Suitable Index Research Articles

Single count of radicle emergence and mean germination time estimate seed vigour of Chinese milk vetch (Astragalus sinicus)

This research explored the relationship between a single count of radicle emergence (RE) and mean germination time (MGT) with seed vigour for Chinese milk vetch (Astragalus sinicus) (CMV), a globally important legume used as a forage, green manure, and rotation crop. Fourteen seed lots of CMV were used to determine standard germination (SG), RE and MGT in the laboratory. Field experiments were conducted at two sites to measure the emergence performance including field emergence (FE), seedling dry weight (SDW) and simplified vigour index (SVI). The SG ranged from 89.0 to 95.5% and was not significantly correlated with field performance at either of two sites. However, both a single count of RE at 20 hours and MGT were highly predictive of FE, SDW and SVI at both sites (R2ranged from 0.612 to 0.897 for RE; 0.604 to 0.870 for MGT). The RE was positively related to field performance while MGT was negatively related. The seed lots with lower RE at 20 hours had lower FE and higher MGT. Overall, both RE at 20 hours and MGT are suitable indices for the vigour evaluation of CMV. However, a single count of RE is more accurate, quick and convenient.

Novel Antibacterial Copolymers Based on Quaternary Ammonium Urethane-Dimethacrylate Analogues and Triethylene Glycol Dimethacrylate.

The growing scale of secondary caries and occurrence of antibiotic-resistant bacterial strains require the development of antibacterial dental composites. It can be achieved by the chemical introduction of quaternary ammonium dimethacrylates into dental composites. In this study, physicochemical and antibacterial properties of six novel copolymers consisting of 60 wt. % quaternary ammonium urethane-dimethacrylate analogues (QAUDMA) and 40 wt. % triethylene glycol dimethacrylate (TEGDMA) were investigated. Uncured compositions had suitable refractive index (RI), density (dm), and glass transition temperature (Tgm). Copolymers had low polymerization shrinkage (S), high degree of conversion (DC) and high glass transition temperature (Tgp). They also showed high antibacterial effectiveness against S. aureus and E. coli bacterial strains. It was manifested by the reduction in cell proliferation, decrease in the number of bacteria adhered on their surfaces, and presence of growth inhibition zones. It can be concluded that the copolymerization of bioactive QAUDMAs with TEGDMA provided copolymers with high antibacterial activity and rewarding physicochemical properties.

Use of Fe (II) and H2O2 along with Heating for the Estimation of the Browning Susceptibility of White Wine

The aim of the present study was to investigate if the use of Fe (II) and H2O2 (Fenton reaction) along with heating can be implicated for the rapid evaluation of the browning susceptibility of white wine. In this context, increasing concentrations of Fe (II) and H2O2 were added to two white wines (Roditis–Malagouzia and Debina), the samples were stored at 45 °C or 18 °C, and the absorbance at 420 nm (browning index) was measured. Moreover, total sulfur dioxide, total phenolics, flavanols, hydroxycinnamates and total free sulfhydryls were assessed during storage of Roditis–Malagouzia wine samples. The results showed that the addition of Fe (II) + H2O2 mixture in white wines increases rapidly the browning index at 45 °C, indicating the ability to develop a rapid test for the estimation of the browning susceptibility of white wines. Results also showed that the level of flavanols is a suitable index to follow the forced oxidative browning of white wine by adding Fe II + H2O2 at 45 °C. Moreover, results indicated that the levels of total free sulfhydryls may be a suitable index to follow the forced oxidative browning of white wine and in general, white wine oxidation.

Drought monitoring and its effects on vegetation and water extent changes using remote sensing data in Urmia Lake watershed, Iran

Abstract The assessment of drought hazards is important due to their socio-economic impacts on water resources, agriculture, and ecosystems. In this study, the effects of drought on changing water area and canopy of the Lake Urmia watershed in the northwest of Iran have been monitored and evaluated. For this purpose, the Standardized Precipitation Index (SPI) was calculated in short and medium periods (1-month and 3-month) to determine the dry-spell periods in the Lake Urmia basin. In reviewing this analysis, the annual average has been examined and evaluated. Furthermore, Moderate Resolution Imaging Spectroradiometer (MODIS) and remote sensing data were used to calculate the Normalized Difference Vegetation Index (NDVI), the Enhanced Vegetation Index (EVI), the Normalized Difference Water Index (NDWI), and the Temperature–Vegetation–Dryness Index (TVDI) to identify the area of water body, water level, and vegetation changes during 20 years (2000–2020). The Pearson correlation coefficient was also employed to explore the relationship between the drought and the remote sensing-derived indices. According to the results of drought analysis, 2000, 2002, 2004, 2006, 2008, 2010, 2012, 2014, 2016, 2018, and 2020 had experienced dry spells in the Lake Urmia basin. The NDWI changes also showed that the maximum area of the Lake Urmia happened in 2000, and its minimum was recorded in 2014. The variation of NDVI values showed that the highest values of vegetation cover were estimated to be 2,850 km2 in.2000, and its lowest value was 1,300 km2 in.2014. The maximum EVI and TDVI were calculated in 2000, while their minimum was observed in 2012 and 2014. Also, the correlation analysis showed that the SPI had the highest correlation with NDVI. Meanwhile, 1-month SPI had a higher correlation than the 3-month SPI with NDVI and EVI. As a concluding remark, NDVI and NDWI were more suitable indices to monitor the changes in vegetation and drought-related water area. The results can be used to make sound decisions regarding the rapid assessment of remote sensing-derived data and water-related indices.

Some measures of kurtosis and their inference on large datasets

This paper deals with the estimation of kurtosis on large datasets. It aims at overcoming two frequent limitations in applications: first, Pearson's standardized fourth moment is computed as a unique measure of kurtosis; second, the fact that data might be just samples is neglected, so that the opportunity of using suitable inferential tools, like standard errors and confidence intervals, is discarded. In the paper, some recent indexes of kurtosis are reviewed as alternatives to Pearson’s standardized fourth moment. The asymptotic distribution of their natural estimators is derived, and it is used as a tool to evaluate efficiency and to build confidence intervals. A simulation study is also conducted to provide practical indications about the choice of a suitable index. As a conclusion, researchers are warned against the use of classical Pearson’s index when the sample size is too low and/or the distribution is skewed and/or heavy-tailed. Specifically, the occurrence of heavy tails can deprive Pearson’s index of any meaning or produce unreliable confidence intervals. However, such limitations can be overcome by reverting to the reviewed alternative indexes, relying just on low-order moments.

Sensitivity and Reliability Analyses in to Actively Controlled Structures Under Earthquake

This study aims for a probabilistic assessment of active seismic control of structures in the presence of uncertainties of the structural model and the stochastic model of the ground acceleration. First, sensitivity analyses based on the Borgonovo sensitivity index are conducted to measure the effect of uncertainty sources on the maximum and root mean square (RMS) of the main structural responses in different seismic hazard regions. Then, the reliability analyses are conducted using Monte Carlo simulation (MCS) and importance sampling (IS) methods to the estimation of failure probabilities and reliability indices of the structures in different seismic hazard regions, force capacity of actuators, and seismic performance levels. Numerical studies carried out on a 10-story structure show that the uncertainties in peak ground acceleration (PGA) and story stiffness have the most effects on the seismic responses of the structure. The effect of the considered uncertainties is negligible on the maximum demand control force. The results also show that equipping the structure with an active control system results in a significant reduction in the failure probabilities of the structure. The target reliability index for the uncontrolled structure in life safety seismic performance level may not be satisfied in high and very high seismic hazard regions, it can however be easily dealt with, using the proposed technique, in the corresponding controlled structures. By increasing the control force capacity, an increment is observed in the reliability index. A high and suitable reliability index is given for both controlled and uncontrolled in the collapse prevention seismic performance level.

Force, Power, and Morphology Asymmetries as Injury Risk Factors in Physically Active Men and Women

This study aimed to investigate whether asymmetry of force, power, and tissue morphology are lower limbs (LL) injury risk factors in physically active adults. Fifty-eight men aged 23.8 ± 1.2 years and forty-seven women aged 23.3 ± 1.0 years were examined. Physical activity level was measured by the International Physical Activity Questionnaire, and injury data were collected with the Injury History Questionnaire. The countermovement jump was performed to evaluate force and power. LL tissue composition was evaluated by a bioimpedance analyzer. The symmetry indices were calculated. A comparison between injured and non-injured subjects in both sexes was conducted to determine indices associated with injuries. The symmetry indices cut-off points were calculated to establish values indicating a significant injury risk increase, and logistic regression was performed. The relative peak force asymmetry above 4.049% was associated with increased injury risk in men. The LL skeletal muscle mass asymmetry above 3.584% was associated with a higher injury risk in women. Increased asymmetry in indicated indices by 1% was associated with 19.8% higher injury risk in men and 82.6% in women. Asymmetry proved to be an injury risk factor. However, a more suitable index for men is relative peak force asymmetry, whereas LL skeletal muscle mass asymmetry is more suitable for women.

Creation and application of future typical weather files in the evaluation of indoor overheating in free-floating buildings

Expected Global warming and heatwaves coupled with the urban heat island effect (UHI) can overheat indoor environments of free-floating buildings in temperate climate regions. Overheating assessment requires practitioners to use appropriate climate data and suitable measurement indices. The aim of this article is first, to propose a practical approach to generate yearly and typical ready-to-use future typical weather datasets (FTWY) using high-resolution Regional Climate Model (RCM) data from Coordinated Regional Climate Downscaling Experiment (CORDEX), and second, investigate the potential of FTWYs in the assessment of indoor overheating, considering UHI effect.To achieve these objectives, three dynamically downscaled (DDS) FTWYs generated from RCMs (IPSL-SMHI, CNRM-ALADIN, MPI-REMO) were compared with one statistically downscaled (ESD) FTWY from Meteonorm, and observed heatwave weather data of 2003. Comparative analysis was performed in two stages: comparison of monthly statistical distribution of climate variables, and analysis of heatwave presence. Urban weather generator (UWG) was used to project UHI effect on two weather files for two buildings, and three overheating measurement indices were used to exploit results. Comparative analysis of weather files show that temperature in a FTWY in the medium future (2040–2070) is likely not as intense as the heatwave of 2003 for Nantes. Results also confirm that it is better to use two weather files, and at least two overheating indices to obtain reliable outputs. This study also revealed that indoor overheating is not limited to densely built areas where impact of UHI is highest; buildings located in sparsely built neighbourhoods are also at risk.

Phytochemical Screening and Antibacterial Activities of Aqueous and Alcoholic Extracts of Averrhoa bilimbi Leaf against Bacteria Isolated from Oral Cavity.

Medicinal herbs have been used as traditional treatments for many pathogens and extracted bioactive compounds from medicinal plants with a suitable therapeutic index for the production of new drugs. Moreover, they are utilized to evaluate different concentrations of aqueous and alcoholic extracts of Averrhoa bilimbi leaves and antibiotics against bacteria isolated from the oral cavity. This study was conducted simultaneously at the Departments of Botany and Biology, Shatrah Hospital, Thi-Qar, Iraq, during March and August 2021. A. bilimbi leaf extracts were utilized in the plant component examination and the assessment of the antibacterial activity. The bacterial strain of Escherichia coliandKlebsiella pneumoniae was isolated from the oral cavity. To test the antibacterial impact of the extracts on bacteria, the agar well diffusion method was used. The phytochemical screening indicated the presence of Alkaloids, Flavonoids, Sapiens, Steroids, Tannins, Glycosides, and Carbohydrates, followed by the absence of Tannins in aqueous extract. Due to the A. bilimbi leaf aqueous and methanol extract against E. coli, areas of inhibition were found (0.20 cm and 0.19 cm) at the concentration of 100 mg/ml, respectively. However, there were no regions of inhibition of the K. pneumoniae trend for both extracts. The sensitivity of bacterial isolates of E. coli and K. pneumonia to antibiotics was also tested through Gentamicin, Amoxycillin, Azithromycin, Ciprofloxacin, Penicillin, and Polymyxin B, and the regions of inhibition appeared against E. coli (0.5cm, 0 cm, 0.34 cm, 0.45 cm, 0 cm, and 0.12 cm, respectively). Furthermore, the regions of inhibition appeared against K. pneumoniae (3 cm, 0.3 cm, 0.4 cm, 0.55 cm, 0 cm, 0.66 cm, respectively). The antibiotics showed a higher inhibition zone, compared to the aqueous and alcoholic extracts; however, further studies are required to be conducted to validate its reliability.

The preoperative hemoglobin, albumin, lymphocyte, and platelet score is a prognostic factor for non-small cell lung cancer patients undergoing adjuvant chemotherapy: a retrospective study.

BackgroundDeveloping a simple, reliable and low-cost biomarkers is crucial to predict the prognosis of non-small cell lung cancer (NSCLC) patients receiving adjuvant chemotherapy. The score combining hemoglobin and albumin levels and lymphocyte and platelet counts (HALP score) is reportedly related to the prognosis of multiple types of tumors. However, few studies have focused on its prognostic value in patients with NSCLC. Our study aimed to investigate the prognostic role of the HALP score and develop a valuable prognostic model for patients with NSCLC undergoing adjuvant chemotherapy.MethodsA total of 362 individuals with NSCLC undergoing adjuvant chemotherapy between 2013 and 2015 were included. The HALP score was computed according to the following formula: hemoglobin (g/L) × albumin (g/L) × lymphocytes (g/L)/platelets (g/L). Furthermore, demographic characteristic, including age, sex, smoking status, and drinking history, were collected from case report forms at admission. The main outcomes were overall survival (OS) and disease-free survival (DFS), which were assessed using Kaplan-Meier analysis with log-rank test. Furthermore, Cox regression analysis was employed to assess the prognostic role of HALP in NSCLC.ResultsWe found the significant associations of clinicopathological features, including sex, pathological stage, tumor size, and lymph node metastasis (LNMets) in univariate Cox regression analysis. In multivariate analysis, NSCLC patients with a high HALP score were significantly associated with lower OS [hazard ratio (HR): 0.707; 95% confidence interval (CI): 0.503–0.995] and DFS (HR: 0.671; 95% CI: 0.491–0.916). The Kaplan-Meier analysis showed that a low HALP score predicted poorer OS (P=0.02) and DFS (P<0.01) outcomes. Furthermore, we performed stratification analysis by tumor node metastasis (TNM) stage, and the result indicated a low HALP score predicted poor OS (P=0.01) and DFS (P=0.04) outcomes in stage III–IV NSCLC patients.ConclusionsOur study demonstrated that the HALP score might be a suitable prognostic index for NSCLC patients undergoing adjuvant chemotherapy. Combining demographic and clinicopathological features with the HALP score may help clinicians predict survival and treatment outcomes.

Risk, crop yields, and weather index insurance in village India

AbstractWe investigate the sources of variability in crop yields and their relative importance in the context of weather index insurance for smallholder farmers in India. Using parcel‐level panel data, multilevel modeling, and Bayesian methods we measure how large a role seasonal variation in weather plays in explaining yield variance. Seasonal variation in weather accounts for 14%–22% of total variance in crop yields, a value that has rarely been convincingly estimated in the economics literature. These calculations shed light on the relatively low rates of uptake of index insurance by resource‐constrained farmers. The results also provide direction for designing more suitable index insurance products.

Reproductive biology of Gattan females Barbus xanthopterus (Heckel, 1843) used for artificial breeding in Fish Hatchery of Marine Science Center

Some aspects of reproductive biology of Gattan Barbus xanthopterus females were studied from 15-30 March, 2009. These fishes were coughed from Huweiza Marsh, Southern Iraq and from Therthar Reservoir, Western Iraq, and used for artificial breeding in Marine Science Center Hatchery. Total lengths ranged between 550-806 mm, total weights ranged between 3100-7250 g, and their age ranged from 3-6 years. It had been found that all examined ovaries were in ripe stage that means females cached from Huweiza Marsh were ready for artificial breeding and possess suitable (3.64- 11.03) gonado somatic index (GSI), while females collected from Therthar Reservoir had low GSI (1.15-1.33). Average of eggs diameters was 1.56 mm for fish of 550 mm total length and 3400 g, while it was 2.09 mm for fish of 802 mm total length and 7005 g. However, generally there was positive relationship between total lengths and eggs diameters with no significant correlation (r = o.47, P&lt;0.01). Absolute fecundity for Gattan was ranged between 1494191-518650 eggs, and relative fecundity was between 85.8-286.2 egg/g, while there was low positive relation between absolute fecundity and total fish weight with no significant correlation (r= 0.33, P&lt;0.01).

Robustness analysis of cyber-coupled power systems with considerations of interdependence of structures, operations and dynamic behaviors

The failure propagation of a networked system is profoundly affected by the operation and dynamic behavior of its constituent systems. In this paper, we propose a novel network-based model to investigate the cascading failure of cyber-coupled power systems. Unlike existing models that assume oversimplified network functions, operational characteristics and failure evolution, our proposed model considers the practical differences between a communication network and a power network in terms of network structure, physical operation and dynamic behavior. A practical trip mechanism is derived according to the instantaneous data transmission overload and the stochastic power flow overload. The effects of communication network connection strength and coupling patterns on the robustness of interdependent systems are also studied. Our study shows that the thermal memory effect of power lines aggravates the failure propagation, and that the robustness of the interdependent system is strongly related to the coupled communication network’s tolerance. Furthermore, coupling patterns based on network similarity have better inhibition effects on cascading failure under random attacks, and node destructiveness is a suitable coupling similarity index that can be used to improve the robustness of the system. However, the strategy is inapplicable when the system is under intentional attacks.

An insight into the sensitivity of fully polarimetric SAR data to biomass of pearl millet crop

The development of polarimetric decomposition techniques improves the capability to understand the complex scattering mechanisms occurring in the dryland crops. The present study is focused on assessing the sensitivity of coherent, incoherent, model and Eigen vector-based decomposition techniques from multitemporal Radarsat-2 polarimetric dataset to scattering mechanisms occurring in the critical growth stages of pearl millet crop. Yamaguchi volume component along with its temporal response was observed to be sensitive and reliable due to its dynamic biomass characterization. Overestimation of volume component and earlier saturation of biomass from 4 kgm−2 were observed limitations in Freeman 2 & 3 component decomposition when dealing with higher vegetation crops. The decrease in volume scattering over increasing biomass proved Van Zyl response contrary to the established understanding. Panicle stage was identified as the critical stage for discriminating pearl millet from similar structured maize and sorghum crops. In this stage, alpha angle generated from Cloude-Pottier decomposition almost reached 550 indicating the increase in contribution of dihedral scattering due to vertical prominent panicles in the pearl millet fields. The various Touzi parameters (α1, Ψ1, φ1 and τ1) were observed to have sensitivity towards changes in crop canopy structures, which will require further research to verify. The proposed Δ(F3-Y4) was the most suitable Volume Difference Index (VDI) for characterizing biomass of erectophile crops as the dynamic biomass response was found even beyond 8 kgm−2.

Toward classification-based sustainable revitalization: Assessing the vitality of traditional villages

Due to different capacities for protection and development, the vitality of traditional villages (VTV) in China varies to a great degree. However, the current classification-based sustainable revitalization strategies still lack an up-to-date vitality assessment. Based on the essential requirement of sustainable revitalization, this study defines the VTV as an integrated capacity to protect and develop and establishes an assessment index system from these two aspects. We also adopt the AHP method to determine suitable index weights for the case area and develop models to quantitatively assess vitality and vitality equalization for a large sample of universal traditional villages in the prefecture-level city. The research conducts the vitality evaluation of 148 traditional villages in Lishui, Zhejiang Province. It is found that the method can also analyze the vitality features of each grade from the spatial distribution and the disadvantaged indicators. The VTV assessed in this study was verified to be robust by the correlation test with the number of Point of Interest. Thus, the method is effective and may contribute to traditional villages’ sustainable revitalization by providing the basis for classifying the policy-making and checking the revitalization effectiveness.

Development a New Flexibility Index Suitable for Power System Operational Planning

Power system flexibility is an important characteristic in both power system planning and operation, which should be evaluated and maintained in the desired value. On the other hand, more renewable energy integration leads to increasing uncertainty and variability in the power system. Therefore, the power system should have the sufficient ability to overcome the adverse effects of uncertainty and variability named as flexibility, which should be improved by suitable tools such as adequate reserve, fast ramp up/down generation sources and suitable energy storage capacity. Power system flexibility evaluation is the main task that needs suitable indices to indicate the level of system flexibility correctly. In the current paper, a well-known system flexibility index named normalized flexibility index, which is used for power system planning horizon is modified to use for the operational planning time zone. In this concept, the flexibility index is separated into two components, each of them indicating the ability of the power system to withstand upward/downward net-load uncertainty and variability. In the further, this is shown these two components are the same as the upward/downward system reserve and can be converted to economic value simply. So, this concept facilitates the economic trade-off between operation cost and system flexibility, improving cost to achieve the best level of system flexibility.

Satellite based impact assessment of temperature and rainfall variability on drought indices in Southern Pakistan

The impacts of temperature and rainfall on drought indices were derived from satellites by using remote sensing techniques over the southern areas of Pakistan from 2000 to 2018. Rainfall from Tropical Rainfall Measuring Mission (TRMM) and temperature from Climate Prediction Center (CPC) are the best performing satellite and observational gridded datasets for studying drought in the region. These two datasets were used to calculate drought indices i.e. Standardized Precipitation Index (SPI), Reconnaissance Drought Index (RDI), and Rainfall Deciles (DI) on a 6-month time scale characterized by the concept of the hydrological year starting from October to March and April to September. Five drought years (2000, 2001, 2002, 2004, and 2018) were identified based on the consensus of three drought indices namely SPI, RDI, and DI. The results of these indices are compared with MODIS products of 16 days Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and 8 days Land Surface Temperature (LST) composites to evaluate the impact of rainfall and temperature. Results show that the Sindh province remains moderately dry from October-March, while the failure of monsoon further intensifies the situation of droughts as observed in 2004. Winter or early spring rainfalls turn out beneficial for Sindh as they reduce the severity of emerging drought. The meteorological drought of October-March may lead to agricultural drought in April-September due to the deficit of summer monsoon having a direct impact on vegetation. Similarly, Balochistan province faces moderate to severe drought conditions due to increased evapotranspiration losses from the surface. RDI based on potential evapotranspiration is more suitable for studying drought as compared to SPI. In addition, EVI is categorized as a more suitable index to monitor drought conditions in Sindh.

An analytical study of sound transmission loss of functionally graded sandwich cylindrical nanoshell integrated with piezoelectric layers

The multidisciplinary nature of piezoelectric (PZ) structures necessitates precise and efficient methods to express their behavior under different conditions. This article extends the general usage of PZ materials by introducing acoustic and fluid loading effects in a way that an unfilled multilayer cylindrical nanoshell with a functionally graded (FG) material core and PZ layers is subjected to preliminary external electric load, acoustic waves and external flow motion. As the properties of a functionally graded material changes along the shell thickness, a power law model is assumed to be governing such variations of desired characteristics. Evidently, this system includes different types of couplings and a comprehensive approach is required to describe the structural response. To this aim, the first-order shear deformation theory (FSDT) is used to define different displacement components. Next, the coupled size-dependent vibroacoustic equations are derived based on in conjunction with nonlocal strain gradient theory (NSGT) with the aid of Hamilton’s variational principle and fluid/structure compatibility conditions. NSGT is complemented with hardening and softening material effects which can greatly enhance the precision of results. It is expected to use the findings of this paper in the optimization of similar systems by selecting suitable FG index, incident angle of sound waves, flow Mach number, nonlocal and strain gradient parameters, starting electric potential and geometric features. One of the important findings of this study is that increasing the electric voltage can obtain better sound insulation at small frequencies, specially prior to the ring frequency.

The Sonographic Evaluation of Gestational Age: A Comparative Study Utilizing Different Biometric Measurement Indices and Fetal Kidney Length

Objective: Various indices have been introduced for estimating sonographic gestational age and have demonstrated varied diagnostic accuracy. The aim of this study was to evaluate the correlation of fetal kidney length (FKL) with some other traditional measurement parameters in determining an accurate gestational age. Materials and Methods: In this prospective study, healthy pregnant women, who had completed a scheduled and routine obstetrical sonogram, were included. During the sonogram, the measurement indices, biparietal diameter (BPD), abdominal circumference (AC), crown rump length (CRL), head circumference (HC), femur length (FL), and FKL were analyzed. The obstetrical measurements had been taken every 4 weeks from the 20th week of the pregnancy, until the end of the pregnancy (e.g., 20th, 24th, 28th, 32nd, 36th, 40th weeks). After data collection, the measurement data were analyzed with SPSS software. Results: There were significant ( P &lt; .05) high strength of associations between FKL and the routine measurements of BPD ( r = 0.668), AC ( r = 0.770), CRL ( r = 0.792), HC ( r = 0.791), and FL ( r = 0.803). Conclusion: These results suggest possible significant positive relationships between FKL and BPD, AC, CRL, HC, and FL. It can be assumed that FKL might be a suitable index for determining gestational age especially in the late second and third trimester, when other measurement indices are less accurate.

Using radiant intensity to characterize the anisotropy of satellite-derived city light at night

Recent studies have described the anisotropy of ALAN based on statistical analysis of a quadratic model-based relationship between radiances derived from the VIIRS Day/Night Band sensor onboard Suomi-NPP and viewing zenith angle (VZA) (Li et al., 2019). Contrary to conventional wisdom, the satellite-observed radiance of ALAN always decreases at first and then increase with VZA, especially for high building areas. This leads to a so-called ‘cold-spot’ effect (i.e. radiance reaches local minimum in a specific VZA) in the VZA-radiance relationship, one that has not been understood using existing remote sensing methods. In this paper, we propose using radiant intensity – a measure of light power in a specific direction– to characterize the anisotropy of satellite-observed artificial lights at night (ALAN). Accordingly, we propose a new study design based on analysis across fourteen global cities. A linear regression model describing the relationship between VZA and radiant intensity resulted in an averaged regression R2 between 0.26 and 0.73 for the cities, suggesting a decay of radiant intensity with increased VZA. We then introduced a cosine-corrected linear model to describe the VZA-radiance relationship, which is mathematically transformed from the linear VZA-intensity model. Our results suggest that the ‘cold spot’ effect in the VZA-radiance relationship is consistent with the revealed phenomenon that the radiant intensity decays with increased VZA. We also constructed indexes related to urban morphology derived from LiDAR data, including the Blocking Index (BI), the Standard Deviation of Building Height (SDBI) and Average Building Height (ABH). These variables were all moderately or strongly correlated (Pearson correlation coefficient < −0.45) to the Change Index (CI), which describes the anisotropic pattern of ALAN in the VZA-intensity relationship, in the four U.S. cities where LiDAR data is accessible. We conclude that radiant intensity is a suitable physical index to characterize the directional distribution of ALAN that can help understand the anisotropy of ALAN.