CEO Duality Leadership And Firm Risk-Taking Propensity

Based on a sample of 290 large U.S. corporations, we find that dual positioning on both CEO and board chairperson positions at the corporate top leads to reduced firm risk-taking propensity, serving managerial risk minimization preferences. We also find empirical evidence that traditionally emphasized control mechanisms of board independence and managerial ownership are ineffective in controlling managerial behavior when CEO duality leadership exists. Additionally, the power balance obtained from concentrated shareholder ownership in the firm has significant impact on controlling managerial behavior regarding firm risk taking. The findings of this research contribute to reducing the controversy surrounding CEO duality leadership by furnishing empirical evidence of how CEO duality leadership in corporate governance structure affects managerial behavior in corporate strategic management

Depuration of gut contents in the intertidal snail Nerita lineata is not necessary for the study of heavy metal contamination and bioavailability: a laboratory study

Some of the scientific papers in the literature regarding heavy metal concentrations in the soft tissues of molluscs are always rejected because there is no depuration of metals before the molluscs samples are analyzed for heavy metal accumulation, although the acceptance of a paper in a journal is assessed based on many other factors. The depuration of gut contents of molluscs has been the initial step before the metal analysis on the soft tissues of molluscs by many researchers. The depuration process in some molluscs involves holding the animals in clean water or clean sediment for a suitable period (8–24 hrs) to purge their guts after exposing them to contaminated conditions, and before they are analyzed for whole-body contaminant burden (Neumann et al., 1999; Gillis et al. , 2004). The depuration ensures that metal-contaminated particles in the animal’s gut do not lead to overestimation of metal bioavailability. Undoubtedly, clearing the gut contents is theoretically a laboratory technique in order to get an accurate estimate of heavy metal concentrations accumulated in the soft tissues of molluscs. In addition, the suggestion on the use of molluscs as biomonitors of metal bioavailability becomes invalid because their soft tissues were not depurated. Consequently, validity on the data of metal concentrations could not be achieved. Therefore, in order to determine if a particular species could be used as biomonitor for metals, depuration of soft tissues of the molluscs is imperative to effectively determine the availability of metal (Riba et al. , 2005; Wang et al. , 2005; Szefer et al. , 1999; Cravo et al. , 2004; Baldwin and Maher, 1997; Nicholson and Szefer, 2003). In standard protocols (ASTM, 2003), although it is not a standard practice to clear the gut of organisms before analyzing their tissues for whole-body metal accumulation, some investigators do transfer animals to clean water conditions in order to purge their guts after they have been collected from the field. In this study, the snail known as Nerita lineata of the Neritidae family, were collected to study if there was any significant difference in the concentrations of Cu and Zn in the soft tissues, before and after four weeks of depuration

Biodiversity of snails: a short review and commentary

This chapter presents a review and commentary of 45 reported publications in the literature on snail biodiversity. Of the 45 papers, it can be concluded that most papers (36 out of 45) fall into three categories: a) Regular checklist of snails is needed, b) New description of snail species would help in the species list documentation, and c) This information is important for future reference and for effective ecosystem management

RTNH+: Enhanced 4D Radar Object Detection Network using Combined CFAR-based Two-level Preprocessing and Vertical Encoding

Four-dimensional (4D) Radar is a useful sensor for 3D object detection and the relative radial speed estimation of surrounding objects under various weather conditions. However, since Radar measurements are corrupted with invalid components such as noise, interference, and clutter, it is necessary to employ a preprocessing algorithm before the 3D object detection with neural networks. In this paper, we propose RTNH+ that is an enhanced version of RTNH, a 4D Radar object detection network, by two novel algorithms. The first algorithm is the combined constant false alarm rate (CFAR)-based two-level preprocessing (CCTP) algorithm that generates two filtered measurements of different characteristics using the same 4D Radar measurements, which can enrich the information of the input to the 4D Radar object detection network. The second is the vertical encoding (VE) algorithm that effectively encodes vertical features of the road objects from the CCTP outputs. We provide details of the RTNH+, and demonstrate that RTNH+ achieves significant performance improvement of 10.14\% in ${{AP}_{3D}^{IoU=0.3}}$ and 16.12\% in ${{AP}_{3D}^{IoU=0.5}}$ over RTNH.Comment: Arxiv preprin

How elevated levels of Cd, Cu and Pb in the surface sediments collected from the drainage receiving metal industrial effluents? Comparison with metal industrial drainage and intertidal sediments in Selangor, Malaysia

Surface sediments were collected in April 2005 from a drainage receiving metal industrial effluents from Serdang in addition to 6 sampling sites from intertidal area and 4 urban drainage sites. The sediment samples were analysed for Cd, Cu and Pb. The metal concentrations at the Serdang industrial drainage sediments were 15.9 μg/g dw for Cd, 1003.5 μg/ g dw for Cu and 1267 μg/g dw for Pb. These metal levels were significantly higher than those in the sediments collected from intertidal area (6 sites) and other urban drainages (4 sites) [Cd: 1.39-3.41 μg/g dw; Cu: 6.64-122.7 μg/g dw; Pb: 26.0-227.7 μg/g dw]. The total concentrations of Cu, Pb and Cd found at Serdang industrial drainage sediments were 48.76, 23.52 and 8.36 times higher than those in the other sites. Based on the metal concentrations in the four geochemical fractions, for Cu, the EFLE, acid-reducible and oxidisable-organic fractions in the sediment at the Serdang industrial drainage was 59.97, 35.26 and 103.74 times, respectively, higher than those in the other sites. For Pb, the EFLE, acid-reducible and oxidisable-organic fractions in the sediment at the Serdang industrial drainage was 3.60, 2.10 and 25.42 times, respectively, higher than those in the other sites. For Cd, the EFLE, acid-reducible and oxidisable-organic fractions in the sediment at the Serdang industrial drainage was 6.17, 11.8 and 12.39 times, respectively, higher than those in the other sites. Thus, the elevated concentrations of Cu, Cd and Pb in the sediments collected from Serdang industrial drainage sediments were evidently receiving point source industrial effluent from the nearby metal factory. Therefore treatment on the factory effluent based on the present findings is necessary

K-Radar: 4D Radar Object Detection for Autonomous Driving in Various Weather Conditions

Unlike RGB cameras that use visible light bands (384$\sim$769 THz) and Lidar that use infrared bands (361$\sim$331 THz), Radars use relatively longer wavelength radio bands (77$\sim$81 GHz), resulting in robust measurements in adverse weathers. Unfortunately, existing Radar datasets only contain a relatively small number of samples compared to the existing camera and Lidar datasets. This may hinder the development of sophisticated data-driven deep learning techniques for Radar-based perception. Moreover, most of the existing Radar datasets only provide 3D Radar tensor (3DRT) data that contain power measurements along the Doppler, range, and azimuth dimensions. As there is no elevation information, it is challenging to estimate the 3D bounding box of an object from 3DRT. In this work, we introduce KAIST-Radar (K-Radar), a novel large-scale object detection dataset and benchmark that contains 35K frames of 4D Radar tensor (4DRT) data with power measurements along the Doppler, range, azimuth, and elevation dimensions, together with carefully annotated 3D bounding box labels of objects on the roads. K-Radar includes challenging driving conditions such as adverse weathers (fog, rain, and snow) on various road structures (urban, suburban roads, alleyways, and highways). In addition to the 4DRT, we provide auxiliary measurements from carefully calibrated high-resolution Lidars, surround stereo cameras, and RTK-GPS. We also provide 4DRT-based object detection baseline neural networks (baseline NNs) and show that the height information is crucial for 3D object detection. And by comparing the baseline NN with a similarly-structured Lidar-based neural network, we demonstrate that 4D Radar is a more robust sensor for adverse weather conditions. All codes are available at https://github.com/kaist-avelab/k-radar.Comment: Accepted at NeurIPS 2022 Datasets and Benchmarks Trac

Tissue distribution of heavy metals (Cd, Cu, Pb and Zn) in the greenlipped mussel perna viridis from Nenasi and Kuala Pontian, East Coast of Peninsular Malaysia

Previous studies reported that the green-lipped mussel Perna viridis were widely found on the west coast of Peninsular Malaysia but not on the east coast of the Peninsula. In this study, surveys and sampling were conducted from Tumpat to Mersing in April 2004, but the mussels were only found at Nenasi and Kuala Pontian in Pahang coastal waters. Therejare, from this study, we confirm that the mussels on the east coast were not as widely found as on the west coast of Peninsular Malaysia. The mussel samples collected were analysed for cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) and the metal concentrations (J.lg/g dry weight) were 1.892.13, 3.84-10.34, 7.95-8.84 and 93.1-119.6 far Cd, Cu, Pb and Zn, respectively. These results indicate that Kuala Pontian samples accumulated higher concentrations of Cu (in remaining soft tissue and mantle) and Zn (in remaining soft tissue, mantle and muscle) compared to those in Nenasi while Cd and Pb showed no significant difference (P> 0.05) between the two sample sites. Since there were no observable anthropogenic inputs ar activities at the two sampling sites, the variation of metal concentrations accumulated in the soft tissues could be mostly attributable to the significant difference in size (shell length, and shell width) and salinity of the two sites. The other environmental factars could also cause differences in the metal bioavailabilities in the coastal waters that were reflected in different concentrations accumulated in the different soft tissues of the mussels

Crystalline style and tissue redistribution in Perna viridis as indicators of Cu and Pb bioavailabilities and contamination in coastal waters

The concentrations of Cu, Pb, and Zn in the crystalline style (CS) and in the remaining soft tissues (ST) of the green-lipped mussel Perna viridis from 10 geographical sites along the coastal waters off peninsular Malaysia were determined. The CS, compared with the remaining ST, accumulated higher levels of Cu in both contaminated and uncontaminated samples, indicating that the style has a higher affinity for the essential Cu to bind with metallothioneins. The similar pattern of Cu accumulation in the different ST of mussels collected from clean and Cu-contaminated sites indicated that the detoxification capacity of the metallothioneins had not been overloaded. For Pb, higher levels of the metal in the CS than in the remaining ST were found only in mussels collected from a contaminated site at Kg. Pasir Puteh. This indicated a tissue redistribution of Pb due to its binding to metallothioneins for Pb detoxification and the potential of the CS as an indicator organ of Pb bioavailability and contamination. For Zn, the above two phenomena were not found since no obvious patterns were observed (lower levels of Zn in the CS than in the remaining ST) in contaminated and uncontaminated samples due to the mechanism of partial regulation. Generally, all the different STs studied (foot, mantle, gonad, CS, gill, muscle, and byssus) are good biomonitoring tissues for Cu and Pb bioavailabilities and contamination. Among these organs, the CS was found to be the best organ for biomonitoring Cu. The present data also suggest the use of the tissue redistribution of Pb in P. viridis as an indicator of Pb bioavailability and contamination in coastal waters