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Abstract Changes in the thermal structure of lake ecosystems have been documented as a response to climate change, but the dynamics of biomass distribution, which fundamentally determines species conservation, has been less studied. An interdisciplinary approach was used to demonstrate the influence of climate‐driven changes on the environmental DNA (eDNA) distribution of two species (Gymnogobius isaza and Palaemon paucidens) in Lake Biwa, the largest monomictic lake in Japan. In field surveys in 2016–2017 (full water circulation) and 2019 (partial water circulation), eDNA concentrations of these species were measured for 43 and 47 samples, respectively, collected from the lake bottom. The correlative relationship was investigated between species' eDNA concentrations and environmental variables. The species–environment relationship was then applied to species' eDNA distributions under existing and future environments calculated by a lake ecosystem model. Based on differences in the estimated eDNA distributions, we suggest that different species respond differently to climate change. The distribution of G. isaza will expand in the future if full water circulation occurs, although it appears to be independent of water circulation at present. Partial water circulation enlarges the distribution area of P. paucidens, but its eDNA concentrations will be low in the future, regardless of the extent of water circulation. These results indicate that species such as P. paucidens, which is now abundant but vulnerable to climate change, require special attention. Furthermore, our study emphasizes the potential application of interdisciplinary methodologies for improved species conservation.

The diagnosis and prevention of the deterioration of iron-steel infrastructure has become an important social issue in recent years. The thickness measurement technique (extremely low-frequency eddy current testing (ELECT)) using a magnetic sensor for detecting steel corrosion at extreme frequency ranges has been previously reported. Using the calibration curves based on the correlation between the phase of the detected magnetic signal and the plate thickness, the plate thickness reduction caused by corrosion can be estimated from the detected phase signal. Iron-steel materials have large changes in electromagnetic characteristics; therefore, the reference calibration data for each type of iron-steel are required for plate thickness estimation. In this study, the effect of electromagnetic characteristics on the magnetic thickness measurement was investigated to improve the thickness estimation. Four types of iron-steel plates (SS400, SM400A, SM490A, and SMA400AW) with thicknesses ranging from 1 mm to 18 mm were measured by ELECT, and the phase change at multiple frequencies of each plate were analyzed. The shift in the phase and linearity regions of the calibration curves for each type of steel plate was observed. To analyze this shift phenomenon, the electromagnetic characteristics (permeability μ and conductivity σ) of each type of steel were measured. Compared with the permeability μ and conductivity σ of each steel plate in the applied magnetic field strength range, the product (σμ) for various steel plates decreased in the following order: SM400 > SS400 >SMA400AW > SM490A. The product of μ and σ is related to the skin depth, indicating the electromagnetic wave attenuation and eddy current phase shift in the material. Therefore, each shift in the calibration curve of each type of iron steel is explained by the changes in the parameters σ and μ.

Infrastructure facilities that were built approximately half a century ago have rapidly aged. Steel sheet piles, the inspection object in this study, are severely corroded, resulting in cave-in damages at wharfs. To solve such a problem, non-destructive inspection techniques are required. We previously demonstrated plate thickness measurement using extremely low-frequency eddy current testing. However, when the steel sheet piles are located in water, shellfish adhere to their surface, causing a lift-off of several tens of millimeters. Therefore, this large lift-off hinders the thickness measurement owing to fluctuations of magnetic signals. In this study, sensor probes with different coil diameters were prototyped and the optimum size for measuring steel sheet piles at high lift-off was investigated. Using the probes, the magnetic field was applied with a lift-off range from 0 to 80 mm, and the intensity and phase of the detected magnetic field were analyzed. Subsequently, by increasing the probe diameter, a good sensitivity was obtained for the thickness estimation with a lift-off of up to 60 mm. Moreover, these probes were used to measure the thickness of actual steel sheet piles, and measurements were successfully obtained at a high lift-off.

Background: Endothelial dysfunction and increased arterial stiffness gradually develop before the manifestation of catastrophic cardiovascular events. Therefore, detection and assessment of vascular function are required to address pre-existing pathological conditions. However, the currently available diagnostic devices and methods are insufficient due to variability among investigators and the time-consuming nature of manual procedures. Methods: Recently, novel devices were developed for the detection of both arterial stiffness and endothelial dysfunction in a single blood pressure measurement using a cuff-oscillometric technique (AVE-1500, Shisei Datum, Japan). API (arterial pressure volume index) is defined as the reciprocal of the slope of the tangent of the brachial artery pressure-volume curve, and AVI (arterial velocity pulse index) is defined as the ratio of the difference between the ejection and reflection waves. In the present study, we performed retrospective, cross-sectional analyses of subjects (n = 102; mean age = 70.5 ± 10.4 years) with detailed coronary angiographic examinations and clinical background parameters. Results: After adjusting for various variables using multiple linear regression analyses, we found that API, but not AVI, was significantly correlated with coronary artery severity and complexity scores. Conclusions: We propose that API may be a new vascular index useful for monitoring and assessing the severity and complexity of atherosclerosis in subjects with coronary artery disease and for evaluating atherosclerotic diseases.

Background: The effect of cardiac pacing on sleep-disordered breathing is controversial. We investigated the long-term effect of cardiac pacing on sleep disordered breathing in patients with conventional indications for permanent pacemakers Methods: Subjects comprised 40 patients (29 men; mean age 69±9 years, mean left ventricle ejection fraction 69±8%, and body mass index 23.6±3.5 kg/m2) who were diagnosed with indications for permanent pacemakers (sick sinus syndrome in 23 patients, atrioventricular block in 15, and brady atrial fibrillation in 2). All patients received polysomnographic evaluations before implantation of permanent pacemakers. After implantation of permanent pacemakers, all patients received polysomnographic evaluations during use of the pacemaker settings (AAI/DDD/VVI at 70 beats per minute). Results: The mean follow-up period was 35±13 months. Before implantation, the distribution of sleep-disordered breathing was as follows: 93% had apnea hypopnea index >5, 58% had apnea hypopnea index >15, and 20% had apnea hypopnea index >30. The mean apnea hypopnea index for all patients was 20±15, for those with obstructive type apnea was 4.9±5.3, and for those with central type apnea was 3.0±4.5. The mean Epworth Sleepiness Score was 5.9±4.0. No patient received continuous positive airway pressure therapy or any other therapy for sleep-disordered breathing during the follow up period. The mean apnea hypopnea index at 1 week after implantation of permanent pacemakers was 21±14 (P=0.8) and the mean apnea hypopnea index at end of follow-up was 11±7 (P

A 60-year-old man with hypertrophic obstructive cardiomyopathy (HOCM) was implanted dual-chamber ICD for the purpose of both the left ventricular outflow tract (LVOT) gradient reduction by ventricular pacing and the primary prevention of ventricular tachyarrhythmia. Because the LVOT gradient reduction and improvement of symptoms by pacing were insufficient, however, a new pacing lead was inserted in the right ventricular apex at a different position 1.5 cm away from the site of the defibrillation lead, and the LVOT gradient greatly declined from 108 to 30 mmHg. This DDD pacing was continued over seven years. On this occasion, he was referred to our hospital because of battery depletion, and a cardiac catheterization study was performed after ICD replacement. The LVOT gradient was 10 mmHg in sinus rhythm. After administration of isoproterenol (0.02γ), the gradient was increased to 92 mmHg in sinus rhythm. DDD pacing using a newly placed ventricular pacing lead significantly decreased the gradient to 36 mmHg. This case study indicated that DDD pacing from a suitable location in the right ventricular apex caused a marked early reduction in the LVOT gradient, and at long-term follow up a further significant effect was obtained, also in sinus rhythm.

The patient was a 64-year-old man with chronic atrial fibrillation with bradycardia. Left ventricular ejection fraction was 34%. He was treated with biventricular pacing. Heart failure improved from NYHA class III to II. Sympathetic nerve activity (SNA. was recorded during 6 minutes of biventricular (BV), right ventricular apical (RVA. and left ventricular (LV. pacing. SNA was significantly lower during biventricular pacing (49.5 ± 4.0/min. compared with RVA (58.8 ±6:9/min, p = 0.016. and LV (63.3 ± 4.3/min, p = 0.002. pacing. BV pacing improves hemodynamics and decreases SNA compared with RVA or LV pacing.

The patient was a 78-year-old man with dilated cardiomyopathy. His cardio-thoracic ratio was 60.4% and left ventricular ejection fraction (LVEF) was 33%. He had been repeatedly admitted for congestive heart failure. He underwent implantation of an implantable cardioverter-defibrillator (ICD) for ventricular fibrillation. We compared the values of BNP and shock impedance stored by the ICD. The correlation coefficient (p-value) between BNP and shock impedance was −0.700 (p < 0.0005), increase of BNP and shock impedance was −0.778 (p < 0.0001), percent increase of BNP and shock impedance was −0.767 (p < 0.0005). In conclusion, there is an inverse relation between BNP and shock impedance, and measurements of shock impedance may be useful in the management of congestive heart failure.

Steel structures in social infrastructures often undergo corrosion and the thickness of these steel plates decreases. Then, the strength of steel structures decreases according to the residual plate thickness. Applications of a steel plate attaching method and a fiber reinforced polymer/plastic (FRP) bonding method are effective for repair and strengthening for these steel structures. In this study, UV-curable glass fiber reinforced polyester resin (UV-GFRPR) sheet was focused instead of FRPs. The aims of this study are to confirm repair and strengthening effects of the UV-GFRPR sheet bonded on both sides of steel plate. The UV-GFRPR sheet consists of a polyester resin and chopped glass fibers and is hardened by radiation of UV source for a certain time. The tensile behavior and strength of steel plate bonded with UV-GFRPR sheets were assessed under axial tensile load. After that, the tensile behavior and strength of specimens were numerically estimated from each stress-strain curve of UV-GFRPR and steel modeled by using Menegotto-Pinto model. Furthermore, nonlinear finite element analysis (FEA) taking into account of the properties of bond layers was carried out to compare the numerical results. From the test results, the yield and ultimate strengths of specimens increased linearly according to the number of laminated layers of UV-GFRPR. Both results of the numerical calculation and the FEA agreed well with the test results. It is concluded that the numerical calculation without the contribution of bond layers can estimate the tensile behavior and strength of steel plate bonded with UV-GFRPR on both sides. [ABSTRACT FROM AUTHOR]

Abstract  In Central Kalimantan, Indonesia, the water of lakes and rivers showed high dissolved organic carbon (DOC) concentration, 5-50mgC/l. There was a clear relationship between DOC concentration and pH. DOC also contributed to low water transparency in the studied lakes. Water colors measured by spectrophotometer showed a strong relationship with DOC concentration, indicating high applicability of water color measurement for estimation of DOC. The development of a simple but quick estimation of DOC will contribute to understanding the seasonal dynamics of DOC, which might regulate both abiotic and biotic conditions in aquatic ecosystems in this area. [ABSTRACT FROM AUTHOR]

Pacemaker. QT interval (QTI) may change when cardiac junction is improved by optimizing the AV delay. QTI is used as the sensor for rate responsive pacemakers. Evoked (e)QTI is measured as the time duration from the ventricular pace-pulse to the T sense point, which is the steepest point of the intracardiac T wave. The relationship between AV delay and eQTI and cardiac function was studied in 13 patients (74.2 ± 9.3 [SD] years old) with an implanted QT-driven DDDR pacemaker. A special pacemaker software module was downloaded into the pacemaker memory for eQTI data logging. AV delay was set at 100, 120, 150, 180, 210, and 240 ms. Cardiac output (CO) was measured by' continuous Doppler echocardiography eQTI was 343.3 ± 22.5, and 343.4 ± 23.2 ms (P < 0.01. repeated ANOVA) and CO was 4.2 ± 0.8, 4.6 ± 0.8, and 4.2 ± 0.8 L/min (P < 0.0001, repeated ANOVA) when AV delay was set at the AV delay shortened by one step (AV[-]) and prolonged by one step (AV[+]) from the AV delay at which QT interval was maximum (AV[max]) in seven patients, in whom the peak AV delay at which the eQTI was maximal could be identified. eQTI decreased from 345.1 ± 20.9 to 339.4 ± 21.1 ms (P < 0.0001) and CO decreased from 4.4 ± 1.4 to 4.1 ± 1.3 L/min (P <0.005) when AV delay was prolonged from AV(max) to AV(+) in all patients. eQTI decreased from 345.1 ± 22.5 to 343.3 ± 22.4 ms (P < 0.0005) and CO decreased from 4.6 ± 0.8 to 4.2 ± 0.8 L/min (P < 0.05) when AV delay was shortened from AV(max) to AV(-) in seven patients. Thus, CO was maximal when AV delay was set at the AV delay at which eQTI was maximal. In conclusion, the optimal AV delay can be predicted from the eQTI sensed by an implanted pacemaker. and automatic setting of the optimal A V delay can be achieved by the QT sensor of an implanted pacemaker. [ABSTRACT FROM AUTHOR]

The article presents several abstracts concerning metabolic and hemodynamic variables related to pacing. One of the abstracts provides that implanted multi-programmable pacemakers were tested according to three treadmill protocols. The first was an incremental symptom limited treadmill test at heart rate 70, the second consisted of 12 minutes of walking at 40% of max exercise level at three pacemaker rates: 70, 100, 115. The third protocol had four exercise tests at submaximal exercise level, 6 minutes on treadmill at rate settings of 70,100,115,130.

There have been few reports about ratchet syndrome. We report a case of ratchet syndrome caused by small hair-pin curve of lead that triggered the lead retract itself. A 69-year-old man with a past history of inferior wall myocardial infarction, presented with progressive congestive heart failure. He underwent implantation of cardiac resynchronization therapy with an implantable cardiac defibrillator (CRTD) at our hospital. At 33 days after implantation, shock lead dislodgement was revealed. X-ray showed that the lead tip was in left subclavian vein, leaving its screw out, and a large part of the proximal portion of the lead was retracted into the pocket, while the other two leads remained in appropriate positions and the device had not rotated. An X-ray series showed that a hair-pin curve had been expanding gradually from just after implantation. In this case, relatively stiff shock lead was markedly bent and expanded the curve in the pocket, and ratchet-like movement occurred. We here report a new type of ratchet syndrome. [ABSTRACT FROM AUTHOR]