tobacco class I beta-1,3-glucanase against Fusarium solani germlings.     

FracSym: Automated symbolic computation of Lie symmetries of fractional differential equations

In this paper, we present an algorithm for the systematic calculation of Lie point symmetries for fractional order differential equations (FDEs) using the method as described by Buckwar & Luchko (1998) and Gazizov, Kasatkin & Lukashchuk (2007, 2009, 2011). The method has been generalised here to allow for the determination of symmetries for FDEs with n$n$ independent variables and for systems of partial FDEs. The algorithm has been implemented in the new MAPLE package FracSym (Jefferson and Carminati 2013) which uses routines from the MAPLE symmetry packages DESOLVII (Vu, Jefferson and Carminati, 2012) and ASP (Jefferson and Carminati, 2013). We introduce FracSym by investigating the symmetries of a number of FDEs; specific forms of any arbitrary functions, which may extend the symmetry algebras, are also determined. For each of the FDEs discussed, selected invariant solutions are then presented.     

Minimal ordering constraints for some families of variable symmetries

Variable symmetries in a constraint satisfaction problem can be broken by adding lexicographic ordering constraints. Existing general methods of generating such sets of ordering constraints can require a huge number of constraints. This adds an unacceptable overhead to the solving process. Methods exist by which this large set of ordering constraints can be reduced to a much smaller set automatically, but their application is also prohibitively costly. In contrast, this paper takes a bottom-up approach. It examines some commonly-occurring families of groups and derives a minimal set of ordering constraints sufficient to break the symmetry each group describes. These minimal sets are then used as building blocks to generate minimal sets of ordering constraints for groups constructed via direct and imprimitive wreath products. Experimental results confirm the value of minimal sets of ordering constraints, which can now be generated much more cheaply than with previous methods.     

Non-surgical alternative in the treatment of skeletal Class III problems

The dental profession is not static, but dynamic. New research findings, along with medical and technological advances, necessitate constant re-examination of treatment philosophies and techniques. What were acceptable treatment techniques in the past may not necessarily be the most effective and best techniques for our patients today. Currently, many practitioners feel that the only treatment for the correction of a skeletal Class III abnormality is via orthognathic surgery in older patients. In some cases it may be the only treatment option. But in most cases today, there are more conservative, non-surgical treatment alternatives in correcting Class III problems in younger aged children. In treating facial-skeletal problems, it must be emphasized that the human face is a biological masterpiece of form and function. Its importance has been documented in arts and sciences since the beginning of modern civilization. It is important enough so that individuals who are blessed with attractive features are afforded greater opportunities in our society. Attractive faces are associated with intelligence, honesty and good work ethics. With the advent of orthognathic surgery, functional appliance, functional regulator, and myofunctional therapy, the dental profession has the capability of leveling out the playing field for many individuals in our society. It does so by being able to correct problems closely associated with the human psyche--the human face. The ability to change facial features brings tremendous prestige to our profession. Along with this prestige comes greater responsibility. Our ability to change facial features entails greater understanding of facial balance and harmony. Ricketts states that the face must conform to stringent proportions known as the "divine proportion" in order for it to be esthetically pleasing. Also, our ability to move facial-skeletal structures entails greater understanding of the biomechanics of the human face. Without this knowledge practitioners can cause iatrogenic problems, such as temporomandibular disorders. Conversely, correcting facial-skeletal abnormalities have been found to alleviate many medical problems, such as chronic headaches, neck-back-shoulder pain, respiratory disorders, auditory disorders, etc. As more and more information is gathered, it is becoming clear that the physical, emotional and psychological health of a human being is intimately related to craniomandibular anatomy. In fact, the jaw and dental structures (with the exception of the tooth enamel) is formed from the neural crest cells along with the endocrine system, while the central nervous system is formed from the neural tube. The entire nervous system, the endocrine system and the dental system are formed from common tissue origin. This can explain why many facial-skeletal corrections are often accompanied by alleviation of many medical and physiological problems. These are exciting times for our profession. However, if we wish to address the needs of our patients well into the next century, we must continue to seek greater and greater knowledge in the area of the craniomandibular anatomy relative to the rest of the human body. It has much to do with facial esthetics, physiologic and psychologic harmony, and TMJ health. This knowledge will enable our profession to have the power to change human lives in a very positive way. As doctors, there can be no greater personal and professional satisfaction than to realize that, through our professional intervention, we are able to offer our patients the possibility of achieving greater happiness and quality of life.     

Bounded Rationality,Group Formation and the Emergence of Trust: An Agent-Based Economic Model

Computational Economics - It is possible to model trust as an investment game, where a player in order to receive a reward or a better outcome, accepts a certain risk of defection by another...     

Focus groups reveal perils and promises of managed care for nurse practitioners

Decades of practice and research suggest that nurse practitioners (NPs) provide cost-effective and high-quality care. Managed care's emphasis on prevention and cost savings led some policy makers to view NPs as a way to meet the need for primary care providers. However, access to and utilization of NPs has increasingly been controlled by managed care organizations (MCOs) through their selection of providers for primary care panels. This study employed qualitative methodology to examine NPs' experiences with MCOs. Three focus groups, comprising 27 NPs in New York and Connecticut, revealed NPs' mixed reactions to managed care and a range of sentiments regarding NPs' efforts to be listed as primary care providers. The results reflected NPs' concerns about their perceived "invisibility," as well as their sense of "invincibility" in the ways in which NPs are responding to the barriers posed by MCOs. They identified barriers to, as well as ways to facilitate, being listed by MCOs, and described the importance of NPs working individually and collectively in negotiating with MCOs.     

Episodic gonadotropin-releasing hormone gene expression revealed by dynamic monitoring of luciferase reporter activity in single, living neurons

The existence of an intrinsic oscillator for pulsatile gonadotropin-releasing hormone (GnRH) secretion in normal and transformed GnRH neurons raises the question of whether the corresponding gene also is expressed in an episodic manner. To resolve this question, we used a modification of conventional luciferase technology, which enabled continuous monitoring of GnRH gene activity in single, living neurons. With this method, the relative rate of endogenous gene expression is estimated by quantification of photons emitted by individual neurons microinjected with a GnRH promoter-driven luciferase reporter construct. Immortalized GT1-1 neurons, which secrete the decapeptide GnRH in a pulsatile manner conceptually identical to that of their nontransformed counterparts in vivo, were chosen as the model for these studies. First, we injected individual cells with purified luciferase protein and established that the reporter half-life was sufficiently short (50 min) to enable detection of transient changes in gene expression. Next, we subjected transfected GT1-1 cells to continuous monitoring of reporter activity for 16 h and found that the majority of them exhibited spontaneous fluctuations of photonic activity over time. Finally, we established that photonic activity accurately reflected endogenous GnRH gene expression by treating transfected GT1-1 cells with phorbol 12-myristate 13 acetate (a consensus inhibitor of GnRH gene expression) and observing a dramatic suppression of photonic emissions from continuously monitored cells. Taken together, these results demonstrate the validity of our "real-time" strategy for dynamically monitoring GnRH gene activity in living neurons. Moreover, our findings indicate that GnRH gene expression as well as neuropeptide release can occur in an intermittent manner.     

New Research Results for Electronic Voting

Voting systems have become controversial in the years following the multiple election disasters that occurred in the United States during and after 2000. Of particular note were the electronic voting (e-voting) systems that were widely deployed to replace the pre-scored punch-card systems, systems that had have been frequently judged to be central to the problem in the 2000 Florida general election. The (premature) deployment of e-voting machines stimulated a new field of security and privacy research around the subject of elections, a subject that has turned out to be more complex and deeper than anyone would have predicted a decade ago. Here we present a sample of some of the finest recent work on election technology from authors on three continents.