Photochromism in single nitrogen-vacancy defect in diamond

Photochromism in single nitrogen-vacancy optical centers in diamond is demonstrated. Time-resolved optical spectroscopy shows that intense irradiation at 514 nm switches the nitrogen-vacancy defects to the negative form. This defect state relaxes back to the neutral form under dark conditions. Temporal anticorrelation of photons emitted by the different charge states of the optical center unambiguously indicates that the nitrogen-vacancy defect accounts for both 575 nm and 638 nm emission bands. Possible mechanism of photochromism involving nitrogen donors is discussed.Comment: 11 pages, 3 figures, submitted to Applied Physics B: Lasers and Optic

Cerebellar Asymmetry and Cortical Connectivity in Monozygotic Twins with Discordant Handedness

Handedness differentiates patterns of neural asymmetry and interhemispheric connectivity in cortical systems that underpin manual and language functions. Contemporary models of cerebellar function incorporate complex motor behaviour and higher-order cognition, expanding upon earlier, traditional associations between the cerebellum and motor control. Structural MRI defined cerebellar volume asymmetries and correlations with corpus callosum (CC) size were compared in 19 pairs of adult female monozygotic twins strongly discordant for handedness (MZHd). Volume and asymmetry of cerebellar lobules were obtained using automated parcellation.CC area and regional widths were obtained from midsagittal planimetric measurements. Within the cerebellum and CC, neurofunctional distinctions were drawn between motor and higher-order cognitive systems. Relationships amongst regional cerebellar asymmetry and cortical connectivity (as indicated by CC widths) were investigated. Interactions between hemisphere and handedness in the anterior cerebellum were due to a larger right-greater-than-left hemispheric asymmetry in right-handed (RH) compared to left-handed (LH) twins. In LH twins only, anterior cerebellar lobule volumes (IV, V) for motor control were associated with CC size, particularly in callosal regions associated with motor cortex connectivity. Superior posterior cerebellar lobule volumes (VI, Crus I, Crus II, VIIb) showed no correlation with CC size in either handedness group. These novel results reflected distinct patterns of cerebellar-cortical relationships delineated by specific CC regions and an anterior-posterior cerebellar topographical mapping. Hence, anterior cerebellar asymmetry may contribute to the greater degree of bilateral cortical organisation of frontal motor function in LH individuals

Association of TNF

Cervical cancer (CCa) is one of the most common malign diseases in women associ-ated with human papillomavirus (HPV). The virus is an initiating factor, but not suf-ficient for the development of cervical intraepithelial lesions (CIN) and CCa. The disease might be a result of the influence of host's genetic factors and polymor-phisms in inflammatory-related genes that modify the immune response to HPV and attribute to cancer susceptibility. We carried out a study to determine the associa-tion between TNF-a-238G/A and TNF-a-308 G/T polymorphisms with HPV-positive CIN and CCa in women living in the Republic of North Macedonia. Using multiplex SNaPshot analysis for single nucleotide polymorphisms (SNPs), we analysed the gen-otype and allele distributions of TNF-a-238G/A and TNF-a-308 G/T in 134 cases (HPV-positive and histologically confirmed CIN and CCa) and in 113 controls (cyto-logical and HPV-negative women). For further analysis, the case group was stratified in three subgroups (all cases: CINs+ CCa− group; CIN2+ -group and CIN1− group). Data analysed using the odds ratio (OR) and chi-square test showed the frequency of AA genotypes and A alleles are not significantly higher in cases compared to the controls for both SNPs: AA of TNF-a-238 (0.7% versus 0%) and TNF-a-308 (1.5% versus 0.9%) as well as A allelic frequency (3.0% versus 1.7%) and (13.1% versus 10.6), respectively. The comparison of the case's subgroups with the control group did not show a statistically significant difference. Compared to controls, TNF-a-238G/A and TNF-a-308 G/T are not associated with the risk of HPV associated CIN or CCa in the studied women

Risk Factor Frequency for Learning Disabilities in Low Socioeconomic Level Preschool Children in Mexico City Frecuencia de factores de riesgo para problemas de aprendizaje en preescolares de bajo nivel socioeconómico en la Ciudad de México Frequência de fatores de risco para dificuldade de aprendizagem em pré-escolares com baixo nível socioeconômico, na Cidade do México

The objective was to identify the frequency of risk factors for Learning Disabilities (LD) in low socioeconomic level children in Mexico City. We studied children by means of: Wechsler, Bender-Gestalt, and Human drawing tests. Average age of male subjects was 5.6±0.9 years, while that of the female group was 5.4±0.5 years. In male subjects, average Total intelligence quotient (T-IQ) score was 98±12.2 while, in the female group, this was 99±12.2. On the Bender-Gestalt test, male subjects had a mental and visual-motor average age of <1 year under chronological age. Female subjects had a mental and visual-motor age 8-7 months under the norm. On the Human drawing test, in male and female subjects, the most frequent at-risk features comprised: self-isolation in 25% of subjects, shyness in 22.4%, and poor internal controls in 22%. In conclusion, we found a high at-risk factor frequency for LD in children of low socioeconomic strata. We highlight the importance of screening children before they attain school age.<br>Nuestro objetivo fue identificar la frecuencia de factores de riesgo para problemas de aprendizaje (PA) en niños de bajo nivel socioeconómico de la Ciudad de México. Se utilizaron las pruebas de inteligencia de Wechsler, Gestáltica Visuomotora de Bender y del Dibujo de la figura humana. La edad promedio en el grupo masculino fue 5,6±0,9 años, del femenino fue 5,4±0,5. En los hombres, el cociente intelectual total (CI-T) fue 98±12,2, en mujeres fue 99±12,2. En la prueba de Bender, los hombres mostraron una edad mental y visuomotora un año menor que la cronológica, las mujeres tuvieron una edad mental y visuomotora 7-8 meses por debajo de la norma. En la Prueba de la figura humana, los hombres y mujeres mostraron mayor frecuencia de: auto-aislamiento 25%, timidez 22,4% y controles internos pobres 22%. En conclusión encontramos una alta frecuencia de factores de riesgo en preescolares de bajo nivel socioeconómico, destacamos la importancia de identificar a los preescolares propensos a tener problemas de aprendizaje (PA).<br>Este estudo objetivou identificar a frequência de fatores de risco para dificuldade de aprendizagem (DA) em crianças com baixo nível socioeconômico, na Cidade do México. A escala de inteligência Wechsler, desenho da figura humana e o teste gestáltico visomotor de Bender foram utilizados. A idade média do grupo masculino foi de 5,6±0,9 anos e do grupo feminino 5,4±0,5 anos. O quociente intelectual total (QI-T) foi de 98±12 no grupo masculino e 99±12,2 no grupo feminino. No teste de Bender, os meninos apresentaram idade mental e visomotora um ano abaixo da idade cronológica, enquanto que as meninas apresentaram idade mental e visomotora 7-8 meses abaixo do normal. As características de alto risco que apresentaram maior frequência, tanto nos meninos como nas meninas, no teste do desenho de figura humana, foram: autoisolamento 25%, timidez 22,4 e controle interno deficiente 22%. Concluindo, alta frequência de fatores de risco para DA foi encontrada em crianças de baixo nível socioeconômico. É importante destacar a importância de se identificar pré-escolares em risco de DA