Printing, characterizing, and assessing transparent 3D printed lenses for optical imaging

High-quality lens production has involved subtractive manufacturing methods for centuries. These methods demand specialist equipment and expertise that often render custom high-grade glass optics inaccessible. A low-cost, accessible, and reproducible method is developed to manufacture high-quality three dimensional (3D) printed lenses using consumer-grade technology. Various planoconvex lenses are produced using a consumer-grade 3D printer and low-cost spin coating setup, and printed lenses are compared to commercial glass counterparts. A range of mechanical and optical methods are introduced to determine the surface quality and curvature of 3D printed lenses. Amongst others, high-resolution interference reflection microscopy methods are used to reconstruct the convex surface of printed lenses and quantify their radius of curvature. The optical throughput and performance of 3D printed lenses are assessed using optical transmissivity measurements and classical beam characterization methods. It is determined that 3D printed lenses have comparable curvature and performance to commercial glass lenses. Finally, the application of 3D printed lenses is demonstrated for brightfield transmission microscopy, resolving sub-cellular structures over a 2.3 mm field-of-view. The high reproducibility and comparable performance of 3D printed lenses present great opportunities for additive manufacturing of bespoke optics for low-cost rapid prototyping and improved accessibility to high-quality optics in low-resource settings

Printing, characterising, and assessing transparent 3D printed lenses for optical imaging

The production of high-quality lenses for optical instrumentation has involved subtractive manufacturing methods for centuries. These methods have demanded specialist equipment and expertise that often render custom high-grade bulk glass optics inaccessible. We aimed to develop a low-cost, accessible, and reproducible method using consumer-grade technology to manufacture high-quality three-dimensional (3D) printed lenses with comparable performance to glass lenses. Various 3D printed planoconvex lenses were produced using a consumer grade 3D printer and low-cost spin coating setup, and printed lenses were compared to their commercial glass counterparts. A range of mechanical and optical methods are introduced to determine the surface curvature of 3D printed lenses, providing a wide range of quality control methods. Amongst others, high-resolution interference reflection microscopy methods were used to reconstruct the convex surface of printed lenses and quantify their radius of curvature. Moreover, the optical throughput and focusing performance of 3D printed lenses were assessed using optical transmissivity measurements and classical beam characterisation methods. We determined that all 3D printed lens prescriptions tested had comparable surface curvature and optical performance to commercial glass lenses. Finally, we demonstrated the application of 3D printed lenses for brightfield transmission microscopy, resolving sub-cellular structures over a 2.3 mm field of view. The high reproducibility and comparable performance of 3D printed lenses present a great opportunity for additive manufacturing in the production of bespoke optical elements for low-cost rapid prototyping and improved accessibility to high-quality optics in low-resource settings

Entangled Stories: The Red Jews in Premodern Yiddish and German Apocalyptic Lore

“Far, far away from our areas, somewhere beyond the Mountains of Darkness, on the other side of the Sambatyon River…there lives a nation known as the Red Jews.” The Red Jews are best known from classic Yiddish writing, most notably from Mendele's Kitser masoes Binyomin hashlishi (The Brief Travels of Benjamin the Third). This novel, first published in 1878, represents the initial appearance of the Red Jews in modern Yiddish literature. This comical travelogue describes the adventures of Benjamin, who sets off in search of the legendary Red Jews. But who are these Red Jews or, in Yiddish, di royte yidelekh? The term denotes the Ten Lost Tribes of Israel, the ten tribes that in biblical times had composed the Northern Kingdom of Israel until they were exiled by the Assyrians in the eighth century BCE. Over time, the myth of their return emerged, and they were said to live in an uncharted location beyond the mysterious Sambatyon River, where they would remain until the Messiah's arrival at the end of time, when they would rejoin the rest of the Jewish people. This article is part of a broader study of the Red Jews in Jewish popular culture from the Middle Ages through modernity. It is partially based on a chapter from my book, Umstrittene Erlöser: Politik, Ideologie und jüdisch-christlicher Messianismus in Deutschland, 1500–1600 (Göttingen: Vandenhoeck & Ruprecht, 2011). Several postdoctoral fellowships have generously supported my research on the Red Jews: a Dr. Meyer-Struckmann-Fellowship of the German Academic Foundation, a Harry Starr Fellowship in Judaica/Alan M. Stroock Fellowship for Advanced Research in Judaica at Harvard University, a research fellowship from the Heinrich Hertz-Foundation, and a YIVO Dina Abramowicz Emerging Scholar Fellowship. I thank the organizers of and participants in the colloquia and conferences where I have presented this material in various forms as well as the editors and anonymous reviewers of AJS Review for their valuable comments and suggestions. I am especially grateful to Jeremy Dauber and Elisheva Carlebach of the Institute for Israel and Jewish Studies at Columbia University, where I was a Visiting Scholar in the fall of 2009, for their generous encouragement to write this article. Sue Oren considerably improved my English. The style employed for Romanization of Yiddish follows YIVO's transliteration standards. Unless otherwise noted, translations from the Yiddish, Hebrew, German, and Latin are my own. Quotations from the Bible follow the JPS translation, and those from the Babylonian Talmud are according to the Hebrew-English edition of the Soncino Talmud by Isidore Epstein

Prenatal diagnosis and linkage disequilibrium with cystic fibrosis for markers surrounding D7S8

Three polymorphic DNA markers surrounding the D7S8 locus were tested for their usefulness in the diagnosis of cystic fibrosis (CF) by linkage analysis. The markers correspond to the loci D7S424 and D7S426. These polymorphisms were studied by centers in the U.S., the United Kingdom, the Netherlands, and Italy, using samples from populations throughout Europe and North America. The additional information provided by these probes increased the heterogeneity of the region from 50% to 58% and was essential for a completely informative diagnosis in one family. A very high degree of linkage disequilibrium was found between these markers, which span a distance of approximately 250kb. In addition, linkage disequilibrium with CF was noted. Significant heterogeneity of linkage disequilibrium was found among the populations, both for the marker-marker pairs and between the markers and CF.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47627/1/439_2004_Article_BF00206745.pd

Assessment and comparative analysis of a rapid diagnostic test (Tubex®) for the diagnosis of typhoid fever among hospitalized children in rural Tanzania

Background: Typhoid fever remains a significant health problem in many developing countries. A rapid test with a performance comparable to that of blood culture would be highly useful. A rapid diagnostic test for typhoid fever, Tubex®, is commercially available that uses particle separation to detect immunoglobulin M directed towards Salmonella Typhi O9 lipopolysaccharide in sera.Methods: We assessed the sensitivity and specificity of the Tubex test among Tanzanian children hospitalized with febrile illness using blood culture as gold standard. Evaluation was done considering blood culture confirmed S. Typhi with non-typhi salmonella (NTS) and non - salmonella isolates as controls as well as with non-salmonella isolates only.Results: Of 139 samples tested with Tubex, 33 were positive for S. Typhi in blood culture, 49 were culture-confirmed NTS infections, and 57 were other non-salmonella infections. Thirteen hemolyzed samples were excluded. Using all non - S. Typhi isolates as controls, we showed a sensitivity of 79% and a specificity of 89%. When the analysis was repeated excluding NTS from the pool of controls we showed a sensitivity of 79% and a specificity of 97%. There was no significant difference in the test performance using the two different control groups (p > 0.05).Conclusion: This first evaluation of the Tubex test in an African setting showed a similar performance to those seen in some Asian settings. Comparison with the earlier results of a Widal test using the same samples showed no significant difference (p > 0.05) for any of the performance indicators, irrespective of the applied control group

Vicarious Group Trauma among British Jews

This is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1007/s11133-016-9337-4Given that literature on the intra- and inter-generational transmission of traumas is mainly based on secondary literature and focuses on the transmission of trauma memory in terms of the historical knowledge of group trauma, this article develops the theory of vicarious group trauma and tests this theory by exploring vicarious traumatization in the everyday lives of Jews in Britain through the methods of observation and in-depth interviewing. Vicarious group trauma is defined as a life or safety-threatening event or abuse that happened to some members of a social group but is felt by other members as their own experience because of their personal affiliation with the group. The article finds that the vicarious sensation of traumatic group experiences can create anxiety, elicit perceptions of threat and, by extension, hypervigilance among Jews. The findings demonstrate that group traumas of the past interpenetrate and interweave with members’ current lives and in this way can also become constitutive of their group identity. An institutional focus on threats to Jews can inform the construction and reinforcement of traumatization symptoms and accordingly vicarious group trauma. This article suggests an association between the level of involvement of group members in the collective’s social structure and the prominence of vicarious group trauma among them

Evaluation of the Widal tube agglutination test for the diagnosis of typhoid fever among children admitted to a rural hdospital in Tanzania and a comparison with previous studies

BACKGROUND: The diagnosis of typhoid fever is confirmed by culture of Salmonella enterica serotype Typhi (S. typhi). However, a more rapid, simpler, and cheaper diagnostic method would be very useful especially in developing countries. The Widal test is widely used in Africa but little information exists about its reliability. METHODS: We assessed the performance of the Widal tube agglutination test among febrile hospitalized Tanzanian children. We calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of various anti-TH and -TO titers using culture-confirmed typhoid fever cases as the "true positives" and all other febrile children with blood culture negative for S. typhi as the "true negatives." RESULTS: We found that 16 (1%) of 1,680 children had culture-proven typhoid fever. A single anti-TH titer of 1:80 and higher was the optimal indicator of typhoid fever. This had a sensitivity of 75%, specificity of 98%, NPV of 100%, but PPV was only 26%. We compared our main findings with those from previous studies. CONCLUSION: Among febrile hospitalized Tanzanian children with a low prevalence of typhoid fever, a Widal titer of > or = 1:80 performed well in terms of sensitivity, specificity, and NPV. However a test with improved PPV that is similarly easy to apply and cost-efficient is desirable

Invasive Salmonellosis among Children Admitted to a Rural Tanzanian Hospital and a Comparison with Previous Studies

BACKGROUND: The importance of invasive salmonellosis in African children is well recognized but there is inadequate information on these infections. We conducted a fever surveillance study in a Tanzanian rural hospital to estimate the case fraction of invasive salmonellosis among pediatric admissions, examine associations with common co-morbidities and describe its clinical features. We compared our main findings with those from previous studies among children in sub-Saharan Africa. METHODOLOGY/PRINCIPAL FINDINGS: From 1 March 2008 to 28 Feb 2009, 1,502 children were enrolled into the study. We collected clinical information and blood for point of care tests, culture, and diagnosis of malaria and HIV. We analyzed the clinical features on admission and outcome by laboratory-confirmed diagnosis. Pathogenic bacteria were isolated from the blood of 156 (10%) children, of which 14 (9%) were S. typhi, 45 (29%) were NTS and 97 (62%) were other pathogenic bacteria. Invasive salmonellosis accounted for 59/156 (38%) bacteremic children. Children with typhoid fever were significantly older and presented with a longer duration of fever. NTS infections were significantly associated with prior antimalarial treatment, malarial complications and with a high risk for death. CONCLUSIONS/SIGNIFICANCE: Invasive salmonellosis, particularly NTS infection, is an important cause of febrile disease among hospitalized children in our rural Tanzanian setting. Previous studies showed considerable variation in the case fraction of S. typhi and NTS infections. Certain suggestive clinical features (such as older age and long duration of fever for typhoid whereas concomitant malaria, anemia, jaundice and hypoglycemia for NTS infection) may be used to distinguish invasive salmonellosis from other severe febrile illness

Model-Based Therapeutic Correction of Hypothalamic-Pituitary-Adrenal Axis Dysfunction

The hypothalamic-pituitary-adrenal (HPA) axis is a major system maintaining body homeostasis by regulating the neuroendocrine and sympathetic nervous systems as well modulating immune function. Recent work has shown that the complex dynamics of this system accommodate several stable steady states, one of which corresponds to the hypocortisol state observed in patients with chronic fatigue syndrome (CFS). At present these dynamics are not formally considered in the development of treatment strategies. Here we use model-based predictive control (MPC) methodology to estimate robust treatment courses for displacing the HPA axis from an abnormal hypocortisol steady state back to a healthy cortisol level. This approach was applied to a recent model of HPA axis dynamics incorporating glucocorticoid receptor kinetics. A candidate treatment that displays robust properties in the face of significant biological variability and measurement uncertainty requires that cortisol be further suppressed for a short period until adrenocorticotropic hormone levels exceed 30% of baseline. Treatment may then be discontinued, and the HPA axis will naturally progress to a stable attractor defined by normal hormone levels. Suppression of biologically available cortisol may be achieved through the use of binding proteins such as CBG and certain metabolizing enzymes, thus offering possible avenues for deployment in a clinical setting. Treatment strategies can therefore be designed that maximally exploit system dynamics to provide a robust response to treatment and ensure a positive outcome over a wide range of conditions. Perhaps most importantly, a treatment course involving further reduction in cortisol, even transient, is quite counterintuitive and challenges the conventional strategy of supplementing cortisol levels, an approach based on steady-state reasoning