Isotope shifts in electron affinities and in binding energies of Pb and hyperfine structure of 207Pb.

The isotope shifts in electron affinities of Pb were measured by Walter et al. [Phys. Rev. A 106, L010801 (2022)] to be -0.002(4) meV for 207-208Pb and -0.003(4) meV for 206-208Pb by scanning the threshold of the photodetachment channel Pb-(S3/2◦4) - Pb (3P0), while Chen and Ning reported 0.015(25) and -0.050(22) meV for the isotope shifts on the binding energies measured relative to 3P2 using the SEVI method [J. Chem. Phys. 145, 084303 (2016)]. Here we revisited these isotope shifts by using our second-generation SEVI spectrometer and obtained -0.001(15) meV for 207-208Pb and -0.001(14) meV for 206-208Pb, respectively. In order to aid the experiment by theory, we performed the first ab initio theoretical calculations of isotope shifts in electron affinities and binding energies of Pb, as well as the hyperfine structure of 207Pb-, by using the MCDHF and RCI methods. The isotope shifts in electron affinities of 207-208Pb and 206-208Pb are -0.0023(8) and -0.0037(13) meV for the 3P0 channel, respectively, in good agreement with Walter et al.'s measurements. The isotope shifts in binding energies relative to 3P1,2, -0.0015(8) and -0.0026(13) meV for 207-208Pb and 206-208Pb, respectively, are compatible with the present measurements. The hyperfine constant for the ground state of 207Pb- obtained by the present calculations, A(S3/2◦4)=-1118 MHz, differs by a factor of 3 from the previous estimation by Bresteau et al. [J. Phys. B: At., Mol. Opt. Phys. 52, 065001 (2019)]. The reliability is supported by the good agreement between the theoretical and experimental hyperfine parameters of 209Bi.

Nuclear Charge Radius of

Collinear laser spectroscopy was performed on the isomer of the aluminium isotope ^{26m}Al. The measured isotope shift to ^{27}Al in the 3s^{2}3p ^{2}P_{3/2}^{○}→3s^{2}4s ^{2}S_{1/2} atomic transition enabled the first experimental determination of the nuclear charge radius of ^{26m}Al, resulting in R_{c}=3.130(15) fm. This differs by 4.5 standard deviations from the extrapolated value used to calculate the isospin-symmetry breaking corrections in the superallowed ß decay of ^{26m}Al. Its corrected Ft value, important for the estimation of V_{ud} in the Cabibbo-Kobayashi-Maskawa matrix, is thus shifted by 1 standard deviation to 3071.4(1.0) s.

Large Shape Staggering in Neutron-Deficient Bi Isotopes.

The changes in the mean-square charge radius (relative to ^{209}Bi), magnetic dipole, and electric quadrupole moments of ^{187,188,189,191}Bi were measured using the in-source resonance-ionization spectroscopy technique at ISOLDE (CERN). A large staggering in radii was found in ^{187,188,189}Bi^{g}, manifested by a sharp radius increase for the ground state of ^{188}Bi relative to the neighboring ^{187,189}Bi^{g}. A large isomer shift was also observed for ^{188}Bi^{m}. Both effects happen at the same neutron number, N=105, where the shape staggering and a similar isomer shift were observed in the mercury isotopes. Experimental results are reproduced by mean-field calculations where the ground or isomeric states were identified by the blocked quasiparticle configuration compatible with the observed spin, parity, and magnetic moment.

Buchnera has changed flatmate but the repeated replacement of co-obligate symbionts is not associated with the ecological expansions of their aphid hosts.

Symbiotic associations with bacteria have facilitated important evolutionary transitions in insects and resulted in long-term obligate interactions. Recent evidence suggests that these associations are not always evolutionarily stable and that symbiont replacement, and/or supplementation of an obligate symbiosis by an additional bacterium, has occurred during the history of many insect groups. Yet, the factors favouring one symbiont over another in this evolutionary dynamic are not well understood; progress has been hindered by our incomplete understanding of the distribution of symbionts across phylogenetic and ecological contexts. While many aphids are engaged into an obligate symbiosis with a single Gammaproteobacterium, Buchnera aphidicola, in species of the Lachninae subfamily, this relationship has evolved into a 'ménage à trois', in which Buchnera is complemented by a cosymbiont, usually Serratia symbiotica. Using deep sequencing of 16S rRNA bacterial genes from 128 species of Cinara (the most diverse Lachninae genus), we reveal a highly dynamic dual symbiotic system in this aphid lineage. Most species host both Serratia and Buchnera but, in several clades, endosymbionts related to Sodalis, Erwinia or an unnamed member of the Enterobacteriaceae have replaced Serratia. Endosymbiont genome sequences from four aphid species confirm that these coresident symbionts fulfil essential metabolic functions not ensured by Buchnera. We further demonstrate through comparative phylogenetic analyses that cosymbiont replacement is not associated with the adaptation of aphids to new ecological conditions. We propose that symbiont succession was driven by factors intrinsic to the phenomenon of endosymbiosis, such as rapid genome deterioration or competitive interactions between bacteria with similar metabolic capabilities.

HIV-1 subtypes and drug resistance mutations among female sex workers varied in different cities and regions of the Democratic Republic of Congo.

BACKGROUND: Complex mosaic structures of HIV-1 were found in the Democratic Republic of Congo (DRC). Currently, there is limited information on the circulating HIV-1 strains, the distribution of these strains and antiretroviral (ART) resistant viruses in different regions of the country, and the HIV-1 strains harbored by the high-risk groups like female sex workers (FSW) reported to be the source of recombinant and ART resistant viruses. METHODS: Dried Blood Spots (DBS), collected from 325 infected FSWs in ten cities from 2012 DRC HIV/STI Integrated Biological and Behavioral Surveillance Survey, were tested for HIV-1 genotypes and antiretroviral resistance mutations. Regional segregation of HIV-1 clades was detected using phylogenetics. The significance for differences in HIV-1 subtype and drug resistance mutations were evaluated using Chi-square tests. RESULTS: There were 145 (env) and 93 (pol) sequences analyzed. Based on env sequences, the predominant subtype was A1 (44%), and recombinants as defined pol sequences comprised 35% of the total sample. Paired sequences of pol and env from DRC FSW revealed mosaic recombinant in 54% of the sequences. Distinct geographic distributions of different HIV-1 subtypes and recombinants were observed. Subtype A1 was prevalent (40%) in Goma located in the East and significantly higher than in Mbuji-Mayi (p<0.05) in the South-central region, or in Lubumbashi in the South. Antiretroviral resistance was detected in 21.5% of 93 pol sequences analyzed, with the M184I/V and K103N mutations that confer high-level resistance to NRTI and NNRTI, respectively, being the most frequent mutations. However, the K103N mutant viruses were found only in the East. CONCLUSION: HIV-1 variants found in DRC FSW reflect those reported to circulate in the general population from the corresponding geographical locations. HIV-1 mosaic genetics were readily detected in FSW. Importantly, ART resistance mutations to NNRTI and NRTI were common in the DRC sex workers.

Evaluation of the Red Blood Cell Advanced Software Application on the CellaVision DM96.

INTRODUCTION: The CellaVision Advanced Red Blood Cell (RBC) Software Application is a new software for advanced morphological analysis of RBCs on a digital microscopy system. Upon automated precharacterization into 21 categories, the software offers the possibility of reclassification of RBCs by the operator. We aimed to define the optimal cut-off to detect morphological RBC abnormalities and to evaluate the precharacterization performance of this software. METHODS: Thirty-eight blood samples of healthy donors and sixty-eight samples of hospitalized patients were analyzed. Different methodologies to define a cut-off between negativity and positivity were used. Sensitivity and specificity were calculated according to these different cut-offs using the manual microscopic method as the gold standard. Imprecision was assessed by measuring analytical within-run and between-run variability and by measuring between-observer variability. RESULTS: By optimizing the cut-off between negativity and positivity, sensitivities exceeded 80% for 'critical' RBC categories (target cells, tear drop cells, spherocytes, sickle cells, and parasites), while specificities exceeded 80% for the other RBC morphological categories. Results of within-run, between-run, and between-observer variabilities were all clinically acceptable. CONCLUSION: The CellaVision Advanced RBC Software Application is an easy-to-use software that helps to detect most RBC morphological abnormalities in a sensitive and specific way without increasing work load, provided the proper cut-offs are chosen. However, evaluation of the images by an experienced observer remains necessary.

Evaluation of schistocyte analysis by a novel automated digital cell morphology application.

INTRODUCTION: The CellaVision Advanced Red Blood Cell (RBC) Software Application is a new software for advanced morphological analysis of RBC, which automatically performs a preliminary characterization and grouping of RBC into 21 morphological categories, including schistocytes. Upon automated classification, the software offers the possibility of reclassification of RBC by the operator. The aim of this study was to evaluate the schistocyte analysis by the CellaVision Advanced RBC Application. METHODS: Schistocyte counts were evaluated comparing the automated count on a CellaVision DM96, both before and after reclassification, with the reference manual microscopic method according to the ICSH criteria. Thirty-six samples of hospitalized patients and 40 samples of controls were analyzed. RESULTS: Within-run, between-run and between-observer coefficients of variation were lower when counted with the CellaVision compared to the manual microscopic count. The very high sensitivity but rather poor specificity implicates the need for reclassification by the operator, following automated analysis. After reclassification, method comparison studies revealed good agreement with the manual microscopic method, with however slightly higher values of schistocytes for the automated analysis. CONCLUSION: The CellaVision Advanced RBC Software Application provides a sensitive and reproducible measurement of schistocytes in peripheral blood, but still requires manual revision. Furthermore, it is an easy-to-use software and an excellent teaching tool that might contribute to standardization in the investigation of schistocyte-related conditions.

Operational families of entanglement classes for symmetric N-qubit States.

We solve the entanglement classification under stochastic local operations and classical communication (SLOCC) for all multipartite symmetric states in the general N-qubit case. For this purpose, we introduce 2 parameters playing a crucial role, namely, the diversity degree and the degeneracy configuration of a symmetric state. Those parameters give rise to a simple method of identifying operational families of SLOCC entanglement classes of all symmetric N-qubit states, where the number of families grows as the partition function of the number of qubits.

Knowledge of HIV, sexual behavior and correlates of risky sex among street children in Kinshasa, Democratic Republic of Congo.

CONTEXT: Homeless children are at risk of getting many diseases, including sexually transmitted infections (STI). The number of street children is on the rise in the Democratic Republic of Congo (DRC), while very little is known about their health problems. OBJECTIVES: To determine knowledge of HIV (transmission and prevention means), sexual activity, exposure to HIV-prevention services, and to identify correlates of risky sexual behaviour (not having used a condom at first or last sexual encounter and/or having multiple sexual partners over a 12-month period) among street children in Kinshasa. RESULTS: At the time of the survey, most participants (85.8%, 95% CI = 83.5-88.1) were sexually experienced and 55.8% had their first sexual intercourse when they were already living on the streets. The median age at first sexual activity was 14.3 years for males and 13.5 years for females. Compared to males (median number of sexual partners = 1), females tended to be more involved with multiple sexual partners (median = 12). Condoms were used less at the fist sexual encounter (20.2%; 95% CI = 17.3-23.1) and the pattern of condom use depended on the type of sexual partners (61.1% at last sexual encounter with a paid/paying partner and 23.1% at last sexual encounter with a non-paid/non-paying partner). In males, sleeping in a NGO-provided night shelter (OR = 0.47; 95% CI = 0.27-0.79), and having had the first sexual intercourse while living on the streets (OR = 0.55; 95% CI = 0.35-0.88) were protective of risky sexual behaviour, while a history of drug use (OR = 3.00; 95% CI = 1.46-6.18), and being aged 20 to 24 years (OR = 1.59; 95% 1.00-2.55) increased the likelihood of displaying risky sexual behaviour. In females, not knowing where to get a condom (OR = 0.04; 95% CI = 0.005-0.29), having started sexual activity when living on the streets (OR = 0.10; 95% CI = 0.01-0.73) and not having an income-generating activity (OR = 0.09; 95% CI = 0.01-0.44) were protective of risky sexual behaviour. CONCLUSION: Street children need to be regarded as a high-risk group for acquiring HIV. The potential benefit of providing homeless youth with night-shelters should be explored more since this could be an opportunity to integrate risk-reduction programmes that take into account all problematic behaviors such as risky sexual behaviour and drug use.

Quantum similarity study of atomic density functions: insights from information theory and the role of relativistic effects.

A novel quantum similarity measure (QSM) is constructed based on concepts from information theory. In an application of QSM to atoms, the new QSM and its corresponding quantum similarity index (QSI) are evaluated throughout the periodic table, using the atomic electron densities and shape functions calculated in the Hartree-Fock approximation. The periodicity of Mendeleev's table is regained for the first time through the evaluation of a QSM. Evaluation of the information theory based QSI demonstrates, however, that the patterns of periodicity are lost due to the renormalization of the QSM, yielding chemically less appealing results for the QSI. A comparison of the information content of a given atom on top of a group with the information content of the elements in the subsequent rows reveals another periodicity pattern. Relativistic effects on the electronic density functions of atoms are investigated. Their importance is quantified in a QSI study by comparing for each atom, the density functions evaluated in the Hartree-Fock and Dirac-Fock approximations. The smooth decreasing of the relevant QSI along the periodic table illustrates in a quantitative way the increase of relativistic corrections with the nuclear charge.

[Segmental dilatation of the small intestine in a 10-year-old child]. / Dilatation segmentaire du grêle chez un enfant de 10 ans.

Segmental dilatation of the small bowel is a rare disease. Formed during the first year of life, it could be due to a malformation or a subacute intestinal ischemia sometimes accompanying a deterioration of the myenteric plexus. The discovery of a dilated ileum in a 10 year old healthy child suggests that the anterior pathogenic hypothesis are invalid, especially because the anatomical study does not find any muscular or neurological deterioration. We may regret not to have measured the tissular V.I.P. which could perhaps have helped in the comprehension of the etiology of this disease.