Vitamin D concentration and psychotic disorder:associations with disease status, clinical variables and urbanicity

Background The association between schizophrenia and decreased vitamin D levels is well documented. Low maternal and postnatal vitamin D levels suggest a possible etiological mechanism. Alternatively, vitamin D deficiency in patients with schizophrenia is presumably (also) the result of disease-related factors or demographic risk factors such as urbanicity. Methods In a study population of 347 patients with psychotic disorder and 282 controls, group differences in vitamin D concentration were examined. Within the patient group, associations between vitamin D, symptom levels and clinical variables were analyzed. Group x urbanicity interactions in the model of vitamin D concentration were examined. Both current urbanicity and urbanicity at birth were assessed. Results Vitamin D concentrations were significantly lower in patients (B= -8.05; 95% confidence interval (CI) -13.68 to -2.42;p= 0.005). In patients, higher vitamin D concentration was associated with lower positive (B= -0.02; 95% CI -0.04 to 0.00;p= 0.049) and negative symptom levels (B= -0.03; 95% CI -0.05 to -0.01;p= 0.008). Group differences were moderated by urbanicity at birth (chi(2)= 6.76 andp= 0.001), but not by current urbanicity (chi(2)= 1.50 andp= 0.224). Urbanicity at birth was negatively associated with vitamin D concentration in patients (B= -5.11; 95% CI -9.41 to -0.81;p= 0.020), but not in controls (B= 0.72; 95% CI -4.02 to 5.46;p= 0.765). Conclusions Lower vitamin D levels in patients with psychotic disorder may in part reflect the effect of psychosis risk mediated by early environmental adversity. The data also suggest that lower vitamin D and psychopathology may be related through direct or indirect mechanisms.</p

Spatial resolution and refractive index contrast of resonant photonic crystal surfaces for biosensing

By depositing a resolution test pattern on top of a Si3N4 photonic crystal resonant surface, we have measured the dependence of spatial resolution on refractive index contrast \Delta n. Our experimental results and finite-difference time-domain (FDTD) simulations at different refractive index contrasts show that the spatial resolution of our device reduces with reduced contrast, which is an important consideration in biosensing, where the contrast may be of order 10{-2} . We also compare 1-D and 2-D gratings, taking into account different incidence polarizations, leading to a better understanding of the excitation and propagation of the resonant modes in these structures, as well as how this contributes to the spatial resolution. At \Delta n = 0.077, we observe resolutions of 2 and 6 \mu\hbox{m} parallel to and perpendicular to the grooves of a 1-D grating, respectively, and show that for polarized illumination of a 2-D grating, resolution remains asymmetrical. Illumination of a 2-D grating at 45 ^{\circ} results in symmetric resolution. At very low index contrast, the resolution worsens dramatically, particularly for \Delta n\ <\ 0.01, where we observe a resolution exceeding 10 \mu\hbox{m} for our device. In addition, we measure a reduction in the resonance linewidth as the index contrast becomes lower, corresponding to a longer resonant mode propagation length in the structure and contributing to the change in spatial resolution

An Organic Vortex Laser

Optical vortex beams are at the heart of a number of novel research directions, both as carriers of information and for the investigation of optical activity and chiral molecules. Optical vortex beams are beams of light with a helical wavefront and associated orbital angular momentum. They are typically generated using bulk optics methods or by a passive element such as a forked grating or a metasurface to imprint the required phase distribution onto an incident beam. Since many applications benefit from further miniaturization, a more integrated yet scalable method is highly desirable. Here, we demonstrate the generation of an azimuthally polarized vortex beam directly by an organic semiconductor laser that meets these requirements. The organic vortex laser uses a spiral grating as a feedback element that gives control over phase, handedness, and degree of helicity of the emitted beam. We demonstrate vortex beams up to an azimuthal index <i>l</i> = 3 that can be readily multiplexed into an array configuration

Challenging point scanning across electron microscopy and optical imaging using computational imaging

Solving challenges of enhanced imaging (resolution or speed) is a continuously changing frontier of research. Within this sphere, ghost imaging (and the closely related single-pixel imaging) has evolved as an alternative to focal plane detector arrays owing to advances in detectors and/or modulation devices. The interest in these techniques is due to their robustness to varied sets of patterns and applicability to a broad range of wavelengths and compatibility with compressive sensing. To achieve a better control of illumination strategies, modulators of many kinds have long been available in the optical regime. However, analogous technology to control of phase and amplitude of electron beams does not exist. We approach this electron microscopy challenge from an optics perspective, with a novel approach to imaging with non-orthogonal pattern sets using ghost imaging. Assessed first in the optical regime and subsequently in electron microscopy, we present a methodology that is applicable at different spectral regions and robust to non-orthogonality. The distributed illumination pattern sets also result in a reduced peak intensity, thereby potentially reducing damage of samples during imaging. This imaging approach is potentially translatable beyond both regimes explored here, as a single-element detector system

Dietary intake in asylum seeker children in The Netherlands, strongly related to age and origin

Objective: To monitor the dietary intake of energy, macro- and micronutrients in asylum seeker children. Design and setting: Cross-sectional study in three asylum seeker centres in The Netherlands. Subjects: Hundred and sixteen children 2-12 years old (86% of the study cohort) provided a dietary history. Method: The dietary intake was estimated by 24 h recall, and the origin of the children was classified in three geographic regions: African (n = 45), Central Asia (n = 34) or Eastern Europe (n = 37). Results: The total energy intake from fat was in 24% of the children above 40En%. Seventy per cent of the children above 4 year of age had a saturated fat intake above 10En%. The children from Eastern Europe had a higher intake of fat and disaccharides than the children from the other regions. Among the children, an intake less than 80% of the recommended daily allowances of micronutrients was found for calcium (42%), iron (49%), vitamin A (45%) and vitamin D (80%). An inadequate dietary intake of iron and vitamin D was significantly more seen among the youngest children, whereas an inadequate intake of calcium and vitamin A was found more among the elder children. Conclusions: The dietary intake of a prominent proportion of these children contains too much fat and insufficient amounts of calcium, iron, vitamin A and vitamin D. The low micronutrient intake of the asylum seeker children can be considered as a nutritional risk. Nutritional education and strategies to improve the macro- and micronutrient intake of asylum seeker children is indicated

Vitamin D levels in children of asylum seekers in The Netherlands in relation to season and dietary intake

Low dietary intake and limited sun exposure during Dutch winters, in particular when combined with highly pigmented skin, could compromise the vitamin D status of asylum seekers' children in The Netherlands. We determined the vitamin D status of children living in The Netherlands, but originating from Africa, Central Asia, or Eastern Europe. In a subgroup, we reassessed the vitamin D status after the summer, during which the children had been assigned at random to remain unsupplemented or to receive vitamin D supplementation. In total 112 children (median age 7.1 yr, range 2-12 yr) were assessed for serum concentrations of 25-Hydroxyvitamin D [25(OH)D], intact parathyroid hormone (I-PTH) and plasma alkaline phosphatase (ALP). Vitamin D deficiency (VDD) and hypovitaminosis D were defined as 25(OH)D below 30 or 50 nmol/L, respectively. Dietary intake of vitamin D and calcium was estimated using a 24 h recall interview. In mid-spring, 13% of the children had VDD, and 42% had hypovitaminos's D. I-PTH and ALP levels were significantly higher in children with VDD. The dietary intake of vitamin D was below 80% of the recommended daily allowances (RDA) in 94% of the children, but the dietary calcium intake was not significantly related to the s-25(OH)D levels found. After the summer, median s-25(OH)D increased with +35 nmol/L (+85%) and +19 nmol/L (+42%) in children with or without supplementation, respectively. The effect of supplementation was most prominent among Aftican children. VDD and hypovitaminosis D are highly prevalent in mid-spring among asylum seekers' children in The Netherlands. Although 25(OH)D levels increase in African children during Dutch summer months, this does not completely correct the compromised vitamin D status. Our data indicate that children from African origin would benefit from vitamin D supplementation

Iron deficiency among children of asylum seekers in the Netherlands

Objectives: To investigate, in asylum seekers' children in the Netherlands, biochemical iron status and the prevalence of iron deficiency (ID) and anemia in relation to age, region of origin, length of stay in the Netherlands, body mass index (BMI), and dietary iron intake. Patients and Methods: Hemoglobin (Hb) and plasma ferritin concentrations were determined in 122 asylum seekers' children (median age, 7.1 years; range, 2-12 y). ID was defined by plasma ferritin levels Results: Twenty percent of the children had compromised iron status (16% with ID, 4% with ID anemia [IDA]). Another 6% of the children had anemia caused by thalassemia. ID was significantly more prevalent in children Conclusions;: Iron deficiency is highly prevalent among the children of asylum seekers in the Netherlands. Our data indicate that systematic biochemical screening for ID is warranted in asylum seekers' children