Embryonic regulation of histone ubiquitination the sea urchin

We have used quantitative 2-D protein electrophoresis and immunoprecipitation to study the patterns of histone ubiquitination at 10 h and 36 h of embryonic development in Strongylocentrotus purpuratus. Variants csH2A, ΑH2A, ΒH2A, ΓH2A, ΔHA, H2AF./Z, ΑH2B, ΒH2B, and ΓH2B showed up to sevenfold differences in level of monoubiquitination between variants, and individual variants showed up to sixfold changes during development. At 36 h of embryogenesis, the late variants were less ubiquitinated than the early variants, althoug h the overall level of ubiquitination was appreciably greater than at 10 h. Antiubiquitin antibodies were used to precipitate formaldehyde-fixed chromatin fragments in order to estimate the degree of ubiquitination of the early histone genes. The 5′ regulatory region of the active H3 gene appeared to be at least twice as ubiquitinated as the adjacent upstream spacer. However, the absolute level of ubiquitination of the early histone gene repeat seemed to be independent of transcriptional activity. These results show that variant-specific ubiquitination of histones is a part of the developmental program in sea urchin embryos, but is not clearly correlated with transcriptional activity of the early histone genes, except perhaps in the regulatory regions. © 1995 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50179/1/1020160308_ftp.pd

A multiplexed immunoassay system based upon reciprocating centrifugal microfluidics

A novel, centrifugal disk-based micro-total analysis system (mu TAS) for low cost and high throughput semi-automated immunoassay processing was developed. A key innovation in the disposable immunoassay disk design is in a fluidic structure that enables very efficient micro-mixing based on a reciprocating mechanism in which centrifugal acceleration acting upon a liquid element first generates and stores pneumatic energy that is then released by a reduction of the centrifugal acceleration, resulting in a reversal of direction of flow of the liquid. Through an alternating sequence of high and low centrifugal acceleration, the system reciprocates the flow of liquid within the disk to maximize incubation/hybridization efficiency between antibodies and antigen macromolecules during the incubation/hybridization stage of the assay. The described reciprocating mechanism results in a reduction in processing time and reagent consumption by one order of magnitude.open121

Antibiotic Treatment of the Tick Vector Amblyomma americanum Reduced Reproductive Fitness

BACKGROUND: The lone star tick Amblyomma americanum is a common pest and vector of infectious diseases for humans and other mammals in the southern and eastern United States. A Coxiella sp. bacterial endosymbiont was highly prevalent in both laboratory-reared and field-collected A. americanum. The Coxiella sp. was demonstrated in all stages of tick and in greatest densities in nymphs and adult females, while a Rickettsia sp. was less prevalent and in lower densities when present. METHODOLOGY/PRINCIPAL FINDINGS: We manipulated the numbers of both bacterial species in laboratory-reared A. americanum by injecting engorged nymphs or engorged, mated females with single doses of an antibiotic (rifampin or tetracycline) or buffer alone. Burdens of the bacteria after molting or after oviposition were estimated by quantitative polymerase chain reaction with primers and probes specific for each bacterial species or, as an internal standard, the host tick. Post-molt adult ticks that had been treated with rifampin or tetracycline had lower numbers of the Coxiella sp. and Rickettsia sp. and generally weighed less than ticks that received buffer alone. Similarly, after oviposition, females treated previously with either antibiotic had lower burdens of both bacterial species in comparison to controls. Treatment of engorged females with either antibiotic was associated with prolonged time to oviposition, lower proportions of ticks that hatched, lower proportions of viable larvae among total larvae, and lower numbers of viable larvae per tick. These fitness estimators were associated with reduced numbers of the Coxiella sp. but not the Rickettsia sp. CONCLUSION/SIGNIFICANCE: The findings indicate that the Coxiella sp. is a primary endosymbiont, perhaps provisioning the obligately hematophagous parasites with essential nutrients. The results also suggest that antibiotics could be incorporated into an integrated pest management plan for control of these and other tick vectors of disease

Multivalent vaccines demonstrate immunogenicity and protect against Coxiella burnetii aerosol challenge

Vaccines are among the most cost-effective public health measures for controlling infectious diseases. Coxiella burnetii is the etiological agent of Q fever, a disease with a wide clinical spectrum that ranges from mild symptoms, such as fever and fatigue, to more severe disease, such as pneumonia and endocarditis. The formalin-inactivated whole-cell vaccine Q-VAX® contains hundreds of antigens and confers lifelong protection in humans, but prior sensitization from infection or vaccination can result in deleterious reactogenic responses to vaccination. Consequently, there is great interest in developing non-reactogenic alternatives based on adjuvanted recombinant proteins. In this study, we aimed to develop a multivalent vaccine that conferred protection with reduced reactogenicity. We hypothesized that a multivalent vaccine consisting of multiple antigens would be more immunogenic and protective than a monovalent vaccine owing to the large number of potential protective antigens in the C. burnetii proteome. To address this, we identified immunogenic T and B cell antigens, and selected proteins were purified to evaluate with a combination adjuvant (IVAX-1), with or without C. burnetii lipopolysaccharide (LPS) in immunogenicity studies in vivo in mice and in a Hartley guinea pig intratracheal aerosol challenge model using C. burnetii strain NMI RSA 493. The data showed that multivalent vaccines are more immunogenic than monovalent vaccines and more closely emulate the protection achieved by Q-VAX. Although six antigens were the most immunogenic, we also discovered that multiplexing beyond four antigens introduces detectable reactogenicity, indicating that there is an upper limit to the number of antigens that can be safely included in a multivalent Q-fever vaccine. C. burnetii LPS also demonstrates efficacy as a vaccine antigen in conferring protection in an otherwise monovalent vaccine formulation, suggesting that its addition in multivalent vaccines, as demonstrated by a quadrivalent formulation, would improve protective responses

The analysis of pressure forces and strain in thickening of vegetal materials

The article analyzes the means of thickening vegetal materials the effectiveness of which depend on the mechanical properties of gravity, pressure and mass. The surface of material being thickened is not steady; therefore the stability of mechanical means and vibrator is reduced. The article includes theoretical cvalunlion of the conditions, factors and indicators of grass mass slope stability and marginal balance affecting the design or selection of constructional elements of compartment and container-type forage storage. An experimental research was carried out pressing the vegetal materials by means of tractor, surface flat inertia type vibrators in which the excitation power is received by rotating the unbalanced mass, and directional and non-directional inertia type vibrators. It was established, that resonant frequency essentially depends only on mass toughness qualities, and changes from 7.0 to 15 Hz. The amplitude of excitation power of galcga and its mixes during resonance increases to 3 times, however in such case the efficiency of mass pressure reduces. The coefficients of pressure increase and the repression of pressure on plant mass layer in the bottom of the container were estimated. After evaluating the application of various tractors and vibratory grass mass thickeners for grass mass pressing, it was established that in both cases the received efficiency rates of grass mass layer are similarVytauto Didžiojo universitetasŽemės ūkio akademij

Highly Prevalent Coxiella sp. Bacterium in the Tick Vector Amblyomma americanum

Laboratory-reared and field-collected Amblyomma americanum ticks were hosts of a Coxiella sp. and a Rickettsia sp. While the Coxiella sp. was detected in 50 of 50 field-collected ticks, the Rickettsia sp. was absent from 32% of ticks. The Coxiella sp. showed evidence of a reduced genome and may be an obligate endosymbiont

Ecological method of silage compaction

Surface unbalanced-throw vibrators, in which the exciting force is generated by turning the unbalanced mass, were studied and evaluated. Directional and non-directional vibrators were manufactured and tested. Using a directional grass mass pressing vibrator, the amplitude frequency characteristics of pressed grass mass were determined. Resonant frequency was found to depend essentially only on mass elastic properties; it varied from 7.0 Hz for goat'srue (Galega orientalis Lam) mass of greater elasticity up to 15 Hz for less elastic chopped maize mass. The amplitude of grass mass pressure during the resonance depends only on mechanical resistance of the pressed mass. The excitation power amplitude of goat's rue and its mixes during the resonance increased by 2.5 to 3 times but the efficiency of mass pressure dropped. The calculated coefficients of pressure enhancement were 5.5 to 5.8, when vibratory packers were used for grass mass pressing. The established pressure increase rate on the plant mass layer, when pressing it on the surface and from the container bottom, was from 3.0 to 7.5 when using directional vibrator, and 4.8 when using non-directional vibrator. After estimating the application of various tractors and vibratory grass mass packers for grass mass compaction it was found that in both cases the received efficiency rates of grass mass layer were similar. However, while using vibratory grass mass packers, these rates were even higher than using a wheeled tractor T-25A. The efficiency of mass compaction by a centrifugal directional vibrator was estimated in an experimental trial. The results indicated that during the vibratory packing the grass layer was compacted intensely for 5 to 10 min. Therefore, it is advisable to use the vibrators of this type to compact the 0.4 to 0.6 m thick grass layers. Operation of such a vibrator resulted in good density of chopped maize - after 20 minVytauto Didžiojo universitetasŽemės ūkio akademij

Research on vibratory effect on grass mass

Vytauto Didžiojo universitetasŽemės ūkio akademij

Noise study of wood chipper LAIMET HP-21 operator working environment

Tyrimai rodo, kad 23-29 % medienos apdirbimo pramonės darbuotojų patiria klausos sutrikimus dėl triukšmo poveikio. Yra žinoma, kad didžioji dalis medienos apdirbimo įrangos sukelia 89-108 dBA triukšmą. Tyrimui naudotas bazinis medienos smulkintuvas LAIMET HP-21, skirtas visų rūšių medienos ir kitos biomasės medžiagų smulkinimui. Gautas produktas tinkamas šildymui, dirbamos žemės padengimui, kompostui, kraikui, popieriaus gamybai. Smulkintuvas pritaikytas visiems 20-200 AG galios traktoriams, kabinamas prie trijų taškų pakabinamos sistemos ir yra varomas tiesiogiai traktoriaus galios tiekimo velenu. Šis ir panašūs įrenginiai turi kūginius sraigtinius peilius, kurie gana efektyviai ruošia geros kokybės skiedras. Mūsų tyrimai rodo, kad smulkintuvo operatoriaus darbo vietoje bendras triukšmo lygis kinta 93-105 dBA ribose ir priklauso nuo smulkintuvo veleno sūkių, stiebų skersmens ir kitų parametrų. Tokie triukšmo lygiai akivaizdžiai viršija leistinas normas, todėl turi būti parinktos ir taikomos darbuotojų apsaugos nuo triukšmo priemonėsStudies show that 23–29 % of wood industry workers suffer hearing loss due to noise exposure. It is known that the majority of woodworking equipment causes 89–108 dBA noise. The purpose of this study was to assess the noise exposure of the used a base wood chipper LAIMET HP-21 intended for chopping all types of wood and other biomass materials. The obtained product is suitable for heating, in covering cultivated land, as compost, animal litter, paper manufacturing. This wood chipper is adapted for all 20-200 HP tractors mounted to the three-point harnesses system and is directly driven by the tractor's supply shaft. This and similar devices have a conical screw blade, which efficiently produces splinter free and even high-quality chips. Our research shows that the operator's position in the overall noise levels exceeds 93-105 dBA range and depends on the shaft speed, stems diameter and other parameters. Such noise levels significantly in excess of the permitted levels, therefore must be required a higher level of ear protection, regardless of length of exposureVilniaus technologijų ir dizaino kolegijaVytauto Didžiojo universitetasŽemės ūkio akademij

Vibratory thickening of grass mass

Flat surface inertia type vibrators in which the excitation force for thickening grass mass is received by turning the unbalanced mass were analyzed and evaluated. Directed and undirected action vibrators were manufactured and tested. The amplitude frequency characteristics of pressed grass mass were evaluated using a directed action grass mass pressing vibrator. It was concluded that resonant frequency depends essentially only on mass toughness qualities, and changes from 7.0 Hz when there is fodder goat's rue (Galega orientalis Lam) mass of greater toughness, up to 15 Hz when thickening chopped maize mass of lesser toughness. The amplitude of grass mass pressure during resonance depends only on the mechanical resistance of the pressed mass. The amplitude of excitation power of goat's rue and its mixes during resonance increased from 2.5 to 3 times but efficiency of mass pressure reduced. The calculated coefficients of pressure enhancement were equal to 5.5-5.8 when vibratory thickeners were used for pressing grass mass. The established repression of pressure on plant mass layer, while pressing mass on the surface and from the bottom of container, was 3.0-7.5 when using the directed action vibrator, and 4.8 when using the undirected action version. After evaluating the application of various tractors and vibratory grass mass thickeners for grass mass pressing it was found that in both cases the received efficiency rates of grass mass layer were similar. However, while using vibratory grass mass thickeners, these rates were even higher than using a wheeled tractor T-25A. The efficiency of mass thickening by centrifugal-directed action vibrator was evaluated by using an experimental trial. The results mdicated that during vibratory thickening the grass layer was thickened intensely for 5-10 min. Therefore, it is advisable to use vibrators of this type for thickening grass layers of 0.4-0.6 m thickness. This vibrator resulted in good density of chopped maize -Vytauto Didžiojo universitetasŽemės ūkio akademij