The appearance of a merging binary black hole very close to a spinning supermassive black hole

The mass and distance of a binary black hole (BBH) are fundamental parameters to measure in gravitational-wave (GW) astronomy. It is well-known that the measurement is affected by cosmological redshift, and recent works also showed that Doppler and gravitational redshifts could further affect the result if the BBH coalesces close to a supermassive black hole (SMBH). Here we consider the additional lensing effect induced by the nearby SMBH on the measurement. We compute the null geodesics originating within $10$ gravitational radii of a Kerr SMBH to determine the redshift and magnification of the GWs emitted by the BBH. We find a positive correlation between redshift and demagnification, which results in a positive correlation between the mass and distance of the BBH in the detector frame. More importantly, we find a higher probability for the signal to appear redshifted and demagnified to a distant observer, rather than blueshifted and magnified. Based on these results, we show that a binary at a cosmological redshift of $z_{\rm cos}=(10^{-2}-10^{-1})$ and composed of BHs of $(10-20)M_\odot$ could masquerade as a BBH at a redshift of $z_{\rm cos}\sim1$ and containing BHs as large as $(44-110)M_\odot$. In the case of extreme demagnification, we also find that the same BBH could appear to be at $z_{\rm cos}>10$ and contain subsolar-mass BHs. Such an effect, if not accounted for, could bias our understanding of the origin of the BHs detected via GWs

Determining the characteristics of Xanthomonas cucurbitae bacterium from the North Central Region and developing effective seed treatment for eradication of the bacterium in pumpkin seeds

Bacterial spot of cucurbits, caused by Xanthomonas cucurbitae, has become a serious threat to pumpkin production in Illinois and other states in the North Central Region (NCR) of the United States. This study was conducted to investigate the characteristics of X. cucurbitae isolates from the NCR and to develop an effective seed treatment to eradicate the pathogen in pumpkin seeds. Characteristics of the pathogen included the cell multiplication of X. cucurbitae at different temperatures and pH levels and pathogenic variation among isolates of the pathogen. Fourteen X. cucurbitae isolates from seven states (Illinois, Indiana, Iowa, Kansas, Michigan, Ohio, and Wisconsin) were tested. The American Type Culture Collection (ATCC) strain 23378 was included in this study as positive control. The result showed that the range of minimum, maximum, and optimum temperatures for cell multiplication of X. cucurbitae were 4-6, 34-36, and 24-30°C, respectively. Cell multiplication and colony development of X. cucurbitae was optimum at pH 6.5-8. For determining pathogenic variation among the isolates, X. cucurbitae was inoculated onto leaves of three-week-old ‘Howden’ and ‘Dickinson’ pumpkins in a greenhouse. Development of the bacterial lesions was recorded from 12 to 168 h post inoculation. The post-inoculation period for the first appearance of the visible lesions was significantly affected by the isolates. However, diameters of the lesions 168 h post inoculation were not significantly different among the isolates. Survival of X. cucurbitae in pumpkin seed was studied using naturally-infected and artificially-inoculated pumpkin seed stored at 4 and 22°C. X. cucurbitae survived longer than 18 months in the seeds at both temperatures and remained viable. The storage temperature significantly affected survival of X. cucurbitae in the seed. The effectiveness of hot-water, hydrochloric acid (HCl), and sodium hypochlorite (NaClO) for eradication of X. cucurbitae in pumpkin seed was tested. The results showed that a hot-water treatment at 55°C for either 10 or 15 min and HCl treatment at 0.5% concentration for 40 min eradicated X. cucurbitae in both naturally-infected and artificially-inoculated pumpkin seeds without any significant adverse effect on either seed germination or seedling vigor. None of the NaClO treatments eradicated X. cucurbitae in the seed

Structured versus non-structured interacting electronic fraud brainstorming in hierarchical audit groups

Both international (ISA 240) and U.S. (SAS No. 99) accounting standard-setters require audit firms to organise a discussion session/ brainstorming session at the audit planning stage for each audit, in order to discuss how and where a company’s financial statements might be susceptible to material misstatement due to fraud. This study introduces a structured interacting electronic brainstorming platform into the audit context and examines whether it improves auditors’ fraud brainstorming performance in the fraud hypotheses generation task when compared with the non-structured interacting electronic brainstorming platform which has been investigated in prior literature. In the structured interacting electronic brainstorming platform, idea inputs are shown by categories rather than in chronological sequence on a computer screen. Understanding the comparative effect of different forms of electronic brainstorming and exploring the most appropriate interacting electronic brainstorming method are important since it is likely to improve the effectiveness of brainstorming sessions in audit firms. The structured interacting electronic brainstorming platform has been found to be useful in improving users’ productivity and creativity in psychology. However, this study finds that the structured interacting electronic brainstorming platform has no effect on the brainstorming performance of the three-person hierarchical audit groups. Moreover, the use of the structured interacting electronic brainstorming platform has no effect on fraud brainstorming performance and mental simulations of seniors, but it even has a negative effect on the fraud brainstorming performance and mental simulations of managers. Furthermore, this study finds that there is no significant correlation between auditors’ brainstorming performance in the fraud hypotheses task and changes in their fraud risk assessments

Boosting with stumps for predicting transcription start sites

Promoter prediction is a difficult but important problem in gene finding, and it is critical for elucidating the regulation of gene expression. We introduce a new promoter prediction program, CoreBoost, which applies a boosting technique with stumps to select important small-scale as well as large-scale features. CoreBoost improves greatly on locating transcription start sites. We also demonstrate that by further utilizing some tissue-specific information, better accuracy can be achieved