Multi-scale Optics for Enhanced Light Collection from a Point Source

High efficiency collection of photons emitted by a point source over a wide field-of-view (FoV) is crucial for many applications. Multi-scale optics over improved light collection by utilizing small optical components placed close to the optical source, while maintaining a wide FoV provided by conventional imaging optics. In this work, we demonstrate collection efficiency of 26% of photons emitted by a point-like source using a micromirror fabricated in silicon with no significant decrease in collection efficiency over a 10 mm object space.Comment: 4 pages, 4 figure

Cross-species parallels in babbling: animals and algorithms

A key feature of vocal ontogeny in a variety of taxa with extensive vocal repertoires is a developmental pattern in which vocal exploration is followed by a period of category formation that results in a mature species-specific repertoire. Vocal development preceding the adult repertoire is often called ‘babbling’, a term used to describe aspects of vocal development in species of vocal-learning birds, some marine mammals, some New World monkeys, some bats and humans. The paper summarizes the results of research on babbling in examples from five taxa and proposes a unifying definition facilitating their comparison. There are notable similarities across these species in the developmental pattern of vocalizations, suggesting that vocal production learning might require babbling. However, the current state of the literature is insufficient to confirm this suggestion. We suggest directions for future research to elucidate this issue, emphasizing the importance of (i) expanding the descriptive data and seeking species with complex mature repertoires where babbling may not occur or may occur only to a minimal extent; (ii) (quasi-)experimental research to tease apart possible mechanisms of acquisition and/or self-organizing development; and (iii) computational modelling as a methodology to test hypotheses about the origins and functions of babbling

Cost-effectiveness analysis of 3-D computerized tomography colonography versus optical colonoscopy for imaging symptomatic gastroenterology patients.

BACKGROUND: When symptomatic gastroenterology patients have an indication for colonic imaging, clinicians have a choice between optical colonoscopy (OC) and computerized tomography colonography with three-dimensional reconstruction (3-D CTC). 3-D CTC provides a minimally invasive and rapid evaluation of the entire colon, and it can be an efficient modality for diagnosing symptoms. It allows for a more targeted use of OC, which is associated with a higher risk of major adverse events and higher procedural costs. A case can be made for 3-D CTC as a primary test for colonic imaging followed if necessary by targeted therapeutic OC; however, the relative long-term costs and benefits of introducing 3-D CTC as a first-line investigation are unknown. AIM: The aim of this study was to assess the cost effectiveness of 3-D CTC versus OC for colonic imaging of symptomatic gastroenterology patients in the UK NHS. METHODS: We used a Markov model to follow a cohort of 100,000 symptomatic gastroenterology patients, aged 50 years or older, and estimate the expected lifetime outcomes, life years (LYs) and quality-adjusted life years (QALYs), and costs (£, 2010-2011) associated with 3-D CTC and OC. Sensitivity analyses were performed to assess the robustness of the base-case cost-effectiveness results to variation in input parameters and methodological assumptions. RESULTS: 3D-CTC provided a similar number of LYs (7.737 vs 7.739) and QALYs (7.013 vs 7.018) per individual compared with OC, and it was associated with substantially lower mean costs per patient (£467 vs £583), leading to a positive incremental net benefit. After accounting for the overall uncertainty, the probability of 3-D CTC being cost effective was around 60 %, at typical willingness-to-pay values of £20,000-£30,000 per QALY gained. CONCLUSION: 3-D CTC is a cost-saving and cost-effective option for colonic imaging of symptomatic gastroenterology patients compared with OC

Scalable Architecture for a Room Temperature Solid-State Quantum Information Processor

The realization of a scalable quantum information processor has emerged over the past decade as one of the central challenges at the interface of fundamental science and engineering. Much progress has been made towards this goal. Indeed, quantum operations have been demonstrated on several trapped ion qubits, and other solid-state systems are approaching similar levels of control. Extending these techniques to achieve fault-tolerant operations in larger systems with more qubits remains an extremely challenging goal, in part, due to the substantial technical complexity of current implementations. Here, we propose and analyze an architecture for a scalable, solid-state quantum information processor capable of operating at or near room temperature. The architecture is applicable to realistic conditions, which include disorder and relevant decoherence mechanisms, and includes a hierarchy of control at successive length scales. Our approach is based upon recent experimental advances involving Nitrogen-Vacancy color centers in diamond and will provide fundamental insights into the physics of non-equilibrium many-body quantum systems. Additionally, the proposed architecture may greatly alleviate the stringent constraints, currently limiting the realization of scalable quantum processors.Comment: 15 pages, 6 figure

Ion-trap quantum information processing: experimental status

Atomic ions trapped in ultra-high vacuum form an especially well-understood and useful physical system for quantum information processing. They provide excellent shielding of quantum information from environmental noise, while strong, well-controlled laser interactions readily provide quantum logic gates. A number of basic quantum information protocols have been demonstrated with trapped ions. Much current work aims at the construction of large-scale ion-trap quantum computers using complex microfabricated trap arrays. Several groups are also actively pursuing quantum interfacing of trapped ions with photons.Comment: review article for Frontiers of Physics replace corrupted TeX fil

PigSNIPE: Scalable Neuroimaging Processing Engine for Minipig MRI

Translation of basic animal research to find effective methods of diagnosing and treating human neurological disorders requires parallel analysis infrastructures. Small animals such as mice provide exploratory animal disease models. However, many interventions developed using small animal models fail to translate to human use due to physical or biological differences. Recently, large-animal minipigs have emerged in neuroscience due to both their brain similarity and economic advantages. Medical image processing is a crucial part of research, as it allows researchers to monitor their experiments and understand disease development. By pairing four reinforcement learning models and five deep learning UNet segmentation models with existing algorithms, we developed PigSNIPE, a pipeline for the automated handling, processing, and analyzing of large-scale data sets of minipig MR images. PigSNIPE allows for image registration, AC-PC alignment, detection of 19 anatomical landmarks, skull stripping, brainmask and intracranial volume segmentation (DICE 0.98), tissue segmentation (DICE 0.82), and caudate-putamen brain segmentation (DICE 0.8) in under two minutes. To the best of our knowledge, this is the first automated pipeline tool aimed at large animal images, which can significantly reduce the time and resources needed for analyzing minipig neuroimages

Influence Of Corrosion On Lipopolysaccharide Affinity For Two Different Titanium Materials

Statement of problem Titanium is subject to corrosion in the oral cavity, which could contribute to periimplantitis. However, the effect of corrosion on the lipopolysaccharide affinity for titanium remains unknown. Purpose This study evaluated the role of corrosion (in artificial saliva at pHs 3, 6.5, and 9) on the lipopolysaccharide (LPS) affinity for commercially pure titanium (cp-Ti) and Ti-6Al-4V alloy. Material and methods Seventy-two titanium disks were anodically polarized in a controlled environment (n=9). Control specimens were not corroded. Deionized water with different concentrations of LPS (1.5, 15, and 150 μg/mL) were used to treat the disks for 24 hours to investigate LPS adherence (n=3). Then specimens were immersed in LPS-free water to evaluate LPS elution at 24, 48, and 72 hours. Data were analyzed by the 2-way, 3-way, and 3-way repeated measures ANOVA, t tests, and the Tukey honestly significant difference (HSD) tests (α=.05). Results A greater corrosion rate of cp-Ti and Ti-6Al-4V alloy and a higher LPS adherence to titanium surfaces (P<.05) were noted at acidic pH. The LPS affinity was higher for the Ti-6Al-4V alloy than for cp-Ti (P<.05). More LPS was eluted from titanium surfaces after a 24-hour interval. Conclusion Lipopolysaccharide affinity for cp-Ti and Ti-6Al-4V alloy is influenced by the corrosion process.1106462470Nakagawa, M., Matsuya, S., Udoh, K., Effects of fluoride and dissolved oxygen concentrations on the corrosion behavior of pure titanium and titanium alloys (2002) Dent Mater J, 21, pp. 83-92Gil, F.J., Canedo, R., Padros, A., Baneres, M.V., Arano, J.M., Fretting corrosion behaviour of ball-and-socket joint on dental implants with different prosthodontic alloys (2003) Biomed Mater Eng, 13, pp. 27-34Nakagawa, M., Matsuya, S., Shiraishi, T., Ohta, M., Effect of fluoride concentration and pH on corrosion behavior of titanium for dental use (1999) J Dent Res, 78, pp. 1568-1572Nikolopoulou, F., Saliva and dental implants (2006) Implant Dent, 15, pp. 372-376Vieira, A.C., Ribeiro, A.R., Rocha, L.A., Celis, J.P., Influence of pH and corrosion inhibitors on the tribocorrosion of titanium in artificial saliva (2006) Wear, 261, pp. 994-1001Azzi, M., Szpunar, J.A., Tribo-electrochemical technique for studying tribocorrosion behavior of biomaterials (2007) Biomol Eng, 24, pp. 443-446De Assis, S.L., Wolynec, S., Costa, I., Corrosion characterization of titanium alloys by electrochemical techniques (2006) Electrochim Acta, 51, pp. 1815-1819Mabilleau, G., Bourdon, S., Joly-Guillou, M.L., Filmon, R., Basle, M.F., Chappard, D., Influence of fluoride, hydrogen peroxide and lactic acid on the corrosion resistance of commercially pure titanium (2006) Acta Biomater, 2, pp. 121-129Souza, M.E., Lima, L., Lima, C.R., Zavaglia, C.A., Freire, C.M., Effects of pH on the electrochemical behaviour of titanium alloys for implant applications (2009) J Mater Sci Mater Med, 20, pp. 549-552Huang, H.H., Effect of fluoride and albumin concentration on the corrosion behavior of Ti-6Al-4V alloy (2003) Biomaterials, 24, pp. 275-282Correa, C.B., Pires, J.R., Fernandes-Filho, R.B., Sartori, R., Vaz, L.G., Fatigue and fluoride corrosion on Streptococcus mutans adherence to titanium-based implant/component surfaces (2009) J Prosthodont, 18, pp. 382-387Joska, L., Fojt, J., Corrosion behaviour of titanium after short-term exposure to an acidic environment containing fluoride ions (2010) J Mater Sci Mater Med, 21, pp. 481-488Quirynen, M., De Soete, M., Van Steenberghe, D., Infectious risks for oral implants: A review of the literature (2002) Clin Oral Implants Res, 13, pp. 1-19Morgan, T.D., Wilson, M., The effects of surface roughness and type of denture acrylic on biofilm formation by Streptococcus oralis in a constant depth film fermentor (2001) J Appl Microbiol, 91, pp. 47-53Bollen, C.M., Papaioanno, W., Van Eldere, J., Schepers, E., Quirynen, M., Van Steenberghe, D., The influence of abutment surface roughness on plaque accumulation and peri-implant mucositis (1996) Clin Oral Implants Res, 7, pp. 201-211Quirynen, M., Bollen, C.M., Willems, G., Van Steenberghe, D., Comparison of surface characteristics of six commercially pure titanium abutments (1994) Int J Oral Maxillofac Implants, 9, pp. 71-76Simon, B.I., Goldman, H.M., Ruben, M.P., Baker, E., The role of endotoxin in periodontal disease. I. A reproducible, quantitative method for determining the amount of endotoxin in human gingival exudate (1969) J Periodontol, 40, pp. 695-701Wilson, M., Biological activities of lipopolysaccharides from oral bacteria and their relevance to the pathogenesis of chronic periodontitis (1995) Sci Prog, 78 (PART 1), pp. 19-34Quirynen, M., Vogels, R., Peeters, W., Van Steenberghe, D., Naert, I., Haffajee, A., Dynamics of initial subgingival colonization of 'pristine' peri-implant pockets (2006) Clin Oral Implants Res, 17, pp. 25-37Giannelli, M., Bani, D., Tani, A., Pini, A., Margheri, M., Zecchi-Orlandini, S., In vitro evaluation of the effects of low-intensity Nd:YAG laser irradiation on the inflammatory reaction elicited by bacterial lipopolysaccharide adherent to titanium dental implants (2009) J Periodontol, 80, pp. 977-984Nelson, S.K., Knoernschild, K.L., Robinson, F.G., Schuster, G.S., Lipopolysaccharide affinity for titanium implant biomaterials (1997) J Prosthet Dent, 77, pp. 76-82Knoernschild, K.L., Tompkins, G.R., Schuster, G.S., Lefebvre, C.A., Russell, C.M., Effect of treatment concentration on lipopolysaccharide affinity for two alloys (1997) Dent Mater, 13, pp. 111-117Knoernschild, K.L., Bacon, W.L., Fischman, G.S., Campbell, S.D., Effect of pH on endotoxin affinity for metal-ceramic alloys (2001) J Prosthet Dent, 86, pp. 644-649Knoernschild, K.L., Lefebvre, C.A., Schuster, G.S., Payant, L.M., Gagnon, F.M., Endotoxin adherence to and elution from two casting alloys (1994) Int J Prosthodont, 7, pp. 22-29Knoernschild, K.L., Tompkins, G.R., Lefebvre, C.A., Schuster, G.S., Porphyromonas gingivalis lipopolysaccharide affinity for two casting alloys (1995) J Prosthet Dent, 74, pp. 33-38Gagnon, F., Knoernschild, K.L., Payant, L., Tompkins, G.R., Litaker, M.S., Schuster, G.S., Endotoxin affinity for provisional restorative resins (1994) J Prosthodont, 3, pp. 228-236Knoernschild, K.L., Tompkins, G.R., Lefebvre, C.A., Griffiths, L.L., Schuster, G.S., Effect of pH on Porphyromonas gingivalis endotoxin affinity for resins (1996) Int J Prosthodont, 9, pp. 239-247Robinson, F.G., Knoernschild, K.L., Sterrett, J.D., Tompkins, G.R., Porphyromonas gingivalis endotoxin affinity for dental ceramics (1996) J Prosthet Dent, 75, pp. 217-227Barao, V.A., Mathew, M.T., Assuncao, W.G., Yuan, J.C., Wimmer, M.A., Sukotjo, C., The role of lipopolysaccharide on the electrochemical behavior of titanium (2011) J Dent Res, 90, pp. 613-618Mathew, M.T., Barao, V.A., Yuan, J.C., Assuncao, W.G., Sukotjo, C., Wimmer, M.A., What is the role of lipopolysaccharide on the tribocorrosive behavior of titanium? (2012) J Mech Behav Biomed Mater, 8, pp. 71-85Barao, V.A., Mathew, M.T., Assuncao, W.G., Yuan, J.C., Wimmer, M.A., Sukotjo, C., Stability of cp-Ti and Ti-6Al-4V alloy for dental implants as a function of saliva pH - An electrochemical study (2012) Clin Oral Implants Res, 23, pp. 1055-1062(2009), http://www.astm.org/Standard/index.shtml, American Society for Testing and Materials. ASTM-G61-G86. Standard Test Method for Conducting Cyclic Potentiodynamic Polarization Measurements for Localized Corrosion Susceptibility of Iron-, Nickel-, or Cobalt-Based Alloys. West Conshohocken, Pa: ASTM(2004), http://www.astm.org/Standard/index.shtml, American Society for Testing and Materials. ASTM-G31-G72. Standard practice for laboratory immersion corrosion testing of metals. 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Microstructural and mechanical characterization of contemporary lingual orthodontic brackets

Objectives:To investigate the composition and the microstructural and mechanical characterization of three different types of lingual brackets.Materials and Methods:Incognito™ (3M Unitek), In-Ovation L (DENTSPLY GAC) and STb™ (Light Lingual System, ORMCO) lingual brackets were studied under the scanning electron microscope employing backscattered electron imaging and their elemental composition was analysed by energy-dispersive X-ray microanalysis. Additionally, Vickers hardness was assessed using a universal hardness-testing machine, and the indentation modulus was measured according to instrumented indentation test. Two-way analysis of variance was conducted employing bracket type and location (base and wing) as discriminating variable. Significant differences among groups were allocated by post hoc Student-Newman-Keuls multiple comparison analysis at 95% level of significance.Results:Three different phases were identified for Incognito and In-Ovation L bracket based on mean atomic number contrast. On the contrary, STb did not show mean atomic contrast areas and thus it is recognized as a single phase. Incognito is a one-piece bracket with the same structure in wing and base regions. Incognito consists mainly of noble metals while In-Ovation L and STb show similar formulations of ferrous alloys in wing and base regions. No significant differences were found between ferrous brackets in hardness and modulus values, but there were significant differences between wing and base regions. Incognito illustrated intermediate values with significant differences from base and wing values of ferrous brackets.Conclusions/Implications:Significant differences exist in microstructure, elemental composition, and mechanical properties among the brackets tested; these might have a series of clinical implications during mechanotherapy