Laser ablation loading of a radiofrequency ion trap

The production of ions via laser ablation for the loading of radiofrequency (RF) ion traps is investigated using a nitrogen laser with a maximum pulse energy of 0.17 mJ and a peak intensity of about 250 MW/cm^2. A time-of-flight mass spectrometer is used to measure the ion yield and the distribution of the charge states. Singly charged ions of elements that are presently considered for the use in optical clocks or quantum logic applications could be produced from metallic samples at a rate of the order of magnitude 10^5 ions per pulse. A linear Paul trap was loaded with Th+ ions produced by laser ablation. An overall ion production and trapping efficiency of 10^-7 to 10^-6 was attained. For ions injected individually, a dependence of the capture probability on the phase of the RF field has been predicted. In the experiment this was not observed, presumably because of collective effects within the ablation plume.Comment: submitted to Appl. Phys. B., special issue on ion trappin

Primary Invasive Aspergillosis of the Digestive Tract: Report of Two Cases and Review of the Literature

BACKGROUND: Disseminated aspergillosis is thought to occur as a result of vascular invasion from the lungs with subsequent bloodstream dissemination, and portals of entry other than sinuses and/or the respiratory tract remain speculative. METHODS: We report two cases of primary aspergillosis in the digestive tract and present a detailed review of eight of the 23 previously-published cases for which detailed data are available. RESULTS AND CONCLUSION: These ten cases presented with symptoms suggestive of typhlitis, with further peritonitis requiring laparotomy and small bowel segmental resection. All cases were characterized by the absence of pulmonary disease at the time of histologically-confirmed gastrointestinal involvement with vascular invasion by branched Aspergillus hyphae. These cases suggest that the digestive tract may represent a portal of entry for Aspergillus species in immunocompromised patients

CD4/CD8 Ratio and Cancer Risk among Adults with HIV

Background: Independent of CD4 cell count, a low CD4/CD8 ratio in people with HIV (PWH) is associated with deleterious immune senescence, activation, and inflammation, which may contribute to carcinogenesis and excess cancer risk. We examined whether low CD4/CD8 ratios predicted cancer among PWH in the United States and Canada. Methods: We examined all cancer-free PWH with 1 or more CD4/CD8 values from North American AIDS Cohort Collaboration on Research and Design observational cohorts with validated cancer diagnoses between 1998 and 2016. We evaluated the association between time-lagged CD4/CD8 ratio and risk of specific cancers in multivariable, time-updated Cox proportional hazard models using restricted cubic spines. Models were adjusted for age, sex, race and ethnicity, hepatitis C virus, and time-updated CD4 cell count, HIV RNA, and history of AIDS-defining illness. Results: Among 83 893 PWH, there were 5628 incident cancers, including lung cancer (n = 755), Kaposi sarcoma (n = 501), non-Hodgkin lymphoma (n = 497), and anal cancer (n = 439). The median age at cohort entry was 43 years. The overall median 6-month lagged CD4/CD8 ratio was 0.52 (interquartile range = 0.30-0.82). Compared with a 6-month lagged CD4/CD8 of 0.80, a CD4/CD8 of 0.30 was associated with increased risk of any incident cancer (adjusted hazard ratio = 1.24 [95% confidence interval = 1.14 to 1.35]). The CD4/CD8 ratio was also inversely associated with non-Hodgkin lymphoma, Kaposi sarcoma, lung cancer, anal cancer, and colorectal cancer in adjusted analyses (all 2-sided P <. 05). Results were similar using 12-, 18-, and 24-month lagged CD4/CD8 values. Conclusions: A low CD4/CD8 ratio up to 24 months before cancer diagnosis was independently associated with increased cancer risk in PWH and may serve as a clinical biomarker

Is there fire? Executive compensation and employee attitudes

10.1108/00483481211212742Personnel Review413260-28

Estudo do potencial do pacu (Piaractus mesopotamicus) como agente de controle biológico de Egeria densa, E. najas e Ceratophyllum demersum Evaluation of the biocontrol potential of pacu (Piaractus mesopotamicus) for Egeria densa, E. najas and Ceratophyllum demersum

Visando fornecer subsídios para elaboração de sistema de manejo integrado das grandes massas de plantas daninhas aquáticas submersas em lagos e represas, o presente trabalho teve como objetivo verificar a eficiência do pacu (Piaractus mesopotamicus) como agente de controle biológico de Egeria densa, E. najas e Ceratophyllum demersum. As espécies de plantas daninhas foram oferecidas individualmente, duas a duas e as três espécies juntas. Verificou-se que este peixe tem uma eficiência média de controle dessas plantas daninhas variando entre 28 e 100%, podendo eliminar uma massa verde dessas plantas, com a mesma quantidade de seu peso, em sete dias. A eficiência de controle diária aumentou com o tempo de predação. O pacu é mais seletivo para E. densa ou E. najas quando na presença de C. demersum. Não ocorreu alteração na eficiência de controle do pacu sobre E. densa ou E. najas em todos os tratamentos e nos três períodos estudados (três, cinco e sete dias).<br>In order to provide basic information for the establishment of integrated management systems for submersed aquatic weeds in lakes and reservoirs, this research evaluated the efficiency of pacu (Piaractus mesopotamicus) as a biocontrol agent of Egeria densa, E. najas and Ceratophyllum demersum. One, two and the three plant species together were offered to the fish. The average efficacy of this fish to control these plants ranged between 28 and 100%. The fish could eliminate a fresh mass of these plants, equivalent to its body weight, in seven days of predation period. Control efficiency increased with increasing duration of the trials. Pacu is more selective in controlling E. densa or E. najas when in the presence of C. demersum. No decreased efficacy was observed in the control of E. densa or E. najas in any of the treatments nor in any of three time periods studied (3, 5, and 7 days)