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Butterflies of the family Pieridae are brightly colored, ranging from white to red, caused by various pterin pigments concentrated in scattering spheroidal beads in the wing scales. Given the sparsity of the beads in the wing scales, the high brightness suggests a scattering strength of the beads that significantly surpasses that of typical cuticular chitin beads with the areal density found in the wing scales. To elucidate this apparent contradiction, the optical signature of the pierids' highly saturated pigmentary colors are analyzed by using Jamin-Lebedeff interference microscopy combined with Kramers-Kronig theory and light scattering modeling. This study shows that extreme pterin pigment concentrations cause a very high refractive index of the beads with values above 2 across the visible wavelength range, thus creating one of the most highly light scattering media thus far discovered in the animal kingdom.

The blue secondary and purple-to-green tail feathers of magpies are structurally coloured due to stacks of hollow, air-containing melanosomes embedded in the keratin matrix of the barbules. We investigated the feathers’ spectral and spatial reflection characteristics by applying (micro)spectrophotometry and imaging scatterometry. To interpret the spectral data, we performed optical modelling, applying the Finite-Difference Time-Domain (FDTD) method as well as an effective media approach, treating the melanosome stacks as multilayers with effective refractive indices dependent on the component media. The differently coloured magpie feathers are realised by adjusting the melanosome size, with the diameter of the melanosomes as well as their hollowness being the most sensitive parameters that influence the appearance of the feathers.

The color of natural objects depends on how they are structured and pigmented. In flowers, both the surface structure of the petals and the pigments they contain determine coloration. The aim of the present study was to assess the contribution of structural coloration, including iridescence, to overall floral coloration. We studied the reflection characteristics of flower petals of various plant species with an imaging scatterometer, which allows direct visualization of the angle dependence of the reflected light in the hemisphere above the petal. To separate the light reflected by the flower surface from the light backscattered by the components inside (e.g. the vacuoles), we also investigated surface casts. A survey among angiosperms revealed three different types of floral surface structure, each with distinct reflections. Petals with a smooth and very flat surface had mirror-like reflections and petal surfaces with cones yielded diffuse reflections. Petals with striations yielded diffraction patterns when single cells were illuminated. The iridescent signal, however, vanished when illumination similar to that found in natural conditions was applied. Pigmentary rather than structural coloration determines the optical appearance of flowers. Therefore, the hypothesized signaling by flowers with striated surfaces to attract potential pollinators presently seems untenable.

The colouration of the common butterflies Aglais urticae (Small Tortoiseshell), Aglais io (Peacock) and Vanessa atalanta (Red Admiral), belonging to the butterfly subfamily Nymphalinae, is due to the species-specific patterning of differently coloured scales on their wings. We investigated the scales’ structural and pigmentary properties by applying scanning electron microscopy, (micro)spectrophotometry, and imaging scatterometry. The anatomy of the wing scales appears to be basically identical, with an approximately flat lower lamina connected by trabeculae to a highly structured upper lamina, which consists of an array of longitudinal, parallel ridges and transversal crossribs. Isolated scales observed at the abwing (upper) side are blue, yellow, orange, red, brown, or black, depending on their pigmentation. The yellow, orange and red scales contain various amounts of 3-OH-kynurenine and ommochrome pigment, black scales contain a high density of melanin, and blue scales have a minor amount of melanin pigment. Observing the scales from their adwing (lower) side always revealed a structural colour, which is blue in the case of blue, red and black scales, but orange for orange scales. The structural colours are created by the lower lamina, which acts as an optical thin-film. Its reflectance spectrum, crucially determined by the lamina thickness, appears to be well-tuned to the scales’ pigmentary spectrum. The colours observed locally on the wing are also due to the degree of scale stacking. Thin films, tuned pigments and combinations of stacked scales together determine the wing colouration of nymphaline butterflies.

Using Jamin-Lebedeff interference microscopy, we measured the wavelength dependence of the refractive index of butterfly wing scales and bird feathers. The refractive index values of the glass scales of the butterfly Graphium sarpedon are, at wavelengths 400, 500 and 600 nm, 1.572, 1.552 and 1.541, and those of the feather barbules of the white goose Anas anas domestica are 1.569, 1.556 and 1.548, respectively. The dispersion spectra of the chitin in the butterfly scales and the keratin in the bird barbules are well described by the Cauchy equation n(lambda) = A + B/lambda(2), with A = 1.517 and B = 8.80 . 10(3) nm(2) for the butterfly chitin and A = 1.532 and B = 5.89 . 10(3) nm(2) for the bird keratin. (C) 2011 Optical Society of America

The breast-plate plumage of male Lawes' parotia (Parotia lawesii) produces dramatic colour changes when this bird of paradise displays on its forest-floor lek. We show that this effect is achieved not solely by the iridescence—that is an angular-dependent spectral shift of the reflected light—which is inherent in structural coloration, but is based on a unique anatomical modification of the breast-feather barbule. The barbules have a segmental structure, and in common with many other iridescent feathers, they contain stacked melanin rodlets surrounded by a keratin film. The unique property of the parotia barbules is their boomerang-like cross section. This allows each barbule to work as three coloured mirrors: a yellow-orange reflector in the plane of the feather, and two symmetrically positioned bluish reflectors at respective angles of about 30°. Movement during the parotia's courtship displays thereby achieves much larger and more abrupt colour changes than is possible with ordinary iridescent plumage. To our knowledge, this is the first example of multiple thin film or multi-layer reflectors incorporated in a single structure (engineered or biological). It nicely illustrates how subtle modification of the basic feather structure can achieve novel visual effects. The fact that the parotia's breast feathers seem to be specifically adapted to give much stronger colour changes than normal structural coloration implies that colour change is important in their courtship display.

Background/Purpose: Gastroesophageal reflux is a major cause of complications after esophageal atresia repair. The suitability of the Nissen fundoplication in these patients is still disputed. Therefore, the authors evaluated the results of their prospective treatment protocol in those patients who underwent a Nissen fundoplication. Methods: From 1984 to 1996, 125 patients underwent anastomosis for esophageal atresia. A Nissen fundoplication was later performed in 29 patients. The prospective protocol included x-ray after 10 days, 6 weeks, 12 weeks, 6 months, and 12 months. Forty-eightNhour pH measurements were performed between 6 and 12 weeks. Mean postfundoplication follow-up was at least 5 years (range, 2 to 13 years). Results: Two of the 29 patients died after the Nissen fundoplication from unrelated causes. A third patient was excluded from the study group. Nineteen of the remaining 26 patients showed severe stricture. pH-metry succeeded in 18 patients, showing pathological reflux in 17. In 24 patients the fundoplication was performed between 1 and 24 months (median, 4 months), in the other 2 patients much later. In 4 of the 26 patients (15%) the Nissen proved to be insufficient and had to be redone. The remaining 22 patients had no short-term or long-term complications. Conclusion: The authors' findings in this group of patients, comparing them with the results reported in the literature, indicate that there is no reason to change their prospective treatment protocol nor their policy to perform Nissen fundoplications at an early stage. J Pediatr Surg 35:573-576. Copyright © 2000 by W.B. Saunders Company.

SUMMARY The wings of the swordtail butterfly Graphium sarpedon (the Common Bluebottle) have blue/green-colored patches that are covered on the underside by two types of scales: white and glass scales. Transmission and scanning electron microscopy revealed that the white scales are classically structured: the upper lamina, with prominent ridges and large open windows, is well separated by trabeculae from a flat, continuous lower lamina. In the glass scales, the upper lamina, with inconspicuous ridges and windows, is almost flat and closely apposed to the equally flat lower lamina. The glass scales thus approximate ideal thin films, in agreement with the observation that they reflect light directionally and are iridescent. Reflectance and transmittance spectra measured from the glass scales with a microspectrophotometer agree with spectra calculated for an ideal non-absorbing thin film. Imaging scatterometry of single, isolated glass scales demonstrated that the reflected light can be strongly polarized, indicating that they function as polarizing reflectors.

SUMMARYThe colours of the common kingfisher, Alcedo atthis, reside in the barbs of the three main types of feather: the orange breast feathers, the cyan back feathers and the blue tail feathers. Scanning electron microscopy showed that the orange barbs contain small pigment granules. The cyan and blue barbs contain spongy nanostructures with slightly different dimensions, causing different reflectance spectra. Imaging scatterometry showed that the pigmented barbs create a diffuse orange scattering and the spongy barb structures create iridescence. The extent of the angle-dependent light scattering increases with decreasing wavelength. All barbs have a cortical envelope with a thickness of a few micrometres. The reflectance spectra of the cortex of the barbs show oscillations when measured from small areas, but when measured from larger areas the spectra become wavelength independent. This can be directly understood with thin film modelling, assuming a somewhat variable cortex thickness. The cortex reflectance appears to be small but not negligible with respect to the pigmentary and structural barb reflectance.

The elytra of the Japanese jewel beetleChrysochroa fulgidissimaare metallic green with purple stripes. Scanning electron microscopy and atomic force microscopy demonstrated that the elytral surface is approximately flat. The accordingly specular green and purple areas have, with normal illumination, 100–150 nm broad reflectance bands, peaking at about 530 and 700 nm. The bands shift progressively towards shorter wavelengths with increasing oblique illumination, and the reflection then becomes highly polarized. Transmission electron microscopy revealed that the epicuticle of the green and purple areas consists of stacks of 16 and 12 layers, respectively. Assuming gradient refractive index values of the layers between 1.6 and 1.7 and applying the classical multilayer theory allowed modelling of the measured polarization- and angle-dependent reflectance spectra. The extreme polarized iridescence exhibited by the elytra of the jewel beetle may have a function in intraspecific recognition.

SUMMARY The wings of the swordtail butterfly Graphium sarpedon nipponum contain the bile pigment sarpedobilin, which causes blue/green colored wing patches. Locally the bile pigment is combined with the strongly blue-absorbing carotenoid lutein, resulting in green wing patches and thus improving camouflage. In the dorsal forewings, the colored patches lack the usual wing scales, but instead have bristles. We have found that on the ventral side most of these patches have very transparent scales that enhance, by reflection, the wing coloration when illuminated from the dorsal side. These glass scales furthermore create a strongly polarized iridescence when illuminated by obliquely incident light from the ventral side, presumably for intraspecific signaling. A few ventral forewing patches have diffusely scattering, white scales that also enhance the blue/green wing coloration when observed from the dorsal side.

We studied the structural as well as spatial and spectral reflectance characteristics of the wing scales of lycaenid butterfly species, where the scale bodies consist of perforated multilayers. The extent of the spatial scattering profiles was measured with a newly built scatterometer. The width of the reflectance spectra, measured with a microspectrophotometer, decreased with the degree of perforation, in agreement with the calculations based on multilayer theory.

Since cerebrospinal fluid shunt malfunction is common and its diagnosis often requires invasive testing, we have evaluated magnetic resonance imaging (MRI) as a noninvasive test for shunt function. In prior experiments, MRI has been shown to be capable of detecting flows as low as 0.4 cc h-1 in shunt systems. Because patient movement and position in an MRI scanner are variable, we have studied the effects of shunt position on the ability to reliably detect the rate of CSF flow. Flow related enhancement of fluid flowing from 0 to 2 cc h-1 was measured in a specialized section of tubing using multiple spin echo scans (TR2000,TE20). The angle of the specialized tubing was varied relative to the axis of the MRI scanner and then the intensity of the MR signal at specific points in the tubing was measured at different flow rates. No flow standards were used as controls. The results show that the linear relationship between signal intensity and flow that had previously been demonstrated was significantly altered by changes of position. Positions angled superior to the axis of the scanner enhanced the signal while lateral changes in the plane of the scan degraded the signal. These results suggest that in order for MRI to become an accurate test for shunt function, techniques must be developed to overcome the effects of shunt position.

Background: Gastroesophageal reflux is a major cause of anastomotic complications after repair of esophageal atresia. For this reason, we evaluated a prospective, postoperative treatment protocol with the emphasis on comparing medical and operative treatment. Study Design: From 1994 to 1995, 26 consecutive patients underwent correction of esophageal atresia in the Sophia Children's Hospital. These patients were enrolled in a decision-making protocol meant to establish the effect of medical treatment on gastroesophageal reflux and stricture formation, the relation between anastomotic tension and reflux, and the question of whether performing a Nissen fundoplication was justified. Patients who showed reflux on the first postoperative x-ray were given medical treatment. Reflux was assessed after 6–12 weeks by x-ray and 48-hour pH-metry (24 hours with and 24 hours without medication). Evaluations were repeated at 18 weeks, 6 months, and 1 year. Twenty-three patients were followed for ≥ 1 year. Results: Twenty-four patients had classic esophageal atresia combined with tracheoesophageal fistula. Two had isolated atresia and underwent a colonic interposition. One of the others died of severe cerebral hemorrhage early after the operation. Twenty-two of the remaining 23 showed reflux on the first postoperative x-ray and were given medical treatment. The mean 3.8% total mild reflux time (range, 0.0–11.0%) decreased to a mean of 1.47% (range, 0.0–6.8%). Medical treatment given according to protocol did not influence severe reflux. Eleven of 23 patients showed stricture formation, requiring a mean of four dilatation procedures (range, 1–9). Defining a real stricture as one needing three or more dilatations, as seen in seven patients, the following results were seen: four nonrefluxing patients (proved by x-ray and pH-metry) needed a mean of 4.2 dilatations (range, 3–7), and three refluxing patients (proved by x-ray and pH-metry) needed a mean of 7.3 dilatations (range, 5–9). Three of seven patients with anastomotic tension had proved gastroesophageal reflux; reflux was also diagnosed in 8 of 15 patients without any tension on the anastomosis. Nine of 23 patients underwent a Nissen fundoplication according to the protocol. In four of them, this was decided because of severe reflux-associated respiratory problems; in one, for resistent stenosis after a Livaditis procedure; and in one with normal pH-metry, the procedure was done on clinical grounds. The latter patient needed an aortopexy at a later stage. A late fundoplication was performed in two patients for persistent gastroesophageal reflux unresponsive to medical treatment, and in one for persistent stenosis and reflux. In all patients, the outcomes were successful, without complications. Conclusions: Medical treatment of gastroesophageal reflux after repair of esophageal atresia has a distinct effect on the duration of reflux and could have a positive effect on the occurrence and treatment of stenosis. There is no clear relation between the occurrence of reflux and tension on the anastomosis. Nissen fundoplication according to the protocol was done appropriately in eight of nine patients.

Background: This study was undertaken to determine baseline values of 24-hour pH-metry in children who had undergone correction for esophageal atresia. Methods: A 24-hour pH-metry without medication was conducted in 13 patients with an uncomplicated postoperative course after correction of esophageal atresia. The pH-metry was performed in the hospital with a flexible glass electrode. Results: The mean reflux index was 4.08%, the mean total number of reflux periods with a pH less than 4 was 21, and the mean number of periods of pH less than 4 lasting longer than 5 minutes was 2.5. Conclusions: Twenty-four-hour pH-metry values in asymptomatic esophageal atresia patients are the same as in children from the same age group with normal anatomy.

In case of congenital diaphragmatic hernia (CDH), survival generally depends not on prenatal diagnosis, planned delivery, and immediate postnatal operation, but on the gravity of pulmonary hypoplasia and persistent hypertension (PPH). Many vasoactive drugs have become available for lowering PPH, but the mortality rate for CDH still amounts to 40% to 70%. Preoperative stabilization might prevent or at least reduce the risk of PPH. This method was evaluated in a pilot study lasting 15 months and involving 13 patients. All were admitted to the pediatric surgical intestive care unit within six hours of birth, all requiring mechanical ventilation. Continuous suction of the stomach and bowel proved successful in reducing the mediastinal shift. Study parameters were alveolar-arterial oxygenation differences ((A-a)DO 2 ), mean airway pressure (MAP), oxygenation index (OI), and ventilation index (VI), measured on admission and at set times before and after surgery. Eight patients did not survive, but in two cases death was not directly related to CDH. The following conclusions were reached: (1) satisfactory ventilation parameters on admission will remain good during the preoperative stabilization phase and will not be affected by its duration or by subsequent surgery, spelling survival; (2) unsatisfactory ventilation parameters on admission may improve with preoperative stabilization, giving these patients a better chance of survival; and (3) poor ventilation parameters on admission that fail to improve with preoperative stabilization will not improve with surgery or postoperatively, spelling death.

Six patients with total colonic aganglionosis (TCA) with ileal involvement were treated with a total colectomy and ileorectal anastomosis according to Rehbein. Follow-up lasted from 1 to 7 years and showed no mortality. Postoperative management consisted of total parenteral nutrition initially, followed by gradual introduction of oral feeding beginning with a low-osmolarity low-residue diet, the use of loperamide, an adequate oral intake of salt, and regular bowel deflation. Major postoperative complications disappeared and all patients demonstrated weight gain by the end of the first postoperative year, with normal feeding and two to three soft stools per day.

Supplemental Digital Content is available in the text., Background: Complex molecular programs in specific cell lineages govern human heart development. Hypoplastic left heart syndrome (HLHS) is the most common and severe manifestation within the spectrum of left ventricular outflow tract obstruction defects occurring in association with ventricular hypoplasia. The pathogenesis of HLHS is unknown, but hemodynamic disturbances are assumed to play a prominent role. Methods: To identify perturbations in gene programs controlling ventricular muscle lineage development in HLHS, we performed whole-exome sequencing of 87 HLHS parent–offspring trios, nuclear transcriptomics of cardiomyocytes from ventricles of 4 patients with HLHS and 15 controls at different stages of heart development, single cell RNA sequencing, and 3D modeling in induced pluripotent stem cells from 3 patients with HLHS and 3 controls. Results: Gene set enrichment and protein network analyses of damaging de novo mutations and dysregulated genes from ventricles of patients with HLHS suggested alterations in specific gene programs and cellular processes critical during fetal ventricular cardiogenesis, including cell cycle and cardiomyocyte maturation. Single-cell and 3D modeling with induced pluripotent stem cells demonstrated intrinsic defects in the cell cycle/unfolded protein response/autophagy hub resulting in disrupted differentiation of early cardiac progenitor lineages leading to defective cardiomyocyte subtype differentiation/maturation in HLHS. Premature cell cycle exit of ventricular cardiomyocytes from patients with HLHS prevented normal tissue responses to developmental signals for growth, leading to multinucleation/polyploidy, accumulation of DNA damage, and exacerbated apoptosis, all potential drivers of left ventricular hypoplasia in absence of hemodynamic cues. Conclusions: Our results highlight that despite genetic heterogeneity in HLHS, many mutations converge on sequential cellular processes primarily driving cardiac myogenesis, suggesting novel therapeutic approaches.

© Springer Nature Switzerland AG 2018. Delineation of organs at risk (OAR) on CT images is a crucial step in the planning of radiotherapy treatment. Manual delineation is time-consuming and high interrater variability is observed within and across radiotherapy centers. Automated delineation of OAR is fast and can lead to more consistent treatment plans. We developed an auto-delineation tool based on a 3D convolutional neural network (CNN) to automatically delineate 16 OAR structures in head and neck cancer (HNC) patients. The CNN was trained off-line using 70 previously collected patient datasets and implemented to be available on-line in clinical routine practice. The tool was applied prospectively for delineation of 20 consecutive new HNC cases within the department of Radiation Oncology, with subsequent manual editing and approval of the contours by the clinical expert. Validation based on the automatically proposed and edited contours shows that the auto-delineation tool is able to achieve highly accurate segmentation results for most OAR. As a result, 3D delineation time is reduced to less than 19 min on average (about 1 min/structure), compared to usually 1 h or more without auto-delineation tool. ispartof: pages:223-232 ispartof: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) vol:11041 LNCS pages:223-232 ispartof: 7th international workshop on clinical image-based procedures: Translational research in medical imaging - CLIP 2018, held in conjunction with MICCAI 2018 location:Granada, Spain date:16 Sep - 16 Sep 2018 status: published

This paper presents a novel method for multi-modal lung image registration constrained by a motion model derived from lung 4DCT. The motion model is estimated based on the results of intra-patient image registration using Principal Component Analysis. The approach with a prior motion model is particularly important for regions where there is not enough information to reliably drive the registration process, as in the case of hyperpolarized Xenon MRI and proton density MRI to CT registration. Simultaneously, the method addresses local variations between images in the supervoxel-based motion model parameters optimization step. We compare our results in terms of the plausibility of the estimated deformations and correlation coefficient with 4DCT-based estimated ventilation maps using state-of-the-art multi-modal image registration methods. Our method achieves higher average correlation scores, showing that the application of Principal Component Analysis-based motion model in the deformable registration, helps to drive the registration for the regions of the lungs with insufficient amount of information.

Background Mucopolysaccharidosis type VI (MPS VI) is a lysosomal storage disorder (LSD), which is caused by a deficiency in the enzyme N-acetylgalactosamine 4-sulfatase (4-sulfatase). MPS VI is characterized by severe skeletal abnormalities, somatic tissue pathology and early death. Treatment possibilities include bone marrow transplantation (BMT) and enzyme replacement therapy (ERT; currently in phase III clinical trial). Early diagnosis of MPS VI will allow treatment before the onset of irreversible pathology. Methods Sensitive immune assays have been developed to detect 4-sulfatase protein and activity in normal control and MPS VI blood-spots. Results Dried blood-spots from MPS VI patients contained no detectable 4-sulfatase protein and activity, compared to 3.5–21 μg/L of 4-sulfatase protein and 291–1298 nmol/min/L of activity for normal human controls. In this evaluation study, the assay was sensitive and 100% specific, allowing reliable detection of individuals with MPS VI. Conclusions The assays reported here have the potential to detect MPS VI patients using dried blood-spots.