Coherent sensing of a mechanical resonator with a single-spin qubit

Mechanical systems can be influenced by a wide variety of small forces, ranging from gravitational to optical, electrical, and magnetic. When mechanical resonators are scaled down to nanometer-scale dimensions, these forces can be harnessed to enable coupling to individual quantum systems. We demonstrate that the coherent evolution of a single electronic spin associated with a nitrogen vacancy center in diamond can be coupled to the motion of a magnetized mechanical resonator. Coherent manipulation of the spin is used to sense driven and Brownian motion of the resonator under ambient conditions with a precision below 6 picometers. With future improvements, this technique could be used to detect mechanical zero-point fluctuations, realize strong spin-phonon coupling at a single quantum level, and implement quantum spin transducers.     

Characterization of single‐nucleotide polymorphism markers in the Mediterranean mussel,Mytilus galloprovincialis

The Mediterranean mussel, Mytilus galloprovincialis, is one of the most important aquaculture species in Europe. Appropriate molecular markers are required to evaluate genetic resources and to trace genealogies in breeding programmes for improving mussel culture. Microsatellites have been commonly applied to this purpose in other species. However, Mediterranean mussel microsatellites have demonstrated high frequencies of null alleles that hamper accurate estimates of population parameters and confident parentage inferences. As alternative markers, we have characterized in silico 25 potential single‐nucleotide polymorphism (SNP) markers in the Mediterranean mussel from expressed sequence tag (EST) public databases. The genotyping of SNPs was performed using a single‐base extension approach. Their polymorphism was evaluated in 47 individuals from an Atlantic population. Out of the 25 potential SNPs tested, 12 were technically feasible (producing a single amplicon) and polymorphic. All were biallelic and had an unbiased heterozygosity ranging from 0.160 to 0.504. One SNP was from a mitochondrial gene. The combined potential of nuclear SNPs for parentage assignment gave an exclusion probability of a false couple of parents of 0.9471. These markers will be useful for evaluating resources and tracing genealogies in genetic breeding programmes implemented to solve the main problems of mussel culture.     

A molecular tool for parentage analysis in the Mediterranean mussel (Mytilus galloprovincialis)

Estimation of selection response and genealogical tracing in family mixtures require an appropriate tool for parentage analysis. In this study, we tested 19 marker loci for parentage analysis allocation in Mediterranean mussel (Mytilus galloprovincialis). To this aim, we reared families in tanks isolated from wild mussel seed, analysed them using the 19 marker loci and characterized their performances based on Mendelian rules. Probabilities of exclusion of a false parent were estimated for different groups of loci and contrasted to the real paternity assignment. Based on this, we chose nine microsatellites with the highest exclusion probabilities and a real paternity assignment of 99.6%. Next, we analysed 600 individuals reared as in the usual production process, where contamination from wild seed is likely. We obtained a real assignment of 94.7% and were able to identify individuals from the wild as the most likely hypothesis to explain the observed incompatibilities with candidate parents. This information was used to evaluate parental contribution in offspring obtained from gamete mixtures of several parents, which bestowed results of interest for future breeding programs of Mediterranean mussel.     

Roles of the two Drosophila CRYPTOCHROME structural domains in circadian photoreception

CRYPTOCHROME (CRY) is the primary circadian photoreceptor in Drosophila. We show that CRY binding to TIMELESS (TIM) is light-dependent in flies and irreversibly commits TIM to proteasomal degradation. In contrast, CRY degradation is dependent on continuous light exposure, indicating that the CRY-TIM interaction is transient. A novel cry mutation (cry(m)) reveals that CRY's photolyase homology domain is sufficient for light detection and phototransduction, whereas the carboxyl-terminal domain regulates CRY stability, CRY-TIM interaction, and circadian photosensitivity. This contrasts with the function of Arabidopsis CRY domains and demonstrates that insect and plant cryptochromes use different mechanisms.     

Statistical properties and performance of pairwise relatedness estimators using turbot (Scophthalmus maximus L.) family data

The statistical properties and performance of four estimators of pairwise relatedness were evaluated in several scenarios using the microsatellite genotype data from a set of large known full‐sibships of turbot. All estimators showed a significant negative bias for the four kinships commonly used in these studies (unrelated: UR, half‐sibs, full‐sibs and parent–offspring), when allele frequencies of the reference population were estimated from the individuals analysed. When these frequencies were obtained from the base population from which all families proceeded, the bias was mostly corrected. The Wang (W) and Li (L) estimators were the least sensitive to this factor, while the Lynch and Ritland (L&R estimator) was the highest one. The error (mean around 0.130) was very similar in all scenarios for W, L and Queller and Goodnight (QG) estimators, while L&R was the highest error‐prone estimator. Parent–offspring kinship resulted in the lowest error, when using W, L and QG estimators, while UR resulted in the lowest error with the L&R estimator. Globally, W was the best‐performing estimator, although L&R could perform better in specific sampling scenarios. In summary, pairwise estimators represent useful tools for kinship classification in aquaculture broodstock management by applying appropriate thresholds depending on the goals of the analysis.     

High-resolution melting curve analysis: a novel method for identification of Mycoplasma species isolated from clinical cases of bovine and porcine respiratory disease

Tropical Animal Health and Production - Mycoplasma species cause wide ranges of infectious diseases in human and animals. The aim of the present study was to evaluate a real-time polymerase chain...     

Urbanization predicts infection risk by a protozoan parasite in non-migratory populations of monarch butterflies from the southern coastal U.S. and Hawaii

Context

Urbanization can affect the density of hosts, altering patterns of infection risk in wildlife. Most studies examining associations between urbanization and host-parasite interactions have focused on vertebrate wildlife that carry zoonotic pathogens, and less is known about responses of other host taxa, including insects.

Objectives

Here we ask whether urban development predicts infection by a protozoan, Ophyrocystis elektroscirrha, in three populations of monarchs (Danaus plexippus): migratory monarchs in northeastern U.S., non-migratory monarchs in southeastern coastal U.S., and non-migratory monarchs in Hawaii.

Methods

We used impervious surface and developed land cover classes from the National Land Cover Database to derive proportional measures of urban development and an index of land cover aggregation at two spatial scales. Parasite data were from previous field sampling (Hawaii) and a citizen science project focused on monarch infection in North America.

Results

Proportional measures of urban development predicted greater infection prevalence for non-migratory monarchs sampled in the southern coastal U.S. and Hawaii, but not in the northern U.S. Aggregations of low intensity development, dominated by single-family housing, predicted greater infection prevalence in monarchs from the northern and southern coastal U.S. populations, but predicted lower infection prevalence in Hawaii.

Conclusions

Because natural habitats have been reduced by land-use change, plantings for monarchs in residential areas and urban gardens has become popular among the public. Mechanisms that underlie higher infection prevalence in urban landscapes remain unknown. Further monitoring and experimental studies are needed to inform strategies for habitat management to lower infection risk for monarchs.

     

A synthetic conjugate polysaccharide vaccine against Haemophilus influenzae type b

Glycoconjugate vaccines provide effective prophylaxis against bacterial infections. To date, however, no commercial vaccine has been available in which the key carbohydrate antigens are produced synthetically. We describe the large-scale synthesis, pharmaceutical development, and clinical evaluation of a conjugate vaccine composed of a synthetic capsular polysaccharide antigen of Haemophilus influenzae type b (Hib). The vaccine was evaluated in clinical trials in Cuba and showed long-term protective antibody titers that compared favorably to licensed products prepared with the Hib polysaccharide extracted from bacteria. This demonstrates that access to synthetic complex carbohydrate-based vaccines is feasible and provides a basis for further development of similar approaches for other human pathogens.     

A microsatellite marker tool for parentage analysis in Senegal sole (Solea senegalensis): Genotyping errors, null alleles and conformance to theoretical assumptions

A set of 50 potential microsatellite loci previously described in several flatfish species was evaluated for designing a suitable tool for parentage assessment in Senegal sole (Solea senegalensis). Low cross-amplification within Pleuronectiformes, even between congeneric species, was achieved. This suggests a low conservation of microsatellite flanking regions in this order regarding other fish orders of similar evolutionary age. Twelve loci showed appropriate amplification and polymorphism to acquire enough statistical power for parentage analysis. All forty-one individuals from one broodstock and 320 offspring were analyzed using this set of markers. The high potential of microsatellites for parentage exclusion (Excl1 = 0.9999; Excl2 = 1) permitted us to trace back all offspring to single pairs of parents. The families obtained were used to analyze the performances of the loci applied and to identify possible sources of error for parentage analysis in Senegal sole. The 2.5% of single mismatches in the families studied were attributed mostly to genotyping errors and to a lesser extent to null alleles. The average mutation rate estimated over 7680 gametes was in the range reported within fish (3.9 × 10^− 4) and did not compromise parentage analysis. All loci conformed to theoretical assumptions (Mendelian segregation, independent segregation), excluding the F13-II8/4/7 and Sol 9A loci, which showed strong genotypic association in the families analyzed. A set of 4 microsatellites (Sol CA13, F13-II8/4/7, Smax-02 and Sse GATA38) was finally selected for parentage evaluation in S. senegalensis combining both enough exclusion potential (> 0.970) and the lowest economic cost.