Dissociative and double photoionization of CO2 from threshold to 90 A

The molecular photoionization, dissociative photoionization and double photoionization cross sections for CO2 were measured from their onsets down to 90 A by using various combinations of mass spectrometers (a coincidence time-of-flight mass spectrometer and a magnetic mass spectrometer) and light sources (synchrotron radiation, and glow and spark discharge). It is concluded that the one broad peak and the three shoulders in the total adsorption cross section curve between 640 and 90 A are caused completely by dissociative ionization processes. Several peaks observed in the cross section curve for the total fragmentation CO(+)3, O(+) and C(+) are compared with those in the photoelectron spectrum reported for CO2

Investigation on the influence of nematophagous fungi as feed additive on nematode infection risk of sheep and goats on pasture

Gastrointestinal nematodes in small ruminants cause high economic losses. Thus on most farms anthelmintic treatment is required. In response to increasing problems with anthelmintic resistance, biological control, for example the use of nematophagous fungi, has received significant attention. The aim of this study was to investigate the effect of Duddingtonia flagrans orally applied to small ruminants on natural infection with gastrointestinal nematodes in a field study in Northern Germany. 20 goats and 20 sheep were fed daily for 3 months with 5x105 spores of D. flagrans per kg bodyweight. Differences in body weight, faecal egg count and larval development in faeces and on pasture in comparison with same-sized control groups were analysed. After 3 months the control goats showed significantly higher mean faecal egg count than the fungus-fed group. No significant difference was found between the two sheep groups. The maximum in larval reduction in faeces was 81.3 % in the sheep groups and 67.9 % in the goat groups (not significant). At the end of the study the body weight gain in the fungus-treated groups was 1.7 kg higher in goats and 0.7 kg higher in sheep than in the control groups (not significant). Regarding the first-year-grazing goats only, the bodyweights revealed significant differences (p<0.05). No statistically significant differences were observed in pasture larval counts. In the study presented here, no clear effect of fungus could be observed. A modified feeding regimen, perhaps with permanent release boluses or feed blocks, may improve the efficacy. Furthermore, it seems that climatic conditions during the study period could have influenced the results and displayed how sensitive the fungus application may be on such parameters

Total and dissociative photoionization cross sections of N2 from threshold to 107 eV

The absolute cross sections for the production of N(+) and N2(+) were measured from the dissociative ionization threshold of 115 A. In addition, the absolute photoabsorption and photoionization cross sections were tabulated between 114 and 796 A. The ionization efficiencies were also given at several discrete wave lengths between 660 and 790 A. The production of N(+) fragment ions are discussed in terms of the doubly excited N2(+) states with binding energies in the range of 24 to 44 eV

Role of cancer stem cells in hepatocarcinogenesis

There has been considerable interest in cancer stem cells (CSCs) among cancer biologists and clinicians, most likely because of their role in the heterogeneity of cancer and their potential application in cancer therapeutics. Recent studies suggest that CSCs play a key role in liver carcinogenesis. A small subpopulation of cancer cells with CSC properties has been identified and characterized from hepatocellular carcinoma (HCC) cell lines, animal models and human primary HCCs. Considering the high mortality and ineffectiveness of current therapies for HCC, understanding the characteristics and function of CSCs is likely to lead to development of new therapies resulting in improvement of patient survival. This review summarizes recent progress in liver cancer stem cell research with regard to the identification, cell origin, regulation of self-renewal capacity, and therapeutic implications of liver CSCs

Financial Development and Economic Growth in Nigeria: The Case Study of Nigeria

The study analyzed the effect of financial development on economic growth in Nigeria using time series data on annual growth rate of gross domestic product, real interest rate, the ratio of gross domestic savings to GDP, ratio of domestic credit to private sector to GDP over the period 1980 and 2019. While the variables real interest rate, the ratio of gross domestic savings to GDP, ratio of domestic credit to private sector to GDP served as explanatory variable, annual growth rate of gross domestic product was used as the dependent variable. The results indicated that two of the variables (real interest rate, gross domestic savings) are inversely related to the&nbsp; dependent variable (GDP annual growth rate) when combined together while domestic credit to private sector is positively related to the dependent variable with the coefficient of multiple determination showing that the model is of high good fit&nbsp; with&nbsp; approximately 93% of gross domestic product being explained by the variables included in the model, while the remaining 7% are factors inducing growth but were not captured in the model. Thus, the study, therefore, concluded that there is the need to adequately deepen the financial system through innovations, adequate and effective regulation and supervision, efficient mobilization of funds and making such funds available for productive investment, and improved services in order to propel economic growth

Evolution of the uniform CPA examination

In this paper there are four research issues. First, the developments that led to the institution of the first CPA Exam are identified. Second, the evolution of the earliest state CPA Examinations into the uniform CPA Examination is investigated. Third, the early CPA Exams are compared to the current exams as a way of illustrating the impact that these first exams have had, and continue to have, on modern exams. Last, in a very subjective way, the rigor of the early examinations is compared to modern examinations in an attempt to draw conclusions about the relative difficulty of the old examinations compared to the modern ones

COVID-19 Pandemic and Volatility Persistence of the Nigerian Crude Oil Price

Impacts of COVID-19 pandemic on the global economy cannot be overemphasized, especially with Nigeria, which largely depends on crude oil as a major source of her revenue. Thus, investigating COVID-19’s impacts on the volatility persistence of Nigerian crude oil price forms the nucleus of this study. Our modelling framework was based on GARCH, EGARCH and GJR-GARCH with two asymmetric innovation distributions &nbsp;Daily price data on the Nigerian crude oil sales (in dollars per barrel), ranging from 4th Jan., 2010 to 27th May, 2021, were obtained from the Central Bank of Nigeria (CBN). To capture the impact of the pandemic, the data were divided into two periods, before Covid-19 was proscribed as a pandemic by World Health Organisation (01/04/2010 to 10/03/2020) and during COVID-19 pandemic (11/03/2020 to 27/05/2021). Result shows that the leverage effect were positive and significant in both periods which indicates that positive shocks increases volatility more than negative news of the same sign. Also, EGARCH-SSTD and GJR-GARCH (1,1)-SSTD were the best fitted models for before and during pandemic respectively. Result shows that volatility persistence was higher during COVID-19 period (1.012639) than before the COVID-19 pandemic (0.988749) .There was also an increase and over persistence in the volatility of Nigerian crude oil price during COVID-19 than before COVID-19 period

On the role of shake-off in single-photon double ionization

The role of shake-off for double ionization of atoms by a single photon with finite energy has become the subject of debate. In this letter, we attempt to clarify the meaning of shake-off at low photon energies by comparing different formulations appearing in the literature and by suggesting a working definition. Moreover, we elaborate on the foundation and justification of a mixed quantum-classical ansatz for the calculation of single-photon double ionization