Search

Background: Mainly because of its long half-life and despite its scientific relevance, spectroscopic measurements of Lu176 forbidden β decays are very limited and lack formulation of shape factors. A direct precise measurement of its Q value is also presently unreported. In addition, the description of forbidden decays provides interesting challenges for nuclear theory. The comparison of precise experimental results with theoretical calculations for these decays can help to test underlying models and can aid the interpretation of data from other experiments. Purpose: Perform the first precision measurements of Lu176β-decay spectra and attempt the observation of its electron capture decays, as well as perform the first precision direct measurement of the Lu176β-decay Q value. Compare the shape of the precisely determined experimental β spectra to theoretical calculations, and compare the end point energy to that obtained from an independent Q value measurement. Method: The Lu176β-decay spectra measurements and the search for electron capture decays were performed with an experimental setup that employed lutetium-containing scintillator crystals and a NaI(Tl) spectrometer for coincidence counting. The β decay Q value was determined via high-precision Penning trap mass spectrometry (PTMS) with the LEBIT facility at the National Superconducting Cyclotron Laboratory. The β-spectrum calculations were performed within the Fermi theory formalism with nuclear structure effects calculated using a shell model approach. Results: Both β transitions of Lu176 were experimentally observed and corresponding shape factors formulated in their entire energy ranges. The search for electron capture decay branches led to an experimental upper limit of 6.3×10-6 relative to its β decays. The Lu176β-decay and electron capture Q values were measured using PTMS to be 1193.0(6) and 108.9(8) keV, respectively. This enabled precise β end point energies of 596.2(6) and 195.3(6) keV to be determined for the primary and secondary β decays, respectively. The conserved vector current hypothesis was applied to calculate the relativistic vector matrix elements. The β-spectrum shape was shown to significantly depend on the Coulomb displacement energy and on the value of the axial vector coupling constant gA, which was extracted according to different assumptions. Conclusion: The implemented self-scintillation method has provided unmatched observations of Lu176, independently validated by the first direct measurements of its β-decay Q value by Penning trap mass spectrometry. Theoretical study of the main β transition led to the extraction of very different effective gA and log10f values, showing that a high-precision description of this transition would require a realistic nuclear structure with nucleus deformation.

Background/Introduction The bactericidal/permeability-increasing fold-containing family-B-member-4 (BPIFB4) serves as a biomarker of healthy aging [1,2] and displays prognostic relevance in vascular pathology [3–5]. We recently described a drop in plasma BPIFB4 level in patients with severe COVID-19 compared to low-grade disease patients [6]. Purpose As COVID-19 is associated with autoimmune features, we developed the methods for determination of Anti-BPIFB4 IgG (autoAbs) and then characterized their neutralizing activity in COVID-19 patients. Methods A sandwich ELISA-based colorimetric assay followed by immunoblot analysis detected the presence of autoAbs against BPIFB4 in 60 hospitalized COVID-19 patients and in 30 healthy volunteers. Compared to the healthy controls, the optical density (OD) level of autoAbs in COVID-19 showed considerable variability distributing over a range between 0.13 and 0.85. We thus divided the patients into two groups, one with OD >0,29 and the other one with a OD >0,29, where 0,29 represents the OD mean value of autoAbs against BPIFB4 in physiological conditions. Results Since patients with higher OD are mainly those who spend in average a higher number of days in hospital, we stratified the patients according to the Length of Stay (LoS) in hospital (Figure 1), and found a trend towards a positive correlation between AutoAbs OD level and length of hospitalization within COVID-19 patients. When present, autoAbs exclusively target the WT-BPIFB4 autoantigens and neglect the recognition of the Longevity-associated-variant-(LAV) of the BPIFB4 gene known for its therapeutic efficacy in cardiomyopathy, atherosclerosis (4), diabetes (6) and platelets' reactivity. As expected, the pre-treatment of human PrP with the recombinant rhLAV-BPIFB4 reduces platelets' aggregation in response to ADP and collagen in COVID-19 patients in vitro. On the other hand, at functional level, the well established LAV-BPIFB4-regulated M2 macrophage polarization (4,7), is neutralized in presence of anti-BPIFB4 autoAbs-enriched plasma. Conclusion We conclude that a significant proportion of hospitalized COVID-19 patients displays BPIFB4-AutoAbs which are positively correlated with the Length of Stay (LoS) in hospital. In future, it will be of utmost importance to clarify if the 4 missense SNPs which distinguish LAV-BPIFB4 gene from its WT-counterpart, are instrumental to prevent the self-tolerance brake-down and the potential development of specific antibodies against endogenous cardiovascular protectors. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Cariplo Foundation (n.2016-0874) to AAP and CV; Ministry of Health (RF-2016-02364864) to AAP and CV

Nuclear properties across the chart of nuclides are key to improving and validating our understanding of the strong interaction in nuclear physics. We present high-precision mass measurements of neutron-rich Fe isotopes performed at the TITAN facility. The multiple-reflection time-of-flight mass spectrometer (MR-ToF-MS), achieving a resolving power greater than $600\,000$ for the first time, enabled the measurement of $^{63-70}$Fe, including first-time high-precision direct measurements ($\delta m/m \sim 10^{-7}$) of $^{68-70}$Fe, as well as the discovery of a long-lived isomeric state in $^{69}$Fe. These measurements are accompanied by both mean-field and ab initio calculations using the most recent realizations which enable theoretical assignment of the spin-parities of the $^{69}$Fe ground and isomeric states. Together with mean-field calculations of quadrupole deformation parameters for the Fe isotope chain, these results benchmark a maximum of deformation in the $N = 40$ island of inversion in Fe, and shed light on trends in level densities indicated in the newly-refined mass surface., Comment: 9 pages, 6 figures

We performed a Penning trap mass measurement of $^{61}{\rm Zn}$ at the National Superconducting Cyclotron Laboratory and NuShellX calculations of the $^{61}{\rm Zn}$ and $^{62}{\rm Ga}$ structure using the GXPF1A Hamiltonian to obtain improved estimates of the $^{61}{\rm Zn}(p,\gamma)^{62}{\rm Ga}$ and $^{60}{\rm Cu}(p,\gamma)^{61}{\rm Zn}$ reaction rates. Surveying astrophysical conditions for type-I X-ray bursts with the code MESA, implementing our improved reaction rates, and taking into account updated nuclear masses for $^{61}{\rm V}$ and $^{61}{\rm Cr}$ from the recent literature, we refine the neutrino luminosity from the important mass number $A=61$ urca cooling source in accreted neutron star crusts. This improves our understanding of the thermal barrier between deep heating in the crust and the shallow depths where extra heat is needed to explain X-ray superbursts, as well as the expected signature of crust urca neutrino emission in light curves of cooling transients., Comment: Submitted

Italy is among the countries most likely to be exposed to high hydrogeological risk. The recent 2018 Hydrogeological Disruption Report by ISPRA (Higher Institute for Environmental Protection and Research) states that about 90% of Italian municipalities fall within areas with hydrogeological risk, that is where the probability of floods/landslides is high (level P3) or very high (P4) or the hydraulic hazard is of medium level. Floods are the most severe and frequent phenomena affecting landscapes, mainly if they occur in urban contexts. Urban development, if nature-based solutions are not taken into account, determines an increase in the impermeable surface, with the effect of reducing the infiltration and water evaporation, and consequently with an increase in runoff peaks and decrease of the concentration times. In this framework, the work here presented numerically analyses the effect of floods in an urban basin, in term of their three-dimensional interaction with buildings. The site under study is Cervinara, a municipality in the Campania region, Italy, hit by severe floods in 1999. Flow peaks were calculated using the VAPI procedure, a regional methodology based on two-component extreme value (TCEV) distribution. The results show that the level of exposure of the buildings, evaluated by calculating the thrust of the interacting water on the exterior walls, is influenced by the local three-dimensional kinematics.

Summary Background Although COVID-19 has greatly affected many low-income and middle-income countries, detailed information about patients admitted to the intensive care unit (ICU) is still scarce. Our aim was to examine ventilation characteristics and outcomes in invasively ventilated patients with COVID-19 in Argentina, an upper middle-income country. Methods In this prospective, multicentre cohort study (SATICOVID), we enrolled patients aged 18 years or older with RT-PCR-confirmed COVID-19 who were on invasive mechanical ventilation and admitted to one of 63 ICUs in Argentina. Patient demographics and clinical, laboratory, and general management variables were collected on day 1 (ICU admission); physiological respiratory and ventilation variables were collected on days 1, 3, and 7. The primary outcome was all-cause in-hospital mortality. All patients were followed until death in hospital or hospital discharge, whichever occurred first. Secondary outcomes were ICU mortality, identification of independent predictors of mortality, duration of invasive mechanical ventilation, and patterns of change in physiological respiratory and mechanical ventilation variables. The study is registered with ClinicalTrials.gov, NCT04611269, and is complete. Findings Between March 20, 2020, and Oct 31, 2020, we enrolled 1909 invasively ventilated patients with COVID-19, with a median age of 62 years [IQR 52–70]. 1294 (67·8%) were men, hypertension and obesity were the main comorbidities, and 939 (49·2%) patients required vasopressors. Lung-protective ventilation was widely used and median duration of ventilation was 13 days (IQR 7–22). Median tidal volume was 6·1 mL/kg predicted bodyweight (IQR 6·0–7·0) on day 1, and the value increased significantly up to day 7; positive end-expiratory pressure was 10 cm H2O (8–12) on day 1, with a slight but significant decrease to day 7. Ratio of partial pressure of arterial oxygen (PaO2) to fractional inspired oxygen (FiO2) was 160 (IQR 111–218), respiratory system compliance 36 mL/cm H2O (29–44), driving pressure 12 cm H2O (10–14), and FiO2 0·60 (0·45–0·80) on day 1. Acute respiratory distress syndrome developed in 1672 (87·6%) of patients; 1176 (61·6%) received prone positioning. In-hospital mortality was 57·7% (1101/1909 patients) and ICU mortality was 57·0% (1088/1909 patients); 462 (43·8%) patients died of refractory hypoxaemia, frequently overlapping with septic shock (n=174). Cox regression identified age (hazard ratio 1·02 [95% CI 1·01–1·03]), Charlson score (1·16 [1·11–1·23]), endotracheal intubation outside of the ICU (ie, before ICU admission; 1·37 [1·10–1·71]), vasopressor use on day 1 (1·29 [1·07–1·55]), D-dimer concentration (1·02 [1·01–1·03]), PaO2/FiO2 on day 1 (0·998 [0·997–0·999]), arterial pH on day 1 (1·01 [1·00–1·01]), driving pressure on day 1 (1·05 [1·03–1·08]), acute kidney injury (1·66 [1·36–2·03]), and month of admission (1·10 [1·03–1·18]) as independent predictors of mortality. Interpretation In patients with COVID-19 who required invasive mechanical ventilation, lung-protective ventilation was widely used but mortality was high. Predictors of mortality in our study broadly agreed with those identified in studies of invasively ventilated patients in high-income countries. The sustained burden of COVID-19 on scarce health-care personnel might have contributed to high mortality over the course of our study in Argentina. These data might help to identify points for improvement in the management of patients in middle-income countries and elsewhere. Funding None. Translation For the Spanish translation of the Summary see Supplementary Materials section.

Background: The neutron-rich $A\ensuremath{\approx}100, N\ensuremath{\approx}62$ mass region is important for both nuclear structure and nuclear astrophysics. The neutron-rich segment of this region has been widely studied to investigate shape coexistence and sudden nuclear deformation. However, the absence of experimental data of more neutron-rich nuclei poses a challenge to further structure studies. The derivatives of the mass surface, namely, the two-neutron separation energy and neutron pairing gap, are sensitive to nuclear deformation and shed light on the stability against deformation in this region. This region also lies along the astrophysical $r$-process path, and hence precise mass values provide experimental input for improving the accuracy of the $r$-process models and the elemental abundances.Purpose: (a) Changes in deformation are searched for via the mass surface in the $A=104$ mass region at the $N=66$ mid-shell crossover. (b) The sensitivity of the astrophysical $r$-process abundances to the mass of Rb and Sr isotopic chains is studied.Methods: Masses of radioactive Rb and Sr isotopes are precisely measured using a Multiple-Reflection Time-of-Flight Mass Separator (MR-TOF-MS) at the TITAN facility. These mass values are used to calculate two-neutron separation energies, two-neutron shell gaps and neutron pairing gaps for nuclear structure physics, and one-neutron separation energies for fractional abundances and astrophysical findings.Results: We report the first mass measurements of $^{103}\mathrm{Rb}$ and $^{103--105}\mathrm{Sr}$ with uncertainties of less than 45 keV/${c}^{2}$. The uncertainties in the mass excess value for $^{102}\mathrm{Rb}$ and $^{102}\mathrm{Sr}$ have been reduced by a factor of 2 relative to a previous measurement. The deviations from the AME extrapolated mass values by more the 0.5 MeV have been found.Conclusions: The metrics obtained from the derivatives of the mass surface demonstrate no existence of a subshell gap or onset of deformation in the $N=66$ region in Rb and Sr isotopes. The neutron pairing gaps studied in this work are lower than the predictions by several mass models. The abundances calculated using the waiting-point approximation for the $r$ process are affected by these new masses in comparison with AME2016 mass values.

A new series of neutron-rich indium mass measurements is reported from the TITAN multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS). These mass measurements cover 125−134In (N=76–85) and include ground states as well as isomeric states. The masses of nuclei in this region are known to be of great importance for accurately modeling r-process nucleosynthesis, and the significance of the reported neutron-rich indium masses is discussed in this context. Results are compared with earlier experimental data where available as well as theoretical mass models. The measurements reported here include the first mass measurements of 133,134In, as well as the first direct mass measurement of 132In. The masses of 125−131In ground states and several isomers were previously measured to higher precision by Penning trap mass spectrometry, which also resolved some low-lying isomers that could not be resolved in this work. The earlier Penning trap measurements serve as excellent cross-checks for the MR-TOF-MS measurements, and in some cases the MR-TOF-MS measurements improve the literature uncertainties of higher-lying isomer masses and excitation energies. A new isomeric state for 128In, recently reported for the first time by the JYFLTRAP group, is also confirmed by the TITAN MR-TOF-MS, with a measured excitation energy of 1813(17) keV.

Journal of physics / Conference series 1643, 012057 (2020). doi:10.1088/1742-6596/1643/1/012057, Published by IOP Publ., Bristol

Background: The quadratic isobaric multiplet mass equation (IMME) has been very successful at predicting the masses of isobaric analog states in the same multiplet, while its coefficients are known to follow specific trends as functions of mass number. The Atomic Mass Evaluation 2016 [Chin. Phys. C 41, 030003 (2017)] $^{44}\mathrm{V}$ mass value results in an anomalous negative $c$ coefficient for the IMME quadratic term; a consequence of large uncertainty and an unresolved isomeric state. The $b$ and $c$ coefficients can provide useful constraints for construction of the isospin-nonconserving Hamiltonians for the $pf$ shell. In addition, the excitation energy of the ${0}^{+},T=2$ level in $^{44}\mathrm{V}$ is currently unknown. This state can be used to constrain the mass of the more exotic $^{44}\mathrm{Cr}$.Purpose: The aim of the experimental campaign was to perform high-precision mass measurements to resolve the difference between $^{44}\mathrm{V}$ isomeric and ground states, to test the IMME using the new ground state mass value and to provide necessary ingredients for the future identification of the ${0}^{+}$, $T=2$ state in $^{44}\mathrm{V}$.Method: High-precision Penning trap mass spectrometry was performed at LEBIT, located at the National Superconducting Cyclotron Laboratory, to measure the cyclotron frequency ratios of [${^{44g,m}\mathrm{VO}]}^{+}$ versus [${^{32}\mathrm{SCO}]}^{+}$, a well-known reference mass, to extract both the isomeric and ground state masses of $^{44}\mathrm{V}$.Results: The mass excess of the ground and isomeric states in $^{44}\mathrm{V}$ were measured to be $\ensuremath{-}23\phantom{\rule{4pt}{0ex}}804.9(80)$ keV/${c}^{2}$ and $\ensuremath{-}23\phantom{\rule{4pt}{0ex}}537.0(55)$ keV/${c}^{2}$, respectively. This yielded a new proton separation energy of ${S}_{p}=1\phantom{\rule{4pt}{0ex}}773(10)$ keV.Conclusion: The new values of the ground state and isomeric state masses of $^{44}\mathrm{V}$ have been used to deduce the IMME $b$ and $c$ coefficients of the lowest ${2}^{+}$ and ${6}^{+}$ triplets in $A=44$. The ${2}^{+}\phantom{\rule{4pt}{0ex}}c$ coefficient is now verified with the IMME trend for lowest multiplets and is in good agreement with the shell-model predictions using charge-dependent Hamiltonians. The mirror energy differences were determined between $^{44}\mathrm{V}$ and $^{44}\mathrm{Sc}$, in line with isospin-symmetry for this multiplet. The new value of the proton separation energy determined, to an uncertainty of 10 keV, will be important for the determination of the ${0}^{+}$, $T=2$ state in $^{44}\mathrm{V}$ and, consequently, for prediction of the mass excess of $^{44}\mathrm{Cr}$.

Background: Ultralow $Q$-value $\ensuremath{\beta}$ decays are interesting processes to study with potential applications to nuclear $\ensuremath{\beta}$-decay theory and neutrino physics. While a number of potential ultralow $Q$-value $\ensuremath{\beta}$-decay candidates exist, improved mass measurements are necessary to determine which of these are energetically allowed.Purpose: To perform precise atomic mass measurements of $^{89}\mathrm{Y}$ and $^{139}\mathrm{La}$. Use these new measurements along with the precisely known atomic masses of $^{89}\mathrm{Sr}$ and $^{139}\mathrm{Ba}$ and nuclear energy level data for $^{89}\mathrm{Y}$ and $^{139}\mathrm{La}$ to determine if there could be an ultralow $Q$-value decay branch in the $\ensuremath{\beta}$ decay of $^{89}\mathrm{Sr}\phantom{\rule{4pt}{0ex}}\ensuremath{\rightarrow}\phantom{\rule{4pt}{0ex}}^{89}\mathrm{Y}$ or $^{139}\mathrm{Ba}\phantom{\rule{4pt}{0ex}}\ensuremath{\rightarrow}\phantom{\rule{4pt}{0ex}}^{139}\mathrm{La}$.Method: High-precision Penning trap mass spectrometry was used to determine the atomic mass of $^{89}\mathrm{Y}$ and $^{139}\mathrm{La}$, from which $\ensuremath{\beta}$-decay $Q$ values for $^{89}\mathrm{Sr}$ and $^{139}\mathrm{Ba}$ were obtained.Results: The $^{89}\mathrm{Sr}\phantom{\rule{4pt}{0ex}}\ensuremath{\rightarrow}\phantom{\rule{4pt}{0ex}}^{89}\mathrm{Y}$ and $^{139}\mathrm{Ba}\phantom{\rule{4pt}{0ex}}\ensuremath{\rightarrow}\phantom{\rule{4pt}{0ex}}^{139}\mathrm{La}\phantom{\rule{4pt}{0ex}}\ensuremath{\beta}$-decay $Q$ values were measured to be ${Q}_{\mathrm{Sr}}=1502.20(0.35)$ keV and ${Q}_{\mathrm{Ba}}=2308.37(0.68)$ keV. These results were compared to energies of excited states in $^{89}\mathrm{Y}$ at 1507.4(0.1) keV, and in $^{139}\mathrm{La}$ at 2310(19) keV and 2313(1) keV to determine $Q$ values of $\ensuremath{-}5.20(0.37)$ keV for the potential ultralow $\ensuremath{\beta}$-decay branch of $^{89}\mathrm{Sr}$ and $\ensuremath{-}1.6(19.0)$ keV and $\ensuremath{-}4.6(1.2)$ keV for those of $^{139}\mathrm{Ba}$.Conclusion: The potential ultralow $Q$-value decay branch of $^{89}\mathrm{Sr}$ to the $^{89}\mathrm{Y}$ ($3/{2}^{\ensuremath{-}}$, 1507.4 keV) state is energetically forbidden and has been ruled out. The potential ultralow $Q$-value decay branch of $^{139}\mathrm{Ba}$ to the 2313 keV state in $^{139}\mathrm{La}$ with unknown ${J}^{\ensuremath{\pi}}$ has also been ruled out at the $4\ensuremath{\sigma}$ level, while more precise energy level data is needed for the $^{139}\mathrm{La}$ ($1/{2}^{+}$, 2310 keV) state to determine if an ultralow $Q$-value $\ensuremath{\beta}$-decay branch to this state is energetically allowed.

Background: The understanding and description of forbidden decays provides interesting challenges for nuclear theory. These calculations could help to test underlying nuclear models and interpret experimental data.Purpose: Compare a direct measurement of the $^{138}\mathrm{La}\phantom{\rule{4pt}{0ex}}\ensuremath{\beta}$-decay $Q$ value with the $\ensuremath{\beta}$-decay spectrum end-point energy measured by Quarati et al. using ${\mathrm{LaBr}}_{3}$ detectors [Appl. Radiat. Isot. 108, 30 (2016)]. Use new precise measurements of the $^{138}\mathrm{La}\phantom{\rule{4pt}{0ex}}\ensuremath{\beta}$-decay and electron capture (EC) $Q$ values to improve theoretical calculations of the $\ensuremath{\beta}$-decay spectrum and EC probabilities.Method: High-precision Penning trap mass spectrometry was used to measure cyclotron frequency ratios of $^{138}\mathrm{La}$, $^{138}\mathrm{Ce}$, and $^{138}\mathrm{Ba}$ ions from which $\ensuremath{\beta}$-decay and EC $Q$ values for $^{138}\mathrm{La}$ were obtained.Results: The $^{138}\mathrm{La}\phantom{\rule{4pt}{0ex}}\ensuremath{\beta}$-decay and EC $Q$ values were measured to be ${Q}_{\ensuremath{\beta}}=1052.42(41)$ keV and ${Q}_{\mathrm{EC}}=1748.41(34)$ keV, improving the precision compared to the values obtained in the most recent atomic mass evaluation [Wang et al., Chin. Phys. C 41, 030003 (2017)] by an order of magnitude. These results are used for improved calculations of the $^{138}\mathrm{La}\phantom{\rule{4pt}{0ex}}\ensuremath{\beta}$-decay shape factor and EC probabilities. New determinations for the $^{138}\mathrm{Ce}$ 2EC $Q$ value and the atomic masses of $^{138}\mathrm{La}$, $^{138}\mathrm{Ce}$, and $^{138}\mathrm{Ba}$ are also reported.Conclusion: The $^{138}\mathrm{La}\phantom{\rule{4pt}{0ex}}\ensuremath{\beta}$-decay $Q$ value measured by Quarati et al. is in excellent agreement with our new result, which is an order of magnitude more precise. Uncertainties in the shape factor calculations for $^{138}\mathrm{La}\phantom{\rule{4pt}{0ex}}\ensuremath{\beta}$ decay using our new $Q$ value are reduced by an order of magnitude. Uncertainties in the EC probability ratios are also reduced and show improved agreement with experimental data.

Nuclear structure and astrophysics studies rely heavily on precision mass measurements of rare isotopes. However, many of these isotopes far from the valley of stability can only be produced at very low rates, which are incompatible with the destructive measurement techniques used by rare isotope Penning trap mass spectrometry facilities. To this end, the Low Energy Beam and Ion Trap facility at the National Superconducting Laboratory is in the process of commissioning a single ion Penning trap (SIPT) mass spectrometer that relies on the non-destructive narrowband Fourier Transform ion cyclotron resonance technique. SIPT is the first Penning trap designed to perform mass measurements of rare isotopes produced via projectile fragmentation at rates on the order of one ion per day. The system details and cryogenic detection design, as well as results from the room and cryogenic temperature commissioning, are discussed at length.

A laser ablation ion source has been developed and implemented at the Low-Energy Beam and Ion Trap (LEBIT) facility at the National Superconducting Cyclotron Laboratory. This offline ion source enhances the capabilities of LEBIT by providing increased access to ions used for calibration measurements and checks of systematic effects as well as stable and long-lived ions of scientific interest. The design of the laser ablation ion source and a demonstration of its successful operation are presented.

Background: The $^{51}\mathrm{Fe}(p,\ensuremath{\gamma})^{52}\mathrm{Co}$ reaction lies along the main rp-process path leading up to the $^{56}\mathrm{Ni}$ waiting point. The uncertainty in the reaction $Q$ value, which determines the equilibrium between the forward proton-capture and reverse photodisintegration $^{52}\mathrm{Co}(\ensuremath{\gamma},p)^{51}\mathrm{Fe}$ reaction, contributes to considerable uncertainty in the reaction rate in the temperature range of interest for Type I x-ray bursts and thus to an $\ensuremath{\approx}10%$ uncertainty in burst ashes lighter than $A=56$.Purpose: With a recent Penning trap mass measurement of $^{52}\mathrm{Co}$ reducing the uncertainty on its mass to 6.6 keV [Nesterenko et al., J. Phys. G 44, 065103 (2017)], the dominant source of uncertainty in the reaction $Q$ value is now the mass of $^{51}\mathrm{Fe}$, reported in the 2016 atomic mass evaluation to a precision of 9 keV [Wang et al., Chin. Phys. C 41, 030003 (2017)]. A new, high-precision Penning trap mass measurement of $^{51}\mathrm{Fe}$ was performed to allow the determination of an improved precision $Q$ value and thus new reaction rates.Method: $^{51}\mathrm{Fe}$ was produced using projectile fragmentation at the Coupled Cyclotron Facility at the National Superconducting Cyclotron Laboratory, and separated using the A1900 fragment separator. The resulting secondary beam was then thermalized in the beam stopping area before a mass measurement was performed using the LEBIT 9.4T Penning trap mass spectrometer.Results: The new mass excess, $\mathrm{ME}=\ensuremath{-}40189.2(1.6)$ keV, is sixfold more precise than the current AME value, and $1.6\ensuremath{\sigma}$ less negative. This value was used to calculate a new proton separation energy for $^{52}\mathrm{Co}$ of 1431(7) keV. New excitation levels were then calculated for $^{52}\mathrm{Co}$ using the nushellx code with the GXPF1A interaction, and a new reaction rate and burst ash composition was calculated.Conclusions: With a new measured $Q$ value, the uncertainty on the $^{51}\mathrm{Fe}(p,\ensuremath{\gamma})$ reaction rate is dominated by the poorly measured $^{52}\mathrm{Co}$ level structure. Reducing this uncertainty would allow a more precise rate calculation and a better determination of the mass abundances in the burst ashes.

International audience; We discuss the motivation and technique of Penning trap mass spectrometry applied to radioactive$^{44}$V and$^{44}^{m}$V, using the LEBIT 9.4 T Penning trap mass spectrometer at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University. A complementary measurement of these nuclides, performed at the CSRe in Lanzhou, China, was recently published, but with errors several times larger than obtainable for a short-lived radionuclide in a Penning trap. Interpretation of the higher precision results is ongoing and a full accounting of this measurement is anticipated in the coming months.

We report the mass measurement of $^{56}\mathrm{Cu}$, using the LEBIT 9.4 T Penning trap mass spectrometer at the National Superconducting Cyclotron Laboratory at Michigan State University. The mass of $^{56}\mathrm{Cu}$ is critical for constraining the reaction rates of the $^{55}\mathrm{Ni}(p,\ensuremath{\gamma})$ $^{56}\mathrm{Cu}(p,\ensuremath{\gamma})$ $^{57}\mathrm{Zn}({\ensuremath{\beta}}^{+})$ $^{57}\mathrm{Cu}$ bypass around the $^{56}\mathrm{Ni}$ waiting point. Previous recommended mass excess values have disagreed by several hundred keV. Our new value, $\mathrm{ME}=\ensuremath{-}38626.7(7.1)\text{ }\text{ }\mathrm{keV}$, is a factor of 30 more precise than the extrapolated value suggested in the 2012 atomic mass evaluation [Chin. Phys. C 36, 1603 (2012)], and more than a factor of 12 more precise than values calculated using local mass extrapolations, while agreeing with the newest 2016 atomic mass evaluation value [Chin. Phys. C 41, 030003 (2017)]. The new experimental average, using our new mass and the value from AME2016, is used to calculate the astrophysical $^{55}\mathrm{Ni}(p,\ensuremath{\gamma})$ and $^{56}\mathrm{Cu}(p,\ensuremath{\gamma})$ forward and reverse rates and perform reaction network calculations of the $rp$ process. These show that the $rp$-process flow redirects around the $^{56}\mathrm{Ni}$ waiting point through the $^{55}\mathrm{Ni}(p,\ensuremath{\gamma})$ route, allowing it to proceed to higher masses more quickly and resulting in a reduction in ashes around this waiting point and an enhancement to higher-mass ashes.

The region near Z=28, N=40 is a subject of great interest for nuclear structure studies due to spectroscopic signatures in $^{68}$Ni suggesting a subshell closure at N=40. Trends in nuclear masses and their derivatives provide a complementary approach to shell structure investigations via separation energies. Penning trap mass spectrometry has provided precise measurements for a number of nuclei in this region, however a complete picture of the mass surfaces has so far been limited by the large uncertainty remaining for nuclei with N > 40 along the iron and cobalt chains. Here we present the first Penning trap measurements of $^{68,69}$Co, performed at the Low-Energy Beam and Ion Trap facility at the National Superconducting Cyclotron Laboratory. In addition, we perform ab initio calculations of ground state and two-neutron separation energies of cobalt isotopes with the valence-space in-medium similarity renormalization group approach based on a particular set of two- and three-nucleon forces which predict saturation in infinite matter. We discuss the importance of these measurements and calculations for understanding the evolution of nuclear structure near $^{68}$Ni., 7 pages, 6 figures

Using high-precision Penning trap mass spectrometry at the Low Energy Beam and Ion Trap facility at the National Superconducting Cyclotron Laboratory we have measured the $Q$ values of the fourth-order forbidden $\ensuremath{\beta}$ decay and electron capture of $^{50}\mathrm{V}$ and the double electron capture $Q$ value of $^{50}\mathrm{Cr}$ with the results ${Q}_{\ensuremath{\beta}}(^{50}\mathrm{V})=1038.1(1)$ keV, ${Q}_{\mathrm{EC}}(^{50}\mathrm{V})=2208.7(1)$ keV, and ${Q}_{2\mathrm{EC}}(^{50}\mathrm{Cr})=1170.5(1)$ keV. In addition, we have measured the atomic masses of $^{46,47,49,50}\mathrm{Ti},^{50,51}\mathrm{V}$, and $^{50,52--54}\mathrm{Cr}$, reducing uncertainties by factors of up to three compared with the most recent atomic mass evaluation $(Ame2016)$ [Chin. Phys. C 41, 030003 (2017)]. Our results are in good agreement with $Ame2016$ for $^{46,47,49,50}\mathrm{Ti}$ and $^{50,54}\mathrm{Cr}$ and show deviations of up to $\ensuremath{\sim}1\phantom{\rule{4pt}{0ex}}\mathrm{keV}\phantom{\rule{4pt}{0ex}}(2.5\ensuremath{\sigma})$ for $^{50,51}\mathrm{V}$ and $^{50,54}\mathrm{Cr}$.

We report the mass measurement of ^{56}Cu, using the LEBIT 9.4 T Penning trap mass spectrometer at the National Superconducting Cyclotron Laboratory at Michigan State University. The mass of ^{56}Cu is critical for constraining the reaction rates of the ^{55}Ni(p,γ) ^{56}Cu(p,γ) ^{57}Zn(β^{+}) ^{57}Cu bypass around the ^{56}Ni waiting point. Previous recommended mass excess values have disagreed by several hundred keV. Our new value, ME=-38626.7(7.1) keV, is a factor of 30 more precise than the extrapolated value suggested in the 2012 atomic mass evaluation [Chin. Phys. C 36, 1603 (2012)CPCHCQ1674-113710.1088/1674-1137/36/12/003], and more than a factor of 12 more precise than values calculated using local mass extrapolations, while agreeing with the newest 2016 atomic mass evaluation value [Chin. Phys. C 41, 030003 (2017)CPCHCQ1674-113710.1088/1674-1137/41/3/030003]. The new experimental average, using our new mass and the value from AME2016, is used to calculate the astrophysical ^{55}Ni(p,γ) and ^{56}Cu(p,γ) forward and reverse rates and perform reaction network calculations of the rp process. These show that the rp-process flow redirects around the ^{56}Ni waiting point through the ^{55}Ni(p,γ) route, allowing it to proceed to higher masses more quickly and resulting in a reduction in ashes around this waiting point and an enhancement to higher-mass ashes.

Background: The observation of neutrinoless double-$\ensuremath{\beta}$ transitions would indicate physics beyond the standard model as the lepton number conservation is violated. For a complete degeneracy in the energy of the initial and final states, the neutrinoless double-electron capture is resonantly enhanced. This shortens the half-life to similar orders of magnitude as the neutrinoless double-$\ensuremath{\beta}$ decay and expands the set of nuclei for the search of neutrinoless double-$\ensuremath{\beta}$ transitions as the observation of either process would be equally likely.Purpose: To clearly identify transitions that are resonantly enhanced, among other parameters the total energy of the decay, ${Q}_{\ensuremath{\varepsilon}\ensuremath{\varepsilon}}$, needs to be measured very precisely. Of the 12 initially identified candidates, the last remaining decay without a precise ${Q}_{\ensuremath{\varepsilon}\ensuremath{\varepsilon}}$ was $^{190}\mathrm{Pt}(0\ensuremath{\nu}\ensuremath{\varepsilon}\ensuremath{\varepsilon})^{190}\mathrm{Os}$.Method: The ${Q}_{\ensuremath{\varepsilon}\ensuremath{\varepsilon}}$ value was determined with the Penning trap mass spectrometer LEBIT by measuring the ratio of the cyclotron frequencies of $^{190}\mathrm{Pt}^{+}$ and $^{190}\mathrm{Os}^{+}$ in a 9.4-T superconducting magnet.Result: The ${Q}_{\ensuremath{\varepsilon}\ensuremath{\varepsilon}}$ value was determined to be 1401.57(47) keV with an uncertainty reduction of an order of magnitude compared to its previously known value. The absolute value is shifted by 17.17(623) keV relative to the previously accepted one. Furthermore, the mass value of $^{190}\mathrm{Pt}$ was found to be shifted by more than three standard deviations. In addition we improved the mass values for $^{186,190}\mathrm{Os}$ and $^{194}\mathrm{Pt}$.Conclusion: Transitions to the two nuclear excited states of $^{190}\mathrm{Os}$ with 1326.9(5) and 1387.00(2) keV energy were identified to be resonantly enhanced within a $1\ensuremath{\sigma}$ uncertainty. The significantly reduced uncertainty of ${Q}_{\ensuremath{\varepsilon}\ensuremath{\varepsilon}}$ confirmed the potential for a resonantly enhanced transition.

We report the determination of the Q(EC) value of the mirror transition of (11)C by measuring the atomic masses of (11)C and (11)B using Penning trap mass spectrometry. More than an order of magnitude improvement in precision is achieved as compared to the 2012 Atomic Mass Evaluation (Ame2012) [Chin. Phys. C 36, 1603 (2012)]. This leads to a factor of 3 improvement in the calculated Ft value. Using the new value, Q(EC)=1981.690(61) keV, the uncertainty on Ft is no longer dominated by the uncertainty on the Q(EC) value. Based on this measurement, we provide an updated estimate of the Gamow-Teller to Fermi mixing ratio and standard model values of the correlation coefficients.

We report the determination of the Q(EC) value of the mirror transition of (11)C by measuring the atomic masses of (11)C and (11)B using Penning trap mass spectrometry. More than an order of magnitude improvement in precision is achieved as compared to the 2012 Atomic Mass Evaluation (Ame2012) [Chin. Phys. C 36, 1603 (2012)]. This leads to a factor of 3 improvement in the calculated Ft value. Using the new value, Q(EC)=1981.690(61) keV, the uncertainty on Ft is no longer dominated by the uncertainty on the Q(EC) value. Based on this measurement, we provide an updated estimate of the Gamow-Teller to Fermi mixing ratio and standard model values of the correlation coefficients.

We report the first direct measurement of the $^{14}\mathrm{O}$ superallowed Fermi $\ensuremath{\beta}$-decay ${Q}_{EC}$ value, the last of the so-called ``traditional nine'' superallowed Fermi $\ensuremath{\beta}$ decays to be measured with Penning trap mass spectrometry. $^{14}\mathrm{O}$, along with the other low-$Z$ superallowed $\ensuremath{\beta}$ emitter, $^{10}\mathrm{C}$, is crucial for setting limits on the existence of possible scalar currents. The new ground state ${Q}_{EC}$ value, 5144.364(25) keV, when combined with the energy of the ${0}^{+}$ daughter state, ${E}_{x}({0}^{+})=2312.798(11)\text{ }\text{ }\mathrm{keV}$ [, Nucl. Phys. A523, 1 (1991)], provides a new determination of the superallowed $\ensuremath{\beta}$-decay ${Q}_{EC}$ value, ${Q}_{EC}(\mathrm{sa})=2831.566(28)\text{ }\text{ }\mathrm{keV}$, with an order of magnitude improvement in precision, and a similar improvement to the calculated statistical rate function $f$. This is used to calculate an improved $\mathcal{F}t$ value of 3073.8(2.8) s.

Experimental searches for neutrinoless double-$\ensuremath{\beta}$ decay offer one of the best opportunities to look for physics beyond the standard model. Detecting this decay would confirm the Majorana nature of the neutrino, and a measurement of its half-life can be used to determine the absolute neutrino mass scale. Important to both tasks is an accurate knowledge of the $Q$ value of the double-$\ensuremath{\beta}$ decay. The LEBIT Penning trap mass spectrometer was used for the first direct experimental determination of the $^{96}\mathrm{Zr}$ double-$\ensuremath{\beta}$ decay $Q$ value: ${Q}_{\ensuremath{\beta}\ensuremath{\beta}}=3355.85(15)$ keV. This value is nearly 7 keV larger than the 2012 Atomic Mass Evaluation [M. Wang et al., Chin. Phys. C 36, 1603 (2012)] value and one order of magnitude more precise. The 3-$\ensuremath{\sigma}$ shift is primarily due to a more accurate measurement of the $^{96}\mathrm{Zr}$ atomic mass: $m{(}^{96}\mathrm{Zr})=95.908\phantom{\rule{0.16em}{0ex}}277\phantom{\rule{0.16em}{0ex}}35(17)$ u. Using the new $Q$ value, the $2\ensuremath{\nu}\ensuremath{\beta}\ensuremath{\beta}$-decay matrix element, $|{M}_{2\ensuremath{\nu}}|$, is calculated. Improved determinations of the atomic masses of all other zirconium $(^{90\ensuremath{-}92,94,96}\mathrm{Zr})$ and molybdenum $({}^{92,94\ensuremath{-}98,100}\mathrm{Mo})$ isotopes using both ${}^{12}{\mathrm{C}}_{8}$ and $^{87}\mathrm{Rb}$ as references are also reported.

We report the first direct measurement of the (14)O superallowed Fermi β-decay QEC value, the last of the so-called "traditional nine" superallowed Fermi β decays to be measured with Penning trap mass spectrometry. (14)O, along with the other low-Z superallowed β emitter, (10)C, is crucial for setting limits on the existence of possible scalar currents. The new ground state QEC value, 5144.364(25) keV, when combined with the energy of the 0(+) daughter state, Ex(0(+))=2312.798(11) keV [F. Ajzenberg-Selove, Nucl. Phys. A523, 1 (1991)], provides a new determination of the superallowed β-decay QEC value, QEC(sa)=2831.566(28) keV, with an order of magnitude improvement in precision, and a similar improvement to the calculated statistical rate function f. This is used to calculate an improved Ft value of 3073.8(2.8) s.

The Low Energy Beam and Ion Trap (LEBIT) Penning trap mass spectrometer was used to perform an improved-precision mass measurement of $^{72}\mathrm{Br}$ and the low-lying isomeric state, $^{72m}\mathrm{Br},$ giving mass excesses of $\ensuremath{-}59\phantom{\rule{0.16em}{0ex}}062.2(1.0)\phantom{\rule{0.16em}{0ex}}\mathrm{keV}$ and $\ensuremath{-}58\phantom{\rule{0.16em}{0ex}}960.9(1.2)\phantom{\rule{0.16em}{0ex}}\mathrm{keV}$, respectively. These values are consistent with the values from the 2012 atomic mass evaluation [Chin. Phys. C 36, 1603 (2012)] and the Nubase2012 evaluation of nuclear properties [Chin. Phys. C 36, 1157 (2012)]. The uncertainties on the mass of the ground state and isomeric state have been reduced by a factor of seven.

The FORS1 instrument on the ESO Very Large Telescope was used to obtain low-resolution circular polarised spectra of nearly a thousand different stars, with the aim of measuring their mean longitudinal magnetic fields. A catalogue of FORS1 magnetic measurements would provide a valuable resource with which to better understand the strengths and limitations of this instrument and of similar low-dispersion, Cassegrain spectropolarimeters. However, FORS1 data reduction has been carried out by a number of different groups using a variety of reduction and analysis techniques. Our understanding of the instrument and our data reduction techniques have both improved over time. A full re-analysis of FORS1 archive data using a consistent and fully documented algorithm would optimise the accuracy and usefulness of a catalogue of field measurements. Based on the ESO FORS pipeline, we have developed a semi-automatic procedure for magnetic field determinations, which includes self-consistent checks for field detection reliability. We have applied our procedure to the full content of circular spectropolarimetric measurements of the FORS1 archive. We have produced a catalogue of spectro-polarimetric observations and magnetic field measurements for about 1400 observations of about 850 different objects. The spectral type of each object has been accurately classified. We have also been able to test different methods for data reduction is a systematic way. The resulting catalogue has been used to produce an estimator for an upper limit to the uncertainty in a field strength measurement of an early type star as a function of the signal-to-noise ratio of the observation. While FORS1 is not necessarily an optimal instrument for the discovery of weak magnetic fields, it is very useful for the systematic study of larger fields, such as those found in Ap/Bp stars and in white dwarfs., Comment: Accepted for publication by A&A

QoL assessment is currently considered essential for clinical trials in HIV infection, as commonly used end-points (CD4 level, viral load, opportunistic diseases) are inadequate to catch the complexity of treatment outcomes. The World Health Organization has recently developed a standardized set of instruments to assess subjective quality of life (QoL) in different medical conditions, including HIV infection. Here we report evidence for the acceptability, reliability and validity of the Italian version of the WHOQOL-HIV. The Italian version of WHOQOL-HIV has been administered in a sample of 151 HIV-positive persons, consecutively attending the largest infectious diseases hospital in southern Italy. Mean time of administration and percentage of missing responses, Cronbach alpha, Pearson coefficient and oneway ANOVA were applied to assess, respectively, acceptability, reliability, convergent and disciminant validity, and sensitivity to change. Mean time of administration was 28 minutes; only 2 questionnaires showed more than 20% of missing responses. Cronbach alpha was above 0.70 in 22 of the 28 sections of the WHOQOL-HIV; it ranged between 0.53 and 0.68 in the remaining 6 sections. Each of the 7 QoL principal domains correlated with overall QoL at a significance level p0.001. Moreover, correlation between principal domains were always statistically significant (p0.01) with only two exceptions. Finally, mean scores in each QoL domain were in the expected direction (worse in AIDS patients as compared to asymptomatic and symptomatic persons). The Italian version of WHOQOL-HIV is a valid and reliable instrument to assess subjective QoL in HIV-positive persons. It seems potentially useful to assess patients' life satisfaction, and to calibrate standards of care in different stages of the infection.

Objective To evaluate the seroprevalence of Chlamydia pneumoniae and age, gender and smoking habits in stable asthmatic patients. Methods Over a period of 3 months, 197 adult patients affected by intermittent-to-severe chronic asthma were enrolled from 16 respiratory disease units in the south of Italy. As a control group, we tested 185 healthy, non-asthmatic subjects matched for age and gender, recruited among hospital staff. All patients were submitted to clinical examination, spirometry and blood collection for C. pneumoniae serology. The presence of infection was investigated by microimmunofluorescence (Micro-IF Test) for C. pneumoniae -specific IgG, IgM and IgA antibodies. Results C. pneumoniae IgG titers ≥1 : 64 were detected in 30.4% of asthmatics and in 30.8% of controls. Correlation of age, gender and smoking habit with C. pneumoniae seropositivity was evaluated by linear regression analysis. Age was significantly associated with C. pneumoniae IgG titer ≥1 : 64 when seropositive asthmatics were tested. Moreover, C. pneumoniae seroprevalence was higher among smokers with a diagnosis of chronic asthma. Conclusions The seroprevalence of C. pneumoniae in stable asthmatics was comparable with the controls; therefore, the study does not support the association between C. pneumoniae antibody titers and stable asthma. However, the analysis for likely confounders such as age, gender and smoking status suggests a possible association of enhanced susceptibility to C. pneumoniae infection with age and smoking habitus.

This study quantified the per cent contribution of water chemistry to otolith chemistry using enriched stable isotopes of strontium ((86) Sr) and barium ((137) Ba). Euryhaline barramundi Lates calcarifer, were reared in marine (salinity 40), estuarine (salinity 20) and freshwater (salinity 0) under different temperature treatments. To calculate the contribution of water to Sr and Ba in otoliths, enriched isotopes in the tank water and otoliths were quantified and fitted to isotope mixing models. Fulton's K and RNA:DNA were also measured to explore the influence of fish condition on sources of element uptake. Water was the predominant source of otolith Sr (between 65 and 99%) and Ba (between 64 and 89%) in all treatments, but contributions varied with temperature (for Ba), or interactively with temperature and salinity (for Sr). Fish condition indices were affected independently by the experimental rearing conditions, as RNA:DNA differed significantly among salinity treatments and Fulton's K was significantly different between temperature treatments. Regression analyses did not detect relations between fish condition and per cent contribution values. General linear models indicated that contributions from water chemistry to otolith chemistry were primarily influenced by temperature and secondly by fish condition, with a relatively minor influence of salinity. These results further the understanding of factors that affect otolith element uptake, highlighting the necessity to consider the influence of environment and fish condition when interpreting otolith element data to reconstruct the environmental histories of fish.

The hemocytes of the pericardial body of Ciona intestinalis were studied by electron microscopy. Our findings showed that stem cells, clear vesicular granulocytes, microgranulocytes, unilocular granulocytes and globular granulocytes are present at the periphery of the smaller-sized pericardial bodies. The stem cells are small round cells with a large nucleus, with or without nucleolus, and homogeneous cytoplasm containing numerous ribosomes. The clear vesicular granulocytes are characterized by an ameboid shape and cytoplasm containing several large electron-lucent vacuoles and small electron-dense granules. The microgranulocytes are variable in shape and contain numerous large electron-dense granules. The unilocular granulocytes show a single large vacuole with an electron-dense or electron-lucent content and a thin layer of peripheral cytoplasm that contains the flattened nucleus. The globular granulocytes are characterized by the presence of large vacuoles containing either fibrogranular material or electron-dense aggregates.

This study sought to differentiate the species of skates encountered in Gulf St Vincent (GSV), South Australia using normalized elliptical Fourier analysis of body shape. Significant intraspecific variation was observed among whole body shapes. This was overcome by limiting subsequent analyses to the anterior snout region, where significant differences in shape were detected among the species examined and provided a high degree of classification success for the skates of GSV. More generally, this approach has the potential to provide a cost- and time-efficient means of discrimination among species of skates. Further research is required to investigate the potentially confounding effects of sexual dimorphism and ontogenetic variation in growth to improve the efficacy of the body shape analysis of the skates and batoids species in general. In addition, this approach requires considerable development to facilitate implementation in a fishery setting.

We synthesized and determined the production of reactive oxygen species (ROS) as 1O2, *-O2, *OH, H2O2 during the photolysis with UV-A light of three antibacterial quinolones and their naphthyl ester derivatives. Singlet oxygen and ROS dose-dependant generation from norfloxacin (1), enoxacin (2), ciprofloxacin (3) and their respective naphthyl ester derivatives 4-6 were detecting in cell-free systems by the histidine assay and by luminol-enhanced chemiluminescence (LCL). Both the electronic absorption and emission spectra were quantified and their photostability determined. The antibacterial activity in darkness and under irradiation of compounds 4, 5 and 6 was tested on E. coli and compared with their parent drugs.