Exchange Anisotropy in Epitaxial and Polycrystalline NiO/NiFe Bilayers

(001) oriented NiO/NiFe bilayers were grown on single crystal MgO (001) substrates by ion beam sputtering in order to determine the effect that the crystalline orientation of the NiO antiferromagnetic layer has on the magnetization curve of the NiFe ferromagnetic layer. Simple models predict no exchange anisotropy for the (001)-oriented surface, which in its bulk termination is magnetically compensated. Nonetheless exchange anisotropy is present in the epitaxial films, although it is approximately half as large as in polycrystalline films that were grown simultaneously. Experiments show that differences in exchange field and coercivity between polycrystalline and epitaxial NiFe/NiO bilayers couples arise due to variations in induced surface anisotropy and not from differences in the degree of compensation of the terminating NiO plane. Implications of these observations for models of induced exchange anisotropy in NiO/NiFe bilayer couples will be discussed.Comment: 23 pages in RevTex format, submitted to Phys Rev B

Abnormal amygdala activation profile in pedophilia

Despite considerable public interest research in neurobiological correlates of pedophilia is scarce. Since amygdala activation is central for emotional valuation, arousal, and salience, we investigated the activation profile of this structure in 10 male subjects with pedophilia (exclusively attracted to boys), all convicted sex-offenders and sentenced to forensic psychiatric treatment along with ten male heterosexual matched controls. We used a sexually non-explicit functional Magnetic Resonance Imaging (fMRI) paradigm with images of men, women, boys or girls randomly embedded in neutral target/non-target geometrical symbols. We applied statistical parametric mapping (SPM2) and SPSS 14 for image processing and analysis. While controls activated significantly less to pictures of children compared to adults, the activation profile was reversed in subjects with pedophilia, who exhibited significantly more activation to children than adults. The highest activation was observed for boys in the patient group, and for women in control participants. Our data show enhanced activation to children's pictures even in an incidental context and suggest the provocative hypothesis that a normally present mechanism for reduced emotional arousal for children relative to adults is reversed in pedophilia, suggesting a neural substrate associated with deviant sexual preference in this condition. More extensive research in this field would be of benefit for both the victims and the offenders

La Campana de Gracia: Any L Batallada 2601 - 1919 febrero 15

Some pathological manifestations of diabetes in the eye include retinopathy, cataracts and elevated intraocular pressure (IOP). Loss of retinal ganglion cells (RGCs) in non-proliferative stages of diabetic retinopathy and small increases in IOP in diabetic patients has raised the possibility that diabetes affects the development and progression of ocular hypertension and glaucoma. The Ins2Akita mutation is known to cause diabetes and retinopathy on a C57BL/6J (B6) background by as early as 3 months of age. Here, the impact of the Akita mutation on glaucoma was assessed using DBA/2J (D2) mice, a widely used mouse model of ocular hypertension induced glaucoma. In D2.Ins2Akita/+ mice, the contribution of diabetes to vascular permeability, IOP elevation, RGC loss, and glaucoma development was assessed. D2.Ins2Akita/+ mice developed a severe diabetic nephropathy and early mortality between 6-8 months of age. This agrees with previous reports showing that the D2 background is more susceptible to diabetes than the B6 background. In addition, D2.Ins2Akita/+ mice had vascular leakage, astrocyte reactivity and a significant increase in IOP. However no RGC loss and no anterograde axonal transport dysfunction were found at 8.5 months of age. Therefore, our data show that despite severe diabetes and an increased IOP compared to controls, RGCs do not lose axon transport or degenerate. This may be due to a DBA/2J-specific genetic modifier(s) that could provide novel and important avenues for developing new therapies for diabetic retinopathy and possibly glaucoma

The Akita mutation increased IOP in DBA/2J mice.

<p>To determine if the Akita mutation caused an increase in IOP in DBA/2J mice, IOP were recorded from D2.<i>Ins2^+/+</i> and D2.<i>Ins2^Akita/+</i> mice at 6 and 8.5 months old. No significant differences in IOP measurements were found between diabetic D2.<i>Ins2^Akita/+</i> and D2.<i>Ins2^+/+</i> at 6 months of age (n = 20 eyes for each genotype; <i>p</i> = 0.106). However by 8.5 months diabetic D2.<i>Ins2^Akita/+</i> showed significant higher IOP levels when compared with wild type D2.<i>Ins2^+/+</i> (n = 38 eyes for each genotype; <i>p</i><0.001).</p