Mechanisms Affecting Recruitment of Yellow Perch in Lake Michigan

Report issued on: August 2001INHS Technical Report prepared for Great Lakes Fishery Trus

Covalent binding studies on the 14C-labeled antitumour compound 2,5-bis(1-aziridinyl)-1,4-benzoquinone. Involvement of semiquinone radical in binding to DNA, and binding to proteins and bacterial macromolecules in situ

2,5-Bis(1-aziridinyl)-1,4-benzoquinone (BABQ) is a compound from which several antitumour drugs are derived, such as Trenimone, Carboquone and Diaziquone (AZQ). The mechanism of DNA binding of BABQ was studied using 14C-labeled BABQ and is in agreement with reduction of the quinone moiety and protonation of the aziridine ring, followed by ring opening and alkylation. The one-electron reduced (semiquinone) form of BABQ alkylates DNA more efficiently than two-electron reduced or non reduced BABQ. Covalent binding to polynucleotides did not unambiguously reveal preference for binding to specific DNA bases. Attempts to elucidate further the molecular structure of DNA adducts by isolation of modified nucleosides from enzymatic digests of reacted DNA failed because of instability of the DNA adducts. The mechanism of covalent binding to protein (bovine serum albumin, BSA) appeared to be completely different from that of covalent binding to DNA. Binding of BABQ to BSA was not enhanced by reduction of the compound and was pH dependent in a way that is opposite to that of DNA alkylation. Glutathione inhibits binding of BABQ to BSA and forms adducts with BABQ in a similar pH dependence as the protein binding. The aziridine group therefore does not seem to be involved in the alkylation of BSA. Incubation of intact E. coli cells, which endogenously reduce BABQ, resulted in binding to both DNA and RNA, but also appreciable protein binding was observed

Student Attitudes and Approaches to Online Homework

Over the past two decades there has been increasing movement toward the use of computers and the internet in conjunction with many courses across the educational spectrum. In addition to having consequences for course delivery, both inside and outside of the classroom, this movement has had an impact on the coursework that is required of students. In this study we consider the use of online homework as an alternative to the traditional medium of pencil and paper. Surveys were conducted to gather data on students\u27 attitudes and practices related to online homework, and these data have been linked to course outcomes. In this paper we present the survey results and examine relationships between student characteristics, study behaviors, and the perceived benefits of online homework systems. In general we find a positive reaction to the use of online homework, with little variance across the particular platforms being used

Diel interactions between prey behaviour and feeding in an invasive fish, the round goby, in a North American river

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72558/1/j.1365-2427.2006.01527.x.pd

Mitosene-DNA adducts. Characterization of two major DNA monoadducts formed by 1,10-bis(acetoxy)-7-methoxymitosene upon reductive activation

Reductive activation of racemic 1,10-bis(acetoxy)-7-methoxymitosene WV15 in the presence of DNA, followed by enzymatic digestion and HPLC analysis, revealed the formation of various DNA adducts. Reduction is a necessary event for adduct formation to occur. This reductive activation was performed under hypoxic conditions in various ways:  (1) chemically, using a 2-fold excess of sodium dithionite (Na2S2O4), (2) enzymatically using NADH-cytochrome c reductase, (3) electrochemically on a mercury pool working electrode, and (4) catalytically, using a H2/PtO2 system. Five different mitosene−DNA adducts were detected. These adducts were also present when poly(dG-dC) was used instead of DNA, but were absent with poly(dA-dT). All were shown to be adducts of guanine. Reduction of 1,10-dihydroxymitosene WV14 in the presence of DNA did not result in detectable adduct formation, demonstrating the importance of good leaving groups for efficient adduct formation by these mitosenes. Finally, two of the adducts were isolated and their structures elucidated, using mass spectrometry, 1H NMR and circular dichroism (CD). The structures were assigned as the diastereoisomers N2-(1‘ ‘-n-hydroxymitosen-10‘ ‘-yl), 2‘-deoxyguanosine (n = α or β). These type of adducts, in which the mitosene C-10 is covalently bonded to the N-2 of a guanosylic group, are different from the well-known mitomycin C 2‘-deoxyguanosine monoadducts, that is linked via the mitomycin C C-1 position, demonstrating that the order of reactivity of the C-1 and C-10 in these mitosenes is reversed, as compared to mitomycin C. The 7-methoxy substituent of WV15 is a likely factor causing this switch. Evidence is presented that the 7-substituent of mitosenes also influences their DNA alkylation site. Adducts 4 and 5 represent the first isolated and structurally characterized covalent adducts of DNA and a synthetic mitosene

What do Professors do all Summer?

It’s a time to take a breath, re-energize, and re-center while also reconnecting with friends and family. Posting about the summer rhythm of life for five professors from In All Things - an online journal for critical reflection on faith, culture, art, and every ordinary-yet-graced square inch of God’s creation. https://inallthings.org/what-do-educators-do-all-summer

Electroproduction of kaons from the proton in a Regge-plus-resonance approach

We present a Regge-plus-resonance (RPR) description of the p(e,e'K^+)Y processes (Y=\Lambda,\Sigma^0) in the resonance region. The background contributions to the RPR amplitude are constrained by the high-energy p(\gamma, K^+)Y data. As a result, the number of free model parameters in the resonance region is considerably reduced compared to typical effective-Lagrangian approaches. We compare a selection of RPR model variants, originally constructed to describe $KY$ photoproduction, with the world electroproduction database. The electromagnetic form factors of the intermediate N^*s and $\Delta^*s are computed in the Bonn constituent-quark model. With this input, we find a reasonable description of the p(e,e'K^+)Y data without adding or readjusting any parameters. It is demonstrated that the electroproduction response functions are extremely useful for fine-tuning both the background and resonant contributions to the reaction dynamics.Comment: 14 pages, 7 figures; added discussion on double counting in the RPR model; accepted for publication in Phys. Lett.

COVID-19: guidance on palliative care from a European Respiratory Society international task force

Copyright ©ERS 2020. BACKGROUND: Many people are dying from coronavirus disease 2019 (COVID-19), but consensus guidance on palliative care in COVID-19 is lacking. This new life-threatening disease has put healthcare systems under pressure, with the increased need of palliative care provided to many patients by clinicians who have limited prior experience in this field. Therefore, we aimed to make consensus recommendations for palliative care for patients with COVID-19 using the Convergence of Opinion on Recommendations and Evidence (CORE) process. METHODS: We invited 90 international experts to complete an online survey including stating their agreement, or not, with 14 potential recommendations. At least 70% agreement on directionality was needed to provide consensus recommendations. If consensus was not achieved on the first round, a second round was conducted. RESULTS: 68 (75.6%) experts responded in the first round. Most participants were experts in palliative care, respiratory medicine or critical care medicine. In the first round, consensus was achieved on 13 recommendations based upon indirect evidence and clinical experience. In the second round, 58 (85.3%) out of 68 of the first-round experts responded, resulting in consensus for the 14th recommendation. CONCLUSION: This multi-national task force provides consensus recommendations for palliative care for patients with COVID-19 concerning: advance care planning; (pharmacological) palliative treatment of breathlessness; clinician-patient communication; remote clinician-family communication; palliative care involvement in patients with serious COVID-19; spiritual care; psychosocial care; and bereavement care. Future studies are needed to generate empirical evidence for these recommendations

Kaon photoproduction: background contributions, form factors and missing resonances

The photoproduction p(gamma, K+)Lambda process is studied within a field-theoretic approach. It is shown that the background contributions constitute an important part of the reaction dynamics. We compare predictions obtained with three plausible techniques for dealing with these background contributions. It appears that the extracted resonance parameters drastically depend on the applied technique. We investigate the implications of the corrections to the functional form of the hadronic form factor in the contact term, recently suggested by Davidson and Workman (Phys. Rev. C 63, 025210). The role of background contributions and hadronic form factors for the identification of the quantum numbers of ``missing'' resonances is discussed.Comment: 11 pages, 7 eps figures, submitted to Phys. Rev.