Abstract: The present invention relates to method for detecting a free histone protein in a biological sample of a subject, e.g. using an immunoassay or a mass spectrometric assay. It also pertains to a method for the diagnosis, prognosis, risk assessment, risk stratification and/or therapy control of a disease or medical condition, comprising detecting a free histone protein or peptide fragment thereof in a biological sample of a subject, wherein the presence of said free histone protein or fragment thereof is indicative for said disease or medical condition.

Abstract: The purpose of the present invention is to provide a simple and highly accurate method for detecting pancreatic exocrine dysfunction with minimal invasiveness to a subject. The method comprising in vitro measurement of two APOA2 protein variants, mutants thereof and/or fragments thereof in a body fluid sample derived from the subject and detection of the presence or absence of pancreatic exocrine dysfunction on the basis of the measured amounts, and a detection kit for pancreatic exocrine dysfunction including antibodies that can specifically bind to said proteins are provided.

Abstract: Embodiments of the invention provides a method for detecting one or more biomarkers derived from a body fluid, comprising performing one or more assays for the biomarkers from a sample of the body fluid, whereby the sample is previously preserved on a solid support; wherein a change in the biomarkers provides an indication of a biological event in the brain. The invention also provides related methods for identifying a person as being at risk of dementia or Alzheimer's disease, monitoring a person for the onset or progression of dementia or Alzheimer's disease, evaluating the effectiveness of a potential pharmaceutical agent.

Abstract: The inventors surprisingly found that neural stimulation caused the synthesis and degradation of proteins into peptides which were then secreted into the cell media within minutes of stimulation by a novel neural-specific and membrane bound proteasome (neuronal membrane proteasome or NMP) that is transmembrane in nature. These secreted, activity-induced, proteasomal peptides (SNAPPs) range in size from about 500 Daltons to about 3000 Daltons. Surprisingly none of the peptides appear to be those previously known to have any neuronal function. Moreover, these SNAPPs have stimulatory activity and are heretofore a new class of signaling molecules. Moreover, the NMP appears to play a highly significant role in aspects of neuronal signaling known to be critical for neuronal function.

Abstract: The subject invention provides a robust, quantitative, and reproducible process and assay for diagnosis of a neurological condition in a subject. The invention provides measurement of two or more biomarkers in a biological fluid such as CSF or serum resulting in a synergistic mechanism for determining the extent of neurological damage in a subject with an abnormal neurological condition and for discerning subtypes thereof or tissue types subjected to damage.

Abstract: High affinity DNA aptamers Seq ID#1-8 for HbA1C and tHb were successfully selected using SELEX after 11 rounds of selection. The tested aptamers bind to HbA1C with dissociation constants in the nanomolar range with the highest affinity aptamer, Seq ID#6, exhibiting a Kd of 2.8 nM. Another aptamer sequence (Seq ID #4) which showed high binding affinity to tHb with a Kd of 2.7 nM was also selected. The HbA1C and tHb-specific aptamers were then applied for the detection of HbA1C % using a voltammetric aptasensor array platform showing remarkable sensitivity and selectivity. The aptasensor array platform was validated using standard human whole blood samples and demonstrated linearity over wide concentration range. The developed platform is superior to current methodologies due to its simplicity, stability and lower cost which will facilitate the early and accurate diagnosis of diabetes.

Abstract: The present invention relates to antagonists of GDF11, for use in the treatment of malignant hematological disease, such as Acute Myeloid Leukemia (AML). The present invention also relates to a method for predicting the responsiveness of a patient affected with malignant haematological disease, such as Acute Myeloid Leukemia, to a chemotherapy treatment.

Abstract: The present disclosure relates to: a composition for diagnosing aortic valve calcification diseases, comprising a preparation, which measures the protein level of inactivated IGF-1, wherein the composition is capable of diagnosing aortic valve calcification diseases involving calcification of aortic valves; a kit for diagnosing aortic valve calcification diseases, comprising the composition; a method for detecting inactivated IGF-1 so as to provide information necessary in the diagnosis of aortic valve calcification diseases; and a method for detecting inactivated IGF-1 so as to provide information necessary in the diagnosis of the progression level of aortic valve calcification diseases.

Abstract: The present invention provides methods and compositions, e.g., kits, for assaying a vitamin D moiety in a sample, comprising or using, inter alia, a buffer that is capable of dissociating a vitamin D moiety from its binding protein and/or a buffer of acidic pH, and at least two antibodies, e.g., at least two monoclonal antibodies, that are separately conjugated to particles, e.g., latex particles, wherein at least one of said antibodies (or the first antibody) has a specific binding affinity towards the vitamin D moiety, and at least another said antibody (or the second antibody) has a specific binding affinity towards the complex formed between the first antibody and the vitamin D moiety, if present in said sample. In some embodiments, the optical change due to the agglutination reaction between the antibodies and the vitamin D moiety is measured for determination of the amount of vitamin D content in the samples. Kits and reaction mixtures for assaying a vitamin D moiety in a sample are also provided.

Abstract: Disclosed is a method for measuring a clotting time, including the steps of: (A) mixing a blood sample, an activator, a phospholipid, and a nickel ion-forming compound to obtain a specimen; and (B) mixing the specimen obtained in step (A) with a calcium salt to prepare a measurement specimen and measuring the clotting time of the measurement specimen.

Abstract: Provided herein are phosphatidylethanolamine (PE)-specific probes and methods of use thereof. In particular, the present invention provides conjugates of PE binding moieties with detectable markers, and methods of use thereof to detect and/or characterize PE within cells.

Abstract: A method for detecting lipoarabinomannan in a biological sample is described, including the step of contacting the biological sample with at least one acid selected from the group consisting of perchloric acid, trifluoroacetic acid, and sulfosalicylic acid. Methods for diagnosing diseases, including tuberculosis, and kits for the described methods are also presented.

Abstract: The disclosure provides methods for differentiating between non-alcoholic fatty liver disease and non-alcoholic steatohepatitis. The method includes measuring eicosanoids and fatty acid levels in a biological sample.

Abstract: Provided herein are compositions, systems, and methods for extracting and detecting at least one HDL-associated protein (e.g., ApoA1) from a sample (e.g., plasma or serum sample). In certain embodiments, a strong organic acid and hydrophilic organic solvent are mixed with the sample; after centrifugation, the supernatant is transferred to a second container where it is mixed with a non-polar organic solvent; after centrifugation, the lower aqueous layer is transferred to a third container; and then at least a portion of the transferred aqueous layer is subjected to a detection assay such that at least one HDL-associated protein is detected.

Abstract: A diagnostic device and diagnostic method for monitoring operation of a technical system with an automation system, wherein values of process variables, which were previously automatically determined as relevant to a diagnosis by analyzing a program for a sequential function chart, are determined when each step of the cycle to be checked is executed and evaluated based on at least one predetermined self-organizing map acquired based on fault-free cycles during a system operation with repeatedly run step sequences such that automatic preselection of the process variables is which are relevant to the diagnosis is performed such that misdiagnoses can advantageously and largely be avoided and the reliability of the diagnostic statement can be increased.

Abstract: A smear transporting apparatus transports a smear slide on which a sample is smeared to a smear-image capture apparatus. The smear transporting apparatus includes a smear-container transport part that transports a first smear container accommodating smear slides to a smear pickup position; a smear transfer part that picks a smear slide whose image is to be captured by the smear-image capture apparatus from the first smear container transported to the smear pickup position, transfers the smear slide to the smear-image capture apparatus, and places the smear slide whose image has been captured by the smear-image capture apparatus in a second smear container different from the first smear container; and a storage that stores the first smear container and the second smear container.

Abstract: An automatic analyser which is capable of detecting a dispensing abnormality with a high degree of accuracy without causing the decrease in the determination performance or the increase in the calculation amount caused by the configuration balance of the reference database is implemented. A dispensing nozzle of a sample dispensing mechanism sucks the dispensing target, and internal pressure of the dispensing nozzle when ejecting the dispensing target to a reaction container is detected through a pressure sensor. A plurality of feature quantities are extracted from a waveform of the detected pressure, and a determination result is output through a linear combination formula using an optimal coefficient for a determination function that receives a plurality of feature quantities and outputs one value. The determination result indicates whether or not dispensing of the sample dispensing mechanism is performed normally in accordance with the magnitude of the output result of the determination function.

Abstract: The present invention provides a fully automatic fecal occult blood detecting analyzer, which is used to detect a sample box (30). The sample box (30) includes a transparent sleeve and a feces collector and test strips provided in the transparent sleeve. The fully automatic fecal occult blood detecting analyzer includes a feeding chain (10) and a main conveying chain (20); a plurality of clamping devices (40) for clamping the sample box (30) are provided on the feeding chain (10) and the main conveying chain (20), respectively; a transferring device is configured to transfer the sample box (30) from the feeding chain (10) to the main conveying chain (20); a pressing device (90); and an image acquisition device is configured to acquire colored tape information presented on the test strips in the sample box (30) on the main conveying chain (20).

Abstract: According to an aspect of the present invention, there is provided an automatic analyzer that detects a liquid level by using an electrostatic capacity system. Feature values are extracted from time-series oscillating frequency data of an alternating current signal that is output by an oscillation circuit in a period from a time point at which a dispensing probe starts moving downward till a time point at which a certain period of time has elapsed. On the basis of the feature values from the time-series oscillating frequency data, it is determined whether or not the liquid level in a container has been detected properly, by using different methods. Whether a gap is present between the tip portion of the dispensing probe and the liquid level in the container and a reason for the gap are determined from a combination of multiple determination results obtained by using the methods.

Abstract: A fluidic bridge device for transport of a fluid sample between a first sample processing device and a second sample processing device. The fluidic bridge may include one or more fluid channels extending between fluid-tight couplings attachable to transfer ports of the first and second sample processing device. In one aspect the first device is a sample preparation device and the second device is an assay device. The fluidic bridge can include at least two fluid conduits, at least one for transport of the prepared sample, and at least one other to facilitate displacement of air to allow flow of the prepared sample through the other fluid conduit. The fluid channels can include one or more of an amplification chamber, a processing chamber, a gas-permeable vent, a bubble trap, a filter, and an external port. Methods of preparing and transporting a fluid sample between devices are provided herein.

Abstract: Systems and methods are disclosed for generating temperature compensated acceleration data in both analog and digital format from a torque balance accelerometer (TBA). During manufacture of the TBA, a calibration process is used consisting of cooling and heating the TBA to discrete temperatures within a range and at each discrete temperature measuring the TBA scale factor and offset. After collecting scale and offset data, said data is loaded into the memory of the TBA. During field operation, sensing a current temperature, retrieving the closest scale and offset correction factors from memory of the TBA, and performing linear interpolation to generate a temperature-compensated output for the TBA.

Abstract: Disclosed is a method for processing a primary signal produced by a sensor detecting the rotation of a rotating target. The primary signal includes pulses having, for a given speed of rotation of the target, a first positive voltage level for rotation in a first determined direction or a second positive voltage level for the opposite direction. A first secondary signal is generated by comparing the primary signal to a first determined voltage threshold between the first and second voltages. A second secondary signal is generated by comparing the primary signal to a second determined voltage threshold between the second voltage level and zero. A determined delay is introduced in the second secondary signal. A determined time threshold is compared to the duration between an active edge of the second secondary signal and the last preceding active edge of the first secondary signal, indicating direction.

Abstract: A pulsar ring which is a detection target ring includes an annular base wall having pickup holes and a plurality of ring attachment portions protruding from an outer peripheral edge portion of the base wall and being fixed, together with a disc attachment portion of a brake disc, to a wheel of a vehicle wheel assembly. Regions corresponding to positions between adjacent ring attachment portions in an inner peripheral edge portion of the base wall are bent to form reinforcing ribs.

Abstract: An article and method are described that measure the average speed of an object. A timer measures the time an object takes to travel from a start to a finish. A goniometer measures the angle between the start, the article, and the finish. A wave generator determines the distances from the article to the start and finish. Using a geometric identity, the distance traveled by the object from the start to the finish can be determined and, using the time, the average speed can be calculated. The article and method are especially suitable for quickly measuring the average speed of objects moving below about 10 m/s and without defining a predetermined path. An electronic processor can be used to automate the method.

Abstract: Multi-path signal processing for microelectromechanical systems (MEMS) sensors is described. An exemplary MEMS sensor apparatus can comprise a single MEMS sensor element and an associated integrated circuit (IC) that facilitates generating multiple output signals having different output signal electrical characteristics required by a host system. Provided implementations can minimize cost and IC die area of associated MEMS sensor apparatuses and systems by employing one or more signal multiplexers (MUXs) on a single common signal path from the single MEMS sensor element. In addition, various methods of generating multiple output signals having different output signal electrical characteristics from a single MEMS sensor element are described.

Abstract: Disclosed is apparatus and a method for detecting udder disease in dairy animals. An accelerometer is attached to each of a plurality of dairy animals. A processor determines a measure of the activity of the dairy animals to which the accelerometers are attached. Data is recorded by and automatically transmitted from a sensor unit secured to an animal, without the requirement for costly and time consuming chemical analysis of milk, or of visual or veterinary inspection of individual animals in a herd. The development of an udder disease in a dairy animal, such as mastitis, may be identified from a decrease in the monitored measure of activity of a dairy animal. A separate baseline measure of activity may be determined for each dairy animal and the activity of a plurality of dairy animals in one or more herds may be taken into account, in order to reduce false positives due to external effects which are not specific to a single dairy animal.

Abstract: A micro-opto-mechanical sensor device comprises a substrate; a moveable structure on the substrate and supported by a plurality of flexible supports, the moveable structure being spaced apart from the substrate; and an optical waveguide between the moveable structure and the substrate, wherein movement of the moveable structure attenuates light in the optical waveguide.

Abstract: An accelerometer is included within the confined space and limited volume of a distal portion of a surgical instrument. The surgical instrument includes an end component, a joint coupled to the end component, a shaft coupled to the joint, and a force transducer and accelerometer apparatus. The force transducer and accelerometer apparatus is coupled between the joint and the shaft. The force transducer and accelerometer apparatus includes a force sensor and an accelerometer. The accelerometer includes an optic fiber having a Fiber Bragg Grating. Information acquired from the Fiber Bragg Grating is used to drive a vibro-tactile haptic feedback output device coupled to a master control arm surgeon grip.

Abstract: Systems and methods are described herein for detecting and measuring inertial parameters, such as acceleration. In particular, the systems and methods relate to vibratory inertial sensors implementing time-domain sensing techniques. Within a composite mass sensor system, a sense mass may oscillate at a frequency different from its actuation frequency, allowing flexibility when integrating the sensor into drive systems without sacrificing sensitivity.

Abstract: System and methods are disclosed herein for converting rotational motion to linear motion. A system comprising a rotational drive can be connected to a proof mass by a first structure comprising a coupling spring. An anchor can be connected to the proof mass by a second structure comprising a drive spring. The coupling spring and the drive spring can be configured to cause the proof mass to move substantially along a first axis when the rotational drive rotates about a second axis.

Abstract: Systems and methods are described herein for determining an inertial parameter. In particular, the systems and methods relate to multiple degrees of freedom inertial sensors implementing time-domain sensing techniques. Within a multiple degrees of freedom inertial sensor system, sense masses may respond to actuation with more than one natural frequency mode, each corresponding to a characteristic motion. Measurement of the inertial parameter can be conducted in the differential natural frequency mode using differential sensing techniques to remove common mode error. The inertial parameter can be acceleration in the vertical dimension. The inertial parameter can be acceleration in the horizontal dimension.

Abstract: In some examples, a sensor device is to mount to a barrier pivotable between an open position and a closed position, the barrier being on a moveable platform. The sensor device includes an accelerometer to measure acceleration data and a rotation sensor to measure rotation about an axis. The sensor device includes at least one processor configured to determine an open/close status of the barrier based on the acceleration data and the rotation data, and an orientation of the moveable platform.

Abstract: A system to recognize user activity includes a filter to form a gravity measurement from a three-dimensional (3D) accelerometer measurement of a user activity; a body component extractor to form a body measurement of the user activity by removing the gravity measurement from the 3D accelerometer measurement; a rotation matrix calculator to form a rotation matrix that is used to rotate the extracted gravity to align with a predetermined direction, and to rotate the 3D accelerometer measurements and the body measurement to be the input to features determiner module; and a features determiner to determine values of a predetermined number of features of the user activity based on the rotated 3D accelerometer measurement and the rotated body measurement in which the predetermined number of features are invariant under arbitrary rotation of the accelerometer measurement around the predetermined direction.

Abstract: A test fixture has a flexible plastic cable that acts as a waveguide. The Device-Under-Test (DUT) is a small transceiver and antenna that operate in the Extremely High-Frequency (EHF) band of 30-300 GHz. The size of the DUT transceiver is very small, limiting the power of emitted electromagnetic radiation so that close-proximity communication is used. The envelope for reception may only extend for about a centimeter from the DUT transceiver, about the same size as the test socket. A slot is formed in the test socket very near to the antenna. The slot receives one end of the plastic waveguide. The slot extends into the envelope by the DUT transceiver so that close-proximity radiation is captured by the plastic waveguide. The waveguide has a high relative permittivity and reflective metalized walls so that the radiation may be carried to a receiver that is outside the envelope.

Abstract: A common board of an adaptor for a tester may include a common insulating plate, a common test signal line, a common power line, and a common ground line. The common test signal line may be arranged in the common insulating plate to provide at least one object with a test signal. The common power line may be arranged in the common insulating plate to provide the object with power. The common ground line may be arranged in the common insulating plate to ground the object. Therefore, when one kind of object may be changed into other different kinds of objects, only the adapting board may be replaced with a new adapting board corresponding to the other kinds of the objects without changing of the entire adaptor.

Abstract: Shielded probe systems are disclosed herein. The shielded probe systems are configured to test a device under test (DUT) and include an enclosure that defines an enclosure volume, a translation stage with a stage surface, a substrate-supporting assembly extending from the stage surface, an electrically conductive shielding structure, an isolation structure, and a thermal shielding structure. The substrate-supporting assembly includes an electrically conductive support surface, which is configured to support a substrate that includes the DUT. The electrically conductive shielding structure defines a shielded volume. The isolation structure electrically isolates the electrically conductive shielding structure from the enclosure and from the translation stage. The thermal shielding structure extends within the enclosure volume and at least partially between the enclosure and the substrate-supporting assembly.

Abstract: Methods and measurements systems are disclosed relating to use of a soft front panel (SFP) to display results of measurement functions. A measurement device may concurrently perform two or more measurement functions to produce two or more respective signal measurements, wherein each measurement function comprises an acquisition function and a processing function. A computer may be configured to display information on a soft front panel on the display device corresponding to two or more of the signal measurements. The computer may receive, from a user, a selection of an update option, wherein the update option indicates a trigger that causes the displayed information to update. Responsive to receiving an indication that the trigger has occurred, the computer may update the displayed information on the soft front panel.

Abstract: Measurement apparatuses and methods are described. A measurement input is coupled with a first terminal of a capacitance via a first switch, and a reference voltage is coupled with the first terminal of the capacitance via a second switch. A measurement circuit is coupled to a second terminal of said capacitance.

Abstract: A dynamic real time transmission line monitor, a dynamic real time transmission line monitoring system, and a method of dynamic real time transmission line monitoring. A dynamic real time transmission line monitor includes a housing installable on a transmission line, the housing including a base portion, and a cover portion coupled to the base portion and defining a cavity of the housing together with the base portion; a sensor configured to sense in real time at least one of a temperature, a position, a current, an acceleration, a vibration, a tilt, a roll, or a distance to a nearest object; and an antenna in the cavity of the housing and configured to transmit a signal including information sensed by the sensor away from the monitor in real time.

Abstract: A device for integrated current measurement inside a high-voltage contact-making means of a hybrid module includes a printed circuit board with at least one current sensor chip that is arranged on the printed circuit board. The device further includes a high-voltage contact-making plug connection, which is mounted on the printed circuit board. The high-voltage contact-making plug connection has at least one Hall ring and one busbar that is passed through the Hall ring, wherein the Hall ring has an open cross section and the sensor chip is at least partially accommodated in the open cross section.

Abstract: A current sensor is configured to measure current flowing in two bus bars aligned in an X direction and extending parallel in a Y direction. A sensing element is arranged such that its magnetism sensing direction is oriented in the X direction on a line passing through the bus bar in a Z direction. A pair of shield plates sandwiches the bus bar and the sensing element therebetween in the Z direction. The bus bar is located between the sensing element and the lower shield plate. The sensing element is located closer to the upper shield plate than to the lower shield plate. At least one of a thickness and a magnetic permeability of the magnetism shield plates is greater in the upper shield plate than in the lower shield plate.

Abstract: An inspection apparatus includes a tester unit that applies a stimulus signal to a semiconductor apparatus, an MO crystal arranged to face a semiconductor apparatus, a light source that outputs light, an optical scanner that irradiates the MO crystal with light output from light source, a light detector that detects light reflected from the MO crystal arranged to face the semiconductor apparatus D and outputs a detection signal, and a computer that generate phase image data based on a phase difference between a reference signal generated based on a stimulus signal and the detection signal, the phase image data including a phase component indicating the phase difference, and generates an image indicating a path of a current from the phase image data.

Abstract: Disclosed is a charge plate monitor for eliminating a stray capacitor in a relay switch by using a voltage feedback method, and an operation method thereof. The charge plate monitor includes: a measurement plate unit including a conductive plate, a ground surface, and an insulator provided between the conductive plate and the ground surface; a noncontact electrometer provided between the conductive plate and the ground surface of the measurement plate unit and detecting an electrical potential of the conductive plate; a measurement unit reading or passing the electrical potential of the conductive plate detected by the noncontact electrometer; and a voltage feedback circuit unit that feeds the electrical potential of the conductive plate passed by the measurement unit back, and applying the electrical potential to a terminal of a relay switch terminal.

Abstract: The invention relates to a method of determining power consumption of an electrical heating system, where the power consumption is defined by a reading of information from a conductor (4, 6) within a thermostat (1). The invention further relates to a thermostat comprising an element for determining the power consumption of an electrical heating system, where the thermostat (1) is provided with a reading element (5) for reading current from a conductor (4, 6) and a reading element (28) reading voltage from a transformer output.

Abstract: Systems and methods for synchronized phasor measurement in a power distribution network are described. In an aspect, the systems and methods quantify the phase angle between voltages or currents at any two points in the distribution network. In another aspect, the systems and methods establish a common time reference between points on a power distribution network by transmitting a synchronization pulse throughout the distribution network. In an additional aspect, the systems and methods extract phasors from a power line waveform by utilizing a phase-locked loop (PLL) and regression of the zero-crossings of the PLL output waveform.

Abstract: An apparatus for analyzing electrical consumption measurements, including: a transferring component for receiving sampled electricity consumption data of at least two phases of power supplied to a machine from at least two sensors, and transferring the data to an application server; an application server for receiving the sampled values and analyzing the sampled values for the at least two phases, thereby obtaining information related to a status of the machine or to a type of manufactured item.

Abstract: Disclosed are various approaches for measuring and reporting the amount of electrical power consumed by an electrical load attached to a guided surface wave receive structure. A guided surface wave receive structure is configured to obtain electrical energy from a guided surface wave traveling along a terrestrial medium. An electrical load is coupled to the guided surface wave receive structure, the electrical load being experienced as a load at an excitation source coupled to a guided surface waveguide probe generating the guided surface wave. An electric power meter coupled to the electrical load and configured to measure the electrical load.

Abstract: A method is presented for measuring the electric field of electromagnetic radiation using the spectroscopic responses of Rydberg atoms to the electromagnetic radiation field. The method entails implementing quantitative models of the Rydberg atom response to the electromagnetic radiation field to provide predetermined atomic properties or spectra for field amplitudes and or frequencies of interest, spectroscopically measuring the response (spectrum) of Rydberg atoms exposed to an unknown electromagnetic radiation field, and obtaining the electric field amplitude and/or frequency of the unknown electromagnetic radiation by using features extracted from the measured spectrum and comparing them to features in a predetermined spectrum among the set of predetermined spectra.

Abstract: A system for remotely measuring antenna input impedance utilizing an automatic antenna tuner in which for any tuner, the tuner input impedance may be established by the values of the components in the circuit at the time that the SWR is at a minimum, with these values being automatically available in terms of the components that are switched in to achieve low SWR. Once having established the input impedance to the tuner, the complex conjugate of the tuner input impedance yields the antenna input impedance, with antenna input impedance sensed at full power at a position remote from the antenna input.

Abstract: A system for determining the radiation pattern of an antenna array comprising a plurality of antenna elements comprises a signal generator for generating a test signal, a number of probes for measuring a magnitude of the signals emitted by the antenna elements when driven with the test signal in a first surface and in a second surface, wherein the distance of the first surface to the antenna elements is smaller than the distance of the second surface to the antenna elements, and a pattern calculation unit for calculating the radiation pattern of the antenna array based on the magnitudes measured in the first surface and the second surface.