174 research outputs found
Polychaetes of commercial interest from the Mediterranean East Coast of Algeria
Three species of polychaetous annelids are commercially collected, as baits, from natural populations along the coast of Algeria. They are collected by semi-professional bait harvesters supplying a variety of local outlets and are used as bait by local fishermen. Bait harvesters commonly use bleaching liquid (10% in sea water) or a KMnO4 (0.5 to 1% in sea water) solution to force Perinereis cultrifera (Nereididae) individuals out of their algal mat. Hediste diversicolor (Nereididae) and Scolelepis squamata(Spionidae) are dug from intertidal mudflats and sandy beaches. Commercial prices and ways of utilization are given for each species. The necessity for the legislative establishment of a regulatory management plan for worm angling is demonstrated
A robust algebraic multilevel domain decomposition preconditioner for sparse symmetric positive definite matrices
Efficient Algebraic Two-Level Schwarz Preconditioner for Sparse Matrices
Domain decomposition methods are among the most efficient for solving sparse
linear systems of equations. Their effectiveness relies on a judiciously chosen
coarse space. Originally introduced and theoretically proved to be efficient
for self-adjoint operators, spectral coarse spaces have been proposed in the
past few years for indefinite and non-self-adjoint operators. This paper
presents a new spectral coarse space that can be constructed in a
fully-algebraic way unlike most existing spectral coarse spaces. We present
theoretical convergence result for Hermitian positive definite diagonally
dominant matrices. Numerical experiments and comparisons against
state-of-the-art preconditioners in the multigrid community show that the
resulting two-level Schwarz preconditioner is efficient especially for
non-self-adjoint operators. Furthermore, in this case, our proposed
preconditioner outperforms state-of-the-art preconditioners
Large-Z atoms in the strong-interaction limit of DFT: Implications for gradient expansions and for the Lieb-Oxford bound
We study numerically the strong-interaction limit of the exchange-correlation
functional for neutral atoms and for Bohr atoms as the number of electrons
increases. Using a compact representation, we analyse the second-order gradient
expansion, comparing it with the one for exchange (weak interaction limit). The
two gradient expansions, at strong and weak interaction, turn out to be very
similar in magnitude, but with opposite signs. We find that the point-charge
plus continuum model is surprisingly accurate for the gradient expansion
coefficient at strong coupling, while generalized gradient approximations such
as PBE and PBEsol severely underestimate it. We then use our results to analyse
the Lieb-Oxford bound from the point of view of slowly-varying densities,
clarifying some aspects on the bound at fixed number of electrons.Comment: 11 pages, 5 figure
Chemsex, Anxiety and Depression Among Gay, Bisexual and Other Men Who have Sex with Men Living with HIV
Funding Research did not receive any specific funding.Peer reviewedPublisher PD
Regularized and Opposite spin-scaled functionals from M{\o}ller-Plesset adiabatic connection -- higher accuracy at lower cost
Non-covalent interactions (NCIs) play a crucial role in biology, chemistry,
material science, and everything in between. To improve pure quantum-chemical
simulations of NCIs, we propose a methodology for constructing approximate
correlation energies by combining an interpolation along the M{\o}ller
adiabatic connection (MP AC) with a regularization and spin-scaling strategy
applied to MP2 correlation energies. This combination yields -SPL2, which exhibits superior accuracy for NCIs compared to
any of the individual strategies. With the formal scaling, -SPL2, is competitive or often outperforms more expensive
dispersion-corrected double hybrids for NCIs.The accuracy of -SPL2 particularly shines for anionic halogen bonded
complexes, where it surpasses standard dispersion-corrected DFT by a factor of
3 to 5.Comment: 12 pages + 5 SI, 8 figures + 6 S
Clinical Comparison of the Performance of Two Marketed Ophthalmic Viscoelastic Devices (OVDs): The Bacterially Derived Healon PRO OVD and Animal-Derived Healon OVD
This clinical investigation compared the clinical performance of two marketed ophthalmic viscoelastic devices (OVDs): the bacterially derived Healon PRO OVD (test) and the animal-derived Healon OVD (control) under normal use conditions during cataract removal and lens implantation. This prospective, multicenter, randomized, parallel, participant/evaluator masked, postmarket investigation enrolled 139 subjects (170 eyes), 116 (143 eyes) of which were treated (73 test; 70 control group). Both test and control OVDs were used, at a minimum, to inflate the anterior chamber and protect the endothelium prior to cataract extraction according to the standard procedure. The surgeon completed a postsurgery OVD clinical performance questionnaire, and intraocular pressure (IOP) was measured before surgery and at the 1 day postoperative visit with Goldmann applanation tonometry. Any IOP measurement of 30 mmHg or higher was considered a "spike"and recorded as a study-specific, serious adverse event. The bacterially derived Healon PRO OVD was found to be statistically noninferior to the overall clinical performance of the animal-derived Healon OVD control; thus, the primary hypothesis was satisfied. There were no statistically significant differences between OVD groups for any of the additional endpoints relating to IOP changes or to safety, thus satisfying additional hypotheses. The Healon PRO OVD showed statistically significant improvements in surgeon ratings for ease of injectability, transparency/visibility, and ease of IOL placement. The safety profile was also similar between OVD groups with regards to serious and/or device-related adverse events, as well as medical and lens findings. The results of this clinical investigation support the safety and effectiveness of the bacterially derived, currently marketed Healon PRO OVD and indicate that the intraocular surgical performance was similar between the two OVDs
Successful treatment of Candida parapsilosis and Pseudomonas aeruginosa infection using medical and surgical management in an injecting drug user with mitral and aortic valve endocarditis: a case report
<p>Abstract</p> <p>Introduction</p> <p>Polymicrobial endocarditis is a well-recognized problem in intravenous drug users and it accounts for 1 to 3% of endocarditis cases overall and up to 9% in other series. The most common combinations of organisms include <it>Staphylococcus aureus</it> and <it>Streptococcus pneumoniae</it> followed by <it>Staphylococcus aureus</it> and <it>Pseudomonas aeruginosa</it>. <it>Candida parapsilosis</it> endocarditis carries a mortality rate of 45%, and each infection with <it>Candida</it> or <it>Pseudomonas</it> endocarditis per se carries a very high mortality rate approaching 85% and 80%, respectively. The combination of <it>P. aeruginosa</it> and <it>C. parapsilosis</it> has never been encountered and there have been no earlier reports of the combination of <it>C. parapsilosis</it> and <it>P. aeruginosa</it> in adult intravenous drug users as a cause of endocarditis.</p> <p>Case presentation</p> <p>We present a 49-year-old man with bivalvular endocarditis with <it>P. aeruginosa</it> and <it>C. parapsilosis</it>. He had a prior bivalvular replacement in 2005 that became infected with the above microorganisms and he was treated with intravenous antibiotics. Because of ongoing intravenous drug use, a second valve replacement was denied. A few days later, the patient presented with septic shock secondary to <it>P. aeruginosa</it> and <it>C. parapsilosis</it> recurrent endocarditis. The infection was cured with a second bivalvular replacement and extended therapy with antibiotics and antifungals.</p> <p>Conclusion</p> <p>This is the first time a patient has presented with <it>P. aeruginosa</it> and <it>C. parapsilosis endocarditis</it>. Relapsing polymicrobial endocarditis can be cured with medical and surgical therapy.</p
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