The quantity of PCR products that are simultaneously amplified from two different loci in a duplex amplification (DA) are significantly lower for one of the loci, as compared to identical PCR amplification in separate single-band amplifications (SBA). This difference in amplification probably occurs already after the second cycle of amplification. To further analyze this phenomenon, we tested different reaction conditions, including annealing times, a wide range of temperatures, various quantities of the template, several nucleotide concentrations, different amounts of TaqI DNA Polymerase, number of amplification cycles and various amounts of primers and primers ratio. Changing the ratio between the sets of primers in DA had the most significant effect on the relative levels of amplification of the loci with an optimal ratio of 4:1 in favor of the set of primers used to amplify the underrepresented fragment. The optimal annealing temperatures for the tested sets of primers were identical in SBA and different in DA. Possible reasons for this phenomenon are discussed.
Derivatives of quinolinium iodide have been found to exhibit second-order nonlinear optical (NLO) response in their crystalline form. The quaternary amine functionality is introduced as an electron-withdrawing group in NLO-active chromophores. While their electron-accepting capabilities are somewhat weaker than those of the nitro group, these organic salts show a much more favorable transparency−nonlinearity tradeoff for blue second harmonic generation (SHG) NLO applications. Here we present crystal growth and characterization via X-ray diffraction (XRD), NMR, FTIR, and optical spectroscopy measurements. Experimental linear optical features are fully consistent with INDO/SCI−SOS theoretical calculations. These latter provide a rationale for the NLO response of these materials. Calculations predict a sizable molecular nonlinearity, which parallels the wavelength of the lowest charge-transfer transition. In addition, a direct correlation between SHG powder response to the β crystallographic angle is observed.
The full multiple spawning (FMS) methodology for solving the time dependent Schrodinger equation for multiple electronic states is extended to reactive collisions on several electronic states. The computational complexity remains unchanged, less than double that of a quasiclassical trajectory computation. It is shown how the spawning approach can describe the bifurcation of the wave function into components exiting in different directions of space, as is the case when rearrangement of the atoms takes place. Low energy H+ + D-2 and H + H-2 + collisions, which result in both reactive and nonreactive charge transfer are used as an illustration. The FMS method is used to generate converged opacity functions and cross sections even at higher energies when dissociation is energetically allowed. This suggests that also on a single potential energy function the FMS method offers a viable route to full dimensional reactive quantal scattering computations. For the H-3(+) system, a diatomics in molecules (DIM) potential energy function is used in a diabatic basis where three electronic states are coupled. Comparison is made with the classical path approximation, the trajectory surface hopping method and stationary quantum mechanical scattering computations, which used the sudden approximation and the coupled states method. For the H+ + D-2 collision, our results are close to those already published. The computations for the H + H-2(+) collision, where the initial channel is an excited one, are distinctly different from the results of earlier, approximate, approaches.
We have previously hypothesized that the osteopenic changes seen in the skeletons of old male BALB/c mice are due to reductions in the availability and/or synthesis of bone TGF-beta which results in fewer, less osteogenic marrow osteoprogenitor cells (CFU-f; OPCs) and lower levels of bone formation. Among other things, this hypothesis would predict that introducing exogenous TGF-beta into old mice (growth factor replacement) should stimulate marrow CFU-f and increase bone formation. In the present study, we have tested this prediction and, indirectly the hypothesis, by injecting human recombinant TGF-beta1, i.p., into both young adult (4 month) and old mice (24 month). The effects of the growth factor on the skeleton were then assessed by measurements of trabecular bone volume, bone formation, fracture healing, and the number, proliferative, apoptotic, and alkaline phosphatase activity of marrow CFU-f/OPCs. Our data show that the introduction of 0.5 or 5.0 ug/day of TGF-beta1 into old mice for 20 days 1) increases trabecular bone volume, bone formation and the mineral apposition rate, 2) augments fracture healing, 3) increases the number and size of CFU-f colonies, and 4) increases proliferation and diminishes apoptosis of CFU-f in primary bone marrow cultures. Importantly, these stimulatory effects of injected growth factor are apparently age-specific, i.e., they are either not seen in young animals or, if seen, are found at much lower levels. While these observations do not exclude other possible mechanisms for the osteopenia of old mice, they provide further support for the hypothesis that, with age, diminished TGF-beta synthesis or availability results in a reduction in the marrow osteoprogenitor pool and bone formation. The findings also demonstrate that the latter changes can be reversed, at least transiently, by introducing exogenous TGF-beta1.
Possible pheromonal control of worker reproduction was tested in Bombus terrestris. The mode of assay included exposure of callow workers to extracts originating from different queen parts and measuring the effect on the in vitro biosynthesis of juvenile hormone (JH), the apparent gonadotropin in this species. Both queen total body extracts applied to dummies consisting of oven-dried or Soxhlet-washed virgin queen bodies and cuticular washes applied to living virgin queens effectively inhibited the biosynthesis of JH in callow workers. None of the five exocrine glands (mandibular, hypopharyngeal, salivary, Dufour's, and tarsal) demonstrated inhibitory activity. Likewise, the use of synthetic 3-hydroxy acids, found in queen mandibular glands, were ineffective in blocking JH biosynthesis in queenless workers. The results suggest that the queen may use a primer pheromone spread on me epicuticle as a means to inhibit worker reproduction. However, our results are not consistent with the prevailing hypothesis that in B. terrestris the main source of the pheromone that inhibits worker reproduction is in the queen's mandibular glands.
In annual colonies of bumble-bees overt queen-worker conflict is limited to a distinct `competition phase' (CPh). In unmanipulated Bombus terrestris colonies, the queen's switch to male production (the `switch point', SP) accounted for only 22% of the variation in the onset of the CPh. In some colonies, the CPh even began before the SP. The CPh was more strongly correlated with the transition in queen production (r=0.79). Replacing the queen eggs with male eggs or doubling the number of workers in young colonies resulted in a significantly earlier onset of the CPh and a significantly earlier transition to queen production. Replacing queen eggs with female eggs did not have this effect. These manipulations did not affect the timing of the queen's switch from female to male production. These findings show that the mechanism underlying the queen-worker conflict in insect societies is more complex than previously appreciated. The onset of queen-worker conflict cannot be attributed simply to a single factor such as the queen's switch to male production or a decrease in queen inhibition. Rather, multiple cues are important.
The mechanisms of regulating worker reproduction in bumblebees were studied by direct behavioral observations and by measuring ovarian development and juvenile hormone (JH) biosynthesis rates in workers under different social conditions. Workers in the last stage of Bombus terrestris is colony development (the competition phase) had the lowest ovarian development and JH biosynthesis rates. Gallows introduced into colonies immediately after queen removal (dequeened colonies) demonstrated a significant increase in ovarian development before, bur not during, the competition phase. These findings differ from the higher ovarian development in colonies during the competition phase predicted by the prevailing hypothesis that worker reproduction starts in response to a decrease in queen inhibition. Reproduction of callows housed with dominant workers in small queenless groups was inhibited as in queenright colonies. This suggests that the reduced ovarian development and JH biosynthesis rates observed in dequeened and normally developing colonies during the competition phase also reflect inhibition by dominant workers. Thus, two distinct stages of inhibition of reproduction seem to exist: (1) before the competition phase, when the queen slows down worker ovarian development and prevents oviposition; (2) during the competition phase, when dominant workers inhibit ovarian development of other workers. Between these stages there seems to be a temporal ``window'' of enhanced worker reproductive development. The queen's typical switch to haploid egg production was not associated with changes in worker ovarian development or JH biosynthesis rates. These findings suggest that regulation of worker reproduction in B. terrestris is not determined by simple changes in the queen's inhibition capacity or by the sex of offspring and that the worker's role is more important than previously believed.
Metabolic pathways are controlled primarily by protein degradation rates. Degradation rates, in turn, are controlled by changes in physiologic condition or nutrient supply. Vitamin B6 is associated with a greater variety of reactions than most other vitamins. Moreover, the vitamin B6 needs of the elderly tend to be higher than those of young adults. Neutrophils seem to be appropriate cells for assessing protein turnover as affected by macronutrients and micronutrients. Thus, we assumed that vitamin B6 supplementation, particularly in an elderly population, would change the turnover rates of the neutrophil proteins. Protein synthesis was measured after 30 minutes of 35S-Met incorporation followed by a 30-minute washout incubation; degradation was measured after an additional 5-hour incubation. Following protein separation, radioactive images of short-lived proteins were electronically separated into bands. Vitamin B6 supplementation significantly increased the synthesis of most neutrop
The Heroe, Scourge of Ingénuité and Naïveté, couched his Lance and spurred his mighty Stallion. He bore on the trembling enemy like a tempest, charged him en véritable sanglier, and — a few echoing pages and many poignant footnotes later — what had been nasty Standardtheorie (more conveniently known to its rather dubious friends as ‘the Snark’) was left a wretched, bloody bundle of opinions squirming on the ground. O great relief! The Menace, the obnoxious (And, if the truth be told, pathetic) Skandalon of modern enlightened Linguistics and Egyptology, is no more — to the everlasting gratitude and awe of future generations.
A real-time spatial–temporal processor based on cascaded nonlinearities converts space-domain images to time-domain waveforms by the interaction of spectrally decomposed ultrashort pulses and spatially Fourier-transformed images carried by quasi-monochromatic light waves. We use four-wave mixing, achieved by cascaded second-order nonlinearities with type II noncollinear phase matching, for femtosecond-rate processing. We present a detailed analysis of the nonlinear mixing process with waves containing wide temporal and angular bandwidths. The wide bandwidths give rise to phase-mismatch terms in each process of the cascade. We define a complex spatial–temporal filter to characterize the effects of the phase-mismatch terms, modeling the deviations from the ideal system response. New experimental results that support our findings are presented.
We report on the observation of a new mechanism for self-trapping of optical beams: self-trapping that stems from spontaneous creation of ferroelectric crystalline clusters, seeded by a weak photorefractive diffusion field. This is an evident observation of the highly nonlinear aspects of propagation in a thermodynamically metastable system, including optically driven crystalline ordering in a medium undergoing a phase transition.
The possible role played by streptolysin S (SLS) of group A streptococci in the pathophysiology of streptococcal infections and in post-streptococcal sequelae is discussed. The following properties of SLS justify its definition as a distinct virulence factor: 1) its presence on the streptococcus surface in a cell-bound form, 2) its continuous and prolonged synthesis by resting streptococci, 3) its non-immunogenicity, 4) its extractability by serum proteins (albumin, alpha lipoprotein), 5) its ability to become transferred directly to target cells while being protected from inhibitory agents in the milieu of inflammation, 6) its ability to bore holes in the membrane phospholipids in a large variety of mammalian cells, 7) its ability to synergize with oxidants, proteolytic enzymes, and with additional host-derived proinflammatory agonists, and 8) its absence in streptococcal mutants associated with a lower pathogenicity for animals. Because tissue damage in streptococcal and post-streptococcal sequelae might be the end result of a distinct synergism between streptococcal and host-derived proinflammatory agonists it is proposed that only cocktails of anti-inflammatory agents including distinct inhibitors of SLS (phospholipids), gamma globulin, inhibitors of reactive oxygen species, proteinases, cationic proteins cytokines etc., will be effective in inhibiting the multiple synergistic interactions which lead to fasciitis, myositis and the flesh-eating syndromes, and often develop into sepsis, septic shock and multiple organ failure. The creation of mutants deficient in SLS and in proteases will help shed light on the specific role played by SLS in the virulence of group A hemolytic streptococci.
The technique and results of free skin grafts have been described in dogs, horses, rabbits, goats and mice, The procedure in cats is, however, described only indirectly in papers relating to dogs, A standard technique has been developed by the authors for use in cats, and is reported for 17 grafts in 16 cats with traumatic injury to the legs resulting in large areas of skin loss, This paper describes the preparation of the wound for grafting, the harvesting of the graft, graft placement, postoperative care and the results of the application of this technique. The success rate in this series of cases was high. This was attributed to proper preparation of the recipient site, collection of the graft and postoperative bandaging, The results suggest that the success rate of free skin grafts in cats is considerably higher than that achieved by the present authors in dogs, and reported for dogs by other surgeons in the literature.
The Nominal Sentence is a convenient code-name for a specific predicative pattern set primarily predicating nouns (that is substantives or adjectives) and pronominals, characterized, not by ‘the absence of a verb’, but as a distinct nexus type that is sometimes paradigmatically opposed (or, in given environments, opposition-neutralized) to both verbal and statal adverb-rheme nexus, and in any case one for which verbal nexus has no constitutive relevance. In the following pages I aim at a structural account — the système des valeurs (opposition and neutralization), definition, typology and documentation — of noun predication patterns on the basis of the Four Branches (Mabinogi) and Owein.
