Transactivation of a ribosomal gene by simian virus 40 large-T antigen requires at least three activities of the protein

Immunoaffinity-purified paired helical filaments (PHFs) from Alzheimer's disease (AD) brain homogenates contain an associated protein kinase activity that is able to induce the phosphorylation of PHF proteins on addition of exogenous MgCl2 and ATP. PHF kinase activity is shown to be present in immunoaffinity-purified PHFs from both sporadic and familial AD, Down's syndrome, and Pick's disease but not from normal brain homogenates. Although initial studies failed to show that the kinase was able to induce the phosphorylation of tau, additional studies presented in this article show that only cyclic AMP-dependent protein kinase-pretreated recombinant tau is a substrate for the PHF kinase activity. Deletional mutagenesis, phosphopeptide mapping, and site-directed mutagenesis have identified the PHF kinase phosphorylation sites as amino acids Thr361 and Ser412 in htau40. In addition, the cyclic AMP-dependent protein kinase phosphorylation sites that direct the PHF kinase have been mapped to amino acids Ser356 and Ser409 in htau40. Additional data demonstrate that these hierarchical phosphorylations in the extreme C terminus of tau allow for the incorporation of recombinant tau into exogenously added AD-derived PHFs, providing evidence that certain unique phosphorylations of tau may play a role in the pathogenesis of neurofibrillary pathology in AD.     

Network encryption

For organizations or individuals who wish to protect the confidentiality of their data when it is in transit across communications networks, network level encryption offers an efficient and proven method for preserving data privacy. Use of encryption on a network also offers anti-hacking protection since a hacker's communications are likely to originate from outside the encrypted network and hence will be discarded. This article provides an overview of the different approaches to network encryption together with the related key management aspects.     

Testing and Application of a Transport Model for Runoff Event Inputs for a Water Supply Reservoir

Effective simulation of the fate and transport of runoff event inflows is an important goal of many water quality modeling initiatives. The set-up and testing of a two-dimensional hydrodynamic transport model is documented for a water supply reservoir, Schoharie Reservoir, New York, that uses specific conductance (SC) as a conservative tracer and focuses on fate and transport of runoff event inputs, particularly the plunging of density currents in summer and fall. Model testing is supported by temporally detailed measurements of meteorological, operational, and tributary (temperature and SC) model drivers, and temporally and spatially replete in-reservoir patterns of SC following multiple runoff events, obtained with a combination of robotic monitoring platforms and gridding with rapid profiling instrumentation. Specific conductance is demonstrated to be an ideal tracer because of the distinct tributary signals and subsequent in-reservoir signatures imparted from runoff events and its close coupling to turbidity patterns that are primary water quality concerns for managers. The model is demonstrated to perform well in simulating in-reservoir signatures of SC following multiple runoff events over the spring to fall interval of 2003, including vertical, longitudinal, and temporal patterns, and features of the thermal stratification regime for the same interval. The validated model is applied in a probabilistic manner on the basis of a 61-year record (239 runoff events) of model drivers to provide a robust representation of the transport of runoff event inputs relative to the location of the water supply intake. This application demonstrates the entry of runoff event inflows as plunging density currents in summer and fall is a recurring phenomenon for this reservoir.     

Penetration of surface-inoculated bacteria as a result of hydrodynamic shock wave treatment of beef steaks

The top surface of the raw eye of round steaks was inoculated with either green fluorescent protein (GFP)-labeled Escherichia coli (E. coli-GFP) or rifampin-resistant E. coli (E. coli-rif). Cryostat sampling in concert with laser scanning confocal microscopy (LSCM) or plating onto antibiotic selective agar was used to determine if hydrodynamic shock wave (HSW) treatment resulted in the movement of the inoculated bacteria from the outer inoculated surface to the interior of intact beef steaks. HSW treatment induced the movement of both marker bacteria into the steaks to a maximum depth of 300 microm (0.3 mm). Because popular steak-cooking techniques involve the application of heat from the exterior surface of the steak to achieve internal temperatures ranging from 55 to 82 degrees C, the extent of bacterial penetration observed in HSW-treated steaks does not appear to pose a safety hazard to consumers.     

Extraocular fast myosin heavy chain expression in the levator palpebrae and retractor bulbi muscles

PURPOSE: To determine whether the levator palpebrae superioris (LPS) and the retractor bulbi (RB) muscles, which share contractile characteristics with extraocular muscles (EOMs), express fast EOM-specific myosin heavy chain (MyHC) in the rabbit and other mammalian species. METHODS: Cryostat sections of rabbit eye and limb muscles were stained by indirect peroxidase immunohistochemical procedures using monoclonal antibodies (MAbs), including one (4A6) against EOM-specific fast MyHC. Myosin heavy chain isoforms from these muscles were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the 4A6-reactive component was identified by immunoblotting. RESULTS: MAb 4A6 stained muscle fibers in rabbit LPS and RB. SDS-PAGE resolved a rabbit EOM-specific MyHC isoform (band 1) from two other components (bands 2 and 3) that comigrated with limb fast MyHCs. MAb 4A6 reacted only with band 1. Rabbit LPS and RB also displayed corresponding MyHC components with the same mobilities and immunoreactivities as bands 1 to 3 in the EOM. MAb 4A6 also stained muscle fibers in monkey and cat LPS, but it failed to stain muscle fibers in cat RB and rat LPS and RB. CONCLUSIONS: The expression of EOM-specific fast MyHC in EOM, LPS, and RB reflect their common developmental origin and similar contractile characteristics. These properties set them apart from other skeletal muscle groups. Eye muscles may constitute a distinct muscle group or allotype characterized by unique properties, including their propensity or resistance to disease.     

Disinfection by calcium hydroxide pastes of dentinal tubules infected with two obligate and one facultative anaerobic bacteria

Bovine dentine cylinders were experimentally infected with Actinomyces israelii, Fusobacterium nucleatum, or Enterococcus faecalis. The latter is a facultative anaerobic bacteria and the others are obligate anaerobes commonly found in endodontic infections. The infected specimens were exposed to pastes of calcium hydroxide mixed with saline solution or camphorated paramonochlorophenol for periods of 1 h, 1 day, and 1 week. The viability of bacteria after these exposure times was evaluated by specimen incubation in culture medium to compare the effectiveness of the pastes in disinfecting dentinal tubules. The calcium hydroxide/camphorated paramonochlorophenol paste effectively killed bacteria in the tubules after a 1-h period of exposure, except for E. faecalis that required one day of exposure. In contrast, the calcium hydroxide/saline paste was ineffective against E. faecalis and F. nucleatum even after 1 week of exposure. The results showed that camphorated paramonochlorophenol increased the antibacterial effects of calcium hydroxide.     

The role of histone acetylation in the allelic expression of the imprinted human insulin-like growth factor II gene

This study examines the relationship between the first cycle of in-vitro fertilization (IVF) and subsequent cycles. The results of all IVF cycles conducted at The Hammersmith Hospital or The Royal Masonic Hospital between 1988 and 1995 were studied including those cycles where egg recovery was abandoned due to poor ovarian response. All patients underwent a standardized treatment protocol. Of those women who achieved a clinical pregnancy during their first IVF attempt, 33% achieved a pregnancy during their second cycle, statistically significantly different from the 24% of patients conceiving during a second cycle who had failed to conceive during their first. 36% of those who achieved a biochemical pregnancy in their first cycle became pregnant in their second. Age was an important factor in the success of IVF treatment, with pregnancy rates of 48% in the 20-25 year age group falling to 8% in those aged > or =41 years. Cumulative pregnancy rates were 26% after one cycle, increasing to 43% after two cycles and reached 80% after seven cycles. A previous pregnancy significantly improved a couple's probability of conception in a later IVF cycle. Overall pregnancy rates per cycle were constant for the first three attempts. Cumulative pregnancy rates continued to rise to 72% after six cycles. Thus the more cycles a couple undergo (up to six) the greater their chance of a pregnancy.     

Effect of altering the daily herbage allowance to cows in mid lactation on the composition, ripening and functionality of low-moisture, part-skim Mozzarella cheese

A retrospective chart review was used to examine sexual behavior (hypersexual, exposing, and victimizing) and cognitive impairment in 200 youth who had serious mental illness. Lower IQ was associated with increased sexual acting-out. For more serious victimizing sexual behaviors, only Verbal IQ differences reached statistical significance. Overall, sexual behavior was strongly associated with a history of sexual abuse. Sexual abuse history was significantly associated only with lower Performance IQ. Therefore, the association between low Verbal IQ and sexual victimizing behavior is distinct from the effects of sexual abuse. Results underscore the importance of verbal cognitive abilities, regardless of overall cognitive level, in the etiology and treatment of sexual behaviors, especially among individuals without a history of sexual abuse.     

Hierarchical bayesian models for regularisation in sequential learning

We show that a hierarchical Bayesian modeling approach allows us to perform regularization in sequential learning. We identify three inference levels within this hierarchy: model selection, parameter estimation, and noise estimation. In environments where data arrive sequentially, techniques such as cross validation to achieve regularization or model selection are not possible. The Bayesian approach, with extended Kalman filtering at the parameter estimation level, allows for regularization within a minimum variance framework. A multilayer perceptron is used to generate the extended Kalman filter nonlinear measurements mapping. We describe several algorithms at the noise estimation level that allow us to implement on-line regularization. We also show the theoretical links between adaptive noise estimation in extended Kalman filtering, multiple adaptive learning rates, and multiple smoothing regularization coefficients.