(Per)chlorate-reducing bacteria can utilize aerobic and anaerobic pathways of aromatic degradation with (per)chlorate as an electron acceptor.

UnlabelledThe pathways involved in aromatic compound oxidation under perchlorate and chlorate [collectively known as (per)chlorate]-reducing conditions are poorly understood. Previous studies suggest that these are oxygenase-dependent pathways involving O2 biogenically produced during (per)chlorate respiration. Recently, we described Sedimenticola selenatireducens CUZ and Dechloromarinus chlorophilus NSS, which oxidized phenylacetate and benzoate, two key intermediates in aromatic compound catabolism, coupled to the reduction of perchlorate or chlorate, respectively, and nitrate. While strain CUZ also oxidized benzoate and phenylacetate with oxygen as an electron acceptor, strain NSS oxidized only the latter, even at a very low oxygen concentration (1%, vol/vol). Strains CUZ and NSS contain similar genes for both the anaerobic and aerobic-hybrid pathways of benzoate and phenylacetate degradation; however, the key genes (paaABCD) encoding the epoxidase of the aerobic-hybrid phenylacetate pathway were not found in either genome. By using transcriptomics and proteomics, as well as by monitoring metabolic intermediates, we investigated the utilization of the anaerobic and aerobic-hybrid pathways on different electron acceptors. For strain CUZ, the results indicated utilization of the anaerobic pathways with perchlorate and nitrate as electron acceptors and of the aerobic-hybrid pathways in the presence of oxygen. In contrast, proteomic results suggest that strain NSS may use a combination of the anaerobic and aerobic-hybrid pathways when growing on phenylacetate with chlorate. Though microbial (per)chlorate reduction produces molecular oxygen through the dismutation of chlorite (ClO2(-)), this study demonstrates that anaerobic pathways for the degradation of aromatics can still be utilized by these novel organisms.ImportanceS. selenatireducens CUZ and D. chlorophilus NSS are (per)chlorate- and chlorate-reducing bacteria, respectively, whose genomes encode both anaerobic and aerobic-hybrid pathways for the degradation of phenylacetate and benzoate. Previous studies have shown that (per)chlorate-reducing bacteria and chlorate-reducing bacteria (CRB) can use aerobic pathways to oxidize aromatic compounds in otherwise anoxic environments by capturing the oxygen produced from chlorite dismutation. In contrast, we demonstrate that S. selenatireducens CUZ is the first perchlorate reducer known to utilize anaerobic aromatic degradation pathways with perchlorate as an electron acceptor and that it does so in preference over the aerobic-hybrid pathways, regardless of any oxygen produced from chlorite dismutation. D. chlorophilus NSS, on the other hand, may be carrying out anaerobic and aerobic-hybrid processes simultaneously. Concurrent use of anaerobic and aerobic pathways has not been previously reported for other CRB or any microorganisms that encode similar pathways of phenylacetate or benzoate degradation and may be advantageous in low-oxygen environments

Transverse instabilities of multiple vortex chains in superconductor-ferromagnet bilayers

Using scanning tunneling microscopy and Ginzburg-Landau simulations we explore vortex configurations in magnetically coupled NbSe$_2$-Permalloy superconductor-ferromagnet bilayer. The Permalloy film with stripe domain structure induces periodic local magnetic induction in the superconductor creating a series of pinning-antipinning channels for externally added magnetic flux quanta. Such laterally confined Abrikosov vortices form quasi-1D arrays (chains). The transitions between multichain states occur through propagation of kinks at the intermediate fields. At high fields we show that the system becomes non-linear due to a change in both the number of vortices and the confining potential. The longitudinal instabilities of the resulting vortex structures lead to vortices `levitating' in the anti-pinning channels.Comment: accepted in PRB-Rapid

Preserved Extra-Foveal Processing of Object Semantics in Alzheimer’s Disease

Alzheimer’s disease (AD) patients underperform on a range of tasks requiring semantic processing, but it is unclear whether this impairment is due to a generalised loss of semantic knowledge or to issues in accessing and selecting such information from memory. The objective of this eye-tracking visual search study was to determine whether semantic expectancy mechanisms known to support object recognition in healthy adults are preserved in AD patients. Furthermore, as AD patients are often reported to be impaired in accessing information in extra-foveal vision, we investigated whether that was also the case in our study. Twenty AD patients and 20 age-matched controls searched for a target object among an array of distractors presented extra-foveally. The distractors were either semantically related or unrelated to the target (e.g., a car in an array with other vehicles or kitchen items). Results showed that semantically related objects were detected with more difficulty than semantically unrelated objects by both groups, but more markedly by the AD group. Participants looked earlier and for longer at the critical objects when these were semantically unrelated to the distractors. Our findings show that AD patients can process the semantics of objects and access it in extra-foveal vision. This suggests that their impairments in semantic processing may reflect difficulties in accessing semantic information rather than a generalised loss of semantic memory

Thymosin β4 and β10 in Sjögren's syndrome: Saliva proteomics and minor salivary glands expression

Background: In the present study, we investigated whether thymosin β (Tβ) in saliva and in minor salivary glands is differentially expressed in patients with primary Sjögren's syndrome (pSS) and patients with autoimmune diseases (systemic sclerosis [SSc], systemic lupus erythematosus [SLE], and rheumatoid arthritis [RA], with and without sicca syndrome [ss]). Methods: Saliva specimens of nine patients with pSS, seven with ss/SSc, seven with ss/SLE, seven with ss/RA, seven with SSc, seven with SLE, and seven with RA, as well as ten healthy subjects, were analyzed using a high-performance liquid chromatograph coupled with a mass spectrometer equipped with an electrospray ionization source to investigate the presence and levels of Tβ4, Tβ4 sulfoxide, and Tβ10. Immunostaining for Tβ4 and Tβ10 was performed on minor salivary glands of patients with pSS and ss. Results: Tβ4 levels were statistically higher in patients with pSS with respect to the other subgroups. Tβ10 was detectable in 66.7 % of patients with pSS and in 42.8 % of those with ss/SSc, while Tβ4 sulfoxide was detectable in 44.4 % of patients with pSS and in 42.9 % of those with ss/SSc. Tβ10 and Tβ4 sulfoxide were not detectable in patients without associated ss and in healthy control subjects. Regarding thymosin immunostaining, all patients had immunoreactivity for Tβ10, and a comparable distribution pattern in the four different subgroups of patients was observed. Tβ4 immunoreactivity was present in patients with ss/SSc and those with ss/SLE, while it was completely absent in patients with pSS and those with ss/RA. Conclusions: Our data show that higher salivary Tβ expression characterizes patients with pSS, while Tβ4 sulfoxide and Tβ10 salivary expression was selectively present in patients with sicca symptoms. Moreover, at the immunohistochemical level in patients with pSS, minor salivary glands showed a peculiar pattern characterized by immunostaining for Tβ10 in acinar cells in the absence of any reactivity for Tβ4. These findings, taken together, suggest a different role for Tβ4 and Tβ10 in patients with pSS who have ss and other autoimmune disease

Memory for spatial locations in a patient with near space neglect and optic ataxia: Involvement of the occipitotemporal stream

Previous studies suggested that the occipitoparietal stream orients attention toward the near/lower space and is involved in immediate reaching, whereas the occipitotemporal stream orients attention toward the far/upper space and is involved in delayed reaching. In the present study, we investigated the role of the occipitotemporal stream in attention orienting and delayed reaching in a patient (GP) with bilateral damage to the occipitoparietal areas and optic ataxia. GP and healthy controls took part in three experiments. In the experiment 1, the participants bisected lines oriented along radial, vertical, and horizontal axes. GP bisected radial lines farther, and vertical lines more above, than the controls, consistent with an attentional bias toward the far/upper space and near/lower space neglect. The experiment 2 consisted of two tasks: (1) an immediate reaching task, in which GP reached target locations under visual control and (2) a delayed visual reaching task, in which GP and controls were asked to reach remembered target locations visually presented. We measured constant and variable distance and direction errors. In immediate reaching task, GP accurately reached target locations. In delayed reaching task, GP overshot remembered target locations, whereas the controls undershot them. Furthermore, variable errors were greater in GP than in the controls. In the experiment 3, GP and controls performed a delayed proprioceptive reaching task. Constant reaching errors did not differ between GP and the controls. However, variable direction errors were greater in GP than in the controls. We suggest that the occipitoparietal damage, and the relatively intact occipitotemporal region, produced in GP an attentional orienting bias toward the far/upper space (experiment 1). In turns, the attentional bias selectively shifted toward the far space remembered visual (experiment 2), but not proprioceptive (experiment 3), target locations. As a whole, these findings further support the hypothesis of an involvement of the occipitotemporal stream in delayed reaching. Furthermore, the observation that in both delayed reaching tasks the variable errors were greater in GP than in the controls suggested that in optic ataxia is present not only a visuo- but also a proprioceptivo-motor integration deficit

The health impact of hazardous waste landfills and illegal dumps contaminated sites: An epidemiological study at ecological level in Italian Region

Background and aim: The implementation of idoneous management of hazardous waste, in contrast to illegal practices, is one of the environment and health priorities of the WHO. The aim of the present study, based on a collaborative agreement between the Italian National Health Institute and a Prosecution Office located in Naples North, was to evaluate the health effects of illegal landfills and burning of urban and hazardous waste in the territory of the Prosecution Office. Methods: The municipalities included in the study territory were investigated with respect to the regional population. Regression analyses were performed in the study area between four classes of an environmental municipal indicator of waste risk (MRI) previously defined, computing the relative risks (RRs) in 2–4 MRI classes, with respect to the first MRI class (the least impacted). The prevalence of reproductive outcomes and cause-specific mortality and hospitalization were analyzed in the general population and in the 0–19-year-old population using SAS software. Results: An increase of mortality and hospitalization risk in both the genders of the whole area, with respect to regional population, were found for overall all cancer cases, cancer of the stomach, the liver, the lung and the kidney, and ischemic heart diseases. An increase of mortality for leukemias in the 0-19-year-old population and in hospitalization risk for certain conditions originating in the perinatal period were observed. Correlation between MRI and the risk of mortality from breast tumors in women (MRI class 2: RR = 1.06; MRI class 3: RR = 1.15; MRI class 4: RR = 1.11) and between MRI and the risk of hospitalization from testis tumors (MRI class 2: RR = 1.25; MRI class 3: RR = 1.31; MRI class 4: RR = 1.32) were found. The hospitalization risk from breast tumors and asthma exceeded significantly in both genders of three and four MRI classes. Among the 0-19-year-old population, correlation between MRI and hospitalization from leukemias (MRI class 2: RR = 1.48; MRI class 3: RR = 1.60; MRI class 4: RR = 1.41) and between MRI and the prevalence of preterm birth (MRI class 2: RR = 1.17; MRI class 3: RR = 1.08; MRI class 4: RR = 1.25) were found. Conclusion: A correlation between health outcomes and the environmental pressure by uncontrolled waste sites was found. Notwithstanding the limitation of the study, the results promote implementing the actions of environmental remediation and the prosecution of illegal practices

Phonon structure in I-V characteristic of MgB2_{2} point-contacts

The search of the phonon structure at the above-gap energies was carried out for $d^{2}V/dI^{2}(V)$ spectra of MgB$_{2}$ point contacts with a normal metal. The two-band model is assumed not only for the gap structure in $dV/dI(V)$-characteristics, but also for phonons in $d^{2}V/dI^{2}(V)$ point-contact spectra, with up to the maximum lattice vibration energy. Since the current is carried mostly by charges of 3D-band, whereas the strong electron-phonon interaction occurs in 2D-band, we observe the phonon peculiarities due to ''proximity'' effect in {\it k}-space, which depends on the variation of interband coupling through the elastic scattering.Comment: 6 pages, 4 figures, revtex4, reported in International Conference "Modern Problems in Superconductivity", 9-13 September, Yalta, Ukrain

Nonmagnetic impurity effects in MgB2_{2}

We study nonmagnetic impurity effects in MgB$_{2}$ using the quasiclassical equations of superconductivity for a weak-coupling two-band model. Parameters in the model are fixed so as to reproduce experiments on MgB$_{2}$ as closely as possible. The quasiparticle density of states and the specific heat are calculated for various values of the interband impurity scattering. The density of states changes gradually from a two-gap structure into the conventional single-gap structure as the interband scattering increases. It is found that the excitation threshold is not a monotonic function of the interband scattering. Calculated results for the specific heat are in good agreements with experiments on samples after irradiation

Scanning Tunneling Spectroscopy in MgB2

We present scanning tunneling microscopy measurements of the surface of superconducting MgB2 with a critical temperature of 39K. In zero magnetic field the conductance spectra can be analyzed in terms of the standard BCS theory with a smearing parameter Gamma. The value of the superconducting gap is 5.2 meV at 4.2 K, with no experimentally significant variation across the surface of the sample. The temperature dependence of the gap follows the BCS form, fully consistent with phonon-mediated superconductivity in this novel superconductor. The application of a magnetic field induces strong pair-breaking as seen in the conductance spectra in fields up to 6 T.Comment: 4 pages, 4 figure