Stable References Research Articles

A fully digital protocol to provide a fixed interim complete denture for immediate loading for a completely edentulous patient: A dental technique

Complete arch immediate-loading implant-supported prostheses can represent a major challenge for the patient and the dental team. Obtaining stable references and an accurate occlusal record after implant placement to provide an interim prosthesis is a difficult task and can deviate from the initial treatment plan. The described technique presents a fully digital protocol to provide an immediate complete arch implant-supported fixed interim prosthesis for edentulous patients by making postoperative cone beam computed tomography and intraoral digital scans that correlate with the previous plan.

A Compensation Method for Active Phased Array Antennas: Using a strain-electromagnetic coupling model

Physical deformation due to service loads seriously degrades the electromagnetic performance of active phased array antennas. However, traditional displacement-based compensation methods are moderately difficult to use because displacement measurements generally require stable references, which are hard to realize for antennas in service. For deformed antennas, strain information is directly related to their displacement, and strain sensors can overcome carrier platform constraints to measure real-time strain without affecting the antenna radiation-field distribution. We thus present a compensation method based on strain information for in-service antennas. First, the minimum number of strain sensors is determined as the main modal-order-based modal effective mass fraction. According to the modal method and analysis of spatial phase-distribution errors related to strain, a coupled strain-electromagnetic model is established to evaluate antenna performance from the measured strain. The corresponding excitation phase from the measured strain is adjusted to compensate antenna performance. Finally, the method is experimentally validated using an X-band active phased array antenna under the influence of typical deformation conditions for both boresight and scanned beams. The results demonstrate that the presented method can effectively compensate for the performance of service antennas directly from the measured strain information.

Factores implicados en el éxito y fracaso de la dacriocistorrinostomía endoscópica desde nuestra experiencia

IntroductionChronic dacryocystitis is the condition secondary to permanent lacrimonasal duct stenosis (LNDS) that generates epiphora and recurrent conjunctivitis. Endoscopic dacryocystorhinostomy (EDCR) is a more natural route than the external route and offers higher success rates than the laser technique. We value this centre's experience in this procedure. Patients and methodsA retrospective review was carried out in our centre of the medical records of adult patients undergoing EDCR due to LNDS between 1995 and 2019. The minimum follow-up period required after surgery was 6 months. ResultsOver 297 months, 167 EDCR procedures were performed on 156 patients, with an average age of 65.7±11.6 years and a male/female ratio of 1/1.98. The functional improvement was 86%, with an anatomical success rate of 87%. Lack of clinical improvement statistically significantly correlated with the age of the patient and the time since onset of the LNDS, the presence of concomitant systemic (especially diabetes mellitus) or ophthalmological disease, the intraoperative finding of a thickened tear sac and absence of drainage of the tear sac when marsupialised. Longer-term stent carriers in the rhinostomy had poorer outcomes. There were no postoperative complications of interest. ConclusionsEDCR is an effective and safe technique, based on stable anatomical references. Failure rate seems to be multifactorial and should be considered in older, multipathological patients, with a long duration of the condition.

Comprehensive evaluation of candidate reference genes for quantitative real-time PCR-based analysis in Caucasian clover

The forage species Caucasian clover (Trifolium ambiguum M. Bieb.), a groundcover plant, is resistant to both cold and drought. However, reference genes for qRT-PCR-based analysis of Caucasian clover are lacking. In this study, 12 reference genes were selected on the basis of transcriptomic data. These genes were used to determine the most stably expressed genes in various organs of Caucasian clover under cold, salt and drought stress for qRT-PCR-based analysis. Reference gene stability was analyzed by geNorm, NormFinder, BestKeeper, the ∆Ct method and RefFinder. Under salt stress, RCD1 and PPIL3 were the most stable reference genes in the leaves, and NLI1 and RCD1 were the most stable references genes in the roots. Under low-temperature stress, APA and EFTu-GTP were the most stable reference genes in the leaves, and the RCD1 and NLI2 genes were highly stable in the roots. Under 10% PEG-6000 stress, NLI1 and NLI2 were highly stable in the leaves, and RCD1 and PPIL3 were the most stable in the roots. Overall, RCD1 and NLI2 were the most stable reference genes in organs under normal conditions and across all samples. The most and least stable reference genes were validated by assessing their appropriateness for normalization via WRKY genes.

El urbanita tecno-nómada y la Ciudad excluyente

Partiendo de un análisis de la evolución de la ciudad industrial a la ciudad posindustrial en la era global y desde una perspectiva interdisciplinar, se trata de describir y argumentar cómo la vida urbana se desprende de las estructuras sólidas y estables de la ciudad; demostrar la eminente separación entre lo vivido y lo construido. Las diferentes movilidades y la inestabilidad en todos los aspectos de la vida, desde lo familiar, privado e íntimo a lo relacional, público y laboral las relaciones se vuelven “líquidas” en la gran ciudad y se van perdiendo los referentes estables. Las nuevas tecnologías digitales y las comunicaciones promueven la vida móvil. El nuevo urbanita tecno-nómada, categoría que incluye el inmigrante precario, el turista, el habitante que se convierte en turista en su propia ciudad y todo un elenco de especies urbanas que buscan oportunidades en la gran ciudad, experimentan el desarraigo, el individualismo y las instituciones debilitadas. En un mundo conectado a distancia a las redes trasnacionales, las grandes ciudades desconectadas interiormente fomentan grandes rupturas, discontinuidades y exclusiones. El método de abordaje de este estudio enfoca el “urbanita” en vez del habitual enfoque del urbanismo en un emergente contexto socio tecnológico y trata de definir cómo se construyen las subjetividades.

NormiRazor: tool applying GPU-accelerated computing for determination of internal references in microRNA transcription studies

BackgroundMulti-gene expression assays are an attractive tool in revealing complex regulatory mechanisms in living organisms. Normalization is an indispensable step of data analysis in all those studies, since it removes unwanted, non-biological variability from data. In targeted qPCR assays it is typically performed with respect to prespecified reference genes, but the lack of robust strategy of their selection is reported in literature, especially in studies concerning circulating microRNAs (miRNA). Unfortunately, this problem impedes translation of scientific discoveries on miRNA biomarkers into widely available laboratory assays. Previous studies concluded that averaged expressions of multi-miRNA combinations are more stable references than single genes. However, due to the number of such combinations the computational load is considerable and may be hindering for objective reference selection in large datasets. Existing implementations of normalization algorithms (geNorm, NormFinder and BestKeeper) have poor performance and may require days to compute stability values for all potential reference as the evaluation is performed sequentially.ResultsWe designed NormiRazor - an integrative tool which implements those methods in a parallel manner on a graphics processing unit (GPU) using CUDA platform. We tested our approach on publicly available miRNA expression datasets. As a result, the times of executions on 8 datasets containing from 50 to 400 miRNAs (subsets of GSE68314) decreased 18.7 ±0.6 (mean ±SD), 104.7 ±4.2 and 76.5 ±2.2 times for geNorm, BestKeeper and NormFinder with respect to previous Python implementation. To allow for easy access to normalization pipeline for biomedical researchers we implemented NormiRazor as an online platform where a user could normalize their datasets based on the automatically selected references. It is available at norm.btm.umed.pl, together with instruction manual and exemplary datasets.ConclusionsNormiRazor allows for an easy, informed choice of reference genes for qPCR transcriptomic studies. As such it can improve comparability and repeatability of experiments and in longer perspective help translate newly discovered biomarkers into readily available assays.

Attachment to and Detachment from Favorite Stores: An Affordance Theory Perspective

AbstractLike homes, neighborhoods, and cities, retail locations offer significant opportunities for attachment far from domestic spheres. In commercial settings, consumers construct personal geographies, and find stable references for their lives. Our work advances previous consumer research by showing how these relationalities are situated, implicitly unstable and often impermanent. Individuals attach to commercial spaces in multiple ways, through both immediate and slow processes. We theorize that multiple affordances of spaces—whether sensual, symbolic, or cerebral—trigger meaningful ties, stimulate new affective and practice repertoires and may exert a transformative power in personal biographies. Bonds evolve in tandem with individuals’ life courses and are also impacted by events beyond consumers’ control, such as store closures. Whether disruptive or constructive, detachments can precipitate constructive change, allowing individuals to mobilize the emotional and cognitive resources at the base of their affective bond with treasured places, and redirect these assets more effectively. Forced and voluntary detachment from retail spaces are thus interpreted as integral and complementary components of attachment.

Compact Current Reference Circuits with Low Temperature Drift and High Compliance Voltage.

Highly accurate and stable current references are especially required for resistive-sensor conditioning. The solutions typically adopted in using resistors and op-amps/transistors display performance mainly limited by resistors accuracy and active components non-linearities. In this work, excellent characteristics of LT199x selectable gain amplifiers are exploited to precisely divide an input current. Supplied with a 100 µA reference IC, the divider is able to exactly source either a ~1 µA or a ~0.1 µA current. Moreover, the proposed solution allows to generate a different value for the output current by modifying only some connections without requiring the use of additional components. Experimental results show that the compliance voltage of the generator is close to the power supply limits, with an equivalent output resistance of about 100 GΩ, while the thermal coefficient is less than 10 ppm/°C between 10 and 40 °C. Circuit architecture also guarantees physical separation of current carrying electrodes from voltage sensing ones, thus simplifying front-end sensor-interface circuitry. Emulating a resistive-sensor in the 10 kΩ–100 MΩ range, an excellent linearity is found with a relative error within ±0.1% after a preliminary calibration procedure. Further advantage is that compliance voltage can be opposite in sign of that obtained with a passive component; therefore, the system is also suitable for conditioning active sensors.

Local dynamic neighborhood based outlier detection approach and its framework for large-scale datasets

Local outlier detection is a hot area and great challenge in data mining, especially for large-scale datasets. On the one hand, traditional algorithms often achieve low-quality detection results and are sensitive to neighborhood size. On the other hand, they are infeasible for large-scale datasets due to at least O(N2) time and space complexity. In light of these, we propose a new local outlier detection algorithm, which is designed based on a new stable neighborhood strategy-dynamic references nearest neighbors (DRNN). Meanwhile, we present a new detection framework by combining the proposed approach and k-mean for large-scale datasets. Experimental results demonstrate that the proposed algorithm can produce higher quality and robust detection results compared to several classic methods. Meanwhile, the new detection framework is able to significantly improve detecting efficiency without sacrificing accuracy.

Low motional impedance distributed Lam\xe9 mode resonators for high frequency timing applications

This paper presents a novel high-Q silicon distributed Lamé mode resonator (DLR) for VHF timing reference applications. The DLR employs the nature of shear wave propagation to enable a cascade of small square Lamé modes in beam or frame configurations with increased transduction area. Combined with high efficiency nano-gap capacitive transduction, it enables low motional impedances while scaling the frequency to VHF range. The DLR designs are robust against common process variations and demonstrate high manufacturability across different silicon substrates and process specifications. Fabricated DLRs in beam and frame configurations demonstrate high performance scalability with high Q-factors ranging from 50 to 250 k, motional impedances <1 kΩ, and high-temperature frequency turnover points >90 °C in the VHF range, and are fabricated using a wafer-level-packaged HARPSS process. Packaged devices show excellent robustness against temperature cycling, device thinning, and aging effects, which makes them a great candidate for stable high frequency references in size-sensitive and power-sensitive 5 G and other IoT applications.

Does it still fit? - Adapting affordance judgments to altered body properties in young and older adults.

Actor-related affordance judgments are decisions about potential actions that arise from environmental as well as bodily and cognitive conditions. The system can be challenged by sudden changes to otherwise rather stable actor references e.g. due to accidental bodily injuries or due to brain damage and resulting motor and cognitive constraints. The current study investigated adaptation to suddenly artificially altered body properties and its reversibility in healthy young versus older adults. Participants were asked to judge whether they would be able to fit their hand through a given horizontal opening (Aperture Task). Body alterations were induced by equipping participants with one hand splint for 24 hours that enlarged the hand in width and height. Participants were tested before and directly after putting the splint on as well as after a habituation period of 24 hours. To assess reversibility, participants were tested again directly after removing the splint and one day later. Judgment accuracy values and detection theory measures were reported. Both, young and older adults judged more conservatively when body properties were altered compared to initial judgments for normal body properties. Especially older adults showed major difficulties in such quick adaptation. Older adults’ judgment accuracy as well as perceptual sensitivity were significantly lowered when body properties were suddenly altered. Importantly, lowered judgment performance occurred for both, the splinted as well as the non-splinted hand in older adults. Only after 24 hours of habituation, older adults tended to regain initial performance levels showing adaptive behavior to the altered condition. Removing the hand splint for one day was sufficient to reverse these adaptive effects. Our study results suggest that aging slows down adaptation to sudden bodily alterations affecting actor-related affordance judgments. We propose that these altered processes may go along with uncertainty and a heightened concern about potential consequences of misjudgments. Clearly, future studies are needed to further elucidate the underlying processes of adaptation in affordance judgments. These may reveal major implications for the aging society and its associated problems with an increased risk of falling or stroke related bodily constraints.

A CMOS slew-rate enhanced OTA for imaging

CMOS Image Sensors have many applications currently. They are present everywhere and almost everyone owns many cameras based on these sensors ranging from mobile phones (with several cameras), to tablets, computers, security devices and cars. Although they work pretty well as we increase their resolution and quality we face a few problems. One of these problems is Flicker noise. The other source of noise, thermal, evolved a lot recently and flicker noise is now the main limitation regarding improving the performance. This work presents a new method to reduce the flicker noise contribution in the overall sensor noise by reducing the time for Double Sampling, allowing to filters more correctly the flicker noise spectrum introduced by the pixel source follower amplifier. We also introduce a way to remove the column induced lag that comes from the column readout circuitry by using strong and stable references. We propose a new amplifier that is used as a buffer for the reference voltage. At the same time Double Sampling is performed. This solution contributes both to reduce the current consumption and time between samples which also contributes to a lower power heat dissipation. The developed circuit can be seen as a generic solution for applications that need stable references and high resolution, resulting in a massively parallel circuit, as it is common in CMOS image sensors. The proposed solution is tested with a circuit containing 3000 readout columns.

Validation of reference genes for expression analysis in three Bupleurum species

Radix Bupleuri (root of Bupleurum spp.) is an important medicinal herb. Its lateral root number is one of the decisive factors that influence the content of a major bioactive component, saikosaponin. To identify genes associated with content and total yield of saikosaponin, it is of key importance to select stable references in gene expression analyses using quantitative real-time polymerase chain reaction (qRT-PCR). In this study, 18 candidate reference genes were selected and evaluated through their expression stability during the lateral root development in tissue samples from B. chinense DC., B. falcatum L. and B. scorzonerifolium Willd. The GeNorm, NormFinder and Bestkeeper methods were used for selecting stably expressed internal controls in the three Bupleurum species. These results revealed that, among these 18 candidate reference genes, ADF7 showed the best performance in all the experimental systems. ADF5 and ADF1b could also be proposed as suitable reference genes for gene expression studies. This study supplied more candidate reference genes to monitor the content and yield of saikosaponin during lateral roots growth in the Bupleurum genus.

The Evolution of PharmVar.

The Evolution of PharmVar.

An on-chip fully electronic molecular clock based on sub-terahertz rotational spectroscopy

Mobile electronic devices require stable, portable and energy-efficient frequency references (or clocks). However, current approaches using quartz-crystal and microelectromechanical oscillators suffer from frequency drift. Recent advances in chip-scale atomic clocks, which probe the hyperfine transitions of evaporated alkali atoms, have led to devices that can overcome this issue, but their complex construction, cost and power consumption limit their broader deployment. Here we show that sub-terahertz rotational transitions of polar gaseous molecules can be used as frequency bases to create low-cost, low-power miniaturized clocks. We report two molecular clocks probing carbonyl sulfide (16O12C32S), which are based on laboratory-scale instruments and complementary metal–oxide–semiconductor chips. Compared with chip-scale atomic clocks, our approach is less sensitive to external influences and offers faster frequency error compensation, and, by eliminating the need for alkali metal evaporation, it offers faster start-up times and lower power consumption. Our work demonstrates the feasibility of monolithic integration of atomic-clock-grade frequency references in mainstream silicon-chip systems. The sub-terahertz rotational transitions of polar molecules can be used as frequency bases to create low-cost, low-power miniaturized clocks.

Identification of reference genes for RT-qPCR in the Antarctic moss Sanionia uncinata under abiotic stress conditions.

Sanionia uncinata is a dominant moss species in the maritime Antarctic. Due to its high adaptability to harsh environments, this extremophile plant has been considered a good target for studying the molecular adaptation mechanisms of plants to a variety of environmental stresses. Despite the importance of S. uncinata as a representative Antarctic plant species for the identification and characterization of genes associated with abiotic stress tolerance, suitable reference genes, which are critical for RT-qPCR analyses, have not yet been identified. In this report, 11 traditionally used and 6 novel candidate reference genes were selected from transcriptome data of S. uncinata and the expression stability of these genes was evaluated under various abiotic stress conditions using three statistical algorithms; geNorm, NormFinder, and BestKeeper. The stability ranking analysis selected the best reference genes depending on the stress conditions. Among the 17 candidates, the most stable references were POB1 and UFD2 for cold stress, POB1 and AKB for drought treatment, and UFD2 and AKB for the field samples from a different water contents in Antarctica. Overall, novel genes POB1 and AKB were the most reliable references across all samples, irrespective of experimental conditions. In addition, 6 novel candidate genes including AKB, POB1 and UFD2, were more stable than the housekeeping genes traditionally used for internal controls, indicating that transcriptome data can be useful for identifying novel robust normalizers. The reference genes validated in this study will be useful for improving the accuracy of RT-qPCR analysis for gene expression studies of S. uncinata in Antarctica and for further functional genomic analysis of bryophytes.

MOF-Based Nano-Cuboids Electrocatalyst for OER-HER Reactions

Recently, metal organic framework (MOF) derived catalysts, typically synthesized using precursors consisting of transition metals and organic linkers, have emerged as promising active and inexpensive electrocatalysts due to their intrinsic advantages of high porosity, three-dimensional structures, and compositional flexibility. In particular, MOFs with organic ligands containing carbon, nitrogen, and sulfur atoms coordinated to transition metal centers have been reported to form three dimensional and uniformly porous structures, resulting in considerably increased active surface area and enhanced physical properties.[1-5] These MOFs, often composed of transition metal atoms such as nickel, cobalt, and iron, and heteroatoms such as nitrogen, sulfur, and phosphorus, are characterized by strong interactions between them[6,7], which can serve as electrocatalytically active sites for HER and OER. The advantages of MOF-derived active materials in advanced energy conversion and storage applications have been recently highlighted as efficient electrocatalysts for fuel cells, metal-air batteries, and electrolyzers. For example, Gadipelli et al. recently reported a design route for the synthesis of MOF-derived electrocatalysts, in which zeolitic imidazolate framework (ZIF) was used as the template. The resulting MOF catalyst containing active Co-N-C species demonstrated efficient ORR and OER activities. Yu et al. reported an active OER electrocatalyst based on porous carbon coated nickel phosphides (NiP) prepared using Ni-based PBA nanoplates as a template. The structural advantages of MOFs allowed NiP catalyst to demonstrate superior electrocatalytic activity towards OER compared to NiO and Ni(OH)2 counterparts. Despite these electrocatalyst developments, however, bi-functional MOF-derived electrocatalysts active towards both HER and OER for water-splitting application have rarely been reported to the best of our knowledge. In this study, we introduce novel MOF containing Ni-Co-Fe transition metal centers, denoted NCF-MOF, as a dual-function water-splitting catalyst for enhancing HER and OER activities. The morphology of the catalyst is revealed to exhibit nano-cuboid structure with multiple meso- and micro-sized pores prepared via a facile synthesis procedure. As MOF catalyst precursors, transition metal-based PBA nanocubes with a chemical formula Mx II[My III(CN)6]z▪H2O, where MII and MIII are divalent and trivalent transition metal cations, respectively, have selected to obtain unique structure and composition of NCF-MOF multi-hollow nano-cuboids. Specifically, PBA nanocube precursors containing nickel, cobalt, and iron have been utilized to maintain the general nano-cuboidal structure, while optimizing the composition of transition metal centers for efficient OER and HER activities. This makes NCF-MOF one of the most promising non-precious electrocatalysts for water-splitting applications in various ways; (i) significantly extended active surface area with high porosity, (ii) formation of active nitrogen species during facile synthesis, and (iii) optimized electronic structure of transition metals for electrocatalysis via oxidation state control. These main electrocatalytic contributors that affect OER and HER have been successfully obtained through careful selection of PBA precursors and the facile synthesis procedure. Furthermore, excellent electrochemical stability has been realized NCF-MOF catalyst which is also attributed to high uniformity of porous nano-cuboidal structure which allow rapid charge transfer and transport of active species. The dual-function of the catalyst and its stability has been confirmed by three-electrode half-cell evaluations, as well as nickel-foam loaded active electrodes for practical demonstrations as efficient and stable References [1] A. Mahmood, W. Guo, H. Tabassum and R. Zou, Adv. Energy Mater., 2016. [2] Z. Li, M. Shao, L. Zhou, R. Zhang, C. Zhang, M. Wei, D. G. Evans and X. Duan, Adv. Mater., 2016, 28, 2337-2344. [3] B. Y. Xia, Y. Yan, N. Li, H. B. Wu, X. W. Lou and X. Wang, Nat. Energy, 2016, 1, 15006. [4] X. Y. Yu, L. Yu, H. B. Wu and X. W. Lou, Angew. Chem. Int. Ed., 2015, 54, 5331-5335. [5] L. Han, X. Y. Yu and X. W. Lou, Adv. Mater., 2016, 28, 4601-4605. [6] T. Y. Ma, S. Dai, M. Jaroniec and S. Z. Qiao, J. Am. Chem. Soc., 2014, 136, 13925-13931. [7] X. F. Lu, P. Q. Liao, J. W. Wang, J. X. Wu, X. W. Chen, C. T. He, J. P. Zhang, G. R. Li and X. M. Chen, J. Am. Chem. Soc., 2016, 138, 8336-8339. Figure 1

Polarized projective mapping as a rapid sensory analysis method applied to South African Chenin Blanc wines

To test the applicability of Polarized Projective Mapping (PPM) to dry South African Chenin Blanc wines, one Projective Mapping (PM) and four PPM experiments were performed using expert judges. PM was used to create an initial product map for comparison with PPM results and to assist in the selection of the three poles. For the purposes of method validation 17 wines were analysed in this set of experiments. As the use of poles as stable references between evaluations allowed, the PPM results from all four PPM experiments were combined in a single statistical analysis. This gave a single figure which compared samples from all evaluations in a “Global MFA”. In this experiment repetitions, blind duplicates, explained variance, confidence ellipses, and grouping trends were used to establish the consistency of the results. All of these parameters indicated good reliability of the results. PPM consistently separated wooded and unwooded wines with acceptable percentage of explained variance and correct groupings of blind duplicates. The overall groupings were also consistent with those found in PM.

Temperature-Compensated $\beta$ -Multiplier Current Reference Circuit

This brief presents the new simple schematic for the temperature stable current references based on the well-known $\boldsymbol {\beta }$ -multiplier circuit. The proposed reference utilizes only four MOS transistors and two lateral PNP transistors, which are usually available in standard CMOS technologies along with one well resistor. The temperature-compensation technique has a low process dependence and needs no trimming. However, resistor trimming can be used to precisely set the output current value. The circuit implementation of the proposed technique was fabricated in a standard 0.35- ${\mu }\text{m}$ CMOS process to source a 16- ${\mu }\text{A}$ current. The digital calibration circuit allows setting of the output current in 32 100 nA-steps. The proposed current reference achieves the supply sensitivity of several %/V without the use of the external bandgap voltage reference for the supply regulation. The measured temperature coefficient is 105 ppm/°C over the temperature range from 0 to 110 °C.

Image registration reveals central lens thickness minimally increases during accommodation.

PurposeTo evaluate anterior chamber depth, central crystalline lens thickness and lens curvature during accommodation.SettingCalifornia Retina Associates, El Centro, CA, USA.DesignHealthy volunteer, prospective, clinical research swept-source optical coherence biometric image registration study of accommodation.MethodsTen subjects (4 females and 6 males) with an average age of 22.5 years (range: 20–26 years) participated in the study. A 45° beam splitter attached to a Zeiss IOLMaster 700 (Carl Zeiss Meditec Inc., Jena, Germany) biometer enabled simultaneous imaging of the cornea, anterior chamber, entire central crystalline lens and fovea in the dilated right eyes of subjects before, and during focus on a target 11 cm from the cornea. Images with superimposable foveal images, obtained before and during accommodation, that met all of the predetermined alignment criteria were selected for comparison. This registration requirement assured that changes in anterior chamber depth and central lens thickness could be accurately and reliably measured. The lens radii of curvatures were measured with a pixel stick circle.ResultsImages from only 3 of 10 subjects met the predetermined criteria for registration. Mean anterior chamber depth decreased, −67 μm (range: −0.40 to −110 μm), and mean central lens thickness increased, 117 μm (range: 100–130 μm). The lens surfaces steepened, anterior greater than posterior, while the lens, itself, did not move or shift its position as appeared from the lack of movement of the lens nucleus, during 7.8 diopters of accommodation, (range: 6.6–9.7 diopters).ConclusionImage registration, with stable invariant references for image correspondence, reveals that during accommodation a large increase in lens surface curvatures is associated with only a small increase in central lens thickness and no change in lens position.