Rigidity of twisted groupoid L^p-operator algebras

In this paper we will study the isomorphism problem for the reduced twisted group and groupoid $L^p$-operator algebras. For a locally compact group $G$ and a continuous 2-cocycle $\sigma$ we will define the reduced $\sigma$-twisted $L^p$-operator algebra $F_\lambda^p(G,\sigma)$. We will show that if $p\neq2$, then two such algebras are isometrically isomorphic if and only if the groups are topologically isomorphic and the continuous 2-cocyles are cohomologous. For a twist $\mathcal{E}$ over an \'etale groupoid $\mathcal{G}$, we define the reduced twisted groupoid $L^p$-operator algebra $F^p_\lambda(\mathcal{G};\mathcal{E})$. In the main result of this paper, we show that for $p\neq 2$ if the groupoids are topologically principal, Hausdorff, \'etale and have a compact unit space, then two such algebras are isometrically isomorphic if and only if the groupoids are isomorphic and the twists are properly isomorphic

Direct imaging of long-range ferromagnetic and antiferromagnetic order in a dipolar metamaterial

Magnetic metamaterials such as artificial spin ice offer a route to tailor magnetic properties. Such materials can be fabricated by lithographically defining arrays of nanoscale magnetic islands. The magnetostatic interactions between the elements are influenced by their shape and geometric arrangement and can lead to long-range ordering. We demonstrate how the magnetic order in a two-dimensional periodic array of circular disks is controlled by the lattice symmetry. Antiferromagnetic and ferromagnetic order extending through the entire array is observed for the square and hexagonal lattice, respectively. Furthermore, we show that a minute deviation from perfect circularity of the elements along a preferred direction results in room-temperature blocking and favors collinear spin textures

Vannkvalitet og anadrom fisk i Høyanger- og Ortneviksvassdraget i Sogn og Fjordane

På oppdrag fra Fylkemannens miljøvernavdeling i Sogn og Fjordane har en undersøkt vannkvalitet, anadrom fisk og bunndyr i Ortneviksvassdraget og Høyangervassdraget (Daleelva). Målet for undersøkelsen, som ble gjennomført i september/oktober 1997, var å vurdere om forsuring er et problem for fisken i vassdragene, samt klarlegge effektene av regulering. Begge vassdagene er påvirket av sur nedbør, og prøvene viste små vannkjemiske forskjeller mellom dem. pH lå i området 5,7-6,0 i Ortneviksvassdraget, og 5,9-6,0 i Daleelva. Konsentrasjonen av labilt aluminium var opp mot 10 µg/L i begge vassdragene. pH er høyere og konsentrasjonen av labilt aluminium er lavere enn det som ble funnet ved prøvetakingen i vassdragene våren 1997. Fiskeundersøkelsen viste at Ortneviksvassdraget har en selvreproduserende og livskraftig bestand av aure. Det ble ikke fanget laks i vassdraget, og dette tyder på at laksebestanden pr.i dag enten er gått tapt eller er tilstede som en marginal restbestand. Dette har trolig sammenheng med den sure vannkvaliteten, og ANC verdiene i vårprøvene ligger i en område hvor en kan vente at laksebestanden er dødd ut. Høyangervassdraget har en selvproduserende bestand av laks, men tetthetene er lave. Aurebestanden derimot er livskraftig, med gjennomgående høye tettheter av ungfisk. Vannkvaliteten med lave ANC verdier og høye AL konsentrasjoner om våren kan bidra til å forklare de lave tetthetene av laks. Høyangervassdraget er i tillegg sterkt reguelert. Effektene av den omfattende reguleringen av vassdraget kan vanskelig tallfestes på bestandsnivå, men det er sannsynlig at den har medført en betydelig reduksjon av produksjonspotensialet for anadrom fisk

Maternal Neural Responses to Infant Cries and Faces: Relationships with Substance Use

Substance abuse in pregnant and recently post-partum women is a major public health concern because of effects on the infant and on the ability of the adult to care for the infant. In addition to the negative health effects of teratogenic substances on fetal development, substance use can contribute to difficulties associated with the social and behavioral aspects of parenting. Neural circuits associated with parenting behavior overlap with circuits involved in addiction (e.g., frontal, striatal, and limbic systems) and thus may be co-opted for the craving/reward cycle associated with substance use and abuse and be less available for parenting. The current study investigates the degree to which neural circuits associated with parenting are disrupted in mothers who are substance-using. Specifically, we used functional magnetic resonance imaging to examine the neural response to emotional infant cues (faces and cries) in substance-using compared to non-using mothers. In response to both faces (of varying emotional valence) and cries (of varying distress levels), substance-using mothers evidenced reduced neural activation in regions that have been previously implicated in reward and motivation as well as regions involved in cognitive control. Specifically, in response to faces, substance users showed reduced activation in prefrontal regions, including the dorsolateral and ventromedial prefrontal cortices, as well as visual processing (occipital lobes) and limbic regions (parahippocampus and amygdala). Similarly, in response to infant cries, substance-using mothers showed reduced activation relative to non-using mothers in prefrontal regions, auditory sensory processing regions, insula and limbic regions (parahippocampus and amygdala). These findings suggest that infant stimuli may be less salient for substance-using mothers, and such reduced saliency may impair developing infant-caregiver attachment and the ability of mothers to respond appropriately to their infants

Strained interface layer contributions to the structural and electronic properties of epitaxial V2O3 films

We report on the transport properties of epitaxial vanadium sesquioxide (V2O3) thin films with thicknesses in the range of 1 to 120 nm. Films with thickness down to nanometer values reveal clear resistivity curves with temperature illustrating that even at these thicknesses the films are above the percolation threshold and continuous over large distances. The results reveal that with reducing thickness the resistivity of the films increases sharply for thicknesses below 4 nm and the metal-insulator transition (MIT) is quenched. We attribute this increase to a strained interface layer of thickness ∼ 4 nm with in-plane lattice parameters corresponding to the Al2O3 substrate. The interface layer displays a suppressed MIT shifted to higher temperatures and has a room temperature resistivity 6 orders of magnitude higher than the thicker V2O3 films.This work was supported by the University of Iceland Research Fund for Doctoral Students, the University of Iceland Research Fund, the Icelandic Student Innovation Fund, and the Icelandic Research Fund (Grant Nos. 207111 and 174271)

Characterization of the major formamidopyrimidine–DNA glycosylase homolog in Mycobacterium tuberculosis and its linkage to variable tandem repeats

The ability to repair DNA damage is likely to play an important role in the survival of facultative intracellular parasites because they are exposed to high levels of reactive oxygen species and nitrogen intermediates inside phagocytes. Correcting oxidative damage in purines and pyrimidines is the primary function of the enzymes formamidopyrimidine (faPy)–DNA glycosylase (Fpg) and endonuclease VIII (Nei) of the base excision repair pathway, respectively. Four gene homologs, belonging to the fpg/nei family, have been identified in Mycobacterium tuberculosis H37Rv. The recombinant protein encoded by M. tuberculosis Rv2924c, termed Mtb-Fpg1, was overexpressed, purified and biochemically characterized. The enzyme removed faPy and 5-hydroxycytosine lesions, as well as 8-oxo-7,8-dihydroguanine (8oxoG) opposite to C, T and G. Mtb-Fpg1 thus exhibited substrate specificities typical for Fpg enzymes. Although Mtb-fpg1 showed nearly complete nucleotide sequence conservation in 32 M. tuberculosis isolates, the region upstream of Mtb-fpg1 in these strains contained tandem repeat motifs of variable length. A relationship between repeat length and Mtb-fpg1 expression level was demonstrated in M. tuberculosis strains, indicating that an increased length of the tandem repeats positively influenced the expression levels of Mtb-fpg1. This is the first example of such a tandem repeat region of variable length being linked to the expression level of a bacterial gene

Distinct Subsets of Noncoding RNAs Are Strongly Associated With BMD and Fracture, Studied in Weight-Bearing and Non–Weight-Bearing Human Bone

We investigated mechanisms resulting in low bone mineral density (BMD) and susceptibility to fracture by comparing noncoding RNAs (ncRNAs) in biopsies of non–weight-bearing (NWB) iliac (n = 84) and weight bearing (WB) femoral (n = 18) postmenopausal bone across BMDs varying from normal (T-score > −1.0) to osteoporotic (T-score ≤ −2.5). Global bone ncRNA concentrations were determined by PCR and microchip analyses. Association with BMD or fracture, adjusted by age and body mass index, were calculated using linear and logistic regression and least absolute shrinkage and selection operator (Lasso) analysis. At 10% false discovery rate (FDR), 75 iliac bone ncRNAs and 94 femoral bone ncRNAs were associated with total hip BMD. Eight of the ncRNAs were common for the two sites, but five of them (miR-484, miR-328-3p, miR-27a-5p, miR-28-3p, and miR-409-3p) correlated positively to BMD in femoral bone, but negatively in iliac bone. Of predicted pathways recognized in bone metabolism, ECM-receptor interaction and prote