Reverse Mapping Research Articles

Camera ISP Modification to Enable Image De-rendering

A camera's image signal processor (ISP) is dedicated hardware that performs a series of processing steps to render a captured raw sensor image to its final display-referred output suitable for viewing and sharing. It is often desirable to be able to revert – or de-render – the ISP-processed image back to the original raw sensor image. Undoing the ISP rendering, however, is not an easy task. This is because ISPs perform many nonlinear routines in the rendering pipeline that are difficult to invert. Moreover, modern cameras often apply scene-specific image processing, resulting in a wide range of possible ISP parameters. In this paper, we propose a modification to the ISP that allows the ISP-rendered image to be reverted back to a raw image. Our approach works by appending a fixed-sampling of the raw sensor values to all captured images. The appended raw samples comprise no more than 8 rows of pixels in the full-sized image and represent a negligible overhead given that 12–16 MP sensors typically have 3000 rows of pixels or more. The appended pixels are rendered along with the captured image to the final output. From these rendered raw samples, a reverse mapping function can be computed to undo the ISP processing. We demonstrate that this method performs almost on par with competing state-ofthe-art approaches for ISP de-rendering while offering a practical solution that is integrable to current camera ISP hardware.

Space-division-multiplexed catadioptric integrated backlight and symmetrical triplet-compound lenticular array based on ORM criterion for 90-degree viewing angle and low-crosstalk directional backlight 3D light-field display.

A novel optical reverse mapping (ORM) method and an ORM criterion are proposed to evaluate the relevance between the directional backlight (DB) 3D light-field display system aberration and the crosstalk. Based on the ORM criterion, the space-division-multiplexed catadioptric integrated backlight (SCIB) and symmetrical triplet-compound lenticular array (triplet LA) are designed. The SCIB is composed of hybrid Fresnel integrated backlight unit (hybrid Fresnel unit) and space-division-multiplexed microprism unit (microprism unit). The hybrid Fresnel unit is used to provide the directional light, and the divergence angle is 2.4-degrees. The average uniformity of 83.02% is achieved. The microprism unit is used to modulate the directional light distribution into three predetermined directions to establish a 90-degree viewing area. Combined with SCIB, the triplet LA is used to suppress the aberrations and reduce the crosstalk. In the experiment, a DB 3D light-field display system based on SCIB and triplet LA is set up. The displayed light-field 3D image can be observed in a 90-degree viewing angle. Compared to the conventional DB 3D display system, the light-field 3D image is aberration-suppressed, and the SSIM values are improved from 0.8462 to 0.9618. Meanwhile, the crosstalk measurement results show that the average crosstalk is 3.49%. The minimum crosstalk is 2.31% and the maximum crosstalk is 4.52%. The crosstalk values in 90-degree are lower than 5%.

Oncological safety of selective axillary dissection after axillary reverse mapping in node-positive breast cancer

IntroductionAlthough the need for axillary lymph node dissection (AD) is decreasing in breast cancer patients, it remains necessary in some cases. Axillary reverse mapping (ARM) enables the detection of upper extremity lymphatic drainage that may be spared during selective axillary dissection (SAD) so as to reduce the risk of lymphedema.The ability of the ARM-SAD procedure to reduce the incidence of lymphedema is being tested in an ongoing randomized trial. Crossover between arm drainage and breast drainage is well documented in the axilla, however, and whether the procedure is oncologically safe remains controversial. We aim to assess the axillary failure rate when a few nodes draining the upper arm are being spared by the ARM-SAD. MethodsWe report oncological outcomes, and axillary failure in particular, in the first 100 consecutive axillary node-positive patients treated with ARM-SAD as part of a pilot study and a randomized trial. ResultsA median of 18 (IQR 14–22) axillary nodes were excised per patient. During the follow-up (median 51 months, IQR 34–91), 11 patients experienced a treatment failure, but only one - treated with neoadjuvant chemotherapy - developed overt axillary disease as a first (and isolated) event. The crude rate of axillary failure was 1.36% (95% CI: 0.19–9.63) with an estimated 5-year crude cumulative incidence of 1.85% (95% CI: 0–5.47%). ConclusionsThe axillary failure rate was low in our patients and did not exceed rates reported in the literature after standard AD, thus indicating that the ARM-SAD procedure is oncologically safe.

Adversarial reverse mapping of equilibrated condensed-phase molecular structures

A tight and consistent link between resolutions is crucial to further expand the impact of multiscale modeling for complex materials. We herein tackle the generation of condensed molecular structures as a refinement—backmapping—of a coarse-grained (CG) structure. Traditional schemes start from a rough coarse-to-fine mapping and perform further energy minimization and molecular dynamics simulations to equilibrate the system. In this study we introduce DeepBackmap: A deep neural network based approach to directly predict equilibrated molecular structures for condensed-phase systems. We use generative adversarial networks to learn the Boltzmann distribution from training data and realize reverse mapping by using the CG structure as a conditional input. We apply our method to a challenging condensed-phase polymeric system. We observe that the model trained in a melt has remarkable transferability to the crystalline phase. The combination of data-driven and physics-based aspects of our architecture help reach temperature transferability with only limited training data.

150 Poster - A patient- and assessor-blinded randomized controlled trial of axillary reverse mapping (ARM) in patients with early breast cancer

Background: Axillary lymph node dissection (ALND) in breast cancer patients is infamous for its accompanying morbidity. Selective preservation of upper extremity lymphatic drainage and accompanying lymph nodes crossing the axillary basin – currently resected during a standard ALND – has been proposed as a valuable surgical refinement.

169 Poster - Selective axillary dissection after axillary reverse mapping in node positive breast cancer patients to prevent breast cancer related lymphedema. The issue of safety

169 Poster - Selective axillary dissection after axillary reverse mapping in node positive breast cancer patients to prevent breast cancer related lymphedema. The issue of safety

Comparison of indocyanine green and methylene blue use for axillary reverse mapping during axillary lymph node dissection.

Axillary reverse mapping (ARM) is a technique to identify arm lymphatic drainage during axillary lymph node dissection (ALND). This study compared the feasibility of ARM using indocyanine green (ICG) or methylene blue (MB), and accessed the oncologic safety of the procedure. Overall, 158 patients qualified for ALND were enrolled. The characteristics of ARM‐identified nodes were recorded with ICG (n = 78) or MB (n = 80) visualization. Fine‐needle aspiration cytology (FNAC) of the nodes were performed and validated by histologic analysis. The nodal identification rate in the ICG group significantly surpassed that of the MB group (87.2% vs 52.5%, P < .05) with fewer complications. Note that 10.9% of the patients had metastatic involvement of the ARM‐identified nodes. Also 80% of the positive nodes were found in areas B and D, while the ARM‐identified nodes mainly located in area A. All the 51 nodes diagnosed as negative of malignancy by FNAC were free of metastasis. Nodal metastasis was significantly correlated with extensive nodel involvement, advanced disease, and the characteristics of identified nodes. In conclusion, ICG appears superior to MB for ARM nodes identification. FNAC, together with the features of primary tumors and ARM nodes, can delineate which nodes could be preserved during ALND.

The Cognitive Study of the Effect of Cultural Artifacts on the Metaphorical Comprehension of Time Concept in Persian

In different cultures, people use space to make linguistic representations of time. In general, there are two different approaches toward deictic time expressions: a Moving Time Metaphor and a Moving Ego Metaphor. In the Moving Time metaphor, time is conceived as moving forward, while in a Moving Ego Metaphor, a moving observer is conceptualized. The purpose of this research is to explore the effect of cultural artifacts on metaphorical comprehension of time expressions in Persian language. In this regard, following Duffy and Feist (2014), the present study was carried out based on the ambiguous question: Wednesday's Meeting suggested by McGlone and Harding (1998). The first experiment directly explores the relationship between responses to the Wednesday's Meeting question in two calendar and meta-language conditions. The second experiment examines the special cultural relations between space and time and the role of the Persian orthography direction in the time reasoning. In the third experiment, based on circular representations of time, the role of the analog clock in resolving the ambiguity is examined from the Noon's Meeting question. This was done by comparing the responses of the participants with the clockwise clock and counterclockwise clock. To this end, 40 Persian speakers were selected from the students of Sistan and Baluchestan University. Chi-square test (using SPSS software) was used for statistical analysis. The findings of this study show that the viewpoint of individuals about the motion of events in time is not only due to their experience in space movement, but also is rooted in their interactive patterns of cultural artifacts as well. In addition, the results show that in interpreting ambiguous metaphorical time expressions, individuals automatically access spatial representations of time and use them. The participants who encountered with reverse space-time mappings had an interference in their responses, reflected through their time reasoning. Consequently, they provide a more precise form of representations of time than merely symbolic speech. Hence, cultural artifacts play an important role in the cognitive process of embodiment, which not only help to recognize embodiment, but also affect it.

Axillary reverse mapping in patients undergoing axillary dissection -a short review of the literature

Axillary lymph node dissection (ALND) can be avoided not only in patients with negative sentinel lymph nodes (SLNs) but also in those with one or two positive SLNs receiving breast or axillary radiation. However, ALND has remained the standard treatment for patients with clinically positive nodes (cN+). Although axillary reverse mapping (ARM) was developed to map and preserve arm lymphatic drainage during ALND, it could not be indicated for cN + patients because metastatic rate of ARM nodes is high. However, a new type of conservative ALND with ARM attempts to preserve ARM lymphatics and nodes except SLNs and other suspicious palpable nodes, including suspicious ARM nodes. This procedure allowed reduction of the rate of arm lymphedema without increasing axillary recurrence, although patients received postoperative chemotherapy and high-risk patients underwent axillary radiation. Thus, a traditional full ALND may not be necessary for cN + patients in the era of effective multimodality therapy.

Clinical study of exploring new axillary zone in sentinel lymph node biopsy of breast cancer

Objective: To explore the application of axillary reverse mapping (ARM) in breast cancer sentinel lymph node biopsy (SLNB), and to collect and record patient's data during operation. Through the specific experimental data, the anatomical location and morphology of the intercostal brachial nerve (ICBN) and the anatomic relationship of the axillary lymph nodes were analyzed to accurately locate the anatomical division of the axillary fossa of sentinel lymph node (SLN) and ARM lymph nodes. Methods: The technique of methylene blue staining for SLN combined with indocyanine green fluorescent staining for axillary reverse mapping was used to analyze the patients of Tianjin Central Hospital of Gynecology Obstetrics from June 2017 to June 2018. The clinical data of 35 patients with T1-2N0M0 breast cancer were analyzed. Results: Of the 35 patients, two cases were excluded from metastatic carcinoma of the SLN. Thirty-three cases were included in the data analysis. Three cases of ICBN were located 0-2.0 cm (9.09%) from the lower edge of the iliac vein, 27 cases were located at 2.0-4.0 cm (81.82%), and 3 cases of ICBN were located greater than 4.0 cm (9.09%). In the region of 0-2.0 cm from the lower edge of the iliac vein, 1-2 ARM lymph nodes were found in 5 cases; in the 2.0-4.0 cm area, SLN was found in 33 cases, 4 of which found 1 coincident lymph node; at>4.0 cm ARM lymph nodes and overlapping lymph nodes were not found in the cm region, and 1-2 SLNs were found in 3 cases. Conclusions: Individual ICBNs vary greatly, with different shapes and distances from the lower edge of the axillary vein. The axillary region below the iliac vein can be divided into three regions: ARM region (0-2.0 cm); SLN region (2.0-4.0 cm); and sentinel gate region (>4.0 cm). The position 2.0 cm from the lower edge of the iliac vein can be used as the boundary between the ARM lymph node and the SLN. 4. There is a certain proportion of coincidence rate between SLN and ARM lymph nodes.

A run-to-run controller for a chemical mechanical planarization process using least squares generative adversarial networks

Achieving high processing quality for chemical mechanical planarization (CMP) in semiconductor manufacturing is difficult due to the distinct process variations associated with this method, such as drift and shift. Run-to-run control aims to maintain the targeted process quality by reducing the effect of process variations. The goal of controller learning is to infer an underlying output–input reverse mapping based on input–output samples considering the process variations. Existing controllers learn reverse mapping by minimizing the total mapping error for sample data. However, this approach often fails to generate inputs for unseen target outputs because conditional input distributions on target outputs are not captured in the learning. In this study, we propose a controller based on a least squares generative adversarial network (LSGAN) that can capture the input distributions. GANs are deep-learning architectures composed of two neural nets: a generator and a discriminator. In the proposed model, the generator attempts to produce fake input distributions that are similar to the real input distributions considering the process variation features extracted using convolutional layers, while the discriminator attempts to detect the fake distributions. Competition in this game drives both networks to improve their performance until the generated input distributions are indistinguishable from the real distributions. An experiment using the data obtained from a work-site CMP tool verified that the proposed model outperformed the comparison models in terms of control accuracy and computation time.

Time series forecasting based on kernel mapping and high-order fuzzy cognitive maps

Fuzzy cognitive maps (FCMs) have emerged as a powerful tool for dealing with the task of time series prediction. Most existing research devoted to designing an effective method to extract feature time series from the original time series, which are used to construct FCMs and predict the time series. However, in existing methods, all extracted feature time series, including the redundant feature time series, were used to develop FCMs instead of selecting the key feature time series (KFTS) to construct FCMs, which limits the generalization and prediction accuracy of the models. In this paper, we propose a framework based on kernel mapping and high-order FCMs (HFCM) to forecast time series inspired by the kernel methods and support vector regression (SVR). The model is termed as Kernel-HFCM. Kernel mapping is designed to map the original one-dimensional time series into multidimensional feature time series, and then the feature selection algorithm is proposed to select the KFTS from the multidimensional feature time series to develop the HFCM. Finally, reverse kernel mapping is used to map the feature time series back to the predicted one-dimensional time series. In comparison to the existing methods, the experimental results on seven benchmark datasets demonstrate the effectiveness of Kernel-HFCM in time series prediction.

Speech Synthesis of Children’s Reading Based on CycleGAN Model

The generation of emotional speech is a challenging and widely applied research topic in the field of speech processing. Because the design method of effective speech feature expression and generation model directly affects the accuracy of emotional speech generation, it is difficult to find a general solution of emotional speech synthesis. In this paper, the CycleGAN model is used as the starting point, and the improved convolution neural network (CNN) model and identity mapping loss scheme are used to achieve effective timing information capture. At the same time, we learn the positive mapping and the reverse mapping to find the best matching design scheme, and retain the speech information in this process, without relying on other audio data. Experiments show that the emotional speech can be accurately recognized by comparing the speech emotion before and after the improvement on the speech corpus of children’s reading. By comparing with the common emotional speech generation model, the advantages of the model proposed in this paper are verified.

Microscopic Picture of Calcium-Assisted Lipid Demixing and Membrane Remodeling Using Multiscale Simulations

The specificity of anionic phospholipids-calcium ion interaction and lipid demixing has been established as a key regulatory mechanism in several cellular signaling processes. The mechanism and implications of this calcium-assisted demixing have not been elucidated from a microscopic point of view. Here, we present an overview of atomic interactions between calcium and phospholipids that can drive nonideal mixing of lipid molecules in a model lipid bilayer composed of zwitterionic (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)) and anionic (1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-l-serine (POPS)) lipids with computer simulations at multiple resolutions. Lipid nanodomain formation and growth were driven by calcium-enabled lipid bridging of the charged phosphatidylserine (PS) headgroups, which were favored against inter-POPS dipole interactions. Consistent with several experimental studies of calcium-associated membrane sculpting, our analyses also suggest modifications in local membrane curvature and cross-leaflet couplings as a response to such induced lateral heterogeneity. In addition, reverse mapping to a complementary atomistic description revealed structural insights in the presence of anionic nanodomains, at timescales not accessed by previous computational studies. This work bridges information across multiple scales to reveal a mechanistic picture of calcium ion's impact on membrane biophysics.

Surgical Approach to Lymphedema Reduction.

For patients who have or may develop lymphedema due to oncologic resection, surgical options are available to prevent and treat this chronic disease. Here, we review the current pathophysiology, classification systems, surgical preventive techniques, and treatment options for lymphedema reduction. Preventive surgical techniques, including de-escalation of axillary surgery, sentinel lymph node biopsy (SLNB), axillary reverse mapping (ARM), and lymphedema microsurgical preventive healing approach (LYMPHA), have been shown to reduce the incidence of lymphedema. Water displacement remains the gold standard for measuring limb volume and classification of lymphedema; however, lymphoscintigraphy and ICG lymphography are two novel imaging techniques that are now utilized to characterize lymphedema and guide management. Complete decongestive therapy (CDT) remains the mainstay of treatment. Vascularized lymph node transfer (VLNT) and lymphovenous bypass have shown promising results, particularly in advanced lymphedema stages. Combination therapy, incorporating both surgical and non-surgical approaches to lymphedema, yields best patient outcomes. Lymphedema is a chronic disease wherein management requires a combination of surgical and conservative treatments. Standardization in lymphedema staging, key outcome indicators, and quantitative data will be critical to establish the absolute best practices in lymphedema diagnosis and treatment.

Recognition of symmetries in reversible maps

We deal with germs of diffeomorphisms that are reversible under an involution. We establish that this condition implies that, in general, both the family of reversing symmetries and the group of symmetries are not finite, in contrast with continuous-time dynamics, where typically there are finitely many reversing symmetries. From this we obtain two chains of fixed-points subspaces of involutory reversing symmetries that we use to obtain geometric information on the discrete dynamics generated by a given diffeomorphism. The results are illustrated by the generic case in arbitrary dimension, when the diffeomorphism is the composition of transversal linear involutions.

Chemical Composition and Immunomodulatory Activity of Hypericum perforatum Essential Oils.

Hypericum L. (Hypericaceae) extracts have been used for their therapeutic effects; however, not much is known about the immunomodulatory activity of essential oils extracted from this plant. We isolated essential oils from the flowers and leaves of H. perforatum and analyzed their chemical composition and innate immunomodulatory activity. Analysis of flower (HEOFl) versus leaf (HEOLv) essential oils using gas chromatography–mass spectrometry revealed that HEOFl was comprised mainly of monoterpenes (52.8%), with an abundance of oxygenated monoterpenes, including cis-p-menth-3-en-1,2-diol (9.1%), α-terpineol (6.1%), terpinen-4-ol (7.4%), and limonen-4-ol (3.2%), whereas the sesquiterpenes were found in trace amounts. In contrast, HEOLv was primarily composed of sesquiterpenes (63.2%), including germacrene D (25.7%) and β-caryophyllene (9.5%). HEOLv also contained oxygenated monoterpenes, including terpinen-4-ol (2.6%), while monoterpene hydrocarbons were found in trace amounts. Both HEOFl and HEOLv inhibited neutrophil Ca2+ mobilization, chemotaxis, and reactive oxygen species (ROS) production, with HEOLv being much more active than HEOFl. Furthermore, the pure sesquiterpenes germacrene D, β-caryophyllene, and α-humulene also inhibited these neutrophil responses, suggesting that these compounds represented the active components of HEOLv. Although reverse pharmacophore mapping suggested that potential protein targets of germacrene D, β-caryophyllene, bicyclogermacrene, and α-humulene could be PIM1 and mitogen-activated protein kinase (MAPK)-activated protein kinase 2 (MAPKAK2), a kinase binding affinity assay did not support this finding, implying that other biological targets are involved. Our results provide a cellular and molecular basis to explain at least part of the beneficial immunotherapeutic properties of the H. perforatum essential oils.

Development of Lee’s exact method for Gauss–Krüger projection

Lee’s exact method was developed to enable the Gauss–Kruger (GK) projection to be implemented without iterative procedures via the expansion of the intermediate mapping (Thompson projection) into series approximations in terms of isothermal coordinates $$\left( \psi , \lambda \right) $$ for the forward mapping and GK coordinates $$\left( x, y \right) $$ for the reverse mapping. The straightforward procedures expressed by new formulas for both forward and reverse mapping of the GK projection were composed by three sequential steps which essentially reveal the mapping procedures and intrinsic properties of the GK projection: The first step of deriving the isothermal coordinates $$\left( \psi , \lambda \right) $$ from the geodetic coordinates $$\left( \varphi , \lambda \right) $$ specifies a conformal mapping (i.e., the Normal Mercator projection) of the Earth ellipsoid surface into the Euclidean plane excluding the South and North poles, and the subsequent two steps allow the GK projection to be expressed analytically via the elliptic functions and integrals. Based on the three-step procedure, the conformality and singularities over the entire ellipsoid of the Normal Mercator, Thompson and GK projections were analyzed and the fundamental domains of them were determined. With respect to the precision and efficiency, it was verified that the new algorithm and the complex latitude method had equivalent precision levels for the same orders of the third flatting n with the Kruger-n series from $$n^2$$ to $$n^{12}$$ but slower about 0.19 to $${0.21}\,\upmu \hbox {s}$$ than the Kruger-n series for a GK coordinates calculating. However, the new formulas provide series approximations for the forward mapping of the Thompson projection and projective transformations for the Normal Mercator, Thompson and GK projections.

Using the axillary reverse mapping technique to screen breast cancer patients with a high risk of lymphedema

BackgroundPreventing breast cancer-related lymphedema (BCRL) by preserving upper lymphatic drainage is still controversial. Our study aimed to use the axillary reverse mapping (ARM) technique in patients who underwent axillary surgery to analyse the correlation between postoperative residual ARM nodes and the occurrence of lymphedema, select candidates at high risk of developing lymphedema, and analyse the oncologic safety of ARM nodes.MethodsPatients undergoing sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (ALND) from October 2015 to February 2016 at the Peking University People’s Hospital Breast Center were prospectively recruited for the study. ARM was performed in all patients before surgery. ARM nodes were separated from SLNB and ALND specimens. Data were collected on the identification of ARM nodes before surgery, number of residual ARM nodes after surgery, nodal status, crossover rate, and correlation between residual ARM nodes and the occurrence of lymphedema.ResultsThe analysis included 78 patients. Of the 53 patients who underwent SLNB, crossover between ARM nodes and breast sentinel lymph nodes (SLNs) was seen in 22 specimens. The incidence of ARM node metastasis was 1.89% (1/53) and 25% (9/36) in the SLNB and ALND groups, respectively. The number of positive axillary lymph nodes was associated with the involvement of ARM nodes (P = 0.036). The incidence of residual ARM nodes was significantly higher in the SLNB group than in the ALND group (67.6% vs. 37.9%, P = 0.016). The incidence of lymphedema was significantly higher in the ALND group than in the SLNB group (33.3% vs. 5.4%, P = 0.003).ConclusionsFor SLNB, the ARM technique can help to resect SLNs more accurately. However, we do not recommend using the ARM technique to preserve ARM nodes in patients undergoing ALND due to oncologic safety issues. Nevertheless, we can predict patients undergoing axillary surgery who are more likely to have a high risk of lymphedema by assessing residual ARM nodes.Trial registrationThis study was registered on ClinicalTrials.gov in February 2016.The clinical trial registration number is NCT02691624.

Conserving the lymphatics from the arm using fluorescence imaging in patients with breast cancer at high risk of postoperative lymphedema: a pilot study.

Postoperative lymphedema in breast cancer survivors is a serious complication that develops from axillary lymph node dissection (ALND), chemotherapy, and radiation therapy. Axillary reverse mapping (ARM) was recently introduced to reduce lymphedema. This pilot study aimed to investigate the feasibility of preserving the ARM node using fluorescence imaging for patients at high risk of lymphedema. We prospectively screened patients with breast cancer who had pathologic node-positive disease at diagnosis and were scheduled for neoadjuvant chemotherapy (NCT). The sentinel lymph node (SLN) was identified using blue dye and radioisotope, while the ARM node was traced using indocyanine green (ICG). In cases in which SLN was negative on the intraoperative frozen section examination, the ARM node and lymphatics were preserved. Of the 20 screened patients, six whose metastatic axillary lymph node (ALN) was converted to clinically node-negative disease after NCT were enrolled. No patients experienced recurrence at 24 months postoperative. Four patients who had a preserved ARM node did not develop lymphedema. One patient whose ARM node was not preserved due to SLN identification failure did not develop postoperative lymphedema. One patient who underwent ALND without ARM node conservation because of metastatic SLN on frozen section examination developed postoperative lymphedema. ARM is oncologically safe, decreases the incidence of postoperative lymphedema, and allows for the early detection of postoperative lymphedema in patients who underwent ALND. Ultimately, ARM may help improve the quality of life of patients with pathologic node-positive breast cancer.