A method for improving global pyranometer measurements by modeling responsivity functions

Accurate global solar radiation measurements are crucial to climate change research and the development of solar energy technologies. Pyranometers produce an electrical signal proportional to global irradiance. The signal-to-irradiance ratio is the responsivity (RS) of the instrument (RS = signal/irradiance = microvolts/(W/m²)). Most engineering measurements are made using a constant RS. It is known that RS varies with day of year, zenith angle, and net infrared radiation. This study proposes a method to find an RS function to model a pyranometer’s changing RS. Using a reference irradiance calculated from direct and diffuse instruments, we found instantaneous RS for two global pyranometers over 31 sunny days in a two-year period. We performed successive independent regressions of the error between the constant and instantaneous RS with respect to zenith angle, day of year, and net infrared to obtain an RS function. An alternative method replaced the infrared regression with an independently developed technique to account for thermal offset. Results show improved uncertainties with the function method than with the single-calibration value. Lower uncertainties also occur using a black-and-white (8-48), rather than all-black (PSP), shaded pyranometer as the diffuse reference instrument. We conclude that the function method is extremely effective in reducing uncertainty in the irradiance measurements for global PSP pyranometers if they are calibrated at the deployment site. Furthermore, it was found that the function method accounts for the pyranometer’s thermal offset, rendering further corrections unnecessary. The improvements in irradiance data achieved in this study will serve to increase the accuracy of solar energy assessments and atmospheric research.     

X-ray diffraction from intact tau aggregates in human brain tissue

We describe an instrument to record x-ray diffraction patterns from diseased regions of human brain tissue by combining an in-line visible light fluorescence microscope with an x-ray diffraction microprobe. We use thiazine red fluorescence to specifically label and detect the filamentous tau protein pathology associated with Pick's disease, as several labs have done previously. We demonstrate that thiazine red-enhanced regions within the tissue show periodic structure in x-ray diffraction that is not observed in healthy tissue. One observed periodicity (4.2 ?) is characteristic of cross-beta sheet structure, consistent with previous results from powder diffraction studies performed on purified, dried tau protein.     

Single-channel currents produced by the serotonin transporter and analysis of a mutation affecting ion permeation

Single-channel activities were observed in outside-out patches excised from oocytes expressing a mammalian 5-hydroxytryptamine (5-HT) transporter. Channel conductance was larger for a mutant in which asparagine177 of the third putative transmembrane domain was replaced by glycine, suggesting that this residue lies within or near the permeation pathway. The N177G mutant enables quantitative single-channel measurements; it displays two conducting states. One state, with conductance of approximately 6 pS, is induced by 5-HT and is permeable to Na+. The other state (conductance of approximately 13 pS) is associated with substrate-independent leakage current and is permeable to both Na+ and Li+. Cl- is not a major current carrier. Channel lifetimes under all conditions measured are approximately 2.5 ms. The single-channel phenomena account for previously observed macroscopic electrophysiological phenomena, including 5-HT-induced transport-associated currents and substrate-independent leakage currents. The channel openings occur several orders of magnitude less frequently than would be expected if one such opening occurred for each transport cycle and therefore do not represent an obligatory step in transport. Nevertheless, single-channel events produced by neurotransmitter transporters indicate the functional and structural similarities between transporters and ion channels and provide a new tool, at single-molecule resolution, for detailed structure-function studies of transporters.     

TFF1 gene expression in human medullary thyroid carcinoma

This epidemiological study investigated the reasons why children in Northern Ireland who need orthodontic treatment do not receive treatment even when it is provided free by the state. A total of 1584 15- and 16-year-olds were examined in 23 high schools with the Index of Orthodontic Treatment Need. The characteristics of the adolescents who had received orthodontic treatment were compared with those who had a definite need for treatment and yet did not receive treatment or advice. One in 10 of the adolescents examined had an unmet need for orthodontic treatment. Logistic regression analysis was used to assess the influence of 11 variables including socioeconomic status, religion, and standard of dental health on the uptake of orthodontic care. This analysis revealed that the only significant predictors of whether an adolescent received orthodontic treatment was the dental attendance pattern of the adolescent, the adolescent's dental health, and the dental attendance pattern of the adolescent's mother. Those adolescents who had good dental health, who regularly attended a dentist, and whose mother regularly attended a dentist were more likely to receive orthodontic treatment.     

The association of shame and guilt with suicidality

1,25-dihydroxyvitamin D3 (VD) is a modulator of growth and differentiation of many cell types, including keratinocytes. We have recently shown in cultured keratinocytes that VD induces tyrosine phosphorylation of proteins involved in signal transduction, such as Shc. In an attempt to identify VD-responsive tyrosine kinases, we studied the effects of VD on the activity of the nonreceptor tyrosine kinase Src. Although VD did not stimulate Src activity in keratinocytes cultured in standard media containing 0.15 mM calcium, preincubation of the cells with 1.8 mM Ca2+ caused a rapid activation of Src in response to VD (10(-8)-10(-7) M). Elevation of calcium concentration alone caused an increase in Src activity as well, but the peak of Src activity was delayed (60 min vs. 15 min) and approximately 2-fold lower in comparison with VD-treated cells. VD treatment also induced tyrosine dephosphorylation of Src and a formation of an Src-Shc-Grb2 complex. Taken together, these findings imply that Src is involved in VD signaling in keratinocytes.     

Nonsyndromal craniosynostosis: longitudinal outcome following cranio-orbital reconstruction in infancy

This paper presents a prospective longitudinal outcome study on patients with nonsyndromal craniosynostosis who were treated with the contemporary craniofacial surgical techniques of suture release, cranial decompression, and cranial and orbital reconstruction and reshaping in infancy. Diagnosis, surgical treatment, and long-term results and complications are reviewed. Preoperative and long-term postoperative intracranial volumes in these patients were evaluated and compared with age and gender match controls throughout the period of the study. From July 1, 1990, to July 1, 1994, 25 patients with isolated nonsyndromal craniosynostosis underwent surgery of the deformity. Eight patients were excluded from the study based on incomplete postoperative computed tomography (CT) records. Of the 17 patients with long-term computerized records, 11 were boys and 6 were girls. The nonsyndromal craniosynostosis patients in this study include six with bilateral coronal craniosynostosis, six with unilateral coronal craniosynostosis, four with sagittal craniosynostosis, and one with metopic craniosynostosis. The average age at the time of surgery for all patients was 9 months, and the average age at the time of the latest follow-up CT scan for all patients in the study was 3.5 years. There were no perioperative complications in this series of patients including no bleeding, no infection, no wound healing complications, and no mortality. Bony fixation included a combination of wire osteosynthesis and rigid microfixation. All patients had only one surgical procedure for the correction of their deformity. Evaluation of both preoperative and long-term postoperative intracranial volume measurements in this series of patients revealed that these volume measurements were comparable with the gender match control groups at all ages throughout the study. The significance of these findings for this longitudinal outcome study is discussed.     

Significance of epidermoid formations in the middle ear in fetuses and children

OBJECTIVE: To determine the incidence, size, and location of epidermoid formations (EFs), which have been suggested to be precursors of congenital cholesteatomas, in temporal bones from fetuses and children. DESIGN: We examined temporal bones from 226 fetuses and children up to the age of 10 years for the incidence, size, and location of EFs. RESULTS: Twenty-five EFs were identified in middle ears of 3 fetuses, 7 neonates, 9 infants, and 2 children aged 2 and 3 years. There was a male-female preponderance of 5:4. Generally, we saw EFs between the anterosuperior edge of the eardrum and the anterior limb of the tympanic ring, but 4 were below the level of the handle of the malleus. Their widths ranged from 25 to 300 microns. Keratinization was not observed in any EF. Contrary to previous reports, we found EFs not only in ears of fetuses, but also in ears of infants and children. CONCLUSION: Although EFs may persist in some ears, possibly developing into congenital cholesteatomas, our findings do not provide direct support for this concept.