Interpretation of very low resolution X-ray electron-density maps using core objects

The interpretation of a 20 Å resolution electron-density map using segmentation and pattern-recognition-based identification of domain shapes is described

Biogenesis of spiroketals by submerged cultured basidiomycete Trametes hirsuta

Volatile spiroketals are well-documented semiochemicals secreted by beetles and wasps for the intra- and interspecies communication. Its use in insect traps and as natural herbicide makes them of commercial interest. Besides insects, fungi are well-known producers, but the fungal biogenesis of spiroketals has remained speculative. Product formation along fatty acid degradation based on non-labeled feeding experiments was assumed. Thus, the observed occurrence of conophthorin and (E)- and (Z)-chalcograns in submerged cultures of the basidiomycete Trametes hirsuta prompted a precursor study aiming at a more detailed insight into their formation. Supplementation of (9Z,12 Z)-octadecadienoic (linoleic) acid resulted in elevated product yields and the identification of a fourth spiroketal, 2,8-dimethyl-1,7-dioxaspiro[5.5]-undecane. However, no intermediates of fatty acid degradation suitable as spiroketal precursors were identified. In addition, the hyphae lacked lipoxygenase activity, which was formerly supposed to be mandatory for spiroketal formation. Supplementation of 1-/2-13C acetate showed incorporation of the label into chalcogran. Therefore, a formation along the polyketide pathway analogous to insects was concluded. Graphical abstract: [Figure not available: see fulltext.

Avoided Antiferromagnetic Order and Quantum Critical Point in CeCoIn5_5

We measured specific heat and resistivity of heavy fermion CeCoIn5 between the superconducting critical field $H_{c2} = 5 T$ and 9 T, with field in the [001] direction, and at temperatures down to 50mK. At 5T the data show Non Fermi Liquid behavior down to the lowest temperatures. At field above 8T the data exhibit crossover from the Fermi liquid to a Non Fermi Liquid behavior. We analyzed the scaling properties of the specific heat, and compared both resistivity and the specific heat with the predictions of a spin-fluctuation theory. Our analysis leads us to suggest that the NFL behavior is due to incipient antiferromagnetism (AF) in CeCoIn5, with the quantum critical point in the vicinity of the $H_{c2}$. Below $H_{c2}$ the AF phase which competes with the paramagnetic ground state is superseded by the superconducting transition.Comment: 5 pages, 3 figure

Magnetic-Field Induced Quantum Critical Point in YbRh2_2Si2_2

We report low-temperature calorimetric, magnetic and resistivity measurements on the antiferromagnetic (AF) heavy-fermion metal YbRh$_2$Si$_2$ (${T_N =}$ 70 mK) as a function of magnetic field $B$. While for fields exceeding the critical value ${B_{c0}}$ at which ${T_N\to0}$ the low temperature resistivity shows an ${AT^2}$ dependence, a ${1/(B-B_{c0})}$ divergence of ${A(B)}$ upon reducing $B$ to ${B_{c0}}$ suggests singular scattering at the whole Fermi surface and a divergence of the heavy quasiparticle mass. The observations are interpreted in terms of a new type of quantum critical point separating a weakly AF ordered from a weakly polarized heavy Landau-Fermi liquid state.Comment: accepted for publication in Phys. Rev. Let

Sinistral shear during Middle Jurassic emplacement of the Matancilla Plutonic Complex in northern Chile (25.4◦ S) as evidence of oblique plate convergence during the early Andean orogeny

component of oblique subduction into an intra-arc shear zone. We document a shear zone at latitude 25.4◦ S near Taltal, Chile that was associated with intrusion of the Matancilla Plutonic Complex at ~169 Ma to evaluate intra-arc deformation and possible tectonic plate configurations during this time period. Polyphase folding of Paleozoic metasedimentary rocks is overprinted by mylonitic fabrics that are most extensive in a zone up to 1.4 km wide in the thermal aureole of the granodioritic Matancilla pluton, where contact metamorphic andalusite porphyroblasts are synkinematic with fabric development. Mylonite in metasedimentary rocks is overprinted by a ~130 Ma granodiorite (zircon U–Pb) and by ~133 Ma postkinematic monazite (U–Pb). Within the Jurassic Matancilla granodiorite, pervasive ductile shear occurs along the intrusive contact while centimeter-scale discrete high-strain zones throughout the pluton are associated with focused hydrothermal alteration and reaction weakening. Mylonitic foliation in the metasedimentary rocks and within the pluton strikes N- to NE and dips steeply, while stretching lineations are subhorizontal on average. Kinematic indicators record dominantly sinistral shear, though some dextral or symmetric indicators and S \u3e L fabrics suggest a component of coaxial strain and flattening. Sinistral strike-slip kinematics in the Matancilla shear zone may indicate that Middle Jurassic convergence had sinistral obliquity that was locally partitioned into the contemporaneous magmatic arc. Sinistral-oblique convergence would require the Phoenix- Farallon spreading center to be north of ~25◦ S in the Middle Jurassic, providing a constraint to plate reconstructions during the early Andean orogeny

READING and FEELING: the effects of a literature-based intervention designed to increase emotional competence in second and third graders

Emotional competence has an important influence on development in school. We hypothesized that reading and discussing children’s books with emotional content increases children’s emotional competence. To examine this assumption, we developed a literature- based intervention, named READING and FEELING, and tested it on 104 second and third graders in their after-school care center. Children who attended the same care center but did not participate in the emotion-centered literary program formed the control group (n = 104). Our goal was to promote emotional competence and to evaluate the effectiveness of the READING and FEELING program. Emotional competence variables were measured prior to the intervention and 9 weeks later, at the end of the program. Results revealed significant improvements in the emotional vocabulary, explicit emotional knowledge, and recognition of masked feelings. Regarding the treatment effect for detecting masked feelings, we found that boys benefited significantly more than girls. These findings underscore the assumption that children’s literature is an appropriate vehicle to support the development of emotional competence in middle childhood

Tectono-metallogenetic evolution of the Fe–Cu deposit of Dominga, northern Chile

The Dominga district in northern Chile (2082 Mt at 23.3 % Fe, 0.07 % Cu) shows a spatial and genetic affinity among distinctive structural elements and Fe–Cu-rich paragenetic mineral assemblages. Deep seated, NE-to-E striking structural elements form a right-lateral duplex-like structural system (early structural system, ESS) that cuts a regionally extensive alteration (stage I) zone. The EES system served as a locus and as path for the emplacement of biotite–magnetite alteration/mineralization (stage IIa) as veins and Fe-bearing layers following altered volcano sedimentary strata. NW-striking actinolite–magnetite hydrothermal breccias, coeval with and part of the ESS, include apatite (stage IIb) crystallized at 127 ± 15 Ma (U–Pb, 2σ). The ESS was also the locus of subsequent alteration/mineralization represented by K-feldspar, epidote, and albite (stage IIIa) and Fe–Cu-rich (vermiculite–anhydrite–chalcopyrite, stage IIIb) mineral associations. Shallowly developed, NNE-striking, left-lateral structural elements defining the El Tofo Structural System (ETSS)—probably part of the Atacama Fault System—clearly crosscut the ESS. Minerals associated with alteration/mineralization stage IIIb also occur as veins and as part of hydrothermal breccias of the ETSS, marking the transition from the ESS to ETSS. Molybdenite associated with alteration/mineralization stage IIIb yielded a Re–Os age of 127.1 ± 0.7 Ma (2σ). Both the ESS and ETSS were cut by left-lateral, NW- to E-striking shallowly developed structural elements (Intermediate Structural System, ISS) on which a hematite–calcite assemblage (stage IV) occurs mostly as infill material of veins and fault veins. The ISS is cut by N-striking, left-lateral, and shallowly developed structural elements (Late Structural System, LSS) showing no evidence of alteration/mineralization. Estimated strain and stress fields indicate an overall NW-trending shortening/compression and NE-trending stretching/tension strike-slip regime probably due to oblique subduction during the Mesozoic. However, the orientations of the stress and strain fields calculated for each structural system suggest a back-and-forth rotation pattern during transition from one structural system to the other—as they change between transtension and transpression—and between alteration/mineralization stages