Drosophila-Chinese hamster hybrid cells from cell lines adapted to grow in the same environmental conditions

SUMMARYEvidence is given concerning the possible production of Drosophila melanogaster-Chinese hamster hybrid cells, after PEG mediated fusion experiments between cell lines adapted to grow in the same environmental conditions: 31o C and a modified mammalian medium. However, autoradiograpy failed to detect viable complementation in Drosophila-Chinese hamster TK− heterokaryons, and this is consistent with the failure to obtain proliferating hybrids in a semiselective HAT medium

Demystifying critics about hydrogen peroxide utilization in recirculating aquaculture systems.

Introduction Recirculation Aquaculture Systems (RAS) use water recycling as the base for an efficient production. Water reutilization demands cleaning techniques to remove accumulating compounds. These include mechanical filtration, biofiltration and a disinfection method. The most common disinfection methods used in RAS are UV and Ozone, both having pros and contras in terms of costs, risks, and application requirements. An alternative to these methods is hydrogen peroxide (H2O2), which, even been classified as a green oxidant, has not been commonly used and is hardly criticized due to acquisition, storage and secure manipulation issues. As H2O2 dissociates into non-toxic environmentally benign by-products including oxygen, its application offers potential savings in terms of oxygenation in RAS. Moreover, H2O2 is used to treat ectoparasitic illness with FDA approved H2O2-35% dosages between 50-1000 mg/L for 15-60 min. Minimum concentrations to which stress responses have been observed in salmonids range between 4-170 mg/L while the limits for biofilter function are around 5 mg/L [1-4]. Materials and methods In the present study, we perform serial experiments in a RAS rearing ~65 kg European seabass (Dicentrarchus labrax, weight ranging from 500-800g) to test the best application possibilities for H2O2 into a system, with concentrations between 2.4-15.8 mg/L/h. We tested two application positions: the bypass between the protein skimmer and the sump (with higher organic burden), and the flow to the rearing tanks (low organic load). We evaluated the impact on physicochemical parameters with focus on oxygen and nitrogen species concentration and the effect of the application on bacterial community of the different compartments (assessed via total bacterial counts in CFU/ml). Dosage was applied for 4 h on a daily basis and rates of decay of H2O2 on the system was assessed with Quantofix Peroxide test sticks (Sigma Aldrich, from 0-25 mg/L and 0-100 mg/L) until total removal. Ozone was switched off during dosage. Smart Digital S-DDA (Grundfos, Germany) dosage pumps were used for a controlled H2O2 application to the system (dosing capacity between 2.4 ml/h and 7.5 L/h). Stress levels of the reared fish was assessed using cortisol and glucose as blood markers. Results With the concentrations used, we accomplish a partial disinfection of the system without reaching levels affecting the bacterial flora of the biofiltration units or the health of the reared fish. We found a significant reduction of the bacterial load with each of the concentration tested. The best application position was the inlet to the protein skimmer, due to the lowest impact to the bacterial flora of the filter and the reared fish. An economically relevant increase in oxygen level of the system as well as the highest disinfection levels were achieved with 15.8 mg/L/h. In this assay, an artificial oxygen depletion was simulated before applying H2O2 to the system, and this was recovered within the first 40 min, even during a feeding period, which normally reduces the oxygen level in the water column. After application, the rates of decay varied from 30 min to 1 h, time after which, no H2O2 was detected in the system. No significant negative effects were found on fish stress markers even when cortisol (Ref: 59.8±49.5 vs. Treat:62.2±43.5) and glucose (Ref: 131.0±34.9 vs. Treat: 155.1±45.3) levels tended to increase during the experiments using increasing H2O2 doses. These markers showed a high variability. During application, the number of fish showing conspicuous low cortisol levels increased. Discussion and conclusion Organic burden in the system, fish stocking density, feeding frequency and biofilter performance were all factors influencing the required H2O2 dosage and its rate of decay in accordance to what has been published [2, 5, 6]. In the present study, we found a relatively rapid decay of H2O2 remnants, supported by the organic load typically present in a RAS rearing at commercial or semi-commercial scales. We recommend to apply H2O2 in positions of the system with high organic burden to avoid affecting biofilter function or promoting nitrite accumulation as previously published [5]. Despite previous results showing negative stress responses of D. labrax to H2O2 application [7], we did not found critical changes on cortisol or glucose related to the treatment. These authors used smaller fish (weight 120-200 g) and doses of 50 ppm/h, which are higher than in the present study. The stress in D. labrax is genetically driven and highly dependent on size/age with individuals having consistent high (439.2 ± 31.1 µg/dl ) or low (247 ± 85.1 µg/dl) cortisol concentrations and, as well as glucose, there is a circadian pattern for these parameters within this species [8, 9]. Glucose levels between 100-150 mg/dl have been reported in the literature for D. labrax [10]. With appropriate knowledge of system performance and microbiological background, H2O2 can be a positive complement to the disinfection spectrum of a RAS. It can be used alternating with common methods to avoid artificial selection of specific microbial groups and can have a positive impact in cases in which parasitic illness are present. Thus, as a disinfection method with a plus for its oxygenation influence, H2O2 can enrich the disinfection portfolio of aquaculture facilities

Piloting a global mentorship initiative to support African emergency nurses

This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.Mentorship is a relationship whereby a person experienced in the specialty supports and guides a less experienced person following a process of relationship building, engagement and development, self-inquiry and reflection (Seekoe, 2014). It involves regular contact with a critical friend who has a mature level of skills and expertise and can advise and support the mentee’s development in order to empower them and build capacity (Seekoe, 2014). In healthcare this relationship usually has formal recognition. Indeed clinical mentorship of nurse initiated antiretroviral therapy in resource limited settings in South Africa suggests that mentorship increases clinical confidence and improves the quality of nursing care (Green, de Azevedo, Patten, Davies, Ibeto, et al., 2014). Bennet, Paina, Ssengooba, Waswa and Imunya (2013) demonstrated in Kenya and Uganda that mentorship programmes have a positive impact on career development and whether to remain in health research. However, in a global healthcare context, one size does not fit all. Limited examples exist of Afrocentric mentorship arrangements which enhance the personal development and expertise of novice health practitioners however no current mentorship infrastructure exists to support the development of emergency nurses in Africa (Brysiewicz, 2012). This paper explains the creation and pilot of a global mentorship initiative through collaboration to support emergency nurses in Africa and, the potential benefits and limitations of such a quest.Peer reviewe

Studies on lectin-induced agglutination of Drosophila embryonic cell lines

The agglutination responses of three Drosophila cell lines to concanavalin A and wheat germ agglutinin have been examined. Although the cell lines were originally derived from late embryonic stages of the Ore-R strain of Drosophila melanogaster, they show quantitative differences in lectin-induced agglutination. Line 1 cells were least agglutinable with both lectins. All three cell lines reached maximum agglutination with concanavalin A concentrations at 25 [mu]g/ml, but the agglutination response to wheat germ agglutinin was biphasic such that an initial rapid increase in agglutination with concentrations up to 25 [mu]g/ml was followed by slower agglutination above this concentration. Cells of lines 1 and 2 from ten-day old cultures exhibited greater lectin-induced agglutination than cells from three-day old cultures. Age-dependent differences were not found for line 3 cells which gave maximum agglutination responses in both young and old cultures. Cell agglutination by concanavalin A was almost completely inhibited by pretreatment of the lectin with methyl-[alpha]--mannopyranoside, but preincubation of wheat germ agglutinin with N-acetyl--glucosamine caused only partial blockage. Lectin-induced agglutination was not reversible by treatment with the monosaccharide inhibitors. These observations have been discussed with reference to the origin of the three cell lines and their cell surface properties.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22690/1/0000243.pd

Exploring the impact of mentoring functions on job satisfaction and organizational commitment of new staff nurses

<p>Abstract</p> <p>Background</p> <p>Although previous studies proved that the implementation of mentoring program is beneficial for enhancing the nursing skills and attitudes, few researchers devoted to exploring the impact of mentoring functions on job satisfaction and organizational commitment of new nurses. In this research we aimed at examining the effects of mentoring functions on the job satisfaction and organizational commitment of new nurses in Taiwan's hospitals.</p> <p>Methods</p> <p>We employed self-administered questionnaires to collect research data and select new nurses from three regional hospitals as samples in Taiwan. In all, 306 nurse samples were obtained. We adopted a multiple regression analysis to test the impact of the mentoring functions.</p> <p>Results</p> <p>Results revealed that career development and role modeling functions have positive effects on the job satisfaction and organizational commitment of new nurses; however, the psychosocial support function was incapable of providing adequate explanation for these work outcomes.</p> <p>Conclusion</p> <p>It is suggested in this study that nurse managers should improve the career development and role modeling functions of mentoring in order to enhance the job satisfaction and organizational commitment of new nurses.</p

What is the impact of shift work on the psychological functioning and resilience of nurses? An integrative review

Aim: To synthesize existing research to determine if nurses who work shifts have poorer psychological functioning and resilience than nurses who do not work shifts. Background: Research exploring the impact of shift work on the psychological functioning and resilience of nurses is limited compared with research investigating the impact of shifts on physical outcomes. Design: Integrative literature review. Data Sources: Relevant databases were searched from January 1995-August 2016 using the combination of keywords: nurse, shift work; rotating roster; night shift; resilient; hardiness; coping; well-being; burnout; mental health; occupational stress; compassion fatigue; compassion satisfaction; stress; anxiety; depression. Review Methods: Two authors independently performed the integrative review processes proposed by Whittemore and Knafl and a quality assessment using the mixed-methods appraisal tool by Pluye et al. Results: A total of 37 articles were included in the review (32 quantitative, 4 qualitative and 1 mixed-methods). Approximately half of the studies directly compared nurse shift workers with non-shift workers. Findings were grouped according to the following main outcomes: (1) general psychological well-being/quality of life; (2) Job satisfaction/burnout; (3) Depression, anxiety and stress; and (4) Resilience/coping. We did not find definitive evidence that shift work is associated with poorer psychological functioning in nurses. Overall, the findings suggest that the impact of shift work on nurse psychological functioning is dependent on several contextual and individual factors. Conclusion: More studies are required which directly compare the psychological outcomes and resilience of nurse shift workers with non-shift workers

Drosophila-Chinese hamster hybrid cells from cell lines adapted to grow in the same environmental conditions

SUMMARYEvidence is given concerning the possible production of Drosophila melanogaster-Chinese hamster hybrid cells, after PEG mediated fusion experiments between cell lines adapted to grow in the same environmental conditions: 31o C and a modified mammalian medium. However, autoradiograpy failed to detect viable complementation in Drosophila-Chinese hamster TK− heterokaryons, and this is consistent with the failure to obtain proliferating hybrids in a semiselective HAT medium