16,845 research outputs found
Effects of Some Commercial Enzymes in the Deinking of Newsprint
The trend of industry, in general, today is one of recycling. This is brought about as a means of conserving our dwindling natural resources and to help abate the pollution problem.
The design of this paper is to see if enzymes can be used successfully and economically in the deinking process of newsprint. Varying concentrations of enzymes, both an amylase and a protease, and a biodegradable detergent were used in a handsheet study. Temperature and pH were controlled so as to not denature the enzymes. It was found that the brightness increase was only minimal with a protease and brightness actually decreased with an amylase. The physical strength characteristics were also found to decrease with the addition of the enzymes.
Therefore, it was concluded that there is very little prospect of enzymes being used in the deinking process to increase brightness or to strengthen the physical properties of newsprint
Terpenoid-Induced Feeding Deterrence and Antennal Response of Honey Bees
Multiple interacting stressors negatively affect the survival and productivity of managed honey bee colonies. Pesticides remain a primary concern for beekeepers, as even sublethal exposures can reduce bee immunocompetence, impair navigation, and reduce social communication. Pollinator protection focuses on pesticide application guidelines; however, a more active protection strategy is needed. One possible approach is the use of feeding deterrents that can be delivered as an additive during pesticide application. The goal of this study was to validate a laboratory assay designed to rapidly screen compounds for behavioral changes related to feeding or feeding deterrence. The results of this investigation demonstrated that the synthetic Nasonov pheromone and its terpenoid constituents citral, nerol, and geraniol could alter feeding behavior in a laboratory assay. Additionally, electroantennogram assays revealed that these terpenoids elicited some response in the antennae; however, only a synthetic Nasonov pheromone, citral, and geraniol elicited responses that differed significantly from control and vehicle detections
Fast Poisson Noise Removal by Biorthogonal Haar Domain Hypothesis Testing
Methods based on hypothesis tests (HTs) in the Haar domain are widely used to
denoise Poisson count data. Facing large datasets or real-time applications,
Haar-based denoisers have to use the decimated transform to meet limited-memory
or computation-time constraints. Unfortunately, for regular underlying
intensities, decimation yields discontinuous estimates and strong "staircase"
artifacts. In this paper, we propose to combine the HT framework with the
decimated biorthogonal Haar (Bi-Haar) transform instead of the classical Haar.
The Bi-Haar filter bank is normalized such that the p-values of Bi-Haar
coefficients (pBH) provide good approximation to those of Haar (pH) for
high-intensity settings or large scales; for low-intensity settings and small
scales, we show that pBH are essentially upper-bounded by pH. Thus, we may
apply the Haar-based HTs to Bi-Haar coefficients to control a prefixed false
positive rate. By doing so, we benefit from the regular Bi-Haar filter bank to
gain a smooth estimate while always maintaining a low computational complexity.
A Fisher-approximation-based threshold imple- menting the HTs is also
established. The efficiency of this method is illustrated on an example of
hyperspectral-source-flux estimation
Violation of Leggett-type inequalities in the spin-orbit degrees of freedom of a single photon
We report the experimental violation of Leggett-type inequalities for a
hybrid entangled state of spin and orbital angular momentum of a single photon.
These inequalities give a physical criterion to verify the possible validity of
a class of hidden-variable theories, originally named "crypto non-local", that
are not excluded by the violation of Bell-type inequalities. In our case, the
tested theories assume the existence of hidden variables associated with
independent degrees of freedom of the same particle, while admitting the
possibility of an influence between the two measurements, i.e. the so-called
contextuality of observables. We observe a violation the Leggett inequalities
for a range of experimental inputs, with a maximum violation of seven standard
deviations, thus ruling out this class of hidden variable models with a high
confidence.Comment: 5 pages, 4 figure
TIV vaccination modulates host responses to influenza virus infection that correlate with protection against bacterial superinfection
Background: Influenza virus infection predisposes to secondary bacterial pneumonia. Currently licensed influenza vaccines aim at the induction of neutralizing antibodies and are less effective if the induction of neutralizing antibodies is low and/or the influenza virus changes its antigenic surface. We investigated the effect of suboptimal vaccination on the outcome of post-influenza bacterial superinfection.
Methods: We established a mouse vaccination model that allows control of disease severity after influenza virus infection despite inefficient induction of virus-neutralizing antibody titers by vaccination. We investigated the effect of vaccination on virus-induced host immune responses and on the outcome of superinfection with Staphylococcus aureus.
Results: Vaccination with trivalent inactivated virus vaccine (TIV) reduced morbidity after influenza A virus infection but did not prevent virus replication completely. Despite the poor induction of influenza-specific antibodies, TIV protected from mortality after bacterial superinfection. Vaccination limited loss of alveolar macrophages and reduced levels of infiltrating pulmonary monocytes after influenza virus infection. Interestingly, TIV vaccination resulted in enhanced levels of eosinophils after influenza virus infection and recruitment of neutrophils in both lungs and mediastinal lymph nodes after bacterial superinfection.
Conclusion: These observations highlight the importance of disease modulation by influenza vaccination, even when suboptimal, and suggest that influenza vaccination is still beneficial to protect during bacterial superinfection in the absence of complete virus neutralization
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Non-synaptic inhibition between grouped neurons in an olfactory circuit.
Diverse sensory organs, including mammalian taste buds and insect chemosensory sensilla, show a marked compartmentalization of receptor cells; however, the functional impact of this organization remains unclear. Here we show that compartmentalized Drosophila olfactory receptor neurons (ORNs) communicate with each other directly. The sustained response of one ORN is inhibited by the transient activation of a neighbouring ORN. Mechanistically, such lateral inhibition does not depend on synapses and is probably mediated by ephaptic coupling. Moreover, lateral inhibition in the periphery can modulate olfactory behaviour. Together, the results show that integration of olfactory information can occur via lateral interactions between ORNs. Inhibition of a sustained response by a transient response may provide a means of encoding salience. Finally, a CO(2)-sensitive ORN in the malaria mosquito Anopheles can also be inhibited by excitation of an adjacent ORN, suggesting a broad occurrence of lateral inhibition in insects and possible applications in insect control
Hardy's paradox tested in the spin-orbit Hilbert space of single photons
We test experimentally the quantum ``paradox'' proposed by Lucien Hardy in
1993 [Phys. Rev. Lett. 71, 1665 (1993)] by using single photons instead of
photon pairs. This is achieved by addressing two compatible degrees of freedom
of the same particle, namely its spin angular momentum, determined by the
photon polarization, and its orbital angular momentum, a property related to
the optical transverse mode. Because our experiment involves a single particle,
we cannot use locality to logically enforce non-contextuality, which must
therefore be assumed based only on the observables' compatibility. On the other
hand, our single-particle experiment can be implemented more simply and allows
larger detection efficiencies than typical two-particle ones, with a potential
future advantage in terms of closing the detection loopholes.Comment: 7 pages, 5 figures and 1 tabl
Shale problems and water-based drilling fluid optimisation in the Hassi Messaoud Algerian oil field
Drilling fluid formulation and properties play a fundamental role in drilling operations. Clay minerals behave initially as a beneficial rheological adjuvant in drilling muds. Nevertheless, the contamination of oil reservoirs by clay minerals present in the drilled geological formation (shales) may generate major problems during drilling as plug formation. In this context, our study deals with the optimisation of drilling conditions in the Hassi Messaoud Algerian field. The mineralogical heterogeneity of this field is first discussed. The rheological and filtration characteristics of water-based muds with different polymer and electrolyte concentrations are investigated. The physical and chemical changes of both drilled formation and drilling fluid during the drilling process are studied. Therefore, depending on the clay present in the geological formation, an optimised drilling fluid system using a new filtration procedure is proposed. A good correlation is found between filtration/rheological properties and inhibition
Fate of conjugated natural and synthetic steroid estrogens in crude sewage and activated sludge batch studies
This document is the unedited author's version of a Submitted Work that was subsequently accepted for publication in Environmental Science & Technology, copyright © American Chemical Society after peer review. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/es801952h.Steroids are excreted from the human body in the conjugated form but are present in sewage influent and effluent as the free steroid, the major source of estrogenic activity observed in water courses. The fate of sulfate and glucuronide conjugated steroid estrogens was investigated in batch studies using activated sludge grown on synthetic sewage in a laboratory-scale Husmann simulation and crude sewage from the field. A clear distinction between the fate of sulfate and glucuronide conjugates was observed in both matrices, with sulfated conjugates proving more recalcitrant and glucuronide deconjugation preferential in crude sewage. For each conjugate, the free steroid was observed in the biotic samples. The degree of free steroid formation was dependent on the conjugate moiety, favoring the glucuronide. Subsequent degradation of the free steroid (and sorption to the activated sludge solid phase) was evaluated. Deconjugation followed the first order reaction rate with rate constants for 17α-ethinylestradiol 3-glucuronide, estriol 16α-glucuronide, and estrone 3-glucuronide determined as 0.32, 0.24, and 0.35 h respectively. The activated sludge solid retention time over the range of 3â9 days had 74 to 94% of sulfate conjugates remaining after 8 h. In contrast, a correlation between increasing temperature and decreasing 17α-ethinylestradiol 3-glucuronide concentrations in the activated sludge observed no conjugate present in the AS following 8 h at 22 °C Based on these batch studies and literature excretion profiles, a hypothesis is presented on which steroids and what form (glucuronide, sulfate, or free) will likely enter the sewage treatment plant.EPSR
The DAG1 transcription factor negatively regulates the seed-to-seedling transition in Arabidopsis acting on ABA and GA levels
BACKGROUND:
In seeds, the transition from dormancy to germination is regulated by abscisic acid (ABA) and gibberellins (GAs), and involves chromatin remodelling. Particularly, the repressive mark H3K27 trimethylation (H3K27me3) has been shown to target many master regulators of this transition. DAG1 (DOF AFFECTING GERMINATION1), is a negative regulator of seed germination in Arabidopsis, and directly represses the GA biosynthetic gene GA3ox1 (gibberellin 3-ÎČ-dioxygenase 1). We set to investigate the role of DAG1 in seed dormancy and maturation with respect to epigenetic and hormonal control.
RESULTS:
We show that DAG1 expression is controlled at the epigenetic level through the H3K27me3 mark during the seed-to-seedling transition, and that DAG1 directly represses also the ABA catabolic gene CYP707A2; consistently, the ABA level is lower while the GA level is higher in dag1 mutant seeds. Furthermore, both DAG1 expression and protein stability are controlled by GAs.
CONCLUSIONS:
Our results point to DAG1 as a key player in the control of the developmental switch between seed dormancy and germination
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