Robustness of the BB84 quantum key distribution protocol against general coherent attacks

It is demonstrated that for the entanglement-based version of the Bennett-Brassard (BB84) quantum key distribution protocol, Alice and Bob share provable entanglement if and only if the estimated qubit error rate is below 25% or above 75%. In view of the intimate relation between entanglement and security, this result sheds also new light on the unconditional security of the BB84 protocol in its original prepare-and-measure form. In particular, it indicates that for small qubit error rates 25% is the ultimate upper security bound for any prepare-and-measure BB84-type QKD protocol. On the contrary, for qubit error rates between 25% and 75% we demonstrate that the correlations shared between Alice and Bob can always be explained by separable states and thus, no secret key can be distilled in this regime.Comment: New improved version. A minor mistake has been eliminate

Biological evaluation of animal and vegetable protein test feeds in broilers and rats

Study was conducted to know the biological value of fish meal, meat meal, blood meal, sesame oil meal, cottonseed meal, and guar meal (Cyamopsis tetragonoloba) in two different species (ten day old broiler chicks, n=96; and weaning albino rats, n=64). These protein sources were added into nitrogen free diet on protein equivalent basis to formulate eight different diets including six test diets, a basal and a standard diet. Results revealed that both chicks and rats showed significant differences (p<0.05) in feed intake, weight gain and feed conversion ratio for animal and protein feeds. Fish meal in most of the measurements was similar (p>0.05) to casein in chicks. Weight gain ranked in declining order for diets containing fish meal, meat meal, sesame oil meal, cotton seed meal, blood meal and guar meal in both species. On standard stock diet ad libitum after drastic restriction period, both species showed a compensatory growth and nitrogen retention

Effects of production system and feeding regimen on carcass and meat quality traits of Naked Neck chicken

To evaluate the effect of a production system and feeding regimen on meat quality attributes of Naked Neck chickens, a total of 150 cockerels at 18 weeks old (1625 ± 70 g) were collected from 10 treatment groups with five replicates of three birds. The factorial arrangement of treatments consisted of two production systems (intensive and free-range) and five nutritional regimens, namely 100% commercial feed; 75% commercial feed plus 25% kitchen waste; 50% commercial feed plus 50% kitchen waste; 25% commercial feed plus 75% kitchen waste; and 100% kitchen waste. Carcass traits, meat quality, and meat organoleptic were found to differ significantly among production systems, feeding regimens, and their interaction. Higher liver weight was observed in birds reared under an intensive system. Higher gizzard weight was noted in birds fed with 100% kitchen waste, whereas lower gizzard weight was observed in birds fed the commercial diet. The meat from cockerels fed with 75% kitchen waste was most yellow, whereas the meat from the birds fed with 100% kitchen waste was least yellow. At two hours after slaughter, pH of the meat was highest in birds fed 50% kitchen waste and lowest in birds fed 100% kitchen waste. The interaction of production system and feeding regimen was significant for overall acceptability score. In conclusion, Naked Neck chickens performed equally well under intensive and free-range systems, irrespective of the level of kitchen waste that they were fed

Lie and Riccati Linearization of a Class of Liénard Type Equations

We construct a linearizing Riccati transformation by using an ansatz and a linearizing point transformation utilizing the Lie point symmetry generators for a three-parameter class of Liénard type nonlinear second-order ordinary differential equations. Since the class of equations also admits an eight-parameter Lie group of point transformations, we utilize the Lie-Tresse linearization theorem to obtain linearizing point transformations as well. The linearizing transformations are used to transform the underlying class of equations to linear third- and second-order ordinary differential equations, respectively. The general solution of this class of equations can then easily be obtained by integrating the linearized equations resulting from both of the linearization approaches. A comparison of the results deduced in this paper is made with the ones obtained by utilizing an approach of mapping the class of equations by a complex point transformation into the free particle equation. Moreover, we utilize the linearizing Riccati transformation to extend the underlying class of equations, and the Lie-Tresse linearization theorem is also used to verify the conditions of linearizability of this new class of equations

Aluminosilicates and yeast-based mycotoxin binders: Their ameliorated effects on growth, immunity and serum chemistry in broilers fed aflatoxin and ochratoxin

The aim of this study was to evaluate the effects of commercial toxin binders on growth performance, organ morphology, immunity and serum biochemistry in broilers. Dietary treatments consisted of the negative control (NC): experimental diet with aflatoxin B1 <20 parts per billion (ppb), ochratoxin A (OTA) <5 ppb; control (C) experimental diet without toxin binder; Z1: toxin binder 1 g/kg of zeta plus; Z2: toxin binder 2 g/kg of zeta plus; TX1: toxin binder 1 g/kg of Toxfin Dry; and TX2: toxin binder 2 g/kg of Toxfin Dry). Except for NC, all diets contained 57 ppb aflatoxin B1 and 23 ppb ochratoxin A. Feed intake was higher in the TX1, TX2, NC, Z2 and Z1 treatments than in the control. Weight gain was higher in Z2, TX2, Z1, TX1 and NC than in C. Feed conversion ratio (FCR) was poor in C. The control had the highest liver weight, though the weights of the spleen, kidneys and hearts of the birds were similar in all treatments. Gizzard weight, thymus weight, and bursa of Fabricius were lowest in C. The weight of the pancreas was similar among treatments. The antibody titres against new castle disease were higher in treatments Z2, Z1, TX2, TX1 and NC than in C. Urea and creatinine concentrations, and aspartate aminotransferase activity in serum were similar among treatments, whereas the serum alanine transaminase activity was higher in C than in Z1, TX1, TX2, Z2 and NC. It was concluded that growth rate, FCR and immunity indices were improved in broilers fed toxin binder. At lower levels of mycotoxin in feed, 1 g/kg of toxin binder (clay based or yeast based) was sufficient to ameliorate the adverse effects of aflatoxin B1 and OTA, whereas at higher levels of mycotoxins, supplementation of toxin binder should be increased.Keywords: alanine aminotransferase, aspartate aminotransferase, carcass characteristics, growth performance, toxin binders, urea, creatinin

Simulator-based learning, the Dunning-Kruger effect and the newly-‘qualified’ Officer of the Watch.

Does simulator-based learning promote inappropriate confidence in the mind of a newly qualified Officer of the Watch

Optimization of DNA extraction from human urinary samples for mycobiome community profiling.

IntroductionRecent data suggest the urinary tract hosts a microbial community of varying composition, even in the absence of infection. Culture-independent methodologies, such as next-generation sequencing of conserved ribosomal DNA sequences, provide an expansive look at these communities, identifying both common commensals and fastidious organisms. A fundamental challenge has been the isolation of DNA representative of the entire resident microbial community, including fungi.Materials and methodsWe evaluated multiple modifications of commonly-used DNA extraction procedures using standardized male and female urine samples, comparing resulting overall, fungal and bacterial DNA yields by quantitative PCR. After identifying protocol modifications that increased DNA yields (lyticase/lysozyme digestion, bead beating, boil/freeze cycles, proteinase K treatment, and carrier DNA use), all modifications were combined for systematic confirmation of optimal protocol conditions. This optimized protocol was tested against commercially available methodologies to compare overall and microbial DNA yields, community representation and diversity by next-generation sequencing (NGS).ResultsOverall and fungal-specific DNA yields from standardized urine samples demonstrated that microbial abundances differed significantly among the eight methods used. Methodologies that included multiple disruption steps, including enzymatic, mechanical, and thermal disruption and proteinase digestion, particularly in combination with small volume processing and pooling steps, provided more comprehensive representation of the range of bacterial and fungal species. Concentration of larger volume urine specimens at low speed centrifugation proved highly effective, increasing resulting DNA levels and providing greater microbial representation and diversity.ConclusionsAlterations in the methodology of urine storage, preparation, and DNA processing improve microbial community profiling using culture-independent sequencing methods. Our optimized protocol for DNA extraction from urine samples provided improved fungal community representation. Use of this technique resulted in equivalent representation of the bacterial populations as well, making this a useful technique for the concurrent evaluation of bacterial and fungal populations by NGS

Postponement of dark-count effects in practical quantum key-distribution by two-way post-processing

The influence of imperfections on achievable secret-key generation rates of quantum key distribution protocols is investigated. As examples of relevant imperfections, we consider tagging of Alice's qubits and dark counts at Bob's detectors, while we focus on a powerful eavesdropping strategy which takes full advantage of tagged signals. It is demonstrated that error correction and privacy amplification based on a combination of a two-way classical communication protocol and asymmetric Calderbank-Shor-Steane codes may significantly postpone the disastrous influence of dark counts. As a result, the distances are increased considerably over which a secret key can be distributed in optical fibres reliably. Results are presented for the four-state, the six-state, and the decoy-state protocols.Comment: Fully revised version (12 pages and 8 figures). Improved figures and discussion added. To appear in Eur. Phys. J.

Controlled information transfer in continuous-time chiral quantum walks

In this paper we investigate properties of continuous time chiral quantum walks, which possess complex valued edge weights in the underlying graph structure, together with an initial Gaussian wavefunction spread over a number of vertices. We demonstrate that, for certain graph topology and phase matching conditions, we are able to direct the flow of probability amplitudes in a specific direction inside the graph network. We design a quantum walk graph analogue of an optical circulator which is a combination of a cycle and semi-infinite chain graphs. Excitations input into the circulator from a semi-infinite chain are routed in a directionally biased fashion to output to a different semi-infinite chain. We examine in detail a two port circulator graph which spatially separates excitations flowing back in forth between the two semi-finite chains to directionally occupy the top or bottom half of the cycle portion of the circulator. This setup can be used, for example, to detect non-Markovian processes, which leads to information and energy back-flow from the bath back into the system